/* roulang page: index */
:root {
  --primary-dark: #0B1B2B;
  --primary-darker: #070F1A;
  --accent-green: #00E5A0;
  --accent-blue: #00B4D8;
  --gradient-main: linear-gradient(135deg, #00E5A0, #00B4D8);
  --text-heading: #F5F8FF;
  --text-body: #B6C2D4;
  --text-muted: #8899AA;
  --card-bg: rgba(255,255,255,0.04);
  --card-border: rgba(255,255,255,0.08);
  --card-hover-border: rgba(0,229,160,0.4);
  --card-shadow: 0 8px 32px rgba(0,0,0,0.35);
  --radius-card: 16px;
  --radius-btn: 12px;
  --radius-img: 12px;
  --section-padding: clamp(4rem, 8vw, 6rem) 0;
  --container-max: 1200px;
  --font-main: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
}
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; }
body {
  font-family: var(--font-main);
  background: var(--primary-dark);
  color: var(--text-body);
  line-height: 1.75;
  overflow-x: hidden;
  position: relative;
}
body::before {
  content: '';
  position: fixed;
  top: -25%;
  left: -15%;
  width: 70vw;
  height: 70vw;
  background: radial-gradient(circle, rgba(0,229,160,0.10) 0%, transparent 70%);
  z-index: 0;
  pointer-events: none;
}
body::after {
  content: '';
  position: fixed;
  bottom: -25%;
  right: -15%;
  width: 70vw;
  height: 70vw;
  background: radial-gradient(circle, rgba(0,180,216,0.10) 0%, transparent 70%);
  z-index: 0;
  pointer-events: none;
}
.grid-overlay {
  position: fixed;
  inset: 0;
  background-image: linear-gradient(rgba(255,255,255,0.02) 1px, transparent 1px), linear-gradient(90deg, rgba(255,255,255,0.02) 1px, transparent 1px);
  background-size: 60px 60px;
  z-index: 0;
  pointer-events: none;
}
.container { max-width: var(--container-max); position: relative; z-index: 1; }
img { max-width: 100%; height: auto; }
a { color: var(--accent-green); text-decoration: none; transition: color 0.25s ease; }
a:hover { color: var(--accent-blue); }
h1, h2, h3, h4, h5 { color: var(--text-heading); font-weight: 700; line-height: 1.3; }

/* Custom Navbar */
.custom-navbar {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 72px;
  background: rgba(11,27,43,0.72);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border-bottom: 1px solid rgba(255,255,255,0.06);
  z-index: 1000;
  padding: 0;
  transition: background 0.35s ease, box-shadow 0.35s ease;
}
.custom-navbar.scrolled {
  background: rgba(7,15,26,0.92);
  box-shadow: 0 8px 32px rgba(0,0,0,0.45);
}
.custom-navbar .navbar-brand {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 0;
  color: var(--text-heading);
  font-weight: 700;
  font-size: 1.35rem;
  letter-spacing: 0.5px;
}
.custom-navbar .navbar-brand:hover { color: var(--accent-green); }
.brand-icon {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 40px;
  height: 40px;
  border-radius: 10px;
  background: var(--gradient-main);
  box-shadow: 0 4px 16px rgba(0,229,160,0.3);
  flex-shrink: 0;
}
.brand-icon svg { width: 22px; height: 22px; fill: #0B1B2B; }
.brand-text { font-size: 1.25rem; }
.brand-text em { font-style: normal; color: var(--accent-green); }
.custom-navbar .navbar-nav { gap: 4px; }
.custom-navbar .nav-link {
  color: var(--text-body);
  font-size: 0.95rem;
  font-weight: 500;
  padding: 0.5rem 1.1rem !important;
  position: relative;
  transition: color 0.25s ease;
}
.custom-navbar .nav-link::after {
  content: '';
  position: absolute;
  bottom: 2px;
  left: 1.1rem;
  right: 1.1rem;
  height: 2px;
  background: var(--gradient-main);
  border-radius: 2px;
  transform: scaleX(0);
  transform-origin: center;
  transition: transform 0.3s ease;
}
.custom-navbar .nav-link:hover { color: var(--text-heading); }
.custom-navbar .nav-link:hover::after,
.custom-navbar .nav-link.active::after { transform: scaleX(1); }
.custom-navbar .nav-link.active { color: var(--text-heading); }
.btn-download {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 0.55rem 1.6rem;
  border-radius: var(--radius-btn);
  background: var(--gradient-main);
  color: #0B1B2B;
  font-weight: 600;
  font-size: 0.95rem;
  border: none;
  box-shadow: 0 4px 16px rgba(0,229,160,0.25);
  transition: all 0.25s ease;
  white-space: nowrap;
}
.btn-download:hover {
  color: #0B1B2B;
  transform: translateY(-2px);
  box-shadow: 0 8px 28px rgba(0,229,160,0.4);
}
.custom-navbar .navbar-toggler {
  border: 1px solid rgba(255,255,255,0.2);
  border-radius: 8px;
  padding: 6px 10px;
}
.custom-navbar .navbar-toggler:focus {
  box-shadow: 0 0 0 3px rgba(0,229,160,0.25);
}
.custom-navbar .navbar-toggler-icon {
  background-image: url("data:image/svg+xml,%3csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 30 30'%3e%3cpath stroke='rgba(255,255,255,0.85)' stroke-linecap='round' stroke-miterlimit='10' stroke-width='2' d='M4 7h22M4 15h22M4 23h22'/%3e%3c/svg%3e");
}

/* Hero */
.hero {
  position: relative;
  min-height: 100vh;
  display: flex;
  align-items: center;
  padding: 140px 0 90px;
  background-color: var(--primary-dark);
  background-image: linear-gradient(135deg, rgba(11,27,43,0.88) 20%, rgba(14,38,56,0.90) 60%, rgba(7,21,36,0.94) 100%), url('/assets/images/backpic/back-1.webp');
  background-size: cover;
  background-position: center;
  overflow: hidden;
}
.hero::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: radial-gradient(ellipse at 20% 40%, rgba(0,229,160,0.08) 0%, transparent 60%);
  pointer-events: none;
}
.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  background: rgba(0,229,160,0.12);
  border: 1px solid rgba(0,229,160,0.3);
  color: var(--accent-green);
  font-size: 0.85rem;
  font-weight: 500;
  padding: 0.35rem 1rem;
  border-radius: 50px;
  margin-bottom: 1.5rem;
  letter-spacing: 0.3px;
}
.hero h1 {
  font-size: min(3rem, 8vw);
  font-weight: 700;
  line-height: 1.2;
  margin-bottom: 1.25rem;
  letter-spacing: 1px;
}
.hero h1 span {
  display: block;
  background: var(--gradient-main);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  font-size: 0.65em;
  margin-top: 0.35rem;
}
.hero-sub {
  font-size: 1.08rem;
  color: var(--text-body);
  max-width: 560px;
  margin-bottom: 2.2rem;
  line-height: 1.8;
}
.hero-btns {
  display: flex;
  flex-wrap: wrap;
  gap: 1rem;
  margin-bottom: 2.5rem;
}
.btn-primary-lg {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  padding: 0.875rem 2.2rem;
  border-radius: var(--radius-btn);
  background: var(--gradient-main);
  color: #0B1B2B;
  font-weight: 700;
  font-size: 1rem;
  border: none;
  box-shadow: 0 4px 20px rgba(0,229,160,0.35);
  transition: all 0.3s ease;
  position: relative;
  overflow: hidden;
}
.btn-primary-lg:hover {
  color: #0B1B2B;
  transform: translateY(-2px);
  box-shadow: 0 8px 32px rgba(0,229,160,0.5);
}
.btn-primary-lg::after {
  content: '';
  position: absolute;
  inset: 0;
  background: linear-gradient(120deg, transparent 30%, rgba(255,255,255,0.3) 50%, transparent 70%);
  transform: translateX(-100%);
  animation: shine 3s infinite;
}
@keyframes shine {
  0% { transform: translateX(-100%); }
  60%, 100% { transform: translateX(100%); }
}
.btn-outline-lg {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  padding: 0.875rem 2.2rem;
  border-radius: var(--radius-btn);
  background: transparent;
  color: var(--text-heading);
  font-weight: 600;
  font-size: 1rem;
  border: 1px solid rgba(255,255,255,0.4);
  transition: all 0.3s ease;
}
.btn-outline-lg:hover {
  border-color: var(--accent-green);
  color: var(--accent-green);
  transform: translateY(-2px);
  box-shadow: 0 4px 20px rgba(0,229,160,0.15);
}
.trust-badges {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
}
.trust-badges span {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  background: rgba(255,255,255,0.06);
  border: 1px solid rgba(255,255,255,0.1);
  border-radius: 50px;
  padding: 0.4rem 1rem;
  font-size: 0.85rem;
  color: var(--text-body);
}
.trust-badges i { color: var(--accent-green); font-size: 0.85rem; }
.hero-visual {
  position: relative;
  text-align: center;
  padding: 1rem;
}
.hero-visual img {
  max-width: 100%;
  max-height: 520px;
  border-radius: 20px;
  box-shadow: 0 24px 64px rgba(0,0,0,0.5);
  border: 1px solid rgba(255,255,255,0.1);
}
.float-badge {
  position: absolute;
  bottom: 15px;
  right: 10px;
  background: rgba(7,15,26,0.85);
  backdrop-filter: blur(12px);
  border: 1px solid rgba(0,229,160,0.3);
  border-radius: 16px;
  padding: 0.9rem 1.4rem;
  text-align: center;
  box-shadow: 0 8px 32px rgba(0,0,0,0.4);
}
.float-badge .num {
  display: block;
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--accent-green);
  line-height: 1.2;
}
.float-badge .label {
  font-size: 0.78rem;
  color: var(--text-muted);
}
.hero-scroll {
  position: absolute;
  bottom: 28px;
  left: 50%;
  transform: translateX(-50%);
  color: var(--text-muted);
  font-size: 1.4rem;
  animation: bounce 2s infinite;
  cursor: pointer;
  transition: color 0.3s ease;
}
.hero-scroll:hover { color: var(--accent-green); }
@keyframes bounce {
  0%, 20%, 50%, 80%, 100% { transform: translateX(-50%) translateY(0); }
  40% { transform: translateX(-50%) translateY(-8px); }
  60% { transform: translateX(-50%) translateY(-4px); }
}

/* Brand Strip */
.brand-strip {
  padding: 2.5rem 0;
  border-top: 1px solid rgba(255,255,255,0.05);
  border-bottom: 1px solid rgba(255,255,255,0.05);
  background: rgba(255,255,255,0.01);
}
.brand-strip .brand-row {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  align-items: center;
  gap: 2.5rem;
}
.brand-strip .brand-row span {
  font-size: 1.05rem;
  font-weight: 600;
  color: rgba(255,255,255,0.4);
  letter-spacing: 2px;
  transition: color 0.3s ease;
}
.brand-strip .brand-row span:hover { color: var(--accent-green); }

/* Section Common */
.section-head {
  text-align: center;
  max-width: 720px;
  margin: 0 auto 3rem;
}
.section-head h2 {
  font-size: clamp(1.8rem, 4vw, 2.4rem);
  font-weight: 700;
  margin-bottom: 0.8rem;
  position: relative;
  display: inline-block;
}
.section-head h2::after {
  content: '';
  display: block;
  width: 48px;
  height: 3px;
  background: var(--gradient-main);
  border-radius: 3px;
  margin: 0.8rem auto 0;
}
.section-head p {
  color: var(--text-body);
  font-size: 1.02rem;
  margin-top: 1rem;
}

/* Feature Slider */
.feature-slider {
  padding: var(--section-padding);
  background: transparent;
  position: relative;
}
.feature-slider .carousel {
  max-width: 860px;
  margin: 0 auto;
}
.slide-card {
  background: var(--card-bg);
  border: 1px solid var(--card-border);
  border-radius: var(--radius-card);
  padding: 1.2rem;
  text-align: center;
  backdrop-filter: blur(12px);
  box-shadow: var(--card-shadow);
  transition: transform 0.35s ease, border-color 0.35s ease;
}
.slide-card:hover {
  transform: translateY(-4px);
  border-color: var(--card-hover-border);
}
.slide-card img {
  width: 100%;
  max-height: 420px;
  object-fit: cover;
  border-radius: 10px;
  margin-bottom: 1rem;
}
.slide-name {
  font-size: 1.3rem;
  font-weight: 600;
  color: var(--text-heading);
  margin-bottom: 0.3rem;
}
.slide-desc {
  color: var(--text-muted);
  font-size: 0.95rem;
}
.feature-slider .carousel-control-prev,
.feature-slider .carousel-control-next {
  width: 48px;
  height: 48px;
  top: 50%;
  transform: translateY(-50%);
  background: rgba(255,255,255,0.08);
  border: 1px solid rgba(255,255,255,0.12);
  border-radius: 50%;
  opacity: 1;
  transition: all 0.3s ease;
}
.feature-slider .carousel-control-prev { left: -60px; }
.feature-slider .carousel-control-next { right: -60px; }
.feature-slider .carousel-control-prev:hover,
.feature-slider .carousel-control-next:hover {
  background: rgba(0,229,160,0.18);
  border-color: rgba(0,229,160,0.4);
}
.feature-slider .carousel-control-prev-icon {
  background-image: url("data:image/svg+xml,%3csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 16 16' fill='%2300E5A0'%3e%3cpath d='M11.354 1.646a.5.5 0 0 1 0 .708L5.707 8l5.647 5.646a.5.5 0 0 1-.708.708l-6-6a.5.5 0 0 1 0-.708l6-6a.5.5 0 0 1 .708 0z'/%3e%3c/svg%3e");
}
.feature-slider .carousel-control-next-icon {
  background-image: url("data:image/svg+xml,%3csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 16 16' fill='%2300E5A0'%3e%3cpath d='M4.646 1.646a.5.5 0 0 1 .708 0l6 6a.5.5 0 0 1 0 .708l-6 6a.5.5 0 0 1-.708-.708L10.293 8 4.646 2.354a.5.5 0 0 1 0-.708z'/%3e%3c/svg%3e");
}
.feature-slider .carousel-indicators {
  position: static;
  margin: 1.2rem 0 0;
}
.feature-slider .carousel-indicators [data-bs-target] {
  width: 10px;
  height: 10px;
  border-radius: 50%;
  background: rgba(255,255,255,0.2);
  border: none;
  transition: all 0.3s ease;
}
.feature-slider .carousel-indicators .active {
  background: var(--accent-green);
  transform: scale(1.2);
}

/* Feature Grid 2x2 */
.feature-grid {
  padding: var(--section-padding);
  background: rgba(255,255,255,0.015);
  border-top: 1px solid rgba(255,255,255,0.04);
  border-bottom: 1px solid rgba(255,255,255,0.04);
  position: relative;
  overflow: hidden;
}
.feature-grid::before {
  content: '';
  position: absolute;
  top: 0;
  right: 0;
  width: 500px;
  height: 500px;
  background: radial-gradient(circle, rgba(0,180,216,0.06) 0%, transparent 70%);
  pointer-events: none;
}
.feature-card {
  background: rgba(255,255,255,0.04);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border: 1px solid rgba(255,255,255,0.08);
  border-radius: var(--radius-card);
  padding: 2rem 1.8rem;
  height: 100%;
  transition: transform 0.35s ease, box-shadow 0.35s ease, border-color 0.35s ease;
  position: relative;
  overflow: hidden;
}
.feature-card:hover {
  transform: translateY(-6px);
  box-shadow: 0 16px 48px rgba(0,0,0,0.45);
  border-color: rgba(0,229,160,0.4);
}
.feature-card::after {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 3px;
  background: var(--gradient-main);
  transform: scaleX(0);
  transform-origin: left;
  transition: transform 0.4s ease;
}
.feature-card:hover::after { transform: scaleX(1); }
.feature-icon {
  width: 60px;
  height: 60px;
  border-radius: 16px;
  background: rgba(0,229,160,0.12);
  border: 1px solid rgba(0,229,160,0.25);
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 1.3rem;
  font-size: 1.5rem;
  color: var(--accent-green);
  transition: background 0.3s ease, transform 0.3s ease;
}
.feature-card:hover .feature-icon {
  background: rgba(0,229,160,0.22);
  transform: scale(1.05);
}
.feature-card h3 {
  font-size: 1.15rem;
  font-weight: 600;
  margin-bottom: 0.6rem;
}
.feature-card p {
  color: var(--text-body);
  font-size: 0.95rem;
  line-height: 1.7;
  margin-bottom: 1rem;
}
.feature-link {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-size: 0.9rem;
  font-weight: 500;
  color: var(--accent-green);
  transition: gap 0.3s ease;
}
.feature-link:hover { gap: 10px; color: var(--accent-blue); }

/* System Requirements */
.system-req {
  padding: var(--section-padding);
  background-color: var(--primary-darker);
  background-image: linear-gradient(135deg, rgba(7,15,26,0.9) 0%, rgba(11,27,43,0.85) 100%), url('/assets/images/backpic/back-2.webp');
  background-size: cover;
  background-position: center;
  position: relative;
}
.req-panel {
  background: rgba(255,255,255,0.04);
  backdrop-filter: blur(14px);
  border: 1px solid rgba(255,255,255,0.08);
  border-radius: var(--radius-card);
  padding: 2rem;
  height: 100%;
  transition: border-color 0.3s ease, transform 0.3s ease;
}
.req-panel:hover {
  border-color: rgba(0,229,160,0.3);
  transform: translateY(-4px);
}
.req-platform {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 1.6rem;
  font-weight: 700;
  color: var(--text-heading);
  margin-bottom: 1.5rem;
}
.req-platform i { color: var(--accent-green); font-size: 1.8rem; }
.req-panel ul { list-style: none; padding: 0; margin: 0; }
.req-panel li {
  padding: 0.8rem 0;
  border-bottom: 1px solid rgba(255,255,255,0.06);
  font-size: 0.95rem;
  color: var(--text-body);
  display: flex;
  gap: 10px;
}
.req-panel li:last-child { border-bottom: none; }
.req-panel li i {
  color: var(--accent-green);
  margin-top: 4px;
  font-size: 0.85rem;
  flex-shrink: 0;
}
.req-panel .req-label {
  color: var(--text-muted);
  font-size: 0.82rem;
  display: block;
  margin-bottom: 2px;
}

/* Reviews */
.reviews {
  padding: var(--section-padding);
  background: transparent;
}
.review-wall {
  gap: 1.2rem;
  justify-content: center;
}
.review-col {
  flex: 0 0 calc(33.333% - 1rem);
  max-width: calc(33.333% - 1rem);
  display: flex;
  flex-direction: column;
  gap: 1.2rem;
}
.review-card {
  background: var(--card-bg);
  border: 1px solid var(--card-border);
  border-radius: var(--radius-card);
  padding: 1.5rem 1.4rem;
  backdrop-filter: blur(12px);
  transition: transform 0.3s ease, border-color 0.3s ease, box-shadow 0.3s ease;
  position: relative;
}
.review-card:hover {
  transform: translateY(-4px);
  border-color: rgba(0,229,160,0.3);
  box-shadow: 0 12px 40px rgba(0,0,0,0.4);
}
.review-stars {
  color: #FFC857;
  font-size: 0.9rem;
  margin-bottom: 0.6rem;
  letter-spacing: 2px;
}
.review-quote {
  color: var(--text-body);
  font-size: 0.93rem;
  line-height: 1.7;
  margin-bottom: 1rem;
}
.review-user {
  display: flex;
  align-items: center;
  gap: 10px;
  border-top: 1px solid rgba(255,255,255,0.05);
  padding-top: 0.8rem;
}
.review-avatar {
  width: 36px;
  height: 36px;
  border-radius: 50%;
  background: var(--gradient-main);
  display: flex;
  align-items: center;
  justify-content: center;
  color: #0B1B2B;
  font-weight: 700;
  font-size: 0.85rem;
  flex-shrink: 0;
}
.review-user .name {
  font-size: 0.9rem;
  font-weight: 600;
  color: var(--text-heading);
}
.review-user .time {
  font-size: 0.78rem;
  color: var(--text-muted);
}

/* News / CMS */
.news-section {
  padding: var(--section-padding);
  background: rgba(255,255,255,0.015);
  border-top: 1px solid rgba(255,255,255,0.04);
  border-bottom: 1px solid rgba(255,255,255,0.04);
}
.news-list {
  display: flex;
  flex-direction: column;
  gap: 1.2rem;
  max-width: 900px;
  margin: 0 auto;
}
.news-card {
  display: flex;
  gap: 1.5rem;
  padding: 1.5rem;
  background: var(--card-bg);
  border: 1px solid var(--card-border);
  border-radius: var(--radius-card);
  backdrop-filter: blur(12px);
  transition: all 0.3s ease;
  position: relative;
  border-left: 4px solid transparent;
}
.news-card:hover {
  border-left: 4px solid var(--accent-green);
  background: rgba(255,255,255,0.06);
  transform: translateX(6px);
}
.news-left {
  flex-shrink: 0;
  width: 120px;
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}
.news-cat {
  display: inline-block;
  background: rgba(0,229,160,0.12);
  border: 1px solid rgba(0,229,160,0.25);
  color: var(--accent-green);
  font-size: 0.78rem;
  font-weight: 500;
  padding: 0.2rem 0.7rem;
  border-radius: 50px;
  align-self: flex-start;
}
.news-date {
  font-size: 0.8rem;
  color: var(--text-muted);
}
.news-right h3 {
  font-size: 1.08rem;
  margin-bottom: 0.4rem;
}
.news-right h3 a {
  color: var(--text-heading);
  transition: color 0.3s ease;
}
.news-right h3 a:hover { color: var(--accent-green); }
.news-right p {
  color: var(--text-body);
  font-size: 0.93rem;
  margin-bottom: 0.5rem;
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
}
.read-more {
  font-size: 0.88rem;
  font-weight: 500;
  color: var(--accent-green);
  display: inline-flex;
  align-items: center;
  gap: 6px;
  transition: gap 0.3s ease;
}
.read-more:hover { gap: 10px; color: var(--accent-blue); }
.empty-state {
  background: var(--card-bg);
  border: 1px dashed rgba(255,255,255,0.15);
  border-radius: var(--radius-card);
  padding: 3rem 2rem;
  text-align: center;
  color: var(--text-muted);
}
.empty-state i {
  font-size: 2.5rem;
  margin-bottom: 0.8rem;
  color: rgba(255,255,255,0.2);
  display: block;
}

/* FAQ */
.faq-section {
  padding: var(--section-padding);
  background: transparent;
}
.faq-section .accordion {
  max-width: 800px;
  margin: 0 auto;
}
.accordion-item {
  background: var(--card-bg);
  border: 1px solid var(--card-border) !important;
  border-radius: var(--radius-card) !important;
  margin-bottom: 1rem;
  overflow: hidden;
  backdrop-filter: blur(12px);
  transition: border-color 0.3s ease;
}
.accordion-item:focus-within {
  border-color: rgba(0,229,160,0.3) !important;
}
.accordion-button {
  background: transparent;
  color: var(--text-heading);
  font-size: 1rem;
  font-weight: 600;
  padding: 1.2rem 1.5rem;
  border: none;
  box-shadow: none;
  position: relative;
}
.accordion-button::after {
  background-image: url("data:image/svg+xml,%3csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 16 16' fill='%2300E5A0'%3e%3cpath fill-rule='evenodd' d='M1.646 4.646a.5.5 0 0 1 .708 0L8 10.293l5.646-5.647a.5.5 0 0 1 .708.708l-6 6a.5.5 0 0 1-.708 0l-6-6a.5.5 0 0 1 0-.708z'/%3e%3c/svg%3e");
  transition: transform 0.35s ease;
}
.accordion-button:not(.collapsed) {
  background: rgba(0,229,160,0.08);
  color: var(--accent-green);
  box-shadow: none;
}
.accordion-button:not(.collapsed)::after {
  transform: rotate(-180deg);
}
.accordion-button:focus {
  box-shadow: none;
  border-color: transparent;
}
.accordion-body {
  padding: 0 1.5rem 1.3rem;
  color: var(--text-body);
  font-size: 0.95rem;
  line-height: 1.8;
}

/* CTA Download */
.cta-download {
  padding: var(--section-padding);
  background-color: var(--primary-dark);
  background-image: linear-gradient(135deg, rgba(11,27,43,0.92) 0%, rgba(7,23,36,0.88) 100%), url('/assets/images/backpic/back-3.png');
  background-size: cover;
  background-position: center;
  text-align: center;
  position: relative;
  overflow: hidden;
}
.cta-download::before {
  content: '';
  position: absolute;
  top: 50%;
  left: 50%;
  width: 700px;
  height: 700px;
  transform: translate(-50%, -50%);
  background: radial-gradient(circle, rgba(0,229,160,0.08) 0%, transparent 70%);
  pointer-events: none;
}
.cta-download h2 {
  font-size: clamp(1.8rem, 4vw, 2.4rem);
  margin-bottom: 0.8rem;
  position: relative;
  z-index: 1;
}
.cta-download p {
  color: var(--text-body);
  max-width: 600px;
  margin: 0 auto 2rem;
  font-size: 1.02rem;
  position: relative;
  z-index: 1;
}
.download-btns {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 1.2rem;
  position: relative;
  z-index: 1;
}
.btn-download-large {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  padding: 0.875rem 2rem;
  border-radius: var(--radius-btn);
  background: var(--gradient-main);
  color: #0B1B2B;
  font-weight: 700;
  font-size: 1rem;
  border: none;
  box-shadow: 0 4px 20px rgba(0,229,160,0.3);
  transition: all 0.3s ease;
  position: relative;
  overflow: hidden;
}
.btn-download-large:hover {
  color: #0B1B2B;
  transform: translateY(-3px);
  box-shadow: 0 8px 32px rgba(0,229,160,0.5);
}
.btn-download-large::after {
  content: '';
  position: absolute;
  inset: 0;
  background: linear-gradient(120deg, transparent 30%, rgba(255,255,255,0.3) 50%, transparent 70%);
  transform: translateX(-100%);
  animation: shine 3s infinite 1.5s;
}
.btn-download-large i { font-size: 1.3rem; }
.btn-download-alt {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  padding: 0.875rem 2rem;
  border-radius: var(--radius-btn);
  background: transparent;
  color: var(--text-heading);
  font-weight: 600;
  font-size: 1rem;
  border: 1px solid rgba(255,255,255,0.3);
  transition: all 0.3s ease;
}
.btn-download-alt:hover {
  border-color: var(--accent-green);
  color: var(--accent-green);
  transform: translateY(-3px);
}
.btn-download-alt i { font-size: 1.3rem; }

/* Footer */
.site-footer {
  background: var(--primary-darker);
  border-top: 1px solid rgba(255,255,255,0.05);
  padding: 3.5rem 0 0;
  position: relative;
  z-index: 1;
}
.footer-brand {
  display: flex;
  align-items: center;
  gap: 10px;
  margin-bottom: 1rem;
}
.footer-brand .brand-text {
  font-size: 1.2rem;
  font-weight: 700;
  color: var(--text-heading);
}
.site-footer p {
  color: var(--text-muted);
  font-size: 0.9rem;
  line-height: 1.8;
}
.site-footer h4 {
  font-size: 1rem;
  font-weight: 600;
  color: var(--text-heading);
  margin-bottom: 1.2rem;
  position: relative;
  padding-bottom: 0.5rem;
}
.site-footer h4::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 32px;
  height: 2px;
  background: var(--gradient-main);
  border-radius: 2px;
}
.site-footer ul {
  list-style: none;
  padding: 0;
  margin: 0;
}
.site-footer ul li { margin-bottom: 0.5rem; }
.site-footer ul li a {
  color: var(--text-muted);
  font-size: 0.9rem;
  transition: color 0.3s ease, padding-left 0.3s ease;
}
.site-footer ul li a:hover {
  color: var(--accent-green);
  padding-left: 4px;
}
.footer-contact {
  display: flex;
  align-items: center;
  gap: 10px;
  margin-bottom: 0.6rem;
  color: var(--text-muted);
  font-size: 0.9rem;
}
.footer-contact i { color: var(--accent-green); font-size: 0.9rem; flex-shrink: 0; }
.footer-bottom {
  margin-top: 3rem;
  border-top: 1px solid rgba(255,255,255,0.05);
  padding: 1.2rem 0;
  text-align: center;
}
.footer-bottom p {
  font-size: 0.85rem;
  color: var(--text-muted);
  margin: 0;
}
.footer-bottom a {
  color: var(--text-muted);
  text-decoration: none;
}
.footer-bottom a:hover { color: var(--accent-green); }

/* Back to top */
.back-to-top {
  position: fixed;
  bottom: 30px;
  right: 30px;
  width: 46px;
  height: 46px;
  border-radius: 50%;
  background: rgba(11,27,43,0.85);
  border: 1px solid rgba(0,229,160,0.3);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--accent-green);
  font-size: 1.1rem;
  z-index: 990;
  opacity: 0;
  visibility: hidden;
  transform: translateY(20px);
  transition: all 0.4s ease;
  backdrop-filter: blur(10px);
}
.back-to-top.show {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
}
.back-to-top:hover {
  background: rgba(0,229,160,0.15);
  color: var(--accent-green);
  box-shadow: 0 4px 20px rgba(0,229,160,0.3);
}

/* Responsive */
@media (max-width: 991.98px) {
  .custom-navbar {
    height: auto;
    min-height: 72px;
  }
  .custom-navbar .navbar-collapse {
    background: rgba(7,15,26,0.97);
    border-radius: 0 0 16px 16px;
    padding: 1rem 1.5rem 1.2rem;
    box-shadow: 0 20px 40px rgba(0,0,0,0.4);
    border-bottom: 1px solid rgba(255,255,255,0.06);
  }
  .custom-navbar .nav-link {
    padding: 0.6rem 0 !important;
    font-size: 1rem;
  }
  .custom-navbar .nav-link::after {
    bottom: 0;
    left: 0;
    right: 0;
  }
  .hero {
    padding: 120px 0 70px;
  }
  .hero h1 {
    font-size: 2.6rem;
  }
  .hero-visual {
    margin-top: 2rem;
  }
  .feature-slider .carousel-control-prev { left: -12px; }
  .feature-slider .carousel-control-next { right: -12px; }
  .review-col {
    flex: 0 0 calc(50% - 1rem);
    max-width: calc(50% - 1rem);
  }
}
@media (max-width: 767.98px) {
  .hero {
    padding: 110px 0 60px;
  }
  .hero h1 {
    font-size: 2.2rem;
  }
  .hero-sub {
    font-size: 0.98rem;
  }
  .hero-btns {
    flex-direction: column;
    align-items: stretch;
  }
  .btn-primary-lg, .btn-outline-lg {
    justify-content: center;
  }
  .trust-badges {
    flex-direction: column;
    align-items: flex-start;
  }
  .hero-visual {
    margin-top: 1.5rem;
  }
  .float-badge {
    bottom: 8px;
    right: 4px;
    padding: 0.6rem 1rem;
  }
  .float-badge .num { font-size: 1.2rem; }
  .feature-slider .carousel-control-prev,
  .feature-slider .carousel-control-next {
    display: none;
  }
  .brand-strip .brand-row {
    gap: 1.2rem;
  }
  .brand-strip .brand-row span {
    font-size: 0.9rem;
  }
  .review-col {
    flex: 0 0 100%;
    max-width: 100%;
  }
  .news-card {
    flex-direction: column;
    gap: 0.8rem;
    padding: 1.2rem;
  }
  .news-left {
    width: 100%;
    flex-direction: row;
    align-items: center;
    justify-content: space-between;
  }
  .download-btns {
    flex-direction: column;
    align-items: center;
  }
  .btn-download-large, .btn-download-alt {
    width: 100%;
    justify-content: center;
  }
  .footer-bottom {
    padding: 1rem 0;
  }
  .back-to-top {
    bottom: 20px;
    right: 20px;
    width: 40px;
    height: 40px;
  }
  .system-req {
    padding: 3rem 0;
  }
}
@media (max-width: 575.98px) {
  .hero h1 {
    font-size: 1.8rem;
  }
  .hero h1 span {
    font-size: 0.7em;
  }
  .section-head {
    margin-bottom: 2rem;
  }
  .feature-card {
    padding: 1.5rem 1.2rem;
  }
  .req-panel {
    padding: 1.5rem 1.2rem;
  }
  .float-badge {
    display: none;
  }
}

/* roulang page: category1 */
:root {
            --primary-bg: #0B1B2B;
            --primary-accent: #00E5A0;
            --secondary-accent: #00B4D8;
            --text-light: #F5F8FF;
            --text-body: #B6C2D4;
            --text-muted: #8899AA;
            --border-subtle: rgba(255, 255, 255, 0.08);
            --card-bg: rgba(255, 255, 255, 0.05);
            --radius-card: 16px;
            --radius-btn: 12px;
            --shadow-card: 0 8px 32px rgba(0, 0, 0, 0.35);
            --shadow-btn: 0 4px 16px rgba(0, 229, 160, 0.25);
            --gradient-primary: linear-gradient(135deg, #00E5A0, #00B4D8);
            --transition-base: all 0.3s ease;
        }

        * {
            box-sizing: border-box;
        }

        html {
            scroll-behavior: smooth;
        }

        body {
            font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
            background-color: var(--primary-bg);
            color: var(--text-body);
            line-height: 1.75;
            overflow-x: hidden;
            position: relative;
        }

        body::before {
            content: "";
            position: fixed;
            inset: 0;
            background:
                radial-gradient(circle at 15% 10%, rgba(0, 229, 160, 0.12), transparent 35%),
                radial-gradient(circle at 85% 90%, rgba(0, 180, 216, 0.10), transparent 35%);
            pointer-events: none;
            z-index: 0;
        }

        body::after {
            content: "";
            position: fixed;
            inset: 0;
            background-image:
                linear-gradient(rgba(255, 255, 255, 0.025) 1px, transparent 1px),
                linear-gradient(90deg, rgba(255, 255, 255, 0.025) 1px, transparent 1px);
            background-size: 40px 40px;
            pointer-events: none;
            z-index: 0;
        }

        a {
            color: var(--primary-accent);
            text-decoration: none;
            transition: var(--transition-base);
        }

        a:hover {
            color: #66f5c4;
        }

        img {
            max-width: 100%;
            height: auto;
        }

        .container {
            max-width: 1200px;
            position: relative;
            z-index: 1;
        }

        .section-padding {
            padding: clamp(4rem, 8vw, 6rem) 0;
        }

        .section-header {
            text-align: center;
            margin-bottom: 3rem;
        }

        .section-header h2 {
            font-size: clamp(1.8rem, 4vw, 2.4rem);
            font-weight: 700;
            color: var(--text-light);
            position: relative;
            display: inline-block;
            margin-bottom: 1rem;
        }

        .section-header h2::after {
            content: "";
            display: block;
            width: 60px;
            height: 4px;
            border-radius: 4px;
            background: var(--gradient-primary);
            margin: 0.75rem auto 0;
        }

        .section-header p {
            max-width: 700px;
            margin: 0 auto;
            color: var(--text-muted);
        }

        .section-header .lead-text {
            font-size: 1.05rem;
            color: var(--text-body);
        }

        /* Navbar */
        .custom-navbar {
            min-height: 72px;
            background: rgba(11, 27, 43, 0.7);
            backdrop-filter: blur(16px);
            -webkit-backdrop-filter: blur(16px);
            border-bottom: 1px solid var(--border-subtle);
            padding-top: 0;
            padding-bottom: 0;
            transition: background 0.3s ease, box-shadow 0.3s ease;
            z-index: 1040;
        }

        .custom-navbar.scrolled {
            background: rgba(7, 15, 26, 0.92);
            box-shadow: 0 8px 32px rgba(0, 0, 0, 0.45);
        }

        .custom-navbar .navbar-brand {
            display: flex;
            align-items: center;
            gap: 0.6rem;
            font-size: 1.2rem;
            font-weight: 700;
            color: var(--text-light);
            padding: 0.5rem 0;
        }

        .custom-navbar .navbar-brand .brand-icon {
            width: 38px;
            height: 38px;
            background: var(--gradient-primary);
            border-radius: 10px;
            display: inline-flex;
            align-items: center;
            justify-content: center;
            box-shadow: 0 0 20px rgba(0, 229, 160, 0.3);
        }

        .custom-navbar .navbar-brand .brand-icon svg {
            width: 22px;
            height: 22px;
            fill: #0B1B2B;
        }

        .custom-navbar .navbar-brand .brand-text {
            line-height: 1.2;
        }

        .custom-navbar .navbar-brand .brand-text em {
            font-style: normal;
            color: var(--primary-accent);
            display: block;
            font-size: 0.75rem;
            font-weight: 600;
            letter-spacing: 0.08em;
        }

        .custom-navbar .navbar-nav .nav-item {
            margin: 0 0.25rem;
        }

        .custom-navbar .navbar-nav .nav-link {
            color: var(--text-body);
            font-size: 0.95rem;
            font-weight: 500;
            padding: 0.5rem 1rem;
            border-radius: 8px;
            position: relative;
            transition: color 0.3s ease;
        }

        .custom-navbar .navbar-nav .nav-link:hover,
        .custom-navbar .navbar-nav .nav-link.active {
            color: var(--text-light);
        }

        .custom-navbar .navbar-nav .nav-link::after {
            content: "";
            position: absolute;
            bottom: 0;
            left: 50%;
            transform: translateX(-50%);
            width: 0;
            height: 2px;
            background: var(--primary-accent);
            border-radius: 2px;
            transition: width 0.3s ease;
        }

        .custom-navbar .navbar-nav .nav-link:hover::after,
        .custom-navbar .navbar-nav .nav-link.active::after {
            width: 24px;
        }

        .btn-download {
            display: inline-flex;
            align-items: center;
            gap: 0.5rem;
            background: var(--gradient-primary);
            color: #0B1B2B;
            font-weight: 700;
            font-size: 0.95rem;
            padding: 0.6rem 1.5rem;
            border-radius: var(--radius-btn);
            border: none;
            box-shadow: var(--shadow-btn);
            transition: var(--transition-base);
        }

        .btn-download:hover,
        .btn-download:focus {
            color: #0B1B2B;
            transform: translateY(-2px);
            box-shadow: 0 8px 24px rgba(0, 229, 160, 0.4);
        }

        .navbar-toggler {
            border: 1px solid var(--border-subtle);
            background: rgba(255, 255, 255, 0.06);
            border-radius: 10px;
            padding: 0.4rem 0.6rem;
        }

        .navbar-toggler:focus {
            box-shadow: 0 0 0 4px rgba(0, 229, 160, 0.15);
        }

        .navbar-toggler-icon {
            width: 20px;
            height: 20px;
            background-image: url("data:image/svg+xml,%3csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 30 30'%3e%3cpath stroke='rgba(255,255,255,0.8)' stroke-linecap='round' stroke-miterlimit='10' stroke-width='2' d='M4 7h22M4 15h22M4 23h22'/%3e%3c/svg%3e");
        }

        /* Hero (Category Page) */
        .category-hero {
            position: relative;
            min-height: 620px;
            display: flex;
            align-items: center;
            padding-top: 140px;
            padding-bottom: 80px;
            background: linear-gradient(180deg, rgba(11, 27, 43, 0.35), rgba(11, 27, 43, 0.88)),
                url('/assets/images/backpic/back-1.webp') center center / cover no-repeat;
            border-bottom: 1px solid var(--border-subtle);
        }

        .category-hero .hero-badge {
            display: inline-flex;
            align-items: center;
            gap: 0.5rem;
            background: rgba(0, 229, 160, 0.12);
            border: 1px solid rgba(0, 229, 160, 0.3);
            color: var(--primary-accent);
            font-size: 0.8rem;
            font-weight: 600;
            padding: 0.35rem 1rem;
            border-radius: 100px;
            margin-bottom: 1.25rem;
            letter-spacing: 0.05em;
        }

        .category-hero h1 {
            font-size: min(3rem, 8vw);
            font-weight: 700;
            color: var(--text-light);
            line-height: 1.2;
            margin-bottom: 1.25rem;
        }

        .category-hero h1 span {
            color: var(--primary-accent);
        }

        .category-hero .lead {
            font-size: 1.1rem;
            color: var(--text-body);
            max-width: 560px;
            margin-bottom: 2rem;
        }

        .hero-actions {
            display: flex;
            flex-wrap: wrap;
            gap: 1rem;
            margin-bottom: 2rem;
        }

        .btn-primary-custom {
            display: inline-flex;
            align-items: center;
            gap: 0.5rem;
            background: var(--gradient-primary);
            color: #0B1B2B;
            font-weight: 700;
            padding: 0.7rem 1.75rem;
            border-radius: var(--radius-btn);
            border: none;
            box-shadow: 0 4px 16px rgba(0, 229, 160, 0.3);
            transition: var(--transition-base);
        }

        .btn-primary-custom:hover {
            color: #0B1B2B;
            transform: translateY(-3px);
            box-shadow: 0 8px 24px rgba(0, 229, 160, 0.45);
        }

        .btn-outline-custom {
            display: inline-flex;
            align-items: center;
            gap: 0.5rem;
            background: transparent;
            border: 1px solid rgba(255, 255, 255, 0.35);
            color: var(--text-light);
            font-weight: 600;
            padding: 0.7rem 1.75rem;
            border-radius: var(--radius-btn);
            transition: var(--transition-base);
        }

        .btn-outline-custom:hover {
            border-color: var(--primary-accent);
            color: var(--primary-accent);
            transform: translateY(-3px);
        }

        .trust-badges {
            display: flex;
            flex-wrap: wrap;
            gap: 0.75rem;
        }

        .trust-badges .badge-custom {
            display: inline-flex;
            align-items: center;
            gap: 0.35rem;
            background: rgba(255, 255, 255, 0.08);
            border: 1px solid var(--border-subtle);
            color: var(--text-body);
            font-size: 0.8rem;
            padding: 0.35rem 0.9rem;
            border-radius: 100px;
            backdrop-filter: blur(8px);
        }

        .trust-badges .badge-custom i {
            color: var(--primary-accent);
            font-size: 0.75rem;
        }

        .hero-visual {
            position: relative;
            text-align: center;
        }

        .hero-visual .glass-frame {
            background: rgba(255, 255, 255, 0.06);
            border: 1px solid var(--border-subtle);
            border-radius: 24px;
            backdrop-filter: blur(14px);
            box-shadow: 0 20px 60px rgba(0, 0, 0, 0.4);
            padding: 1rem;
            display: inline-block;
            max-width: 360px;
            width: 100%;
            transition: var(--transition-base);
        }

        .hero-visual .glass-frame img {
            border-radius: 16px;
            width: 100%;
            aspect-ratio: 4 / 3;
            object-fit: cover;
        }

        .hero-visual .float-stat {
            position: absolute;
            bottom: -20px;
            right: 10px;
            background: rgba(11, 27, 43, 0.85);
            backdrop-filter: blur(12px);
            border: 1px solid rgba(0, 229, 160, 0.3);
            border-radius: 20px;
            padding: 0.5rem 1.25rem;
            display: flex;
            align-items: center;
            gap: 0.6rem;
            box-shadow: 0 8px 32px rgba(0, 0, 0, 0.45);
        }

        .hero-visual .float-stat .stat-value {
            font-weight: 700;
            font-size: 1.2rem;
            color: var(--primary-accent);
            line-height: 1.1;
        }

        .hero-visual .float-stat .stat-label {
            font-size: 0.75rem;
            color: var(--text-muted);
        }

        /* Download Methods */
        .download-methods {
            position: relative;
            z-index: 1;
            background: transparent;
            margin-top: -40px;
        }

        .method-card {
            background: var(--card-bg);
            border: 1px solid var(--border-subtle);
            border-radius: var(--radius-card);
            padding: 1.75rem;
            height: 100%;
            backdrop-filter: blur(12px);
            box-shadow: var(--shadow-card);
            transition: var(--transition-base);
            position: relative;
            overflow: hidden;
        }

        .method-card:hover {
            transform: translateY(-8px);
            border-color: rgba(0, 229, 160, 0.4);
            box-shadow: 0 16px 40px rgba(0, 0, 0, 0.5);
        }

        .method-icon {
            width: 56px;
            height: 56px;
            background: var(--gradient-primary);
            border-radius: 14px;
            display: inline-flex;
            align-items: center;
            justify-content: center;
            color: #0B1B2B;
            font-size: 1.4rem;
            margin-bottom: 1.25rem;
            box-shadow: 0 0 30px rgba(0, 229, 160, 0.2);
        }

        .method-card h3 {
            font-size: 1.2rem;
            font-weight: 700;
            color: var(--text-light);
            margin-bottom: 0.75rem;
        }

        .method-card p {
            font-size: 0.9rem;
            color: var(--text-muted);
            margin-bottom: 1rem;
        }

        .method-tag {
            display: inline-block;
            background: rgba(0, 229, 160, 0.1);
            color: var(--primary-accent);
            font-size: 0.75rem;
            border: 1px solid rgba(0, 229, 160, 0.2);
            padding: 0.2rem 0.6rem;
            border-radius: 6px;
        }

        /* Preparation */
        .prep-section {
            position: relative;
            z-index: 1;
        }

        .prep-panel {
            background: rgba(255, 255, 255, 0.04);
            border: 1px solid var(--border-subtle);
            border-radius: 20px;
            padding: 2.5rem 2rem;
            height: 100%;
            backdrop-filter: blur(12px);
            transition: var(--transition-base);
        }

        .prep-panel:hover {
            border-color: rgba(0, 229, 160, 0.3);
        }

        .prep-panel h3 {
            font-size: 1.3rem;
            font-weight: 700;
            color: var(--text-light);
            margin-bottom: 1.5rem;
            display: flex;
            align-items: center;
            gap: 0.6rem;
        }

        .prep-panel h3 i {
            color: var(--primary-accent);
        }

        .check-list {
            list-style: none;
            padding: 0;
            margin: 0;
        }

        .check-list li {
            display: flex;
            gap: 0.75rem;
            padding: 0.6rem 0;
            border-bottom: 1px solid rgba(255, 255, 255, 0.05);
            font-size: 0.95rem;
            color: var(--text-body);
            align-items: flex-start;
        }

        .check-list li:last-child {
            border-bottom: none;
        }

        .check-list li i {
            color: var(--primary-accent);
            margin-top: 0.3rem;
            font-size: 0.85rem;
        }

        /* Steps */
        .steps-section {
            position: relative;
            z-index: 1;
            background: rgba(0, 0, 0, 0.18);
            border-top: 1px solid var(--border-subtle);
            border-bottom: 1px solid var(--border-subtle);
        }

        .step-card {
            text-align: center;
            background: rgba(255, 255, 255, 0.04);
            border: 1px solid var(--border-subtle);
            border-radius: var(--radius-card);
            padding: 2rem 1.5rem;
            height: 100%;
            position: relative;
            transition: var(--transition-base);
            backdrop-filter: blur(8px);
        }

        .step-card:hover {
            transform: translateY(-6px);
            border-color: rgba(0, 229, 160, 0.35);
        }

        .step-number {
            width: 48px;
            height: 48px;
            background: var(--gradient-primary);
            color: #0B1B2B;
            border-radius: 50%;
            display: inline-flex;
            align-items: center;
            justify-content: center;
            font-weight: 800;
            font-size: 1.2rem;
            margin-bottom: 1.25rem;
            box-shadow: 0 0 20px rgba(0, 229, 160, 0.25);
        }

        .step-card h3 {
            font-size: 1.15rem;
            font-weight: 600;
            color: var(--text-light);
            margin-bottom: 0.75rem;
        }

        .step-card p {
            font-size: 0.9rem;
            color: var(--text-muted);
            margin: 0;
        }

        /* Scenarios */
        .scenarios-section {
            position: relative;
            z-index: 1;
        }

        .scene-card {
            background: rgba(255, 255, 255, 0.04);
            border: 1px solid var(--border-subtle);
            border-radius: var(--radius-card);
            padding: 1.75rem;
            height: 100%;
            display: flex;
            gap: 1.25rem;
            transition: var(--transition-base);
            backdrop-filter: blur(10px);
        }

        .scene-card:hover {
            border-color: rgba(0, 229, 160, 0.35);
            transform: translateY(-4px);
            background: rgba(255, 255, 255, 0.07);
        }

        .scene-icon {
            flex-shrink: 0;
            width: 52px;
            height: 52px;
            background: rgba(0, 229, 160, 0.1);
            border: 1px solid rgba(0, 229, 160, 0.2);
            border-radius: 12px;
            display: inline-flex;
            align-items: center;
            justify-content: center;
            font-size: 1.3rem;
            color: var(--primary-accent);
        }

        .scene-card h3 {
            font-size: 1.1rem;
            font-weight: 700;
            color: var(--text-light);
            margin-bottom: 0.5rem;
        }

        .scene-card p {
            font-size: 0.9rem;
            color: var(--text-muted);
            margin: 0;
        }

        /* Version Info */
        .version-section {
            position: relative;
            z-index: 1;
        }

        .version-panel {
            background: linear-gradient(135deg, rgba(0, 229, 160, 0.08), rgba(0, 180, 216, 0.06));
            border: 1px solid rgba(0, 229, 160, 0.2);
            border-radius: 24px;
            padding: 2.5rem 1.5rem;
            backdrop-filter: blur(12px);
        }

        .version-item {
            padding: 1.25rem;
            text-align: center;
            border-right: 1px solid rgba(255, 255, 255, 0.07);
        }

        .version-item:last-child {
            border-right: none;
        }

        .version-item .v-label {
            font-size: 0.8rem;
            color: var(--text-muted);
            text-transform: uppercase;
            letter-spacing: 0.05em;
            margin-bottom: 0.5rem;
        }

        .version-item .v-value {
            font-size: 1.3rem;
            font-weight: 700;
            color: var(--text-light);
        }

        .version-item .v-value i {
            color: var(--primary-accent);
            margin-right: 0.25rem;
        }

        /* FAQ */
        .faq-section {
            position: relative;
            z-index: 1;
            background: rgba(0, 0, 0, 0.15);
            border-top: 1px solid var(--border-subtle);
            border-bottom: 1px solid var(--border-subtle);
        }

        .faq-accordion .accordion-item {
            background: rgba(255, 255, 255, 0.04);
            border: 1px solid var(--border-subtle);
            border-radius: 16px !important;
            margin-bottom: 1rem;
            overflow: hidden;
            transition: var(--transition-base);
        }

        .faq-accordion .accordion-item:hover {
            border-color: rgba(0, 229, 160, 0.25);
        }

        .faq-accordion .accordion-button {
            background: transparent;
            color: var(--text-light);
            font-weight: 600;
            font-size: 1rem;
            padding: 1.25rem 1.5rem;
            border: none;
            box-shadow: none;
            position: relative;
        }

        .faq-accordion .accordion-button:hover,
        .faq-accordion .accordion-button:focus {
            background: rgba(0, 229, 160, 0.04);
            box-shadow: none;
        }

        .faq-accordion .accordion-button::after {
            background-image: none;
            content: "+";
            font-family: sans-serif;
            font-size: 1.4rem;
            font-weight: 400;
            color: var(--primary-accent);
            width: auto;
            height: auto;
            transition: transform 0.3s ease;
            display: inline-flex;
            align-items: center;
            justify-content: center;
        }

        .faq-accordion .accordion-button:not(.collapsed) {
            background: rgba(0, 229, 160, 0.08);
            color: var(--primary-accent);
            box-shadow: none;
        }

        .faq-accordion .accordion-button:not(.collapsed)::after {
            content: "−";
            transform: none;
        }

        .faq-accordion .accordion-body {
            color: var(--text-body);
            font-size: 0.95rem;
            padding: 0 1.5rem 1.25rem;
        }

        .faq-accordion .accordion-body p {
            margin: 0;
        }

        /* CTA */
        .cta-download-section {
            position: relative;
            z-index: 1;
            background: linear-gradient(135deg, rgba(0, 229, 160, 0.08), rgba(0, 180, 216, 0.05)),
                url('/assets/images/backpic/back-2.webp') center center / cover no-repeat;
            border-top: 1px solid var(--border-subtle);
            border-bottom: 1px solid var(--border-subtle);
        }

        .cta-download-section .cta-inner {
            background: rgba(11, 27, 43, 0.75);
            backdrop-filter: blur(14px);
            border-radius: 24px;
            border: 1px solid var(--border-subtle);
            padding: 4rem 2rem;
            text-align: center;
        }

        .cta-download-section h2 {
            font-size: clamp(1.8rem, 4vw, 2.4rem);
            font-weight: 700;
            color: var(--text-light);
            margin-bottom: 1rem;
        }

        .cta-download-section .cta-desc {
            max-width: 560px;
            margin: 0 auto 2rem;
            color: var(--text-body);
        }

        .cta-buttons {
            display: flex;
            flex-wrap: wrap;
            justify-content: center;
            gap: 1rem;
        }

        .btn-store {
            display: inline-flex;
            align-items: center;
            gap: 0.6rem;
            padding: 0.875rem 2rem;
            border-radius: var(--radius-btn);
            font-weight: 600;
            font-size: 0.95rem;
            border: none;
            transition: var(--transition-base);
        }

        .btn-store i {
            font-size: 1.2rem;
        }

        .btn-store-ios {
            background: #F5F8FF;
            color: #0B1B2B;
            box-shadow: 0 4px 12px rgba(255, 255, 255, 0.1);
        }

        .btn-store-ios:hover {
            background: #ffffff;
            color: #0B1B2B;
            transform: translateY(-3px);
            box-shadow: 0 8px 24px rgba(255, 255, 255, 0.15);
        }

        .btn-store-android {
            background: var(--gradient-primary);
            color: #0B1B2B;
            box-shadow: var(--shadow-btn);
        }

        .btn-store-android:hover {
            color: #0B1B2B;
            transform: translateY(-3px);
            box-shadow: 0 8px 24px rgba(0, 229, 160, 0.4);
        }

        .btn-store-qr {
            background: rgba(255, 255, 255, 0.06);
            color: var(--text-light);
            border: 1px solid var(--border-subtle);
            backdrop-filter: blur(8px);
        }

        .btn-store-qr:hover {
            border-color: var(--primary-accent);
            color: var(--primary-accent);
            transform: translateY(-3px);
            background: rgba(0, 229, 160, 0.08);
        }

        /* Footer */
        .site-footer {
            background: #070F1A;
            padding: 4.5rem 0 0;
            position: relative;
            z-index: 1;
            border-top: 1px solid var(--border-subtle);
        }

        .site-footer .footer-brand {
            display: flex;
            align-items: center;
            gap: 0.75rem;
            margin-bottom: 1rem;
        }

        .site-footer .footer-brand .brand-icon {
            width: 40px;
            height: 40px;
            background: var(--gradient-primary);
            border-radius: 10px;
            display: inline-flex;
            align-items: center;
            justify-content: center;
        }

        .site-footer .footer-brand .brand-icon svg {
            width: 22px;
            height: 22px;
            fill: #0B1B2B;
        }

        .site-footer .footer-brand .brand-text {
            font-weight: 700;
            font-size: 1.15rem;
            color: var(--text-light);
        }

        .site-footer p {
            font-size: 0.9rem;
            color: var(--text-muted);
            margin-bottom: 0.5rem;
        }

        .site-footer h4 {
            font-size: 1rem;
            font-weight: 700;
            color: var(--text-light);
            margin-bottom: 1.25rem;
            position: relative;
            padding-bottom: 0.5rem;
        }

        .site-footer h4::after {
            content: "";
            position: absolute;
            bottom: 0;
            left: 0;
            width: 28px;
            height: 2px;
            background: var(--primary-accent);
            border-radius: 2px;
        }

        .site-footer ul {
            list-style: none;
            padding: 0;
            margin: 0;
        }

        .site-footer ul li {
            margin-bottom: 0.5rem;
        }

        .site-footer ul li a {
            color: var(--text-muted);
            font-size: 0.9rem;
            transition: color 0.3s ease;
        }

        .site-footer ul li a:hover {
            color: var(--primary-accent);
        }

        .site-footer .footer-contact {
            color: var(--text-muted);
            font-size: 0.9rem;
            margin-bottom: 0.5rem;
            display: flex;
            align-items: center;
            gap: 0.5rem;
        }

        .site-footer .footer-contact i {
            color: var(--primary-accent);
            width: 16px;
            text-align: center;
        }

        .site-footer .footer-bottom {
            border-top: 1px solid rgba(255, 255, 255, 0.06);
            padding: 1.5rem 0;
            margin-top: 3rem;
            text-align: center;
        }

        .site-footer .footer-bottom p {
            margin: 0;
            font-size: 0.85rem;
            color: #758497;
        }

        .site-footer .footer-bottom a {
            color: #758497;
        }

        .site-footer .footer-bottom a:hover {
            color: var(--primary-accent);
        }

        /* Responsive */
        @media (max-width: 991px) {
            .category-hero {
                min-height: auto;
                padding-top: 120px;
                padding-bottom: 60px;
            }

            .hero-visual {
                margin-top: 2.5rem;
            }

            .hero-visual .float-stat {
                right: auto;
                left: 20px;
            }

            .version-item {
                border-right: none;
                border-bottom: 1px solid rgba(255, 255, 255, 0.07);
            }

            .version-item:last-child {
                border-bottom: none;
            }
        }

        @media (max-width: 767px) {
            .category-hero {
                padding-top: 110px;
                text-align: center;
            }

            .hero-actions {
                justify-content: center;
            }

            .trust-badges {
                justify-content: center;
            }

            .cta-buttons {
                flex-direction: column;
                align-items: stretch;
                max-width: 360px;
                margin: 0 auto;
            }

            .btn-store {
                justify-content: center;
            }

            .download-methods {
                margin-top: 0;
            }

            .check-list li {
                font-size: 0.9rem;
            }
        }

        @media (max-width: 520px) {
            .section-padding {
                padding: 3.5rem 0;
            }

            .custom-navbar .navbar-brand {
                font-size: 1.05rem;
            }

            .prep-panel {
                padding: 1.5rem;
            }

            .scene-card {
                flex-direction: column;
                gap: 0.75rem;
            }
        }

        @media (min-width: 992px) {
            .btn-download.d-none.d-lg-inline-flex {
                margin-left: 0.5rem;
            }
        }

/* roulang page: article */
:root {
    --bg-deep: #0B1B2B;
    --bg-footer: #070F1A;
    --primary: #00E5A0;
    --secondary: #00B4D8;
    --gradient: linear-gradient(135deg, #00E5A0, #00B4D8);
    --text-heading: #F5F8FF;
    --text-body: #B6C2D4;
    --text-weak: #8899AA;
    --border-glass: rgba(255, 255, 255, 0.08);
    --card-bg: rgba(255, 255, 255, 0.05);
    --radius: 16px;
    --radius-btn: 12px;
    --shadow-card: 0 8px 32px rgba(0, 0, 0, 0.35);
    --shadow-btn: 0 4px 16px rgba(0, 229, 160, 0.25);
    --font-main: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
    --space-section: clamp(4rem, 8vw, 6rem) 0;
}
*,
*::before,
*::after {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}
html {
    scroll-behavior: smooth;
}
body {
    font-family: var(--font-main);
    background:
        radial-gradient(ellipse at top left, rgba(0, 229, 160, 0.12), transparent 55%),
        radial-gradient(ellipse at bottom right, rgba(0, 180, 216, 0.10), transparent 50%),
        linear-gradient(rgba(255, 255, 255, 0.02) 1px, transparent 1px),
        linear-gradient(90deg, rgba(255, 255, 255, 0.02) 1px, transparent 1px),
        var(--bg-deep);
    background-size: auto, auto, 36px 36px, 36px 36px, auto;
    background-attachment: fixed;
    color: var(--text-body);
    line-height: 1.75;
    font-size: 1rem;
    overflow-x: hidden;
}
a {
    color: var(--primary);
    text-decoration: none;
    transition: color .25s ease;
}
a:hover {
    color: #fff;
}
img {
    max-width: 100%;
    display: block;
}
button,
input {
    font-family: inherit;
}
.container {
    max-width: 1200px;
}
section {
    padding: var(--space-section);
}
.section-head {
    text-align: center;
    margin-bottom: 3rem;
}
.section-head h2 {
    color: var(--text-heading);
    font-size: clamp(1.8rem, 4vw, 2.4rem);
    font-weight: 700;
    position: relative;
    display: inline-block;
    padding-bottom: 1rem;
    margin-bottom: 0.75rem;
}
.section-head h2::after {
    content: "";
    position: absolute;
    left: 50%;
    bottom: 0;
    transform: translateX(-50%);
    width: 56px;
    height: 4px;
    border-radius: 4px;
    background: var(--gradient);
}
.section-head p {
    color: var(--text-weak);
    max-width: 640px;
    margin: 0 auto;
    font-size: 1rem;
}
.btn-download {
    background: var(--gradient);
    color: #071019;
    font-weight: 700;
    border: none;
    border-radius: var(--radius-btn);
    padding: 0.55rem 1.4rem;
    box-shadow: var(--shadow-btn);
    transition: all .3s ease;
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
}
.btn-download:hover,
.btn-download:focus {
    color: #071019;
    filter: brightness(1.08);
    transform: translateY(-2px);
    box-shadow: 0 8px 22px rgba(0, 229, 160, 0.35);
}
.btn-outline-light {
    border: 1px solid rgba(255, 255, 255, 0.25);
    color: var(--text-body);
    border-radius: var(--radius-btn);
    padding: 0.5rem 1.25rem;
    transition: all .3s ease;
    background: transparent;
}
.btn-outline-light:hover {
    border-color: var(--primary);
    color: var(--primary);
    background: rgba(0, 229, 160, 0.06);
    transform: translateY(-2px);
}
/* ===== Navbar ===== */
.custom-navbar {
    background: rgba(11, 27, 43, 0.72);
    backdrop-filter: blur(16px);
    -webkit-backdrop-filter: blur(16px);
    border-bottom: 1px solid rgba(255, 255, 255, 0.06);
    padding: 0.9rem 0;
    min-height: 72px;
    transition: background .3s ease, box-shadow .3s ease;
}
.custom-navbar.scrolled {
    background: rgba(7, 15, 26, 0.94);
    box-shadow: 0 6px 30px rgba(0, 0, 0, 0.35);
}
.custom-navbar .navbar-brand {
    display: inline-flex;
    align-items: center;
    gap: 0.6rem;
    padding: 0;
}
.brand-icon {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 36px;
    height: 36px;
    border-radius: 10px;
    background: var(--gradient);
    box-shadow: 0 4px 14px rgba(0, 229, 160, 0.35);
}
.brand-icon svg {
    width: 22px;
    height: 22px;
    fill: #071019;
}
.brand-text {
    color: var(--text-heading);
    font-size: 1.25rem;
    font-weight: 700;
    line-height: 1.2;
    white-space: nowrap;
}
.brand-text em {
    font-style: normal;
    background: var(--gradient);
    -webkit-background-clip: text;
    background-clip: text;
    -webkit-text-fill-color: transparent;
}
.custom-navbar .navbar-nav {
    gap: 0.25rem;
}
.custom-navbar .nav-link {
    color: var(--text-body);
    font-weight: 500;
    padding: 0.55rem 0.9rem;
    position: relative;
    border-radius: 8px;
    transition: color .25s ease;
}
.custom-navbar .nav-link::after {
    content: "";
    position: absolute;
    left: 0.9rem;
    right: 0.9rem;
    bottom: 0;
    height: 2px;
    border-radius: 2px;
    background: var(--gradient);
    transform: scaleX(0);
    transform-origin: left;
    transition: transform .3s ease;
}
.custom-navbar .nav-link:hover {
    color: var(--text-heading);
}
.custom-navbar .nav-link:hover::after,
.custom-navbar .nav-link.active::after {
    transform: scaleX(1);
}
.custom-navbar .nav-link.active {
    color: var(--primary);
}
.navbar-toggler {
    border: 1px solid rgba(255, 255, 255, 0.18);
    border-radius: 10px;
    padding: 0.4rem 0.6rem;
}
.navbar-toggler:focus {
    box-shadow: 0 0 0 4px rgba(0, 229, 160, 0.15);
}
.navbar-toggler-icon {
    background-image: url("data:image/svg+xml,%3csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 30 30'%3e%3cpath stroke='rgba(255,255,255,0.85)' stroke-linecap='round' stroke-miterlimit='10' stroke-width='2' d='M4 7h22M4 15h22M4 23h22'/%3e%3c/svg%3e");
}
/* ===== Article Hero ===== */
.article-hero {
    position: relative;
    padding: 160px 0 60px;
    background:
        linear-gradient(135deg, rgba(7, 15, 26, 0.92), rgba(11, 27, 43, 0.78)),
        url('/assets/images/backpic/back-2.webp') center center / cover no-repeat;
    border-bottom: 1px solid rgba(255, 255, 255, 0.06);
}
.article-breadcrumb {
    background: transparent;
    padding: 0;
    margin-bottom: 1.25rem;
    list-style: none;
    display: flex;
    flex-wrap: wrap;
    gap: 0.25rem;
}
.article-breadcrumb li {
    color: var(--text-weak);
    font-size: 0.875rem;
}
.article-breadcrumb li + li::before {
    content: "/";
    margin: 0 0.5rem;
    color: rgba(255, 255, 255, 0.25);
}
.article-breadcrumb a {
    color: var(--primary);
}
.article-breadcrumb a:hover {
    color: #fff;
}
.article-title {
    color: var(--text-heading);
    font-size: clamp(2rem, 5vw, 3rem);
    font-weight: 700;
    line-height: 1.2;
    margin-bottom: 1.25rem;
    letter-spacing: 0.01em;
}
.article-meta {
    display: flex;
    align-items: center;
    flex-wrap: wrap;
    gap: 1rem;
    color: var(--text-weak);
    font-size: 0.9rem;
}
.badge-category {
    display: inline-flex;
    align-items: center;
    background: rgba(0, 229, 160, 0.14);
    border: 1px solid rgba(0, 229, 160, 0.2);
    color: var(--primary);
    border-radius: 999px;
    padding: 0.25rem 1rem;
    font-size: 0.85rem;
    font-weight: 600;
}
/* ===== Article Body ===== */
.article-body {
    padding: 4rem 0 3rem;
}
.article-layout {
    max-width: 840px;
    margin: 0 auto;
}
.article-summary {
    border-left: 4px solid var(--primary);
    background: rgba(0, 229, 160, 0.05);
    padding: 1.5rem 1.75rem;
    border-radius: 0 14px 14px 0;
    color: #D3DEEA;
    font-size: 1rem;
    line-height: 1.8;
    margin-bottom: 2.5rem;
}
.article-content {
    max-width: 68ch;
    width: 100%;
    font-size: 1.05rem;
    line-height: 1.75;
    color: #C9D5E3;
}
.article-content p {
    margin-bottom: 1.5rem;
}
.article-content h2 {
    color: var(--text-heading);
    font-size: 1.6rem;
    font-weight: 700;
    margin: 2.5rem 0 1.25rem;
    padding-left: 0.9rem;
    border-left: 4px solid var(--primary);
    line-height: 1.3;
}
.article-content h3 {
    color: var(--text-heading);
    font-size: 1.3rem;
    font-weight: 600;
    margin: 2rem 0 1rem;
}
.article-content a {
    color: var(--primary);
    border-bottom: 1px solid rgba(0, 229, 160, 0.3);
}
.article-content a:hover {
    color: #fff;
    border-bottom-color: #fff;
}
.article-content img {
    border-radius: var(--radius);
    margin: 1.25rem auto;
    box-shadow: var(--shadow-card);
}
.article-content blockquote {
    border-left: 3px solid var(--secondary);
    background: rgba(255, 255, 255, 0.03);
    padding: 1.1rem 1.4rem;
    border-radius: 0 12px 12px 0;
    color: #DBE7F2;
    margin-bottom: 1.5rem;
}
.article-content pre {
    background: #0A1521;
    border: 1px solid var(--border-glass);
    border-radius: var(--radius);
    padding: 1.25rem;
    overflow-x: auto;
    color: var(--text-body);
    margin-bottom: 1.5rem;
}
.article-content code {
    background: rgba(255, 255, 255, 0.1);
    border-radius: 6px;
    padding: 0.15rem 0.5rem;
    font-size: 0.9em;
    color: var(--primary);
}
.article-content ul,
.article-content ol {
    padding-left: 1.4rem;
    margin-bottom: 1.5rem;
}
.article-content li {
    margin-bottom: 0.5rem;
}
.article-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 0.6rem;
    margin-top: 2.5rem;
}
.article-tag {
    display: inline-flex;
    align-items: center;
    background: rgba(255, 255, 255, 0.05);
    border: 1px solid rgba(255, 255, 255, 0.1);
    color: var(--text-body);
    padding: 0.35rem 1rem;
    border-radius: 999px;
    font-size: 0.85rem;
    transition: all .25s ease;
}
.article-tag:hover {
    border-color: var(--primary);
    color: var(--primary);
    background: rgba(0, 229, 160, 0.08);
}
.article-nav {
    display: flex;
    justify-content: space-between;
    gap: 1rem;
    flex-wrap: wrap;
    margin-top: 2.5rem;
    border-top: 1px solid var(--border-glass);
    padding-top: 2rem;
}
/* ===== Related ===== */
.related-section {
    background: rgba(255, 255, 255, 0.015);
    border-top: 1px solid var(--border-glass);
    border-bottom: 1px solid var(--border-glass);
}
.related-card {
    display: block;
    height: 100%;
    background: var(--card-bg);
    border: 1px solid var(--border-glass);
    border-radius: var(--radius);
    overflow: hidden;
    transition: transform .3s ease, box-shadow .3s ease, border-color .3s ease;
}
.related-card:hover {
    transform: translateY(-6px);
    border-color: rgba(0, 229, 160, 0.4);
    box-shadow: 0 14px 40px rgba(0, 0, 0, 0.4);
}
.related-card .rc-thumb {
    width: 100%;
    aspect-ratio: 16 / 9;
    overflow: hidden;
    background: #0A1521;
}
.related-card .rc-thumb img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: transform .4s ease;
}
.related-card:hover .rc-thumb img {
    transform: scale(1.05);
}
.related-card .rc-body {
    padding: 1.4rem 1.5rem 1.6rem;
}
.related-card h3 {
    color: var(--text-heading);
    font-size: 1.1rem;
    font-weight: 600;
    margin-bottom: 0.6rem;
}
.related-card p {
    color: var(--text-body);
    font-size: 0.9rem;
    line-height: 1.65;
    margin-bottom: 0.9rem;
}
.rc-link {
    color: var(--primary);
    font-size: 0.9rem;
    font-weight: 600;
    display: inline-flex;
    align-items: center;
    gap: 0.4rem;
}
.rc-link i {
    transition: transform .25s ease;
}
.related-card:hover .rc-link i {
    transform: translateX(4px);
}
/* ===== FAQ ===== */
.faq-section {
    padding: var(--space-section);
}
.accordion-item {
    background: var(--card-bg);
    border: 1px solid var(--border-glass) !important;
    border-radius: var(--radius) !important;
    overflow: hidden;
    margin-bottom: 1rem;
}
.accordion-button {
    background: transparent;
    color: var(--text-heading);
    font-weight: 600;
    font-size: 1rem;
    padding: 1.25rem 1.5rem;
    box-shadow: none !important;
    border: none;
    transition: background .3s ease, color .3s ease;
}
.accordion-button:focus {
    box-shadow: 0 0 0 4px rgba(0, 229, 160, 0.12) !important;
    border-radius: var(--radius);
}
.accordion-button:not(.collapsed) {
    background: rgba(0, 229, 160, 0.07);
    color: var(--primary);
}
.accordion-button::after {
    background-image: url("data:image/svg+xml,%3csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 16 16' fill='%23B6C2D4'%3e%3cpath d='M8 4a.5.5 0 0 1 .5.5v3h3a.5.5 0 0 1 0 1h-3v3a.5.5 0 0 1-1 0v-3h-3a.5.5 0 0 1 0-1h3v-3A.5.5 0 0 1 8 4z'/%3e%3c/svg%3e");
    background-size: 1rem;
    transition: transform .3s ease;
}
.accordion-button:not(.collapsed)::after {
    background-image: url("data:image/svg+xml,%3csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 16 16' fill='%2300E5A0'%3e%3cpath d='M4 8a.5.5 0 0 1 .5-.5h7a.5.5 0 0 1 0 1h-7A.5.5 0 0 1 4 8z'/%3e%3c/svg%3e");
}
.accordion-body {
    color: var(--text-body);
    padding: 0 1.5rem 1.4rem;
    line-height: 1.75;
}
/* ===== CTA ===== */
.cta-section {
    position: relative;
    background: linear-gradient(135deg, rgba(0, 229, 160, 0.08), rgba(0, 180, 216, 0.06));
    border-top: 1px solid var(--border-glass);
    text-align: center;
    overflow: hidden;
}
.cta-section::before {
    content: "";
    position: absolute;
    width: 420px;
    height: 420px;
    border-radius: 50%;
    background: radial-gradient(circle, rgba(0, 229, 160, 0.12), transparent 70%);
    top: -160px;
    left: 50%;
    transform: translateX(-50%);
    pointer-events: none;
}
.cta-section h2 {
    color: var(--text-heading);
    font-size: clamp(2rem, 5vw, 2.8rem);
    font-weight: 700;
    margin-bottom: 1rem;
}
.cta-section p {
    color: var(--text-body);
    max-width: 620px;
    margin: 0 auto 2.5rem;
    font-size: 1.05rem;
}
.download-buttons {
    display: flex;
    gap: 1rem;
    justify-content: center;
    flex-wrap: wrap;
}
.btn-download-large {
    display: inline-flex;
    align-items: center;
    gap: 0.65rem;
    background: var(--gradient);
    color: #071019;
    font-weight: 700;
    padding: 0.875rem 2rem;
    border-radius: var(--radius-btn);
    box-shadow: var(--shadow-btn);
    animation: pulse-glow 2.8s ease-in-out infinite;
    transition: all .3s ease;
}
.btn-download-large:hover {
    color: #071019;
    transform: translateY(-3px) scale(1.02);
    box-shadow: 0 10px 30px rgba(0, 229, 160, 0.4);
}
.btn-download-large i {
    font-size: 1.3rem;
}
@keyframes pulse-glow {
    0%, 100% { box-shadow: 0 4px 16px rgba(0, 229, 160, 0.25); }
    50% { box-shadow: 0 4px 28px rgba(0, 229, 160, 0.45); }
}
/* ===== Footer ===== */
.site-footer {
    background: var(--bg-footer);
    padding: 4rem 0 0;
    border-top: 1px solid rgba(255, 255, 255, 0.05);
}
.footer-brand {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    margin-bottom: 1rem;
}
.site-footer h4 {
    color: var(--text-heading);
    font-size: 1rem;
    font-weight: 600;
    margin-bottom: 1.1rem;
}
.site-footer p {
    color: var(--text-weak);
    font-size: 0.9rem;
    line-height: 1.7;
    margin-bottom: 0.85rem;
}
.site-footer ul {
    list-style: none;
    padding: 0;
    margin: 0;
}
.site-footer ul li {
    margin-bottom: 0.6rem;
}
.site-footer ul a {
    color: var(--text-weak);
    font-size: 0.9rem;
    transition: color .25s ease, padding-left .25s ease;
}
.site-footer ul a:hover {
    color: var(--primary);
    padding-left: 4px;
}
.footer-contact {
    color: var(--text-weak);
    font-size: 0.9rem;
    display: flex;
    align-items: center;
    gap: 0.6rem;
    margin-bottom: 0.75rem;
}
.footer-contact i {
    color: var(--primary);
    width: 18px;
    text-align: center;
}
.footer-bottom {
    border-top: 1px solid rgba(255, 255, 255, 0.05);
    padding: 1.5rem 0;
    margin-top: 3.5rem;
    text-align: center;
}
.footer-bottom p {
    color: var(--text-weak);
    font-size: 0.85rem;
    margin: 0;
}
.footer-bottom a {
    color: var(--text-body);
}
.footer-bottom a:hover {
    color: var(--primary);
}
/* ===== Back Top ===== */
.back-top {
    position: fixed;
    right: 24px;
    bottom: 24px;
    width: 46px;
    height: 46px;
    border: none;
    border-radius: var(--radius-btn);
    background: var(--gradient);
    color: #071019;
    font-size: 1.1rem;
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 1000;
    box-shadow: var(--shadow-btn);
    opacity: 0;
    visibility: hidden;
    transform: translateY(16px);
    transition: all .3s ease;
    cursor: pointer;
}
.back-top.show {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
}
.back-top:hover {
    filter: brightness(1.1);
    transform: translateY(-4px);
}
/* ===== Responsive ===== */
@media (max-width: 991px) {
    .custom-navbar .navbar-collapse {
        padding: 1rem 0;
    }
    .custom-navbar .navbar-nav {
        gap: 0;
    }
    .custom-navbar .nav-link {
        padding: 0.7rem 0.5rem;
    }
    .custom-navbar .nav-link::after {
        left: 0.5rem;
        right: 0.5rem;
    }
    .article-hero {
        padding: 130px 0 50px;
    }
}
@media (max-width: 767px) {
    .article-hero {
        padding: 110px 0 42px;
    }
    .article-title {
        font-size: 1.75rem;
    }
    .article-summary {
        padding: 1.1rem 1.25rem;
    }
    .article-content {
        font-size: 1rem;
    }
    .download-buttons {
        flex-direction: column;
        align-items: center;
    }
    .btn-download-large {
        width: 100%;
        justify-content: center;
    }
    .article-nav {
        flex-direction: column;
        align-items: stretch;
    }
    .article-nav .btn {
        justify-content: center;
    }
    .back-top {
        right: 16px;
        bottom: 16px;
        width: 42px;
        height: 42px;
    }
}
@media (max-width: 575px) {
    .brand-text {
        font-size: 1.1rem;
    }
    .article-breadcrumb {
        font-size: 0.75rem;
    }
    .article-meta {
        gap: 0.6rem;
        font-size: 0.8rem;
    }
}

/* roulang page: category2 */
:root {
  --primary: #0B1B2B;
  --accent: #00E5A0;
  --accent-secondary: #00B4D8;
  --gradient: linear-gradient(135deg, #00E5A0, #00B4D8);
  --text-title: #F5F8FF;
  --text-body: #B6C2D4;
  --text-muted: #8899AA;
  --border-color: rgba(255, 255, 255, 0.08);
  --card-bg: rgba(255, 255, 255, 0.04);
  --radius: 16px;
  --radius-sm: 12px;
  --shadow: 0 8px 32px rgba(0, 0, 0, 0.35);
  --font-stack: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
}

*, *::before, *::after {
  box-sizing: border-box;
}

html, body {
  overflow-x: hidden;
}

body {
  margin: 0;
  font-family: var(--font-stack);
  font-size: 1rem;
  line-height: 1.75;
  background-color: var(--primary);
  color: var(--text-body);
  background-image:
    radial-gradient(ellipse at top left, rgba(0, 229, 160, 0.12), transparent 45%),
    radial-gradient(ellipse at bottom right, rgba(0, 180, 216, 0.12), transparent 45%),
    linear-gradient(rgba(255, 255, 255, 0.025) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255, 255, 255, 0.025) 1px, transparent 1px);
  background-size: 100% 100%, 100% 100%, 32px 32px, 32px 32px;
}

img {
  max-width: 100%;
  height: auto;
}

a {
  color: var(--accent);
  text-decoration: none;
  transition: color 0.25s ease;
}

a:hover {
  color: #fff;
}

ul, ol {
  padding-left: 0;
  list-style: none;
}

.container {
  max-width: 1200px;
}

section {
  padding: clamp(4rem, 8vw, 6rem) 0;
}

/* ===== Header / Nav ===== */
.custom-navbar {
  min-height: 72px;
  background: rgba(11, 27, 43, 0.72);
  border-bottom: 1px solid rgba(255, 255, 255, 0.06);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  transition: background 0.35s ease;
}

.custom-navbar.scrolled {
  background: rgba(7, 15, 26, 0.92);
}

.navbar-brand {
  display: inline-flex;
  align-items: center;
  gap: 0.65rem;
  font-weight: 700;
  color: var(--text-title);
}

.navbar-brand:hover {
  color: var(--text-title);
}

.brand-icon {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 38px;
  height: 38px;
  background: var(--gradient);
  border-radius: 10px;
  padding: 7px;
}

.brand-icon svg {
  width: 100%;
  height: 100%;
  fill: #0B1B2B;
}

.brand-text {
  font-size: 1.15rem;
  letter-spacing: 0.5px;
  color: var(--text-title);
}

.brand-text em {
  font-style: normal;
  color: var(--accent);
}

.custom-navbar .nav-link {
  color: var(--text-body);
  font-size: 0.95rem;
  font-weight: 500;
  padding: 0.45rem 1rem;
  margin: 0 0.15rem;
  position: relative;
  border-radius: 6px;
  transition: color 0.25s ease;
}

.custom-navbar .nav-link::after {
  content: "";
  position: absolute;
  left: 1rem;
  right: 1rem;
  bottom: 0;
  height: 2px;
  background: var(--accent);
  border-radius: 2px;
  transform: scaleX(0);
  transform-origin: center;
  transition: transform 0.3s ease;
}

.custom-navbar .nav-link:hover {
  color: var(--text-title);
}

.custom-navbar .nav-link:hover::after {
  transform: scaleX(1);
}

.custom-navbar .nav-link.active {
  color: var(--accent);
}

.custom-navbar .nav-link.active::after {
  transform: scaleX(1);
}

.navbar-toggler {
  border: 1px solid rgba(255, 255, 255, 0.2);
  padding: 0.35rem 0.6rem;
  border-radius: 8px;
}

.navbar-toggler:focus {
  box-shadow: 0 0 0 4px rgba(0, 229, 160, 0.15);
}

.navbar-toggler-icon {
  background-image: url("data:image/svg+xml,%3csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 30 30'%3e%3cpath stroke='rgba(245,248,255,0.9)' stroke-linecap='round' stroke-miterlimit='10' stroke-width='2' d='M4 7h22M4 15h22M4 23h22'/%3e%3c/svg%3e");
}

/* ===== Buttons ===== */
.btn {
  border-radius: var(--radius-sm);
  font-weight: 600;
  transition: transform 0.25s ease, box-shadow 0.25s ease, background 0.25s ease, border-color 0.25s ease;
}

.btn-download {
  background: var(--gradient);
  color: #0B1B2B;
  border: none;
  padding: 0.6rem 1.5rem;
  border-radius: var(--radius-sm);
  box-shadow: 0 4px 16px rgba(0, 229, 160, 0.25);
  letter-spacing: 0.02em;
}

.btn-download:hover,
.btn-download:focus {
  color: #0B1B2B;
  background: linear-gradient(135deg, #1ffcb5, #22c8f5);
  transform: translateY(-2px);
  box-shadow: 0 6px 22px rgba(0, 229, 160, 0.4);
}

.btn-download-lg {
  background: var(--gradient);
  color: #0B1B2B;
  border: none;
  padding: 0.875rem 2rem;
  font-size: 1.05rem;
  border-radius: var(--radius-sm);
  box-shadow: 0 4px 16px rgba(0, 229, 160, 0.25);
}

.btn-download-lg:hover,
.btn-download-lg:focus {
  color: #0B1B2B;
  background: linear-gradient(135deg, #1ffcb5, #22c8f5);
  transform: translateY(-2px);
  box-shadow: 0 8px 24px rgba(0, 229, 160, 0.4);
}

.btn-outline-light {
  background: transparent;
  border: 1px solid rgba(255, 255, 255, 0.5);
  color: var(--text-title);
  padding: 0.875rem 2rem;
  font-size: 1.05rem;
  border-radius: var(--radius-sm);
}

.btn-outline-light:hover,
.btn-outline-light:focus {
  border-color: var(--accent);
  color: var(--accent);
  background: rgba(0, 229, 160, 0.08);
  transform: translateY(-2px);
}

.btn-ios,
.btn-android,
.btn-scan {
  background: rgba(255, 255, 255, 0.06);
  border: 1px solid rgba(255, 255, 255, 0.12);
  color: var(--text-title);
  padding: 0.875rem 1.8rem;
  border-radius: var(--radius-sm);
  font-size: 1rem;
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  transition: border-color 0.25s ease, background 0.25s ease, transform 0.25s ease, box-shadow 0.25s ease;
}

.btn-ios:hover,
.btn-android:hover,
.btn-scan:hover {
  border-color: var(--accent);
  color: var(--accent);
  background: rgba(0, 229, 160, 0.06);
  transform: translateY(-2px);
  box-shadow: 0 6px 20px rgba(0, 229, 160, 0.15);
}

/* ===== Hero ===== */
.cat-hero {
  position: relative;
  padding: clamp(7rem, 12vw, 10rem) 0 clamp(3.5rem, 6vw, 5rem);
  background:
    linear-gradient(135deg, rgba(11, 27, 43, 0.92), rgba(0, 180, 216, 0.35)),
    url('/assets/images/backpic/back-1.webp') center center / cover no-repeat;
  border-bottom: 1px solid rgba(255, 255, 255, 0.06);
}

.breadcrumb-custom {
  font-size: 0.875rem;
  color: var(--text-muted);
  margin-bottom: 1.25rem;
}

.breadcrumb-custom a {
  color: var(--text-muted);
}

.breadcrumb-custom a:hover {
  color: var(--accent);
}

.cat-hero h1 {
  font-size: min(3rem, 8vw);
  font-weight: 700;
  line-height: 1.2;
  color: var(--text-title);
  margin-bottom: 1rem;
}

.cat-hero h1 span {
  display: block;
  background: var(--gradient);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
  color: transparent;
}

.cat-hero .lead {
  font-size: 1.1rem;
  color: var(--text-body);
  line-height: 1.8;
  max-width: 680px;
}

.hero-buttons {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
  margin-top: 2rem;
}

.trust-badges {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
  margin-top: 2rem;
}

.trust-badges .badge-item {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  background: rgba(245, 248, 255, 0.06);
  border: 1px solid rgba(255, 255, 255, 0.1);
  border-radius: 999px;
  padding: 0.4rem 1rem;
  font-size: 0.85rem;
  color: var(--text-title);
}

.trust-badges .badge-item i {
  color: var(--accent);
}

/* ===== Section Title ===== */
.section-title {
  text-align: center;
  margin-bottom: clamp(2.5rem, 5vw, 3.5rem);
}

.section-title h2 {
  font-size: clamp(1.8rem, 4vw, 2.4rem);
  font-weight: 700;
  color: var(--text-title);
  margin-bottom: 0.5rem;
}

.section-title h2::before {
  content: "";
  display: inline-block;
  width: 42px;
  height: 4px;
  background: var(--gradient);
  border-radius: 2px;
  vertical-align: middle;
  margin-right: 0.75rem;
}

.section-title p {
  max-width: 680px;
  margin: 0 auto;
  color: var(--text-body);
}

/* ===== Cards ===== */
.glass-card {
  background: var(--card-bg);
  border: 1px solid var(--border-color);
  border-radius: var(--radius);
  padding: 1.5rem;
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  box-shadow: var(--shadow);
  height: 100%;
  transition: transform 0.3s ease, border-color 0.3s ease, box-shadow 0.3s ease;
}

.glass-card:hover {
  transform: translateY(-6px);
  border-color: rgba(0, 229, 160, 0.4);
  box-shadow: 0 14px 40px rgba(0, 0, 0, 0.45);
}

.glass-card .card-icon {
  width: 58px;
  height: 58px;
  background: var(--gradient);
  border-radius: 14px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  font-size: 1.4rem;
  color: #0B1B2B;
  margin-bottom: 1rem;
}

.glass-card h3 {
  font-size: 1.15rem;
  font-weight: 600;
  color: var(--text-title);
  margin-bottom: 0.5rem;
}

.glass-card p {
  font-size: 0.925rem;
  color: var(--text-body);
  line-height: 1.7;
  margin-bottom: 0;
}

/* ===== Category Main Grid ===== */
.category-main {
  background: rgba(255, 255, 255, 0.015);
}

.content-card {
  display: flex;
  flex-direction: column;
  gap: 0;
  background: var(--card-bg);
  border: 1px solid var(--border-color);
  border-left: 4px solid var(--accent);
  border-radius: var(--radius);
  overflow: hidden;
  margin-bottom: 1.5rem;
  transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.content-card:hover {
  transform: translateY(-4px);
  box-shadow: 0 12px 36px rgba(0, 0, 0, 0.4);
}

.content-card-img {
  width: 100%;
  aspect-ratio: 16 / 9;
  overflow: hidden;
  background-color: rgba(0, 0, 0, 0.2);
}

.content-card-img img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
}

.content-card-body {
  padding: 1.5rem;
}

.content-card-body .tag {
  display: inline-block;
  font-size: 0.8rem;
  color: var(--accent);
  border: 1px solid rgba(0, 229, 160, 0.45);
  background: rgba(0, 229, 160, 0.07);
  border-radius: 999px;
  padding: 0.2rem 0.8rem;
  margin-bottom: 0.75rem;
}

.content-card-body h3 {
  font-size: 1.2rem;
  font-weight: 600;
  color: var(--text-title);
  margin-bottom: 0.5rem;
}

.content-card-body p {
  font-size: 0.925rem;
  color: var(--text-body);
  margin-bottom: 0.75rem;
}

.content-card-body .more-link {
  font-size: 0.9rem;
  color: var(--accent);
  font-weight: 500;
}

.content-card-body .more-link:hover {
  color: #fff;
}

/* ===== Hot Ranking ===== */
.hot-ranking {
  background: var(--card-bg);
  border: 1px solid var(--border-color);
  border-radius: var(--radius);
  padding: 1.75rem;
  position: sticky;
  top: 96px;
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
}

.hot-ranking h3 {
  font-size: 1.3rem;
  font-weight: 700;
  color: var(--text-title);
  margin-bottom: 1.25rem;
  padding-bottom: 0.75rem;
  border-bottom: 1px solid var(--border-color);
}

.hot-ranking ol {
  margin: 0;
  padding: 0;
}

.hot-ranking li {
  display: flex;
  align-items: flex-start;
  gap: 0.75rem;
  padding: 0.85rem 0;
  border-bottom: 1px solid rgba(255, 255, 255, 0.04);
}

.hot-ranking li:last-child {
  border-bottom: none;
  padding-bottom: 0;
}

.hot-ranking .num {
  flex-shrink: 0;
  width: 28px;
  height: 28px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  background: rgba(0, 229, 160, 0.1);
  border: 1px solid rgba(0, 229, 160, 0.25);
  border-radius: 8px;
  font-size: 0.8rem;
  font-weight: 700;
  color: var(--accent);
}

.hot-ranking li:nth-child(1) .num {
  background: var(--gradient);
  color: #0B1B2B;
  border-color: transparent;
}

.hot-ranking li:nth-child(2) .num {
  background: rgba(255, 200, 87, 0.18);
  border-color: rgba(255, 200, 87, 0.4);
  color: #FFC857;
}

.hot-ranking .rank-text {
  flex: 1;
}

.hot-ranking .rank-text a {
  display: block;
  font-size: 0.925rem;
  color: var(--text-title);
  line-height: 1.45;
  transition: color 0.25s ease;
}

.hot-ranking .rank-text a:hover {
  color: var(--accent);
}

.hot-ranking .rank-text time {
  font-size: 0.8rem;
  color: var(--text-muted);
}

/* ===== Login Flow ===== */
.login-flow {
  background: rgba(255, 255, 255, 0.015);
}

.flow-step {
  position: relative;
  background: var(--card-bg);
  border: 1px solid var(--border-color);
  border-radius: var(--radius);
  padding: 1.75rem;
  height: 100%;
  text-align: center;
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  transition: transform 0.3s ease, border-color 0.3s ease;
}

.flow-step:hover {
  transform: translateY(-4px);
  border-color: rgba(0, 229, 160, 0.35);
}

.flow-step .step-num {
  width: 46px;
  height: 46px;
  margin: 0 auto 1rem;
  background: var(--gradient);
  border-radius: 50%;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  font-size: 1.15rem;
  font-weight: 700;
  color: #0B1B2B;
}

.flow-step h3 {
  font-size: 1.05rem;
  font-weight: 600;
  color: var(--text-title);
  margin-bottom: 0.5rem;
}

.flow-step p {
  font-size: 0.88rem;
  color: var(--text-body);
  margin-bottom: 0;
}

/* ===== Topic List ===== */
.topic-list {
  background: transparent;
}

.topic-list .topic-item {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  background: rgba(255, 255, 255, 0.025);
  border: 1px solid rgba(255, 255, 255, 0.06);
  border-radius: var(--radius-sm);
  padding: 0.85rem 1.15rem;
  margin-bottom: 0.75rem;
  transition: background 0.25s ease, border-color 0.25s ease, transform 0.25s ease;
}

.topic-item:hover {
  background: rgba(0, 229, 160, 0.05);
  border-color: rgba(0, 229, 160, 0.3);
  transform: translateX(4px);
}

.topic-item i {
  color: var(--accent);
  font-size: 0.9rem;
  width: 20px;
  text-align: center;
  flex-shrink: 0;
}

.topic-item a {
  color: var(--text-body);
  font-size: 0.95rem;
  flex: 1;
}

.topic-item a:hover {
  color: var(--accent);
}

/* ===== FAQ ===== */
.faq-section {
  background: rgba(255, 255, 255, 0.015);
}

.accordion-item {
  background: var(--card-bg);
  border: 1px solid var(--border-color) !important;
  border-radius: var(--radius-sm) !important;
  margin-bottom: 0.75rem;
  overflow: hidden;
  transition: border-color 0.25s ease, background 0.25s ease;
}

.accordion-item:has(.accordion-button:not(.collapsed)) {
  background: rgba(0, 229, 160, 0.08);
  border-color: rgba(0, 229, 160, 0.3) !important;
}

.accordion-button {
  background: transparent;
  color: var(--text-title);
  font-size: 1rem;
  font-weight: 600;
  padding: 1.1rem 1.25rem;
  border: none;
}

.accordion-button::after {
  background-image: url("data:image/svg+xml,%3csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 16 16' fill='%2300E5A0'%3e%3cpath d='M8 4a1 1 0 0 1 .995.9L9 5v2h2a1 1 0 0 1 .9.995L12 8a1 1 0 0 1-.9.995L11 9H9v2a1 1 0 0 1-1.995.9L7 11V9H5a1 1 0 0 1-.9-.995L4 8a1 1 0 0 1 .9-.995L5 7h2V5a1 1 0 0 1 1-1z'/%3e%3c/svg%3e");
  filter: none;
}

.accordion-button:not(.collapsed) {
  background: rgba(0, 229, 160, 0.06);
  color: var(--accent);
  box-shadow: none;
}

.accordion-button:focus {
  box-shadow: 0 0 0 4px rgba(0, 229, 160, 0.15);
  border-radius: var(--radius-sm);
}

.accordion-body {
  color: var(--text-body);
  padding: 0 1.25rem 1.1rem;
  font-size: 0.95rem;
  line-height: 1.75;
}

/* ===== CTA ===== */
.cta-download {
  position: relative;
  text-align: center;
  background:
    linear-gradient(135deg, rgba(11, 27, 43, 0.95), rgba(0, 180, 216, 0.25)),
    url('/assets/images/backpic/back-3.png') center center / cover no-repeat;
  border-top: 1px solid rgba(255, 255, 255, 0.06);
  border-bottom: 1px solid rgba(255, 255, 255, 0.06);
}

.cta-download h2 {
  font-size: clamp(1.8rem, 4vw, 2.4rem);
  font-weight: 700;
  color: var(--text-title);
  margin-bottom: 0.75rem;
}

.cta-download p {
  font-size: 1.05rem;
  color: var(--text-body);
  max-width: 600px;
  margin: 0 auto 2rem;
}

.cta-download .btn-group-lg {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 1rem;
}

/* ===== Footer ===== */
.site-footer {
  background: #070F1A;
  padding: clamp(3.5rem, 6vw, 5rem) 0 0;
  border-top: 1px solid rgba(255, 255, 255, 0.05);
}

.footer-brand {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  font-size: 1.2rem;
  font-weight: 700;
  color: var(--text-title);
  margin-bottom: 0.85rem;
}

.site-footer p {
  font-size: 0.9rem;
  color: #7a8a9d;
  line-height: 1.75;
}

.site-footer h4 {
  font-size: 1rem;
  font-weight: 600;
  color: var(--text-title);
  margin-bottom: 1rem;
}

.site-footer ul {
  margin: 0;
  padding: 0;
}

.site-footer ul li {
  margin-bottom: 0.6rem;
}

.site-footer ul a {
  color: #7a8a9d;
  font-size: 0.9rem;
}

.site-footer ul a:hover {
  color: var(--accent);
}

.footer-contact {
  display: flex;
  align-items: center;
  gap: 0.55rem;
  color: #7a8a9d;
  font-size: 0.9rem;
  margin-bottom: 0.6rem;
}

.footer-contact i {
  color: var(--accent);
  width: 18px;
  text-align: center;
}

.footer-bottom {
  border-top: 1px solid rgba(255, 255, 255, 0.05);
  padding: 1.25rem 0;
  margin-top: 3rem;
  text-align: center;
}

.footer-bottom p {
  font-size: 0.85rem;
  color: #637083;
  margin: 0;
}

.footer-bottom a {
  color: #8ca2b8;
}

.footer-bottom a:hover {
  color: var(--accent);
}

/* ===== Back to top ===== */
.back-top {
  position: fixed;
  right: 24px;
  bottom: 24px;
  width: 46px;
  height: 46px;
  border-radius: 50%;
  background: var(--gradient);
  color: #0B1B2B;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.1rem;
  box-shadow: 0 4px 16px rgba(0, 229, 160, 0.3);
  z-index: 999;
  opacity: 0;
  visibility: hidden;
  transform: translateY(10px);
  transition: opacity 0.3s ease, transform 0.3s ease, visibility 0.3s ease;
}

.back-top.show {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
}

.back-top:hover {
  transform: translateY(-3px);
  box-shadow: 0 8px 24px rgba(0, 229, 160, 0.4);
}

/* ===== Responsive ===== */
@media (max-width: 991.98px) {
  .custom-navbar .nav-link {
    padding: 0.6rem 0.75rem;
  }

  .custom-navbar .nav-link::after {
    display: none;
  }

  .custom-navbar .nav-link.active {
    background: rgba(0, 229, 160, 0.1);
    border-radius: 8px;
  }

  .cat-hero {
    text-align: center;
  }

  .breadcrumb-custom {
    justify-content: center;
  }

  .cat-hero .lead,
  .cat-hero h1 {
    margin-left: auto;
    margin-right: auto;
  }

  .hero-buttons,
  .trust-badges {
    justify-content: center;
  }

  .hot-ranking {
    position: static;
    margin-top: 1.5rem;
  }

  .flow-step {
    margin-bottom: 1rem;
  }
}

@media (max-width: 767.98px) {
  .content-card {
    flex-direction: column;
  }

  .cta-download .btn-group-lg {
    flex-direction: column;
    width: 100%;
    max-width: 360px;
    margin: 0 auto;
  }

  .btn-ios,
  .btn-android,
  .btn-scan {
    justify-content: center;
    width: 100%;
  }

  .hero-buttons {
    flex-direction: column;
    width: 100%;
  }

  .hero-buttons .btn {
    width: 100%;
    justify-content: center;
  }

  .trust-badges {
    flex-direction: column;
    align-items: center;
  }

  .brand-text {
    font-size: 1.05rem;
  }

  section {
    padding: 3rem 0;
  }
}

@media (max-width: 520px) {
  .cat-hero h1 {
    font-size: 2.1rem;
  }

  .glass-card {
    padding: 1.25rem;
  }

  .btn-download-lg,
  .btn-outline-light {
    width: 100%;
  }

  .trust-badges .badge-item {
    width: 100%;
    justify-content: center;
  }
}

@media (min-width: 768px) {
  .content-card {
    flex-direction: row;
    align-items: stretch;
  }

  .content-card-img {
    width: 260px;
    flex-shrink: 0;
    aspect-ratio: 16 / 10;
  }

  .content-card-body {
    flex: 1;
  }
}