/* roulang page: index */
/* ===== Design Variables ===== */
:root {
  --primary: #1a2a4a;
  --primary-light: #2d4a7a;
  --primary-dark: #0f1a2e;
  --secondary: #d4a853;
  --secondary-light: #e8c97a;
  --secondary-dark: #b8913a;
  --accent: #3b82f6;
  --bg: #f0f2f5;
  --bg-card: #ffffff;
  --bg-dark: #0a1220;
  --bg-section: #f8f9fb;
  --text: #111827;
  --text-light: #6b7280;
  --text-white: #ffffff;
  --text-muted: #9ca3af;
  --border: #e5e7eb;
  --border-light: #f0f0f0;
  --radius: 16px;
  --radius-sm: 10px;
  --radius-xs: 6px;
  --shadow: 0 4px 24px rgba(0,0,0,0.06);
  --shadow-md: 0 8px 32px rgba(0,0,0,0.08);
  --shadow-lg: 0 16px 48px rgba(0,0,0,0.12);
  --shadow-glow: 0 0 30px rgba(212,168,83,0.15);
  --transition: all 0.3s cubic-bezier(0.4,0,0.2,1);
  --font-sans: 'Inter', 'Segoe UI', system-ui, -apple-system, BlinkMacSystemFont, sans-serif;
  --max-width: 1200px;
  --header-h: 120px;
}

/* ===== Reset & Base ===== */
*,*::before,*::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; -webkit-font-smoothing: antialiased; }
body {
  font-family: var(--font-sans);
  font-size: 16px;
  line-height: 1.7;
  color: var(--text);
  background: var(--bg);
  min-height: 100vh;
}
a { color: inherit; text-decoration: none; transition: var(--transition); }
a:hover { color: var(--secondary); }
img { max-width: 100%; height: auto; display: block; }
button, input, textarea, select { font-family: inherit; font-size: inherit; outline: none; border: none; }
button { cursor: pointer; background: none; }
ul, ol { list-style: none; }
h1, h2, h3, h4, h5, h6 { line-height: 1.25; font-weight: 700; color: var(--text); }
h1 { font-size: 2.75rem; }
h2 { font-size: 2rem; }
h3 { font-size: 1.375rem; }
h4 { font-size: 1.125rem; }
p { margin-bottom: 0.75rem; }
.container {
  width: 100%;
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 24px;
}
.section-padding { padding: 5rem 0; }
.section-title {
  text-align: center;
  margin-bottom: 3rem;
}
.section-title h2 {
  position: relative;
  display: inline-block;
  margin-bottom: 0.75rem;
}
.section-title h2::after {
  content: '';
  display: block;
  width: 60px;
  height: 4px;
  background: linear-gradient(90deg, var(--secondary), var(--secondary-light));
  border-radius: 4px;
  margin: 0.75rem auto 0;
}
.section-title p {
  color: var(--text-light);
  font-size: 1.1rem;
  max-width: 600px;
  margin: 0 auto;
}
.btn {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.75rem 2rem;
  border-radius: 50px;
  font-weight: 600;
  font-size: 0.95rem;
  transition: var(--transition);
  border: 2px solid transparent;
  white-space: nowrap;
}
.btn-primary {
  background: linear-gradient(135deg, var(--secondary), var(--secondary-dark));
  color: var(--primary-dark);
  border-color: var(--secondary);
}
.btn-primary:hover {
  background: transparent;
  color: var(--secondary);
  box-shadow: 0 0 20px rgba(212,168,83,0.25);
  transform: translateY(-2px);
}
.btn-outline {
  background: transparent;
  color: var(--text-white);
  border-color: rgba(255,255,255,0.4);
}
.btn-outline:hover {
  background: rgba(255,255,255,0.1);
  border-color: var(--text-white);
  transform: translateY(-2px);
}
.btn-ghost {
  background: transparent;
  color: var(--text);
  border-color: var(--border);
}
.btn-ghost:hover {
  border-color: var(--secondary);
  color: var(--secondary);
  transform: translateY(-2px);
}
.card {
  background: var(--bg-card);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  transition: var(--transition);
  overflow: hidden;
}
.card:hover {
  box-shadow: var(--shadow-md);
  transform: translateY(-4px);
}
.tag {
  display: inline-block;
  padding: 0.25rem 0.75rem;
  border-radius: 50px;
  font-size: 0.8rem;
  font-weight: 500;
  background: rgba(212,168,83,0.12);
  color: var(--secondary-dark);
}
.badge {
  display: inline-flex;
  align-items: center;
  gap: 0.3rem;
  padding: 0.2rem 0.6rem;
  border-radius: var(--radius-xs);
  font-size: 0.75rem;
  font-weight: 600;
  background: var(--primary);
  color: var(--text-white);
}
.badge-gold {
  background: linear-gradient(135deg, var(--secondary), var(--secondary-light));
  color: var(--primary-dark);
}
/* ===== Header & Nav ===== */
.header {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  z-index: 1000;
  background: rgba(10,18,32,0.92);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border-bottom: 1px solid rgba(255,255,255,0.06);
  transition: var(--transition);
}
.header .header-inner {
  display: flex;
  flex-direction: column;
}
.header-top {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0.75rem 0;
  gap: 1rem;
}
.header .logo {
  font-size: 1.5rem;
  font-weight: 800;
  color: var(--text-white);
  letter-spacing: 0.5px;
  white-space: nowrap;
}
.header .logo span {
  color: var(--secondary);
}
.header .logo small {
  font-size: 0.7rem;
  font-weight: 400;
  color: var(--text-muted);
  margin-left: 0.4rem;
  letter-spacing: 1px;
}
.header-search {
  flex: 1;
  max-width: 360px;
  position: relative;
  display: none;
}
@media (min-width: 768px) {
  .header-search { display: block; }
}
.header-search input {
  width: 100%;
  padding: 0.5rem 1rem 0.5rem 2.5rem;
  border-radius: 50px;
  background: rgba(255,255,255,0.08);
  color: var(--text-white);
  font-size: 0.9rem;
  border: 1px solid rgba(255,255,255,0.1);
  transition: var(--transition);
}
.header-search input::placeholder { color: var(--text-muted); }
.header-search input:focus {
  background: rgba(255,255,255,0.14);
  border-color: var(--secondary);
  box-shadow: 0 0 20px rgba(212,168,83,0.08);
}
.header-search i {
  position: absolute;
  left: 0.9rem;
  top: 50%;
  transform: translateY(-50%);
  color: var(--text-muted);
  font-size: 0.9rem;
}
.header-actions {
  display: flex;
  align-items: center;
  gap: 0.75rem;
}
.header-actions .btn { padding: 0.5rem 1.25rem; font-size: 0.85rem; }
.header .menu-toggle {
  display: none;
  color: var(--text-white);
  font-size: 1.5rem;
  padding: 0.25rem;
  background: none;
  border: none;
  cursor: pointer;
}
/* Nav Tabs */
.nav-tabs-wrapper {
  border-top: 1px solid rgba(255,255,255,0.06);
  overflow-x: auto;
  -webkit-overflow-scrolling: touch;
  scrollbar-width: none;
}
.nav-tabs-wrapper::-webkit-scrollbar { display: none; }
.nav-tabs {
  display: flex;
  gap: 0.25rem;
  padding: 0.5rem 0;
  min-width: max-content;
}
.nav-tabs a {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  padding: 0.45rem 1.2rem;
  border-radius: 50px;
  font-size: 0.9rem;
  font-weight: 500;
  color: var(--text-muted);
  transition: var(--transition);
  white-space: nowrap;
}
.nav-tabs a:hover {
  color: var(--text-white);
  background: rgba(255,255,255,0.06);
}
.nav-tabs a.active {
  color: var(--primary-dark);
  background: linear-gradient(135deg, var(--secondary), var(--secondary-light));
  font-weight: 600;
  box-shadow: 0 4px 16px rgba(212,168,83,0.2);
}
.nav-tabs a i { font-size: 0.8rem; }
/* ===== Hero ===== */
.hero {
  position: relative;
  min-height: 88vh;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 8rem 0 5rem;
  background: var(--bg-dark);
  overflow: hidden;
}
.hero-bg {
  position: absolute;
  inset: 0;
  background: url('/assets/images/backpic/back-1.png') center center / cover no-repeat;
  opacity: 0.35;
  transform: scale(1.02);
  transition: transform 8s ease;
}
.hero:hover .hero-bg { transform: scale(1.06); }
.hero-overlay {
  position: absolute;
  inset: 0;
  background: linear-gradient(135deg, rgba(10,18,32,0.88) 0%, rgba(10,18,32,0.60) 50%, rgba(10,18,32,0.88) 100%);
}
.hero-content {
  position: relative;
  z-index: 2;
  text-align: center;
  max-width: 820px;
  padding: 0 24px;
}
.hero-content .badge-hero {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.4rem 1.2rem;
  border-radius: 50px;
  background: rgba(212,168,83,0.15);
  color: var(--secondary-light);
  font-size: 0.85rem;
  font-weight: 500;
  border: 1px solid rgba(212,168,83,0.2);
  margin-bottom: 1.5rem;
  backdrop-filter: blur(4px);
}
.hero-content .badge-hero i { font-size: 0.75rem; }
.hero-content h1 {
  font-size: 3.5rem;
  font-weight: 800;
  color: var(--text-white);
  line-height: 1.15;
  margin-bottom: 1.25rem;
  letter-spacing: -0.5px;
}
.hero-content h1 span {
  background: linear-gradient(135deg, var(--secondary), var(--secondary-light));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}
.hero-content p {
  font-size: 1.2rem;
  color: rgba(255,255,255,0.7);
  max-width: 640px;
  margin: 0 auto 2rem;
  line-height: 1.8;
}
.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 1rem;
  justify-content: center;
  margin-bottom: 2.5rem;
}
.hero-stats {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 2rem 3rem;
  padding-top: 2rem;
  border-top: 1px solid rgba(255,255,255,0.08);
}
.hero-stats .stat-item { text-align: center; }
.hero-stats .stat-num {
  font-size: 1.75rem;
  font-weight: 800;
  color: var(--secondary);
  display: block;
}
.hero-stats .stat-label {
  font-size: 0.85rem;
  color: var(--text-muted);
  margin-top: 0.15rem;
}
/* ===== Intro Section ===== */
.intro-section {
  background: var(--bg-card);
}
.intro-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 4rem;
  align-items: center;
}
.intro-image {
  border-radius: var(--radius);
  overflow: hidden;
  box-shadow: var(--shadow-lg);
  position: relative;
}
.intro-image img { width: 100%; height: auto; display: block; }
.intro-image::after {
  content: '';
  position: absolute;
  inset: 0;
  border-radius: var(--radius);
  box-shadow: inset 0 0 30px rgba(0,0,0,0.06);
  pointer-events: none;
}
.intro-text h2 { margin-bottom: 1rem; }
.intro-text h2 span { color: var(--secondary-dark); }
.intro-text .lead {
  font-size: 1.1rem;
  color: var(--text-light);
  margin-bottom: 1.5rem;
  line-height: 1.8;
}
.intro-features {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1rem;
  margin-top: 1.5rem;
}
.intro-features li {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  font-size: 0.95rem;
  color: var(--text);
}
.intro-features li i {
  color: var(--secondary);
  font-size: 1rem;
  width: 1.2rem;
  text-align: center;
}
/* ===== Categories Section ===== */
.categories-section {
  background: var(--bg-section);
}
.cat-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 1.5rem;
}
.cat-card {
  position: relative;
  border-radius: var(--radius);
  overflow: hidden;
  background: var(--bg-card);
  box-shadow: var(--shadow);
  transition: var(--transition);
  cursor: pointer;
  border: 1px solid var(--border-light);
}
.cat-card:hover {
  box-shadow: var(--shadow-md);
  transform: translateY(-6px);
}
.cat-card .cat-img {
  width: 100%;
  height: 180px;
  object-fit: cover;
  display: block;
  transition: var(--transition);
}
.cat-card:hover .cat-img { transform: scale(1.05); }
.cat-card .cat-body {
  padding: 1.25rem 1.5rem 1.5rem;
}
.cat-card .cat-body h3 {
  font-size: 1.15rem;
  margin-bottom: 0.4rem;
}
.cat-card .cat-body p {
  font-size: 0.9rem;
  color: var(--text-light);
  margin-bottom: 0.75rem;
}
.cat-card .cat-meta {
  display: flex;
  align-items: center;
  justify-content: space-between;
}
.cat-card .cat-meta .tag { font-size: 0.75rem; }
.cat-card .cat-meta .btn-link {
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--primary-light);
  display: inline-flex;
  align-items: center;
  gap: 0.3rem;
}
.cat-card .cat-meta .btn-link:hover { color: var(--secondary); gap: 0.6rem; }
/* ===== News / CMS Section ===== */
.news-section {
  background: var(--bg-card);
}
.news-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
  gap: 1.5rem;
}
.news-card {
  display: flex;
  flex-direction: column;
  border-radius: var(--radius);
  background: var(--bg-section);
  overflow: hidden;
  transition: var(--transition);
  border: 1px solid var(--border-light);
}
.news-card:hover {
  box-shadow: var(--shadow-md);
  transform: translateY(-4px);
  border-color: var(--secondary);
}
.news-card .news-img {
  width: 100%;
  height: 180px;
  object-fit: cover;
  display: block;
  transition: var(--transition);
}
.news-card:hover .news-img { transform: scale(1.03); }
.news-card .news-body {
  padding: 1.25rem 1.5rem 1.5rem;
  flex: 1;
  display: flex;
  flex-direction: column;
}
.news-card .news-body .news-cat {
  display: inline-block;
  padding: 0.2rem 0.7rem;
  border-radius: 50px;
  font-size: 0.75rem;
  font-weight: 600;
  background: rgba(26,42,74,0.08);
  color: var(--primary-light);
  margin-bottom: 0.6rem;
  align-self: flex-start;
}
.news-card .news-body h3 {
  font-size: 1.1rem;
  margin-bottom: 0.5rem;
  line-height: 1.4;
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
}
.news-card .news-body p {
  font-size: 0.9rem;
  color: var(--text-light);
  flex: 1;
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
  margin-bottom: 0.75rem;
}
.news-card .news-body .news-time {
  font-size: 0.8rem;
  color: var(--text-muted);
  display: flex;
  align-items: center;
  gap: 0.4rem;
}
.news-empty {
  grid-column: 1 / -1;
  text-align: center;
  padding: 3rem 1rem;
  color: var(--text-light);
  font-size: 1.1rem;
}
.news-empty i { font-size: 2rem; color: var(--text-muted); margin-bottom: 1rem; display: block; }
/* ===== Stats / Data Section ===== */
.stats-section {
  background: var(--bg-dark);
  position: relative;
  overflow: hidden;
}
.stats-section::before {
  content: '';
  position: absolute;
  inset: 0;
  background: url('/assets/images/backpic/back-2.png') center center / cover no-repeat;
  opacity: 0.08;
}
.stats-section .container { position: relative; z-index: 1; }
.stats-section .section-title h2 { color: var(--text-white); }
.stats-section .section-title p { color: var(--text-muted); }
.stats-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 2rem;
  text-align: center;
}
.stat-block { padding: 1.5rem; }
.stat-block .stat-icon {
  font-size: 2.2rem;
  color: var(--secondary);
  margin-bottom: 0.75rem;
}
.stat-block .stat-number {
  font-size: 2.5rem;
  font-weight: 800;
  color: var(--text-white);
  line-height: 1.2;
}
.stat-block .stat-number span { color: var(--secondary); }
.stat-block .stat-desc {
  color: var(--text-muted);
  font-size: 0.95rem;
  margin-top: 0.3rem;
}
/* ===== Process / Steps Section ===== */
.process-section {
  background: var(--bg-section);
}
.process-steps {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 2rem;
  position: relative;
}
.process-steps::before {
  content: '';
  position: absolute;
  top: 3rem;
  left: 12%;
  right: 12%;
  height: 2px;
  background: linear-gradient(90deg, var(--secondary), var(--secondary-light), var(--secondary));
  opacity: 0.3;
}
.step-card {
  text-align: center;
  padding: 2rem 1.5rem;
  position: relative;
  background: var(--bg-card);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  transition: var(--transition);
  border: 1px solid var(--border-light);
}
.step-card:hover {
  box-shadow: var(--shadow-md);
  transform: translateY(-4px);
}
.step-card .step-num {
  width: 48px;
  height: 48px;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--secondary), var(--secondary-dark));
  color: var(--primary-dark);
  font-weight: 800;
  font-size: 1.2rem;
  display: flex;
  align-items: center;
  justify-content: center;
  margin: 0 auto 1rem;
  position: relative;
  z-index: 2;
}
.step-card h4 { margin-bottom: 0.5rem; }
.step-card p { font-size: 0.9rem; color: var(--text-light); margin-bottom: 0; }
/* ===== FAQ Section ===== */
.faq-section {
  background: var(--bg-card);
}
.faq-list {
  max-width: 800px;
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
}
.faq-item {
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  overflow: hidden;
  transition: var(--transition);
  background: var(--bg-section);
}
.faq-item:hover { border-color: var(--secondary); }
.faq-question {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 1.2rem 1.5rem;
  cursor: pointer;
  font-weight: 600;
  font-size: 1rem;
  transition: var(--transition);
  background: none;
  width: 100%;
  text-align: left;
  color: var(--text);
  gap: 1rem;
}
.faq-question:hover { color: var(--secondary-dark); }
.faq-question i {
  font-size: 0.9rem;
  color: var(--text-muted);
  transition: var(--transition);
  flex-shrink: 0;
}
.faq-item.active .faq-question i { transform: rotate(180deg); color: var(--secondary); }
.faq-answer {
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.4s ease, padding 0.3s ease;
  padding: 0 1.5rem;
  color: var(--text-light);
  font-size: 0.95rem;
  line-height: 1.75;
}
.faq-item.active .faq-answer {
  max-height: 300px;
  padding: 0 1.5rem 1.2rem;
}
/* ===== CTA Section ===== */
.cta-section {
  background: var(--bg-dark);
  position: relative;
  overflow: hidden;
}
.cta-section::before {
  content: '';
  position: absolute;
  inset: 0;
  background: url('/assets/images/backpic/back-3.png') center center / cover no-repeat;
  opacity: 0.07;
}
.cta-section .container { position: relative; z-index: 1; text-align: center; }
.cta-section h2 {
  font-size: 2.25rem;
  color: var(--text-white);
  margin-bottom: 1rem;
}
.cta-section p {
  color: var(--text-muted);
  font-size: 1.1rem;
  max-width: 560px;
  margin: 0 auto 2rem;
}
.cta-section .btn { font-size: 1.05rem; padding: 0.9rem 2.5rem; }
/* ===== Footer ===== */
.footer {
  background: var(--primary-dark);
  color: var(--text-muted);
  padding: 3.5rem 0 0;
}
.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: 2.5rem;
  padding-bottom: 2.5rem;
  border-bottom: 1px solid rgba(255,255,255,0.06);
}
.footer-brand .logo {
  font-size: 1.3rem;
  font-weight: 800;
  color: var(--text-white);
  display: inline-block;
  margin-bottom: 0.75rem;
}
.footer-brand .logo span { color: var(--secondary); }
.footer-brand p { font-size: 0.9rem; line-height: 1.7; max-width: 320px; }
.footer-col h4 {
  color: var(--text-white);
  font-size: 1rem;
  font-weight: 600;
  margin-bottom: 1rem;
}
.footer-col ul li { margin-bottom: 0.5rem; }
.footer-col ul li a {
  font-size: 0.9rem;
  color: var(--text-muted);
  transition: var(--transition);
}
.footer-col ul li a:hover { color: var(--secondary); padding-left: 3px; }
.footer-bottom {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  align-items: center;
  padding: 1.25rem 0;
  font-size: 0.85rem;
  color: var(--text-muted);
}
.footer-bottom a { color: var(--text-muted); }
.footer-bottom a:hover { color: var(--secondary); }
.footer-socials {
  display: flex;
  gap: 0.75rem;
}
.footer-socials a {
  width: 36px;
  height: 36px;
  border-radius: 50%;
  border: 1px solid rgba(255,255,255,0.1);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--text-muted);
  transition: var(--transition);
  font-size: 0.9rem;
}
.footer-socials a:hover {
  border-color: var(--secondary);
  color: var(--secondary);
  background: rgba(212,168,83,0.08);
  transform: translateY(-2px);
}
/* ===== Mobile Responsive ===== */
@media (max-width: 1024px) {
  .intro-grid { grid-template-columns: 1fr; gap: 2.5rem; }
  .intro-image { order: -1; max-height: 340px; }
  .intro-image img { object-fit: cover; height: 100%; }
  .stats-grid { grid-template-columns: repeat(2, 1fr); gap: 1.5rem; }
  .process-steps { grid-template-columns: 1fr 1fr; gap: 1.5rem; }
  .process-steps::before { display: none; }
  .footer-grid { grid-template-columns: 1fr 1fr; }
}
@media (max-width: 768px) {
  :root { --header-h: 100px; }
  .header .menu-toggle { display: block; }
  .header-actions .btn span { display: none; }
  .header-actions .btn { padding: 0.5rem 0.9rem; }
  .header-search { display: none; }
  .mobile-search { display: block; padding: 0.5rem 0 0.75rem; }
  .mobile-search input { width: 100%; padding: 0.55rem 1rem 0.55rem 2.5rem; border-radius: 50px; background: rgba(255,255,255,0.08); color: var(--text-white); border: 1px solid rgba(255,255,255,0.1); }
  .mobile-search input::placeholder { color: var(--text-muted); }
  .mobile-search i { position: absolute; left: 0.9rem; top: 50%; transform: translateY(-50%); color: var(--text-muted); }
  .mobile-search .search-wrap { position: relative; max-width: 100%; }
  .nav-tabs-wrapper { border-top: none; }
  .nav-tabs { padding: 0.25rem 0 0.5rem; gap: 0.2rem; }
  .nav-tabs a { padding: 0.35rem 0.9rem; font-size: 0.82rem; }
  .hero { min-height: 70vh; padding: 7rem 0 3rem; }
  .hero-content h1 { font-size: 2.2rem; }
  .hero-content p { font-size: 1rem; }
  .hero-stats { gap: 1.5rem 2rem; }
  .hero-stats .stat-num { font-size: 1.4rem; }
  h2 { font-size: 1.6rem; }
  .section-padding { padding: 3rem 0; }
  .intro-grid { gap: 2rem; }
  .intro-features { grid-template-columns: 1fr; }
  .cat-grid { grid-template-columns: 1fr; }
  .news-grid { grid-template-columns: 1fr; }
  .stats-grid { grid-template-columns: repeat(2, 1fr); gap: 1rem; }
  .stat-block .stat-number { font-size: 2rem; }
  .process-steps { grid-template-columns: 1fr; gap: 1rem; }
  .step-card { padding: 1.5rem; }
  .faq-question { padding: 1rem 1.2rem; font-size: 0.95rem; }
  .faq-answer { padding: 0 1.2rem; }
  .cta-section h2 { font-size: 1.6rem; }
  .footer-grid { grid-template-columns: 1fr; gap: 1.5rem; }
  .footer-bottom { flex-direction: column; gap: 0.75rem; text-align: center; }
}
@media (max-width: 520px) {
  .hero-content h1 { font-size: 1.75rem; }
  .hero-stats { flex-direction: column; gap: 1rem; }
  .hero-actions { flex-direction: column; align-items: center; }
  .hero-actions .btn { width: 100%; max-width: 280px; justify-content: center; }
  .stats-grid { grid-template-columns: 1fr; }
  .section-title p { font-size: 0.95rem; }
}
/* ===== Scrollbar ===== */
::-webkit-scrollbar { width: 6px; height: 6px; }
::-webkit-scrollbar-track { background: var(--bg-dark); }
::-webkit-scrollbar-thumb { background: var(--primary-light); border-radius: 12px; }
::-webkit-scrollbar-thumb:hover { background: var(--secondary); }
/* ===== Focus accessibility ===== */
a:focus-visible, button:focus-visible, input:focus-visible {
  outline: 2px solid var(--secondary);
  outline-offset: 3px;
  border-radius: 4px;
}

/* roulang page: category1 */
/* ===== 设计变量 ===== */
    :root {
      --primary: #1a56db;
      --primary-light: #3b82f6;
      --primary-dark: #1e40af;
      --primary-bg: #eff6ff;
      --accent: #f59e0b;
      --accent-light: #fbbf24;
      --accent-dark: #d97706;
      --bg-white: #ffffff;
      --bg-light: #f8fafc;
      --bg-dark: #0f172a;
      --bg-mid: #1e293b;
      --text-primary: #0f172a;
      --text-secondary: #475569;
      --text-muted: #94a3b8;
      --text-inverse: #ffffff;
      --border-light: #e2e8f0;
      --border-mid: #cbd5e1;
      --radius-sm: 8px;
      --radius-md: 12px;
      --radius-lg: 20px;
      --radius-xl: 28px;
      --shadow-sm: 0 1px 3px rgba(0,0,0,0.06), 0 1px 2px rgba(0,0,0,0.04);
      --shadow-md: 0 4px 12px rgba(0,0,0,0.08);
      --shadow-lg: 0 12px 40px rgba(0,0,0,0.12);
      --shadow-xl: 0 20px 60px rgba(0,0,0,0.15);
      --transition: 0.25s cubic-bezier(0.4,0,0.2,1);
      --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, 'Noto Sans SC', sans-serif;
      --container-max: 1200px;
      --header-height: 120px;
    }

    /* ===== Reset & Base ===== */
    *, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
    html { scroll-behavior: smooth; -webkit-text-size-adjust: 100%; }
    body {
      font-family: var(--font-sans);
      font-size: 16px;
      line-height: 1.7;
      color: var(--text-primary);
      background: var(--bg-white);
      -webkit-font-smoothing: antialiased;
      -moz-osx-font-smoothing: grayscale;
    }
    img { max-width: 100%; height: auto; display: block; border-radius: var(--radius-sm); }
    a { color: var(--primary); text-decoration: none; transition: var(--transition); }
    a:hover { color: var(--primary-dark); }
    a:focus-visible { outline: 3px solid var(--primary-light); outline-offset: 2px; border-radius: 4px; }
    button, input, textarea { font-family: inherit; font-size: inherit; }
    button { cursor: pointer; border: none; background: none; }
    ul, ol { list-style: none; }
    h1, h2, h3, h4, h5, h6 { line-height: 1.25; font-weight: 700; color: var(--text-primary); }
    h1 { font-size: clamp(2rem, 5vw, 3.2rem); }
    h2 { font-size: clamp(1.5rem, 3.5vw, 2.2rem); }
    h3 { font-size: clamp(1.1rem, 2vw, 1.4rem); }
    h4 { font-size: 1.1rem; }
    p { margin-bottom: 1rem; color: var(--text-secondary); }
    .container {
      width: 100%;
      max-width: var(--container-max);
      margin: 0 auto;
      padding: 0 24px;
    }
    section { padding: 80px 0; }
    .section-title {
      text-align: center;
      margin-bottom: 16px;
    }
    .section-sub {
      text-align: center;
      max-width: 640px;
      margin: 0 auto 48px;
      color: var(--text-secondary);
      font-size: 1.05rem;
    }
    .tag {
      display: inline-block;
      padding: 4px 14px;
      border-radius: 50px;
      font-size: 0.8rem;
      font-weight: 600;
      background: var(--primary-bg);
      color: var(--primary);
      letter-spacing: 0.3px;
    }
    .tag-accent {
      background: #fef3c7;
      color: var(--accent-dark);
    }

    /* ===== Header & 双层导航 ===== */
    .header {
      position: sticky;
      top: 0;
      z-index: 1000;
      background: var(--bg-white);
      border-bottom: 1px solid var(--border-light);
      box-shadow: 0 2px 12px rgba(0,0,0,0.04);
    }
    .header-inner { display: flex; flex-direction: column; }
    /* 第一行：品牌 + 搜索/CTA */
    .header-top {
      display: flex;
      align-items: center;
      justify-content: space-between;
      padding: 12px 0;
      gap: 16px;
      flex-wrap: wrap;
    }
    .logo {
      font-size: 1.6rem;
      font-weight: 800;
      color: var(--text-primary);
      letter-spacing: -0.5px;
      display: flex;
      align-items: center;
      gap: 2px;
    }
    .logo span { color: var(--primary); }
    .logo:hover { color: var(--text-primary); opacity: 0.85; }
    .header-actions {
      display: flex;
      align-items: center;
      gap: 12px;
    }
    .header-search {
      display: flex;
      align-items: center;
      background: var(--bg-light);
      border: 1px solid var(--border-light);
      border-radius: 50px;
      padding: 6px 16px;
      transition: var(--transition);
    }
    .header-search:focus-within {
      border-color: var(--primary-light);
      box-shadow: 0 0 0 3px rgba(59,130,246,0.15);
    }
    .header-search input {
      border: none;
      background: transparent;
      padding: 6px 0;
      min-width: 160px;
      outline: none;
      color: var(--text-primary);
    }
    .header-search input::placeholder { color: var(--text-muted); }
    .header-search button {
      color: var(--text-muted);
      font-size: 1rem;
      padding: 4px 8px;
      transition: var(--transition);
    }
    .header-search button:hover { color: var(--primary); }
    .btn-header {
      padding: 8px 20px;
      background: var(--primary);
      color: var(--text-inverse);
      border-radius: 50px;
      font-weight: 600;
      font-size: 0.9rem;
      transition: var(--transition);
      white-space: nowrap;
    }
    .btn-header:hover { background: var(--primary-dark); color: var(--text-inverse); transform: translateY(-1px); box-shadow: var(--shadow-md); }
    /* 第二行：频道 Tabs */
    .nav-tabs {
      display: flex;
      gap: 4px;
      padding: 6px 0 10px;
      overflow-x: auto;
      -webkit-overflow-scrolling: touch;
      scrollbar-width: none;
      flex-wrap: nowrap;
    }
    .nav-tabs::-webkit-scrollbar { display: none; }
    .nav-tabs a {
      display: inline-flex;
      align-items: center;
      gap: 8px;
      padding: 8px 20px;
      border-radius: 50px;
      font-size: 0.92rem;
      font-weight: 500;
      color: var(--text-secondary);
      background: transparent;
      transition: var(--transition);
      white-space: nowrap;
      border: 1px solid transparent;
    }
    .nav-tabs a i { font-size: 0.85rem; }
    .nav-tabs a:hover { background: var(--bg-light); color: var(--text-primary); border-color: var(--border-light); }
    .nav-tabs a.active {
      background: var(--primary);
      color: var(--text-inverse);
      border-color: var(--primary);
      box-shadow: var(--shadow-sm);
    }
    .nav-tabs a.active:hover { background: var(--primary-dark); }
    .mobile-menu-btn { display: none; font-size: 1.4rem; color: var(--text-primary); padding: 4px 8px; }

    /* ===== Hero / Banner ===== */
    .category-hero {
      position: relative;
      padding: 100px 0 80px;
      background: var(--bg-dark);
      overflow: hidden;
      min-height: 420px;
      display: flex;
      align-items: center;
    }
    .category-hero .hero-bg {
      position: absolute;
      inset: 0;
      background: url('/assets/images/backpic/back-1.png') center center / cover no-repeat;
      opacity: 0.3;
      pointer-events: none;
    }
    .category-hero .hero-overlay {
      position: absolute;
      inset: 0;
      background: linear-gradient(135deg, rgba(15,23,42,0.92) 40%, rgba(30,41,59,0.7) 100%);
      pointer-events: none;
    }
    .category-hero .container { position: relative; z-index: 2; }
    .category-hero .hero-tag { margin-bottom: 16px; }
    .category-hero h1 {
      color: var(--text-inverse);
      font-size: clamp(2.2rem, 5vw, 3.4rem);
      font-weight: 800;
      letter-spacing: -0.5px;
      margin-bottom: 20px;
      max-width: 720px;
    }
    .category-hero h1 span { color: var(--accent); }
    .category-hero .hero-desc {
      color: rgba(255,255,255,0.8);
      font-size: 1.15rem;
      max-width: 580px;
      margin-bottom: 32px;
      line-height: 1.7;
    }
    .category-hero .hero-actions { display: flex; gap: 16px; flex-wrap: wrap; }
    .btn-primary {
      display: inline-flex;
      align-items: center;
      gap: 10px;
      padding: 14px 32px;
      background: var(--primary);
      color: var(--text-inverse);
      border-radius: 50px;
      font-weight: 600;
      font-size: 1rem;
      transition: var(--transition);
      box-shadow: var(--shadow-md);
    }
    .btn-primary:hover { background: var(--primary-dark); color: var(--text-inverse); transform: translateY(-2px); box-shadow: var(--shadow-lg); }
    .btn-secondary {
      display: inline-flex;
      align-items: center;
      gap: 10px;
      padding: 14px 32px;
      background: rgba(255,255,255,0.1);
      color: var(--text-inverse);
      border-radius: 50px;
      font-weight: 600;
      font-size: 1rem;
      border: 1px solid rgba(255,255,255,0.25);
      transition: var(--transition);
      backdrop-filter: blur(4px);
    }
    .btn-secondary:hover { background: rgba(255,255,255,0.2); color: var(--text-inverse); border-color: rgba(255,255,255,0.4); }

    /* ===== 分类简介 ===== */
    .intro-section { background: var(--bg-white); }
    .intro-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 60px;
      align-items: center;
    }
    .intro-content h2 { margin-bottom: 16px; }
    .intro-content p { margin-bottom: 16px; }
    .intro-content .intro-stats {
      display: grid;
      grid-template-columns: repeat(3,1fr);
      gap: 20px;
      margin-top: 28px;
    }
    .intro-content .stat-item {
      text-align: center;
      padding: 16px 8px;
      background: var(--bg-light);
      border-radius: var(--radius-md);
      border: 1px solid var(--border-light);
    }
    .intro-content .stat-item .num {
      font-size: 1.8rem;
      font-weight: 800;
      color: var(--primary);
      line-height: 1.2;
    }
    .intro-content .stat-item .label { font-size: 0.85rem; color: var(--text-muted); margin-top: 4px; }
    .intro-image img { border-radius: var(--radius-lg); box-shadow: var(--shadow-lg); width: 100%; object-fit: cover; }

    /* ===== 全球节点 ===== */
    .nodes-section { background: var(--bg-light); }
    .nodes-grid {
      display: grid;
      grid-template-columns: repeat(auto-fill, minmax(280px,1fr));
      gap: 24px;
    }
    .node-card {
      background: var(--bg-white);
      border-radius: var(--radius-md);
      overflow: hidden;
      border: 1px solid var(--border-light);
      transition: var(--transition);
      box-shadow: var(--shadow-sm);
    }
    .node-card:hover { transform: translateY(-4px); box-shadow: var(--shadow-lg); border-color: var(--primary-light); }
    .node-card .card-img {
      width: 100%;
      height: 180px;
      object-fit: cover;
    }
    .node-card .card-body { padding: 20px 22px 24px; }
    .node-card .card-body h3 { margin-bottom: 8px; }
    .node-card .card-body p { font-size: 0.92rem; margin-bottom: 12px; }
    .node-card .card-meta {
      display: flex;
      justify-content: space-between;
      align-items: center;
      padding-top: 12px;
      border-top: 1px solid var(--border-light);
      font-size: 0.85rem;
      color: var(--text-muted);
    }
    .node-card .card-meta .badge {
      display: inline-flex;
      align-items: center;
      gap: 4px;
      padding: 2px 12px;
      border-radius: 50px;
      font-size: 0.75rem;
      font-weight: 600;
    }
    .badge-green { background: #dcfce7; color: #16a34a; }
    .badge-blue { background: #dbeafe; color: #2563eb; }
    .badge-orange { background: #fef3c7; color: #d97706; }
    .badge-purple { background: #ede9fe; color: #7c3aed; }

    /* ===== 接入方案 ===== */
    .plans-section { background: var(--bg-white); }
    .plans-grid {
      display: grid;
      grid-template-columns: repeat(auto-fill, minmax(320px,1fr));
      gap: 28px;
    }
    .plan-card {
      background: var(--bg-light);
      border-radius: var(--radius-md);
      padding: 32px 28px;
      border: 1px solid var(--border-light);
      transition: var(--transition);
      position: relative;
    }
    .plan-card:hover { border-color: var(--primary-light); box-shadow: var(--shadow-md); transform: translateY(-2px); }
    .plan-card .plan-icon {
      width: 52px;
      height: 52px;
      display: flex;
      align-items: center;
      justify-content: center;
      border-radius: var(--radius-sm);
      background: var(--primary-bg);
      color: var(--primary);
      font-size: 1.4rem;
      margin-bottom: 16px;
    }
    .plan-card h3 { margin-bottom: 8px; }
    .plan-card p { font-size: 0.92rem; margin-bottom: 16px; }
    .plan-card .plan-features { margin-bottom: 20px; }
    .plan-card .plan-features li {
      display: flex;
      align-items: center;
      gap: 10px;
      font-size: 0.9rem;
      color: var(--text-secondary);
      padding: 6px 0;
    }
    .plan-card .plan-features li i { color: var(--primary); width: 16px; font-size: 0.85rem; }
    .plan-card .plan-link {
      font-weight: 600;
      color: var(--primary);
      display: inline-flex;
      align-items: center;
      gap: 6px;
    }
    .plan-card .plan-link:hover { gap: 10px; }
    .plan-card .plan-popular {
      position: absolute;
      top: -10px;
      right: 20px;
      background: var(--accent);
      color: var(--text-primary);
      padding: 4px 16px;
      border-radius: 50px;
      font-size: 0.75rem;
      font-weight: 700;
      letter-spacing: 0.5px;
    }

    /* ===== 使用流程 ===== */
    .steps-section { background: var(--bg-dark); color: var(--text-inverse); }
    .steps-section .section-title { color: var(--text-inverse); }
    .steps-section .section-sub { color: rgba(255,255,255,0.7); }
    .steps-grid {
      display: grid;
      grid-template-columns: repeat(auto-fit, minmax(220px,1fr));
      gap: 32px;
      counter-reset: step;
    }
    .step-item {
      counter-increment: step;
      text-align: center;
      padding: 28px 20px;
      background: rgba(255,255,255,0.05);
      border-radius: var(--radius-md);
      border: 1px solid rgba(255,255,255,0.08);
      transition: var(--transition);
      position: relative;
    }
    .step-item:hover { background: rgba(255,255,255,0.08); border-color: rgba(255,255,255,0.15); transform: translateY(-4px); }
    .step-item .step-num {
      width: 48px;
      height: 48px;
      margin: 0 auto 16px;
      display: flex;
      align-items: center;
      justify-content: center;
      border-radius: 50%;
      background: var(--primary);
      color: var(--text-inverse);
      font-weight: 800;
      font-size: 1.2rem;
    }
    .step-item h3 { color: var(--text-inverse); margin-bottom: 8px; font-size: 1.1rem; }
    .step-item p { color: rgba(255,255,255,0.7); font-size: 0.92rem; margin-bottom: 0; }

    /* ===== FAQ ===== */
    .faq-section { background: var(--bg-light); }
    .faq-list { max-width: 780px; margin: 0 auto; }
    .faq-item {
      background: var(--bg-white);
      border-radius: var(--radius-md);
      margin-bottom: 12px;
      border: 1px solid var(--border-light);
      overflow: hidden;
      transition: var(--transition);
    }
    .faq-item:hover { border-color: var(--border-mid); box-shadow: var(--shadow-sm); }
    .faq-question {
      padding: 18px 24px;
      display: flex;
      justify-content: space-between;
      align-items: center;
      cursor: pointer;
      font-weight: 600;
      color: var(--text-primary);
      font-size: 1rem;
      background: none;
      width: 100%;
      text-align: left;
      transition: var(--transition);
    }
    .faq-question i { color: var(--text-muted); transition: var(--transition); font-size: 0.85rem; }
    .faq-item.active .faq-question i { transform: rotate(180deg); color: var(--primary); }
    .faq-answer {
      padding: 0 24px;
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.35s ease, padding 0.35s ease;
    }
    .faq-item.active .faq-answer {
      max-height: 300px;
      padding: 0 24px 20px;
    }
    .faq-answer p { font-size: 0.95rem; margin-bottom: 0; color: var(--text-secondary); }

    /* ===== CTA ===== */
    .cta-section {
      background: var(--primary);
      padding: 80px 0;
      text-align: center;
    }
    .cta-section h2 {
      color: var(--text-inverse);
      font-size: clamp(1.6rem, 3vw, 2.2rem);
      margin-bottom: 12px;
    }
    .cta-section p {
      color: rgba(255,255,255,0.85);
      font-size: 1.05rem;
      max-width: 560px;
      margin: 0 auto 28px;
    }
    .cta-section .btn-cta {
      display: inline-flex;
      align-items: center;
      gap: 10px;
      padding: 16px 40px;
      background: var(--bg-white);
      color: var(--primary);
      border-radius: 50px;
      font-weight: 700;
      font-size: 1.05rem;
      transition: var(--transition);
      box-shadow: var(--shadow-lg);
    }
    .cta-section .btn-cta:hover { background: var(--bg-light); transform: translateY(-2px); box-shadow: var(--shadow-xl); }

    /* ===== Footer ===== */
    .footer {
      background: var(--bg-dark);
      color: rgba(255,255,255,0.8);
      padding: 60px 0 20px;
    }
    .footer-grid {
      display: grid;
      grid-template-columns: 1.5fr 1fr 1fr 1fr;
      gap: 40px;
      margin-bottom: 40px;
    }
    .footer-brand .logo { color: var(--text-inverse); font-size: 1.5rem; margin-bottom: 12px; display: inline-block; }
    .footer-brand .logo span { color: var(--primary-light); }
    .footer-brand p { color: rgba(255,255,255,0.6); font-size: 0.92rem; line-height: 1.7; max-width: 320px; }
    .footer-col h4 { color: var(--text-inverse); font-size: 1rem; margin-bottom: 16px; font-weight: 600; }
    .footer-col ul li { margin-bottom: 10px; }
    .footer-col ul li a { color: rgba(255,255,255,0.6); font-size: 0.9rem; transition: var(--transition); }
    .footer-col ul li a:hover { color: var(--primary-light); padding-left: 4px; }
    .footer-bottom {
      padding-top: 24px;
      border-top: 1px solid rgba(255,255,255,0.08);
      display: flex;
      justify-content: space-between;
      align-items: center;
      flex-wrap: wrap;
      gap: 16px;
      font-size: 0.85rem;
      color: rgba(255,255,255,0.5);
    }
    .footer-socials { display: flex; gap: 12px; }
    .footer-socials a {
      width: 36px;
      height: 36px;
      display: flex;
      align-items: center;
      justify-content: center;
      border-radius: 50%;
      background: rgba(255,255,255,0.06);
      color: rgba(255,255,255,0.5);
      font-size: 1rem;
      transition: var(--transition);
    }
    .footer-socials a:hover { background: var(--primary); color: var(--text-inverse); transform: translateY(-2px); }

    /* ===== 响应式 ===== */
    @media (max-width: 1024px) {
      .footer-grid { grid-template-columns: 1fr 1fr; gap: 30px; }
      .intro-grid { gap: 40px; }
    }
    @media (max-width: 768px) {
      :root { --header-height: 100px; }
      section { padding: 56px 0; }
      .header-top { padding: 10px 0; }
      .header-search input { min-width: 100px; }
      .mobile-menu-btn { display: block; }
      .nav-tabs { padding: 4px 0 8px; gap: 4px; }
      .nav-tabs a { padding: 6px 14px; font-size: 0.82rem; gap: 4px; }
      .nav-tabs a i { font-size: 0.75rem; }
      .category-hero { padding: 72px 0 56px; min-height: 320px; }
      .category-hero h1 { font-size: clamp(1.6rem, 5vw, 2.2rem); }
      .category-hero .hero-desc { font-size: 1rem; }
      .intro-grid { grid-template-columns: 1fr; gap: 32px; }
      .intro-content .intro-stats { grid-template-columns: repeat(3,1fr); gap: 12px; }
      .intro-content .stat-item .num { font-size: 1.4rem; }
      .nodes-grid { grid-template-columns: 1fr 1fr; }
      .plans-grid { grid-template-columns: 1fr; }
      .steps-grid { grid-template-columns: 1fr 1fr; gap: 20px; }
      .footer-grid { grid-template-columns: 1fr 1fr; gap: 24px; }
      .footer-bottom { flex-direction: column; text-align: center; }
      .cta-section { padding: 56px 0; }
    }
    @media (max-width: 520px) {
      .container { padding: 0 16px; }
      .header-top { flex-wrap: wrap; }
      .header-search { order: 3; width: 100%; }
      .header-search input { min-width: 0; flex: 1; }
      .nav-tabs a { padding: 6px 12px; font-size: 0.78rem; }
      .nodes-grid { grid-template-columns: 1fr; }
      .steps-grid { grid-template-columns: 1fr; }
      .footer-grid { grid-template-columns: 1fr; }
      .category-hero .hero-actions { flex-direction: column; }
      .btn-primary, .btn-secondary { width: 100%; justify-content: center; }
      .intro-content .intro-stats { grid-template-columns: 1fr 1fr; }
    }

    /* ===== 辅助 ===== */
    .sr-only { position: absolute; width: 1px; height: 1px; padding: 0; margin: -1px; overflow: hidden; clip: rect(0,0,0,0); border: 0; }

/* roulang page: article */
/* ===== Design Variables ===== */
:root {
  --primary: #2563eb;
  --primary-dark: #1d4ed8;
  --primary-light: #3b82f6;
  --primary-bg: #eff6ff;
  --secondary: #0f172a;
  --accent: #f59e0b;
  --accent-light: #fbbf24;
  --bg: #ffffff;
  --bg-alt: #f8fafc;
  --bg-dark: #0f172a;
  --bg-card: #ffffff;
  --text: #1e293b;
  --text-light: #64748b;
  --text-white: #ffffff;
  --border: #e2e8f0;
  --radius: 16px;
  --radius-sm: 10px;
  --radius-xs: 6px;
  --shadow: 0 4px 24px rgba(0,0,0,0.06);
  --shadow-md: 0 8px 32px rgba(0,0,0,0.08);
  --shadow-lg: 0 16px 48px rgba(0,0,0,0.12);
  --shadow-btn: 0 4px 14px rgba(37,99,235,0.35);
  --transition: 0.3s cubic-bezier(0.4,0,0.2,1);
  --font: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, 'Noto Sans SC', sans-serif;
  --max-width: 1200px;
  --header-h: 72px;
  --nav-h: 52px;
}

/* ===== Reset & Base ===== */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; -webkit-text-size-adjust: 100%; }
body { font-family: var(--font); font-size: 16px; line-height: 1.7; color: var(--text); background: var(--bg); -webkit-font-smoothing: antialiased; -moz-osx-font-smoothing: grayscale; }
a { color: var(--primary); text-decoration: none; transition: color var(--transition); }
a:hover { color: var(--primary-dark); }
a:focus-visible { outline: 2px solid var(--primary); outline-offset: 2px; border-radius: var(--radius-xs); }
img { max-width: 100%; height: auto; display: block; }
ul, ol { list-style: none; }
button, input, textarea { font-family: inherit; font-size: inherit; }
button { cursor: pointer; border: none; background: none; }
.container { width: 100%; max-width: var(--max-width); margin: 0 auto; padding: 0 24px; }
.sr-only { position: absolute; width: 1px; height: 1px; padding: 0; margin: -1px; overflow: hidden; clip: rect(0,0,0,0); border: 0; }

/* ===== Header ===== */
.header { position: sticky; top: 0; z-index: 100; background: rgba(255,255,255,0.97); backdrop-filter: blur(16px); -webkit-backdrop-filter: blur(16px); border-bottom: 1px solid var(--border); }
.header-inner { display: flex; align-items: center; justify-content: space-between; height: var(--header-h); }
.logo { font-size: 1.5rem; font-weight: 800; color: var(--text); letter-spacing: -0.02em; display: flex; align-items: center; gap: 2px; }
.logo span { color: var(--primary); }
.logo:hover { color: var(--text); }
.header-actions { display: flex; align-items: center; gap: 16px; }
.search-box { position: relative; width: 200px; }
.search-box input { width: 100%; padding: 8px 36px 8px 14px; border: 1px solid var(--border); border-radius: 50px; background: var(--bg-alt); font-size: 0.875rem; color: var(--text); outline: none; transition: all var(--transition); }
.search-box input:focus { border-color: var(--primary); box-shadow: 0 0 0 3px rgba(37,99,235,0.12); }
.search-box button { position: absolute; right: 10px; top: 50%; transform: translateY(-50%); color: var(--text-light); }
.btn-cta { display: inline-flex; align-items: center; gap: 8px; padding: 10px 24px; background: var(--primary); color: #fff; border-radius: 50px; font-weight: 600; font-size: 0.875rem; transition: all var(--transition); box-shadow: var(--shadow-btn); }
.btn-cta:hover { background: var(--primary-dark); color: #fff; transform: translateY(-2px); box-shadow: 0 8px 24px rgba(37,99,235,0.4); }
.btn-cta:active { transform: translateY(0); }

/* ===== Nav Tabs ===== */
.nav-tabs { display: flex; align-items: center; gap: 4px; background: var(--bg-alt); padding: 4px; border-radius: 50px; overflow-x: auto; -webkit-overflow-scrolling: touch; scrollbar-width: none; }
.nav-tabs::-webkit-scrollbar { display: none; }
.nav-tabs a { display: flex; align-items: center; gap: 8px; padding: 8px 20px; border-radius: 50px; font-size: 0.875rem; font-weight: 500; color: var(--text-light); white-space: nowrap; transition: all var(--transition); }
.nav-tabs a i { font-size: 0.9rem; }
.nav-tabs a:hover { color: var(--text); background: rgba(37,99,235,0.06); }
.nav-tabs a.active { background: var(--primary); color: #fff; box-shadow: 0 4px 12px rgba(37,99,235,0.3); }
.nav-tabs a.active:hover { background: var(--primary-dark); color: #fff; }
.nav-row { display: flex; align-items: center; justify-content: space-between; height: var(--nav-h); }

/* ===== Article Hero ===== */
.article-hero { position: relative; padding: 80px 0 60px; margin-top: 0; background: var(--bg-dark); overflow: hidden; }
.article-hero-bg { position: absolute; inset: 0; background: url('/assets/images/backpic/back-2.png') center center / cover no-repeat; opacity: 0.35; transform: scale(1.02); }
.article-hero-bg::after { content: ''; position: absolute; inset: 0; background: linear-gradient(135deg, rgba(15,23,42,0.85) 0%, rgba(30,64,175,0.6) 100%); }
.article-hero .container { position: relative; z-index: 2; }
.article-breadcrumb { display: flex; align-items: center; gap: 8px; flex-wrap: wrap; margin-bottom: 24px; font-size: 0.85rem; color: rgba(255,255,255,0.65); }
.article-breadcrumb a { color: rgba(255,255,255,0.75); }
.article-breadcrumb a:hover { color: #fff; }
.article-breadcrumb .sep { color: rgba(255,255,255,0.4); }
.article-category { display: inline-flex; align-items: center; gap: 6px; padding: 6px 16px; background: rgba(255,255,255,0.12); backdrop-filter: blur(8px); border-radius: 50px; font-size: 0.8rem; font-weight: 500; color: #fff; margin-bottom: 20px; }
.article-category i { font-size: 0.75rem; }
.article-hero h1 { font-size: 2.6rem; font-weight: 800; color: #fff; line-height: 1.25; letter-spacing: -0.02em; max-width: 860px; margin-bottom: 20px; }
.article-meta { display: flex; align-items: center; gap: 24px; flex-wrap: wrap; color: rgba(255,255,255,0.7); font-size: 0.9rem; }
.article-meta span { display: flex; align-items: center; gap: 6px; }
.article-meta i { font-size: 0.85rem; }

/* ===== Article Body ===== */
.article-section { padding: 60px 0 40px; background: var(--bg); }
.article-layout { display: grid; grid-template-columns: 1fr 280px; gap: 48px; }
.article-main { min-width: 0; }
.article-content { font-size: 1.05rem; line-height: 1.9; color: var(--text); }
.article-content p { margin-bottom: 1.5em; }
.article-content h2, .article-content h3 { margin-top: 1.8em; margin-bottom: 0.8em; font-weight: 700; color: var(--secondary); }
.article-content h2 { font-size: 1.6rem; }
.article-content h3 { font-size: 1.25rem; }
.article-content ul, .article-content ol { margin-bottom: 1.5em; padding-left: 1.5em; }
.article-content li { margin-bottom: 0.5em; list-style: disc; }
.article-content ol li { list-style: decimal; }
.article-content a { color: var(--primary); text-decoration: underline; text-underline-offset: 2px; }
.article-content blockquote { margin: 1.8em 0; padding: 20px 28px; border-left: 4px solid var(--primary); background: var(--primary-bg); border-radius: 0 var(--radius-sm) var(--radius-sm) 0; color: var(--text-light); font-style: italic; }
.article-content img { border-radius: var(--radius-sm); margin: 1.5em 0; box-shadow: var(--shadow); }
.article-content code { background: var(--bg-alt); padding: 2px 8px; border-radius: 4px; font-size: 0.9em; }

/* ===== Sidebar ===== */
.article-sidebar { position: sticky; top: calc(var(--header-h) + var(--nav-h) + 24px); align-self: start; }
.sidebar-card { background: var(--bg-alt); border-radius: var(--radius); padding: 28px 24px; margin-bottom: 24px; border: 1px solid var(--border); }
.sidebar-card h3 { font-size: 1.05rem; font-weight: 700; margin-bottom: 16px; display: flex; align-items: center; gap: 8px; color: var(--secondary); }
.sidebar-card h3 i { color: var(--primary); }
.sidebar-list li { margin-bottom: 12px; }
.sidebar-list a { display: flex; align-items: flex-start; gap: 12px; font-size: 0.9rem; color: var(--text); line-height: 1.5; transition: all var(--transition); }
.sidebar-list a:hover { color: var(--primary); }
.sidebar-list .num { flex-shrink: 0; width: 24px; height: 24px; display: flex; align-items: center; justify-content: center; background: var(--primary); color: #fff; border-radius: 50%; font-size: 0.75rem; font-weight: 700; }
.sidebar-tags { display: flex; flex-wrap: wrap; gap: 8px; }
.sidebar-tags a { padding: 6px 14px; background: var(--bg); border: 1px solid var(--border); border-radius: 50px; font-size: 0.8rem; color: var(--text-light); transition: all var(--transition); }
.sidebar-tags a:hover { border-color: var(--primary); color: var(--primary); background: var(--primary-bg); }

/* ===== Share Bar ===== */
.share-bar { display: flex; align-items: center; gap: 12px; margin-top: 40px; padding-top: 28px; border-top: 1px solid var(--border); }
.share-bar span { font-size: 0.9rem; font-weight: 600; color: var(--text-light); }
.share-bar a { display: flex; align-items: center; justify-content: center; width: 40px; height: 40px; border-radius: 50%; background: var(--bg-alt); color: var(--text-light); transition: all var(--transition); font-size: 1.1rem; }
.share-bar a:hover { background: var(--primary); color: #fff; transform: translateY(-2px); }

/* ===== Related Posts ===== */
.related-section { padding: 60px 0; background: var(--bg-alt); }
.related-header { display: flex; align-items: center; justify-content: space-between; margin-bottom: 32px; }
.related-header h2 { font-size: 1.6rem; font-weight: 700; color: var(--secondary); }
.related-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 24px; }
.related-card { background: var(--bg-card); border-radius: var(--radius); overflow: hidden; border: 1px solid var(--border); transition: all var(--transition); }
.related-card:hover { transform: translateY(-6px); box-shadow: var(--shadow-lg); border-color: transparent; }
.related-card-img { position: relative; width: 100%; aspect-ratio: 16 / 10; overflow: hidden; background: var(--bg-alt); }
.related-card-img img { width: 100%; height: 100%; object-fit: cover; transition: transform 0.5s ease; }
.related-card:hover .related-card-img img { transform: scale(1.05); }
.related-card-body { padding: 18px 20px 22px; }
.related-card-body h3 { font-size: 0.95rem; font-weight: 600; line-height: 1.5; margin-bottom: 10px; display: -webkit-box; -webkit-line-clamp: 2; -webkit-box-orient: vertical; overflow: hidden; }
.related-card-body h3 a { color: var(--text); }
.related-card-body h3 a:hover { color: var(--primary); }
.related-card-meta { display: flex; align-items: center; gap: 12px; font-size: 0.8rem; color: var(--text-light); }
.related-card-meta span { display: flex; align-items: center; gap: 4px; }

/* ===== CTA ===== */
.cta-section { padding: 72px 0; background: var(--bg-dark); position: relative; overflow: hidden; }
.cta-section::before { content: ''; position: absolute; inset: 0; background: url('/assets/images/backpic/back-3.png') center center / cover no-repeat; opacity: 0.1; }
.cta-section .container { position: relative; z-index: 2; text-align: center; }
.cta-section h2 { font-size: 2.2rem; font-weight: 800; color: #fff; margin-bottom: 16px; }
.cta-section p { font-size: 1.1rem; color: rgba(255,255,255,0.7); max-width: 560px; margin: 0 auto 32px; }
.cta-group { display: flex; align-items: center; justify-content: center; gap: 16px; flex-wrap: wrap; }
.btn-cta-light { display: inline-flex; align-items: center; gap: 8px; padding: 14px 36px; background: #fff; color: var(--primary-dark); border-radius: 50px; font-weight: 700; font-size: 1rem; transition: all var(--transition); box-shadow: var(--shadow-btn); }
.btn-cta-light:hover { background: var(--primary-bg); color: var(--primary-dark); transform: translateY(-2px); box-shadow: 0 8px 28px rgba(0,0,0,0.25); }
.btn-outline-light { display: inline-flex; align-items: center; gap: 8px; padding: 14px 36px; border: 2px solid rgba(255,255,255,0.3); color: #fff; border-radius: 50px; font-weight: 600; font-size: 1rem; transition: all var(--transition); }
.btn-outline-light:hover { border-color: #fff; color: #fff; background: rgba(255,255,255,0.1); transform: translateY(-2px); }

/* ===== Footer ===== */
.footer { background: var(--secondary); color: rgba(255,255,255,0.7); padding: 60px 0 0; }
.footer-grid { display: grid; grid-template-columns: 1.8fr 1fr 1fr 1fr; gap: 40px; margin-bottom: 40px; }
.footer-brand .logo { color: #fff; margin-bottom: 16px; }
.footer-brand .logo span { color: var(--primary-light); }
.footer-brand p { font-size: 0.9rem; line-height: 1.7; max-width: 340px; }
.footer-col h4 { color: #fff; font-size: 1rem; font-weight: 700; margin-bottom: 18px; }
.footer-col ul li { margin-bottom: 10px; }
.footer-col ul a { color: rgba(255,255,255,0.6); font-size: 0.9rem; transition: all var(--transition); }
.footer-col ul a:hover { color: #fff; padding-left: 4px; }
.footer-bottom { display: flex; align-items: center; justify-content: space-between; padding: 24px 0; border-top: 1px solid rgba(255,255,255,0.08); font-size: 0.85rem; }
.footer-socials { display: flex; gap: 12px; }
.footer-socials a { display: flex; align-items: center; justify-content: center; width: 38px; height: 38px; border-radius: 50%; background: rgba(255,255,255,0.08); color: rgba(255,255,255,0.6); transition: all var(--transition); font-size: 1rem; }
.footer-socials a:hover { background: var(--primary); color: #fff; transform: translateY(-2px); }

/* ===== Not Found ===== */
.not-found { text-align: center; padding: 80px 0; }
.not-found i { font-size: 4rem; color: var(--text-light); margin-bottom: 24px; opacity: 0.4; }
.not-found h2 { font-size: 1.8rem; font-weight: 700; color: var(--secondary); margin-bottom: 12px; }
.not-found p { color: var(--text-light); margin-bottom: 24px; font-size: 1.05rem; }
.not-found .btn-cta { display: inline-flex; }

/* ===== Responsive ===== */
@media (max-width: 1024px) {
  .related-grid { grid-template-columns: repeat(2, 1fr); }
  .article-layout { grid-template-columns: 1fr; gap: 32px; }
  .article-sidebar { position: static; }
  .sidebar-card { padding: 20px; }
}

@media (max-width: 768px) {
  .header-inner { height: 60px; }
  .search-box { width: 140px; }
  .btn-cta span { display: none; }
  .nav-tabs a { padding: 6px 16px; font-size: 0.8rem; }
  .nav-tabs a i { font-size: 0.8rem; }
  .article-hero { padding: 48px 0 40px; }
  .article-hero h1 { font-size: 1.8rem; }
  .article-meta { gap: 16px; font-size: 0.8rem; }
  .related-grid { grid-template-columns: 1fr; }
  .footer-grid { grid-template-columns: 1fr 1fr; gap: 24px; }
  .footer-bottom { flex-direction: column; gap: 16px; text-align: center; }
  .cta-section h2 { font-size: 1.6rem; }
  .cta-section p { font-size: 0.95rem; }
  .article-content { font-size: 1rem; }
}

@media (max-width: 520px) {
  .container { padding: 0 16px; }
  .header-inner { height: 56px; }
  .logo { font-size: 1.2rem; }
  .search-box { width: 100px; }
  .search-box input { padding: 6px 32px 6px 12px; font-size: 0.8rem; }
  .nav-tabs { border-radius: 40px; padding: 3px; }
  .nav-tabs a { padding: 5px 14px; font-size: 0.75rem; gap: 4px; }
  .article-hero h1 { font-size: 1.4rem; }
  .article-hero { padding: 32px 0 28px; }
  .article-category { font-size: 0.7rem; padding: 4px 12px; }
  .article-section { padding: 32px 0 24px; }
  .related-section { padding: 40px 0; }
  .cta-section { padding: 48px 0; }
  .cta-section h2 { font-size: 1.3rem; }
  .btn-cta-light, .btn-outline-light { padding: 12px 24px; font-size: 0.9rem; }
  .footer-grid { grid-template-columns: 1fr; gap: 20px; }
  .footer { padding: 40px 0 0; }
  .sidebar-card { padding: 16px; }
}

/* ===== Utility ===== */
.text-center { text-align: center; }
.mt-8 { margin-top: 8px; }
.mt-16 { margin-top: 16px; }
.mt-24 { margin-top: 24px; }
.mb-8 { margin-bottom: 8px; }
.mb-16 { margin-bottom: 16px; }
.mb-24 { margin-bottom: 24px; }