/* roulang page: index */
:root{
  --primary:#4f46e5;
  --primary-dark:#4338ca;
  --primary-light:#eef2ff;
  --accent:#06b6d4;
  --accent-light:#cffafe;
  --bg:#f8fafc;
  --bg-dark:#0f172a;
  --bg-gray:#f1f5f9;
  --card:#ffffff;
  --text:#1e293b;
  --text-muted:#64748b;
  --border:#e2e8f0;
  --radius-sm:8px;
  --radius-md:14px;
  --radius-lg:24px;
  --shadow-xs:0 1px 3px rgba(15,23,42,0.04);
  --shadow-sm:0 2px 12px rgba(15,23,42,0.06);
  --shadow-md:0 8px 30px rgba(15,23,42,0.08);
  --shadow-lg:0 16px 50px rgba(15,23,42,0.12);
  --transition:all 0.3s ease;
  --font:"PingFang SC","Microsoft YaHei","Segoe UI",Roboto,sans-serif;
}
*,*::before,*::after{box-sizing:border-box;margin:0;padding:0}
html{scroll-behavior:smooth}
body{
  font-family:var(--font);
  background:var(--bg);
  color:var(--text);
  line-height:1.7;
  font-size:16px;
  -webkit-font-smoothing:antialiased;
}
img{max-width:100%;display:block}
a{text-decoration:none;color:inherit;transition:var(--transition)}
button{font-family:var(--font);cursor:pointer;border:none;background:none;transition:var(--transition)}
input,textarea{font-family:var(--font)}
.container{max-width:1200px;margin:0 auto;padding:0 24px;width:100%}

/* Header */
.site-header{
  position:sticky;top:0;z-index:1000;background:rgba(255,255,255,0.92);backdrop-filter:blur(16px);-webkit-backdrop-filter:blur(16px);
  border-bottom:1px solid var(--border);
  box-shadow:0 2px 20px rgba(15,23,42,0.04);
}
.header-row{
  display:flex;align-items:center;justify-content:center;gap:48px;height:76px;position:relative;
}
.brand-logo{
  font-size:24px;font-weight:800;color:var(--primary);letter-spacing:0.5px;display:flex;align-items:center;gap:8px;flex-shrink:0;
}
.brand-logo i{font-size:22px;color:var(--accent)}
.brand-logo:hover{color:var(--primary-dark)}
.nav-left,.nav-right{display:flex;align-items:center;gap:8px}
.nav-link{
  display:inline-flex;align-items:center;gap:6px;padding:8px 18px;border-radius:20px;font-size:15px;font-weight:500;color:var(--text);
  transition:var(--transition);
}
.nav-link:hover{color:var(--primary);background:var(--primary-light)}
.nav-link.active{color:var(--primary);background:var(--primary-light);font-weight:600}
.mobile-toggle{display:none;position:absolute;right:24px;top:50%;transform:translateY(-50%);font-size:22px;color:var(--text);padding:8px;border-radius:8px}
.mobile-toggle:hover{background:var(--bg-gray)}
.mobile-nav{display:none;flex-direction:column;padding:12px 24px 20px;border-top:1px solid var(--border);background:#fff}
.mobile-nav.open{display:flex}
.mobile-link{padding:14px 12px;border-radius:10px;font-size:15px;font-weight:500;color:var(--text);border-bottom:1px solid var(--bg-gray)}
.mobile-link:last-child{border-bottom:none}
.mobile-link:hover{background:var(--primary-light);color:var(--primary)}
.mobile-link.active{color:var(--primary);font-weight:600}

/* Hero */
.hero{
  position:relative;background:linear-gradient(135deg,rgba(15,23,42,0.88) 0%,rgba(30,27,75,0.85) 50%,rgba(6,182,212,0.7) 100%),url('/assets/images/backpic/back-1.png') center/cover no-repeat;
  color:#fff;padding:120px 0 100px;overflow:hidden;
}
.hero-inner{max-width:860px;margin:0 auto;text-align:center}
.hero-badge{
  display:inline-flex;align-items:center;gap:8px;background:rgba(255,255,255,0.12);border:1px solid rgba(255,255,255,0.25);
  padding:8px 20px;border-radius:30px;font-size:14px;font-weight:500;letter-spacing:0.5px;margin-bottom:28px;backdrop-filter:blur(8px);
}
.hero-badge i{color:var(--accent)}
.hero h1{
  font-size:52px;line-height:1.2;font-weight:800;margin-bottom:20px;letter-spacing:1px;
}
.hero h1 span{background:linear-gradient(135deg,#c7d2fe,#22d3ee);-webkit-background-clip:text;-webkit-text-fill-color:transparent;background-clip:text}
.hero-sub{
  font-size:18px;color:rgba(255,255,255,0.85);max-width:640px;margin:0 auto 40px;line-height:1.8;
}
.hero-btns{display:flex;gap:16px;justify-content:center;flex-wrap:wrap;margin-bottom:56px}
.btn{
  display:inline-flex;align-items:center;gap:10px;padding:14px 32px;border-radius:50px;font-size:16px;font-weight:600;
  transition:var(--transition);border:1px solid transparent;letter-spacing:0.5px;
}
.btn-primary{background:var(--primary);color:#fff;box-shadow:0 8px 30px rgba(79,70,229,0.35)}
.btn-primary:hover{background:var(--primary-dark);transform:translateY(-2px);box-shadow:0 12px 36px rgba(79,70,229,0.45)}
.btn-ghost{background:rgba(255,255,255,0.1);color:#fff;border-color:rgba(255,255,255,0.4);backdrop-filter:blur(4px)}
.btn-ghost:hover{background:rgba(255,255,255,0.2);transform:translateY(-2px)}
.hero-stats{
  display:flex;justify-content:center;gap:64px;padding-top:48px;border-top:1px solid rgba(255,255,255,0.15);flex-wrap:wrap;
}
.hero-stat{text-align:center}
.hero-stat .num{font-size:32px;font-weight:800;color:#fff;display:block;line-height:1.2}
.hero-stat .lbl{font-size:13px;color:rgba(255,255,255,0.7);margin-top:4px;letter-spacing:0.5px}

/* Sections */
.section{padding:96px 0}
.section-head{text-align:center;max-width:720px;margin:0 auto 56px}
.section-tag{display:inline-block;background:var(--primary-light);color:var(--primary);font-size:13px;font-weight:600;padding:6px 18px;border-radius:20px;letter-spacing:1px;margin-bottom:16px}
.section-title{font-size:38px;font-weight:800;line-height:1.3;margin-bottom:16px;color:var(--text)}
.section-sub{font-size:16px;color:var(--text-muted);line-height:1.7}

/* Features */
.features{background:var(--card)}
.features-grid{display:grid;grid-template-columns:repeat(4,1fr);gap:24px}
.feat-card{
  background:#fff;border:1px solid var(--border);border-radius:var(--radius-md);padding:40px 28px;text-align:center;
  transition:var(--transition);position:relative;overflow:hidden;
}
.feat-card::before{content:'';position:absolute;top:0;left:0;right:0;height:4px;background:linear-gradient(90deg,var(--primary),var(--accent));opacity:0;transition:var(--transition)}
.feat-card:hover{box-shadow:var(--shadow-md);transform:translateY(-6px);border-color:transparent}
.feat-card:hover::before{opacity:1}
.feat-icon{
  width:64px;height:64px;border-radius:18px;background:var(--primary-light);display:flex;align-items:center;justify-content:center;margin:0 auto 20px;font-size:26px;color:var(--primary);
}
.feat-card:nth-child(2) .feat-icon{background:var(--accent-light);color:var(--accent)}
.feat-card:nth-child(3) .feat-icon{background:#ecfdf5;color:#10b981}
.feat-card:nth-child(4) .feat-icon{background:#fef3c7;color:#f59e0b}
.feat-card h3{font-size:19px;font-weight:700;margin-bottom:10px}
.feat-card p{font-size:14px;color:var(--text-muted);line-height:1.7}

/* Category Entry */
.category-section{background:var(--bg)}
.category-card{
  display:grid;grid-template-columns:1fr 1fr;gap:48px;background:#fff;border-radius:var(--radius-lg);overflow:hidden;
  box-shadow:var(--shadow-md);border:1px solid var(--border);align-items:center;
}
.category-img{position:relative;min-height:340px;overflow:hidden}
.category-img img{width:100%;height:100%;object-fit:cover;position:absolute;inset:0;transition:transform 0.6s ease}
.category-card:hover .category-img img{transform:scale(1.05)}
.category-body{padding:48px 48px 48px 0}
.category-body .tag{display:inline-block;background:var(--primary-light);color:var(--primary);font-size:13px;font-weight:600;padding:5px 16px;border-radius:20px;margin-bottom:16px}
.category-body h3{font-size:28px;font-weight:800;margin-bottom:14px}
.category-body p{color:var(--text-muted);font-size:15px;line-height:1.8;margin-bottom:24px}
.category-links{display:flex;gap:16px;flex-wrap:wrap}
.category-links a.btn{font-size:14px;padding:10px 24px}

/* News */
.news-section{background:var(--card)}
.news-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:24px}
.news-card{
  background:#fff;border:1px solid var(--border);border-radius:var(--radius-md);padding:28px;display:flex;flex-direction:column;
  transition:var(--transition);position:relative;
}
.news-card:hover{box-shadow:var(--shadow-md);transform:translateY(-4px);border-color:var(--primary)}
.news-meta{display:flex;align-items:center;gap:12px;margin-bottom:14px}
.news-category{background:var(--primary-light);color:var(--primary);font-size:12px;font-weight:600;padding:3px 12px;border-radius:14px}
.news-date{font-size:12px;color:var(--text-muted)}
.news-title{font-size:17px;font-weight:700;line-height:1.5;margin-bottom:8px;flex-grow:1}
.news-card:hover .news-title{color:var(--primary)}
.news-summary{font-size:13px;color:var(--text-muted);line-height:1.6;margin-bottom:16px;display:-webkit-box;-webkit-line-clamp:2;-webkit-box-orient:vertical;overflow:hidden}
.news-link{display:inline-flex;align-items:center;gap:6px;font-size:14px;font-weight:600;color:var(--primary)}
.news-link i{font-size:12px;transition:transform 0.3s}
.news-card:hover .news-link i{transform:translateX(4px)}
.news-empty{
  text-align:center;padding:60px 20px;background:var(--bg-gray);border-radius:var(--radius-md);color:var(--text-muted);font-size:16px;
}

/* Process */
.process-section{background:var(--bg)}
.process-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:32px;position:relative}
.process-grid::before{
  content:'';position:absolute;top:48px;left:15%;right:15%;height:2px;background:linear-gradient(90deg,var(--primary),var(--accent));opacity:0.3;
}
.process-step{text-align:center;padding:0 16px;position:relative}
.step-num{
  width:64px;height:64px;border-radius:50%;background:linear-gradient(135deg,var(--primary),var(--accent));color:#fff;
  display:flex;align-items:center;justify-content:center;font-size:22px;font-weight:700;margin:0 auto 24px;box-shadow:0 8px 30px rgba(79,70,229,0.3);
  position:relative;z-index:1;
}
.process-step h3{font-size:19px;font-weight:700;margin-bottom:10px}
.process-step p{font-size:14px;color:var(--text-muted);line-height:1.7}

/* Showcase */
.showcase-section{background:var(--card)}
.showcase-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:28px}
.showcase-card{
  background:#fff;border:1px solid var(--border);border-radius:var(--radius-md);overflow:hidden;transition:var(--transition);
  display:flex;flex-direction:column;
}
.showcase-card:hover{box-shadow:var(--shadow-lg);transform:translateY(-8px)}
.showcase-img{position:relative;height:220px;overflow:hidden}
.showcase-img img{width:100%;height:100%;object-fit:cover;transition:transform 0.5s ease}
.showcase-card:hover .showcase-img img{transform:scale(1.06)}
.showcase-body{padding:28px;flex-grow:1;display:flex;flex-direction:column}
.showcase-body .badge{display:inline-block;background:var(--accent-light);color:var(--accent);font-size:12px;font-weight:600;padding:3px 12px;border-radius:14px;margin-bottom:12px;align-self:flex-start}
.showcase-body h3{font-size:18px;font-weight:700;margin-bottom:8px}
.showcase-body p{font-size:14px;color:var(--text-muted);line-height:1.7;flex-grow:1}

/* FAQ */
.faq-section{background:var(--bg)}
.faq-list{max-width:800px;margin:0 auto}
.faq-item{
  background:#fff;border:1px solid var(--border);border-radius:var(--radius-md);margin-bottom:16px;overflow:hidden;
  transition:var(--transition);
}
.faq-item:hover{border-color:var(--primary)}
.faq-item summary{
  padding:22px 28px;font-size:16px;font-weight:600;cursor:pointer;list-style:none;display:flex;align-items:center;justify-content:space-between;gap:16px;
}
.faq-item summary::-webkit-details-marker{display:none}
.faq-item summary::after{content:'\f078';font-family:'Font Awesome 6 Free';font-weight:900;font-size:14px;color:var(--text-muted);transition:var(--transition)}
.faq-item[open] summary::after{transform:rotate(180deg);color:var(--primary)}
.faq-item[open] summary{border-bottom:1px solid var(--border);background:var(--primary-light)}
.faq-answer{padding:20px 28px;font-size:15px;color:var(--text-muted);line-height:1.8;background:#fff}

/* CTA */
.cta-section{
  position:relative;background:linear-gradient(135deg,rgba(15,23,42,0.92),rgba(30,27,75,0.88)),url('/assets/images/backpic/back-2.png') center/cover no-repeat;
  color:#fff;padding:100px 0;text-align:center;
}
.cta-inner{max-width:700px;margin:0 auto}
.cta-inner h2{font-size:38px;font-weight:800;margin-bottom:16px}
.cta-inner p{font-size:17px;color:rgba(255,255,255,0.8);margin-bottom:36px;line-height:1.8}
.cta-inner .btn-primary{background:#fff;color:var(--primary);box-shadow:0 8px 30px rgba(255,255,255,0.25)}
.cta-inner .btn-primary:hover{background:var(--primary-light);transform:translateY(-2px)}

/* Footer */
.site-footer{background:var(--bg-dark);color:#94a3b8;padding:64px 0 32px}
.footer-grid{display:grid;grid-template-columns:2fr 1fr 1fr;gap:48px;margin-bottom:48px}
.footer-brand .brand-logo{color:#fff;font-size:24px;margin-bottom:16px;display:inline-flex;align-items:center;gap:8px}
.footer-brand .brand-logo i{color:var(--accent)}
.footer-brand p{font-size:14px;line-height:1.8;max-width:320px}
.footer-col h4{color:#fff;font-size:15px;font-weight:600;margin-bottom:18px;letter-spacing:0.5px}
.footer-col a{display:block;font-size:14px;color:#94a3b8;padding:6px 0;transition:var(--transition)}
.footer-col a:hover{color:#fff;padding-left:4px}
.footer-bottom{
  border-top:1px solid rgba(255,255,255,0.08);padding-top:28px;text-align:center;font-size:13px;color:#64748b;
}
.footer-bottom a{color:#94a3b8}

/* Responsive */
@media(max-width:1024px){
  .features-grid{grid-template-columns:repeat(2,1fr)}
  .news-grid{grid-template-columns:repeat(2,1fr)}
  .showcase-grid{grid-template-columns:repeat(2,1fr)}
  .process-grid::before{left:10%;right:10%}
  .header-row{gap:24px}
}
@media(max-width:768px){
  .section{padding:64px 0}
  .hero{padding:80px 0 64px}
  .hero h1{font-size:36px}
  .nav-left,.nav-right{display:none}
  .mobile-toggle{display:flex}
  .header-row{justify-content:center;height:64px}
  .brand-logo{font-size:20px}
  .features-grid{grid-template-columns:1fr}
  .category-card{grid-template-columns:1fr}
  .category-body{padding:32px}
  .category-img{min-height:240px}
  .news-grid{grid-template-columns:1fr}
  .showcase-grid{grid-template-columns:1fr}
  .process-grid{grid-template-columns:1fr;gap:48px}
  .process-grid::before{display:none}
  .hero-stats{gap:32px}
  .hero-stat .num{font-size:24px}
  .section-title{font-size:28px}
  .footer-grid{grid-template-columns:1fr;gap:32px}
  .cta-inner h2{font-size:28px}
  .faq-item summary{padding:18px 20px;font-size:15px}
  .faq-answer{padding:16px 20px}
  .hero-btns{flex-direction:column;align-items:center}
  .btn{width:100%;max-width:300px;justify-content:center}
}
@media(max-width:520px){
  .container{padding:0 16px}
  .hero h1{font-size:28px}
  .hero-sub{font-size:15px}
  .section-title{font-size:24px}
  .feat-card{padding:28px 20px}
  .category-body{padding:24px}
  .news-card{padding:20px}
  .footer-bottom{font-size:12px}
}

/* Focus states */
a:focus-visible,button:focus-visible,summary:focus-visible{
  outline:3px solid var(--accent);outline-offset:2px;border-radius:4px;
}

/* roulang page: article */
:root {
  --primary: #2563eb;
  --primary-dark: #1e40af;
  --primary-light: #60a5fa;
  --accent: #0ea5e9;
  --accent-warm: #f59e0b;
  --bg: #f8fafc;
  --bg-alt: #f1f5f9;
  --surface: #ffffff;
  --text: #0f172a;
  --text-weak: #64748b;
  --text-soft: #94a3b8;
  --border: #e2e8f0;
  --border-strong: #cbd5e1;
  --radius-sm: 8px;
  --radius: 16px;
  --radius-lg: 24px;
  --shadow-sm: 0 1px 2px rgba(15, 23, 42, 0.04);
  --shadow: 0 4px 6px -1px rgba(15, 23, 42, 0.08), 0 2px 4px -2px rgba(15, 23, 42, 0.04);
  --shadow-md: 0 10px 15px -3px rgba(15, 23, 42, 0.08), 0 4px 6px -4px rgba(15, 23, 42, 0.05);
  --shadow-lg: 0 20px 25px -5px rgba(15, 23, 42, 0.1), 0 8px 10px -6px rgba(15, 23, 42, 0.06);
  --space-xs: 0.5rem;
  --space-sm: 0.75rem;
  --space-md: 1rem;
  --space-lg: 1.5rem;
  --space-xl: 2rem;
  --space-2xl: 3rem;
  --space-3xl: 4rem;
  --container: 1200px;
  --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;
  --font-serif: "Georgia", "Songti SC", "SimSun", serif;
}

*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  scroll-behavior: smooth;
  font-size: 16px;
  -webkit-text-size-adjust: 100%;
}

body {
  font-family: var(--font-sans);
  font-size: 1rem;
  line-height: 1.75;
  color: var(--text);
  background-color: var(--bg);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

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

a {
  color: var(--primary);
  text-decoration: none;
  transition: color 0.2s ease;
}

a:hover {
  color: var(--primary-dark);
}

button {
  font-family: inherit;
  cursor: pointer;
  border: none;
  background: none;
}

input, textarea, select {
  font-family: inherit;
  font-size: 1rem;
}

.container {
  max-width: var(--container);
  margin: 0 auto;
  padding: 0 var(--space-lg);
  width: 100%;
}

/* ==================== Header / Nav ==================== */
.site-header {
  background: rgba(255, 255, 255, 0.92);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border);
  position: sticky;
  top: 0;
  z-index: 100;
  box-shadow: var(--shadow-sm);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-xl);
  min-height: 76px;
  position: relative;
}

.brand-logo {
  font-size: 1.4rem;
  font-weight: 800;
  letter-spacing: -0.02em;
  color: var(--text);
  display: flex;
  align-items: center;
  gap: 0.5rem;
  white-space: nowrap;
}

.brand-logo i {
  color: var(--primary);
  font-size: 1.35rem;
}

.brand-logo span {
  background: linear-gradient(135deg, var(--primary), var(--accent));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.nav-left,
.nav-right {
  display: flex;
  align-items: center;
  gap: var(--space-md);
}

.nav-right {
  position: absolute;
  right: 0;
  top: 50%;
  transform: translateY(-50%);
}

.nav-left {
  position: absolute;
  left: 0;
  top: 50%;
  transform: translateY(-50%);
}

.nav-link {
  color: var(--text-weak);
  font-size: 0.95rem;
  font-weight: 500;
  padding: 0.5rem 0.85rem;
  border-radius: var(--radius-sm);
  transition: all 0.2s ease;
  display: flex;
  align-items: center;
  gap: 0.4rem;
}

.nav-link:hover {
  color: var(--primary);
  background: var(--bg-alt);
}

.nav-link.active {
  color: var(--primary);
  font-weight: 600;
  background: rgba(37, 99, 235, 0.08);
}

.nav-cta {
  background: var(--primary);
  color: #fff;
  padding: 0.5rem 1.25rem;
  border-radius: 999px;
  font-weight: 600;
  font-size: 0.9rem;
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  transition: all 0.2s ease;
  box-shadow: 0 2px 8px rgba(37, 99, 235, 0.3);
}

.nav-cta:hover {
  background: var(--primary-dark);
  color: #fff;
  transform: translateY(-2px);
  box-shadow: 0 4px 16px rgba(37, 99, 235, 0.35);
}

.header-mobile-toggle {
  display: none;
  font-size: 1.4rem;
  color: var(--text);
  background: none;
  border: none;
  padding: 0.5rem;
  cursor: pointer;
}

/* ==================== Breadcrumb ==================== */
.breadcrumb-wrap {
  background: linear-gradient(135deg, rgba(37, 99, 235, 0.06), rgba(14, 165, 233, 0.06));
  border-bottom: 1px solid var(--border);
  padding: 1.2rem 0;
}

.breadcrumb {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  font-size: 0.9rem;
  color: var(--text-weak);
  flex-wrap: wrap;
}

.breadcrumb i {
  font-size: 0.8rem;
  color: var(--text-soft);
}

.breadcrumb a {
  color: var(--primary);
  font-weight: 500;
}

.breadcrumb a:hover {
  color: var(--primary-dark);
}

.breadcrumb .current {
  color: var(--text);
  font-weight: 600;
}

/* ==================== Article Layout ==================== */
.article-layout {
  padding: var(--space-2xl) 0;
}

.article-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 340px;
  gap: var(--space-2xl);
  align-items: start;
}

.article-main {
  background: var(--surface);
  border-radius: var(--radius-lg);
  border: 1px solid var(--border);
  box-shadow: var(--shadow-sm);
  overflow: hidden;
  min-width: 0;
}

.article-hero-image {
  position: relative;
  height: 380px;
  background: linear-gradient(135deg, var(--primary-dark), var(--accent));
  display: flex;
  align-items: center;
  justify-content: center;
  overflow: hidden;
}

.article-hero-image::before {
  content: '';
  position: absolute;
  inset: 0;
  background-image: url('/assets/images/backpic/back-2.png');
  background-size: cover;
  background-position: center;
  opacity: 0.35;
}

.article-hero-image::after {
  content: '';
  position: absolute;
  inset: 0;
  background: linear-gradient(to top, rgba(15, 23, 42, 0.6), transparent);
}

.article-hero-image .hero-icon {
  position: relative;
  z-index: 2;
  font-size: 4rem;
  color: #fff;
  text-shadow: 0 4px 20px rgba(0, 0, 0, 0.3);
}

.article-header {
  padding: var(--space-2xl) var(--space-2xl) var(--space-lg);
}

.article-category-badge {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  background: linear-gradient(135deg, var(--primary), var(--accent));
  color: #fff;
  font-size: 0.8rem;
  font-weight: 600;
  padding: 0.3rem 0.9rem;
  border-radius: 999px;
  margin-bottom: var(--space-md);
  box-shadow: 0 2px 10px rgba(37, 99, 235, 0.3);
}

.article-title {
  font-size: 2.1rem;
  font-weight: 800;
  line-height: 1.35;
  color: var(--text);
  letter-spacing: -0.02em;
  margin-bottom: var(--space-md);
}

.article-meta {
  display: flex;
  align-items: center;
  gap: var(--space-lg);
  color: var(--text-weak);
  font-size: 0.9rem;
  flex-wrap: wrap;
  padding-top: var(--space-md);
  border-top: 1px solid var(--border);
}

.article-meta-item {
  display: flex;
  align-items: center;
  gap: 0.4rem;
}

.article-meta-item i {
  color: var(--primary-light);
  font-size: 0.9rem;
}

.article-body {
  padding: var(--space-lg) var(--space-2xl) var(--space-2xl);
  font-size: 1.02rem;
  line-height: 1.9;
  color: #1e293b;
}

.article-body p {
  margin-bottom: 1.5rem;
}

.article-body h2 {
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--text);
  margin: 2rem 0 1rem;
  padding-bottom: 0.6rem;
  border-bottom: 2px solid var(--border);
  position: relative;
}

.article-body h2::after {
  content: '';
  position: absolute;
  bottom: -2px;
  left: 0;
  width: 48px;
  height: 2px;
  background: linear-gradient(90deg, var(--primary), var(--accent));
}

.article-body h3 {
  font-size: 1.2rem;
  font-weight: 700;
  color: var(--text);
  margin: 1.8rem 0 0.8rem;
}

.article-body ul,
.article-body ol {
  margin: 0 0 1.5rem 1.2rem;
  padding-left: 0.5rem;
}

.article-body li {
  margin-bottom: 0.5rem;
}

.article-body ul li {
  position: relative;
  padding-left: 0.5rem;
}

.article-body ul li::marker {
  color: var(--primary);
}

.article-body ol li::marker {
  color: var(--primary);
  font-weight: 600;
}

.article-body blockquote {
  border-left: 4px solid var(--primary);
  background: var(--bg-alt);
  padding: 1rem 1.5rem;
  margin: 1.5rem 0;
  border-radius: 0 var(--radius) var(--radius) 0;
  font-style: italic;
  color: var(--text-weak);
}

.article-body code {
  background: var(--bg-alt);
  border: 1px solid var(--border);
  border-radius: 4px;
  padding: 0.2rem 0.4rem;
  font-size: 0.9em;
  font-family: "SF Mono", "Cascadia Code", Consolas, monospace;
}

.article-body pre {
  background: #0f172a;
  color: #e2e8f0;
  padding: 1.2rem;
  border-radius: var(--radius);
  overflow-x: auto;
  margin: 1.5rem 0;
}

.article-body pre code {
  background: transparent;
  border: none;
  padding: 0;
  color: inherit;
}

.article-body img {
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  margin: 1.5rem 0;
}

.article-body a {
  color: var(--primary);
  text-decoration: underline;
  text-underline-offset: 3px;
  text-decoration-color: rgba(37, 99, 235, 0.3);
}

.article-body a:hover {
  color: var(--primary-dark);
  text-decoration-color: var(--primary-dark);
}

.article-body table {
  width: 100%;
  border-collapse: collapse;
  margin: 1.5rem 0;
  font-size: 0.95rem;
}

.article-body th,
.article-body td {
  border: 1px solid var(--border);
  padding: 0.8rem 1rem;
  text-align: left;
}

.article-body th {
  background: var(--bg-alt);
  font-weight: 600;
  color: var(--text);
}

/* ==================== Article Sidebar ==================== */
.article-sidebar {
  display: flex;
  flex-direction: column;
  gap: var(--space-xl);
  position: sticky;
  top: 100px;
}

.sidebar-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  box-shadow: var(--shadow-sm);
  padding: var(--space-lg);
}

.sidebar-card-title {
  font-size: 1.1rem;
  font-weight: 700;
  color: var(--text);
  margin-bottom: var(--space-md);
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.sidebar-card-title i {
  color: var(--primary);
}

.sidebar-card-title::after {
  content: '';
  flex: 1;
  height: 2px;
  background: linear-gradient(90deg, var(--primary-light), transparent);
  border-radius: 2px;
}

.sidebar-list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 0.4rem;
}

.sidebar-list li {
  margin: 0;
  padding: 0;
}

.sidebar-list a {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  color: var(--text-weak);
  padding: 0.6rem 0.8rem;
  border-radius: var(--radius-sm);
  font-size: 0.92rem;
  transition: all 0.2s ease;
}

.sidebar-list a:hover,
.sidebar-list a.active {
  color: var(--primary);
  background: rgba(37, 99, 235, 0.06);
  font-weight: 500;
}

.sidebar-list a i {
  font-size: 0.8rem;
  color: var(--primary-light);
  width: 16px;
  text-align: center;
}

.sidebar-tag-cloud {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
}

.sidebar-tag {
  display: inline-flex;
  align-items: center;
  gap: 0.3rem;
  background: var(--bg-alt);
  border: 1px solid var(--border);
  color: var(--text-weak);
  font-size: 0.82rem;
  padding: 0.3rem 0.8rem;
  border-radius: 999px;
  transition: all 0.2s ease;
}

.sidebar-tag:hover {
  background: var(--primary);
  border-color: var(--primary);
  color: #fff;
  transform: translateY(-2px);
  box-shadow: 0 4px 12px rgba(37, 99, 235, 0.2);
}

.sidebar-cta-box {
  background: linear-gradient(135deg, var(--primary-dark), var(--accent));
  border: none;
  color: #fff;
  position: relative;
  overflow: hidden;
}

.sidebar-cta-box::before {
  content: '';
  position: absolute;
  inset: 0;
  background-image: url('/assets/images/coverpic/cover-3.png');
  background-size: cover;
  background-position: center;
  opacity: 0.15;
}

.sidebar-cta-box .sidebar-card-title {
  color: #fff;
  position: relative;
  z-index: 1;
}

.sidebar-cta-box .sidebar-card-title i {
  color: var(--accent-warm);
}

.sidebar-cta-box .sidebar-card-title::after {
  background: linear-gradient(90deg, rgba(255, 255, 255, 0.4), transparent);
}

.sidebar-cta-text {
  font-size: 0.9rem;
  line-height: 1.6;
  color: rgba(255, 255, 255, 0.9);
  margin-bottom: var(--space-md);
  position: relative;
  z-index: 1;
}

.sidebar-cta-btn {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  background: #fff;
  color: var(--primary-dark);
  font-weight: 600;
  font-size: 0.9rem;
  padding: 0.6rem 1.2rem;
  border-radius: 999px;
  transition: all 0.2s ease;
  position: relative;
  z-index: 1;
}

.sidebar-cta-btn:hover {
  transform: translateY(-2px);
  box-shadow: 0 6px 20px rgba(255, 255, 255, 0.2);
  color: var(--primary);
}

/* ==================== Article Footer / Share ==================== */
.article-footer {
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: var(--space-md);
  margin-top: var(--space-2xl);
  padding-top: var(--space-lg);
  border-top: 1px solid var(--border);
}

.article-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
}

.article-tag {
  font-size: 0.8rem;
  color: var(--text-weak);
  background: var(--bg-alt);
  border: 1px solid var(--border);
  padding: 0.25rem 0.8rem;
  border-radius: 999px;
  transition: all 0.2s;
}

.article-tag:hover {
  background: var(--primary);
  border-color: var(--primary);
  color: #fff;
}

.article-share {
  display: flex;
  gap: 0.5rem;
}

.share-btn {
  width: 40px;
  height: 40px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--bg-alt);
  color: var(--text-weak);
  font-size: 1rem;
  transition: all 0.2s ease;
  border: 1px solid var(--border);
}

.share-btn:hover {
  background: var(--primary);
  color: #fff;
  border-color: var(--primary);
  transform: translateY(-2px);
  box-shadow: 0 4px 12px rgba(37, 99, 235, 0.3);
}

/* ==================== Related Posts ==================== */
.related-section {
  padding: var(--space-2xl) 0;
  background: var(--bg-alt);
  border-top: 1px solid var(--border);
}

.section-header {
  text-align: center;
  margin-bottom: var(--space-2xl);
}

.section-subtitle {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  background: rgba(37, 99, 235, 0.08);
  color: var(--primary);
  font-size: 0.85rem;
  font-weight: 600;
  padding: 0.3rem 1rem;
  border-radius: 999px;
  margin-bottom: var(--space-sm);
}

.section-title {
  font-size: 2rem;
  font-weight: 800;
  color: var(--text);
  letter-spacing: -0.02em;
  line-height: 1.3;
}

.section-desc {
  color: var(--text-weak);
  font-size: 1rem;
  max-width: 640px;
  margin: 0.8rem auto 0;
}

.related-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--space-lg);
}

.related-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  overflow: hidden;
  transition: all 0.3s ease;
  display: flex;
  flex-direction: column;
  box-shadow: var(--shadow-sm);
}

.related-card:hover {
  transform: translateY(-6px);
  box-shadow: var(--shadow-lg);
  border-color: var(--border-strong);
}

.related-card-image {
  height: 160px;
  background: linear-gradient(135deg, var(--primary-light), var(--accent));
  position: relative;
  overflow: hidden;
}

.related-card-image img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform 0.5s ease;
}

.related-card:hover .related-card-image img {
  transform: scale(1.05);
}

.related-card-body {
  padding: var(--space-lg);
  flex: 1;
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}

.related-card-body h3 {
  font-size: 1.05rem;
  font-weight: 700;
  line-height: 1.5;
  color: var(--text);
}

.related-card-body h3 a {
  color: var(--text);
}

.related-card-body h3 a:hover {
  color: var(--primary);
}

.related-card-body p {
  font-size: 0.9rem;
  color: var(--text-weak);
  line-height: 1.6;
  flex: 1;
}

.related-card-meta {
  display: flex;
  align-items: center;
  justify-content: space-between;
  font-size: 0.82rem;
  color: var(--text-soft);
  border-top: 1px solid var(--border);
  padding-top: 0.75rem;
  margin-top: auto;
}

/* ==================== CTA Section ==================== */
.cta-section {
  background: linear-gradient(135deg, var(--primary-dark) 0%, var(--accent) 100%);
  padding: var(--space-2xl) 0;
  position: relative;
  overflow: hidden;
}

.cta-section::before {
  content: '';
  position: absolute;
  inset: 0;
  background-image: url('/assets/images/backpic/back-3.png');
  background-size: cover;
  background-position: center;
  opacity: 0.2;
}

.cta-inner {
  position: relative;
  z-index: 1;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-xl);
  flex-wrap: wrap;
}

.cta-content {
  color: #fff;
}

.cta-content h2 {
  font-size: 1.8rem;
  font-weight: 800;
  margin-bottom: 0.8rem;
  line-height: 1.3;
}

.cta-content p {
  color: rgba(255, 255, 255, 0.85);
  max-width: 540px;
  font-size: 0.95rem;
}

.cta-actions {
  display: flex;
  gap: var(--space-md);
  flex-wrap: wrap;
}

.cta-btn-primary {
  background: #fff;
  color: var(--primary-dark);
  font-weight: 700;
  padding: 0.8rem 1.8rem;
  border-radius: 999px;
  font-size: 0.95rem;
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  transition: all 0.2s ease;
}

.cta-btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 30px rgba(255, 255, 255, 0.25);
  color: var(--primary);
}

.cta-btn-ghost {
  border: 2px solid rgba(255, 255, 255, 0.6);
  color: #fff;
  font-weight: 600;
  padding: 0.7rem 1.6rem;
  border-radius: 999px;
  font-size: 0.95rem;
  transition: all 0.2s ease;
}

.cta-btn-ghost:hover {
  border-color: #fff;
  background: rgba(255, 255, 255, 0.1);
  color: #fff;
  transform: translateY(-2px);
}

/* ==================== Footer ==================== */
.site-footer {
  background: #0f172a;
  color: #94a3b8;
  padding: var(--space-3xl) 0 var(--space-lg);
  position: relative;
}

.site-footer::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: linear-gradient(90deg, var(--primary), var(--accent), var(--accent-warm), var(--primary));
  background-size: 200% 100%;
  animation: gradientMove 6s linear infinite;
}

@keyframes gradientMove {
  0% { background-position: 0% 50%; }
  100% { background-position: 200% 50%; }
}

.footer-grid {
  display: grid;
  grid-template-columns: 1.5fr 1fr 1fr;
  gap: var(--space-2xl);
  margin-bottom: var(--space-3xl);
}

.footer-brand .brand-logo {
  color: #fff;
  font-size: 1.3rem;
  margin-bottom: var(--space-md);
}

.footer-brand .brand-logo i {
  color: var(--primary-light);
}

.footer-brand p {
  font-size: 0.92rem;
  line-height: 1.7;
  color: #94a3b8;
  max-width: 360px;
}

.footer-col h4 {
  color: #fff;
  font-size: 1rem;
  font-weight: 600;
  margin-bottom: var(--space-md);
  position: relative;
  padding-bottom: 0.6rem;
}

.footer-col h4::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 32px;
  height: 2px;
  background: var(--primary);
  border-radius: 2px;
}

.footer-col a {
  display: block;
  color: #94a3b8;
  font-size: 0.92rem;
  padding: 0.35rem 0;
  transition: all 0.2s ease;
}

.footer-col a:hover {
  color: #fff;
  padding-left: 0.5rem;
}

.footer-col a i {
  margin-right: 0.4rem;
  font-size: 0.8rem;
  color: var(--primary-light);
}

.footer-bottom {
  border-top: 1px solid rgba(148, 163, 184, 0.15);
  padding-top: var(--space-lg);
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: var(--space-md);
  font-size: 0.85rem;
  color: #64748b;
}

.footer-bottom-links {
  display: flex;
  gap: var(--space-lg);
}

.footer-bottom-links a {
  color: #64748b;
  font-size: 0.85rem;
}

.footer-bottom-links a:hover {
  color: #fff;
}

/* ==================== Empty / Error State ==================== */
.empty-state {
  text-align: center;
  padding: var(--space-3xl) var(--space-xl);
}

.empty-state-icon {
  font-size: 4rem;
  color: var(--primary-light);
  margin-bottom: var(--space-lg);
  opacity: 0.6;
}

.empty-state h2 {
  font-size: 1.8rem;
  font-weight: 800;
  color: var(--text);
  margin-bottom: var(--space-md);
}

.empty-state p {
  color: var(--text-weak);
  font-size: 1rem;
  margin-bottom: var(--space-xl);
}

.empty-state .btn-back {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  background: var(--primary);
  color: #fff;
  font-weight: 600;
  padding: 0.75rem 1.8rem;
  border-radius: 999px;
  transition: all 0.2s ease;
  box-shadow: 0 4px 16px rgba(37, 99, 235, 0.25);
}

.empty-state .btn-back:hover {
  background: var(--primary-dark);
  color: #fff;
  transform: translateY(-2px);
  box-shadow: 0 6px 24px rgba(37, 99, 235, 0.35);
}

/* ==================== Mobile Menu ==================== */
.mobile-menu {
  display: none;
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: rgba(255, 255, 255, 0.98);
  z-index: 200;
  padding: 2rem;
  flex-direction: column;
  gap: 1rem;
  backdrop-filter: blur(20px);
}

.mobile-menu.open {
  display: flex;
}

.mobile-menu-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 1rem;
}

.mobile-menu-close {
  font-size: 1.6rem;
  color: var(--text);
  background: none;
  border: none;
  cursor: pointer;
  padding: 0.5rem;
}

.mobile-menu a {
  display: flex;
  align-items: center;
  gap: 0.8rem;
  padding: 1rem;
  border-radius: var(--radius);
  color: var(--text);
  font-size: 1.1rem;
  font-weight: 500;
  border-bottom: 1px solid var(--border);
}

.mobile-menu a.active {
  background: rgba(37, 99, 235, 0.08);
  color: var(--primary);
}

.mobile-menu a i {
  width: 24px;
  text-align: center;
  color: var(--primary-light);
}

/* ==================== Responsive ==================== */
@media (max-width: 1024px) {
  .article-grid {
    grid-template-columns: 1fr;
    gap: var(--space-xl);
  }
  
  .article-sidebar {
    position: static;
    flex-direction: row;
    flex-wrap: wrap;
  }
  
  .sidebar-card {
    flex: 1;
    min-width: 260px;
  }

  .related-grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .header-inner {
    gap: var(--space-lg);
  }
  
  .nav-link {
    padding: 0.5rem 0.7rem;
    font-size: 0.9rem;
  }
}

@media (max-width: 768px) {
  .header-inner {
    justify-content: flex-start;
    min-height: 64px;
    gap: 0;
  }
  
  .header-mobile-toggle {
    display: block;
    font-size: 1.3rem;
    padding: 0.5rem;
    color: var(--text);
    margin-right: 0.5rem;
  }
  
  .brand-logo {
    font-size: 1.25rem;
    margin-left: 0.25rem;
  }
  
  .nav-left,
  .nav-right {
    display: none;
  }

  .article-hero-image {
    height: 260px;
  }
  
  .article-header {
    padding: var(--space-xl) var(--space-lg) var(--space-md);
  }
  
  .article-title {
    font-size: 1.5rem;
  }
  
  .article-body {
    padding: var(--space-lg) var(--space-lg) var(--space-xl);
    font-size: 0.98rem;
  }

  .article-meta {
    gap: var(--space-sm);
    flex-direction: column;
    align-items: flex-start;
  }

  .related-grid {
    grid-template-columns: 1fr;
  }

  .footer-grid {
    grid-template-columns: 1fr;
    gap: var(--space-xl);
  }

  .cta-inner {
    flex-direction: column;
    align-items: flex-start;
    text-align: left;
  }

  .article-footer {
    flex-direction: column;
    align-items: flex-start;
  }
}

@media (max-width: 520px) {
  .container {
    padding: 0 1rem;
  }
  
  .brand-logo {
    font-size: 1.1rem;
  }
  
  .brand-logo i {
    font-size: 1.1rem;
  }
  
  .article-title {
    font-size: 1.3rem;
  }
  
  .article-hero-image {
    height: 200px;
  }
  
  .section-title {
    font-size: 1.4rem;
  }
  
  .article-meta-item {
    font-size: 0.8rem;
    gap: 0.3rem;
  }
  
  .sidebar-card {
    min-width: 100%;
  }
  
  .breadcrumb {
    font-size: 0.8rem;
    gap: 0.3rem;
  }

  .cta-content h2 {
    font-size: 1.4rem;
  }
  
  .cta-actions {
    width: 100%;
  }
  
  .cta-btn-primary,
  .cta-btn-ghost {
    width: 100%;
    justify-content: center;
    text-align: center;
  }
  
  .footer-bottom {
    flex-direction: column;
    text-align: center;
    justify-content: center;
  }
  
  .footer-bottom-links {
    flex-wrap: wrap;
    justify-content: center;
    gap: 0.8rem;
  }
}

/* ==================== Print / Accessibility ==================== */
@media print {
  .site-header,
  .site-footer,
  .article-sidebar,
  .breadcrumb-wrap,
  .cta-section,
  .related-section {
    display: none;
  }
  
  .article-grid {
    display: block;
  }
  
  body {
    background: #fff;
  }
}

a:focus-visible,
button:focus-visible,
input:focus-visible {
  outline: 3px solid rgba(37, 99, 235, 0.4);
  outline-offset: 2px;
}

::selection {
  background: rgba(37, 99, 235, 0.15);
  color: var(--text);
}

::-webkit-scrollbar {
  width: 10px;
}

::-webkit-scrollbar-track {
  background: var(--bg);
}

::-webkit-scrollbar-thumb {
  background: var(--border-strong);
  border-radius: 5px;
}

::-webkit-scrollbar-thumb:hover {
  background: var(--primary-light);
}

/* roulang page: category1 */
:root {
      --primary: #2563eb;
      --primary-dark: #1e40af;
      --primary-light: #dbeafe;
      --accent: #06b6d4;
      --accent-light: #cffafe;
      --bg: #f8fafc;
      --bg-alt: #eef2f7;
      --dark: #0f172a;
      --text: #1e293b;
      --text-weak: #64748b;
      --border: #e2e8f0;
      --card-bg: #ffffff;
      --radius: 18px;
      --radius-sm: 10px;
      --shadow: 0 10px 30px rgba(15, 23, 42, 0.06);
      --shadow-lg: 0 24px 60px rgba(15, 23, 42, 0.12);
      --font-family: "Inter", "PingFang SC", "Microsoft YaHei", system-ui, -apple-system, sans-serif;
      --header-h: 76px;
      --space: 16px;
      --space-lg: 24px;
      --space-xl: 56px;
      --transition: .3s cubic-bezier(.4, 0, .2, 1);
    }

    *,
    *::before,
    *::after {
      box-sizing: border-box;
      margin: 0;
      padding: 0;
    }

    html {
      scroll-behavior: smooth;
      -webkit-text-size-adjust: 100%;
    }

    body {
      font-family: var(--font-family);
      font-size: 16px;
      line-height: 1.7;
      color: var(--text);
      background: var(--bg);
      min-height: 100vh;
    }

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

    a {
      text-decoration: none;
      color: inherit;
      transition: color var(--transition);
    }

    button {
      font-family: inherit;
      border: none;
      cursor: pointer;
      background: none;
    }

    input,
    textarea {
      font-family: inherit;
    }

    ul,
    ol {
      list-style: none;
    }

    :focus-visible {
      outline: 3px solid rgba(37, 99, 235, 0.4);
      outline-offset: 2px;
    }

    .container {
      width: 100%;
      max-width: 1200px;
      margin: 0 auto;
      padding: 0 var(--space-lg);
    }

    .site-header {
      position: sticky;
      top: 0;
      z-index: 1000;
      background: rgba(255, 255, 255, 0.85);
      backdrop-filter: blur(16px);
      -webkit-backdrop-filter: blur(16px);
      border-bottom: 1px solid rgba(226, 232, 240, 0.6);
      box-shadow: 0 2px 20px rgba(15, 23, 42, 0.04);
    }

    .header-inner {
      display: flex;
      align-items: center;
      justify-content: space-between;
      height: var(--header-h);
      position: relative;
    }

    .nav-left,
    .nav-right {
      display: flex;
      align-items: center;
      gap: 4px;
    }

    .nav-link {
      display: inline-flex;
      align-items: center;
      gap: 8px;
      padding: 10px 18px;
      border-radius: 999px;
      font-size: 15px;
      font-weight: 500;
      color: var(--text);
      transition: all var(--transition);
      white-space: nowrap;
    }

    .nav-link i {
      font-size: 14px;
      color: var(--text-weak);
      transition: color var(--transition);
    }

    .nav-link:hover {
      background: var(--bg-alt);
      color: var(--primary);
    }

    .nav-link:hover i {
      color: var(--primary);
    }

    .nav-link.active {
      background: var(--primary-light);
      color: var(--primary-dark);
      font-weight: 600;
    }

    .nav-link.active i {
      color: var(--primary);
    }

    .brand-logo {
      position: absolute;
      left: 50%;
      top: 50%;
      transform: translate(-50%, -50%);
      display: inline-flex;
      align-items: center;
      gap: 10px;
      font-size: 22px;
      font-weight: 800;
      letter-spacing: -0.02em;
      color: var(--dark);
      padding: 8px 18px;
      border-radius: 20px;
      transition: all var(--transition);
      white-space: nowrap;
    }

    .brand-logo i {
      font-size: 26px;
      color: var(--primary);
      background: var(--primary-light);
      width: 40px;
      height: 40px;
      display: inline-flex;
      align-items: center;
      justify-content: center;
      border-radius: 12px;
      transition: transform var(--transition);
    }

    .brand-logo:hover i {
      transform: rotate(-6deg) scale(1.04);
    }

    .nav-toggle {
      display: none;
      width: 42px;
      height: 42px;
      border-radius: 12px;
      background: var(--bg-alt);
      color: var(--dark);
      font-size: 17px;
      align-items: center;
      justify-content: center;
      transition: all var(--transition);
    }

    .nav-toggle:hover {
      background: var(--primary-light);
      color: var(--primary);
    }

    .mobile-menu {
      display: none;
      flex-direction: column;
      gap: 8px;
      padding: 16px 24px 20px;
      background: #fff;
      border-bottom: 1px solid var(--border);
    }

    .mobile-menu.open {
      display: flex;
    }

    .mobile-menu .nav-link {
      display: flex;
      align-items: center;
      gap: 10px;
      width: 100%;
      padding: 14px 18px;
      border-radius: 14px;
      font-size: 16px;
    }

    .mobile-menu .nav-link:hover {
      background: var(--bg-alt);
    }

    .page-hero {
      position: relative;
      background: url('/assets/images/backpic/back-1.png') center center / cover no-repeat;
      min-height: 480px;
      display: flex;
      align-items: center;
      margin-bottom: 0;
      overflow: hidden;
    }

    .page-hero::before {
      content: "";
      position: absolute;
      inset: 0;
      background: linear-gradient(120deg, rgba(15, 23, 42, 0.88) 0%, rgba(15, 23, 42, 0.55) 55%, rgba(6, 182, 212, 0.2) 100%);
      z-index: 1;
    }

    .hero-content {
      position: relative;
      z-index: 2;
      padding: 70px 24px;
      max-width: 720px;
      margin: 0;
      color: #fff;
    }

    .hero-badge {
      display: inline-flex;
      align-items: center;
      gap: 8px;
      background: rgba(255, 255, 255, 0.15);
      border: 1px solid rgba(255, 255, 255, 0.25);
      padding: 8px 18px;
      border-radius: 999px;
      font-size: 14px;
      font-weight: 500;
      margin-bottom: 20px;
      backdrop-filter: blur(8px);
    }

    .hero-badge i {
      color: var(--accent);
    }

    .hero-content h1 {
      font-size: 52px;
      line-height: 1.15;
      font-weight: 800;
      letter-spacing: -0.03em;
      margin-bottom: 18px;
    }

    .hero-content p {
      font-size: 18px;
      line-height: 1.7;
      color: rgba(255, 255, 255, 0.85);
      margin-bottom: 32px;
      max-width: 560px;
    }

    .hero-actions {
      display: flex;
      flex-wrap: wrap;
      gap: 14px;
    }

    .btn {
      display: inline-flex;
      align-items: center;
      justify-content: center;
      gap: 10px;
      padding: 14px 28px;
      border-radius: 999px;
      font-size: 15px;
      font-weight: 600;
      transition: all var(--transition);
      border: 1px solid transparent;
    }

    .btn-primary {
      background: var(--primary);
      color: #fff;
      box-shadow: 0 8px 24px rgba(37, 99, 235, 0.28);
    }

    .btn-primary:hover {
      background: var(--primary-dark);
      transform: translateY(-2px);
      box-shadow: 0 12px 32px rgba(37, 99, 235, 0.35);
    }

    .btn-ghost {
      background: rgba(255, 255, 255, 0.1);
      color: #fff;
      border-color: rgba(255, 255, 255, 0.3);
      backdrop-filter: blur(8px);
    }

    .btn-ghost:hover {
      background: rgba(255, 255, 255, 0.18);
      border-color: rgba(255, 255, 255, 0.5);
      transform: translateY(-2px);
    }

    .btn-light {
      background: #fff;
      color: var(--primary-dark);
      box-shadow: 0 8px 24px rgba(15, 23, 42, 0.15);
    }

    .btn-light:hover {
      transform: translateY(-2px);
      box-shadow: 0 12px 32px rgba(15, 23, 42, 0.2);
    }

    .section-block {
      padding: 80px 0;
    }

    .section-head {
      text-align: center;
      max-width: 640px;
      margin: 0 auto 52px;
    }

    .section-tag {
      display: inline-flex;
      align-items: center;
      gap: 6px;
      font-size: 13px;
      font-weight: 600;
      letter-spacing: 0.04em;
      text-transform: uppercase;
      color: var(--primary);
      background: var(--primary-light);
      padding: 6px 16px;
      border-radius: 999px;
      margin-bottom: 14px;
    }

    .section-tag i {
      font-size: 12px;
    }

    .section-head h2 {
      font-size: 34px;
      line-height: 1.25;
      font-weight: 800;
      letter-spacing: -0.02em;
      color: var(--dark);
      margin-bottom: 12px;
    }

    .section-head p {
      font-size: 16px;
      color: var(--text-weak);
      line-height: 1.7;
    }

    /* topic tags */
    .topic-section {
      padding: 64px 0 20px;
      background: var(--bg);
    }

    .topic-grid {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 20px;
    }

    .topic-card {
      display: flex;
      flex-direction: column;
      align-items: center;
      text-align: center;
      background: var(--card-bg);
      border: 1px solid var(--border);
      border-radius: var(--radius);
      padding: 30px 22px;
      transition: all var(--transition);
      box-shadow: var(--shadow);
    }

    .topic-card:hover {
      transform: translateY(-4px);
      box-shadow: var(--shadow-lg);
      border-color: var(--primary);
    }

    .topic-card i {
      font-size: 30px;
      color: var(--primary);
      background: var(--primary-light);
      width: 64px;
      height: 64px;
      display: flex;
      align-items: center;
      justify-content: center;
      border-radius: 18px;
      margin-bottom: 16px;
      transition: transform var(--transition);
    }

    .topic-card:hover i {
      transform: scale(1.06);
    }

    .topic-card h3 {
      font-size: 16px;
      font-weight: 700;
      color: var(--dark);
      margin-bottom: 6px;
    }

    .topic-card p {
      font-size: 13px;
      color: var(--text-weak);
      line-height: 1.6;
    }

    /* guide grid */
    .guide-section {
      padding: 70px 0 40px;
      background: var(--bg);
    }

    .guide-grid {
      display: grid;
      grid-template-columns: repeat(2, 1fr);
      gap: 28px;
    }

    .guide-card {
      background: var(--card-bg);
      border-radius: var(--radius);
      border: 1px solid var(--border);
      box-shadow: var(--shadow);
      overflow: hidden;
      transition: all var(--transition);
      display: flex;
      flex-direction: column;
    }

    .guide-card:hover {
      transform: translateY(-6px);
      box-shadow: var(--shadow-lg);
      border-color: rgba(37, 99, 235, 0.25);
    }

    .guide-cover {
      position: relative;
      aspect-ratio: 16 / 9;
      overflow: hidden;
      background: var(--bg-alt);
    }

    .guide-cover img {
      width: 100%;
      height: 100%;
      object-fit: cover;
      transition: transform 0.5s ease;
    }

    .guide-card:hover .guide-cover img {
      transform: scale(1.05);
    }

    .guide-cover::after {
      content: "";
      position: absolute;
      inset: 0;
      background: linear-gradient(180deg, transparent 55%, rgba(15, 23, 42, 0.25));
      pointer-events: none;
    }

    .guide-body {
      padding: 26px 26px 24px;
      display: flex;
      flex-direction: column;
      flex: 1;
    }

    .guide-meta {
      display: flex;
      align-items: center;
      gap: 12px;
      margin-bottom: 14px;
    }

    .badge {
      display: inline-flex;
      align-items: center;
      gap: 6px;
      background: var(--primary-light);
      color: var(--primary-dark);
      font-size: 13px;
      font-weight: 600;
      padding: 5px 14px;
      border-radius: 999px;
    }

    .guide-time {
      font-size: 13px;
      color: var(--text-weak);
      display: inline-flex;
      align-items: center;
      gap: 5px;
    }

    .guide-body h3 {
      font-size: 20px;
      font-weight: 700;
      line-height: 1.45;
      color: var(--dark);
      margin-bottom: 10px;
    }

    .guide-body h3 a {
      transition: color var(--transition);
    }

    .guide-body h3 a:hover {
      color: var(--primary);
    }

    .guide-body p {
      font-size: 14px;
      color: var(--text-weak);
      line-height: 1.65;
      margin-bottom: 18px;
      flex: 1;
    }

    .guide-footer {
      display: flex;
      align-items: center;
      justify-content: space-between;
      padding-top: 14px;
      border-top: 1px solid var(--border);
      font-size: 13px;
    }

    .guide-views {
      color: var(--text-weak);
      display: inline-flex;
      align-items: center;
      gap: 7px;
    }

    .guide-link {
      color: var(--primary);
      font-weight: 600;
      display: inline-flex;
      align-items: center;
      gap: 8px;
      transition: gap var(--transition);
    }

    .guide-link:hover {
      gap: 12px;
    }

    /* steps */
    .steps-section {
      background: var(--dark);
      padding: 80px 0;
      color: #fff;
      position: relative;
      overflow: hidden;
    }

    .steps-section::before {
      content: "";
      position: absolute;
      width: 400px;
      height: 400px;
      border-radius: 50%;
      background: radial-gradient(circle, rgba(37, 99, 235, 0.35), transparent 70%);
      top: -100px;
      right: -100px;
      pointer-events: none;
    }

    .steps-section .section-head h2 {
      color: #fff;
    }

    .steps-section .section-head p {
      color: rgba(255, 255, 255, 0.7);
    }

    .steps-section .section-tag {
      background: rgba(255, 255, 255, 0.15);
      color: #fff;
    }

    .steps-grid {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 24px;
      position: relative;
      z-index: 2;
    }

    .step-card {
      background: rgba(255, 255, 255, 0.06);
      border: 1px solid rgba(255, 255, 255, 0.1);
      border-radius: var(--radius);
      padding: 30px 24px;
      backdrop-filter: blur(8px);
      transition: all var(--transition);
    }

    .step-card:hover {
      background: rgba(255, 255, 255, 0.1);
      transform: translateY(-4px);
      border-color: rgba(255, 255, 255, 0.2);
    }

    .step-num {
      font-size: 13px;
      font-weight: 700;
      color: var(--accent);
      letter-spacing: 0.08em;
      text-transform: uppercase;
      margin-bottom: 14px;
    }

    .step-card h3 {
      font-size: 18px;
      font-weight: 700;
      margin-bottom: 10px;
    }

    .step-card p {
      font-size: 14px;
      color: rgba(255, 255, 255, 0.65);
      line-height: 1.6;
    }

    /* stats */
    .stats-section {
      padding: 64px 0;
      background: var(--bg-alt);
    }

    .stats-grid {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 24px;
    }

    .stat-item {
      text-align: center;
      background: var(--card-bg);
      border-radius: var(--radius);
      padding: 36px 20px;
      border: 1px solid var(--border);
      box-shadow: var(--shadow);
      transition: all var(--transition);
    }

    .stat-item:hover {
      transform: translateY(-3px);
      box-shadow: var(--shadow-lg);
    }

    .stat-num {
      display: block;
      font-size: 38px;
      font-weight: 800;
      letter-spacing: -0.02em;
      color: var(--primary);
      margin-bottom: 8px;
    }

    .stat-label {
      font-size: 14px;
      color: var(--text-weak);
      font-weight: 500;
    }

    /* faq */
    .faq-section {
      padding: 80px 0;
      background: var(--bg);
    }

    .faq-list {
      max-width: 780px;
      margin: 0 auto;
      display: flex;
      flex-direction: column;
      gap: 14px;
    }

    .faq-item {
      background: var(--card-bg);
      border: 1px solid var(--border);
      border-radius: var(--radius-sm);
      overflow: hidden;
      transition: all var(--transition);
    }

    .faq-item:hover {
      border-color: rgba(37, 99, 235, 0.3);
      box-shadow: var(--shadow);
    }

    .faq-item[open] {
      border-color: var(--primary);
    }

    .faq-item summary {
      padding: 20px 24px;
      font-size: 16px;
      font-weight: 600;
      color: var(--dark);
      cursor: pointer;
      display: flex;
      align-items: center;
      gap: 12px;
      list-style: none;
      transition: color var(--transition);
    }

    .faq-item summary::-webkit-details-marker {
      display: none;
    }

    .faq-item summary::before {
      content: "\f059";
      font-family: "Font Awesome 6 Free";
      font-weight: 400;
      font-size: 18px;
      color: var(--primary);
      flex-shrink: 0;
    }

    .faq-item[open] summary {
      color: var(--primary-dark);
    }

    .faq-item .faq-answer {
      padding: 0 24px 20px 58px;
      font-size: 14px;
      color: var(--text);
      line-height: 1.7;
      animation: fadeIn .3s ease;
    }

    @keyframes fadeIn {
      from { opacity: 0; transform: translateY(-4px); }
      to { opacity: 1; transform: translateY(0); }
    }

    /* cta */
    .cta-section {
      padding: 0 0 80px;
      background: var(--bg);
    }

    .cta-box {
      background: linear-gradient(135deg, var(--primary) 0%, #4f46e5 55%, var(--accent) 120%);
      border-radius: 28px;
      padding: 56px 48px;
      text-align: center;
      color: #fff;
      position: relative;
      overflow: hidden;
    }

    .cta-box::before {
      content: "";
      position: absolute;
      width: 280px;
      height: 280px;
      border-radius: 50%;
      background: rgba(255, 255, 255, 0.08);
      top: -120px;
      right: -80px;
    }

    .cta-box::after {
      content: "";
      position: absolute;
      width: 180px;
      height: 180px;
      border-radius: 50%;
      background: rgba(255, 255, 255, 0.05);
      bottom: -70px;
      left: 40px;
    }

    .cta-box h2 {
      font-size: 30px;
      font-weight: 800;
      margin-bottom: 12px;
      position: relative;
      z-index: 2;
    }

    .cta-box p {
      font-size: 16px;
      color: rgba(255, 255, 255, 0.9);
      margin-bottom: 26px;
      position: relative;
      z-index: 2;
    }

    .cta-box .btn {
      position: relative;
      z-index: 2;
    }

    /* footer */
    .site-footer {
      background: var(--dark);
      color: rgba(255, 255, 255, 0.7);
      padding: 56px 0 0;
    }

    .footer-grid {
      display: grid;
      grid-template-columns: 1.6fr 1fr 1fr;
      gap: 44px;
      padding-bottom: 40px;
    }

    .footer-brand .brand-logo {
      position: static;
      transform: none;
      color: #fff;
      font-size: 20px;
      padding: 0;
      margin-bottom: 14px;
      background: none;
    }

    .footer-brand .brand-logo i {
      background: rgba(37, 99, 235, 0.3);
      color: #fff;
    }

    .footer-brand p {
      font-size: 14px;
      line-height: 1.7;
      color: rgba(255, 255, 255, 0.55);
      max-width: 320px;
    }

    .footer-col {
      display: flex;
      flex-direction: column;
      gap: 12px;
    }

    .footer-col h4 {
      font-size: 15px;
      font-weight: 700;
      color: #fff;
      margin-bottom: 8px;
    }

    .footer-col a {
      font-size: 14px;
      color: rgba(255, 255, 255, 0.55);
      display: inline-flex;
      align-items: center;
      gap: 8px;
      transition: all var(--transition);
      width: fit-content;
    }

    .footer-col a:hover {
      color: #fff;
      transform: translateX(3px);
    }

    .footer-bottom {
      border-top: 1px solid rgba(255, 255, 255, 0.08);
      padding: 20px 0;
      text-align: center;
      font-size: 13px;
      color: rgba(255, 255, 255, 0.4);
    }

    /* responsive */
    @media (max-width: 1024px) {
      .topic-grid {
        grid-template-columns: repeat(2, 1fr);
      }

      .steps-grid {
        grid-template-columns: repeat(2, 1fr);
      }

      .stats-grid {
        grid-template-columns: repeat(2, 1fr);
      }

      .hero-content h1 {
        font-size: 40px;
      }
    }

    @media (max-width: 768px) {
      .header-inner {
        display: flex;
        justify-content: space-between;
      }

      .brand-logo {
        position: static;
        transform: none;
        order: 0;
        font-size: 18px;
      }

      .brand-logo i {
        width: 32px;
        height: 32px;
        font-size: 16px;
      }

      .nav-left,
      .nav-right {
        display: none;
      }

      .nav-toggle {
        display: flex;
        order: 1;
      }

      .header-inner > .brand-logo {
        order: 0;
      }

      .header-inner > .nav-toggle {
        order: 2;
      }

      .page-hero {
        min-height: 420px;
      }

      .hero-content {
        padding: 50px 0;
      }

      .hero-content h1 {
        font-size: 34px;
      }

      .hero-content p {
        font-size: 16px;
      }

      .section-block {
        padding: 56px 0;
      }

      .section-head h2 {
        font-size: 28px;
      }

      .guide-grid {
        grid-template-columns: 1fr;
      }

      .cta-box {
        padding: 40px 24px;
      }

      .cta-box h2 {
        font-size: 24px;
      }

      .footer-grid {
        grid-template-columns: 1fr;
        gap: 30px;
      }

      .steps-grid {
        gap: 16px;
      }

      .step-card {
        padding: 22px 20px;
      }
    }

    @media (max-width: 520px) {
      .container {
        padding: 0 16px;
      }

      .hero-content h1 {
        font-size: 28px;
      }

      .hero-content p {
        font-size: 15px;
      }

      .topic-grid,
      .steps-grid,
      .stats-grid {
        grid-template-columns: 1fr;
      }

      .guide-body {
        padding: 20px;
      }

      .guide-body h3 {
        font-size: 18px;
      }

      .faq-item summary {
        padding: 16px 18px;
        font-size: 15px;
      }

      .faq-item .faq-answer {
        padding: 0 18px 16px 48px;
        font-size: 14px;
      }

      .footer-grid {
        gap: 24px;
      }

      .btn {
        width: 100%;
      }

      .hero-actions {
        flex-direction: column;
      }
    }