/* roulang page: index */
:root {
      --black: #0A0E17;
      --red: #E63946;
      --gold: #C9A96E;
      --dark-card: #1A1F2A;
      --mid-gray: #6B7280;
      --light-gray: #F2F4F7;
      --white: #FFFFFF;
      --text-body: #D1D5DB;
      --border-gold: rgba(201, 169, 110, 0.15);
      --shadow-card: 0 4px 20px rgba(0,0,0,0.3);
      --shadow-hover: 0 8px 30px rgba(0,0,0,0.5);
      --radius-lg: 12px;
      --radius-md: 8px;
      --transition: 0.25s ease;
      --font-sans: -apple-system, "PingFang SC", "Microsoft YaHei", "Helvetica Neue", sans-serif;
    }
    * { box-sizing: border-box; margin: 0; padding: 0; }
    body {
      font-family: var(--font-sans);
      background: var(--black);
      color: var(--text-body);
      line-height: 1.7;
      font-size: 16px;
      -webkit-font-smoothing: antialiased;
    }
    .container {
      max-width: 1280px;
      margin: 0 auto;
      padding: 0 24px;
    }
    img { max-width: 100%; height: auto; display: block; }
    a { text-decoration: none; color: inherit; transition: var(--transition); }
    h1, h2, h3, h4 { color: var(--white); font-weight: 600; }
    h1 { font-size: 56px; font-weight: 700; letter-spacing: -0.02em; line-height: 1.1; }
    h2 { font-size: 40px; font-weight: 600; margin-bottom: 16px; position: relative; display: inline-block; }
    h2::after {
      content: '';
      display: block;
      width: 60px;
      height: 2px;
      background: var(--gold);
      margin-top: 8px;
    }
    h3 { font-size: 24px; font-weight: 600; }
    .section {
      padding: 100px 0;
    }
    @media (max-width: 1024px) {
      h1 { font-size: 42px; }
      h2 { font-size: 32px; }
      .section { padding: 70px 0; }
    }
    @media (max-width: 768px) {
      h1 { font-size: 36px; }
      h2 { font-size: 28px; }
      h3 { font-size: 20px; }
      .section { padding: 60px 0; }
    }
    /* 导航 */
    .header {
      position: fixed; top: 0; left: 0; width: 100%; z-index: 1000;
      background: transparent; transition: background 0.3s, backdrop-filter 0.3s;
      padding: 16px 0; border-bottom: 1px solid transparent;
    }
    .header.scrolled {
      background: rgba(10,14,23,0.85);
      backdrop-filter: blur(12px);
      border-bottom: 1px solid rgba(201,169,110,0.2);
    }
    .nav-container {
      display: flex; align-items: center; justify-content: space-between;
      max-width: 1280px; margin: 0 auto; padding: 0 24px;
    }
    .logo {
      display: flex; flex-direction: column;
    }
    .logo-text {
      font-size: 24px; font-weight: 700; color: var(--gold); letter-spacing: 1px;
    }
    .logo-domain {
      font-size: 12px; color: var(--mid-gray); letter-spacing: 0.5px;
    }
    .nav-links {
      display: flex; gap: 32px; align-items: center;
    }
    .nav-links a {
      color: #D1D5DB; font-weight: 500; font-size: 15px; position: relative;
    }
    .nav-links a:hover { color: var(--gold); }
    .btn-primary {
      background: var(--red); color: white; padding: 12px 28px; border-radius: var(--radius-md);
      font-weight: 600; display: inline-block; border: none; cursor: pointer;
      transition: 0.25s ease; box-shadow: 0 4px 12px rgba(230,57,70,0.3);
    }
    .btn-primary:hover { background: #C62D3A; transform: translateY(-2px); }
    .btn-outline {
      background: transparent; border: 1px solid var(--gold); color: var(--gold);
      padding: 12px 28px; border-radius: var(--radius-md); font-weight: 600;
    }
    .btn-outline:hover { background: rgba(201,169,110,0.1); }
    .btn-ghost {
      background: transparent; border: 1px solid white; color: white;
      padding: 12px 28px; border-radius: var(--radius-md); font-weight: 600;
    }
    .btn-ghost:hover { background: white; color: var(--black); }
    .hamburger {
      display: none; flex-direction: column; gap: 5px; cursor: pointer;
    }
    .hamburger span { width: 25px; height: 2px; background: white; transition: 0.3s; }
    @media (max-width: 768px) {
      .nav-links { display: none; }
      .hamburger { display: flex; }
      .mobile-menu {
        display: none; position: fixed; top: 0; left: 0; width: 100%; height: 100vh;
        background: rgba(10,14,23,0.98); backdrop-filter: blur(20px);
        flex-direction: column; justify-content: center; align-items: center; gap: 40px;
        z-index: 999;
      }
      .mobile-menu.active { display: flex; }
      .mobile-menu a { font-size: 22px; color: white; }
    }
    /* Hero */
    .hero {
      min-height: 100vh; display: flex; align-items: center; justify-content: center;
      text-align: center; position: relative; background: radial-gradient(circle at center, #1A1F2A 0%, #0A0E17 80%);
      overflow: hidden;
    }
    .hero-bg {
      position: absolute; inset: 0; background: url('/assets/images/backpic/back-1.webp') center/cover no-repeat;
      opacity: 0.25; z-index: 0;
    }
    .hero-content { position: relative; z-index: 2; max-width: 800px; }
    .hero h1 { color: white; margin-bottom: 24px; }
    .hero-sub {
      font-size: 18px; color: #D1D5DB; margin-bottom: 40px;
    }
    .hero-buttons { display: flex; gap: 20px; justify-content: center; flex-wrap: wrap; }
    /* 卡片 */
    .card {
      background: var(--dark-card); border: 1px solid var(--border-gold);
      border-radius: var(--radius-lg); padding: 32px; box-shadow: var(--shadow-card);
      transition: 0.3s;
    }
    .card:hover {
      transform: translateY(-4px); box-shadow: var(--shadow-hover), 0 0 0 1px rgba(201,169,110,0.5);
    }
    .grid-3 {
      display: grid; grid-template-columns: repeat(3,1fr); gap: 24px;
    }
    .grid-2 {
      display: grid; grid-template-columns: repeat(2,1fr); gap: 24px;
    }
    @media (max-width: 1024px) {
      .grid-3 { grid-template-columns: repeat(2,1fr); }
    }
    @media (max-width: 768px) {
      .grid-3, .grid-2 { grid-template-columns: 1fr; }
    }
    .icon-gold {
      width: 48px; height: 48px; color: var(--gold); margin-bottom: 20px;
    }
    .gold-line {
      height: 2px; background: linear-gradient(90deg, var(--gold), transparent);
      margin-top: 16px; width: 50px; transition: width 0.3s;
    }
    .card:hover .gold-line { width: 100%; }
    /* 功能标签切换 */
    .tabs { display: flex; gap: 16px; margin-bottom: 32px; flex-wrap: wrap; }
    .tab {
      padding: 10px 24px; background: transparent; border: 1px solid rgba(255,255,255,0.15);
      border-radius: 30px; color: #ccc; cursor: pointer; transition: 0.2s;
    }
    .tab.active { background: var(--red); border-color: var(--red); color: white; }
    .tab-content { display: none; }
    .tab-content.active { display: block; }
    .feature-list { list-style: none; display: grid; gap: 16px; }
    .feature-list li { display: flex; align-items: center; gap: 12px; }
    /* 价格卡片 */
    .pricing-card {
      background: #1A1F2A; border: 1px solid var(--border-gold); border-radius: var(--radius-lg);
      padding: 32px; text-align: center;
    }
    .pricing-card.featured {
      border-color: var(--red); background: #1F2633;
    }
    .price { font-size: 42px; font-weight: 700; color: var(--gold); }
    /* FAQ */
    .faq-item {
      border-bottom: 1px solid rgba(255,255,255,0.1); padding: 20px 0;
    }
    .faq-question {
      font-size: 18px; font-weight: 600; display: flex; justify-content: space-between;
      cursor: pointer;
    }
    .faq-answer {
      max-height: 0; overflow: hidden; transition: max-height 0.3s ease; color: #aaa;
    }
    .faq-item.open .faq-answer { max-height: 200px; margin-top: 12px; }
    /* Footer */
    .footer {
      background: #0F141E; padding: 60px 0 30px; color: #6B7280;
    }
    .footer-grid { display: grid; grid-template-columns: repeat(4,1fr); gap: 30px; }
    @media (max-width: 768px) {
      .footer-grid { grid-template-columns: 1fr; }
    }
    .animate-on-scroll {
      opacity: 0; transform: translateY(30px);
      transition: opacity 0.6s ease-out, transform 0.6s ease-out;
    }
    .animate-on-scroll.visible { opacity: 1; transform: translateY(0); }