/* roulang page: index */
:root {
      --deep-ebony: #1A1410;
      --oak-bg: #2D241B;
      --champagne-gold: #C8A96E;
      --warm-white: #E8E0D5;
      --warm-gray: #A0988C;
      --card-surface: #231D15;
      --highlight-gold: #D4AF37;
      --body-bg-start: #0F0C09;
      --body-bg-end: #1A1410;
      --border-subtle: rgba(200,169,110,0.15);
      --shadow-card: 0 4px 24px rgba(0,0,0,0.4);
      --shadow-hover: 0 8px 40px rgba(200,169,110,0.12);
      --radius-card: 12px;
      --radius-btn: 8px;
      --radius-tag: 6px;
    }
    * {
      box-sizing: border-box;
    }
    body {
      margin: 0;
      font-family: 'Noto Sans SC', 'Inter', system-ui, sans-serif;
      background: radial-gradient(circle at 20% 10%, #1A1410, #0F0C09 80%);
      color: var(--warm-white);
      line-height: 1.75;
      -webkit-font-smoothing: antialiased;
      scroll-behavior: smooth;
    }
    .serif {
      font-family: 'Noto Serif SC', 'Playfair Display', serif;
    }
    .sans {
      font-family: 'Noto Sans SC', 'Inter', sans-serif;
    }
    .number-font {
      font-family: 'Playfair Display', 'Inter', serif;
    }
    .container-custom {
      max-width: 1280px;
      margin: 0 auto;
      padding-left: 24px;
      padding-right: 24px;
    }
    @media (max-width: 640px) {
      .container-custom {
        padding-left: 16px;
        padding-right: 16px;
      }
    }
    /* 导航栏 */
    .navbar {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      z-index: 50;
      background: transparent;
      transition: background 0.3s ease, box-shadow 0.3s ease;
      backdrop-filter: blur(0px);
    }
    .navbar.scrolled {
      background: var(--deep-ebony);
      box-shadow: 0 2px 12px rgba(0,0,0,0.6);
      border-bottom: 1px solid var(--champagne-gold);
      backdrop-filter: blur(12px);
    }
    .nav-link {
      color: var(--warm-white);
      transition: color 0.2s;
      font-weight: 400;
      letter-spacing: 0.02em;
      padding: 0.5rem 0.75rem;
      border-radius: 6px;
    }
    .nav-link:hover {
      color: var(--champagne-gold);
    }
    .mega-panel {
      position: absolute;
      top: 100%;
      right: 0;
      width: 620px;
      background: var(--oak-bg);
      border-radius: 0 0 12px 12px;
      padding: 1.5rem;
      box-shadow: 0 20px 30px rgba(0,0,0,0.7);
      opacity: 0;
      visibility: hidden;
      transform: translateY(8px);
      transition: opacity 0.25s ease, transform 0.25s ease, visibility 0.25s;
      display: flex;
      gap: 2rem;
      border: 1px solid var(--border-subtle);
      backdrop-filter: blur(12px);
    }
    .mega-trigger:hover .mega-panel {
      opacity: 1;
      visibility: visible;
      transform: translateY(0);
    }
    @media (max-width: 1024px) {
      .mega-panel {
        width: 90vw;
        right: auto;
        left: 0;
        flex-direction: column;
      }
    }
    .hamburger-menu {
      display: none;
    }
    @media (max-width: 768px) {
      .desktop-nav {
        display: none;
      }
      .hamburger-menu {
        display: block;
      }
      .mobile-menu {
        display: none;
        position: fixed;
        top: 70px;
        left: 0;
        width: 100%;
        background: var(--deep-ebony);
        padding: 1.5rem;
        flex-direction: column;
        gap: 1rem;
        border-bottom: 1px solid var(--champagne-gold);
        z-index: 49;
      }
      .mobile-menu.active {
        display: flex;
      }
    }
    /* 装饰纹理 */
    .ding-pattern {
      background-image: radial-gradient(circle at 20% 30%, rgba(200,169,110,0.03) 1px, transparent 1px);
      background-size: 60px 60px;
    }
    .section-title {
      font-family: 'Noto Serif SC', serif;
      font-weight: 600;
      font-size: 2.25rem;
      letter-spacing: 0.02em;
      margin-bottom: 1rem;
      position: relative;
      display: inline-block;
    }
    .section-title::after {
      content: '';
      position: absolute;
      left: 0;
      bottom: -8px;
      width: 40px;
      height: 2px;
      background: var(--champagne-gold);
    }
    .card-hover {
      transition: transform 0.3s, box-shadow 0.3s;
    }
    .card-hover:hover {
      transform: translateY(-4px);
      box-shadow: var(--shadow-hover);
    }
    .btn-primary {
      background: var(--champagne-gold);
      color: #1A1410;
      padding: 14px 32px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      letter-spacing: 0.03em;
      transition: all 0.3s;
      display: inline-block;
      text-align: center;
      border: none;
      cursor: pointer;
    }
    .btn-primary:hover {
      background: var(--highlight-gold);
      box-shadow: 0 8px 20px rgba(200,169,110,0.3);
    }
    .btn-outline {
      background: transparent;
      border: 1px solid var(--champagne-gold);
      color: var(--champagne-gold);
      padding: 14px 32px;
      border-radius: var(--radius-btn);
      font-weight: 500;
      transition: all 0.3s;
      display: inline-block;
      text-align: center;
    }
    .btn-outline:hover {
      background: rgba(200,169,110,0.1);
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.4s ease;
    }
    .faq-item.active .faq-answer {
      max-height: 200px;
    }
    .faq-item.active .faq-icon {
      transform: rotate(45deg);
    }
    @media (max-width: 640px) {
      .section-title {
        font-size: 1.8rem;
      }
    }
    .image-cover {
      object-fit: cover;
      width: 100%;
      height: 100%;
    }