/* roulang page: index */
:root {
      --primary-black: #0B0B0B;
      --accent-gold: #D4AF37;
      --warm-gold: #C8A951;
      --bg-warm: #F5F3EF;
      --dark-bg: #1A1A1A;
      --text-primary: #1A1A1A;
      --text-secondary: #5C5C5C;
      --text-on-dark: #FFFFFF;
      --border-light: #E8E5DF;
      --card-shadow: 0 4px 20px rgba(0,0,0,0.04);
      --card-shadow-hover: 0 12px 32px rgba(0,0,0,0.08);
      --radius-sm: 4px;
      --radius-md: 8px;
      --font-title: 'Noto Sans SC', system-ui, -apple-system, sans-serif;
      --font-body: 'Noto Sans SC', system-ui, -apple-system, sans-serif;
      --font-number: 'Oswald', sans-serif;
      --font-english: 'Inter', sans-serif;
      --container-max: 1280px;
      --section-gap-desktop: 120px;
      --section-gap-tablet: 80px;
      --section-gap-mobile: 60px;
      --nav-height: 72px;
      --transition-smooth: 0.3s cubic-bezier(0.25, 0.46, 0.45, 0.94);
    }

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

    body {
      font-family: var(--font-body);
      background-color: var(--bg-warm);
      color: var(--text-primary);
      line-height: 1.6;
      font-size: 16px;
      -webkit-font-smoothing: antialiased;
      -moz-osx-font-smoothing: grayscale;
      overflow-x: hidden;
    }

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

    a {
      text-decoration: none;
      color: inherit;
      transition: color 0.2s;
    }

    button, .btn {
      cursor: pointer;
      font-family: var(--font-body);
      border: none;
      background: none;
      display: inline-flex;
      align-items: center;
      justify-content: center;
      gap: 8px;
      transition: var(--transition-smooth);
    }

    .container {
      max-width: var(--container-max);
      margin: 0 auto;
      padding: 0 24px;
    }

    @media (max-width: 768px) {
      .container {
        padding: 0 16px;
      }
    }

    /* 排版辅助 */
    h2 {
      font-family: var(--font-title);
      font-weight: 700;
      font-size: 40px;
      line-height: 1.2;
      letter-spacing: -0.02em;
      color: var(--primary-black);
      margin-bottom: 16px;
    }

    h3 {
      font-family: var(--font-title);
      font-weight: 700;
      font-size: 20px;
      line-height: 1.4;
      color: var(--primary-black);
    }

    .section-gap {
      margin-bottom: var(--section-gap-desktop);
    }

    @media (max-width: 1023px) {
      .section-gap {
        margin-bottom: var(--section-gap-tablet);
      }
      h2 {
        font-size: 36px;
      }
    }

    @media (max-width: 767px) {
      .section-gap {
        margin-bottom: var(--section-gap-mobile);
      }
      h2 {
        font-size: 28px;
      }
    }

    .gold-line {
      width: 40px;
      height: 2px;
      background-color: var(--accent-gold);
      display: inline-block;
      margin-bottom: 20px;
      transition: width 0.3s ease;
    }

    .gold-line:hover {
      width: 60px;
    }

    /* 导航 */
    .navbar {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: var(--nav-height);
      background: rgba(255,255,255,0.85);
      backdrop-filter: blur(12px);
      box-shadow: 0 1px 0 rgba(0,0,0,0.05);
      z-index: 1000;
      display: flex;
      align-items: center;
      transition: background 0.3s;
    }

    .nav-container {
      display: flex;
      align-items: center;
      justify-content: space-between;
      width: 100%;
    }

    .logo {
      display: flex;
      align-items: center;
      gap: 10px;
      font-weight: 700;
      font-size: 20px;
      color: var(--primary-black);
    }

    .logo i {
      color: var(--accent-gold);
      font-size: 28px;
    }

    .nav-menu {
      display: flex;
      gap: 40px;
      list-style: none;
      font-weight: 700;
      font-size: 14px;
      letter-spacing: 0.04em;
      text-transform: uppercase;
    }

    .nav-menu a {
      color: var(--text-primary);
      position: relative;
      padding: 8px 0;
    }

    .nav-menu a::after {
      content: '';
      position: absolute;
      bottom: 0;
      left: 0;
      width: 0;
      height: 2px;
      background: var(--accent-gold);
      transition: width 0.3s ease;
    }

    .nav-menu a:hover::after,
    .nav-menu a.active::after {
      width: 100%;
    }

    .hamburger {
      display: none;
      font-size: 24px;
      color: var(--primary-black);
      background: none;
      border: none;
    }

    @media (max-width: 767px) {
      .nav-menu {
        position: fixed;
        top: 0;
        right: -100%;
        width: 70%;
        height: 100vh;
        background: var(--primary-black);
        flex-direction: column;
        justify-content: center;
        align-items: center;
        gap: 32px;
        transition: right 0.4s ease;
        z-index: 999;
      }
      .nav-menu.active {
        right: 0;
      }
      .nav-menu a {
        color: var(--text-on-dark);
        font-size: 18px;
      }
      .hamburger {
        display: block;
        z-index: 1001;
      }
    }

    /* 按钮 */
    .btn-primary {
      background: var(--accent-gold);
      color: var(--primary-black);
      font-weight: 700;
      padding: 16px 40px;
      border-radius: var(--radius-sm);
      letter-spacing: 0.04em;
      font-size: 16px;
      box-shadow: 0 4px 12px rgba(212, 175, 55, 0.2);
    }

    .btn-primary:hover {
      background: var(--warm-gold);
      box-shadow: 0 6px 18px rgba(200, 169, 81, 0.3);
    }

    .btn-outline {
      background: transparent;
      border: 2px solid var(--primary-black);
      color: var(--primary-black);
      font-weight: 700;
      padding: 14px 38px;
      border-radius: var(--radius-sm);
    }

    .btn-outline:hover {
      background: var(--primary-black);
      color: #fff;
    }

    @media (max-width: 767px) {
      .btn-primary, .btn-outline {
        width: 100%;
        max-width: 360px;
      }
    }

    /* Hero */
    .hero {
      background: url('/assets/images/backpic/back-1.webp') center/cover no-repeat;
      min-height: 90vh;
      display: flex;
      align-items: center;
      position: relative;
      margin-top: var(--nav-height);
    }

    .hero-overlay {
      position: absolute;
      inset: 0;
      background: linear-gradient(90deg, rgba(0,0,0,0.75) 0%, rgba(0,0,0,0.3) 100%);
    }

    .hero-content {
      position: relative;
      z-index: 2;
      color: var(--text-on-dark);
      max-width: 700px;
      padding: 120px 0;
    }

    .hero h1 {
      font-family: var(--font-title);
      font-size: 56px;
      font-weight: 700;
      line-height: 1.1;
      margin-bottom: 24px;
    }

    .hero p {
      font-size: 18px;
      color: rgba(255,255,255,0.85);
      margin-bottom: 40px;
    }

    @media (max-width: 767px) {
      .hero h1 {
        font-size: 36px;
      }
      .hero p {
        font-size: 16px;
      }
    }

    /* 卡片系统 */
    .card-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
    }

    .card {
      background: #FFFFFF;
      border: 1px solid var(--border-light);
      border-radius: var(--radius-md);
      box-shadow: var(--card-shadow);
      transition: var(--transition-smooth);
      overflow: hidden;
    }

    .card:hover {
      transform: translateY(-4px);
      box-shadow: var(--card-shadow-hover);
      border-color: var(--accent-gold);
    }

    .card-img {
      height: 200px;
      background-size: cover;
      background-position: center;
    }

    .card-body {
      padding: 24px;
    }

    @media (max-width: 1023px) {
      .card-grid {
        grid-template-columns: repeat(2, 1fr);
      }
    }

    @media (max-width: 767px) {
      .card-grid {
        grid-template-columns: 1fr;
      }
    }

    /* 不对称网格 */
    .asymmetric-grid {
      display: grid;
      grid-template-columns: 1.2fr 0.9fr;
      gap: 24px;
    }

    .asymmetric-grid .card:last-child {
      display: flex;
      flex-direction: column;
      justify-content: center;
    }

    @media (max-width: 767px) {
      .asymmetric-grid {
        grid-template-columns: 1fr;
      }
    }

    /* 数据模块 */
    .stats {
      display: flex;
      justify-content: space-around;
      flex-wrap: wrap;
      gap: 24px;
    }

    .stat-item {
      text-align: center;
    }

    .stat-number {
      font-family: var(--font-number);
      font-size: 64px;
      color: var(--accent-gold);
      line-height: 1;
    }

    /* FAQ */
    .faq-item {
      border-top: 1px solid var(--border-light);
      border-bottom: 1px solid var(--border-light);
    }

    .faq-question {
      width: 100%;
      display: flex;
      justify-content: space-between;
      align-items: center;
      padding: 20px 0;
      font-weight: 700;
      font-size: 18px;
      background: none;
      border: none;
      cursor: pointer;
    }

    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.4s ease;
      color: var(--text-secondary);
    }

    .faq-item.active .faq-answer {
      max-height: 200px;
      padding-bottom: 20px;
    }

    /* 页脚 */
    .footer {
      background: var(--primary-black);
      color: #B0B0B0;
      padding: 60px 0 30px;
    }

    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr;
      gap: 40px;
    }

    @media (max-width: 767px) {
      .footer-grid {
        grid-template-columns: 1fr;
      }
    }

    .fade-in {
      opacity: 0;
      transform: translateY(20px);
      transition: opacity 0.6s ease, transform 0.6s ease;
    }

    .fade-in.visible {
      opacity: 1;
      transform: translateY(0);
    }