/* roulang page: index */
:root {
      --color-primary: #1A1A2E;
      --color-accent: #E2B04A;
      --color-bg: #F7F5F0;
      --color-card: #FFFFFF;
      --color-text: #1A1A2E;
      --color-text-secondary: #5A5A6E;
      --color-text-muted: #8A8A9A;
      --color-border: #E5E0D8;
      --radius-card: 12px;
      --radius-btn: 8px;
      --shadow-card: 0 2px 12px rgba(26,26,46,0.06);
      --shadow-hover: 0 8px 28px rgba(26,26,46,0.12);
      --font-title: 'PingFang SC', 'Microsoft YaHei', 'Noto Sans SC', sans-serif;
      --font-body: 'PingFang SC', 'Microsoft YaHei', 'Hiragino Sans GB', sans-serif;
      --transition-base: 0.3s ease;
    }

    * {
      box-sizing: border-box;
    }

    body {
      font-family: var(--font-body);
      background-color: var(--color-bg);
      color: var(--color-text);
      margin: 0;
      line-height: 1.7;
      font-size: 16px;
      -webkit-font-smoothing: antialiased;
    }

    h1, h2, h3, .font-title {
      font-family: var(--font-title);
      font-weight: 600;
      letter-spacing: -0.3px;
    }

    .container {
      max-width: 1280px;
      margin-left: auto;
      margin-right: auto;
      padding-left: 16px;
      padding-right: 16px;
    }

    /* 导航 */
    .navbar {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: 72px;
      display: flex;
      align-items: center;
      justify-content: center;
      z-index: 50;
      transition: background 0.3s ease, box-shadow 0.3s ease;
      background: transparent;
    }

    .navbar.scrolled {
      background: rgba(255,255,255,0.95);
      backdrop-filter: blur(12px);
      box-shadow: 0 4px 20px rgba(0,0,0,0.04);
    }

    .nav-inner {
      display: flex;
      align-items: center;
      justify-content: space-between;
      width: 100%;
      max-width: 1280px;
      padding: 0 20px;
    }

    .logo {
      display: flex;
      align-items: center;
      gap: 8px;
      font-weight: 700;
      font-size: 1.5rem;
      color: var(--color-primary);
      text-decoration: none;
      letter-spacing: 1px;
    }

    .logo i {
      color: var(--color-accent);
      font-size: 1.8rem;
    }

    .nav-links {
      display: flex;
      align-items: center;
      gap: 8px;
      background: transparent;
      padding: 6px;
      border-radius: 40px;
    }

    .nav-links a {
      padding: 8px 20px;
      border-radius: 30px;
      color: var(--color-text-secondary);
      font-weight: 500;
      font-size: 0.95rem;
      text-decoration: none;
      transition: all 0.2s;
      white-space: nowrap;
    }

    .nav-links a:hover {
      background: rgba(26,26,46,0.05);
      color: var(--color-primary);
    }

    .nav-links a.active {
      color: var(--color-accent);
      font-weight: 600;
      position: relative;
    }

    .nav-links a.active::after {
      content: '';
      position: absolute;
      bottom: 4px;
      left: 20px;
      right: 20px;
      height: 2px;
      background: var(--color-accent);
      border-radius: 2px;
    }

    .btn-primary {
      background: var(--color-accent);
      color: var(--color-primary);
      font-weight: 600;
      padding: 10px 26px;
      border-radius: var(--radius-btn);
      border: none;
      cursor: pointer;
      text-decoration: none;
      display: inline-flex;
      align-items: center;
      justify-content: center;
      transition: all 0.25s;
      font-size: 0.95rem;
      box-shadow: 0 4px 10px rgba(226,176,74,0.25);
    }

    .btn-primary:hover {
      background: #C99A3A;
      transform: scale(1.03);
      box-shadow: 0 8px 18px rgba(226,176,74,0.35);
    }

    .btn-outline {
      background: transparent;
      border: 1.5px solid var(--color-primary);
      color: var(--color-primary);
      font-weight: 500;
      padding: 10px 26px;
      border-radius: var(--radius-btn);
      text-decoration: none;
      display: inline-flex;
      align-items: center;
      transition: 0.25s;
    }

    .btn-outline:hover {
      background: rgba(26,26,46,0.05);
    }

    .btn-text {
      color: var(--color-accent);
      font-weight: 500;
      text-decoration: none;
      border-bottom: 1px solid transparent;
      transition: 0.2s;
    }

    .btn-text:hover {
      border-bottom: 1px solid var(--color-accent);
    }

    /* 移动端导航 */
    .mobile-nav {
      display: none;
      position: fixed;
      bottom: 0;
      left: 0;
      width: 100%;
      background: rgba(255,255,255,0.96);
      backdrop-filter: blur(16px);
      border-top: 1px solid var(--color-border);
      justify-content: space-around;
      align-items: center;
      padding: 8px 10px 20px;
      z-index: 55;
      box-shadow: 0 -4px 12px rgba(0,0,0,0.02);
    }

    .mobile-nav a {
      display: flex;
      flex-direction: column;
      align-items: center;
      font-size: 0.7rem;
      color: var(--color-text-secondary);
      text-decoration: none;
      font-weight: 500;
    }
    .mobile-nav i {
      font-size: 1.3rem;
      margin-bottom: 2px;
    }
    .mobile-nav .btn-primary-mobile {
      background: var(--color-accent);
      color: #1A1A2E;
      padding: 10px 22px;
      border-radius: 40px;
      font-weight: 700;
      box-shadow: 0 6px 14px rgba(226,176,74,0.4);
    }

    /* 区块间距 */
    section {
      padding: 100px 0;
    }

    @media (max-width: 768px) {
      section {
        padding: 70px 0;
      }
      .desktop-nav {
        display: none;
      }
      .mobile-nav {
        display: flex;
      }
      .navbar {
        height: 64px;
      }
    }

    @media (min-width: 769px) {
      .mobile-nav {
        display: none;
      }
    }

    /* 卡片与动画 */
    .card-hover {
      transition: all 0.3s ease;
    }
    .card-hover:hover {
      transform: translateY(-4px);
      box-shadow: var(--shadow-hover);
    }

    .fade-up {
      opacity: 0;
      transform: translateY(24px);
      transition: opacity 0.6s ease-out, transform 0.6s ease-out;
    }
    .fade-up.visible {
      opacity: 1;
      transform: translateY(0);
    }

    /* 对比表高亮 */
    .highlight-col {
      background: rgba(226,176,74,0.08);
      border: 1px solid var(--color-accent);
    }

    /* 手风琴 */
    .faq-item {
      border-bottom: 1px solid var(--color-border);
      padding: 18px 0;
      cursor: pointer;
    }
    .faq-question {
      font-weight: 600;
      font-size: 1.1rem;
      display: flex;
      justify-content: space-between;
      align-items: center;
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.4s ease;
      color: var(--color-text-secondary);
    }
    .waterfall-grid {
      columns: 3;
      column-gap: 24px;
    }
    @media (max-width: 1024px) {
      .waterfall-grid {
        columns: 2;
      }
    }
    @media (max-width: 640px) {
      .waterfall-grid {
        columns: 1;
      }
    }
    .waterfall-item {
      break-inside: avoid;
      margin-bottom: 24px;
    }