/* roulang page: index */
:root {
      --color-primary: #F04E23;
      --color-primary-deep: #D03D1A;
      --color-dark: #1A1A1A;
      --color-bg: #F7F5F2;
      --color-accent: #00C2BA;
      --color-white: #FFFFFF;
      --color-gray-600: #4B5563;
      --color-gray-500: #6B7280;
      --font-sans: "PingFang SC", "Microsoft YaHei", "Hiragino Sans GB", sans-serif;
      --shadow-card: 0 2px 16px rgba(0,0,0,0.04);
      --shadow-card-hover: 0 8px 30px rgba(0,0,0,0.08);
    }

    * {
      box-sizing: border-box;
    }

    body {
      font-family: var(--font-sans);
      background-color: var(--color-bg);
      color: var(--color-dark);
      line-height: 1.75;
      margin: 0;
      padding: 0;
      -webkit-font-smoothing: antialiased;
      -moz-osx-font-smoothing: grayscale;
    }

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

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

    button, input, textarea {
      font-family: inherit;
    }

    .container {
      max-width: 1280px;
      margin-left: auto;
      margin-right: auto;
      padding-left: 24px;
      padding-right: 24px;
    }

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

    /* 自定义动画 */
    @keyframes fadeInUp {
      0% { opacity: 0; transform: translateY(20px); }
      100% { opacity: 1; transform: translateY(0); }
    }

    .animate-fade-in-up {
      animation: fadeInUp 0.6s ease-out forwards;
    }

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

    .reveal.visible {
      opacity: 1;
      transform: translateY(0);
    }

    /* 导航滚动阴影 */
    .main-nav {
      transition: box-shadow 0.3s ease, background-color 0.3s ease;
    }

    .main-nav.scrolled {
      background-color: rgba(255,255,255,0.98);
      box-shadow: 0 4px 20px rgba(0,0,0,0.05);
    }

    /* 卡片hover */
    .card-hover {
      transition: transform 0.25s ease-out, box-shadow 0.25s ease-out;
    }
    .card-hover:hover {
      transform: translateY(-4px);
      box-shadow: var(--shadow-card-hover);
    }

    /* FAQ 图标旋转 */
    .faq-toggle {
      transition: transform 0.3s ease;
    }
    .faq-item.active .faq-toggle {
      transform: rotate(45deg);
    }

    /* 案例封面缩放 */
    .case-cover {
      transition: transform 0.3s ease;
    }
    .case-card:hover .case-cover {
      transform: scale(1.03);
    }

    /* 高亮行 */
    .compare-row:hover {
      background-color: rgba(240, 78, 35, 0.04);
    }

    /* 移动端导航 */
    @media (max-width: 768px) {
      .mobile-menu {
        display: none;
        position: absolute;
        top: 72px;
        left: 0;
        right: 0;
        background: white;
        flex-direction: column;
        padding: 20px;
        box-shadow: 0 10px 25px rgba(0,0,0,0.1);
        z-index: 50;
      }
      .mobile-menu.open {
        display: flex;
      }
    }