/* roulang page: index */
:root {
      --color-primary: #0B2B26;
      --color-accent: #D4A84B;
      --color-bg: #FAFAF7;
      --color-dark: #0F1A18;
      --color-text: #1C1C1C;
      --color-muted: #4A4A4A;
      --color-light: #8C8C8C;
      --color-border: #E5E2DA;
      --shadow-card: 0 1px 2px rgba(0,0,0,0.04), 0 4px 16px rgba(0,0,0,0.04);
      --shadow-card-hover: 0 8px 30px rgba(0,0,0,0.08);
      --shadow-nav: 0 4px 20px rgba(0,0,0,0.15);
    }
    * {
      box-sizing: border-box;
    }
    html {
      scroll-behavior: smooth;
    }
    body {
      margin: 0;
      font-family: system-ui, -apple-system, 'PingFang SC', 'Microsoft YaHei', sans-serif;
      background-color: #FAFAF7;
      color: #1C1C1C;
      line-height: 1.75;
      -webkit-font-smoothing: antialiased;
    }
    img {
      max-width: 100%;
      height: auto;
      display: block;
    }
    a {
      text-decoration: none;
      color: inherit;
    }
    button, input, textarea {
      font-family: inherit;
    }
    .container-custom {
      max-width: 1280px;
      margin-left: auto;
      margin-right: auto;
      padding-left: 24px;
      padding-right: 24px;
    }
    @media (min-width: 768px) {
      .container-custom {
        padding-left: 32px;
        padding-right: 32px;
      }
    }
    @media (min-width: 1024px) {
      .container-custom {
        padding-left: 40px;
        padding-right: 40px;
      }
    }

    /* 导航玻璃效果 */
    .nav-glass {
      background: rgba(255,255,255,0.08);
      backdrop-filter: blur(20px);
      -webkit-backdrop-filter: blur(20px);
      border-bottom: 1px solid rgba(255,255,255,0.15);
      transition: background 0.3s ease, box-shadow 0.3s ease, border-color 0.3s ease;
    }
    .nav-scrolled {
      background: rgba(11,43,38,0.95);
      backdrop-filter: blur(16px);
      -webkit-backdrop-filter: blur(16px);
      border-bottom: 1px solid rgba(255,255,255,0.08);
      box-shadow: 0 4px 20px rgba(0,0,0,0.15);
    }
    .nav-link {
      color: rgba(255,255,255,0.85);
      font-weight: 500;
      font-size: 15px;
      position: relative;
      transition: color 0.2s;
    }
    .nav-link::after {
      content: '';
      position: absolute;
      bottom: -4px;
      left: 0;
      width: 0;
      height: 2px;
      background-color: #D4A84B;
      transition: width 0.25s ease;
    }
    .nav-link:hover {
      color: #fff;
    }
    .nav-link:hover::after {
      width: 100%;
    }
    .scrolled .nav-link {
      color: #FAFAF7;
    }
    .scrolled .nav-link:hover {
      color: #D4A84B;
    }

    /* 移动端菜单 */
    .mobile-menu {
      background: rgba(11,43,38,0.98);
      backdrop-filter: blur(24px);
      -webkit-backdrop-filter: blur(24px);
    }
    .mobile-link {
      font-size: 20px;
      font-weight: 500;
      border-bottom: 1px solid rgba(255,255,255,0.1);
      padding: 16px 0;
      color: #FAFAF7;
    }

    /* 动画 */
    @keyframes fadeInUp {
      from {
        opacity: 0;
        transform: translateY(24px);
      }
      to {
        opacity: 1;
        transform: translateY(0);
      }
    }
    .animate-fade-in-up {
      animation: fadeInUp 0.6s ease forwards;
    }
    .animate-delay-1 { animation-delay: 0.1s; }
    .animate-delay-2 { animation-delay: 0.2s; }
    .animate-delay-3 { animation-delay: 0.3s; }
    .animate-delay-4 { animation-delay: 0.4s; }

    /* FAQ 手风琴 */
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.4s ease;
    }
    .faq-item.open .faq-answer {
      max-height: 200px;
    }
    .faq-icon {
      transition: transform 0.3s ease;
    }
    .faq-item.open .faq-icon {
      transform: rotate(45deg);
    }

    /* 卡片悬停 */
    .card-hover {
      transition: transform 0.35s cubic-bezier(0.25, 0.46, 0.45, 0.94), box-shadow 0.35s ease;
    }
    .card-hover:hover {
      transform: translateY(-4px);
      box-shadow: 0 8px 30px rgba(0,0,0,0.08);
    }
    @media (hover: none) {
      .card-hover:hover {
        transform: none;
      }
    }

    /* 案例图片缩放 */
    .case-img-container img {
      transition: transform 0.4s ease;
    }
    .case-card:hover .case-img-container img {
      transform: scale(1.04);
    }
    .case-title-underline {
      background-image: linear-gradient(to right, #D4A84B, #D4A84B);
      background-size: 0 2px;
      background-position: 0 100%;
      background-repeat: no-repeat;
      transition: background-size 0.3s ease;
    }
    .case-card:hover .case-title-underline {
      background-size: 100% 2px;
    }

    /* 按钮状态 */
    .btn-primary {
      background-color: #0B2B26;
      color: white;
      border-radius: 8px;
      padding: 14px 32px;
      font-weight: 600;
      transition: background-color 0.25s, transform 0.25s;
      display: inline-block;
    }
    .btn-primary:hover {
      background-color: #0a3a32;
      transform: scale(1.03);
    }
    .btn-outline {
      background: transparent;
      border: 1.5px solid #0B2B26;
      color: #0B2B26;
      border-radius: 8px;
      padding: 14px 32px;
      font-weight: 600;
      transition: background-color 0.25s, color 0.25s;
    }
    .btn-outline:hover {
      background-color: rgba(11,43,38,0.08);
    }
    .btn-accent {
      background-color: #D4A84B;
      color: #0B2B26;
      border-radius: 6px;
      padding: 8px 20px;
      font-weight: 600;
      transition: background-color 0.25s;
    }
    .btn-accent:hover {
      background-color: #c99a3a;
    }
    .btn-light-outline {
      border: 1.5px solid rgba(255,255,255,0.7);
      color: white;
      background: transparent;
      border-radius: 8px;
      padding: 14px 32px;
      font-weight: 600;
      transition: background 0.25s;
    }
    .btn-light-outline:hover {
      background: rgba(255,255,255,0.1);
    }