/* roulang page: index */
/* 设计变量与基础重置 */
    :root {
      --primary-orange: #FF5E13;
      --primary-dark: #E54D0B;
      --deep-blue: #0F172A;
      --warm-bg: #FAF9F7;
      --soft-orange-bg: #FFF5F0;
      --white: #FFFFFF;
      --gray-light: #F3F4F6;
      --gray-text: #4B5563;
      --gray-muted: #9CA3AF;
      --border-light: #E5E7EB;
      --shadow-color: rgba(255, 94, 19, 0.08);
      --font-sans: "PingFang SC", "Microsoft YaHei", "Hiragino Sans GB", sans-serif;
      --font-number: "Inter", "SF Pro Display", system-ui, -apple-system;
      --radius-card: 1.5rem;
      --radius-sm: 0.75rem;
    }
    * {
      box-sizing: border-box;
      margin: 0;
      padding: 0;
    }
    body {
      font-family: var(--font-sans);
      background-color: var(--warm-bg);
      color: var(--deep-blue);
      line-height: 1.5;
      -webkit-font-smoothing: antialiased;
      overflow-x: hidden;
    }
    img {
      max-width: 100%;
      height: auto;
      display: block;
    }
    a {
      text-decoration: none;
      color: inherit;
      transition: color 0.2s ease;
    }
    button, .btn {
      cursor: pointer;
      font-family: inherit;
      transition: all 0.25s ease;
    }
    .number-font {
      font-family: var(--font-number);
      font-weight: 700;
    }
    /* 自定义卡片投影与微交互 */
    .card-shadow {
      box-shadow: 0 8px 30px rgba(0, 0, 0, 0.04), 0 2px 8px rgba(0, 0, 0, 0.02);
    }
    .card-hover:hover {
      transform: translateY(-6px);
      box-shadow: 0 20px 35px var(--shadow-color), 0 8px 15px rgba(0,0,0,0.03);
      transition: all 0.3s cubic-bezier(0.2, 0.9, 0.4, 1);
    }
    /* 导航 active 状态 */
    .nav-link {
      position: relative;
      font-size: 0.875rem;
      font-weight: 500;
      letter-spacing: 0.02em;
      color: #374151;
      padding-bottom: 6px;
    }
    .nav-link::after {
      content: '';
      position: absolute;
      bottom: 0;
      left: 0;
      width: 0;
      height: 2px;
      background: var(--primary-orange);
      border-radius: 2px;
      transition: width 0.25s ease;
      box-shadow: 0 0 6px rgba(255,94,19,0.6);
    }
    .nav-link:hover::after,
    .nav-link.active::after {
      width: 100%;
    }
    .nav-link.active {
      color: var(--primary-orange);
    }
    /* 按钮系统 */
    .btn-primary {
      background: var(--primary-orange);
      color: white;
      border-radius: 9999px;
      padding: 0.9rem 2.2rem;
      font-weight: 600;
      letter-spacing: 0.02em;
      display: inline-flex;
      align-items: center;
      justify-content: center;
      box-shadow: 0 10px 20px -8px rgba(255,94,19,0.4);
      border: none;
    }
    .btn-primary:hover {
      background: var(--primary-dark);
      transform: translateY(-2px);
      box-shadow: 0 16px 28px -8px rgba(255,94,19,0.5);
    }
    .btn-outline {
      background: transparent;
      border: 2px solid var(--deep-blue);
      color: var(--deep-blue);
      border-radius: 9999px;
      padding: 0.85rem 2.1rem;
      font-weight: 600;
      letter-spacing: 0.02em;
      display: inline-flex;
      align-items: center;
      justify-content: center;
    }
    .btn-outline:hover {
      background: var(--deep-blue);
      color: white;
      transform: translateY(-2px);
    }
    /* 徽章样式 */
    .badge-stats {
      background: rgba(255,255,255,0.85);
      backdrop-filter: blur(6px);
      border-radius: 9999px;
      padding: 0.25rem 1rem;
      font-size: 0.75rem;
      font-weight: 700;
      color: var(--primary-orange);
      display: inline-block;
      letter-spacing: 0.03em;
      font-family: var(--font-number);
    }
    /* FAQ 手风琴 */
    .faq-item {
      border-bottom: 1px solid var(--border-light);
    }
    .faq-question {
      cursor: pointer;
      padding: 1.5rem 0;
      display: flex;
      justify-content: space-between;
      align-items: center;
      font-weight: 500;
      font-size: 1.1rem;
      transition: color 0.2s;
    }
    .faq-question:hover {
      color: var(--primary-orange);
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.4s ease, padding 0.3s ease;
      color: #4B5563;
      line-height: 1.7;
      padding-left: 1rem;
      border-left: 3px solid transparent;
    }
    .faq-item.open .faq-answer {
      max-height: 300px;
      padding: 0 0 1.8rem 1rem;
      border-left-color: var(--primary-orange);
    }
    .faq-icon {
      font-size: 1.4rem;
      transition: transform 0.3s ease;
      color: #9CA3AF;
    }
    .faq-item.open .faq-icon {
      transform: rotate(45deg);
      color: var(--primary-orange);
    }
    /* 装饰线条 */
    .section-divider {
      width: 64px;
      height: 4px;
      background: var(--primary-orange);
      border-radius: 2px;
      margin: 0.75rem 0 1.5rem;
    }
    .section-divider.center {
      margin-left: auto;
      margin-right: auto;
    }
    /* 移动端菜单 */
    .mobile-menu {
      transition: opacity 0.3s ease, visibility 0.3s;
    }
    @media (max-width: 767px) {
      .hero-right {
        order: -1;
        margin-bottom: 2rem;
      }
      .grid-cols-uneven {
        grid-template-columns: 1fr;
      }
      .case-columns {
        column-count: 1;
      }
    }
    @media (min-width: 768px) and (max-width: 1023px) {
      .case-columns {
        column-count: 2;
      }
    }