/* roulang page: index */
:root {
      --primary: #7A1A2E;
      --primary-deep: #5E1423;
      --skyblue: #7AB2D4;
      --skyblue-light: rgba(122, 178, 212, 0.15);
      --gold: #C8963E;
      --dark: #1C1C1E;
      --gray-light: #F7F5F2;
      --card-bg: #FFFFFF;
      --text: #2D2A26;
      --text-secondary: #6B6560;
      --text-on-dark: #FFFFFF;
      --border-light: rgba(0,0,0,0.06);
      --shadow-card: 0 4px 14px rgba(0,0,0,0.05);
      --shadow-hover: 0 12px 28px rgba(122,26,46,0.08);
      --radius-card: 14px;
      --radius-btn: 8px;
      --radius-tag: 30px;
      --font-title: 'PingFang SC', 'Noto Sans SC', 'Helvetica Neue', system-ui, -apple-system, sans-serif;
      --font-body: 'PingFang SC', 'Noto Sans SC', 'Helvetica Neue', system-ui, sans-serif;
      --max-width: 1200px;
      --header-height: 72px;
    }
    * {
      margin: 0;
      padding: 0;
      box-sizing: border-box;
    }
    html {
      scroll-behavior: smooth;
      scroll-padding-top: var(--header-height);
    }
    body {
      font-family: var(--font-body);
      color: var(--text);
      background-color: #FFFFFF;
      line-height: 1.6;
      -webkit-font-smoothing: antialiased;
    }
    .container {
      max-width: var(--max-width);
      margin: 0 auto;
      padding: 0 24px;
    }
    a {
      text-decoration: none;
      color: inherit;
      transition: color 0.2s, background 0.2s;
    }
    img {
      max-width: 100%;
      height: auto;
      display: block;
    }
    button, .btn {
      font-family: var(--font-body);
      cursor: pointer;
      border: none;
      background: none;
      font-weight: 600;
      transition: all 0.25s ease;
    }
    /* 导航桌面 */
    .desktop-nav {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: var(--header-height);
      background: rgba(28,28,30,0.92);
      backdrop-filter: blur(12px);
      -webkit-backdrop-filter: blur(12px);
      display: flex;
      align-items: center;
      justify-content: space-between;
      padding: 0 32px;
      z-index: 1000;
      box-shadow: 0 4px 16px rgba(0,0,0,0.08);
    }
    .logo-area {
      display: flex;
      align-items: center;
      gap: 10px;
    }
    .logo-icon {
      width: 34px;
      height: 34px;
      background: var(--primary);
      mask: url('data:image/svg+xml;utf8,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24"><path d="M12 2L2 7v6c0 5.5 4.8 10.7 10 12 5.2-1.3 10-6.5 10-12V7l-10-5z"/></svg>') center/cover no-repeat;
      background: var(--primary);
    }
    .brand-text {
      font-weight: 700;
      font-size: 1.4rem;
      letter-spacing: 0.5px;
      color: white;
      font-family: var(--font-title);
    }
    .nav-links {
      display: flex;
      gap: 28px;
      align-items: center;
    }
    .nav-links a {
      color: rgba(255,255,255,0.9);
      font-weight: 500;
      font-size: 0.95rem;
      padding: 6px 0;
      border-bottom: 2px solid transparent;
      transition: 0.2s;
    }
    .nav-links a:hover, .nav-links a.active {
      color: var(--skyblue);
      border-bottom-color: var(--skyblue);
    }
    .btn-nav-register {
      background: var(--primary);
      color: white;
      padding: 10px 22px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      margin-left: 12px;
    }
    .btn-nav-register:hover {
      background: var(--primary-deep);
      transform: translateY(-1px);
    }
    /* 移动底部tab */
    .mobile-bottom-nav {
      display: none;
      position: fixed;
      bottom: 0;
      left: 0;
      width: 100%;
      background: white;
      border-top: 1px solid rgba(0,0,0,0.06);
      justify-content: space-around;
      padding: 8px 0 12px;
      z-index: 999;
      box-shadow: 0 -4px 12px rgba(0,0,0,0.04);
    }
    .mobile-tab {
      display: flex;
      flex-direction: column;
      align-items: center;
      font-size: 0.7rem;
      color: var(--text-secondary);
      gap: 4px;
    }
    .mobile-tab i {
      font-size: 1.3rem;
      color: inherit;
    }
    .mobile-tab.active {
      color: var(--primary);
      font-weight: 600;
    }
    /* 汉堡菜单 */
    .hamburger {
      display: none;
      flex-direction: column;
      gap: 5px;
      cursor: pointer;
    }
    .hamburger span {
      width: 24px;
      height: 2.5px;
      background: white;
      border-radius: 2px;
    }
    .mobile-menu {
      display: none;
      position: fixed;
      top: var(--header-height);
      left: 0;
      width: 100%;
      background: rgba(28,28,30,0.98);
      backdrop-filter: blur(20px);
      flex-direction: column;
      padding: 24px;
      z-index: 998;
    }
    .mobile-menu a {
      color: white;
      padding: 14px 0;
      border-bottom: 1px solid rgba(255,255,255,0.1);
      font-weight: 500;
    }
    /* Hero */
    .hero {
      min-height: 100vh;
      display: flex;
      align-items: center;
      background: linear-gradient(135deg, rgba(28,28,30,0.7) 0%, rgba(122,26,46,0.3) 100%), url('/assets/images/backpic/back-1.webp') center/cover no-repeat;
      position: relative;
      color: white;
      padding-top: var(--header-height);
    }
    .hero-content {
      max-width: 700px;
      padding: 40px 0;
    }
    .hero h1 {
      font-size: clamp(2.4rem, 6vw, 4.5rem);
      font-weight: 800;
      letter-spacing: -0.02em;
      line-height: 1.2;
      margin-bottom: 20px;
    }
    .hero-sub {
      font-size: 1.2rem;
      opacity: 0.9;
      margin-bottom: 36px;
    }
    .hero-buttons {
      display: flex;
      gap: 16px;
      flex-wrap: wrap;
    }
    .btn-primary {
      background: var(--primary);
      color: white;
      padding: 15px 36px;
      border-radius: var(--radius-btn);
      font-weight: 700;
      box-shadow: 0 6px 16px rgba(122,26,46,0.3);
    }
    .btn-primary:hover {
      background: var(--primary-deep);
      transform: translateY(-2px);
    }
    .btn-outline {
      border: 2px solid white;
      color: white;
      padding: 15px 36px;
      border-radius: var(--radius-btn);
      font-weight: 600;
    }
    .btn-outline:hover {
      background: rgba(255,255,255,0.1);
    }
    .floating-stat {
      position: absolute;
      right: 8%;
      bottom: 15%;
      background: rgba(255,255,255,0.12);
      backdrop-filter: blur(12px);
      padding: 16px 24px;
      border-radius: 14px;
      font-weight: 700;
    }
    /* sections */
    section {
      padding: 90px 0;
    }
    .section-title {
      font-size: 2.4rem;
      font-weight: 700;
      text-align: center;
      margin-bottom: 16px;
    }
    .title-decor {
      width: 56px;
      height: 4px;
      background: var(--skyblue);
      margin: 0 auto 48px;
      border-radius: 2px;
    }
    .bg-light {
      background: var(--gray-light);
    }
    .bg-dark {
      background: var(--dark);
      color: white;
    }
    /* 优势卡片 */
    .grid-4 {
      display: grid;
      grid-template-columns: repeat(4,1fr);
      gap: 28px;
    }
    .advantage-card {
      background: white;
      padding: 32px 20px;
      border-radius: var(--radius-card);
      box-shadow: var(--shadow-card);
      text-align: center;
    }
    .icon-circle {
      width: 60px;
      height: 60px;
      background: var(--skyblue-light);
      border-radius: 50%;
      display: flex;
      align-items: center;
      justify-content: center;
      margin: 0 auto 20px;
      color: var(--skyblue);
      font-size: 1.8rem;
    }
    /* 服务网格 */
    .grid-2x2 {
      display: grid;
      grid-template-columns: repeat(2,1fr);
      gap: 32px;
    }
    .service-card {
      background: white;
      border-radius: var(--radius-card);
      padding: 28px;
      display: flex;
      gap: 24px;
      box-shadow: var(--shadow-card);
      transition: all 0.3s;
    }
    .service-card:hover {
      transform: translateY(-5px);
      box-shadow: var(--shadow-hover);
      border-left: 4px solid var(--primary);
    }
    /* 数据统计 */
    .stats-grid {
      display: grid;
      grid-template-columns: repeat(4,1fr);
      gap: 24px;
      text-align: center;
    }
    .stat-number {
      font-size: 3rem;
      font-weight: 800;
      color: var(--gold);
    }
    /* 案例卡片 */
    .cases-grid {
      display: grid;
      grid-template-columns: repeat(2,1fr);
      gap: 32px;
    }
    .case-card {
      background: white;
      border-radius: var(--radius-card);
      overflow: hidden;
      display: flex;
      flex-direction: column;
    }
    /* faq */
    .faq-item {
      border-bottom: 1px solid var(--border-light);
    }
    .faq-question {
      width: 100%;
      text-align: left;
      padding: 20px 8px;
      font-weight: 600;
      font-size: 1.1rem;
      display: flex;
      justify-content: space-between;
      background: transparent;
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: 0.3s;
      padding: 0 8px;
    }
    .faq-answer.open {
      max-height: 160px;
      padding-bottom: 16px;
    }
    .cta-banner {
      background: linear-gradient(120deg, #7A1A2E 0%, #1C1C1E 100%);
      padding: 70px 0;
      text-align: center;
      color: white;
    }
    footer {
      background: var(--dark);
      color: #ccc;
      padding: 60px 0 30px;
    }
    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1.5fr;
      gap: 32px;
    }
    @media (max-width: 1024px) {
      .grid-4 { grid-template-columns: repeat(2,1fr); }
      .stats-grid { grid-template-columns: repeat(2,1fr); }
    }
    @media (max-width: 768px) {
      .desktop-nav .nav-links { display: none; }
      .hamburger { display: flex; }
      .mobile-bottom-nav { display: flex; }
      .grid-2x2, .cases-grid { grid-template-columns: 1fr; }
      .footer-grid { grid-template-columns: 1fr; }
      .hero h1 { font-size: 2.5rem; }
    }