/* roulang page: index */
:root {
      --primary: #E8452D;
      --primary-hover: #C0392B;
      --primary-soft: rgba(232, 69, 45, 0.08);
      --secondary: #1E1E1E;
      --accent: #FFB800;
      --bg: #FAFAF7;
      --white: #FFFFFF;
      --text: #1A1A1A;
      --text-secondary: #5C5C5C;
      --border: #E5E5E0;
      --shadow-card: 0 2px 12px rgba(0,0,0,0.04);
      --shadow-card-hover: 0 8px 28px rgba(0,0,0,0.10);
      --radius-lg: 12px;
      --radius: 8px;
      --transition: 0.3s ease;
      --font-cn: "PingFang SC", "Microsoft YaHei", "Noto Sans SC", system-ui, sans-serif;
      --font-en: "Inter", "SF Pro Display", system-ui, sans-serif;
      --max-width: 1200px;
      --header-height: 68px;
    }

    * {
      margin: 0;
      padding: 0;
      box-sizing: border-box;
    }

    body {
      font-family: var(--font-cn);
      background-color: var(--bg);
      color: var(--text);
      line-height: 1.6;
      font-size: 16px;
      -webkit-font-smoothing: antialiased;
    }

    .container {
      max-width: var(--max-width);
      margin: 0 auto;
      padding: 0 20px;
    }

    /* 排版 */〤
    h1, h2, h3, h4 {
      font-weight: 700;
      line-height: 1.3;
    }

    h1 {
      font-size: 42px;
      letter-spacing: -0.5px;
      color: var(--white);
    }

    h2 {
      font-size: 32px;
      line-height: 1.25;
      color: var(--text);
      margin-bottom: 12px;
    }

    h3 {
      font-size: 20px;
      font-weight: 600;
      color: var(--text);
    }

    p {
      color: var(--text-secondary);
      line-height: 1.7;
    }

    a {
      text-decoration: none;
      color: inherit;
      transition: var(--transition);
    }

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

    /* 按钮系统 */
    .btn {
      display: inline-flex;
      align-items: center;
      justify-content: center;
      gap: 6px;
      font-weight: 600;
      border-radius: var(--radius);
      transition: var(--transition);
      cursor: pointer;
      border: 2px solid transparent;
      font-family: var(--font-cn);
      white-space: nowrap;
    }

    .btn-primary {
      background-color: var(--primary);
      color: white;
      padding: 14px 32px;
      border: none;
    }

    .btn-primary:hover {
      background-color: var(--primary-hover);
      transform: scale(1.03);
      box-shadow: 0 6px 16px rgba(232, 69, 45, 0.3);
    }

    .btn-outline {
      background: transparent;
      border: 2px solid var(--primary);
      color: var(--primary);
      padding: 14px 32px;
    }

    .btn-outline:hover {
      background-color: var(--primary-soft);
      transform: translateY(-2px);
    }

    .btn-white {
      background: white;
      color: var(--primary);
      padding: 14px 32px;
      border: none;
      font-weight: 700;
    }

    .btn-white:hover {
      background: #f0f0f0;
      transform: scale(1.02);
    }

    .btn-sm {
      padding: 10px 22px;
      font-size: 14px;
    }

    /* 导航 */
    .header {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: var(--header-height);
      background: var(--white);
      box-shadow: 0 1px 8px rgba(0,0,0,0.04);
      z-index: 100;
      display: flex;
      align-items: center;
    }

    .nav {
      display: flex;
      justify-content: space-between;
      align-items: center;
      width: 100%;
    }

    .logo {
      font-size: 24px;
      font-weight: 800;
      color: var(--primary);
      display: flex;
      align-items: center;
      gap: 6px;
      letter-spacing: -0.3px;
    }
    .logo i {
      font-size: 20px;
      color: var(--accent);
    }

    .nav-menu {
      display: flex;
      align-items: center;
      gap: 32px;
    }

    .nav-link {
      font-size: 15px;
      font-weight: 500;
      color: var(--secondary);
      transition: color 0.2s;
    }

    .nav-link:hover {
      color: var(--primary);
    }

    .hamburger {
      display: none;
      font-size: 24px;
      background: none;
      border: none;
      color: var(--secondary);
      cursor: pointer;
    }

    .nav-cta {
      margin-left: 16px;
    }

    /* 移动菜单 */
    .mobile-menu {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: 100vh;
      background: rgba(0,0,0,0.5);
      backdrop-filter: blur(4px);
      z-index: 99;
      display: none;
      flex-direction: column;
      align-items: center;
      justify-content: center;
      opacity: 0;
      transition: opacity 0.25s;
    }

    .mobile-menu.active {
      display: flex;
      opacity: 1;
    }

    .mobile-menu-content {
      background: white;
      width: 80%;
      max-width: 320px;
      border-radius: var(--radius-lg);
      padding: 40px 24px;
      display: flex;
      flex-direction: column;
      gap: 32px;
      text-align: center;
      box-shadow: var(--shadow-card-hover);
    }

    .mobile-nav-link {
      font-size: 20px;
      font-weight: 600;
      color: var(--secondary);
    }

    /* Hero */
    .hero {
      min-height: 100vh;
      display: flex;
      align-items: center;
      background: linear-gradient(135deg, rgba(30,30,30,0.85) 0%, rgba(25,25,25,0.7) 100%), url('/assets/images/backpic/back-1.webp') center/cover no-repeat;
      background-blend-mode: overlay;
      padding-top: var(--header-height);
    }

    .hero-content {
      max-width: 650px;
    }

    .hero-tag {
      color: var(--accent);
      font-weight: 600;
      font-size: 14px;
      letter-spacing: 2px;
      text-transform: uppercase;
      margin-bottom: 24px;
      display: inline-block;
      background: rgba(255,255,255,0.1);
      padding: 6px 14px;
      border-radius: 20px;
    }

    .hero-title {
      font-size: 48px;
      margin-bottom: 20px;
      line-height: 1.15;
    }

    .hero-sub {
      font-size: 18px;
      color: rgba(255,255,255,0.85);
      max-width: 500px;
      margin-bottom: 32px;
      line-height: 1.7;
    }

    .hero-buttons {
      display: flex;
      flex-wrap: wrap;
      gap: 16px;
    }

    .scroll-indicator {
      position: absolute;
      bottom: 30px;
      left: 50%;
      transform: translateX(-50%);
      color: rgba(255,255,255,0.8);
      font-size: 28px;
      animation: bounce 2s infinite;
    }

    @keyframes bounce {
      0%, 20%, 50%, 80%, 100% { transform: translateX(-50%) translateY(0); }
      40% { transform: translateX(-50%) translateY(-12px); }
      60% { transform: translateX(-50%) translateY(-6px); }
    }

    /* 版块通用 */
    section {
      padding: 100px 0;
    }

    .section-title {
      text-align: center;
      margin-bottom: 56px;
    }
    .section-title h2 {
      margin-bottom: 8px;
    }
    .section-title p {
      color: var(--text-secondary);
      font-size: 17px;
    }

    /* 优势 */
    .grid-4 {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 24px;
    }

    .advantage-item {
      background: var(--white);
      padding: 28px;
      border-radius: var(--radius-lg);
      border: 1px solid var(--border);
      text-align: center;
      transition: var(--transition);
    }
    .advantage-item:hover {
      transform: translateY(-6px);
      box-shadow: var(--shadow-card-hover);
    }
    .icon-circle {
      width: 56px;
      height: 56px;
      background: rgba(232,69,45,0.08);
      border-radius: 50%;
      display: flex;
      align-items: center;
      justify-content: center;
      margin: 0 auto 20px;
      color: var(--primary);
      font-size: 24px;
    }

    /* 服务卡片 */
    .grid-3 {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
    }

    .service-card {
      background: white;
      border-radius: var(--radius-lg);
      overflow: hidden;
      border: 1px solid var(--border);
      transition: var(--transition);
    }
    .service-card:hover {
      transform: translateY(-4px);
      box-shadow: var(--shadow-card-hover);
    }
    .card-img {
      height: 200px;
      background-color: #f0f0ed;
      background-size: cover;
      background-position: center;
      display: flex;
      align-items: center;
      justify-content: center;
      color: #aaa;
    }
    .card-body {
      padding: 24px;
    }
    .card-link {
      color: var(--primary);
      font-weight: 600;
      margin-top: 10px;
      display: inline-block;
    }

    /* 数据统计 */
    .stats-grid {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      text-align: center;
      gap: 30px;
    }
    .stat-number {
      font-family: var(--font-en);
      font-size: 48px;
      font-weight: 800;
      color: var(--primary);
      line-height: 1.2;
    }
    .stat-label {
      color: var(--text-secondary);
      font-size: 16px;
    }

    /* 案例 */
    .case-card {
      background: white;
      border-radius: var(--radius-lg);
      overflow: hidden;
      border: 1px solid var(--border);
      transition: var(--transition);
    }
    .case-card:hover {
      transform: translateY(-5px);
      box-shadow: var(--shadow-card-hover);
    }
    .case-img {
      height: 180px;
      background: #ddd;
    }

    /* 流程 */
    .process-steps {
      display: flex;
      justify-content: space-between;
      align-items: flex-start;
      position: relative;
    }
    .process-steps::before {
      content: '';
      position: absolute;
      top: 28px;
      left: 8%;
      width: 84%;
      height: 2px;
      background: #E5E5E0;
      z-index: 0;
    }
    .step {
      display: flex;
      flex-direction: column;
      align-items: center;
      width: 22%;
      position: relative;
      z-index: 1;
    }
    .step-num {
      width: 56px;
      height: 56px;
      background: white;
      border: 2px solid #E5E5E0;
      border-radius: 50%;
      display: flex;
      align-items: center;
      justify-content: center;
      font-weight: 700;
      font-size: 22px;
      color: var(--text);
      margin-bottom: 16px;
      background: white;
    }
    .step.active .step-num {
      border-color: var(--primary);
      background: var(--primary);
      color: white;
      box-shadow: 0 0 0 6px rgba(232,69,45,0.15);
    }

    /* FAQ */
    .faq-list {
      max-width: 800px;
      margin: 0 auto;
    }
    .faq-item {
      border-bottom: 1px solid var(--border);
      padding: 18px 0;
    }
    .faq-question {
      display: flex;
      justify-content: space-between;
      align-items: center;
      cursor: pointer;
      font-weight: 600;
      font-size: 18px;
      color: var(--text);
      background: none;
      border: none;
      width: 100%;
      text-align: left;
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.35s ease;
      color: var(--text-secondary);
      padding-right: 20px;
    }
    .faq-item.active .faq-answer {
      max-height: 140px;
      margin-top: 12px;
    }
    .faq-icon {
      transition: transform 0.3s;
    }
    .faq-item.active .faq-icon {
      transform: rotate(45deg);
    }

    /* CTA */
    .cta-block {
      background: var(--primary);
      padding: 80px 0;
      text-align: center;
    }
    .cta-block h2 {
      color: white;
      font-size: 32px;
    }
    .cta-block p {
      color: rgba(255,255,255,0.9);
      margin: 16px 0 28px;
    }

    /* Footer */
    .footer {
      background: #1E1E1E;
      color: #CCCCCC;
      padding: 60px 0 20px;
    }
    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1fr;
      gap: 30px;
      margin-bottom: 40px;
    }
    .footer a:hover {
      color: white;
    }

    @media (max-width: 1024px) {
      .grid-4 { grid-template-columns: repeat(2,1fr); }
      .stats-grid { grid-template-columns: repeat(2,1fr); }
    }

    @media (max-width: 768px) {
      .nav-menu { display: none; }
      .hamburger { display: block; }
      .grid-3, .grid-4, .footer-grid { grid-template-columns: 1fr; }
      .process-steps { flex-direction: column; align-items: center; gap: 30px; }
      .process-steps::before { display: none; }
      .step { width: 80%; }
      h1 { font-size: 32px; }
      h2 { font-size: 26px; }
      section { padding: 70px 0; }
      .hero { min-height: 90vh; }
    }