/* roulang page: index */
:root {
      --primary: #D32F2F;
      --primary-dark: #B71C1C;
      --primary-light: rgba(211, 47, 47, 0.08);
      --secondary: #1A1A1A;
      --accent: #F5A623;
      --bg-light: #FAFAFA;
      --bg-gray: #F0F0F0;
      --card-bg: #FFFFFF;
      --card-hover: #F5F5F5;
      --text-main: #1A1A1A;
      --text-secondary: #555555;
      --text-light: #FFFFFF;
      --text-muted: rgba(255,255,255,0.7);
      --border-light: #E5E5E5;
      --radius-sm: 8px;
      --radius-md: 12px;
      --radius-lg: 20px;
      --shadow-sm: 0 4px 20px rgba(0,0,0,0.04);
      --shadow-hover: 0 12px 28px rgba(0,0,0,0.08);
      --font-sans: "PingFang SC", "Microsoft YaHei", "Helvetica Neue", sans-serif;
      --font-number: "Inter", "Roboto", sans-serif;
      --max-width: 1280px;
      --nav-height: 72px;
    }
    * {
      margin: 0;
      padding: 0;
      box-sizing: border-box;
    }
    body {
      font-family: var(--font-sans);
      background-color: var(--bg-light);
      color: var(--text-main);
      line-height: 1.7;
      font-size: 16px;
      -webkit-font-smoothing: antialiased;
    }
    img {
      max-width: 100%;
      display: block;
    }
    a {
      text-decoration: none;
      color: inherit;
      transition: color 0.2s;
    }
    button, input, textarea {
      font-family: inherit;
    }
    .container {
      max-width: var(--max-width);
      margin: 0 auto;
      padding: 0 24px;
      width: 100%;
    }
    /* 导航 */
    .nav {
      position: sticky;
      top: 0;
      z-index: 50;
      background: rgba(255,255,255,0.92);
      backdrop-filter: blur(8px);
      height: var(--nav-height);
      display: flex;
      align-items: center;
      border-bottom: 1px solid rgba(0,0,0,0.04);
      box-shadow: 0 1px 8px rgba(0,0,0,0.04);
    }
    .nav .container {
      display: flex;
      align-items: center;
      justify-content: space-between;
    }
    .logo {
      font-weight: 700;
      font-size: 22px;
      color: var(--primary);
      display: flex;
      align-items: center;
      gap: 8px;
    }
    .logo span {
      color: var(--secondary);
      font-weight: 600;
    }
    .nav-links {
      display: flex;
      align-items: center;
      gap: 8px;
      list-style: none;
    }
    .nav-links a {
      padding: 10px 18px;
      border-radius: 40px;
      font-weight: 500;
      color: var(--text-secondary);
      transition: background 0.2s, color 0.2s;
    }
    .nav-links a:hover {
      background: var(--primary-light);
      color: var(--primary);
    }
    .btn-nav {
      background: var(--primary);
      color: white !important;
      font-weight: 600;
      margin-left: 12px;
    }
    .btn-nav:hover {
      background: var(--primary-dark) !important;
    }
    .hamburger {
      display: none;
      flex-direction: column;
      gap: 5px;
      cursor: pointer;
      background: none;
      border: none;
      padding: 8px;
    }
    .hamburger span {
      width: 24px;
      height: 2px;
      background: var(--secondary);
      transition: 0.2s;
      display: block;
    }
    @media (max-width: 768px) {
      .nav-links {
        position: fixed;
        top: 0;
        left: 0;
        width: 100%;
        height: 100vh;
        background: white;
        flex-direction: column;
        justify-content: center;
        align-items: center;
        gap: 24px;
        display: none;
        z-index: 40;
      }
      .nav-links.active {
        display: flex;
      }
      .hamburger {
        display: flex;
        z-index: 50;
      }
      .btn-nav {
        margin-left: 0;
      }
    }
    /* Hero */
    .hero {
      background: linear-gradient(135deg, rgba(211,47,47,0.88) 0%, rgba(26,26,26,0.7) 100%), url('/assets/images/backpic/back-1.webp') center/cover no-repeat;
      min-height: 85vh;
      display: flex;
      align-items: center;
      color: white;
      position: relative;
    }
    .hero .container {
      display: flex;
      align-items: center;
      gap: 48px;
      flex-wrap: wrap;
    }
    .hero-content {
      flex: 1 1 400px;
    }
    .hero h1 {
      font-size: 48px;
      font-weight: 700;
      letter-spacing: -0.5px;
      line-height: 1.2;
      margin-bottom: 20px;
    }
    .hero-sub {
      font-size: 18px;
      color: rgba(255,255,255,0.9);
      margin-bottom: 32px;
      max-width: 500px;
    }
    .btn-primary {
      background: var(--primary);
      color: white;
      font-weight: 600;
      padding: 14px 36px;
      border-radius: var(--radius-sm);
      display: inline-block;
      transition: background 0.25s, transform 0.2s;
      border: none;
      cursor: pointer;
      font-size: 16px;
    }
    .btn-primary:hover {
      background: var(--primary-dark);
      transform: translateY(-2px);
    }
    .hero-image {
      flex: 1 1 400px;
      position: relative;
    }
    .hero-image img {
      border-radius: var(--radius-md);
      box-shadow: 0 20px 40px rgba(0,0,0,0.3);
      width: 100%;
    }
    @media (max-width: 768px) {
      .hero {
        min-height: auto;
        padding: 60px 0;
      }
      .hero h1 {
        font-size: 32px;
      }
    }
    /* 数据看板 */
    .metrics {
      background: var(--secondary);
      padding: 80px 0;
    }
    .metrics-grid {
      display: grid;
      grid-template-columns: repeat(3,1fr);
      gap: 32px;
      text-align: center;
    }
    .metric-item .number {
      font-family: var(--font-number);
      font-size: 56px;
      font-weight: 800;
      color: var(--accent);
      display: block;
    }
    .metric-item .label {
      color: rgba(255,255,255,0.7);
      font-size: 16px;
      margin-top: 8px;
    }
    @media (max-width: 768px) {
      .metrics-grid {
        grid-template-columns: 1fr;
      }
      .metric-item .number {
        font-size: 40px;
      }
    }
    /* 通用板块 */
    section {
      padding: 100px 0;
    }
    .section-title {
      font-size: 36px;
      font-weight: 600;
      margin-bottom: 16px;
    }
    .section-sub {
      color: var(--text-secondary);
      margin-bottom: 48px;
    }
    /* 服务矩阵 */
    .services-grid {
      display: grid;
      grid-template-columns: repeat(2,1fr);
      gap: 24px;
    }
    .service-card {
      background: var(--card-bg);
      border-radius: var(--radius-md);
      padding: 28px 24px;
      box-shadow: var(--shadow-sm);
      transition: all 0.25s;
      display: flex;
      flex-direction: column;
      position: relative;
      overflow: hidden;
    }
    .service-card:hover {
      transform: translateY(-4px);
      box-shadow: var(--shadow-hover);
      background: var(--card-hover);
    }
    .service-card::before {
      content: '';
      position: absolute;
      top: 0;
      left: 0;
      width: 16px;
      height: 16px;
      background: var(--primary);
      border-radius: 0 0 8px 0;
    }
    .service-icon {
      font-size: 28px;
      color: var(--primary);
      margin-bottom: 16px;
    }
    .service-card h3 {
      font-size: 20px;
      font-weight: 600;
      margin-bottom: 8px;
    }
    .service-desc {
      color: var(--text-secondary);
      font-size: 15px;
      margin-bottom: 16px;
    }
    .service-img {
      width: 60px;
      height: 60px;
      object-fit: cover;
      border-radius: 8px;
      align-self: flex-end;
      margin-top: auto;
    }
    @media (max-width: 768px) {
      .services-grid {
        grid-template-columns: 1fr;
      }
    }
    /* 对比 */
    .comparison-wrapper {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 24px;
    }
    .comp-col {
      background: white;
      border-radius: var(--radius-md);
      padding: 32px;
      box-shadow: var(--shadow-sm);
    }
    .comp-col.highlight {
      background: var(--primary);
      color: white;
    }
    .comp-row {
      display: flex;
      justify-content: space-between;
      padding: 12px 0;
      border-bottom: 1px solid var(--border-light);
    }
    .comp-col.highlight .comp-row {
      border-color: rgba(255,255,255,0.2);
    }
    .gold-check {
      color: var(--accent);
      font-weight: bold;
    }
    @media (max-width: 768px) {
      .comparison-wrapper {
        grid-template-columns: 1fr;
      }
    }
    /* FAQ */
    .faq-item {
      background: white;
      border-radius: var(--radius-md);
      margin-bottom: 16px;
      box-shadow: var(--shadow-sm);
      overflow: hidden;
      transition: all 0.3s;
    }
    .faq-question {
      padding: 20px 24px;
      font-weight: 600;
      font-size: 18px;
      cursor: pointer;
      display: flex;
      justify-content: space-between;
      align-items: center;
      background: white;
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.3s ease;
      padding: 0 24px;
      color: var(--text-secondary);
    }
    .faq-item.active {
      border-left: 4px solid var(--primary);
    }
    .faq-item.active .faq-answer {
      max-height: 200px;
      padding: 0 24px 20px;
    }
    /* 表单 */
    .contact-form {
      background: white;
      border-radius: var(--radius-md);
      padding: 40px;
      max-width: 480px;
      margin: 0 auto;
      box-shadow: var(--shadow-sm);
    }
    .form-group {
      margin-bottom: 20px;
    }
    input, textarea {
      width: 100%;
      padding: 14px 16px;
      border: 1px solid var(--border-light);
      border-radius: var(--radius-sm);
      font-size: 16px;
      transition: border 0.2s;
    }
    input:focus, textarea:focus {
      outline: none;
      border-color: var(--primary);
    }
    .btn-full {
      width: 100%;
    }
    /* 页脚 */
    .footer {
      background: var(--secondary);
      color: rgba(255,255,255,0.8);
      padding: 60px 0 20px;
    }
    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1fr;
      gap: 32px;
    }
    .footer a:hover {
      color: var(--primary);
    }
    .copyright {
      border-top: 1px solid rgba(255,255,255,0.1);
      margin-top: 40px;
      padding-top: 20px;
      text-align: center;
      font-size: 14px;
    }
    @media (max-width: 768px) {
      .footer-grid {
        grid-template-columns: 1fr;
      }
    }