/* roulang page: index */
:root {
      --bg-primary: #0A0E17;
      --bg-secondary: #0F1520;
      --bg-card: #1B2330;
      --border-color: #2C3A4D;
      --accent: #E62E2E;
      --accent-hover: #FF3B3B;
      --text-primary: #FFFFFF;
      --text-secondary: #B0B8C5;
      --text-muted: #6B7383;
      --success: #00C897;
      --warning: #F5A623;
      --font-sans: 'PingFang SC', 'Microsoft YaHei', 'Helvetica Neue', sans-serif;
      --font-mono: 'DIN Alternate', 'Roboto Mono', 'SF Mono', monospace;
      --radius-card: 8px;
      --radius-btn: 4px;
      --shadow-card: 0 4px 20px rgba(0, 0, 0, 0.25);
      --shadow-glow: 0 8px 32px rgba(230, 46, 46, 0.15);
      --container-max: 1280px;
      --header-height: 64px;
    }

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

    body {
      font-family: var(--font-sans);
      background-color: var(--bg-primary);
      color: var(--text-secondary);
      line-height: 1.75;
      font-size: 16px;
      -webkit-font-smoothing: antialiased;
      scroll-behavior: smooth;
    }

    .container {
      max-width: var(--container-max);
      margin: 0 auto;
      padding: 0 24px;
    }

    h1, h2, h3, h4 {
      color: var(--text-primary);
      font-weight: 700;
      letter-spacing: -0.3px;
    }

    h1 {
      font-size: 48px;
      line-height: 1.2;
      margin-bottom: 16px;
    }

    h2 {
      font-size: 32px;
      margin-bottom: 24px;
      position: relative;
      display: inline-block;
    }

    h2::after {
      content: '';
      position: absolute;
      left: 0;
      bottom: -8px;
      width: 48px;
      height: 3px;
      background: var(--accent);
      border-radius: 2px;
    }

    h3 {
      font-size: 20px;
      margin-bottom: 12px;
      font-weight: 600;
    }

    p {
      margin-bottom: 1.2em;
    }

    a {
      color: var(--text-secondary);
      text-decoration: none;
      transition: color 0.2s;
    }

    a:hover {
      color: var(--text-primary);
    }

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

    button, .btn {
      cursor: pointer;
      font-family: inherit;
    }

    /* 导航 */
    .header {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: var(--header-height);
      background: rgba(10, 14, 23, 0.92);
      backdrop-filter: blur(12px);
      border-bottom: 1px solid var(--border-color);
      z-index: 100;
      display: flex;
      align-items: center;
    }

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

    .logo {
      font-size: 22px;
      font-weight: 700;
      color: var(--text-primary);
      letter-spacing: 1px;
      white-space: nowrap;
    }
    .logo span {
      color: var(--accent);
    }

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

    .nav-links a {
      font-size: 15px;
      font-weight: 500;
      color: var(--text-secondary);
      padding: 8px 0;
      border-bottom: 2px solid transparent;
      transition: all 0.2s;
    }

    .nav-links a:hover,
    .nav-links a.active {
      color: var(--text-primary);
      border-bottom-color: var(--accent);
    }

    .hamburger {
      display: none;
      flex-direction: column;
      gap: 5px;
      background: none;
      border: none;
      width: 28px;
      height: 20px;
      justify-content: center;
    }
    .hamburger span {
      width: 100%;
      height: 2px;
      background: var(--text-primary);
      border-radius: 2px;
      transition: 0.2s;
    }

    /* 板块通用 */
    .section {
      padding: 80px 0;
    }

    .section-dark {
      background-color: var(--bg-secondary);
    }

    .section-deep {
      background-color: #080C12;
    }

    /* 按钮 */
    .btn-primary {
      background: var(--accent);
      color: white;
      border: none;
      padding: 0 28px;
      height: 48px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      font-size: 16px;
      display: inline-flex;
      align-items: center;
      justify-content: center;
      transition: background 0.2s ease, transform 0.1s;
      text-decoration: none;
    }
    .btn-primary:hover {
      background: var(--accent-hover);
      color: white;
      transform: translateY(-1px);
    }

    .btn-secondary {
      background: transparent;
      color: var(--accent);
      border: 1.5px solid var(--accent);
      padding: 0 28px;
      height: 48px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      font-size: 16px;
      display: inline-flex;
      align-items: center;
      justify-content: center;
      transition: all 0.2s;
      text-decoration: none;
    }
    .btn-secondary:hover {
      background: rgba(230, 46, 46, 0.1);
      color: var(--accent-hover);
      border-color: var(--accent-hover);
    }

    /* 卡片 */
    .card {
      background: var(--bg-card);
      border: 1px solid var(--border-color);
      border-radius: var(--radius-card);
      padding: 24px;
      box-shadow: var(--shadow-card);
      transition: transform 0.25s ease, box-shadow 0.25s ease;
    }
    .card:hover {
      transform: translateY(-4px);
      box-shadow: var(--shadow-glow);
    }

    /* Hero */
    .hero {
      padding: 120px 0 80px;
      display: flex;
      align-items: center;
      gap: 48px;
      background-image: url('/assets/images/backpic/back-1.webp');
      background-size: cover;
      background-position: center;
      position: relative;
      background-blend-mode: overlay;
      background-color: rgba(10, 14, 23, 0.75);
    }

    .hero-content {
      flex: 1;
    }
    .hero-data {
      flex: 1;
      display: flex;
      gap: 20px;
      justify-content: flex-end;
    }
    .metric-card {
      background: rgba(27, 35, 48, 0.8);
      backdrop-filter: blur(8px);
      border: 1px solid var(--border-color);
      border-radius: var(--radius-card);
      padding: 24px;
      text-align: center;
      min-width: 140px;
    }
    .metric-number {
      font-family: var(--font-mono);
      font-size: 48px;
      font-weight: 700;
      color: var(--accent);
      line-height: 1.2;
    }
    .metric-label {
      color: var(--text-secondary);
      margin-top: 8px;
      font-size: 14px;
    }

    /* 优势卡片非对称 */
    .advantages-grid {
      display: grid;
      grid-template-columns: 5fr 3.5fr 3.5fr;
      gap: 24px;
      margin-top: 32px;
    }

    /* 服务矩阵 */
    .service-row {
      display: flex;
      flex-direction: column;
      gap: 24px;
      margin-top: 32px;
    }
    .service-item {
      display: flex;
      background: var(--bg-card);
      border-radius: var(--radius-card);
      overflow: hidden;
      border: 1px solid var(--border-color);
      transition: all 0.25s;
    }
    .service-item:hover {
      border-color: var(--accent);
      box-shadow: var(--shadow-glow);
    }
    .service-img {
      width: 200px;
      flex-shrink: 0;
      background-color: #0F1520;
    }
    .service-img img {
      width: 100%;
      height: 100%;
      object-fit: cover;
    }
    .service-text {
      padding: 24px;
      flex: 1;
    }
    .tags {
      display: flex;
      flex-wrap: wrap;
      gap: 8px;
      margin: 12px 0;
    }
    .tag {
      background: #2C3A4D;
      color: #B0B8C5;
      padding: 4px 12px;
      border-radius: 20px;
      font-size: 13px;
    }

    /* 对比表 */
    .compare-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 32px;
      margin-top: 32px;
    }
    .compare-card {
      padding: 28px;
      border-radius: var(--radius-card);
    }
    .compare-left {
      background: #1B2330;
      border: 1px solid #2C3A4D;
    }
    .compare-right {
      background: #15202B;
      border: 1px solid var(--success);
      box-shadow: 0 0 20px rgba(0, 200, 151, 0.08);
    }
    .compare-row {
      display: flex;
      justify-content: space-between;
      padding: 14px 0;
      border-bottom: 1px solid #2C3A4D;
    }

    /* FAQ */
    .faq-list {
      margin-top: 24px;
    }
    .faq-item {
      background: var(--bg-card);
      border-radius: var(--radius-card);
      margin-bottom: 12px;
      overflow: hidden;
    }
    .faq-question {
      padding: 20px 24px;
      font-weight: 600;
      font-size: 18px;
      color: var(--text-primary);
      cursor: pointer;
      display: flex;
      justify-content: space-between;
      align-items: center;
      background: #1B2330;
      border: none;
      width: 100%;
      text-align: left;
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.3s ease;
      background: #141C27;
      padding: 0 24px;
      color: var(--text-secondary);
    }
    .faq-answer.open {
      max-height: 200px;
      padding: 20px 24px;
    }

    /* 表单 */
    .form-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 40px;
      margin-top: 32px;
    }
    .input-field {
      width: 100%;
      background: #0A0E17;
      border: 1px solid #2C3A4D;
      border-radius: 4px;
      padding: 14px 16px;
      color: white;
      font-size: 16px;
      margin-bottom: 16px;
      transition: border 0.2s;
    }
    .input-field:focus {
      outline: none;
      border-color: var(--accent);
    }
    .trust-badge {
      display: flex;
      align-items: center;
      gap: 16px;
      margin-bottom: 24px;
      color: var(--text-primary);
    }
    .badge-icon {
      font-size: 24px;
      color: var(--accent);
    }

    /* 页脚 */
    .footer {
      background: #06090F;
      padding: 32px 0;
      display: flex;
      justify-content: space-between;
      color: var(--text-muted);
      font-size: 14px;
      border-top: 1px solid #1B2330;
    }

    @media (max-width: 1024px) {
      .hero {
        flex-direction: column;
        padding: 100px 24px 60px;
      }
      .hero-data {
        justify-content: center;
        flex-wrap: wrap;
      }
      .advantages-grid {
        grid-template-columns: 1fr 1fr;
      }
      .compare-grid {
        grid-template-columns: 1fr;
      }
      .form-grid {
        grid-template-columns: 1fr;
      }
      .service-img {
        width: 150px;
      }
      h1 {
        font-size: 36px;
      }
      h2 {
        font-size: 28px;
      }
    }

    @media (max-width: 768px) {
      .nav-links {
        display: none;
        position: fixed;
        top: var(--header-height);
        left: 0;
        width: 100%;
        background: rgba(10,14,23,0.98);
        flex-direction: column;
        padding: 32px;
        gap: 24px;
        backdrop-filter: blur(16px);
      }
      .nav-links.mobile-open {
        display: flex;
      }
      .hamburger {
        display: flex;
      }
      .advantages-grid {
        grid-template-columns: 1fr;
      }
      .service-item {
        flex-direction: column;
      }
      .service-img {
        width: 100%;
        height: 180px;
      }
      .hero {
        text-align: center;
      }
      .metric-card {
        min-width: 100px;
      }
      .metric-number {
        font-size: 36px;
      }
      h1 {
        font-size: 32px;
      }
      h2 {
        font-size: 24px;
      }
      .footer {
        flex-direction: column;
        gap: 12px;
        text-align: center;
      }
    }