/* roulang page: index */
:root {
      --primary: #0B2B26;
      --primary-light: #15473E;
      --accent: #FF6A3D;
      --accent-hover: #E55A2B;
      --bg: #F5F7F6;
      --card-bg: #FFFFFF;
      --text: #1A1A1A;
      --text-muted: #5A6A66;
      --border: #E0E4E2;
      --radius-card: 12px;
      --radius-btn: 8px;
      --radius-tag: 6px;
      --shadow-sm: 0 2px 12px rgba(0,0,0,0.04);
      --shadow-hover: 0 8px 24px rgba(11,43,38,0.12);
      --font-mono: "DIN Alternate", "Roboto Mono", monospace;
      --font-sans: "PingFang SC", "Microsoft YaHei", "Hiragino Sans GB", sans-serif;
      --spacing-section: 80px;
      --container-max: 1200px;
    }

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

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

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

    a {
      text-decoration: none;
      color: inherit;
    }

    button, input {
      font-family: inherit;
    }

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

    /* 导航 */
    #nav {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      background: rgba(255,255,255,0.98);
      backdrop-filter: blur(8px);
      z-index: 50;
      height: 64px;
      border-bottom: 1px solid transparent;
      transition: border-color 0.2s;
      display: flex;
      align-items: center;
    }

    #nav.scrolled {
      border-bottom: 1px solid var(--border);
      box-shadow: 0 2px 8px rgba(0,0,0,0.02);
    }

    .nav-container {
      display: flex;
      align-items: center;
      justify-content: space-between;
      width: 100%;
      max-width: var(--container-max);
      margin: 0 auto;
      padding: 0 24px;
    }

    .logo {
      font-size: 20px;
      font-weight: 700;
      color: var(--primary);
      letter-spacing: -0.3px;
    }

    .nav-links {
      display: flex;
      align-items: center;
      gap: 28px;
      list-style: none;
    }

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

    .nav-links a:hover {
      color: var(--accent);
    }

    .btn-nav {
      background: var(--accent);
      color: white !important;
      padding: 8px 20px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      font-size: 14px;
    }

    .btn-nav:hover {
      background: var(--accent-hover);
    }

    .hamburger {
      display: none;
      flex-direction: column;
      gap: 5px;
      background: none;
      border: none;
      cursor: pointer;
    }

    .hamburger span {
      width: 24px;
      height: 2px;
      background: var(--primary);
      border-radius: 4px;
      transition: 0.2s;
    }

    .mobile-menu {
      display: none;
      position: fixed;
      top: 64px;
      left: 0;
      width: 100%;
      background: var(--primary);
      padding: 24px;
      flex-direction: column;
      gap: 20px;
      z-index: 45;
      list-style: none;
    }

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

    .mobile-menu a {
      color: white;
      font-size: 18px;
      font-weight: 500;
    }

    /* Hero */
    #hero {
      background: linear-gradient(135deg, #0B2B26 0%, #15473E 100%);
      min-height: 90vh;
      display: flex;
      align-items: center;
      padding-top: 80px;
      position: relative;
      overflow: hidden;
    }

    .hero-grid {
      display: flex;
      align-items: center;
      gap: 60px;
      width: 100%;
    }

    .hero-text {
      flex: 0 0 55%;
      color: white;
    }

    .hero-text h1 {
      font-size: 36px;
      font-weight: 700;
      line-height: 1.2;
      letter-spacing: -0.5px;
      margin-bottom: 16px;
    }

    .hero-text p {
      font-size: 16px;
      opacity: 0.9;
      margin-bottom: 32px;
      max-width: 480px;
    }

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

    .btn-primary {
      background: var(--accent);
      color: white;
      padding: 14px 32px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      font-size: 16px;
      border: none;
      cursor: pointer;
      transition: background 0.2s, transform 0.2s;
      display: inline-block;
    }

    .btn-primary:hover {
      background: var(--accent-hover);
      transform: scale(1.03);
    }

    .btn-secondary {
      background: transparent;
      color: white;
      border: 2px solid rgba(255,255,255,0.7);
      padding: 14px 32px;
      border-radius: var(--radius-btn);
      font-weight: 600;
      font-size: 16px;
      cursor: pointer;
      transition: 0.2s;
      display: inline-block;
    }

    .btn-secondary:hover {
      background: white;
      color: var(--primary);
      border-color: white;
    }

    .hero-visual {
      flex: 1;
      display: flex;
      align-items: center;
      justify-content: center;
      position: relative;
      height: 320px;
    }

    .data-ring {
      position: absolute;
      width: 140px;
      height: 140px;
      border-radius: 50%;
      border: 2px solid rgba(255,255,255,0.2);
      display: flex;
      flex-direction: column;
      align-items: center;
      justify-content: center;
      background: rgba(255,255,255,0.05);
      backdrop-filter: blur(4px);
      animation: float 4s infinite alternate;
    }

    .ring-1 { top: 0; left: 10%; }
    .ring-2 { bottom: 0; right: 5%; animation-delay: 1s; }
    .ring-3 { top: 40%; right: 20%; width: 110px; height: 110px; animation-delay: 0.5s; }

    .data-number {
      font-family: var(--font-mono);
      font-size: 28px;
      font-weight: 700;
      color: var(--accent);
    }

    .data-label {
      font-size: 12px;
      color: rgba(255,255,255,0.8);
    }

    @keyframes float {
      0% { transform: translateY(0); }
      100% { transform: translateY(-15px); }
    }

    /* 数据看板 */
    #dashboard {
      background: var(--primary);
      padding: 48px 0;
      margin-top: -1px;
    }

    .stats-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 32px;
      text-align: center;
    }

    .stat-item {
      color: white;
    }

    .stat-number {
      font-family: var(--font-mono);
      font-size: 36px;
      font-weight: 700;
      color: var(--accent);
    }

    .stat-label {
      font-size: 13px;
      color: #A0B2AE;
      margin-top: 8px;
    }

    /* 服务矩阵 */
    #services {
      padding: var(--spacing-section) 0;
    }

    .section-title {
      font-size: 28px;
      font-weight: 700;
      color: var(--primary);
      margin-bottom: 40px;
      text-align: center;
    }

    .services-grid {
      display: grid;
      grid-template-columns: repeat(2, 1fr);
      gap: 24px;
    }

    .service-card {
      background: var(--card-bg);
      border-radius: var(--radius-card);
      padding: 32px;
      box-shadow: var(--shadow-sm);
      transition: box-shadow 0.3s, transform 0.2s;
      display: flex;
      gap: 20px;
      align-items: flex-start;
    }

    .service-card:hover {
      box-shadow: var(--shadow-hover);
      transform: translateY(-4px);
      outline: 1px solid rgba(255,106,61,0.2);
    }

    .service-icon {
      width: 32px;
      height: 32px;
      background: var(--primary);
      border-radius: 8px;
      display: flex;
      align-items: center;
      justify-content: center;
      color: white;
      font-weight: 700;
      flex-shrink: 0;
    }

    .service-card h3 {
      font-size: 20px;
      font-weight: 600;
      color: var(--primary);
      margin-bottom: 8px;
    }

    .service-card p {
      color: var(--text-muted);
      font-size: 14px;
      line-height: 1.6;
    }

    /* 对比 */
    #compare {
      padding: var(--spacing-section) 0;
      background: white;
    }

    .compare-wrapper {
      display: flex;
      gap: 0;
      max-width: 900px;
      margin: 0 auto;
      border-radius: var(--radius-card);
      overflow: hidden;
      box-shadow: var(--shadow-sm);
    }

    .compare-col {
      flex: 1;
      padding: 40px;
    }

    .compare-left {
      background: #f0f2f1;
    }

    .compare-right {
      background: #F0F7F5;
      border-left: 2px solid var(--primary);
    }

    .compare-col h4 {
      font-size: 22px;
      margin-bottom: 24px;
    }

    .compare-row {
      display: flex;
      justify-content: space-between;
      padding: 12px 0;
      border-bottom: 1px solid var(--border);
      font-size: 15px;
    }

    /* 流程 */
    #how-it-works {
      padding: var(--spacing-section) 0;
    }

    .steps {
      display: flex;
      justify-content: space-between;
      align-items: center;
      position: relative;
    }

    .step {
      text-align: center;
      flex: 1;
    }

    .step-circle {
      width: 48px;
      height: 48px;
      background: var(--primary);
      color: white;
      border-radius: 50%;
      display: flex;
      align-items: center;
      justify-content: center;
      font-weight: 700;
      font-size: 20px;
      margin: 0 auto 12px;
    }

    .step p {
      font-weight: 600;
      color: var(--primary);
    }

    .step-line {
      flex: 0.2;
      height: 2px;
      background: var(--border);
      margin: 0 8px;
    }

    /* FAQ */
    #faq {
      padding: var(--spacing-section) 0;
      background: white;
    }

    .faq-list {
      max-width: 800px;
      margin: 0 auto;
    }

    .faq-item {
      border-bottom: 1px solid var(--border);
    }

    .faq-question {
      width: 100%;
      background: none;
      border: none;
      padding: 20px 0;
      font-size: 16px;
      font-weight: 600;
      text-align: left;
      display: flex;
      justify-content: space-between;
      cursor: pointer;
      color: var(--primary);
    }

    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.3s ease;
      font-size: 15px;
      color: var(--text-muted);
      padding: 0 0;
    }

    .faq-item.active .faq-answer {
      max-height: 200px;
      padding-bottom: 20px;
    }

    /* CTA */
    #cta {
      background: linear-gradient(180deg, #0B2B26 0%, #0A1F1C 100%);
      padding: 80px 0;
      text-align: center;
      color: white;
    }

    .cta-form {
      display: flex;
      max-width: 480px;
      margin: 32px auto 0;
      gap: 12px;
    }

    .cta-form input {
      flex: 1;
      padding: 14px;
      border-radius: var(--radius-btn);
      border: none;
      font-size: 16px;
    }

    /* Footer */
    #footer {
      background: #0A1F1C;
      color: #A0B2AE;
      padding: 60px 0 30px;
    }

    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1fr;
      gap: 40px;
    }

    @media (max-width: 1024px) {
      .hero-grid {
        flex-direction: column;
        text-align: center;
      }
      .hero-text {
        flex: unset;
      }
      .services-grid {
        grid-template-columns: 1fr;
      }
    }

    @media (max-width: 767px) {
      .nav-links { display: none; }
      .hamburger { display: flex; }
      .hero-text h1 { font-size: 28px; }
      .stats-grid { grid-template-columns: 1fr; }
      .compare-wrapper { flex-direction: column; }
      .steps { flex-direction: column; gap: 24px; }
      .step-line { display: none; }
      .cta-form { flex-direction: column; }
      .footer-grid { grid-template-columns: 1fr; }
    }