/* roulang page: index */
/* ----- 设计变量与重置 ----- */
    :root {
      --primary-deep-green: #0B2B1F;
      --accent-racing-orange: #F15A24;
      --gold-highlight: #E8A817;
      --bg-warm-white: #F9F7F4;
      --card-white: #FFFFFF;
      --text-dark: #2C2C2C;
      --text-muted-green: #889C93;
      --text-light-green: #B7C9C0;
      --border-light: #E0E0E0;
      --shadow-sm: 0 2px 12px rgba(0,0,0,0.04);
      --shadow-hover: 0 8px 24px rgba(0,0,0,0.08);
      --radius-card: 12px;
      --radius-btn: 8px;
      --transition-base: 0.25s ease;
      
      --font-heading: 'Noto Sans SC', sans-serif;
      --font-body: 'Inter', 'Noto Sans SC', sans-serif;
      --font-metrics: 'Inter', 'DIN Alternate', sans-serif;
      
      --max-width: 1280px;
      --header-height: 72px;
    }

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

    html {
      scroll-behavior: smooth;
    }

    body {
      font-family: var(--font-body);
      background-color: var(--bg-warm-white);
      color: var(--text-dark);
      line-height: 1.7;
      font-size: 16px;
      font-weight: 400;
      -webkit-font-smoothing: antialiased;
    }

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

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

    button, input {
      font-family: var(--font-body);
      outline: none;
    }

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

    /* ----- 导航系统 (白底平台导航) ----- */
    #header {
      position: sticky;
      top: 0;
      z-index: 100;
      background: rgba(255,255,255,0.95);
      backdrop-filter: blur(10px);
      height: var(--header-height);
      display: flex;
      align-items: center;
      box-shadow: 0 1px 8px rgba(0,0,0,0.04);
      border-bottom: 1px solid rgba(0,0,0,0.03);
    }

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

    .logo {
      display: flex;
      align-items: center;
      gap: 8px;
      font-family: var(--font-heading);
      font-weight: 700;
      font-size: 20px;
      color: var(--primary-deep-green);
      letter-spacing: -0.3px;
    }

    .logo-icon {
      display: flex;
      align-items: center;
      justify-content: center;
      width: 28px;
      height: 28px;
      position: relative;
    }

    .logo-icon::before {
      content: "";
      width: 18px;
      height: 18px;
      background: var(--accent-racing-orange);
      border-radius: 50%;
      position: absolute;
      right: 0;
      bottom: 0;
    }

    .logo-icon::after {
      content: "";
      width: 8px;
      height: 8px;
      background: var(--primary-deep-green);
      border-radius: 2px;
      position: absolute;
      left: 0;
      top: 0;
    }

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

    .nav-links a {
      font-size: 16px;
      font-weight: 500;
      color: var(--text-dark);
      position: relative;
      padding: 4px 0;
      transition: color var(--transition-base);
    }

    .nav-links a::after {
      content: "";
      position: absolute;
      left: 0;
      bottom: -2px;
      width: 0;
      height: 2px;
      background: var(--accent-racing-orange);
      transition: width var(--transition-base);
    }

    .nav-links a:hover,
    .nav-links a.active {
      color: var(--accent-racing-orange);
    }

    .nav-links a:hover::after,
    .nav-links a.active::after {
      width: 100%;
    }

    .menu-toggle {
      display: none;
      background: none;
      border: none;
      font-size: 24px;
      color: var(--primary-deep-green);
      cursor: pointer;
    }

    /* 移动端抽屉菜单 */
    .mobile-drawer {
      position: fixed;
      top: 0;
      right: -100%;
      width: 280px;
      height: 100vh;
      background: var(--primary-deep-green);
      z-index: 200;
      transition: right 0.35s ease;
      padding: 32px 24px;
      display: flex;
      flex-direction: column;
      gap: 24px;
    }

    .mobile-drawer.open {
      right: 0;
    }

    .drawer-close {
      align-self: flex-end;
      background: none;
      border: none;
      color: white;
      font-size: 28px;
      cursor: pointer;
    }

    .mobile-drawer a {
      color: white;
      font-size: 18px;
      font-weight: 500;
      padding: 12px 16px;
      border-radius: 12px;
      background: rgba(255,255,255,0.08);
      transition: background var(--transition-base);
    }

    .mobile-drawer a:hover {
      background: var(--accent-racing-orange);
    }

    .overlay {
      position: fixed;
      inset: 0;
      background: rgba(0,0,0,0.5);
      z-index: 150;
      display: none;
    }

    .overlay.show {
      display: block;
    }

    /* ----- 板块通用样式 ----- */
    section {
      padding: 100px 0;
    }

    .section-title {
      font-family: var(--font-heading);
      font-weight: 700;
      font-size: 36px;
      line-height: 1.3;
      color: var(--primary-deep-green);
      text-align: center;
      margin-bottom: 16px;
    }

    .section-subtitle {
      text-align: center;
      color: var(--text-muted-green);
      max-width: 600px;
      margin: 0 auto 48px;
      font-size: 18px;
    }

    /* ----- Hero 首屏 ----- */
    #hero {
      background: radial-gradient(circle at 30% 30%, #0e3a28, #041A10);
      position: relative;
      overflow: hidden;
      padding: 0;
      min-height: 90vh;
      display: flex;
      align-items: center;
    }

    #hero::before {
      content: "";
      position: absolute;
      inset: 0;
      background-image: url('/assets/images/backpic/back-1.webp');
      background-size: cover;
      background-position: center;
      opacity: 0.25;
      mix-blend-mode: overlay;
    }

    .hero-container {
      display: flex;
      align-items: center;
      gap: 48px;
      position: relative;
      z-index: 2;
      width: 100%;
    }

    .hero-text {
      flex: 1 1 45%;
    }

    .hero-title {
      font-family: var(--font-heading);
      font-weight: 700;
      font-size: 48px;
      line-height: 1.2;
      color: white;
      letter-spacing: -0.5px;
      margin-bottom: 20px;
    }

    .hero-subtitle {
      font-size: 18px;
      color: var(--text-light-green);
      max-width: 480px;
      margin-bottom: 32px;
    }

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

    .btn-primary {
      background: var(--accent-racing-orange);
      color: white;
      font-weight: 500;
      font-size: 16px;
      padding: 14px 32px;
      border-radius: var(--radius-btn);
      border: none;
      cursor: pointer;
      letter-spacing: 0.5px;
      transition: background var(--transition-base), box-shadow var(--transition-base);
      display: inline-block;
      text-align: center;
    }

    .btn-primary:hover {
      background: #D9441A;
      box-shadow: 0 0 16px rgba(241,90,36,0.4);
    }

    .btn-secondary {
      background: transparent;
      color: white;
      border: 1.5px solid white;
      font-weight: 500;
      font-size: 16px;
      padding: 14px 32px;
      border-radius: var(--radius-btn);
      cursor: pointer;
      letter-spacing: 0.5px;
      transition: all var(--transition-base);
      display: inline-block;
      text-align: center;
    }

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

    .hero-visual {
      flex: 1 1 50%;
      display: flex;
      justify-content: center;
      align-items: center;
    }

    .hero-visual img {
      max-height: 420px;
      border-radius: 24px;
      box-shadow: 0 20px 40px rgba(0,0,0,0.4);
      animation: float 6s ease-in-out infinite;
    }

    @keyframes float {
      0% { transform: translateY(0); }
      50% { transform: translateY(-12px); }
      100% { transform: translateY(0); }
    }

    /* ----- 实时数据看板 ----- */
    #metrics {
      background: var(--primary-deep-green);
      color: white;
    }

    .metrics-grid {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 1px;
      background: rgba(255,255,255,0.1);
      border-radius: var(--radius-card);
      overflow: hidden;
    }

    .metric-item {
      background: rgba(255,255,255,0.05);
      backdrop-filter: blur(4px);
      padding: 32px 20px;
      text-align: center;
      display: flex;
      flex-direction: column;
      gap: 8px;
    }

    .metric-number {
      font-family: var(--font-metrics);
      font-weight: 700;
      font-size: 40px;
      line-height: 1.2;
      color: white;
    }

    .metric-label {
      font-size: 14px;
      color: var(--text-light-green);
    }

    .metric-icon {
      font-size: 24px;
      color: var(--accent-racing-orange);
      margin-bottom: 4px;
    }

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

    .service-card {
      background: var(--card-white);
      border-radius: var(--radius-card);
      padding: 28px 24px;
      box-shadow: var(--shadow-sm);
      display: flex;
      flex-direction: column;
      gap: 16px;
      border-left: 4px solid var(--accent-racing-orange);
      transition: transform var(--transition-base), box-shadow var(--transition-base), border-left-width var(--transition-base);
    }

    .service-card:hover {
      transform: translateY(-4px);
      box-shadow: var(--shadow-hover);
      border-left-width: 8px;
    }

    .service-icon {
      font-size: 36px;
      color: var(--accent-racing-orange);
    }

    .service-card h3 {
      font-family: var(--font-heading);
      font-weight: 700;
      font-size: 24px;
      color: var(--primary-deep-green);
    }

    .service-desc {
      font-size: 14px;
      color: #5a6e65;
    }

    .feature-list {
      list-style: none;
      display: flex;
      flex-direction: column;
      gap: 8px;
    }

    .feature-list li {
      font-size: 14px;
      display: flex;
      align-items: center;
      gap: 8px;
      color: var(--text-dark);
    }

    .feature-list i {
      color: var(--accent-racing-orange);
      font-size: 14px;
    }

    .card-link {
      color: var(--accent-racing-orange);
      font-weight: 500;
      margin-top: auto;
      display: inline-flex;
      align-items: center;
      gap: 4px;
      transition: gap var(--transition-base);
    }

    .card-link:hover {
      gap: 8px;
    }

    /* ----- 结果对比 ----- */
    .comparison-wrapper {
      display: flex;
      gap: 32px;
      align-items: stretch;
    }

    .compare-col {
      flex: 1;
      background: var(--card-white);
      border-radius: var(--radius-card);
      padding: 32px;
      box-shadow: var(--shadow-sm);
    }

    .compare-col.left {
      border: 1px solid #ddd;
      opacity: 0.8;
    }

    .compare-col.right {
      border: 2px solid var(--accent-racing-orange);
      background: #fef9f6;
    }

    .compare-col h3 {
      font-family: var(--font-heading);
      font-weight: 700;
      font-size: 24px;
      margin-bottom: 24px;
    }

    .compare-list {
      list-style: none;
      display: flex;
      flex-direction: column;
      gap: 20px;
    }

    .compare-list li {
      display: flex;
      align-items: center;
      gap: 12px;
      font-size: 16px;
    }

    .right .compare-list li i {
      color: var(--accent-racing-orange);
    }

    .left .compare-list li i {
      color: #999;
    }

    /* ----- FAQ 手风琴 ----- */
    .faq-list {
      max-width: 800px;
      margin: 0 auto;
    }

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

    .faq-question {
      width: 100%;
      background: none;
      border: none;
      padding: 20px 0;
      font-family: var(--font-heading);
      font-weight: 500;
      font-size: 18px;
      color: var(--primary-deep-green);
      display: flex;
      justify-content: space-between;
      align-items: center;
      cursor: pointer;
      text-align: left;
    }

    .faq-question i {
      transition: transform 0.3s ease;
      color: var(--accent-racing-orange);
    }

    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.3s ease;
      background: #F4F4F4;
      border-radius: 0 0 8px 8px;
    }

    .faq-answer p {
      padding: 20px;
      margin: 0;
      color: #333;
    }

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

    .faq-item.active .faq-question i {
      transform: rotate(180deg);
    }

    /* ----- 转化表单 ----- */
    #contact {
      background: linear-gradient(135deg, #0B2B1F 0%, #041A10 100%);
    }

    .contact-form {
      max-width: 680px;
      margin: 0 auto;
      display: flex;
      gap: 16px;
      flex-wrap: wrap;
      justify-content: center;
    }

    .contact-form input {
      flex: 1 1 200px;
      padding: 14px 16px;
      border-radius: var(--radius-btn);
      border: 1px solid #CCC;
      background: white;
      font-size: 16px;
      transition: border var(--transition-base), box-shadow var(--transition-base);
    }

    .contact-form input:focus {
      border-color: var(--accent-racing-orange);
      box-shadow: 0 0 0 3px rgba(241,90,36,0.2);
    }

    .privacy-note {
      text-align: center;
      margin-top: 16px;
      font-size: 12px;
      color: var(--text-light-green);
    }

    /* ----- 页脚 ----- */
    footer {
      background: #0A1F16;
      padding: 48px 24px;
      text-align: center;
      color: var(--text-muted-green);
    }

    .footer-logo {
      font-family: var(--font-heading);
      font-weight: 700;
      font-size: 20px;
      color: white;
      margin-bottom: 8px;
    }

    /* ----- 响应式设计 ----- */
    @media (max-width: 1024px) {
      .hero-container {
        flex-direction: column;
        text-align: center;
      }
      .hero-subtitle {
        max-width: 100%;
      }
      .hero-cta {
        justify-content: center;
      }
      .services-grid {
        grid-template-columns: repeat(2, 1fr);
      }
      .comparison-wrapper {
        flex-direction: column;
      }
    }

    @media (max-width: 768px) {
      .nav-links {
        display: none;
      }
      .menu-toggle {
        display: block;
      }
      .metrics-grid {
        grid-template-columns: repeat(2, 1fr);
      }
      .services-grid {
        grid-template-columns: 1fr;
      }
      .hero-title {
        font-size: 32px;
      }
      section {
        padding: 60px 0;
      }
      .contact-form {
        flex-direction: column;
      }
    }