/* roulang page: index */
:root {
      --primary-charcoal: #1A1A1A;
      --primary-orange: #F04E30;
      --orange-hover: #D03A20;
      --warm-white: #F9F7F4;
      --cool-gray: #E5E0D8;
      --deep-blue-gray: #2C3A47;
      --gold-accent: #D4AF37;
      --text-body: #2C3A47;
      --text-muted: #5A6872;
      --white: #FFFFFF;
      --shadow-sm: 0 2px 8px rgba(0,0,0,0.04);
      --shadow-md: 0 8px 20px rgba(0,0,0,0.06);
      --shadow-lg: 0 12px 24px rgba(0,0,0,0.08);
      --radius-card: 12px;
      --radius-sm: 8px;
      --radius-btn: 8px;
      --spacing-section: 100px;
      --max-width: 1280px;
      --nav-height: 72px;
    }
    * {
      margin: 0;
      padding: 0;
      box-sizing: border-box;
    }
    body {
      font-family: 'Noto Sans SC', 'Inter', system-ui, -apple-system, sans-serif;
      background-color: var(--warm-white);
      color: var(--text-body);
      font-size: 16px;
      line-height: 1.7;
      -webkit-font-smoothing: antialiased;
      overflow-x: hidden;
    }
    .container {
      max-width: var(--max-width);
      margin: 0 auto;
      padding: 0 24px;
    }
    h1, h2, h3, h4 {
      color: var(--primary-charcoal);
      font-weight: 600;
    }
    h1 {
      font-size: 42px;
      font-weight: 700;
      letter-spacing: -0.5px;
      line-height: 1.2;
    }
    h2 {
      font-size: 30px;
      line-height: 1.3;
      margin-bottom: 20px;
      display: flex;
      align-items: center;
      gap: 12px;
    }
    h3 {
      font-size: 20px;
      line-height: 1.4;
    }
    p {
      color: var(--text-body);
      margin-bottom: 16px;
    }
    a {
      text-decoration: none;
      color: inherit;
      transition: color 0.25s ease;
    }
    img {
      max-width: 100%;
      height: auto;
      display: block;
    }
    button, .btn {
      cursor: pointer;
      font-family: inherit;
      transition: all 0.25s ease;
      display: inline-flex;
      align-items: center;
      justify-content: center;
      gap: 8px;
      border: none;
      font-weight: 600;
      border-radius: var(--radius-btn);
      white-space: nowrap;
    }
    .btn-primary {
      background-color: var(--primary-orange);
      color: var(--white);
      padding: 14px 32px;
      font-size: 16px;
      box-shadow: 0 4px 10px rgba(240,78,48,0.25);
    }
    .btn-primary:hover {
      background-color: var(--orange-hover);
      transform: scale(1.02);
      box-shadow: 0 8px 16px rgba(240,78,48,0.35);
    }
    .btn-outline {
      background: transparent;
      border: 2px solid var(--primary-charcoal);
      color: var(--primary-charcoal);
      padding: 12px 28px;
      font-size: 15px;
    }
    .btn-outline:hover {
      background: var(--primary-charcoal);
      color: var(--white);
      transform: translateY(-2px);
    }
    .tag {
      font-size: 13px;
      font-weight: 500;
      letter-spacing: 1px;
      text-transform: uppercase;
      padding: 4px 12px;
      border-radius: 20px;
      background: rgba(240,78,48,0.08);
      color: var(--primary-orange);
    }
    /* 导航 */
    .main-nav {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: var(--nav-height);
      background: rgba(255,255,255,0.95);
      backdrop-filter: blur(12px);
      box-shadow: 0 2px 12px rgba(0,0,0,0.04);
      z-index: 1000;
      display: flex;
      align-items: center;
    }
    .nav-container {
      display: flex;
      justify-content: space-between;
      align-items: center;
      width: 100%;
      max-width: var(--max-width);
      margin: 0 auto;
      padding: 0 24px;
    }
    .logo {
      font-size: 24px;
      font-weight: 700;
      color: var(--primary-charcoal);
      letter-spacing: 1px;
      display: flex;
      align-items: center;
      gap: 6px;
    }
    .logo i {
      color: var(--primary-orange);
      font-size: 28px;
    }
    .nav-links {
      display: flex;
      align-items: center;
      gap: 32px;
      list-style: none;
    }
    .nav-links a {
      font-weight: 500;
      color: var(--text-muted);
      font-size: 15px;
      position: relative;
      padding: 6px 0;
    }
    .nav-links a:hover,
    .nav-links a.active {
      color: var(--primary-orange);
    }
    .nav-cta {
      background: var(--primary-orange);
      color: white !important;
      padding: 10px 24px !important;
      border-radius: var(--radius-btn);
      font-weight: 600 !important;
    }
    .hamburger {
      display: none;
      background: transparent;
      border: none;
      font-size: 24px;
      color: var(--primary-charcoal);
      cursor: pointer;
    }
    .mobile-menu {
      position: fixed;
      top: 0;
      right: -100%;
      width: 80%;
      max-width: 320px;
      height: 100vh;
      background: var(--primary-charcoal);
      z-index: 2000;
      transition: right 0.3s ease;
      padding: 80px 32px 32px;
      display: flex;
      flex-direction: column;
      gap: 24px;
    }
    .mobile-menu.open {
      right: 0;
    }
    .mobile-menu a {
      color: var(--warm-white);
      font-size: 18px;
      font-weight: 500;
      border-bottom: 1px solid rgba(255,255,255,0.1);
      padding-bottom: 12px;
    }
    .close-menu {
      position: absolute;
      top: 24px;
      right: 24px;
      background: transparent;
      border: none;
      font-size: 28px;
      color: white;
    }
    .overlay {
      position: fixed;
      inset: 0;
      background: rgba(0,0,0,0.5);
      z-index: 1500;
      display: none;
    }
    .overlay.show {
      display: block;
    }
    /* Hero */
    .hero {
      min-height: 92vh;
      display: flex;
      align-items: center;
      background: linear-gradient(90deg, rgba(26,26,26,0.88) 0%, rgba(249,247,244,0.2) 100%), url('/assets/images/backpic/back-1.webp') center/cover no-repeat;
      margin-top: 0;
      padding-top: var(--nav-height);
      color: white;
    }
    .hero-content {
      max-width: 600px;
      padding: 40px 0;
    }
    .hero h1 {
      color: var(--warm-white);
      font-size: 48px;
      line-height: 1.15;
      margin-bottom: 20px;
    }
    .hero .highlight {
      color: var(--primary-orange);
      display: block;
    }
    .hero p {
      color: rgba(255,255,255,0.9);
      font-size: 18px;
      margin-bottom: 32px;
    }
    .hero .trust {
      font-size: 14px;
      color: rgba(255,255,255,0.7);
      margin-top: 16px;
      display: flex;
      align-items: center;
      gap: 8px;
    }
    /* Sections */
    section {
      padding: var(--spacing-section) 0;
    }
    .section-header {
      margin-bottom: 48px;
    }
    .section-header h2 {
      border-left: 4px solid var(--primary-orange);
      padding-left: 20px;
    }
    /* 核心优势 非对称网格 */
    .features-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 24px;
    }
    .feature-large {
      grid-row: span 2;
      background: var(--white);
      border: 1px solid var(--cool-gray);
      border-radius: var(--radius-card);
      padding: 40px 32px;
      transition: all 0.25s;
      display: flex;
      flex-direction: column;
      justify-content: center;
      background: #FFFCF7;
    }
    .feature-card {
      background: var(--white);
      border: 1px solid var(--cool-gray);
      border-radius: var(--radius-card);
      padding: 32px;
      transition: all 0.25s;
      display: flex;
      flex-direction: column;
      gap: 12px;
    }
    .feature-card:hover, .feature-large:hover {
      border-color: var(--primary-orange);
      box-shadow: var(--shadow-lg);
      transform: translateY(-4px);
    }
    .feature-icon {
      font-size: 32px;
      color: var(--primary-orange);
      margin-bottom: 8px;
    }
    .feature-large .feature-icon {
      font-size: 48px;
    }
    /* 功能分组交替 */
    .feature-row {
      display: flex;
      align-items: center;
      gap: 60px;
      margin-bottom: 80px;
    }
    .feature-row.reverse {
      flex-direction: row-reverse;
    }
    .feature-text {
      flex: 1;
    }
    .feature-image {
      flex: 1;
      border-radius: 16px;
      overflow: hidden;
      transition: transform 0.3s;
    }
    .feature-image:hover {
      transform: scale(1.02);
    }
    .feature-image img {
      width: 100%;
      height: auto;
      object-fit: cover;
      aspect-ratio: 4/3;
    }
    /* 场景横向滚动 */
    .scenarios-scroll {
      display: flex;
      gap: 24px;
      overflow-x: auto;
      padding-bottom: 16px;
      scrollbar-width: thin;
      -webkit-overflow-scrolling: touch;
    }
    .scenario-card {
      min-width: 320px;
      border-radius: var(--radius-card);
      background: white;
      overflow: hidden;
      box-shadow: var(--shadow-sm);
      transition: 0.25s;
    }
    .scenario-card:hover {
      box-shadow: var(--shadow-md);
      transform: translateY(-4px);
    }
    .scenario-card img {
      width: 100%;
      height: 200px;
      object-fit: cover;
    }
    .scenario-info {
      padding: 20px;
    }
    /* 数据区深色背景 */
    .stats-section {
      background: var(--primary-charcoal);
      color: white;
    }
    .stats-grid {
      display: flex;
      justify-content: space-around;
      flex-wrap: wrap;
      gap: 32px;
    }
    .stat-item {
      text-align: center;
    }
    .stat-number {
      font-size: 64px;
      font-weight: 700;
      color: var(--gold-accent);
    }
    .stat-label {
      color: rgba(255,255,255,0.8);
    }
    .partners {
      display: flex;
      flex-wrap: wrap;
      justify-content: center;
      gap: 32px;
      margin-top: 48px;
      filter: grayscale(1);
      opacity: 0.7;
    }
    .partners span {
      font-size: 24px;
      font-weight: 600;
      color: white;
      letter-spacing: 2px;
    }
    /* FAQ */
    .faq-item {
      border-bottom: 1px dashed var(--cool-gray);
      padding: 20px 0;
    }
    .faq-question {
      display: flex;
      justify-content: space-between;
      align-items: center;
      font-weight: 500;
      cursor: pointer;
      font-size: 18px;
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.4s ease, padding 0.3s;
      background: #F4F1EC;
      border-radius: 8px;
      margin-top: 8px;
    }
    .faq-answer.open {
      max-height: 200px;
      padding: 16px 20px;
    }
    /* CTA */
    .cta-section {
      background: linear-gradient(rgba(26,26,26,0.85), rgba(26,26,26,0.9)), url('/assets/images/backpic/back-2.webp') center/cover;
      text-align: center;
      color: white;
    }
    .cta-section h2 {
      color: white;
      justify-content: center;
      border: none;
    }
    .form-group {
      margin-bottom: 16px;
    }
    .form-input {
      width: 100%;
      padding: 14px 0;
      border: none;
      border-bottom: 2px solid var(--cool-gray);
      background: transparent;
      font-size: 16px;
      outline: none;
      transition: 0.2s;
      color: white;
    }
    .form-input:focus {
      border-bottom-color: var(--primary-orange);
      border-bottom-width: 3px;
    }
    /* Footer */
    footer {
      background: var(--primary-charcoal);
      color: var(--warm-white);
      padding: 60px 0 30px;
    }
    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1fr;
      gap: 40px;
    }
    .footer-links a {
      display: block;
      color: #aaa;
      margin-bottom: 8px;
    }
    .footer-links a:hover {
      color: var(--primary-orange);
    }
    .social-icons i {
      font-size: 24px;
      margin-right: 20px;
      color: #aaa;
      transition: 0.2s;
    }
    .social-icons i:hover {
      color: var(--primary-orange);
    }
    .copyright {
      border-top: 1px solid rgba(255,255,255,0.1);
      margin-top: 40px;
      padding-top: 20px;
      text-align: center;
      color: #777;
    }

    @media (max-width: 1024px) {
      .features-grid {
        grid-template-columns: 1fr;
      }
      .feature-large {
        grid-row: span 1;
      }
    }
    @media (max-width: 768px) {
      :root {
        --spacing-section: 60px;
      }
      h1 { font-size: 32px; }
      h2 { font-size: 26px; }
      .nav-links { display: none; }
      .hamburger { display: block; }
      .hero { min-height: 85vh; }
      .hero h1 { font-size: 36px; }
      .feature-row, .feature-row.reverse {
        flex-direction: column;
        gap: 32px;
      }
      .footer-grid {
        grid-template-columns: 1fr;
        gap: 24px;
      }
      .scenario-card {
        min-width: 260px;
      }
      .stats-number {
        font-size: 48px;
      }
      .container {
        padding: 0 20px;
      }
    }