/* roulang page: index */
:root {
      --primary: #F04E30;
      --primary-hover: #D43D24;
      --secondary: #00C2BA;
      --dark-bg: #1A1D23;
      --card-bg: #ffffff;
      --dark-card: #252830;
      --light-bg: #F5F7FA;
      --border-light: #E2E6ED;
      --text-main: #1F2937;
      --text-secondary: #6B7280;
      --text-on-dark: #E5E7EB;
      --white: #FFFFFF;
      --radius-lg: 20px;
      --radius-md: 16px;
      --radius-sm: 12px;
      --radius-btn: 12px;
      --shadow-sm: 0 8px 30px rgba(0,0,0,0.06);
      --shadow-glow: 0 12px 40px rgba(240,78,48,0.12);
      --font-title: 'PingFang SC', 'Microsoft YaHei', 'Helvetica Neue', sans-serif;
      --font-number: 'DIN Alternate', 'Bebas Neue', 'Helvetica Neue', sans-serif;
      --transition: all 0.25s ease;
    }
    * { box-sizing: border-box; margin: 0; padding: 0; }
    body {
      font-family: 'PingFang SC', 'Microsoft YaHei', 'Helvetica Neue', sans-serif;
      background-color: var(--light-bg);
      color: var(--text-main);
      line-height: 1.5;
      scroll-behavior: smooth;
      -webkit-font-smoothing: antialiased;
    }
    a { text-decoration: none; color: inherit; }
    img { max-width: 100%; display: block; }
    .container { max-width: 1280px; margin: 0 auto; padding: 0 24px; width: 100%; }

    /* 导航 */
    .main-header {
      position: fixed; top: 0; left: 0; width: 100%; height: 72px;
      background: rgba(26,29,35,0.92); backdrop-filter: blur(12px);
      z-index: 1000; display: flex; align-items: center;
      transition: background 0.3s ease; box-shadow: 0 4px 20px rgba(0,0,0,0.1);
    }
    .main-header.scrolled { background: rgba(26,29,35,1); }
    .header-container {
      display: flex; justify-content: space-between; align-items: center; width: 100%;
      max-width: 1280px; padding: 0 24px; margin: 0 auto;
    }
    .logo {
      display: flex; align-items: center; gap: 8px; font-weight: 800; font-size: 1.8rem;
      color: var(--white); letter-spacing: 1px;
    }
    .logo i { color: var(--primary); font-size: 2rem; }
    .nav-links { display: flex; gap: 32px; align-items: center; }
    .nav-links a {
      color: #ccc; font-weight: 500; font-size: 1rem;
      padding-bottom: 6px; border-bottom: 2px solid transparent;
      transition: var(--transition);
    }
    .nav-links a:hover, .nav-links a.active { color: var(--secondary); border-bottom-color: var(--primary); }
    .mobile-menu-btn { display: none; background: none; border: none; color: var(--white); font-size: 1.8rem; cursor: pointer; }
    @media (max-width: 768px) {
      .nav-links { display: none; position: fixed; top: 72px; left: 0; width: 100%; background: var(--dark-bg); flex-direction: column; padding: 24px; gap: 20px; }
      .nav-links.open { display: flex; }
      .mobile-menu-btn { display: block; }
      .main-header { height: 56px; }
      .logo { font-size: 1.4rem; }
    }

    /* 首屏 Hero */
    .hero {
      background: linear-gradient(135deg, #1A1D23 0%, #2A2E36 70%);
      min-height: 90vh; display: flex; align-items: center; padding: 120px 0 80px;
    }
    .hero-grid { display: grid; grid-template-columns: 1.2fr 0.9fr; gap: 60px; align-items: center; }
    .hero-content h1 {
      font-size: 3.8rem; font-weight: 800; letter-spacing: 1px;
      background: linear-gradient(to right, #fff, #F04E30); -webkit-background-clip: text; -webkit-text-fill-color: transparent;
      background-clip: text; margin-bottom: 24px;
    }
    .hero-sub { font-size: 1.2rem; color: #B0B8C1; margin-bottom: 32px; max-width: 500px; }
    .cta-group { display: flex; gap: 16px; flex-wrap: wrap; margin-bottom: 40px; }
    .btn-primary {
      background: var(--primary); color: white; padding: 14px 36px; border-radius: var(--radius-btn);
      font-weight: bold; border: none; cursor: pointer; transition: var(--transition); box-shadow: 0 4px 15px rgba(240,78,48,0.4);
      font-size: 1rem;
    }
    .btn-primary:hover { background: var(--primary-hover); transform: translateY(-2px); }
    .btn-outline {
      border: 2px solid var(--secondary); color: var(--secondary); padding: 14px 36px;
      border-radius: var(--radius-btn); font-weight: bold; background: transparent; transition: var(--transition);
    }
    .btn-outline:hover { background: rgba(0,194,186,0.1); }
    .badge-row { display: flex; gap: 24px; flex-wrap: wrap; }
    .badge {
      background: rgba(255,255,255,0.06); backdrop-filter: blur(4px); padding: 12px 20px;
      border-radius: 40px; color: #ddd; display: flex; align-items: center; gap: 8px; font-size: 0.95rem;
      border: 1px solid rgba(255,255,255,0.1);
    }
    .badge i { color: var(--secondary); }
    .hero-visual {
      display: flex; flex-direction: column; gap: 24px; align-items: flex-end;
    }
    .stat-card {
      background: rgba(255,255,255,0.05); backdrop-filter: blur(8px); padding: 20px 28px; border-radius: var(--radius-md);
      border: 1px solid rgba(255,255,255,0.1); min-width: 180px; text-align: center;
    }
    .stat-number {
      font-family: var(--font-number); font-size: 2.5rem; font-weight: 700; color: var(--secondary); display: block;
    }
    .stat-label { color: #aaa; font-size: 0.9rem; margin-top: 4px; }
    @media (max-width: 1024px) {
      .hero-grid { grid-template-columns: 1fr; gap: 40px; text-align: center; }
      .hero-visual { flex-direction: row; flex-wrap: wrap; justify-content: center; }
      .badge-row { justify-content: center; }
      .cta-group { justify-content: center; }
    }
    @media (max-width: 768px) {
      .hero-content h1 { font-size: 2.4rem; }
    }

    /* 深色板块通用 */
    .dark-section {
      background: var(--dark-bg); color: var(--text-on-dark); padding: 90px 0;
    }

    /* 数据指标看板 */
    #data-dashboard .grid-4 {
      display: grid; grid-template-columns: repeat(4,1fr); gap: 24px;
    }
    .metric-card {
      background: #252830; padding: 32px 20px; border-radius: var(--radius-md); text-align: center;
      border: 1px solid #3A3F48; transition: var(--transition);
    }
    .metric-card:hover { border-color: var(--secondary); transform: translateY(-4px); }
    .metric-value { font-family: var(--font-number); font-size: 2.8rem; color: var(--secondary); font-weight: 700; }
    .metric-desc { color: #aaa; margin-top: 10px; font-size: 1rem; }

    /* 服务矩阵 */
    #services { padding: 100px 0 80px; }
    .section-title { font-size: 2.5rem; font-weight: 700; margin-bottom: 16px; text-align: center; }
    .section-subtitle { color: var(--text-secondary); text-align: center; max-width: 640px; margin: 0 auto 48px; }
    .services-grid {
      display: grid; grid-template-columns: 1fr 1fr 1fr 1fr; gap: 24px;
    }
    .service-card {
      background: var(--card-bg); border-radius: 20px; padding: 32px 24px; box-shadow: var(--shadow-sm);
      transition: var(--transition); border: 1px solid var(--border-light);
    }
    .service-card.large { grid-column: span 1; grid-row: span 1; background: linear-gradient(135deg, #FFF5F4 0%, white 100%); }
    .service-card:hover {
      transform: translateY(-6px); box-shadow: var(--shadow-glow); border-color: transparent;
    }
    .service-icon { width: 56px; height: 56px; background: var(--primary); color: white; border-radius: 18px; display: flex; align-items: center; justify-content: center; font-size: 1.8rem; margin-bottom: 20px; }
    .service-card h3 { font-size: 1.5rem; font-weight: 650; margin-bottom: 10px; }
    .service-card p { color: var(--text-secondary); margin-bottom: 16px; font-size: 0.95rem; }
    .arrow-link { color: var(--primary); font-weight: 600; display: flex; align-items: center; gap: 6px; }
    @media (max-width: 1024px) {
      .services-grid { grid-template-columns: repeat(2, 1fr); }
      .grid-4 { grid-template-columns: repeat(2,1fr); }
    }
    @media (max-width: 768px) {
      .services-grid { grid-template-columns: 1fr; }
      .grid-4 { grid-template-columns: 1fr; }
    }

    /* 结果对比 */
    #comparison .comparison-container {
      display: grid; grid-template-columns: 1fr 1fr; gap: 40px; align-items: center;
    }
    .vs-badge {
      background: var(--primary); width: 64px; height: 64px; border-radius: 50%;
      display: flex; align-items: center; justify-content: center; color: white; font-weight: 800; font-size: 1.5rem;
      margin: 0 auto 30px;
    }
    .compare-card {
      background: #252830; border-radius: 24px; padding: 30px; text-align: center;
    }
    .compare-card h3 { font-size: 1.8rem; margin-bottom: 16px; font-weight: 600; }
    .compare-list { list-style: none; display: flex; flex-direction: column; gap: 16px; }
    .compare-list li { display: flex; justify-content: space-between; background: rgba(255,255,255,0.04); padding: 12px 16px; border-radius: 40px; }
    .compare-list .highlight { color: var(--secondary); font-weight: 700; }
    @media (max-width: 768px) {
      .comparison-container { grid-template-columns: 1fr; gap: 32px; }
    }

    /* 案例数据 */
    #cases { padding: 90px 0; }
    .cases-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(280px, 1fr)); gap: 24px; }
    .case-item { background: white; border-radius: 20px; overflow: hidden; box-shadow: var(--shadow-sm); transition: var(--transition); }
    .case-item:hover { box-shadow: var(--shadow-glow); transform: translateY(-4px); }
    .case-img { height: 180px; background-size: cover; }
    .case-content { padding: 24px; }
    .case-content h4 { font-size: 1.4rem; }

    /* FAQ */
    .faq-item { border-bottom: 1px solid var(--border-light); }
    .faq-question {
      width: 100%; background: none; border: none; padding: 24px 16px; font-size: 1.2rem; font-weight: 600;
      display: flex; justify-content: space-between; cursor: pointer; text-align: left;
    }
    .faq-answer { max-height: 0; overflow: hidden; transition: 0.3s; padding: 0 16px; background: #F9FAFB; border-radius: 12px; }
    .faq-answer.open { max-height: 200px; padding: 16px; }

    /* 表单 */
    #contact { background: white; padding: 80px 0; }
    .contact-card {
      background: var(--card-bg); padding: 48px; border-radius: 28px; box-shadow: 0 20px 50px rgba(0,0,0,0.05);
    }
    .form-group input, .form-group textarea { width: 100%; padding: 14px; border: 1px solid #ddd; border-radius: 12px; font-size: 1rem; }
    .trust-badges { display: flex; gap: 24px; margin-top: 20px; justify-content: center; }

    footer { background: var(--dark-bg); color: #aaa; padding: 60px 0 30px; }
    .footer-grid { display: grid; grid-template-columns: repeat(4,1fr); gap: 30px; }
    @media (max-width: 768px) {
      .footer-grid { grid-template-columns: 1fr; }
    }