/* roulang page: index */
:root {
      --primary: #E84A2D;
      --primary-hover: #C73D24;
      --secondary: #1A1A2E;
      --accent: #00C9A7;
      --accent-hover: #00b394;
      --warm-bg: #F5F0EB;
      --white: #FFFFFF;
      --gray-50: #f9fafb;
      --gray-100: #f3f4f6;
      --gray-200: #e5e7eb;
      --gray-300: #d1d5db;
      --gray-400: #9ca3af;
      --gray-500: #6b7280;
      --gray-600: #4b5563;
      --gray-700: #374151;
      --gray-800: #1f2937;
      --gray-900: #111827;
      --text-main: #1A1A2E;
      --text-secondary: #4b5563;
      --text-muted: #9ca3af;
      --border-light: rgba(0,0,0,0.04);
      --border-default: #e5e7eb;
      --radius-sm: 8px;
      --radius-md: 12px;
      --radius-lg: 16px;
      --shadow-sm: 0 2px 8px rgba(0,0,0,0.04);
      --shadow-md: 0 6px 16px rgba(0,0,0,0.06);
      --shadow-lg: 0 12px 24px rgba(232,74,45,0.12);
      --shadow-xl: 0 20px 32px rgba(0,0,0,0.12);
      --font-heading: 'Noto Sans SC', 'Inter', system-ui, sans-serif;
      --font-body: 'Noto Sans SC', 'Inter', system-ui, sans-serif;
      --font-mono: 'Inter', monospace;
      --max-width: 1200px;
      --header-height: 80px;
      --section-gap: 80px;
      --transition: 0.2s ease;
    }
    * {
      margin: 0;
      padding: 0;
      box-sizing: border-box;
    }
    html {
      scroll-behavior: smooth;
      font-size: 16px;
    }
    body {
      font-family: var(--font-body);
      background-color: var(--white);
      color: var(--text-main);
      line-height: 1.75;
      -webkit-font-smoothing: antialiased;
    }
    img {
      max-width: 100%;
      height: auto;
      display: block;
    }
    a {
      text-decoration: none;
      color: inherit;
      transition: color var(--transition);
    }
    button, input, textarea {
      font-family: inherit;
    }
    .container {
      width: 100%;
      max-width: var(--max-width);
      margin: 0 auto;
      padding: 0 24px;
    }
    /* 导航 */
    .header {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: var(--header-height);
      background: rgba(26, 26, 46, 0.85);
      backdrop-filter: blur(12px);
      -webkit-backdrop-filter: blur(12px);
      z-index: 100;
      display: flex;
      align-items: center;
      transition: background 0.3s ease, box-shadow 0.3s ease;
    }
    .header.scrolled {
      background: rgba(26, 26, 46, 0.95);
      box-shadow: 0 4px 20px rgba(0,0,0,0.2);
    }
    .header .container {
      display: flex;
      justify-content: space-between;
      align-items: center;
    }
    .logo {
      font-family: var(--font-heading);
      font-weight: 700;
      font-size: 1.5rem;
      color: #fff;
      letter-spacing: 1px;
      display: flex;
      align-items: baseline;
      gap: 4px;
    }
    .logo .brand-main {
      color: var(--primary);
    }
    .logo .brand-sub {
      font-size: 0.9rem;
      font-weight: 400;
      color: rgba(255,255,255,0.7);
      margin-left: 2px;
    }
    .nav-links {
      display: flex;
      gap: 32px;
      align-items: center;
    }
    .nav-links a {
      font-size: 0.9rem;
      font-weight: 500;
      color: rgba(255,255,255,0.75);
      transition: color 0.2s, border-color 0.2s;
      padding-bottom: 4px;
      border-bottom: 2px solid transparent;
    }
    .nav-links a:hover {
      color: #fff;
      border-bottom-color: var(--primary);
    }
    .mobile-nav {
      display: none;
    }
    /* 底部胶囊导航 (移动端) */
    .bottom-nav {
      display: none;
      position: fixed;
      bottom: 16px;
      left: 50%;
      transform: translateX(-50%);
      background: rgba(26,26,46,0.9);
      backdrop-filter: blur(20px);
      border-radius: 40px;
      padding: 8px 24px;
      z-index: 110;
      box-shadow: 0 8px 24px rgba(0,0,0,0.25);
      gap: 20px;
    }
    .bottom-nav a {
      color: rgba(255,255,255,0.7);
      font-size: 0.75rem;
      display: flex;
      flex-direction: column;
      align-items: center;
      gap: 4px;
      font-weight: 500;
      transition: color 0.2s;
    }
    .bottom-nav a.cta-mobile {
      background: var(--primary);
      color: #fff;
      padding: 10px 18px;
      border-radius: 32px;
      font-weight: 600;
      margin: 0 4px;
      box-shadow: 0 4px 12px rgba(232,74,45,0.4);
    }
    /* Hero */
    .hero {
      padding-top: calc(var(--header-height) + 40px);
      padding-bottom: 60px;
      background: linear-gradient(135deg, #1A1A2E 0%, #2a2a40 100%);
      color: #fff;
      min-height: 90vh;
      display: flex;
      align-items: center;
      position: relative;
      overflow: hidden;
    }
    .hero .container {
      display: flex;
      align-items: center;
      gap: 48px;
      flex-wrap: wrap;
    }
    .hero-content {
      flex: 1 1 400px;
    }
    .hero h1 {
      font-size: clamp(2.4rem, 5vw, 3.2rem);
      font-weight: 700;
      line-height: 1.2;
      margin-bottom: 1.2rem;
      color: #fff;
    }
    .hero h1 .highlight {
      color: var(--primary);
      border-bottom: 3px solid var(--primary);
    }
    .hero-sub {
      font-size: 1.25rem;
      color: rgba(255,255,255,0.8);
      margin-bottom: 2rem;
    }
    .btn-group {
      display: flex;
      gap: 16px;
      flex-wrap: wrap;
    }
    .btn {
      display: inline-block;
      padding: 12px 28px;
      border-radius: var(--radius-sm);
      font-weight: 600;
      font-size: 0.95rem;
      text-align: center;
      transition: all 0.25s ease;
      cursor: pointer;
      border: none;
      letter-spacing: 0.3px;
    }
    .btn-primary {
      background: var(--primary);
      color: #fff;
      box-shadow: 0 4px 14px rgba(232,74,45,0.35);
    }
    .btn-primary:hover {
      background: var(--primary-hover);
      box-shadow: 0 6px 18px rgba(232,74,45,0.5);
    }
    .btn-outline {
      background: transparent;
      border: 2px solid var(--primary);
      color: #fff;
    }
    .btn-outline:hover {
      background: var(--primary);
      border-color: var(--primary);
      color: #fff;
    }
    .btn-accent {
      background: var(--accent);
      color: #1A1A2E;
      font-weight: 600;
    }
    .btn-accent:hover {
      background: var(--accent-hover);
    }
    .hero-image {
      flex: 1 1 450px;
      background: rgba(255,255,255,0.05);
      border-radius: var(--radius-lg);
      overflow: hidden;
      box-shadow: 0 20px 40px rgba(0,0,0,0.4);
    }
    .hero-image img {
      width: 100%;
      height: auto;
      border-radius: var(--radius-lg);
    }
    /* 通用区块 */
    section {
      padding: var(--section-gap) 0;
    }
    .section-title {
      font-size: 2.2rem;
      font-weight: 700;
      margin-bottom: 16px;
      color: var(--secondary);
    }
    .section-sub {
      color: var(--text-secondary);
      margin-bottom: 40px;
      font-size: 1.1rem;
    }
    /* 指标看板 */
    .dashboard-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
    }
    .stat-card {
      background: var(--warm-bg);
      border-radius: var(--radius-md);
      padding: 28px 24px;
      box-shadow: var(--shadow-sm);
      transition: all 0.25s;
      border-top: 4px solid transparent;
      text-align: center;
    }
    .stat-card:nth-child(1) { border-top-color: var(--primary); }
    .stat-card:nth-child(2) { border-top-color: var(--secondary); }
    .stat-card:nth-child(3) { border-top-color: var(--accent); }
    .stat-number {
      font-family: var(--font-mono);
      font-size: 2.8rem;
      font-weight: 700;
      color: var(--secondary);
    }
    .stat-label {
      color: var(--text-secondary);
      font-size: 0.9rem;
      margin-top: 8px;
    }
    /* 服务矩阵 2x3 */
    .services-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
    }
    .service-card {
      background: #fff;
      border-radius: var(--radius-md);
      padding: 28px 24px;
      border: 1px solid var(--border-light);
      box-shadow: var(--shadow-sm);
      transition: transform 0.2s, box-shadow 0.25s;
      display: flex;
      flex-direction: column;
    }
    .service-card:hover {
      transform: translateY(-6px);
      box-shadow: var(--shadow-lg);
    }
    .service-icon {
      width: 48px;
      height: 48px;
      background: var(--primary);
      border-radius: 12px;
      display: flex;
      align-items: center;
      justify-content: center;
      margin-bottom: 20px;
      color: #fff;
      font-size: 1.5rem;
    }
    .service-card h3 {
      font-size: 1.25rem;
      margin-bottom: 8px;
    }
    .service-desc {
      color: var(--text-secondary);
      font-size: 0.9rem;
      flex: 1;
    }
    /* 效能对比 */
    .compare-wrapper {
      display: flex;
      gap: 24px;
      align-items: stretch;
      background: #f8f9fa;
      border-radius: var(--radius-lg);
      padding: 32px;
    }
    .compare-col {
      flex: 1;
    }
    .compare-item {
      display: flex;
      align-items: center;
      margin-bottom: 18px;
    }
    .bar-bg {
      flex: 1;
      height: 12px;
      background: #e5e7eb;
      border-radius: 20px;
      margin: 0 12px;
      overflow: hidden;
    }
    .bar-fill {
      height: 100%;
      border-radius: 20px;
      background: var(--gray-400);
    }
    .bar-fill.green {
      background: var(--accent);
    }
    /* FAQ */
    .faq-item {
      border-bottom: 1px solid var(--border-default);
      padding: 18px 0;
    }
    .faq-question {
      display: flex;
      justify-content: space-between;
      align-items: center;
      font-weight: 600;
      cursor: pointer;
      font-size: 1.1rem;
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.35s ease;
      color: var(--text-secondary);
    }
    .faq-item.active .faq-answer {
      max-height: 200px;
      margin-top: 12px;
    }
    /* 联系表单 */
    .contact-bg {
      background: var(--secondary);
      color: #fff;
      border-radius: var(--radius-lg);
      padding: 48px;
    }
    .form-group input, .form-group textarea {
      width: 100%;
      padding: 12px;
      border-radius: var(--radius-sm);
      border: none;
      margin-top: 8px;
    }
    /* 页脚 */
    .footer {
      background: var(--secondary);
      color: #ccc;
      padding: 48px 0 24px;
    }
    .footer-grid {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 32px;
    }
    @media (max-width: 1024px) {
      .services-grid { grid-template-columns: repeat(2, 1fr); }
      .dashboard-grid { grid-template-columns: repeat(2, 1fr); }
    }
    @media (max-width: 768px) {
      .header .nav-links { display: none; }
      .bottom-nav { display: flex; }
      .hero .container { flex-direction: column; }
      .services-grid { grid-template-columns: 1fr; }
      .dashboard-grid { grid-template-columns: 1fr; }
      .compare-wrapper { flex-direction: column; }
      .footer-grid { grid-template-columns: 1fr 1fr; }
    }