/* roulang page: index */
:root {
      --primary: #1B2A2A;
      --accent: #C2D500;
      --accent-hover: #A8B800;
      --bg-warm: #F7F6F3;
      --white: #FFFFFF;
      --text-main: #1A1A1A;
      --text-secondary: #5C5C5C;
      --text-light: #B0B0B0;
      --text-on-dark: #E0E0E0;
      --border-light: #EBEBEB;
      --border-card: #E5E5E5;
      --shadow-sm: 0 1px 3px rgba(0,0,0,0.04), 0 1px 2px rgba(0,0,0,0.06);
      --shadow-hover: 0 10px 25px rgba(0,0,0,0.08), 0 4px 10px rgba(0,0,0,0.04);
      --radius-sm: 4px;
      --radius-md: 8px;
      --font-mono: 'Inter', 'SF Pro Display', system-ui, -apple-system, sans-serif;
      --font-sans: 'PingFang SC', 'Microsoft YaHei', 'Hiragino Sans GB', system-ui, -apple-system, sans-serif;
      --transition-base: 0.3s ease;
      --transition-fast: 0.25s ease;
    }
    *, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
    html { scroll-behavior: smooth; }
    body {
      font-family: var(--font-sans);
      background-color: var(--bg-warm);
      color: var(--text-main);
      line-height: 1.7;
      font-size: 16px;
      -webkit-font-smoothing: antialiased;
    }
    .container {
      max-width: 1280px;
      margin: 0 auto;
      padding: 0 24px;
    }
    /* 导航 */
    .nav {
      position: sticky;
      top: 0;
      z-index: 50;
      background: var(--white);
      height: 72px;
      display: flex;
      align-items: center;
      border-bottom: 1px solid transparent;
      transition: box-shadow var(--transition-base);
    }
    .nav.scrolled { box-shadow: var(--shadow-sm); border-bottom-color: var(--border-light); }
    .nav-container {
      display: flex;
      align-items: center;
      justify-content: space-between;
      width: 100%;
    }
    .logo {
      font-weight: 700;
      font-size: 1.8rem;
      letter-spacing: -0.5px;
      color: var(--primary);
      text-decoration: none;
    }
    .logo span { color: var(--accent); }
    .nav-links {
      display: flex;
      align-items: center;
      gap: 32px;
    }
    .nav-links a {
      text-decoration: none;
      color: var(--text-main);
      font-weight: 500;
      font-size: 0.95rem;
      position: relative;
      padding: 6px 0;
      transition: color var(--transition-fast);
    }
    .nav-links a::after {
      content: '';
      position: absolute;
      bottom: 0;
      left: 0;
      width: 0;
      height: 2px;
      background: var(--accent);
      transition: width var(--transition-fast);
    }
    .nav-links a:hover,
    .nav-links a.active { color: var(--accent); }
    .nav-links a:hover::after,
    .nav-links a.active::after { width: 100%; }
    .btn-primary {
      background: var(--accent);
      color: var(--primary);
      border: none;
      font-weight: 600;
      padding: 12px 28px;
      border-radius: var(--radius-sm);
      cursor: pointer;
      font-size: 0.95rem;
      text-decoration: none;
      display: inline-block;
      transition: background var(--transition-fast), transform var(--transition-fast), box-shadow var(--transition-fast);
    }
    .btn-primary:hover {
      background: var(--accent-hover);
      transform: translateY(-2px);
      box-shadow: 0 8px 18px rgba(194, 213, 0, 0.25);
    }
    .btn-outline {
      background: transparent;
      color: var(--accent);
      border: 2px solid var(--accent);
      font-weight: 600;
      padding: 12px 28px;
      border-radius: var(--radius-sm);
      cursor: pointer;
      font-size: 0.95rem;
      text-decoration: none;
      display: inline-block;
      transition: all var(--transition-fast);
    }
    .btn-outline:hover {
      background: rgba(194, 213, 0, 0.1);
      transform: translateY(-2px);
    }
    .hamburger {
      display: none;
      flex-direction: column;
      gap: 5px;
      background: none;
      border: none;
      cursor: pointer;
      padding: 4px;
    }
    .hamburger span {
      width: 24px;
      height: 2px;
      background: var(--primary);
      transition: var(--transition-base);
    }
    /* 移动端导航面板 */
    .mobile-menu {
      display: none;
      position: fixed;
      top: 72px;
      left: 0;
      width: 100%;
      background: var(--primary);
      padding: 32px 24px;
      flex-direction: column;
      gap: 24px;
      z-index: 45;
      transform: translateY(-10px);
      opacity: 0;
      transition: opacity 0.3s ease, transform 0.3s ease;
    }
    .mobile-menu.open {
      display: flex;
      opacity: 1;
      transform: translateY(0);
    }
    .mobile-menu a {
      color: white;
      font-size: 1.3rem;
      font-weight: 500;
      text-decoration: none;
      border-bottom: 1px solid rgba(255,255,255,0.15);
      padding-bottom: 12px;
    }
    /* Hero */
    .hero {
      background: var(--primary);
      background-image: url('/assets/images/backpic/back-1.webp');
      background-size: cover;
      background-position: center;
      background-blend-mode: overlay;
      color: white;
      padding: 100px 0 80px;
      position: relative;
      overflow: hidden;
    }
    .hero-grid {
      display: flex;
      align-items: center;
      gap: 48px;
    }
    .hero-content { flex: 1; }
    .hero h1 {
      font-size: 3rem;
      font-weight: 700;
      line-height: 1.2;
      margin-bottom: 20px;
      color: white;
    }
    .hero-sub {
      font-size: 1.2rem;
      opacity: 0.8;
      margin-bottom: 32px;
      max-width: 500px;
    }
    .hero-actions { display: flex; gap: 16px; flex-wrap: wrap; }
    .hero-data {
      flex: 0 0 300px;
      background: rgba(255,255,255,0.08);
      backdrop-filter: blur(8px);
      border-radius: var(--radius-md);
      padding: 24px;
      display: flex;
      flex-direction: column;
      gap: 20px;
    }
    .scrolling-tags {
      display: flex;
      gap: 12px;
      overflow: hidden;
      white-space: nowrap;
      margin-top: 16px;
    }
    .tag {
      background: var(--accent);
      color: var(--primary);
      font-weight: 600;
      padding: 6px 18px;
      border-radius: 20px;
      font-size: 0.85rem;
    }
    /* 区块通用 */
    section { padding: 90px 0; }
    .section-title {
      font-size: 2.25rem;
      font-weight: 600;
      margin-bottom: 16px;
      color: var(--primary);
    }
    .section-sub {
      color: var(--text-secondary);
      margin-bottom: 48px;
      font-size: 1.1rem;
    }
    /* 数据看板 */
    .stats-grid {
      display: grid;
      grid-template-columns: repeat(4,1fr);
      gap: 24px;
    }
    .stat-card {
      background: var(--white);
      padding: 32px 24px;
      border-radius: var(--radius-md);
      box-shadow: var(--shadow-sm);
      text-align: center;
    }
    .stat-number {
      font-family: var(--font-mono);
      font-size: 2.8rem;
      font-weight: 700;
      color: var(--accent);
      margin-bottom: 8px;
    }
    .stat-label { color: var(--text-secondary); font-weight: 500; }
    /* 服务矩阵 */
    .services-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
    }
    .service-card {
      background: var(--white);
      border: 1px solid var(--border-card);
      border-radius: var(--radius-md);
      padding: 32px;
      transition: all var(--transition-base);
    }
    .service-card:hover {
      border-color: var(--accent);
      box-shadow: var(--shadow-hover);
      transform: translateY(-4px);
    }
    .service-icon {
      font-size: 2.5rem;
      color: var(--accent);
      margin-bottom: 20px;
    }
    .service-card h3 {
      font-size: 1.4rem;
      font-weight: 600;
      margin-bottom: 12px;
    }
    .service-desc {
      color: var(--text-secondary);
      margin-bottom: 18px;
      font-size: 0.95rem;
    }
    .text-link {
      color: var(--accent);
      font-weight: 600;
      text-decoration: none;
      border-bottom: 1px solid transparent;
      transition: border-color var(--transition-fast);
    }
    .text-link:hover { border-bottom-color: var(--accent); }
    /* 对比区 */
    .compare-wrapper {
      display: flex;
      gap: 32px;
      align-items: center;
    }
    .compare-col {
      flex: 1;
      background: var(--white);
      border-radius: var(--radius-md);
      padding: 32px;
      box-shadow: var(--shadow-sm);
    }
    .compare-col.dark {
      background: #F2F2F2;
      color: #4A4A4A;
    }
    .compare-col.highlight {
      border: 2px solid var(--accent);
      background: var(--white);
    }
    .compare-value {
      font-size: 2.2rem;
      font-weight: 700;
      color: var(--accent);
    }
    .vs-divider {
      font-weight: 700;
      font-size: 1.8rem;
      color: var(--text-secondary);
    }
    /* 优势卡片 */
    .advantages-grid {
      display: grid;
      grid-template-columns: repeat(3,1fr);
      gap: 32px;
    }
    .adv-card {
      background: #EDEDE9;
      border-radius: var(--radius-md);
      padding: 40px 28px;
      text-align: center;
    }
    .adv-icon {
      font-size: 2.8rem;
      margin-bottom: 18px;
    }
    /* 品牌墙 */
    .brand-grid {
      display: flex;
      flex-wrap: wrap;
      justify-content: center;
      gap: 40px;
      align-items: center;
    }
    .brand-item {
      filter: grayscale(100%);
      opacity: 0.7;
      transition: filter 0.3s, opacity 0.3s;
      font-weight: 600;
      font-size: 1.3rem;
      color: #666;
    }
    .brand-item:hover {
      filter: grayscale(0%);
      opacity: 1;
      color: var(--primary);
    }
    /* FAQ */
    .faq-list {
      max-width: 800px;
      margin: 0 auto;
    }
    .faq-item {
      border-bottom: 1px solid var(--border-light);
      padding: 20px 0;
    }
    .faq-question {
      font-weight: 600;
      font-size: 1.1rem;
      cursor: pointer;
      display: flex;
      justify-content: space-between;
      align-items: center;
      color: var(--text-main);
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.4s ease;
      color: var(--text-secondary);
    }
    .faq-item.open .faq-answer { max-height: 200px; padding-top: 16px; }
    .faq-item.open .faq-question { color: var(--accent); }
    /* CTA 区块 */
    .cta-section {
      background: var(--primary);
      color: white;
    }
    .cta-grid {
      display: flex;
      gap: 48px;
      align-items: center;
    }
    .cta-form {
      display: flex;
      gap: 20px;
      flex-wrap: wrap;
    }
    .input-group {
      flex: 1;
      position: relative;
    }
    .input-group input, .input-group textarea {
      width: 100%;
      background: transparent;
      border: none;
      border-bottom: 2px solid rgba(255,255,255,0.5);
      padding: 12px 4px;
      color: white;
      font-size: 1rem;
      outline: none;
      transition: border-color 0.3s;
    }
    .input-group input:focus, .input-group textarea:focus {
      border-bottom-color: var(--accent);
    }
    .footer {
      background: #1A1A1A;
      color: var(--text-light);
      padding: 60px 0 30px;
    }
    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1.5fr;
      gap: 40px;
    }
    .footer a {
      color: var(--text-light);
      text-decoration: none;
    }
    .footer a:hover { color: var(--accent); }
    .copyright {
      border-top: 1px solid #333;
      margin-top: 40px;
      padding-top: 20px;
      text-align: center;
      color: #707070;
    }
    @media (max-width: 1024px) {
      .hero-grid { flex-direction: column; }
      .services-grid { grid-template-columns: repeat(2,1fr); }
    }
    @media (max-width: 768px) {
      .nav-links { display: none; }
      .hamburger { display: flex; }
      .hero h1 { font-size: 2.2rem; }
      .stats-grid { grid-template-columns: repeat(2,1fr); }
      .services-grid { grid-template-columns: 1fr; }
      .advantages-grid { grid-template-columns: 1fr; }
      .compare-wrapper { flex-direction: column; }
      .footer-grid { grid-template-columns: 1fr 1fr; }
      .cta-grid { flex-direction: column; }
    }
    @media (max-width: 480px) {
      .footer-grid { grid-template-columns: 1fr; }
      .hero-actions { flex-direction: column; }
    }
    .fade-up {
      opacity: 0;
      transform: translateY(20px);
      transition: opacity 0.6s ease, transform 0.6s ease;
    }
    .fade-up.visible {
      opacity: 1;
      transform: translateY(0);
    }