/* roulang page: index */
:root {
      --primary: #2B3A67;
      --primary-soft: #3E5080;
      --secondary: #A3B1C6;
      --accent: #00C9A7;
      --accent-hover: #00A88C;
      --bg: #F8F9FC;
      --card-bg: #FFFFFF;
      --text: #1E2330;
      --text-secondary: #6B7280;
      --border-light: #E5E7EB;
      --success: #10B981;
      --warning: #F59E0B;
      --error: #EF4444;
      --radius-lg: 12px;
      --radius-md: 8px;
      --radius-full: 50px;
      --shadow-sm: 0 2px 12px rgba(0, 0, 0, 0.04);
      --shadow-md: 0 6px 24px rgba(0, 0, 0, 0.08);
      --font-sans: -apple-system, BlinkMacSystemFont, "PingFang SC", "Microsoft YaHei", "Helvetica Neue", sans-serif;
      --max-width: 1200px;
    }

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

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

    .container {
      max-width: var(--max-width);
      margin: 0 auto;
      padding: 0 40px;
    }

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

    a {
      text-decoration: none;
      color: inherit;
      transition: color 0.2s ease;
    }

    button, input, textarea {
      font-family: inherit;
    }

    /* 导航 */
    .main-header {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      height: 64px;
      background: #FFFFFF;
      box-shadow: 0 1px 8px rgba(0,0,0,0.04);
      z-index: 100;
      display: flex;
      align-items: center;
    }

    .nav-container {
      display: flex;
      align-items: center;
      justify-content: space-between;
      width: 100%;
      max-width: var(--max-width);
      margin: 0 auto;
      padding: 0 40px;
    }

    .logo {
      display: flex;
      align-items: center;
      gap: 8px;
      font-size: 22px;
      font-weight: 700;
      color: var(--primary);
      letter-spacing: -0.02em;
    }

    .logo-icon {
      width: 18px;
      height: 18px;
      background: var(--accent);
      border-radius: 50%;
      box-shadow: 0 0 8px rgba(0,201,167,0.4);
      position: relative;
    }
    .logo-icon::after {
      content: "";
      position: absolute;
      top: 4px;
      left: 4px;
      width: 4px;
      height: 4px;
      background: white;
      border-radius: 50%;
      opacity: 0.9;
    }

    .nav-menu {
      display: flex;
      list-style: none;
      gap: 32px;
      align-items: center;
    }

    .nav-menu a {
      font-size: 15px;
      color: var(--text-secondary);
      padding: 8px 0;
      border-bottom: 2px solid transparent;
      transition: 0.2s;
    }

    .nav-menu a:hover,
    .nav-menu a.active {
      color: var(--primary);
      border-bottom-color: var(--primary);
    }

    .hamburger {
      display: none;
      flex-direction: column;
      gap: 5px;
      background: none;
      border: none;
      cursor: pointer;
      padding: 8px;
    }
    .hamburger span {
      display: block;
      width: 22px;
      height: 1.5px;
      background: var(--primary);
      border-radius: 2px;
    }

    /* 区块通用 */
    section {
      padding: 100px 0;
    }

    .section-title {
      font-size: 30px;
      font-weight: 700;
      color: var(--text);
      margin-bottom: 16px;
      letter-spacing: -0.02em;
      line-height: 1.3;
    }
    .section-sub {
      font-size: 16px;
      color: var(--text-secondary);
      margin-bottom: 48px;
      max-width: 700px;
    }

    /* Hero */
    .hero {
      padding: 140px 0 100px;
      background-color: var(--bg);
      background-image: radial-gradient(circle at 20% 30%, rgba(43,58,103,0.03) 0%, transparent 35%);
    }
    .hero-grid {
      display: grid;
      grid-template-columns: 1.2fr 0.9fr;
      gap: 60px;
      align-items: center;
    }
    .hero-left h1 {
      font-size: 44px;
      font-weight: 700;
      line-height: 1.3;
      letter-spacing: -0.02em;
      color: var(--text);
      margin-bottom: 20px;
    }
    .hero-left p {
      font-size: 18px;
      color: var(--text-secondary);
      margin-bottom: 32px;
      max-width: 500px;
    }
    .hero-buttons {
      display: flex;
      gap: 16px;
      flex-wrap: wrap;
    }
    .btn-primary {
      background: var(--accent);
      color: white;
      border: none;
      padding: 14px 32px;
      border-radius: var(--radius-full);
      font-weight: 600;
      font-size: 16px;
      cursor: pointer;
      transition: background 0.2s, transform 0.1s;
      display: inline-block;
    }
    .btn-primary:hover {
      background: var(--accent-hover);
      transform: translateY(-1px);
    }
    .btn-outline {
      background: transparent;
      border: 1.5px solid var(--primary);
      color: var(--primary);
      padding: 14px 32px;
      border-radius: var(--radius-full);
      font-weight: 600;
      font-size: 16px;
      cursor: pointer;
      transition: 0.2s;
    }
    .btn-outline:hover {
      background: rgba(43,58,103,0.04);
    }
    .hero-right img {
      border-radius: 16px;
      background: #EFF1F7;
      width: 100%;
      aspect-ratio: 4/3;
      object-fit: cover;
    }

    /* 亮点网格 */
    .advantages-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
    }
    .adv-card {
      background: var(--card-bg);
      padding: 32px 24px;
      border-radius: var(--radius-lg);
      box-shadow: var(--shadow-sm);
      transition: 0.25s ease;
    }
    .adv-card:hover {
      transform: translateY(-4px);
      box-shadow: var(--shadow-md);
    }
    .adv-icon {
      font-size: 28px;
      color: var(--accent);
      margin-bottom: 16px;
    }
    .adv-card h3 {
      font-size: 20px;
      font-weight: 600;
      margin-bottom: 8px;
    }
    .adv-card p {
      font-size: 15px;
      color: var(--text-secondary);
    }

    /* 产品瀑布流 */
    .products-masonry {
      column-count: 3;
      column-gap: 24px;
    }
    .product-card {
      break-inside: avoid;
      background: var(--card-bg);
      border-radius: var(--radius-lg);
      box-shadow: var(--shadow-sm);
      margin-bottom: 24px;
      overflow: hidden;
      transition: 0.2s;
    }
    .product-card:hover {
      box-shadow: var(--shadow-md);
    }
    .product-card img {
      width: 100%;
      height: auto;
      aspect-ratio: 16/9;
      object-fit: cover;
      transition: transform 0.3s;
    }
    .product-card:hover img {
      transform: scale(1.03);
    }
    .product-info {
      padding: 20px;
    }
    .product-tag {
      display: inline-block;
      background: rgba(0,201,167,0.1);
      color: var(--accent);
      font-size: 13px;
      padding: 4px 12px;
      border-radius: 20px;
      margin-bottom: 8px;
    }
    .product-info h3 {
      font-size: 20px;
      font-weight: 600;
      margin-bottom: 6px;
    }
    .product-info p {
      font-size: 15px;
      color: var(--text-secondary);
    }

    /* 方案对比 */
    .compare-row {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 24px;
    }
    .compare-card {
      background: var(--card-bg);
      border-radius: var(--radius-lg);
      padding: 32px;
      box-shadow: var(--shadow-sm);
      border-left: 4px solid transparent;
    }
    .compare-card.recommend {
      border-left-color: var(--accent);
    }
    .compare-card h3 {
      font-size: 22px;
      font-weight: 700;
      margin-bottom: 20px;
    }
    .compare-list {
      list-style: none;
      margin-bottom: 24px;
    }
    .compare-list li {
      display: flex;
      align-items: center;
      gap: 8px;
      margin-bottom: 12px;
      font-size: 15px;
    }
    .compare-list i {
      color: var(--success);
    }

    /* 案例 */
    .case-scroll {
      display: flex;
      gap: 24px;
      overflow-x: auto;
      padding-bottom: 8px;
      scroll-snap-type: x mandatory;
    }
    .case-item {
      flex: 0 0 280px;
      background: var(--card-bg);
      border-radius: var(--radius-lg);
      padding: 24px;
      box-shadow: var(--shadow-sm);
      scroll-snap-align: start;
    }
    .case-number {
      font-size: 32px;
      font-weight: 700;
      color: var(--primary);
    }

    /* FAQ */
    .faq-list {
      display: flex;
      flex-direction: column;
      gap: 12px;
    }
    .faq-item {
      background: var(--card-bg);
      border: 1px solid var(--secondary);
      border-radius: var(--radius-md);
      overflow: hidden;
    }
    .faq-question {
      display: flex;
      justify-content: space-between;
      align-items: center;
      padding: 20px 24px;
      font-weight: 600;
      cursor: pointer;
      background: white;
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.3s ease;
      background: #F8F9FC;
      padding: 0 24px;
    }
    .faq-item.open .faq-answer {
      max-height: 200px;
      padding: 16px 24px;
    }
    .faq-answer p {
      font-size: 15px;
      color: var(--text-secondary);
    }

    /* CTA */
    .cta-section {
      background: var(--primary);
      color: white;
      text-align: center;
      padding: 80px 0;
    }
    .cta-form {
      display: flex;
      flex-wrap: wrap;
      gap: 16px;
      max-width: 700px;
      margin: 32px auto 0;
      justify-content: center;
    }
    .cta-form input,
    .cta-form textarea {
      flex: 1 1 200px;
      padding: 14px 16px;
      border-radius: var(--radius-md);
      border: 1px solid var(--secondary);
      background: white;
      font-size: 15px;
    }
    .cta-form textarea {
      flex-basis: 100%;
      min-height: 90px;
    }
    .cta-form button {
      background: var(--accent);
      color: white;
      border: none;
      padding: 14px 40px;
      border-radius: var(--radius-full);
      font-weight: 600;
      cursor: pointer;
    }

    /* Footer */
    .footer {
      background: #1E2330;
      color: #A3B1C6;
      padding: 60px 0 20px;
    }
    .footer-grid {
      display: grid;
      grid-template-columns: 1.5fr 1fr 1fr 1fr;
      gap: 40px;
      margin-bottom: 40px;
    }
    .footer-logo {
      font-size: 20px;
      font-weight: 700;
      color: white;
    }
    .copyright {
      text-align: center;
      border-top: 1px solid rgba(255,255,255,0.1);
      padding-top: 20px;
      font-size: 13px;
    }

    @media (max-width: 1024px) {
      .container { padding: 0 24px; }
      .nav-menu { gap: 20px; }
      .hero-grid { grid-template-columns: 1fr; }
      .advantages-grid { grid-template-columns: repeat(2,1fr); }
      .products-masonry { column-count: 2; }
      .compare-row { grid-template-columns: 1fr; }
    }
    @media (max-width: 640px) {
      .nav-menu { display: none; }
      .hamburger { display: flex; }
      .advantages-grid { grid-template-columns: 1fr; }
      .products-masonry { column-count: 1; }
      .hero-left h1 { font-size: 30px; }
      .footer-grid { grid-template-columns: 1fr; }
    }