/* roulang page: index */
:root {
      --primary-blue: #1A5F7A;
      --panda-black: #1E1E1E;
      --accent-cyan: #00E5FF;
      --accent-cyan-hover: #00B8D4;
      --bg-light: #F8FAFC;
      --card-white: #FFFFFF;
      --block-light: #EDF2F7;
      --text-main: #1E293B;
      --text-secondary: #475569;
      --text-muted: #64748B;
      --text-light: #94A3B8;
      --white: #FFFFFF;
      --success-green: #10B981;
      --soft-red: #EF4444;
      --border-light: #E2E8F0;
      --shadow-sm: 0 2px 8px rgba(0,0,0,0.04);
      --shadow-md: 0 8px 30px rgba(0,0,0,0.08);
      --radius-sm: 8px;
      --radius-md: 12px;
      --radius-lg: 16px;
      --radius-xl: 24px;
      --font-sans: 'PingFang SC', 'Microsoft YaHei', 'Helvetica Neue', Arial, sans-serif;
      --transition: 0.25s ease;
    }
    * { box-sizing: border-box; margin: 0; padding: 0; }
    body {
      font-family: var(--font-sans);
      background-color: var(--bg-light);
      color: var(--text-main);
      line-height: 1.5;
      -webkit-font-smoothing: antialiased;
    }
    a { text-decoration: none; color: inherit; }
    img { max-width: 100%; height: auto; display: block; }
    button, input, textarea { font-family: inherit; }
    .container {
      max-width: 1280px;
      margin: 0 auto;
      padding: 0 24px;
    }
    /* 导航 */
    .nav-bar {
      position: sticky;
      top: 0;
      z-index: 100;
      background: var(--white);
      height: 72px;
      display: flex;
      align-items: center;
      border-bottom: 1px solid transparent;
      transition: box-shadow var(--transition);
    }
    .nav-bar.scrolled {
      box-shadow: 0 2px 12px rgba(0,0,0,0.06);
    }
    .nav-container {
      display: flex;
      justify-content: space-between;
      align-items: center;
      width: 100%;
    }
    .logo {
      font-size: 24px;
      font-weight: 800;
      color: var(--panda-black);
      display: flex;
      align-items: center;
      gap: 8px;
      letter-spacing: -0.3px;
    }
    .logo i { color: var(--accent-cyan); font-size: 28px; }
    .nav-links {
      display: flex;
      gap: 28px;
      list-style: none;
      align-items: center;
    }
    .nav-links a {
      font-weight: 500;
      color: var(--text-secondary);
      font-size: 15px;
      transition: color var(--transition);
      padding-bottom: 4px;
      border-bottom: 2px solid transparent;
    }
    .nav-links a:hover,
    .nav-links a.active {
      color: var(--accent-cyan);
      border-bottom-color: var(--accent-cyan);
    }
    .btn-nav {
      background: var(--accent-cyan);
      color: var(--panda-black) !important;
      padding: 10px 20px !important;
      border-radius: var(--radius-sm);
      font-weight: 700;
      font-size: 14px;
      border-bottom: none !important;
      transition: background var(--transition), transform var(--transition);
    }
    .btn-nav:hover {
      background: var(--accent-cyan-hover);
      transform: translateY(-1px);
      border-bottom: none !important;
    }
    .hamburger {
      display: none;
      flex-direction: column;
      gap: 5px;
      cursor: pointer;
      background: transparent;
      border: none;
      padding: 8px;
    }
    .hamburger span {
      width: 25px;
      height: 2.5px;
      background: var(--panda-black);
      border-radius: 4px;
      transition: var(--transition);
    }
    .mobile-menu {
      display: none;
      position: fixed;
      top: 72px;
      left: 0;
      width: 100%;
      background: var(--white);
      flex-direction: column;
      padding: 32px;
      box-shadow: var(--shadow-md);
      gap: 20px;
      z-index: 99;
      transform: translateY(-100%);
      opacity: 0;
      transition: transform 0.3s ease, opacity 0.2s ease;
    }
    .mobile-menu.open {
      transform: translateY(0);
      opacity: 1;
    }
    .mobile-menu a {
      font-size: 18px;
      font-weight: 600;
      color: var(--text-main);
    }
    /* 区块通用 */
    section {
      padding: 80px 0;
    }
    .section-title {
      font-size: 36px;
      font-weight: 700;
      line-height: 1.3;
      margin-bottom: 16px;
      text-align: center;
      position: relative;
      color: var(--text-main);
    }
    .section-title::after {
      content: '';
      display: block;
      width: 48px;
      height: 8px;
      background: var(--accent-cyan);
      margin: 12px auto 0;
      border-radius: 4px;
    }
    /* Hero */
    .hero {
      padding: 60px 0 80px;
      background: linear-gradient(180deg, rgba(0,0,0,0.02) 0%, var(--bg-light) 100%);
    }
    .hero-grid {
      display: flex;
      align-items: center;
      gap: 48px;
    }
    .hero-left {
      flex: 1 1 55%;
    }
    .hero-right {
      flex: 1 1 45%;
      position: relative;
    }
    .hero-right img {
      border-radius: var(--radius-xl);
      box-shadow: var(--shadow-md);
      width: 100%;
      object-fit: cover;
    }
    .hero h1 {
      font-size: 48px;
      font-weight: 800;
      line-height: 1.2;
      letter-spacing: -0.5px;
      color: var(--panda-black);
      margin-bottom: 20px;
    }
    .hero .subtitle {
      font-size: 18px;
      color: var(--text-secondary);
      margin-bottom: 36px;
      max-width: 480px;
    }
    .btn-group {
      display: flex;
      gap: 16px;
      flex-wrap: wrap;
    }
    .btn-primary {
      background: var(--accent-cyan);
      color: var(--panda-black);
      font-weight: 700;
      padding: 14px 32px;
      border-radius: var(--radius-sm);
      border: none;
      cursor: pointer;
      font-size: 16px;
      display: inline-flex;
      align-items: center;
      gap: 8px;
      transition: background var(--transition), transform var(--transition), box-shadow var(--transition);
      box-shadow: 0 4px 10px rgba(0,229,255,0.25);
    }
    .btn-primary:hover {
      background: var(--accent-cyan-hover);
      transform: translateY(-2px);
      box-shadow: 0 8px 18px rgba(0,184,212,0.35);
    }
    .btn-outline {
      background: transparent;
      border: 2px solid var(--primary-blue);
      color: var(--primary-blue);
      font-weight: 700;
      padding: 14px 32px;
      border-radius: var(--radius-sm);
      cursor: pointer;
      font-size: 16px;
      display: inline-flex;
      align-items: center;
      gap: 8px;
      transition: var(--transition);
    }
    .btn-outline:hover {
      background: var(--primary-blue);
      color: var(--white);
    }
    /* 核心优势卡片 */
    .cards-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
      margin-top: 40px;
    }
    .core-card {
      background: var(--card-white);
      padding: 32px;
      border-radius: var(--radius-lg);
      box-shadow: var(--shadow-sm);
      transition: box-shadow var(--transition), transform var(--transition);
    }
    .core-card:hover {
      box-shadow: var(--shadow-md);
      transform: translateY(-4px);
    }
    .core-icon {
      font-size: 32px;
      color: var(--accent-cyan);
      margin-bottom: 20px;
    }
    .core-card h3 {
      font-size: 20px;
      font-weight: 600;
      margin-bottom: 12px;
    }
    .core-card p {
      color: var(--text-secondary);
      font-size: 15px;
    }
    /* 亮点网格 */
    .highlights-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 24px;
      margin-top: 40px;
    }
    .highlight-card {
      background: var(--card-white);
      border-radius: var(--radius-lg);
      overflow: hidden;
      box-shadow: var(--shadow-sm);
      transition: var(--transition);
    }
    .highlight-card:hover {
      box-shadow: var(--shadow-md);
    }
    .highlight-card img {
      aspect-ratio: 16/9;
      object-fit: cover;
      width: 100%;
      transition: transform 0.3s;
    }
    .highlight-card:hover img {
      transform: scale(1.03);
    }
    .highlight-content {
      padding: 20px 24px;
    }
    .highlight-content h3 {
      font-size: 18px;
      font-weight: 700;
      color: var(--primary-blue);
    }
    .highlight-content p {
      color: var(--text-muted);
      font-size: 14px;
      margin-top: 6px;
    }
    /* 案例瀑布流 */
    .cases-masonry {
      columns: 3;
      column-gap: 24px;
      margin-top: 40px;
    }
    .case-card {
      break-inside: avoid;
      background: var(--card-white);
      border-radius: var(--radius-lg);
      overflow: hidden;
      margin-bottom: 24px;
      box-shadow: var(--shadow-sm);
      transition: var(--transition);
    }
    .case-card:hover {
      transform: translateY(-4px);
      box-shadow: var(--shadow-md);
    }
    .case-card img {
      width: 100%;
      border-radius: var(--radius-lg) var(--radius-lg) 0 0;
    }
    .case-info {
      padding: 20px;
    }
    .case-tag {
      display: inline-block;
      background: #EDF2F7;
      color: var(--primary-blue);
      font-size: 12px;
      font-weight: 600;
      padding: 4px 10px;
      border-radius: 20px;
      margin-bottom: 8px;
    }
    .case-title {
      font-weight: 700;
      font-size: 18px;
      margin: 8px 0 4px;
    }
    /* 对比 */
    .comparison-wrapper {
      display: flex;
      gap: 24px;
      margin-top: 40px;
    }
    .compare-col {
      flex: 1;
      background: var(--card-white);
      border-radius: var(--radius-lg);
      padding: 32px;
    }
    .left-col {
      background: #FEF2F2;
    }
    .right-col {
      background: #F0FDF4;
    }
    .compare-col h3 {
      font-size: 24px;
      font-weight: 700;
      margin-bottom: 24px;
    }
    .compare-item {
      display: flex;
      align-items: center;
      gap: 12px;
      margin-bottom: 16px;
      font-size: 16px;
    }
    /* FAQ */
    .faq-list {
      max-width: 800px;
      margin: 40px auto 0;
    }
    .faq-item {
      border-bottom: 1px solid var(--border-light);
      padding: 18px 0;
      cursor: pointer;
    }
    .faq-question {
      display: flex;
      justify-content: space-between;
      align-items: center;
      font-weight: 700;
      font-size: 18px;
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.3s ease;
      color: var(--text-secondary);
      background: #F1F5F9;
      border-radius: 8px;
      margin-top: 8px;
      padding: 0 20px;
    }
    .faq-item.open .faq-answer {
      max-height: 200px;
      padding: 20px;
    }
    /* 联系 */
    .contact-grid {
      display: flex;
      gap: 48px;
      margin-top: 40px;
      background: #F1F5F9;
      border-radius: var(--radius-lg);
      padding: 48px;
    }
    .contact-form {
      flex: 2;
    }
    .contact-info {
      flex: 1;
    }
    .input-group {
      margin-bottom: 20px;
    }
    .input-group label {
      display: block;
      font-weight: 600;
      margin-bottom: 6px;
    }
    .input-group input,
    .input-group textarea {
      width: 100%;
      padding: 12px 16px;
      border: 1px solid var(--border-light);
      border-radius: var(--radius-sm);
      background: white;
      transition: border 0.2s;
    }
    .input-group input:focus,
    .input-group textarea:focus {
      outline: none;
      border-color: var(--accent-cyan);
    }
    .btn-submit {
      background: var(--accent-cyan);
      color: var(--panda-black);
      border: none;
      font-weight: 700;
      padding: 14px 32px;
      border-radius: var(--radius-sm);
      width: 100%;
      cursor: pointer;
      transition: var(--transition);
    }
    .btn-submit:hover {
      background: var(--accent-cyan-hover);
    }
    footer {
      background: var(--panda-black);
      color: #CBD5E1;
      padding: 48px 0;
    }
    .footer-content {
      display: flex;
      justify-content: space-between;
      align-items: center;
      flex-wrap: wrap;
    }
    @media (max-width: 1024px) {
      .hero-grid { flex-direction: column; }
      .cards-grid, .highlights-grid { grid-template-columns: repeat(2,1fr); }
      .cases-masonry { columns: 2; }
      .comparison-wrapper { flex-direction: column; }
    }
    @media (max-width: 768px) {
      .nav-links { display: none; }
      .hamburger { display: flex; }
      .mobile-menu { display: flex; }
      .cards-grid, .highlights-grid { grid-template-columns: 1fr; }
      .cases-masonry { columns: 1; }
      .contact-grid { flex-direction: column; padding: 24px; }
      .hero h1 { font-size: 36px; }
      section { padding: 48px 0; }
    }