:root {
      --primary: #2563eb;
      --primary-dark: #1d4ed8;
      --primary-light: #dbeafe;
      --light-bg: #f9fafb;
      --dark-text: #111827;
      --gray-100: #f3f4f6;
      --gray-200: #e5e7eb;
      --gray-300: #d1d5db;
      --gray-400: #9ca3af;
      --gray-600: #4b5563;
      --success: #10b981;
      --warning: #f59e0b;
      --danger: #ef4444;
      --radius: 12px;
      --shadow-sm: 0 2px 6px rgba(0,0,0,0.05);
      --shadow-md: 0 4px 12px rgba(0,0,0,0.08);
      --shadow-lg: 0 10px 25px rgba(0,0,0,0.1);
    }

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

    body {
      font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'PingFang SC', 'Microsoft YaHei', sans-serif;
      line-height: 1.7;
      color: var(--dark-text);
      background-color: #fff;
      overflow-x: hidden;
    }

    /* ====== 头部 & 导航 ====== */
    header {
      background: linear-gradient(135deg, #f0f9ff 0%, #e0f2fe 100%);
      padding: 1.8rem 1rem 3rem;
      border-bottom: 1px solid var(--gray-200);
      position: relative;
      overflow: hidden;
    }

    header::before {
      content: "";
      position: absolute;
      top: -100px;
      right: -100px;
      width: 300px;
      height: 300px;
      border-radius: 50%;
      background: radial-gradient(circle, rgba(37,99,235,0.08) 0%, transparent 70%);
    }

    .navbar {
      display: flex;
      justify-content: space-between;
      align-items: center;
      max-width: 1000px;
      margin: 0 auto;
      padding: 0 1rem;
      position: relative;
      z-index: 2;
    }

    .logo {
      font-size: 1.2rem;
      font-weight: 800;
      color: var(--primary-dark);
      text-decoration: none;
      display: flex;
      align-items: center;
      gap: 0.6rem;
      transition: all 0.3s ease;
    }

    .logo-icon {
      background: var(--primary);
      color: white;
      width: 100px;
      height: 80px;
      border-radius: 8px;
      display: flex;
      align-items: center;
      justify-content: center;
      font-weight: bold;
      font-size: 2.6rem;
      box-shadow: var(--shadow-sm);
    }
    .pageLogo{display: flex;
    flex-wrap: nowrap;
    flex-direction: column;}
    .pageLogo .en{font-size: 1.1rem;
    text-align: center;}
    .pageLogo .cn{    font-size: 0.85rem;
    text-align: center;}
    .nav-links {
          display: flex;
        gap: 0.5rem;
        align-items: flex-end;
        flex-wrap: nowrap;
        flex-direction: column;
    }
    .channel{display: flex;gap: 1.5rem;}

    .nav-links a {
      text-decoration: none;
      color: var(--gray-600);
      font-weight: 500;
      transition: all 0.2s ease;
      position: relative;
      padding: 0.5rem 0;    font-size: 0.9rem;
    }

    .nav-links a:hover {
      color: var(--primary);
    }

    .nav-links a::after {
      content: '';
      position: absolute;
      bottom: 0;
      left: 0;
      width: 0;
      height: 2px;
      background: var(--primary);
      transition: width 0.3s ease;
    }

    .nav-links a:hover::after {
      width: 100%;
    }

    .auth-section {
      display: flex;
      align-items: center;
      gap: 1rem;
    }

    .user-info {
      display: flex;
      align-items: center;
      gap: 0.6rem;
      background: white;
      padding:0.12rem 0.6rem 0.12rem  0.15rem;
      border-radius: 999px;
      border: 1px solid var(--gray-200);
      font-size: 0.6rem;
      box-shadow: var(--shadow-sm);
    }

    .user-avatar {
      width: 28px;
      height: 28px;
      border-radius: 50%;
      background: var(--primary);
      color: white;
      display: flex;
      align-items: center;
      justify-content: center;
      font-size: 0.6rem;
      font-weight: bold;
    }

    .lang-switcher {
      background: transparent;
      border: 1px solid var(--gray-300);
      color: var(--gray-600);
      cursor: pointer;
      font-size: 0.6rem;
      padding: 0.2rem 0.6rem;
      border-radius: 8px;
      transition: all 0.2s;
    }

    .lang-switcher:hover {
      background: var(--primary-light);
      border-color: var(--primary);
      color: var(--primary-dark);
    }

    /* ====== 英文标题 + 悬停效果 ====== */
    .hero {
      text-align: center;
      max-width: 800px;
      margin: 2rem auto 0;
      position: relative;
      z-index: 2;
    }

    .hero h1 {
      font-size: 2.8rem;
      font-weight: 800;
      margin-bottom: 1rem;
      background: linear-gradient(135deg, var(--primary-dark), #0ea5e9);
      -webkit-background-clip: text;
      background-clip: text;
      color: transparent;
      line-height: 1.2;
      animation: fadeInUp 1s ease-out;
    }

    .hero h5 {
      font-size: 1.25rem;
      font-weight: 600;
      color: var(--gray-600);
      margin-bottom: 1.5rem;
      opacity: 0.9;
      animation: fadeInUp 1s ease-out 0.2s both;
    }

    .hero p {
      font-size: 1.15rem;
      color: var(--gray-600);
      margin: 0 auto 1.8rem;
      max-width: 700px;
      animation: fadeInUp 1s ease-out 0.4s both;
    }

    .tagline {
      background: linear-gradient(135deg, var(--primary), #0ea5e9);
      color: white;
      padding: 0.7rem 2rem;
      display: inline-block;
      border-radius: 999px;
      font-size: 0.95rem;
      margin-top: 1rem;
      font-weight: 600;
      box-shadow: var(--shadow-md);
      animation: fadeInUp 1s ease-out 0.6s both;
    }

    /* ====== 主体内容 ====== */
    main {
      max-width: 1000px;
      margin: 3rem auto;
      padding: 0 1.5rem;
    }

    section {
      margin-bottom: 4rem;
    }

    h2 {
      font-size: 2rem;
      margin-bottom: 1.5rem;
      color: var(--primary-dark);
      position: relative;
      font-weight: 700;
      animation: fadeInUp 1s ease-out;
    }

    h2::before {
      content: '';
      display: block;
      width: 50px;
      height: 4px;
      background: linear-gradient(to right, var(--primary), #0ea5e9);
      margin-bottom: 1rem;
      border-radius: 2px;
    }

    h3 {
      font-size: 1.35rem;
      margin: 1.5rem 0 1rem;
      color: var(--dark-text);
      font-weight: 600;
      animation: fadeInUp 1s ease-out;
    }

    p {
      margin-bottom: 1.2rem;
      color: var(--gray-600);
      animation: fadeInUp 1s ease-out;
    }

    .features {
      display: grid;
      grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
      gap: 1.8rem;
      margin-top: 1.8rem;
    }

    .feature-card {
      background: white;
      padding: 1.8rem;
      border-radius: var(--radius);
      border: 1px solid var(--gray-200);
      transition: all 0.3s ease;
      box-shadow: var(--shadow-sm);
      animation: fadeInUp 1s ease-out;
    }

    .feature-card:hover {
      transform: translateY(-6px);
      box-shadow: var(--shadow-lg);
      border-color: var(--primary-light);
    }

    .feature-card h4 {
      font-size: 1.25rem;
      margin-bottom: 0.8rem;
      color: var(--primary-dark);
      display: flex;
      align-items: center;
      gap: 0.5rem;
    }

    .feature-icon {
      background: var(--primary-light);
      color: var(--primary);
      width: 32px;
      height: 32px;
      border-radius: 8px;
      display: flex;
      align-items: center;
      justify-content: center;
      font-weight: bold;
    }

    .core-values ul {
      padding-left: 1.8rem;
      margin: 1.2rem 0;
    }

    .core-values li {
      margin-bottom: 0.7rem;
      position: relative;
    }

    .core-values li::before {
      content: "✓";
      color: var(--success);
      font-weight: bold;
      position: absolute;
      left: -1.5rem;
    }

    .ecosystem {
      background: linear-gradient(135deg, #f8fafc 0%, #f1f5f9 100%);
      padding: 2.2rem;
      border-radius: var(--radius);
      margin-top: 1.8rem;
      border: 1px solid var(--gray-200);
    }
    .model-card{border:1px solid #cdcdcd;border-radius:1rem;padding:1rem;margin:1rem 0;background:#fcfcfc;}
    /* ====== API 文档区域 —— 完全重做 ====== */
    .api-section {
      background: #f5f5f5;
      border-left: 1px solid #ffffff;;
      padding: 2rem;
      border-radius: 0.75rem;
      margin: 1.5rem 0;
      box-shadow: var(--shadow-sm);
    }

    .api-links {
      display: grid;
      grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
      gap: 1.5rem;
      margin-top: 1.5rem;
    }

    .api-link-item {
      background: white;
      padding: 1.5rem;
      border-radius: var(--radius);
      border: 1px solid var(--gray-200);
      transition: all 0.3s ease;
      box-shadow: var(--shadow-sm);
      animation: fadeInUp 1s ease-out;
    }

    .api-link-item:hover {
      transform: translateY(-4px);
      box-shadow: var(--shadow-md);
      border-color: var(--primary-light);
    }

    .api-link-item h4 {
      color: var(--primary-dark);
      margin-bottom: 0.7rem;
      font-size: 1.15rem;
      font-weight: 600;
    }

    .btn {
      display: inline-block;
      background: var(--primary);
      color: white;
      padding: 0.6rem 1.2rem;
      border-radius: 8px;
      text-decoration: none;
      font-weight: 600;
      transition: all 0.25s;
      border: none;
      cursor: pointer;
      font-size: 0.65rem;
      box-shadow: var(--shadow-sm);
    }

    .btn:hover {
      background: var(--primary-dark);
      transform: translateY(-2px);
      box-shadow: var(--shadow-md);
    }

    .btn-outline {
      background: transparent;
      border: 1px solid var(--primary);
      color: var(--primary);
      box-shadow: none;
    }

    .btn-outline:hover {
      background: var(--primary-light);
      transform: translateY(-2px);
      box-shadow: var(--shadow-sm);
    }

    /* ====== 底部增强 ====== */
    footer {
      text-align: center;
      padding: 2.5rem 1rem 1.5rem;
      color: var(--gray-600);
      font-size: 0.95rem;
      border-top: 1px solid var(--gray-200);
      background:#f0f9ff;
    }

    .footer-links {
      display: flex;
      justify-content: center;
      gap: 1.5rem;
      margin: 1.2rem 0;
    }

    .footer-links a {
      color: var(--gray-600);
      text-decoration: none;
      font-weight: 500;
      transition: color 0.2s;
    }

    .footer-links a:hover {
      color: var(--primary);
    }

    .footer-social {
      display: flex;
      justify-content: center;
      gap: 1rem;
      margin-top: 1rem;
    }

    .social-icon {
      width: 32px;
      height: 32px;
      background: var(--gray-200);
      border-radius: 50%;
      display: flex;
      align-items: center;
      justify-content: center;
      color: var(--gray-600);
      font-size: 0.9rem;
      transition: all 0.2s;
    }

    .social-icon:hover {
      background: var(--primary);
      color: white;
      transform: scale(1.1);
    }

    /* ====== 动画 ====== */
    @keyframes fadeInUp {
      from {
        opacity: 0;
        transform: translateY(20px);
      }
      to {
        opacity: 1;
        transform: translateY(0);
      }
    }

    @keyframes pulse {
      0% { transform: scale(1); }
      50% { transform: scale(1.05); }
      100% { transform: scale(1); }
    }

    .btn:hover {
      animation: pulse 0.5s ease-in-out;
    }

    /* 响应式 */
    @media (max-width: 768px) {
      .navbar {
        flex-direction: column;
        gap: 1.2rem;
      }
      .hero h1 {
        font-size: 2.2rem;
      }
      .hero h5 {
        font-size: 1.1rem;
      }
      .process-steps,
      .governance-model,
      .api-links {
        grid-template-columns: 1fr;
      }
      .nav-links {
        gap: 0.3rem;
      }
    }