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

    body {
      font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
      line-height: 1.6;
      background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
      min-height: 100vh;
    }

    .main-container {
      padding: 40px 0;
    }

    .header-section {
      text-align: center;
      color: white;
      margin-bottom: 60px;
    }

    .main-title {
      font-size: 3rem;
      font-weight: 800;
      margin-bottom: 1rem;
      text-shadow: 0 2px 10px rgba(0,0,0,0.3);
    }

    .main-subtitle {
      font-size: 1.2rem;
      opacity: 0.9;
      font-weight: 400;
    }

    /* 卡片网格 */
    .cards-grid {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 20px;
      margin-bottom: 60px;
    }

    .category-card {
      background: rgba(255, 255, 255, 0.95);
      backdrop-filter: blur(20px);
      border-radius: 20px;
      padding: 30px 20px;
      text-align: center;
      cursor: pointer;
      transition: all 0.4s ease;
      border: 2px solid transparent;
      position: relative;
      overflow: hidden;
      height: 180px;
      display: flex;
      flex-direction: column;
      justify-content: center;
    }

    .category-card::before {
      content: '';
      position: absolute;
      top: 0;
      left: 0;
      width: 100%;
      height: 100%;
      background: linear-gradient(135deg, rgba(102, 126, 234, 0.1) 0%, rgba(118, 75, 162, 0.1) 100%);
      opacity: 0;
      transition: opacity 0.3s ease;
    }

    .category-card:hover::before {
      opacity: 1;
    }

    .category-card:hover {
      transform: translateY(-10px);
      box-shadow: 0 20px 40px rgba(0,0,0,0.2);
      border-color: rgba(255,255,255,0.3);
    }

    .category-card.active {
      background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
      color: white;
      transform: translateY(-5px);
      box-shadow: 0 15px 30px rgba(0,0,0,0.3);
    }

    .category-card.active::before {
      opacity: 0;
    }

    .card-icon {
      font-size: 2.5rem;
      margin-bottom: 15px;
      color: #667eea;
      transition: all 0.3s ease;
      position: relative;
      z-index: 2;
    }

    .category-card.active .card-icon {
      color: white;
    }

    .card-title {
      font-size: 1rem;
      font-weight: 600;
      color: #1e293b;
      line-height: 1.3;
      position: relative;
      z-index: 2;
    }

    .category-card.active .card-title {
      color: white;
    }

    .card-desc {
      font-size: 0.85rem;
      color: #64748b;
      margin-top: 8px;
      position: relative;
      z-index: 2;
    }

    .category-card.active .card-desc {
      color: rgba(255,255,255,0.9);
    }

    /* 详情展示区域 */
    .details-section {
      background: rgba(255, 255, 255, 0.95);
      backdrop-filter: blur(20px);
      border-radius: 24px;
      padding: 40px;
      margin-top: 40px;
      box-shadow: 0 20px 40px rgba(0,0,0,0.1);
      border: 1px solid rgba(255,255,255,0.2);
      opacity: 0;
      transform: translateY(30px);
      transition: all 0.5s ease;
    }

    .details-section.show {
      opacity: 1;
      transform: translateY(0);
    }

    .details-content {
      display: grid;
      grid-template-columns: 2fr 1fr;
      gap: 40px;
      margin-top: 30px;
    }

    .left-column {
      display: flex;
      flex-direction: column;
      gap: 30px;
    }

    .detail-block {
      background: #f8fafc;
      border-radius: 16px;
      padding: 25px;
      border: 1px solid #e2e8f0;
    }

    .detail-block h3 {
      font-size: 1.4rem;
      font-weight: 700;
      color: #1e293b;
      margin-bottom: 20px;
      display: flex;
      align-items: center;
      gap: 10px;
    }

    .detail-block h3 i {
      color: #667eea;
      font-size: 1.2rem;
    }

    .problem-text {
      color: #64748b;
      line-height: 1.6;
      margin-bottom: 15px;
    }

    .cases-list {
      list-style: none;
      padding: 0;
    }

    .cases-list li {
      background: white;
      padding: 20px;
      border-radius: 12px;
      margin-bottom: 15px;
      border: 1px solid #e2e8f0;
      transition: all 0.3s ease;
    }

    .cases-list li:hover {
      border-color: #667eea;
      background: #f1f5f9;
      transform: translateY(-2px);
      box-shadow: 0 4px 12px rgba(0,0,0,0.1);
    }

    .case-title {
      font-weight: 600;
      color: #1e293b;
      margin-bottom: 8px;
      font-size: 1.1rem;
    }

    .case-desc {
      font-size: 0.9rem;
      color: #64748b;
      line-height: 1.5;
      margin-bottom: 12px;
    }

    .case-btn {
      background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
      color: white;
      border: none;
      padding: 8px 16px;
      border-radius: 20px;
      font-size: 0.85rem;
      font-weight: 500;
      text-decoration: none;
      display: inline-flex;
      align-items: center;
      gap: 6px;
      transition: all 0.3s ease;
    }

    .case-btn:hover {
      transform: translateY(-1px);
      box-shadow: 0 4px 12px rgba(102, 126, 234, 0.4);
      color: white;
      text-decoration: none;
    }

    .scenarios-list {
      list-style: none;
      padding: 0;
    }

    .scenarios-list li {
      padding: 8px 0;
      border-bottom: 1px solid #e2e8f0;
      color: #64748b;
      display: flex;
      align-items: center;
      gap: 10px;
    }

    .scenarios-list li:last-child {
      border-bottom: none;
    }

    .scenarios-list li i {
      color: #667eea;
      font-size: 0.8rem;
    }

    /* 响应式设计 */
    @media (max-width: 1200px) {
      .cards-grid {
        grid-template-columns: repeat(2, 1fr);
        gap: 15px;
      }
      
      .details-content {
        grid-template-columns: 1fr;
        gap: 25px;
      }
    }

    @media (max-width: 768px) {
      .cards-grid {
        grid-template-columns: 1fr;
      }
      
      .main-title {
        font-size: 2rem;
      }
      
      .category-card {
        height: auto;
        padding: 25px 20px;
      }
      
      .details-section {
        padding: 25px;
      }
      
      .detail-block {
        padding: 20px;
      }
    }

    .pulse {
      animation: pulse 2s infinite;
    }

    @keyframes pulse {
      0% {
        box-shadow: 0 0 0 0 rgba(102, 126, 234, 0.7);
      }
      70% {
        box-shadow: 0 0 0 10px rgba(102, 126, 234, 0);
      }
      100% {
        box-shadow: 0 0 0 0 rgba(102, 126, 234, 0);
      }
    }