:root {
      --panel-header: #34495e;
      --panel-bg: #ecf0f1;
      --resize-handle: #bdc3c7;
    }
    
    body {
      font-family: Arial, sans-serif;
      margin: 0;
      padding: 0;
      background-color: #f5f6fa;
    }
    
    .dashboard {
      display: flex;
      flex-wrap: wrap;
      gap: 15px;
      padding: 15px;
      height: 100vh;
    }
    
    .panel {
      background-color: var(--panel-bg);
      border-radius: 8px;
      box-shadow: 0 4px 6px rgba(0,0,0,0.1);
      display: flex;
      flex-direction: column;
      min-width: 200px;
      min-height: 150px;
    }
    
    .panel-header {
      background-color: var(--panel-header);
      color: white;
      padding: 10px 15px;
      border-radius: 8px 8px 0 0;
      cursor: move;
      user-select: none;
    }
    
    .panel-content {
      flex: 1;
      padding: 15px;
      overflow: auto;
    }
    
    /* 调整大小手柄 */
    .resize-handle {
      width: 100%;
      height: 5px;
      background-color: var(--resize-handle);
      cursor: ns-resize;
      position: relative;
    }
    
    .resize-handle::after {
      content: "≡";
      position: absolute;
      left: 50%;
      top: -8px;
      transform: translateX(-50%);
      color: var(--panel-header);
      font-size: 16px;
    }
    
    /* 面板大小和位置 */
    .panel-1 {
      flex: 2 1 400px;
    }
    
    .panel-2 {
      flex: 1 1 300px;
    }
    
    .panel-3 {
      flex: 1 1 200px;
    }
    
    /* 响应式调整 */
    @media (max-width: 768px) {
      .panel {
        flex: 1 1 100%;
      }
    }