html, body {
      max-width: 100%;
      overflow-x: hidden;
      margin-top: 0;
      font-family: Arial, sans-serif;
      background-color: #fdfdfd;
    }

    .container {
      max-width: 1200px;
      margin: 0 auto;
      box-sizing: border-box;
      
    }

    .wrapper {
      display: flex;
      flex-wrap: wrap;
      gap: 10px;
      max-width: 1200px;
      width: 100%;
      margin: 0 auto;
    }

    .header {
      background-color: #0785c1;
      padding: 10px 0;
      width: 100%;
      position: fixed;
      top: 0;
      left: 0;
      z-index: 999;
      box-shadow: 0 2px 5px rgba(0,0,0,0.1);
      color: #fff;
      text-align: center;
    }

    .footer {
      max-width: 1200px;
      width: 100%;
      margin: 20px auto 0;
      font-size: 14px;
      text-align: center;
      padding: 10px;
    }

    .main-content {
      flex: 1;
      background: #ffffff;
      padding: 0 2px;
      box-sizing: border-box;
      min-width: 0;
    
    }

    .sidebar-left,
    .sidebar-right {
      width: 250px;
      background-color: #f4f4f4;
      box-sizing: border-box;
    }

    .sidebar-right {
      background-color: #fff;
    }

    .sidebar {
      padding: 10px;
      background: linear-gradient(135deg, #0785c1, #0596d8);
      width: 250px;
      position: relative;
    
    }
    .sidebar-inner {
      padding: 6px;
      position: absolute; /* trạng thái gốc */
      top: 0;
      left: 0;
      width: 100%;
      box-sizing: border-box; /* QUAN TRỌNG: giữ padding khi fixed */

    }
    .sidebar h3 {
      color: #fff;
      text-align: center;
      font-weight: bold;
      margin-bottom: 15px;
    }

   

    @media (max-width: 1200px) {
      .container {
        padding: 0 1px;
      }

      .header {
        flex-direction: column;
        align-items: center;
        gap: 10px;
        padding: 15px 10px;
      }

      .wrapper {
        flex-direction: column;
        width: 100%;
        padding-top: 0;
      }

      .sidebar-left,
      .sidebar-right,
      .main-content {
        width: 100%;
      }

      .sidebar {
        position: fixed;
        left: -300px;
        top: 0;
        height: 100vh;
        width: 300px;
        background-color: #fff;
        z-index: 99;
        transition: left 0.3s ease-in-out;
        overflow-y: auto;
        padding: 20px;
        box-shadow: 2px 0 5px rgba(0,0,0,0.1);
      }

      .sidebar.active {
        left: 0;
        transform: translateX(0);
      }

      .toggle-btn {
        display: block;
        position: fixed;
        top: 3px;
        left: 15px;
        z-index: 1000;
        background-color: transparent;
        color: white;
        border: none;
        padding: 10px 14px;
        border-radius: 6px;
        font-size: 30px;
        cursor: pointer;
      }

      .close-btn {
        display: block;
        position: absolute;
        top: 10px;
        right: 10px;
        background-color: transparent;
        border: none;
        font-size: 24px;
        color: #fff;
        cursor: pointer;
      }
    }

    @media (min-width: 769px) {
      .toggle-btn,
      .close-btn {
        display: none;
      }
    }