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

  body {
      font-family: Arial, Tahoma, Helvetica, "微软雅黑", sans-serif;
      line-height: 2;
      font-size: 14px;
      color: #333;
      background-color: #f5f7fa;
      min-height: 100vh;
  }

  ul {
      list-style: none;
  }

  ::-webkit-scrollbar {
      width: 8px;
      height: 8px;
  }

  ::-webkit-scrollbar-track {
      background: #f1f1f1;
      border-radius: 4px;
  }

  ::-webkit-scrollbar-thumb {
      background: #c1c1c1;
      border-radius: 4px;
      transition: background 0.2s ease;
  }

  ::-webkit-scrollbar-thumb:hover {
      background: #a8a8a8;
  }

  ::-webkit-scrollbar-thumb:active {
      background: #888888;
  }

  .sidebar::-webkit-scrollbar {
      width: 6px;
  }

  .sidebar::-webkit-scrollbar-track {
      background: transparent;
  }

  .sidebar::-webkit-scrollbar-thumb {
      background: #d0d0d0;
      border-radius: 3px;
  }

  .sidebar::-webkit-scrollbar-thumb:hover {
      background: #b0b0b0;
  }

  .underline {
      text-decoration: underline;
  }

  .bold {
      font-weight: bold;
  }

  .text-indent {
      text-indent: 2em;
  }

  .strikethrough {
      text-decoration: line-through;
  }

  .wrapper {
      display: flex;
      min-height: 100vh;
  }

  .sidebar {
      width: 300px;
      background-color: #fff;
      border-right: 1px solid #e0e0e0;
      padding: 20px;
      position: fixed;
      height: 100vh;
      overflow-y: auto;
      top: 0;
      left: 0;
      z-index: 100;
  }

  h3 {
      font-size: 16px;
      margin: 20px 0px;
      padding-bottom: 10px;
  }

  .sidebar ul {
      list-style: none;
  }

  a {
      color: #00599c;
      text-decoration: none;
  }

  a:hover {
      color: #096ac6;
      text-decoration: underline;
  }

  a:active {
      color: #096ac6;
      text-decoration: underline;
  }

  .sidebar a {
      text-decoration: none;
      display: block;
      padding: 8px 12px;
      border-radius: 4px;
      transition: all 0.2s ease;
  }

  .sidebar a:hover {
      background-color: #e8f0fe;
  }

  .sidebar a.active {
      background-color: #e8f0fe;
      font-weight: 500;
  }

  .content {
      flex: 1;
      min-height: 100vh;
  }

  .container {
      padding: 40px 30px 30px 320px;
      background-color: #fff;
      min-height: 100vh;
      position: relative;
  }

  .prelink {
      position: absolute;
      top: 14px;
      left: 310px;
  }

  h1 {
      text-align: center;
      margin-bottom: 24px;
      font-size: 24px;
      font-weight: 600;
  }

  .update-date {
      margin: 20px 0;
  }


  .intro {
      text-indent: 2em;
  }

  .table-of-contents {
      margin: 20px 0px;
  }

  .table-of-contents ul {
      margin-top: -20px;
      list-style: none;
  }

  .section {
      margin: 20px 0px;
  }

  @media (max-width: 1080px) {
      .sidebar {
          display: none;
      }

      .content {
          margin-left: 0;
      }

      .container {
          padding: 30px 15px 20px;
      }

      h1 {
          font-size: 20px;
          margin-bottom: 16px;
      }

      .prelink {
          top: 4px;
          left: 4px;
      }

  }