body {
    margin: 0;
    font-family: 'Noto Sans KR', sans-serif;
    color: #333;
    background: #f5f7fa;
    /* 去掉 pointer-events: none; 避免页面无交互 */
  }

  h1.title {
    text-align: center;
    font-size: 34px;
    padding: 25px 20px 15px;
    font-weight: 700;
    color: #1B263B;
  }

  .top-section {
    display: flex;
    flex-wrap: wrap;
    max-width: 1200px;
    margin: 0 auto;
    background: #fff;
    border-radius: 12px;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.05);
    overflow: hidden;
  }

  #map {
    flex: 1;
    min-height: 450px;
    min-width: 300px;
  }

  .intro {
    flex: 1;
    padding: 35px 25px;
    background: #f8fafc;
    font-size: 17px;
    line-height: 1.9;
    min-width: 300px;
    color: #444;
    user-select: none; /* 只禁用简介文字选择 */
  }

  .timeline {
    max-width: 900px;
    margin: 50px auto;
    position: relative;
    padding: 0 20px;
  }

  .timeline::before {
    content: '';
    position: absolute;
    left: 50%;
    top: 0;
    bottom: 0;
    width: 2px;
    background: #d0d4d9;
    transform: translateX(-50%);
  }

  .row {
    display: flex;
    justify-content: flex-start;
    margin: 30px 0;
    opacity: 0;
    transition: opacity 0.8s, transform 0.5s ease-out;
  }

  .row.right {
    justify-content: flex-end;
  }

  .row.visible {
    opacity: 1;
    transform: translateY(0);
  }

  .event {
    width: 48%;
    padding: 15px 20px;
    background: #fff;
    border-radius: 8px;
    transition: transform 0.3s ease, box-shadow 0.3s ease;
  }

  .event:hover {
    transform: translateY(-5px);
    box-shadow: 0 6px 12px rgba(0, 0, 0, 0.1);
  }

  .left .event {
    text-align: right;
  }

  .right .event {
    text-align: left;
  }

  .year {
    font-size: 36px;
    font-weight: 700;
    margin-bottom: 8px;
    color: #1B263B;
  }

  .desc {
    font-size: 18px;
    color: #444;
    font-weight: 400;
  }

  @media (max-width: 768px) {
    .top-section {
      flex-direction: column;
      border-radius: 0;
      box-shadow: none;
    }

    #map {
      height: 280px;
    }

    .intro {
      padding: 20px 15px;
      font-size: 15px;
      line-height: 1.7;
    }

    .timeline {
      margin: 30px 15px;
      padding: 0 15px;
    }

    .timeline::before {
      left: 15px;
    }

    .row, .row.right {
      justify-content: flex-start;
    }

    .event {
      width: 100%;
      text-align: left;
      margin-bottom: 15px;
      margin-left: 30px;
      padding: 12px 15px;
    }

    .year {
      font-size: 28px;
    }

    .desc {
      font-size: 16px;
    }
  }

  @media (max-width: 480px) {
    h1.title {
      font-size: 24px;
      padding: 15px 10px;
    }

    #map {
      height: 220px;
    }

    .intro {
      font-size: 13px;
      padding: 12px 10px;
    }

    .timeline {
      margin: 20px 10px;
      padding: 0 10px;
    }

    .timeline::before {
      left: 10px;
    }

    .event {
      margin-left: 25px;
      padding: 10px 12px;
    }
  }