/* 头部标题 */
    .top-title {
      text-align: center;
      margin-top:20px;
      margin-bottom: 100px;
    }
    .top-title h1 {
      font-size: 42px;
      color: #0b2242;
      letter-spacing: 2px;
      margin-bottom: 16px;
      font-weight: 700;
    }
    .top-title p {
      font-size: 18px;
      color: #63728a;
    }
    .top-title::after {
      content: "";
      display: block;
      width: 90px;
      height: 3px;
      background: linear-gradient(90deg, var(--zh-blue), #36CFC9);
      margin: 22px auto 0;
      border-radius: 2px;
    }

    /* 阶段标题 */
    .stage-name {
      font-size: 23px;
      color: var(--zh-blue);
      font-weight: 600;
      margin: 70px 0 32px 0;
      display: flex;
      align-items: center;
    }
    .stage-name::before {
      content: "";
      width: 7px;
      height: 24px;
      background: linear-gradient(180deg, var(--zh-blue), #36CFC9);
      border-radius: 3px;
      margin-right: 14px;
    }

    /* 时间轴容器 */
    .timeline {
      position: relative;
      padding-left: 56px;
    }
    /* 中轴线 */
    .timeline::before {
      content: "";
      position: absolute;
      left: 8px;
      top: 0;
      width: 3px;
      height: 100%;
      background: linear-gradient(180deg, var(--zh-blue), #36CFC9);
      opacity: 0.75;
      border-radius: 3px;
    }

    /* 时间条目 */
    .timeline-item {
      position: relative;
      margin-bottom: 52px;
      opacity: 0;
      transform: translateY(35px);
      transition: all 0.65s ease;
    }
    .timeline-item.active {
      opacity: 1;
      transform: translateY(0);
    }

    /* 圆点 */
    .timeline-item::before {
      content: "";
      position: absolute;
      left: -56px;
      top: 8px;
      width: 20px;
      height: 20px;
      border-radius: 50%;
      background: linear-gradient(135deg, var(--zh-blue), #36CFC9);
      border: 4px solid #f6f8fc;
      box-shadow: 0 0 10px rgba(22, 93, 255, 0.22);
      z-index: 2;
    }

    /* 卡片样式 */
    .timeline-card {
      background: #fff;
      padding: 28px 36px;
      border-radius: 16px;
      box-shadow: 0 6px 28px rgba(22, 93, 255, 0.05);
      border: 1px solid rgba(22, 93, 255, 0.04);
      transition: 0.35s ease;
      overflow: hidden;
      position: relative;
    }
    .timeline-card::after {
      content: "";
      position: absolute;
      left: 0;
      top: 0;
      width: 4px;
      height: 100%;
      background: linear-gradient(180deg, var(--zh-blue), #36CFC9);
      opacity: 0;
      transition: 0.35s;
    }
    .timeline-card:hover {
      transform: translateY(-5px);
      box-shadow: 0 10px 35px rgba(22, 93, 255, 0.1);
    }
    .timeline-card:hover::after {
      opacity: 1;
    }

    .year-text {
      font-size: 23px;
      color: var(--zh-blue);
      font-weight: 700;
      margin-bottom: 10px;
      letter-spacing: 1px;
    }
    .desc-text {
      font-size: 16px;
      line-height: 1.8;
      color: #444e60;
    }
    .data-highlight {
      color: var(--zh-blue);
      font-weight: 600;
    }

    /* 最后未来卡片特殊底色 */
    .future-card {
      background: linear-gradient(135deg, #f0f7ff, #ebfbfa);
    }

    /* 移动端适配 */
    @media (max-width: 768px) {
      body {
        padding: 50px 15px;
      }
      .top-title h1 {
        font-size: 30px;
      }
      .top-title {
        margin-bottom: 70px;
      }
      .stage-name {
        font-size: 20px;
        margin: 50px 0 25px 0;
      }
      .timeline {
        padding-left: 38px;
      }
      .timeline-item::before {
        left: -40px;
        width: 16px;
        height: 16px;
      }
      .timeline-card {
        padding: 22px 24px;
      }
      .year-text {
        font-size: 21px;
      }
    }