:root {
    --color1: #0056b3;
}
.timeline {
    position: relative;
    max-width: 1200px;
    margin: 0 auto;
}

.timeline::after {
    content: '';
    position: absolute;
    width: 4px;
    background-color: var(--primary-color);
    top: 0;
    bottom: 0;
    left: 120px;
    margin-left: -2px;
}

.timeline-item {
    position: relative;
    margin-bottom: 50px;
    display: flex;
}

.timeline-year {
    width: 100px;
    text-align: right;
    font-size: 24px;
    font-weight: bold;
    color: var(--primary-color);
    padding-right: 20px;
    flex-shrink: 0;
}

.timeline-content {
    position: relative;
    padding-left: 40px;
    flex-grow: 1;
}

.timeline-content::before {
    /* content: ''; */
    position: absolute;
    width: 20px;
    height: 20px;
    background-color: #fff;
    border: 4px solid var(--primary-color);
    border-radius: 50%;
    top: 5px;
    left: -10px;
    z-index: 1;
}

.timeline-event {
    margin-bottom: 20px;
    background-color: #f9f9f9;
    padding: 15px;
    border-radius: 6px;
    box-shadow: 0 2px 5px rgba(0, 0, 0, 0.1);
}

.timeline-date {
    font-weight: bold;
    color: var(--primary-color);
    margin-bottom: 5px;
    font-size: 18px;
}

.timeline-description {
    color: #333;
    line-height: 1.6;
}

/* 响应式调整 */
@media screen and (max-width: 768px) {
    .timeline::after {
        left: 60px;
    }
    
    .timeline-year {
        width: 50px;
        font-size: 18px;
    }
    
    .timeline-content {
        padding-left: 30px;
    }
}