.timeline-container {
    position: relative;
    max-width: 1200px;
    margin: 0 auto;
    padding: 20px 0;
}

.timeline-container::after {
    content: '';
    position: absolute;
    width: 6px;
    background-color: #4CAF50;
    top: 0;
    bottom: 0;
    left: 50%;
    margin-left: -3px;
}

.timeline-entry {
    padding: 10px 40px;
    position: relative;
    background-color: inherit;
    width: calc(50% - 40px);
    box-sizing: border-box;
}

.timeline-entry:nth-child(odd) {
    left: 0;
}

.timeline-entry:nth-child(even) {
    left: 50%;
}

.timeline-year {
    position: absolute;
    width: 50px;
    height: 50px;
    right: -25px;
    background-color: #4CAF50;
    top: 15px;
    border-radius: 50%;
    z-index: 1;
    color: white;
    text-align: center;
    line-height: 50px;
    font-weight: bold;
    font-size: 1.2em;
}

.timeline-entry:nth-child(even) .timeline-year {
    left: -0rem;
}

.timeline-content {
    padding: 20px 30px;
    background-color: white;
    position: relative;
    border-radius: 6px;
    box-shadow: 0 1px 6px rgba(0, 0, 0, 0.1);
}

.timeline-content h3 {
    margin-top: 0;
    color: #333;
}

.timeline-content p {
    margin-bottom: 0;
    line-height: 1.6;
    color: #666;
}

/* Responsive design */
@media screen and (max-width: 600px) {
    .timeline-container::after {
        left: 31px;
    }
    
    .timeline-entry {
        width: 100%;
        padding-left: 70px;
        padding-right: 25px;
    }
    
    .timeline-entry:nth-child(even) {
        left: 0%;
    }
    
    .timeline-year {
        left: 6px;
    }
    
    .timeline-entry:nth-child(even) .timeline-year {
        left: 6px;
    }
}