/**
 * Timeline - About Dr. Dinshah K. Mehta
 * Center-aligned timeline with per-year hover preview image.
 */
.timeline {
    list-style: none;
    margin: 0;
    padding: 0;
    position: relative;
}
.timeline::before {
    content: "";
    position: absolute;
    left: 50%;
    top: 0;
    bottom: 0;
    width: 2px;
    background: var(--color-accent, #7d6b5c);
    transform: translateX(-50%);
}
@media (max-width: 767px) {
    .timeline::before {
        left: 12px;
        transform: none;
    }
}

.timeline-item {
    position: relative;
    margin-bottom: var(--space-xl);
    padding-left: 0;
}
@media (max-width: 767px) {
    .timeline-item {
        margin-bottom: var(--space-md);
    }
}
.timeline-item:last-child { margin-bottom: 0; }
.timeline-item.reveal {
    opacity: 0;
    transform: translateY(16px);
    transition: opacity 0.5s ease, transform 0.5s ease;
}
.timeline-item.reveal.is-visible {
    opacity: 1;
    transform: translateY(0);
}

.timeline-marker {
    position: absolute;
    left: 50%;
    transform: translateX(-50%);
    z-index: 1;
}
@media (max-width: 767px) {
    .timeline-marker {
        left: 12px;
    }
}
.timeline-year {
    display: inline-block;
    padding: var(--space-xs) var(--space-md);
    background: var(--color-accent, #7d6b5c);
    color: var(--color-white, #fff);
    font-size: 0.875rem;
    font-weight: 600;
    border-radius: 4px;
}

.timeline-content {
    padding: var(--space-md);
    background: var(--color-bg-alt, #eeede8);
    border-radius: 8px;
    border: 1px solid var(--color-border, #ddd9d2);
}
.timeline-content h3 {
    margin: 0 0 var(--space-sm);
    font-size: 1.125rem;
    font-weight: 600;
}
.timeline-content p {
    margin: 0;
    font-size: var(--font-body);
}
@media (min-width: 768px) {
    .timeline-item:nth-child(odd) .timeline-content { margin-left: 0; margin-right: calc(50% + var(--space-lg)); text-align: right; }
    .timeline-item:nth-child(even) .timeline-content { margin-left: calc(50% + var(--space-lg)); margin-right: 0; text-align: left; }
}
@media (max-width: 767px) {
    .timeline-content {
        margin-left: 44px;
        margin-right: 0;
        text-align: left;
        padding: var(--space-sm) var(--space-md);
    }
}

.timeline-hover-preview {
    position: absolute;
    top: 50%;
    transform: translateY(-50%);
    width: min(280px, 28vw);
    margin: 0;
    opacity: 0;
    visibility: hidden;
    pointer-events: none;
    transition: opacity 0.18s ease, visibility 0.18s ease;
    z-index: 3;
}
.timeline-hover-preview img {
    width: 100%;
    max-height: 210px;
    display: block;
    object-fit: contain;
    border-radius: 10px;
    border: 1px solid var(--color-border, #ddd9d2);
    background: #f8f7f4;
    box-shadow: 0 8px 24px rgba(0, 0, 0, 0.16);
}
@media (min-width: 768px) {
    .timeline-item:nth-child(odd) .timeline-hover-preview { left: calc(50% + var(--space-2xl)); }
    .timeline-item:nth-child(even) .timeline-hover-preview { right: calc(50% + var(--space-2xl)); }
}
.timeline-item:hover .timeline-hover-preview,
.timeline-item:focus-within .timeline-hover-preview {
    opacity: 1;
    visibility: visible;
}
@media (max-width: 767px) {
    .timeline-hover-preview {
        display: none;
    }
}