/* ===================================================================
   Snake Timeline Component Styles
   Production-ready with accessibility & performance optimizations
   =================================================================== */

:root {
    --timeline-accent: #4F46E5;
    --timeline-bg: #ffffff;
    --timeline-text: #1f2937;
    --timeline-border: #e5e7eb;
    --timeline-shadow: rgba(0, 0, 0, 0.1);
}

[data-theme="dark"] {
    --timeline-bg: #1f2937;
    --timeline-text: #f9fafb;
    --timeline-border: #374151;
    --timeline-shadow: rgba(0, 0, 0, 0.3);
}

/* === Container === */
.snake-timeline-wrapper {
    padding: 80px 20px;
    background: var(--bg-primary, var(--timeline-bg));
    overflow: hidden;
}

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

/* === Header === */
.snake-timeline-title {
    font-size: clamp(2rem, 5vw, 3rem);
    font-weight: 800;
    text-align: center;
    margin-bottom: 16px;
    color: var(--text-primary, var(--timeline-text));
    letter-spacing: -0.02em;
}

.snake-timeline-subtitle {
    font-size: clamp(1rem, 2vw, 1.25rem);
    text-align: center;
    color: var(--text-secondary, #6b7280);
    margin-bottom: 60px;
    max-width: 600px;
    margin-left: auto;
    margin-right: auto;
}

/* === SVG Path === */
.snake-path {
    position: absolute;
    top: 120px;
    left: 0;
    width: 100%;
    height: calc(100% - 120px);
    pointer-events: none;
    z-index: 0;
}

.snake-path-line {
    stroke-dasharray: 1000;
    stroke-dashoffset: 1000;
    transition: stroke-dashoffset 0.5s ease-out;
}

/* === Timeline Nodes === */
.snake-timeline-nodes {
    position: relative;
    z-index: 1;
    padding: 40px 0;
}

.timeline-node {
    display: flex;
    align-items: center;
    margin-bottom: 120px;
    opacity: 0;
    transform: translateY(50px);
    transition: opacity 0.6s ease, transform 0.6s ease;
}

.timeline-node.is-visible {
    opacity: 1;
    transform: translateY(0);
}

/* Left/Right Positioning */
.timeline-node-left {
    justify-content: flex-start;
    padding-right: 50%;
}

.timeline-node-right {
    justify-content: flex-end;
    padding-left: 50%;
    flex-direction: row-reverse;
}

/* === Node Dot === */
.timeline-node-dot {
    width: 24px;
    height: 24px;
    border-radius: 50%;
    background: var(--accent, var(--timeline-accent));
    border: 4px solid var(--bg-primary, var(--timeline-bg));
    box-shadow: 0 0 0 2px var(--accent, var(--timeline-accent));
    flex-shrink: 0;
    margin: 0 30px;
    position: relative;
    z-index: 2;
}

/* === Node Card === */
.timeline-node-card {
    background: var(--bg-secondary, #f9fafb);
    border: 1px solid var(--border-color, var(--timeline-border));
    border-radius: 16px;
    padding: 24px;
    box-shadow: 0 4px 6px -1px var(--timeline-shadow);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
    max-width: 500px;
}

.timeline-node-card:hover {
    transform: translateY(-4px);
    box-shadow: 0 10px 15px -3px var(--timeline-shadow);
}

.timeline-node-card:focus-within {
    outline: 2px solid var(--accent, var(--timeline-accent));
    outline-offset: 2px;
}

/* === Image === */
.timeline-node-image-wrapper {
    border-radius: 12px;
    overflow: hidden;
    margin-bottom: 16px;
}

.timeline-node-image {
    width: 100%;
    height: auto;
    display: block;
    object-fit: cover;
    aspect-ratio: 3/2;
}

/* === Content === */
.timeline-node-content {
    padding-top: 8px;
}

.timeline-node-year {
    display: inline-block;
    font-size: 0.875rem;
    font-weight: 700;
    color: var(--accent, var(--timeline-accent));
    background: rgba(79, 70, 229, 0.1);
    padding: 4px 12px;
    border-radius: 6px;
    margin-bottom: 12px;
    letter-spacing: 0.05em;
}

.timeline-node-title {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--text-primary, var(--timeline-text));
    margin-bottom: 8px;
    line-height: 1.3;
}

.timeline-node-topic {
    font-size: 1rem;
    color: var(--text-secondary, #6b7280);
    margin-bottom: 12px;
    font-weight: 500;
}

.timeline-node-excerpt {
    font-size: 0.95rem;
    color: var(--text-secondary, #6b7280);
    line-height: 1.6;
}

/* === Color Variations === */
.timeline-node.primary .timeline-node-dot {
    background: var(--primary, #4F46E5);
    box-shadow: 0 0 0 2px var(--primary, #4F46E5);
}

.timeline-node.secondary .timeline-node-dot {
    background: var(--secondary, #10b981);
    box-shadow: 0 0 0 2px var(--secondary, #10b981);
}

.timeline-node.accent .timeline-node-dot {
    background: var(--accent, #f59e0b);
    box-shadow: 0 0 0 2px var(--accent, #f59e0b);
}

/* === Empty State === */
.snake-timeline-empty {
    text-align: center;
    padding: 60px 20px;
    color: var(--text-secondary, #6b7280);
    font-size: 1.125rem;
}

/* ===================================================================
   REDUCED MOTION SUPPORT (Accessibility)
   =================================================================== */
@media (prefers-reduced-motion: reduce) {
    .snake-path-line {
        stroke-dasharray: 0;
        stroke-dashoffset: 0;
    }
    
    .timeline-node {
        opacity: 1;
        transform: none;
    }
    
    .timeline-node-card {
        transition: none;
    }
}

/* ===================================================================
   RESPONSIVE DESIGN (Mobile-first)
   =================================================================== */
@media (max-width: 768px) {
    .snake-timeline-wrapper {
        padding: 60px 16px;
    }
    
    .snake-path {
        display: none; /* Hide path on mobile for simplicity */
    }
    
    .timeline-node {
        margin-bottom: 60px;
        padding: 0 !important;
        flex-direction: column !important;
    }
    
    .timeline-node-left,
    .timeline-node-right {
        padding: 0;
    }
    
    .timeline-node-dot {
        position: absolute;
        left: 16px;
        margin: 0;
    }
    
    .timeline-node-card {
        width: 100%;
        max-width: 100%;
        margin-left: 60px;
    }
}

/* ===================================================================
   PRINT STYLES
   =================================================================== */
@media print {
    .snake-path {
        display: none;
    }
    
    .timeline-node {
        page-break-inside: avoid;
        opacity: 1;
        transform: none;
    }
}