/* ===== Timeline Page Specific Styles ===== */

/* ===== Timeline Controls ===== */
.timeline-controls {
    background-color: var(--bg-secondary);
    padding: var(--spacing-lg) 0;
    border-bottom: 1px solid var(--border-color);
    position: sticky;
    top: 70px;
    z-index: 100;
}

.era-selector {
    display: flex;
    gap: 0.5rem;
    margin-bottom: var(--spacing-md);
    overflow-x: auto;
    padding-bottom: 0.5rem;
}

.era-btn {
    padding: 0.75rem 1.5rem;
    background-color: var(--bg-tertiary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    color: var(--text-secondary);
    font-size: 0.875rem;
    font-weight: 600;
    cursor: pointer;
    transition: var(--transition);
    white-space: nowrap;
}

.era-btn:hover {
    border-color: var(--accent-primary);
    color: var(--accent-primary);
}

.era-btn.active {
    background: linear-gradient(135deg, var(--accent-primary), var(--accent-secondary));
    border-color: var(--accent-primary);
    color: white;
}

.timeline-filters {
    display: grid;
    grid-template-columns: 1fr 1fr auto auto;
    gap: var(--spacing-md);
    align-items: center;
}

.timeline-filters select {
    padding: 0.75rem;
    background-color: var(--bg-tertiary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    color: var(--text-primary);
    font-size: 0.875rem;
    cursor: pointer;
    transition: var(--transition);
}

.timeline-filters select:hover {
    border-color: var(--accent-primary);
}

.zoom-btn {
    padding: 0.75rem 1rem;
    background-color: var(--bg-tertiary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    color: var(--text-primary);
    font-size: 1rem;
    cursor: pointer;
    transition: var(--transition);
}

.zoom-btn:hover {
    border-color: var(--accent-primary);
    color: var(--accent-primary);
    background-color: rgba(59, 130, 246, 0.1);
}

/* ===== Timeline Section ===== */
.timeline-section {
    padding: var(--spacing-2xl) 0;
    background: linear-gradient(180deg, var(--bg-primary) 0%, var(--bg-secondary) 100%);
}

.timeline-wrapper {
    position: relative;
    padding-left: var(--spacing-lg);
}

.timeline-line {
    position: absolute;
    left: 30px;
    top: 0;
    bottom: 0;
    width: 3px;
    background: linear-gradient(180deg, 
        var(--accent-primary) 0%, 
        var(--accent-secondary) 50%,
        var(--accent-tertiary) 100%
    );
    box-shadow: 0 0 10px rgba(59, 130, 246, 0.5);
}

/* ===== Timeline Era ===== */
.timeline-era {
    margin-bottom: var(--spacing-2xl);
    position: relative;
}

.era-header {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
    margin-bottom: var(--spacing-xl);
    padding: var(--spacing-md);
    background-color: var(--bg-secondary);
    border-left: 4px solid var(--accent-primary);
    border-radius: var(--radius-md);
}

.era-header h2 {
    font-family: var(--font-display);
    font-size: 2rem;
    color: var(--accent-primary);
    margin: 0;
}

.era-period {
    color: var(--text-muted);
    font-size: 0.875rem;
    font-weight: 600;
    padding: 0.5rem 1rem;
    background-color: rgba(59, 130, 246, 0.1);
    border-radius: var(--radius-sm);
}

/* ===== Timeline Items ===== */
.timeline-item {
    position: relative;
    margin-bottom: var(--spacing-xl);
    padding-left: var(--spacing-2xl);
    transition: var(--transition);
}

.timeline-item:hover .timeline-content {
    transform: translateX(10px);
    box-shadow: 0 10px 30px rgba(59, 130, 246, 0.2);
    border-color: var(--accent-primary);
}

.timeline-marker {
    position: absolute;
    left: -8px;
    top: 8px;
    width: 20px;
    height: 20px;
    border-radius: 50%;
    border: 3px solid var(--bg-primary);
    z-index: 10;
    box-shadow: 0 0 10px rgba(0, 0, 0, 0.5);
}

.timeline-marker.uap {
    background-color: var(--accent-primary);
    box-shadow: 0 0 15px var(--accent-primary);
}

.timeline-marker.et {
    background-color: var(--accent-secondary);
    box-shadow: 0 0 15px var(--accent-secondary);
}

.timeline-marker.ancient {
    background-color: var(--warning);
    box-shadow: 0 0 15px var(--warning);
}

.timeline-marker.disclosure {
    background-color: var(--accent-tertiary);
    box-shadow: 0 0 15px var(--accent-tertiary);
}

.timeline-marker.space {
    background-color: var(--success);
    box-shadow: 0 0 15px var(--success);
}

.timeline-content {
    background-color: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    padding: var(--spacing-md);
    transition: var(--transition);
}

.timeline-date {
    display: inline-block;
    font-family: var(--font-display);
    font-size: 0.875rem;
    font-weight: 700;
    color: var(--accent-primary);
    background-color: rgba(59, 130, 246, 0.1);
    padding: 0.375rem 0.875rem;
    border-radius: var(--radius-sm);
    margin-bottom: var(--spacing-sm);
}

.timeline-content h3 {
    font-size: 1.5rem;
    color: var(--text-primary);
    margin-bottom: var(--spacing-sm);
}

.timeline-content p {
    color: var(--text-secondary);
    line-height: 1.7;
    margin-bottom: var(--spacing-md);
}

.timeline-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
    margin-bottom: var(--spacing-sm);
}

.tag {
    padding: 0.25rem 0.75rem;
    border-radius: var(--radius-sm);
    font-size: 0.75rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.tag.uap {
    background-color: rgba(59, 130, 246, 0.2);
    color: var(--accent-primary);
}

.tag.et {
    background-color: rgba(139, 92, 246, 0.2);
    color: var(--accent-secondary);
}

.tag.ancient {
    background-color: rgba(245, 158, 11, 0.2);
    color: var(--warning);
}

.tag.disclosure {
    background-color: rgba(6, 182, 212, 0.2);
    color: var(--accent-tertiary);
}

.tag.space {
    background-color: rgba(16, 185, 129, 0.2);
    color: var(--success);
}

.tag-significance {
    border: 1px solid;
}

.tag-significance.critical {
    background-color: rgba(239, 68, 68, 0.1);
    border-color: var(--danger);
    color: var(--danger);
}

.tag-significance.major {
    background-color: rgba(245, 158, 11, 0.1);
    border-color: var(--warning);
    color: var(--warning);
}

.tag-significance.notable {
    background-color: rgba(59, 130, 246, 0.1);
    border-color: var(--accent-primary);
    color: var(--accent-primary);
}

.timeline-link {
    color: var(--accent-primary);
    text-decoration: none;
    font-weight: 600;
    font-size: 0.875rem;
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    transition: var(--transition);
}

.timeline-link:hover {
    color: var(--accent-secondary);
    gap: 0.75rem;
}

.timeline-link i {
    font-size: 0.75rem;
}

/* ===== Responsive Design for Timeline ===== */
@media (max-width: 768px) {
    .timeline-controls {
        position: relative;
        top: 0;
    }
    
    .era-selector {
        overflow-x: auto;
        -webkit-overflow-scrolling: touch;
    }
    
    .timeline-filters {
        grid-template-columns: 1fr;
    }
    
    .zoom-btn {
        width: 100%;
    }
    
    .timeline-wrapper {
        padding-left: var(--spacing-md);
    }
    
    .timeline-line {
        left: 15px;
    }
    
    .timeline-marker {
        left: -14px;
        width: 16px;
        height: 16px;
    }
    
    .timeline-item {
        padding-left: var(--spacing-lg);
    }
    
    .era-header {
        flex-direction: column;
        align-items: flex-start;
        gap: var(--spacing-xs);
    }
    
    .era-header h2 {
        font-size: 1.5rem;
    }
    
    .timeline-content h3 {
        font-size: 1.25rem;
    }
}

@media (max-width: 480px) {
    .timeline-section {
        padding: var(--spacing-lg) 0;
    }
    
    .timeline-era {
        margin-bottom: var(--spacing-xl);
    }
    
    .timeline-item {
        margin-bottom: var(--spacing-lg);
    }
    
    .era-header h2 {
        font-size: 1.25rem;
    }
    
    .timeline-content {
        padding: var(--spacing-sm);
    }
    
    .timeline-content h3 {
        font-size: 1.125rem;
    }
    
    .timeline-tags {
        flex-direction: column;
    }
}

/* ===== Animation for Timeline Items ===== */
@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.timeline-item {
    animation: fadeInUp 0.6s ease-out;
}

/* Stagger animation delays */
.timeline-item:nth-child(1) { animation-delay: 0.1s; }
.timeline-item:nth-child(2) { animation-delay: 0.2s; }
.timeline-item:nth-child(3) { animation-delay: 0.3s; }
.timeline-item:nth-child(4) { animation-delay: 0.4s; }
.timeline-item:nth-child(5) { animation-delay: 0.5s; }