/* Atomic Theory Timeline — Styles */

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    background-color: aliceblue;
    color: #222;
}

/* ── Page header ─────────────────────────────────── */
header {
    background: linear-gradient(135deg, #5c3317 0%, #1a3a5c 100%);
    color: white;
    padding: 16px 20px 12px;
    text-align: center;
}

header h1 {
    font-size: 1.4rem;
    font-weight: 700;
    margin-bottom: 4px;
}

header p {
    font-size: 0.85rem;
    opacity: 0.85;
}

/* ── Filter buttons ──────────────────────────────── */
#filter-bar {
    display: flex;
    gap: 8px;
    flex-wrap: wrap;
    padding: 10px 16px;
    background: #f0f4f8;
    border-bottom: 1px solid #d0d8e4;
    align-items: center;
}

#filter-bar label {
    font-size: 0.8rem;
    font-weight: 600;
    color: #555;
    margin-right: 4px;
}

.filter-btn {
    padding: 5px 14px;
    border: 2px solid transparent;
    border-radius: 20px;
    font-size: 0.8rem;
    font-weight: 600;
    cursor: pointer;
    color: white;
    transition: opacity 0.2s, transform 0.1s;
}

.filter-btn:hover { opacity: 0.85; transform: translateY(-1px); }
.filter-btn.active { border-color: #222; }

.filter-btn[data-cat="all"]                  { background: #555; }
.filter-btn[data-cat="Ancient Philosophy"]   { background: #8b5e3c; }
.filter-btn[data-cat="Classical Atomic Theory"] { background: #1a6e8a; }
.filter-btn[data-cat="Quantum Model"]        { background: #4a3080; }

/* ── Navigation controls ─────────────────────────── */
#nav-bar {
    display: flex;
    gap: 6px;
    padding: 8px 16px;
    background: #f0f4f8;
    border-bottom: 1px solid #d0d8e4;
    align-items: center;
    justify-content: center;
}

.nav-btn {
    padding: 4px 12px;
    border: 1px solid #b0b8c4;
    border-radius: 6px;
    background: white;
    cursor: pointer;
    font-size: 0.85rem;
    color: #333;
    transition: background 0.15s;
}

.nav-btn:hover { background: #e4eaf2; }

/* ── Timeline container ──────────────────────────── */
#timeline-container {
    padding: 10px 80px;
    overflow: hidden;
}

#timeline {
    border-radius: 6px;
}

/* Prevent scroll hijack inside iframe */
.vis-timeline { overflow: visible !important; }
.vis-panel.vis-center { overflow: visible !important; }
.vis-item .vis-item-overflow { overflow: visible !important; }

/* ── vis-timeline item colours ───────────────────── */
.vis-item.vis-Ancient-Philosophy,
.vis-item.vis-Ancient-Philosophy.vis-selected {
    background-color: #8b5e3c;
    border-color: #6b4229;
    color: white;
}

.vis-item.vis-Classical-Atomic-Theory,
.vis-item.vis-Classical-Atomic-Theory.vis-selected {
    background-color: #1a6e8a;
    border-color: #104f66;
    color: white;
}

.vis-item.vis-Quantum-Model,
.vis-item.vis-Quantum-Model.vis-selected {
    background-color: #4a3080;
    border-color: #30205a;
    color: white;
}

/* ── Tooltip ─────────────────────────────────────── */
.vis-tooltip {
    background: #2c3e50 !important;
    color: white !important;
    padding: 10px 15px !important;
    border-radius: 8px !important;
    font-size: 13px !important;
    max-width: 300px !important;
    line-height: 1.4 !important;
    word-wrap: break-word !important;
    overflow-wrap: break-word !important;
    white-space: normal !important;
    box-sizing: border-box !important;
}

.vis-tooltip div {
    max-width: 280px !important;
    word-wrap: break-word !important;
    overflow-wrap: break-word !important;
    white-space: normal !important;
}

/* ── Detail panel ────────────────────────────────── */
#detail-panel {
    margin: 0 16px 12px;
    padding: 16px 20px;
    background: white;
    border-radius: 8px;
    border-left: 5px solid #555;
    box-shadow: 0 2px 8px rgba(0,0,0,0.08);
    min-height: 80px;
    display: flex;
    flex-direction: column;
    gap: 6px;
}

#detail-panel h3 {
    font-size: 1.1rem;
    color: #222;
}

#detail-panel .detail-date {
    font-size: 0.8rem;
    font-weight: 600;
    color: #666;
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

#detail-panel .detail-body {
    font-size: 0.9rem;
    line-height: 1.55;
    color: #333;
}

#detail-panel .detail-context {
    margin-top: 6px;
    padding: 8px 12px;
    background: #f5f7fa;
    border-radius: 6px;
    font-size: 0.82rem;
    color: #555;
    line-height: 1.45;
}

#detail-panel .detail-context strong {
    color: #333;
}

/* ── Legend ──────────────────────────────────────── */
#legend {
    display: flex;
    gap: 16px;
    flex-wrap: wrap;
    padding: 8px 16px 12px;
    font-size: 0.8rem;
    color: #555;
    align-items: center;
    justify-content: center;
}

.legend-item {
    display: flex;
    align-items: center;
    gap: 6px;
}

.legend-dot {
    width: 14px;
    height: 14px;
    border-radius: 3px;
}

/* ── Instructions ────────────────────────────────── */
#instructions {
    text-align: center;
    font-size: 0.78rem;
    color: #888;
    padding: 4px 16px 6px;
}