/* ============================================
   RIVERS OF CIVILIZATION — STREAMGRAPH STYLES
   ============================================ */

:root {
    --bg-primary: #0a0a1a;
    --bg-secondary: #111128;
    --bg-tertiary: #16162e;
    --text-primary: #e8e8f0;
    --text-secondary: #a0a0c0;
    --text-muted: #606080;
    --border-color: rgba(255,255,255,0.06);
    --shadow-md: 0 4px 20px rgba(0,0,0,0.4);
    --shadow-lg: 0 8px 40px rgba(0,0,0,0.5);
    --glass-bg: rgba(20,20,40,0.85);
    --glass-border: rgba(255,255,255,0.08);
    --header-height: 56px;
    --era-bar-height: 32px;
    --footer-height: 24px;
}

[data-theme="light"] {
    --bg-primary: #f5f3ef;
    --bg-secondary: #ffffff;
    --bg-tertiary: #eae6df;
    --text-primary: #1a1a2e;
    --text-secondary: #4a4a6a;
    --text-muted: #8888a8;
    --border-color: rgba(0,0,0,0.08);
    --shadow-md: 0 4px 20px rgba(0,0,0,0.1);
    --shadow-lg: 0 8px 40px rgba(0,0,0,0.15);
    --glass-bg: rgba(255,255,255,0.9);
    --glass-border: rgba(0,0,0,0.06);
}

/* ============ RESET ============ */
*, *::before, *::after { margin: 0; padding: 0; box-sizing: border-box; }
html, body { height: 100%; overflow: hidden; }
body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
    background: var(--bg-primary);
    color: var(--text-primary);
    transition: background 0.4s ease, color 0.4s ease;
}

/* ============ ERA BACKGROUNDS ============ */
.sg-era-bg {
    position: fixed;
    top: 0; left: 0; right: 0; bottom: 0;
    z-index: 0;
    pointer-events: none;
    overflow: hidden;
}

.sg-era-bg-layer {
    position: absolute;
    top: 0; left: 0; right: 0; bottom: 0;
    background-size: cover;
    background-position: center;
    background-repeat: no-repeat;
    opacity: 0;
    transition: opacity 1.2s ease;
    will-change: opacity;
}

[data-theme="dark"] .sg-era-bg-layer {
    filter: brightness(0.3) saturate(0.7);
}

[data-theme="light"] .sg-era-bg-layer {
    filter: brightness(0.85) saturate(0.5);
}

/* ============ HEADER ============ */
.sg-header {
    position: fixed;
    top: 0; left: 0; right: 0;
    height: var(--header-height);
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 0 20px;
    background: var(--glass-bg);
    backdrop-filter: blur(16px);
    border-bottom: 1px solid var(--glass-border);
    z-index: 100;
}

.sg-main {
    z-index: 1;
}

.sg-title {
    font-family: 'Playfair Display', serif;
    font-size: 1.3rem;
    font-weight: 800;
    letter-spacing: -0.02em;
    display: flex;
    align-items: center;
    gap: 8px;
}

.sg-title-icon {
    font-size: 1.5rem;
    opacity: 0.7;
}

.sg-subtitle {
    font-size: 0.7rem;
    color: var(--text-muted);
    font-weight: 400;
    letter-spacing: 0.04em;
    margin-top: 1px;
}

.sg-header-right {
    display: flex;
    align-items: center;
    gap: 6px;
}

.sg-btn {
    width: 34px;
    height: 34px;
    border-radius: 8px;
    border: 1px solid var(--border-color);
    background: transparent;
    color: var(--text-secondary);
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all 0.2s ease;
}

.sg-btn:hover {
    background: var(--border-color);
    color: var(--text-primary);
}

.sg-zoom-group {
    display: flex;
    align-items: center;
    gap: 4px;
    margin-left: 8px;
    padding-left: 8px;
    border-left: 1px solid var(--border-color);
}

.sg-zoom-label {
    font-size: 0.72rem;
    font-weight: 600;
    color: var(--text-muted);
    min-width: 40px;
    text-align: center;
}

/* Theme toggle icons */
[data-theme="dark"] .icon-sun { display: none; }
[data-theme="dark"] .icon-moon { display: block; }
[data-theme="light"] .icon-sun { display: block; }
[data-theme="light"] .icon-moon { display: none; }
.icon-sun, .icon-moon { display: none; }

/* ============ MAIN ============ */
.sg-main {
    position: fixed;
    top: var(--header-height);
    left: 0; right: 0;
    bottom: calc(var(--era-bar-height) + var(--footer-height));
    overflow: hidden;
}

.sg-scroll {
    width: 100%;
    height: 100%;
    overflow-x: auto;
    overflow-y: hidden;
    position: relative;
    cursor: grab;
}

.sg-scroll:active {
    cursor: grabbing;
}

.sg-scroll canvas {
    position: absolute;
    top: 0;
    left: 0;
}

#bgCanvas { z-index: 1; }
#fgCanvas { z-index: 2; }

/* Scrollbar */
.sg-scroll::-webkit-scrollbar { height: 6px; }
.sg-scroll::-webkit-scrollbar-track { background: transparent; }
.sg-scroll::-webkit-scrollbar-thumb {
    background: var(--text-muted);
    border-radius: 3px;
    opacity: 0.4;
}

/* ============ FOOTER ============ */
.sg-footer {
    position: fixed;
    bottom: 0; left: 0; right: 0;
    height: var(--footer-height);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 0.55rem;
    color: var(--text-muted);
    background: var(--bg-secondary);
    border-top: 1px solid var(--glass-border);
    z-index: 100;
    letter-spacing: 0.03em;
}

/* ============ ERA BAR ============ */
.sg-era-bar {
    position: fixed;
    bottom: var(--footer-height); left: 0; right: 0;
    height: var(--era-bar-height);
    display: flex;
    z-index: 100;
    background: var(--bg-secondary);
    border-top: 1px solid var(--glass-border);
}

.sg-era-segment {
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 0.6rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.08em;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
    padding: 0 6px;
    min-width: fit-content;
}

/* ============ LEGEND ============ */
.sg-legend {
    position: fixed;
    top: var(--header-height);
    right: -280px;
    width: 270px;
    bottom: calc(var(--era-bar-height) + var(--footer-height));
    background: var(--glass-bg);
    backdrop-filter: blur(16px);
    border-left: 1px solid var(--glass-border);
    z-index: 50;
    overflow-y: auto;
    padding: 16px;
    transition: right 0.35s cubic-bezier(0.4, 0, 0.2, 1);
}

.sg-legend.active {
    right: 0;
}

.sg-legend-title {
    font-size: 0.75rem;
    text-transform: uppercase;
    letter-spacing: 0.08em;
    color: var(--text-muted);
    margin-bottom: 12px;
}

.sg-legend-group {
    margin-bottom: 16px;
}

.sg-legend-region {
    font-size: 0.7rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.06em;
    margin-bottom: 6px;
    padding-bottom: 4px;
    border-bottom: 1px solid var(--border-color);
}

.sg-legend-item {
    display: flex;
    align-items: center;
    gap: 8px;
    padding: 3px 0;
    font-size: 0.72rem;
    color: var(--text-secondary);
}

.sg-legend-swatch {
    width: 12px;
    height: 8px;
    border-radius: 3px;
    flex-shrink: 0;
}

.sg-legend-name {
    flex: 1;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

.sg-legend-dates {
    font-size: 0.6rem;
    color: var(--text-muted);
    white-space: nowrap;
}

/* ============ TOOLTIP ============ */
.sg-tooltip {
    position: fixed;
    display: none;
    padding: 10px 14px;
    background: var(--glass-bg);
    backdrop-filter: blur(12px);
    border: 1px solid var(--glass-border);
    border-radius: 10px;
    box-shadow: var(--shadow-lg);
    pointer-events: none;
    z-index: 200;
    max-width: 240px;
    transition: opacity 0.15s ease;
}

.sg-tip-name {
    font-weight: 700;
    font-size: 0.9rem;
    margin-bottom: 3px;
}

.sg-tip-range {
    font-size: 0.75rem;
    color: var(--text-secondary);
}

.sg-tip-region {
    font-size: 0.65rem;
    color: var(--text-muted);
    margin-top: 2px;
    text-transform: uppercase;
    letter-spacing: 0.06em;
}

.sg-tip-year {
    font-size: 0.7rem;
    color: var(--text-muted);
    margin-top: 4px;
    padding-top: 4px;
    border-top: 1px solid var(--border-color);
}

/* ============ DETAIL PANEL ============ */
.sg-detail-overlay {
    position: fixed;
    inset: 0;
    background: rgba(0,0,0,0.5);
    backdrop-filter: blur(6px);
    z-index: 300;
    display: flex;
    align-items: center;
    justify-content: center;
    opacity: 0;
    visibility: hidden;
    transition: all 0.3s ease;
}

.sg-detail-overlay.active {
    opacity: 1;
    visibility: visible;
}

.sg-detail {
    background: var(--glass-bg);
    backdrop-filter: blur(20px);
    border: 1px solid var(--glass-border);
    border-radius: 16px;
    padding: 28px;
    max-width: 480px;
    width: 90%;
    max-height: 80vh;
    overflow-y: auto;
    box-shadow: var(--shadow-lg);
    position: relative;
    transform: translateY(20px);
    transition: transform 0.3s ease;
}

.sg-detail-overlay.active .sg-detail {
    transform: translateY(0);
}

.sg-detail-close {
    position: absolute;
    top: 12px;
    right: 12px;
    width: 30px;
    height: 30px;
    border: none;
    background: var(--border-color);
    color: var(--text-muted);
    border-radius: 50%;
    cursor: pointer;
    font-size: 1.1rem;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all 0.2s ease;
}

.sg-detail-close:hover {
    background: var(--text-muted);
    color: var(--bg-primary);
}

/* ============ BACK LINK ============ */
/* removed */

/* ============ WORLD MAP PANEL ============ */
.sg-map-panel {
    position: fixed;
    top: calc(var(--header-height) + 12px);
    left: 14px;
    width: 340px;
    z-index: 60;
    background: var(--glass-bg);
    backdrop-filter: blur(20px);
    border: 1px solid var(--glass-border);
    border-radius: 14px;
    box-shadow: var(--shadow-lg);
    overflow: hidden;
    transition: opacity 0.3s ease, transform 0.3s ease, width 0.3s ease;
}

.sg-map-panel.expanded {
    width: min(680px, calc(100vw - 28px));
}

.sg-map-panel.hidden {
    opacity: 0;
    pointer-events: none;
    transform: translateY(-10px) scale(0.96);
}

.sg-map-header {
    display: flex;
    align-items: center;
    gap: 8px;
    padding: 8px 12px;
    border-bottom: 1px solid var(--border-color);
}

.sg-map-icon {
    font-size: 1rem;
}

.sg-map-year {
    font-family: 'Playfair Display', serif;
    font-weight: 800;
    font-size: 0.95rem;
    flex: 1;
    letter-spacing: -0.01em;
}

.sg-map-toggle {
    width: 24px !important;
    height: 24px !important;
    border-radius: 6px !important;
    flex-shrink: 0;
}

.sg-map-expand {
    width: 24px !important;
    height: 24px !important;
    border-radius: 6px !important;
    flex-shrink: 0;
    font-size: 0.85rem;
    line-height: 1;
}

.sg-map-body {
    position: relative;
    width: 100%;
    aspect-ratio: 2 / 1;
    overflow: hidden;
    cursor: default;
}

.sg-map-body canvas {
    width: 100%;
    height: 100%;
    display: block;
}

.sg-map-civs {
    padding: 6px 10px 8px;
    display: flex;
    flex-wrap: wrap;
    gap: 4px;
    max-height: 52px;
    overflow: hidden;
    border-top: 1px solid var(--border-color);
}

.sg-map-civ-tag {
    display: inline-flex;
    align-items: center;
    gap: 4px;
    padding: 2px 7px;
    border-radius: 4px;
    font-size: 0.58rem;
    font-weight: 600;
    background: rgba(255,255,255,0.06);
    color: var(--text-secondary);
    white-space: nowrap;
}

.sg-map-civ-dot {
    width: 6px;
    height: 6px;
    border-radius: 50%;
    flex-shrink: 0;
}

.sg-map-show {
    position: fixed;
    top: calc(var(--header-height) + 12px);
    left: 14px;
    z-index: 55;
    width: 36px !important;
    height: 36px !important;
    border-radius: 10px !important;
    font-size: 1.1rem;
    display: none;
}

.sg-map-panel.hidden ~ .sg-map-show {
    display: flex;
}

/* ============ RESPONSIVE ============ */
@media (max-width: 768px) {
    .sg-header { padding: 0 10px; }
    .sg-title { font-size: 1rem; }
    .sg-subtitle { display: none; }
    .sg-legend { width: 220px; right: -230px; }
    .sg-map-panel { width: 260px; }
}