/* ─── Reset & base ─────────────────────────────────────────────────────────── */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

/* ── Dark theme (default) ── */
:root {
    --bg:          #0a0a1a;
    --panel-bg:    #111128;
    --border:      #2a2a4a;
    --text:        #ccd6f6;
    --accent:      #5599ff;
    --btn-bg:      #1e2246;
    --btn-hover:   #2a3066;
    --btn-active:  #4466cc;
    --panel-w:     280px;
    --scene-bg:    #0a0a1a;   /* WebGL clear colour (updated via JS on theme change) */
    --logo-bg:     #000000;
    --overlay-txt: rgba(180,200,255,0.92);
    --overlay-shadow: 0 1px 4px rgba(0,0,0,0.85);
    --mcclure-col: rgba(150,175,230,0.85);
    --mcclure-hover: rgba(190,215,255,1);
}

/* ── Light theme ── */
body.light-theme {
    --bg:          #fdfcfb;
    --panel-bg:    #f5f3f0;
    --border:      #aab4d8;
    --text:        #1a1a3a;
    --accent:      #2244bb;
    --btn-bg:      #d0d6ee;
    --btn-hover:   #bec6e8;
    --btn-active:  #5577cc;
    --logo-bg:     #ffffff;
    --overlay-txt: rgba(15,30,110,0.9);
    --overlay-shadow: 0 1px 3px rgba(180,195,240,0.7);
    --mcclure-col: rgba(25,55,140,0.85);
    --mcclure-hover: rgba(10,30,110,1);
}

html, body {
    width: 100%; height: 100%;
    overflow: hidden;
    background: var(--bg);
    color: var(--text);
    font-family: 'Segoe UI', system-ui, sans-serif;
    font-size: 13px;
}

/* ─── Layout ───────────────────────────────────────────────────────────────── */
#app {
    display: flex;
    width: 100%; height: 100%;
}

#canvas-container {
    position: relative;
    flex: 1;
    overflow: hidden;
}

#three-canvas {
    display: block;
    width: 100%;
    height: 100%;
}

/* ─── Controls panel ───────────────────────────────────────────────────────── */
#controls-panel {
    width: var(--panel-w);
    flex-shrink: 0;
    background: var(--panel-bg);
    border-left: 1px solid var(--border);
    overflow-y: auto;
    padding: 16px 14px;
    display: flex;
    flex-direction: column;
    gap: 16px;
}

#controls-panel h1 {
    font-size: 14px;
    font-weight: 700;
    color: var(--accent);
    letter-spacing: 0.05em;
    text-transform: uppercase;
    border-bottom: 1px solid var(--border);
    padding-bottom: 8px;
}

/* ─── Control group ────────────────────────────────────────────────────────── */
.ctrl-group {
    background: rgba(255,255,255,0.03);
    border: 1px solid var(--border);
    border-radius: 6px;
    padding: 12px;
    display: flex;
    flex-direction: column;
    gap: 10px;
}

.ctrl-group h2 {
    font-size: 11px;
    font-weight: 600;
    letter-spacing: 0.08em;
    text-transform: uppercase;
    color: #7a9fd4;
    margin-bottom: 2px;
}

/* ─── Sliders ──────────────────────────────────────────────────────────────── */
.slider-row {
    display: flex;
    flex-direction: column;
    gap: 4px;
}

.slider-row label {
    display: flex;
    justify-content: space-between;
    align-items: center;
    color: var(--text);
}

.slider-row label .unit {
    color: #7a9fd4;
    font-size: 11px;
}

.slider-row input[type=range] {
    width: 100%;
    accent-color: var(--accent);
    cursor: pointer;
    height: 4px;
}

/* ─── Visualisation buttons ────────────────────────────────────────────────── */
#viz-buttons {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 6px;
}

.viz-btn {
    padding: 7px 4px;
    background: var(--btn-bg);
    border: 1px solid var(--border);
    border-radius: 5px;
    color: var(--text);
    font-size: 12px;
    cursor: pointer;
    transition: background 0.15s, border-color 0.15s;
    text-align: center;
}

.viz-btn:hover {
    background: var(--btn-hover);
    border-color: var(--accent);
}

.viz-btn.active {
    background: var(--btn-active);
    border-color: var(--accent);
    color: #fff;
    font-weight: 600;
}

/* ─── Pause button ─────────────────────────────────────────────────────────── */
#pause-btn {
    width: 100%;
    padding: 9px;
    background: var(--btn-bg);
    border: 1px solid var(--border);
    border-radius: 5px;
    color: var(--text);
    font-size: 13px;
    cursor: pointer;
    transition: background 0.15s;
}
#pause-btn:hover { background: var(--btn-hover); }

/* ─── Info / legend ────────────────────────────────────────────────────────── */
.info-row {
    font-size: 11px;
    color: #6a82a4;
    line-height: 1.6;
}

/* ─── Colour legend ────────────────────────────────────────────────────────── */
#color-legend {
    display: flex;
    align-items: center;
    gap: 6px;
    font-size: 11px;
    color: #7a9fd4;
}

#legend-bar {
    flex: 1;
    height: 8px;
    border-radius: 4px;
    background: linear-gradient(to right, #0055ff, #00aaff, #00ff88, #ffff00, #ff4400);
}

/* ─── Scale bar overlay ────────────────────────────────────────────────────── */
#scale-bar-container {
    position: absolute;
    bottom: 18px;
    left: 20px;
    display: flex;
    flex-direction: column;
    align-items: flex-start;
    gap: 3px;
    pointer-events: none;
}

#scale-bar {
    height: 3px;
    background: #88aacc;
    min-width: 20px;
    position: relative;
}

/* End caps on scale bar */
#scale-bar::before,
#scale-bar::after {
    content: '';
    position: absolute;
    top: -4px;
    width: 2px;
    height: 11px;
    background: #88aacc;
}
#scale-bar::before { left: 0; }
#scale-bar::after  { right: 0; }

#scale-label {
    font-size: 11px;
    color: #88aacc;
    letter-spacing: 0.04em;
}

/* ─── Scrollbar (WebKit) ───────────────────────────────────────────────────── */
#controls-panel::-webkit-scrollbar { width: 4px; }
#controls-panel::-webkit-scrollbar-track { background: transparent; }
#controls-panel::-webkit-scrollbar-thumb { background: var(--border); border-radius: 2px; }

/* ─── Scene title overlay (top-center) ────────────────────────────────────── */
#scene-title {
    position: absolute;
    top: 14px;
    left: 50%;
    transform: translateX(-50%);
    color: var(--overlay-txt);
    font-size: 18px;
    font-weight: 600;
    white-space: nowrap;
    pointer-events: none;
    text-shadow: var(--overlay-shadow);
    letter-spacing: 0.02em;
    z-index: 5;
}

/* ─── Dark / Light theme toggle (top-right) ───────────────────────────────── */
#theme-btn {
    position: absolute;
    top: 10px;
    right: 10px;
    padding: 5px 13px;
    background: rgba(10, 15, 50, 0.72);
    border: 1px solid rgba(100,140,230,0.4);
    border-radius: 20px;
    color: #aac0ff;
    font-size: 12px;
    cursor: pointer;
    backdrop-filter: blur(4px);
    transition: background 0.2s, color 0.2s;
    z-index: 10;
}
#theme-btn:hover { background: rgba(30, 50, 130, 0.85); }

body.light-theme #theme-btn {
    background: rgba(220, 228, 250, 0.82);
    border-color: rgba(60,90,190,0.35);
    color: #1a3088;
}
body.light-theme #theme-btn:hover { background: rgba(195, 210, 245, 0.9); }

/* ─── OU logo (bottom-right) ──────────────────────────────────────────────── */
#logo-container {
    position: absolute;
    bottom: 14px;
    right: 14px;
    padding: 5px 8px;
    border-radius: 6px;
    background: var(--logo-bg);
    border: 1px solid rgba(100,130,220,0.25);
    line-height: 0;
    transition: background 0.25s;
}
#ou-logo {
    width: 84px;
    height: auto;
    display: block;
}

/* ─── McClure link (bottom-center) ────────────────────────────────────────── */
#mcclure-link {
    position: absolute;
    bottom: 14px;
    left: 50%;
    transform: translateX(-50%);
    color: var(--mcclure-col);
    font-size: 15px;
    text-decoration: none;
    white-space: nowrap;
    text-shadow: var(--overlay-shadow);
    letter-spacing: 0.03em;
    transition: color 0.18s;
    z-index: 5;
}
#mcclure-link:hover {
    color: var(--mcclure-hover);
    text-decoration: underline;
}