:root {
    --bg: #0a0c10;
    --bg-card: #12161d;
    --bg-elev: #161b23;
    --border: #232a35;
    --border-hi: #313b49;
    --text: #e6edf3;
    --muted: #8b949e;
    --accent: #4cc2ff;
    --accent-2: #7c5cff;
    --ok: #3fb950;
    --warn: #d29922;
}

* { box-sizing: border-box; margin: 0; padding: 0; }
html, body { height: 100%; }
body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
    background: var(--bg);
    color: var(--text);
    overflow: hidden;
    -webkit-font-smoothing: antialiased;
}

/* Visible keyboard focus for all interactive elements. */
a:focus-visible, button:focus-visible, input:focus-visible,
select:focus-visible, textarea:focus-visible, [tabindex]:focus-visible {
    outline: 2px solid var(--accent);
    outline-offset: 2px;
}

.app { display: flex; flex-direction: column; height: 100vh; }

/* Top bar */
.topbar {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 16px;
    padding: 10px 16px;
    background: var(--bg-card);
    border-bottom: 1px solid var(--border);
    flex-wrap: wrap;
}
.brand { display: inline-flex; align-items: center; gap: 10px; color: var(--text); text-decoration: none; font-weight: 700; }
.brand img { width: 28px; height: 28px; border-radius: 7px; box-shadow: 0 0 0 1px var(--border); }
.brand em { color: var(--muted); font-style: normal; font-weight: 500; font-size: 0.85rem; }
.topbar-tools { display: flex; align-items: center; gap: 8px; flex-wrap: wrap; }
.sep { width: 1px; height: 22px; background: var(--border); margin: 0 4px; }

.tbtn {
    background: var(--bg-elev);
    border: 1px solid var(--border-hi);
    color: var(--text);
    padding: 7px 13px;
    border-radius: 8px;
    font-size: 0.85rem;
    font-family: inherit;
    cursor: pointer;
    transition: border-color .15s ease, background .15s ease;
    text-decoration: none;
    display: inline-block;
}
.tbtn:hover { border-color: var(--accent); }
.tbtn.sm { padding: 5px 10px; font-size: 0.8rem; }
.tbtn.ghost { background: transparent; color: var(--muted); }
.tbtn.primary { background: linear-gradient(135deg, var(--accent), var(--accent-2)); border-color: transparent; color: #06121c; font-weight: 600; }
.tbtn[data-toggle="true"] { background: linear-gradient(135deg, var(--accent), var(--accent-2)); border-color: transparent; color: #06121c; font-weight: 600; }
.tbtn:disabled { opacity: 0.5; cursor: not-allowed; }

/* Workspace: three columns by default; demos can override grid-template-columns */
.workspace { flex: 1; display: grid; grid-template-columns: 280px 1fr 300px; min-height: 0; }

.panel {
    background: var(--bg-card);
    overflow-y: auto;
    display: flex;
    flex-direction: column;
}
.panel-left { border-right: 1px solid var(--border); }
.panel-right { border-left: 1px solid var(--border); }

.dock { padding: 16px; border-bottom: 1px solid var(--border); }
.dock h3 {
    font-size: 0.72rem;
    text-transform: uppercase;
    letter-spacing: 0.12em;
    color: var(--muted);
    margin-bottom: 12px;
}

.kv { list-style: none; display: flex; flex-direction: column; gap: 8px; }
.kv li { display: flex; justify-content: space-between; gap: 12px; font-size: 0.85rem; }
.kv span { color: var(--muted); }
.kv strong { font-weight: 600; font-variant-numeric: tabular-nums; }

/* Form controls */
.field { margin-bottom: 10px; }
.field label { display: flex; justify-content: space-between; font-size: 0.78rem; color: var(--muted); margin-bottom: 4px; }
.field input[type=range] { width: 100%; accent-color: var(--accent); }

.field-sm { display: flex; flex-direction: column; gap: 4px; }
.field-sm.wide { margin-bottom: 10px; }
.field-sm label { font-size: 0.72rem; color: var(--muted); }
.field-sm input, .field-sm select, .roi-coords input,
.field input[type=number], .field input[type=text], .field select {
    background: var(--bg);
    border: 1px solid var(--border-hi);
    border-radius: 6px;
    color: var(--text);
    padding: 6px 8px;
    font-size: 0.82rem;
    font-family: inherit;
    width: 100%;
}
.roi-coords { display: grid; grid-template-columns: 1fr 1fr 1fr 1fr; gap: 6px; margin: 10px 0; }
.row { display: flex; gap: 8px; flex-wrap: wrap; }
.row > * { flex: 1; }
.check { display: flex; align-items: center; gap: 8px; font-size: 0.85rem; margin-bottom: 8px; cursor: pointer; }
.check input { width: 16px; height: 16px; accent-color: var(--accent); }

.samples { display: grid; grid-template-columns: 1fr 1fr 1fr; gap: 8px; }
.samples img {
    width: 100%;
    aspect-ratio: 1;
    object-fit: cover;
    border-radius: 8px;
    border: 1px solid var(--border-hi);
    cursor: pointer;
    transition: border-color .15s ease, transform .15s ease;
}
.samples img:hover { border-color: var(--accent); transform: translateY(-1px); }
.samples img.active { border-color: var(--accent); box-shadow: 0 0 0 2px rgba(76, 194, 255, 0.4); }

.hint { font-size: 0.75rem; color: var(--muted); margin-top: 10px; line-height: 1.5; }
kbd {
    background: var(--bg);
    border: 1px solid var(--border-hi);
    border-radius: 4px;
    padding: 1px 5px;
    font-size: 0.72rem;
    font-family: ui-monospace, monospace;
}
code { font-family: ui-monospace, monospace; font-size: 0.82em; color: var(--accent); }

/* Viewer */
.viewer { position: relative; background: #06080b; overflow: hidden; min-height: 0; }
.viewer canvas { position: absolute; inset: 0; width: 100%; height: 100%; display: block; cursor: grab; }
.viewer canvas.panning { cursor: grabbing; }
.viewer canvas.roi-mode { cursor: crosshair; }
.viewer.dropping { outline: 2px dashed var(--accent); outline-offset: -2px; }

.viewer-hint {
    position: absolute;
    inset: 0;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: 8px;
    text-align: center;
    color: var(--muted);
    pointer-events: none;
    padding: 24px;
}
.viewer-hint strong { color: var(--text); font-size: 1.2rem; }
.viewer-hint span { max-width: 420px; font-size: 0.9rem; }
.viewer-hint.hidden { display: none; }

.statusbar {
    position: absolute;
    left: 0; right: 0; bottom: 0;
    background: rgba(10, 12, 16, 0.85);
    border-top: 1px solid var(--border);
    padding: 5px 14px;
    font-size: 0.78rem;
    color: var(--muted);
    font-variant-numeric: tabular-nums;
    backdrop-filter: blur(6px);
    pointer-events: none;
}

/* Tabs */
.tabs { display: flex; gap: 6px; flex-wrap: wrap; margin-bottom: 12px; }
.tab {
    background: var(--bg-elev);
    border: 1px solid var(--border);
    color: var(--muted);
    padding: 5px 11px;
    border-radius: 7px;
    font-size: 0.8rem;
    cursor: pointer;
}
.tab.active { border-color: var(--accent); color: var(--text); }

/* Matrix / table readouts */
.matrix { font-family: ui-monospace, monospace; font-size: 0.82rem; display: grid; grid-template-columns: repeat(3, 1fr); gap: 4px 10px; background: var(--bg); border: 1px solid var(--border); border-radius: 8px; padding: 10px; }
.matrix span { text-align: right; font-variant-numeric: tabular-nums; }

/* Fatal error banner (asset load failures etc.) */
.demo-fatal {
    position: fixed;
    left: 50%;
    top: 18px;
    transform: translateX(-50%);
    z-index: 100;
    max-width: min(92vw, 560px);
    background: #2a1216;
    border: 1px solid #e5534b;
    color: #ffd9d6;
    padding: 12px 18px;
    border-radius: 10px;
    font-size: 0.88rem;
    box-shadow: 0 8px 30px rgba(0,0,0,.5);
}

/* Badges */
.badge { display: inline-block; font-size: 0.72rem; padding: 2px 8px; border-radius: 999px; background: var(--bg-elev); border: 1px solid var(--border-hi); color: var(--muted); }
.badge.ok { color: var(--ok); border-color: var(--ok); }

/* Small canvases (plots, swatches) */
.plot, .mini { width: 100%; background: var(--bg); border: 1px solid var(--border); border-radius: 8px; display: block; }
.swatch { width: 26px; height: 26px; border-radius: 6px; border: 1px solid var(--border-hi); display: inline-block; vertical-align: middle; }

@media (max-width: 900px) {
    body { overflow: auto; }
    .app { height: auto; }
    .workspace { grid-template-columns: 1fr !important; }
    .viewer { height: 60vh; }
    .panel { max-height: none; }
    /* 2x2 viewer grids (multi-camera, color-correction): stack vertically
       and give each cell a usable height on phones. */
    .mc-center, .cc-center { grid-template-columns: 1fr; grid-template-rows: none; }
    .mc-cell, .cc-cell { min-height: 42vh; }
    .mc-info, .cc-info { min-height: 0; }
}