.keys-page {
    max-width: 920px;
    margin: 0 auto;
    padding: 2rem 1rem 3rem;
    color: var(--text-primary);
}

.keys-page [hidden] {
    display: none !important;
}

.keys-header h1 {
    margin: 0 0 0.5rem;
}

.keys-history {
    margin: 0.75rem 0 1.75rem;
    padding: 0.75rem 1rem;
    background: var(--bg-secondary);
    border: 1px solid var(--border-light);
    border-radius: 8px;
}

.keys-header p,
.keys-history,
.keys-status,
.keys-students > p,
.keys-practice p {
    color: var(--text-secondary);
    line-height: 1.6;
}

.keys-figure {
    font-family: var(--font-sans);
    font-variant-numeric: lining-nums tabular-nums;
}

.key-heatmap {
    display: grid;
    gap: 0.4rem;
    padding: 1rem;
    background: var(--bg-secondary);
    border: 1px solid var(--border-light);
    border-radius: 12px;
    overflow-x: auto;
}

.key-heatmap-row {
    display: flex;
    gap: 0.4rem;
}

.key-heatmap-row-1 { padding-left: 1.4rem; }
.key-heatmap-row-2 { padding-left: 2.1rem; }
.key-heatmap-row-3 { padding-left: 0; }
.key-heatmap-row-4 { justify-content: center; }

.key-heatmap-key {
    flex: 0 0 2.6rem;
    height: 2.6rem;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: 6px;
    border: 1px solid var(--border-medium);
    font-family: var(--font-sans);
    font-variant-numeric: lining-nums tabular-nums;
    font-weight: 600;
    color: var(--text-primary);
    background: var(--bg-primary);
}

.key-heatmap-key.is-measured {
    background: color-mix(in srgb, var(--error) var(--key-heat, 8%), var(--bg-primary));
}

.key-heatmap-key.is-quiet {
    background: var(--bg-tertiary);
    color: var(--text-secondary);
    opacity: 0.7;
}

.key-heatmap-space {
    flex: 0 0 18rem;
}

.key-heatmap-shift {
    flex: 0 0 5.4rem;
}

.keys-legend {
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    gap: 0.4rem 0.6rem;
    margin: 0.6rem 0 0;
    font-size: 0.85rem;
    color: var(--text-secondary);
}

.keys-legend-swatch {
    display: inline-block;
    width: 1rem;
    height: 1rem;
    border-radius: 3px;
    border: 1px solid var(--border-medium);
    margin-left: 0.6rem;
}

.keys-legend-note {
    margin: 0.4rem 0 1.75rem;
    font-size: 0.85rem;
    color: var(--text-secondary);
}

.keys-legend-swatch.is-quiet { background: var(--bg-tertiary); }
.keys-legend-swatch.is-low { background: color-mix(in srgb, var(--error) 10%, var(--bg-primary)); }
.keys-legend-swatch.is-high { background: color-mix(in srgb, var(--error) 70%, var(--bg-primary)); }

.keys-button {
    color: var(--accent-primary);
    font-weight: 600;
}

.keys-button {
    display: inline-block;
    padding: 0.55rem 1.1rem;
    border-radius: 8px;
    background: var(--accent-primary);
    color: var(--text-inverse);
    text-decoration: none;
}

.keys-button:hover {
    filter: brightness(0.9);
}

.keys-student {
    margin-bottom: 0.75rem;
    border: 1px solid var(--border-light);
    border-radius: 10px;
    background: var(--bg-secondary);
}

.keys-student summary {
    cursor: pointer;
    padding: 0.75rem 1rem;
    color: var(--text-primary);
}

.keys-student summary span {
    color: var(--text-secondary);
}

.keys-student .key-heatmap {
    margin: 0 1rem 1rem;
    background: var(--bg-primary);
}

@media (min-width: 760px) {
    .key-heatmap {
        grid-template-columns: max-content;
        justify-content: center;
    }
}

@media (max-width: 640px) {
    .key-heatmap-key { flex-basis: 1.9rem; height: 2.1rem; font-size: 0.8rem; }
    .key-heatmap-space { flex-basis: 12rem; }
    .key-heatmap-shift { flex-basis: 3.4rem; }
    .key-heatmap-row-1, .key-heatmap-row-2, .key-heatmap-row-3 { padding-left: 0; }
}