/* Metronome (RT-FUN-107).
 *
 * Contrast rule (docs/contrast-conventions.md): the tempo readout is the result
 * box, so values use --rt-result-ink and labels --rt-result-muted; neither
 * appears on a light surface. Everything else sits on light and uses --rt-ink*.
 *
 * CLS rule (docs/cls-conventions.md): the readout, the beat dots and the tap
 * hint all reserve their height, so nothing shifts when the first click plays
 * or the tempo name changes length (Largo → Prestissimo).
 */

/* ---------- tempo readout (the result box) ---------- */

.metro-readout {
    padding: 22px; border-radius: 10px;
    background: var(--rt-result-bg);
    text-align: center;
    min-height: 168px;                 /* reserved */
}
.metro-bpm-line { display: flex; align-items: baseline; justify-content: center; gap: 10px; }
#metro-bpm-value {
    font-family: var(--rt-font-mono); font-size: 56px; font-weight: 700; line-height: 1;
    color: var(--rt-result-ink);
    min-width: 3ch;                    /* 20 → 400 must not shift the row */
    display: inline-block;
}
.metro-bpm-unit {
    font-family: var(--rt-font-mono); font-size: 14px; font-weight: 700;
    letter-spacing: .08em; text-transform: uppercase; color: var(--rt-result-muted);
}
#metro-tempo-name {
    display: block; margin-top: 6px; min-height: 22px;
    font-size: 16px; font-style: italic; color: var(--rt-result-muted);
}
#metro-signature {
    display: block; margin-top: 2px; min-height: 20px;
    font-family: var(--rt-font-mono); font-size: 12.5px; color: var(--rt-result-muted);
}

/* beat dots */
#metro-dots {
    display: flex; justify-content: center; gap: 10px;
    margin-top: 16px; min-height: 18px;   /* reserved for up to 16 dots */
    flex-wrap: wrap;
}
.metro-dot {
    width: 14px; height: 14px; border-radius: 50%;
    background: rgba(255, 255, 255, .18);
    transition: transform .06s linear, background-color .06s linear;
}
.metro-dot--accent { box-shadow: inset 0 0 0 2px rgba(255, 255, 255, .45); }
.metro-dot.is-on { background: var(--rt-accent); transform: scale(1.35); }
@media (prefers-reduced-motion: reduce) { .metro-dot { transition: none; } .metro-dot.is-on { transform: none; } }

/* ---------- transport ---------- */

.metro-transport { display: flex; align-items: center; justify-content: center; gap: 12px; margin: 18px 0 6px; }
#metro-toggle {
    min-width: 132px; padding: 13px 26px;
    font-size: 17px; font-weight: 700; border-radius: 8px; cursor: pointer;
    border: 1px solid var(--rt-accent); background: var(--rt-accent); color: #fff;
}
#metro-toggle:hover { filter: brightness(1.06); }
#metro.is-playing #metro-toggle { background: var(--rt-surface); color: var(--rt-accent); }

.metro-btn {
    padding: 10px 14px; font-family: var(--rt-font-mono); font-size: 14px; font-weight: 600;
    border-radius: 8px; cursor: pointer;
    border: 1px solid var(--rt-hairline); background: var(--rt-surface); color: var(--rt-ink);
}
.metro-btn:hover { border-color: var(--rt-accent); color: var(--rt-accent); }

#metro-tap-hint {
    display: block; text-align: center; min-height: 20px; margin-bottom: 14px;
    font-size: 13px; color: var(--rt-ink-soft);
}

/* ---------- slider ---------- */

.metro-slider-row { display: flex; align-items: center; gap: 12px; margin: 4px 0 16px; }
#metro-bpm { flex: 1 1 auto; min-width: 0; accent-color: var(--rt-accent); }

/* ---------- settings ---------- */

.metro-settings {
    display: grid; grid-template-columns: 1fr 1fr; gap: 14px;
    padding: 14px; margin-top: 4px;
    background: var(--rt-surface-2); border: 1px solid var(--rt-hairline); border-radius: 8px;
}
@media (max-width: 620px) { .metro-settings { grid-template-columns: 1fr; } }
.metro-field { display: flex; flex-direction: column; gap: 5px; }
.metro-field label {
    font-family: var(--rt-font-mono); font-size: 11.5px; font-weight: 700;
    text-transform: uppercase; letter-spacing: .05em; color: var(--rt-ink-muted);
}
.metro-field select {
    padding: 9px 10px; font-size: 15px; border-radius: 6px;
    border: 1px solid var(--rt-hairline); background: var(--rt-surface); color: var(--rt-ink);
}
.metro-check { display: flex; align-items: center; gap: 8px; font-size: 14px; color: var(--rt-ink); }
.metro-check input { accent-color: var(--rt-accent); width: 17px; height: 17px; }

/* ---------- presets ---------- */

.metro-presets { display: flex; flex-wrap: wrap; gap: 8px; justify-content: center; margin-top: 14px; }
.metro-preset {
    padding: 6px 12px; border-radius: 999px; cursor: pointer;
    font-family: var(--rt-font-mono); font-size: 12.5px;
    border: 1px solid var(--rt-hairline); background: var(--rt-surface); color: var(--rt-ink-soft);
}
.metro-preset:hover { border-color: var(--rt-accent); color: var(--rt-accent); }

/* ---------- keyboard help + notes ---------- */

.metro-keys { margin-top: 16px; font-size: 13px; color: var(--rt-ink-soft); text-align: center; }
.metro-keys kbd {
    display: inline-block; padding: 2px 7px; margin: 0 1px;
    font-family: var(--rt-font-mono); font-size: 12px;
    border: 1px solid var(--rt-hairline); border-bottom-width: 2px; border-radius: 4px;
    background: var(--rt-surface); color: var(--rt-ink);
}
#metro-note {
    margin-top: 12px; padding: 10px 12px; border-radius: 6px;
    background: #fef2f2; border: 1px solid #fecaca;
    font-size: 13.5px; color: var(--rt-ink);
}