/* Key Signature Zapper — classroom key-signature arcade. Namespaced kz-.
   Structure mirrors note-zapper.css; the moving item is a VexFlow clef+key
   signature ("flyer") absolutely positioned inside a fixed-height field. */

body { display: block; padding: 0; margin: 0; }

.kz-page { max-width: 900px; margin: 0 auto; padding: 24px 20px 48px; }

.kz-head { text-align: center; margin-bottom: 18px; }
.kz-head h1 { font-size: 34px; font-weight: 800; letter-spacing: -.02em; margin: 0 0 6px; color: var(--text, #0f172a); }
.kz-head p { color: var(--text-light, #64748b); font-size: 15.5px; margin: 0; }

.kz-stage { background: var(--card, #fff); border: 1px solid var(--border, #e2e8f0); border-radius: 18px;
    padding: 18px 20px 20px; box-shadow: var(--shadow, 0 1px 3px rgba(0,0,0,.1)); }

.kz-controls { display: flex; flex-wrap: wrap; gap: 14px 18px; justify-content: center;
    padding-bottom: 14px; margin-bottom: 14px; border-bottom: 1px solid var(--border, #e2e8f0); }
.kz-group-label { display: block; text-align: center; font-size: 11.5px; font-weight: 700; letter-spacing: .06em;
    text-transform: uppercase; color: var(--text-light, #64748b); margin-bottom: 6px; }
.kz-toggle { display: flex; background: var(--bg, #f8fafc); border: 1px solid var(--border, #e2e8f0); border-radius: 10px; padding: 3px; }
.kz-toggle button { border: 0; background: transparent; font: inherit; font-weight: 700; font-size: 13.5px;
    color: var(--text-light, #64748b); padding: 7px 12px; border-radius: 8px; cursor: pointer; white-space: nowrap; }
.kz-toggle button.active { background: var(--primary, #0d9488); color: #fff; }

.kz-mode-note { text-align: center; font-size: 13.5px; color: var(--text-light, #64748b); max-width: 560px; margin: 8px auto 0; line-height: 1.6; }

.kz-start, .kz-again { display: block; margin: 18px auto 0; font: inherit; font-weight: 800; font-size: 18px;
    padding: 14px 44px; border-radius: 14px; border: 0; cursor: pointer; color: #fff;
    background: linear-gradient(135deg, #14b8a6, #0d9488); box-shadow: 0 6px 18px rgba(13,148,136,.35); }

.kz-hud { display: flex; justify-content: center; gap: 26px; flex-wrap: wrap; font-weight: 800;
    font-size: 17px; color: var(--text, #0f172a); margin-bottom: 6px; }
.kz-hud .l { font-size: 11px; font-weight: 700; letter-spacing: .05em; text-transform: uppercase;
    color: var(--text-light, #64748b); display: block; text-align: center; }
.kz-hud > div { text-align: center; min-width: 64px; }
.kz-timer { font-variant-numeric: tabular-nums; color: var(--primary, #0d9488); }

/* The playfield: a light staff area the signature flies across. Always light
   so the (black) VexFlow staff stays readable in dark mode. */
.kz-field { position: relative; height: 160px; background: #fff; border: 1px solid var(--border, #e2e8f0);
    border-radius: 14px; overflow: hidden; }
.kz-flyer { position: absolute; top: 5px; left: 0; will-change: transform; }
.kz-flyer svg { display: block; }
.kz-flyer svg * { stroke: #111; }

.kz-feedback { text-align: center; min-height: 34px; font-size: 22px; font-weight: 800; margin: 8px 0 2px; }
.kz-feedback.kz-good { color: var(--primary, #0d9488); }
.kz-feedback.kz-bad { color: #dc2626; }

.kz-keys { display: grid; grid-template-columns: repeat(8, 1fr); gap: 8px; margin-top: 4px; }
.kz-key { font: inherit; font-size: clamp(16px, 2.4vw, 24px); font-weight: 800; padding: 14px 0;
    border-radius: 12px; border: 2px solid var(--border, #e2e8f0); background: var(--bg, #f8fafc);
    color: var(--text, #0f172a); cursor: pointer; user-select: none; touch-action: manipulation; }
.kz-key:hover { border-color: var(--primary, #0d9488); color: var(--primary, #0d9488); }
.kz-key:active { transform: scale(.96); }

.kz-keys-hint { text-align: center; font-size: 12.5px; color: var(--text-light, #64748b); margin: 10px 0 0; }

.kz-play-actions { display: flex; justify-content: center; gap: 12px; margin-top: 12px; }
.kz-small-btn { font: inherit; font-weight: 700; font-size: 13.5px; padding: 9px 18px; border-radius: 10px;
    border: 2px solid var(--border, #e2e8f0); background: transparent; color: var(--text-light, #64748b); cursor: pointer; }
.kz-small-btn:hover { border-color: var(--primary, #0d9488); color: var(--primary, #0d9488); }

.kz-over { text-align: center; }
.kz-over h2 { font-size: 26px; font-weight: 800; color: var(--text, #0f172a); margin: 6px 0 4px; }
.kz-over-score { font-size: 64px; font-weight: 800; color: var(--primary, #0d9488); line-height: 1.1; }
.kz-over-sub { color: var(--text-light, #64748b); font-weight: 600; margin: 4px 0 14px; }
.kz-over-stats { display: flex; justify-content: center; gap: 24px; color: var(--text-light, #64748b);
    font-weight: 700; font-size: 14.5px; }
.kz-over-stats b { color: var(--text, #0f172a); font-size: 20px; display: block; text-align: center; }

/* Fullscreen (desktop native) */
.kz-stage:fullscreen { display: flex; flex-direction: column; justify-content: center;
    border-radius: 0; padding: 3vh 5vw; overflow: auto; }
.kz-stage:fullscreen .kz-field { height: 42vh; }
.kz-stage:fullscreen .kz-hud { font-size: 24px; gap: 40px; }
.kz-stage:fullscreen .kz-feedback { font-size: 32px; }

/* Faux-fullscreen fallback for iPhone (no element.requestFullscreen there) */
.kz-faux-fs { position: fixed; inset: 0; z-index: 9999; margin: 0; border-radius: 0;
    display: flex; flex-direction: column; justify-content: center; overflow: auto;
    padding: 3vh 4vw; background: var(--card, #fff); }
body.kz-faux-fs-lock { overflow: hidden; }
.kz-faux-fs .kz-field { height: 40vh; }
.kz-faux-fs .kz-hud { font-size: 20px; gap: 24px; }

#leaderboard { margin-top: 26px; }

.kz-info { margin-top: 30px; color: var(--text-light, #64748b); font-size: 15px; line-height: 1.7; }
.kz-info h2 { font-size: 21px; font-weight: 800; color: var(--text, #0f172a); margin: 24px 0 8px; }
.kz-info a { color: var(--primary, #0d9488); font-weight: 700; text-decoration: none; }
.kz-info a:hover { text-decoration: underline; }

@media (max-width: 560px) {
    .kz-stage { padding: 12px 10px 14px; }
    .kz-controls { gap: 10px 12px; }
    .kz-keys { grid-template-columns: repeat(5, 1fr); gap: 7px; }
    .kz-key { padding: 12px 0; }
    .kz-field { height: 130px; }
    .kz-hud { gap: 16px; }
}