/* ============================================================
   Kids Kingdom - Pro Piano
   Dark professional theme (matches Xylophone/Harmonica). Real
   piano key layout: white keys in a row, black keys positioned
   between the correct white keys (no black key between E-F or
   B-C, exactly like a real keyboard).
   ============================================================ */

.piano-wrap {
    --piano-bg:      #0a0f1e;
    --piano-surface: #111827;
    --piano-card:    #1a2035;
    --piano-border:  #2a3550;
    --piano-accent:  #3b82f6;
    --piano-green:   #10b981;
    --piano-text:    #e2e8f0;
    --piano-muted:   #64748b;

    background: var(--piano-bg);
    border-radius: 20px;
    overflow: hidden;
    box-shadow: 0 8px 60px rgba(59,130,246,0.15);
    width: 100%;
    max-width: 100%;
    box-sizing: border-box;
    margin: 30px auto;
}

/* ================= TOOLBAR ================= */
.piano-toolbar {
    background: var(--piano-surface);
    border-bottom: 1px solid var(--piano-border);
    padding: 14px 18px;
    display: flex;
    flex-wrap: wrap;
    gap: 12px;
    align-items: center;
    justify-content: space-between;
}

.piano-tabs {
    display: flex;
    gap: 6px;
    flex-wrap: wrap;
}

.piano-tab-btn {
    background: var(--piano-card);
    color: var(--piano-muted);
    border: 1px solid var(--piano-border);
    border-radius: 30px;
    padding: 7px 16px;
    font-family: var(--font-heading);
    font-size: 0.82rem;
    font-weight: 700;
    cursor: pointer;
    transition: all 0.2s;
}

.piano-tab-btn:hover,
.piano-tab-btn.active {
    background: var(--piano-accent);
    color: #fff;
    border-color: var(--piano-accent);
    box-shadow: 0 0 14px rgba(59,130,246,0.4);
}

.piano-ctrl {
    display: flex;
    align-items: center;
    gap: 6px;
}

.piano-ctrl label {
    color: var(--piano-muted);
    font-size: 0.78rem;
    white-space: nowrap;
}

.piano-ctrl input[type="range"] {
    width: 80px;
    accent-color: var(--piano-accent);
}

/* ================= SONGS PANEL ================= */
.piano-songs-panel {
    display: none;
    padding: 14px 18px;
    border-bottom: 1px solid var(--piano-border);
    flex-wrap: wrap;
    gap: 8px;
}

.piano-songs-panel.active { display: flex; }

.piano-song-btn {
    background: var(--piano-card);
    color: var(--piano-text);
    border: 1px solid var(--piano-border);
    border-radius: 20px;
    padding: 7px 16px;
    font-family: var(--font-heading);
    font-size: 0.82rem;
    font-weight: 700;
    cursor: pointer;
    transition: all 0.2s;
}

.piano-song-btn:hover { border-color: var(--piano-accent); color: var(--piano-accent); }

.piano-song-btn.playing {
    background: var(--piano-accent);
    color: #fff;
    border-color: var(--piano-accent);
}

/* ================= LEARN MODE PANEL ================= */
.piano-learn-panel {
    display: none;
    padding: 14px 18px;
    border-bottom: 1px solid var(--piano-border);
    flex-wrap: wrap;
    gap: 14px;
    align-items: center;
}

.piano-learn-panel.active { display: flex; }

.piano-learn-stat {
    background: var(--piano-card);
    border: 1px solid var(--piano-border);
    border-radius: 12px;
    padding: 8px 16px;
    text-align: center;
    min-width: 70px;
}

.piano-learn-stat .num {
    display: block;
    font-family: var(--font-heading);
    font-size: 1.2rem;
    font-weight: 800;
    color: var(--piano-accent);
}

.piano-learn-stat .lbl {
    font-size: 0.65rem;
    color: var(--piano-muted);
    text-transform: uppercase;
    letter-spacing: 0.04em;
}

.piano-learn-start-btn {
    background: var(--piano-green);
    color: #06281c;
    border: none;
    border-radius: 20px;
    padding: 9px 22px;
    font-family: var(--font-heading);
    font-weight: 800;
    font-size: 0.85rem;
    cursor: pointer;
}

.piano-learn-msg {
    color: var(--piano-muted);
    font-size: 0.8rem;
    flex: 1 1 200px;
}

/* ================= KEYBOARD AREA ================= */
.piano-body-wrap {
    padding: 30px 18px 16px;
    overflow-x: auto;
    -webkit-overflow-scrolling: touch;
}

.piano-keyboard {
    position: relative;
    display: flex;
    min-width: 700px;
    height: 200px;
    border-radius: 10px;
    overflow: visible;
    box-shadow: 0 10px 40px rgba(0,0,0,0.6);
}

.piano-white-key {
    flex: 1 1 0;
    background: linear-gradient(180deg, #fdfdfd 0%, #e8e8e8 92%, #d4d4d4 100%);
    border: 1px solid #94a3b8;
    border-radius: 0 0 6px 6px;
    display: flex;
    align-items: flex-end;
    justify-content: center;
    padding-bottom: 10px;
    cursor: pointer;
    color: #64748b;
    font-size: 0.68rem;
    font-weight: 800;
    position: relative;
    z-index: 1;
    transition: background 0.08s;
    -webkit-user-select: none;
    user-select: none;
    touch-action: manipulation;
}

.piano-white-key:hover { background: linear-gradient(180deg, #fff 0%, #f1f5f9 92%, #e2e8f0 100%); }

.piano-white-key.is-active {
    background: linear-gradient(180deg, #bfdbfe 0%, #93c5fd 92%, #60a5fa 100%);
    color: #1e3a8a;
}

.piano-white-key.is-glowing {
    animation: pianoGlowWhite 0.9s ease-in-out infinite;
}

@keyframes pianoGlowWhite {
    0%, 100% { box-shadow: inset 0 0 0 rgba(16,185,129,0); }
    50%      { box-shadow: inset 0 0 30px 6px rgba(16,185,129,0.7); background: linear-gradient(180deg,#d1fae5,#6ee7b7); }
}

.piano-black-key {
    position: absolute;
    top: 0;
    width: 5.6%;
    height: 60%;
    background: linear-gradient(180deg, #1e293b 0%, #0f172a 85%, #000 100%);
    border: 1px solid #000;
    border-radius: 0 0 4px 4px;
    z-index: 2;
    cursor: pointer;
    display: flex;
    align-items: flex-end;
    justify-content: center;
    padding-bottom: 8px;
    color: #94a3b8;
    font-size: 0.55rem;
    font-weight: 800;
    box-shadow: 0 4px 8px rgba(0,0,0,0.5);
    transition: background 0.08s;
    -webkit-user-select: none;
    user-select: none;
    touch-action: manipulation;
}

.piano-black-key:hover { background: linear-gradient(180deg, #334155 0%, #1e293b 85%, #0a0f1e 100%); }

.piano-black-key.is-active {
    background: linear-gradient(180deg, #7c3aed 0%, #5b21b6 85%, #4c1d95 100%);
    color: #ede9fe;
}

.piano-black-key.is-glowing {
    animation: pianoGlowBlack 0.9s ease-in-out infinite;
}

@keyframes pianoGlowBlack {
    0%, 100% { box-shadow: 0 4px 8px rgba(0,0,0,0.5); }
    50%      { box-shadow: 0 0 24px 6px rgba(16,185,129,0.85); }
}

.piano-key-hint {
    display: flex;
    flex-wrap: wrap;
    gap: 12px;
    justify-content: center;
    padding: 16px 18px 18px;
    color: var(--piano-muted);
    font-size: 0.75rem;
}

.piano-body-wrap::-webkit-scrollbar { height: 4px; }
.piano-body-wrap::-webkit-scrollbar-track { background: var(--piano-surface); }
.piano-body-wrap::-webkit-scrollbar-thumb { background: var(--piano-border); border-radius: 2px; }

.piano-particle-canvas {
    position: fixed;
    top: 0; left: 0;
    width: 100%; height: 100%;
    pointer-events: none;
    z-index: 9999;
}

/* ================= RESPONSIVE ================= */
@media (max-width: 768px) {
    .piano-toolbar { padding: 10px 14px; }
    .piano-tab-btn { padding: 6px 12px; font-size: 0.78rem; }
    .piano-body-wrap { padding: 22px 10px 8px; }
    .piano-keyboard { min-width: 580px; height: 160px; }
    .piano-white-key { font-size: 0.6rem; }
}

@media (max-width: 480px) {
    .piano-keyboard { min-width: 480px; height: 135px; }
    .piano-white-key { font-size: 0.55rem; }
    .piano-black-key { font-size: 0.48rem; }
}