*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

:root {
    --bg: #1a1a2e;
    --surface: #16213e;
    --border: #0f3460;
    --primary: #00d4ff;
    --text: #e8e8e8;
    --text-dim: #a0a0a0;
    --success: #00ff88;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    background: var(--bg);
    color: var(--text);
    min-height: 100vh;
}

header {
    background: var(--surface);
    padding: 16px 24px;
    border-bottom: 1px solid var(--border);
    display: flex;
    align-items: baseline;
    gap: 16px;
}

header h1 {
    color: var(--primary);
    font-size: 1.5rem;
    font-weight: 600;
}

header .subtitle {
    color: var(--text-dim);
    font-size: 0.9rem;
}

header .github-link {
    margin-left: auto;
    display: inline-flex;
    align-items: center;
    gap: 6px;
    background: var(--border);
    color: var(--text);
    text-decoration: none;
    padding: 8px 14px;
    border-radius: 6px;
    border: 1px solid var(--primary);
    font-size: 0.9rem;
    font-weight: 500;
    transition: background-color 0.15s, color 0.15s, border-color 0.15s;
}

header .github-link:focus-visible {
    outline: 2px solid var(--success);
    outline-offset: 2px;
}

header .github-link:hover {
    background: var(--primary);
    color: var(--bg);
}

header .github-link svg {
    width: 18px;
    height: 18px;
    fill: currentColor;
}

main {
    max-width: 900px;
    margin: 0 auto;
    padding: 20px;
}

/* Keyboard */
.keyboard-section {
    background: var(--surface);
    border-radius: 12px;
    padding: 20px;
    margin-bottom: 20px;
    border: 1px solid var(--border);
}

.keyboard {
    display: flex;
    justify-content: center;
    height: 140px;
    position: relative;
}

.key {
    cursor: pointer;
    transition: background-color 0.05s;
    user-select: none;
}

.key:focus-visible {
    outline: 2px solid var(--success);
    outline-offset: 2px;
    z-index: 10;
}

.key.white {
    width: 40px;
    height: 100%;
    background: linear-gradient(180deg, #fff 0%, #f5f5f5 85%, #e0e0e0 100%);
    border: 1px solid #aaa;
    border-radius: 0 0 5px 5px;
    position: relative;
    z-index: 1;
    box-shadow: 0 2px 4px rgba(0,0,0,0.2);
}

.key.black {
    width: 24px;
    height: 58%;
    background: linear-gradient(180deg,
        #555 0%,
        #444 2%,
        #333 5%,
        #222 20%,
        #1a1a1a 80%,
        #111 95%,
        #080808 100%);
    border: 1px solid #000;
    border-top: none;
    border-radius: 0 0 4px 4px;
    position: absolute;
    z-index: 2;
    left: auto;
    right: -12px;
    box-shadow:
        -1px 0 0 #000,
        1px 0 0 #000,
        0 0 3px 1px rgba(0,0,0,0.5),
        0 4px 6px rgba(0,0,0,0.6),
        inset 0 -1px 2px rgba(255,255,255,0.05),
        inset 0 1px 0 rgba(80,80,80,0.3);
}

.key.black::before {
    content: '';
    position: absolute;
    top: 0;
    left: 1px;
    right: 1px;
    height: 6px;
    background: linear-gradient(180deg, #777 0%, #555 40%, #333 100%);
    border-radius: 1px 1px 3px 3px;
}

.key.black::after {
    content: '';
    position: absolute;
    top: 2px;
    left: 4px;
    right: 4px;
    height: 3px;
    background: linear-gradient(90deg, transparent 0%, rgba(255,255,255,0.15) 50%, transparent 100%);
    border-radius: 2px;
}

.key.white.active {
    background: var(--primary);
}

.key.black.active {
    background: var(--primary);
}

.key-label {
    position: absolute;
    bottom: 6px;
    left: 50%;
    transform: translateX(-50%);
    font-size: 10px;
    color: #666;
    pointer-events: none;
}

.key-hint {
    text-align: center;
    margin-top: 12px;
    color: var(--text-dim);
    font-size: 0.85rem;
}

/* Panels */
.panels {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 20px;
}

@media (max-width: 700px) {
    .panels { grid-template-columns: 1fr; }
}

.panel {
    background: var(--surface);
    border-radius: 12px;
    padding: 16px;
    border: 1px solid var(--border);
}

.panel h2 {
    color: var(--primary);
    font-size: 1rem;
    margin-bottom: 12px;
    padding-bottom: 8px;
    border-bottom: 1px solid var(--border);
}

/* Controls */
.control-row {
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.control-row label {
    display: flex;
    justify-content: space-between;
    align-items: center;
    color: var(--text);
    font-size: 0.9rem;
}

.control-row select,
.control-row input[type="range"] {
    width: 120px;
}

select {
    background: var(--border);
    color: var(--text);
    border: 1px solid #0a2040;
    border-radius: 4px;
    padding: 6px 8px;
    font-size: 0.85rem;
}

input[type="range"] {
    accent-color: var(--primary);
}

/* Melody */
.melody-controls {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
    margin-bottom: 12px;
}

.examples {
    display: flex;
    flex-wrap: wrap;
    gap: 6px;
    margin-bottom: 12px;
}

button {
    background: var(--border);
    color: var(--primary);
    border: 1px solid var(--primary);
    border-radius: 6px;
    padding: 8px 14px;
    font-size: 0.85rem;
    cursor: pointer;
    transition: background-color 0.15s, color 0.15s, border-color 0.15s;
    display: inline-flex;
    align-items: center;
    gap: 6px;
}

button svg {
    flex-shrink: 0;
}

button:hover:not(:disabled) {
    background: var(--primary);
    color: var(--bg);
}

button:focus-visible {
    outline: 2px solid var(--success);
    outline-offset: 2px;
}

button:disabled {
    opacity: 0.5;
    cursor: not-allowed;
}

.examples button {
    padding: 6px 10px;
    font-size: 0.8rem;
}

#melody-display {
    background: #0d1421;
    color: #88cc88;
    padding: 12px;
    border-radius: 6px;
    font-family: monospace;
    font-size: 0.8rem;
    line-height: 1.5;
    height: 80px;
    overflow-y: auto;
    white-space: pre-wrap;
}

#melody-display:empty::before {
    content: "No melody loaded";
    color: var(--text-dim);
}

/* Status */
#status {
    text-align: center;
    padding: 12px;
    color: var(--text-dim);
    font-size: 0.9rem;
}

#status.ready { color: var(--success); }
#status.error { color: #ff6b6b; }
#status.playing { color: var(--primary); }

/* Accessibility: Reduced motion preference */
@media (prefers-reduced-motion: reduce) {
    *, *::before, *::after {
        transition: none !important;
        animation: none !important;
    }
}