:root {
    --bg-color: #f8fafc;
    --card-bg: #ffffff;
    --text-main: #1e293b;
    --text-sub: #64748b;
    --primary: #3b82f6;
    --primary-hover: #2563eb;
    --border: #e2e8f0;
    --error-bg: #fef2f2;
    --error-text: #dc2626;
    --accent: #8b5cf6;
}

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

body {
    font-family: 'Helvetica Neue', Arial, sans-serif;
    background-color: var(--bg-color);
    color: var(--text-main);
    height: 100vh;
    display: flex;
    flex-direction: column;
}

header {
    background: var(--card-bg);
    border-bottom: 1px solid var(--border);
    padding: 12px 24px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    flex-wrap: wrap;
    gap: 10px;
}

header h1 {
    font-size: 1.25rem;
    font-weight: 700;
    white-space: nowrap;
}

.header-buttons {
    display: flex;
    gap: 8px;
}

.btn {
    padding: 8px 18px;
    border: none;
    border-radius: 8px;
    font-size: 0.875rem;
    font-weight: 600;
    cursor: pointer;
    transition: background 0.15s, transform 0.1s;
}

.btn:active { transform: scale(0.97); }

.btn-primary {
    background: var(--primary);
    color: #fff;
}
.btn-primary:hover { background: var(--primary-hover); }

.btn-accent {
    background: var(--accent);
    color: #fff;
}
.btn-accent:hover { background: #7c3aed; }

.btn-outline {
    background: transparent;
    border: 1px solid var(--border);
    color: var(--text-main);
}
.btn-outline:hover { background: #f1f5f9; }

main {
    flex: 1;
    min-height: 0;
    display: flex;
    overflow: hidden;
}

.input-panel {
    width: 380px;
    min-width: 300px;
    border-right: 1px solid var(--border);
    background: var(--card-bg);
    display: flex;
    flex-direction: column;
    overflow-y: auto;
}

.input-panel textarea {
    flex: 1;
    min-height: 250px;
    padding: 16px;
    border: none;
    outline: none;
    resize: none;
    font-family: 'SF Mono', 'Fira Code', 'Consolas', monospace;
    font-size: 0.9rem;
    line-height: 1.6;
    color: var(--text-main);
    background: transparent;
}

.input-panel textarea::placeholder { color: #94a3b8; }

.panel-section {
    padding: 12px 16px;
    border-top: 1px solid var(--border);
}

.panel-section h3 {
    font-size: 0.75rem;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    color: var(--text-sub);
    margin-bottom: 8px;
}

.sample-buttons {
    display: flex;
    flex-wrap: wrap;
    gap: 6px;
}

.sample-btn {
    padding: 5px 12px;
    border: 1px solid var(--border);
    border-radius: 6px;
    background: var(--bg-color);
    font-size: 0.8rem;
    cursor: pointer;
    transition: background 0.15s;
}
.sample-btn:hover { background: #e2e8f0; }

.reference {
    font-size: 0.78rem;
    color: var(--text-sub);
    line-height: 1.6;
}

.reference code {
    background: #f1f5f9;
    padding: 1px 5px;
    border-radius: 3px;
    font-size: 0.75rem;
}

.preview-panel {
    flex: 1;
    overflow: auto;
    padding: 24px;
    background: var(--bg-color);
}

#vexflow-output {
    background: #fff;
    border-radius: 12px;
    box-shadow: 0 1px 3px rgba(0,0,0,0.08);
    padding: 24px;
    min-height: 300px;
}

#vexflow-output svg {
    display: block;
    max-width: 100%;
}

.score-title {
    font-size: 1.4rem;
    font-weight: 700;
    text-align: center;
    margin-bottom: 4px;
}

.score-meta {
    font-size: 0.85rem;
    color: var(--text-sub);
    text-align: center;
    margin-bottom: 16px;
}

.error-message {
    background: var(--error-bg);
    color: var(--error-text);
    padding: 12px 16px;
    border-radius: 8px;
    font-size: 0.85rem;
    line-height: 1.5;
}

.transpose-controls {
    display: none;
    align-items: center;
    gap: 6px;
}

.transpose-controls.visible {
    display: flex;
}

.transpose-controls .btn {
    padding: 6px 12px;
    font-size: 0.8rem;
    min-width: 36px;
}

.transpose-display {
    font-size: 0.85rem;
    font-weight: 700;
    min-width: 32px;
    text-align: center;
    color: var(--text-main);
}

.transpose-display.shifted {
    color: var(--primary);
}

.transpose-label {
    font-size: 0.75rem;
    color: var(--text-sub);
    margin-right: 2px;
}

.display-controls {
    display: none;
    align-items: center;
    gap: 6px;
}

.display-controls.visible {
    display: flex;
}

.display-label {
    font-size: 0.75rem;
    color: var(--text-sub);
    margin-right: 2px;
}

.display-select {
    padding: 5px 8px;
    border: 1px solid var(--border);
    border-radius: 6px;
    font-size: 0.8rem;
    background: #fff;
    color: var(--text-main);
    cursor: pointer;
}

.toggle-label {
    display: flex;
    align-items: center;
    gap: 4px;
    font-size: 0.8rem;
    color: var(--text-main);
    cursor: pointer;
}

.toggle-label input[type="checkbox"] {
    cursor: pointer;
}

.toggle-label.disabled {
    opacity: 0.4;
    cursor: not-allowed;
}

.toggle-label.disabled input[type="checkbox"] {
    cursor: not-allowed;
}

.playback-controls {
    display: none;
    align-items: center;
    gap: 6px;
}

.playback-controls.visible {
    display: flex;
}

.playback-controls .btn {
    padding: 6px 12px;
    font-size: 0.8rem;
}

.btn-play {
    background: #22c55e;
    color: #fff;
}
.btn-play:hover:not(:disabled) { background: #16a34a; }

.btn-pause {
    background: #eab308;
    color: #fff;
}
.btn-pause:hover:not(:disabled) { background: #ca8a04; }

.btn-stop {
    background: #ef4444;
    color: #fff;
}
.btn-stop:hover:not(:disabled) { background: #dc2626; }

.playback-controls .btn:disabled {
    opacity: 0.4;
    cursor: not-allowed;
    transform: none;
}

.volume-group { display: flex; align-items: center; gap: 4px; margin-left: 6px; border-left: 1px solid var(--border); padding-left: 10px; }
.btn-volume { background: transparent; border: none; cursor: pointer; font-size: 1.1rem; padding: 4px; line-height: 1; border-radius: 4px; }
.btn-volume:hover { background: #f1f5f9; }
.btn-volume.muted { color: var(--text-sub); }
.volume-slider { -webkit-appearance: none; appearance: none; width: 80px; height: 4px; border-radius: 2px; background: var(--border); outline: none; cursor: pointer; }
.volume-slider::-webkit-slider-thumb { -webkit-appearance: none; appearance: none; width: 14px; height: 14px; border-radius: 50%; background: var(--primary); cursor: pointer; }
.volume-slider::-moz-range-thumb { width: 14px; height: 14px; border: none; border-radius: 50%; background: var(--primary); cursor: pointer; }

.autoscroll-controls {
    display: none;
    align-items: center;
    gap: 8px;
}
.autoscroll-controls.visible { display: flex; }

.btn-autoscroll {
    background: #8b5cf6;
    color: #fff;
    padding: 6px 12px;
    font-size: 0.8rem;
}
.btn-autoscroll:hover { background: #7c3aed; }
.btn-autoscroll.active {
    background: #6d28d9;
    box-shadow: inset 0 2px 4px rgba(0,0,0,0.2);
}

.autoscroll-speed-group {
    display: flex;
    align-items: center;
    gap: 4px;
    font-size: 0.8rem;
    white-space: nowrap;
}
.autoscroll-speed-slider {
    -webkit-appearance: none;
    appearance: none;
    width: 80px;
    height: 4px;
    border-radius: 2px;
    background: var(--border);
    outline: none;
    cursor: pointer;
}
.autoscroll-speed-slider::-webkit-slider-thumb {
    -webkit-appearance: none;
    appearance: none;
    width: 14px;
    height: 14px;
    border-radius: 50%;
    background: #8b5cf6;
    cursor: pointer;
}
.autoscroll-speed-slider::-moz-range-thumb {
    width: 14px;
    height: 14px;
    border: none;
    border-radius: 50%;
    background: #8b5cf6;
    cursor: pointer;
}

.playback-cursor {
    fill: rgba(59, 130, 246, 0.15);
    stroke: rgba(59, 130, 246, 0.4);
    stroke-width: 1;
    pointer-events: none;
}

.mobile-tab-bar {
    display: none;
}
.tab-group {
    display: flex;
    background: var(--border);
    border-radius: 10px;
    padding: 3px;
    max-width: 280px;
    margin: 0 auto;
}
.tab-btn {
    flex: 1;
    padding: 7px 0;
    border: none;
    border-radius: 8px;
    font-size: 0.875rem;
    font-weight: 600;
    cursor: pointer;
    background: transparent;
    color: var(--text-sub);
    transition: background 0.15s, color 0.15s;
}
.tab-btn[aria-selected="true"] {
    background: var(--card-bg);
    color: var(--text-main);
    box-shadow: 0 1px 3px rgba(0,0,0,0.1);
}

@media (max-width: 768px) {
    .mobile-tab-bar {
        display: block;
        position: sticky;
        top: 0;
        z-index: 100;
        background: var(--bg-color);
        padding: 8px 16px;
        border-bottom: 1px solid var(--border);
    }
    main {
        flex-direction: column;
        overflow: auto;
    }
    main.show-input .preview-panel {
        display: none;
    }
    main.show-result .input-panel {
        display: none;
    }
    .input-panel {
        width: 100%;
        min-width: unset;
        border-right: none;
        border-bottom: 1px solid var(--border);
    }
    .input-panel textarea {
        min-height: 180px;
    }
    .preview-panel {
        padding: 16px;
    }
    #vexflow-output {
        padding: 12px;
    }
    .volume-slider {
        width: 60px;
    }
}

.site-nav {
    margin: 16px 0;
    display: flex;
    gap: 18px;
    justify-content: center;
    font-size: 13px;
}

.site-nav a {
    color: var(--primary);
    text-decoration: none;
}

.site-nav a:hover {
    text-decoration: underline;
}

/* Camera UI */
.btn-camera {
    background: #06b6d4;
    color: #fff;
}
.btn-camera:hover { background: #0891b2; }
.btn-camera.active {
    background: #0e7490;
    box-shadow: inset 0 2px 4px rgba(0,0,0,0.2);
}

.camera-panel {
    display: none;
    position: fixed;
    bottom: 16px;
    left: 16px;
    z-index: 200;
    width: 340px;
    background: var(--card-bg);
    border-radius: 12px;
    box-shadow: 0 8px 30px rgba(0,0,0,0.15);
    border: 1px solid var(--border);
    padding: 16px;
}
.camera-panel.open { display: block; }

.camera-panel-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 12px;
}
.camera-panel-header h3 {
    font-size: 0.85rem;
    font-weight: 700;
    color: var(--text-main);
}
.camera-close-btn {
    background: transparent;
    border: none;
    font-size: 1.2rem;
    cursor: pointer;
    color: var(--text-sub);
    padding: 4px;
    line-height: 1;
    border-radius: 4px;
}
.camera-close-btn:hover { background: #f1f5f9; }

.camera-panel-btns {
    display: flex;
    align-items: center;
    gap: 4px;
}
.camera-minimize-btn {
    background: transparent;
    border: none;
    font-size: 1.2rem;
    cursor: pointer;
    color: var(--text-sub);
    padding: 4px;
    line-height: 1;
    border-radius: 4px;
}
.camera-minimize-btn:hover { background: #f1f5f9; }

.camera-panel.minimized .camera-preview-wrapper {
    max-height: 0;
    overflow: hidden;
}
.camera-panel.minimized .camera-settings {
    display: none;
}
.camera-panel.minimized .camera-status {
    margin-bottom: 0;
}
.camera-panel.minimized {
    padding: 10px 16px;
    width: auto;
    min-width: 220px;
}
.camera-panel.minimized .camera-panel-header {
    margin-bottom: 0;
}
.camera-panel-header { cursor: default; }
.camera-panel-header h3 { cursor: pointer; }

.camera-preview-wrapper {
    position: relative;
    width: 100%;
    aspect-ratio: 4 / 3;
    background: #000;
    border-radius: 8px;
    overflow: hidden;
    margin-bottom: 12px;
}
.camera-preview-wrapper video,
.camera-preview-wrapper canvas {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    transform: scaleX(-1);
}
.camera-preview-wrapper canvas {
    pointer-events: none;
}

.camera-status {
    font-size: 0.75rem;
    color: var(--text-sub);
    text-align: center;
    margin-bottom: 8px;
    min-height: 1.2em;
}
.camera-status.error { color: var(--error-text); }

.camera-settings {
    display: flex;
    flex-direction: column;
    gap: 8px;
}

.camera-setting-row {
    display: flex;
    align-items: center;
    gap: 8px;
}
.camera-setting-row label {
    font-size: 0.75rem;
    color: var(--text-sub);
    min-width: 80px;
    flex-shrink: 0;
}
.camera-setting-row input[type="range"] {
    flex: 1;
    -webkit-appearance: none;
    appearance: none;
    height: 4px;
    border-radius: 2px;
    background: var(--border);
    outline: none;
    cursor: pointer;
}
.camera-setting-row input[type="range"]::-webkit-slider-thumb {
    -webkit-appearance: none;
    appearance: none;
    width: 14px;
    height: 14px;
    border-radius: 50%;
    background: #06b6d4;
    cursor: pointer;
}
.camera-setting-row input[type="range"]::-moz-range-thumb {
    width: 14px;
    height: 14px;
    border: none;
    border-radius: 50%;
    background: #06b6d4;
    cursor: pointer;
}
.camera-setting-row .setting-value {
    font-size: 0.75rem;
    color: var(--text-main);
    font-weight: 600;
    min-width: 36px;
    text-align: right;
}
.camera-setting-row select {
    flex: 1;
    padding: 4px 8px;
    border: 1px solid var(--border);
    border-radius: 6px;
    font-size: 0.75rem;
    background: #fff;
    color: var(--text-main);
    cursor: pointer;
}

.camera-debug {
    font-size: 0.7rem;
    color: var(--text-sub);
    text-align: center;
    margin-top: 8px;
    font-family: 'SF Mono', 'Fira Code', 'Consolas', monospace;
}

/* Nod indicator */
.nod-indicator {
    position: fixed;
    right: 0;
    top: 0;
    width: 6px;
    height: 100vh;
    background: #06b6d4;
    opacity: 0;
    z-index: 300;
    pointer-events: none;
}
.nod-indicator.flash {
    animation: nod-fade 0.6s ease-out forwards;
}
@keyframes nod-fade {
    0% { opacity: 0.9; }
    100% { opacity: 0; }
}

@media (max-width: 768px) {
    .camera-panel {
        bottom: 0;
        left: 0;
        right: 0;
        width: 100%;
        border-radius: 12px 12px 0 0;
    }
    .camera-panel.minimized {
        width: 100%;
        min-width: unset;
        border-radius: 12px 12px 0 0;
    }
}

@media print {
    .camera-panel, .btn-camera, .nod-indicator {
        display: none !important;
    }
    header, .input-panel, .header-buttons, .playback-controls, .display-controls, .autoscroll-controls, .site-nav, .mobile-tab-bar {
        display: none !important;
    }
    body {
        display: block !important;
        overflow: visible !important;
        height: auto !important;
        min-height: 0 !important;
    }
    main {
        display: block !important;
        overflow: visible !important;
        height: auto !important;
    }
    .preview-panel {
        display: block !important;
        padding: 0 !important;
        overflow: visible !important;
    }
    #vexflow-output {
        box-shadow: none !important;
        border-radius: 0 !important;
        padding: 0 !important;
    }
    #vexflow-output svg {
        width: 100% !important;
        height: auto !important;
    }
    #print-lines svg {
        break-inside: avoid;
    }
    .score-title, .score-meta {
        break-after: avoid;
    }
}