:root {
    --bg-color: #1a1a1a;
    --text-color: #e0e0e0;
    --accent-color: #4caf50;
    --error-color: #ff5252;
    --input-bg: #2d2d2d;
    --border-color: #444;
}

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

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
    background-color: var(--bg-color);
    color: var(--text-color);
    line-height: 1.6;
    display: flex;
    justify-content: center;
    padding: 20px;
}

.app-container {
    width: 100%;
    max-width: 600px;
    display: flex;
    flex-direction: column;
    gap: 20px;
}

header h1 {
    text-align: center;
    font-weight: 300;
    letter-spacing: 2px;
}

.controls {
    display: flex;
    flex-wrap: wrap;
    gap: 15px;
    background: var(--input-bg);
    padding: 15px;
    border-radius: 8px;
    border: 1px solid var(--border-color);
}

.control-item {
    flex: 1 1 45%;
    display: flex;
    flex-direction: column;
    min-width: 120px;
}

.checkbox-item {
    flex-direction: row;
    align-items: center;
    gap: 10px;
}

input[type="range"] {
    width: 100%;
    margin-top: 5px;
}

.time-sig-selector {
    display: flex;
    align-items: center;
    gap: 5px;
}

select {
    background: var(--bg-color);
    color: var(--text-color);
    border: 1px solid var(--border-color);
    padding: 5px;
    border-radius: 4px;
    font-size: 1rem;
}

.editor {
    display: flex;
    flex-direction: column;
    gap: 10px;
}

textarea {
    width: 100%;
    background: var(--input-bg);
    color: var(--text-color);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    padding: 15px;
    font-family: monospace;
    font-size: 1.1rem;
    resize: vertical;
}

textarea:focus {
    outline: 2px solid var(--accent-color);
}

.visualization {
    background: var(--input-bg);
    border-radius: 8px;
    padding: 20px;
    border: 1px solid var(--border-color);
    min-height: 80px;
    text-align: center;
}

.visualization h2 {
    font-size: 0.9rem;
    color: #888;
    margin-bottom: 10px;
    text-transform: uppercase;
}

.output-area {
    font-family: 'Noto Music', sans-serif;
    font-size: 2.5rem; /* Large for musical symbols */
    line-height: 1.2;
    word-break: break-all;
}

.bar-line {
    color: var(--text-color);
    margin: 0 10px;
    vertical-align: middle;
    font-family: 'Noto Music', sans-serif;
    font-size: 2.5rem;
    opacity: 0.8;
}

.loop-boundary {
    color: var(--text-color);
    font-family: 'Noto Music', sans-serif;
    font-size: 2.5rem;
    margin: 0 5px;
    vertical-align: middle;
}

.padding-rest {
    opacity: 0.5; /* Fade out auto-padded rests */
    color: #aaa;
}

.error-msg {
    color: var(--error-color);
    font-family: monospace;
    font-size: 0.9rem;
    margin-top: 10px;
    background: rgba(255, 82, 82, 0.1);
    padding: 10px;
    border-radius: 4px;
}

.hidden {
    display: none;
}

.info {
    font-size: 0.9rem;
    color: #bbb;
    background: rgba(255, 255, 255, 0.03);
    padding: 15px;
    border-radius: 8px;
    border: 1px dashed var(--border-color);
}

.description {
    margin-bottom: 12px;
    color: var(--text-color);
}

.notation-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 8px;
    font-size: 0.85rem;
}

.notation-item code {
    background: #000;
    padding: 2px 4px;
    border-radius: 3px;
    color: var(--accent-color);
}

.actions {
    display: flex;
    gap: 10px;
}

.btn {
    flex: 1;
    padding: 12px;
    border: none;
    border-radius: 6px;
    font-size: 1rem;
    cursor: pointer;
    font-weight: 600;
    transition: background 0.2s;
}

.btn.primary {
    background-color: var(--accent-color);
    color: white;
}

.btn.primary:hover {
    filter: brightness(1.1);
}

.btn.secondary {
    background-color: #555;
    color: white;
}

.btn:disabled {
    opacity: 0.5;
    cursor: not-allowed;
}

@media (max-width: 400px) {
    .controls {
        flex-direction: column;
    }
    .control-item {
        width: 100%;
    }
}