:root {
    --primary-color: #2c3e50;
    --secondary-color: #34495e;
    --accent-color: #3498db;
    --success-color: #2ecc71;
    --warning-color: #e74c3c;
    --flat-color: #3498db;
    --sharp-color: #e74c3c;
    --background-color: #ecf0f1;
}

.container {
    /* max-width: 800px; */
    margin: 0 auto;
    padding: 2rem;
}

.tagline {
    color: var(--secondary-color);
    font-size: 1.1rem;
}

/* Tuner Display */
.tuner-display {
    background: white;
    border-radius: 1rem;
    padding: 2rem;
    margin-bottom: 2rem;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
}

.needle-container {
    position: relative;
    width: 200px;
    height: 100px;
    margin: 0 auto 2rem;
}

.needle {
    position: absolute;
    top: 0;
    left: 50%;
    width: 4px;
    height: 80px;
    background-color: var(--primary-color);
    transform-origin: bottom center;
    transition: transform 0.3s ease-out;
}

.needle-center {
    position: absolute;
    bottom: 0;
    left: 50%;
    width: 12px;
    height: 12px;
    background-color: var(--primary-color);
    border-radius: 50%;
    transform: translateX(-50%);
}

.frequency-display {
    text-align: center;
    margin-bottom: 1rem;
}

.note {
    font-size: 4rem;
    font-weight: bold;
    margin-bottom: 0.5rem;
}

.frequency {
    font-size: 1.5rem;
    color: var(--secondary-color);
    margin-bottom: 0.5rem;
}

.cents {
    font-size: 1.2rem;
    color: var(--secondary-color);
}

.tuning-status {
    text-align: center;
    font-size: 1.2rem;
    font-weight: bold;
}

.status-text {
    padding: 0.5rem 1rem;
    border-radius: 0.5rem;
    display: inline-block;
    transition: all 0.3s ease;
}

.status-text.in-tune {
    background-color: var(--success-color);
    color: white;
}

.status-text.flat {
    background-color: var(--flat-color);
    color: white;
}

.status-text.sharp {
    background-color: var(--sharp-color);
    color: white;
}

/* Controls */
.controls {
    margin-bottom: 2rem;
}

.strings-container {
    display: flex;
    justify-content: center;
    gap: 1rem;
    margin-bottom: 1.5rem;
}

.string-btn {
    width: 3rem;
    height: 3rem;
    border: none;
    border-radius: 50%;
    background-color: var(--secondary-color);
    color: white;
    font-size: 1.2rem;
    font-weight: bold;
    cursor: pointer;
    transition: all 0.3s ease;
}

.string-btn:hover {
    background-color: var(--accent-color);
    transform: scale(1.1);
}

.string-btn.selected {
    background-color: var(--accent-color);
    box-shadow: 0 0 10px var(--accent-color);
}

.tuning-selector {
    text-align: center;
    margin-bottom: 1rem;
}

.tuning-selector label {
    margin-right: 0.5rem;
}

select {
    padding: 0.5rem;
    border-radius: 0.5rem;
    border: 1px solid var(--secondary-color);
    font-size: 1rem;
}

.control-btn {
    display: block;
    width: 100%;
    max-width: 300px;
    margin: 0.5rem auto;
    padding: 0.75rem;
    border: none;
    border-radius: 0.5rem;
    background-color: var(--accent-color);
    color: white;
    font-size: 1rem;
    cursor: pointer;
    transition: background-color 0.3s ease;
}

.control-btn:hover {
    background-color: #2980b9;
}


/* Error Message */
.error-message {
    background-color: #e74c3c;
    color: white;
    padding: 1rem;
    border-radius: 0.5rem;
    margin-bottom: 1rem;
    text-align: center;
}

/* Responsive Design */
@media (max-width: 600px) {
    .container {
        padding: 1rem;
    }

    h1 {
        font-size: 2rem;
    }

    .note {
        font-size: 3rem;
    }

    .strings-container {
        flex-wrap: wrap;
    }

    .string-btn {
        width: 2.5rem;
        height: 2.5rem;
        font-size: 1rem;
    }
}

/* Accessibility */
@media (prefers-reduced-motion: reduce) {
    .needle,
    .string-btn,
    .status-text {
        transition: none;
    }
}

:focus-visible {
    outline: 3px solid var(--accent-color);
    outline-offset: 2px;
}