.tone-panel {
    max-width: 580px;
    margin: 0 auto;
    text-align: center;
    padding: 40px 32px
}

.freq-display {
    margin-bottom: 20px
}

.freq-value {
    font-size: 4rem;
    font-weight: 800;
    color: var(--primary);
    line-height: 1
}

.freq-unit {
    font-size: 1.4rem;
    color: var(--text-light);
    font-weight: 600;
    margin-left: 4px
}

.waveform-select {
    display: flex;
    gap: 8px;
    justify-content: center;
    margin-bottom: 28px
}

.wave-btn {
    padding: 10px 22px;
    border-radius: 20px;
    background: var(--bg);
    border: 1.5px solid var(--border);
    color: var(--text-light);
    font-size: 0.88rem;
    font-weight: 600;
    transition: var(--transition)
}

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

.tone-controls {
    display: grid;
    grid-template-columns: 2fr 1fr 1fr;
    gap: 16px;
    margin-bottom: 24px;
    text-align: left
}

.tone-controls input[type="number"] {
    width: 100%;
    padding: 10px 12px;
    border: 1.5px solid var(--border);
    border-radius: var(--radius-sm);
    background: var(--bg);
    color: var(--text);
    font-size: 0.92rem
}

.preset-freqs {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
    justify-content: center;
    margin-bottom: 24px
}

#waveCanvas {
    width: 100%;
    max-width: 500px;
    height: 120px;
    background: var(--bg);
    border-radius: var(--radius-sm);
    border: 1px solid var(--border);
    margin: 0 auto 24px;
    display: block
}

.play-btn {
    width: 100%;
    padding: 16px;
    border-radius: var(--radius);
    background: var(--primary);
    color: #fff;
    font-size: 1.1rem;
    font-weight: 700;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 10px;
    transition: var(--transition)
}

.play-btn:hover {
    background: var(--primary-dark)
}

.play-btn.playing {
    background: #e74c3c
}

.play-btn.playing:hover {
    background: #c0392b
}

.tutorial-link-box {
    max-width: 580px;
    margin: 20px auto 0;
    text-align: center;
    padding: 16px;
    background: var(--bg-card);
    border-radius: var(--radius-sm);
    border: 1px dashed var(--border)
}

.tutorial-link-box a {
    font-weight: 600;
    font-size: 0.92rem
}

@media(max-width:768px) {
    .tone-panel {
        padding: 28px 18px
    }

    .freq-value {
        font-size: 3rem
    }

    .tone-controls {
        grid-template-columns: 1fr
    }

    .waveform-select {
        flex-wrap: wrap
    }
}

@media(max-width:480px) {
    .freq-value {
        font-size: 2.4rem
    }

    .wave-btn {
        padding: 8px 16px;
        font-size: 0.82rem
    }
}