.synth-controls {
    display: flex;
    flex-wrap: wrap;
    align-items: stretch;
    justify-content: center;
    gap: 8px;
    margin: 10px 0 12px;
}

.synth-control-btn {
    appearance: none;
    box-sizing: border-box;
    width: 128px;
    min-height: 42px;
    margin: 0;
    padding: 9px 10px;
    border: 1px solid #2f7a2f;
    border-radius: 0;
    background: #0f210f;
    color: #9eff9e;
    cursor: pointer;
    font: 700 11px/1.2 "Courier New", Courier, monospace;
    letter-spacing: .06em;
    text-align: center;
    text-transform: uppercase;
    transition: background-color 80ms linear, border-color 80ms linear, box-shadow 80ms linear;
}

@media (hover: hover) {
    .synth-control-btn:hover:not(:disabled) {
        border-color: #7cff7c;
        background: #143214;
    }
}

.synth-control-btn:focus-visible {
    outline: 1px solid #c7ffc7;
    outline-offset: 3px;
}

.synth-control-btn:active:not(:disabled),
.synth-control-btn.active,
.synth-control-btn.tap,
.synth-control-btn[aria-pressed="true"] {
    border-color: #7cff7c;
    background: #174217;
    box-shadow: inset 0 0 0 1px #7cff7c, 0 0 8px rgba(124, 255, 124, .18);
}

.synth-control-btn:disabled {
    cursor: not-allowed;
    opacity: .42;
}

@media (max-width: 420px) {
    .synth-controls {
        gap: 7px;
        margin-top: 8px;
    }

    .synth-control-btn {
        width: min(128px, 100%);
        min-height: 44px;
        padding: 9px 7px;
        font-size: 10px;
    }
}

@media (prefers-reduced-motion: reduce) {
    .synth-control-btn {
        transition: none;
    }
}