.circle-fifths {
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
}

.cof-layout {
    display: flex;
    flex-wrap: wrap;
    gap: 1.5rem;
    align-items: flex-start;
}

/* Square wheel; key buttons positioned by left/top percentages. */
.cof-wheel {
    position: relative;
    flex: 1 1 20rem;
    max-width: 26rem;
    aspect-ratio: 1;
    border-radius: 50%;
    background:
        radial-gradient(circle at center, var(--surface) 38%, transparent 39%),
        conic-gradient(from 0deg, var(--accent-weak), var(--bg), var(--accent-weak));
    border: 1px solid var(--border);
    box-shadow: var(--shadow);
}

.cof-seg {
    position: absolute;
    transform: translate(-50%, -50%);
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: 0.1rem;
    width: 4rem;
    height: 4rem;
    padding: 0.2rem;
    border-radius: 50%;
    border: 1px solid var(--border-strong);
    background: var(--surface);
    color: var(--text);
    cursor: pointer;
    transition: background 0.15s, border-color 0.15s, transform 0.15s;
}

.cof-seg:hover {
    border-color: var(--accent);
}

.cof-seg[aria-pressed='true'] {
    background: var(--accent);
    border-color: var(--accent);
    color: #fff;
    transform: translate(-50%, -50%) scale(1.08);
}

.cof-major {
    font-size: 1.05rem;
    font-weight: 700;
    line-height: 1;
}

.cof-minor {
    font-size: 0.7rem;
    color: var(--muted);
    line-height: 1;
}

.cof-seg[aria-pressed='true'] .cof-minor {
    color: rgba(255, 255, 255, 0.85);
}

.cof-detail {
    flex: 1 1 16rem;
    display: flex;
    flex-direction: column;
    gap: 0.6rem;
    padding: 1.25rem;
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: 12px;
    box-shadow: var(--shadow);
}

.cof-key {
    margin: 0;
    font-size: 1.6rem;
    color: var(--accent-strong);
}

.cof-line {
    margin: 0;
    color: var(--muted);
}

.cof-line strong {
    color: var(--text);
}

.cof-acc {
    font-variant-numeric: tabular-nums;
    letter-spacing: 0.04em;
}

.cof-chords-label {
    margin-top: 0.4rem;
    font-weight: 600;
    color: var(--text);
}

.cof-chords {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
}

.cof-chord {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 0.2rem;
    min-width: 3rem;
    padding: 0.5rem 0.4rem;
    border: 1px solid var(--border);
    border-radius: 8px;
    background: var(--bg);
}

.cof-roman {
    font-size: 0.7rem;
    font-weight: 600;
    color: var(--muted);
}

.cof-symbol {
    font-size: 1.1rem;
    font-weight: 700;
    color: var(--accent-strong);
    line-height: 1;
}