.playing-controls {
    display: flex;
    gap: 16px;
    align-items: flex-end;
    flex-wrap: wrap;
    background: var(--panel);
    border: 2px solid var(--ink);
    box-shadow: var(--shadow);
    border-radius: var(--r);
    padding: 16px 24px;
    margin-bottom: 32px;
    width: fit-content;
    margin-left: auto;
    margin-right: auto;
}

.playing-controls .control-group { flex: 1; min-width: 160px; }

/* ── Section titles ─────────────────────────────── */
.play-section { margin-bottom: 36px; }

.section-title {
    font-size: 0.72rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 1.2px;
    color: var(--text-dim);
    margin-bottom: 14px;
}

/* ── Static progressions ────────────────────────── */
.progressions-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 12px;
}

@media (max-width: 900px) { .progressions-grid { grid-template-columns: repeat(2, 1fr); } }
@media (max-width: 560px) { .progressions-grid { grid-template-columns: 1fr; } }

.prog-card {
    background: var(--panel);
    border: 2px solid var(--ink);
    box-shadow: var(--shadow);
    border-radius: var(--r);
    overflow: hidden;
    transition: border-color 0.2s;
}

.prog-card:hover { border-color: var(--accent); }

.prog-header {
    display: flex;
    align-items: baseline;
    justify-content: space-between;
    gap: 8px;
    padding: 12px 16px;
    border-bottom: 1px solid var(--border);
}

.prog-name {
    font-family: var(--font-display);
    font-size: 0.95rem;
    font-weight: 600;
    color: var(--text);
}

.prog-label {
    font-size: 0.68rem;
    color: var(--text-dim);
    text-transform: uppercase;
    letter-spacing: 0.6px;
    white-space: nowrap;
}

.prog-chords { padding: 4px 0; }

.prog-chord {
    display: flex;
    align-items: center;
    gap: 10px;
    padding: 6px 16px;
}

.prog-chord-roman {
    font-family: var(--font-display);
    font-size: 0.78rem;
    width: 32px;
    flex-shrink: 0;
}

.prog-chord-name {
    font-size: 0.855rem;
    color: var(--text-dim);
}

.prog-placeholder {
    grid-column: 1 / -1;
    padding: 28px;
    text-align: center;
    color: var(--text-dim);
    font-size: 0.875rem;
    background: var(--panel);
    border: 1px dashed var(--border);
    border-radius: var(--r);
}

/* ── Generator ──────────────────────────────────── */
.generator-panel {
    background: var(--panel);
    border: 2px solid var(--ink);
    box-shadow: var(--shadow);
    border-radius: var(--r);
    padding: 20px 24px;
    display: flex;
    flex-direction: column;
    gap: 16px;
}

.gen-row {
    display: flex;
    align-items: center;
    gap: 16px;
    flex-wrap: wrap;
}

.gen-label {
    font-size: 0.78rem;
    font-weight: 700;
    color: var(--text-dim);
    text-transform: uppercase;
    letter-spacing: 0.5px;
    min-width: 48px;
}

.pill-group { display: flex; gap: 6px; flex-wrap: wrap; }

.pill {
    padding: 5px 14px;
    border: 1px solid var(--border);
    border-radius: 20px;
    background: var(--panel2);
    color: var(--text-dim);
    font-size: 0.8rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.15s;
}

.pill:hover { border-color: var(--text-dim); color: var(--text); }

.pill.active {
    border-color: var(--accent);
    background: rgba(197, 66, 31, 0.1);
    color: var(--accent);
}

.btn-generate {
    align-self: flex-start;
    padding: 12px 24px;
    background: var(--accent);
    color: var(--on-accent);
    border: 2px solid var(--ink);
    border-radius: var(--r);
    box-shadow: var(--shadow);
    font-size: 0.84rem;
}

.btn-generate:hover { transform: translate(-2px, -2px); box-shadow: 5px 5px 0 var(--ink); }
.btn-generate:active { transform: translate(3px, 3px); box-shadow: none; }

/* ── Generator result ───────────────────────────── */
.gen-result {
    margin-top: 12px;
    background: var(--panel);
    border: 2px solid var(--ink);
    box-shadow: var(--shadow);
    border-radius: var(--r);
    padding: 20px 24px;
    animation: fadeIn 0.2s ease;
}

.gen-result.hidden { display: none; }

@keyframes fadeIn { from { opacity: 0; transform: translateY(6px); } to { opacity: 1; transform: none; } }

.gen-context {
    font-size: 0.78rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.8px;
    color: var(--accent3);
    margin-bottom: 14px;
}

.gen-chords {
    display: flex;
    gap: 10px;
    flex-wrap: wrap;
    margin-bottom: 20px;
}

.gen-chord {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 3px;
    background: var(--panel2);
    border: 1px solid var(--border);
    border-radius: var(--r);
    padding: 12px 18px;
    min-width: 76px;
}

.gen-roman {
    font-family: var(--font-display);
    font-size: 0.75rem;
}

.gen-note {
    font-family: var(--font-display);
    font-size: 1.35rem;
    font-weight: 700;
    color: var(--text);
}

.gen-quality {
    font-size: 0.68rem;
    color: var(--text-dim);
}

.gen-explanation {
    border-top: 1px solid var(--border);
    padding-top: 16px;
    display: flex;
    flex-direction: column;
    gap: 8px;
}

.gen-why {
    font-size: 0.875rem;
    color: var(--text-dim);
    line-height: 1.6;
}

.gen-why strong { color: var(--text); }

.gen-tip {
    font-size: 0.875rem;
    color: var(--accent3);
    line-height: 1.6;
}

/* ── Song Structures ────────────────────────────── */
.structures-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 12px;
}

@media (max-width: 900px) { .structures-grid { grid-template-columns: repeat(2, 1fr); } }
@media (max-width: 560px) { .structures-grid { grid-template-columns: 1fr; } }

@media (max-width: 600px) {
    .playing-controls {
        width: 100%;
        margin-left: 0;
        margin-right: 0;
    }

    .challenge-panel {
        flex-direction: column;
        gap: 16px;
    }

    .challenge-actions {
        flex-direction: row;
        justify-content: flex-start;
    }
}

.struct-card {
    background: var(--panel);
    border: 2px solid var(--ink);
    border-left: 8px solid var(--struct-color);
    box-shadow: var(--shadow);
    border-radius: var(--r);
    padding: 16px;
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.struct-header {
    display: flex;
    align-items: baseline;
    justify-content: space-between;
    gap: 8px;
}

.struct-name-title {
    font-family: var(--font-display);
    font-size: 0.9rem;
    font-weight: 700;
    color: var(--text);
}

.struct-style {
    font-size: 0.65rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.6px;
    color: var(--struct-color);
    background: color-mix(in srgb, var(--struct-color) 12%, transparent);
    padding: 2px 7px;
    border-radius: 4px;
    white-space: nowrap;
}

.struct-sections {
    display: flex;
    flex-direction: column;
    gap: 6px;
}

.struct-section {
    display: flex;
    align-items: center;
    gap: 10px;
}

.struct-label {
    font-size: 0.65rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.5px;
    color: var(--text-dim);
    min-width: 80px;
    flex-shrink: 0;
}

.struct-chords {
    display: flex;
    gap: 6px;
    flex-wrap: wrap;
}

.struct-chord {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 1px;
    background: var(--panel2);
    border: 1px solid var(--border);
    border-radius: 6px;
    padding: 4px 8px;
    min-width: 36px;
}

.struct-roman {
    font-family: var(--font-display);
    font-size: 0.65rem;
}

.struct-chord .struct-name {
    font-size: 0.78rem;
    font-weight: 700;
    color: var(--text);
}

.struct-tip {
    font-size: 0.78rem;
    color: var(--text-dim);
    line-height: 1.5;
    border-top: 1px solid var(--border);
    padding-top: 10px;
    margin-top: auto;
}

/* ── Chord Substitutions ────────────────────────── */
.sub-groups {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 12px;
}

@media (max-width: 700px) { .sub-groups { grid-template-columns: 1fr; } }

.sub-card {
    background: var(--panel);
    border: 2px solid var(--ink);
    border-left: 8px solid var(--sub-color);
    box-shadow: var(--shadow);
    border-radius: var(--r);
    padding: 16px;
    display: flex;
    flex-direction: column;
    gap: 10px;
}

.sub-fn {
    font-size: 0.68rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 1px;
    color: var(--sub-color);
    background: color-mix(in srgb, var(--sub-color) 12%, transparent);
    display: inline-block;
    padding: 3px 8px;
    border-radius: 4px;
    align-self: flex-start;
}

.sub-chords {
    display: flex;
    flex-direction: column;
    gap: 6px;
}

.sub-chord {
    display: flex;
    align-items: center;
    gap: 10px;
}

.sub-roman {
    font-family: var(--font-display);
    font-size: 0.78rem;
    min-width: 32px;
    flex-shrink: 0;
}

.sub-note {
    font-family: var(--font-display);
    font-size: 0.875rem;
    font-weight: 600;
    color: var(--text);
}

.sub-quality {
    font-size: 0.75rem;
    font-weight: 400;
    color: var(--text-dim);
}

.sub-desc {
    font-size: 0.78rem;
    color: var(--text-dim);
    line-height: 1.5;
    border-top: 1px solid var(--border);
    padding-top: 10px;
}

/* ── Challenge ──────────────────────────────────── */
.challenge-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin-bottom: 10px;
}

.done-counter {
    font-size: 0.75rem;
    font-weight: 600;
    color: var(--text-dim);
    font-variant-numeric: tabular-nums;
}

.challenge-filters { margin-bottom: 12px; }

.challenge-filters .pill[data-cat="all"]       { --cat-color: #b5547f; }
.challenge-filters .pill[data-cat="fretboard"] { --cat-color: #c5421f; }
.challenge-filters .pill[data-cat="rhythm"]    { --cat-color: #c0871f; }
.challenge-filters .pill[data-cat="technique"] { --cat-color: #7c4b86; }
.challenge-filters .pill[data-cat="theory"]    { --cat-color: #1f7a6d; }
.challenge-filters .pill[data-cat="ear"]       { --cat-color: #4f7d46; }

.challenge-filters .pill,
.challenge-filters .pill.active,
.challenge-filters .pill:hover {
    border-color: var(--cat-color);
    color: var(--cat-color);
    background: color-mix(in srgb, var(--cat-color) 10%, transparent);
}

.challenge-filters .pill.active {
    background: var(--cat-color);
    color: var(--ink);
}

.challenge-filters .pill:hover {
    background: color-mix(in srgb, var(--cat-color) 20%, transparent);
}

.challenge-panel {
    background: var(--panel);
    border: 2px solid var(--ink);
    border-left: 8px solid var(--cat-color, var(--accent2));
    box-shadow: var(--shadow);
    border-radius: var(--r);
    padding: 20px 24px;
    display: flex;
    align-items: flex-start;
    justify-content: space-between;
    gap: 24px;
    transition: transform 0.12s, box-shadow 0.12s;
}

.challenge-content { flex: 1; }

.challenge-cat {
    font-size: 0.65rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 1px;
    color: var(--cat-color, var(--text-dim));
    background: color-mix(in srgb, var(--cat-color, var(--accent2)) 15%, transparent);
    display: inline-block;
    padding: 2px 8px;
    border-radius: 4px;
    margin-bottom: 8px;
}

.challenge-tag {
    font-family: var(--font-display);
    font-size: 0.9rem;
    font-weight: 700;
    color: var(--text);
    margin-bottom: 10px;
}

.challenge-text {
    font-size: 0.925rem;
    color: var(--text);
    line-height: 1.65;
}

.challenge-actions {
    display: flex;
    flex-direction: column;
    gap: 8px;
    flex-shrink: 0;
}

.btn-done {
    padding: 9px 16px;
    border: 1.5px solid var(--ink);
    border-radius: var(--r);
    box-shadow: var(--shadow-sm);
    background: var(--cat-color, var(--accent3));
    color: var(--on-accent);
    font-size: 0.74rem;
    white-space: nowrap;
    transition: transform 0.1s, box-shadow 0.1s;
}

.btn-done:hover { transform: translate(-1px, -1px); box-shadow: 3px 3px 0 var(--ink); }
.btn-done:active { transform: translate(2px, 2px); box-shadow: none; }

.btn-done.is-done {
    background: var(--panel2);
    color: var(--text-dim);
    box-shadow: none;
}

.btn-challenge {
    padding: 9px 16px;
    border: 1.5px solid var(--ink);
    border-radius: var(--r);
    box-shadow: var(--shadow-sm);
    background: var(--ink);
    color: var(--on-accent);
    font-size: 0.74rem;
    white-space: nowrap;
    transition: transform 0.1s, box-shadow 0.1s;
}

.btn-challenge:hover { transform: translate(-1px, -1px); box-shadow: 3px 3px 0 var(--cat-color, var(--accent2)); }
.btn-challenge:active { transform: translate(2px, 2px); box-shadow: none; }