.builder {
  flex: 1;
  padding: var(--space-page);
  overflow-y: auto;
  width: 100%;
  max-width: var(--content-max);
  margin: 0 auto;
}

.builder__playback {
  display: flex;
  flex-wrap: wrap;
  align-items: flex-end;
  gap: 0.75rem 1rem;
  margin-bottom: 0.85rem;
  padding: 0.75rem 0.9rem;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  background: linear-gradient(180deg, rgba(255, 255, 255, 0.03), transparent 50%), var(--surface);
  box-shadow: var(--shadow-sm);
}

.builder-playback-field {
  display: flex;
  flex-direction: column;
  gap: 0.3rem;
  min-width: 7.5rem;
}


.builder-playback-field--action {
  min-width: 0;
}

.builder-playback-field--action .btn {
  white-space: nowrap;
}

.builder__playback .theory-toggle {
  padding: 0.15rem;
}

.builder-playback-field__label {
  font-size: 0.72rem;
  font-weight: 600;
  color: var(--text-muted);
  letter-spacing: 0.04em;
}

.builder-playback-field__input,
.builder-playback-field__select {
  width: 100%;
  min-width: 6.5rem;
  padding: 0.5rem 0.65rem;
  border: 1px solid var(--border);
  border-radius: 8px;
  background: var(--surface-2);
  color: var(--text);
  font-family: inherit;
  font-size: 0.9rem;
  font-weight: 600;
}

.builder-playback-field__input:focus,
.builder-playback-field__select:focus {
  outline: none;
  border-color: var(--accent);
}

.builder__toolbar {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.75rem;
  margin-bottom: 1.5rem;
}

.builder__save-status {
  font-size: 0.78rem;
  color: var(--text-muted);
  padding: 0 0.25rem;
}

.btn {
  padding: 0.65rem 1.25rem;
  border-radius: 999px;
  border: 1px solid var(--border);
  font-family: inherit;
  font-size: 0.9rem;
  font-weight: 700;
  cursor: pointer;
  transition: background var(--dur) var(--ease), border-color var(--dur) var(--ease),
    color var(--dur) var(--ease), transform var(--dur) var(--ease);
}

.btn--primary {
  background: var(--surface-2);
  color: var(--text);
}

.btn--primary:hover {
  border-color: var(--accent-line);
  color: var(--accent);
  transform: translateY(-1px);
}

.btn--accent {
  background: var(--accent-soft);
  color: var(--accent);
  border-color: var(--accent-line);
}

.btn--accent:hover:not(:disabled) {
  background: rgba(108, 158, 255, 0.25);
  border-color: rgba(108, 158, 255, 0.55);
  transform: translateY(-1px);
}

.btn--accent:disabled {
  opacity: 0.6;
  cursor: wait;
}

.btn--ghost {
  background: transparent;
  color: var(--text-muted);
}

.btn--ghost:hover {
  color: var(--text);
  background: var(--surface-2);
}


.builder__chain {
  --chain-gap: 0.65rem;
  --chain-cols: 6;
  display: grid;
  grid-template-columns: repeat(
    auto-fill,
    minmax(
      max(8rem, (100% - var(--chain-gap) * (var(--chain-cols) - 1)) / var(--chain-cols)),
      1fr
    )
  );
  gap: var(--chain-gap);
  align-items: start;
}

.builder__empty {
  width: 100%;
  grid-column: 1 / -1;
  text-align: center;
  color: var(--text-muted);
  padding: 3rem 1rem;
}

.chain-connector {
  display: none;
}

.chain-block {
  width: 100%;
  max-width: none;
  min-width: 0;
  padding: 0.6rem;
  border-radius: var(--radius);
  background: linear-gradient(180deg, rgba(255, 255, 255, 0.03), transparent 40%), var(--surface);
  border: 1px solid var(--border);
  box-shadow: var(--shadow-sm);
  text-align: center;
  transition: border-color var(--dur) var(--ease), box-shadow var(--dur) var(--ease);
}

.chain-block:hover {
  border-color: var(--border-strong);
  box-shadow: var(--shadow-lift);
}


.chain-block--seq {
  width: 100%;
}

@media (min-width: 400px) {
  .chain-block--seq {
    grid-column: span 2;
  }
}

.chain-block--seq .seq-preview--diagrams,
.chain-block--seq .seq-preview--compact,
.chain-block--seq .seq-preview--full {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(3.2rem, 1fr));
  gap: 0.3rem;
  align-items: start;
}

.chain-block--seq .seq-preview__item .diagram-svg {
  width: 100%;
  max-width: 70px;
  height: auto;
}

.chain-block--seq .seq-preview__name {
  font-size: 0.68rem;
}

.chain-block__type {
  font-size: 0.65rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--accent);
  margin-right: auto;
}

.chain-block__header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 0.35rem;
  margin-bottom: 0.35rem;
}

.chain-block__grip {
  display: inline-grid;
  place-items: center;
  width: 1.6rem;
  height: 1.6rem;
  margin: 0;
  padding: 0;
  border: 1px solid transparent;
  border-radius: 6px;
  background: transparent;
  color: var(--text-muted);
  font-size: 0.85rem;
  letter-spacing: -0.12em;
  line-height: 1;
  cursor: grab;
  touch-action: none;
  flex-shrink: 0;
}

.chain-block__grip:hover,
.chain-block__grip:focus-visible {
  border-color: var(--border-strong);
  background: var(--surface-2);
  color: var(--studio-link);
  outline: none;
}

.chain-block__grip.is-plan-locked {
  cursor: not-allowed;
  color: var(--text-muted);
  opacity: 0.85;
}

.chain-block__grip.is-plan-locked:hover,
.chain-block__grip.is-plan-locked:focus-visible {
  color: var(--text-muted);
  border-color: var(--border);
  background: transparent;
}

.chain-block__num {
  font-size: 0.7rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--text-muted);
}

.chain-block__remove {
  width: 24px;
  height: 24px;
  border: none;
  border-radius: 6px;
  background: transparent;
  color: var(--text-muted);
  font-size: 1.1rem;
  cursor: pointer;
  line-height: 1;
}

.chain-block__remove:hover {
  background: rgba(255, 80, 80, 0.15);
  color: #ff6b6b;
}

.chain-block__fields {
  display: flex;
  flex-direction: column;
  gap: 0.3rem;
  margin-bottom: 0.4rem;
  text-align: left;
}

.chain-block__label {
  display: flex;
  flex-direction: column;
  gap: 0.15rem;
  font-size: 0.68rem;
  font-weight: 600;
  color: var(--text-muted);
}

.chain-block__label .key-select {
  width: 100%;
  font-size: 0.8rem;
  padding: 0.35rem 1.6rem 0.35rem 0.5rem;
}

.chain-block__chord {
  margin: 0 0 0.25rem;
  font-size: clamp(1rem, 2.2vw, 1.25rem);
  font-weight: 700;
  color: var(--chord);
  font-family: "JetBrains Mono", monospace;
}

.chain-block__diagram {
  display: flex;
  justify-content: center;
  margin-bottom: 0.25rem;
}

.chain-block__diagram .diagram-svg {
  width: 100%;
  max-width: 104px;
  height: auto;
}

.chain-block__note {
  margin: 0.35rem 0 0;
  font-size: 0.7rem;
  color: var(--text-muted);
}

.chain-block__play {
  margin-top: 0.5rem;
  width: 100%;
}

.chain-block__sequence {
  margin: 0 0 0.75rem;
  font-size: 0.75rem;
  color: var(--text-muted);
  font-family: "JetBrains Mono", monospace;
  line-height: 1.6;
}

.chain-block__capo-note {
  margin: 0.5rem 0 0;
  font-size: 0.7rem;
  color: #f0a050;
}

.seq-preview {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  justify-content: center;
  margin-bottom: 0.5rem;
}

.seq-preview--compact {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(3.2rem, 1fr));
  gap: 0.45rem;
}

.seq-preview--diagrams {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(3.2rem, 1fr));
  gap: 0.45rem;
}

.seq-preview--diagrams:empty {
  display: none;
}

.seq-preview--full {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(3.2rem, 1fr));
  gap: 0.45rem;
  margin-top: 0.5rem;
  padding-top: 0.5rem;
  border-top: 1px solid var(--border);
}

.seq-preview--full[hidden] {
  display: none;
}

.seq-preview--compact:empty {
  display: none;
}

.seq-expand-btn {
  width: 100%;
  margin: 0.35rem 0 0.5rem;
  padding: 0.45rem 0.6rem;
  border-radius: 8px;
  border: 1px solid var(--border);
  background: var(--surface-2);
  color: var(--text-muted);
  font-family: inherit;
  font-size: 0.72rem;
  font-weight: 600;
  cursor: pointer;
  transition: border-color 0.15s, color 0.15s;
}

.seq-expand-btn:hover {
  border-color: var(--accent);
  color: var(--accent);
}

.chain-block--seq-expanded .seq-expand-btn {
  border-color: rgba(108, 158, 255, 0.35);
  color: var(--accent);
}

.seq-preview__item {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.25rem;
}

.seq-preview__name {
  font-size: 0.75rem;
  font-weight: 700;
  color: var(--chord);
  font-family: "JetBrains Mono", monospace;
}

.seq-preview__item .diagram-svg {
  width: 72px;
  height: auto;
}

@media (max-width: 768px) {
  .builder {
    padding: 1rem;
  }

  .builder__chain {
    gap: 0.35rem;
  }

  .chain-block {
    padding: 0.45rem;
  }

  .chain-block__header {
    margin-bottom: 0.35rem;
  }

  .chain-block__chord {
    font-size: 0.95rem;
  }

  .chain-block__fields {
    gap: 0.35rem;
    margin-bottom: 0.5rem;
  }

  .chain-block__label {
    font-size: 0.6rem;
  }

  .chain-block__label .key-select {
    font-size: 0.7rem;
    padding: 0.3rem 1.25rem 0.3rem 0.4rem;
  }

  .chain-block__diagram .diagram-svg {
    max-width: 72px;
  }

  .chain-block--seq .seq-preview__item .diagram-svg {
    max-width: 56px;
  }

  .chain-block__play {
    font-size: 0.65rem;
    padding: 0.35rem;
  }
}

.theory-toggle {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  padding: 0.25rem;
  border-radius: 8px;
  border: 1px solid var(--border);
  background: var(--surface);
}

.theory-toggle__label {
  font-size: 0.75rem;
  font-weight: 600;
  color: var(--text-muted);
  padding: 0 0.35rem 0 0.5rem;
}

.theory-toggle__btn {
  border: none;
  border-radius: 6px;
  padding: 0.45rem 0.75rem;
  font-family: inherit;
  font-size: 0.8rem;
  font-weight: 600;
  cursor: pointer;
  background: transparent;
  color: var(--text-muted);
}

.theory-toggle__btn.is-active {
  background: var(--accent-soft);
  color: var(--accent);
}

.theory-panel {
  margin-bottom: 1.5rem;
  padding: 1rem 1.25rem;
  border-radius: var(--radius);
  border: 1px solid rgba(108, 158, 255, 0.25);
  background: rgba(108, 158, 255, 0.06);
}

.theory-panel__title {
  margin: 0 0 0.35rem;
  font-size: 1rem;
}

.theory-panel__context {
  margin: 0 0 0.75rem;
  font-size: 0.8rem;
  color: var(--text-muted);
}

.theory-panel__section-filter {
  margin-bottom: 1rem;
}

.theory-panel__section-label {
  display: block;
  margin-bottom: 0.4rem;
  font-size: 0.72rem;
  font-weight: 600;
  color: var(--text-muted);
}

.theory-section-btns {
  display: flex;
  flex-wrap: wrap;
  gap: 0.35rem;
}

.theory-section-btn {
  padding: 0.35rem 0.6rem;
  border-radius: 999px;
  border: 1px solid var(--border);
  background: var(--surface);
  color: var(--text-muted);
  font-family: inherit;
  font-size: 0.72rem;
  cursor: pointer;
  transition: border-color 0.15s, background 0.15s, color 0.15s;
}

.theory-section-btn:hover {
  border-color: var(--accent);
  color: var(--text);
}

.theory-section-btn.is-active {
  border-color: rgba(108, 158, 255, 0.45);
  background: var(--accent-soft);
  color: var(--accent);
  font-weight: 600;
}

.theory-panel__groups {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 1rem;
}

.theory-panel__heading {
  margin: 0 0 0.5rem;
  font-size: 0.75rem;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--accent);
}

.theory-panel__list {
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}

.theory-panel__empty {
  margin: 0;
  font-size: 0.8rem;
  color: var(--text-muted);
}

.theory-suggestion {
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  gap: 0.2rem;
  width: 100%;
  text-align: left;
  padding: 0.65rem 0.75rem;
  border-radius: 8px;
  border: 1px solid var(--border);
  background: var(--surface);
  cursor: pointer;
  font-family: inherit;
  transition: border-color 0.15s, background 0.15s;
}

.theory-suggestion:hover {
  border-color: var(--accent);
  background: var(--surface-2);
}

.theory-suggestion__main {
  font-size: 0.9rem;
  font-weight: 700;
  color: var(--chord);
  font-family: "JetBrains Mono", monospace;
}

.theory-suggestion__sub {
  font-size: 0.72rem;
  color: var(--text-muted);
  line-height: 1.4;
}

.theory-suggestion__section {
  font-size: 0.68rem;
  color: #f0a050;
  line-height: 1.35;
}


.builder__timeline {
  margin: 0 0 0.85rem;
  padding: 0.7rem 0.85rem 0.8rem;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  background: var(--surface);
}

.builder__timeline.is-plan-locked {
  border-style: dashed;
}

.builder__timeline.is-plan-locked .builder-timeline__track {
  cursor: not-allowed;
  opacity: 0.88;
}

.builder__timeline.is-plan-locked .builder-timeline__seg {
  cursor: not-allowed;
}

.builder-timeline__track {
  position: relative;
  display: flex;
  align-items: stretch;
  min-height: 2.6rem;
  border-radius: 8px;
  overflow: hidden;
  background: rgba(0, 0, 0, 0.25);
  border: 1px solid var(--border);
  cursor: pointer;
  touch-action: manipulation;
}

.builder-timeline__segments {
  display: flex;
  width: 100%;
  min-height: 2.6rem;
  z-index: 1;
}

.builder-timeline__seg {
  display: grid;
  place-items: center;
  margin: 0;
  padding: 0.35rem 0.4rem;
  border: none;
  border-right: 2px solid rgba(169, 143, 255, 0.45);
  background: rgba(124, 90, 240, 0.12);
  color: var(--text);
  font: inherit;
  cursor: pointer;
  min-width: 0;
}

.builder-timeline__seg:last-child {
  border-right: none;
}

.builder-timeline__seg--seq {
  background: rgba(61, 214, 172, 0.1);
  border-right-color: rgba(61, 214, 172, 0.4);
}

.builder-timeline__seg:hover,
.builder-timeline__seg:focus-visible {
  background: rgba(124, 90, 240, 0.22);
  outline: none;
}

.builder-timeline__seg--seq:hover,
.builder-timeline__seg--seq:focus-visible {
  background: rgba(61, 214, 172, 0.2);
}

.builder-timeline__seg-label {
  display: block;
  max-width: 100%;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
  font-size: 0.72rem;
  font-weight: 600;
  line-height: 1.2;
}

.builder-timeline__ticks {
  pointer-events: none;
  position: absolute;
  inset: 0;
  z-index: 2;
}

.builder-timeline__tick {
  position: absolute;
  top: 18%;
  bottom: 18%;
  width: 1px;
  background: rgba(155, 150, 176, 0.35);
  transform: translateX(-0.5px);
}

.builder-timeline__tick--block {
  top: 8%;
  bottom: 8%;
  width: 2px;
  background: rgba(169, 143, 255, 0.65);
}

.builder-timeline__head {
  pointer-events: none;
  position: absolute;
  top: 0;
  bottom: 0;
  left: 0;
  z-index: 3;
  width: 2px;
  background: var(--studio-fill);
  box-shadow: 0 0 10px rgba(124, 90, 240, 0.7);
  transform: translateX(-1px);
}

.builder-timeline__head::before {
  content: "";
  position: absolute;
  top: -3px;
  left: 50%;
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--studio-link);
  transform: translateX(-50%);
}

.builder-timeline__meta {
  margin: 0.45rem 0 0;
  font-size: 0.72rem;
  color: var(--text-muted);
  line-height: 1.45;
}


.chain-block.is-dragging {
  opacity: 0.35;
}

.chain-block--placeholder {
  min-height: 8rem;
  border: 2px dashed var(--accent-line);
  border-radius: var(--radius);
  background: rgba(124, 90, 240, 0.08);
  box-shadow: none;
}

.chain-block--ghost {
  position: fixed;
  z-index: 500;
  pointer-events: none;
  opacity: 0.92;
  margin: 0;
  box-shadow: var(--shadow-lift);
  transform: rotate(1.5deg) scale(0.98);
}

body.is-chain-dragging {
  cursor: grabbing;
  user-select: none;
}

body.is-chain-dragging .chain-block__grip {
  cursor: grabbing;
}