/* PIXEL / SIGNAL · 화면 스타일
 * 구조: 고정 트랜스포트 → [무대 · 신호 지도 · 타임라인 | 설정 패널] → 작동 원리
 * 글꼴: 모든 글자와 폼 컨트롤에 Pretendard(자체 호스팅)를 쓴다.
 * 색: 흰 작업면과 검정 글자, 어두운 무대, 크림슨 신호색. 값은 tokens.css에 있다.
 */
@import url("tokens.css");

*,
*::before,
*::after {
  box-sizing: border-box;
}

html {
  background-color: var(--color-page);
  color: var(--color-ink);
  scroll-padding-top: 5rem;
}

body {
  margin: 0;
  background-color: var(--color-page);
  color: var(--color-ink);
  font-family: var(--font-body);
  font-size: var(--text-md);
  font-synthesis: none;
  line-height: 1.55;
  overflow-x: clip;
}

button,
input,
select,
optgroup,
option,
output,
textarea {
  font: inherit;
  letter-spacing: inherit;
}

button,
select,
input[type="range"],
label[for] {
  cursor: pointer;
}

button {
  white-space: nowrap;
  line-height: 1;
}

h1,
h2,
h3,
p,
dl,
dd,
ol,
figure {
  margin: 0;
}

h1,
h2,
h3,
p,
dd {
  overflow-wrap: anywhere;
  word-break: keep-all;
}

:focus-visible {
  outline: var(--rule-active) solid var(--color-focus);
  outline-offset: 2px;
}

.audio-actions:focus-within .timeline-add {
  outline: var(--rule-active) solid var(--color-focus);
  outline-offset: 2px;
}

button:disabled,
select:disabled,
input:disabled {
  cursor: not-allowed;
  opacity: 0.45;
}

.visually-hidden {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0 0 0 0);
  white-space: nowrap;
  border: 0;
}

.skip-link {
  position: absolute;
  inset-block-start: var(--space-2);
  inset-inline-start: var(--space-2);
  z-index: calc(var(--z-overlay) + 1);
  padding: var(--space-2) var(--space-3);
  background-color: var(--color-ink);
  color: var(--color-page);
  font-size: var(--text-sm);
  transform: translateY(-200%);
}

.skip-link:focus {
  transform: none;
}

/* ── 상단 ─────────────────────────────────────────────── */

.topbar {
  min-height: 3.25rem;
  padding-inline: max(var(--page-gutter), env(safe-area-inset-left));
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-4);
  border-bottom: var(--rule-hairline) solid var(--color-rule);
  font-size: var(--text-sm);
}

.brand {
  min-height: var(--control-height);
  display: inline-flex;
  align-items: center;
  gap: var(--space-3);
  color: var(--color-ink);
  font-weight: 600;
  letter-spacing: var(--tracking-label);
  text-decoration: none;
  white-space: nowrap;
}

.brand-mark {
  width: 1.125rem;
  height: var(--rule-active);
  background-color: var(--color-accent);
  box-shadow: 0 0.3125rem 0 var(--color-accent);
}

.portfolio-return {
  display: flex;
  flex-wrap: wrap;
  justify-content: flex-end;
  gap: 0 var(--space-4);
}

.text-link {
  min-height: var(--control-height);
  display: inline-flex;
  align-items: center;
  color: var(--color-ink);
  text-decoration-color: var(--color-accent);
  text-decoration-thickness: var(--rule-hairline);
  text-underline-offset: 0.2em;
  white-space: nowrap;
}

.intro,
.instrument,
.workflow,
.foot-line {
  width: calc(100% - 2 * var(--page-gutter));
  max-width: var(--page-max);
  margin-inline: auto;
}

.intro {
  padding-block: var(--space-5);
  display: grid;
  gap: var(--space-3);
}

.intro-kicker {
  margin-bottom: var(--space-2);
  color: var(--color-accent-strong);
  font-size: var(--text-xs);
  letter-spacing: var(--tracking-label);
}

h1 {
  font-size: clamp(1.5rem, 3.2vw, 2.5rem);
  font-weight: 600;
  letter-spacing: -0.02em;
  line-height: 1.2;
}

.lede {
  max-width: 40rem;
  color: var(--color-ink-2);
  font-size: var(--text-sm);
}

/* ── 악기 ─────────────────────────────────────────────── */

.instrument {
  margin-bottom: var(--space-7);
  border: var(--rule-hairline) solid var(--color-rule);
}

.instrument-head {
  position: sticky;
  inset-block-start: 0;
  z-index: var(--z-overlay);
  padding: var(--space-2) var(--space-3);
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: var(--space-2) var(--space-4);
  background-color: var(--color-page);
  border-bottom: var(--rule-hairline) solid var(--color-rule);
}

.transport {
  display: flex;
  gap: var(--space-2);
}

.transport-button {
  min-width: var(--control-height);
  height: var(--control-height);
  padding-inline: var(--space-3);
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-2);
  border: var(--rule-hairline) solid var(--color-rule);
  border-radius: 0;
  background-color: var(--color-page);
  color: var(--color-ink);
  font-size: var(--text-sm);
  font-weight: 600;
}

.transport-button.primary {
  min-width: 6.75rem;
  background-color: var(--color-accent);
  border-color: var(--color-accent);
  color: var(--color-accent-ink);
}

.play-icon {
  width: 0;
  height: 0;
  border-block: 0.4rem solid transparent;
  border-inline-start: 0.7rem solid currentColor;
}

.is-playing .play-icon {
  width: 0.7rem;
  height: 0.8rem;
  border: 0;
  background-image: linear-gradient(90deg, currentColor 0 35%, transparent 35% 65%, currentColor 65%);
}

.rewind-icon {
  width: 0.8rem;
  height: 0.8rem;
  background-image:
    linear-gradient(currentColor, currentColor),
    linear-gradient(to top left, currentColor 50%, transparent 50%),
    linear-gradient(to bottom left, currentColor 50%, transparent 50%);
  background-size: 0.15rem 100%, 0.6rem 50%, 0.6rem 50%;
  background-position: left, right top, right bottom;
  background-repeat: no-repeat;
}

.record-icon {
  width: 0.7rem;
  height: 0.7rem;
  border-radius: 50%;
  background-color: var(--color-accent);
}

.record.is-recording {
  background-color: var(--color-ink);
  color: var(--color-page);
}

.record.is-recording .record-icon {
  border-radius: 0;
}

.transport-readout {
  min-width: 7rem;
  display: grid;
  font-size: var(--text-xs);
  font-variant-numeric: tabular-nums;
  letter-spacing: var(--tracking-label);
  line-height: 1.4;
}

.transport-readout strong {
  color: var(--color-accent-strong);
  font-weight: 600;
}

.transport-readout span {
  color: var(--color-muted);
}

.audio-console {
  min-width: 0;
  margin-inline-start: auto;
  display: flex;
  align-items: center;
  gap: var(--space-3);
  font-size: var(--text-xs);
}

.audio-state {
  min-width: 0;
  color: var(--color-muted);
  letter-spacing: var(--tracking-label);
}

.audio-state.is-live {
  color: var(--color-ink);
}

.audio-state.is-live::before {
  content: "";
  width: 0.5rem;
  height: 0.5rem;
  margin-inline-end: var(--space-2);
  display: inline-block;
  border-radius: 50%;
  background-color: var(--color-success);
}

.audio-console button,
.origin-inspector button {
  min-height: var(--control-height);
  padding-inline: var(--space-3);
  border: var(--rule-hairline) solid currentColor;
  border-radius: 0;
  background-color: transparent;
  color: inherit;
  font-size: var(--text-sm);
}

.workspace {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
}

.stage-column {
  min-width: 0;
  padding: var(--space-3);
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: var(--space-3);
  align-content: start;
}

.stage-head {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: var(--space-2) var(--space-4);
}

.stage-head h2,
.panel-title h2 {
  font-size: var(--text-md);
  font-weight: 600;
  line-height: 1.3;
}

.transport-note {
  color: var(--color-ink-2);
  font-size: var(--text-xs);
}

.transport-note span {
  margin-inline-end: var(--space-2);
  color: var(--color-muted);
}

.origin-mode-switch {
  margin-inline-start: auto;
  display: grid;
  grid-template-columns: repeat(2, auto);
  border: var(--rule-hairline) solid var(--color-rule);
}

.origin-mode-switch button {
  min-height: var(--control-height);
  padding-inline: var(--space-3);
  border: 0;
  border-radius: 0;
  background-color: var(--color-page);
  color: var(--color-ink-2);
  font-size: var(--text-xs);
  font-weight: 600;
  letter-spacing: var(--tracking-label);
}

.origin-mode-switch button span {
  margin-inline-start: var(--space-1);
  font-weight: 400;
  letter-spacing: 0;
}

.origin-mode-switch button[aria-pressed="true"] {
  background-color: var(--color-ink);
  color: var(--color-page);
}

.stage {
  position: relative;
  width: 100%;
  aspect-ratio: 16 / 9;
  max-height: 72dvh;
  overflow: hidden;
  background-color: var(--color-stage);
  color: var(--color-stage-ink);
  touch-action: none;
  user-select: none;
}

#visualCanvas {
  width: 100%;
  height: 100%;
  display: block;
  object-fit: contain;
}

.stage-grid {
  position: absolute;
  inset: 0;
  pointer-events: none;
  background-image:
    linear-gradient(var(--color-grid-line) var(--rule-hairline), transparent var(--rule-hairline)),
    linear-gradient(90deg, var(--color-grid-line) var(--rule-hairline), transparent var(--rule-hairline));
  background-size: 3rem 3rem;
}

.stage-label {
  position: absolute;
  padding: var(--space-1) var(--space-2);
  background-color: var(--color-stage-overlay);
  color: var(--color-stage-ink);
  font-size: var(--text-2xs);
  font-variant-numeric: tabular-nums;
  letter-spacing: var(--tracking-label);
  pointer-events: none;
}

.bottom-right {
  inset-block-end: var(--space-2);
  inset-inline-end: var(--space-2);
}

.stage[data-origin-mode="explain"] #pixelReadout {
  display: none;
}

.drop-hint {
  position: absolute;
  inset: 0;
  display: none;
  place-content: center;
  gap: var(--space-2);
  padding: var(--space-5);
  border: var(--rule-active) dashed var(--color-accent);
  background-color: var(--color-page-overlay);
  color: var(--color-ink);
  text-align: center;
  pointer-events: none;
}

.drop-hint strong {
  font-size: clamp(1.25rem, 4vw, 2rem);
  font-weight: 600;
  line-height: 1.2;
}

.drop-hint span {
  color: var(--color-ink-2);
  font-size: var(--text-sm);
}

.stage.is-dragover .drop-hint,
.stage.is-empty .drop-hint {
  display: grid;
}

.stage-toolbar {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  gap: var(--space-1) var(--space-4);
  color: var(--color-muted);
  font-size: var(--text-xs);
}

.stage-toolbar p:first-child {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-1) var(--space-4);
}

.import-status {
  color: var(--color-ink);
}

.import-status[data-state="error"] {
  color: var(--color-accent-strong);
}

.origin-inspector {
  padding: var(--space-3);
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: var(--space-3);
  align-items: center;
  background-color: var(--color-stage-2);
  color: var(--color-stage-ink);
}

.origin-inspector[hidden] {
  display: none;
}

.origin-copy {
  min-width: 0;
  display: grid;
  gap: var(--space-1);
}

.origin-copy > span {
  color: var(--color-stage-muted);
  font-size: var(--text-xs);
}

.origin-copy strong {
  font-size: var(--text-sm);
  font-weight: 600;
  font-variant-numeric: tabular-nums;
}

.origin-copy p {
  color: var(--color-stage-muted);
  font-size: var(--text-xs);
  font-variant-numeric: tabular-nums;
}

.origin-inspector button[data-state="success"] {
  border-color: var(--color-success);
  background-color: var(--color-success);
  color: var(--color-ink);
}

.origin-inspector[data-audible="false"] .origin-copy strong {
  color: var(--color-stage-muted);
}

/* ── 신호 지도 · 타임라인 (어두운 면) ───────────────────── */

.signal-atlas,
.deck-overview {
  min-width: 0;
  background-color: var(--color-stage-2);
  color: var(--color-stage-ink);
}

.signal-atlas-head,
.deck-heading {
  min-height: 3rem;
  padding: var(--space-2) var(--space-3);
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-1) var(--space-4);
  border-bottom: var(--rule-hairline) solid var(--color-stage-rule);
}

.signal-atlas-head > div,
.deck-heading > div {
  min-width: 0;
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: var(--space-1) var(--space-3);
}

.signal-atlas-head h2,
.deck-heading h2 {
  font-size: var(--text-sm);
  font-weight: 600;
}

.signal-atlas-head span,
.signal-atlas-head output,
.signal-view figcaption,
.timeline-ruler,
.timeline-toolbar {
  color: var(--color-stage-muted);
  font-size: var(--text-xs);
  font-variant-numeric: tabular-nums;
}

.signal-atlas-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
}

.signal-view {
  min-width: 0;
  background-color: var(--color-stage);
  border-bottom: var(--rule-hairline) solid var(--color-stage-rule);
}

.signal-view:last-child {
  border-bottom: 0;
}

.signal-view figcaption {
  min-height: 2rem;
  padding-inline: var(--space-3);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-3);
  border-bottom: var(--rule-hairline) solid var(--color-stage-rule);
}

.signal-view figcaption em {
  color: var(--color-accent-soft);
  font-style: normal;
  white-space: nowrap;
}

.signal-view canvas {
  width: 100%;
  height: 6.5rem;
  display: block;
  cursor: crosshair;
  touch-action: none;
}

.signal-view canvas:focus-visible,
.timeline-playhead:focus-visible,
.timeline-clip:focus-visible,
.stage:focus-visible {
  outline-offset: -2px;
}

.timeline-add {
  min-height: var(--control-height);
  padding-inline: var(--space-4);
  display: inline-flex;
  align-items: center;
  background-color: var(--color-stage-ink);
  color: var(--color-stage);
  font-size: var(--text-sm);
  font-weight: 600;
  white-space: nowrap;
}

/* 눈금과 트랙은 같은 폭으로 함께 확대·스크롤된다. 왼쪽 여백은 트랙 머리(V/M/S)의 자리다. */
.timeline-ruler,
.timeline-content {
  width: calc((100% - var(--track-head-width)) * var(--timeline-zoom));
  margin-inline-start: var(--track-head-width);
}

.timeline-ruler {
  position: sticky;
  inset-block-start: 0;
  z-index: 6;
  height: 1.75rem;
  background-color: var(--color-stage-2);
  box-shadow: calc(-1 * var(--track-head-width)) 0 0 var(--color-stage-2), 0 var(--rule-hairline) 0 var(--color-stage-rule);
}

.timeline-ruler span {
  position: absolute;
  inset-block: 0;
  display: flex;
  align-items: center;
  transform: translateX(-50%);
  white-space: nowrap;
}

.timeline-ruler span:nth-child(1) { inset-inline-start: 0; transform: none; }
.timeline-ruler span:nth-child(2) { inset-inline-start: 25%; }
.timeline-ruler span:nth-child(3) { inset-inline-start: 50%; }
.timeline-ruler span:nth-child(4) { inset-inline-start: 75%; }
.timeline-ruler span:nth-child(5) { inset-inline-end: 0; transform: none; }

.timeline-viewport {
  --track-head-width: 10.25rem;
  --timeline-zoom: 1;
  position: relative;
  width: 100%;
  min-height: 9rem;
  max-height: 24rem;
  overflow: auto;
  overscroll-behavior-inline: contain;
  scrollbar-color: var(--color-stage-muted) var(--color-stage-3);
}

.timeline-content {
  position: relative;
  min-height: 9rem;
  cursor: col-resize;
}

#timelineCanvas {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  display: block;
  pointer-events: none;
}

.timeline-tracks {
  position: relative;
  min-height: 9rem;
}

.timeline-track {
  position: relative;
  height: 4.5rem;
  border-bottom: var(--rule-hairline) solid var(--color-stage-rule);
}

.track-head {
  position: sticky;
  inset-inline-start: 0;
  inset-block-start: 0.375rem;
  z-index: 5;
  width: var(--track-head-width);
  height: 3.75rem;
  margin-inline-start: calc(-1 * var(--track-head-width));
  display: inline-flex;
  align-items: center;
  justify-content: space-between;
  background-color: var(--color-stage-2);
  border-inline-start: var(--rule-active) solid var(--color-accent);
  border-inline-end: var(--rule-hairline) solid var(--color-stage-rule);
  font-size: var(--text-xs);
  cursor: default;
}

.track-id {
  padding-inline: var(--space-2);
  font-variant-numeric: tabular-nums;
}

.track-audio-actions {
  padding-inline-end: var(--space-2);
  display: flex;
  gap: var(--space-1);
}

.track-audio-actions button {
  width: 2rem;
  height: 2rem;
  padding: 0;
  border: var(--rule-hairline) solid var(--color-stage-rule);
  border-radius: 0;
  background-color: var(--color-stage-3);
  color: var(--color-stage-muted);
  font-size: var(--text-xs);
  font-weight: 600;
}

.track-audio-actions button.is-active {
  border-color: var(--color-stage-ink);
  background-color: var(--color-stage-ink);
  color: var(--color-stage);
}

.track-audio-actions .track-mute.is-active {
  border-color: var(--color-accent);
  background-color: var(--color-accent);
  color: var(--color-accent-ink);
}

.track-audio-actions .track-solo.is-active {
  border-color: var(--color-success);
  background-color: var(--color-success);
  color: var(--color-ink);
}

.timeline-clip {
  position: absolute;
  inset-block-start: 0.375rem;
  min-width: 2.125rem;
  height: 3.75rem;
  overflow: hidden;
  border: var(--rule-hairline) solid var(--color-clip-border);
  background-color: var(--color-stage-3);
  background-size: auto 100%;
  background-repeat: repeat-x;
  cursor: grab;
  touch-action: none;
}

.timeline-clip:active {
  cursor: grabbing;
}

.timeline-clip.selected {
  border-color: var(--color-accent);
  box-shadow: inset 0 0 0 var(--rule-hairline) var(--color-accent);
}

.timeline-clip.is-hidden {
  opacity: 0.32;
}

.timeline-clip.is-muted {
  opacity: 0.58;
  filter: saturate(0.25);
}

.timeline-clip.is-hidden.is-muted {
  opacity: 0.25;
}

.timeline-clip.is-solo {
  border-color: var(--color-success);
  box-shadow: inset 0 0 0 var(--rule-hairline) var(--color-success);
}

.clip-shade {
  position: absolute;
  inset: 0;
  background-image: linear-gradient(90deg, var(--color-stage-overlay-soft), transparent 45%, var(--color-stage-overlay));
  pointer-events: none;
}

.clip-copy {
  position: absolute;
  inset-inline: 1rem 5.25rem;
  inset-block-end: var(--space-2);
  min-width: 0;
  display: flex;
  align-items: center;
  gap: var(--space-2);
  overflow: hidden;
  font-size: var(--text-xs);
  pointer-events: none;
  text-shadow: 0 0 0.25rem var(--color-stage);
}

.clip-copy strong {
  min-width: 0;
  overflow: hidden;
  font-weight: 600;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.clip-copy span {
  color: var(--color-accent-soft);
  font-variant-numeric: tabular-nums;
  white-space: nowrap;
}

.clip-handle {
  position: absolute;
  inset-block: 0;
  z-index: 2;
  width: 1.5rem;
  padding: 0;
  border: 0;
  background-color: transparent;
  cursor: ew-resize;
}

.clip-handle::after {
  content: "";
  position: absolute;
  inset-block: 0;
  width: 0.25rem;
  background-color: var(--color-clip-handle);
}

.clip-handle.left,
.clip-handle.left::after {
  inset-inline-start: 0;
}

.clip-handle.right,
.clip-handle.right::after {
  inset-inline-end: 0;
}

.clip-actions {
  position: absolute;
  inset-block-start: var(--space-2);
  inset-inline-end: 1.75rem;
  z-index: 2;
  display: flex;
  gap: var(--space-1);
  opacity: 0;
  pointer-events: none;
}

.timeline-clip.selected .clip-actions,
.timeline-clip:focus-within .clip-actions {
  opacity: 1;
  pointer-events: auto;
}

.clip-actions button {
  width: 2rem;
  height: 2rem;
  padding: 0;
  border: var(--rule-hairline) solid var(--color-clip-border);
  border-radius: 0;
  background-color: var(--color-clip-action);
  color: var(--color-stage-ink);
  font-size: var(--text-xs);
}

.timeline-playhead {
  position: absolute;
  inset-block: 0;
  inset-inline-start: 0;
  z-index: 4;
  width: var(--rule-hairline);
  background-color: var(--color-stage-ink);
  cursor: ew-resize;
  touch-action: none;
}

.timeline-playhead::before {
  content: "";
  position: absolute;
  inset-block: 0;
  inset-inline: -0.75rem;
}

.timeline-playhead i {
  position: absolute;
  inset-block-start: 0;
  inset-inline-start: -0.3rem;
  width: 0.65rem;
  height: 0.6rem;
  background-color: var(--color-accent);
  clip-path: polygon(0 0, 100% 0, 50% 100%);
}

.timeline-toolbar {
  padding: var(--space-2) var(--space-3);
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-2) var(--space-4);
  border-top: var(--rule-hairline) solid var(--color-stage-rule);
}

.timeline-toolbar > span {
  flex: 1 1 16rem;
}

.timeline-toolbar label {
  flex: 0 1 16rem;
  color: var(--color-stage-ink);
}

.timeline-toolbar output {
  color: var(--color-accent-soft);
}

.timeline-toolbar input[type="range"]::-webkit-slider-runnable-track {
  background-color: var(--color-stage-muted);
}

.timeline-toolbar input[type="range"]::-moz-range-track {
  background-color: var(--color-stage-muted);
}

/* ── 폼 컨트롤 ────────────────────────────────────────── */

label {
  min-width: 0;
  display: grid;
  gap: var(--space-1);
  color: var(--color-ink-2);
  font-size: var(--text-xs);
}

label > span {
  min-width: 0;
  display: flex;
  justify-content: space-between;
  gap: var(--space-2);
}

output {
  color: var(--color-accent-strong);
  font-variant-numeric: tabular-nums;
}

select {
  width: 100%;
  height: var(--control-height);
  padding-inline: var(--space-2);
  border: var(--rule-hairline) solid var(--color-rule);
  border-radius: 0;
  background-color: var(--color-page);
  color: var(--color-ink);
  font-size: var(--text-sm);
}

input[type="range"] {
  width: 100%;
  height: 2rem;
  margin: 0;
  appearance: none;
  background-color: transparent;
}

input[type="range"]::-webkit-slider-runnable-track {
  height: var(--rule-active);
  background-color: var(--color-ink);
}

input[type="range"]::-webkit-slider-thumb {
  width: 0.875rem;
  height: 1.5rem;
  margin-block-start: -0.6875rem;
  appearance: none;
  border: 0;
  border-radius: 0;
  background-color: var(--color-accent);
}

input[type="range"]::-moz-range-track {
  height: var(--rule-active);
  background-color: var(--color-ink);
}

input[type="range"]::-moz-range-thumb {
  width: 0.875rem;
  height: 1.5rem;
  border: 0;
  border-radius: 0;
  background-color: var(--color-accent);
}

/* ── 설정 패널 ────────────────────────────────────────── */

.side-panel {
  min-width: 0;
  border-top: var(--rule-hairline) solid var(--color-rule);
}

.panel {
  padding: var(--space-4) var(--space-3);
  border-bottom: var(--rule-hairline) solid var(--color-rule-soft);
}

.panel:last-child {
  border-bottom: 0;
}

.panel-title {
  margin-bottom: var(--space-3);
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  justify-content: space-between;
  gap: var(--space-1) var(--space-3);
}

.panel-title > div:first-child {
  min-width: 0;
}

.panel-sub {
  color: var(--color-muted);
  font-size: var(--text-xs);
}

#selectedLayerName {
  max-width: 14rem;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.panel-actions {
  display: flex;
  gap: var(--space-3);
}

.link-button {
  min-height: var(--control-height);
  padding: 0;
  border: 0;
  background-color: transparent;
  color: var(--color-ink);
  font-size: var(--text-sm);
  text-decoration: underline;
  text-underline-offset: 0.2em;
}

.delete-button {
  color: var(--color-accent-strong);
}

.control-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: var(--space-3) var(--space-4);
  align-items: end;
}

.span-2 {
  grid-column: 1 / -1;
}

.mix-row,
.meter-wrap {
  min-height: 2rem;
  display: grid;
  grid-template-columns: 4.5rem minmax(0, 1fr) 3.5rem;
  gap: var(--space-3);
  align-items: center;
  font-size: var(--text-xs);
  font-variant-numeric: tabular-nums;
}

.mix-row > i,
.meter {
  height: 0.375rem;
  overflow: hidden;
  background-color: var(--color-rule-soft);
}

.mix-row > i b,
.meter i {
  width: 0;
  height: 100%;
  display: block;
  background-color: var(--color-accent);
}

.mix-row > em {
  color: var(--color-muted);
  font-style: normal;
  text-align: end;
}

.meter-wrap {
  margin-top: var(--space-2);
  padding-top: var(--space-2);
  border-top: var(--rule-hairline) solid var(--color-rule-soft);
  font-weight: 600;
}

.meter i {
  background-color: var(--color-ink);
}

.meter-wrap > span:last-child {
  font-weight: 400;
  text-align: end;
}

/* ── 작동 원리 ────────────────────────────────────────── */

.workflow {
  margin-bottom: var(--space-7);
}

.section-heading {
  margin-bottom: var(--space-5);
  padding-top: var(--space-5);
  border-top: var(--rule-hairline) solid var(--color-rule);
}

.section-heading h2 {
  font-size: clamp(1.375rem, 2.6vw, 2rem);
  font-weight: 600;
  letter-spacing: -0.02em;
  line-height: 1.25;
}

.workflow-lede {
  max-width: 42rem;
  margin-top: var(--space-2);
  color: var(--color-ink-2);
  font-size: var(--text-sm);
}

.flow {
  padding: 0;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  border-top: var(--rule-hairline) solid var(--color-rule);
  list-style: none;
}

.flow-node {
  min-width: 0;
  padding: var(--space-4) 0;
  display: grid;
  grid-template-columns: 4rem minmax(0, 1fr);
  gap: var(--space-1) var(--space-4);
  align-items: start;
  border-bottom: var(--rule-hairline) solid var(--color-rule-soft);
}

.flow-node > span {
  grid-column: 2;
  color: var(--color-accent-strong);
  font-size: var(--text-xs);
  font-variant-numeric: tabular-nums;
}

.flow-node h3 {
  grid-column: 2;
  font-size: var(--text-md);
  font-weight: 600;
}

.flow-node p {
  grid-column: 2;
  color: var(--color-ink-2);
  font-size: var(--text-sm);
}

.node-visual {
  position: relative;
  grid-column: 1;
  grid-row: 1 / 4;
  width: 4rem;
  height: 4rem;
}

.layers-visual i {
  position: absolute;
  inset-inline-start: 0.25rem;
  inset-block-start: 0.25rem;
  width: 2.75rem;
  height: 2.25rem;
  border: var(--rule-hairline) solid var(--color-muted);
  background-color: var(--color-page);
}

.layers-visual i:nth-child(2) {
  transform: translate(0.35rem, 0.35rem);
}

.layers-visual i:nth-child(3) {
  transform: translate(0.7rem, 0.7rem);
  border-color: var(--color-accent);
  background-color: var(--color-accent-soft);
}

.blend-visual i {
  position: absolute;
  inset-inline-start: 0.25rem;
  inset-block-start: 0.6rem;
  width: 2.5rem;
  height: 2.5rem;
  border-radius: 50%;
  background-color: var(--color-ink-2);
  mix-blend-mode: multiply;
}

.blend-visual i:nth-child(2) {
  inset-inline-start: 1.35rem;
  background-color: var(--color-accent);
}

.scan-visual {
  background-image: repeating-linear-gradient(90deg, transparent 0 0.45rem, var(--color-rule-soft) 0.45rem 0.5rem);
}

.scan-visual i {
  position: absolute;
  inset-block: 0;
  inset-inline-start: 55%;
  width: var(--rule-active);
  background-color: var(--color-accent);
}

.map-visual,
.sound-visual {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-1);
}

.map-visual {
  align-items: end;
}

.map-visual i {
  width: 0.5rem;
  background-color: var(--color-rule-soft);
}

.map-visual i:nth-child(1) { height: 25%; }
.map-visual i:nth-child(2) { height: 70%; background-color: var(--color-accent); }
.map-visual i:nth-child(3) { height: 42%; }
.map-visual i:nth-child(4) { height: 88%; }

.sound-visual i {
  width: var(--rule-active);
  height: 28%;
  background-color: var(--color-ink);
}

.sound-visual i:nth-child(2),
.sound-visual i:nth-child(4) {
  height: 62%;
}

.sound-visual i:nth-child(3) {
  height: 95%;
  background-color: var(--color-accent);
}

.mapping-grid {
  margin-top: var(--space-6);
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  border-top: var(--rule-hairline) solid var(--color-rule);
  border-inline-start: var(--rule-hairline) solid var(--color-rule-soft);
}

.mapping-grid div {
  min-width: 0;
  padding: var(--space-3);
  display: grid;
  gap: var(--space-2);
  border-inline-end: var(--rule-hairline) solid var(--color-rule-soft);
  border-bottom: var(--rule-hairline) solid var(--color-rule-soft);
}

.mapping-grid dt {
  color: var(--color-muted);
  font-size: var(--text-xs);
}

.mapping-grid dd {
  font-size: var(--text-lg);
  font-weight: 600;
}

.mapping-rationale {
  margin-top: var(--space-6);
}

.mapping-rationale h3 {
  margin-bottom: var(--space-3);
  font-size: var(--text-lg);
  font-weight: 600;
}

.mapping-rationale dl {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
}

.mapping-rationale dl > div {
  padding-block: var(--space-3);
  border-top: var(--rule-hairline) solid var(--color-rule-soft);
}

.mapping-rationale dt {
  margin-bottom: var(--space-1);
  font-size: var(--text-sm);
  font-weight: 600;
}

.mapping-rationale dd {
  color: var(--color-ink-2);
  font-size: var(--text-sm);
}

.foot-line {
  padding-block: var(--space-4) max(var(--space-4), env(safe-area-inset-bottom));
  color: var(--color-muted);
  border-top: var(--rule-hairline) solid var(--color-rule);
  font-size: var(--text-xs);
}

.foot-line p {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  gap: var(--space-2);
}

/* ── 상호작용 · 반응형 ────────────────────────────────── */

@media (hover: hover) and (pointer: fine) {
  .text-link:hover,
  .link-button:hover {
    color: var(--color-accent-strong);
  }

  .transport-button:hover,
  .audio-console button:hover,
  .origin-mode-switch button:hover,
  select:hover {
    box-shadow: inset 0 0 0 var(--rule-hairline) currentColor;
  }

  .timeline-add:hover,
  .origin-inspector button:hover,
  .clip-actions button:hover,
  .track-audio-actions button:hover {
    box-shadow: inset 0 0 0 var(--rule-active) var(--color-accent);
  }

  .timeline-clip:hover .clip-actions {
    opacity: 1;
    pointer-events: auto;
  }
}

@media (pointer: coarse) {
  .clip-actions button,
  .track-audio-actions button {
    width: 2.25rem;
    height: var(--control-height);
  }

  .timeline-viewport {
    --track-head-width: 11rem;
  }

  .clip-handle {
    width: 2.25rem;
  }

  .clip-actions {
    inset-inline-end: 2.5rem;
  }

  input[type="range"] {
    height: var(--control-height);
  }
}

@media (max-width: 29.99rem) {
  .transport-button:not(.primary) {
    padding-inline: 0;
  }

  .transport-button:not(.primary) .button-label {
    display: none;
  }

  .transport-button.primary {
    min-width: 5.75rem;
  }

  .audio-console {
    flex: 1 1 100%;
    justify-content: space-between;
  }
}

@media (min-width: 40rem) {
  .intro {
    grid-template-columns: minmax(0, 1.4fr) minmax(16rem, 1fr);
    gap: var(--space-6);
    align-items: end;
  }

  .origin-inspector {
    grid-template-columns: minmax(0, 1fr) auto;
  }

  .signal-atlas-grid {
    grid-template-columns: minmax(0, 0.72fr) minmax(0, 1.28fr);
  }

  .signal-view {
    border-inline-end: var(--rule-hairline) solid var(--color-stage-rule);
    border-bottom: 0;
  }

  .signal-view:last-child {
    border-inline-end: 0;
  }

  .signal-view canvas {
    height: 8rem;
  }

  .side-panel {
    display: grid;
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .panel {
    padding-inline: var(--space-4);
  }

  .panel:nth-child(odd) {
    border-inline-end: var(--rule-hairline) solid var(--color-rule-soft);
  }

  .mapping-grid {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

  .mapping-rationale dl {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    column-gap: var(--space-6);
  }
}

@media (min-width: 68rem) {
  .workspace {
    grid-template-columns: minmax(0, 1fr) var(--panel-width);
    align-items: start;
  }

  .stage-column {
    padding: var(--space-4);
  }

  .side-panel {
    display: block;
    align-self: stretch;
    border-top: 0;
    border-inline-start: var(--rule-hairline) solid var(--color-rule);
  }

  .panel:nth-child(odd) {
    border-inline-end: 0;
  }

  .flow {
    grid-template-columns: repeat(5, minmax(0, 1fr));
    column-gap: var(--space-5);
    border-bottom: var(--rule-hairline) solid var(--color-rule-soft);
  }

  .flow-node {
    padding-block: var(--space-4);
    display: flex;
    flex-direction: column;
    gap: var(--space-2);
    border-bottom: 0;
  }

  .node-visual {
    order: -1;
    margin-bottom: var(--space-2);
  }

  .mapping-grid {
    grid-template-columns: repeat(7, minmax(0, 1fr));
  }
}

@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation: none;
    transition: none;
  }
}