/* ============================================================
   Design Tokens
   ============================================================ */
:root {
  /* Palette: Silverlining (lospec.com/palette-list/silverlining)
     #2e2c3e  #3d3141  #7a616a  #c49483
     #ddbea0  #fff8ca  #dcebe2  #b7ddfd */

  /* Colors — background */
  --color-bg: #2e2c3e;
  --color-on-bg: #ddbea0;
  --color-on-bg-muted: #7a616a;

  /* Colors — surface */
  --color-surface: #3d3141;
  --color-on-surface: #ddbea0;
  --color-on-surface-strong: #fff8ca;

  /* Colors — primary */
  --color-primary: #c49483;
  --color-on-primary: #2e2c3e;
  --color-primary-bright: #ddbea0;
  --color-primary-hover: #ddbea0;
  --color-primary-subtle: #3d3141;

  /* Colors — accent */
  --color-accent: #b7ddfd;
  --color-accent-hover: #dcebe2;
  --color-accent-warm: #fff8ca;

  /* Colors — disabled */
  --color-disabled: #4a3f4a;

  /* Colors — border */
  --color-border: #7a616a;

  /* Colors — canvas */
  --color-canvas-bg: #2e2c3e;

  /* Spacing */
  --spacing-xs: 4px;
  --spacing-sm: 8px;
  --spacing-md: 12px;
  --spacing-lg: 16px;
  --spacing-xl: 20px;
  --spacing-2xl: 24px;

  /* Radii */
  --radius-sm: 0;
  --radius-md: 0;
  --radius-lg: 0;

  /* Sizes */
  --topbar-h: 48px;
  --toolbar-w: 48px;
  --btn-size-sm: 36px;
  --btn-size-md: 40px;

  /* Typography */
  --font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  --font-sm: 0.8125rem;
  --font-md: 0.875rem;
  --font-lg: 1.125rem;

  /* Transitions */
  --transition-fast: 0.15s ease;
}

/* ============================================================
   Reset
   ============================================================ */
*,
*::before,
*::after {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

/* ============================================================
   Base elements
   ============================================================ */
body {
  font-family: var(--font-family);
  background: var(--color-bg);
  color: var(--color-on-bg);
  overflow: hidden;
  height: 100vh;
  display: flex;
  flex-direction: column;
}

button {
  font: inherit;
  cursor: pointer;
  background: none;
  border: 1px solid transparent;
  color: var(--color-on-bg-muted);
  display: inline-flex;
  align-items: center;
  justify-content: center;
  transition: all var(--transition-fast);
}

button:hover {
  color: var(--color-on-bg);
}

button:disabled {
  cursor: default;
  color: var(--color-disabled);
  pointer-events: none;
}

input[type="text"],
select {
  width: 100%;
  padding: var(--spacing-sm) var(--spacing-md);
  background: var(--color-bg);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  color: var(--color-on-bg);
  font: var(--font-md) var(--font-family);
  outline: none;
  margin-bottom: var(--spacing-md);
}

input[type="text"]:focus,
select:focus {
  border-color: var(--color-primary);
}

input[type="range"] {
  accent-color: var(--color-primary);
}

label {
  display: block;
  margin-bottom: var(--spacing-xs);
  font-size: var(--font-sm);
  color: var(--color-on-bg-muted);
}

hr {
  border: none;
  width: 28px;
  height: 1px;
  background: var(--color-border);
  margin: var(--spacing-xs) 0;
}

/* ============================================================
   Header (top bar)
   ============================================================ */
body > header {
  height: var(--topbar-h);
  background: var(--color-surface);
  border-bottom: 1px solid var(--color-border);
  flex-shrink: 0;
}

body > header > .wrapper {
  display: flex;
  align-items: center;
  height: 100%;
  padding: 0 var(--spacing-md);
  gap: var(--spacing-md);
}

body > header nav {
  display: flex;
  gap: var(--spacing-xs);
}

body > header nav button {
  border-color: var(--color-border);
  width: var(--btn-size-sm);
  height: var(--btn-size-sm);
  border-radius: var(--radius-sm);
  font-size: var(--font-lg);
  color: var(--color-on-bg);
}

body > header nav button:hover:not(:disabled) {
  background: var(--color-border);
}

body > header nav button:disabled {
  color: var(--color-on-bg-muted);
}

body > header nav button.active {
  color: var(--color-primary);
  border-color: var(--color-primary);
}

#bpm-input {
  width: 48px;
  padding: var(--spacing-xs);
  background: var(--color-bg);
  border: 1px solid var(--color-border);
  color: var(--color-on-bg);
  font-size: var(--font-sm);
  text-align: center;
  border-radius: var(--radius-sm);
  margin: 0;
}

#bpm-input:focus {
  border-color: var(--color-primary);
  outline: none;
}

#timeline-wrap {
  flex: 1;
  height: 28px;
  position: relative;
  cursor: pointer;
}

#timeline-wrap canvas {
  width: 100%;
  height: 100%;
  display: block;
}

body > header time {
  font-size: var(--font-md);
  font-variant-numeric: tabular-nums;
  color: var(--color-on-bg-muted);
  min-width: 50px;
  text-align: right;
}

/* ============================================================
   Main layout
   ============================================================ */
main {
  display: flex;
  flex: 1;
  overflow: hidden;
}

/* ============================================================
   Aside (toolbar)
   ============================================================ */
#toolbar-left {
  width: var(--toolbar-w);
  background: var(--color-surface);
  border-right: 1px solid var(--color-border);
  display: flex;
  flex-direction: column;
  align-items: center;
  padding: var(--spacing-sm) 0;
  gap: var(--spacing-xs);
  flex-shrink: 0;
}

#toolbar-left button {
  width: var(--btn-size-md);
  height: var(--btn-size-md);
  border-radius: var(--radius-md);
}

#toolbar-left button:hover {
  background: var(--color-primary-subtle);
}

#toolbar-left button.active {
  color: var(--color-primary);
  border-color: var(--color-primary);
  background: var(--color-primary-subtle);
}

/* ============================================================
   Canvas area
   ============================================================ */
#canvas-area {
  flex: 1;
  overflow: hidden;
  cursor: crosshair;
}

#canvas-area canvas {
  display: block;
}

/* ============================================================
   Right panel
   ============================================================ */
#panel {
  width: 220px;
  background: var(--color-surface);
  border-left: 1px solid var(--color-border);
  padding: var(--spacing-md);
  flex-shrink: 0;
  overflow-y: auto;
}

#panel h3 {
  font-size: var(--font-lg);
  color: var(--color-on-surface-strong);
  margin-bottom: var(--spacing-md);
}

#panel p {
  font-size: var(--font-sm);
  color: var(--color-on-bg-muted);
  margin-bottom: var(--spacing-md);
}

#panel input[type="range"] {
  width: 100%;
  margin-bottom: var(--spacing-sm);
}

#note-error {
  color: var(--color-primary);
  font-size: var(--font-sm);
  margin-top: calc(var(--spacing-xs) * -1);
  margin-bottom: var(--spacing-sm);
}

/* Color picker swatches */
#color-picker {
  display: flex;
  gap: var(--spacing-xs);
  margin-bottom: var(--spacing-md);
  flex-wrap: wrap;
}

#color-picker button {
  width: 24px;
  height: 24px;
  padding: 0;
  border: 2px solid transparent;
}

#color-picker button.selected {
  border-color: var(--color-on-surface-strong);
}

/* Transpose buttons */
.transpose-buttons {
  display: flex;
  gap: var(--spacing-xs);
  margin-bottom: var(--spacing-md);
}

.transpose-buttons button {
  flex: 1;
  padding: var(--spacing-xs);
  font-size: var(--font-sm);
  font-family: monospace;
  color: var(--color-on-bg);
  border: 1px solid var(--color-border);
}

.transpose-buttons button:hover {
  background: var(--color-border);
}

/* Shortcut list */
#shortcut-list {
  display: grid;
  grid-template-columns: auto 1fr;
  gap: 2px var(--spacing-sm);
}

#shortcut-list dt {
  font-size: 11px;
  color: var(--color-on-surface-strong);
  font-family: monospace;
}

#shortcut-list dd {
  font-size: 11px;
  color: var(--color-on-bg-muted);
}