/* ── Theme Contract ─────────────────────────────────────────────────────────
   Scoped to .tb303 so vars don't bleed into other instruments on the same page.
   ──────────────────────────────────────────────────────────────────────── */
.tb303 {
  --color-bg:            #111010;
  --color-panel:         #1e1c19;
  --color-panel-raised:  #2a2720;
  --color-border:        #3a3530;
  --color-accent:        #e8520a;   /* TB-303 orange */
  --color-accent-glow:   #ff6b1a44;
  --color-step-active:   #ffcc00;
  --color-slide:         #4a9eff;
  --color-rest:          #555;
  --color-text:          #d8d0c4;
  --color-text-dim:      #7a7068;
  --color-text-bright:   #ffffff;
  --color-knob-body:     #3a3530;
  --color-knob-ring:     #555048;
  --color-knob-dot:      var(--color-accent);
  --color-btn-active:    var(--color-accent);
  --color-flag-rest:     #888;
  --color-flag-accent:   #f0c030;
  --color-flag-slide:    var(--color-slide);
  --color-run:           #3a9e4a;
  --color-stop:          #9e3a3a;

  --knob-size:           60px;
  --step-size:           52px;
  --font-ui:             'Courier New', 'Courier', monospace;
  --radius:              4px;
  --radius-lg:           8px;
  --gap:                 8px;
}

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

button {
  font-family: inherit;
  font-size: inherit;
  cursor: pointer;
  border: none;
  background: none;
}

input {
  font-family: inherit;
  font-size: inherit;
}

/* ── TB-303 Shell ───────────────────────────────────────────────────────── */
.tb303 {
  background: var(--color-panel);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: 16px;
  width: 100%;
  display: flex;
  flex-direction: column;
  gap: 12px;
  box-shadow: 0 8px 32px #00000066;
  font-family: var(--font-ui);
  font-size: 11px;
  color: var(--color-text);
}

/* ── Header ─────────────────────────────────────────────────────────────── */
.tb303__header {
  display: flex;
  align-items: center;
  gap: 16px;
  border-bottom: 1px solid var(--color-border);
  padding-bottom: 12px;
  flex-wrap: wrap;
}

.tb303__brand {
  display: flex;
  flex-direction: column;
  line-height: 1.1;
  flex: 0 0 auto;
}

.tb303__model {
  font-size: 22px;
  font-weight: bold;
  color: var(--color-accent);
  letter-spacing: 2px;
}

.tb303__subtitle {
  font-size: 9px;
  color: var(--color-text-dim);
  letter-spacing: 3px;
  text-transform: uppercase;
}

/* ── Controls Row ────────────────────────────────────────────────────────── */
.controls {
  display: flex;
  flex-wrap: wrap;
  gap: 16px 20px;
  padding: 12px;
  background: var(--color-panel-raised);
  border-radius: var(--radius);
  border: 1px solid var(--color-border);
}

.knob-group {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 6px;
}

.knob__label {
  font-size: 9px;
  letter-spacing: 1px;
  color: var(--color-text-dim);
  text-transform: uppercase;
}

/* ── Knob ─────────────────────────────────────────────────────────────────── */
.knob {
  width: var(--knob-size);
  height: var(--knob-size);
  cursor: ns-resize;
  user-select: none;
  touch-action: none;
  outline: none;
}

.knob:focus-visible {
  outline: 2px solid var(--color-accent);
  border-radius: 50%;
}

.knob__body {
  width: 100%;
  height: 100%;
  border-radius: 50%;
  background: radial-gradient(circle at 38% 35%, #4a4540, var(--color-knob-body));
  border: 2px solid var(--color-knob-ring);
  box-shadow: 0 2px 6px #00000088, inset 0 1px 2px #ffffff18;
  position: relative;
  display: flex;
  align-items: center;
  justify-content: center;
}

/* Full-size transparent overlay that rotates around the knob center */
.knob__indicator {
  position: absolute;
  inset: 0;
  border-radius: 50%;
  transform: rotate(var(--knob-angle, -135deg));
}

/* Visible dot on the indicator, near the outer edge */
.knob__indicator::after {
  content: '';
  position: absolute;
  bottom: 7px;
  left: 50%;
  transform: translateX(-50%);
  width: 4px;
  height: 4px;
  border-radius: 50%;
  background: var(--color-knob-dot);
  box-shadow: 0 0 5px var(--color-accent-glow);
}

/* ── Pattern Bank ────────────────────────────────────────────────────────── */
.pattern-bank-section {
  display: flex;
  align-items: center;
  gap: 10px;
}

.section-label {
  font-size: 9px;
  letter-spacing: 2px;
  color: var(--color-text-dim);
  text-transform: uppercase;
  white-space: nowrap;
}

.pattern-bank {
  display: flex;
  flex-wrap: wrap;
  gap: 4px;
}

.pattern-btn {
  padding: 4px 7px;
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  color: var(--color-text-dim);
  font-size: 10px;
  transition: all 0.1s;
  min-width: 30px;
  text-align: center;
}

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

.pattern-btn--active {
  border-color: var(--color-accent);
  color: var(--color-accent);
  background: #e8520a18;
  box-shadow: 0 0 6px var(--color-accent-glow);
}

/* ── Step Sequencer ──────────────────────────────────────────────────────── */
.steps-section {
  padding-top: 4px;
}

.steps-container {
  display: grid;
  grid-template-columns: repeat(16, 1fr);
  gap: 4px;
}

@media (max-width: 720px) {
  .tb303 { --knob-size: 50px; }
  .steps-container { grid-template-columns: repeat(8, 1fr); }
}

@media (max-width: 420px) {
  .tb303 { --knob-size: 40px; }
  .steps-container { grid-template-columns: repeat(4, 1fr); }
}

/* ── Single Step ─────────────────────────────────────────────────────────── */
.step {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 4px;
  padding: 6px 2px;
  border-radius: var(--radius);
  border: 1px solid transparent;
  background: var(--color-panel-raised);
  transition: border-color 0.08s, background 0.08s;
  min-width: 0;
}

.step--active {
  border-color: var(--color-step-active);
  background: #ffcc0014;
  box-shadow: 0 0 8px #ffcc0044;
}

.step__number {
  font-size: 8px;
  color: var(--color-text-dim);
  line-height: 1;
}

.step__note-btn {
  font-family: var(--font-ui);
  font-size: 10px;
  color: var(--color-text);
  background: #111;
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 3px 2px;
  width: 100%;
  text-align: center;
  transition: border-color 0.1s;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

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

.step__flags {
  display: flex;
  gap: 2px;
}

/* ── Toggle Buttons (R/A/S) ──────────────────────────────────────────────── */
.toggle-btn {
  width: 16px;
  height: 14px;
  border-radius: 2px;
  border: 1px solid var(--color-border);
  font-size: 8px;
  font-weight: bold;
  color: var(--color-text-dim);
  background: #0a0a0a;
  transition: all 0.1s;
  line-height: 1;
  padding: 0;
}

.toggle-btn:focus-visible {
  outline: 2px solid var(--color-accent);
  outline-offset: 2px;
}

.step__rest[aria-pressed="true"] {
  background: var(--color-flag-rest);
  border-color: var(--color-flag-rest);
  color: #fff;
}

.step__accent[aria-pressed="true"] {
  background: var(--color-flag-accent);
  border-color: var(--color-flag-accent);
  color: #111;
}

.step__slide[aria-pressed="true"] {
  background: var(--color-flag-slide);
  border-color: var(--color-flag-slide);
  color: #fff;
}

/* ── Note Editor Dialog ───────────────────────────────────────────────────── */
.note-editor {
  background: var(--color-panel);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  color: var(--color-text);
  padding: 0;
  max-width: 480px;
  width: 94vw;
}

.note-editor::backdrop {
  background: #00000099;
}

.note-editor__header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 10px 14px;
  border-bottom: 1px solid var(--color-border);
}

.note-editor__title {
  font-size: 11px;
  letter-spacing: 2px;
  color: var(--color-text-dim);
}

.note-editor__close {
  font-size: 18px;
  color: var(--color-text-dim);
  line-height: 1;
  padding: 0 4px;
}

.note-editor__close:hover { color: var(--color-text); }

.note-grid {
  display: grid;
  grid-template-columns: repeat(12, 1fr);
  gap: 3px;
  padding: 12px;
}

.note-grid__btn {
  padding: 6px 2px;
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  font-family: var(--font-ui);
  font-size: 9px;
  color: var(--color-text-dim);
  background: #111;
  text-align: center;
  transition: all 0.1s;
}

.note-grid__btn:hover {
  border-color: var(--color-accent);
  color: var(--color-accent);
  background: #e8520a10;
}

.note-grid__btn--sharp {
  background: #0d0d0d;
  color: #555;
}

.note-grid__btn--selected {
  border-color: var(--color-accent);
  background: var(--color-accent);
  color: #fff;
  box-shadow: 0 0 6px var(--color-accent-glow);
}