:root {
  --bg: #f3f4f8;
  --panel: #ffffff;
  --ink: #1f2333;
  --muted: #6b7280;
  --accent: #4f46e5;
  --accent-dark: #4338ca;
  --border: #e2e4ec;
  --shadow: 0 1px 3px rgba(31, 35, 51, 0.08), 0 8px 24px rgba(31, 35, 51, 0.06);
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  min-height: 100vh;
  background: var(--bg);
  color: var(--ink);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
}

.app {
  max-width: 1000px;
  margin: 0 auto;
  padding: 40px 24px 80px;
}

.app-header {
  text-align: center;
  margin-bottom: 32px;
}

.app-header h1 {
  margin: 0 0 6px;
  font-size: 2rem;
  letter-spacing: -0.02em;
}

.subtitle {
  margin: 0;
  color: var(--muted);
  font-size: 0.95rem;
}

.controls {
  display: flex;
  flex-wrap: wrap;
  align-items: flex-end;
  gap: 24px;
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: 14px;
  padding: 20px 24px;
  box-shadow: var(--shadow);
  margin-bottom: 28px;
}

.control-group {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.control-group label {
  font-size: 0.8rem;
  font-weight: 600;
  color: var(--muted);
  text-transform: uppercase;
  letter-spacing: 0.04em;
}

#tempo-value {
  color: var(--ink);
  font-weight: 700;
}

select,
input[type="range"] {
  font-family: inherit;
}

select {
  padding: 9px 12px;
  border-radius: 8px;
  border: 1px solid var(--border);
  background: #fff;
  font-size: 0.95rem;
  min-width: 160px;
  color: var(--ink);
}

input[type="range"] {
  width: 200px;
  accent-color: var(--accent);
}

.toggle-label {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 0.8rem;
  font-weight: 600;
  color: var(--muted);
  text-transform: uppercase;
  letter-spacing: 0.04em;
  cursor: pointer;
  white-space: nowrap;
}

.toggle-switch {
  position: relative;
  display: inline-block;
  width: 38px;
  height: 22px;
  flex-shrink: 0;
}

.toggle-switch input[type="checkbox"] {
  position: absolute;
  inset: 0;
  margin: 0;
  opacity: 0;
  cursor: pointer;
}

.toggle-track {
  position: absolute;
  inset: 0;
  background: #d1d3dd;
  border-radius: 999px;
  transition: background-color 0.15s ease;
}

.toggle-track::before {
  content: "";
  position: absolute;
  top: 2px;
  left: 2px;
  width: 18px;
  height: 18px;
  background: #fff;
  border-radius: 50%;
  box-shadow: 0 1px 2px rgba(31, 35, 51, 0.3);
  transition: transform 0.15s ease;
}

.toggle-switch input[type="checkbox"]:checked + .toggle-track {
  background: var(--accent);
}

.toggle-switch input[type="checkbox"]:checked + .toggle-track::before {
  transform: translateX(16px);
}

.toggle-switch input[type="checkbox"]:focus-visible + .toggle-track {
  outline: 2px solid var(--accent);
  outline-offset: 2px;
}

/* Playhead tracking: the notehead currently being played turns red. */
.playhead-active .vf-notehead path,
.playhead-active .vf-notehead ellipse {
  fill: #dc2626;
  stroke: #dc2626;
}

.buttons {
  flex-direction: row;
  gap: 10px;
  margin-left: auto;
}

.btn {
  border: none;
  border-radius: 8px;
  padding: 10px 20px;
  font-size: 0.95rem;
  font-weight: 600;
  cursor: pointer;
  transition: background-color 0.15s ease, transform 0.05s ease, opacity 0.15s ease;
}

.btn:active {
  transform: translateY(1px);
}

.btn:disabled {
  opacity: 0.6;
  cursor: default;
}

.btn-primary {
  background: var(--accent);
  color: #fff;
}

.btn-primary:hover:not(:disabled) {
  background: var(--accent-dark);
}

.btn-secondary {
  background: #eef0fb;
  color: var(--accent-dark);
}

.btn-secondary:hover:not(:disabled) {
  background: #e0e3f9;
}

.btn-ghost {
  background: transparent;
  color: var(--muted);
  border: 1px solid var(--border);
}

.btn-ghost:hover:not(:disabled) {
  background: #f0f1f5;
}

.seed-panel {
  align-items: flex-start;
}

.file-btn {
  display: inline-flex;
  align-items: center;
}

.seed-list-wrap {
  flex-basis: 100%;
}

.seed-empty-msg {
  margin: 0;
  color: var(--muted);
  font-size: 0.9rem;
}

.seed-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.seed-item {
  display: flex;
  align-items: center;
  gap: 8px;
  background: #eef0fb;
  border-radius: 999px;
  padding: 6px 8px 6px 14px;
  font-size: 0.85rem;
  color: var(--ink);
}

.seed-item-name {
  font-weight: 600;
}

.seed-item-meta {
  color: var(--muted);
}

.seed-item-remove {
  border: none;
  background: transparent;
  color: var(--muted);
  cursor: pointer;
  font-size: 1rem;
  line-height: 1;
  padding: 2px 4px;
  border-radius: 50%;
}

.seed-item-remove:hover {
  background: #d9dcf3;
  color: var(--ink);
}

.score-panel {
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: 14px;
  padding: 24px;
  box-shadow: var(--shadow);
  overflow-x: auto;
}

.score {
  display: flex;
  justify-content: center;
  min-width: fit-content;
}

@media (max-width: 640px) {
  .controls {
    flex-direction: column;
    align-items: stretch;
  }

  .buttons {
    margin-left: 0;
    justify-content: flex-end;
  }

  input[type="range"] {
    width: 100%;
  }
}