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

:root {
  --bg: #0a0a0f;
  --surface: #12121a;
  --surface-2: #1a1a26;
  --border: #2a2a3d;
  --text: #e8e8f0;
  --text-muted: #8888a0;
  --accent: #ff6b35;
  --accent-glow: rgba(255, 107, 53, 0.35);
  --radius: 8px;
  --font-display: 'Syne', system-ui, sans-serif;
  --font-mono: 'JetBrains Mono', monospace;
}

html {
  font-size: 16px;
}

body {
  min-height: 100vh;
  background: var(--bg);
  background-image:
    radial-gradient(ellipse 80% 50% at 50% -20%, rgba(255, 107, 53, 0.12), transparent),
    radial-gradient(ellipse 60% 40% at 100% 100%, rgba(78, 205, 196, 0.06), transparent);
  color: var(--text);
  font-family: var(--font-mono);
  line-height: 1.5;
}

.app {
  max-width: 960px;
  margin: 0 auto;
  padding: 24px 20px 40px;
}

/* Header */
.header {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
  margin-bottom: 32px;
}

.header__brand {
  display: flex;
  align-items: center;
  gap: 14px;
}

.header__logo {
  font-size: 2rem;
  color: var(--accent);
  filter: drop-shadow(0 0 12px var(--accent-glow));
}

.header__title {
  font-family: var(--font-display);
  font-size: 1.75rem;
  font-weight: 800;
  letter-spacing: -0.02em;
}

.header__tagline {
  font-size: 0.75rem;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.08em;
}

.header__transport {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

/* Buttons */
.btn {
  padding: 10px 18px;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  background: var(--surface);
  color: var(--text);
  font-family: inherit;
  font-size: 0.8125rem;
  font-weight: 600;
  cursor: pointer;
  transition: background 0.15s, border-color 0.15s, transform 0.1s;
}

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

.btn:active {
  transform: scale(0.97);
}

.btn--primary {
  background: var(--accent);
  border-color: var(--accent);
  color: #0a0a0f;
}

.btn--primary:hover {
  background: #ff8555;
  border-color: #ff8555;
}

.btn--primary.btn--playing {
  background: #e05a2a;
  border-color: #e05a2a;
}

.btn--ghost {
  background: transparent;
}

.btn--accent {
  background: transparent;
  border-color: #4ecdc4;
  color: #4ecdc4;
}

.btn--accent:hover {
  background: rgba(78, 205, 196, 0.12);
  border-color: #4ecdc4;
}

.btn--accent:disabled {
  opacity: 0.5;
  cursor: wait;
}

.btn--small {
  padding: 6px 12px;
  font-size: 0.75rem;
}

/* Controls */
.controls {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 20px;
  margin-bottom: 28px;
  padding: 20px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 12px;
}

.control label {
  display: block;
  font-size: 0.6875rem;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--text-muted);
  margin-bottom: 8px;
}

.control__row {
  display: flex;
  align-items: center;
  gap: 10px;
}

.control input[type='range'] {
  flex: 1;
  height: 6px;
  appearance: none;
  background: var(--surface-2);
  border-radius: 3px;
  outline: none;
}

.control input[type='range']::-webkit-slider-thumb {
  appearance: none;
  width: 16px;
  height: 16px;
  border-radius: 50%;
  background: var(--accent);
  cursor: pointer;
  box-shadow: 0 0 8px var(--accent-glow);
}

.control output {
  min-width: 2.5rem;
  font-weight: 700;
  color: var(--accent);
}

.control__unit {
  font-size: 0.75rem;
  color: var(--text-muted);
}

.control select {
  flex: 1;
  padding: 8px 12px;
  background: var(--surface-2);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  color: var(--text);
  font-family: inherit;
  font-size: 0.8125rem;
}

/* Sequencer */
.sequencer {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 20px;
  overflow-x: auto;
}

.sequencer__labels {
  display: flex;
  flex-direction: column;
  gap: 6px;
  margin-bottom: 8px;
  padding-left: 0;
}

.track-label {
  display: flex;
  align-items: center;
  gap: 10px;
  height: 36px;
}

.track-label__name {
  font-size: 0.75rem;
  font-weight: 600;
  min-width: 72px;
}

.pad {
  width: 36px;
  height: 36px;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  background: var(--surface-2);
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: transform 0.1s, box-shadow 0.15s;
}

.pad__dot {
  width: 10px;
  height: 10px;
  border-radius: 50%;
  background: var(--track-color, var(--accent));
  opacity: 0.7;
}

.pad:hover {
  border-color: var(--track-color, var(--accent));
}

.pad--hit {
  transform: scale(0.92);
  box-shadow: 0 0 16px color-mix(in srgb, var(--track-color, var(--accent)) 50%, transparent);
}

.sequencer__grid-wrap {
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.sequencer__beats {
  display: grid;
  grid-template-columns: repeat(16, 1fr);
  gap: 4px;
  margin-left: 82px;
  margin-bottom: 4px;
}

.beat-marker {
  font-size: 0.625rem;
  color: var(--text-muted);
  text-align: center;
  height: 16px;
}

.beat-marker--downbeat {
  color: var(--accent);
  font-weight: 700;
}

.sequencer__grid {
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.grid-row {
  display: grid;
  grid-template-columns: repeat(16, 1fr);
  gap: 4px;
  margin-left: 82px;
}

.step {
  aspect-ratio: 1;
  min-width: 28px;
  min-height: 28px;
  border: 1px solid var(--border);
  border-radius: 4px;
  background: var(--surface-2);
  cursor: pointer;
  transition: background 0.1s, border-color 0.1s, box-shadow 0.15s;
}

.step:hover {
  border-color: var(--text-muted);
}

.step--active {
  background: color-mix(in srgb, var(--track-color, var(--accent)) 35%, var(--surface-2));
  border-color: var(--track-color, var(--accent));
  box-shadow: inset 0 0 8px color-mix(in srgb, var(--track-color, var(--accent)) 30%, transparent);
}

.step--playing {
  box-shadow: 0 0 12px var(--accent-glow);
  border-color: var(--accent);
}

/* Align labels with grid rows */
.sequencer {
  display: grid;
  grid-template-columns: auto 1fr;
  grid-template-rows: auto 1fr;
  gap: 0 12px;
}

.sequencer__labels {
  grid-column: 1;
  grid-row: 2;
  margin-bottom: 0;
  padding-top: 24px;
}

.sequencer__grid-wrap {
  grid-column: 2;
  grid-row: 1 / 3;
}

.sequencer__beats {
  margin-left: 0;
}

.grid-row {
  margin-left: 0;
}

/* Footer */
.footer {
  margin-top: 24px;
  text-align: center;
  font-size: 0.75rem;
  color: var(--text-muted);
}

.footer kbd {
  padding: 2px 6px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 4px;
  font-family: inherit;
  font-size: 0.6875rem;
}

/* Responsive */
@media (max-width: 640px) {
  .header {
    flex-direction: column;
    align-items: flex-start;
  }

  .sequencer {
    grid-template-columns: 1fr;
  }

  .sequencer__labels {
    grid-row: 1;
    flex-direction: row;
    flex-wrap: wrap;
    padding-top: 0;
    margin-bottom: 16px;
  }

  .track-label {
    flex-direction: column;
    height: auto;
    gap: 4px;
  }

  .sequencer__grid-wrap {
    grid-column: 1;
    grid-row: 2;
  }

  .step {
    min-width: 22px;
    min-height: 22px;
  }
}