* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
  font-family: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
}

.page {
  background: #0f172a;
  border-radius: 24px;
  padding: 24px 20px 32px;
  width: 100%;
  box-shadow: 0 20px 40px rgba(0, 0, 0, 0.5);
  max-width: 1100px;
}

body {
  background: #050816;
  color: #ffffff;
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 16px;
}

.card {
  background: #0b1120;
  border-radius: 20px;
  padding: 20px;
  border: 1px solid rgba(255, 255, 255, 0.08);
}

.single-card {
  margin-top: 20px;
}

.card-title {
  text-align: center;
  font-size: 18px;
  margin-bottom: 12px;
}

h1 {
  text-align: center;
  font-size: 28px;
  margin-bottom: 4px;
}

.subtitle {
  text-align: center;
  font-size: 14px;
  color: #9ca3af;
  margin-bottom: 20px;
}

.label {
  display: block;
  margin-bottom: 8px;
  font-size: 15px;
}

#intervalSlider {
  width: 100%;
  margin: 10px 0 8px;
}

.value {
  text-align: center;
  font-size: 18px;
  margin-bottom: 20px;
}

.bpm-readout {
  text-align: center;
  font-size: 16px;
  color: #a5b4fc;
  margin-bottom: 18px;
}

.buttons {
  display: flex;
  justify-content: center;
  gap: 16px;
  margin-bottom: 12px;
}

.btn {
  padding: 10px 22px;
  border-radius: 999px;
  border: none;
  font-size: 16px;
  cursor: pointer;
  font-weight: 600;
}

.btn.start {
  background-color: #22c55e;
  color: #052e16;
}

.btn.playlist {
  background-color: #6366f1;
  color: #e0e7ff;
  width: 100%;
  margin-bottom: 12px;
}

.btn.playlist:active {
  background-color: #4338ca;
}

.btn.start:active,
.btn.start.pressed {
  background-color: #15803d;
  color: #f0fdf4;
}

.btn.stop {
  background-color: #ef4444;
  color: #450a0a;
}

.btn.stop:active,
.btn.stop.pressed {
  background-color: #b91c1c;
  color: #fee2e2;
}

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

.note {
  font-size: 12px;
  text-align: center;
  color: #9ca3af;
}

.note.small {
  font-size: 11px;
  margin-top: -6px;
  margin-bottom: 16px;
}

.playlist-status {
  min-height: 18px;
  text-align: center;
  font-size: 13px;
  color: #d1d5db;
  margin-bottom: 16px;
}

.playlist-status.loading {
  color: #facc15;
}

.playlist-status.success {
  color: #4ade80;
}

.playlist-status.error {
  color: #f87171;
}

.tone-controls {
  margin-top: 24px;
  padding: 16px;
  border-radius: 16px;
  background: #111b34;
  border: 1px solid rgba(255, 255, 255, 0.05);
}

.tone-controls h2 {
  font-size: 16px;
  margin-bottom: 12px;
  text-align: center;
}

.comments {
  margin-top: 32px;
  padding: 20px;
  border-radius: 20px;
  border: 1px solid rgba(255, 255, 255, 0.08);
  background: #0b1120;
}

.comments h2 {
  font-size: 18px;
  margin-bottom: 8px;
  text-align: center;
}

.comments p {
  text-align: center;
  color: #9ca3af;
  margin-bottom: 16px;
  font-size: 14px;
}