:root {
  --bg-primary: #0d0d0d;
  --bg-card: #1a1a2e;
  --bg-panel: #141422;
  --accent: #d4a017;
  --accent-hover: #e8b52a;
  --text: #e0e0e0;
  --text-muted: #888;
  --border: #2a2a3e;
}

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

body {
  background: var(--bg-primary);
  color: var(--text);
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  min-height: 100vh;
  display: flex;
  justify-content: center;
  align-items: flex-start;
  padding-top: 8vh;
}

.container {
  max-width: 640px;
  width: 100%;
  padding: 2rem 1.5rem;
}

/* Header */
header {
  text-align: center;
  margin-bottom: 2.5rem;
}

h1 {
  font-size: 2.8rem;
  font-weight: 800;
  letter-spacing: 0.15em;
  color: var(--accent);
  margin-bottom: 0.25rem;
}

.subtitle {
  font-size: 0.95rem;
  color: var(--text-muted);
  margin-bottom: 1rem;
}

.formula {
  font-family: 'SF Mono', 'JetBrains Mono', 'Fira Code', monospace;
  font-size: 1.05rem;
  color: var(--accent);
  letter-spacing: 0.08em;
  opacity: 0.85;
}

/* Generator Panel */
.generator-panel {
  display: flex;
  gap: 1rem;
  align-items: flex-end;
  justify-content: center;
  margin-bottom: 2rem;
}

.key-selector {
  display: flex;
  flex-direction: column;
  gap: 0.4rem;
}

.key-selector label {
  font-size: 0.8rem;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.1em;
}

.key-selector select {
  background: var(--bg-card);
  color: var(--text);
  border: 1px solid var(--border);
  border-radius: 6px;
  padding: 0.6rem 2rem 0.6rem 0.8rem;
  font-size: 1rem;
  cursor: pointer;
  appearance: none;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='8'%3E%3Cpath d='M1 1l5 5 5-5' stroke='%23888' stroke-width='1.5' fill='none'/%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: right 0.7rem center;
}

.key-selector select:focus {
  outline: none;
  border-color: var(--accent);
}

/* Buttons */
.btn-primary,
.btn-download {
  border: none;
  border-radius: 6px;
  padding: 0.65rem 1.8rem;
  font-size: 0.95rem;
  font-weight: 600;
  cursor: pointer;
  transition: background 0.2s, transform 0.1s;
}

.btn-primary {
  background: var(--accent);
  color: #000;
}

.btn-primary:hover {
  background: var(--accent-hover);
  transform: scale(1.02);
}

.btn-primary:active {
  transform: scale(0.98);
}

.btn-download {
  background: transparent;
  color: var(--accent);
  border: 1.5px solid var(--accent);
  padding: 0.6rem 2rem;
}

.btn-download:hover:not(:disabled) {
  background: var(--accent);
  color: #000;
}

.btn-download:disabled {
  opacity: 0.35;
  cursor: not-allowed;
}

/* Chord Display */
.chord-display {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 0.4rem;
  flex-wrap: wrap;
  margin-bottom: 2rem;
  min-height: 80px;
}

.chord-display.hidden {
  display: none;
}

.chord-arrow {
  color: var(--text-muted);
  font-size: 1.2rem;
  opacity: 0.5;
}

.chord-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 0.7rem 0.9rem;
  text-align: center;
  min-width: 72px;
  display: flex;
  flex-direction: column;
  gap: 0.2rem;
  transition: border-color 0.2s;
}

.chord-card:hover {
  border-color: var(--accent);
}

.chord-card .degree {
  font-size: 0.65rem;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.chord-card .name {
  font-size: 1.1rem;
  font-weight: 700;
  color: var(--accent);
  font-family: 'SF Mono', 'JetBrains Mono', 'Fira Code', monospace;
}

.chord-card .beats {
  font-size: 0.6rem;
  color: var(--text-muted);
}

/* Download Section */
.download-section {
  text-align: center;
  margin-bottom: 2rem;
}

.download-section.hidden {
  display: none;
}

.status-text {
  margin-top: 0.8rem;
  font-size: 0.85rem;
  color: var(--text-muted);
}

/* Footer */
footer {
  text-align: center;
  padding-top: 2rem;
  border-top: 1px solid var(--border);
}

footer p {
  font-size: 0.75rem;
  color: var(--text-muted);
  letter-spacing: 0.03em;
}

/* Responsive */
@media (max-width: 480px) {
  body {
    padding-top: 4vh;
  }

  h1 {
    font-size: 2.2rem;
  }

  .generator-panel {
    flex-direction: column;
    align-items: stretch;
  }

  .btn-primary {
    width: 100%;
  }

  .chord-card {
    min-width: 58px;
    padding: 0.5rem 0.6rem;
  }

  .chord-card .name {
    font-size: 0.95rem;
  }
}