:root {
  --bg-main: #0f1115;
  --bg-card: #181b21;
  --bg-input: #1f232b;
  --border: #2a2f38;
  --text-main: #e4e6eb;
  --text-muted: #9ca3af;
  --accent: #4285f4; /* Google Blue */
  --accent-hover: #3367d6;
  --accent-glow: rgba(66, 133, 244, 0.4);
  --danger: #ea4335;
  --success: #34a853;
  --radius: 12px;
  --transition: 0.2s cubic-bezier(0.4, 0, 0.2, 1);
}

* { box-sizing: border-box; }

body {
  font-family: 'Google Sans', 'Inter', system-ui, sans-serif;
  background-color: var(--bg-main);
  color: var(--text-main);
  margin: 0;
  padding: 24px;
  line-height: 1.5;
}

header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 32px;
  padding-bottom: 24px;
  border-bottom: 1px solid var(--border);
}

h1, h2, h3 { margin: 0; font-weight: 500; }
h1 { font-size: 1.5rem; }
h2 { font-size: 1.25rem; }
h3 { font-size: 1.1rem; margin-bottom: 16px; }

nav { display: flex; gap: 8px; }

.tab-btn {
  padding: 8px 16px;
  background: transparent;
  border: 1px solid var(--border);
  color: var(--text-muted);
  border-radius: 8px;
  cursor: pointer;
  font-family: inherit;
  font-weight: 500;
  transition: var(--transition);
}

.tab-btn:hover { color: var(--text-main); border-color: #3a4049; }
.tab-btn.active { background: var(--accent); color: white; border-color: var(--accent); }

.view { display: none; animation: fadeIn 0.3s ease; }
.view.active { display: block; }

.panel-header { margin-bottom: 24px; }
.panel-header p { color: var(--text-muted); margin: 4px 0 0; font-size: 0.9rem; }

.glass-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 24px;
  margin-bottom: 24px;
}

.layout-grid {
  display: grid;
  grid-template-columns: 2fr 1fr;
  gap: 24px;
  align-items: start;
}

@media (max-width: 1024px) {
  .layout-grid { grid-template-columns: 1fr; }
}

.controls {
  display: flex;
  gap: 24px;
  align-items: flex-end;
  flex-wrap: wrap;
}

.control-group { display: flex; flex-direction: column; gap: 8px; }
.control-group label, .tempo-control label { font-size: 0.85rem; color: var(--text-muted); }

input, select {
  padding: 10px 12px;
  background: var(--bg-input);
  border: 1px solid var(--border);
  border-radius: 8px;
  color: var(--text-main);
  font-family: inherit;
  font-size: 0.95rem;
  outline: none;
  transition: var(--transition);
}

input:focus, select:focus { border-color: var(--accent); box-shadow: 0 0 0 3px var(--accent-glow); }

/* Segmented Control */
.segmented-control {
  display: flex;
  background: var(--bg-input);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 4px;
}

.seg-btn, .play-mode-btn {
  background: transparent;
  border: none;
  color: var(--text-muted);
  padding: 6px 12px;
  border-radius: 6px;
  cursor: pointer;
  font-family: inherit;
  transition: var(--transition);
}

.seg-btn.active, .play-mode-btn.active {
  background: var(--accent);
  color: white;
  box-shadow: 0 2px 4px rgba(0,0,0,0.2);
}

/* Piano */
.piano-keyboard {
  position: relative;
  height: 160px;
  display: flex;
  background: #000;
  padding: 12px;
  border-radius: 8px;
  box-shadow: inset 0 2px 10px rgba(0,0,0,0.5);
}

.key-white {
  flex-grow: 1;
  height: 100%;
  background: #f8f9fa;
  border: 1px solid #ccc;
  border-radius: 0 0 4px 4px;
  margin: 0 1px;
  display: flex;
  align-items: flex-end;
  justify-content: center;
  padding-bottom: 12px;
  font-size: 0.75rem;
  color: #333;
  cursor: pointer;
  position: relative;
  transition: background 0.1s;
}

.key-white:hover { background: #e0e0e0; }
.key-white.active { background: rgba(66, 133, 244, 0.2); border-color: var(--accent); }
.key-white.root-note { background: var(--accent); color: white; font-weight: bold; }
.key-white.highlight-chord { background: var(--success); color: white; box-shadow: 0 0 15px var(--success); }

.key-black {
  position: absolute;
  width: 6%;
  height: 60%;
  background: #222;
  border-radius: 0 0 3px 3px;
  z-index: 2;
  display: flex;
  align-items: flex-end;
  justify-content: center;
  padding-bottom: 6px;
  font-size: 0.65rem;
  color: #aaa;
  cursor: pointer;
}

.key-black:hover { background: #000; }
.key-black.active { background: #1a3a5c; }
.key-black.root-note { background: #0d47a1; color: white; }
.key-black.highlight-chord { background: var(--success); color: white; box-shadow: 0 0 15px var(--success); }

/* Degrees */
.degrees-wrap {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(140px, 1fr));
  gap: 12px;
}

.degree-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 16px;
  cursor: pointer;
  transition: var(--transition);
  text-align: center;
}

.degree-card:hover {
  transform: translateY(-2px);
  border-color: var(--accent);
  box-shadow: 0 4px 12px rgba(0,0,0,0.3);
}

.degree-card .numeral { font-size: 1.2rem; font-weight: bold; color: var(--accent); margin-bottom: 4px; }
.degree-card .chord-name { font-size: 1.1rem; font-weight: 500; margin-bottom: 8px; }
.degree-card .chord-notes { font-size: 0.75rem; color: var(--text-muted); }

/* Progression Builder */
.col-right { position: sticky; top: 24px; }
.section-header { display: flex; justify-content: space-between; align-items: center; margin-bottom: 16px; }

.text-btn { background: none; border: none; color: var(--text-muted); cursor: pointer; font-family: inherit; }
.text-btn:hover { color: var(--danger); }

.progression-wrap {
  min-height: 80px;
  background: var(--bg-input);
  border: 1px dashed var(--border);
  border-radius: 8px;
  padding: 16px;
  display: flex;
  gap: 12px;
  flex-wrap: wrap;
  align-items: center;
  margin-bottom: 20px;
}

.empty-prog { color: var(--text-muted); font-size: 0.9rem; }

.prog-chord {
  background: var(--bg-card);
  border: 1px solid var(--accent);
  color: var(--text-main);
  padding: 8px 12px;
  border-radius: 6px;
  font-weight: 500;
  display: flex;
  flex-direction: column;
  align-items: center;
  transition: var(--transition);
}

.prog-chord.playing {
  background: var(--accent);
  color: white;
  transform: scale(1.05);
  box-shadow: 0 0 15px var(--accent-glow);
}

.prog-chord .prog-numeral { font-size: 0.7rem; opacity: 0.8; margin-bottom: 2px; }

.playback-controls {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 16px;
  border-top: 1px solid var(--border);
  padding-top: 16px;
}

.tempo-control { display: flex; align-items: center; gap: 8px; }
.tempo-control input { width: 60px; text-align: center; }

.primary-btn {
  background: var(--accent);
  color: white;
  border: none;
  padding: 10px 24px;
  border-radius: 8px;
  font-weight: 600;
  cursor: pointer;
  transition: var(--transition);
}

.primary-btn:hover { background: var(--accent-hover); box-shadow: 0 4px 12px var(--accent-glow); }

/* Utilities for Reverb/EQ */
.secondary-btn {
  background: var(--bg-input);
  border: 1px solid var(--border);
  color: var(--text-main);
  padding: 8px 16px;
  border-radius: 6px;
  cursor: pointer;
  transition: var(--transition);
}
.secondary-btn:hover { border-color: var(--accent); color: var(--accent); }

table { width: 100%; border-collapse: collapse; }
th, td { padding: 12px; text-align: left; border-bottom: 1px solid var(--border); }
th { font-weight: 500; color: var(--text-muted); }

.presets-wrap, .bands-wrap {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(250px, 1fr));
  gap: 16px;
}

.preset-card, .band-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 16px;
}

.spectrum-container { margin-bottom: 24px; padding: 24px; }
.spectrum-labels { display: flex; justify-content: space-between; font-size: 0.8rem; color: var(--text-muted); margin-bottom: 8px; }
.spectrum-bar {
  height: 60px;
  background: linear-gradient(90deg, #ea4335, #fbbc05, #34a853, #4285f4);
  border-radius: 6px;
  position: relative;
  opacity: 0.8;
}
.spectrum-marker { position: absolute; top: 0; width: 2px; height: 100%; background: rgba(255,255,255,0.9); }
.spectrum-text { position: absolute; top: -24px; font-size: 0.75rem; font-weight: 500; color: white; background: #000; padding: 2px 6px; border-radius: 4px; transform: translateX(-50%); }

@keyframes fadeIn { from { opacity: 0; transform: translateY(10px); } to { opacity: 1; transform: translateY(0); } }