:root {
  --bg-primary: #0f172a;
  --bg-secondary: #1e293b;
  --bg-card: #1e293b;
  --bg-hover: #334155;
  --text-primary: #e2e8f0;
  --text-secondary: #94a3b8;
  --text-muted: #64748b;
  --accent-blue: #3b82f6;
  --accent-green: #10b981;
  --accent-yellow: #f59e0b;
  --border-color: #334155;
}

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

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  background: var(--bg-primary);
  color: var(--text-primary);
  min-height: 100vh;
  line-height: 1.6;
}

.dla-container { max-width: 1400px; margin: 0 auto; padding: 20px; }

header { text-align: center; margin-bottom: 24px; }
header h1 {
  font-size: 1.8rem; font-weight: 700;
  background: linear-gradient(135deg, var(--accent-blue), var(--accent-green));
  -webkit-background-clip: text; -webkit-text-fill-color: transparent; background-clip: text;
  margin-bottom: 6px;
}
header .subtitle { color: var(--text-secondary); font-size: 0.95rem; }

.main-layout { display: grid; grid-template-columns: 1fr 320px; gap: 20px; }
@media (max-width: 1024px) { .main-layout { grid-template-columns: 1fr; } }

.canvas-section {
  background: var(--bg-card); border-radius: 12px; border: 1px solid var(--border-color); overflow: hidden;
}
.canvas-wrapper { position: relative; width: 100%; aspect-ratio: 1 / 1; min-height: 400px; background: #000; }
.canvas-wrapper canvas { width: 100%; height: 100%; display: block; }

.legend-bar {
  display: flex; flex-wrap: wrap; gap: 16px; padding: 12px 16px;
  background: var(--bg-secondary); border-top: 1px solid var(--border-color);
  font-size: 0.8rem; color: var(--text-secondary);
}
.legend-item { display: flex; align-items: center; gap: 6px; }
.legend-swatch { width: 16px; height: 12px; border-radius: 2px; }

.controls-panel { display: flex; flex-direction: column; gap: 16px; }

.control-card {
  background: var(--bg-card); border-radius: 12px; border: 1px solid var(--border-color); padding: 16px;
}
.control-card h3 {
  font-size: 0.85rem; font-weight: 600; color: var(--text-secondary);
  text-transform: uppercase; letter-spacing: 0.05em; margin-bottom: 12px;
}

.preset-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 8px; }
.preset-grid .preset-btn:last-child:nth-child(odd) { grid-column: 1 / -1; }
.preset-btn {
  background: var(--bg-primary); border: 1px solid var(--border-color); border-radius: 8px;
  padding: 10px 8px; color: var(--text-primary); font-size: 0.8rem; cursor: pointer;
  transition: all 0.2s; text-align: center;
}
.preset-btn:hover { background: var(--bg-hover); border-color: var(--accent-blue); }
.preset-btn.active { background: rgba(59,130,246,0.15); border-color: var(--accent-blue); color: var(--accent-blue); }
.preset-btn .preset-name { display: block; font-weight: 600; margin-bottom: 2px; }
.preset-btn .preset-desc { font-size: 0.7rem; color: var(--text-muted); }

.slider-group { margin-bottom: 14px; }
.slider-group:last-child { margin-bottom: 0; }
.slider-label {
  display: flex; justify-content: space-between; align-items: center;
  font-size: 0.8rem; color: var(--text-secondary); margin-bottom: 6px;
}
.slider-value { font-weight: 600; color: var(--text-primary); min-width: 60px; text-align: right; }

input[type="range"] {
  width: 100%; height: 6px; -webkit-appearance: none; appearance: none;
  background: var(--bg-primary); border-radius: 3px; outline: none;
}
input[type="range"]::-webkit-slider-thumb {
  -webkit-appearance: none; width: 16px; height: 16px; border-radius: 50%;
  background: var(--accent-blue); cursor: pointer; transition: transform 0.15s;
}
input[type="range"]::-webkit-slider-thumb:hover { transform: scale(1.2); }
input[type="range"]::-moz-range-thumb {
  width: 16px; height: 16px; border-radius: 50%; background: var(--accent-blue); cursor: pointer; border: none;
}

.select-control {
  width: 100%; padding: 8px 12px;
  background: var(--bg-primary); border: 1px solid var(--border-color); border-radius: 8px;
  color: var(--text-primary); font-size: 0.85rem;
  cursor: pointer; outline: none; transition: border-color 0.2s;
  -webkit-appearance: none; appearance: none;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='12' viewBox='0 0 12 12'%3E%3Cpath fill='%2394a3b8' d='M6 8L1 3h10z'/%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: right 12px center;
  padding-right: 32px;
}
.select-control:focus { border-color: var(--accent-blue); }

.toggle-group { display: flex; gap: 8px; }
.toggle-btn {
  flex: 1; padding: 8px 12px; background: var(--bg-primary); border: 1px solid var(--border-color);
  border-radius: 8px; color: var(--text-secondary); font-size: 0.8rem; cursor: pointer; transition: all 0.2s;
}
.toggle-btn:hover { background: var(--bg-hover); }
.toggle-btn.active { background: rgba(59,130,246,0.15); border-color: var(--accent-blue); color: var(--accent-blue); }

.playback-controls { display: flex; gap: 8px; }
.play-btn, .step-btn, .reset-btn-inline {
  flex: 1; padding: 10px; background: var(--bg-primary); border: 1px solid var(--border-color);
  border-radius: 8px; color: var(--text-secondary); cursor: pointer; transition: all 0.2s;
  display: flex; align-items: center; justify-content: center;
}
.play-btn:hover, .step-btn:hover, .reset-btn-inline:hover { background: var(--bg-hover); color: var(--text-primary); }
.play-btn.playing { background: rgba(16,185,129,0.15); border-color: var(--accent-green); color: var(--accent-green); }

.stats-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 8px; }
.stat-item { background: var(--bg-primary); border-radius: 8px; padding: 10px; text-align: center; }
.stat-label { font-size: 0.7rem; color: var(--text-muted); margin-bottom: 4px; }
.stat-value { font-size: 1.1rem; font-weight: 700; color: var(--accent-blue); }

.reset-btn {
  width: 100%; padding: 10px; background: var(--bg-primary); border: 1px solid var(--border-color);
  border-radius: 8px; color: var(--text-secondary); font-size: 0.85rem; cursor: pointer; transition: all 0.2s;
}
.reset-btn:hover { background: var(--bg-hover); color: var(--text-primary); }

.explanation {
  background: var(--bg-card); border-radius: 12px; border: 1px solid var(--border-color);
  padding: 24px; margin-top: 20px;
}
.explanation h2 { font-size: 1.1rem; margin-bottom: 16px; color: var(--text-primary); }
.explanation p { color: var(--text-secondary); font-size: 0.9rem; margin-bottom: 12px; line-height: 1.7; }
.explanation p:last-child { margin-bottom: 0; }
.explanation .how-to-use {
  background: var(--bg-primary); padding: 12px 16px; border-radius: 8px;
  border-left: 3px solid var(--accent-blue); margin-top: 8px;
}

@media (max-width: 768px) {
  .dla-container { padding: 12px; }
  header h1 { font-size: 1.4rem; }
  .canvas-wrapper { aspect-ratio: 1 / 1; min-height: 300px; }
  .preset-grid { grid-template-columns: 1fr; }
  .preset-grid .preset-btn:last-child:nth-child(odd) { grid-column: auto; }
}