* { box-sizing: border-box; }

:root {
  --bg: #f5f5f7;
  --bg-card: #ffffff;
  --bg-input: #f0f0f3;
  --border: #d0d0d5;
  --border-hover: #6c63ff;
  --text: #1a1a2e;
  --text-secondary: #666;
  --text-muted: #999;
  --accent: #6c63ff;
  --slider-track: #d0d0d5;
  --shadow: rgba(0,0,0,0.06);
}

[data-theme="dark"] {
  --bg: #0f0f1a;
  --bg-card: #1a1a2e;
  --bg-input: #1a1a2e;
  --border: #2a2a4a;
  --border-hover: #6c63ff;
  --text: #e0e0e0;
  --text-secondary: #888;
  --text-muted: #555;
  --accent: #6c63ff;
  --slider-track: #2a2a4a;
  --shadow: rgba(0,0,0,0.3);
}

body {
  margin: 0;
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  background: var(--bg);
  color: var(--text);
  min-height: 100vh;
  transition: background 0.2s, color 0.2s;
}

.theme-toggle {
  position: fixed;
  top: 16px;
  right: 16px;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 6px 12px;
  cursor: pointer;
  font-size: 18px;
  z-index: 100;
  transition: all 0.2s;
}
.theme-toggle:hover { border-color: var(--accent); }