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

:root {
  --bg: #f8f9fa;
  --bg-panel: #ffffff;
  --bg-hover: #f1f3f5;
  --text: #1e1e1e;
  --text-muted: #868e96;
  --border: #dee2e6;
  --shadow: rgba(0,0,0,0.10);
  --shadow-lg: rgba(0,0,0,0.15);
  --accent: #1971c2;
  --badge-input: #2f9e44;
  --badge-output: #9c36b5;
  --badge-transverse: #495057;
}

[data-theme="dark"] {
  --bg: #1a1b1e;
  --bg-panel: #25262b;
  --bg-hover: #2c2e33;
  --text: #c1c2c5;
  --text-muted: #868e96;
  --border: #373a40;
  --shadow: rgba(0,0,0,0.30);
  --shadow-lg: rgba(0,0,0,0.45);
  --accent: #74c0fc;
}

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

a { color: var(--accent); text-decoration: none; }
a:hover { text-decoration: underline; }

button {
  cursor: pointer;
  font-family: inherit;
}

/* Scrollbar */
::-webkit-scrollbar { width: 6px; }
::-webkit-scrollbar-track { background: transparent; }
::-webkit-scrollbar-thumb { background: var(--border); border-radius: 3px; }