:root {
  --bg: #0d1117;
  --surface: #161b22;
  --border: #30363d;
  --text: #e6edf3;
  --muted: #8b949e;
  --accent: #58a6ff;
  --green: #3fb950;
  --radius: 8px;
}

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

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

.container {
  max-width: 800px;
  margin: 0 auto;
  padding: 2rem 1.5rem;
}

h1 {
  font-size: 2rem;
  margin-bottom: 0.25rem;
}

h1 code {
  color: var(--accent);
  font-weight: 700;
}

.subtitle {
  color: var(--muted);
  margin-bottom: 2rem;
  font-size: 1.1rem;
}

h2 {
  font-size: 1.2rem;
  margin: 2rem 0 1rem;
  color: var(--muted);
  text-transform: uppercase;
  letter-spacing: 0.05em;
  font-weight: 600;
}

/* Checkbox grid */
.grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(140px, 1fr));
  gap: 0.5rem;
}

.grid label {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.5rem 0.75rem;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  cursor: pointer;
  transition: border-color 0.15s;
  font-size: 0.95rem;
}

.grid label:hover {
  border-color: var(--accent);
}

.grid input[type="checkbox"] {
  accent-color: var(--accent);
  width: 16px;
  height: 16px;
}

.grid input[type="checkbox"]:checked + span {
  color: var(--accent);
}

/* Command preview */
.command-box {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1rem 1.25rem;
  margin-top: 1rem;
  display: flex;
  align-items: center;
  gap: 0.75rem;
}

.command-box code {
  flex: 1;
  font-family: 'SF Mono', 'Fira Code', 'Cascadia Code', monospace;
  font-size: 0.95rem;
  color: var(--green);
  word-break: break-all;
}

.command-box .prefix {
  color: var(--muted);
  user-select: none;
}

button {
  background: var(--accent);
  color: var(--bg);
  border: none;
  border-radius: var(--radius);
  padding: 0.5rem 1rem;
  font-size: 0.85rem;
  font-weight: 600;
  cursor: pointer;
  transition: opacity 0.15s;
  white-space: nowrap;
}

button:hover { opacity: 0.85; }
button:active { opacity: 0.7; }

button.secondary {
  background: var(--surface);
  color: var(--text);
  border: 1px solid var(--border);
}

.btn-group {
  display: flex;
  gap: 0.5rem;
}

/* Instructions */
.steps {
  margin-top: 2rem;
  padding: 1.25rem;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
}

.steps ol {
  padding-left: 1.25rem;
}

.steps li {
  margin-bottom: 0.5rem;
  color: var(--muted);
}

.steps code {
  font-family: 'SF Mono', 'Fira Code', monospace;
  font-size: 0.85rem;
  color: var(--text);
  background: var(--bg);
  padding: 0.1rem 0.4rem;
  border-radius: 4px;
}

/* Footer */
footer {
  margin-top: 3rem;
  padding-top: 1.5rem;
  border-top: 1px solid var(--border);
  color: var(--muted);
  font-size: 0.85rem;
  text-align: center;
}

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

footer a:hover { text-decoration: underline; }

/* Responsive */
@media (max-width: 600px) {
  .container { padding: 1.5rem 1rem; }
  h1 { font-size: 1.5rem; }
  .grid { grid-template-columns: repeat(2, 1fr); }
}