:root {
  color-scheme: light dark;
  --bg: #0b0d12;
  --card: #12151d;
  --text: #e6e8ee;
  --muted: #9aa3b2;
  --accent: #4f8cff;
  --border: #232838;
  --code-bg: #0a0c10;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  min-height: 100vh;
  display: grid;
  place-items: center;
  font-family: system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
  background: var(--bg);
  color: var(--text);
}

.card {
  width: min(520px, 92vw);
  padding: 2rem;
  border: 1px solid var(--border);
  border-radius: 14px;
  background: var(--card);
  box-shadow: 0 10px 40px rgba(0, 0, 0, 0.4);
}

h1 {
  margin: 0 0 0.5rem;
  font-size: 1.6rem;
}

p {
  margin: 0 0 1rem;
  color: var(--muted);
  line-height: 1.5;
}

code {
  background: var(--code-bg);
  border: 1px solid var(--border);
  border-radius: 4px;
  padding: 0.1rem 0.35rem;
}

button {
  padding: 0.6rem 1rem;
  border: 1px solid var(--border);
  border-radius: 8px;
  background: var(--accent);
  color: #fff;
  font-size: 1rem;
  cursor: pointer;
}

button:hover {
  filter: brightness(1.08);
}

button:active {
  transform: translateY(1px);
}

pre {
  margin: 1rem 0 0;
  padding: 0.8rem;
  border-radius: 8px;
  background: var(--code-bg);
  border: 1px solid var(--border);
  white-space: pre-wrap;
  word-break: break-word;
  min-height: 3rem;
}