:root { color-scheme: dark; --bg: #0d1117; --fg: #e6edf3; --accent: #58a6ff; }
* { box-sizing: border-box; }
body { margin: 0; background: var(--bg); color: var(--fg); font: 16px/1.4 system-ui, sans-serif; }
header { padding: 1rem 1.5rem; }
h1 { margin: 0; color: var(--accent); }
header p { margin: .25rem 0 0; opacity: .7; }
main { display: grid; place-items: center; padding: 0 1rem 1rem; }
canvas { max-width: 100%; height: auto; background: #010409; border: 1px solid #30363d; border-radius: 8px; }