:root {
  --ink: #f4f6fa;
  --ink-muted: #9ba6b7;
  --canvas: #080b10;
  --card: #111720;
  --accent: #477bff;
  --hairline: rgba(255, 255, 255, 0.07);
  color-scheme: dark;
}

* { box-sizing: border-box; }

body {
  margin: 0;
  min-height: 100vh;
  background: var(--canvas);
  color: var(--ink);
  font: 17px/1.5 -apple-system, BlinkMacSystemFont, "SF Pro Text", "Segoe UI", Roboto, sans-serif;
  -webkit-font-smoothing: antialiased;
}

main { max-width: 560px; margin: 0 auto; padding: 48px 24px 64px; }
main.document { max-width: 720px; }

.mark {
  width: 48px; height: 48px; border-radius: 14px;
  display: grid; place-items: center;
  background: rgba(71, 123, 255, 0.12); color: var(--accent);
  font-weight: 700; font-size: 22px; letter-spacing: -0.5px;
}

h1 { font-size: 34px; line-height: 1.15; letter-spacing: -1px; margin: 28px 0 12px; font-weight: 600; }
h2 { font-size: 21px; margin: 32px 0 8px; font-weight: 600; }
p, li { color: var(--ink-muted); }
strong { color: var(--ink); font-weight: 600; }
a { color: var(--accent); }

.card {
  background: var(--card); border: 1px solid var(--hairline); border-radius: 16px;
  padding: 20px; margin: 24px 0;
}

.button {
  display: block; width: 100%; padding: 16px; margin: 12px 0 0;
  border: 0; border-radius: 16px; background: var(--accent); color: #fff;
  font: inherit; font-weight: 600; text-align: center; text-decoration: none; cursor: pointer;
}
.button.secondary { background: transparent; color: var(--accent); border: 1px solid var(--accent); }
.button[hidden] { display: none; }

.code {
  font: 14px/1.4 ui-monospace, "SF Mono", Menlo, monospace; color: var(--ink);
  word-break: break-all; background: var(--canvas); border: 1px solid var(--hairline);
  border-radius: 10px; padding: 12px; margin: 8px 0 0;
}

.steps { padding-left: 20px; }
.meta { font-size: 14px; }
.todo { background: rgba(255, 196, 0, 0.12); color: #ffd666; border-radius: 4px; padding: 0 4px; }
footer { margin-top: 48px; font-size: 14px; color: var(--ink-muted); }
footer a { color: var(--ink-muted); }