*, *::before, *::after { box-sizing: border-box; }
body { margin: 0; font: 17px/1.6 system-ui, -apple-system, "Segoe UI", Roboto, sans-serif; color: #10202b; background: #f4f8fa; }
header { display: flex; align-items: center; justify-content: space-between; max-width: 820px; margin: 0 auto; padding: 20px; }
.brand { font-weight: 700; color: #0a6f8f; text-decoration: none; }
nav a { margin-left: 18px; color: #10202b; }
main { max-width: 820px; margin: 0 auto; padding: 0 20px 64px; }
figure { margin: 0 0 28px; }
img { display: block; width: 100%; height: auto; border-radius: 10px; }
figcaption { margin-top: 8px; font-size: 14px; color: #557080; }
h1 { font-size: 34px; line-height: 1.2; margin: 0 0 12px; }
code { padding: 1px 5px; border-radius: 4px; background: #e2edf2; font-size: 0.9em; }
.checks { padding-left: 20px; }
.checks li { margin: 6px 0; }