:root {
  color-scheme: light dark;
  --ground: #F4F5F7; --surface: #FFFFFF; --ink: #1B2230; --muted: #535D6E; --line: #D9DEE6; --blue-text: #21468B;
  --sans: "Source Sans 3", "Segoe UI", system-ui, -apple-system, sans-serif;
  --serif: "Source Serif 4", Georgia, "Times New Roman", serif;
}
:root[data-theme="dark"] { --ground: #0F141D; --surface: #171D29; --ink: #E7EBF2; --muted: #A4AEC0; --line: #2A3344; --blue-text: #9DB4EC; }
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) { --ground: #0F141D; --surface: #171D29; --ink: #E7EBF2; --muted: #A4AEC0; --line: #2A3344; --blue-text: #9DB4EC; }
}
* { box-sizing: border-box; }
body { margin: 0; background: var(--ground); color: var(--ink); font: 17px/1.6 var(--sans); }
main { max-width: 760px; margin: 0 auto; padding: 32px 24px 64px; }
.back { display: inline-block; margin-bottom: 20px; color: var(--blue-text); }
h1 { font-family: var(--serif); font-size: 32px; line-height: 1.2; margin: 0 0 16px; }
h2 { font-family: var(--serif); font-size: 21px; margin: 32px 0 8px; }
p { margin: 0 0 12px; }
a { color: var(--blue-text); }
.stand { color: var(--muted); font-size: 15px; }
.inline-btn { font: inherit; padding: 6px 14px; border: 1px solid var(--blue-text); border-radius: 4px; background: transparent; color: var(--blue-text); cursor: pointer; margin-left: 6px; }
code { font-size: 0.92em; }