:root {
  --bg: #f4f7fa;
  --bg-elev: #ffffff;
  --fg: #0f1a24;
  --fg-muted: #566371;
  --line: #d8e0e7;
  --accent: #0b7f8a;
  --accent-ink: #ffffff;
  color-scheme: light;
}
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --bg: #0b1418;
    --bg-elev: #131c20;
    --fg: #e3e9ec;
    --fg-muted: #93a0a8;
    --line: #26323a;
    --accent: #4fd1dc;
    --accent-ink: #00363b;
    color-scheme: dark;
  }
}
:root[data-theme="dark"] {
  --bg: #0b1418;
  --bg-elev: #131c20;
  --fg: #e3e9ec;
  --fg-muted: #93a0a8;
  --line: #26323a;
  --accent: #4fd1dc;
  --accent-ink: #00363b;
  color-scheme: dark;
}

*, *::before, *::after { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--fg);
  font: 16px/1.65 system-ui, -apple-system, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
}
a { color: var(--accent); }
.wrap { max-width: 760px; margin: 0 auto; padding: 0 16px; }

.nav { border-bottom: 1px solid var(--line); background: var(--bg-elev); }
.nav .wrap { display: flex; align-items: center; gap: 16px; height: 64px; }
.brand { display: flex; align-items: center; gap: 10px; text-decoration: none; color: var(--fg); font-weight: 700; }
.brand img { width: 30px; height: 30px; border-radius: 8px; }
.lang { margin-left: auto; display: inline-flex; border: 1px solid var(--line); border-radius: 999px; padding: 3px; }
.lang button {
  border: 0;
  background: none;
  color: var(--fg-muted);
  font: inherit;
  font-size: 13px;
  font-weight: 600;
  padding: 4px 10px;
  border-radius: 999px;
  cursor: pointer;
  min-width: 40px;
}
.lang button[aria-pressed="true"] { background: var(--accent); color: var(--accent-ink); }

main.wrap { padding-top: 48px; padding-bottom: 24px; }
article + article { margin-top: 64px; padding-top: 40px; border-top: 1px solid var(--line); }
article[hidden] + article { margin-top: 0; padding-top: 0; border-top: 0; }
h1 { font-size: clamp(28px, 4vw, 36px); line-height: 1.15; letter-spacing: -.02em; margin: 0 0 6px; }
.updated { color: var(--fg-muted); font-size: 14px; margin: 0 0 28px; }
.summary {
  background: var(--bg-elev);
  border: 1px solid var(--line);
  border-left: 3px solid var(--accent);
  border-radius: 12px;
  padding: 14px 18px;
  margin: 0 0 32px;
}
h2 { font-size: 19px; letter-spacing: -.01em; margin: 32px 0 8px; }
p, li { color: var(--fg); }
ul { padding-left: 22px; }
li + li { margin-top: 6px; }
.muted { color: var(--fg-muted); }

footer { padding: 32px 0 48px; color: var(--fg-muted); font-size: 14px; }
footer .wrap { display: flex; flex-wrap: wrap; gap: 8px 20px; border-top: 1px solid var(--line); padding-top: 20px; }
footer a { color: var(--fg-muted); }
:focus-visible { outline: 2px solid var(--accent); outline-offset: 2px; border-radius: 6px; }