:root {
  --ground: #f4f5f1;
  --surface: #ffffff;
  --ink: #13201c;
  --secondary: #3e4b46;
  --tertiary: #56645f;
  --line: #dfe3dd;
  --brand: #0b6e58;
  --brand-tint: #e3f2ec;
}

@media (prefers-color-scheme: dark) {
  :root {
    --ground: #0d1513;
    --surface: #15201d;
    --ink: #eef2ef;
    --secondary: #c3ccc8;
    --tertiary: #9aa6a1;
    --line: #26332f;
    --brand: #5cc8a8;
    --brand-tint: #17332b;
  }
}

* { box-sizing: border-box; }

html { -webkit-text-size-adjust: 100%; }

body {
  margin: 0;
  background: var(--ground);
  color: var(--ink);
  font: 17px/1.6 "Be Vietnam Pro", -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
}

main {
  max-width: 720px;
  margin: 0 auto;
  padding: 48px 16px 64px;
}

header.brand {
  display: flex;
  align-items: center;
  gap: 14px;
  margin-bottom: 32px;
}

header.brand img { width: 52px; height: 52px; border-radius: 12px; }
header.brand a { color: inherit; text-decoration: none; font-weight: 700; font-size: 22px; }

h1 { font-size: 32px; line-height: 1.2; margin: 0 0 8px; letter-spacing: -0.01em; }
h2 { font-size: 21px; margin: 36px 0 8px; }
h3 { font-size: 17px; margin: 24px 0 4px; }
p, li { color: var(--secondary); }
ul { padding-left: 22px; }
li { margin: 4px 0; }
strong { color: var(--ink); }
a { color: var(--brand); }

.meta { color: var(--tertiary); font-size: 15px; margin: 0 0 24px; }

nav.lang {
  display: inline-flex;
  gap: 4px;
  padding: 4px;
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: 999px;
  margin-bottom: 8px;
}

nav.lang a {
  padding: 6px 14px;
  border-radius: 999px;
  text-decoration: none;
  font-size: 15px;
  font-weight: 600;
}

nav.lang a:hover { background: var(--brand-tint); }

section.lang { padding-top: 16px; }
section.lang + section.lang { border-top: 1px solid var(--line); margin-top: 48px; }

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

.card > :first-child { margin-top: 0; }
.card > :last-child { margin-bottom: 0; }

.links { display: grid; gap: 12px; margin-top: 24px; }
.links a {
  display: block;
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: 14px;
  padding: 16px 20px;
  text-decoration: none;
  font-weight: 600;
}
.links a span { display: block; color: var(--tertiary); font-weight: 400; font-size: 15px; }

footer { margin-top: 56px; color: var(--tertiary); font-size: 14px; }