:root {
  color-scheme: light;
  --bg: #ffffff;
  --surface: #f2f3f5;
  --text: #111214;
  --muted: #5f6166;
  --line: #e4e5e8;
  --accent: #00785f;
}

@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    color-scheme: dark;
    --bg: #121212;
    --surface: #1c1c1e;
    --text: #f5f5f7;
    --muted: #9a9aa0;
    --line: #2a2a2d;
    --accent: #2ecfa8;
  }
}

:root[data-theme="dark"] {
  color-scheme: dark;
  --bg: #121212;
  --surface: #1c1c1e;
  --text: #f5f5f7;
  --muted: #9a9aa0;
  --line: #2a2a2d;
  --accent: #2ecfa8;
}

* { box-sizing: border-box; }

body {
  margin: 0;
  padding: 0 20px;
  background: var(--bg);
  color: var(--text);
  font: 16px/1.6 -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  -webkit-text-size-adjust: 100%;
}

main {
  max-width: 42rem;
  margin: 0 auto;
  padding-block: 1rem 5rem;
}

html[data-lang]:not([data-lang="en"]) [data-lang="en"],
html[data-lang]:not([data-lang="uk"]) [data-lang="uk"],
html[data-lang]:not([data-lang="pl"]) [data-lang="pl"],
html[data-lang]:not([data-lang="de"]) [data-lang="de"],
html[data-lang]:not([data-lang="es"]) [data-lang="es"],
html[data-lang]:not([data-lang="pt-BR"]) [data-lang="pt-BR"] { display: none !important; }
html:not([data-lang]) [data-lang]:not([data-lang="en"]),
html:not([data-lang]) .controls { display: none; }

.topbar {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  padding-block: 12px;
  border-bottom: 1px solid var(--line);
}

.topbar nav { display: flex; flex-wrap: wrap; gap: 4px 16px; font-size: 0.9rem; }
.topbar nav a:first-child { font-weight: 700; color: var(--text); text-decoration: none; }

.controls { display: flex; align-items: center; gap: 8px; }

.lang {
  min-height: 36px;
  padding: 0 32px 0 14px;
  border: 1px solid var(--line);
  border-radius: 999px;
  background:
    linear-gradient(45deg, transparent 50%, var(--muted) 50%) calc(100% - 19px) 55% / 5px 5px no-repeat,
    linear-gradient(135deg, var(--muted) 50%, transparent 50%) calc(100% - 14px) 55% / 5px 5px no-repeat,
    transparent;
  color: var(--text);
  font: inherit;
  font-size: 0.85rem;
  appearance: none;
  -webkit-appearance: none;
  cursor: pointer;
}

.lang:hover { border-color: var(--muted); }

.theme-toggle {
  display: inline-grid;
  place-items: center;
  width: 36px;
  height: 36px;
  border: 1px solid var(--line);
  border-radius: 999px;
  background: transparent;
  color: var(--text);
  cursor: pointer;
}

.theme-toggle svg { width: 18px; height: 18px; }

button:focus-visible,
select:focus-visible,
a:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 2px;
}

header {
  padding-block: 2rem 1rem;
  border-bottom: 1px solid var(--line);
  margin-bottom: 2rem;
}

h1 { font-size: 1.9rem; line-height: 1.15; letter-spacing: -0.02em; margin: 0 0 0.5rem; }
h2 { font-size: 1.25rem; line-height: 1.25; letter-spacing: -0.01em; margin: 2.5rem 0 0.75rem; }
h3 { font-size: 1rem; margin: 1.5rem 0 0.5rem; }

p, li { color: var(--text); }
ul, ol { padding-left: 1.25rem; }
li { margin-bottom: 0.4rem; }

.lede { color: var(--muted); font-size: 1.05rem; }
.meta { color: var(--muted); font-size: 0.875rem; margin: 0; }

.callout {
  background: var(--surface);
  border-radius: 12px;
  padding: 1rem 1.25rem;
  margin: 1.5rem 0;
}
.callout p:first-child { margin-top: 0; }
.callout p:last-child { margin-bottom: 0; }

a { color: var(--accent); }

table { border-collapse: collapse; width: 100%; margin: 1rem 0; font-size: 0.95rem; }
th, td { text-align: left; padding: 0.5rem 0.75rem 0.5rem 0; border-bottom: 1px solid var(--line); vertical-align: top; }
th { font-weight: 600; }

footer {
  margin-top: 4rem;
  padding-top: 1.5rem;
  border-top: 1px solid var(--line);
  color: var(--muted);
  font-size: 0.875rem;
}