:root {
  --bg: #f5f6f8;
  --card: #ffffff;
  --stroke: #e3e6eb;
  --text: #0e1116;
  --muted: #5b6472;
  --accent: #10b981;
  --accent-soft: rgba(16, 185, 129, 0.12);
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #07090c;
    --card: #11151b;
    --stroke: #1e242d;
    --text: #f3f5f8;
    --muted: #9aa3b2;
    --accent: #1fd59b;
    --accent-soft: rgba(31, 213, 155, 0.14);
  }
}

* { box-sizing: border-box; }

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font: 16px/1.6 -apple-system, BlinkMacSystemFont, "SF Pro Text", "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  -webkit-font-smoothing: antialiased;
}

main {
  max-width: 760px;
  margin: 0 auto;
  padding: 32px 16px 64px;
}

header {
  display: flex;
  align-items: center;
  gap: 14px;
  margin-bottom: 24px;
}

header img {
  width: 56px;
  height: 56px;
  border-radius: 14px;
  corner-shape: squircle;
}

header .brand { font-size: 24px; font-weight: 800; letter-spacing: -0.5px; }
header .sub { color: var(--muted); font-size: 14px; }

nav.lang {
  margin-left: auto;
  display: flex;
  gap: 4px;
  padding: 3px;
  border-radius: 14px;
  corner-shape: squircle;
  background: var(--card);
  border: 1px solid var(--stroke);
}

nav.lang button {
  border: 0;
  background: transparent;
  color: var(--muted);
  font: inherit;
  font-size: 14px;
  font-weight: 600;
  padding: 6px 12px;
  border-radius: 11px;
  cursor: pointer;
}

nav.lang button[aria-pressed="true"] { background: var(--accent-soft); color: var(--text); }

.card {
  background: var(--card);
  border: 1px solid var(--stroke);
  border-radius: 28px;
  corner-shape: squircle;
  padding: 24px 22px;
}

h1 { font-size: 30px; line-height: 1.2; letter-spacing: -0.8px; margin: 0 0 6px; }
h2 { font-size: 19px; letter-spacing: -0.3px; margin: 28px 0 8px; }
p, li { color: var(--text); }
.muted { color: var(--muted); font-size: 14px; }
a { color: var(--accent); }
ul { padding-left: 20px; }

.links { display: flex; flex-wrap: wrap; gap: 12px; margin-top: 16px; }
.links a {
  text-decoration: none;
  font-weight: 600;
  padding: 10px 16px;
  border-radius: 14px;
  corner-shape: squircle;
  background: var(--accent-soft);
}

[data-lang] { display: none; }
html[lang="en"] [data-lang="en"], html[lang="pl"] [data-lang="pl"] { display: block; }

footer { margin-top: 28px; text-align: center; }