:root {
  --bg: #12141a;
  --surface: #181b23;
  --line: #2a2e3a;
  --text: #e8eaf0;
  --muted: #a8adbd;
  --accent: #6f8cff;
}

* { box-sizing: border-box; }

body {
  margin: 0;
  padding: 3rem 1.5rem 6rem;
  background: var(--bg);
  color: var(--text);
  font: 16px/1.7 system-ui, "Segoe UI", sans-serif;
}

main { max-width: 44rem; margin: 0 auto; }

header { margin-bottom: 3rem; }
header .mark {
  display: inline-grid; place-items: center;
  width: 44px; height: 44px; border-radius: 11px;
  background: linear-gradient(145deg, #7d97ff, #3a4fc4);
  color: #fff; font-size: 1.3rem; line-height: 1;
}
header h1 { font-size: 1.6rem; margin: 1rem 0 .25rem; }
header p { color: var(--muted); margin: 0; }

h2 { font-size: 1.05rem; margin: 2.5rem 0 .6rem; }
p, li { color: #ced2df; }
ul { padding-left: 1.2rem; }
li { margin-bottom: .4rem; }

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

.note {
  background: var(--surface);
  border: 1px solid var(--line);
  border-left: 3px solid var(--accent);
  border-radius: 10px;
  padding: 1rem 1.2rem;
  margin: 1.5rem 0;
}

footer {
  margin-top: 4rem; padding-top: 1.5rem;
  border-top: 1px solid var(--line);
  color: var(--muted); font-size: .9rem;
}
footer a { margin-right: 1.2rem; }

@media (prefers-color-scheme: light) {
  :root { --bg: #ffffff; --surface: #f6f7fb; --line: #e2e5ee; --text: #14161c; --muted: #5b6172; }
  p, li { color: #333947; }
}