:root {
  --bg: #ffffff;
  --fg: #1f2933;
  --muted: #5f6b76;
  --accent: #0f8f8a;
  --rule: #e4e8eb;
  --todo-bg: #fff3b0;
  --todo-fg: #5c4a00;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #14181c;
    --fg: #e6eaed;
    --muted: #9aa5ae;
    --accent: #4fd1c5;
    --rule: #2a3138;
    --todo-bg: #5c4a00;
    --todo-fg: #fff3b0;
  }
}

* { box-sizing: border-box; }

body {
  margin: 0;
  padding: 2rem 1.25rem 4rem;
  background: var(--bg);
  color: var(--fg);
  font: 1rem/1.65 -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
}

main { max-width: 42rem; margin: 0 auto; }

h1 { font-size: 1.9rem; line-height: 1.25; margin: 0 0 0.25rem; }
h2 { font-size: 1.25rem; margin: 2.5rem 0 0.5rem; padding-top: 1.5rem; border-top: 1px solid var(--rule); }
h3 { font-size: 1.05rem; margin: 1.5rem 0 0.25rem; }
p, ul { margin: 0.6rem 0; }
ul { padding-left: 1.25rem; }
li { margin: 0.3rem 0; }

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

.meta { color: var(--muted); font-size: 0.9rem; }
.lang { float: right; font-size: 0.9rem; }

mark.todo {
  background: var(--todo-bg);
  color: var(--todo-fg);
  padding: 0 0.25em;
  border-radius: 3px;
}