:root { color-scheme: light dark; }
* { box-sizing: border-box; }
body {
  margin: 0;
  font-family: Arial, "Segoe UI", sans-serif;
  line-height: 1.8;
  color: #16263d;
  background: #f7fafc;
  padding: env(safe-area-inset-top) env(safe-area-inset-right) env(safe-area-inset-bottom) env(safe-area-inset-left);
}
.wrap { max-width: 760px; margin: 0 auto; padding: 24px 18px 64px; }
h1 { font-size: 24px; margin: 12px 0 4px; }
h2 { font-size: 18px; margin: 28px 0 8px; }
p, li { font-size: 16px; }
ul { padding-inline-start: 22px; }
a { color: #00706d; }
.back { display: inline-block; margin-bottom: 16px; font-size: 15px; }
.meta { color: #5b6b7f; font-size: 14px; }
.box { background: #fff; border: 1px solid #e2e8f0; border-radius: 12px; padding: 16px 18px; margin: 16px 0; }
.todo { color: #9a3412; }
.highlight { background: #fff7ed; border: 1px solid #fed7aa; border-radius: 12px; padding: 14px 16px; }
a:focus-visible, .back:focus-visible { outline: 3px solid #00706d; outline-offset: 2px; border-radius: 4px; }
@media (prefers-color-scheme: dark) {
  body { background: #0e1621; color: #e6edf5; }
  .box { background: #16202c; border-color: #25303d; }
  .meta { color: #93a3b5; }
  a { color: #4cc8c0; }
  .highlight { background: #2a1e12; border-color: #5a3a1c; }
}
@media (max-width: 640px) {
  h1 { font-size: 21px; }
  h2 { font-size: 17px; }
  p, li { font-size: 15px; }
}