:root {
  --bg: #fdfdfc; --fg: #16181d; --muted: #666b75; --line: #e4e5e8;
  --accent: #0b6e69; --soft: #f1f2f3; --code: #f1f2f3;
  --sans: system-ui, -apple-system, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  --serif: Georgia, "Iowan Old Style", "Palatino Linotype", serif;
  --mono: ui-monospace, "Cascadia Code", Consolas, Menlo, monospace;
  color-scheme: light;
}
[data-theme="dark"] {
  --bg: #101216; --fg: #e7e8ea; --muted: #9a9fa9; --line: #262a31;
  --accent: #5fd0c8; --soft: #181b21; --code: #181b21;
  color-scheme: dark;
}
* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }
body { margin: 0; background: var(--bg); color: var(--fg); font: 17px/1.65 var(--serif); }
a { color: var(--accent); text-underline-offset: 3px; }
a:focus-visible, button:focus-visible, input:focus-visible, textarea:focus-visible { outline: 2px solid var(--accent); outline-offset: 2px; }
.muted { color: var(--muted); }

.site-header, main, .site-footer { max-width: 720px; margin: 0 auto; padding-left: 20px; padding-right: 20px; }
.site-header { display: flex; flex-wrap: wrap; gap: 12px 24px; align-items: center; justify-content: space-between; padding-top: 22px; padding-bottom: 22px; border-bottom: 1px solid var(--line); font-family: var(--sans); font-size: 15px; }
.brand { font-weight: 700; font-size: 18px; color: var(--fg); text-decoration: none; letter-spacing: -0.01em; }
.site-header nav { display: flex; flex-wrap: wrap; gap: 6px 18px; align-items: center; }
.site-header nav a { color: var(--muted); text-decoration: none; }
.site-header nav a:hover, .site-header nav a[aria-current] { color: var(--fg); }
.toggle { font: inherit; color: var(--fg); background: none; border: 1px solid var(--line); border-radius: 6px; padding: 4px 10px; cursor: pointer; }
.toggle:hover { background: var(--soft); }

main { padding-top: 40px; padding-bottom: 60px; min-height: 70vh; }
h1 { font: 700 2.1rem/1.2 var(--sans); letter-spacing: -0.02em; margin: 0 0 8px; }
h2 { font: 650 1.35rem/1.3 var(--sans); margin: 2em 0 0.5em; }
h3 { font: 650 1.1rem/1.3 var(--sans); margin: 1.6em 0 0.4em; }
.lead { font: 1.15rem/1.5 var(--sans); color: var(--muted); margin: 0 0 24px; }

.tools { display: flex; flex-direction: column; gap: 14px; margin: 36px 0 8px; font-family: var(--sans); }
input[type=search], input[type=text], input[type=email], textarea { width: 100%; font: 16px var(--sans); color: var(--fg); background: var(--bg); border: 1px solid var(--line); border-radius: 8px; padding: 10px 12px; }
textarea { min-height: 140px; resize: vertical; }

.post { padding: 22px 0; border-bottom: 1px solid var(--line); }
.post h2 { margin: 0 0 4px; font-size: 1.3rem; }
.post h2 a { color: var(--fg); text-decoration: none; }
.post h2 a:hover { color: var(--accent); }
.post p:last-child { margin: 6px 0 0; }
.meta { font: 14px var(--sans); color: var(--muted); display: flex; flex-wrap: wrap; gap: 4px 12px; margin: 0; }
.tag { color: var(--accent); }

.prose { margin-top: 28px; }
.prose p { margin: 0 0 1.2em; }
.prose ul { padding-left: 1.3em; margin: 0 0 1.2em; }
.prose img { max-width: 100%; height: auto; border-radius: 6px; display: block; }
.prose figure { margin: 1.6em 0; }
.prose figcaption { font: 14px var(--sans); color: var(--muted); margin-top: 8px; }
code { font: 0.88em var(--mono); background: var(--code); padding: 0.15em 0.4em; border-radius: 4px; }
pre { background: var(--code); border: 1px solid var(--line); border-radius: 8px; padding: 14px 16px; overflow-x: auto; margin: 0 0 1.2em; }
pre code { background: none; padding: 0; font-size: 14px; line-height: 1.55; }

#comments { margin-top: 56px; border-top: 1px solid var(--line); }
form { display: flex; flex-direction: column; gap: 16px; font-family: var(--sans); margin-top: 24px; }
label { display: flex; flex-direction: column; gap: 6px; font-size: 15px; }
form button[type=submit] { align-self: flex-start; font: 600 15px var(--sans); color: var(--bg); background: var(--fg); border: 0; border-radius: 8px; padding: 10px 20px; cursor: pointer; }
form button[disabled] { opacity: .5; cursor: not-allowed; }
.hp { position: absolute; left: -9999px; height: 0; overflow: hidden; }
#form-msg { margin: 0; font-size: 15px; color: var(--muted); }

.site-footer { display: flex; justify-content: space-between; padding-top: 20px; padding-bottom: 40px; border-top: 1px solid var(--line); font: 14px var(--sans); color: var(--muted); }
.site-footer a { color: var(--muted); }
@media (max-width: 520px) { body { font-size: 16px; } h1 { font-size: 1.7rem; } }

/* sort + filter */
.controls { display: grid; grid-template-columns: 1fr 1fr; gap: 12px; }
select { width: 100%; font: 16px var(--sans); color: var(--fg); background: var(--bg); border: 1px solid var(--line); border-radius: 8px; padding: 10px 12px; min-height: 44px; }
input[type=search], input[type=text], input[type=email] { min-height: 44px; }
.post, .prose, .meta { overflow-wrap: anywhere; }

/* mobile */
@media (max-width: 600px) {
  .site-header, main, .site-footer { padding-left: 16px; padding-right: 16px; }
  .site-header { padding-top: 14px; padding-bottom: 14px; gap: 8px; }
  .site-header nav { width: 100%; gap: 0 16px; }
  .site-header nav a, .toggle { min-height: 40px; display: inline-flex; align-items: center; }
  .toggle { margin-left: auto; }
  main { padding-top: 24px; padding-bottom: 40px; }
  .controls { grid-template-columns: 1fr; }
  .tools { margin-top: 24px; }
  .post { padding: 18px 0; }
  pre { margin-left: -16px; margin-right: -16px; border-radius: 0; border-left: 0; border-right: 0; }
  form button[type=submit] { width: 100%; min-height: 44px; }
}
@media (prefers-reduced-motion: reduce) { * { transition: none !important; scroll-behavior: auto !important; } }

/* comments */
#comments { padding-top: 8px; }
.giscus, .giscus-frame { width: 100%; max-width: 100%; }
.giscus { margin-top: 12px; }