:root {
  --bg: #f4f3ee;
  --surface: #ffffff;
  --text: #1f2421;
  --muted: #5b625d;
  --accent: #5d6b3a;
  --accent-text: #ffffff;
  --accent-soft: #e6ead9;
  --border: #dcdad2;
  --wifi: #3d6fb4;
  --bt: #8a5a9e;
}
@media (prefers-color-scheme: dark) {
  :root {
    --bg: #161917;
    --surface: #1f2421;
    --text: #e9ebe6;
    --muted: #a3aaa4;
    --accent: #a9bb78;
    --accent-text: #161917;
    --accent-soft: #2a3122;
    --border: #343a36;
    --wifi: #7fa8e0;
    --bt: #c39ad6;
  }
}
* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font: 17px/1.6 system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
}
main { max-width: 760px; margin: 0 auto; padding: 48px 16px 64px; }
header { display: flex; align-items: center; gap: 20px; margin-bottom: 32px; }
header img { width: 96px; height: 96px; border-radius: 50%; flex: none; }
h1 { font-size: 2rem; line-height: 1.2; margin: 0; }
h2 { font-size: 1.4rem; line-height: 1.3; margin: 56px 0 8px; scroll-margin-top: 16px; }
h3 { font-size: 1.08rem; margin: 28px 0 4px; }
p, li { color: var(--text); }
.lede { color: var(--muted); margin: 4px 0 0; }
.muted { color: var(--muted); }
.cards { display: grid; grid-template-columns: repeat(auto-fit, minmax(220px, 1fr)); gap: 16px; margin: 24px 0; }
.card { background: var(--surface); border: 1px solid var(--border); border-radius: 14px; padding: 20px; }
.card h3 { margin: 0 0 6px; font-size: 1.05rem; }
.card p { margin: 0; color: var(--muted); font-size: 0.95rem; }
.card.wifi { border-top: 4px solid var(--wifi); }
.card.bt { border-top: 4px solid var(--bt); }
.card.both { border-top: 4px solid var(--accent); }
.card ul { margin: 8px 0 0; padding-left: 18px; color: var(--muted); font-size: 0.93rem; }
.card li { color: var(--muted); }
a { color: var(--accent); }
.button {
  display: inline-block; background: var(--accent); color: var(--accent-text);
  text-decoration: none; padding: 10px 18px; border-radius: 999px; font-weight: 600;
}
footer { margin-top: 56px; padding-top: 16px; border-top: 1px solid var(--border); color: var(--muted); font-size: 0.9rem; }
table { width: 100%; border-collapse: collapse; margin: 12px 0; font-size: 0.95rem; }
th, td { text-align: left; vertical-align: top; padding: 8px 10px; border-bottom: 1px solid var(--border); }
th { color: var(--muted); font-weight: 600; }
td.y { color: var(--accent); font-weight: 600; white-space: nowrap; }
td.n { color: var(--muted); white-space: nowrap; }

nav.toc { background: var(--surface); border: 1px solid var(--border); border-radius: 14px; padding: 14px 20px; margin: 24px 0; }
nav.toc ol { margin: 0; padding-left: 20px; columns: 2 220px; column-gap: 32px; }
nav.toc li { margin: 2px 0; }

figure { margin: 24px 0; }
figure.wide, .cards.wide { margin-left: calc(50% - min(48vw, 520px)); margin-right: calc(50% - min(48vw, 520px)); }
figure img { display: block; width: 100%; height: auto; border-radius: 12px; border: 1px solid var(--border); }
figure.narrow img { max-width: 560px; margin: 0 auto; }
figcaption { color: var(--muted); font-size: 0.9rem; margin-top: 8px; text-align: center; }
figure.wide figcaption { max-width: 760px; margin-left: auto; margin-right: auto; padding: 0 16px; }

.diagram { background: var(--surface); border: 1px solid var(--border); border-radius: 14px; padding: 16px; }
.diagram svg { display: block; width: 100%; height: auto; }
.diagram text { fill: var(--text); font: 15px system-ui, -apple-system, "Segoe UI", Roboto, sans-serif; }
.diagram .small { fill: var(--muted); font-size: 13px; }
.diagram .box { fill: var(--bg); stroke: var(--border); stroke-width: 1.5; }
.diagram .wifi { stroke: var(--wifi); fill: none; stroke-width: 3; }
.diagram .bt { stroke: var(--bt); fill: none; stroke-width: 3; stroke-dasharray: 8 6; }
.diagram .wifi-t { fill: var(--wifi); font-weight: 600; }
.diagram .bt-t { fill: var(--bt); font-weight: 600; }

.callout { background: var(--accent-soft); border-radius: 12px; padding: 14px 18px; margin: 20px 0; }
.callout p { margin: 0; }

details { background: var(--surface); border: 1px solid var(--border); border-radius: 12px; margin: 10px 0; }
details > summary { cursor: pointer; padding: 12px 16px; font-weight: 600; list-style: none; position: relative; padding-right: 40px; }
details > summary::-webkit-details-marker { display: none; }
details > summary::after { content: "+"; position: absolute; right: 16px; top: 10px; color: var(--muted); font-weight: 400; font-size: 1.2rem; }
details[open] > summary::after { content: "–"; }
details > div { padding: 0 16px 12px; }
details > div p { margin: 8px 0; }
.tag { display: inline-block; font-size: 0.75rem; font-weight: 600; border-radius: 999px; padding: 1px 8px; margin-left: 6px; vertical-align: 2px; }
.tag.wifi { background: color-mix(in srgb, var(--wifi) 18%, transparent); color: var(--wifi); }
.tag.bt { background: color-mix(in srgb, var(--bt) 18%, transparent); color: var(--bt); }

kbd { font: 0.88em ui-monospace, Consolas, monospace; background: var(--surface); border: 1px solid var(--border); border-bottom-width: 2px; border-radius: 5px; padding: 0 5px; }
code { font: 0.9em ui-monospace, Consolas, monospace; }
pre { background: var(--surface); border: 1px solid var(--border); border-radius: 10px; padding: 12px 16px; overflow-x: auto; font-size: 0.9rem; }

@media (max-width: 520px) {
  header { flex-direction: column; align-items: flex-start; }
  table { display: block; overflow-x: auto; }
  figure.wide, .cards.wide { margin-left: 0; margin-right: 0; }
}

figure.strips { background: var(--surface); border: 1px solid var(--border); border-radius: 14px; padding: 18px 18px 12px; }
.strip {
  --key: #d9dde3; --ink: #3a4048; --accent: #5d6b3a;
  font: 22px/44px ui-monospace, "Cascadia Mono", Consolas, monospace; color: var(--ink);
  background: var(--key); border: 1px solid #b9bec6; border-radius: 10px;
  height: 46px; padding: 0 12px; white-space: pre; overflow: hidden; margin-top: 6px;
}
.strip .faint { opacity: 0.35; }
.strip .last { color: var(--accent); font-weight: 700; }
.strip .sel { background: color-mix(in srgb, var(--accent) 35%, transparent); }
.strip .caret { display: inline-block; width: 2px; height: 26px; margin: 0 -1px; background: var(--ink); vertical-align: -5px; }
figure.strips figcaption { text-align: left; margin: 6px 0 14px; }
figure.strips figcaption.note { font-style: italic; margin-bottom: 0; }
@media (prefers-color-scheme: dark) {
  .strip { --key: #3a3f46; --ink: #e3e6ea; --accent: #b5c77f; border-color: #50565e; }
}
@media (max-width: 520px) {
  .strip { font-size: 15px; }
}