:root{--bg:#ffffff;--bg2:#f3f7ff;--fg:#0b1220;--muted:#4b5a70;--line:#dbe4f0;--card:#ffffff;--accent:#0a7f75;--accent-fg:#ffffff;--code:#eef2f8;--note:#e3f6f3;--warn:#fff3d6;--red:#d81b3c;
--c1:#e11d48;--c2:#d97706;--c3:#0d9488;--c4:#2563eb;--c5:#7c3aed;--w-usb:#2563eb;--w-pwr:#dc2626;--w-bus:#0b1220;--shadow:0 1px 2px rgba(11,18,32,.06),0 8px 24px rgba(11,18,32,.06)}
@media (prefers-color-scheme:dark){:root:not([data-theme=light]){--bg:#0b1220;--bg2:#101a2e;--fg:#e8eefb;--muted:#9db0cc;--line:#22314d;--card:#111b30;--accent:#3ee0c8;--accent-fg:#06201c;--code:#15223a;--note:#0f2b2b;--warn:#3a2f17;--red:#ff6b7d;
--c1:#fb7185;--c2:#fbbf24;--c3:#2dd4bf;--c4:#60a5fa;--c5:#a78bfa;--w-usb:#60a5fa;--w-pwr:#ff7a6b;--w-bus:#e8eefb;--shadow:0 1px 2px rgba(0,0,0,.4),0 8px 24px rgba(0,0,0,.3)}}
*{box-sizing:border-box}
html{-webkit-text-size-adjust:100%;scroll-behavior:smooth;scroll-padding-top:110px}
body{margin:0;background:var(--bg);color:var(--fg);font:17px/1.65 system-ui,-apple-system,"Segoe UI",Roboto,sans-serif}
.wrap{max-width:1180px;margin:0 auto;padding:0 20px}
a{color:var(--accent)}
.stripe{height:5px;background:linear-gradient(90deg,#e11d48,#f59e0b,#0d9488,#2563eb,#7c3aed)}
.top{background:var(--bg);border-bottom:1px solid var(--line);position:sticky;top:0;z-index:10;box-shadow:0 2px 12px rgba(11,18,32,.05)}
.bar{display:flex;flex-wrap:wrap;gap:8px 28px;align-items:center;justify-content:space-between;padding-top:10px;padding-bottom:10px}
.brand{display:flex;align-items:center;gap:14px;text-decoration:none;color:var(--fg)}
.logo{display:block;flex:none}
.bt{display:flex;flex-direction:column;line-height:1.1}
.bn{font:800 clamp(1.3rem,3.4vw,1.85rem)/1.1 ui-monospace,SFMono-Regular,Menlo,Consolas,monospace;letter-spacing:-.03em}
.bl{color:var(--red)}
.bc{font-weight:500;color:var(--muted)}
.cur{display:inline-block;width:.5em;height:1em;background:var(--accent);margin-left:4px;vertical-align:-.14em;animation:blink 1.1s steps(1) infinite}
@keyframes blink{50%{opacity:0}}
@media (prefers-reduced-motion:reduce){.cur{animation:none}html{scroll-behavior:auto}}
.bs{display:flex;margin-top:5px;align-items:center;gap:6px;font-size:.8rem;font-weight:600;letter-spacing:.1em;text-transform:uppercase;color:var(--muted)}
.arm{display:block;flex:none}
nav{display:flex;flex-wrap:wrap;gap:4px 6px}
nav a{white-space:nowrap;text-decoration:none;color:var(--fg);font-weight:600;font-size:.98rem;padding:8px 14px;border-radius:999px}
nav a:hover{background:var(--bg2)}
nav a[aria-current]{background:var(--accent);color:var(--accent-fg)}
.layout{display:grid;grid-template-columns:minmax(0,1fr) 300px;gap:56px;align-items:start;padding-top:36px;padding-bottom:64px}
.main{min-width:0}
.side{position:sticky;top:112px;display:flex;flex-direction:column;gap:20px}
.side-card{background:var(--card);border:1px solid var(--line);border-radius:16px;padding:18px 20px;box-shadow:var(--shadow)}
.side-card:first-child{border-top:5px solid var(--c1)}
.side-h{margin:0 0 12px;font-size:.85rem;letter-spacing:.12em;text-transform:uppercase;color:var(--muted)}
.contribs{list-style:none;margin:0;padding:0;display:flex;flex-direction:column;gap:14px}
.contribs li{display:flex;align-items:center;gap:12px}
.contribs strong{display:block;line-height:1.25;font-size:1.02rem}
.contribs a{font-size:.88rem;text-decoration:none;font-weight:600}
.contribs a:hover{text-decoration:underline}
.av{flex:none;width:44px;height:44px;border-radius:50%;background:var(--c);color:#fff;display:grid;place-items:center;font-weight:800;font-size:1rem;letter-spacing:.02em}
.side-note{margin:14px 0 0;padding-top:12px;border-top:1px solid var(--line);font-size:.85rem;color:var(--muted)}
.side-list{list-style:none;margin:0;padding:0;display:flex;flex-direction:column;gap:2px}
.side-list a{display:flex;align-items:center;gap:10px;padding:7px 8px;border-radius:10px;text-decoration:none;color:var(--fg);font-size:.93rem;line-height:1.3}
.side-list a:hover,.side-list a[aria-current]{background:var(--bg2)}
.side-list a[aria-current]{font-weight:700}
.dot{flex:none;width:26px;height:26px;border-radius:8px;background:var(--c);color:#fff;display:grid;place-items:center;font-weight:800;font-size:.85rem}
.side-links{list-style:none;margin:0;padding:0}
.side-links li{padding:6px 0;border-bottom:1px solid var(--line)}
.side-links li:last-child{border:0}
.side-links a{text-decoration:none;font-weight:600}
.side-links a:hover{text-decoration:underline}
h1{font-size:clamp(1.9rem,4.4vw,2.7rem);line-height:1.15;margin:.25em 0 .4em;letter-spacing:-.02em}
.page-title{font-size:clamp(2.2rem,5.4vw,3.4rem);display:flex;align-items:center;gap:16px;margin-top:0}
.title-arm{flex:none}
h2{font-size:1.5rem;margin:2em 0 .5em}
h2.sec{font-size:1.7rem;margin:2.2em 0 .6em;display:flex;align-items:center;gap:12px}
h2.sec::before{content:"";width:8px;height:1.4em;border-radius:4px;background:linear-gradient(180deg,var(--c1),var(--c4))}
h3{font-size:1.15rem;margin:1.7em 0 .35em}
.lede{font-size:1.15rem;color:var(--muted)}
.tag{font-size:.8rem;letter-spacing:.08em;text-transform:uppercase;color:var(--accent);font-weight:700;margin:0}
.tag.pill{display:inline-block;background:var(--note);padding:5px 12px;border-radius:999px}
code{background:var(--code);padding:.1em .35em;border-radius:5px;font:.88em ui-monospace,SFMono-Regular,Menlo,monospace}
pre{background:var(--code);padding:14px 16px;border-radius:12px;overflow-x:auto;line-height:1.5;border:1px solid var(--line)}
pre code{padding:0;background:none}
.note{background:var(--note);border-left:5px solid var(--accent);padding:14px 18px;border-radius:0 12px 12px 0;margin:1.4em 0}
.note.warn{background:var(--warn);border-color:#f59e0b}
table{border-collapse:collapse;width:100%;margin:1em 0;display:block;overflow-x:auto}
th,td{border-bottom:1px solid var(--line);padding:9px 12px;text-align:left;vertical-align:top}
thead th{background:var(--bg2);color:var(--fg)}
th{white-space:nowrap;color:var(--muted);font-weight:700}
.figs{display:grid;grid-template-columns:repeat(auto-fit,minmax(260px,1fr));gap:18px;margin:1.4em 0;align-items:start}
figure{margin:0}
figure img{width:100%;height:auto;border-radius:12px;border:1px solid var(--line)}
figcaption{font-size:.9rem;color:var(--muted);margin-top:8px}
.photo{margin:1.4em auto;max-width:420px}
.wide{margin:1.4em 0}
.wide img{width:100%;height:auto;border-radius:12px;border:1px solid var(--line)}
.diagram{overflow-x:auto;margin:1.2em 0;border:1px solid var(--line);border-radius:14px;background:var(--card);padding:10px;box-shadow:var(--shadow)}
.diagram svg{display:block;width:100%;min-width:760px;height:auto}
.diagram .b{fill:var(--bg);stroke:var(--muted);stroke-width:1.5}
.diagram .m{fill:var(--note);stroke:var(--accent)}
.diagram .t{fill:var(--fg);font-size:15.5px;font-weight:600}
.diagram .ts{fill:var(--muted);font-size:13.5px}
.diagram .tl{fill:var(--accent);font-size:12.5px;font-weight:700;letter-spacing:.05em}
.diagram path{stroke-width:3;stroke-linecap:round;stroke-linejoin:round}
.diagram .w-usb{stroke:var(--w-usb)}
.diagram .w-pwr{stroke:var(--w-pwr)}
.diagram .w-bus{stroke:var(--w-bus)}
.ph{border:2px dashed var(--line);border-radius:14px;padding:24px 16px;text-align:center;color:var(--muted);margin:.8em 0;background:var(--bg2)}
video{width:100%;height:auto;max-height:80vh;border-radius:12px;border:1px solid var(--line);background:#000}
.toc{padding-left:1.2em}
.toc li{margin:.4em 0}
.toc span{display:block;color:var(--muted);font-size:.93rem}
.exp{margin-top:3.4em;padding-top:0}
.exp-head{display:flex;align-items:center;gap:22px;padding:22px 26px;border-radius:18px;border-left:10px solid var(--c);background:var(--bg2);background:linear-gradient(90deg,color-mix(in srgb,var(--c) 16%,var(--bg)),var(--bg2) 70%);box-shadow:var(--shadow)}
.exp-num{flex:none;width:84px;height:84px;border-radius:20px;background:var(--c);color:#fff;display:grid;place-items:center;font:800 3.2rem/1 system-ui,sans-serif}
.exp-tag{margin:0 0 2px;font-size:1.2rem;font-weight:800;letter-spacing:.1em;text-transform:uppercase;color:var(--c)}
.exp h2{margin:0;font-size:clamp(1.7rem,3.8vw,2.6rem);line-height:1.15;letter-spacing:-.02em}
.exp .lede{margin-top:1em}
.exp h3{border-left:5px solid var(--c);padding-left:12px}
.links code,.item code{font-size:.85em}
.hero{background:var(--bg2);background:radial-gradient(circle at 1px 1px,color-mix(in srgb,var(--fg) 10%,transparent) 1px,transparent 0) 0 0/22px 22px,linear-gradient(120deg,color-mix(in srgb,var(--c3) 14%,var(--bg)),color-mix(in srgb,var(--c4) 12%,var(--bg)) 55%,color-mix(in srgb,var(--c1) 12%,var(--bg)));border:1px solid var(--line);border-radius:24px;padding:36px;box-shadow:var(--shadow)}
.hero h1{margin-top:.5em}
.brand-hero{display:flex;align-items:center;gap:24px;flex-wrap:wrap;margin:0 0 20px}
.brand-hero img:first-child{flex:none}
.bh-name{margin:0;font:800 clamp(1.5rem,4.4vw,2.35rem)/1.1 ui-monospace,SFMono-Regular,Menlo,Consolas,monospace;letter-spacing:-.04em}
.bh-sub{display:flex;align-items:center;gap:10px;margin:10px 0 0;color:var(--muted);text-transform:uppercase;letter-spacing:.12em;font-size:1rem;font-weight:700}
.btn{display:inline-block;background:var(--accent);color:var(--accent-fg);padding:12px 22px;border-radius:12px;text-decoration:none;font-weight:700;margin:4px 8px 4px 0;border:2px solid var(--accent)}
.btn:hover{filter:brightness(1.08)}
.btn.ghost{background:transparent;color:var(--accent)}
.list{display:flex;flex-direction:column;gap:14px}
.list.cols{display:grid;grid-template-columns:repeat(auto-fill,minmax(300px,1fr))}
.item{display:flex;align-items:flex-start;gap:14px;background:var(--card);border:1px solid var(--line);border-top:4px solid var(--c,var(--accent));border-radius:14px;padding:16px 18px;text-decoration:none;color:var(--fg);box-shadow:var(--shadow);transition:transform .15s,box-shadow .15s}
.item:hover{transform:translateY(-2px)}
.badge{flex:none;width:38px;height:38px;border-radius:11px;background:var(--c,var(--accent));color:#fff;display:grid;place-items:center;font-weight:800;font-size:1.1rem}
.it{display:flex;flex-direction:column;gap:2px}
.it strong{line-height:1.3}
.it span{color:var(--muted);font-size:.93rem;line-height:1.45}
.links{list-style:none;padding:0;margin:0}
.links li{display:flex;flex-direction:column;padding:10px 0;border-bottom:1px solid var(--line)}
.links span{color:var(--muted);font-size:.93rem}
.pager{display:flex;justify-content:space-between;gap:16px;margin-top:44px;padding-top:18px;border-top:1px solid var(--line);font-weight:600}
footer{background:#0b1220;color:#b7c4dc;font-size:.92rem;padding:26px 0 32px;border-top:5px solid var(--c4)}
footer p{margin:.2em 0}
footer strong{color:#fff}
footer a{color:#5eead4}
@media (max-width:980px){
.layout{grid-template-columns:minmax(0,1fr);gap:32px}
.side{position:static}
.hero{padding:22px}
.exp-head{padding:16px;gap:14px}
.exp-num{width:60px;height:60px;font-size:2.2rem;border-radius:16px}
}
@media (min-width:981px){.toc-inline{display:none}}