:root{
  --bg:#ffffff;--bg2:#f5f5f7;--card:#f5f5f7;--card2:#ffffff;--line:rgba(0,0,0,.08);--line2:rgba(0,0,0,.14);
  --text:#1d1d1f;--text2:#6e6e73;--text3:#86868b;--accent:#0066cc;--accent2:#0071e3;--green:#1f9d55;--led:#30c35a;
  --warn:#bf4800;--work:rgba(48,195,90,.16);--work-strong:rgba(48,195,90,.32);--night:rgba(0,0,0,.035);--sel:rgba(0,113,227,.12);
  --nav:rgba(255,255,255,.72);--shadow:0 1px 2px rgba(0,0,0,.04),0 8px 28px rgba(0,0,0,.06);
  --r:22px;--r2:14px;--max:1120px;--pad:clamp(20px,4vw,40px);
  --font:-apple-system,BlinkMacSystemFont,"SF Pro Display","SF Pro Text","Segoe UI Variable Display","Segoe UI",Roboto,"Helvetica Neue",Arial,sans-serif;
  --mono:ui-monospace,"SF Mono",SFMono-Regular,Menlo,Consolas,monospace;
  --ease:cubic-bezier(.25,.1,.25,1);
  color-scheme:light;
}
@media (prefers-color-scheme:dark){:root:not([data-theme=light]){
  --bg:#000;--bg2:#0b0b0c;--card:#161618;--card2:#1c1c1e;--line:rgba(255,255,255,.09);--line2:rgba(255,255,255,.16);
  --text:#f5f5f7;--text2:#a1a1a6;--text3:#86868b;--accent:#2997ff;--accent2:#0a84ff;--green:#30d158;--led:#30d158;--warn:#ff9f0a;
  --work:rgba(48,209,88,.16);--work-strong:rgba(48,209,88,.34);--night:rgba(255,255,255,.03);--sel:rgba(41,151,255,.18);
  --nav:rgba(22,22,23,.72);--shadow:0 1px 2px rgba(0,0,0,.4),0 8px 28px rgba(0,0,0,.4);color-scheme:dark}}
:root[data-theme=dark]{
  --bg:#000;--bg2:#0b0b0c;--card:#161618;--card2:#1c1c1e;--line:rgba(255,255,255,.09);--line2:rgba(255,255,255,.16);
  --text:#f5f5f7;--text2:#a1a1a6;--text3:#86868b;--accent:#2997ff;--accent2:#0a84ff;--green:#30d158;--led:#30d158;--warn:#ff9f0a;
  --work:rgba(48,209,88,.16);--work-strong:rgba(48,209,88,.34);--night:rgba(255,255,255,.03);--sel:rgba(41,151,255,.18);
  --nav:rgba(22,22,23,.72);--shadow:0 1px 2px rgba(0,0,0,.4),0 8px 28px rgba(0,0,0,.4);color-scheme:dark}
*,*::before,*::after{box-sizing:border-box}
html{-webkit-text-size-adjust:100%;text-size-adjust:100%;scroll-padding-top:72px}
body{margin:0;background:var(--bg);color:var(--text);font:17px/1.47 var(--font);letter-spacing:-.022em;-webkit-font-smoothing:antialiased;-moz-osx-font-smoothing:grayscale;text-rendering:optimizeLegibility}
a{color:var(--accent);text-decoration:none}a:hover{text-decoration:underline}
button,input,select{font:inherit;color:inherit;letter-spacing:inherit}
button{cursor:pointer;-webkit-tap-highlight-color:transparent}
:focus-visible{outline:3px solid color-mix(in srgb,var(--accent2) 60%,transparent);outline-offset:2px;border-radius:8px}
.sr{position:absolute!important;width:1px;height:1px;overflow:hidden;clip:rect(0 0 0 0);white-space:nowrap}
.wrap{max-width:var(--max);margin:0 auto;padding:0 var(--pad)}
code{font-family:var(--mono);font-size:.86em;background:var(--card);padding:.12em .4em;border-radius:6px}
.nav{position:sticky;top:0;z-index:50;background:var(--nav);-webkit-backdrop-filter:saturate(180%) blur(20px);backdrop-filter:saturate(180%) blur(20px);border-bottom:1px solid var(--line)}
.nav .wrap{display:flex;align-items:center;gap:12px;height:52px}
.logo{display:flex;align-items:center;gap:8px;color:var(--text);font-weight:600;font-size:19px;letter-spacing:-.03em}
.logo:hover{text-decoration:none}.logo svg{width:28px;height:28px;flex:none}
.logo b{font-weight:600}.logo span{color:var(--text3);font-weight:500}
.spacer{flex:1}
.searchbtn{display:flex;align-items:center;gap:8px;height:34px;min-width:260px;padding:0 10px 0 12px;border-radius:10px;border:1px solid var(--line);background:var(--card);color:var(--text2);font-size:14px;transition:border-color .2s var(--ease)}
.searchbtn:hover{border-color:var(--line2)}.searchbtn svg{width:15px;height:15px;flex:none}
.searchbtn kbd{margin-left:auto;font:500 12px var(--font);color:var(--text3);border:1px solid var(--line2);border-radius:6px;padding:1px 6px}
.iconbtn{width:36px;height:36px;display:grid;place-items:center;border-radius:10px;border:0;background:transparent;color:var(--text)}
.iconbtn:hover{background:var(--card)}.iconbtn svg{width:19px;height:19px}
.btn{display:inline-flex;align-items:center;gap:7px;height:36px;padding:0 16px;border-radius:999px;border:1px solid var(--line2);background:transparent;font-size:14px;font-weight:500;color:var(--text);transition:background .2s var(--ease),border-color .2s var(--ease),transform .12s}
.btn:hover{background:var(--card);text-decoration:none}.btn:active{transform:scale(.97)}
.btn svg{width:16px;height:16px}
.btn.primary{background:var(--accent2);border-color:transparent;color:#fff}.btn.primary:hover{background:color-mix(in srgb,var(--accent2) 88%,#000)}
.tablewrap{overflow-x:auto;border-radius:var(--r2);border:1px solid var(--line)}
table.diff{width:100%;border-collapse:collapse;font-size:15px;font-variant-numeric:tabular-nums}
.diff th{text-align:left;font-size:12.5px;font-weight:600;color:var(--text2);padding:10px 16px;background:var(--card)}
.diff td{padding:10px 16px;border-top:1px solid var(--line)}
.faq details{border-top:1px solid var(--line);padding:2px 0}
.faq details:last-child{border-bottom:1px solid var(--line)}
.faq summary{cursor:pointer;list-style:none;padding:14px 32px 14px 0;font-weight:600;position:relative}
.faq summary::-webkit-details-marker{display:none}
.faq summary::after{content:"";position:absolute;right:6px;top:50%;width:8px;height:8px;border-right:2px solid var(--text3);border-bottom:2px solid var(--text3);transform:translateY(-70%) rotate(45deg);transition:transform .25s var(--ease)}
.faq details[open] summary::after{transform:translateY(-30%) rotate(-135deg)}
.faq details p{margin:0 0 16px;color:var(--text2)}
footer{border-top:1px solid var(--line);margin-top:clamp(40px,6vw,80px);padding:36px 0 48px;font-size:13px;color:var(--text2);background:var(--bg2)}
.fcols{display:grid;grid-template-columns:repeat(5,1fr);gap:24px}
.fcols h4{margin:0 0 10px;font-size:13px;font-weight:600;color:var(--text)}
.fcols ul{list-style:none;margin:0;padding:0}.fcols li{margin:7px 0}
.fcols a{color:var(--text2)}.fcols a:hover{color:var(--text)}
.legal{border-top:1px solid var(--line);margin-top:28px;padding-top:18px;display:flex;flex-wrap:wrap;gap:8px 20px;justify-content:space-between}
@media (max-width:720px){.fcols{grid-template-columns:repeat(2,1fr)}}
.menuwrap{position:relative}
.menubtn{display:inline-flex;align-items:center;gap:7px;height:34px;padding:0 10px 0 11px;border-radius:10px;border:1px solid var(--line);background:var(--card);color:var(--text);font-size:14px;font-weight:550;letter-spacing:-.01em}
.menubtn:hover,.menubtn[aria-expanded=true]{border-color:var(--line2);background:var(--card2)}
.menubtn svg{width:16px;height:16px;flex:none}.menubtn .chev{width:11px;height:11px;color:var(--text3);transition:transform .2s var(--ease)}
.menubtn[aria-expanded=true] .chev{transform:rotate(180deg)}
.menu{position:absolute;top:calc(100% + 10px);left:0;width:min(372px,calc(100vw - 24px));background:var(--card2);border:1px solid var(--line2);border-radius:18px;box-shadow:var(--shadow),0 24px 60px rgba(0,0,0,.2);padding:8px;z-index:60}
.menu[hidden]{display:none}
.menu a{display:flex;gap:13px;align-items:center;padding:10px 12px;border-radius:12px;color:var(--text)}
.menu a:hover,.menu a:focus-visible{background:var(--card);text-decoration:none}
.menu a svg{width:22px;height:22px;flex:none;color:var(--accent2)}
.menu a b{display:block;font-size:15px;font-weight:600;letter-spacing:-.015em}
.menu a small{display:block;font-size:13px;color:var(--text2);margin-top:1px;letter-spacing:-.005em}
@media (max-width:720px){.menuwrap{position:static}.menu{position:fixed;left:12px;right:12px;top:60px;width:auto}}
@media (max-width:360px){.nav .wrap{gap:4px;padding:0 12px}.logo{font-size:17px;gap:6px}.logo svg{width:24px;height:24px}.seg button{padding:4px 7px}}
@media (max-width:560px){.menubtn{width:36px;padding:0;justify-content:center;border:0;background:transparent}.menubtn .mt,.menubtn .chev{display:none}.menubtn svg{width:19px;height:19px}.nav .wrap{gap:8px}.logo b span{display:none}}

/* ================= blog ================= */
body.blog{background:var(--bg)}
.nav .navlink{font-size:14px;font-weight:550;color:var(--text2);padding:7px 10px;border-radius:10px;letter-spacing:-.01em}
.nav .navlink:hover,.nav .navlink[aria-current=page]{color:var(--text);background:var(--card);text-decoration:none}
@media (max-width:560px){.nav .navlink{display:none}}
.progress{position:fixed;left:0;top:0;height:3px;width:0;background:var(--accent2);z-index:80;transition:width .08s linear}
.crumbs{display:flex;flex-wrap:wrap;gap:4px 8px;font-size:13.5px;color:var(--text2);margin:26px 0 14px;letter-spacing:-.005em}
.crumbs a{color:var(--text2)}.crumbs a:hover{color:var(--text)}.crumbs i{font-style:normal;color:var(--text3)}
.tags{display:flex;flex-wrap:wrap;gap:8px;margin:0 0 16px}
.tag{display:inline-flex;align-items:center;height:26px;padding:0 11px;border-radius:999px;background:var(--card);font-size:12.5px;font-weight:600;color:var(--text2);letter-spacing:0}
.tag.series{background:color-mix(in srgb,var(--accent2) 14%,transparent);color:var(--accent)}
.post-hero{padding:clamp(4px,1.5vw,16px) 0 clamp(20px,3vw,34px)}
.post-hero.pillar{background:radial-gradient(900px 380px at 90% -20%,color-mix(in srgb,var(--accent2) 16%,transparent),transparent 70%),radial-gradient(600px 300px at -5% 110%,color-mix(in srgb,var(--green) 10%,transparent),transparent 70%);border-radius:var(--r);padding:clamp(22px,4vw,48px);margin-top:6px}
.post-hero h1{font-size:clamp(32px,5.4vw,58px);line-height:1.07;font-weight:700;letter-spacing:-.038em;margin:0 0 16px;max-width:22ch}
.post-hero.pillar h1{max-width:24ch}
.dek{font-size:clamp(18px,2.1vw,22px);line-height:1.45;color:var(--text2);max-width:52ch;margin:0;letter-spacing:-.015em}
.byline{display:flex;flex-wrap:wrap;gap:6px 18px;font-size:14px;color:var(--text2);margin-top:22px;letter-spacing:-.005em}
.byline b{color:var(--text);font-weight:600}.byline a{color:var(--text)}
.post-layout{display:grid;grid-template-columns:minmax(0,720px) 250px;gap:clamp(32px,5vw,76px);justify-content:center;align-items:start;margin-top:clamp(6px,2vw,20px)}
.toc{position:sticky;top:78px;font-size:14px;max-height:calc(100vh - 100px);overflow:auto;padding-bottom:12px}
.toc h2{font-size:12px;font-weight:600;letter-spacing:.07em;text-transform:uppercase;color:var(--text3);margin:0 0 10px}
.toc ol{list-style:none;margin:0;padding:0;border-left:1px solid var(--line)}
.toc a{display:block;padding:6px 0 6px 14px;margin-left:-1px;border-left:2px solid transparent;color:var(--text2);line-height:1.35;letter-spacing:-.005em}
.toc a:hover{color:var(--text);text-decoration:none}.toc a.on{color:var(--text);border-left-color:var(--accent2);font-weight:600}
.toc-m{display:none;background:var(--card);border-radius:var(--r2);padding:2px 16px;margin:0 0 26px}
.toc-m summary{cursor:pointer;font-weight:600;font-size:15px;padding:12px 0;list-style:none}
.toc-m summary::-webkit-details-marker{display:none}
.toc-m ol{margin:0 0 10px;padding-left:20px;font-size:15px}.toc-m li{margin:6px 0}
@media (max-width:1040px){.post-layout{grid-template-columns:minmax(0,720px)}.toc{display:none}.toc-m{display:block}}
.article{font-size:19px;line-height:1.74;letter-spacing:-.011em;color:var(--text)}
.article>:first-child{margin-top:0}
.article p{margin:0 0 1.15em}
.article h2{font-size:clamp(26px,3vw,34px);line-height:1.17;font-weight:700;letter-spacing:-.03em;margin:2.2em 0 .6em;scroll-margin-top:78px}
.article h3{font-size:clamp(20px,2.2vw,24px);line-height:1.25;font-weight:650;letter-spacing:-.022em;margin:1.8em 0 .5em;scroll-margin-top:78px}
.article h2 .anchor,.article h3 .anchor{opacity:0;margin-left:.4em;font-weight:500;color:var(--text3);text-decoration:none}
.article h2:hover .anchor,.article h3:hover .anchor,.article .anchor:focus{opacity:1}
.article a{color:var(--accent);text-decoration:underline;text-decoration-color:color-mix(in srgb,var(--accent) 35%,transparent);text-underline-offset:3px;text-decoration-thickness:1px}
.article a:hover{text-decoration-color:currentColor}
.article ul,.article ol{margin:0 0 1.2em;padding-left:1.35em}.article li{margin:.4em 0}
.article li::marker{color:var(--text3)}
.article blockquote{margin:1.6em 0;padding:.2em 0 .2em 1.3em;border-left:3px solid var(--accent2);color:var(--text);font-size:1.06em;font-style:italic}
.article blockquote p{margin:0 0 .5em}.article blockquote footer{font-size:14px;font-style:normal;color:var(--text2);margin:0;padding:0;border:0;background:none}
.article .tablewrap{margin:1.5em 0}
.article table.diff{font-size:15px}.article .diff th,.article .diff td{padding:10px 14px;vertical-align:top}.article .diff td{line-height:1.45}
.article .diff th[scope=row]{background:none;color:var(--text);font-size:inherit;font-weight:600;border-top:1px solid var(--line)}.article .diff thead th{font-size:12.5px}
.article code{font-size:.84em}
.takeaways{background:var(--card);border-radius:var(--r);padding:20px 24px 8px;margin:0 0 2em;border:1px solid var(--line)}
.takeaways .k{font-size:12px;font-weight:600;letter-spacing:.07em;text-transform:uppercase;color:var(--accent);margin:0 0 8px}
.takeaways ul{margin:0 0 12px;padding-left:1.2em;font-size:17px;line-height:1.55}.takeaways li{margin:.4em 0}
.callout{background:color-mix(in srgb,var(--accent2) 8%,var(--card));border-radius:var(--r2);padding:16px 20px 6px;margin:1.6em 0;border:1px solid color-mix(in srgb,var(--accent2) 20%,transparent);font-size:17px;line-height:1.62}
.callout .k{font-size:13px;font-weight:650;margin:0 0 6px;letter-spacing:-.005em}
.article .timeline{list-style:none;margin:1.8em 0;padding:0;position:relative}
.timeline::before{content:"";position:absolute;left:7px;top:8px;bottom:8px;width:2px;background:var(--line2)}
.article .timeline li{position:relative;padding:0 0 22px 36px;margin:0;font-size:17px;line-height:1.6}
.timeline li::before{content:"";position:absolute;left:0;top:7px;width:16px;height:16px;border-radius:50%;background:var(--bg);border:3px solid var(--accent2)}
.timeline .when{display:block;font-weight:700;font-size:15px;letter-spacing:-.005em;color:var(--accent);font-variant-numeric:tabular-nums;margin-bottom:2px}
.article .stats{list-style:none;margin:1.8em 0;padding:0;display:grid;grid-template-columns:repeat(auto-fit,minmax(200px,1fr));gap:12px}
.article .stats li{background:var(--card);border-radius:var(--r2);padding:16px 18px;margin:0;border:1px solid var(--line);min-width:0}
.stats b{display:block;overflow-wrap:anywhere;font-size:clamp(22px,2.6vw,27px);font-weight:700;letter-spacing:-.03em;line-height:1.15;font-variant-numeric:tabular-nums}
.stats span{display:block;font-size:14.5px;line-height:1.4;color:var(--text2);margin-top:5px}
.toolcta{display:flex;align-items:center;justify-content:space-between;gap:18px 24px;flex-wrap:wrap;background:var(--card);border:1px solid var(--line);border-radius:var(--r);padding:20px 24px;margin:2em 0}
.toolcta .k{font-size:12px;font-weight:600;letter-spacing:.07em;text-transform:uppercase;color:var(--text3);margin:0 0 4px}
.toolcta .h{font-size:20px;font-weight:650;letter-spacing:-.022em;margin:0 0 2px;line-height:1.25}
.toolcta p.b{font-size:15.5px;line-height:1.5;color:var(--text2);margin:0;max-width:42ch}
.toolcta .btn{height:42px;padding:0 20px;font-size:15px}
.article .btn,.article .btn:hover{text-decoration:none}.article .btn.primary{color:#fff}
.sec-h{font-size:clamp(24px,2.8vw,30px);font-weight:700;letter-spacing:-.028em;margin:2.2em 0 .6em;line-height:1.2;scroll-margin-top:78px}
.article .faq{margin:0 0 1em}.article .faq summary{font-size:18px;letter-spacing:-.015em}.article .faq details p{font-size:17px;line-height:1.65}
.sources{margin:0;padding-left:1.4em;font-size:16px;line-height:1.55;color:var(--text2)}.sources li{margin:.55em 0}.sources a{word-break:break-word}
.aboutbox{margin:2.4em 0 0;padding:20px 24px;background:var(--card);border-radius:var(--r);font-size:15px;line-height:1.6;color:var(--text2);border:1px solid var(--line)}
.aboutbox p{margin:0 0 .7em}.aboutbox p:last-child{margin:0}.aboutbox b{color:var(--text)}
.aboutbox a{color:var(--accent);text-decoration:underline;text-underline-offset:3px}
.seriesnav{display:grid;grid-template-columns:1fr 1fr;gap:12px;margin:2.4em 0 0}
.seriesnav a{display:block;padding:16px 18px;border-radius:var(--r2);background:var(--card);border:1px solid var(--line);color:var(--text);min-height:84px}
.seriesnav a:hover{border-color:var(--accent2);text-decoration:none}
.seriesnav small{display:block;font-size:12px;font-weight:600;letter-spacing:.06em;text-transform:uppercase;color:var(--text3);margin-bottom:4px}
.seriesnav b{font-size:16px;font-weight:600;letter-spacing:-.015em;line-height:1.3}
.seriesnav .next{text-align:right;grid-column:2}
@media (max-width:560px){.seriesnav{grid-template-columns:1fr}.seriesnav .next{grid-column:1;text-align:left}}
.related{margin:clamp(40px,6vw,72px) 0 0}
.related h2,.blog-sec h2{font-size:clamp(22px,2.6vw,28px);font-weight:700;letter-spacing:-.026em;margin:0 0 18px}
.cards{display:grid;grid-template-columns:repeat(auto-fill,minmax(280px,1fr));gap:16px}
.cardp{display:flex;flex-direction:column;gap:10px;background:var(--card);border:1px solid var(--line);border-radius:var(--r);padding:20px 22px;color:var(--text);transition:transform .2s var(--ease),border-color .2s var(--ease)}
.cardp:hover{transform:translateY(-2px);border-color:var(--line2);text-decoration:none}
.cardp .cat{font-size:12px;font-weight:600;letter-spacing:.06em;text-transform:uppercase;color:var(--accent)}
.cardp h3{font-size:19px;font-weight:650;letter-spacing:-.022em;line-height:1.25;margin:0}
.cardp p{font-size:15px;line-height:1.5;color:var(--text2);margin:0}
.cardp .meta{margin-top:auto;font-size:13px;color:var(--text3);display:flex;gap:10px;flex-wrap:wrap;padding-top:4px}
/* list page */
.blog-hero{text-align:center;padding:clamp(40px,7vw,84px) 0 clamp(20px,3vw,36px)}
.blog-hero h1{font-size:clamp(36px,6vw,64px);font-weight:700;letter-spacing:-.04em;line-height:1.05;margin:0 0 14px}
.blog-hero p{font-size:clamp(18px,2.2vw,22px);color:var(--text2);max-width:46ch;margin:0 auto;line-height:1.45;letter-spacing:-.015em}
.blog-sec{margin:clamp(28px,5vw,56px) 0}
.series-box{background:radial-gradient(900px 400px at 95% -30%,color-mix(in srgb,var(--accent2) 14%,transparent),transparent 70%),var(--card);border:1px solid var(--line);border-radius:calc(var(--r) + 6px);padding:clamp(20px,3.5vw,40px)}
.series-box .lede{font-size:17px;color:var(--text2);max-width:60ch;margin:-6px 0 22px;line-height:1.55}
.series-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(240px,1fr));gap:14px;counter-reset:part}
.series-grid .cardp{background:var(--bg);counter-increment:part}
.series-grid .cardp .cat::before{content:"Part " counter(part) " · "}
.filters{display:flex;flex-wrap:wrap;gap:8px;align-items:center;margin:0 0 20px}
.filters button{height:34px;padding:0 14px;border-radius:999px;border:1px solid var(--line2);background:transparent;font-size:14px;font-weight:550;color:var(--text2)}
.filters button:hover{color:var(--text);border-color:var(--text3)}
.filters button[aria-pressed=true]{background:var(--text);color:var(--bg);border-color:transparent}
.filters input{margin-left:auto;height:36px;min-width:min(260px,100%);border-radius:10px;border:1px solid var(--line);background:var(--card);padding:0 12px;font-size:15px;color:var(--text)}
.cardp[hidden]{display:none}
.empty{color:var(--text2);padding:20px 0}
/* plain pages (about, policy) */
.page{max-width:760px;margin:0 auto}
.page h1{font-size:clamp(34px,5vw,52px);font-weight:700;letter-spacing:-.035em;line-height:1.1;margin:10px 0 14px}
@media print{.nav,footer,.toc,.toc-m,.progress,.toolcta{display:none}.article{font-size:12pt}}