:root{color-scheme:dark;--background:#121418;--surface:#1c1c1e;--surface-raised:#262a31;--border:#2c2c2e;--border-strong:#373d49;--text-primary:#fff;--text-secondary:#919eab;--accent:#edfd3a;--accent-hover:#fde047;--text-on-accent:#000;--info:#3ad9fd;--success:#52c41a;--info-fill:#3ad9fd26;--info-border:#3ad9fd4d;--warn-fill:#ffe16a26;--warn-border:#ffe16a4d;--ok-fill:#52c41a26;--ok-border:#52c41a4d;--neutral-fill:#919eab26;--neutral-border:#919eab4d;}
*,*::before,*::after{box-sizing:border-box}
html{scroll-behavior:smooth;-webkit-text-size-adjust:100%}
body{margin:0;font-family:-apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,Helvetica,Arial,sans-serif;background:var(--background);color:var(--text-primary);line-height:1.5}
h1,h2,h3,p,ul,ol,figure,dl{margin:0}ul,ol{padding:0;list-style:none}
a{color:inherit;text-decoration:none}
:focus-visible{outline:2px solid var(--accent);outline-offset:2px;border-radius:4px}
.page{display:flex;min-height:100vh;flex-direction:column}.page>main{flex:1}
.wrap{max-width:72rem;margin:0 auto;padding:0 1rem}.narrow{max-width:48rem;margin:0 auto;padding:0 1rem}
@media(min-width:768px){.wrap,.narrow{padding:0 1.5rem}}
.sr-only{position:absolute;width:1px;height:1px;overflow:hidden;clip:rect(0,0,0,0);white-space:nowrap}
.skip{position:absolute;left:-999px;top:12px;z-index:50;background:var(--accent);color:var(--text-on-accent);padding:.5rem .75rem;border-radius:.5rem;font-size:.875rem;font-weight:600}.skip:focus{left:1rem}
.ico{width:1em;height:1em;flex:none;vertical-align:-.125em;fill:none;stroke:currentColor;stroke-width:2;stroke-linecap:round;stroke-linejoin:round}
/* header */
.site-header{position:sticky;top:0;z-index:30;border-bottom:1px solid var(--border);background:var(--background)}
.hbar{display:flex;height:4rem;align-items:center;justify-content:space-between;gap:1rem}
.brand{display:flex;align-items:center;gap:.5rem;font-weight:600;font-size:1rem;letter-spacing:-.01em}
.brand-ico{display:flex;width:2rem;height:2rem;align-items:center;justify-content:center;border:1px solid var(--border-strong);background:var(--surface-raised);border-radius:.5rem;color:var(--accent);font-size:1rem}
.btn-ghost{display:inline-flex;align-items:center;gap:.375rem;border:1px solid var(--border-strong);background:var(--surface-raised);padding:.5rem 1rem;border-radius:.5rem;font-size:.875rem;font-weight:600;transition:background .15s}.btn-ghost:hover{background:var(--surface)}
.catnav{border-top:1px solid var(--border)}
.catnav ul{display:flex;gap:.25rem;overflow-x:auto;padding:.5rem 1rem;max-width:72rem;margin:0 auto}
@media(min-width:768px){.catnav ul{padding:.5rem 1.5rem}}
.catnav li{flex:none}.catnav a{display:block;border-radius:.5rem;padding:.375rem .75rem;font-size:.875rem;font-weight:500;color:var(--text-secondary);transition:.15s;white-space:nowrap}
.catnav a:hover{background:var(--surface);color:var(--text-primary)}.catnav a[aria-current=page]{background:var(--surface-raised);color:var(--text-primary)}
/* footer */
.site-footer{margin-top:4rem;border-top:1px solid var(--border);background:var(--surface)}
.fgrid{display:grid;gap:2rem;padding:3rem 1rem}@media(min-width:768px){.fgrid{grid-template-columns:repeat(3,1fr);padding:3rem 1.5rem}}
.fgrid .t{font-size:1rem;font-weight:600}.fgrid p.d{margin-top:.5rem;font-size:.875rem;line-height:1.5rem;color:var(--text-secondary)}
.fgrid .h{font-size:.75rem;font-weight:600;text-transform:uppercase;letter-spacing:.05em;color:var(--text-secondary)}
.fgrid ul{margin-top:.75rem;display:grid;gap:.5rem}.fgrid ul a{font-size:.875rem;color:var(--text-secondary)}.fgrid ul a:hover{color:var(--text-primary)}
.flink{display:inline-block;margin-top:1rem;font-size:.875rem;font-weight:500;color:var(--info);text-decoration:underline;text-underline-offset:4px}
/* shared */
.eyebrow{font-size:.75rem;font-weight:600;text-transform:uppercase;letter-spacing:.05em;color:var(--text-secondary)}
.link,.prose a,.src a,.back a{color:var(--info);font-weight:500;text-decoration:underline;text-decoration-color:var(--border-strong);text-underline-offset:4px;transition:.15s}.link:hover,.prose a:hover,.src a:hover{text-decoration-color:var(--info)}
.prose strong{font-weight:600;color:var(--text-primary)}
.crumbs ol{display:flex;flex-wrap:wrap;align-items:center;gap:.25rem;font-size:.875rem;color:var(--text-secondary)}.crumbs li{display:flex;align-items:center;gap:.25rem}.crumbs a:hover{color:var(--text-primary)}.crumbs [aria-current]{color:var(--text-primary)}
.grid{display:grid;gap:1rem}@media(min-width:768px){.g2{grid-template-columns:repeat(2,1fr)}.g3m{grid-template-columns:repeat(3,1fr)}}@media(min-width:1024px){.g3{grid-template-columns:repeat(3,1fr)}}
.card{display:flex;height:100%;flex-direction:column;border:1px solid var(--border);background:var(--surface);border-radius:.75rem;padding:1.25rem;transition:.15s}.card:hover{border-color:var(--border-strong);background:var(--surface-raised)}
.card .ct{margin-top:.5rem;font-size:1rem;font-weight:600;line-height:1.5rem}.card .cd{margin-top:.5rem;flex:1;font-size:.875rem;line-height:1.5rem;color:var(--text-secondary);display:-webkit-box;-webkit-line-clamp:3;-webkit-box-orient:vertical;overflow:hidden}
.card .cr{margin-top:1rem;display:inline-flex;align-items:center;gap:.25rem;font-size:.875rem;font-weight:500;color:var(--info)}
/* home */
.hero{display:grid;gap:2.5rem;padding:3rem 0}@media(min-width:768px){.hero{padding:4rem 0}}@media(min-width:1024px){.hero{grid-template-columns:7fr 5fr;align-items:center}}
.hero h1{margin-top:1rem;font-size:2.25rem;font-weight:700;line-height:1.2;letter-spacing:-.02em}@media(min-width:768px){.hero h1{font-size:3rem}}
.hero .lead{margin-top:1.25rem;max-width:42rem;font-size:1.125rem;line-height:2rem;color:var(--text-secondary)}
.hero .acts{margin-top:2rem;display:flex;flex-wrap:wrap;gap:.75rem}
.btn2{display:inline-flex;align-items:center;gap:.5rem;padding:.625rem 1.25rem;border-radius:.5rem;font-size:.875rem;font-weight:600}.btn2.b{border:1px solid var(--border-strong);background:var(--surface-raised)}.btn2.b:hover{background:var(--surface)}.btn2.t{color:var(--text-secondary)}.btn2.t:hover{color:var(--text-primary)}
.facts{border:1px solid var(--border-strong);background:var(--surface);border-radius:.75rem;padding:1.5rem}.facts h2{font-size:1rem;font-weight:600}.facts .s{margin-top:.25rem;font-size:.75rem;color:var(--text-secondary)}
.facts ul{margin-top:1rem;display:grid;gap:.75rem}.facts li{display:flex;gap:.5rem;font-size:.875rem;line-height:1.5rem}.facts li .ico{margin-top:.25rem;color:var(--success)}
.btn-acc{display:inline-flex;min-height:2.75rem;align-items:center;justify-content:center;gap:.5rem;background:var(--accent);color:var(--text-on-accent);padding:.625rem 1.25rem;border-radius:.5rem;font-size:.875rem;font-weight:600;transition:.15s}.btn-acc:hover{background:var(--accent-hover)}.facts .btn-acc{margin-top:1.5rem;width:100%}
.sect{border-top:1px solid var(--border);padding:3rem 0;scroll-margin-top:8rem}.sect>h2{font-size:1.5rem;font-weight:600}.sect>.grid{margin-top:1.5rem}
.topic{margin-top:2rem}.topic+.topic{margin-top:3rem}.topic .tr{display:flex;flex-wrap:wrap;align-items:flex-end;justify-content:space-between;gap:.5rem}.topic h3{font-size:1.125rem;font-weight:600}.topic .td{margin-top:.25rem;font-size:.875rem;color:var(--text-secondary)}.topic>.grid{margin-top:1rem}
/* category */
.chead{margin-top:1.5rem;max-width:48rem}.chead .em{font-size:2.25rem}.chead h1{margin-top:.75rem;font-size:1.875rem;font-weight:700;letter-spacing:-.02em}@media(min-width:768px){.chead h1{font-size:2.25rem}}
.chead .in{margin-top:1rem;font-size:1.125rem;line-height:2rem;color:var(--text-secondary)}.chead .n{margin-top:.5rem;font-size:.875rem;color:var(--text-secondary)}
.pad{padding-top:2rem;padding-bottom:2rem}@media(min-width:768px){.pad{padding-top:3rem;padding-bottom:3rem}}
/* article */
.pill{display:inline-flex;align-items:center;gap:.375rem;border:1px solid var(--border-strong);background:var(--surface);border-radius:9999px;padding:.25rem .75rem;font-size:.75rem;font-weight:600;text-transform:uppercase;letter-spacing:.05em;color:var(--text-secondary)}.pill:hover{color:var(--text-primary)}
.ahead{margin-top:1.5rem;max-width:48rem}.ahead h1{margin-top:1rem;font-size:1.875rem;font-weight:700;line-height:1.2;letter-spacing:-.02em}@media(min-width:768px){.ahead h1{font-size:2.25rem}}
.ahead .ds{margin-top:1rem;font-size:1.125rem;line-height:2rem;color:var(--text-secondary)}
.meta{margin-top:1.5rem;display:flex;flex-wrap:wrap;gap:.5rem 1.5rem;font-size:.875rem;color:var(--text-secondary)}.meta li{display:flex;align-items:center;gap:.375rem}
.alayout{margin-top:2.5rem;display:grid;gap:2.5rem}@media(min-width:1024px){.alayout{grid-template-columns:repeat(12,1fr)}.alayout aside.toc{order:2;grid-column:span 3}.alayout article{order:1;grid-column:span 9;max-width:48rem}}
article{min-width:0}
.toc .mob{border:1px solid var(--border);background:var(--surface);border-radius:.75rem;padding:1rem}.toc .mob summary{cursor:pointer;font-size:.875rem;font-weight:600}.toc .mob nav{margin-top:.75rem}
.toc .desk{display:none}@media(min-width:1024px){.toc .mob{display:none}.toc .desk{display:block;position:sticky;top:8rem}}
.toc .desk p{margin-bottom:.5rem;padding:0 .5rem;font-size:.75rem;font-weight:600;text-transform:uppercase;letter-spacing:.05em;color:var(--text-secondary)}
.toc ol{display:grid;gap:.125rem}.toc ol a{display:block;border-radius:.375rem;padding:.375rem .5rem;font-size:.875rem;line-height:1.25rem;color:var(--text-secondary);transition:.15s}.toc ol a:hover{background:var(--surface);color:var(--text-primary)}
.quick{border:1px solid var(--info-border);background:var(--info-fill);border-radius:.75rem;padding:1.5rem}.quick h2{font-size:.75rem;font-weight:600;text-transform:uppercase;letter-spacing:.05em;color:var(--info)}.quick .q{margin-top:.5rem;font-size:1.125rem;font-weight:600;line-height:1.75rem}.quick .a{margin-top:.5rem;line-height:1.75rem}
article p.p,.intro{margin-top:1rem;line-height:2rem}.intro{margin-top:1.5rem}
article section.s{margin-top:3rem}article section.s>h2{font-size:1.5rem;font-weight:600;line-height:1.25;scroll-margin-top:8rem}
article h3.h3{margin-top:2rem;font-size:1.125rem;font-weight:600}
article ul.ul,article ol.ol{margin-top:1rem;padding-left:1.5rem;line-height:1.75rem;display:grid;gap:.5rem}article ul.ul{list-style:disc}article ol.ol{list-style:decimal;gap:.75rem}article .ul li::marker,article .ol li::marker{color:var(--text-secondary)}article .ol li::marker{font-weight:600}article .ol li{padding-left:.25rem}
.callout{margin:1.5rem 0;border:1px solid;border-radius:.75rem;padding:1.25rem}.callout .ttl{display:flex;align-items:center;gap:.5rem;font-weight:600}.callout p.b{margin-top:.5rem;line-height:1.75rem}.callout ul{margin-top:.75rem;display:grid;gap:.5rem}.callout li{display:flex;gap:.5rem;line-height:1.75rem}.callout li>span:first-child{color:var(--text-secondary)}
.k-tip{border-color:var(--info-border);background:var(--info-fill)}.k-warning{border-color:var(--warn-border);background:var(--warn-fill)}.k-checklist{border-color:var(--ok-border);background:var(--ok-fill)}.k-takeaways{border-color:var(--border-strong);background:var(--surface-raised)}.k-calc{border-color:var(--border-strong);background:var(--surface)}.k-prompt{border-color:var(--neutral-border);background:var(--neutral-fill)}.k-fluxlio{border-color:var(--info-border);background:var(--surface-raised)}
figure.tbl{margin:1.5rem 0}table{width:100%;border-collapse:collapse;font-size:.875rem}caption{margin-bottom:.75rem;text-align:left;font-size:.875rem;font-weight:600}
thead{display:none}tbody{display:block}tbody tr{display:block;margin-bottom:.75rem;border:1px solid var(--border);background:var(--surface);border-radius:.75rem;padding:1rem}tbody td{display:block;padding:.25rem 0;line-height:1.5rem;vertical-align:top}td .lb{display:block;font-size:.75rem;font-weight:600;text-transform:uppercase;letter-spacing:.05em;color:var(--text-secondary)}td.c0 .v{font-weight:500}
@media(min-width:1024px){table{border:1px solid var(--border);border-radius:.75rem;overflow:hidden;border-collapse:separate;border-spacing:0}caption{display:block}thead{display:table-header-group}thead tr{background:var(--surface-raised)}th{padding:.75rem 1rem;text-align:left;font-size:.75rem;font-weight:600;text-transform:uppercase;letter-spacing:.05em;color:var(--text-secondary)}tbody{display:table-row-group}tbody tr{display:table-row;margin:0;border:0;border-radius:0;padding:0;background:none}tbody td{display:table-cell;padding:.75rem 1rem;border-top:1px solid var(--border)}td .lb{display:none}}
figure.pre{margin:1.5rem 0;overflow:hidden;border:1px solid var(--border);background:var(--surface);border-radius:.75rem}figure.pre figcaption{border-bottom:1px solid var(--border);padding:.5rem 1rem;font-size:.75rem;font-weight:600;text-transform:uppercase;letter-spacing:.05em;color:var(--text-secondary)}figure.pre pre{margin:0;overflow-x:auto;white-space:pre-wrap;padding:1rem;font-family:ui-monospace,SFMono-Regular,Menlo,Consolas,monospace;font-size:.875rem;line-height:1.5rem}
.cta{margin:2rem 0;border:1px solid var(--border);background:var(--surface);border-radius:.75rem;padding:1.5rem}.cta.primary{border-color:var(--border-strong);background:var(--surface-raised)}.cta .h{font-size:1.125rem;font-weight:600}.cta .b{margin-top:.5rem;line-height:1.75rem;color:var(--text-secondary)}
.cta .btn{margin-top:1rem;display:inline-flex;min-height:2.75rem;align-items:center;gap:.5rem;padding:.625rem 1.25rem;border-radius:.5rem;font-size:.875rem;font-weight:600;border:1px solid var(--border-strong);background:var(--surface-raised);transition:.15s}.cta .btn:hover{background:var(--background)}.cta.primary .btn{background:var(--accent);color:var(--text-on-accent);border-color:var(--accent)}.cta.primary .btn:hover{background:var(--accent-hover)}
.faq{margin-top:3rem}.faq>h2{font-size:1.5rem;font-weight:600;scroll-margin-top:8rem}.faq .box{margin-top:1rem;border:1px solid var(--border);background:var(--surface);border-radius:.75rem}.faq details{padding:1.25rem}.faq details+details{border-top:1px solid var(--border)}
.faq summary{display:flex;cursor:pointer;list-style:none;align-items:flex-start;justify-content:space-between;gap:1rem}.faq summary::-webkit-details-marker{display:none}.faq summary h3{font-size:1rem;font-weight:600}.faq summary .ico{margin-top:.125rem;font-size:1.25rem;color:var(--text-secondary);transition:transform .15s}.faq details[open] summary .ico{transform:rotate(180deg)}.faq details p{margin-top:.75rem;line-height:1.75rem;color:var(--text-secondary)}.faq details p a{color:var(--info)}
.src{margin-top:3rem}.src h2{font-size:1.25rem;font-weight:600}.src .n{margin-top:.5rem;font-size:.875rem;line-height:1.5rem;color:var(--text-secondary)}.src ul{margin-top:.75rem;display:grid;gap:.5rem}.src li{font-size:.875rem;line-height:1.5rem}
.note{margin-top:2.5rem;border:1px solid var(--border);background:var(--surface);border-radius:.75rem;padding:1rem;font-size:.875rem;line-height:1.5rem;color:var(--text-secondary)}.note strong{color:var(--text-primary)}
.related{margin-top:4rem;border-top:1px solid var(--border);padding-top:2.5rem}.related h2{font-size:1.25rem;font-weight:600}.related .grid{margin-top:1rem}
/* about / 404 */
.about h1{margin-top:1.5rem;font-size:1.875rem;font-weight:700;letter-spacing:-.02em}.about .lead{margin-top:1rem;font-size:1.125rem;line-height:2rem;color:var(--text-secondary)}.about h2{margin-top:2.5rem;font-size:1.25rem;font-weight:600}.about ul.dot{margin-top:1rem;list-style:disc;padding-left:1.5rem;display:grid;gap:.5rem;line-height:1.75rem}.about .sub{margin-top:.5rem;font-size:.875rem;color:var(--text-secondary)}.about ul.chk{margin-top:1rem;display:grid;gap:.75rem}.about ul.chk li{display:flex;gap:.5rem;line-height:1.75rem}.about ul.chk .ico{margin-top:.375rem;color:var(--success)}.about p.ct{margin-top:.5rem;line-height:1.75rem;color:var(--text-secondary)}
.nf{padding:6rem 1rem;text-align:center}.nf .c{font-family:ui-monospace,Menlo,monospace;font-size:.875rem;color:var(--text-secondary)}.nf h1{margin-top:.5rem;font-size:1.875rem;font-weight:700}.nf p{margin-top:.75rem;color:var(--text-secondary)}.nf a{display:inline-flex;margin-top:1.5rem;border:1px solid var(--border-strong);background:var(--surface);border-radius:.5rem;padding:.625rem 1rem;font-size:.875rem;font-weight:600;color:var(--text-primary)}.nf a:hover{background:var(--surface-raised)}