:root{--bg:#120f07;--bg2:#1b160b;--ink:#0b0904;--line:#39301f;--tx:#efe8e6;--mu:#b7aaa3;--v:#3c7fff;--vs:#76a3ff;--ice:#f5955f;--dk:#040c1a;
--fd:"Tilt Neon","Figtree",system-ui,sans-serif;--fb:"Figtree",system-ui,-apple-system,"Segoe UI",sans-serif;--fm:"Martian Mono",ui-monospace,Consolas,monospace;
--cut:polygon(0 0,calc(100% - 18px) 0,100% 18px,100% 100%,18px 100%,0 calc(100% - 18px));--cs:polygon(0 0,calc(100% - 10px) 0,100% 10px,100% 100%,10px 100%,0 calc(100% - 10px))}
*,*::before,*::after{box-sizing:border-box}
html{background:#120f07;-webkit-text-size-adjust:100%;scroll-behavior:smooth;scroll-padding-top:96px}
body{margin:0;background:radial-gradient(900px 520px at 50% -140px,rgba(60,127,255,.17),transparent 70%),radial-gradient(700px 600px at 108% 38%,rgba(245,149,95,.06),transparent 70%),var(--bg);background-color:var(--bg);background-repeat:no-repeat;min-height:100vh;color:var(--tx);font:400 17px/1.68 var(--fb);overflow-x:hidden}
a{color:var(--vs);text-underline-offset:3px}
a:hover{color:var(--ice)}
:focus-visible{outline:2px solid var(--ice);outline-offset:3px}
h1,h2,h3{font-family:var(--fd);font-weight:400;line-height:1.15;margin:0;overflow-wrap:break-word}
p{margin:0 0 1em}
code,pre,kbd{font-family:var(--fm)}
.skip{position:absolute;left:-9999px;top:0;background:var(--v);color:var(--dk);padding:12px 16px;z-index:99;font-weight:700}
.skip:focus{left:8px;top:8px}

/* header: sticky clipped sign box */
.hd{position:sticky;top:10px;z-index:50;max-width:940px;margin:10px auto 0;padding:0 14px}
.hd-in{position:relative;display:flex;align-items:center;gap:14px;padding:6px 8px 6px 16px;filter:drop-shadow(0 6px 18px rgba(0,0,0,.6))}
.hd-in::before,.hd-in::after{content:"";position:absolute;inset:0;clip-path:var(--cs);background:var(--v);z-index:0}
.hd-in::after{inset:1.5px;background:#19150a}
.hd-in>*{position:relative;z-index:1}
.logo{display:inline-flex;align-items:center;gap:9px;min-height:44px;font:400 1.22rem/1 var(--fd);color:var(--v);text-decoration:none;white-space:nowrap;text-shadow:0 0 12px rgba(60,127,255,.65);margin-right:auto}
.logo:hover{color:var(--v)}
.lu{color:var(--ice);text-shadow:0 0 12px rgba(245,149,95,.7)}
.dead{font-style:normal;color:#24437a;text-shadow:none;animation:flick 5s steps(1) infinite}
@keyframes flick{0%,6%,9%,62%,64%{color:#24437a;text-shadow:none}7%,10%,63%,66%{color:var(--v);text-shadow:0 0 12px rgba(60,127,255,.65)}}
.lmark{width:26px;height:26px;flex:none}
svg .t-ice,svg .t-hot,svg .t-dim{fill:none;stroke-linejoin:round;stroke-linecap:round}
.t-ice{stroke:var(--ice);stroke-width:5}.t-hot{stroke:var(--v);stroke-width:7}.t-dim{stroke:#5a3e2b;stroke-width:4}
.lmark .t-ice{stroke-width:9}.lmark .t-hot{stroke-width:11}.lmark .t-dim{display:none}
.nav{display:flex;align-items:center;gap:2px}
.nav a:not(.btn){display:inline-flex;align-items:center;min-height:44px;padding:0 11px;color:var(--tx);text-decoration:none;font:500 .93rem var(--fb)}
.nav a:not(.btn):hover{color:var(--ice)}
.nav a[aria-current]{color:var(--ice);box-shadow:inset 0 -2px 0 var(--ice)}
.navcta{margin-left:8px}
.burger{display:none;width:46px;height:44px;background:none;border:0;padding:12px 11px;cursor:pointer;flex-direction:column;justify-content:space-between}
.burger span{display:block;height:2px;background:var(--ice);box-shadow:0 0 6px var(--ice)}
.burger span:nth-child(2){width:70%;background:var(--v);box-shadow:0 0 6px var(--v)}

/* buttons */
.btn{display:inline-flex;align-items:center;justify-content:center;min-height:46px;padding:0 22px;background:var(--v);color:var(--dk);font:700 .98rem var(--fb);text-decoration:none;border:0;cursor:pointer;clip-path:var(--cs);transition:background .15s,color .15s;text-align:center}
.btn:hover{background:#6296ff;color:var(--dk)}
.btn.ghost{background:rgba(245,149,95,.07);color:var(--ice);box-shadow:inset 0 0 0 1.5px var(--ice)}
.btn.ghost:hover{background:rgba(245,149,95,.18);color:#ffffff}
.btn.big{min-height:54px;padding:0 28px;font-size:1.05rem}
.btn.sm{min-height:44px;padding:0 14px;font-size:.88rem}
.btns{display:flex;flex-wrap:wrap;gap:12px;margin:26px 0 0}

/* page frame: one letter column */
.pg{max-width:708px;margin:0 auto;padding:0 14px 30px;counter-reset:s}
.sec{margin-top:74px}
.hero{position:relative;padding-top:64px}
.phead{padding-top:44px;position:relative}
.eyebrow{display:inline-block;font:400 .74rem/1.4 var(--fm);letter-spacing:.08em;text-transform:uppercase;color:var(--ice);margin:0 0 20px;padding:6px 12px;background:rgba(245,149,95,.08);clip-path:var(--cs)}
h1{font-size:clamp(2.15rem,7.2vw,3.7rem);color:var(--v);text-shadow:3px 3px 0 #101e3a,0 0 22px rgba(60,127,255,.5);letter-spacing:.005em}
.phead h1,.keytop h1{font-size:clamp(1.8rem,5.4vw,2.7rem)}
.lead{font-size:1.14rem;color:var(--tx);margin:22px 0 0}
.hsign{position:absolute;width:140px;height:140px;right:-200px;top:70px;filter:drop-shadow(0 0 12px rgba(245,149,95,.45))}
.bul{list-style:none;margin:24px 0 0;padding:0}
.bul li{position:relative;padding:7px 0 7px 34px;color:var(--mu)}
.bul li::before{content:"";position:absolute;left:0;top:19px;width:16px;height:2px;background:var(--ice);box-shadow:0 0 7px var(--ice)}
.bul li::after{content:"";position:absolute;left:15px;top:19px;width:9px;height:2px;background:var(--ice);transform-origin:left center;transform:rotate(-45deg);box-shadow:0 0 7px var(--ice)}
.crumbs{display:flex;flex-wrap:wrap;font:400 .72rem/1.5 var(--fm);color:var(--mu);margin:0 0 20px}
.crumbs a{color:var(--mu);text-decoration:none;display:inline-flex;align-items:center;min-height:44px}
.crumbs span{display:inline-flex;align-items:center;min-height:44px;color:var(--ice)}
.crumbs a::after{content:"/";color:var(--v);margin:0 9px}
.crumbs a:hover{color:var(--ice)}
.meta{font:400 .74rem var(--fm);color:var(--mu);margin:18px 0 0}

/* section head: numeral plate + heading on a bent tube */
.sh{--c:var(--v);display:flex;align-items:center;gap:14px;margin:0 0 26px;counter-increment:s}
.sh.ice{--c:var(--ice)}
.sh::before{content:counter(s,decimal-leading-zero);flex:none;font:600 .78rem/1 var(--fm);background:var(--c);color:var(--ink);padding:9px 10px;clip-path:polygon(7px 0,100% 0,100% calc(100% - 7px),calc(100% - 7px) 100%,0 100%,0 7px)}
.sh h2{font-size:clamp(1.5rem,4.6vw,2.05rem);color:var(--tx);min-width:0;flex:0 1 auto}
.tube{--c:inherit;position:relative;flex:1 1 30px;min-width:30px;height:2px;margin-right:18px;background:var(--c,var(--v));box-shadow:0 0 9px var(--c,var(--v))}
.tube::after{content:"";position:absolute;left:100%;top:0;width:18px;height:2px;background:inherit;box-shadow:inherit;transform-origin:left center;transform:rotate(45deg)}
.tube::before{content:"";position:absolute;left:calc(100% + 10px);top:10px;width:7px;height:7px;background:#ffeedd;box-shadow:0 0 6px #ffffff}

/* two-corner-cut plate with a tube edge */
.cut{--c:var(--v);position:relative;padding:24px;filter:drop-shadow(0 0 9px rgba(60,127,255,.2));min-width:0}
.cut.ice,.cards.alt .cut{--c:var(--ice);filter:drop-shadow(0 0 9px rgba(245,149,95,.16))}
.cut::before,.cut::after{content:"";position:absolute;inset:0;clip-path:var(--cut);background:var(--c);z-index:0}
.cut::after{inset:1.5px;background:var(--bg2)}
.cut>*{position:relative;z-index:1}
.cards{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:16px}
.cards.one{grid-template-columns:minmax(0,1fr)}
.cd{padding:22px 22px 20px}
.cd h3{font-size:1.2rem;color:var(--v);margin:0 0 8px;padding-right:14px}
.cards.alt .cd h3,.cards.one .cd h3{color:var(--ice)}
.cd p{margin:0;color:var(--mu);font-size:.96rem;line-height:1.6;overflow-wrap:break-word}
.cards:not(.alt):not(.one) .cd:nth-child(4n+2),.cards:not(.alt):not(.one) .cd:nth-child(4n+3){--c:#5b4d35;filter:none}

/* facts */
.facts{padding:0;margin-top:44px;display:grid}
.fact{padding:16px 14px;min-width:0;display:flex;flex-direction:column;gap:6px}
.fact b{font:400 1.24rem/1.15 var(--fd);color:var(--ice);text-shadow:0 0 12px rgba(245,149,95,.5);overflow-wrap:break-word}
.fact span{font:400 .66rem/1.45 var(--fm);color:var(--mu);text-transform:uppercase;letter-spacing:.04em;overflow-wrap:break-word}
.f5{grid-template-columns:repeat(5,minmax(0,1fr))}
.f5 .fact+.fact{box-shadow:inset 1px 0 0 var(--line)}
.frows .fact,.fcol .fact{flex-direction:row;align-items:baseline;gap:16px;padding:15px 22px}
.frows .fact+.fact,.fcol .fact+.fact{box-shadow:inset 0 1px 0 var(--line)}
.frows .fact b{flex:0 0 42%;font-size:1.6rem;color:var(--v);text-shadow:0 0 14px rgba(60,127,255,.5)}
.fcol{margin-top:24px}
.fcol .fact{padding:11px 18px}
.fcol .fact b{flex:0 0 46%;font-size:1.05rem}

/* steps */
.steps{list-style:none;margin:0;padding:0;counter-reset:st}
.steps li{position:relative;counter-increment:st;padding:0 0 28px 68px}
.steps li::before{content:counter(st);position:absolute;left:0;top:0;width:44px;height:44px;display:flex;align-items:center;justify-content:center;font:400 1.5rem/1 var(--fd);color:var(--v);box-shadow:inset 0 0 0 1.5px var(--v);clip-path:var(--cs);text-shadow:0 0 10px rgba(60,127,255,.7)}
.steps li::after{content:"";position:absolute;left:21px;top:52px;bottom:8px;width:2px;background:linear-gradient(var(--v),rgba(60,127,255,.1))}
.steps li:last-child{padding-bottom:0}.steps li:last-child::after{display:none}
.steps h3{font-size:1.24rem;margin:0 0 6px;padding-top:8px}
.steps p{margin:0;color:var(--mu)}

/* code */
.codecut{padding:8px}
.codetabs{display:flex;gap:2px;padding:0 6px;border-bottom:1px solid var(--line);overflow-x:auto}
.codetabs button{min-height:44px;padding:0 16px;background:none;border:0;color:var(--mu);font:400 .78rem var(--fm);cursor:pointer;white-space:nowrap}
.codetabs button[aria-selected="true"]{color:var(--v);box-shadow:inset 0 -2px 0 var(--v);text-shadow:0 0 10px rgba(60,127,255,.6)}
pre.code{position:relative;margin:0;padding:50px 18px 18px;background:var(--ink);color:#e4dad5;font-size:.78rem;line-height:1.75;overflow-x:auto;max-width:100%;tab-size:2}
.prose pre.code{margin:1.4em 0;border:1px solid var(--line);border-left:2px solid var(--v)}
pre.code code{font-size:inherit;white-space:pre}
pre.code .k{color:var(--vs)}pre.code .s{color:var(--ice)}pre.code .c{color:#a3928a}
.copy{position:absolute;top:6px;right:6px;min-height:36px;min-width:44px;padding:0 12px;background:#272010;border:1px solid var(--line);color:var(--ice);font:400 .68rem var(--fm);cursor:pointer}
.copy:hover{border-color:var(--ice)}

/* prose */
.prose{overflow-wrap:break-word}
.prose h2{font-size:clamp(1.45rem,4.4vw,1.9rem);color:var(--tx);margin:2.3em 0 .8em;padding-bottom:12px;background:linear-gradient(90deg,var(--v) 0,var(--v) 64px,rgba(60,127,255,.12) 64px,transparent) bottom left/100% 2px no-repeat}
.prose>h2:first-child{margin-top:0}
.prose h3{font-size:1.24rem;color:var(--ice);margin:1.8em 0 .5em}
.prose h4{font:700 1rem var(--fb);margin:1.5em 0 .4em}
.prose p,.prose li{color:#dfd6d3}
.prose ul,.prose ol{padding-left:1.3em;margin:0 0 1.1em}
.prose li{margin:.35em 0}
.prose li::marker{color:var(--v)}
.prose :not(pre)>code{font-size:.82em;background:#2b2210;color:var(--ice);padding:2px 6px;word-break:break-word}
.prose table{display:block;overflow-x:auto;max-width:100%;border-collapse:collapse;margin:1.4em 0;font-size:.9rem}
.prose th,.prose td{padding:10px 14px;border-bottom:1px solid var(--line);text-align:left;vertical-align:top;min-width:110px}
.prose th{font:400 .68rem var(--fm);text-transform:uppercase;letter-spacing:.05em;color:var(--v);border-bottom:2px solid var(--v);white-space:nowrap}
.prose strong{color:var(--tx)}

/* faq */
.faq details{border-bottom:1px solid var(--line)}
.faq summary{display:flex;align-items:center;gap:14px;min-height:58px;padding:10px 0;cursor:pointer;list-style:none;font:400 1.14rem/1.3 var(--fd)}
.faq summary::-webkit-details-marker{display:none}
.faq summary span{flex:1;min-width:0}
.faq summary::after{content:"";flex:none;width:16px;height:16px;background:linear-gradient(var(--ice),var(--ice)) center/100% 2px no-repeat,linear-gradient(var(--ice),var(--ice)) center/2px 100% no-repeat;transition:transform .2s}
.faq details[open] summary{color:var(--ice)}
.faq details[open] summary::after{transform:rotate(45deg)}
.faq details p{color:var(--mu);margin:0 0 18px;padding-right:30px}

/* end cta */
.endcta{padding:34px 28px;text-align:left}
.endcta h2{font-size:clamp(1.5rem,4.6vw,2.1rem);color:var(--v);text-shadow:0 0 16px rgba(60,127,255,.45);margin-bottom:10px}
.endcta p{color:var(--mu);margin:0}
.endcta .btns{margin-top:22px}

/* key page */
.keytop{display:grid;gap:22px;padding-top:28px}
.kt-a,.kt-b,.kt-f{min-width:0}
.kt-b .lead{margin-top:0;font-size:1.05rem;color:var(--mu)}
.formcut{padding:24px}
.tabs2{display:grid;grid-template-columns:1fr 1fr;gap:6px;margin:0 0 18px;padding:4px;background:var(--ink)}
.tabs2 button{min-height:44px;background:none;border:0;color:var(--mu);font:700 .92rem var(--fb);cursor:pointer;clip-path:var(--cs)}
.tabs2 button[aria-selected="true"]{background:var(--v);color:var(--dk)}
.msg:empty{display:none}
.msg{margin:0 0 14px;padding:11px 14px;font-size:.92rem;background:rgba(245,149,95,.09);border-left:2px solid var(--ice);color:var(--tx)}
.msg.err{background:rgba(60,127,255,.14);border-left-color:var(--v);color:#b8cfff}
.row{margin:0 0 14px}
.row label,.calc label{display:block;font:400 .68rem var(--fm);text-transform:uppercase;letter-spacing:.06em;color:var(--mu);margin:0 0 7px}
input,select,textarea{width:100%;min-height:46px;padding:10px 13px;background:var(--ink);border:1px solid #5b4c33;border-radius:0;color:var(--tx);font:400 1rem var(--fb)}
textarea{min-height:150px;resize:vertical;line-height:1.5}
input:focus,select:focus,textarea:focus{outline:2px solid var(--ice);outline-offset:1px;border-color:var(--ice)}
.note{font-size:.84rem;color:var(--mu);margin:8px 0 0}
form[data-form] .btn,form[data-support] .btn{width:100%;min-height:52px;margin-top:4px}
form[data-support]{margin-top:0!important}
.keyout{display:none}
.keyout.on{display:block}
.keyout h3{font-size:1.4rem;color:var(--ice);margin:0 0 12px}
.keybox{display:flex;align-items:center;gap:10px;padding:8px 8px 8px 14px;background:var(--ink);border:1px solid var(--ice);margin:0 0 6px}
.keybox span{flex:1;min-width:0;font:400 .82rem/1.5 var(--fm);color:var(--ice);word-break:break-all}
.keyout p{font-size:.94rem}
.keyout code{font-size:.8rem;color:var(--ice);word-break:break-all}
.mut{color:var(--mu)}
.acts{display:flex;flex-wrap:wrap;gap:8px;margin:14px 0 10px}

/* calculator */
.calc{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:16px}
.calc>div{min-width:0}
.calc>div:last-child{grid-column:1/-1;padding-top:16px;border-top:1px solid var(--line)}
.calc output{display:block;font:400 2.5rem/1.1 var(--fd);color:var(--v);text-shadow:0 0 18px rgba(60,127,255,.55);overflow-wrap:break-word}

/* hanging toc + takeaways */
.hang{margin-top:54px}
.toc{margin:0 0 40px}
.toc .cut{padding:20px 22px}
.toc-h{font:400 .7rem var(--fm);text-transform:uppercase;letter-spacing:.08em;color:var(--ice);margin:0 0 10px}
.toc ol{list-style:none;margin:0;padding:0;counter-reset:t}
.toc li{counter-increment:t}
.toc a{display:flex;gap:10px;align-items:baseline;min-height:44px;padding:9px 0;color:var(--tx);text-decoration:none;font-size:.92rem;line-height:1.4}
.toc a::before{content:counter(t,decimal-leading-zero);font:400 .66rem var(--fm);color:var(--v)}
.toc a:hover{color:var(--ice)}
.take{margin-top:36px}
.take .toc-h{color:var(--v)}
.take ul{list-style:none;margin:0;padding:0}
.take li{position:relative;padding:8px 0 8px 26px;border-top:1px solid var(--line)}
.take li:first-child{border-top:0}
.take li::before{content:"";position:absolute;left:0;top:19px;width:12px;height:2px;background:var(--v);box-shadow:0 0 7px var(--v)}
.sup{margin-top:34px}
.nf{padding-top:110px;padding-bottom:90px}

/* footer */
.ft{margin-top:90px;padding:0 14px 44px}
.ft-in{max-width:680px;margin:0 auto}
.ft .tube{display:block;margin:0 18px 30px 0}
.ft-tag{color:var(--mu);margin:4px 0 14px;font-size:.95rem}
.ft-l{display:flex;flex-wrap:wrap;gap:0 22px;margin:0 0 14px}
.ft-l a{display:inline-flex;align-items:center;min-height:44px;color:var(--tx);text-decoration:none;font-size:.93rem}
.ft-l a:hover{color:var(--ice)}
.legal{font:400 .68rem/1.6 var(--fm);color:var(--mu);margin:0}

@media(min-width:1040px){
.pg-key{max-width:1040px}
.pg-key>.sec,.pg-key>.sec~*{max-width:680px;margin-left:auto;margin-right:auto}
.keytop{grid-template-columns:minmax(0,1fr) 440px;grid-template-areas:"a f" "b f";column-gap:48px;align-items:start;grid-template-rows:auto 1fr;padding-top:34px}
.kt-a{grid-area:a}.kt-b{grid-area:b}.kt-f{grid-area:f;padding-top:14px}
}
@media(min-width:1200px){
.hang{position:relative}
.toc{position:absolute;top:0;bottom:0;right:calc(100% + 34px);width:228px;margin:0}
.toc .cut{position:sticky;top:96px;max-height:calc(100vh - 120px);overflow-y:auto}
}
@media(max-width:1339px){.hsign{position:static;display:block;width:84px;height:84px;margin:0 0 22px}.nfsign{margin-bottom:22px}}
@media(max-width:900px){
.burger{display:flex}
.nav{display:none;position:absolute;left:0;right:0;top:calc(100% + 6px);flex-direction:column;align-items:stretch;gap:0;padding:8px 14px 14px;background:#19150a;box-shadow:inset 0 0 0 1.5px var(--v),0 18px 40px rgba(0,0,0,.7)}
.nav.open{display:flex}
.nav a:not(.btn){min-height:48px;border-bottom:1px solid var(--line);padding:0 4px}
.nav a[aria-current]{box-shadow:none}
.navcta{margin:12px 0 0}
}
@media(max-width:640px){
body{font-size:16px}
.hero{padding-top:40px}.phead{padding-top:26px}.keytop{padding-top:14px;gap:16px}
.sec{margin-top:56px}
.cards{grid-template-columns:minmax(0,1fr)}
.f5{grid-template-columns:repeat(2,minmax(0,1fr))}
.f5 .fact:first-child{grid-column:1/-1}
.f5 .fact+.fact{box-shadow:inset 0 1px 0 var(--line)}
.f5 .fact:nth-child(odd):not(:first-child){box-shadow:inset 0 1px 0 var(--line),inset 1px 0 0 var(--line)}
.frows .fact{flex-direction:column;gap:4px}.frows .fact b{flex:none}
.calc{grid-template-columns:minmax(0,1fr)}
.cut{padding:18px}.codecut{padding:6px}.facts{padding:0}
.btns .btn.big{flex:1 1 100%}
.steps li{padding-left:58px}
.crumbs{margin-bottom:8px}
.keytop h1{font-size:1.55rem}
}
@media(prefers-reduced-motion:reduce){*{animation:none!important;transition:none!important}html{scroll-behavior:auto}}