.stack-page{--stack-accent:#B11226;--stack-tint:rgba(177,18,38,.045)}
.stack-page.case-dark{--stack-accent:#FEC422;--stack-tint:rgba(254,196,34,.045)}
.stack-page main{position:relative;z-index:1}
.stack-hero{display:grid;grid-template-columns:1.05fr 1fr;gap:70px;align-items:center;padding:150px var(--gutter) 88px;min-height:760px;overflow:hidden}
.stack-hero h1{font:600 clamp(2.8rem,4.3vw,4.1rem)/1.06 var(--display);letter-spacing:-.04em;max-width:680px}
.stack-hero h1 span{color:var(--stack-accent)}
.stack-hero-copy>p{font:400 1.02rem/1.85 var(--sans);color:var(--ink-3);max-width:540px;margin-top:26px}
.stack-actions{display:flex;align-items:center;gap:24px;flex-wrap:wrap;margin-top:30px}
.stack-page .btn-primary{font:600 .94rem var(--display);background:var(--stack-accent);border-color:var(--stack-accent);color:white}
.stack-page.case-dark .btn-primary{color:#141414}
.stack-text-link{font:600 .9rem/1.5 var(--display);color:var(--ink);text-decoration:none;display:inline-block;border:0;background:transparent;cursor:pointer;padding:0}
.stack-text-link:hover{color:var(--stack-accent)}
.stack-system{width:100%;max-width:540px;margin:auto;font-family:var(--display)}
.stack-system-input{padding:22px 15px;text-align:center;border:1px solid var(--line-strong);border-radius:12px;background:var(--bg-soft)}
.stack-system-input>span{font-size:1rem;font-weight:500}
.stack-system-input>div{display:flex;justify-content:center;gap:8px;margin-top:18px;flex-wrap:wrap}
.stack-system-input b{font:400 .72rem var(--sans);padding:7px 9px;background:var(--bg);border:1px solid var(--line);border-radius:4px;color:var(--ink-3)}
.stack-conduit{height:45px;display:flex;justify-content:space-evenly;overflow:hidden}
.stack-conduit i{display:block;position:relative;width:1px;height:100%;background:var(--line-strong)}
.stack-conduit i::after{content:'';position:absolute;top:-12px;left:-1px;width:3px;height:12px;background:var(--stack-accent);animation:stack-signal 3.5s linear infinite;opacity:.7}
.stack-conduit i:nth-child(2)::after{animation-delay:1.2s}.stack-conduit i:nth-child(3)::after{animation-delay:2.4s}
@keyframes stack-signal{to{transform:translateY(70px)}}
.stack-system-core{border:1px solid var(--stack-accent);border-radius:12px;background:var(--bg);box-shadow:0 18px 55px -28px var(--stack-accent);padding:26px 18px 18px}
.stack-wordmark{font:600 1.8rem var(--display);letter-spacing:-.05em;text-align:center;color:var(--ink)}
.stack-wordmark sup{font-size:.55rem;vertical-align:super;margin-left:4px;letter-spacing:0}
.stack-system-agents{display:grid;grid-template-columns:1fr 1fr;gap:15px;margin-top:23px}
.stack-system-agents>div{padding:14px 6px;text-align:center;background:var(--stack-tint);border-radius:7px}
.stack-code-mark{display:block;font:400 1.65rem var(--display);color:var(--stack-accent);margin-bottom:8px}
.stack-system-agents strong{font:500 .98rem var(--display);display:block}
.stack-system-agents small{font:400 .64rem var(--sans);color:var(--ink-3);display:block;margin-top:8px}
.stack-system-core>p{font:400 .72rem var(--sans);text-align:center;margin-top:20px;color:var(--ink-3)}
.stack-conduit-short{height:30px}
.stack-system-controls{display:flex;justify-content:center;gap:18px;font-size:.75rem;font-weight:500;padding:17px 8px;border-top:1px solid var(--line-strong);border-bottom:1px solid var(--line-strong)}
.stack-system-controls span::before{content:'✓';color:var(--stack-accent);margin-right:6px}
.stack-system-note{font:400 .72rem/1.6 var(--sans);color:var(--ink-3);text-align:center;margin-top:16px}
.stack-section{padding:76px var(--gutter);scroll-margin-top:95px}
.stack-page h2{font:500 clamp(2rem,3.1vw,2.9rem)/1.13 var(--display);letter-spacing:-.035em}
.stack-section-heading{display:grid;grid-template-columns:1fr 1fr;gap:65px;align-items:start;margin-bottom:42px}
.stack-section p{font:400 .96rem/1.8 var(--sans);color:var(--ink-3)}
.stack-collections,.stack-foundation,.stack-faq{background:var(--bg-soft);border-top:1px solid var(--line);border-bottom:1px solid var(--line)}
.stack-collection-grid{display:grid;grid-template-columns:1fr 1fr;gap:50px}
.stack-collection-grid article{border-top:1px solid var(--line-strong);padding-top:23px;scroll-margin-top:110px}
.stack-collection-icon{font:500 1.7rem var(--display);color:var(--stack-accent);margin-bottom:12px}
.stack-collection-grid h3{font:500 1.7rem var(--display);letter-spacing:-.025em;margin-bottom:15px}
.stack-collection-grid p{max-width:520px}
.stack-collection-grid ul{list-style:none;display:flex;flex-wrap:wrap;gap:9px;margin:25px 0;min-height:84px;align-content:start}
.stack-collection-grid li{padding:8px 11px;border:1px solid var(--line-strong);font:500 .8rem var(--display);border-radius:4px;color:var(--ink-2)}
.stack-delivery-strip{display:flex;justify-content:space-between;align-items:center;gap:20px;margin-top:44px;padding-top:26px;border-top:1px solid var(--line-strong)}
.stack-delivery-strip strong{font:400 .9rem var(--sans);color:var(--ink-3)}
.stack-delivery-strip>div{display:flex;gap:28px;font:500 1rem var(--display);color:var(--ink)}
.stack-workflow-tabs{display:grid;grid-template-columns:repeat(4,1fr);border-bottom:1px solid var(--line-strong);margin-bottom:32px}
.stack-workflow-tabs button{font:500 1.05rem/1.4 var(--display);padding:18px 8px;text-align:left;background:none;color:var(--ink-3);border:0;border-bottom:3px solid transparent;cursor:pointer}
.stack-workflow-tabs button[aria-selected=true]{color:var(--ink);border-bottom-color:var(--stack-accent)}
.stack-workflow-top{display:flex;align-items:flex-start;justify-content:space-between;gap:40px;margin-bottom:35px}
.stack-workflow-top h3{font:500 1.65rem var(--display);letter-spacing:-.02em;margin-bottom:12px}
.stack-workflow-top p{max-width:630px;font-size:.9rem}
.stack-workflow-agent{max-width:300px;min-width:220px;border-left:1px solid var(--line-strong);padding-left:22px}
.stack-workflow-agent span,.stack-flow-artifact span{display:block;font:400 .77rem var(--sans);color:var(--ink-3);margin-bottom:9px}
.stack-workflow-agent strong{font:500 .94rem/1.5 var(--display)}
.stack-flow-stages{display:grid;grid-template-columns:repeat(5,minmax(0,1fr));gap:24px;margin:16px 0 25px}
.stack-flow-stages button{position:relative;display:block;padding:20px 10px;border:1px solid var(--line-strong);background:var(--bg-soft);color:var(--ink);text-align:center;border-radius:8px;cursor:pointer;min-height:145px;transition:border-color .2s,background .2s}
.stack-flow-stages button:not(:last-child)::after{content:'→';position:absolute;left:100%;top:50%;width:25px;transform:translateY(-50%);color:var(--ink-3);font:400 17px var(--display)}
.stack-flow-stages button[aria-selected=true]{border-color:var(--stack-accent);box-shadow:0 0 0 1px var(--stack-accent)}
.stack-flow-stages button:nth-child(4){border-style:dashed}
.stack-step-symbol{display:block;color:var(--stack-accent);font:500 1.75rem var(--display);height:35px;margin-bottom:8px}
.stack-flow-stages strong{display:block;font:500 1.05rem var(--display);margin-bottom:8px}
.stack-flow-stages small{display:block;font:400 .74rem/1.45 var(--sans);color:var(--ink-3)}
#flow-detail{display:grid;grid-template-columns:1.5fr 1fr;gap:40px;padding:26px 28px;background:var(--stack-tint);border-left:2px solid var(--stack-accent);min-height:142px}
#flow-detail h4{font:500 1.2rem var(--display);margin-bottom:10px}
#flow-detail p{font-size:.9rem;max-width:700px}
.stack-flow-artifact{align-self:center;border-left:1px solid var(--line-strong);padding-left:28px}
.stack-flow-artifact strong{font:500 1rem/1.5 var(--display)}
.stack-workflow-bottom{display:flex;justify-content:space-between;gap:20px;align-items:center;margin-top:22px}
.stack-workflow-bottom>span{font:400 .75rem/1.6 var(--sans);color:var(--ink-3)}
.stack-foundation-grid{display:grid;grid-template-columns:repeat(4,1fr);gap:32px}
.stack-foundation-grid article{border-top:1px solid var(--line-strong);padding-top:24px}
.stack-foundation-grid svg{width:26px;height:26px;color:var(--stack-accent);margin-bottom:17px}
.stack-foundation-grid h3{font:500 1.28rem var(--display);letter-spacing:-.02em;margin-bottom:15px}
.stack-foundation-grid p{font-size:.88rem}
.stack-proof-grid{display:grid;grid-template-columns:1fr 1fr;gap:50px}
.stack-proof-grid a{display:block;text-decoration:none;color:var(--ink);border-top:1px solid var(--line-strong);padding-top:25px}
.stack-proof-grid a>strong{font:500 clamp(3rem,5vw,4.5rem)/1 var(--display);letter-spacing:-.045em;color:var(--stack-accent);display:block;margin-bottom:12px}
.stack-proof-grid a>span{font:400 .9rem var(--sans);color:var(--ink-3)}
.stack-proof-grid h3{font:500 1.4rem/1.3 var(--display);margin:25px 0 15px}
.stack-proof-grid small{font:500 .85rem var(--display)}
.stack-faq{display:grid;grid-template-columns:.8fr 1.2fr;gap:70px}
.stack-faq details{border-top:1px solid var(--line-strong)}
.stack-faq details:last-child{border-bottom:1px solid var(--line-strong)}
.stack-faq summary{font:500 1.1rem/1.45 var(--display);cursor:pointer;list-style:none;padding:23px 35px 23px 0;position:relative}
.stack-faq summary::-webkit-details-marker{display:none}
.stack-faq summary::after{content:'+';position:absolute;right:2px;top:23px;color:var(--stack-accent)}
.stack-faq details[open] summary::after{content:'−'}
.stack-faq details p{padding-bottom:25px;padding-right:25px;font-size:.91rem}
.stack-cta{display:flex;align-items:center;justify-content:space-between;gap:40px}
.stack-cta p{max-width:610px;margin-top:22px}
.stack-page :focus-visible{outline:2px solid var(--stack-accent);outline-offset:5px}
@media(max-width:1050px){.stack-hero{gap:35px;padding-top:125px}.stack-system-controls{gap:10px;font-size:.64rem}.stack-wordmark{font-size:1.65rem}.stack-system-agents strong{font-size:.86rem}.stack-foundation-grid{grid-template-columns:1fr 1fr}.stack-flow-stages{gap:15px}.stack-flow-stages button:not(:last-child)::after{width:16px}.stack-faq{gap:40px}}
@media(max-width:720px){.stack-hero{grid-template-columns:1fr;padding:118px var(--gutter) 48px;min-height:0;gap:40px}.stack-hero h1{font-size:clamp(2.5rem,9vw,3.3rem)}.stack-hero-copy>p{font-size:.97rem}.stack-system{max-width:480px}.stack-section{padding:48px var(--gutter)}.stack-section-heading{grid-template-columns:1fr;gap:22px;margin-bottom:30px}.stack-collection-grid{grid-template-columns:1fr;gap:35px}.stack-collection-grid ul{min-height:0}.stack-delivery-strip{display:block}.stack-delivery-strip>div{gap:22px;margin-top:18px;font-size:.91rem}.stack-workflow-tabs{grid-template-columns:1fr 1fr}.stack-workflow-tabs button{font-size:.94rem}.stack-workflow-top{display:block}.stack-workflow-agent{margin-top:22px;max-width:none;padding:0;border:0}.stack-flow-stages{grid-template-columns:repeat(5,minmax(0,1fr));gap:5px}.stack-flow-stages button{min-height:92px;padding:10px 2px;border-radius:5px}.stack-flow-stages button::after{display:none}.stack-flow-stages strong{font-size:.65rem;margin:0}.stack-flow-stages small{display:none}.stack-step-symbol{font-size:1.4rem;height:28px}.stack-flow-stages button:nth-child(4){border-style:dashed}#flow-detail{grid-template-columns:1fr;gap:20px;padding:22px 18px;min-height:275px}.stack-flow-artifact{border-left:0;border-top:1px solid var(--line-strong);padding:15px 0 0}.stack-workflow-bottom{align-items:flex-start}.stack-workflow-bottom>span{max-width:210px;font-size:.7rem}.stack-workflow-bottom button{white-space:nowrap;font-size:.8rem}.stack-foundation-grid{grid-template-columns:1fr 1fr;gap:25px 20px}.stack-foundation-grid h3{font-size:1.1rem}.stack-proof-grid{grid-template-columns:1fr;gap:35px}.stack-faq{grid-template-columns:1fr;gap:28px}.stack-cta{display:block}.stack-cta .btn-primary{margin-top:28px}.stack-system-core{padding:23px 12px 16px}.stack-system-agents{gap:8px}.stack-system-input b{font-size:.65rem}.stack-system-controls{gap:8px;font-size:.62rem}}
@media(prefers-reduced-motion:reduce){.stack-page *{animation:none!important;transition:none!important;scroll-behavior:auto!important}}