/* Hallmark / OpenAI public-reference study / Arka editorial adaptation.
 * Neutral surfaces, sans-serif hierarchy, quiet controls. P5 H5 E4 S5 R5 V4. */
.arka-logo-frame{aspect-ratio:1821/519;background:transparent;isolation:auto}
.arka-logo-frame img.arka-logo{position:static;display:block;width:100%;height:100%;object-fit:contain;object-position:left center;filter:invert(1);mix-blend-mode:normal}
.site-header{height:72px;padding-inline:40px;gap:28px}
.site-header .arka-logo-frame{width:118px}.desktop-nav{gap:28px}
.desktop-nav a,.deck-link{font-size:13px}.deck-link{padding:10px 17px;border-radius:24px;background:var(--color-selected)}
.desktop-nav a:after{display:none}.desktop-nav a:hover{color:var(--color-ink)}
.hero-copy{left:max(64px,calc((100% - 1240px)/2));top:26%}
.hero h1 .arka-logo-frame{width:340px;height:78px}
.hero-title{font-size:38px;line-height:1.15;margin-top:34px;font-weight:400}
.hero-description{font-size:16px;line-height:1.6;margin-top:25px}
.hero .primary-action{border-radius:24px;gap:20px;min-height:46px;padding:11px 20px;font-size:13px;min-width:0}
.hero-bottom,.chapter-label,.signal-index,.stack-number,.investor-status{font-family:var(--font-body)}
.hero-bottom{font-size:11px}.chapter-label{font-size:12px;color:var(--color-muted)}
.chapter-index{gap:48px}.chapter-index a{font-size:13px;padding-block:24px}.chapter-index a>span{font-family:var(--font-body);font-size:11px}.chapter-index a strong{font-weight:400}
.opening{padding:96px 0}.opening h2{font-size:52px;line-height:1.13;font-weight:400}
.opening .content-wide>p{font-size:16px}.opening-bottom{margin-top:42px}.discovery-count>strong{font-size:52px;font-weight:400}
.workflow-goal{padding:72px 0}.workflow-heading h2{font-size:44px}.workflow-heading>p{font-size:16px}.workflow-principles h3{font-size:20px}
.software-showcase{padding:88px 0 72px;background:var(--color-paper)}
.software-masthead h2{font-size:64px}.software-statement{font-size:26px;line-height:1.35;max-width:620px}
.software-masthead .text-action{font-size:13px;gap:12px}
.software-switcher{gap:12px}.software-switcher button{border-radius:24px;padding:10px 20px;min-height:42px;font-size:13px}
.software-switcher button[aria-selected=true]{background:var(--color-selected)}.software-indicator{display:none}
.software-display{border-radius:8px;border-color:var(--color-rule)}.software-footnote h3{font-size:22px}
.software-disclosure{font-family:var(--font-body);font-size:11px}
.material-copy h2{font-size:60px;line-height:1.1}.material-copy .chapter-label{margin-bottom:24px}
.anatomy .section-heading h2{font-size:48px}.section-heading{padding-top:72px}.section-heading p{font-size:13px}
.scene-heading,.finish-control{font-family:var(--font-body)}.segmented{border:0;border-radius:8px;background:var(--color-selected)}.segmented button{border-radius:6px}
.icon-button{border-color:transparent;border-radius:50%}.icon-button:hover{background:var(--color-selected)}
.part-tabs button,.tech-tabs button{font-size:14px}.part-panel h3{font-size:28px}
.hardware-section{padding-top:88px}.architecture-heading h2{font-size:44px}.architecture-heading>p{font-size:15px}
.hardware-detail h3{font-size:30px}.map-view-control{border-radius:8px}.map-view-control button{border-radius:6px}
.technology{padding-top:88px}.technology h2{font-size:48px}.technology-heading>p{font-size:16px;line-height:1.65}
.tech-intro h3{font-size:29px}.signal-diagram button[aria-pressed=true]{border-bottom-width:1px}
.assay-explainer .architecture-heading h2{font-size:42px}.reaction-lab{border-radius:8px}.reaction-heading h3{font-size:28px}
.investor-section{padding:72px 0}.investor-section h2{font-size:44px}.investor-action{font-size:18px}
.site-footer{padding-top:36px;padding-bottom:36px}.site-footer .arka-logo-frame{width:118px}
@media(max-width:1100px){
 .site-header{padding-inline:30px}.desktop-nav{gap:20px}.hero-copy{left:36px}.hero h1 .arka-logo-frame{width:300px;height:69px}.hero-title{font-size:34px}
 .opening h2{font-size:46px}.workflow-heading h2{font-size:40px}.software-masthead h2{font-size:56px}.architecture-heading h2{font-size:40px}.technology h2{font-size:44px}
}
@media(max-width:760px){
 .site-header{height:64px;padding-inline:20px}.site-header .arka-logo-frame{width:105px}.mobile-nav{top:64px;background:var(--color-wash);box-shadow:none;padding:12px 20px}
 .mobile-nav a{font-size:14px}.hero-copy{top:96px;left:20px}.hero h1 .arka-logo-frame{width:240px;height:55px}.hero-title{font-size:28px;line-height:1.18;margin-top:24px}.hero .primary-action{margin-top:22px;min-height:44px}
 .hero-canvas{top:312px}.hero-bottom{font-size:10px}.chapter-index{gap:14px}.chapter-index a{font-size:11px;padding-block:20px;grid-template-columns:minmax(0,1fr)}.chapter-index a strong{white-space:nowrap}.chapter-index a svg{display:none}
 .opening{padding:64px 0}.opening h2{font-size:36px}.opening .content-wide>p{font-size:14px}.discovery-count>strong{font-size:48px}
 .workflow-goal{padding:56px 0}.workflow-heading h2{font-size:34px}.workflow-heading>p{font-size:14px}.workflow-principles h3{font-size:20px}
 .software-showcase{padding:64px 0 48px}.software-masthead h2{font-size:48px}.software-statement{font-size:22px;max-width:340px}.software-switcher{gap:4px}.software-switcher button{font-size:11px;padding:8px 6px;gap:6px;min-height:40px}.software-footnote h3{font-size:22px}.software-disclosure{font-size:10px}
 .material-copy h2{font-size:42px}.anatomy .section-heading h2{font-size:36px}.section-heading{padding-top:56px}.hardware-section{padding-top:60px}.architecture-heading h2{font-size:34px}.architecture-heading>p{font-size:14px}.hardware-detail h3{font-size:29px}
 .technology{padding-top:60px}.technology h2{font-size:36px}.technology-heading>p{font-size:14px}.assay-explainer .architecture-heading h2{font-size:34px}.reaction-heading h3{font-size:26px}.investor-section h2{font-size:36px}.investor-section{padding:56px 0}
}
@media(max-width:360px){.hero-title{font-size:26px}.opening h2{font-size:32px}.workflow-heading h2{font-size:32px}.software-masthead h2{font-size:44px}.software-statement{font-size:21px}.software-switcher button{font-size:10px}.architecture-heading h2,.technology h2{font-size:32px}.chapter-index a{font-size:10px}}

/* Hallmark: product-first hero / approved monochrome identity. P5 H5 E4 S5 R5 V4. */
.hero-visual{height:min(1040px,calc(100svh - 76px));min-height:0}
.hero-visual .hero-brand{position:absolute;top:96px;left:24px;right:24px;display:flex;justify-content:center;z-index:1}
.hero-visual h1 .arka-logo-frame{width:180px;height:auto}
.hero-visual .hero-canvas{inset:152px 0 178px}
.hero-visual .hero-copy{top:auto;left:24px;right:24px;bottom:62px;max-width:none;transform:none;display:flex;flex-direction:column;align-items:center;text-align:center}
.hero-visual .hero-title{font-size:28px;line-height:1.25;margin:0}
.hero-visual .hero-title span{color:var(--color-muted)}
.hero-visual .primary-action{margin-top:18px}
.hero-visual .hero-bottom{left:20px;right:20px;bottom:20px;justify-content:center;text-align:center;font-size:10px;line-height:1.4}
@media(max-width:760px){
 .hero-visual .hero-brand{top:82px}
 .hero-visual h1 .arka-logo-frame{width:148px}
 .hero-visual .hero-canvas{inset:130px 0 188px}
 .hero-visual .hero-copy{bottom:54px;left:16px;right:16px}
 .hero-visual .hero-title{font-size:24px;line-height:1.25}
 .hero-visual .hero-title span{display:block}
 .hero-visual .primary-action{margin-top:16px}
 .hero-visual .hero-bottom{bottom:16px;font-size:10px}
}
@media(max-height:650px){
 .hero-visual .hero-brand{top:76px}
 .hero-visual h1 .arka-logo-frame{width:132px}
 .hero-visual .hero-canvas{top:120px}
}

.scene-poster,.scene-poster img{display:block;width:100%;height:100%;object-fit:contain}
.scene-poster{position:absolute;inset:0;pointer-events:none}
html:not(.js-ready) :is(.hero-copy,.opening .content-wide,.section-heading h2,.technology-heading h2,.part-panel>div,.tech-panel>div,.hardware-detail>div){opacity:1!important;transform:none!important}
html:not(.js-ready) .scene-loading{display:none}
html:not(.js-ready) .assembly-sequence{height:380px}
html:not(.js-ready) .assembly-sticky{height:380px;min-height:0}
html:not(.js-ready) .assembly-sticky .product-canvas{background:url('assets/collar.webp') center / contain no-repeat}