/* Three quiet model transitions. Existing chapter layout and palette are untouched. */
#primary:has(.b02-scroll){overflow:clip}
.b02-scroll{position:relative;height:clamp(860px,128svh,1120px);margin:48px 0 22px;isolation:isolate}
.b02-stage{position:sticky;top:90px;min-height:440px;height:calc(100svh - 180px);max-height:620px;display:grid;grid-template-columns:minmax(0,.82fr) minmax(0,1.18fr);align-items:center;gap:24px}
.b02-stage:before{content:'';position:absolute;inset:-12% -3%;z-index:-1;pointer-events:none;background:radial-gradient(ellipse at 68% 52%,rgba(238,185,143,.27),rgba(244,211,180,.12) 36%,transparent 68%)}
.b02-copy{position:relative;z-index:2;max-width:430px;padding-block:32px}
.b02-copy h3{font-size:clamp(28px,3.3vw,43px)!important;line-height:1.38!important;font-weight:500!important;letter-spacing:-.035em;margin:0 0 22px!important;text-wrap:balance}
.b02-copy p{font-size:18px!important;line-height:1.8!important;color:var(--brief-muted);margin:0;max-width:360px}
.b02-visual{position:relative;width:100%;height:100%;min-width:0;min-height:0;pointer-events:none}
.b02-visual canvas,.b02-poster{position:absolute;inset:0;display:block;width:100%;height:100%;object-fit:contain}
.b02-visual canvas{opacity:0;transition:opacity .4s ease;z-index:1}
.b02-poster{mix-blend-mode:multiply;padding:6%;transition:opacity .4s ease}
.b02-visual.is-ready canvas{opacity:1}.b02-visual.is-ready .b02-poster{opacity:0}
.b02-motion{display:inline-flex;align-items:center;gap:9px;margin-top:28px;border:0;border-bottom:1px solid var(--brief-line);border-radius:0;background:transparent;padding:9px 0;font:inherit;font-size:14px;line-height:1.5;color:var(--brief-muted);cursor:pointer}
.b02-motion:before{content:'Ⅱ';font-size:13px;font-weight:600}.b02-motion[aria-pressed=true]:before{content:'▷';font-size:16px}
.b02-motion:hover{color:var(--brief-ink)}.b02-motion:focus-visible{outline:2px solid #ba8056;outline-offset:5px}
.b02-motion[hidden]{display:none}
.b02-status{position:absolute;width:1px;height:1px;padding:0;margin:-1px;overflow:hidden;clip:rect(0,0,0,0);white-space:nowrap;border:0}
@media(max-width:700px){
 .b02-scroll{height:1050px;height:130svh;min-height:760px;margin-top:36px}
 .b02-stage{top:78px;min-height:480px;height:calc(100svh - 150px);grid-template-columns:1fr;grid-template-rows:auto minmax(0,1fr);gap:0}
 .b02-copy{max-width:none;padding:10px 0 0}.b02-copy h3{font-size:28px!important;line-height:1.32!important;margin-bottom:12px!important}
 .b02-copy p{max-width:100%;font-size:16px!important;line-height:1.65!important}.b02-motion{margin-top:10px;padding:5px 0;font-size:14px}
 .b02-stage:before{inset:10% -5% -5%;background:radial-gradient(ellipse at 50% 65%,rgba(238,185,143,.24),transparent 68%)}
 .b02-visual{min-height:280px}.b02-poster{padding:3%}
}
@media(prefers-reduced-motion:reduce){.b02-scroll{height:auto;min-height:0}.b02-stage{position:relative;top:auto}.b02-visual canvas,.b02-poster{transition:none}.b02-motion{display:none}}