:root{font-family:'Be Vietnam Pro',system-ui,sans-serif;color:#111a2d;background:#f5f8ff;--ink:#111a2d;--muted:#68758a;--line:#dce4f0;--blue:#0759d9;--blue-dark:#0648b5;--blue-soft:#edf3ff;--green:#16845b;--red:#b13b4b;--panel:#fff}
*{box-sizing:border-box}body{margin:0;height:100dvh;display:flex;flex-direction:column;overflow:hidden;font-size:14px}[hidden]{display:none!important}button,input,select{font:inherit}button,a,input,select{-webkit-tap-highlight-color:transparent}button{cursor:pointer;background:#fff;border:1px solid var(--line);border-radius:8px;color:var(--ink);min-height:36px;padding:8px 12px;transition:background .16s,border-color .16s,color .16s}button:hover{border-color:#b5cbee;background:#f5f8ff}button:disabled{opacity:.45;cursor:not-allowed}a{color:var(--blue);text-decoration:none}a:hover{text-decoration:underline}h1,h2,h3,p{margin:0}p{line-height:1.7}h1,h2{letter-spacing:-.04em;font-weight:800}h2{font-size:27px;line-height:1.18}h3{font-size:13px}button:focus-visible,a:focus-visible,input:focus-visible,select:focus-visible,#stage:focus-visible{outline:3px solid #8ab8ff;outline-offset:3px}.primary{display:inline-flex;align-items:center;justify-content:center;background:var(--blue);border:1px solid var(--blue);color:#fff;border-radius:9px;font-weight:700;padding:11px 18px;box-shadow:0 5px 12px #0759d912}.primary:hover{background:var(--blue-dark);border-color:var(--blue-dark);color:white;text-decoration:none}.secondary{background:white}.wide{width:100%;margin-top:16px;min-height:44px}.iconbtn{font-size:11px;background:transparent;white-space:nowrap}.sr-only,.skip:not(:focus){position:absolute;width:1px;height:1px;overflow:hidden;clip:rect(0,0,0,0);white-space:nowrap}.skip:focus{position:absolute;top:8px;left:12px;z-index:100;background:#fff;padding:12px}
/* Match the live Brain-Course header and typography. */
.site-header{height:74px;flex:0 0 74px;display:flex;align-items:center;justify-content:space-between;gap:32px;padding:0 clamp(24px,4vw,64px);background:white;border-bottom:1px solid var(--line)}.brand{display:flex;align-items:center;gap:10px;white-space:nowrap;color:var(--ink)}.brand:hover{text-decoration:none}.brand img{display:block;width:43px;height:43px;object-fit:contain}.brand>span{display:grid;gap:3px}.brand b{font-size:22px;font-weight:800;letter-spacing:-.035em;line-height:1.1}.brand small{font-size:9px;color:#6e7890}.site-links{display:flex;align-items:center;gap:28px}.site-links a{font-size:13px;font-weight:700;color:#27334a}.site-links .current{color:var(--blue)}.account-links{display:flex;align-items:center;gap:24px;font-size:12px;font-weight:700}
.lab-shell{width:min(1480px,100%);padding:22px 32px 24px;margin:0 auto;display:flex;flex-direction:column;flex:1;min-height:0}.lab-intro{display:flex;justify-content:space-between;align-items:center;gap:20px;margin-bottom:20px}.breadcrumb{font-size:10px;font-weight:600;color:var(--muted);display:inline-block;margin-bottom:6px}.breadcrumb span{color:#b3bdcc;padding:0 8px}.title-line{display:flex;align-items:center;gap:22px}h1{font-size:34px;line-height:1.1}h1>span{color:var(--blue)}.title-line p{color:var(--muted);font-size:12px}.free-label{display:flex;align-items:center;gap:7px;font-size:10px;color:#3d6d5b;white-space:nowrap}.free-label i{width:6px;height:6px;background:#2c9b6b;border-radius:50%}.lab-toolbar{display:flex;align-items:center;justify-content:space-between;gap:18px;margin-bottom:12px}.mode-tabs{display:flex;gap:5px}.mode-tabs button{display:flex;align-items:center;gap:8px;padding:9px 18px;border-color:transparent;background:transparent;font-size:12px;font-weight:700;min-height:41px}.mode-tabs img{width:20px;height:20px;object-fit:contain;opacity:.55}.mode-tabs button.active{color:var(--blue);background:white;border-color:var(--line);box-shadow:0 3px 7px #233f6e06}.mode-tabs button.active img{opacity:.95;filter:invert(25%) sepia(95%) saturate(1500%) hue-rotate(199deg) brightness(.8)}.study-controls{display:flex;align-items:center;gap:9px}.focus-control{display:flex;align-items:center;gap:9px;font-size:10px;color:var(--muted)}select{font:inherit;border:1px solid var(--line);border-radius:7px;color:#32445e;background:white;padding:8px 9px;max-width:100%;font-size:11px;min-height:35px}.study-controls .iconbtn{border-color:transparent}.study-controls #help{font-weight:700;border:1px solid var(--line);width:29px;min-height:29px;padding:4px;border-radius:50%}
.workspace{display:grid;grid-template-columns:minmax(0,1fr) 326px;border:1px solid var(--line);border-radius:15px;background:#fff;flex:1;min-height:0;overflow:hidden;box-shadow:0 8px 24px #24395904}.stage-wrap{position:relative;min-width:0;min-height:0;display:flex;flex-direction:column;background:radial-gradient(ellipse at 47% 46%,#fff 8%,#f5f8fe 80%)}.stage-heading{display:flex;align-items:center;gap:14px;min-height:54px;padding:12px 18px 0;z-index:4;flex-shrink:0}.stage-heading p{font-size:10px;color:var(--muted);margin-left:auto}.stage-heading #model-status{display:none}#library-toggle{display:flex;align-items:center;gap:8px;font-size:11px;padding:7px 10px;min-height:32px;box-shadow:0 2px 5px #203b6510}#library-toggle img{width:16px;height:16px;opacity:.55}#library-toggle span{margin-left:10px;color:var(--muted)}#library-toggle[aria-expanded=true]{background:var(--blue-soft);border-color:#9fbbeb}#stage{position:relative;flex:1;min-height:100px;touch-action:none;outline:none}#stage canvas{position:absolute;inset:0;display:block;width:100%;height:100%;touch-action:none}#loading{position:absolute;inset:45% 15px auto;text-align:center;color:var(--muted);font-size:16px}.stage-status{display:flex;align-items:center;justify-content:center;gap:20px;min-height:27px;padding:0 18px 6px;font-size:10px;color:var(--muted);flex-shrink:0}.mouse-help{font-size:9px;color:#8a96a9}#selection-strip{display:flex;align-items:center;gap:6px;font-size:10px;color:#526681}.dot{width:7px;height:7px;flex:0 0 7px;border-radius:50%;background:var(--region,#0759d9);display:inline-block}
.viewer-tools{padding:0 18px 17px;flex-shrink:0}.view-controls{display:flex;justify-content:center;align-items:center;gap:3px;margin:0 0 13px}.view-controls button{padding:5px 10px;min-height:28px;font-size:10px;background:transparent;border-color:transparent;border-radius:6px}.view-controls button.active{background:#e8f0ff;color:var(--blue);font-weight:700}.view-controls button:hover{background:#fff;border-color:var(--line)}.tool-divider{height:16px;border-left:1px solid var(--line);margin:0 5px}.model-controls{display:flex;align-items:center;gap:20px;border-top:1px solid var(--line);padding-top:13px}.layer-tabs{display:flex;border:1px solid var(--line);border-radius:7px;padding:3px;background:white;flex-shrink:0}.layer-tabs button{border:0;font-size:10px;padding:5px 9px;min-height:27px;border-radius:4px;color:var(--muted)}.layer-tabs button[aria-pressed=true]{background:var(--blue-soft);color:var(--blue);font-weight:700}.control-line{display:flex;flex:1;align-items:center;gap:15px}.control-line label{font-size:10px;white-space:nowrap}.control-line output{color:var(--muted);font-size:9px;margin-left:6px;display:none}input[type=range]{accent-color:var(--blue);width:100%;height:4px;margin:0;cursor:pointer;min-width:50px}.view-options{position:relative}.view-options>button{font-size:10px;border:0;background:transparent;white-space:nowrap;padding:5px 0;min-height:28px;color:var(--muted)}#view-options-panel{position:absolute;bottom:calc(100% + 12px);right:0;z-index:15;display:grid;gap:5px;padding:8px;background:white;border:1px solid var(--line);box-shadow:0 8px 28px #1c366822;border-radius:9px;width:165px}#view-options-panel button{font-size:11px;text-align:left;border:0}#view-options-panel button[aria-pressed=true]{background:var(--blue-soft);color:var(--blue)}
.library{position:absolute;top:57px;left:18px;z-index:12;width:276px;max-height:calc(100% - 145px);background:#fff;border:1px solid var(--line);border-radius:11px;box-shadow:0 14px 45px #23395528;padding:14px;display:flex;flex-direction:column;overflow:hidden}.library-top{display:flex;justify-content:space-between;align-items:center;font-size:12px;margin-bottom:10px}.library-top button{font-size:21px;min-height:26px;padding:0 5px;border:0;line-height:1}.search input{width:100%;font-size:12px;padding:10px;border:1px solid var(--line);border-radius:6px;background:#f9fbff;color:var(--ink)}#group-filter{width:100%;margin:7px 0 12px;font-size:11px}#structure-list{overflow:auto;scrollbar-width:thin;min-height:70px}.group-title{font-size:9px;font-weight:700;letter-spacing:.05em;color:var(--muted);margin:14px 7px 6px;text-transform:uppercase}.group-title:first-child{margin-top:2px}.structure-row{border:0;background:transparent;display:flex;align-items:center;gap:8px;font-size:11px;min-height:33px;width:100%;padding:7px 8px;text-align:left}.structure-row.active{background:var(--blue-soft);color:var(--blue);font-weight:600}.structure-row .sub{padding-left:7px}.extension{font-size:8px;color:var(--muted);margin-left:auto}
.activity{border-left:1px solid var(--line);background:#fff;min-height:0;overflow:hidden}#activity-content{height:100%;overflow:auto;padding:26px;scrollbar-width:thin}.eyebrow,.question-kind{font-size:9px;font-weight:700;letter-spacing:.09em;color:var(--blue);text-transform:uppercase;margin-bottom:12px}.tag{display:flex;align-items:center;gap:7px;font-size:11px;color:var(--muted);margin:11px 0 20px}.detail-tabs{display:flex;border-bottom:1px solid var(--line);gap:18px;margin:0 0 18px}.detail-tabs button{padding:9px 0;border:0;background:none;min-height:34px;border-radius:0;color:var(--muted);font-size:11px;border-bottom:2px solid transparent}.detail-tabs button.active{color:var(--blue);border-bottom-color:var(--blue);font-weight:700}.detail-block h3{font-size:11px;margin-bottom:8px;color:var(--ink);font-weight:700}.detail-block p{font-size:12px;color:#526079;line-height:1.85}.detail-context{font-size:10px;margin-top:16px;color:var(--muted)}.detail-context summary{cursor:pointer;color:var(--blue)}.detail-context p{margin-top:8px;font-size:10px;line-height:1.7}.is-detail{display:flex;flex-direction:column}.detail-content{flex:1;min-height:100px}.detail-actions{display:flex;gap:7px;margin-top:20px;flex-wrap:wrap}.detail-actions button{font-size:10px;min-height:31px;padding:6px 9px}.ced{font-size:9px;color:#8490a5;margin-top:12px}.actions{display:flex;flex-wrap:wrap;gap:6px;margin-top:15px}.actions button{font-size:11px}.quiet{font-size:10px;color:var(--muted);line-height:1.7;margin-top:14px}.nuance{font-size:11px;color:var(--muted)}.setup-copy{font-size:12px;color:var(--muted);margin-top:12px}.setup-icon{width:36px;height:36px;margin-bottom:14px;opacity:.8}.activity-cards{display:grid;grid-template-columns:1fr 1fr;gap:8px;margin-top:20px}.activity-card{text-align:left;padding:12px 10px;font-size:12px;font-weight:700;min-height:83px}.activity-card small{display:block;font-weight:400;color:var(--muted);font-size:9px;margin-top:6px;line-height:1.4}.activity-card[aria-pressed=true]{color:var(--blue);border-color:#82abed;background:var(--blue-soft)}.activity-card img{width:19px;height:19px;display:block;margin-bottom:8px;opacity:.65}.setup-options{display:flex;gap:15px;align-items:center;margin-top:20px}.field{font-size:11px;display:flex;justify-content:space-between;align-items:center;gap:10px;margin:14px 0}.field select{flex:1}.check{display:flex;align-items:center;gap:7px;font-size:10px;color:var(--muted);margin:12px 0}.check input{accent-color:var(--blue)}.location-note{font-size:11px;margin-top:18px;line-height:1.75;color:var(--muted)}
/* Question content may scroll; answer controls remain available. */
#activity-content.is-question{display:flex;flex-direction:column;padding:0;overflow:hidden}.question-scroll{flex:1;min-height:0;overflow:auto;padding:22px 24px 16px;scrollbar-width:thin}.session-top{display:flex;align-items:center;justify-content:space-between;color:var(--muted);font-size:10px;margin-bottom:16px}.session-top button{font-size:9px;border:0;min-height:25px;padding:3px 0}.progress-track{height:4px;background:#eef2f8;border-radius:8px;overflow:hidden;margin-bottom:20px}.progress-track>div{height:100%;background:var(--blue);border-radius:8px;transition:width .2s}.question-text{font-size:21px;line-height:1.5;letter-spacing:-.025em;font-weight:700}.answer-method{display:none}.question-instruction{font-size:10px;color:var(--muted);margin-top:13px;line-height:1.75}.answer-dock{flex-shrink:0;padding:12px 24px 18px;border-top:1px solid var(--line);background:#fff}.answer-choice{font-size:10px;color:var(--muted);line-height:1.6}.answer-dock .wide{margin-top:10px;min-height:41px;font-size:12px;padding:10px}.feedback:empty{display:none}.feedback{margin-top:10px;padding:11px 12px;border-radius:8px;font-size:11px;line-height:1.6;max-height:132px;overflow:auto}.feedback strong{display:block;margin-bottom:4px}.feedback p{font-size:10px;line-height:1.7}.feedback.good{color:#166c4b;background:#eef8f2;border:1px solid #cfe8db}.feedback.bad{color:#9c3545;background:#fff3f3;border:1px solid #f1d4da}.feedback.neutral{color:#3e5b87;background:#f1f5fc;border:1px solid #dce6f4}.session-actions{display:flex;gap:10px;margin-top:8px}.session-actions button{font-size:9px;flex:1;min-height:27px;padding:4px 1px;border:0;background:none;color:var(--muted);white-space:nowrap}.session-actions button:hover{color:var(--blue)}.answer-list{display:grid;gap:8px;margin-top:19px}.answer-option{text-align:left;font-size:11px;padding:11px;line-height:1.5}.answer-option.selected{background:var(--blue-soft);color:var(--blue);border-color:#83adee}.score-ring{width:110px;height:110px;border-radius:50%;background:conic-gradient(var(--blue) calc(var(--score)*1%),#edf2fa 0);display:grid;place-items:center;margin:24px auto}.score-ring>span{width:94px;height:94px;background:#fff;border-radius:50%;display:grid;place-items:center;font-size:28px;font-weight:800}.score-description{text-align:center;font-size:12px}.review-item{border-top:1px solid var(--line);padding:16px 0;font-size:11px}.review-status{font-size:9px;color:var(--muted);margin-bottom:6px}.review-item p{font-size:10px;margin-top:6px}.score-title{font-size:25px}#exit-prompt{flex-shrink:0;margin:10px;max-height:160px}.review-item b{display:block}.detail-block:has(.review-item){margin-top:22px}
#tooltip{position:absolute;pointer-events:none;z-index:6;background:#fff;color:var(--ink);border:1px solid #d4e0f2;border-radius:8px;padding:10px 13px;box-shadow:0 5px 24px #2546761c;font-size:12px;font-weight:600;max-width:230px;opacity:0;visibility:hidden;transform:translateY(4px);transition:opacity .16s,transform .16s,visibility 0s linear .16s}#tooltip.visible{opacity:1;visibility:visible;transform:translateY(0);transition:opacity .16s,transform .16s,visibility 0s}#aim{display:none;position:absolute;left:50%;top:50%;transform:translate(-50%,-50%);pointer-events:none;color:var(--blue);font-size:26px;text-shadow:0 0 4px white}#stage.keyboard-aim #aim{display:block}#feedback-flash{position:absolute;inset:0;pointer-events:none;z-index:3;opacity:0;background:radial-gradient(ellipse at 50% 48%,#f7a4ba40,#e865854d)}.flash-wrong{animation:answer-wash .55s ease-out}@keyframes answer-wash{0%{opacity:0}22%{opacity:.75}100%{opacity:0}}
/* Feedback belongs with the question. Effects are clipped to this card. */
#next-question.awaiting-celebration{visibility:hidden}
#question-feedback{position:relative;isolation:isolate;margin-top:22px;padding:22px 20px;border-radius:12px;max-height:none;overflow:hidden}
#question-feedback h3{font-size:19px;line-height:1.45;letter-spacing:-.025em;margin:0 0 10px;font-weight:700;color:var(--ink)}
#question-feedback p{font-size:14px;line-height:1.8;color:#405771}
#question-feedback.good{background:linear-gradient(145deg,#eff9f5,#f9fcff);border:1px solid #cbe7dd}
#question-feedback.bad{background:#fff6f8;border-color:#f0d6df}
#question-feedback.bad h3{color:#9c3545}
.feedback-success{display:flex;align-items:center;gap:10px;margin-bottom:15px;font-size:15px;font-weight:700;color:#127b60}
.success-check{display:grid;place-items:center;flex:0 0 34px;width:34px;height:34px;border-radius:50%;background:#16866c;color:#fff;box-shadow:0 0 0 6px #dff3eb;animation:success-check .42s cubic-bezier(.2,.8,.3,1.2) both}
.success-check svg{width:24px;height:24px}
.answer-celebration{position:absolute;inset:0;overflow:hidden;pointer-events:none;z-index:1}
.celebration-piece{position:absolute;left:var(--origin);top:65px;width:5px;height:9px;border-radius:1px;background:var(--color);opacity:0;animation:answer-confetti 1.2s var(--delay) cubic-bezier(.17,.7,.32,1) both;will-change:transform,opacity}
.celebration-piece.is-star{width:11px;height:11px;border-radius:0;clip-path:polygon(50% 0,61% 34%,98% 36%,69% 58%,79% 95%,50% 74%,21% 95%,31% 58%,2% 36%,39% 34%)}
@keyframes answer-confetti{0%{opacity:0;transform:translate(-50%,0) scale(.25) rotate(0deg)}12%{opacity:1}52%{opacity:1;transform:translate(var(--dx),var(--dy)) scale(1) rotate(var(--spin))}100%{opacity:0;transform:translate(var(--dx),var(--fall)) scale(.6) rotate(var(--spin))}}
@keyframes success-check{0%{opacity:0;transform:scale(.55)}65%{opacity:1;transform:scale(1.12)}100%{opacity:1;transform:scale(1)}}

dialog{max-width:660px;width:calc(100% - 36px);max-height:85vh;padding:32px;border:1px solid var(--line);border-radius:16px;color:var(--ink);background:white}dialog::backdrop{background:#14264466;backdrop-filter:blur(4px)}dialog h2{margin-bottom:16px}dialog h3{margin:22px 0 8px}dialog p,dialog li{font-size:12px;line-height:1.8}dialog li{margin-bottom:8px}.dialog-close{position:absolute;top:10px;right:12px;border:0;font-size:22px}.text-mode-message{font-size:13px!important;padding:15px;line-height:1.7}
@media(min-width:1500px){.workspace{grid-template-columns:minmax(0,1fr) 365px}.lab-shell{padding-top:26px}.lab-intro{margin-bottom:24px}h1{font-size:39px}#activity-content{padding:30px}.detail-block p{font-size:13px}.question-scroll{padding:28px}.answer-dock{padding:16px 28px 22px}.question-text{font-size:23px}.stage-heading{padding:17px 24px 0}.viewer-tools{padding:0 26px 21px}}
@media(max-width:1100px){.site-header{padding:0 24px;gap:20px}.site-links{gap:19px}.brand b{font-size:20px}.account-links{gap:16px}.lab-shell{padding:18px 22px 20px}.title-line{gap:16px}.title-line p{font-size:11px}.free-label{font-size:9px}.workspace{grid-template-columns:minmax(0,1fr) 300px}.stage-heading p{font-size:9px}.stage-status .mouse-help{display:none}.model-controls{gap:12px}.control-line{gap:9px}.layer-tabs button{font-size:9px;padding:5px 7px}.view-options>button{font-size:9px}.control-line label{font-size:9px}.viewer-tools{padding:0 14px 15px}#activity-content{padding:23px}.question-scroll{padding:22px}.answer-dock{padding:12px 22px 16px}.study-controls{gap:5px}.mode-tabs button{padding:8px 13px}.mode-tabs img{width:17px;height:17px}}
@media(max-width:880px){.site-links{display:none}.site-header{height:68px;flex-basis:68px}.lab-intro{align-items:flex-start}.title-line{display:block}.title-line p{margin-top:8px}.free-label{margin-top:25px;max-width:155px;white-space:normal;line-height:1.7}.lab-shell{padding:17px 16px}.lab-toolbar{gap:10px}.mode-tabs button{padding:8px 10px}.study-controls #sound{display:none}.focus-control{font-size:0;gap:0}.focus-control select{font-size:10px;max-width:157px}.workspace{grid-template-columns:minmax(0,1fr) 280px}.model-controls{flex-wrap:wrap;gap:10px}.control-line{min-width:120px}.view-options{margin-left:auto}.stage-heading p{display:none}.stage-status{padding-inline:12px}#activity-content{padding:22px}.question-scroll{padding:20px}.answer-dock{padding:12px 20px}.stage-status{min-height:35px}}
@media(max-width:650px){body{height:auto;min-height:100dvh;overflow:auto}.site-header{padding:0 16px;gap:10px;height:66px;flex-basis:66px}.brand img{width:34px;height:34px}.brand b{font-size:17px}.brand small{font-size:7px}.brand{gap:7px}.account-links>a:not(.primary){display:none}.account-links .primary{font-size:10px;padding:9px 11px}.lab-shell{padding:18px 12px;display:block}.lab-intro{margin-bottom:17px;gap:10px}h1{font-size:31px}.title-line p{font-size:10px;max-width:190px;line-height:1.65}.breadcrumb{font-size:8px}.free-label{font-size:8px;max-width:105px;margin-top:23px;gap:5px;align-items:flex-start}.free-label i{margin-top:4px;flex-shrink:0}.lab-toolbar{flex-wrap:wrap;gap:9px}.mode-tabs{width:100%;gap:4px}.mode-tabs button{flex:1;justify-content:center;min-height:39px}.study-controls{width:100%;justify-content:flex-end}.study-controls .focus-control{font-size:10px;gap:8px;margin-right:auto}.study-controls #sound{display:block}.workspace{display:flex;flex-direction:column;overflow:visible}.stage-wrap{height:490px;border-radius:15px 15px 0 0;overflow:hidden}.activity{border-left:0;border-top:1px solid var(--line);border-radius:0 0 15px 15px}.stage-heading{padding:11px 14px 0}.stage-heading p{display:block;font-size:8px}.viewer-tools{padding:0 12px 15px}.model-controls{gap:10px}.view-options{display:none}.control-line{min-width:120px}.layer-tabs button{padding:5px 7px}.view-controls{margin-bottom:11px}#activity-content{height:auto;padding:24px}.detail-content{min-height:0}.is-detail .detail-actions{margin-top:15px}.session-active .workspace{flex-direction:column-reverse}.session-active .stage-wrap{border-radius:0 0 15px 15px}.session-active .activity{border-radius:15px 15px 0 0;border-top:0;border-bottom:1px solid var(--line)}#activity-content.is-question{height:auto;min-height:400px}.question-scroll{padding:19px 21px 14px}.question-scroll{overflow:visible;flex:none}#question-feedback{padding:20px;margin-top:18px}.question-text{font-size:20px}.setup-copy{max-width:330px}.activity-cards{grid-template-columns:repeat(4,minmax(0,1fr));gap:5px}.activity-card{font-size:10px;padding:10px 7px;min-height:76px}.activity-card small{font-size:8px}.activity-card img{width:18px;height:18px}.library{left:12px;width:260px}.stage-status .mouse-help{display:none}.stage-status{min-height:26px}.study-controls .iconbtn{min-height:31px}.detail-tabs{margin-bottom:15px}}
@media(max-height:720px) and (min-width:881px){.lab-shell{padding-top:14px;padding-bottom:15px}.lab-intro{margin-bottom:15px}h1{font-size:30px}.lab-toolbar{margin-bottom:9px}.stage-heading{min-height:46px}.viewer-tools{padding-bottom:13px}.view-controls{margin-bottom:8px}.model-controls{padding-top:10px}#activity-content{padding-top:22px;padding-bottom:21px}.question-scroll{padding-top:18px}.is-detail .tag{margin-bottom:13px}.detail-actions{margin-top:12px}.detail-context{margin-top:10px}}
@media(prefers-reduced-motion:reduce){*,*::before,*::after{animation:none!important;transition:none!important}#tooltip{transform:none}}

.lab-help{max-width:580px;padding:32px}.lab-help section{margin-top:20px}.lab-help h3{margin:0 0 7px;font-size:14px}.lab-help p{font-size:13px;color:var(--muted);line-height:1.8}.lab-help .help-model-note{margin-top:22px;font-size:11px}.help-footer{display:flex;gap:24px;border-top:1px solid var(--line);padding-top:18px;margin-top:22px;font-size:12px}
/* Expanded notes must retain their own height before the action buttons. */
.is-detail>*{flex-shrink:0}.is-detail .detail-content{flex:1 0 auto;min-height:0}
.is-detail .detail-context p{overflow-wrap:anywhere}
/* Pretext supplies the exact review-panel heights; only one opens at a time. */
#activity-content.is-review{display:flex;flex-direction:column;overflow:hidden;padding:0}
.results-heading{padding:24px 24px 18px;flex-shrink:0;border-bottom:1px solid var(--line)}
.results-heading .eyebrow{margin-bottom:8px}.results-heading .score-title{font-size:27px}
.results-score{display:flex;align-items:center;gap:18px;margin:17px 0 12px}
.results-score>strong{font-size:40px;line-height:1;font-weight:800;letter-spacing:-.045em;color:var(--blue)}
.results-score>strong span{font-size:24px}.results-score p{font-size:11px;line-height:1.65;color:var(--muted)}
.results-note{font-size:10px;color:var(--muted);line-height:1.6}
.review-scroll{flex:1;min-height:150px;overflow-y:scroll;scrollbar-width:thin;scrollbar-color:#acc2e3 transparent;scrollbar-gutter:stable;padding:0 14px;overscroll-behavior:contain;overflow-anchor:none}
.review-scroll:focus-visible{outline:2px solid #8ab8ff;outline-offset:-3px}
.review-list>.review-item{border:0;border-bottom:1px solid var(--line);padding:0}
.review-item>h3{margin:0}.review-toggle{display:flex;align-items:center;gap:10px;width:100%;padding:17px 10px;border:0;border-radius:0;background:transparent;text-align:left;min-height:75px}
.review-toggle:hover,.review-toggle[aria-expanded=true]{background:#f7faff}
.review-heading{flex:1;min-width:0}.review-number{display:block;font-size:12px;font-weight:700;color:var(--ink)}
.review-target{display:block;font-size:10px;line-height:1.65;color:var(--muted);font-weight:400;margin-top:3px}
.review-outcome{font-size:9px;font-weight:600;border-radius:5px;padding:4px 6px;white-space:nowrap}.review-outcome.is-correct{background:#eaf6f1;color:#12765b}.review-outcome.is-revisit{background:#f1f4fa;color:#586b87}
.review-chevron{width:7px;height:7px;border-right:1.5px solid var(--muted);border-bottom:1.5px solid var(--muted);transform:rotate(45deg);transition:transform .26s ease;margin-right:3px;flex-shrink:0}
.review-toggle[aria-expanded=true] .review-chevron{transform:rotate(225deg)}
.review-body{height:0;overflow:clip;transition:height .28s cubic-bezier(.2,.7,.3,1)}
.review-copy{padding:4px 16px 18px}.review-copy p{color:#40536f}.review-copy [data-review-copy=label]{color:var(--ink)}.review-copy .review-context{color:var(--muted)}
.results-actions{display:grid;grid-template-columns:1fr 1fr;gap:8px;padding:16px 24px;border-top:1px solid var(--line);flex-shrink:0}
.results-actions button{font-size:11px}.results-actions .review-export{grid-column:1/-1;padding:3px;border:0;min-height:24px;background:none;font-size:9px;color:var(--muted)}
@media(max-width:650px){#activity-content.is-review{height:auto}.review-scroll{flex:none;max-height:440px}.results-heading{padding:22px}.results-actions{padding:16px 22px}}
/* Keep starting an activity visible on laptop-height screens. */
#activity-content.is-setup{display:flex;flex-direction:column;padding:0;overflow:hidden}
.setup-scroll{padding:24px 26px 18px;flex:1;min-height:0;overflow:auto;scrollbar-width:thin}
.setup-dock{padding:14px 26px 24px;border-top:1px solid var(--line);flex-shrink:0}
.setup-dock .field{margin:0 0 12px}.setup-dock .check{margin:10px 0 0}.setup-dock .wide{margin-top:14px}
#setup-status:empty{display:none}.activity-card{display:flex;align-items:center;gap:8px;min-height:58px;padding:13px 10px;font-size:12px}
.activity-card img{width:22px;height:22px;margin:0}.detail-block p{font-size:13px}.stage-status{font-size:11px}.view-controls button{font-size:11px}.layer-tabs button{font-size:11px}.control-line label{font-size:11px}
@media(min-width:1500px){.setup-scroll{padding:30px}.setup-dock{padding:16px 30px 26px}}
@media(max-width:1100px){.setup-scroll{padding:22px}.setup-dock{padding:14px 22px 22px}.layer-tabs button{font-size:10px;padding:5px 7px}.control-line label{font-size:10px}.model-controls{gap:10px}}
@media(max-width:650px){#activity-content.is-setup{height:auto}.setup-scroll{overflow:visible;padding:22px}.setup-dock{padding:16px 22px 22px}.activity-cards{grid-template-columns:repeat(2,minmax(0,1fr))}.activity-card{min-height:50px}.view-options{display:block}.model-controls{flex-wrap:wrap}.view-options>button{font-size:10px}}