:root{color-scheme:light;font-family:Segoe UI,Inter,ui-sans-serif,system-ui,sans-serif;background:#f5f6f0;color:#20362d;font-synthesis:none}*{box-sizing:border-box}html{min-width:280px;min-height:100%;background:#f5f6f0}body{min-width:280px;min-height:100vh;margin:0;background:#f5f6f0}button,input,textarea,select{font:inherit}button{color:inherit}.prototype-app,.p-auth-shell{--p-bg: #f5f6f0;--p-paper: #fff;--p-ink: #20362d;--p-muted: #64716a;--p-line: #dce4dc;--p-accent: #245c49;--p-accent-dark: #173f31;--p-on-accent: #fff;--p-soft: #e7f2e6;--p-gold: #f4d578;--p-gold-ink: #655016;--p-attention: #f8e7c7;min-height:100vh;background:var(--p-bg);color:var(--p-ink);font-size:15px;line-height:1.5}.prototype-app h1,.prototype-app h2,.prototype-app h3,.prototype-app p,.p-auth-shell h1,.p-auth-shell h2,.p-auth-shell p{margin:0}.prototype-app h1,.p-auth-shell h1{font-size:clamp(2rem,5vw,2.55rem);line-height:1.08;letter-spacing:-.045em;font-weight:600}.prototype-app h2,.p-auth-shell h2{font-size:clamp(1.35rem,3vw,1.7rem);line-height:1.2;letter-spacing:-.025em;font-weight:600}.prototype-app h3{font-size:1.05rem}.prototype-app small{display:block;color:var(--p-muted)}.p-skip{position:fixed;top:.5rem;left:.5rem;z-index:100;padding:.65rem .85rem;border-radius:9px;background:var(--p-ink);color:#fff;transform:translateY(-160%)}.p-skip:focus{transform:translateY(0)}.p-header{position:sticky;top:0;z-index:20;display:grid;grid-template-columns:minmax(190px,1fr) auto minmax(190px,1fr);align-items:center;gap:1rem;min-height:74px;padding:.85rem clamp(1rem,4vw,2.2rem);border-bottom:1px solid var(--p-line);background:color-mix(in srgb,var(--p-paper) 94%,transparent);backdrop-filter:blur(12px)}.p-brand{display:flex;align-items:center;gap:.6rem;width:fit-content;padding:0;border:0;background:transparent;font-size:1.1rem;font-weight:700;cursor:pointer}.p-mark{display:grid;width:32px;height:34px;place-items:center;border-radius:10px;background:var(--p-accent);color:var(--p-on-accent);font-size:1.25rem;font-weight:700;transform:rotate(-5deg)}.p-mark.large{width:52px;height:56px;margin-bottom:1.5rem;border-radius:15px;font-size:2rem}.p-role-badge,.p-pill{display:inline-flex;align-items:center;gap:.35rem;width:fit-content;padding:.3rem .65rem;border-radius:999px;background:var(--p-soft);color:var(--p-accent);font-size:.75rem;font-weight:700;white-space:nowrap}.p-pill.gold{background:var(--p-gold);color:var(--p-gold-ink)}.p-nav{display:flex;gap:.25rem}.p-nav button{min-height:42px;padding:.55rem .9rem;border:0;border-radius:10px;background:transparent;color:var(--p-muted);cursor:pointer}.p-nav button[aria-current=page]{background:var(--p-soft);color:var(--p-accent);font-weight:700}.p-avatar{justify-self:end;display:grid;width:44px;height:44px;place-items:center;border:1px solid var(--p-line);border-radius:50%;background:var(--p-paper);font-weight:700;cursor:pointer}.p-avatar[aria-current=page]{border-color:var(--p-accent);background:var(--p-soft);color:var(--p-accent)}.p-main{width:min(920px,calc(100% - 2rem));min-height:calc(100vh - 132px);margin:0 auto;padding:clamp(2rem,6vw,3.4rem) 0 3rem}.p-footer{display:flex;justify-content:space-between;gap:1rem;padding:1rem clamp(1rem,4vw,2.2rem);border-top:1px solid var(--p-line);color:var(--p-muted);font-size:.8rem}.p-intro{display:flex;justify-content:space-between;gap:1rem;margin-bottom:1.7rem}.p-intro>div{max-width:710px}.p-intro h1{margin:.45rem 0 .55rem}.p-intro p:not(.p-kicker){color:var(--p-muted);font-size:1.05rem}.p-kicker{color:var(--p-muted);font-size:.76rem;font-weight:750;letter-spacing:.08em;text-transform:uppercase}.p-muted{color:var(--p-muted)}.p-primary,.p-secondary,.p-back,.p-link,.p-list-button,.p-option{cursor:pointer}.p-primary,.p-secondary,.p-back{display:inline-flex;min-height:44px;align-items:center;justify-content:center;gap:.6rem;padding:.7rem 1rem;border-radius:11px;font-weight:650}.p-primary{border:1px solid var(--p-accent);background:var(--p-accent);color:var(--p-on-accent);box-shadow:0 3px 0 var(--p-accent-dark)}.p-secondary,.p-back{border:1px solid var(--p-line);background:var(--p-paper)}.p-back{margin-bottom:1.5rem;color:var(--p-accent)}.p-link{padding:.35rem 0;border:0;background:transparent;color:var(--p-accent);font-weight:650;text-decoration:underline;text-underline-offset:3px}.p-primary.wide{width:100%}.p-primary:disabled,.p-secondary:disabled{cursor:default;opacity:.55;box-shadow:none}.p-primary:hover:not(:disabled),.p-secondary:hover:not(:disabled),.p-back:hover,.p-list-button:hover,.p-option:hover:not(:disabled){filter:brightness(.97)}button:focus-visible,input:focus-visible,textarea:focus-visible,summary:focus-visible{outline:3px solid color-mix(in srgb,var(--p-accent) 60%,white);outline-offset:3px}.p-actions{display:flex;align-items:center;flex-wrap:wrap;gap:.75rem;margin-top:1.5rem}.p-actions.compact{margin-top:.85rem}.p-actions.center{justify-content:center}.p-confirm{display:flex;align-items:flex-start;gap:.65rem;max-width:38rem;color:var(--p-muted)}.p-confirm input{width:auto;margin-top:.2rem}.p-toolbar{display:flex;justify-content:space-between;align-items:center;gap:1rem;margin-bottom:1rem;color:var(--p-muted)}.p-trail{display:flex;align-items:center;gap:.8rem;margin:1rem 0 1.4rem;color:var(--p-muted);font-size:.82rem}.p-trail>div{height:7px;flex:1;overflow:hidden;border-radius:10px;background:var(--p-line)}.p-trail i,.p-question-progress i{display:block;height:100%;border-radius:inherit;background:var(--p-accent);transition:width .25s ease}.p-question-progress{height:7px;margin:.8rem 0 1.2rem;overflow:hidden;border-radius:10px;background:var(--p-line)}.p-quest-card,.p-panel,.p-problem,.p-course-card{border:1px solid var(--p-line);border-radius:17px;background:var(--p-paper)}.p-quest-card{padding:clamp(1.35rem,4vw,2rem);box-shadow:0 5px 0 var(--p-line)}.p-quest-card h2{margin:1rem 0 .5rem}.p-card-top,.p-panel-head{display:flex;justify-content:space-between;align-items:flex-start;gap:1rem}.p-meta{display:flex;flex-wrap:wrap;gap:1.2rem;margin-top:1rem;color:var(--p-muted);font-size:.86rem}.p-meta span{display:inline-flex;align-items:center;gap:.4rem}.p-review-invite{display:flex;align-items:center;justify-content:space-between;gap:1rem;margin-top:1.6rem;padding-top:1.35rem;border-top:1px solid var(--p-line)}.p-review-invite strong{display:block;margin:.2rem 0}.p-course-card{display:grid;grid-template-columns:auto minmax(0,1fr) auto;align-items:center;gap:1.2rem;padding:1.35rem}.p-course-symbol{display:grid;width:54px;height:54px;place-items:center;border-radius:15px;background:var(--p-soft);color:var(--p-accent);font-weight:750}.p-course-card h2{margin-bottom:.25rem}.p-course-card p{margin-bottom:.65rem;color:var(--p-muted)}.p-course-actions{display:flex;flex-wrap:wrap;justify-content:flex-end;gap:.6rem}.p-metric-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:.85rem;margin-bottom:1.2rem}.p-metric-grid article{display:grid;gap:.35rem;min-height:130px;padding:1.15rem;border:1px solid var(--p-line);border-radius:14px;background:var(--p-paper)}.p-metric-grid article span,.p-metric-grid article small{color:var(--p-muted)}.p-metric-grid article strong{font-size:1.35rem;line-height:1.15}.p-panel{margin:1rem 0;padding:1.3rem}.p-panel h2{margin-bottom:.75rem}.p-panel-head p{color:var(--p-muted)}.p-list-row,.p-list-button{display:flex;align-items:center;justify-content:space-between;gap:1rem;width:100%;min-height:64px;padding:.85rem 0;border:0;border-bottom:1px solid var(--p-line);background:transparent;text-align:left}.p-list-row:last-child,.p-list-button:last-child{border-bottom:0}.p-list-row>div,.p-list-button>span:first-child{min-width:0;flex:1}.p-list-row time{color:var(--p-muted)}.p-dot{width:9px;height:9px;flex:0 0 auto;border-radius:50%;background:var(--p-accent)}.p-facts{margin:0}.p-facts div{display:flex;justify-content:space-between;gap:1rem;padding:.7rem 0;border-bottom:1px solid var(--p-line)}.p-facts dt{color:var(--p-muted)}.p-facts dd{margin:0;text-align:right}.p-steps{display:flex;gap:.7rem;margin:0 0 1.2rem;padding:0;list-style:none}.p-steps li{display:flex;align-items:center;gap:.45rem;flex:1;color:var(--p-muted)}.p-steps li span{display:grid;width:28px;height:28px;place-items:center;border-radius:50%;background:var(--p-line)}.p-steps li[aria-current=step],.p-steps li.done{color:var(--p-accent);font-weight:650}.p-steps li[aria-current=step] span,.p-steps li.done span{background:var(--p-accent);color:var(--p-on-accent)}.p-problem{padding:clamp(1.1rem,4vw,1.6rem)}.p-problem h2{margin:.5rem 0 .8rem}.p-quest-review-list{display:grid;gap:.6rem;margin:1rem 0}.p-quest-review-list .p-list-button>span:first-child{display:grid;gap:.35rem;min-width:0}.p-quest-review-list .math-text{font-size:.95rem;line-height:1.5;font-weight:400}.p-quest-submit{margin-top:1.5rem;padding-top:1rem;border-top:1px solid var(--p-line)}.p-question-prompt{margin-bottom:1.25rem}.p-question-prompt h2{font-size:clamp(1.2rem,2.4vw,1.5rem);line-height:1.45;font-weight:650}.p-question-givens{padding:.85rem 1rem;margin:1rem 0;border-left:3px solid var(--p-line);background:var(--p-bg);border-radius:0 8px 8px 0}.p-question-givens h3{margin:0 0 .45rem;font:inherit;font-weight:650}.p-question-givens p{margin:0;font-size:1rem;line-height:1.85}.p-question-instructions{color:var(--p-muted);font-size:.9rem;line-height:1.6;margin:.6rem 0 0}.p-question-instructions h3{margin:.8rem 0 .25rem;font-size:.95rem;color:var(--p-ink)}.p-question-instructions p{margin:0 0 .8rem}.p-save-status{margin:.75rem 0;font-size:.9rem;color:var(--p-muted)}.p-question-prompt,.p-feedback{overflow-wrap:anywhere}.p-question-prompt .math-fragment,.p-feedback .math-fragment{max-width:100%;overflow-x:auto;vertical-align:middle}.p-question-prompt .katex{font-size:1.08em}.p-question-givens .math-fragment.inline{display:inline-block;margin:.12rem .08rem}.p-diagram-hint{margin:1rem 0}.p-diagram-hint summary{cursor:pointer;color:var(--p-green);font-weight:600;padding:.5rem 0}.p-beam{display:block;width:100%;max-width:580px;height:auto;margin:1rem auto;color:var(--p-ink)}.p-beam text{fill:currentColor;stroke:none;font:15px Segoe UI,sans-serif}.p-option{display:flex;gap:.8rem;width:100%;min-height:52px;align-items:center;margin-top:.6rem;padding:.7rem .85rem;border:1px solid var(--p-line);border-radius:10px;background:var(--p-paper);text-align:left}.p-option>.p-option-letter{display:grid;flex:0 0 25px;width:25px;height:25px;place-items:center;border:1px solid var(--p-line);border-radius:6px;color:var(--p-muted);font-size:.78rem}.p-option.selected{border-color:var(--p-accent);background:var(--p-soft)}.p-option.correct{border-color:var(--p-accent);background:var(--p-soft);color:var(--p-accent)}.p-feedback{margin-top:1rem;padding:1rem;border-radius:12px;background:var(--p-soft);color:var(--p-accent)}.p-feedback.attention{background:var(--p-attention);color:var(--p-gold-ink)}.p-feedback p{margin:.25rem 0}.p-review-grid{display:grid;grid-template-columns:1fr 1fr;gap:1rem;align-items:start}.p-form,.p-auth-card form{display:grid;gap:.9rem}.p-course-fields{min-width:0;margin:0;padding:0;border:0}.p-form label,.p-auth-card label,.p-field{display:grid;gap:.4rem;color:var(--p-muted);font-weight:650}.p-form input,.p-form textarea,.p-auth-card input,.p-field input,.p-field textarea,.p-field select{width:100%;min-width:0;padding:.75rem;border:1px solid var(--p-line);border-radius:9px;background:var(--p-paper);color:var(--p-ink)}.p-form textarea{min-height:105px;resize:vertical}.p-status{min-height:1.5em;margin-top:.75rem!important;color:var(--p-muted)}.p-upload{display:grid;gap:.8rem}.p-file-picker{display:grid;min-height:165px;place-content:center;gap:.35rem;padding:1.4rem;border:2px dashed var(--p-line);border-radius:13px;background:var(--p-bg);text-align:center;cursor:pointer}.p-file-picker input{position:absolute;width:1px;height:1px;overflow:hidden;clip:rect(0,0,0,0)}.p-file-picker span{color:var(--p-accent);font-size:1.05rem;font-weight:750}.p-file-picker small{color:var(--p-muted)}.p-complete{max-width:610px;margin:2rem auto;text-align:center}.p-complete h1{margin:.6rem 0}.p-complete>p:not(.p-kicker){color:var(--p-muted)}.p-medal{display:grid;width:76px;height:76px;margin:0 auto 1.2rem;place-items:center;border:7px solid var(--p-paper);outline:1px solid var(--p-line);border-radius:23px;background:var(--p-gold);color:var(--p-gold-ink);font-size:2.1rem;transform:rotate(-6deg)}.p-receipt{display:grid;gap:.6rem;max-width:430px;margin:1.5rem auto;padding:1rem;border:1px solid var(--p-line);border-radius:13px;background:var(--p-paper);text-align:left}.p-receipt div{display:flex;justify-content:space-between;gap:1rem}.p-receipt span{color:var(--p-muted)}.p-state{display:grid;min-height:50vh;place-content:center;gap:.75rem;text-align:center}.p-state.compact{min-height:180px}.p-spinner{width:36px;height:36px;justify-self:center;border:4px solid var(--p-line);border-top-color:var(--p-accent);border-radius:50%;animation:p-spin .8s linear infinite}@keyframes p-spin{to{transform:rotate(360deg)}}.p-auth-shell{display:grid;grid-template-columns:minmax(0,1fr) minmax(360px,520px);align-items:center;gap:clamp(2rem,7vw,7rem);min-height:100vh;padding:clamp(1.2rem,5vw,4rem)}.p-auth-story{max-width:650px}.p-auth-story h1{max-width:610px;margin:.7rem 0 1rem;font-size:clamp(3rem,7vw,5.2rem)}.p-auth-story>p:last-of-type{max-width:600px;color:var(--p-muted);font-size:1.1rem}.p-trust-note{display:flex;gap:.8rem;margin-top:2rem;padding:1rem;border-left:4px solid var(--p-accent);background:var(--p-soft)}.p-trust-note span{color:var(--p-muted)}.p-auth-card{padding:clamp(1.4rem,4vw,2rem);border:1px solid var(--p-line);border-radius:17px;background:var(--p-paper);box-shadow:0 12px 35px #20362d14}.p-auth-card h2{margin:.35rem 0 1.3rem}.p-auth-card details{margin-top:1rem;padding-top:1rem;border-top:1px solid var(--p-line);color:var(--p-muted)}.p-auth-card summary{width:fit-content;cursor:pointer;color:var(--p-accent)}@media(max-width:760px){.p-header{grid-template-columns:1fr auto;padding:.7rem 1rem}.p-nav{grid-column:1 / -1;grid-row:2;width:100%}.p-nav button{flex:1;padding-inline:.5rem}.p-main{min-height:calc(100vh - 180px)}.p-course-card,.p-review-grid,.p-metric-grid{grid-template-columns:1fr}.p-course-actions{justify-content:flex-start}.p-course-symbol{display:none}.p-auth-shell{grid-template-columns:1fr;align-items:start}.p-auth-story h1{font-size:clamp(2.6rem,12vw,4rem)}.p-trust-note{display:grid}}@media(max-width:460px){.p-main{width:min(100% - 1.25rem,920px);padding-top:1.5rem}.p-role-badge{display:none}.p-review-invite,.p-card-top,.p-panel-head,.p-facts div,.p-footer{align-items:stretch;flex-direction:column}.p-actions>button,.p-review-invite>button,.p-panel-head>button{width:100%}.p-steps li{flex-direction:column;align-items:flex-start;font-size:.78rem}.p-auth-shell{padding:1rem}}@media(prefers-reduced-motion:reduce){*,*:before,*:after{scroll-behavior:auto!important;animation:none!important;transition:none!important}}.p-user-row{display:flex;align-items:center;justify-content:space-between;gap:1rem;padding:1rem 0;border-bottom:1px solid var(--p-line);flex-wrap:wrap;overflow-wrap:anywhere}.p-user-row p{margin:.25rem 0}.p-pdf-viewer{width:100%;min-width:0}.p-pdf-viewer iframe{display:block;width:100%;height:min(75vh,800px);min-height:360px;border:1px solid var(--p-line);border-radius:8px;background:var(--p-paper)}.p-form select{width:100%;padding:.8rem;border:1px solid var(--p-line);border-radius:8px;background:var(--p-paper);color:inherit;font:inherit}.p-math-answer,.p-pack-diagram{min-width:0;max-width:100%;width:100%}.p-math-answer math-field{display:block;width:100%;min-width:0;max-width:100%;min-height:64px;padding:12px;border:1px solid #bdcec5;border-radius:12px;background:#fff;font-size:1.3rem}.p-pack-diagram{margin:20px 0;border:1px solid #d9e2da;border-radius:14px;padding:16px;background:#fff}.p-diagram-scroll{width:100%;min-width:0;overflow:auto;max-height:75vh}.p-pack-diagram img,.p-panel.p-form img{display:block;width:100%;height:auto;max-width:100%}.p-structured-diagram{display:block;width:100%;min-width:420px}.p-diagram-label{color:#173e33;font-size:20px;line-height:1.5}.p-pack-diagram figcaption{color:#50685b;font-size:.9rem;margin:12px 0}.math-fragment.display{display:block;overflow-x:auto;max-width:100%}.math-text.preserve-whitespace{white-space:pre-wrap}.p-option>.p-option-text{flex:1 1 0;min-width:0;white-space:normal;overflow-wrap:break-word}.p-pack-card{grid-template-columns:minmax(0,1fr) auto}.p-pack-card>div{min-width:0}.p-lesson-toc{display:grid;gap:10px;margin:20px 0}.p-lesson-toc a{color:var(--p-green, #235c4b)}[id^=pack-lesson-]{scroll-margin-top:100px;border-top:1px solid #d9e2da;margin-top:24px;padding-top:16px}.p-answer-actions{position:static;background:var(--p-paper);padding:12px 0}.p-math-answer{scroll-margin-bottom:calc(var(--student-keyboard-height, 0px) + 90px)}.p-problem:has(.p-math-answer){padding-bottom:calc(var(--student-keyboard-height, 0px) + 24px)}.p-pack-card .p-course-actions{min-width:140px}@media(max-width:600px){.p-pack-card{grid-template-columns:1fr}}.p-study-help{margin:1rem 0;text-align:left}.p-study-help>div{margin-top:.8rem;padding:1rem;border:1px solid var(--p-border, #d4ded7);border-radius:12px}.p-lesson-reading{max-width:68ch;line-height:1.8;margin:1.5rem 0}.p-lesson-reading aside{margin-top:1rem}.p-study-help details,.p-lesson-reading details{margin-top:.8rem}.p-study-help summary,.p-lesson-reading summary{cursor:pointer;padding:.6rem 0}.p-lesson-reading .math-fragment{max-width:100%;overflow-x:auto;vertical-align:middle}.p-study-closeout{text-align:left}.p-study-closeout p{max-width:65ch}.p-roadmap h2{margin-top:.3rem}.p-roadmap-next{margin:1.2rem 0;padding:1.2rem;background:var(--p-soft);border:1px solid var(--p-line);border-radius:12px}.p-roadmap-next h3{margin:.4rem 0}.p-roadmap-topics{list-style:none;margin:1.5rem 0;padding:0}.p-roadmap-topic{display:grid;grid-template-columns:2rem minmax(0,1fr);gap:1rem;position:relative;padding:1rem;margin:.8rem 0;border:1px solid transparent;border-radius:10px}.p-roadmap-topic:not(:last-child):after{content:"";position:absolute;left:2rem;top:calc(100% - .3rem);height:1.4rem;border-left:2px solid var(--p-line)}.p-roadmap-topic.suggested{background:var(--p-soft);border-color:var(--p-accent)}.p-roadmap-marker{display:grid;place-items:center;width:2rem;height:2rem;border:1px solid var(--p-line);background:var(--p-paper);font-weight:600}.p-roadmap-topic h3{margin:0 0 .5rem;font-size:1rem}.p-roadmap-topic h3 button{text-align:left;font:inherit;overflow-wrap:anywhere}.p-roadmap-topic p{margin:.6rem 0}.p-roadmap-topic small{color:var(--p-muted)}.p-roadmap-evidence{display:flex;gap:.5rem;align-items:center;flex-wrap:wrap}.p-roadmap-topic summary{cursor:pointer;font-size:.85rem;color:var(--p-muted)}.p-roadmap-more{margin-bottom:1rem}.p-roadmap-more>summary{cursor:pointer;color:var(--p-accent);padding:.7rem 0}.p-roadmap-status.review{background:var(--p-attention)}.p-roadmap-status.strong{background:var(--p-soft)}.p-roadmap-reviews{border-top:1px solid var(--p-line);padding-top:1rem}.p-roadmap-reviews summary{cursor:pointer}.p-roadmap-reviews .p-list-row{flex-wrap:wrap}@media(max-width:460px){.p-roadmap-topic{padding:.7rem 0;gap:.6rem}.p-roadmap-topic:not(:last-child):after{left:1rem}.p-roadmap-next{padding:.9rem}.p-roadmap-next button{width:100%;white-space:normal}}