/*! tailwindcss v4.3.3 | MIT License | https://tailwindcss.com */@layer theme{:host,:root{--font-sans:-apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,"Helvetica Neue","Noto Sans",Arial,sans-serif,"Apple Color Emoji","Segoe UI Emoji","Segoe UI Symbol","Noto Color Emoji";--font-mono:ui-monospace,SFMono-Regular,Menlo,Monaco,Consolas,"Liberation Mono","Courier New",monospace;--default-font-family:var(--font-sans);--default-mono-font-family:var(--font-mono)}}@layer base{*,::backdrop,:after,:before{box-sizing:border-box;border:0 solid;margin:0;padding:0}::file-selector-button{box-sizing:border-box;border:0 solid;margin:0;padding:0}:host,html{-webkit-text-size-adjust:100%;tab-size:4;line-height:1.5;font-family:var(--default-font-family,-apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,"Helvetica Neue","Noto Sans",Arial,sans-serif,"Apple Color Emoji","Segoe UI Emoji","Segoe UI Symbol","Noto Color Emoji");font-feature-settings:var(--default-font-feature-settings,normal);font-variation-settings:var(--default-font-variation-settings,normal);-webkit-tap-highlight-color:transparent}hr{height:0;color:inherit;border-top-width:1px}abbr:where([title]){-webkit-text-decoration:underline dotted;text-decoration:underline dotted}h1,h2,h3,h4,h5,h6{font-size:inherit;font-weight:inherit}a{color:inherit;-webkit-text-decoration:inherit;text-decoration:inherit}b,strong{font-weight:bolder}code,kbd,pre,samp{font-family:var(--default-mono-font-family,ui-monospace,SFMono-Regular,Menlo,Monaco,Consolas,"Liberation Mono","Courier New",monospace);font-feature-settings:var(--default-mono-font-feature-settings,normal);font-variation-settings:var(--default-mono-font-variation-settings,normal);font-size:1em}small{font-size:80%}sub,sup{vertical-align:baseline;font-size:75%;line-height:0;position:relative}sub{bottom:-.25em}sup{top:-.5em}table{text-indent:0;border-color:inherit;border-collapse:collapse}:-moz-focusring:where(:not(iframe)){outline:auto}progress{vertical-align:baseline}summary{display:list-item}menu,ol,ul{list-style:none}audio,canvas,embed,iframe,img,object,svg,video{vertical-align:middle;display:block}img,video{max-width:100%;height:auto}button,input,optgroup,select,textarea{font:inherit;font-feature-settings:inherit;font-variation-settings:inherit;letter-spacing:inherit;color:inherit;opacity:1;background-color:#0000;border-radius:0}::file-selector-button{font:inherit;font-feature-settings:inherit;font-variation-settings:inherit;letter-spacing:inherit;color:inherit;opacity:1;background-color:#0000;border-radius:0}:where(select:is([multiple],[size])) optgroup{font-weight:bolder}:where(select:is([multiple],[size])) optgroup option{padding-inline-start:20px}::file-selector-button{margin-inline-end:4px}::placeholder{opacity:1}@supports (not ((-webkit-appearance:-apple-pay-button))) or (contain-intrinsic-size:1px){::placeholder{color:currentColor}@supports (color:color-mix(in lab,red,red)){::placeholder{color:color-mix(in oklab,currentcolor 50%,transparent)}}}textarea{resize:vertical}::-webkit-search-decoration{-webkit-appearance:none}::-webkit-date-and-time-value{min-height:1lh;text-align:inherit}::-webkit-datetime-edit{display:inline-flex}::-webkit-datetime-edit-fields-wrapper{padding:0}::-webkit-datetime-edit,::-webkit-datetime-edit-year-field{padding-block:0}::-webkit-datetime-edit-day-field,::-webkit-datetime-edit-month-field{padding-block:0}::-webkit-datetime-edit-hour-field,::-webkit-datetime-edit-minute-field{padding-block:0}::-webkit-datetime-edit-millisecond-field,::-webkit-datetime-edit-second-field{padding-block:0}::-webkit-datetime-edit-meridiem-field{padding-block:0}::-webkit-calendar-picker-indicator{line-height:1}:-moz-ui-invalid{box-shadow:none}button,input:where([type=button],[type=reset],[type=submit]){appearance:button}::file-selector-button{appearance:button}::-webkit-inner-spin-button,::-webkit-outer-spin-button{height:auto}[hidden]:where(:not([hidden=until-found])){display:none!important}}@layer components;@layer utilities{.sr-only{clip-path:inset(50%);white-space:nowrap;border-width:0;width:1px;height:1px;margin:-1px;padding:0;position:absolute;overflow:hidden}.block{display:block}.contents{display:contents}}:root{--ink:#17231f;--muted:#66716c;--paper:#fffdf7;--canvas:#f2f0e8;--line:#dcd9cf;--green:#183b35;--teal:#17675f;--teal-soft:#dcebe6;--orange:#ad4b22;--orange-soft:#f9e7d8;--yellow:#f4ca64;--violet:#57528f;--violet-soft:#e8e6f3;--shadow:0 12px 35px #1d282214}*{box-sizing:border-box}html{background:var(--canvas);color:var(--ink)}body{min-height:100vh;margin:0;font-family:Inter,ui-sans-serif,system-ui,-apple-system,BlinkMacSystemFont,Segoe UI,sans-serif}button,input,textarea{font:inherit}a,button{-webkit-tap-highlight-color:transparent}a:focus-visible,button:focus-visible,input:focus-visible,summary:focus-visible,textarea:focus-visible{outline-offset:2px;outline:3px solid #75a9a1}.sr-only{clip:rect(0,0,0,0);white-space:nowrap;border:0;width:1px;height:1px;margin:-1px;padding:0;position:absolute;overflow:hidden}.brand-mark{color:var(--ink);letter-spacing:-.03em;align-items:center;gap:10px;font-weight:800;text-decoration:none;display:inline-flex}.brand-mark>span{width:35px;height:35px;color:var(--paper);background:var(--green);border-radius:10px;place-items:center;font-family:Georgia,serif;font-size:21px;display:grid;box-shadow:inset -5px -5px #00000014}.eyebrow{color:var(--orange);letter-spacing:.13em;text-transform:uppercase;font-size:11px;font-weight:800}.landing-shell{background:radial-gradient(circle at 80% 20%,#efe7ce 0,transparent 28%),var(--canvas);flex-direction:column;min-height:100vh;display:flex;overflow:hidden}.landing-nav{border-bottom:1px solid var(--line);justify-content:space-between;align-items:center;width:min(1180px,100% - 40px);min-height:84px;margin:0 auto;display:flex}.quiet-link{color:var(--green);font-size:13px;font-weight:700;text-decoration:none}.hero-grid{grid-template-columns:1.05fr .8fr;align-items:center;gap:8vw;width:min(1180px,100% - 40px);margin:auto;padding:70px 0;display:grid}.hero-grid h1{letter-spacing:-.065em;max-width:760px;margin:12px 0 24px;font-family:Georgia,Times New Roman,serif;font-size:clamp(55px,7vw,102px);font-weight:500;line-height:.92}.hero-grid h1 em{color:var(--orange);font-weight:500}.hero-copy{max-width:610px;color:var(--muted);font-family:Georgia,serif;font-size:clamp(18px,2vw,23px);line-height:1.55}.hero-actions{align-items:center;gap:20px;margin-top:34px;display:flex}.hero-actions>span{color:var(--muted);font-size:12px}.primary-action{color:#fff;background:var(--green);border-radius:12px;align-items:center;min-height:50px;padding:0 22px;font-weight:750;text-decoration:none;display:inline-flex;box-shadow:0 9px 25px #183b352e}.hero-card{border:1px solid var(--line);box-shadow:var(--shadow);background:#fffdf7c7;border-radius:24px;padding:34px;position:relative;transform:rotate(1.5deg)}.hero-card:before{content:"";z-index:-1;background:var(--green);border-radius:24px;position:absolute;inset:10px -10px -10px 10px;transform:rotate(-3deg)}.mini-book{border-bottom:1px solid var(--line);align-items:stretch;gap:20px;padding-bottom:25px;display:flex}.mini-book>span{color:#fff;background:var(--orange);border-radius:9px 9px 14px 14px;place-items:center;width:72px;font:700 27px Georgia,serif;display:grid}.mini-book small{color:var(--muted);letter-spacing:.14em;margin-bottom:8px;display:block}.mini-book strong{font:600 29px/1.05 Georgia,serif}.loop-list{padding:17px 0}.loop-list p{border-bottom:1px dashed var(--line);align-items:center;gap:14px;min-height:47px;margin:0;font-size:14px;font-weight:650;display:flex}.loop-list b{color:var(--orange);font:700 13px Georgia,serif}.proof-note{color:#fdf7e7;background:var(--green);border-radius:9px;padding:13px 15px;font-size:12px;line-height:1.4}.landing-footer{border-top:1px solid var(--line);width:min(1180px,100% - 40px);min-height:65px;color:var(--muted);text-transform:uppercase;letter-spacing:.08em;justify-content:space-between;align-items:center;margin:0 auto;font-size:11px;display:flex}.reader-app{background:var(--canvas);flex-direction:column;height:100dvh;display:flex;overflow:hidden}.reader-topbar{border-bottom:1px solid var(--line);-webkit-backdrop-filter:blur(14px);backdrop-filter:blur(14px);background:#fffdf7f0;grid-template-columns:230px minmax(180px,1fr) auto;align-items:center;gap:24px;min-height:67px;padding:0 18px;display:grid}.chapter-crumb{min-width:0}.chapter-crumb small{color:var(--muted);text-transform:uppercase;letter-spacing:.1em;font-size:9px;display:block}.chapter-crumb b{text-overflow:ellipsis;white-space:nowrap;font:600 15px Georgia,serif;display:block;overflow:hidden}.topbar-actions{align-items:center;gap:9px;display:flex}.network-pill{min-height:32px;color:var(--teal);background:var(--teal-soft);border-radius:999px;align-items:center;gap:6px;padding:0 10px;font-size:10px;font-weight:700;display:inline-flex}.network-pill i,.status-dot{background:#32a673;border-radius:50%;width:7px;height:7px;box-shadow:0 0 0 3px #32a67321}.lite-toggle{min-height:36px;color:var(--muted);align-items:center;gap:6px;font-size:11px;display:inline-flex}.language-switch{border:1px solid var(--line);background:#fff;border-radius:10px;padding:3px;display:flex}.language-switch button{min-width:43px;min-height:32px;color:var(--muted);cursor:pointer;background:0 0;border:0;border-radius:7px;padding:0 9px;font-size:11px;font-weight:750}.language-switch button.active{color:#fff;background:var(--green)}.progress-ribbon{background:#e3e0d6;height:5px;position:relative}.progress-ribbon>span{background:linear-gradient(90deg,var(--orange),var(--yellow));height:100%;transition:width .25s;display:block}.progress-ribbon p{z-index:5;color:var(--muted);text-transform:uppercase;letter-spacing:.08em;margin:0;font-size:9px;position:absolute;top:11px;right:18px}.progress-ribbon p b{color:var(--ink);margin-inline-start:7px}.learning-grid{flex:1;grid-template-columns:minmax(500px,1fr) 310px 330px;gap:10px;min-height:0;padding:22px 12px 12px;display:grid}.reader-pane{border:1px solid var(--line);background:var(--paper);min-width:0;min-height:0;box-shadow:var(--shadow);border-radius:16px;grid-template-columns:190px minmax(0,1fr);display:grid;overflow:hidden}.contents-rail{border-inline-end:1px solid var(--line);background:#ebe9df;flex-direction:column;min-height:0;padding:20px 12px 14px;display:flex}.rail-label{color:var(--muted);letter-spacing:.11em;text-transform:uppercase;margin:0 6px 10px;font-size:9px;font-weight:800}.chapter-number{color:#fff;background:var(--orange);border-radius:8px 8px 13px 13px;place-items:center;width:52px;height:58px;margin:0 6px 18px;font:700 20px Georgia,serif;display:grid;box-shadow:inset 0 -6px #00000014}.contents-rail nav{flex-direction:column;gap:6px;display:flex;overflow-y:auto}.contents-rail nav button{min-height:58px;color:var(--muted);text-align:start;cursor:pointer;background:0 0;border:0;border-radius:10px;grid-template-columns:8px 30px 1fr;align-items:start;gap:7px;padding:10px 8px;display:grid;position:relative}.contents-rail nav button:hover{background:#ffffff8c}.contents-rail nav button.active{color:var(--green);background:var(--paper);box-shadow:0 4px 15px #1d28220f}.contents-rail nav small{padding-top:1px;font-size:10px}.contents-rail nav b{font-size:11px;line-height:1.3}.mastery-dot{background:#c7c5bd;border-radius:50%;width:7px;height:7px;margin-top:4px}.mastery-dot[data-state=attempted]{background:var(--yellow)}.mastery-dot[data-state=mastered]{background:#32a673}.mastery-meter{border-top:1px solid var(--line);margin-top:auto;padding:14px 6px 0}.mastery-meter>span{color:var(--muted);justify-content:space-between;font-size:10px;display:flex}.mastery-meter>div{background:#d7d4c9;border-radius:9px;height:5px;margin-top:8px;overflow:hidden}.mastery-meter i{background:#32a673;height:100%;display:block}.reading-surface{flex-direction:column;min-width:0;min-height:0;display:flex}.reading-toolbar{border-bottom:1px solid var(--line);justify-content:space-between;align-items:center;min-height:52px;padding:0 17px;display:flex}.reading-toolbar>div:first-child{color:var(--muted);align-items:center;gap:8px;font-size:10px;display:flex}.reading-toolbar b{width:35px;height:28px;color:var(--green);background:var(--teal-soft);border-radius:7px;place-items:center;display:grid}.font-controls{gap:4px;display:flex}.font-controls button{border:1px solid var(--line);min-width:44px;min-height:36px;color:var(--muted);cursor:pointer;background:#fff;border-radius:8px}.chapter-copy{scroll-behavior:smooth;flex:1;min-height:0;padding:38px clamp(22px,5vw,68px) 60px;overflow-y:auto}.chapter-copy>*{max-width:720px;margin-inline:auto}.chapter-copy>.eyebrow{margin-bottom:10px;font-size:.62em}.chapter-copy>h1{letter-spacing:-.035em;align-items:baseline;gap:14px;margin-top:0;margin-bottom:30px;font:600 2.25em/1.05 Georgia,Times New Roman,serif;display:flex}.chapter-copy>h1 span{color:var(--orange);letter-spacing:.02em;font-size:.43em}.prose-block p{color:#35413c;margin:0 0 22px;font:1.03em/1.8 Georgia,Times New Roman,serif}[dir=rtl] .chapter-copy,[dir=rtl] .prose-block p{font-family:Noto Nastaliq Urdu,Noto Naskh Arabic,serif;line-height:2}.callout{border-inline-start:4px solid var(--teal);background:var(--teal-soft);border-radius:0 10px 10px 0;margin-top:25px;margin-bottom:25px;padding:16px 18px}[dir=rtl] .callout{border-radius:10px 0 0 10px}.callout b{color:var(--teal);letter-spacing:.08em;text-transform:uppercase;margin-bottom:5px;font-size:.67em;display:block}.callout p{color:#30443e;margin:0;font-size:.84em;line-height:1.55}.callout-misconception{border-color:var(--orange);background:var(--orange-soft)}.callout-misconception b{color:#a64c25}.callout-misconception p{color:#663d2b}.equation-card{background:#f3f9f6;border:1px solid #cbded9;border-radius:14px;margin-top:28px;margin-bottom:28px;padding:20px}.block-skeleton{background:linear-gradient(90deg,#e9e6dc 25%,#f5f3eb 50%,#e9e6dc 75%) 0 0/200% 100%;border-radius:14px;max-width:720px;height:260px;margin:28px auto;animation:block-pulse 1.4s infinite}.diagram-skeleton{height:330px}@keyframes block-pulse{0%{background-position:100% 0}to{background-position:-100% 0}}.equation-heading{justify-content:space-between;align-items:center;gap:12px;display:flex}.math-display{color:var(--green);font-size:1.16em;overflow-x:auto}.equation-card>p{color:var(--muted);font-size:.76em;line-height:1.55}.live-badge{color:var(--teal);background:var(--teal-soft);letter-spacing:.1em;border-radius:999px;align-self:flex-start;padding:5px 7px;font-size:9px;font-weight:800}.slider-stack{gap:17px;margin-top:20px;display:grid}.slider-control>span{color:var(--muted);justify-content:space-between;align-items:center;margin-bottom:8px;font-size:.7em;display:flex}.slider-control output{min-width:69px;color:var(--green);text-align:center;background:#fff;border:1px solid #cadbd6;border-radius:7px;padding:4px 7px;font-weight:750}.slider-control input{width:100%;min-height:44px;accent-color:var(--teal);cursor:pointer}.slider-control input::-webkit-slider-thumb{width:24px;height:24px}.readout-row{flex-wrap:wrap;gap:9px;margin-top:18px;display:flex}.readout{color:#fff;background:var(--green);border-radius:10px;min-width:145px;padding:12px 14px}.readout span{color:#bad2ca;margin-bottom:3px;font-size:.63em;display:block}.readout strong{font:600 1.25em Georgia,serif}.readout small{font-size:.56em}.equation-note{background:#fff0bf;border-radius:9px;flex:1;min-width:190px;margin:0;padding:11px;color:#725524!important;font-size:.7em!important}.inline-error{color:#a22c2c!important}.diagram-card{border:1px solid var(--line);background:#f7f5ee;border-radius:14px;margin-top:28px;margin-bottom:28px;padding:12px}.diagram-host{border-radius:10px;place-items:center;min-height:210px;display:grid;overflow:auto}.diagram-host svg{width:100%;min-width:410px;height:auto}.diagram-host [id]{cursor:pointer}.diagram-loading{color:var(--muted);font-size:.8em}.diagram-card figcaption{color:var(--muted);padding:8px 5px 2px;font-size:.65em;line-height:1.4}.chip-row{flex-wrap:wrap;gap:7px;padding:10px 4px 3px;display:flex}.toggle-chip{border:1px solid var(--line);min-height:38px;color:var(--green);cursor:pointer;background:#fff;border-radius:999px;padding:0 11px;font-size:.66em;font-weight:700}.toggle-chip[aria-pressed=true]{background:var(--teal-soft);border-color:#a8c7bf}.hotspot-tip{color:#5d4920;background:#ffedb6;border-radius:8px;margin:8px 4px 3px;padding:9px 11px;font-size:.68em}.hotspot-list{flex-wrap:wrap;gap:6px;padding:6px 4px 2px;display:flex}.hotspot-list button{color:#4b514e;text-align:start;cursor:pointer;background:#fffdf7;border:1px dashed #aaa69b;border-radius:8px;min-height:44px;padding:7px 10px;font-size:.62em}.worked-example{border:1px solid var(--line);background:#fff;border-radius:13px;margin-top:28px;margin-bottom:28px}.worked-example summary{cursor:pointer;min-height:60px;color:var(--ink);padding:14px 42px 14px 17px;font-size:.78em;line-height:1.45;position:relative}.worked-example summary span{color:var(--violet);letter-spacing:.09em;text-transform:uppercase;font-size:.78em;font-weight:800;display:block}.worked-example ol{margin:0;padding:0 17px 16px;list-style:none}.worked-example li{border-top:1px dashed var(--line);gap:12px;padding:12px 0;display:flex}.worked-example li>span{color:#fff;background:var(--violet);border-radius:50%;flex:none;place-items:center;width:26px;height:26px;font-size:.7em;display:grid}.worked-example li p{color:var(--muted);margin:0 0 5px;font-size:.72em}.worked-example code{color:var(--violet);font-size:.75em}.checkpoint-button{color:#fff;background:var(--green);text-align:start;cursor:pointer;border:0;border-radius:13px;grid-template-columns:36px 1fr auto 18px;align-items:center;gap:10px;width:100%;min-height:66px;margin-top:30px;padding:11px 15px;display:grid}.checkpoint-button>span{width:34px;height:34px;color:var(--green);background:var(--yellow);border-radius:50%;place-items:center;display:grid}.checkpoint-button b{font-size:.77em}.checkpoint-button small{color:#bad2ca;font-size:.6em}.checkpoint-button i{font-style:normal}.section-stepper{border-top:1px solid var(--line);background:#f8f6ef;grid-template-columns:1fr 45px 1fr;align-items:center;gap:8px;min-height:63px;padding:0 15px;display:grid}.section-stepper button{min-height:44px;color:var(--muted);text-align:start;cursor:pointer;background:0 0;border:0;align-items:center;gap:9px;display:flex}.section-stepper button:last-child{text-align:end;justify-content:flex-end}.section-stepper button:disabled{opacity:.35;cursor:default}.section-stepper button span{text-overflow:ellipsis;white-space:nowrap;flex-direction:column;max-width:160px;font-size:10px;font-weight:700;display:flex;overflow:hidden}.section-stepper small{color:#6c6d66;text-transform:uppercase;letter-spacing:.08em;font-size:8px}.section-stepper>div{color:var(--muted);place-items:center;font-size:10px;display:grid}.mobile-panel{min-width:0;min-height:0}.side-panel{border:1px solid var(--line);background:var(--paper);height:100%;min-height:0;box-shadow:var(--shadow);border-radius:16px;flex-direction:column;display:flex;overflow:hidden}.panel-heading{border-bottom:1px solid var(--line);align-items:center;gap:10px;min-height:67px;padding:0 14px;display:flex}.panel-icon{color:#fff;border-radius:10px;flex:none;place-items:center;width:36px;height:36px;font-weight:900;display:grid}.tutor-icon{background:var(--violet)}.practice-icon{background:var(--teal)}.panel-heading>div:nth-child(2){flex:1;min-width:0}.panel-heading small{color:var(--muted);letter-spacing:.09em;font-size:8px;font-weight:800;display:block}.panel-heading h2{margin:1px 0 0;font:650 16px Georgia,serif}.context-strip,.question-count{color:var(--muted);font-size:10px}.context-strip{border-bottom:1px solid var(--line);min-height:43px;background:#f5f3eb;align-items:center;gap:9px;padding:0 13px;display:flex}.context-strip span{color:var(--green);background:var(--teal-soft);border-radius:5px;padding:4px 6px;font-weight:800}.context-strip b{text-overflow:ellipsis;white-space:nowrap;overflow:hidden}.selection-context{color:#514d79;background:var(--violet-soft);border-radius:9px;margin:10px 10px 0;padding:10px}.selection-context small{letter-spacing:.08em;font-size:8px;font-weight:800}.selection-context p{max-height:54px;margin:4px 0 0;font:12px/1.45 Georgia,serif;overflow:hidden}.message-list{flex-direction:column;flex:1;gap:9px;min-height:0;padding:13px;display:flex;overflow-y:auto}.message{border-radius:12px;max-width:91%;padding:11px 12px;font-size:11.5px;line-height:1.55}.message.tutor{color:#3e3b5c;background:var(--violet-soft);border-bottom-left-radius:3px;align-self:flex-start}.message.student{color:#fff;background:var(--green);border-bottom-right-radius:3px;align-self:flex-end}[dir=rtl] .message.tutor{border-radius:12px 12px 12px 3px}[dir=rtl] .message.student{border-radius:12px 12px 3px}.composer{border-top:1px solid var(--line);grid-template-columns:1fr 42px;gap:7px;padding:10px;display:grid}.composer textarea{resize:none;border:1px solid var(--line);min-height:48px;color:var(--ink);background:#f8f6ef;border-radius:10px;padding:9px 10px;font-size:11px;line-height:1.4}.composer button{color:#fff;background:var(--violet);cursor:pointer;border:0;border-radius:10px;align-self:end;width:42px;height:42px;font-size:18px}.composer button:disabled{opacity:.4;cursor:default}.prototype-disclaimer{color:#929087;text-align:center;margin:0;padding:5px 10px 9px;font-size:8px}.practice-body{flex:1;min-height:0;padding:18px 15px;overflow-y:auto}.question-kind{width:fit-content;color:var(--teal);background:var(--teal-soft);letter-spacing:.1em;border-radius:6px;margin:0 0 12px;padding:4px 7px;font-size:8px;font-weight:850}.practice-body h3{margin:0 0 18px;font:600 18px/1.35 Georgia,serif}.option-stack{gap:8px;display:grid}.option-stack button{border:1px solid var(--line);min-height:49px;color:var(--ink);text-align:start;cursor:pointer;background:#fff;border-radius:10px;grid-template-columns:29px 1fr;align-items:center;gap:9px;padding:7px 10px;font-size:11px;display:grid}.option-stack button span{width:28px;height:28px;color:var(--muted);background:#efede5;border-radius:7px;place-items:center;font-size:10px;font-weight:800;display:grid}.option-stack button.selected{border-color:var(--teal);box-shadow:0 0 0 2px #1f766d1f}.option-stack button.selected span{color:#fff;background:var(--teal)}.numeric-answer{color:var(--muted);gap:7px;font-size:10px;font-weight:700;display:grid}.numeric-answer input{border:1px solid var(--line);min-height:52px;color:var(--ink);background:#fff;border-radius:10px;padding:0 13px;font-size:16px}.check-answer{color:#fff;background:var(--green);cursor:pointer;border:0;border-radius:10px;width:100%;min-height:48px;margin-top:15px;font-size:11px;font-weight:750}.check-answer:disabled{opacity:.35;cursor:default}.feedback-card{background:#fff7df;border:1px solid #dec89a;border-radius:12px;margin-top:16px;padding:13px}.feedback-card.correct{background:#ebf6ef;border-color:#aad0bd}.feedback-card.incorrect{background:#fbeae4;border-color:#dfb1a2}.feedback-score{align-items:center;gap:10px;display:flex}.feedback-score>span{color:#fff;background:var(--orange);border-radius:50%;flex:none;place-items:center;width:48px;height:48px;font-size:11px;font-weight:800;display:grid}.feedback-card.correct .feedback-score>span{background:#2e8c65}.feedback-score small{color:var(--muted);text-transform:uppercase;letter-spacing:.09em;font-size:8px}.feedback-score h4{margin:1px 0 0;font:600 14px Georgia,serif}.component-list{gap:8px;margin-top:13px;display:grid}.component-list>div{border-top:1px dashed #00000021;gap:8px;padding-top:9px;display:flex}.component-list>div>span{color:#fff;background:var(--orange);border-radius:50%;flex:none;place-items:center;width:22px;height:22px;font-size:10px;font-weight:900;display:grid}.component-list p{color:var(--muted);margin:0;font-size:9.5px;line-height:1.4}.component-list b{color:var(--ink);display:block}.next-step{color:#3e3b5c;background:#57528f1a;border-radius:8px;margin:13px 0 0;padding:10px;font-size:10px;line-height:1.45}.next-step b{letter-spacing:.08em;margin-bottom:2px;font-size:8px;display:block}.empty-state{color:var(--muted);padding:30px 20px;font-size:12px;line-height:1.5}.mobile-switcher{display:none}.lite-mode *{scroll-behavior:auto!important;transition:none!important;animation:none!important}@media (prefers-reduced-motion:reduce){*,:after,:before{scroll-behavior:auto!important;transition:none!important;animation:none!important}}@media (max-width:1180px){.learning-grid{grid-template-columns:minmax(480px,1fr) 285px 305px}.reader-pane{grid-template-columns:160px minmax(0,1fr)}.contents-rail{padding-inline:8px}}@media (max-width:980px){.reader-app{padding-bottom:65px}.reader-topbar{grid-template-columns:auto 1fr auto;gap:10px;min-height:62px;padding:0 12px}.reader-topbar .brand-mark strong{display:none}.reader-topbar .brand-mark>span{width:34px;height:34px}.lite-toggle,.network-pill{display:none}.chapter-crumb b{font-size:13px}.learning-grid{padding:18px 10px 10px;display:block}.mobile-panel,.reader-pane{height:100%;display:none}.reader-pane[data-mobile-active=true]{display:grid}.mobile-panel[data-mobile-active=true]{display:block}.reader-pane{grid-template-columns:minmax(0,1fr)}.contents-rail{display:none}.side-panel{max-width:680px;margin:0 auto}.mobile-switcher{z-index:20;border-top:1px solid var(--line);-webkit-backdrop-filter:blur(13px);backdrop-filter:blur(13px);inset-inline:0;background:#fffdf7f7;grid-template-columns:repeat(3,1fr);height:65px;display:grid;position:fixed;bottom:0}.mobile-switcher button{min-height:58px;color:var(--muted);background:0 0;border:0;flex-direction:column;justify-content:center;align-items:center;gap:2px;font-size:9px;font-weight:700;display:flex}.mobile-switcher button span{font-size:17px}.mobile-switcher button.active{color:var(--teal)}}@media (max-width:720px){.hero-grid,.landing-footer,.landing-nav{width:min(100% - 28px,600px)}.landing-nav{min-height:68px}.quiet-link{font-size:10px}.hero-grid{grid-template-columns:1fr;gap:58px;padding:55px 0 80px}.hero-grid h1{font-size:clamp(52px,17vw,78px)}.hero-actions{flex-direction:column;align-items:flex-start}.hero-card{margin:0 8px;padding:23px}.landing-footer{flex-direction:column;justify-content:center;align-items:flex-start;gap:5px;padding:15px 0}.chapter-crumb small{display:none}.topbar-actions{gap:3px}.language-switch button{min-width:39px}.progress-ribbon p{display:none}.learning-grid{padding:10px 7px 7px}.reader-pane,.side-panel{border-radius:13px}.reading-toolbar{min-height:48px}.chapter-copy{padding:28px 18px 45px}.chapter-copy>h1{font-size:1.85em}.prose-block p{font-size:.98em}.diagram-card{margin-inline:-5px}.checkpoint-button{grid-template-columns:36px 1fr 18px}.checkpoint-button small{display:none}.section-stepper button span{max-width:110px}}