/* Quiet field notes: a fixed paper palette inspired by illustrated travel journals. */
:root{
 --ink:#474e65;--muted:#69716f;--paper:#fbf7ee;--soft:#e9eee7;--line:#d7d5c9;
 --blue:#a9bdcd;--sage:#8ca5a0;--rose:#e7ccc4;--night:#303749;--blue-soft:#e3eaf0;
 background:#f2eee4;color:var(--ink);font-family:-apple-system,BlinkMacSystemFont,"Segoe UI",sans-serif;
}
body{background-image:url("assets/paper-grain.svg")}
button{color:inherit}input,select,textarea{accent-color:var(--ink)}
button:focus-visible,a:focus-visible,input:focus-visible,textarea:focus-visible,select:focus-visible,summary:focus-visible{outline-color:#607e91}
aside{background:#e8e8df;border-color:#c9cabc;padding-top:34px}
/* Root clipping must not create a scroll container around sticky navigation. */
html,body{overflow-x:clip}
@media(min-width:651px){
 .shell>aside{align-self:flex-start;position:sticky;top:0;height:100dvh;overflow-y:auto;overscroll-behavior:contain}
 .shell>aside>.brand,.shell>aside>nav,.shell>aside>.sidebar-bottom{flex-shrink:0}
}
.brand{margin-bottom:46px;gap:11px}.brand b{background:var(--ink);border:3px double #e8e8df;outline:1px solid var(--ink);border-radius:3px;color:var(--paper)}
.brand small{color:#65716f;font-size:8px;letter-spacing:1px}.brand span{font-size:18px}
aside nav{gap:9px}aside nav button{border:1px solid transparent;border-radius:4px;color:#5e696a;position:relative}
aside nav button.active{background:#d6e0df;color:#364852;border-color:#b9cbc9}
aside nav button.active:before{content:"";height:16px;width:2px;background:#627b85;position:absolute;left:-8px;top:calc(50% - 8px)}
aside nav #mistake-count{background:var(--paper);color:var(--ink);font-size:11px}
.sidebar-bottom{border-top:1px solid #c9cabc;margin-top:auto;padding-top:22px;margin-left:8px;margin-right:8px;padding-left:0;padding-right:0}
.sidebar-bottom .tag{color:#586768;font-size:10px}.sidebar-bottom p{font-size:22px;color:var(--ink)}.sidebar-bottom small{font-size:11px}
.workspace>header{background:#f5f1e8;border-color:var(--line);color:#677270;height:64px;letter-spacing:2px}
.save-label{font-size:11px;color:#5b6b65}.save-label:before{background:#73968b}
main{padding-top:32px;max-width:1550px}
h1{color:var(--ink);font-size:46px;line-height:1.1;letter-spacing:-1.6px;font-weight:400}h2,h3{color:var(--ink)}
.eyebrow,.section-label{color:#566e73;font-weight:600;font-size:10px;letter-spacing:1.7px}
.learn-intro{margin-bottom:25px;min-height:215px;gap:22px;position:relative}
.learn-intro>div{min-width:0;flex:1}.learn-intro h1{font-size:clamp(32px,3.1vw,49px);margin-top:17px;margin-bottom:17px;line-height:1.15}
.learn-intro p{margin-bottom:12px;font-size:13px}.hero-caption{font-size:9px;letter-spacing:1.8px;color:#697c7b}
.collection-art{width:36%;max-width:360px;height:auto;flex-shrink:0}
.home-strip{grid-template-columns:1.6fr 1fr 1fr;gap:16px;margin-bottom:32px}
.continue-card,.mini-stat{border-radius:4px;border-color:var(--line);min-height:138px;padding:21px 23px}
.continue-card{background:var(--ink);color:var(--paper);position:relative;overflow:hidden;border:4px double #8793a5;box-shadow:none}
.continue-card:after{content:"";position:absolute;right:-42px;bottom:-68px;width:160px;height:160px;border:1px solid #7d899e;border-radius:50%;pointer-events:none}
.continue-card .eyebrow{color:#d8e2e3;font-size:9px}.continue-card strong{color:var(--paper);font-size:20px;font-weight:500;z-index:1}.continue-card small{color:#d2dfe6;font-size:12px}
.mini-stat{background:var(--paper);box-shadow:none}.mini-stat>span{font-size:12px}.mini-stat strong{font-size:32px}.mini-stat>small{font-size:11px}
.revisit-card{background:#ece8df}.progress{height:4px;background:#e0e1d8;border-radius:0}.progress>div{background:#73918d}
.study-grid{grid-template-columns:220px minmax(0,1fr);gap:24px}
.chapters .section-label{padding:8px 12px 12px;border-bottom:1px solid var(--line);font-size:10px;margin-bottom:5px}
.chapter{border-radius:4px;position:relative;padding:13px 12px;gap:11px}.chapter strong{font-size:12px;font-weight:550}.chapter small{font-size:11px;color:#707d78}
.chapter:hover{background:#e8ece6}.chapter.selected{background:#e1e8e9;border-color:#bbcacc;box-shadow:none}
.chapter-symbol{color:#738d94;font-size:21px}.chapter-done{color:#476a60}
.chapter-symbol{width:24px;min-width:24px;display:inline-flex;align-items:center;justify-content:center;flex-shrink:0}.chapter-symbol svg{display:block;width:23px;height:23px}
.panel,.task-pane,.results-pane{border-color:#cbcfc7;border-radius:5px;background:var(--paper);box-shadow:0 4px 16px #474e6504}
.learning-panel{padding:28px;position:relative}
.chapter-heading{padding-bottom:4px}.chapter-heading .eyebrow{margin-bottom:10px}.chapter-heading h2{font:30px/1.2 Georgia,"Times New Roman",serif;letter-spacing:-.6px;margin-bottom:11px}.chapter-heading p{font-size:13px}
.step-nav{gap:5px;padding-bottom:18px;margin-bottom:24px;border-color:var(--line)}
.step-nav button{font-size:11px;padding:10px 5px;border-radius:3px;color:#667172}
.step-nav button span{border-color:#c5ccc6;color:#647778}
.step-nav button.active{background:#e8edeb;color:#354d59}.step-nav button.active span{background:var(--ink);border-color:var(--ink);color:var(--paper)}
.section-heading{margin-top:22px}.section-heading h3{font:23px/1.35 Georgia,"Times New Roman",serif;letter-spacing:-.3px}.section-heading p{font-size:12px}
.idea-card{background:#eef0e7;border:1px solid #d8ddcf;border-radius:3px;padding:19px 17px;position:relative}
.idea-card:after{content:"";position:absolute;right:0;top:0;width:15px;height:15px;background:linear-gradient(225deg,var(--paper) 48%,#d8ddcf 49%,#d8ddcf 52%,transparent 53%)}
.idea-card p{color:#536562;font-size:12px}.idea-card h3{font-size:14px;font-weight:600}.idea-index{font-size:24px;color:#7f9691}
.lesson-detail{border-color:#d5d8cc;border-radius:3px;background:#faf7ef}.lesson-detail summary{font-weight:500;padding:16px 18px}
.lesson-detail summary:before{color:#698a87}.lesson-detail[open]{background:var(--paper)}
.detail-state{font-size:11px}.lesson p{color:#5e6d69}.pitfall{background:#f3e9df;border-color:#bb9180}.pitfall .eyebrow{color:#876654}
.code-label,.editor-top{background:#394255;color:#c3d4d6}.code-label{border-radius:4px 4px 0 0;font-size:10px}
pre,.trace-code,.lab-editor{background:var(--night);color:#e1e9e8}.trace-line{color:#e1e9e8;font-size:12px}.trace-line>span{color:#95a7b3;font-size:11px}
.trace-line.current{background:#45526a;border-left-color:#b9cddf;color:#f7f5ee}
.primary,.secondary,.check{border-radius:3px;font-weight:500;font-size:12px;padding:10px 15px;min-height:40px}
.primary{background:var(--ink);border-color:var(--ink);color:var(--paper);box-shadow:none}.primary:hover{background:#353d54}
.secondary,.check{background:var(--paper);border-color:#c3cec9;color:#485e63}.secondary:hover:not(:disabled),.check:hover{background:#e8edeb;border-color:#98aeae}
.check.done{background:#deebe2;border-color:#b0c5b4;color:#3e6556}
.flow-diagram{gap:7px;margin:22px 0}.flow-node{background:#efefe6;border-color:#d1d5c9;color:#606c6c;border-radius:3px;font-size:11px;min-height:67px}
.flow-node small{color:inherit;font-size:10px;visibility:hidden}.flow-node.current{background:#dbe7eb;border-color:#829eae;color:#3e596c}.flow-node.current small,.flow-node:disabled small{visibility:visible}.flow-node:hover{background:#e2e9e8}
.flow-arrow{color:#95a7a2}
.trace-code{border:1px solid #434e63;border-radius:4px;padding-top:0;padding-bottom:16px;min-width:0}
.trace-file-label{display:flex;gap:12px;justify-content:space-between;font-size:10px;color:#b4c6cf;padding:12px 15px;margin-bottom:10px;border-bottom:1px solid #4c586c;background:#394255;letter-spacing:.7px}
.trace-file-label>span:last-child{font-size:9px;letter-spacing:1.3px}
.trace-inspector{background:#eaf0ec;border-color:#c9d6ce;border-radius:4px;padding:18px;display:block}
.trace-inspector .eyebrow{font-size:10px;color:#4c6a65}.state-value{font-size:13px;color:#3b5858;margin:8px 0 21px;min-height:24px}
.trace-inspector pre{background:#f8faf4;border:1px solid #d5dfd5;color:#3e5753;font-size:12px;border-radius:2px;margin:8px 0 18px;min-height:44px}
.trace-inspector p{font-size:12px;color:#556c64;line-height:1.7}
.trace-choice{background:#e8eae3;border-radius:3px;padding:4px}.trace-choice button{font-size:12px;color:#5e7472;border-radius:2px}.trace-choice button.active{background:var(--paper);color:var(--ink)}
.trace-experiment{display:grid;grid-template-columns:1.5fr 1fr;align-items:center;gap:20px;border:1px solid #cecdc0;background:#f0eee2;border-radius:3px;padding:15px 18px}
.trace-experiment label{display:flex;align-items:center;gap:12px;font-size:12px;font-weight:600;color:#596968}.trace-experiment output{font:20px Georgia,serif;color:var(--ink)}
.trace-experiment p{margin:5px 0 0;font-size:11px;color:#65726d;line-height:1.6}
.trace-experiment input,.trace-timeline input{width:100%;min-width:0;accent-color:#647f90;height:24px;margin:0}
.trace-timeline{display:flex;align-items:center;gap:18px;border-top:1px solid var(--line);padding-top:18px;margin-top:22px}
.trace-timeline label{font-size:11px;white-space:nowrap;min-width:82px;color:#62716e}
.trace-controls{flex-wrap:wrap;gap:8px;margin-top:16px;justify-content:flex-end}.trace-controls>button:first-child{margin-right:auto}
.trace-speed{font-size:11px;display:flex;align-items:center;gap:7px;margin-right:7px;color:#61716f}
.trace-speed select{border:1px solid #c3cec9;background:var(--paper);color:var(--ink);font-size:12px;min-height:40px;border-radius:3px;padding:5px 7px}
.trace-controls .primary{min-width:92px}.trace-controls [data-trace="back"],.trace-controls [data-trace="next"]{min-width:40px}
.trace-status{font-size:11px;line-height:1.7;color:#687872;margin:12px 0 0;min-height:19px}
.trace-supplied-input{border:1px solid var(--line);padding:12px 15px;background:#f0eee2}.trace-supplied-input pre{background:transparent;color:var(--ink);padding:5px 0 0;margin:0;white-space:pre-wrap}
.stage-card,.task-card{border-radius:4px;background:#edf0e8;border-color:#cfd8cd}.stage-icon{color:#b4c6c0}.task-card p{color:#596f65}.task-card>span:last-child{color:#4b6c6c}
.stat{border-radius:3px}.badge{background:#e5e9e1;color:#526b62;border-radius:2px;font-size:11px}
.option{background:#faf7ef;border-radius:3px;border-color:#d5d5c9}.option:hover{background:#eef0e8}.option:has(input:checked){background:#e0e8ed;border-color:#839cae}
input[type=radio]{accent-color:var(--ink)}.feedback{border-radius:3px;background:#e5eee4;border-color:#bbd0bd}.feedback.wrong{background:#f3e7df;border-color:#d7bbab}
.studio-badge{color:#8aa4a4}.lab-select,.exercise-search,.lab-input{background:var(--paper);color:var(--ink);border-color:#c3cec9;border-radius:3px}
.editor-pane{background:var(--night);border-color:#434e63;border-radius:4px}.cm-editor,.cm-gutters{background:var(--night)!important}.cm-gutters{color:#95a7b3!important}.cm-focused .cm-selectionBackground,.cm-selectionBackground{background:#4a5b78!important}
.run-toolbar{background:#394255;border-color:#4c586c}.run-toolbar .primary{background:#b8cddc;border-color:#b8cddc;color:#28374a}.run-toolbar .primary:hover{background:#cedde6}.run-toolbar .secondary{background:#465168;border-color:#6d7d8f;color:#e2e9eb}
.editor-top small{color:#b0c1cb}.sample-pair pre,.result-comparison pre{background:#edf0e8;color:#3f5d57}.task-section>p,.lab-details p,.task-section ol{color:#586d66}.test-result{background:#e8eee4;border-color:#c6d3bd}.test-result.fail,.error-card{background:#f3e7df;border-color:#d7bbab}
.lab-output{border-radius:3px}.lab-status{color:#526d67;font-size:12px}.lab-mobile-tabs{background:#e0e5df;border-radius:4px}.lab-mobile-tabs button{border-radius:2px}.lab-mobile-tabs button[aria-selected=true]{color:var(--ink)}
.step-footer{border-color:var(--line)}.step-footer>span{font-size:11px}
.workspace>footer{border-top:1px solid var(--line);margin:20px 36px 0;padding:18px 0 28px;font-size:11px;color:#6d7972}
dialog{background:var(--paper);color:var(--ink);border-color:#c3cec9;border-radius:5px}dialog::backdrop{background:#30374966}
@media(min-width:901px){.study-grid>.learning-panel{height:auto;max-height:calc(100dvh - 48px);min-height:580px;scrollbar-color:#aebeb7 transparent}.study-grid>.chapters{scrollbar-color:#aebeb7 transparent}}
@media(min-width:1450px){.trace-layout{grid-template-columns:1.2fr 1fr}.idea-grid{grid-template-columns:repeat(3,minmax(0,1fr))}}
@media(max-width:1100px){.learn-intro{min-height:190px}.learn-intro h1{font-size:36px}.collection-art{width:32%}.study-grid{grid-template-columns:190px minmax(0,1fr);gap:18px}.learning-panel{padding:23px}.continue-card,.mini-stat{padding:19px 17px}.continue-card strong{font-size:18px}}
@media(max-width:900px){.brand span{font-size:16px}.learn-intro{min-height:185px}.learn-intro h1{font-size:32px}.collection-art{width:34%;min-width:155px}.study-grid{grid-template-columns:1fr;gap:24px}.chapters{grid-template-columns:repeat(2,minmax(0,1fr))}.chapters .section-label{grid-column:1/-1}.idea-grid{grid-template-columns:1fr}.idea-card{display:grid;grid-template-columns:28px 1fr;gap:0 14px}.idea-index{grid-row:1/3;margin:0}.idea-card p{grid-column:2}.trace-layout{grid-template-columns:1fr}.trace-inspector{display:block}.trace-experiment{grid-template-columns:1fr;gap:10px}}
@media(max-width:650px){
 aside{padding:16px 18px 12px;background:#e8e8df}.brand{margin:0 0 14px}.brand span{font-size:18px}.brand small{font-size:8px}.brand b{height:37px;width:35px;line-height:31px}
 aside nav{gap:5px}aside nav button{padding:9px 3px;min-height:50px;font-size:10px}.nav-text{font-size:10px}aside nav button.active:before{display:none}.sidebar-bottom{display:none}
 .workspace>header{height:46px;padding:0 18px;letter-spacing:1px;font-size:9px}.save-label{font-size:10px}
 main{padding:26px 18px}h1{font-size:35px;letter-spacing:-1px}.learn-intro{min-height:0;flex-direction:column;align-items:flex-start;gap:20px;margin-bottom:25px}.learn-intro h1{font-size:36px;letter-spacing:-1px}.learn-intro p{font-size:12px}.hero-caption{font-size:9px}
 .collection-art{width:100%;max-width:320px;min-width:0;margin:0 auto}.home-strip{grid-template-columns:1fr 1fr;gap:12px;margin-bottom:27px}.continue-card{grid-column:1/-1;min-height:134px}.continue-card strong{font-size:21px}.mini-stat{padding:16px;min-height:133px}
 .chapter strong{font-size:12px}.chapter small{font-size:10px}.chapter{gap:8px;padding:12px 9px}.chapter-symbol{font-size:19px}
 .learning-panel{padding:22px 16px}.chapter-heading h2{font-size:27px}.chapter-heading p{font-size:12px}.step-nav{gap:2px}.step-nav button{font-size:10px;padding:9px 2px;min-height:68px}
 .idea-card{padding:17px 16px}.idea-card p{font-size:12px}.idea-card h3{font-size:14px}.lesson-detail summary{font-size:12px;padding:15px 12px}.lesson{padding:0 12px 18px}.detail-state{font-size:10px}
 .trace-file-label{padding:11px 12px}.trace-file-label>span:last-child{font-size:9px}.trace-line{font-size:12px}.trace-inspector{padding:16px}.trace-inspector>*{grid-column:auto!important;grid-row:auto!important}.trace-inspector .eyebrow{font-size:10px}
 .flow-diagram{gap:4px}.flow-node{font-size:10px;min-height:68px;padding:10px 3px}.flow-node small{font-size:9px}.flow-arrow{font-size:11px}
 .trace-experiment{padding:13px}.trace-experiment p{font-size:11px}.trace-timeline{gap:12px}.trace-timeline label{font-size:11px}
 .trace-controls{gap:7px}.trace-controls .secondary,.trace-controls .primary{padding:10px 11px;min-height:44px;font-size:12px}.trace-speed{margin-right:0;gap:5px;order:2;width:100%;justify-content:flex-end}.trace-speed select{min-height:44px;padding:5px;font-size:16px}.trace-controls .primary{min-width:84px}.trace-controls [data-trace="reset"]{padding:10px}
 .step-footer>span{font-size:10px}.step-footer .primary,.step-footer .secondary{font-size:11px;padding:10px 11px;min-height:44px}.primary,.secondary,.check{min-height:44px}
 .workspace>footer{margin:15px 18px 0;padding:18px 0 24px;font-size:10px}.lab-select,.exercise-search,.lab-input{font-size:16px}.results-heading .badge{font-size:9px}.lab-label>span{font-size:10px;float:none;display:block}
}
@media(max-width:380px){.trace-controls{justify-content:space-between}.trace-controls>button:first-child{margin-right:0}.trace-speed{order:2;width:100%;justify-content:flex-end}.step-footer{flex-wrap:wrap}.hero-caption{letter-spacing:1px}.learn-intro h1{font-size:31px}}
@media(prefers-reduced-motion:no-preference){
 button,a,input,select{transition:background-color .18s ease,border-color .18s ease,box-shadow .18s ease,transform .18s ease}
 .continue-card:hover,.task-card:hover{transform:translateY(-3px);box-shadow:0 7px 16px #474e6510}
 .chapter:hover{transform:translateX(2px)}.progress>div{transition:width .4s ease}
 main.page-enter{animation:page-arrive .24s ease-out}#learning-step{animation:page-arrive .24s ease-out}.feedback{animation:page-arrive .25s ease-out}.flow-node.current{animation:none}
 .trace-inspector.state-updated .state-value{animation:state-change .35s ease-out}
 .lesson-detail[open] .lesson{animation:page-arrive .22s ease-out}
 .collection-art{transition:transform .5s ease}.learn-intro:hover .collection-art{transform:translateY(-4px)}
 @keyframes page-arrive{from{opacity:.5;transform:translateY(5px)}to{opacity:1;transform:translateY(0)}}
 @keyframes state-change{from{color:#7794ac;transform:translateY(2px)}to{color:#3b5858;transform:translateY(0)}}

}
@media(prefers-reduced-motion:reduce){*,*:before,*:after{scroll-behavior:auto!important;animation:none!important;transition:none!important}}