/* Standalone offline course; all fonts and assets are local. */
:root{--paper:#f7f8f4;--ink:#233931;--sub:#66786f;--line:#dce5db;--green:#25634c;--green-light:#e7f1e8;--lime:#d6ef88;--orange:#b75d30;--orange-light:#fff0e2;--blue:#386387;--white:#fff;--radius:18px;font-family:"Segoe UI","Microsoft YaHei",system-ui,sans-serif;color:var(--ink);background:var(--paper);font-synthesis:none}
*{box-sizing:border-box}body{margin:0}button,input,select{font:inherit}button{cursor:pointer}button:disabled{cursor:default;opacity:.4}a{color:var(--green)}button,a,input,select,summary{touch-action:manipulation}button:focus-visible,a:focus-visible,input:focus-visible,select:focus-visible,summary:focus-visible{outline:3px solid #88ae54;outline-offset:3px}button{color:inherit}h1,h2,h3,p{margin:0}h1{font-size:clamp(27px,3.1vw,40px);letter-spacing:-1.4px;font-weight:650;line-height:1.3}h2{font-size:22px;letter-spacing:-.6px;font-weight:650}h3{font-size:17px;font-weight:650;line-height:1.6}p{line-height:1.8}small{font-size:12px}pre,code{font-family:Consolas,"Cascadia Code",monospace}pre{margin:0;white-space:pre-wrap;overflow-wrap:anywhere;line-height:1.8}code{font-size:.94em}button{border:0;background:transparent}button,a{ -webkit-tap-highlight-color:transparent}.shell{display:grid;grid-template-columns:248px minmax(0,1fr);min-height:100vh;max-width:1680px;margin:auto}.sidebar{border-right:1px solid var(--line);padding:35px 23px;display:flex;flex-direction:column;gap:0;position:sticky;top:0;height:100vh;min-height:610px;background:#f0f4ed}.brand{text-decoration:none;display:flex;align-items:center;gap:11px;font-weight:650;font-size:15px;letter-spacing:-.2px}.brand small{display:block;font-weight:400;color:var(--sub);margin-top:6px}.brand-mark{width:40px;height:42px;flex:0 0 40px;background:var(--ink);border-radius:12px;color:#e8f2dc;display:flex;align-items:center;justify-content:center;font-size:21px;position:relative;font-family:Consolas,monospace}.brand-mark span{color:var(--lime);position:absolute;right:4px;top:0;font-size:19px}.sidebar-label,.tiny-label{font-size:11px;letter-spacing:1.2px;color:var(--sub);font-weight:600}.sidebar-label{margin:48px 10px 17px}#lesson-nav{display:grid;gap:9px}.lesson-link{padding:16px 12px;display:flex;gap:12px;border-radius:12px;text-decoration:none;color:var(--sub);align-items:center;border:1px solid transparent}.lesson-link:hover{background:#e5ece1}.lesson-link[aria-current="page"]{background:var(--white);border-color:var(--line);color:var(--ink);box-shadow:0 3px 12px #223b2c06}.lesson-link .num{font-family:Consolas,monospace;font-size:17px;color:#869585}.lesson-link[aria-current="page"] .num{color:var(--green)}.lesson-link strong{display:block;font-size:13px;line-height:1.6;font-weight:600}.lesson-link small{display:block;font-size:10px;letter-spacing:.5px;margin-top:5px;color:var(--sub)}.catalog-button{display:flex;align-items:center;gap:9px;text-align:left;padding:15px 10px;border-top:1px solid var(--line);margin-top:22px;font-size:12px}.catalog-button span:last-child{margin-left:auto}.side-note{padding:24px 12px;margin-top:auto}.side-note p{font-size:13px;margin:10px 0;color:#52685a}.side-note small{line-height:1.8;color:var(--sub)}.rhythm{display:flex;gap:5px;margin:17px 0}.rhythm i{width:16px;height:4px;background:#d9e3d4;border-radius:9px}.rhythm i:nth-child(-n+3){background:#7c9d67}.offline{font-size:11px;color:var(--sub);padding:18px 12px 0;border-top:1px solid var(--line)}.offline small{display:block;margin-top:8px;font-size:10px}.status-dot{display:inline-block;width:6px;height:6px;border-radius:50%;background:#669864;margin-right:6px}main{min-width:0;padding:0 44px;max-width:1380px;width:100%;margin:auto}.topbar{height:78px;display:flex;align-items:center;justify-content:space-between;border-bottom:1px solid var(--line);font-size:12px;color:var(--sub);gap:12px}.divider{padding:0 10px;color:#a9b6a8}.text-button{font-size:13px;font-weight:500;padding:8px 4px;color:var(--green);white-space:normal}.text-button:hover{text-decoration:underline;text-underline-offset:5px}.lesson-hero{display:flex;justify-content:space-between;align-items:center;gap:20px;padding:32px 0 23px}.eyebrow{font-size:11px;letter-spacing:1.2px;color:var(--green);font-weight:650;margin-bottom:10px}.lead{font-size:14px;color:var(--sub);margin-top:13px}.hero-symbol{flex:0 0 100px;width:100px;height:100px;background:#e7eedc;border-radius:50%;display:flex;align-items:center;justify-content:center;flex-direction:column;transform:rotate(-8deg);color:#628044}.hero-symbol span{font-size:46px;line-height:1.1;font-family:Consolas,monospace}.hero-symbol small{font-size:8px;letter-spacing:1.4px;margin-top:3px}.lesson-goal{display:flex;align-items:center;gap:17px;background:#edf2e7;border:1px solid #e1e9d9;padding:13px 17px;border-radius:11px;font-size:12px;margin-bottom:25px}.goal-label{font-weight:650;color:#5c7750;white-space:nowrap}.lesson-goal p{color:#566650}.tabs{display:flex;gap:26px;border-bottom:1px solid var(--line);margin-bottom:25px}.tabs button{font-size:13px;color:var(--sub);padding:0 0 14px;border-bottom:3px solid transparent;margin-bottom:-1px;white-space:nowrap}.tabs button span{font-family:Consolas,monospace;margin-right:7px;font-size:11px;color:#91a088}.tabs button[aria-selected="true"]{color:var(--green);border-color:var(--green);font-weight:650}.panel{padding-bottom:8px}.panel[hidden]{display:none}.section-heading{display:flex;align-items:center;justify-content:space-between;gap:12px;margin-bottom:20px}.section-heading .eyebrow{margin-bottom:6px;font-size:10px}.trace-tag{font-size:10px;border:1px solid #cdddca;padding:6px 10px;border-radius:20px;color:#638359;white-space:nowrap}.lab-selectors{display:flex;gap:15px;margin-bottom:17px}.lab-selectors label{display:flex;align-items:center;gap:10px;font-size:11px;color:var(--sub);min-width:0;flex:1}.lab-selectors select{min-width:0;flex:1;max-width:100%;font-size:12px;background:#fff;color:var(--ink);border:1px solid var(--line);border-radius:8px;padding:9px 28px 9px 10px}.lab{background:white;border:1px solid var(--line);border-radius:var(--radius);overflow:hidden;box-shadow:0 8px 26px #29402c05;display:grid;grid-template-columns:minmax(0,.95fr) minmax(0,1.05fr)}.code-side,.visual-side{min-width:0}.code-side{background:#f7faf6;border-right:1px solid var(--line);display:flex;flex-direction:column}.pane-heading{display:flex;align-items:center;justify-content:space-between;padding:15px 18px;font-size:12px;border-bottom:1px solid var(--line);gap:10px}.pane-heading small{font-size:10px;color:#7a8b79}.pane-heading>span:first-child{font-weight:600}.file-dot{display:inline-block;width:7px;height:7px;border-radius:2px;background:#76a086;margin-right:8px}.code-lines{padding:16px 0;flex:1;min-height:236px;font-size:12px;font-family:Consolas,"Cascadia Code",monospace}.code-line{display:flex;align-items:flex-start;line-height:1.9;min-height:27px;border-left:3px solid transparent;padding:2px 9px 2px 0;transition:background .18s}.line-number{flex:0 0 37px;text-align:right;padding-right:13px;color:#92a18f;font-size:10px;user-select:none}.code-text{white-space:pre-wrap;overflow-wrap:anywhere;min-width:0}.code-line.active{background:#dfeecb;border-left-color:#668e3d}.code-line.active .line-number{color:#54782f}.syn-key{color:#925283}.syn-str{color:#9b6a26}.syn-num{color:#246e92}.syn-comment{color:#6c8276}.code-foot{font-size:10px;color:#82917d;padding:13px 16px;border-top:1px solid var(--line);display:flex;justify-content:space-between;gap:10px}.live-indicator{font-size:10px;font-weight:400;color:#7a8b79}.scene{padding:20px 22px 8px;min-height:235px;background-image:radial-gradient(#d8e1d5 .6px,transparent .6px);background-size:15px 15px}.scene-caption{font-size:10px;color:#728370;text-align:center;letter-spacing:1px;margin-bottom:13px}.input-stream{display:flex;flex-wrap:wrap;justify-content:center;gap:8px;min-height:35px}.input-token{border:1px solid #d7e3d1;background:#fff;padding:8px 13px;border-radius:8px;font-family:Consolas,monospace;font-size:15px;position:relative}.input-token.used{background:#e8f0e0;color:#5c7853;border-color:#cdddbf}.input-token.used::after{content:'✓';position:absolute;right:-4px;top:-6px;width:14px;height:14px;font-size:9px;text-align:center;line-height:14px;border-radius:50%;background:var(--green);color:#fff}.flow-arrow{text-align:center;color:#b1c79b;font-size:25px;line-height:1.3;margin:9px 0}.variable-grid{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:10px;max-width:365px;margin:auto}.variable-box{background:#fff;border:1px solid #dfe5d8;border-radius:11px;padding:12px 14px;min-width:0;transition:background .2s,border-color .2s}.variable-box.changed{background:#f5fadf;border-color:#b9d771;box-shadow:0 0 0 2px #dceeac40}.variable-meta{display:flex;justify-content:space-between;gap:7px;align-items:center}.variable-meta code{font-size:12px;color:#516950;overflow-wrap:anywhere}.type-label{font-size:9px;color:#879477;flex:0 0 auto}.variable-value{display:block;font-size:23px;margin-top:8px;font-family:Consolas,monospace;overflow-wrap:anywhere}.empty-scene{text-align:center;font-size:12px;color:#7b8c73;padding:20px 8px;border:1px dashed #ceddc6;border-radius:12px;grid-column:1/-1}.variable-strip{display:flex;gap:7px;flex-wrap:wrap;padding:13px 18px 16px;min-height:47px}.variable-pill{font-family:Consolas,monospace;font-size:10px;color:#6b7c65;background:#f2f5ed;padding:4px 8px;border-radius:5px;overflow-wrap:anywhere;max-width:100%}.variable-pill.changed{background:#e7f3ca;color:#496d2d}.execution-note{grid-column:1/-1;border-top:1px solid var(--line);padding:13px 20px;background:#f1f6e9;display:flex;align-items:flex-start;gap:11px;font-size:12px;color:#506746;min-height:56px}.note-dot{width:6px;height:6px;flex:0 0 6px;border-radius:50%;background:#8ea971;margin-top:8px}.output-pane{grid-column:1/-1;padding:16px 21px;display:flex;align-items:flex-start;gap:25px;border-top:1px solid #e4ecd9}.output-pane>div{flex:0 0 134px}.output-pane small{display:block;color:#8b9885;font-size:10px;margin-top:5px}.output-pane pre{font-size:14px;color:var(--green);flex:1;min-width:0;min-height:28px}.lab-controls{grid-column:1/-1;padding:16px 20px;display:flex;align-items:center;justify-content:space-between;border-top:1px solid var(--line);gap:12px}.playback{display:flex;align-items:center;gap:8px;flex-wrap:wrap}.primary,.secondary,.icon-button{display:inline-flex;justify-content:center;align-items:center;gap:12px;border-radius:8px;min-height:37px;padding:9px 16px;font-size:12px;font-weight:550}.primary{background:var(--green);color:#fff;box-shadow:0 2px 3px #19342510}.primary:hover:not(:disabled){background:#194b38}.secondary,.icon-button{background:#fff;border:1px solid #d6e0d2}.secondary:hover:not(:disabled),.icon-button:hover:not(:disabled){background:#edf3e5}.icon-button{width:36px;padding:7px;font-size:17px}.step-progress{width:90px;flex:0 0 90px;text-align:right;font-size:10px;color:var(--sub);font-family:Consolas,monospace}.step-progress progress{display:block;width:100%;height:4px;margin-top:8px;appearance:none;border:0;border-radius:4px;overflow:hidden;background:#e7eddf}.step-progress progress::-webkit-progress-bar{background:#e7eddf}.step-progress progress::-webkit-progress-value{background:#799d4d}.lab-caption{font-size:11px;color:#788770;margin-top:14px;line-height:1.8}.section-next{display:flex;align-items:center;justify-content:space-between;margin-top:27px;padding:17px 0;border-top:1px solid var(--line);font-size:13px;color:var(--sub);gap:10px}.checkpoint{grid-column:1/-1;padding:20px;background:#fff8e8;border-top:1px solid #f1dfb3}.checkpoint[hidden]{display:none}.checkpoint .eyebrow{color:#9f7840;font-size:10px}.checkpoint p{font-size:13px;margin-top:5px}.prediction-controls{display:flex;flex-wrap:wrap;gap:9px;align-items:center;margin-top:12px}.prediction-controls input{background:#fff;border:1px solid #dfd4b9;border-radius:8px;padding:9px 11px;font-size:13px;width:160px;max-width:100%;min-width:0}.prediction-feedback{grid-column:1/-1;font-size:12px;padding:0 20px;color:var(--green);line-height:1.8;background:#fafcf5}.prediction-feedback:not(:empty){padding:12px 20px;border-top:1px solid var(--line)}.prediction-feedback.incorrect{color:#965626;background:#fff7ec}.flow-svg{width:100%;display:block;max-height:260px;overflow:visible}.flow-svg text{font-family:"Segoe UI","Microsoft YaHei",sans-serif;fill:#657660;font-size:15px}.flow-svg .edge{stroke:#d8e2ce;stroke-width:2;fill:none}.flow-svg .edge.on{stroke:#72a44b;stroke-width:3}.flow-svg .node{fill:#fff;stroke:#d5e0cc;stroke-width:1.4}.flow-svg .node.on{fill:#edf7d5;stroke:#9fbe60;stroke-width:2}.flow-svg .on-label{fill:#355b24;font-weight:600}.boolean-gates{display:grid;gap:12px}.gate{display:grid;grid-template-columns:50px 1fr auto;align-items:center;gap:10px;background:#fff;border:1px solid var(--line);border-radius:10px;padding:13px 12px}.gate code{font-size:11px}.gate b{font:600 14px Consolas,monospace;color:var(--green)}.gate-value{font-family:Consolas,monospace;font-size:12px;color:#7b8b73}.gate.done{background:#f3f9e6;border-color:#b9d193}.loop-track{display:flex;justify-content:center;gap:9px;margin:6px 0 21px;flex-wrap:wrap}.loop-token{width:39px;height:39px;display:flex;align-items:center;justify-content:center;border-radius:50%;border:1px solid #cfdec0;background:#fff;color:#778d66;font:17px Consolas,monospace;position:relative}.loop-token.visited{background:#e7f0d8}.loop-token.current{border-color:#8faf48;background:#daedab;box-shadow:0 0 0 4px #eff6df;color:#365320}.loop-token.skipped{background:#fff0e2;border-color:#e3b080;color:#9c622c}.sum-block{border:1px solid #d7e6bf;border-radius:14px;padding:18px;text-align:center;background:linear-gradient(120deg,#f2f8e7,#fff);max-width:320px;margin:auto}.sum-block .sum-label{font-size:10px;color:#81906f;letter-spacing:1px}.sum-number{font-family:Consolas,monospace;font-size:43px;line-height:1.4;color:#527433;overflow-wrap:anywhere}.sum-history{font:12px Consolas,monospace;color:#7b8d66;line-height:1.8;margin-top:3px}.loop-callout{text-align:center;font-size:11px;color:var(--sub);margin-top:12px;line-height:1.7}.loop-callout.control-jump{color:#ac6331}.learn-intro{padding:23px 26px;background:#eaf1df;border-radius:14px;margin-bottom:22px;font-size:15px;line-height:1.9;color:#526a43}.concept-grid{display:grid;grid-template-columns:1fr 1fr;gap:17px}.concept{border:1px solid var(--line);border-radius:13px;padding:23px;background:#fff;min-width:0}.concept-index{color:#86a05e;font:13px Consolas,monospace;display:block;margin-bottom:10px}.concept pre{background:#f2f6ed;border-radius:8px;padding:13px;margin:14px 0;font-size:12px;color:#42623b}.concept p{font-size:13px;color:var(--sub)}.practice-intro{font-size:13px;color:var(--sub);margin-bottom:18px;line-height:1.9}.practice-intro code{background:#eaf0e2;padding:3px 6px;border-radius:4px}.exercise-grid{display:grid;gap:18px}.exercise{background:#fff;border:1px solid var(--line);border-radius:14px;padding:23px;min-width:0}.exercise-top{display:flex;align-items:center;justify-content:space-between;gap:12px;margin-bottom:12px}.exercise-id{font:11px Consolas,monospace;color:#8b9b7e}.exercise-kind{font-size:10px;background:#edf4e3;padding:5px 9px;border-radius:5px;color:#678146}.exercise p{font-size:13px;margin:10px 0 15px;color:var(--sub)}.exercise pre,.hint pre{padding:15px;background:#f3f7ef;border:1px solid #e5ecd9;border-radius:8px;font-size:12px}.file-location{display:flex;justify-content:space-between;align-items:center;flex-wrap:wrap;gap:9px;font-size:11px;margin:14px 0;color:var(--sub)}.file-location code{overflow-wrap:anywhere}.hint{border-top:1px solid #e6eddf;padding:11px 0;font-size:12px}.hint summary{cursor:pointer;color:#687f55;line-height:1.8}.hint p{margin:10px 0;font-size:12px;line-height:1.9}.hint.answer summary{color:#a06e39}.hint pre{margin-top:10px}.hint-group{margin-top:18px}.check-command{border-top:1px solid #edf0e7;padding-top:13px;margin-top:10px;font-size:11px;color:#819070}.check-command code{display:inline-block;color:var(--green);margin-top:6px;overflow-wrap:anywhere}.cheat-table{width:100%;border-collapse:collapse;font-size:12px;margin-top:16px;table-layout:fixed}.cheat-table th{text-align:left;padding:12px;background:#edf3e4;font-size:11px;font-weight:600}.cheat-table th:first-child{width:22%}.cheat-table th:nth-child(2){width:36%}.cheat-table td{padding:15px 12px;border-bottom:1px solid var(--line);vertical-align:top;line-height:1.9;overflow-wrap:anywhere}.cheat-table td pre{font-size:11px}.review-block{margin:27px 0}.error-card{border-left:3px solid #d8bd91;background:#fffaf3;padding:17px 20px;margin-top:13px;border-radius:0 9px 9px 0}.error-card h3{font-size:13px;color:#8d653a}.error-card pre{font-size:12px;margin:10px 0;color:#806b51}.error-card p{font-size:12px;color:#7c7768}.oral-card{border:1px solid var(--line);background:#fff;border-radius:12px;padding:22px}.oral-card p{font-size:14px;margin:12px 0;line-height:1.9}.checklist{display:grid;gap:13px;margin:18px 0}.checklist label{display:flex;align-items:flex-start;gap:10px;font-size:13px;line-height:1.8}.checklist input{accent-color:var(--green);width:17px;height:17px;margin:3px 0 0;flex:0 0 17px}.self-rating{display:flex;gap:9px;flex-wrap:wrap;margin:14px 0}.self-rating button{font-size:12px;padding:10px 15px;border:1px solid var(--line);border-radius:8px;background:#fff}.self-rating button[aria-pressed="true"]{background:#e5f1ce;border-color:#a9c77c;color:#506e38}.session-note{font-size:11px;color:#8b967f;line-height:1.8}footer{display:flex;justify-content:space-between;border-top:1px solid var(--line);padding:22px 0 30px;font-size:10px;color:#8c9985;gap:12px;margin-top:20px}dialog{border:1px solid var(--line);border-radius:18px;padding:29px;width:min(680px,calc(100% - 32px));max-height:85vh;overflow-y:auto;color:var(--ink);box-shadow:0 20px 90px #19352625}dialog::backdrop{background:#19352640;backdrop-filter:blur(4px)}.dialog-header{display:flex;justify-content:space-between;align-items:center;gap:10px}.dialog-intro{font-size:12px;color:var(--sub);margin:14px 0 22px}.catalog-stage{border-left:2px solid #d8e4ca;padding:0 0 24px 22px;margin-left:8px;position:relative}.catalog-stage::before{content:'';position:absolute;top:6px;left:-5px;width:8px;height:8px;background:#a1ba7f;border-radius:50%}.catalog-stage h3{font-size:14px;margin-bottom:11px}.catalog-items{display:grid;gap:8px}.catalog-item{display:flex;align-items:center;justify-content:space-between;gap:10px;font-size:12px;color:var(--sub);line-height:1.6}.catalog-item .ready{font-size:10px;color:var(--green);white-space:nowrap}.catalog-item .planned{font-size:10px;color:#9ba38f;white-space:nowrap}.catalog-item a{text-underline-offset:4px}.guide-list{padding-left:23px;font-size:13px;line-height:1.9;margin:22px 0}.guide-list li{margin-bottom:17px}.guide-list code{overflow-wrap:anywhere}.guide-note{font-size:12px;color:var(--sub);line-height:1.8;background:#f0f5e9;padding:16px;border-radius:9px}.sr-only{position:absolute;width:1px;height:1px;overflow:hidden;clip-path:inset(50%);white-space:nowrap}.skip{position:absolute;left:-9999px;top:0}.skip:focus{left:8px;top:8px;z-index:10;background:#fff;padding:14px}.scene.animate .changed,.scene.animate .current{animation:settle .25s ease-out}@keyframes settle{from{transform:translateY(-3px)}to{transform:translateY(0)}}
@media(min-width:1450px){main{padding:0 62px}.code-lines{font-size:14px}.line-number{font-size:11px}.code-line{min-height:30px}.scene{padding:23px 30px 13px}.variable-value{font-size:27px}.lab-selectors select{font-size:13px}}
@media(max-width:1150px){.shell{grid-template-columns:208px minmax(0,1fr)}.sidebar{padding:28px 15px}main{padding:0 27px}.brand{font-size:13px}.brand small{font-size:10px}.lab-selectors{gap:10px}.lab-selectors label{align-items:flex-start;flex-direction:column;gap:7px}.lab-selectors select{width:100%}.tabs{gap:19px}.tabs button{font-size:12px}.hero-symbol{width:78px;height:78px;flex-basis:78px}.scene{padding:17px 15px 9px}.code-lines{font-size:11px}.variable-value{font-size:21px}.pane-heading{padding:13px 12px}.pane-heading small{font-size:9px}.lab-controls{padding:14px}.step-progress{flex-basis:65px;width:65px}.primary,.secondary{padding:9px 11px}.playback{gap:5px}.line-number{flex-basis:29px;padding-right:9px}}
@media(max-width:940px){.lab{grid-template-columns:1fr}.code-side{border-right:0;border-bottom:1px solid var(--line)}.code-lines{min-height:0;font-size:13px}.scene{min-height:205px}.visual-side .scene{padding:20px 30px 7px}.variable-strip{justify-content:center}.concept-grid{grid-template-columns:1fr}.hero-symbol{display:none}.section-heading{align-items:flex-start}.trace-tag{font-size:9px}.tabs{gap:16px}.tabs button span{margin-right:4px}.loop-track{margin-bottom:15px}.flow-svg{max-height:240px}.boolean-gates{max-width:370px;margin:auto}}
@media(max-width:700px){.shell{display:block}.sidebar{position:static;height:auto;min-height:0;padding:20px 20px 14px;border-right:0;border-bottom:1px solid var(--line)}.brand{font-size:14px}.brand small{font-size:11px}.brand-mark{width:36px;height:36px;flex-basis:36px;font-size:18px}.sidebar-label,.side-note,.offline{display:none}#lesson-nav{display:flex;gap:6px;margin-top:18px}.lesson-link{flex:1;min-width:0;display:block;padding:10px 9px;position:relative}.lesson-link .num{font-size:11px}.lesson-link strong{font-size:11px;margin-top:6px}.lesson-link small{display:none}.catalog-button{border:0;padding:8px 0 0;margin-top:9px;font-size:11px;justify-content:flex-end}.catalog-button span:last-child{margin-left:0}main{padding:0 20px}.topbar{height:53px;font-size:10px}.topbar .text-button{font-size:11px}.lesson-hero{padding:24px 0 20px}.eyebrow{font-size:10px}h1{font-size:29px;letter-spacing:-1px}.lead{font-size:12px}.lesson-goal{display:block;padding:12px 14px;font-size:11px}.lesson-goal p{margin-top:4px}.tabs{gap:0;justify-content:space-between;margin-bottom:22px}.tabs button{font-size:11px;padding-bottom:11px}.tabs button span{display:block;text-align:left;margin-bottom:5px}h2{font-size:20px}.section-heading{gap:8px}.trace-tag{font-size:8px;padding:5px 7px}.lab-selectors{gap:9px}.lab-selectors label{font-size:10px}.lab-selectors select{font-size:11px;padding:9px 20px 9px 8px}.lab{border-radius:13px}.pane-heading{padding:12px 15px}.code-lines{font-size:12px}.visual-side .scene{padding:19px 16px 8px}.execution-note{padding:13px 15px;font-size:11px}.output-pane{padding:14px 15px;gap:15px}.output-pane>div{flex-basis:102px}.output-pane small{font-size:9px}.output-pane pre{font-size:12px}.lab-controls{flex-wrap:wrap;padding:13px}.playback{gap:6px;flex:1}.primary,.secondary{font-size:11px;padding:9px 11px}.step-progress{flex:1 1 100%;display:flex;align-items:center;gap:12px;text-align:left}.step-progress progress{flex:1;margin:0}.lab-caption{font-size:10px}.section-next{font-size:11px;margin-top:20px}.checkpoint{padding:15px}.prediction-controls input{flex:1 1 100%;width:100%;font-size:16px}.prediction-controls .primary{min-height:39px}.concept{padding:19px}.learn-intro{padding:18px;font-size:13px}.exercise{padding:18px}.exercise p{font-size:12px}.exercise pre{font-size:11px}.practice-intro{font-size:12px}.check-command{font-size:10px}.cheat-table{font-size:11px}.cheat-table th{font-size:10px;padding:10px 6px}.cheat-table td{padding:12px 6px}.cheat-table td pre{font-size:10px}.cheat-table th:first-child{width:22%}.cheat-table th:nth-child(2){width:39%}footer{font-size:9px;flex-direction:column;gap:5px}.oral-card{padding:17px}.oral-card p{font-size:13px}dialog{padding:22px}.flow-svg text{font-size:17px}.guide-list{font-size:12px}}
@media(prefers-reduced-motion:reduce){*,*::before,*::after{animation:none!important;transition:none!important;scroll-behavior:auto!important}}
/* Long study sessions need readable code and prose at native screen scale. */
.code-lines{font-size:14px}.code-line{min-height:30px}.concept p,.exercise p,.practice-intro{font-size:14px}.concept pre,.exercise pre,.hint pre{font-size:13px}.execution-note{font-size:13px}.variable-pill{font-size:11px}.scene-caption{font-size:11px}.loop-callout{font-size:12px}.sum-history{font-size:13px}.code-foot{font-size:11px}.code-line.active .code-text{font-weight:550}.flow-arrow{transition:color .25s}.scene.animate .flow-arrow{color:#7da355}.scene.animate .variable-box.changed{animation:variable-arrive .38s ease-out}@keyframes variable-arrive{from{transform:translateY(-7px);background:#e4f3b2}to{transform:translateY(0);background:#f5fadf}}
@media(max-width:1150px) and (min-width:941px){.code-lines{font-size:13px}}
@media(max-width:700px){.code-lines{font-size:13px}.concept p,.exercise p,.practice-intro{font-size:13px}.concept pre,.exercise pre,.hint pre{font-size:12px}.execution-note{font-size:12px}.variable-pill{font-size:10px}.code-foot{font-size:10px}}
@media(prefers-reduced-motion:reduce){.scene.animate .variable-box.changed{animation:none}}
/* Foundation atlas: indexed cells, identities, scopes and work-count diagrams. */
.sample-case{display:grid;grid-template-columns:1fr 1fr;gap:12px;margin:14px 0 19px}.sample-case>div{min-width:0}.sample-case small{display:block;font-size:10px;letter-spacing:.5px;color:#8b9b7c;margin-bottom:7px}.sample-case pre{background:#fbfcf8;padding:12px;min-height:50px;font-size:12px}
.object-slot.changed-slot{background:#fff0dc;border-color:#d2a367;color:#9f5e2a;box-shadow:0 0 0 2px #f8ead7}.change-legend{text-align:center;font-size:10px;color:#a97b44;margin:10px 0}
.sidebar{overflow-y:auto;min-height:0;padding-top:27px;padding-bottom:22px}.sidebar-label{margin-top:28px;margin-bottom:12px}#lesson-nav{gap:5px}.lesson-link{padding:11px 9px;gap:9px}.lesson-link small{letter-spacing:0;margin-top:3px}.catalog-button{margin-top:15px}.side-note{padding:18px 10px}.side-note p{margin:8px 0}.side-note .rhythm{margin:10px 0}.rhythm i{background:#7c9d67}.hero-symbol span{white-space:nowrap}
.container-heading{display:flex;align-items:center;justify-content:space-between;gap:10px;font-size:11px;color:var(--sub);margin:4px 0 15px}.container-heading code{font-size:14px;color:var(--green);font-weight:600}.container-heading span{line-height:1.6}.index-cells{display:flex;flex-wrap:wrap;gap:8px;align-items:center}.index-cell{position:relative;min-width:46px;flex:0 0 auto;text-align:center;border:1px solid #d4dfcd;border-radius:9px;background:#fff;padding:5px 10px;transition:background .2s;max-width:100%}.index-cell strong{font:600 19px/1.8 Consolas,monospace;display:block;color:#42623b;overflow-wrap:anywhere}.index-cell small{display:block;font:10px Consolas,monospace;color:#7f9271}.index-cell .negative-index{border-top:1px solid #edf1e6;padding-top:4px;margin-top:3px;color:#9e9275}.index-cell.selected{background:#eaf5cd;border-color:#a4c869;box-shadow:0 0 0 2px #edf5dd}.index-cell.cell-changed strong{color:#9b582a}.index-legend{display:flex;justify-content:space-between;gap:10px;font-size:10px;color:#829072;margin:11px 0 18px}.index-legend span{line-height:1.6}.container-empty{padding:18px;border:1px dashed #cad8be;border-radius:9px;color:#7d8f70;font-size:12px;text-align:center}.slice-ribbon{border-left:3px solid #9bbc55;background:#eff7df;padding:11px;font-size:11px;display:flex;gap:12px;flex-wrap:wrap;margin:12px 0}.slice-ribbon s{text-decoration:none;color:#a77045}.derived-values{border-top:1px dashed #d8e2cf;margin-top:19px;padding-top:15px;display:flex;gap:8px;flex-wrap:wrap}.derived-values>.scene-caption{flex:1 1 100%;margin-bottom:3px;text-align:left}.mini-value{display:flex;flex-direction:column;gap:6px;padding:10px 13px;background:#fff;border:1px solid #d9e5d2;border-radius:9px;min-width:70px;max-width:100%;overflow-wrap:anywhere}.mini-value code{font-size:11px;color:#7c8f70}.mini-value strong{font:600 16px Consolas,monospace;color:var(--green)}.mini-value small{font-size:9px;color:#96a18b}.derived-row{flex:1 1 100%;display:flex;gap:16px;align-items:center;min-width:0}.derived-row>code{font-size:12px;min-width:34px}.derived-row .index-cells{flex:1;min-width:0}.derived-row .index-cell{min-width:42px}.derived-row .index-cell strong{font-size:16px}
.word-stream{display:flex;justify-content:center;gap:7px;flex-wrap:wrap}.word-token{border:1px solid #d5dfca;padding:8px 10px;border-radius:7px;background:#fff;font:13px Consolas,monospace;display:flex;flex-direction:column;gap:5px;align-items:center}.word-token small{font-size:9px;color:#94a183}.word-token.current{background:#e1efbd;border-color:#9ab960;box-shadow:0 0 0 3px #f0f6e4}.word-token.visited{background:#f1f5e9;color:#8c9b7e}.subtle{font-size:11px;color:#89977b}.mapping-grid{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:10px}.mapping-card{display:flex;align-items:center;gap:9px;border:1px solid #d7e1ce;border-radius:11px;padding:14px 12px;background:#fff;min-width:0}.mapping-key{font:13px Consolas,monospace;overflow-wrap:anywhere;min-width:0;flex:1}.mapping-arrow{color:#a9bd8b}.mapping-card b{font:600 27px Consolas,monospace;color:var(--green)}.mapping-card.selected{background:#f1f8df;border-color:#aac577}.calculation-strip{margin-top:18px;display:flex;align-items:center;justify-content:center;gap:13px;padding:12px;background:#f2f6ea;border-radius:9px;font-size:11px;color:#798966;flex-wrap:wrap}.calculation-strip b{color:#5b7b38;font:600 18px Consolas,monospace;margin-left:4px}.calculation-strip+.scene-caption{margin-top:9px;font-size:10px;letter-spacing:0}.set-arena{border:2px dashed #c4d8ae;background:#f9fcf2;border-radius:23px;padding:15px}.unique-pills{display:flex;justify-content:center;flex-wrap:wrap;gap:12px;padding:12px 0}.unique-pill{width:58px;height:58px;border-radius:50%;border:1px solid #bdcf9e;display:flex;align-items:center;justify-content:center;background:#fff;font:14px Consolas,monospace;max-width:100%;overflow-wrap:anywhere}.unique-pill.selected{background:#deedb9;border-color:#99b653}.set-arena~.scene-caption{margin-top:16px;letter-spacing:0}
.scope-stack{display:grid;gap:0}.scope-card{border:1px solid #d4dfce;background:#f9fbf5;border-radius:12px;overflow:hidden}.scope-card.is-active{border-color:#97b66b;box-shadow:0 0 0 2px #eaf2dc}.scope-heading{background:#edf3e5;padding:11px 13px;display:flex;justify-content:space-between;gap:9px;font-size:10px;color:#728760}.scope-heading code{font-size:12px;color:#45613a;overflow-wrap:anywhere}.scope-values{display:flex;flex-wrap:wrap;gap:8px;padding:13px}.scope-values .empty-scene{width:100%;padding:10px}.scope-connector{text-align:center;font-size:10px;color:#91a477;letter-spacing:.5px;padding:9px}.return-parcel{margin:16px 0 8px;padding:14px;border:1px solid #e6d3ae;border-radius:11px;background:#fff8e8;display:flex;flex-direction:column;align-items:center;gap:7px}.return-parcel>span{font-size:10px;color:#a38450;letter-spacing:.8px}.return-parcel strong{font:600 29px Consolas,monospace;color:#926333}.return-parcel small{font-size:10px;color:#a38b68;text-align:center}
.reference-map{display:grid;gap:15px}.reference-row{display:grid;grid-template-columns:94px 19px minmax(0,1fr);gap:8px;align-items:center}.reference-names{display:flex;flex-direction:column;gap:6px;min-width:0}.reference-names code{border-radius:6px;border:1px solid #cbdbb7;background:#edf5de;font-size:11px;text-align:center;padding:8px 4px;overflow-wrap:anywhere}.reference-names small{font-size:9px;text-align:center;color:#8b9a79}.reference-arrow{font-size:24px;color:#91b260}.object-card{border:1px solid #c8d8b4;border-radius:10px;overflow:hidden;background:#fff;min-width:0}.object-heading{background:#eff5e5;display:flex;justify-content:space-between;align-items:center;padding:8px 10px;color:#849870;font-size:9px;gap:5px}.object-heading code{color:#5d7c3e;font-size:11px}.object-slots{display:flex;gap:5px;padding:10px;flex-wrap:wrap}.object-slot{min-width:35px;min-height:34px;padding:8px;display:flex;align-items:center;justify-content:center;background:#f8faf3;border:1px solid #dce7cf;border-radius:5px;font:14px Consolas,monospace;overflow-wrap:anywhere}.reference-slot{font-size:12px;color:#6c87a2;border-color:#d3dfe7;background:#f0f5f8}.inner-layer{margin-top:17px;padding-top:14px;border-top:1px dashed #cbdabb}.inner-layer>.scene-caption{letter-spacing:0}.inner-objects{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:9px}.inner-object{border-color:#cbdbe5}.inner-object .object-heading{background:#edf3f7;color:#8193a1}.inner-object .object-heading code{color:#54728b}.inner-object .object-slot{font-size:13px;min-width:29px;padding:6px}.reference-map~.scene-caption{margin-top:11px;letter-spacing:0}
.sort-row+.sort-row{border-top:1px dashed #d0dfbe;margin-top:18px;padding-top:14px}.rank-list{display:grid;gap:8px}.rank-card{display:grid;grid-template-columns:20px minmax(25px,1fr) auto minmax(95px,1.3fr);align-items:center;gap:8px;padding:13px 10px;background:#fff;border:1px solid #d7e2cc;border-radius:9px;font-size:12px;min-width:0}.rank-position{font:12px Consolas,monospace;color:#92a87a}.rank-card strong{font-weight:600;overflow-wrap:anywhere}.rank-card>span:nth-child(3){font-size:11px;color:#788d62}.rank-card code{font-size:11px;color:#997447;text-align:right;overflow-wrap:anywhere}.rank-card.selected{border-color:#a1bf73;background:#f0f8e0}.rank-list~.scene-caption{margin-top:14px;letter-spacing:0}.complexity-header{display:flex;align-items:center;justify-content:space-between;gap:9px;background:#edf5df;padding:12px;border-radius:10px;color:#7d9166}.complexity-header>span{font-size:10px}.complexity-header strong{font:600 21px Consolas,monospace;color:#4d7133}.complexity-header small{font-size:9px}.work-bars{display:grid;gap:17px;margin:20px 0}.work-label{display:flex;gap:10px;align-items:center;font-size:11px;color:#81936d;margin-bottom:7px}.work-label code{min-width:43px;color:#55763b;font-size:12px}.work-label b{margin-left:auto;font:600 16px Consolas,monospace;color:#507534}.work-label small{font-size:10px;color:#8a9d76;font-weight:400}.work-track{height:8px;border-radius:6px;background:#eef2e6;overflow:hidden}.work-track>div{height:100%;background:#a7c86c;border-radius:6px;transition:width .2s}.work-row:nth-child(2) .work-track>div{background:#70a788}.work-row:nth-child(3) .work-track>div{background:#d5b277}.pair-board{display:grid;grid-template-columns:repeat(var(--pair-n),1fr);gap:5px;max-width:280px;margin:0 auto 10px}.pair-cell{display:flex;align-items:center;justify-content:center;aspect-ratio:1.65;border-radius:5px;border:1px solid #dce5d1;background:#f9fbf5;color:#a9b89a;font:11px Consolas,monospace}.pair-cell.done{background:#e8f1d9;border-color:#bbd295;color:#6b8b47}.pair-cell.latest{background:#d5e7ae;border-color:#99b567;color:#3f6023}.scene.animate .cell-changed,.scene.animate .selected{animation:settle .25s ease-out}
@media(min-width:701px) and (max-height:950px){.side-note{display:none}.offline{margin-top:auto}.sidebar{padding-top:20px}.sidebar-label{margin-top:22px}}
@media(max-width:1150px) and (min-width:941px){.reference-row{grid-template-columns:76px 16px minmax(0,1fr);gap:5px}.reference-names code{font-size:10px}.rank-card{grid-template-columns:15px 1fr auto;gap:6px}.rank-card code{grid-column:2/-1;text-align:left}.mapping-grid{grid-template-columns:1fr}.index-cell{min-width:39px;padding:5px 7px}}
@media(max-width:700px){#lesson-nav{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:5px}.lesson-link{display:flex;padding:9px;gap:9px;min-height:46px}.lesson-link .num{font-size:12px}.lesson-link strong{font-size:11px;margin-top:0}.lesson-link:last-child{grid-column:1/-1}.sidebar{padding-top:18px;padding-bottom:12px}.catalog-button{min-height:36px}.index-cell{min-width:39px;padding:5px 8px}.index-cell strong{font-size:17px}.index-legend{font-size:9px}.reference-row{grid-template-columns:80px 16px minmax(0,1fr);gap:6px}.reference-names code{font-size:10px}.object-slots{padding:8px;gap:4px}.object-slot{min-width:29px;padding:6px;font-size:12px}.object-heading{padding:8px;font-size:9px}.reference-slot{font-size:11px}.mini-value{min-width:63px;padding:9px}.mini-value strong{font-size:15px}.mapping-grid{gap:7px}.mapping-card{gap:6px;padding:12px 9px}.mapping-key{font-size:12px}.mapping-card b{font-size:22px}.rank-card{grid-template-columns:17px 1fr auto;gap:6px}.rank-card code{grid-column:2/-1;text-align:left}.scene-caption{letter-spacing:.2px}.complexity-header{gap:7px}.complexity-header strong{font-size:19px}.complexity-header small{font-size:8px}.primary,.secondary,.icon-button{min-height:42px}}
@media(max-width:360px){.mapping-grid{grid-template-columns:1fr}.inner-objects{grid-template-columns:1fr}.reference-row{grid-template-columns:66px 14px minmax(0,1fr);gap:5px}.reference-names code{font-size:9px}.object-heading{padding:7px 5px}.object-slot{min-width:26px;font-size:11px}.reference-slot{font-size:10px}.scope-heading{font-size:9px;padding:10px}.index-cells{gap:5px}.index-cell{min-width:33px;padding:4px 7px}.work-label{gap:6px}.complexity-header{flex-wrap:wrap}}
@media print{.sidebar,.topbar,.lesson-hero,.lesson-goal,.tabs,.panel:not(#panel-review),footer,dialog,.self-rating,.session-note,button{display:none!important}.shell{display:block}main{padding:0;max-width:none}#panel-review{display:block!important}.cheat-table{font-size:11px}.review-block{break-inside:avoid}.error-card{background:white}.checklist{display:none}.review-block:last-child{display:none}}