:root{font-family:Inter,ui-sans-serif,system-ui,sans-serif;color:#182c2a;background:#f7f8f4;line-height:1.6;--green:#176452;--muted:#647570;--line:#dce3dc}*{box-sizing:border-box}body{margin:0}a{color:inherit;text-decoration:none}button,input,select,textarea{font:inherit}button,a,select{ -webkit-tap-highlight-color:transparent}button,.button{cursor:pointer;border:1px solid var(--line);background:white;border-radius:7px;padding:10px 18px;color:#183b32;font-weight:600}button:hover,.button:hover{border-color:var(--green);background:#edf3ed}a:focus-visible,button:focus-visible,input:focus-visible,textarea:focus-visible,select:focus-visible{outline:3px solid #d4a548;outline-offset:3px}.primary{background:var(--green);color:white;border-color:var(--green)}.primary:hover{background:#104c3d;color:white}header{max-width:1280px;margin:auto;display:flex;align-items:center;justify-content:space-between;padding:25px 38px;border-bottom:1px solid var(--line);gap:24px}.brand{display:flex;align-items:center;gap:10px;font-size:12px;font-weight:800;letter-spacing:1px}.brand>span:last-child{color:var(--muted);font-weight:500}.logo{background:var(--green);color:#fff;font-size:27px;line-height:34px;width:35px;text-align:center;border-radius:8px}nav{display:flex;gap:30px;font-size:14px}nav a.active{color:var(--green);font-weight:700}small,.eyebrow{font-size:10px;letter-spacing:1.5px;font-weight:700}nav small{background:#e9ece4;padding:3px 5px;border-radius:3px;margin-left:4px}.local{font-size:11px;color:var(--green);border:1px solid var(--line);padding:5px 10px;border-radius:20px}main{max-width:1204px;margin:0 auto;padding:45px 0 80px;min-height:76vh}.hero{display:grid;grid-template-columns:1.15fr 1fr;gap:60px;align-items:center;padding:26px 0 56px}.eyebrow{color:var(--green);display:block;margin-bottom:17px}h1{font-size:58px;line-height:1.1;letter-spacing:-2.5px;font-weight:650;margin:0 0 24px}h1 em{font-style:normal;color:var(--green)}p{color:var(--muted)}.hero p{max-width:470px;font-size:17px}.actions{display:flex;gap:12px;margin:26px 0}.subnote{font-size:12px;color:var(--muted)}.diagram{height:325px;position:relative;background-color:#edf1e8;background-image:linear-gradient(#dce4d766 1px,transparent 1px),linear-gradient(90deg,#dce4d766 1px,transparent 1px);background-size:26px 26px;border:1px solid #dce3d5;border-radius:14px;overflow:hidden}.diagram svg{width:100%;height:100%}.diagram .tag{position:absolute;bottom:18px;left:20px;background:#ffffffde;padding:7px 13px;border-radius:5px;font:11px monospace;color:var(--green)}.diagram .top{position:absolute;top:17px;left:20px;font:10px monospace;letter-spacing:1px;color:#687768}.stats{display:flex;border-top:1px solid var(--line);border-bottom:1px solid var(--line);padding:20px 0;gap:65px;margin-bottom:43px}.stats strong{font-size:22px;margin-right:12px}.stats span{font-size:12px;color:var(--muted)}.section-head{display:flex;justify-content:space-between;align-items:center;margin:22px 0}h2{font-size:26px;letter-spacing:-.6px;margin:0}h3{font-size:19px;margin:12px 0}.section-head a{font-size:13px;color:var(--green)}.cards{display:grid;grid-template-columns:repeat(2,1fr);gap:20px}.card{border:1px solid var(--line);border-radius:10px;background:#fff;padding:25px;transition:transform .15s,border-color .15s}.card:hover{border-color:#93ad98;transform:translateY(-2px)}.card-top{display:flex;align-items:center;justify-content:space-between}.number{font:13px monospace;color:#8a9790}.badge{font-size:11px;background:#eaf3e8;color:#32644a;border-radius:4px;padding:3px 8px}.card p{font-size:14px;min-height:42px}.card-bottom{border-top:1px solid #edf0e9;margin-top:22px;padding-top:17px;display:flex;justify-content:space-between;font-size:12px;color:var(--muted)}.card-bottom strong{color:var(--green)}.banner{margin-top:32px;border-radius:10px;background:#eaf0e5;padding:27px;display:flex;align-items:center;justify-content:space-between;gap:20px}.banner p{margin:5px 0;font-size:14px}.page-title{font-size:40px;letter-spacing:-1.5px}.filters{display:flex;gap:12px;margin:30px 0}input,select{padding:11px 14px;border:1px solid var(--line);border-radius:6px;background:white;color:#28463c}input{flex:1;min-width:0}.back{font-size:13px;color:var(--muted)}.workspace{display:grid;grid-template-columns:1fr 1fr;gap:28px;margin-top:28px}.panel{border:1px solid var(--line);border-radius:10px;background:white;padding:25px}.panel h2{font-size:19px}.panel p,.panel li{font-size:14px}.tabs{display:flex;border-bottom:1px solid var(--line);gap:16px;margin:0 0 24px}.tabs button{border:0;border-radius:0;padding:8px 0 12px;font-size:13px;background:none;color:var(--muted)}.tabs button.selected{color:var(--green);border-bottom:2px solid var(--green)}.editor-head{display:flex;justify-content:space-between;align-items:center;margin-bottom:18px}textarea{width:100%;height:340px;resize:vertical;background:#172c29;color:#e1ece1;border:0;border-radius:6px;padding:20px;font:13px/1.8 ui-monospace,monospace;tab-size:4}pre{white-space:pre-wrap;overflow-wrap:anywhere;background:#eef2ec;border-radius:6px;padding:16px;font-size:12px}table{width:100%;border-collapse:collapse;font-size:13px}td,th{text-align:left;border-bottom:1px solid var(--line);padding:14px 7px}details{padding:16px 0;border-bottom:1px solid var(--line)}summary{cursor:pointer;font-weight:600;font-size:14px}.notice{border-left:3px solid #d2ab61;background:#faf6ec;padding:13px;font-size:12px;color:#78653e;margin-top:20px}.progress-track{height:8px;background:#e4eadf;border-radius:10px;margin:22px 0}.progress-track span{display:block;height:100%;background:var(--green);border-radius:10px}.empty{text-align:center;padding:45px;border:1px dashed var(--line);grid-column:1/-1}.project-list{display:grid;grid-template-columns:repeat(3,1fr);gap:18px}.project-list .card{display:flex;flex-direction:column}.project-list details{margin-top:auto}footer{max-width:1204px;margin:auto;border-top:1px solid var(--line);padding:26px 0;display:flex;justify-content:space-between;font-size:11px;color:var(--muted)}#status{font-size:12px;color:var(--green)}@media(min-width:1500px){main{padding-top:65px}}@media(max-width:1280px){main,footer{margin-left:38px;margin-right:38px}}@media(max-width:850px){.hero{gap:25px}h1{font-size:44px}.local{display:none}.workspace{grid-template-columns:1fr}.project-list{grid-template-columns:1fr}.stats{gap:25px}}@media(max-width:600px){header{padding:20px;flex-wrap:wrap;gap:20px}nav{gap:25px;width:100%;justify-content:space-between}main,footer{margin-left:20px;margin-right:20px}main{padding-top:30px}.hero{grid-template-columns:1fr;padding-top:0;gap:15px}h1{font-size:42px}.diagram{height:240px}.stats{gap:16px;justify-content:space-between}.stats strong{display:block}.stats span{font-size:10px}.cards{grid-template-columns:1fr}.banner{align-items:flex-start;flex-direction:column}.filters{flex-direction:column}.page-title{font-size:32px}footer{gap:15px;flex-wrap:wrap}.panel{padding:18px}.actions{flex-wrap:wrap}}

button:disabled{opacity:.6;cursor:wait}.test-result.pass summary{color:#176452}.test-result.fail summary{color:#a24032}#run-results{overflow-wrap:anywhere}#run-results pre{max-height:220px;overflow:auto}
/* VS Code-inspired editor surface */
.code-editor{margin-top:9px;border:1px solid #353535;border-radius:7px;overflow:hidden;background:#1e1e1e;box-shadow:0 8px 24px #1112}
.code-titlebar{display:flex;justify-content:space-between;align-items:center;background:#252526;color:#b9b9b9;font:12px ui-monospace,monospace}
.file-tab{background:#1e1e1e;border-top:2px solid #007acc;padding:11px 16px;color:#eee}.file-icon{color:#75beff;margin-right:9px}.editor-hint{padding-right:12px;font-size:9px;letter-spacing:1px;color:#888}
.code-body{display:flex;height:360px;min-height:240px;resize:vertical;overflow:hidden}.line-numbers{width:48px;flex-shrink:0;text-align:right;padding:16px 10px 16px 0;white-space:pre;overflow:hidden;color:#858585;user-select:none;font:13px/23px ui-monospace,SFMono-Regular,Consolas,monospace}
.code-viewport{position:relative;flex:1;min-width:0}.code-highlight,.code-editor textarea{position:absolute;inset:0;width:100%;height:100%;margin:0;border:0;border-radius:0;padding:16px 16px 16px 0;font:13px/23px ui-monospace,SFMono-Regular,Consolas,monospace!important;white-space:pre;overflow-wrap:normal;word-break:normal;tab-size:4;letter-spacing:0;overflow:auto;text-align:left}
.code-highlight{background:#1e1e1e;color:#d4d4d4;pointer-events:none;scrollbar-width:none}.code-highlight::-webkit-scrollbar{display:none}.code-highlight code{font:inherit}
.code-editor textarea{background:transparent;color:transparent;caret-color:#fff;resize:none;-webkit-text-fill-color:transparent}.code-editor textarea::selection{background:#264f78aa}.code-editor textarea:focus-visible{outline:1px solid #007acc;outline-offset:-1px}
.syntax-keyword{color:#569cd6}.syntax-string{color:#ce9178}.syntax-comment{color:#6a9955}.syntax-number{color:#b5cea8}
.code-statusbar{display:flex;justify-content:space-between;gap:8px;padding:4px 10px;background:#007acc;color:#fff;font:10px/1.5 ui-monospace,monospace}.math-block{overflow-x:auto;padding:10px 0}.panel mjx-container{max-width:100%}.panel code{font-size:.92em}.panel li{margin:8px 0}.math-fallback{color:#94672b}
@media(max-width:600px){.editor-hint{display:none}.code-statusbar span:first-child{display:none}.code-body{height:310px}}

.code-editor .code-highlight code{font:inherit}

.editor-head{flex-wrap:wrap;gap:10px}.editor-head h2{margin-right:auto}#fullscreen{font-size:11px;padding:7px 10px}.actions{flex-wrap:wrap}
body.workspace-expanded{overflow:hidden}body.workspace-expanded>header,body.workspace-expanded>footer{display:none}
body.workspace-expanded main{max-width:none;margin:0;padding:0;height:100dvh;min-height:0}
body.workspace-expanded main>.back,body.workspace-expanded main>.section-head,body.workspace-expanded main>h1,body.workspace-expanded main>p{display:none}
body.workspace-expanded .workspace{position:fixed;inset:0;z-index:50;margin:0;padding:16px;background:#f7f8f4;gap:16px;grid-template-columns:minmax(0,1fr) minmax(0,1.2fr)}
body.workspace-expanded .workspace>.panel{overflow:auto;min-width:0}body.workspace-expanded .code-body{height:50dvh;resize:vertical}
@media(max-width:700px){body.workspace-expanded .workspace{grid-template-columns:1fr;overflow:auto;position:fixed}body.workspace-expanded .workspace>.panel{overflow:visible}body.workspace-expanded .code-body{height:45dvh}}

/* The Robot Lab design refresh */
:root{--green:#11624f;--green-dark:#0c4a3c;--ink:#14231f;--muted:#5d6e69;--line:#e1e7e1;--bg:#f6f7f3;--card:#fff;--accent:#d9a441;color:var(--ink);background:var(--bg);font-family:Inter,"Segoe UI Variable","Segoe UI",ui-sans-serif,system-ui,-apple-system,sans-serif;-webkit-font-smoothing:antialiased}
body{background:radial-gradient(1200px 500px at 85% -120px,#dfece4 0,transparent 70%),var(--bg)}
header{position:sticky;top:0;z-index:20;max-width:none;padding:16px max(38px,calc((100vw - 1204px)/2));background:#f6f7f3d9;backdrop-filter:saturate(1.4) blur(10px);-webkit-backdrop-filter:saturate(1.4) blur(10px)}
.brand{gap:11px;letter-spacing:0}.logo{display:grid;place-items:center;width:34px;height:34px;border-radius:9px;background:linear-gradient(140deg,#178066,var(--green-dark));color:#fff;box-shadow:0 4px 12px #11624f40,inset 0 1px 0 #ffffff30}
.brand-name{font-size:18px;font-weight:500;letter-spacing:-.4px;color:var(--muted)}.brand-name b{color:var(--ink);font-weight:800}footer .brand-name{font-size:13px}
nav a{position:relative;color:var(--muted);transition:color .15s}nav a:hover,nav a.active{color:var(--ink)}nav a.active::after{content:"";position:absolute;left:0;right:0;bottom:-6px;height:2px;border-radius:2px;background:var(--green)}nav a.active{font-weight:600}
.local{background:#fff;font-weight:600}
h1{font-weight:700;letter-spacing:-2px}.hero h1 em{background:linear-gradient(90deg,var(--green),#2a9a7c);-webkit-background-clip:text;background-clip:text;color:transparent}
button,.button{border-radius:9px;transition:background .15s,border-color .15s,box-shadow .15s,transform .1s}button:active,.button:active{transform:translateY(1px)}
.primary{background:linear-gradient(180deg,#167560,var(--green));box-shadow:0 6px 16px -6px #11624f99}.primary:hover{background:var(--green-dark)}
.diagram{border-radius:18px;box-shadow:0 24px 48px -28px #0c4a3c55}
.stats{border:1px solid var(--line);border-radius:14px;background:var(--card);padding:22px 28px}.stats strong{font-variant-numeric:tabular-nums;color:var(--green)}
.card{position:relative;border-radius:14px;padding:24px 26px;box-shadow:0 1px 2px #14231f0a;transition:transform .18s,border-color .18s,box-shadow .18s}.card:hover{transform:translateY(-3px);border-color:#a9c4b4;box-shadow:0 16px 32px -20px #0c4a3c66}
.card h3{margin:14px 0 6px;letter-spacing:-.3px}
.number{font:700 13px/1 ui-monospace,SFMono-Regular,Consolas,monospace;color:var(--green);background:#e8f1ec;border-radius:7px;padding:7px 9px;letter-spacing:.5px}
.badge{font-weight:600;border-radius:999px;padding:3px 10px}.badge.easy{background:#e3f3e8;color:#1f6b45}.badge.medium{background:#fbf0d9;color:#8a5a0e}.badge.hard{background:#fbe4e0;color:#9b3324}.badge.done{background:var(--green);color:#fff}
.card-bottom strong{transition:transform .18s}.card:hover .card-bottom strong{transform:translateX(3px)}
.banner{border-radius:16px;background:linear-gradient(120deg,#0f4f41,#167560);color:#eaf4ef}.banner h3{color:#fff}.banner p{color:#cfe3da}.banner .eyebrow{color:#9fd8c2}.banner .button{background:#fff;border-color:#fff}
input,select{border-radius:9px;transition:border-color .15s,box-shadow .15s}input:focus,select:focus{border-color:var(--green);box-shadow:0 0 0 3px #11624f22;outline:none}
.panel{border-radius:14px;box-shadow:0 1px 2px #14231f0a}.tabs button{font-weight:600}.tabs button:hover{background:none;color:var(--ink)}
footer{max-width:none;padding:26px max(38px,calc((100vw - 1204px)/2));margin:0;align-items:center}
@media(max-width:1280px){footer{margin:0}}@media(max-width:850px){.brand-name{font-size:16px}}@media(max-width:600px){header{padding:14px 20px}footer{margin:0;padding:22px 20px}.stats{padding:16px}}
.section-head{align-items:flex-end;gap:16px}.section-head>.eyebrow{margin:0}
.sim-bar{display:flex;flex-wrap:wrap;align-items:center;gap:10px;margin-bottom:12px}.sim-bar button{padding:6px 12px;font-size:13px}.sim-bar select{padding:6px 10px;font-size:13px}.sim-mode{display:flex;gap:14px;font-size:13px;margin-right:auto}.sim-mode label{display:flex;align-items:center;gap:5px;cursor:pointer}.sim-mode input{flex:none}.sim-time{flex:1;min-width:120px;padding:0}.sim-stage{border:1px solid var(--line);border-radius:8px;background:#fbfcfa;overflow:hidden}.sim-stage canvas{display:block;width:100%}.sim-legend{display:flex;gap:16px;font-size:11px;margin:6px 0 10px}.sim-legend .ref,.sim-out .ref{color:#2f6fd6}.sim-legend .mine,.sim-out .mine{color:#e07b16}.sim-legend .bad,.sim-out .bad{color:#d23c3c}.sim-grid{display:grid;grid-template-columns:1fr 1fr;gap:20px}.sim-control{display:grid;grid-template-columns:1fr 92px 54px;align-items:center;gap:4px 8px;font-size:12px;margin-bottom:8px}.sim-control span{grid-column:1/-1}.sim-control input[type=range]{padding:0}.sim-control input[type=number]{padding:4px 6px;font-size:12px}.sim-control em{font-style:normal;font-size:11px;color:var(--muted)}.sim-toggle{display:flex;gap:6px;align-items:center;font-size:12px;margin:6px 0}.sim-toggle input{flex:none}.sim h4{margin:0 0 6px;font-size:13px}.sim-out{display:grid;grid-template-columns:auto 1fr;gap:4px 10px;font:12px ui-monospace,monospace;margin:0}.sim-out dt{color:var(--muted)}.sim-out dd{margin:0;overflow-wrap:anywhere}.sim-out pre{margin:0;padding:0;background:none;font:inherit;white-space:pre-wrap;color:inherit}.sim-caption{border-top:1px solid var(--line);margin-top:12px;padding-top:10px;font-size:14px;overflow-x:auto}@media(max-width:600px){.sim-grid{grid-template-columns:1fr}}