@import url('https://fonts.googleapis.com/css2?family=DM+Sans:wght@400;500;600;700&family=JetBrains+Mono:wght@400;500&display=swap');
:root{--navy:#111d35;--ink:#18243a;--muted:#687386;--line:#e2e7ec;--bg:#f5f7fa;--green:#178568;--mint:#6de2b5;--purple:#7356bd;--white:#fff}*{box-sizing:border-box}body{margin:0;color:var(--ink);background:var(--bg);font:16px/1.7 'DM Sans','Microsoft YaHei',sans-serif}button,input,textarea,select{font:inherit}button,a,input,textarea,select{-webkit-tap-highlight-color:transparent}button{cursor:pointer}a{color:inherit;text-decoration:none}button:focus-visible,a:focus-visible,select:focus-visible,summary:focus-visible{outline:3px solid #7c67cb;outline-offset:3px}button:disabled{opacity:.5;cursor:not-allowed}button{border:0}h1,h2,h3,p{margin-top:0}h1{font-size:30px;line-height:1.4;letter-spacing:-1px}h2{font-size:23px;line-height:1.5}h3{font-size:18px}small{font-size:12px}.app{display:flex;min-height:100vh}.sidebar{width:220px;position:fixed;inset:0 auto 0 0;padding:32px 20px 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var(--line);margin-top:23px;padding-top:18px}.task-heading{font-size:15px;font-weight:700;display:flex;align-items:center;gap:8px}.task-heading span{display:grid;place-items:center;background:#e4f4ec;border-radius:50%;width:23px;height:23px;color:var(--green);font-size:13px}.steps{padding-left:23px;color:#526076;font-size:14px}.steps li{padding:4px 0 7px 5px}.steps li::marker{color:var(--green);font-weight:600}.editor-side{min-width:0}.editor{border:1px solid #26364f;border-radius:12px;overflow:hidden;background:#152136;color:#d7e4f4;box-shadow:0 5px 18px #10233509}.editor-title{display:flex;justify-content:space-between;align-items:center;background:#1c2b42;padding:13px 18px;border-bottom:1px solid #2a394e;font:12px 'JetBrains Mono',monospace}.file-label{display:flex;align-items:center;gap:9px}.file-label i{font-style:normal;color:#ffe18b;font-weight:600;font-size:11px}.editor-title 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var(--line);padding:23px;border-radius:10px}.stat b{font-size:34px;display:block}.stat span{color:var(--muted);font-size:13px}.empty{padding:60px 30px;background:#fff;border:1px dashed #cbd5dd;border-radius:12px;text-align:center;color:var(--muted)}.empty h2{color:var(--ink)}.note-card{padding:23px;background:#fff;border:1px solid var(--line);border-radius:9px;margin-bottom:13px}.note-card h2{font-size:17px;margin-bottom:10px}.note-card p{font-size:15px;white-space:pre-wrap;overflow-wrap:anywhere}.note-card a{color:var(--green);font-size:13px}.muted{color:var(--muted);font-size:13px}.search-input{border:1px solid var(--line);border-radius:7px;padding:10px 14px;background:white;min-width:240px;font-size:14px}.history{background:white;border:1px solid var(--line);border-radius:10px;padding:20px}.history-row{display:flex;justify-content:space-between;gap:15px;padding:12px 0;border-bottom:1px solid #edf0f3;font-size:14px}.history-row time{font-size:12px;color:var(--muted)}footer{border-top:1px solid var(--line);display:flex;align-items:center;gap:16px;padding:17px 36px;font-size:10px;letter-spacing:1px;color:#8b97a6}footer span{letter-spacing:0;font-size:11px;margin-right:auto}footer button,footer label{background:none;font-size:11px;letter-spacing:0;color:#6f7d8f;padding:0;cursor:pointer}.toast{position:fixed;bottom:25px;left:50%;transform:translate(-50%,20px);opacity:0;pointer-events:none;background:#1d3044;color:white;padding:11px 21px;border-radius:8px;font-size:14px;z-index:40;max-width:90vw;transition:.2s}.toast.visible{opacity:1;transform:translate(-50%,0)}dialog{border:0;border-radius:15px;max-width:650px;width:90%;padding:28px;box-shadow:0 20px 100px #0003;color:var(--ink)}dialog::backdrop{background:#101c3590;backdrop-filter:blur(3px)}dialog p,dialog li{font-size:14px;line-height:1.9}dialog li{margin-bottom:12px}.dialog-head{display:flex;justify-content:space-between;align-items:center}.dialog-head h2{font-size:22px}.skip{position:fixed;top:-100px;z-index:60;background:white;padding:10px}.skip:focus{top:10px}.mobile-course{display:none}.reflection{background:#eaf5f0;padding:15px;border-radius:7px;font-size:14px;color:#376851;margin-top:18px}.solution-banner{font-size:12px;background:#fff5de;color:#926e25;padding:8px 14px;border-top:1px solid #ead8aa}.result-table{border-collapse:collapse;font:13px/1.7 'JetBrains Mono',monospace;width:100%}.result-table th,.result-table td{padding:7px 10px;text-align:left;border-bottom:1px solid var(--line)}.runtime-stop{color:#efb4aa;background:transparent;font-size:12px}.resource-list{font-size:14px;padding-left:20px}.resource-list a{text-decoration:underline;color:var(--green)}
@media(min-width:1600px){main{padding-top:38px}.lesson-body{padding:30px 36px}.code-wrap{min-height:290px}}@media(max-width:1150px){.sidebar{width:185px;padding:27px 13px 17px}.surface{margin-left:185px;width:calc(100% - 185px)}main{padding:24px}.topbar{padding:0 24px}.workspace{gap:17px;grid-template-columns:minmax(260px,1fr) minmax(280px,1fr)}.lesson-body{padding:22px}.track-grid{grid-template-columns:repeat(2,minmax(0,1fr))}.brand{font-size:23px}.daily{padding:12px 8px}.editor-actions small{display:none}}@media(max-width:870px){.sidebar{width:72px;padding:22px 10px}.brand{padding:0;justify-content:center}.brand>span:last-child,.nav-label,.side-bottom{display:none}nav{margin-top:35px}nav a{font-size:0;padding:12px;justify-content:center}nav a span{font-size:23px}nav a.active:after{display:none}.surface{margin-left:72px;width:calc(100% - 72px)}.workspace{grid-template-columns:1fr}.editor-side{display:flex;flex-direction:column}.lesson-top{align-items:flex-start}.course-switch{max-width:210px}.code-wrap{min-height:200px}textarea.code{min-height:180px}.project-grid{grid-template-columns:1fr}footer{flex-wrap:wrap;padding:18px 24px}footer span{display:none}}@media(max-width:550px){.sidebar{position:relative;width:100%;padding:12px 16px;flex-direction:row;align-items:center;justify-content:space-between}.brand-icon{font-size:17px;padding:8px 8px 8px 3px;border-radius:6px}nav{flex-direction:row;margin:0;gap:4px}nav a{padding:8px}nav a span{font-size:21px}.app{display:block}.surface{margin:0;width:100%}.topbar{height:52px;padding:0 18px}.breadcrumb{font-size:11px}.save-state{font-size:10px}.top-actions{gap:9px}main{padding:21px 16px}.lesson-top{flex-direction:column;gap:12px}.lesson-top h1{font-size:23px}.course-switch{max-width:100%;width:100%}.lesson-body{padding:22px}.panel-tabs{padding:0 22px}.track-grid{grid-template-columns:1fr}.route-head{align-items:start;flex-direction:column}.route-head h1{font-size:26px}.journey-banner{padding:24px;align-items:start;flex-direction:column}.journey-banner h2{font-size:22px}.stats-grid{gap:9px}.stat{padding:16px 12px}.stat b{font-size:26px}.stat span{font-size:11px}.project-stage{padding:20px}.course-row{padding:16px 14px;gap:11px}.course-row .right{font-size:10px}.lesson-bottom{align-items:flex-start}.lesson-bottom .primary{white-space:nowrap;padding:10px 15px}.lesson-bottom span{font-size:11px}.search-input{width:100%}.history-row{flex-direction:column;gap:3px}}
.evidence-item{padding:18px 0;border-bottom:1px solid var(--line)}.evidence-title{display:flex;justify-content:space-between;gap:16px;align-items:center;margin-bottom:12px;font-size:14px;font-weight:600}.evidence-title select{font-size:12px;background:#fff;border:1px solid var(--line);border-radius:5px;padding:7px}.evidence-item textarea{width:100%;min-height:95px;resize:vertical;border:1px solid var(--line);border-radius:6px;padding:12px;font-size:14px;line-height:1.8}.evidence-result{font-size:14px;padding:17px 0;color:var(--green)}@media(max-width:600px){.evidence-title{align-items:start;flex-direction:column}}
/* Learning hub, daily practice and review workbench */
.export-content{display:block;width:100%;height:240px;box-sizing:border-box;margin:12px 0;padding:12px;font:12px/1.6 Consolas,monospace;border:1px solid #d4dde3;border-radius:8px;resize:vertical}#export-dialog{width:min(720px,calc(100vw - 32px));max-height:90vh;overflow:auto}#export-dialog h2{font-size:18px;overflow-wrap:anywhere}
.hub-grid{display:grid;grid-template-columns:1.15fr 1fr;gap:24px;margin:24px 0}.challenge-card{background:#e9f8f0;border:1px solid #b7e5ce;border-radius:20px;padding:30px}.challenge-card .eyebrow{color:#287857}.challenge-top{display:flex;align-items:center;justify-content:space-between;gap:12px}.challenge-card h2{font-size:28px;margin:14px 0}.challenge-card h3{font-size:20px}.challenge-card p{color:#52675e;line-height:1.8}.xp-badge{background:#111d35;color:#80e5bb;padding:12px 20px;border-radius:40px;font-weight:750;white-space:nowrap}.continue-card{margin:0!important;display:flex;flex-direction:column;align-items:flex-start;justify-content:center}.continue-card .back-link{margin:20px 0 0}.mastery-steps{display:grid;grid-template-columns:repeat(4,1fr);gap:22px}.mastery-steps b{color:#27745c}.mastery-steps p{font-size:14px;line-height:1.8}.quick-card{display:block;background:white;border:1px solid #e1e7ed;border-radius:18px;padding:24px;color:inherit;text-decoration:none}.quick-card:hover{border-color:#529f82}.quick-card h2{font-size:19px}.quick-card p{color:#687586;line-height:1.8}.standalone-code{display:block;width:100%;box-sizing:border-box;min-height:230px;resize:vertical;border:1px solid #38465b;border-radius:12px;background:#162237;color:#e6f1fb;padding:18px;font:14px/1.8 Consolas,monospace;tab-size:2;margin:12px 0 18px}.short-code{min-height:110px}.audit-grid{align-items:start}.audit-grid .project-stage{min-width:0;margin:0}.audit-grid select{padding:10px 14px;margin-bottom:18px;border:1px solid #cfd9df;border-radius:8px;background:white;max-width:100%}.audit-grid label{display:block;font-size:14px;line-height:1.7}.audit-grid pre,#daily-result{white-space:pre-wrap;overflow-wrap:anywhere;font-size:13px}.finding{background:#fff6e7;border-left:3px solid #d39a3f;padding:14px 16px;margin-bottom:12px;border-radius:4px}.finding p{font-size:13px;margin:6px 0!important;line-height:1.7}.audit-clear{background:#edf5f1;padding:14px;border-radius:8px}.evidence-note{display:block;width:100%;box-sizing:border-box;min-height:120px;padding:12px;border:1px solid #d5dedf;border-radius:10px;margin:10px 0 16px;resize:vertical}.mastery-panel{margin-top:24px}.support-row{flex-wrap:wrap;gap:10px}.project-stage .quiz{margin:18px 0}.project-stage fieldset{border:0;padding:0}.project-stage .option{display:flex;gap:10px;padding:12px 0}.project-stage .option input{flex-shrink:0}.project-stage>label{font-weight:600}.project-stage pre{max-width:100%;box-sizing:border-box}.project-stage p{overflow-wrap:anywhere}
@media(max-width:1100px){.hub-grid{grid-template-columns:1fr}.mastery-steps{grid-template-columns:repeat(2,1fr)}}
@media(max-width:600px){.challenge-card{padding:22px}.challenge-card h2{font-size:23px}.mastery-steps{grid-template-columns:1fr}.challenge-top{align-items:flex-start}.xp-badge{padding:8px 14px}.standalone-code{font-size:13px}.audit-grid .support-row button{flex:1;min-width:110px}}
@media(max-width:550px){.sidebar{flex-direction:column;align-items:stretch;gap:14px}.brand{justify-content:flex-start;align-self:flex-start}.brand>span:last-child{display:block;font-size:19px}.brand small{font-size:8px}nav{display:grid;grid-template-columns:repeat(4,minmax(0,1fr));width:100%;min-width:0;gap:5px}nav a{min-width:0;font-size:11px;line-height:1.5;padding:8px 3px;gap:5px;flex-direction:column}nav a span{font-size:19px}.top-actions{flex-shrink:0}.breadcrumb{min-width:0}.lesson-bottom{flex-wrap:wrap;gap:12px}.lesson-bottom span{flex:1;min-width:90px}}