@import url('https://fonts.googleapis.com/css2?family=DM+Mono:wght@400;500&family=Manrope:wght@400;500;600;700;800&display=swap');
.lesson-sidebar.compact-rail{width:64px;padding:8px 0;overflow-y:auto}.compact-rail #lesson-list{display:flex;flex-direction:column;align-items:center;gap:6px}.compact-rail .lesson-btn{width:44px;height:44px;padding:0;border:0;border-radius:10px;display:grid;place-items:center;background:#fff}.compact-rail .lesson-btn:hover{background:#edf4ec}.compact-rail .lesson-btn.active{background:var(--green);color:#fff}.compact-rail .lesson-btn.complete:not(.active){background:#e1f3e7;color:#267247}.compact-rail .lesson-num{width:auto;height:auto;background:transparent;border-radius:0;font:600 12px var(--mono)}.exercise-view .exercise-main{margin-left:64px;padding:12px}.exercise-view .exercise-grid{height:calc(100vh - 90px);grid-template-columns:minmax(360px,.85fr) minmax(520px,1.4fr);gap:12px}.exercise-view .task-panel{grid-template-rows:minmax(120px,.52fr) minmax(300px,1.3fr) minmax(110px,.48fr);overflow:hidden}.exercise-view .question-list{overflow:auto;padding-right:3px}.exercise-view .exercise-code .editor-shell{min-height:240px}
@media(max-width:980px){.lesson-sidebar.compact-rail{position:static;width:100%;height:60px;max-height:none;padding:8px;overflow-x:auto;overflow-y:hidden;border-right:0;border-bottom:1px solid var(--line)}.compact-rail #lesson-list{flex-direction:row;gap:6px}.compact-rail .lesson-btn{min-width:40px;width:40px;height:40px}.exercise-view .exercise-main{margin-left:0;padding:9px}.exercise-view .exercise-grid{height:auto}.exercise-view .task-panel{grid-template-rows:none}.exercise-view .exercise-code .editor-shell{min-height:300px}}
.stage-badge{display:inline-block;margin:0 7px 4px 0;padding:3px 6px;border-radius:5px;background:#edf1ed;color:var(--green);font:600 8px var(--mono);font-style:normal;text-transform:uppercase;letter-spacing:.08em}.question-btn.done .stage-badge{background:#ccebd5}
.syntax-card details{margin:12px -15px -15px;border-top:1px solid var(--line);padding:0 15px}.syntax-card summary{cursor:pointer;padding:11px 0;font-weight:700;color:var(--green);list-style:none}.syntax-card summary::after{content:'＋';float:right}.syntax-card details[open] summary::after{content:'−'}.syntax-detail{display:grid;gap:10px;padding-bottom:15px}.syntax-detail div{background:#f7f9f6;border-radius:7px;padding:9px}.syntax-detail b{display:block;font-size:10px;text-transform:uppercase;letter-spacing:.08em;margin-bottom:4px}.syntax-detail span{font-size:12px;line-height:1.55;color:var(--muted)}.play-body{height:calc(100vh - 154px);display:grid;grid-template-columns:250px 1fr;min-height:0}.play-body .lab{height:100%;padding-top:0}.play-command-sidebar{background:#fff;border-right:1px solid var(--line);overflow:auto}.play-command-head{position:sticky;top:0;background:#fff;border-bottom:1px solid var(--line);padding:15px;z-index:3}.play-command-head>div{padding-right:30px}.play-command-head .search{margin-top:12px;padding:8px}.play-command-head>#toggle-play-commands{position:absolute;right:10px;top:12px;border:1px solid var(--line);background:#fff;width:28px;height:28px;border-radius:7px;cursor:pointer}.play-command-group h3{font-size:9px;letter-spacing:.12em;text-transform:uppercase;color:#879188;padding:12px 13px 5px;margin:0}.play-command{width:100%;border:0;background:#fff;padding:9px 13px;text-align:left;cursor:pointer}.play-command:hover{background:#eef5ed}.play-command code{display:block;white-space:nowrap;overflow:hidden;text-overflow:ellipsis;font:10px var(--mono)}.play-command small{color:var(--muted)}.play-body.commands-collapsed{grid-template-columns:48px 1fr}.commands-collapsed .play-command-head>div,.commands-collapsed .play-command-head .search,.commands-collapsed #play-command-list{display:none}.commands-collapsed .play-command-head{height:100%}.commands-collapsed #toggle-play-commands{right:9px;transform:rotate(180deg)}@media(max-width:980px){.play-body,.play-body.commands-collapsed{height:auto;display:block}.play-command-sidebar{max-height:280px;border-right:0;border-bottom:1px solid var(--line)}.commands-collapsed .play-command-head{height:52px}.play-body .lab{height:auto}}
:root{--ink:#17211b;--muted:#68746c;--line:#dce4dd;--paper:#f3f5f1;--card:#fff;--green:#236c4b;--lime:#d9f36a;--navy:#111b28;--red:#b63b31;--mono:'DM Mono',monospace}*{box-sizing:border-box}body{margin:0;background:var(--paper);color:var(--ink);font:14px Manrope,system-ui,sans-serif}.topbar{height:66px;background:#fff;border-bottom:1px solid var(--line);display:flex;align-items:center;padding:0 22px;gap:24px;position:sticky;top:0;z-index:20}.brand{display:flex;align-items:center;gap:10px;color:inherit;text-decoration:none}.brand span{display:grid;place-items:center;width:34px;height:34px;border-radius:9px;background:var(--ink);color:var(--lime);font:600 12px var(--mono)}.tabs{display:flex;align-self:stretch;margin:auto;gap:4px}.tabs button{border:0;background:transparent;padding:0 17px;color:var(--muted);font-weight:700;cursor:pointer;border-bottom:3px solid transparent}.tabs button.active{color:var(--ink);border-color:var(--green)}.tabs span{font:9px var(--mono);background:#e9eee9;padding:3px 5px;border-radius:9px}.ghost,.dark,.primary{border:1px solid var(--line);background:#fff;padding:9px 13px;border-radius:8px;font-weight:700;cursor:pointer}.dark{background:var(--navy);color:#fff;border-color:var(--navy)}.primary{background:var(--lime);border-color:var(--lime)}.view{display:none}.view.active{display:block}.eyebrow{font:600 10px var(--mono);letter-spacing:.15em;color:var(--green);margin:0 0 7px}.hero{padding:55px max(24px,8vw) 30px;background:#fff;border-bottom:1px solid var(--line)}.hero h1{font-size:clamp(34px,5vw,60px);line-height:.98;letter-spacing:-.05em;margin:0}.hero>p:not(.eyebrow){color:var(--muted)}.search{display:flex;gap:9px;align-items:center;border:1px solid var(--line);padding:11px 13px;border-radius:9px;background:#fff}.search.wide{max-width:650px;margin-top:25px}.search input{border:0;outline:0;width:100%;font:inherit}.syntax-list{padding:30px max(24px,8vw) 70px}.syntax-group{margin-bottom:35px}.syntax-group h2{font-size:12px;text-transform:uppercase;letter-spacing:.14em}.syntax-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(280px,1fr));gap:10px}.syntax-card{background:#fff;border:1px solid var(--line);border-radius:11px;padding:15px;min-width:0}.syntax-card code{display:block;font:12px/1.5 var(--mono);white-space:nowrap;overflow:hidden;text-overflow:ellipsis;color:#164f38}.syntax-card p{color:var(--muted);margin:8px 0}.syntax-meta{display:flex;justify-content:space-between;align-items:center}.syntax-meta small{color:#879188}.syntax-card button{border:0;background:#edf4ec;border-radius:6px;padding:6px 8px;cursor:pointer}.play-toolbar{height:88px;display:flex;align-items:center;justify-content:space-between;padding:15px 24px}.play-toolbar h1{margin:0;font-size:22px}.play-toolbar label{font-size:11px;color:var(--muted)}select{display:block;margin-top:5px;border:1px solid var(--line);border-radius:7px;padding:7px;background:#fff}.lab{height:calc(100vh - 154px);padding:0 16px 16px;display:grid;grid-template-columns:minmax(380px,1fr) minmax(420px,1.1fr);grid-template-rows:1fr 1fr;gap:13px}.panel{background:#fff;border:1px solid var(--line);border-radius:12px;overflow:hidden;display:flex;flex-direction:column;min-height:0}.data-panel{grid-row:1/3}.panel-head{min-height:62px;border-bottom:1px solid var(--line);padding:13px 16px;display:flex;align-items:center;justify-content:space-between}.panel h2{font-size:14px;margin:0}.panel h2 code{font:13px var(--mono);color:var(--green)}.tag,.shortcut,.score{font:500 10px var(--mono);background:#eef1ed;padding:6px 8px;border-radius:6px;color:var(--muted)}.table-wrap{overflow:auto;flex:1}table{width:100%;border-collapse:collapse;font-size:12px}th{position:sticky;top:0;background:#f7f9f6;text-align:left}th,td{padding:10px 12px;border-bottom:1px solid #e8ede8;white-space:nowrap}.idx{color:#9aa39d;font:10px var(--mono)}.null{color:#a06a5f;font:italic 11px var(--mono)}.code-panel{background:var(--navy);border-color:#263342;color:#e5edf5}.code-panel .panel-head{border-color:#2b3744}.code-panel .eyebrow{color:var(--lime)}.editor-shell{flex:1;display:grid;grid-template-columns:40px 1fr;min-height:125px;background:var(--navy)}.editor-shell textarea,.editor-shell>div{border:0;outline:0;resize:none;background:transparent;color:#e3ebf2;padding:15px 0;font:13px/1.75 var(--mono)}.editor-shell>div{text-align:right;padding-right:10px;color:#536273;white-space:pre}.editor-shell textarea{padding-right:13px;width:100%}.runbar{border-top:1px solid #2b3744;padding:9px 11px;display:flex;align-items:center;justify-content:space-between;color:#8694a1;font-size:11px}.runbar button{background:var(--lime);border:0;border-radius:7px;padding:9px 13px;font-weight:800}.output{overflow:auto;padding:13px;flex:1}.output.error{background:#fff6f4;color:var(--red)}.output pre{white-space:pre-wrap;font:12px/1.6 var(--mono);margin:0}.empty{height:100%;display:grid;place-content:center;gap:4px;text-align:center;color:#879188}.empty b{color:#616d65}.success{background:#e2f5e8;color:#237046}.failed{background:#fce8e5;color:#a5332b}.neutral{background:#eef1ed}.chart-box{height:100%;min-height:140px;display:grid;place-items:center;background:repeating-linear-gradient(0deg,#fff,#fff 29px,#edf1ed 30px);color:var(--green);font:700 18px var(--mono)}.lesson-sidebar{position:fixed;top:66px;bottom:0;width:275px;background:#fff;border-right:1px solid var(--line);overflow:auto}.side-head{padding:23px 19px;border-bottom:1px solid var(--line);position:sticky;top:0;background:#fff;z-index:2}.side-head h2{margin:0 0 14px}.progress-track{height:6px;border-radius:6px;background:#e8ece8;overflow:hidden}.progress-track i{display:block;height:100%;width:0;background:var(--green)}.side-head small{display:block;margin-top:7px;color:var(--muted)}.lesson-btn{width:100%;border:0;border-bottom:1px solid #edf0ed;background:#fff;padding:13px 16px;text-align:left;display:grid;grid-template-columns:30px 1fr auto;gap:8px;cursor:pointer}.lesson-btn.active{background:#eef5ed}.lesson-num{width:25px;height:25px;display:grid;place-items:center;background:#edf0ed;border-radius:50%;font:10px var(--mono)}.lesson-btn b{font-size:12px}.lesson-btn small{display:block;color:var(--muted);margin-top:3px}.lesson-count{font:9px var(--mono);color:var(--muted)}.exercise-main{margin-left:275px;padding:25px}.exercise-head{display:flex;justify-content:space-between;align-items:start;margin-bottom:18px}.exercise-head h1{margin:0;font-size:27px}.exercise-head p:not(.eyebrow){color:var(--muted);margin-bottom:0}.exercise-grid{display:grid;grid-template-columns:minmax(350px,.9fr) minmax(430px,1.1fr);gap:14px;height:calc(100vh - 175px)}.exercise-data{height:100%}.task-panel{display:grid;grid-template-rows:auto minmax(210px,.8fr) minmax(120px,.5fr);gap:10px;min-height:0}.question-list{display:flex;flex-direction:column;gap:7px}.question-btn{border:1px solid var(--line);background:#fff;border-radius:9px;padding:11px;text-align:left;display:flex;gap:10px;cursor:pointer}.question-btn.active{border-color:#6a8774;background:#f7faf5}.question-btn.done{background:#e4f5e8;border-color:#8bc79d}.question-letter{font:600 11px var(--mono);width:22px;height:22px;display:grid;place-items:center;border-radius:50%;background:#edf0ed}.question-btn.done .question-letter{background:#3b9b61;color:#fff}.exercise-code{border-radius:11px;overflow:hidden;background:var(--navy);display:flex;flex-direction:column}.exercise-code .editor-shell{min-height:130px}.exercise-actions{padding:9px;display:flex;gap:7px;border-top:1px solid #2b3744}.exercise-actions .ghost{background:#202d3a;border-color:#354354;color:#bdc8d1}.exercise-actions .dark{margin-left:auto}.feedback{padding:9px 12px;color:#a9b5bf;font-size:11px;border-top:1px solid #2b3744}.feedback.good{color:#8fe0aa}.feedback.bad{color:#ff9f96}.compact{background:#fff;border:1px solid var(--line);border-radius:10px;min-height:0}.output .meta{margin-top:8px;color:var(--muted);font:10px var(--mono)}button:focus-visible,input:focus-visible,textarea:focus-visible,select:focus-visible{outline:2px solid #79a629;outline-offset:2px}@media(max-width:980px){.topbar{padding:0 10px}.brand strong,.ghost#reset-button{display:none}.tabs button{padding:0 8px}.lab{height:auto;display:flex;flex-direction:column}.panel{min-height:340px}.lesson-sidebar{position:static;width:auto;max-height:260px;border-right:0}.exercise-main{margin:0;padding:14px}.exercise-grid{display:flex;flex-direction:column;height:auto}.exercise-data{height:380px}.task-panel{display:flex;flex-direction:column}.exercise-code{min-height:300px}.compact{min-height:180px}}@media(max-width:560px){.brand{display:none}.tabs{margin:0 auto}.hero{padding:35px 18px}.syntax-list{padding:20px 12px}.play-toolbar{padding:12px}.exercise-actions{flex-wrap:wrap}.exercise-actions .dark{margin-left:0}.exercise-head h1{font-size:22px}}