:root{color-scheme:light;--bg: #ffffff;--ink: #202124;--muted: #5f6368;--line: #dadce0;--soft: #f8f9fa;--accent: #1a73e8;--accent-soft: #e8f0fe;--accent-ink: #ffffff;--green: #137333;--on-green: #ffffff;--green-soft: #e6f4ea;--danger: #c5221f;--highlight: #fef7e0;--font-sans: "Noto Sans KR", system-ui, -apple-system, "Segoe UI", "Apple SD Gothic Neo", "Malgun Gothic", sans-serif;--font-mono: "Roboto Mono", ui-monospace, SFMono-Regular, Menlo, Consolas, monospace}@media(prefers-color-scheme:dark){:root:not([data-theme=light]){color-scheme:dark;--bg: #202124;--ink: #e8eaed;--muted: #9aa0a6;--line: #3c4043;--soft: #292a2d;--accent: #8ab4f8;--accent-soft: #1f2d45;--accent-ink: #202124;--green: #81c995;--on-green: #202124;--green-soft: #1e3a29;--danger: #f28b82;--highlight: #3c3320}}:root[data-theme=dark]{color-scheme:dark;--bg: #202124;--ink: #e8eaed;--muted: #9aa0a6;--line: #3c4043;--soft: #292a2d;--accent: #8ab4f8;--accent-soft: #1f2d45;--accent-ink: #202124;--green: #81c995;--on-green: #202124;--green-soft: #1e3a29;--danger: #f28b82;--highlight: #3c3320}*,*:before,*:after{box-sizing:border-box}html{-webkit-text-size-adjust:100%}body{margin:0;background:var(--bg);color:var(--ink);font-family:var(--font-sans);font-size:15px;line-height:1.6;overflow-wrap:break-word}h1,h2,h3,p{margin:0}button,input,textarea{font:inherit;color:inherit}a{color:inherit}img{max-width:100%;height:auto}:focus-visible{outline:2px solid var(--accent);outline-offset:2px}.sr-only{position:absolute;width:1px;height:1px;padding:0;margin:-1px;overflow:hidden;clip:rect(0,0,0,0);white-space:nowrap;border:0}.muted{color:var(--muted)}.num{font-variant-numeric:tabular-nums;white-space:nowrap}.boot,.page{max-width:880px;margin:0 auto;padding:16px}.page-head{padding:8px 0 16px;border-bottom:1px solid var(--line);margin-bottom:16px}.page-head h1{font-size:22px;font-weight:500;margin-bottom:4px}.back{display:inline-block;color:var(--muted);text-decoration:none;font-size:13px;padding:6px 0;min-height:32px}.back:hover{color:var(--ink)}.btn{display:inline-flex;align-items:center;justify-content:center;gap:6px;min-height:36px;padding:6px 14px;border:1px solid var(--line);border-radius:18px;background:var(--bg);font-weight:500;cursor:pointer;text-decoration:none}.btn:disabled{opacity:.5;cursor:default}.btn-primary{background:var(--accent);border-color:var(--accent);color:var(--accent-ink)}.btn-secondary{background:var(--accent-soft);border-color:transparent;color:var(--accent)}.btn-ghost{border-color:transparent;background:none;color:var(--muted)}.btn-ghost:hover{color:var(--ink);background:var(--soft)}.icon-btn{width:30px;height:30px;display:inline-grid;place-items:center;border:0;border-radius:50%;background:none;color:var(--muted);cursor:pointer}.icon-btn:hover{background:var(--soft);color:var(--ink)}.notice{padding:16px;border:1px solid var(--line);border-radius:12px;background:var(--soft)}.notice h2{font-size:17px;font-weight:500;margin-bottom:6px}.notice p{margin-bottom:12px;color:var(--muted)}.center{text-align:center;padding-top:48px}.progress{display:flex;align-items:center;gap:10px;font-size:13px;color:var(--muted)}.bar{flex:1;min-width:60px;height:6px;border-radius:3px;background:var(--soft);border:1px solid var(--line);overflow:hidden}.bar>span{display:block;height:100%;background:var(--accent);transition:width .2s ease}.card-grid{list-style:none;margin:0;padding:0;display:grid;gap:12px;grid-template-columns:repeat(auto-fill,minmax(min(260px,100%),1fr))}.card{display:block;height:100%;padding:16px;border:1px solid var(--line);border-radius:12px;background:var(--bg);text-decoration:none}.card:hover{border-color:var(--accent);background:var(--soft)}.card h2{font-size:17px;font-weight:500;margin-bottom:6px;text-wrap:balance}.card .summary{color:var(--muted);font-size:14px;margin-bottom:12px}.card .meta{margin-top:10px;font-size:12px;color:var(--muted)}.course-head{padding:8px 0 16px;border-bottom:1px solid var(--line);margin-bottom:14px}.course-head h1{font-size:22px;font-weight:500;margin:2px 0 6px;text-wrap:balance}.course-head p{margin-bottom:12px}.units{list-style:none;margin:0;padding:0;display:grid;gap:8px}.unit-link{display:grid;grid-template-columns:40px minmax(0,1fr) auto;gap:12px;align-items:center;padding:12px 14px;border:1px solid var(--line);border-radius:10px;background:var(--bg);text-decoration:none}.unit-link:hover{background:var(--soft);border-color:var(--accent)}.unit-link .idx{font-size:13px;color:var(--muted);text-align:center;font-variant-numeric:tabular-nums}.unit-main{min-width:0;display:block}.unit-main .t{display:block;font-weight:500;text-wrap:balance}.unit-link .chip{display:inline-block;margin:4px 6px 0 0;padding:1px 8px;border-radius:999px;background:var(--soft);border:1px solid var(--line);font-size:12px;color:var(--muted)}.state{font-size:12px;white-space:nowrap;text-align:right}.state-done{color:var(--green);font-weight:500}.state-doing{color:var(--accent)}.state-none{color:var(--muted)}@media(max-width:520px){.unit-link{grid-template-columns:28px minmax(0,1fr)}.unit-link .state{grid-column:2;text-align:left}}.badges{display:flex;flex-wrap:wrap;gap:6px;margin-top:8px}.badge{display:inline-block;padding:2px 8px;border-radius:999px;border:1px solid var(--line);font-size:12px;color:var(--muted)}.badge-done{color:var(--green);border-color:var(--green);background:var(--green-soft)}.badge-quiz{color:var(--green);border-color:var(--green)}.badge-doing{color:var(--accent)}.topbar{position:sticky;top:0;z-index:5;display:flex;align-items:center;flex-wrap:wrap;gap:8px 12px;padding:8px 12px;background:var(--bg);border-bottom:1px solid var(--line)}.topbar .back{max-width:34vw;overflow:hidden;text-overflow:ellipsis;white-space:nowrap;padding:4px 0}.topbar .file{flex:1 1 140px;min-width:0;font-size:16px;font-weight:500;overflow:hidden;text-overflow:ellipsis;white-space:nowrap}.conn{display:inline-flex;align-items:center;font-size:12px;color:var(--muted);white-space:nowrap}.conn:before{content:"";display:inline-block;width:7px;height:7px;margin-right:6px;border-radius:50%;background:var(--muted)}.conn-note{font-size:12px;color:var(--muted);white-space:nowrap}.conn[data-phase=ready]:before{background:var(--green)}.conn[data-phase=connecting]:before,.conn[data-phase=closing]:before{background:var(--accent)}.topbar-actions{display:flex;align-items:center;gap:6px;flex-wrap:wrap}.banner{padding:8px 14px;background:var(--highlight);border-bottom:1px solid var(--line);font-size:14px}.shell{display:grid;grid-template-columns:minmax(0,1fr);min-height:calc(100vh - 52px)}.rail{display:none}.notebook{min-width:0;width:100%;max-width:860px;padding:12px 12px 72px}.step{margin-bottom:18px;scroll-margin-top:70px}.cell{display:grid;grid-template-columns:34px minmax(0,1fr);gap:6px;margin-bottom:10px}.gutter{display:flex;flex-direction:column;align-items:center;padding-top:8px;gap:4px}.count{font-family:var(--font-mono);font-size:11px;color:var(--muted)}.box{min-width:0;border:1px solid var(--line);border-radius:8px;background:var(--bg);overflow:hidden}.text{min-width:0;padding:6px 4px;border-radius:8px;cursor:pointer}.text:hover{background:var(--soft)}.text .step-no{font-size:12px;color:var(--muted)}.text h2{font-size:19px;font-weight:500;margin:2px 0 4px;text-wrap:balance}.text .goal{color:var(--ink)}.text .hint{margin-top:6px;font-size:13px;color:var(--muted)}.is-selected{outline:2px solid var(--accent);outline-offset:2px}textarea.code-input.is-selected,.output.is-selected{outline-offset:-2px}.code-toolbar{display:flex;align-items:center;gap:8px;padding:6px 8px;background:var(--soft);border-bottom:1px solid var(--line)}.btn-run{min-height:30px;padding:2px 12px;font-size:13px;border-color:var(--accent);color:var(--accent);background:var(--bg)}.code-input{display:block;width:100%;min-height:3.5em;margin:0;padding:10px 12px;border:0;resize:vertical;background:var(--bg);font-family:var(--font-mono);font-size:13px;line-height:1.5;white-space:pre;overflow-x:auto;tab-size:4}.output{position:relative;min-width:0;padding:8px 12px 10px;border-top:1px solid var(--line)}.output-head{display:flex;align-items:center;justify-content:space-between;min-height:30px}.output-label{font-size:12px;color:var(--muted)}.output-body{min-width:0}.output-empty{font-size:13px;color:var(--muted)}.out-text{margin:2px 0 0;font-family:var(--font-mono);font-size:13px;line-height:1.5;white-space:pre-wrap;overflow-wrap:anywhere}.out-text.is-error{color:var(--danger)}.out-img{display:block;margin-top:6px;border-radius:6px}.out-notice{margin-top:6px;font-size:13px;color:var(--muted)}.run-status{margin-top:6px;font-size:12px;color:var(--muted)}.table-wrap{max-width:100%;overflow-x:auto}table.df{border-collapse:collapse;font-family:var(--font-mono);font-size:13px;margin-top:4px}table.df th,table.df td{padding:4px 10px;border-bottom:1px solid var(--line);text-align:right;white-space:nowrap}table.df th{color:var(--muted);font-weight:500}table.df tr.is-hl td,table.df .is-hl-col{background:var(--highlight)}.cell-quiz .box{padding:12px 14px;border-color:var(--green);background:var(--green-soft)}.quiz-q{font-weight:500;margin-bottom:8px}.choices{margin:0 0 8px;padding:0;border:0;min-width:0}.choices legend{font-weight:500;padding:0;margin-bottom:8px}.choice,.num-field{display:flex;align-items:center;gap:8px;padding:6px 10px;margin-bottom:6px;border:1px solid var(--line);border-radius:6px;background:var(--bg);cursor:pointer}.num-field input{width:9em;min-height:34px;padding:4px 8px;border:1px solid var(--line);border-radius:6px;background:var(--bg)}.btn-check{min-height:34px;border:0;border-radius:6px;padding:6px 14px;background:var(--green);color:var(--on-green);font-weight:500;cursor:pointer}.btn-check:disabled{opacity:.5;cursor:default}.feedback{margin-top:8px;padding:8px 10px;border-radius:6px;background:var(--bg);border:1px solid var(--line)}.feedback.is-correct{border-color:var(--green)}.feedback.is-wrong{border-color:var(--danger)}.feedback-title{font-weight:500}.feedback .explain{margin-top:4px;font-size:14px;color:var(--muted);white-space:pre-wrap}.problem{margin-top:8px;font-size:13px;color:var(--danger)}.result-row{display:flex;align-items:center;flex-wrap:wrap;gap:10px;margin-bottom:10px}.verdict{font-size:14px;color:var(--muted)}.verdict.is-ok{color:var(--green);font-weight:500}.verdict.is-bad{color:var(--danger)}.panel{min-width:0;padding:16px;border-top:1px solid var(--line);background:var(--bg)}.panel-title{font-size:15px;font-weight:500}.panel-target{font-size:12px;color:var(--muted);margin-top:2px}.empty-hint{margin-top:12px;color:var(--muted)}.topic{margin-top:14px}.topic .kind{font-size:11px;color:var(--muted);letter-spacing:.04em}.topic h3{font-size:17px;font-weight:500;margin:2px 0 8px;text-wrap:balance}.topic-body{white-space:pre-wrap;overflow-wrap:anywhere}.topic-body strong{font-weight:700}.fig{margin:10px 0 0;padding:10px;border:1px solid var(--line);border-radius:8px}.fig figcaption,.fig-caption{margin-top:6px;font-size:12px;color:var(--muted)}.fig-caption{margin-top:10px}.fig-svg{display:block;width:100%;height:auto}.fig-svg .axis{stroke:var(--line);stroke-width:1}.fig-svg .axis-label,.fig-svg .value-label,.fig-svg .x-label{fill:var(--muted);font-size:10px;font-family:var(--font-sans)}.fig-svg .figure-bar.muted{fill:var(--muted);opacity:.45}.fig-svg .figure-bar.accent{fill:var(--accent)}.fig-svg .line{stroke:var(--muted);stroke-width:1.5}.fig-svg .figure-dot.muted{fill:var(--muted)}.fig-svg .figure-dot.accent{fill:var(--accent)}@media(min-width:561px){.rail{display:flex;flex-direction:column;align-items:center;gap:4px;padding:10px 0;border-right:1px solid var(--line);position:sticky;top:52px;align-self:start;max-height:calc(100vh - 60px);overflow:auto}.rail-link{width:30px;height:30px;display:grid;place-items:center;border-radius:50%;font-size:12px;color:var(--muted);text-decoration:none}.rail-link:hover{background:var(--soft);color:var(--ink)}.shell{grid-template-columns:52px minmax(0,1fr)}.panel{grid-column:1 / -1}.notebook{padding:14px 18px 72px}.cell{grid-template-columns:40px minmax(0,1fr)}}@media(min-width:900px){.shell{grid-template-columns:52px minmax(0,1fr) minmax(0,340px)}.panel{grid-column:auto;border-top:0;border-left:1px solid var(--line);position:sticky;top:52px;align-self:start;max-height:calc(100vh - 60px);overflow:auto}}@media(prefers-reduced-motion:reduce){*,*:before,*:after{transition:none!important;animation:none!important;scroll-behavior:auto!important}}