@import url('https://fonts.googleapis.com/css2?family=Noto+Sans+KR:wght@400;500;600;700;800&family=JetBrains+Mono:wght@400;500&display=swap');
.chapters{display:grid;grid-template-columns:repeat(3,1fr);gap:16px;margin:0 0 30px}.chapter-card{display:flex;flex-direction:column;align-items:flex-start;gap:7px;padding:22px 24px;border:1px solid #dce3d7;background:#fff;border-radius:12px;color:#71816e;cursor:pointer;text-align:left;font-family:inherit}.chapter-card.selected{border:2px solid #237c57;padding:21px 23px;background:#eef5e9}.chapter-card strong{font-size:18px;color:#23382f}.chapter-card>span:not(.chapter-number){font-size:12px}.chapter-card .chapter-number{font:10px 'JetBrains Mono',monospace;letter-spacing:1px;color:#237c57}.chapter-card small{font-size:11px;margin-top:5px;color:#237c57}@media(max-width:650px){.chapters{grid-template-columns:1fr;gap:9px}.chapter-card{padding:15px}.chapter-card.selected{padding:14px}.chapter-card strong{font-size:16px}.chapter-card>span:not(.chapter-number){font-size:10px}}
:root{--ink:#23382f;--muted:#79857c;--green:#237c57;--line:#e1e7df;--paper:#f6f7f2}*{box-sizing:border-box}body{margin:0;color:var(--ink);background:var(--paper);font-family:'Noto Sans KR',sans-serif;font-size:14px}header{height:86px;max-width:1200px;margin:auto;display:flex;align-items:center;justify-content:space-between;border-bottom:1px solid var(--line);padding:0 24px}.brand{display:flex;align-items:center;gap:13px;color:var(--ink);text-decoration:none;font-weight:800;font-size:18px}.logo{font:500 22px 'JetBrains Mono',monospace;color:white;background:var(--green);padding:7px 9px;border-radius:11px}.logo span{color:#c6ed95}.local{font-size:12px;color:var(--muted)}main{max-width:1152px;margin:auto}.intro{display:flex;align-items:center;justify-content:space-between;padding:50px 0 40px;gap:30px}.eyebrow{font-size:10px;font-weight:700;letter-spacing:2px;color:var(--green)}h1{font-size:43px;line-height:1.35;letter-spacing:-2px;margin:14px 0}h1 span{color:var(--green)}.intro p{color:var(--muted);line-height:1.9;margin:10px 0}.summary{background:#eaf0e4;width:340px;padding:28px;border:1px solid #dce6d5;border-radius:18px}.summary-top{display:flex;justify-content:space-between;font-size:12px;font-weight:600}.summary strong{display:block;font-size:39px;margin:18px 0 14px}.summary small{font-size:13px;color:#6c7b67;font-weight:400}.track{height:7px;background:#d7e1cf;border-radius:10px;overflow:hidden}#progress{height:100%;background:var(--green);transition:width .3s}.summary p{font-size:11px;margin:15px 0 0}.workspace{display:grid;grid-template-columns:258px 1fr;gap:28px;align-items:start}.aside-title{display:flex;justify-content:space-between;font-size:12px;font-weight:700;margin:7px 10px 18px}.aside-title span{font-size:9px;letter-spacing:1px;color:#98a192}.group{font-size:10px;color:var(--muted);margin:20px 11px 9px;letter-spacing:.7px}nav button{width:100%;border:none;background:none;text-align:left;display:flex;align-items:center;gap:12px;padding:12px 10px;border-radius:9px;color:#627164;cursor:pointer;font-family:inherit;font-size:12px}nav button.active{background:#e4ecdf;color:#205c41;font-weight:700}nav button .num{border:1px solid #dce2d7;border-radius:6px;width:25px;height:25px;display:grid;place-items:center;font-size:10px;background:#fff}nav button.passed .num{background:var(--green);color:#fff;border-color:var(--green)}nav button .arrow{margin-left:auto}.tip{margin:25px 10px;padding:18px 0;border-top:1px solid var(--line);font-size:11px;color:var(--muted)}.tip b{color:#63745d}.tip p{line-height:1.9}.problem{padding:32px 36px;background:#fff;border:1px solid var(--line);border-radius:17px;box-shadow:0 5px 22px #263c2403}.problem-top{display:flex;justify-content:space-between;align-items:center;font-size:10px;color:var(--muted)}#category{color:var(--green);background:#eef5e9;padding:6px 10px;border-radius:5px;font-weight:700}h2{font-size:25px;letter-spacing:-.7px;margin:22px 0 10px}#description{line-height:1.9;color:#728073;white-space:pre-line;font-size:13px}pre{background:#23362e;color:#e2ecde;padding:22px;border-radius:10px;font:12px/1.9 'JetBrains Mono',monospace;overflow:auto;white-space:pre-wrap;tab-size:4;margin:22px 0}.answer-label{display:flex;justify-content:space-between;align-items:center;margin:24px 0 10px;font-weight:600;font-size:12px}#editor-tag{font:10px 'JetBrains Mono',monospace;color:#929c91}textarea{display:block;width:100%;min-height:158px;resize:vertical;background:#fafbf8;border:1px solid #dce3d7;border-radius:9px;padding:17px;color:var(--ink);font:13px/1.8 'JetBrains Mono',monospace;tab-size:4}textarea:focus{outline:2px solid #73ab88;outline-offset:2px}.input-note{font-size:11px;color:#919b8e}.actions{display:flex;gap:10px;align-items:center;margin:24px 0}.primary,.secondary{font-family:inherit;font-size:12px;font-weight:600;padding:11px 17px;border-radius:7px;cursor:pointer}.primary{background:var(--green);border:1px solid var(--green);color:white}.primary span{margin-left:18px}.secondary{background:white;border:1px solid var(--line);color:#60735f}button:hover{filter:brightness(.95)}button:focus-visible,a:focus-visible,summary:focus-visible{outline:3px solid #81ad66;outline-offset:3px}button:disabled{opacity:.45;cursor:default}#saved{font-size:10px;color:var(--muted);margin-left:auto}details{border-top:1px solid var(--line);padding:17px 0;color:#6b7c67;font-size:12px}summary{cursor:pointer;font-weight:500}details p{line-height:1.9}#reflection label{display:block;margin:14px 0;line-height:1.8}#notes{min-height:90px;font-family:inherit;font-size:12px}.hint,#result{border-radius:8px;background:#f4f6ed;padding:16px;margin-bottom:20px;font-size:12px;line-height:1.9;white-space:pre-wrap;overflow-wrap:anywhere}#result.success{background:#eaf5ed;color:#236541}#result.failure{background:#fff3e9;color:#955d29}#result pre{margin:12px 0 0;font-size:11px}.pager{display:flex;justify-content:space-between;align-items:center;border-top:1px solid var(--line);padding-top:22px;margin-top:7px}#step{font-size:11px;color:var(--muted)}footer{padding:30px 0;display:flex;justify-content:space-between;color:#939d8f;font-size:10px;gap:15px}footer a{color:inherit}.footer-dot{margin:0 10px;color:#c2cabc}@media(max-width:1200px){main{padding:0 24px}}@media(max-width:760px){header{height:70px}.brand{font-size:15px}.local{display:none}.intro{padding:30px 0;align-items:stretch}.intro h1{font-size:32px}.summary{width:210px;padding:20px}.workspace{grid-template-columns:1fr;gap:15px}aside .tip,.aside-title,.group{display:none}nav{display:flex;overflow:auto;gap:7px;padding-bottom:8px}nav button{min-width:150px;width:auto;font-size:11px;padding:9px}.problem{padding:24px 20px}footer{flex-direction:column}h2{font-size:22px}}@media(max-width:480px){main{padding:0 16px}.intro{flex-direction:column;gap:15px}.intro h1 br{display:none}.intro h1{font-size:29px}.intro p br{display:none}.summary{width:100%;padding:18px}.summary strong{font-size:28px;margin:10px 0}.summary p{margin-top:9px}.eyebrow{font-size:8px}.actions{flex-wrap:wrap}.primary,.secondary{padding:10px 12px}}

#plot-preview{margin:20px 0;border:1px solid var(--line);border-radius:10px;padding:18px;background:#fafbf8}#plot-preview figcaption{font-weight:600;font-size:13px;margin-bottom:12px}#plot-preview figcaption span{display:block;font-size:10px;color:var(--muted);font-weight:400;margin-top:5px}#plot-image{display:block;width:100%;height:auto;background:#fff;border-radius:6px}#plot-preview p{font-size:10px;color:var(--muted);line-height:1.8;margin:10px 0 0}