:root{--bg:#faf9f6;--ink:#2a2724;--sub:#6b6560;--accent:#d97757;--line:#ece7df;--card:#fff}
*{box-sizing:border-box}
body{margin:0;background:var(--bg);color:var(--ink);font-family:'Pretendard Variable',Pretendard,system-ui,-apple-system,'Apple SD Gothic Neo',sans-serif;line-height:1.75;font-size:17px;-webkit-font-smoothing:antialiased}
a{color:var(--accent);text-decoration:none}
a:hover{text-decoration:underline}
.lec-top{display:flex;justify-content:space-between;align-items:center;gap:16px;padding:14px 20px;border-bottom:1px solid var(--line);background:var(--bg);position:sticky;top:0;z-index:10;flex-wrap:wrap}
.lec-brand{font-weight:700;color:var(--ink)}
.lec-nav a{margin-left:16px;color:var(--sub);font-size:14.5px}
.lec-main{max-width:760px;margin:0 auto;padding:32px 20px 64px}
.lec-crumb{font-size:13px;color:var(--sub);margin-bottom:18px}
.lec-crumb a{color:var(--sub)}
.lec-badge{display:inline-block;font-size:13px;color:var(--accent);font-weight:600;margin-bottom:4px}
.lec-part{font-size:13px;color:var(--sub);margin:0 0 6px}
.lec-byline{font-size:13px;color:var(--sub);margin:-14px 0 22px}
.lec-byline a{color:var(--sub);text-decoration:underline;text-decoration-color:#dcd4c8}
h1{font-size:30px;line-height:1.3;margin:6px 0 24px;letter-spacing:-.01em}
.lec-h{font-size:21px;margin:34px 0 12px;letter-spacing:-.01em}
.lec-lead{font-size:18px;color:var(--ink)}
.lec-note{font-size:14px;color:var(--sub);background:#fff8f4;border:1px solid #f0ddd2;border-radius:8px;padding:10px 14px}
.lec-summary{background:var(--card);border:1px solid var(--line);border-radius:12px;padding:8px 18px 14px;margin:20px 0}
.lec-summary .lec-h{font-size:16px;margin:14px 0 6px;color:var(--sub)}
.lec-rows{width:100%;border-collapse:collapse;font-size:15px}
.lec-rows th{text-align:left;white-space:nowrap;vertical-align:top;padding:8px 14px 8px 0;color:var(--ink);font-weight:600;width:1%}
.lec-rows td{padding:8px 0;color:var(--sub);border-bottom:1px solid var(--line)}
.lec-rows tr:last-child td{border-bottom:none}
.lec-body p{margin:14px 0}
.lec-list,.lec-steps{margin:14px 0;padding-left:22px}
.lec-list li,.lec-steps li{margin:7px 0}
.lec-intro{font-size:18px;color:var(--ink);background:#fffdfb;border-left:3px solid var(--accent);padding:10px 16px;border-radius:0 8px 8px 0}
.lec-tip{background:#f3f8f1;border:1px solid #d9e9d3;border-radius:10px;padding:12px 16px;margin:18px 0;font-size:15.5px;color:#3c5a33}
.lec-prompt{background:#2a2724;color:#f0ece6;border-radius:10px;padding:14px 16px;margin:18px 0;overflow-x:auto;font-size:14px;line-height:1.6;white-space:pre-wrap;word-break:break-word}
.lec-prompt code{font-family:'DM Mono',ui-monospace,SFMono-Regular,Menlo,monospace}
.lec-fig{margin:20px 0;text-align:center}
.lec-fig svg{max-width:100%;height:auto}
.lec-fig figcaption{font-size:13px;color:var(--sub);margin-top:8px}
.lec-pager{display:flex;justify-content:space-between;gap:14px;margin-top:40px;padding-top:20px;border-top:1px solid var(--line);font-size:14px}
.lec-pager .next{margin-left:auto;text-align:right}
.lec-track{margin:30px 0}
.lec-track .lec-h small{font-weight:400;color:var(--sub);font-size:14px}
.lec-track-goal{color:var(--sub);font-size:15px;margin:-4px 0 12px}
.lec-toc{list-style:none;margin:0;padding:0}
.lec-toc li{border-bottom:1px solid var(--line)}
.lec-toc a{display:flex;gap:12px;align-items:baseline;padding:12px 4px;color:var(--ink)}
.lec-toc a:hover{background:#fff;text-decoration:none}
.lec-toc .no{color:var(--accent);font-weight:600;white-space:nowrap;font-size:14px;min-width:48px}
.lec-foot{max-width:760px;margin:0 auto;padding:28px 20px 56px;border-top:1px solid var(--line);font-size:13.5px;color:var(--sub)}
.lec-foot a{color:var(--sub)}
.lec-copy{margin-top:10px;font-size:12px;color:#a39c92}
@media(max-width:520px){h1{font-size:25px}body{font-size:16px}}