@keyframes rise{0%{opacity:0;transform:translateY(10px)}to{opacity:1;transform:none}}@keyframes reload{0%{opacity:.1}to{opacity:1}}@keyframes blink{0%,to{opacity:.3}50%{opacity:1}}.lesson{--lightningcss-light:initial;--lightningcss-dark: ;color-scheme:light;--bg:#fff;--text:#24262b;--muted:#6a6e78;--line:#e6e6e3;--surface:#f7f6f2;--accent:#f6ce60;--accent-strong:#e8b73a;--accent-deep:#c9951a;--accent-ink:#8a6300;--accent-soft:#fff6dc;--on-accent:#1f1b12;--seg-off:#ececea;--seg-now:#fbe3a0;--good:#1f8f55;--good-soft:#e9f6ef;--bad:#cf3f3f;--bad-soft:#fcefef;--mono:ui-monospace,"SF Mono",Menlo,Consolas,monospace;--page:#fff;--ink:#24262b;--line-2:#d9d8d1;--dim:#9c9a92;--acc:#8a6300;--acc-strong:#e8b73a;--acc-soft:#fff6dc;--acc-fill:#f6ce60;--acc-deep:#c9951a;--on-acc:#1f1b12;--raised:#f7f6f2;background:var(--bg);color:var(--text);word-break:keep-all;min-height:100vh;margin:0;font-family:-apple-system,BlinkMacSystemFont,Apple SD Gothic Neo,Pretendard,Malgun Gothic,sans-serif;font-size:17px;line-height:1.85}.lesson :is(h1,h2,h3,h4){font-weight:700}.lesson .sec ul{list-style:outside}.lesson .insights ol{list-style:decimal}.lesson svg{display:inline}.lesson [hidden]{display:none!important}.lesson button{font:inherit}.lesson code{font-family:var(--mono);background:#f2f1ec;border-radius:4px;padding:1px 6px;font-size:.88em}.lesson .top{z-index:10;background:#fff;border-bottom:1px solid #f0efea;position:sticky;top:0}.lesson .top-in{grid-template-columns:44px 1fr 44px;align-items:center;gap:16px;max-width:1120px;margin:0 auto;padding:14px 20px;display:grid}.lesson .icon-btn{cursor:pointer;width:44px;height:44px;color:var(--text);background:0 0;border:0;border-radius:10px;place-items:center;display:grid}.lesson .icon-btn:hover{background:#f3f2ee}.lesson .icon-btn:focus-visible,.lesson .btn:focus-visible,.lesson .choice:focus-visible{outline:3px solid var(--accent-strong);outline-offset:2px}.lesson .segs{align-items:center;gap:5px;display:flex}.lesson .segs i{background:var(--seg-off);border-radius:5px;flex:1;height:10px;transition:background .35s}.lesson .segs i.done{background:var(--accent)}.lesson .segs i.now{background:var(--seg-now)}.lesson .segs .gap{background:0 0;flex:0 0 8px;height:0}.lesson .top-label{color:var(--muted);justify-content:space-between;gap:12px;margin-top:6px;font-size:13px;line-height:1.4;display:flex}.lesson .top-label b{color:var(--text);font-weight:600}.lesson .top-head{justify-content:space-between;align-items:center;gap:12px;margin:-4px 0 8px;display:flex}.lesson .top-count{color:var(--muted);font-variant-numeric:tabular-nums;flex:none;font-size:13px}.lesson .top-step{flex:none;align-items:center;gap:6px;display:flex}.lesson .step-btn{border:1px solid var(--line);height:28px;color:var(--text);cursor:pointer;background:#fff;border-radius:8px;align-items:center;gap:2px;padding:0 9px;font-size:13px;font-weight:600;line-height:1;transition:border-color .15s,background .15s;display:inline-flex}.lesson .step-btn:hover:not([disabled]){border-color:var(--accent-strong);background:var(--accent-soft)}.lesson .step-btn:focus-visible{outline:3px solid var(--accent-strong);outline-offset:2px}.lesson .step-btn[disabled]{opacity:.35;cursor:default}.lesson .top-step .top-count{text-align:center;min-width:44px}@media (max-width:560px){.lesson .step-txt{display:none}.lesson .step-btn{padding:0 6px}.lesson .top-step .top-count{min-width:36px}}.lesson .drawer-bg{z-index:40;opacity:0;pointer-events:none;background:#19160f52;transition:opacity .2s;position:fixed;inset:0}.lesson .drawer-bg.open{opacity:1;pointer-events:auto}.lesson .drawer{z-index:41;background:#fff;width:340px;max-width:88vw;padding:22px 0 32px;transition:transform .25s;position:fixed;top:0;bottom:0;left:0;overflow-y:auto;transform:translate(-102%);box-shadow:4px 0 24px #00000014}.lesson .drawer.open{transform:none}.lesson .drawer:not(.open){visibility:hidden;box-shadow:none;transition:transform .25s,visibility 0s .25s}.lesson .drawer-title{border-bottom:1px solid var(--line);margin-bottom:8px;padding:0 22px 14px}.lesson .drawer-title small{color:var(--muted);font-size:13px;display:block}.lesson .drawer-title b{font-size:17px}.lesson .toc-topic{justify-content:space-between;padding:14px 22px 4px;font-size:14px;font-weight:700;display:flex}.lesson .toc-topic span{color:var(--muted);font-size:13px;font-weight:400}.lesson .toc-sec{text-align:left;width:100%;color:var(--text);cursor:pointer;background:0 0;border:0;align-items:center;gap:10px;padding:7px 22px;font-size:14.5px;display:flex}.lesson .toc-sec .dot{border:2px solid #d6d5cf;border-radius:50%;flex:none;place-items:center;width:16px;height:16px;display:grid}.lesson .toc-sec.done .dot{background:var(--accent);border-color:var(--accent)}.lesson .toc-sec.done .dot:after{content:"";border-left:2px solid var(--on-accent);border-bottom:2px solid var(--on-accent);width:6px;height:3px;transform:rotate(-45deg)translate(1px,-1px)}.lesson .toc-sec.now{background:var(--accent-soft);font-weight:700}.lesson .toc-sec.now .dot{border-color:var(--accent-strong)}.lesson .toc-sec[disabled]{color:#b4b3ad;cursor:default}.lesson .doc h1{letter-spacing:-.02em;margin:0 0 28px;font-size:32px;line-height:1.3}.lesson .doc .kicker{color:var(--accent-ink);letter-spacing:.02em;margin:0 0 8px;font-size:13.5px;font-weight:700}.lesson .sec h2{border-bottom:1px solid var(--line);letter-spacing:-.01em;margin:44px 0 16px;padding-bottom:12px;font-size:23px}.lesson .sec h3{margin:36px 0 10px;font-size:19px}.lesson .fig-cap{color:var(--muted);text-align:center;margin:-14px 0 24px;font-size:14px}.lesson .terms li{margin-bottom:4px}.lesson .terms a{color:inherit;text-decoration:none}.lesson .terms a:hover b{text-decoration:underline;-webkit-text-decoration-color:var(--accent-strong);text-decoration-color:var(--accent-strong);text-underline-offset:4px}.lesson .sec a.term{color:inherit;-webkit-text-decoration:underline dotted var(--accent-deep);text-decoration:underline dotted var(--accent-deep);text-underline-offset:4px;text-decoration-thickness:1.5px;position:relative}.lesson .sec a.term:hover{background:var(--accent-soft)}@media (hover:hover){.lesson .sec a.term:after{content:attr(data-def);z-index:20;background:var(--text);width:max-content;max-width:min(320px,80vw);color:var(--bg);text-align:left;white-space:normal;opacity:0;pointer-events:none;border-radius:8px;padding:8px 12px;font-size:13.5px;font-weight:400;line-height:1.55;transition:opacity .12s;position:absolute;bottom:calc(100% + 8px);left:50%;transform:translate(-50%);box-shadow:0 12px 32px #1f1b121f}.lesson .sec a.term:hover:after,.lesson .sec a.term:focus-visible:after{opacity:1}}.lesson .lesson-fig{margin:24px 0 28px}.lesson .lesson-fig img{border:1px solid var(--line);border-radius:12px;width:100%;height:auto;display:block}.lesson .lesson-fig figcaption{color:var(--muted);text-align:center;margin-top:8px;font-size:14px}.lesson .sec mark{color:inherit;background:linear-gradient(#0000 52%,#fde58a 52%);padding:0 1px}.lesson .sec u{text-decoration:underline;-webkit-text-decoration-color:var(--accent-strong);text-decoration-color:var(--accent-strong);text-underline-offset:4px;text-decoration-thickness:2px}.lesson .sec em{color:#4a4d55;font-style:italic}.lesson .sec :is(b,strong){font-weight:700}.lesson .sec code{font-family:ui-monospace,SF Mono,Menlo,Consolas,Apple SD Gothic Neo,Pretendard,Malgun Gothic,sans-serif}.lesson .sec:first-child h2{margin-top:0}.lesson .sec p{margin:0 0 16px}.lesson .sec ul{margin:0 0 16px;padding-left:1.3em}.lesson .sec li{margin-bottom:6px}.lesson .sec-in{animation:.35s rise}.lesson .callout{background:var(--surface);border-radius:10px;margin:20px 0 24px;overflow:hidden}.lesson .callout .ch{border-bottom:1px solid #ebe9e1;padding:10px 16px;font-size:15.5px;font-weight:700}.lesson .callout .cb{padding:14px 16px;font-size:16px}.lesson .callout .cb p:last-child,.lesson .callout .cb ul{margin-bottom:0}.lesson .callout.warn{background:var(--bad-soft)}.lesson .callout.warn .ch{color:#9b2c2c;border-color:#f3dada}.lesson .lab{border:1px solid var(--line);border-radius:12px;margin:24px 0 28px;overflow:hidden}.lesson .lab-h{border-bottom:1px solid var(--line);background:var(--surface);justify-content:space-between;align-items:center;padding:10px 16px;font-size:14px;display:flex}.lesson .lab-h b{color:var(--accent-ink)}.lesson .lab-b{padding:16px}.lesson .plain{border-collapse:collapse;width:100%;margin:8px 0 20px;font-size:15.5px}.lesson .plain th,.lesson .plain td{border:1px solid var(--line);text-align:left;padding:8px 12px}.lesson .plain th{background:var(--surface);font-weight:700}.lesson .plain td code{background:0 0;padding:0}.lesson .btn{background:var(--accent);color:var(--on-accent);cursor:pointer;box-shadow:0 3px 0 var(--accent-deep);border:0;border-radius:10px;padding:11px 22px;font-size:16px;font-weight:700;transition:transform 50ms}.lesson .btn:hover{background:#f4c546}.lesson .btn:active{box-shadow:0 1px 0 var(--accent-deep);transform:translateY(2px)}.lesson .btn.ghost{color:var(--text);background:#fff;border:1px solid #d9d8d1;box-shadow:0 3px #e6e5df}.lesson .btn.ghost:hover{background:#faf9f6}.lesson .btn[disabled]{color:#a9a7a0;cursor:default;background:#eceae4;box-shadow:0 3px #dcdad3}.lesson .qcard{border:1px solid var(--line);background:#fff;border-radius:12px;padding:26px 28px}.lesson .qcard.ok{border-color:var(--good)}.lesson .qcard.no{border-color:var(--bad)}.lesson .qlabel{color:var(--accent-ink);margin-bottom:6px;font-size:13px;font-weight:700}.lesson .qcard h3{margin:0 0 6px;font-size:19px;line-height:1.5}.lesson .qhint{color:var(--muted);margin:0 0 16px;font-size:14.5px}.lesson .qhint.ok{color:var(--good);font-weight:700}.lesson .qhint.no{color:var(--bad);font-weight:700}.lesson .choices{gap:8px;display:grid}.lesson .choices.two{grid-template-columns:1fr 1fr}.lesson .choice{text-align:center;cursor:pointer;width:100%;color:var(--text);background:#fff;border:1px solid #dddcd5;border-radius:10px;padding:14px;font-size:16.5px;font-weight:600;display:block}.lesson .choice:hover{border-color:var(--accent-strong)}.lesson .choice.sel{border-color:var(--accent-strong);background:var(--accent-soft)}.lesson .choice.ok{border-color:var(--good);background:var(--good-soft);color:var(--good)}.lesson .choice.no{border-color:var(--bad);background:var(--bad-soft);color:var(--bad)}.lesson .choice code{background:0 0}.lesson .explain{background:var(--surface);border-radius:8px;margin-top:12px;padding:12px 14px;font-size:15px}.lesson .qact{justify-content:flex-end;gap:8px;margin-top:16px;display:flex}.lesson .modal-bg{z-index:60;background:#19160f73;justify-content:center;align-items:center;padding:16px;display:none;position:fixed;inset:0}.lesson .modal-bg.open{display:flex}.lesson .modal{text-align:center;background:#fff;border-radius:14px;width:440px;max-width:100%;overflow:hidden}.lesson .modal-art{background:var(--accent);height:8px}.lesson .modal-b{padding:28px 24px 8px;font-size:15.5px;line-height:1.7}.lesson .modal-b h3{margin:0 0 8px;font-size:21px}.lesson .modal-b .next-up{background:var(--surface);border-radius:8px;margin:14px 0 0;padding:8px 14px;font-size:14.5px;display:inline-block}.lesson .modal-f{justify-content:center;gap:10px;padding:20px 24px 26px;display:flex}.lesson .w-seg{background:#f1f0eb;border-radius:10px;flex-wrap:wrap;gap:4px;margin-bottom:14px;padding:4px;display:inline-flex}.lesson .w-seg-btn{cursor:pointer;color:var(--muted);background:0 0;border:0;border-radius:7px;align-items:baseline;gap:6px;padding:7px 12px;font-size:14.5px;display:inline-flex}.lesson .w-seg-btn.is-on{color:var(--text);background:#fff;font-weight:700;box-shadow:0 1px 2px #281e0024}.lesson .w-seg-btn b{font-family:var(--mono);font-size:13px}.lesson .w-seg-btn small{font-size:12.5px}.lesson .w-phones{grid-template-columns:1fr 1fr;gap:12px;display:grid}.lesson .w-phone{border:1px solid var(--line);border-radius:12px;flex-direction:column;min-height:160px;padding:12px;transition:background .3s;display:flex}.lesson .w-phone.is-flash{background:var(--accent-soft)}.lesson .w-phone-title{color:var(--muted);margin-bottom:6px;font-size:13px;font-weight:700}.lesson .w-phone-list,.lesson .sec .w-phone-list{flex:1;margin:0 0 10px;padding:0;font-size:15px;line-height:1.6;list-style:none}.lesson .w-phone-list li{align-items:center;gap:8px;margin:0;padding:2px 0;display:flex}.lesson .w-dot{background:var(--accent-strong);border-radius:50%;flex:none;width:7px;height:7px}.lesson .w-phone-empty{color:#aaa9a2}.lesson .w-phone-form{gap:6px;display:flex}.lesson .w-input,.lesson .w-select{font:inherit;background:#fff;border:1px solid #d9d8d1;border-radius:8px;flex:1;min-width:0;padding:6px 10px;font-size:15px}.lesson .w-input:focus,.lesson .w-select:focus{outline:2px solid var(--accent-strong);outline-offset:1px}.lesson .w-btn{background:var(--accent);color:var(--on-accent);cursor:pointer;box-shadow:0 2px 0 var(--accent-deep);border:0;border-radius:8px;padding:7px 14px;font-size:14.5px;font-weight:700}.lesson .w-btn-sm{padding:5px 12px;font-size:14px}.lesson .w-btn-ghost{color:var(--text);box-shadow:none;background:#fff;border:1px solid #d9d8d1}.lesson .w-btn[disabled]{opacity:.4;cursor:default}.lesson .w-btn.is-flash{background:var(--accent-soft)}.lesson .w-actions{flex-wrap:wrap;gap:8px;margin-top:12px;display:flex}.lesson .w-note{color:var(--muted);min-height:1.6em;margin:10px 0 0;font-size:15px;line-height:1.6}.lesson .w-note.is-warn{color:var(--bad);font-weight:600}.lesson .w-ctl{margin-bottom:10px}.lesson .w-field{color:var(--muted);align-items:center;gap:10px;font-size:14.5px;display:flex}.lesson .w-field .w-select,.lesson .w-field .w-input{flex:0 220px}.lesson .w-code{font-family:var(--mono);color:#ece9df;white-space:pre-wrap;background:#23211c;border-radius:10px;margin:0 0 16px;padding:12px 16px;font-size:14.5px;line-height:1.6}.lesson .lab .w-code{margin:0}.lesson .w-sql-kw{color:var(--accent);font-weight:600}.lesson .w-sql-str{color:#a8d89a}.lesson .w-sql-num{color:#f2a07b}.lesson .w-table-wrap{margin-top:12px;overflow-x:auto}.lesson .w-table-cap{font-family:var(--mono);color:var(--muted);margin-bottom:4px;font-size:13px}.lesson .w-table{border-collapse:collapse;width:100%;font-size:15px}.lesson .w-table th,.lesson .w-table td{border:1px solid var(--line);text-align:left;padding:7px 12px;transition:background .3s,opacity .5s}.lesson .w-table th{background:var(--surface);font-family:var(--mono);white-space:nowrap;font-size:13px}.lesson .w-table .w-bool{font-family:var(--mono);font-size:14px}.lesson .w-table tr.is-hi td{background:var(--accent-soft)}.lesson .w-table tr.is-new td{background:var(--good-soft)}.lesson .w-table tr.is-gone td{background:var(--bad-soft);opacity:.25}.lesson .w-table tr.is-dim td{color:#b9b8b1}.lesson .w-table td.is-changed{box-shadow:inset 0 0 0 2px var(--good)}.lesson .w-table th.is-hi{color:var(--accent-ink)}.lesson .w-table .w-empty td{color:#aaa9a2;text-align:center}.lesson .w-pk,.lesson .w-fk{color:var(--accent-ink);margin-left:6px;font-family:-apple-system,sans-serif;font-size:11px;font-weight:700}.lesson .w-fk{color:var(--good)}.lesson .w-two{grid-template-columns:2fr 3fr;gap:12px;display:grid}.lesson .w-switch{cursor:pointer;align-items:center;gap:10px;font-size:15px;font-weight:600;display:inline-flex}.lesson .w-switch input{opacity:0;position:absolute}.lesson .w-switch-ui{background:#d8d6cf;border-radius:12px;width:40px;height:24px;transition:background .2s;position:relative}.lesson .w-switch-ui:after{content:"";background:#fff;border-radius:50%;width:18px;height:18px;transition:left .2s;position:absolute;top:3px;left:3px;box-shadow:0 1px 2px #0003}.lesson .w-switch input:checked+.w-switch-ui{background:var(--good)}.lesson .w-switch input:checked+.w-switch-ui:after{left:19px}.lesson .w-switch input:focus-visible+.w-switch-ui{outline:2px solid var(--accent-strong);outline-offset:2px}.lesson .w-flow{grid-template-columns:1fr auto 1fr;align-items:center;gap:10px;margin:14px 0 4px;display:grid}.lesson .w-node{border:1px solid var(--line);text-align:center;border-radius:10px;padding:8px 12px;line-height:1.5}.lesson .w-node b{font-size:15px;display:block}.lesson .w-node small{color:var(--muted);font-size:13px}.lesson .w-node.is-guard{border-color:var(--good);box-shadow:0 0 0 3px var(--good-soft)}.lesson .w-arrow{text-align:center;color:var(--muted);min-width:110px;font-size:13px}.lesson .w-arrow:after{content:"→";font-size:18px;line-height:1;display:block}.lesson .w-checks{flex-wrap:wrap;gap:8px;margin-bottom:12px;display:flex}.lesson .w-check{cursor:pointer;border:1px solid #d9d8d1;border-radius:999px;align-items:center;gap:6px;padding:6px 12px;font-size:14.5px;display:inline-flex}.lesson .w-check.is-on{border-color:var(--accent-strong);background:var(--accent-soft);font-weight:700}.lesson .w-check input{accent-color:var(--accent-deep);margin:0}.lesson .w-prompt{border:1px solid var(--line);border-radius:10px;overflow:hidden}.lesson .w-prompt-head{background:var(--surface);color:var(--muted);justify-content:space-between;align-items:center;padding:6px 12px;font-size:13px;font-weight:700;display:flex}.lesson .w-prompt-body{white-space:pre-wrap;margin:0;padding:12px 14px;font-family:inherit;font-size:15px;line-height:1.7}@media (max-width:720px){.lesson body{font-size:16px}.lesson .top-in{grid-template-columns:40px 1fr 40px;gap:10px;padding:10px 12px}.lesson .segs{gap:3px}.lesson .segs i{height:8px}.lesson .segs .gap{flex-basis:4px}.lesson .doc h1{font-size:25px}.lesson .sec h2{font-size:20px}.lesson .w-phones,.lesson .w-two,.lesson .w-flow{grid-template-columns:1fr}.lesson .qcard{padding:20px 16px}.lesson .choices.two{grid-template-columns:1fr}}.lesson .prompt-quote{border-left:3px solid var(--accent);background:var(--accent-soft);border-radius:0 10px 10px 0;margin:4px 0 20px;padding:14px 18px;font-size:16.5px}.lesson .w-cmt{color:#9c988a}.lesson .app-mock{border:1px solid var(--line);background:#fff;border-radius:12px;max-width:420px;margin:20px auto 24px;overflow:hidden;box-shadow:0 8px 24px #281e0012}.lesson .app-bar{border-bottom:1px solid var(--line);background:#f3f2ee;align-items:center;gap:10px;padding:8px 12px;display:flex}.lesson .app-dots{gap:5px;display:inline-flex}.lesson .app-dots i{background:#dcdad3;border-radius:50%;width:9px;height:9px}.lesson .app-url{font-family:var(--mono);color:var(--muted);background:#fff;border-radius:6px;flex:1;padding:2px 10px;font-size:12px}.lesson .app-body{padding:16px 18px 18px}.lesson .app-title{margin-bottom:10px;font-size:17px;font-weight:800}.lesson .app-list{margin:0 0 12px;padding:0;list-style:none}.lesson .sec .app-list{padding:0}.lesson .app-list li{border-bottom:1px solid #f1f0ec;align-items:center;gap:10px;margin:0;padding:7px 0;font-size:15px;display:flex}.lesson .app-list em{color:var(--muted);margin-left:auto;font-size:12.5px;font-style:normal}.lesson .app-check{border:2px solid #cfcdc5;border-radius:4px;flex:none;width:16px;height:16px}.lesson .app-check.on{background:var(--accent);border-color:var(--accent-strong)}.lesson .app-input{border:1px solid var(--line);color:#aaa9a2;border-radius:8px;justify-content:space-between;align-items:center;padding:6px 6px 6px 12px;font-size:14px;display:flex}.lesson .app-input b{background:var(--accent);color:var(--on-accent);border-radius:6px;padding:4px 12px;font-size:13px}.lesson .chat{border:1px solid var(--line);background:#fbfaf7;border-radius:12px;max-height:460px;padding:0 14px 14px;overflow-y:auto}.lesson .chat-head{color:var(--muted);border-bottom:1px solid var(--line);background:#fbfaf7;margin-bottom:8px;padding:10px 0;font-size:13.5px;font-weight:700;position:sticky;top:0}.lesson .chat-day{text-align:center;color:var(--muted);margin:14px 0 8px;font-size:12.5px}.lesson .chat-day:before,.lesson .chat-day:after{content:"—";color:#d6d4cc;margin:0 8px}.lesson .chat-msg{flex-direction:column;align-items:flex-start;margin:8px 0;display:flex}.lesson .chat-msg.me{align-items:flex-end}.lesson .chat-who{color:var(--muted);margin:0 0 3px 4px;font-size:12.5px}.lesson .chat-bubble{border:1px solid var(--line);background:#fff;border-radius:14px;max-width:80%;padding:9px 13px;font-size:15px;line-height:1.55}.lesson .chat-msg.me .chat-bubble{background:var(--accent);border-color:var(--accent-strong);color:var(--on-accent)}.lesson .chat-msg.is-new{animation:.3s rise}.lesson ol.need{counter-reset:n;gap:8px;margin:8px 0 20px;padding:0;list-style:none;display:grid}.lesson ol.need li{counter-increment:n;border:1px solid var(--line);border-radius:10px;grid-template-columns:34px 1fr;column-gap:12px;margin:0;padding:12px 14px;display:grid}.lesson ol.need li:before{content:counter(n);background:var(--accent);width:28px;height:28px;color:var(--on-accent);border-radius:8px;grid-row:span 2;place-items:center;font-size:14px;font-weight:800;display:grid}.lesson ol.need b{font-size:16px}.lesson ol.need span{color:var(--muted);font-size:15px}.lesson .flow-mini{flex-wrap:wrap;justify-content:center;align-items:center;gap:10px;margin:20px 0;display:flex}.lesson .flow-mini span{border:1px solid var(--line);background:#fff;border-radius:10px;padding:8px 16px;font-size:15px;font-weight:700}.lesson .flow-mini span.is-db{background:var(--accent);border-color:var(--accent-strong);color:var(--on-accent)}.lesson .flow-mini i{color:var(--muted);font-style:normal}.lesson .cmp-wrap{overflow-x:auto}.lesson .cmp td,.lesson .cmp th{text-align:center;white-space:nowrap}.lesson .cmp td:first-child{text-align:left;white-space:normal;min-width:150px}.lesson .cmp th:last-child,.lesson .cmp td:last-child{background:var(--accent-soft)}.lesson .cmp .ok{color:var(--good);font-weight:800}.lesson .cmp .no{color:var(--bad);font-weight:800}.lesson .cmp .mid{color:#a07400;font-weight:800}.lesson .cmp .na{color:#aaa9a2;font-size:13px}.lesson .cmp small{color:var(--muted);font-size:11.5px;font-weight:400;display:block}.lesson .w-race-intro{color:var(--muted);margin:0 0 10px;font-size:15px}.lesson .w-race-log,.lesson .sec .w-race-log{gap:6px;min-height:40px;margin:0;padding:0;list-style:none;display:grid}.lesson .w-race-step{border:1px solid var(--line);border-radius:8px;align-items:baseline;gap:10px;margin:0;padding:8px 12px;font-size:14.5px;animation:.3s rise;display:flex}.lesson .w-race-step.is-warn{background:var(--bad-soft);border-color:#f0c9c9}.lesson .w-race-empty{color:#aaa9a2;font-size:14.5px}.lesson .w-who{border-radius:6px;flex:none;padding:1px 8px;font-size:12.5px}.lesson .w-who-a{color:#2f4f9e;background:#e8eefc}.lesson .w-who-b{color:#8a3a8a;background:#f6e6f6}.lesson .w-who-db{background:var(--accent);color:var(--on-accent)}.lesson .w-race-box{border:1px solid var(--line);border-radius:10px;margin-top:12px;padding:10px 14px}.lesson .w-race-result,.lesson .sec .w-race-result{margin:0;padding-left:1.2em;font-size:15px}.lesson .w-race-result li{margin:2px 0}.lesson .w-race-result .is-lost{color:var(--bad);text-decoration:line-through}.lesson .insight{background:#fffaf0;border:1px solid #f4e2ac;border-radius:12px;margin:24px 0;padding:18px 20px 16px 22px;position:relative}.lesson .insight:before{content:"";background:var(--accent);border-radius:0 4px 4px 0;width:4px;position:absolute;top:14px;bottom:14px;left:0}.lesson .insight-label{letter-spacing:.06em;color:var(--on-accent);background:var(--accent);border-radius:6px;margin-bottom:6px;padding:1px 8px;font-size:12px;font-weight:800;display:inline-block}.lesson .insight p{margin:0;font-size:17px;line-height:1.75}.lesson .insights{color:#f2efe6;background:#23211c;border-radius:14px;margin:28px 0;padding:22px 24px}.lesson .insights h3{color:var(--accent);margin:0 0 12px;font-size:17px}.lesson .insights ol{margin:0;padding-left:1.3em}.lesson .insights li{margin:0 0 8px;line-height:1.65}.lesson .gaps td:last-child{color:var(--muted)}.lesson .w-canvas-box{border:1px solid var(--line);background:#fdfcf9;border-radius:12px;width:100%;overflow:hidden}.lesson .w-canvas{display:block}.lesson .app-mock.live{max-width:none;box-shadow:none;margin:0}.lesson .app-mock.is-reload .app-body{animation:.45s reload}.lesson .app-refresh{width:26px;height:26px;color:var(--muted);cursor:pointer;background:0 0;border:0;border-radius:6px;place-items:center;margin-left:2px;display:grid}.lesson .app-refresh:hover{background:#e9e7df}.lesson .app-list li.is-hi{background:var(--accent-soft)}.lesson .app-list li{border-radius:6px;padding-left:4px;padding-right:4px}.lesson .app-list li.is-gone{opacity:.25;text-decoration:line-through;transition:opacity .5s}.lesson button.app-check{cursor:pointer;background:#fff;padding:0}.lesson button.app-check.on{background:var(--accent)}.lesson .app-done{color:#a9a7a0;text-decoration:line-through}.lesson .app-del{color:#b4b2aa;cursor:pointer;background:0 0;border:0;border-radius:6px;margin-left:auto;padding:2px 6px;font-size:18px;line-height:1}.lesson .app-del:hover{color:var(--bad);background:var(--bad-soft)}.lesson .app-list li em+.app-del{margin-left:4px}.lesson .app-week{color:var(--muted);background:#f1f0eb;border-radius:4px;padding:0 6px;font-size:11.5px}.lesson .app-input{gap:6px}.lesson form.app-input{color:var(--text);padding:4px 4px 4px 10px}.lesson .app-in{min-width:0;font:inherit;background:0 0;border:0;outline:0;flex:1;font-size:14px}.lesson .app-add{background:var(--accent);color:var(--on-accent);cursor:pointer;border:0;border-radius:6px;padding:5px 12px;font-size:13px;font-weight:700}.lesson .app-clear{width:100%;color:var(--muted);cursor:pointer;background:#fff;border:1px dashed #d9d8d1;border-radius:8px;margin-top:10px;padding:7px;font-size:13.5px}.lesson .app-clear:hover{border-color:var(--bad);color:var(--bad)}.lesson .app-empty{color:#aaa9a2;justify-content:center}.lesson .bt-grid{grid-template-columns:minmax(0,1fr) minmax(0,1fr);align-items:start;gap:16px;display:grid}.lesson .bt-cap{color:var(--muted);margin:0 0 6px;font-size:12.5px;font-weight:700}.lesson .bt-grid .w-table-wrap{margin-top:0}.lesson .bt-grid .w-code{margin-bottom:8px;font-size:13px}.lesson .console{color:#ece9df;background:#23211c;border-radius:12px;min-height:210px;overflow:hidden}.lesson .console-h{color:#a8a497;border-bottom:1px solid #3a372f;padding:8px 12px;font-size:12px}.lesson .console-b{gap:8px;padding:8px 12px 12px;display:grid}.lesson .console-empty{color:#8d897c;padding:8px 0;font-size:13.5px}.lesson .console-row{border-radius:6px;gap:2px;padding:6px 8px;display:grid}.lesson .console-row code{color:#ece9df;white-space:pre-wrap;word-break:normal;overflow-wrap:anywhere;background:0 0;padding:0;font-size:13px}.lesson .console-row small{color:#a8a497;font-size:12px}.lesson .console-row.is-new{background:#34312a;animation:.3s rise}.lesson .console-row.is-bad{background:#4a2626}.lesson .console-row.is-bad small{color:#ffb3b3}.lesson .sql-actions{align-items:center}.lesson .sql-actions .w-switch{margin-right:auto;font-size:14px}.lesson .dt-frame{border:1px solid var(--line);border-radius:12px;overflow:hidden}.lesson .dt-hint{color:var(--muted);background:var(--surface);border-bottom:1px solid var(--line);padding:8px 12px;font-size:12.5px}.lesson .devtools{background:#fff;font-size:13px}.lesson .dt-tabs{background:#f3f3f3;border-bottom:1px solid #e5e5e5;gap:2px;padding:0 8px;display:flex}.lesson .dt-tabs span{color:#555;padding:7px 10px;font-size:12.5px}.lesson .dt-files{font-family:var(--mono);white-space:pre;border-right:1px solid #e5e5e5;padding:6px 0;font-size:12px}.lesson .dt-file{color:#555;padding:3px 10px}.lesson .dt-file.on{color:#1a3a8a;background:#e8f0fe}.lesson .dt-code{font-family:var(--mono);padding:6px 0;font-size:12.5px;overflow-x:auto}.lesson .dt-line.c{color:#888}.lesson .dt-line.hl{color:#a01d1d;box-shadow:inset 3px 0 0 var(--bad);background:#fdecec;font-weight:600}.lesson .dt-line.ok{color:#17643b;background:#e9f6ef}.lesson .env-card{margin-top:12px}@media (max-width:720px){.lesson .bt-grid,.lesson .dt-body{grid-template-columns:1fr}.lesson .dt-files{display:none}.lesson .insight p{font-size:16px}}.lesson .insight{padding:16px 20px 16px 22px}.lesson .insight p{font-size:16.5px}.lesson .cv-tabs{grid-template-columns:repeat(auto-fit,minmax(120px,1fr));gap:6px;margin-bottom:10px;display:grid}.lesson .cv-tab{border:1px solid var(--line);text-align:left;cursor:pointer;color:var(--text);background:#fff;border-radius:10px;gap:1px;padding:8px 12px;display:grid}.lesson .cv-tab b{font-size:14.5px}.lesson .cv-tab small{color:var(--muted);font-size:12px;font-family:var(--mono)}.lesson .cv-tab.on{border-color:var(--accent-strong);background:var(--accent-soft);box-shadow:inset 0 0 0 1px var(--accent-strong)}.lesson .cv-tab:disabled{opacity:.55;cursor:default}.lesson .cv-cap{background:var(--surface);border-radius:10px;min-height:64px;margin-top:10px;padding:12px 14px}.lesson .cv-cap p{margin:0;font-size:15.5px;line-height:1.65}.lesson .cv-cap p.cv-sub{color:var(--muted);margin-top:4px;font-size:14.5px}.lesson .cv-step{color:var(--accent-ink);background:#fff;border:1px solid #efdca2;border-radius:6px;margin:0 6px 4px 0;padding:0 8px;font-size:12px;font-weight:700;display:inline-block}.lesson .cv-ctl{flex-wrap:wrap;align-items:center;gap:8px;margin-top:12px;display:flex}.lesson .cv-ctl .btn{padding:9px 16px;font-size:15px}.lesson .cv-sep{background:var(--line);width:1px;height:24px;margin:0 4px}.lesson .cv-btn{cursor:pointer;color:var(--text);background:#fff;border:1px solid #d9d8d1;border-radius:10px;align-items:center;gap:7px;padding:8px 13px;font-size:14.5px;font-weight:600;display:inline-flex}.lesson .cv-btn:hover{background:#faf9f6;border-color:#c9c7bf}.lesson .cv-btn:disabled{opacity:.45;cursor:default}.lesson .cv-btn i{color:#fff;border-radius:50%;place-items:center;width:20px;height:20px;font-size:11px;font-style:normal;font-weight:800;display:grid}.lesson .bw{background:#fff;border:1px solid #dcdad3;border-radius:12px;overflow:hidden;box-shadow:0 10px 30px -18px #281e0059}.lesson .bw-tabs{background:#eceae4;align-items:flex-end;gap:4px;padding:7px 10px 0;display:flex}.lesson .bw-tab{min-width:0;max-width:220px;color:var(--text);background:#fff;border-radius:9px 9px 0 0;align-items:center;gap:8px;padding:6px 12px;font-size:12.5px;display:flex}.lesson .bw-tab i{color:#a3a198;margin-left:6px;font-style:normal}.lesson .bw-title{white-space:nowrap;text-overflow:ellipsis;overflow:hidden}.lesson .bw-fav{background:var(--accent);width:16px;height:16px;color:var(--on-accent);border-radius:4px;flex:none;place-items:center;display:grid}.lesson .bw-bar{border-bottom:1px solid #ebe9e3;align-items:center;gap:8px;padding:6px 10px;display:flex}.lesson .bw-nav{color:#b3b1a9;gap:6px;display:inline-flex}.lesson .bw-reload{color:#6f6d65;cursor:pointer;background:0 0;border:0;border-radius:6px;place-items:center;width:26px;height:26px;padding:0;display:grid}.lesson button.bw-reload:hover{background:#efede7}.lesson .bw-url{color:#4b4a45;white-space:nowrap;background:#f3f2ee;border-radius:999px;flex:1;align-items:center;gap:6px;min-width:0;padding:4px 12px;font-size:12.5px;display:flex;overflow:hidden}.lesson .bw-lock{color:#8c8a82;display:inline-flex}.lesson .bw-page{background:#fff}.lesson .bw.is-reload .bw-page{animation:.5s reload}.lesson .sb{color:#222;font-size:14px;line-height:1.5}.lesson .sb-nav{border-bottom:1px solid #f0eee8;justify-content:space-between;align-items:center;padding:10px 16px;display:flex}.lesson .sb-logo{letter-spacing:-.01em;align-items:center;gap:8px;font-size:14.5px;font-weight:800;display:flex}.lesson .sb-mark{width:22px;height:22px;color:var(--accent);background:#23211c;border-radius:6px;place-items:center;display:grid}.lesson .sb-team{display:flex}.lesson .sb-team .av{margin-left:-6px;box-shadow:0 0 0 2px #fff}.lesson .sb-me{background:#f3f2ee;border-radius:999px;gap:4px;padding:3px;display:flex}.lesson .sb-me-btn{color:#6a685f;cursor:pointer;background:0 0;border:0;border-radius:999px;align-items:center;gap:6px;padding:3px 10px 3px 3px;font-size:12.5px;font-weight:600;display:inline-flex}.lesson .sb-me-btn.on{color:#222;background:#fff;box-shadow:0 1px 2px #0000001f}.lesson .av{color:#fff;border-radius:50%;flex:none;place-items:center;width:26px;height:26px;font-size:11.5px;font-weight:800;display:inline-grid}.lesson .av.av-sm{width:20px;height:20px;font-size:10px}.lesson .sb-main{padding:14px 16px 12px}.lesson .sb-head{flex-wrap:wrap;justify-content:space-between;align-items:center;gap:10px;margin-bottom:10px;display:flex}.lesson .sb-h{align-items:center;gap:8px;display:flex}.lesson .sb-h b{letter-spacing:-.01em;font-size:16px}.lesson .sb-count{color:#6a685f;background:#f1f0eb;border-radius:999px;padding:0 8px;font-size:12px;font-weight:700}.lesson .sb-tabs{gap:2px;font-size:12.5px;display:flex}.lesson .sb-tabs span{color:#8a887f;border-radius:6px;padding:3px 10px}.lesson .sb-tabs span.on{color:#fff;background:#23211c;font-weight:600}.lesson .sb-add{border:1px solid #e5e3dc;border-radius:10px;align-items:center;gap:8px;margin-bottom:8px;padding:6px 6px 6px 10px;display:flex}.lesson .sb-add:focus-within{border-color:var(--accent-strong);box-shadow:0 0 0 3px #fbecc0}.lesson .sb-in{min-width:0;font:inherit;background:0 0;border:0;outline:0;flex:1;font-size:14px}.lesson .sb-add-btn{color:#fff;cursor:pointer;background:#23211c;border:0;border-radius:7px;padding:6px 12px;font-size:12.5px;font-weight:700}.lesson .sb-list,.lesson .sec .sb-list{margin:0;padding:0;list-style:none}.lesson .sb-row{border-radius:8px;align-items:center;gap:10px;margin:0;padding:8px 6px;transition:background .15s,opacity .5s;display:flex}.lesson .sb-row+.sb-row{border-top:1px solid #f3f2ee}.lesson .sb-row:hover,.lesson .sb-row.is-hi{background:#fbf7ea}.lesson .sb-row.is-gone{opacity:.2;text-decoration:line-through}.lesson .sb-row:focus-visible{outline:2px solid var(--accent-strong)}.lesson .sb-check{color:#23211c;background:#fff;border:1.5px solid #cfcdc5;border-radius:6px;flex:none;place-items:center;width:20px;height:20px;padding:0;display:grid}.lesson button.sb-check{cursor:pointer}.lesson .sb-check.on{background:var(--accent);border-color:var(--accent-strong)}.lesson .sb-txt{flex:1;min-width:0;display:grid}.lesson .sb-title{font-size:14px;font-weight:600}.lesson .sb-title.done{color:#a9a7a0;font-weight:500;text-decoration:line-through}.lesson .sb-meta{color:#8a887f;align-items:center;gap:5px;margin-top:1px;font-size:12px;display:flex}.lesson .sb-tag{color:#6a685f;background:#f1f0eb;border-radius:4px;padding:0 6px;font-size:11px}.lesson .sb-del{color:#b4b2aa;cursor:pointer;opacity:.6;background:0 0;border:0;border-radius:7px;place-items:center;width:28px;height:28px;display:grid}.lesson .sb-row:hover .sb-del{opacity:1}.lesson .sb-del:hover{color:var(--bad);background:#fcecec}.lesson .sb-empty{text-align:center;color:#aaa9a2;padding:18px 0}.lesson .sb-foot{border-top:1px solid #f3f2ee;flex-wrap:wrap;justify-content:space-between;align-items:center;gap:10px;margin-top:10px;padding-top:10px;display:flex}.lesson .sb-prog{color:#8a887f;align-items:center;gap:8px;font-size:12px;display:flex}.lesson .sb-prog i{background:#efede7;border-radius:3px;width:70px;height:5px;display:block;overflow:hidden}.lesson .sb-prog b{background:var(--accent-strong);height:100%;transition:width .3s;display:block}.lesson .sb-clear{color:#6a685f;cursor:pointer;background:#fff;border:1px solid #e5e3dc;border-radius:7px;padding:4px 10px;font-size:12px}.lesson .sb-clear:hover{border-color:var(--bad);color:var(--bad)}.lesson .sb.compact .sb-main{padding:12px 12px 10px}.lesson .split{grid-template-columns:minmax(0,1fr) minmax(0,1fr);align-items:start;gap:14px;display:grid}.lesson .split-col{gap:8px;min-width:0;display:grid}.lesson .split-cap{color:var(--muted);letter-spacing:.02em;font-size:12px;font-weight:700}.lesson .dbv{background:#fff;border:1px solid #e3e1da;border-radius:10px;font-size:13px;overflow:hidden}.lesson .dbv-bar{background:#f7f6f2;border-bottom:1px solid #e9e7e0;align-items:center;gap:8px;padding:7px 12px;display:flex}.lesson .dbv-ico{color:#3fa37a;display:inline-flex}.lesson .dbv-bar b{font-family:var(--mono);font-size:13px}.lesson .dbv-rows{color:var(--muted);margin-left:auto;font-size:11.5px}.lesson .dbv-scroll{overflow-x:auto}.lesson .dbv-t{border-collapse:collapse;width:100%}.lesson .dbv-t th{text-align:left;white-space:nowrap;background:#fcfbf8;border-bottom:1px solid #ecebe5;border-right:1px solid #f2f1ec;padding:6px 10px;font-weight:600}.lesson .dbv-col{font-family:var(--mono);font-size:12.5px}.lesson .dbv-type{font-family:var(--mono);color:#a3a198;font-size:10.5px;font-weight:400;display:block}.lesson .dbv-key{color:#8a6300;vertical-align:2px;background:#fbefc8;border-radius:3px;margin-left:6px;padding:0 4px;font-size:9.5px;font-weight:800;display:inline-block}.lesson .dbv-key.fk{color:#2f6b52;background:#ddf1e6}.lesson .dbv-t td{font-family:var(--mono);white-space:nowrap;border-bottom:1px solid #f3f2ee;border-right:1px solid #f6f5f1;padding:6px 10px;font-size:12.5px;transition:background .3s,opacity .5s}.lesson .dbv-t td.n{color:#6a685f}.lesson .dbv-t td.b.true{color:var(--good)}.lesson .dbv-t td.b.false{color:#a3a198}.lesson .dbv-t tr.is-hi td{background:#fdf5dc}.lesson .dbv-t tr.is-new td{background:#e7f5ed}.lesson .dbv-t tr.is-gone td{opacity:.25;background:#fcecec}.lesson .dbv-t tr.is-dim td{color:#c9c7bf}.lesson .dbv-t td.is-changed{box-shadow:inset 0 0 0 2px var(--good)}.lesson .dbv-t th.is-hi,.lesson .dbv-t td.col-hi{background-color:#fffaf0}.lesson .dbv-empty td{text-align:center;color:#aaa9a2;padding:14px;font-family:inherit}.lesson .ql{color:#e9e6dc;background:#1f1d19;border-radius:10px;overflow:hidden}.lesson .ql-bar{border-bottom:1px solid #34312a;justify-content:space-between;align-items:center;padding:7px 12px;font-size:12px;display:flex}.lesson .ql-bar b{color:#cfcbbf;font-weight:600}.lesson .ql-live{color:#7fd1a5;align-items:center;gap:5px;font-size:11px;display:inline-flex}.lesson .ql-live:before{content:"";background:#7fd1a5;border-radius:50%;width:6px;height:6px}.lesson .ql-b{gap:4px;min-height:56px;padding:6px;display:grid}.lesson .ql-empty{color:#8d897c;padding:10px 8px;font-size:13px}.lesson .ql-row{border-radius:6px;grid-template-columns:auto auto minmax(0,1fr);align-items:start;gap:8px;padding:6px 8px;display:grid}.lesson .ql-row.is-new{background:#2d2a23;animation:.3s rise}.lesson .ql-row.is-bad{background:#4a2424}.lesson .ql-row time{font-family:var(--mono);color:#8d897c;padding-top:2px;font-size:11px}.lesson .ql-badge{font-family:var(--mono);border-radius:4px;margin-top:1px;padding:1px 6px;font-size:10.5px;font-weight:800}.lesson .ql-badge.insert{color:#8fe3b5;background:#1f4a33}.lesson .ql-badge.update{color:#f6ce60;background:#4d3c12}.lesson .ql-badge.delete{color:#ff9f9f;background:#5a2323}.lesson .ql-badge.select{color:#9cc2ff;background:#1e3557}.lesson .ql-main code{color:#ece9df;white-space:pre-wrap;word-break:normal;overflow-wrap:anywhere;background:0 0;padding:0;font-size:12.5px;display:block}.lesson .ql-main small{color:#a8a497;font-size:11.5px}.lesson .ql-row.is-bad small{color:#ffb3b3}.lesson .ql .w-sql-kw{color:#f6ce60}.lesson .bw.with-dt .bw-page{background:#fff}.lesson .dt-page-hint{color:var(--muted);background:#fbfaf7;border-bottom:1px solid #ebe9e3;padding:6px 12px;font-size:12px}.lesson .devtools{color:#303030;background:#fff;font-size:12.5px}.lesson .dt-tabs{background:#f1f3f4;border-bottom:1px solid #dadce0;gap:0;padding:0 6px;display:flex;overflow-x:auto}.lesson .dt-tabs span{color:#5f6368;white-space:nowrap;padding:6px 10px;font-size:12px}.lesson .dt-tabs span.on{color:#1a73e8;background:#fff;box-shadow:inset 0 -2px #1a73e8}.lesson .dt-search{color:#5f6368;background:#fff;border-bottom:1px solid #e8eaed;align-items:center;gap:8px;padding:5px 10px;font-size:12px;display:flex}.lesson .dt-search code{color:#202124;background:#fff;border:1px solid #c4c7c5;border-radius:3px;padding:0 6px}.lesson .dt-search em{color:#1a73e8;font-style:normal}.lesson .dt-body{grid-template-columns:190px minmax(0,1fr);min-height:180px;display:grid}.lesson .dt-tree{border-right:1px solid #e8eaed;padding:6px 0;font-size:12px}.lesson .dt-node{color:#3c4043;white-space:nowrap;align-items:center;gap:6px;padding:3px 10px;display:flex}.lesson .dt-node.l1{padding-left:22px}.lesson .dt-node.l2{padding-left:36px}.lesson .dt-node.on{color:#174ea6;background:#e8f0fe}.lesson .dt-node svg{color:#80868b;flex:none}.lesson .dt-editor{min-width:0}.lesson .dt-file-tab{background:#fff;border-bottom:2px solid #1a73e8;padding:4px 12px;font-size:12px;display:inline-block}.lesson .dt-code{font-family:var(--mono);border-top:1px solid #e8eaed;padding:6px 0;font-size:12px;overflow-x:auto}.lesson .dt-line{white-space:pre;gap:12px;padding:1px 10px;display:flex}.lesson .dt-no{color:#9aa0a6;text-align:right;flex:none;width:16px}.lesson .dt-line.cm .dt-src{color:#188038}.lesson .dt-src .k{color:#a142f4}.lesson .dt-src .s{color:#c5221f}.lesson .dt-src mark{color:inherit;background:#fde293;border-radius:2px}.lesson .dt-line.hl{box-shadow:inset 3px 0 0 var(--bad);background:#fce8e6}.lesson .dt-line.ok{background:#e6f4ea}.lesson .env{border:1px solid #e3e1da;border-radius:10px;margin-top:10px;overflow:hidden}.lesson .env-h{background:#f7f6f2;align-items:center;gap:8px;padding:7px 12px;font-size:12.5px;display:flex}.lesson .env-h b{font-family:var(--mono)}.lesson .env-tag{color:var(--good);margin-left:auto;font-size:11.5px}.lesson .env-b{font-family:var(--mono);background:#fff;margin:0;padding:10px 12px;font-size:12.5px;overflow-x:auto}.lesson .pol{background:#fff;border:1px solid #e3e1da;border-radius:10px;overflow:hidden}.lesson .pol-h{background:#f7f6f2;border-bottom:1px solid #e9e7e0;align-items:center;gap:8px;padding:8px 12px;font-size:13px;display:flex}.lesson .pol-h b{font-family:var(--mono)}.lesson .pol-sub{color:var(--muted);margin-left:auto;font-size:12px}.lesson .pol-row{cursor:pointer;border-bottom:1px solid #f1efe9;justify-content:space-between;align-items:center;gap:12px;padding:12px;display:flex}.lesson .pol-row b{font-size:14px;display:block}.lesson .pol-row small{color:var(--muted);font-size:12.5px}.lesson .pol-rule{padding:10px 12px 12px;font-size:13px}.lesson .pol-rule small{color:var(--muted);margin-bottom:2px;font-size:11.5px;display:block}.lesson .pol-rule.off{opacity:.4}.lesson .devtools.net{border:1px solid #dadce0;border-radius:10px;overflow:hidden}.lesson .net-req{border-bottom:1px solid #e8eaed;align-items:center;gap:8px;padding:7px 10px;display:flex}.lesson .net-m{font-family:var(--mono);color:#1a73e8;font-size:11px;font-weight:700}.lesson .net-req code{background:0 0;padding:0;font-size:12px}.lesson .net-s{font-family:var(--mono);color:var(--good);margin-left:auto;font-size:11.5px}.lesson .net-sub{color:#5f6368;background:#f8f9fa;border-bottom:1px solid #e8eaed;padding:5px 10px;font-size:11.5px}.lesson .net-body{font-family:var(--mono);color:#202124;max-height:220px;margin:0;padding:10px 12px;font-size:11.5px;line-height:1.5;overflow:auto}.lesson .ai{background:#fff;border:1px solid #dcdad3;border-radius:14px;overflow:hidden}.lesson .ai-top{border-bottom:1px solid #eeece6;justify-content:space-between;align-items:center;padding:9px 14px;font-size:13px;display:flex}.lesson .ai-top span{font-family:var(--mono);color:var(--muted);font-size:12px}.lesson .ai-thread{background:#fbfaf7;gap:10px;min-height:150px;padding:14px;display:grid}.lesson .ai-empty{color:var(--muted);text-align:center;align-self:center;font-size:14px}.lesson .ai-msg{align-items:flex-start;gap:8px;display:flex}.lesson .ai-msg.me{justify-content:flex-end}.lesson .ai-av{width:26px;height:26px;color:var(--accent);background:#23211c;border-radius:8px;flex:none;place-items:center;font-size:10.5px;font-weight:800;display:grid}.lesson .ai-bubble{background:#fff;border:1px solid #eceae3;border-radius:12px;max-width:85%;padding:10px 13px;font-size:14px;line-height:1.6}.lesson .ai-bubble p{margin:0}.lesson .ai-bubble p+p{margin-top:2px}.lesson .ai-msg.me .ai-bubble{background:#f1efe8;border-color:#e6e3da}.lesson .ai-bubble.typing{gap:4px;padding:13px 14px;display:inline-flex}.lesson .ai-bubble.typing i{background:#b9b6ac;border-radius:50%;width:6px;height:6px;animation:1s infinite blink}.lesson .ai-bubble.typing i:nth-child(2){animation-delay:.15s}.lesson .ai-bubble.typing i:nth-child(3){animation-delay:.3s}.lesson .ai-comp{border-top:1px solid #eeece6;padding:10px 12px 12px}.lesson .ai-text{min-height:48px;padding:4px 2px 10px;font-size:14px;line-height:1.6}.lesson .ai-comp-f{align-items:flex-end;gap:10px;display:flex}.lesson .ai-chips{flex-wrap:wrap;flex:1;gap:6px;display:flex}.lesson .ai-chip{color:#55534c;cursor:pointer;background:#fff;border:1px dashed #cfcdc5;border-radius:999px;padding:4px 11px;font-size:12.5px}.lesson .ai-chip.on{border-style:solid;border-color:var(--accent-strong);background:var(--accent-soft);color:var(--text);font-weight:600}.lesson .ai-send{color:#fff;cursor:pointer;background:#23211c;border:0;border-radius:10px;flex:none;place-items:center;width:34px;height:34px;display:grid}.lesson .ai-send:disabled{opacity:.4}.lesson .msgr{background:#b9cfe0;border:1px solid #dcdad3;border-radius:18px;max-width:420px;margin:0 auto;overflow:hidden}.lesson .msgr-h{background:#ffffff8c;align-items:center;gap:10px;padding:11px 14px;font-size:14px;display:flex}.lesson .msgr-n{color:#55606b;font-size:13px}.lesson .msgr-b{max-height:440px;padding:6px 12px 14px;overflow-y:auto}.lesson .msgr-day{text-align:center;color:#fff;margin:12px 0 6px;font-size:11.5px}.lesson .msgr-day:before{content:none}.lesson .msgr-row{align-items:flex-start;gap:8px;margin-top:8px;display:flex}.lesson .msgr-row.cont{margin-top:3px;padding-left:34px}.lesson .msgr-row.me{justify-content:flex-end}.lesson .msgr-row.me.cont{padding-left:0}.lesson .msgr-row .av{width:26px;height:26px}.lesson .msgr-col{gap:2px;min-width:0;display:grid}.lesson .msgr-who{color:#3d4852;font-size:12px}.lesson .msgr-line{align-items:flex-end;gap:5px;display:flex}.lesson .msgr-row.me .msgr-line{flex-direction:row-reverse}.lesson .msgr-bub{color:#222;background:#fff;border-radius:14px;max-width:260px;padding:7px 11px;font-size:14px;line-height:1.5;display:inline-block}.lesson .msgr-row.me .msgr-bub{background:#fbe56a}.lesson .msgr-line time{color:#4f5b66;white-space:nowrap;font-size:10.5px}.lesson .msgr-row.is-new{animation:.3s rise}@media (max-width:760px){.lesson .split,.lesson .dt-body{grid-template-columns:1fr}.lesson .dt-tree,.lesson .sb-tabs{display:none}}.lesson .page{max-width:860px;margin:0 auto;padding:40px 32px 96px}.lesson .next-card{border:1px solid var(--line);cursor:pointer;text-align:left;background:#fff;border-radius:12px;justify-content:space-between;align-items:center;gap:16px;width:100%;margin:36px 0 0;padding:18px 22px;transition:border-color .15s,background .15s;display:flex}.lesson .next-card:hover{border-color:var(--accent-strong);background:var(--accent-soft)}.lesson .next-card small{color:var(--muted);font-size:13px;display:block}.lesson .next-card b{font-size:17px}.lesson .next-card .arrow{background:var(--accent);width:40px;height:40px;color:var(--on-accent);box-shadow:0 3px 0 var(--accent-deep);border-radius:50%;flex:none;place-items:center;display:grid}.lesson .next-card.topic{background:var(--accent-soft);border-color:var(--accent-strong)}.lesson .prev-link{color:var(--muted);cursor:pointer;background:0 0;border:0;margin-top:14px;padding:4px 0;font-size:14.5px;display:inline-block}.lesson .prev-link:hover{color:var(--text);text-decoration:underline}.lesson .quiz{max-width:720px;margin:0 auto}.lesson .dev-topic+.dev-topic{border-top:2px dashed var(--line);margin-top:96px;padding-top:48px}.lesson .dev-q+.dev-q{margin-top:20px}.lesson .sec{scroll-margin-top:120px}.lesson .dev-dock{z-index:30;align-items:center;gap:8px;display:flex;position:fixed;bottom:16px;right:16px}.lesson .dev-toggle{color:#ece9df;cursor:pointer;background:#23211c;border:0;border-radius:10px;align-items:center;gap:8px;padding:7px 10px 7px 8px;font-size:13px;font-weight:600;line-height:1.4;display:inline-flex;box-shadow:0 4px 14px #0000002e}.lesson .dev-toggle:hover{background:#2f2c25}.lesson .dev-toggle:focus-visible{outline:3px solid var(--accent-strong);outline-offset:2px}.lesson .dev-toggle-k{color:var(--accent);font-family:var(--mono);background:#3a362d;border-radius:5px;padding:1px 6px;font-size:11px;font-weight:700}.lesson .dev-toggle-sw{background:#5a564c;border-radius:9px;width:30px;height:18px;transition:background .2s;position:relative}.lesson .dev-toggle-sw:after{content:"";background:#fff;border-radius:50%;width:14px;height:14px;transition:left .2s;position:absolute;top:2px;left:2px}.lesson .dev-toggle[aria-checked=true] .dev-toggle-sw{background:var(--accent-strong)}.lesson .dev-toggle[aria-checked=true] .dev-toggle-sw:after{left:14px}@media (max-width:720px){.lesson .page{padding:24px 16px 72px}}.lesson .lcode{background:#0d1117;border:1px solid #30363d;border-radius:10px;margin:0 0 18px;overflow:hidden}.lesson .lab .lcode{margin:0}.lesson .lcode-h{color:#8b949e;background:#161b22;border-bottom:1px solid #30363d;justify-content:space-between;align-items:center;gap:12px;padding:7px 10px 7px 14px;font-family:ui-monospace,SF Mono,Menlo,Consolas,Apple SD Gothic Neo,Pretendard,Malgun Gothic,sans-serif;font-size:12px;display:flex}.lesson .lcode-copy{color:#8b949e;font-family:var(--mono);cursor:pointer;background:#0d1117;border:1px solid #30363d;border-radius:6px;padding:1px 10px;font-size:11.5px}.lesson .lcode-copy:hover{color:#e6edf3;border-color:#6e7681}.lesson .lcode-copy.done{color:#f6ce60;border-color:#9e7a1e}.lesson .lcode-copy:focus-visible{outline:3px solid var(--accent-strong);outline-offset:2px}.lesson .lcode pre{margin:0;padding:12px 16px;font-family:ui-monospace,SF Mono,Menlo,Consolas,Apple SD Gothic Neo,Pretendard,Malgun Gothic,sans-serif;font-size:14px;line-height:1.65;overflow-x:auto;background:0 0!important}.lesson .lcode pre code{font-family:inherit;font-size:inherit;color:inherit;white-space:pre;background:0 0;padding:0}.lesson .figseq{border:1px solid var(--line);background:#fff;border-radius:12px;display:grid;overflow:hidden}.lesson .figseq img{opacity:0;animation:figseq calc(var(--n)*1.2s)infinite;animation-delay:calc(var(--i)*1.2s);border:0;border-radius:0;grid-area:1/1}@keyframes figseq{0%{opacity:0}4%{opacity:1}25%{opacity:1}29%{opacity:0}to{opacity:0}}@media (prefers-reduced-motion:reduce){.lesson .figseq{background:var(--line);grid-template-columns:1fr 1fr;gap:1px}.lesson .figseq img{opacity:1;background:#fff;grid-area:auto;animation:none}}.lesson .dev-blog{position:relative}.lesson .dev-btn{color:#ece9df;cursor:pointer;background:#23211c;border:0;border-radius:10px;padding:8px 12px;font-size:13px;font-weight:600;line-height:1.4;box-shadow:0 4px 14px #0000002e}.lesson .dev-btn:hover{background:#2f2c25}.lesson .dev-btn:disabled{opacity:.45;cursor:default}.lesson .dev-btn.primary{background:var(--accent-strong);color:#23211c}.lesson .dev-btn:focus-visible{outline:3px solid var(--accent-strong);outline-offset:2px}.lesson .dev-pop{color:#ece9df;background:#23211c;border-radius:12px;width:min(340px,100vw - 32px);padding:14px;font-size:13.5px;position:absolute;bottom:calc(100% + 10px);right:0;box-shadow:0 10px 30px #00000047}.lesson .dev-pop-h{color:var(--accent);margin:0 0 10px;font-weight:700}.lesson .dev-pop label{gap:4px;margin-bottom:10px;display:grid}.lesson .dev-pop label span{color:#a8a497;font-size:12px}.lesson .dev-pop select{color:#ece9df;background:#2f2c25;border:1px solid #4a463c;border-radius:8px;width:100%;padding:6px 8px;font-size:13.5px}.lesson .dev-pop-st{color:#e3a19a;margin:0 0 10px;font-size:12.5px}.lesson .dev-pop-st.ok{color:#a8d89a}.lesson .dev-pop-row{gap:8px;display:flex}.lesson .dev-pop-row .dev-btn{box-shadow:none;background:#3a362d}.lesson .dev-pop-row .dev-btn.primary{background:var(--accent-strong);color:#23211c}.lesson .dev-pop-msg{color:#d8d4c8;margin:10px 0 0;font-size:12.5px;line-height:1.6}.lesson .dev-pop-msg.ok{color:#a8d89a}.lesson .dev-pop-msg.err{color:#e3a19a}.lesson.lesson-embed{background:0 0;min-height:0;margin:32px 0;font-size:16px;line-height:1.7}.lesson.lesson-embed .lab{background:#fff;margin:0}.lesson.lesson-embed .lesson-fig{margin:0}.lesson.lesson-embed .lab-h b{white-space:nowrap}