@font-face{font-family:DM Sans;font-style:normal;font-display:swap;font-weight:400;src:url(/assets/dm-sans-latin-400-normal-CW0RaeGs.woff2) format("woff2"),url(/assets/dm-sans-latin-400-normal-BwCSEQnW.woff) format("woff")}@font-face{font-family:DM Sans;font-style:normal;font-display:swap;font-weight:500;src:url(/assets/dm-sans-latin-500-normal-B9HHJjqV.woff2) format("woff2"),url(/assets/dm-sans-latin-500-normal-Dr3UlScf.woff) format("woff")}@font-face{font-family:DM Sans;font-style:normal;font-display:swap;font-weight:600;src:url(/assets/dm-sans-latin-600-normal-Aqo67rzb.woff2) format("woff2"),url(/assets/dm-sans-latin-600-normal-BmdmIIQ2.woff) format("woff")}@font-face{font-family:DM Sans;font-style:normal;font-display:swap;font-weight:700;src:url(/assets/dm-sans-latin-700-normal-DvUfVpUG.woff2) format("woff2"),url(/assets/dm-sans-latin-700-normal-CUSSCpQX.woff) format("woff")}@font-face{font-family:IBM Plex Mono;font-style:normal;font-display:swap;font-weight:400;src:url(/assets/ibm-plex-mono-latin-400-normal-DMJ8VG8y.woff2) format("woff2"),url(/assets/ibm-plex-mono-latin-400-normal-CvHOgSBP.woff) format("woff")}@font-face{font-family:IBM Plex Mono;font-style:normal;font-display:swap;font-weight:500;src:url(/assets/ibm-plex-mono-latin-500-normal-DSY6xOcd.woff2) format("woff2"),url(/assets/ibm-plex-mono-latin-500-normal-CB9ihrfo.woff) format("woff")}@font-face{font-family:IBM Plex Mono;font-style:normal;font-display:swap;font-weight:600;src:url(/assets/ibm-plex-mono-latin-600-normal-BgSNZQsw.woff2) format("woff2"),url(/assets/ibm-plex-mono-latin-600-normal-DWFSQ4vo.woff) format("woff")}.qlab{--qlab-ink: #17313b;--qlab-muted: #526670;--qlab-line: #c9d9da;--qlab-accent: #087b72;--qlab-paper: #f7fbfa;color:var(--qlab-ink);display:grid;gap:1.2rem;max-width:940px;padding:clamp(1rem,3vw,2rem);background:var(--qlab-paper);border:1px solid var(--qlab-line);border-radius:20px;font-family:ui-sans-serif,system-ui,sans-serif;line-height:1.45}.qlab h2,.qlab h3,.qlab p{margin:0}.qlab h2{font-size:clamp(1.35rem,3vw,2rem);letter-spacing:-.035em}.qlab h3{font-size:1.07rem}.qlab small,.qlab .qlab-muted{color:var(--qlab-muted)}.qlab-head{display:flex;justify-content:space-between;gap:1rem;align-items:start}.qlab-kicker{color:var(--qlab-accent);font-weight:800;font-size:.73rem;letter-spacing:.12em;text-transform:uppercase}.qlab-tools{display:flex;gap:.4rem;flex-wrap:wrap}.qlab button,.qlab select,.qlab input{font:inherit}.qlab button{background:#fff;border:1px solid var(--qlab-line);border-radius:9px;color:var(--qlab-ink);padding:.48rem .73rem;cursor:pointer}.qlab button:hover:not(:disabled),.qlab button:focus-visible{border-color:var(--qlab-accent);outline-color:var(--qlab-accent)}.qlab button:disabled{opacity:.48;cursor:not-allowed}.qlab .qlab-primary{background:var(--qlab-accent);border-color:var(--qlab-accent);color:#fff;font-weight:700}.qlab-card{background:#fff;border:1px solid var(--qlab-line);border-radius:14px;padding:clamp(.9rem,2vw,1.3rem);display:grid;gap:.85rem}.qlab-data{overflow-x:auto}.qlab table{border-collapse:collapse;width:max-content;min-width:min(100%,490px);font-variant-numeric:tabular-nums}.qlab th,.qlab td{border-bottom:1px solid #e4eded;text-align:center;padding:.4rem .65rem;white-space:nowrap}.qlab th:first-child,.qlab td:first-child{text-align:left;font-weight:700}.qlab th{color:var(--qlab-muted);font-size:.82rem}.qlab input,.qlab select{width:5.7rem;min-height:2.2rem;border:1px solid var(--qlab-line);border-radius:8px;padding:.25rem .4rem;background:#fff;color:var(--qlab-ink)}.qlab input:focus,.qlab select:focus{outline:2px solid var(--qlab-accent);outline-offset:1px}.qlab-field{display:inline-grid;gap:.22rem;font-size:.84rem;color:var(--qlab-muted);font-weight:700}.qlab-fields,.qlab-choices,.qlab-actions{display:flex;gap:.65rem;flex-wrap:wrap;align-items:end}.qlab-choices button{min-width:4.4rem;font-weight:700}.qlab-track{display:flex;flex-wrap:wrap;gap:.24rem;align-items:stretch}.qlab-slot{min-width:3.6rem;min-height:3.3rem;padding:.35rem .3rem;border:1px dashed #b2c8ca;border-radius:9px;display:grid;place-content:center;text-align:center;font-variant-numeric:tabular-nums;background:#f8fbfa}.qlab-slot strong{font-size:.96rem}.qlab-slot small{font-size:.67rem}.qlab-slot.filled{background:#e4f4f0;border-style:solid;border-color:#9ed0c6}.qlab-slot.current{border:2px solid var(--qlab-accent);background:#fff}.qlab-slot.overhead{background:#f4edf7;border-color:#d5c1df}.qlab-status{border-left:4px solid var(--qlab-accent);padding:.58rem .8rem;background:#e9f5f2;border-radius:5px;min-height:2.3rem}.qlab-status.error{border-color:#b65542;background:#fcf0ec}.qlab-hints{display:grid;justify-items:start;gap:.5rem}.qlab-hint{background:#f0f6f4;border:1px solid #d7e9e3;border-radius:9px;padding:.55rem .7rem}.qlab-done{font-weight:700;color:#075f55}.qlab-bitstrip{display:flex;width:fit-content;max-width:100%;font-family:ui-monospace,SFMono-Regular,Menlo,monospace;font-weight:700}.qlab-bitstrip span{border:1px solid #a7c9c5;padding:.5rem;background:#e6f5f2}.qlab-bitstrip span+span{border-left:0;background:#f2ebfa;border-color:#c8b7d9}.qlab-address{display:grid;gap:.7rem;padding:.8rem 0;border-top:1px solid #e0ebea}.qlab-address:first-of-type{border-top:0}.qlab-address h4{margin:0;font:700 1rem ui-monospace,monospace}.qlab-address .qlab-field input{width:6.7rem}.qlab-path{display:flex;align-items:center;gap:.4rem;flex-wrap:wrap}.qlab-path span{padding:.35rem .5rem;border:1px solid var(--qlab-line);border-radius:7px;background:#fff}.qlab-path b{color:var(--qlab-accent)}@media(max-width:600px){.qlab{min-width:0;padding:14px;gap:16px;font-size:15px}.qlab-head{display:grid;gap:10px}.qlab-head h2{font-size:22px}.qlab-card{min-width:0;padding:14px;gap:14px}.qlab button{min-height:46px;padding:10px 13px;font-size:15px;touch-action:manipulation}.qlab-tools button{min-width:74px}.qlab-choices{display:grid;grid-template-columns:repeat(auto-fit,minmax(90px,1fr));gap:8px}.qlab-choices button{min-width:0}.qlab-fields{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:12px;align-items:stretch}.qlab-field{min-width:0;font-size:13px}.qlab input,.qlab select,.qlab-address .qlab-field input{width:100%;min-width:0;min-height:46px;font-size:16px}.qlab-fields>button{grid-column:1 / -1}.qlab-track{position:relative;flex-wrap:nowrap;overflow-x:auto;max-width:100%;padding:4px 0 9px;overscroll-behavior-x:contain;scrollbar-width:thin}.qlab-slot{flex:0 0 52px;min-height:58px}.qlab-data{max-width:100%;overscroll-behavior-x:contain}.qlab-data:not(.qlab-mobile-cards){border-right:2px solid #a8c4c1}.qlab th,.qlab td{padding:9px 10px}.qlab-path{gap:7px}.qlab-path span{font-size:13px}.qlab-bitstrip{font-size:13px;overflow-x:auto}.qlab-bitstrip span{min-width:0;overflow-wrap:anywhere}.qlab-mobile-cards{overflow:visible}.qlab-mobile-cards table,.qlab-mobile-cards tbody{display:block;width:100%;min-width:0}.qlab-mobile-cards thead{display:none}.qlab-mobile-cards tr{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:0 12px;border:1px solid var(--qlab-line);border-radius:8px;padding:8px 12px 12px;margin-bottom:10px}.qlab-mobile-cards td{display:grid;gap:3px;min-width:0;padding:7px 0;text-align:left;white-space:normal;border-bottom:1px solid #e4eded;font-variant-numeric:tabular-nums}.qlab-mobile-cards td:before{content:attr(data-label);color:var(--qlab-muted);font-size:11px;font-weight:600}.qlab-mobile-cards td:first-child{grid-column:1 / -1;font-size:16px;border-bottom-color:var(--qlab-line)}.qlab-mobile-cards td:last-child{border-bottom:0}.qlab-mobile-cards input{width:100%;min-width:0}}@media(pointer:coarse)and (min-width:601px){.qlab button,.qlab input,.qlab select{min-height:46px;touch-action:manipulation}.qlab input,.qlab select{font-size:16px}}.slab{--sl-ink: #172434;--sl-sub: #536478;--sl-line: #c6d2df;--sl-blue: #235b96;--sl-light: #eef4fa;color:var(--sl-ink);background:#fbfcfd;border:1px solid var(--sl-line);border-radius:16px;padding:clamp(1rem,3vw,1.8rem);display:grid;gap:1rem;max-width:980px;font:400 1rem/1.5 ui-sans-serif,system-ui,sans-serif}.slab *{box-sizing:border-box}.slab h2,.slab h3,.slab p{margin:0}.slab h2{font-size:clamp(1.45rem,3vw,2.1rem);letter-spacing:-.035em;line-height:1.1}.slab h3{font-size:1.05rem}.slab-head{display:flex;align-items:start;justify-content:space-between;gap:1rem}.slab-kicker{color:var(--sl-blue);font-size:.73rem;font-weight:800;letter-spacing:.12em;text-transform:uppercase;margin-bottom:.25rem}.slab-tools,.slab-actions{display:flex;flex-wrap:wrap;gap:.5rem}.slab button,.slab input{font:inherit}.slab button{cursor:pointer;padding:.48rem .72rem;color:var(--sl-ink);border:1px solid var(--sl-line);border-radius:8px;background:#fff}.slab button:hover:not(:disabled){border-color:var(--sl-blue);background:var(--sl-light)}.slab button:focus-visible,.slab input:focus-visible{outline:2px solid var(--sl-blue);outline-offset:2px}.slab button:disabled{opacity:.5;cursor:not-allowed}.slab .slab-primary{background:var(--sl-blue);color:#fff;border-color:var(--sl-blue);font-weight:700}.slab .slab-primary:hover:not(:disabled){background:#164a80;color:#fff}.slab-panel{background:#fff;border:1px solid var(--sl-line);border-radius:12px;padding:1rem;display:grid;gap:.85rem}.slab-muted{color:var(--sl-sub)}.slab-code{font:500 .88rem/1.5 ui-monospace,SFMono-Regular,Menlo,Consolas,monospace;white-space:pre-wrap;background:#172434;color:#eff5fc;padding:.8rem 1rem;border-radius:9px;overflow-x:auto}.slab-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(165px,1fr));gap:.7rem}.slab-tile{background:#f5f8fb;border:1px solid #dce5ee;border-radius:9px;padding:.65rem .75rem;display:grid;gap:.3rem}.slab-tile strong{font-size:.88rem}.slab-tile small{color:var(--sl-sub)}.slab-input{display:grid;gap:.25rem;font-weight:650;font-size:.86rem}.slab-input input{width:min(100%,10rem);min-height:2.3rem;border:1px solid var(--sl-line);border-radius:7px;padding:.25rem .45rem;color:var(--sl-ink);background:#fff}.slab-feedback{border-left:4px solid #23755f;background:#eaf6f0;padding:.6rem .8rem;border-radius:5px}.slab-feedback.error{border-color:#b4563d;background:#fbefeb}.slab-hints{display:grid;justify-items:start;gap:.45rem}.slab-hints p{border:1px solid #dce5ee;border-radius:7px;padding:.5rem .65rem;background:var(--sl-light)}.slab-done{color:#146c55;font-weight:750}.slab-chain{display:flex;gap:.45rem;flex-wrap:wrap;align-items:center}.slab-chain span{border:1px solid var(--sl-line);background:#f8fafc;padding:.4rem .6rem;border-radius:8px}.slab-log{margin:0;padding-left:1.4rem;display:grid;gap:.15rem;font:.83rem/1.4 ui-monospace,SFMono-Regular,Menlo,Consolas,monospace}.slab-progress{color:var(--sl-sub);font-size:.82rem;font-weight:700}.slab-memory{display:grid;grid-template-columns:repeat(32,minmax(24px,1fr));min-width:768px;min-height:90px;gap:3px}.slab-memory-wrap{overflow-x:auto;padding-bottom:.3rem}.slab-memory-mobile{display:none}.slab .slab-mobile-block{display:grid;grid-template-columns:minmax(0,1fr) auto;align-items:center;gap:5px 10px;width:100%;min-height:68px;text-align:left;padding:9px 12px;border:2px solid #b9c8d7;background:#f5f8fb}.slab .slab-mobile-block.allocated{border-color:#345b83;background:#e7eff6}.slab .slab-mobile-block.buddy{border-color:#c57838;background:#fff0d9}.slab-mobile-info{display:grid;line-height:1.25}.slab-mobile-info strong{font-size:14px}.slab-mobile-info small{color:var(--sl-sub);font-size:11px}.slab-mobile-size{font:700 14px ui-monospace,monospace}.slab-mobile-bar{grid-column:1 / -1;height:5px;background:#e0e8ee}.slab-mobile-bar i{display:block;height:100%;background:#5380aa}.slab-mobile-block.allocated .slab-mobile-bar i{background:#345b83}.slab-mobile-block.buddy .slab-mobile-bar i{background:#c57838}.slab .slab-block{min-width:0;padding:.35rem .18rem;display:grid;align-content:center;text-align:center;line-height:1.25;border:2px solid #b9c8d7;background:#edf3f8}.slab .slab-block.allocated{color:#fff;background:#345b83;border-color:#345b83}.slab .slab-block.buddy{border-color:#c57838;background:#fff0d9}.slab .slab-block small{font-size:.64rem}.slab-marking{display:flex;gap:.5rem;flex-wrap:wrap}.slab-place{border:2px solid #9bb5cf;width:6.7rem;min-height:6.7rem;border-radius:50%;display:grid;place-content:center;text-align:center;background:#f2f7fb;padding:.4rem}.slab-place strong{font-size:.8rem}.slab-place b{font-size:1.3rem;color:#174e86}.slab-place.empty{border-style:dashed;color:#77889b}.slab-process{display:flex;gap:.45rem;flex-wrap:wrap}.slab-process>div{flex:1 1 180px;border:1px solid var(--sl-line);border-radius:8px;padding:.6rem;background:#f7f9fc}.slab-process .active{border-color:#2d7b92;background:#eaf7f8}.slab-columns{display:grid;grid-template-columns:repeat(auto-fit,minmax(220px,1fr));gap:.8rem}@media(max-width:600px){.slab{min-width:0;padding:14px;gap:16px;font-size:15px}.slab-head{display:grid;gap:10px}.slab h2{font-size:22px}.slab-panel{min-width:0;padding:14px;gap:14px}.slab button{min-height:46px;padding:10px 12px;font-size:15px;touch-action:manipulation}.slab-tools button{min-width:74px}.slab-actions{display:grid;grid-template-columns:repeat(auto-fit,minmax(130px,1fr));gap:8px}.slab-actions button{min-width:0}.slab-input input{width:100%;min-height:46px;font-size:16px}.slab-grid{grid-template-columns:repeat(auto-fit,minmax(min(100%,160px),1fr))}.slab-columns{grid-template-columns:1fr}.slab-chain{gap:6px}.slab-chain span{font-size:13px;overflow-wrap:anywhere}.slab-code{font-size:12px;line-height:1.6}.slab-place{width:calc(25% - 6px);min-width:0;min-height:72px;border-radius:9px;padding:5px 2px}.slab-place strong{font-size:11px}.slab-place b{font-size:18px}.slab-marking{gap:8px}.slab-memory-wrap{display:none}.slab-memory-mobile{display:grid;gap:8px}}@media(pointer:coarse)and (min-width:601px){.slab button,.slab-input input{min-height:46px;touch-action:manipulation}.slab-input input{font-size:16px}.slab-memory-wrap{display:none}.slab-memory-mobile{display:grid;grid-template-columns:repeat(auto-fit,minmax(190px,1fr));gap:8px}}:root{font-family:DM Sans,ui-sans-serif,system-ui,sans-serif;color:#202a30;background:#f3f2ec;font-synthesis:none}*{box-sizing:border-box}html{scroll-behavior:smooth}body{margin:0;min-width:320px}button,input,select,textarea{font:inherit}button{cursor:pointer}button:disabled{cursor:not-allowed}a{color:inherit}:focus-visible{outline:3px solid #0a7777;outline-offset:3px}::selection{background:#c7e6e2}.app-shell{min-height:100vh}.site-head{height:75px;padding:0 clamp(20px,3.2vw,52px);border-bottom:1px solid #cfd3ce;background:#f7f6f1;display:flex;align-items:center;gap:30px;position:relative;z-index:3}.brand{display:flex;align-items:center;gap:13px;min-width:290px}.brand-mark{width:37px;height:37px;background:#202a30;color:#e7e3d8;display:grid;place-items:center;font:600 11px IBM Plex Mono,monospace;letter-spacing:-.06em}.brand-mark span{color:#61b9b5}.brand strong{display:block;font-size:17px;line-height:1.12;letter-spacing:-.035em}.brand small{display:block;margin-top:3px;color:#68737a;font-size:11px;letter-spacing:.025em}.head-progress{margin-left:auto;width:min(240px,24vw);font:500 11px IBM Plex Mono,monospace;color:#68737a;text-transform:uppercase}.progress-track{height:3px;background:#d9ddda;margin-top:8px}.progress-track i{display:block;height:100%;background:#0a7777}.continue{text-decoration:none;border:1px solid #202a30;padding:10px 14px;font-size:12px;font-weight:700;white-space:nowrap;transition:background .15s,color .15s}.continue:hover{background:#202a30;color:#fff}.continue span{margin-left:8px}.app-grid{display:grid;grid-template-columns:270px minmax(0,1fr);max-width:1680px;margin:auto;min-height:calc(100vh - 75px)}.chapter-rail{border-right:1px solid #cfd3ce;background:#eaece6;padding:31px 0 20px;display:flex;flex-direction:column}.rail-title{padding:0 24px 19px;color:#697477;display:flex;justify-content:space-between;font:600 10px IBM Plex Mono,monospace;letter-spacing:.13em}.rail-title span{color:#9ba5a3}.chapter-list{display:grid}.chapter-picker{display:none}.chapter-tab{min-height:74px;display:flex;align-items:center;text-decoration:none;gap:14px;padding:14px 20px 14px 24px;border-top:1px solid #d6dcd5;position:relative}.chapter-tab:last-child{border-bottom:1px solid #d6dcd5}.chapter-tab:hover{background:#f4f6ef}.chapter-tab.active{background:#f3f2ec}.chapter-tab.active:before{content:"";width:4px;position:absolute;left:0;top:0;bottom:0;background:#0a7777}.chapter-code{color:#75817e;align-self:flex-start;margin-top:3px;font:600 11px IBM Plex Mono,monospace}.chapter-tab.active .chapter-code{color:#0a7777}.chapter-tab-main{min-width:0;flex:1}.chapter-tab-main strong{display:block;font-size:13px;line-height:1.25;letter-spacing:-.015em}.chapter-tab-main small{display:block;color:#77837f;margin-top:5px;font:10px IBM Plex Mono,monospace}.tab-arrow{color:#899591;font-size:15px}.rail-end{margin-top:auto;display:flex;align-items:center;gap:5px;padding:30px 24px 0;color:#78837e;font:9px IBM Plex Mono,monospace;letter-spacing:.055em}.signal-dot{display:inline-block;width:6px;height:6px;background:#0a7777;margin-right:3px}.page-main{min-width:0}.map-page{max-width:1060px;margin:0 auto;padding:clamp(30px,5vw,72px) clamp(22px,5vw,74px) 90px}.map-kicker{font:600 11px IBM Plex Mono,monospace;letter-spacing:.12em;color:#0a7777;display:flex;align-items:center;gap:13px}.map-kicker .line{width:28px;height:1px;background:#aab9b4}h1,h2,p{margin-top:0}.map-page h1{margin:20px 0 12px;font-size:clamp(42px,5vw,69px);line-height:1.02;letter-spacing:-.065em;font-weight:600;max-width:720px}.map-description{color:#586668;font-size:clamp(16px,1.55vw,20px);line-height:1.5;max-width:730px;margin-bottom:43px}.map-key{display:flex;flex-wrap:wrap;gap:25px;color:#75817e;font:10px IBM Plex Mono,monospace;text-transform:uppercase;letter-spacing:.04em;padding-bottom:15px;border-bottom:1px solid #bfc8c2}.map-key span{display:flex;gap:7px;align-items:center}.map-key b{width:7px;height:7px;display:inline-block}.key-note{background:#0a7777}.key-lab{background:#202a30}.key-paper{background:#b16c1e}.lesson-path{border-bottom:1px solid #bfc8c2}.path-row{display:grid;grid-template-columns:40px 110px minmax(0,1fr) 66px 28px;align-items:center;min-height:88px;gap:10px;border-bottom:1px solid #d5d9d2;text-decoration:none;padding:12px 10px 12px 0}.path-row:last-child{border-bottom:0}.path-row:hover{background:#edf0e9}.path-row.lab{background:#e5ebe7}.path-row.lab:hover{background:#dce7e1}.path-row.paper{border-left:3px solid #b16c1e;padding-left:12px;background:#f7f0e3}.path-row.paper:hover{background:#f4e8d2}.path-number,.path-time{color:#88948e;font:11px IBM Plex Mono,monospace}.path-type{color:#6d7976;font:600 10px IBM Plex Mono,monospace;text-transform:uppercase;letter-spacing:.04em}.path-row.paper .path-type{color:#a05f16}.path-content strong{display:block;font-size:17px;font-weight:600;letter-spacing:-.025em;line-height:1.2}.path-content small{display:block;font-size:12px;line-height:1.4;color:#687670;margin-top:5px}.path-content em{display:block;color:#98601f;margin-top:6px;font: 10px IBM Plex Mono,monospace}.path-status{font-size:20px;color:#8b9892;text-align:right}.path-row.done .path-status{color:#0a7777}.map-footnote{margin-top:20px;font-size:12px;color:#728079}.lesson-page{padding:0 clamp(22px,3.4vw,55px) 70px}.lesson-topline{max-width:1240px;margin:auto;display:flex;justify-content:space-between;gap:15px;padding:29px 0 24px;border-bottom:1px solid #cdd3cd;color:#7d8983;font:600 11px IBM Plex Mono,monospace;text-transform:uppercase;letter-spacing:.04em}.lesson-topline a{color:#376c6b;text-decoration:none}.lesson-topline a:hover{text-decoration:underline}.lesson-layout{max-width:1240px;margin:auto;display:grid;grid-template-columns:minmax(0,760px) minmax(200px,250px);justify-content:space-between;gap:clamp(28px,4vw,72px)}.lesson-layout main{min-width:0}.reading-column{padding:clamp(34px,4vw,65px) 0 70px}.lesson-label,.source-overline{font:700 10px IBM Plex Mono,monospace;letter-spacing:.15em;color:#0a7777;display:flex;align-items:center;gap:8px}.label-number{color:#919b95;margin-left:8px}.label-mark{width:8px;height:8px;background:#0a7777;display:inline-block}.label-mark.lab{background:#202a30}.reading-column h1{font-size:clamp(39px,4.1vw,61px);letter-spacing:-.064em;line-height:1.05;font-weight:600;margin:20px 0 13px}.lesson-objective{font-size:clamp(16px,1.5vw,19px);line-height:1.48;color:#65716c;max-width:680px;margin-bottom:40px}.note-block{padding:30px 0;border-top:1px solid #cdd3cc}.block-heading{display:flex;align-items:baseline;gap:19px}.block-heading span{flex:0 0 27px;color:#8b9690;font:600 11px IBM Plex Mono,monospace}.block-heading h2{font-size:clamp(19px,1.8vw,23px);font-weight:600;letter-spacing:-.038em;margin-bottom:12px}.note-block p{font-size:16px;line-height:1.72;max-width:700px;color:#334148;margin:0 0 15px 46px}.system-figure{margin:22px 0 0 46px;width:min(100% - 46px,620px);padding:14px 16px 10px;background:#fbfaf6;border:1px solid #d6ddd5}.system-figure svg{width:100%;height:auto;display:block}.system-figure figcaption{border-top:1px solid #e5e9e3;padding-top:7px;color:#7c8982;font:10px IBM Plex Mono,monospace}.code-sample{white-space:pre-wrap;overflow-wrap:anywhere;margin:15px 0 16px 46px;padding:19px 20px;color:#e7eee9;background:#233139;border-left:4px solid #0a7777;line-height:1.6;font:12px IBM Plex Mono,monospace}.check-panel{background:#e7ebe5;border-top:3px solid #0a7777;margin-top:20px;padding:clamp(22px,3vw,35px)}.check-eyebrow,.paper-instructions span,.answer-heading span{color:#0a7777;font:700 10px IBM Plex Mono,monospace;letter-spacing:.12em}.check-panel h2{font-size:clamp(20px,2vw,27px);font-weight:600;letter-spacing:-.035em;line-height:1.3;margin:12px 0 22px}.check-options{display:grid;gap:8px}.check-option{width:100%;display:flex;text-align:left;align-items:center;gap:13px;min-height:50px;background:#f9faf5;border:1px solid #c9d4ca;color:#243138;padding:10px 13px;font-size:14px}.check-option span{font:600 11px IBM Plex Mono,monospace;color:#77908b;border-right:1px solid #c9d4ca;padding-right:13px}.check-option:hover{border-color:#0a7777}.check-option.selected{background:#e0eeeb;border:2px solid #0a7777;padding:9px 12px}.check-option.wrong{border-color:#a4453d;background:#f8eae4}.check-option.correct{border-color:#0a7777}.check-footer{display:flex;align-items:flex-start;gap:18px;margin-top:18px;flex-wrap:wrap}.action-primary,.action-secondary{min-height:42px;padding:10px 16px;border:1px solid #202a30;font-size:12px;font-weight:700}.action-primary{background:#202a30;color:#fff}.action-primary:hover:not(:disabled){background:#0a7777;border-color:#0a7777}.action-primary:disabled{opacity:.45}.action-secondary{background:transparent;color:#202a30}.action-secondary:hover{background:#e9ebe4}.feedback{color:#9f4c3d;font-size:13px;max-width:520px;line-height:1.5;margin:9px 0 0}.feedback.good{color:#086c6b}.evidence-rail{padding-top:63px}.rail-panel{border-top:1px solid #cdd3cd;padding:15px 0 25px}.rail-label{color:#8a958f;font:700 10px IBM Plex Mono,monospace;letter-spacing:.11em;margin-bottom:12px}.rail-panel strong{display:block;font-size:13px;line-height:1.45;font-weight:600}.rail-panel p{color:#7b8882;font-size:12px;line-height:1.52;margin:8px 0 0}.source-reference{color:#697771;font-size:11px;line-height:1.45;margin:0 0 9px;overflow-wrap:anywhere}.rail-paper{display:flex;justify-content:space-between;text-decoration:none;border-bottom:1px solid #d8ddd6;padding:9px 0;font-size:12px;color:#99601e}.rail-paper:hover{text-decoration:underline}.lesson-bottom-nav{border-top:1px solid #cbd2cb;margin:0 0 35px;padding-top:20px;display:flex;justify-content:space-between;gap:18px}.lesson-bottom-nav a{color:#315e5d;font-size:13px;text-decoration:none;max-width:45%}.lesson-bottom-nav a:hover{text-decoration:underline}.lab-intro{color:#3d4b4e;font-size:16px;line-height:1.6;margin:-13px 0 25px}.lab-page .qlab,.lab-page .slab{border-radius:3px;box-shadow:none}.lab-page .qlab{max-width:none;background:#f7f8f2}.paper-page .lesson-objective{margin-bottom:28px}.paper-band{background:#b16c1e;color:#fff9ee;min-height:90px;display:flex;align-items:center;justify-content:space-between;padding:17px 21px;margin-bottom:32px}.paper-band div{display:grid;gap:3px}.paper-band .source-overline{color:#ffe1b5;margin-bottom:4px}.paper-band strong{font-size:18px;letter-spacing:-.025em}.paper-band div>span:last-child{font:11px IBM Plex Mono,monospace;color:#ffe8c5}.paper-icon{font-size:28px}.paper-instructions{border-top:1px solid #d8cebd;padding-top:17px}.paper-instructions span,.answer-heading span{color:#9e611f}.paper-instructions p{color:#6a756f;font-size:14px;margin:8px 0 16px}.paper-question{background:#fffefa;border:1px solid #d9cbb7;padding:clamp(20px,3vw,32px)}.paper-question pre{margin:0;white-space:pre-wrap;overflow-wrap:anywhere;font:14px/1.7 IBM Plex Mono,monospace;color:#283039}.paper-preview{margin-top:22px;height:min(57vw,490px);overflow:hidden;border:1px solid #ddd1bd;background:#fff}.paper-preview img{width:100%;height:auto;display:block}.source-links{display:flex;align-items:center;flex-wrap:wrap;gap:10px;padding:13px 0 28px;color:#697772;font:11px IBM Plex Mono,monospace}.source-links a{color:#8c551b}.paper-answer{padding:22px 0 28px;border-top:1px solid #cebfa8}.answer-heading{display:flex;justify-content:space-between;align-items:center;gap:14px}.answer-text{font-size:15px;line-height:1.65;color:#334148;background:#ecf2eb;border-left:3px solid #0a7777;padding:18px 20px;margin:20px 0;white-space:pre-line}.key-caution{background:#fff0dc;border-left:3px solid #b16c1e;padding:14px 17px;font-size:13px;line-height:1.55}.term{display:inline;padding:0 1px;border:0;border-bottom:2px dotted #0a7777;border-radius:0;background:transparent;color:#086b6b;font-weight:600;text-align:inherit;line-height:inherit}.term.first{background:#d7e9e4;border-bottom-style:solid}.term.repeat{color:inherit;border-bottom:1px dotted #609a92;font-weight:inherit}.term:hover{background:#c0dfd8}.term-card{position:fixed;z-index:50;width:min(340px,calc(100vw - 24px));max-height:min(76vh,460px);overflow:auto;padding:17px 18px;background:#fffefa;color:#263139;border:1px solid #0a7777;box-shadow:4px 5px #bfd7cf}.term-card-head{display:flex;justify-content:space-between;align-items:start;gap:8px}.term-card strong{font-size:17px;letter-spacing:-.025em}.term-card p{font-size:13px;line-height:1.55;margin:12px 0}.term-card small{display:block;border-top:1px solid #d6ddd5;padding-top:10px;font-size:12px;line-height:1.5;color:#586a69}.term-card .system-figure{width:100%;margin:10px 0;padding:5px}.term-card .system-figure svg{max-height:120px}.icon-button{border:none;background:none;font-size:22px;line-height:1;color:#75837d}.icon-button:hover{color:#202a30}.loading{padding:40px}@media(max-width:1150px){.lesson-layout{grid-template-columns:minmax(0,1fr) 190px;gap:26px}.chapter-rail{width:220px}.app-grid{grid-template-columns:220px minmax(0,1fr)}.chapter-tab{padding-left:14px;gap:8px}.rail-title,.rail-end{padding-left:14px;padding-right:14px}}@media(max-width:850px){.site-head{height:66px;padding:0 20px}.brand{min-width:0}.brand small{display:none}.head-progress{margin-left:auto;width:110px}.continue{display:none}.app-grid{display:block}.chapter-rail{width:auto;padding:0;border-right:0;border-bottom:1px solid #cfd3ce}.rail-title,.rail-end{display:none}.chapter-list{display:flex;overflow-x:auto;scrollbar-width:thin}.chapter-tab{flex:0 0 auto;min-height:49px;max-width:220px;border-top:0;border-right:1px solid #d6dcd5;padding:9px 13px}.chapter-tab:last-child{border-bottom:0}.chapter-tab.active:before{height:3px;width:auto;right:0;top:auto}.chapter-code{margin-top:2px}.chapter-tab-main small,.tab-arrow{display:none}.lesson-layout{display:block}.evidence-rail{padding:0 0 10px;border-top:1px solid #cdd3cd}.rail-panel{padding:15px 0}.map-page{padding-top:42px}}@media(max-width:590px){.brand strong{font-size:15px}.brand-mark{width:31px;height:31px}.head-progress{font-size:9px;width:90px}.map-page h1,.reading-column h1{font-size:38px}.map-key{gap:10px 16px}.path-row{grid-template-columns:28px 1fr 24px;gap:8px;min-height:80px}.path-type,.path-time{display:none}.path-content strong{font-size:15px}.path-content small{font-size:11px}.lesson-page{padding-left:20px;padding-right:20px}.reading-column{padding-top:38px}.note-block p,.system-figure,.code-sample{margin-left:0;width:100%}.block-heading{gap:8px}.paper-question pre{font-size:12px}.term-card{bottom:12px!important;top:auto!important;left:12px!important;width:calc(100vw - 24px);max-height:60vh}.answer-heading{align-items:start;flex-direction:column}}@media(max-width:590px){.site-head{height:62px;padding:0 16px}.chapter-rail{padding:8px 16px}.chapter-list{display:none}.chapter-picker{display:grid;grid-template-columns:auto minmax(0,1fr);align-items:center;gap:12px;color:#65756f;font:600 11px IBM Plex Mono,monospace;text-transform:uppercase;letter-spacing:.04em}.chapter-picker select{min-width:0;width:100%;min-height:46px;border:1px solid #b8c6bd;border-radius:3px;background:#f7f8f2;color:#203239;padding:0 12px;font:600 14px DM Sans,sans-serif;text-transform:none;letter-spacing:0}.map-page{padding:31px 16px max(55px,env(safe-area-inset-bottom))}.map-page h1,.reading-column h1{font-size:clamp(33px,9vw,40px)}.map-description{margin-bottom:30px}.path-row{grid-template-columns:27px minmax(0,1fr) 24px;gap:11px;padding:15px 6px 15px 0;min-height:80px}.path-row.paper{padding-left:9px}.path-content strong{font-size:16px}.path-content small{font-size:13px}.path-content em{font-size:10px;line-height:1.4}.lesson-page{padding:0 16px max(36px,env(safe-area-inset-bottom))}.lesson-topline{padding:15px 0;align-items:center}.lesson-topline a{display:flex;align-items:center;min-height:44px;max-width:75%;line-height:1.3}.reading-column{padding:31px 0 42px}.lesson-objective{margin-bottom:31px}.note-block p,.system-figure,.code-sample{margin-left:0;width:100%}.block-heading{gap:8px}.code-sample{font-size:13px;padding:14px}.check-panel{margin-left:-16px;margin-right:-16px;padding:22px 16px}.check-option{min-height:54px;font-size:15px}.action-primary,.action-secondary{min-height:48px;font-size:14px}.lesson-bottom-nav{gap:9px;padding-top:13px}.lesson-bottom-nav a{display:flex;align-items:center;min-height:48px;max-width:50%;padding:8px 0;font-size:14px;line-height:1.35}.lesson-bottom-nav a:last-child{margin-left:auto;text-align:right;justify-content:flex-end}.paper-question{padding:16px}.paper-question pre{font-size:14px;line-height:1.65}.paper-preview{height:auto;max-height:65vh;overflow:auto}.source-links{font-size:12px;gap:6px}.source-links a{display:inline-flex;align-items:center;min-height:44px;padding:8px;border:1px solid #d9cbb7}.term-card{bottom:max(12px,env(safe-area-inset-bottom))!important;top:auto!important;left:12px!important;width:calc(100vw - 24px);max-height:min(70vh,560px);font-size:15px}.term-card p{font-size:14px}.icon-button{min-width:44px;min-height:44px}.answer-heading{align-items:start;flex-direction:column}}@media(pointer:coarse){a,button,select{touch-action:manipulation}.action-primary,.action-secondary,.icon-button{min-height:46px}}