@charset "UTF-8";
/* Algorithm classroom: continuous reading layout aligned with Vision Daily. */
:root{color-scheme:light dark;--bg:#f5f6fb;--surface:#fff;--text:#202a43;--muted:#616e88;--line:#e1e5f0;--accent:#5d50c6;--accent-hover:#493cab;--soft:#eeecfb;--code:#f4f5fa;--blue:#edf1fc;--warm:#96541e;--warm-soft:#fff4e6;--mark:#fff0be;--mark-ink:#55400c;--green:var(--accent);--ink:var(--text);--white:var(--surface);--paper:var(--bg)}
*{box-sizing:border-box}html{scroll-behavior:smooth;scroll-padding-top:76px}body{margin:0;background:var(--bg);color:var(--text);font:15px/1.9 "Microsoft YaHei","PingFang SC",system-ui,sans-serif;letter-spacing:.05px}[hidden]{display:none!important}h1,h2,h3,h4,p{margin:0}h1{font-size:30px;line-height:1.45;letter-spacing:-.6px}h2{font-size:21px;line-height:1.5;letter-spacing:-.2px}h3{font-size:18px;line-height:1.6}p+p{margin-top:13px}a{color:var(--accent);text-decoration:none}a:hover{text-decoration:underline;text-underline-offset:3px}button,input,select,textarea{font:inherit}button,a,input,select,textarea,summary{-webkit-tap-highlight-color:transparent;touch-action:manipulation}button{cursor:pointer;color:inherit;transition:background .15s,border-color .15s,color .15s}button:disabled{opacity:.48;cursor:default}a:focus-visible,button:focus-visible,input:focus-visible,select:focus-visible,textarea:focus-visible,summary:focus-visible{outline:3px solid var(--accent);outline-offset:3px}code,pre{font-family:Consolas,"Cascadia Code",monospace}code{font-size:.95em}p code,li code,.sample-output code{background:var(--code);border-radius:4px;padding:2px 5px;overflow-wrap:anywhere}mark{background:var(--mark);color:var(--mark-ink);padding:1px 3px;border-radius:3px;font-weight:600;box-decoration-break:clone;-webkit-box-decoration-break:clone}.skip{position:fixed;top:-80px;left:16px;z-index:100;background:var(--surface);border:2px solid var(--accent);border-radius:7px;padding:8px 15px;font-size:12px}.skip:focus{top:12px}
/* Desktop frame and course navigation. */
.app-shell{display:grid;grid-template-columns:260px minmax(0,1fr);max-width:1600px;min-height:100vh;margin:0 auto}.sidebar{position:sticky;top:0;height:100vh;height:100dvh;min-width:0;padding:30px 22px 22px;border-right:1px solid var(--line);background:var(--bg);display:flex;flex-direction:column}.brand{display:flex;align-items:center;gap:12px;flex:0 0 auto;color:var(--text);font-size:23px;font-weight:750;letter-spacing:1.3px;line-height:1.4}.brand:hover{text-decoration:none}.brand small{display:block;font-size:8px;font-weight:400;letter-spacing:1.7px;color:var(--muted);margin-top:4px}.brand-mark{display:grid;place-items:center;width:42px;height:44px;flex:0 0 42px;border-radius:12px;color:#fff;background:var(--accent);font-size:22px;letter-spacing:0;box-shadow:0 4px 10px #5d50c620}.sidebar-intro{margin:20px 0 0;font-size:12px;color:var(--muted)}.main-nav{display:grid;grid-template-columns:1fr 1fr;gap:3px;margin:26px 0 23px}.nav-button{display:flex;align-items:center;gap:7px;padding:7px 6px;border:1px solid transparent;border-radius:6px;background:transparent;color:var(--muted);text-align:left;font-size:11px;white-space:nowrap}.nav-button>span{font-size:13px}.nav-button:hover{color:var(--accent);background:var(--surface)}.nav-button.active{color:var(--accent);background:var(--soft)}.sidebar-label{display:flex;justify-content:space-between;align-items:baseline;gap:10px;flex:0 0 auto;margin:0 3px 11px;font-size:12px;font-weight:650}#read-count{color:var(--muted);font-size:10px;font-weight:400;white-space:nowrap}.lesson-list{overflow-y:auto;overflow-x:hidden;min-height:0;flex:1;padding:0 4px 8px 0;scrollbar-width:thin;scrollbar-color:var(--line) transparent}.lesson-item{display:flex;align-items:center;gap:10px;width:100%;margin:3px 0;padding:10px 9px;border:1px solid transparent;border-radius:9px;color:var(--muted);background:transparent;text-align:left;line-height:1.55}.lesson-item>span:last-child{min-width:0}.lesson-item:hover{background:var(--surface);border-color:var(--line)}.lesson-item.selected{color:var(--accent);background:var(--soft);border-color:color-mix(in srgb,var(--accent) 20%,transparent)}.lesson-item strong{display:block;font-size:12px;font-weight:550;overflow-wrap:anywhere}.lesson-item small{display:block;font-size:10px;color:var(--muted);margin-top:4px}.lesson-no{width:24px;height:24px;flex:0 0 24px;display:grid;place-items:center;background:var(--surface);border:1px solid var(--line);border-radius:50%;font:11px/1 Consolas,monospace}.selected .lesson-no{background:var(--accent);border-color:var(--accent);color:#fff}.sidebar-bottom{flex:0 0 auto;padding-top:17px;margin-top:10px;border-top:1px solid var(--line);font-size:10px;color:var(--muted)}.sidebar-bottom small{display:block;margin-top:3px;font-size:9px}.live-dot{display:inline-block;width:5px;height:5px;border-radius:50%;background:var(--accent);vertical-align:middle;margin-right:6px}.shell{min-width:0;background:var(--surface);padding:30px 52px 32px}.topbar{display:flex;align-items:center;justify-content:space-between;gap:14px;min-height:34px;margin:0 0 18px;color:var(--muted);font-size:12px}.topbar-actions{display:flex;align-items:center;gap:10px}.schedule-pill{font-size:10px}#focus-reading{display:inline-flex;align-items:center;justify-content:center;gap:5px;min-height:33px;padding:6px 10px;border:1px solid var(--line);border-radius:7px;background:var(--surface);font-size:11px;color:var(--text);white-space:nowrap}#focus-reading:hover,#focus-reading[aria-pressed=true]{color:var(--accent);background:var(--soft)}#focus-reading svg{width:14px;height:14px}.mobile-course-nav{display:none}#content{min-width:0}footer{margin-top:38px;padding-top:18px;border-top:1px solid var(--line);font-size:10px;color:var(--muted)}footer span{margin-left:12px}.loading{padding:45px 0;color:var(--muted)}
/* Compact lesson heading and continuous chapters. */
.eyebrow,.card-kicker{font-size:10px;letter-spacing:1px;color:var(--accent)}.card-kicker{display:block;margin-bottom:7px}.back-catalog{display:inline-block;font-size:11px;margin-bottom:13px}.hero{position:relative;overflow:hidden;padding:22px 26px;border:1px solid var(--line);border-radius:18px;background:linear-gradient(115deg,var(--soft),var(--surface) 82%)}.hero:after{content:"";position:absolute;width:210px;height:210px;right:-75px;top:-100px;border:33px solid #7770cc09;border-radius:50%;pointer-events:none}.hero>*{position:relative;z-index:1}.hero h1{margin:8px 0 0}.hero .eyebrow{font-size:10px}.hero .subtitle{margin-top:12px;font-size:13px;color:var(--muted)}.lesson-overview{margin:17px 0 19px}.focus-strip{display:block;margin:0;padding:0 0 0 19px;list-style:disc}.focus-item{display:list-item;margin:0;padding:3px 0;font-size:13px;line-height:1.85}.focus-item::marker{color:var(--accent)}.focus-item>strong,.focus-item>span{font-size:inherit;color:var(--text);font-weight:600;margin-right:9px}.focus-item p{display:inline;margin:0}.lesson-actions,.actions{display:flex;flex-wrap:wrap;align-items:center;gap:9px 16px;margin:12px 0 0}.lesson-actions a{font-size:11px}.publication-note{font-size:11px;color:var(--warm);margin-top:10px}.lesson-meta{display:flex;flex-wrap:wrap;gap:0;color:var(--muted);font-size:11px;margin-top:9px}.lesson-meta span+span:before{content:"·";padding:0 8px}.tabs,.lesson-nav{position:sticky;top:0;z-index:20;display:flex;align-items:stretch;gap:25px;padding:12px 0 0;margin:0 0 32px;border-bottom:1px solid var(--line);background:var(--surface);overflow-x:auto;scrollbar-width:none}.tabs::-webkit-scrollbar{display:none}.tab,.lesson-nav [data-tab]{display:inline-flex;align-items:center;gap:6px;min-height:44px;padding:8px 1px 13px;margin-bottom:-1px;border:0;border-bottom:2px solid transparent;border-radius:0;color:var(--muted);background:transparent;white-space:nowrap;font-size:12px;text-decoration:none;flex:0 0 auto}.tab:hover{color:var(--accent)}.tab[aria-current=true],.tab[aria-selected=true],.lesson-nav [aria-current=true],.tab.active{border-bottom-color:var(--accent);color:var(--accent)}.lesson-chapter{margin:0 0 38px;scroll-margin-top:78px;min-width:0}.section-head{display:flex;align-items:baseline;justify-content:space-between;gap:18px;margin-bottom:13px;padding:0 0 13px;border-bottom:1px solid var(--line)}.section-head p{font-size:11px;color:var(--muted);margin-top:5px}.section-step{color:var(--muted);font-size:10px;white-space:nowrap}.grid-two{display:block;min-width:0}.grid-two>*,.roadmap-layout>*,.resource-grid>*{min-width:0}.card{min-width:0;padding:22px 2px 25px;border:0;border-bottom:1px solid var(--line);border-radius:0;background:transparent}.card h3{margin:0 0 12px}.card p,.prose{font-size:14px;line-height:1.95;overflow-wrap:anywhere}.card .small-prose,.small-prose{font-size:12px;color:var(--muted)}.tip{margin-top:17px;padding:13px 16px;border-left:2px solid var(--accent);border-radius:0 6px 6px 0;background:var(--soft);font-size:13px;line-height:1.85;overflow-wrap:anywhere}.tip>strong{display:block;font-size:12px;margin-bottom:3px}.tip p{margin:0;font-size:13px}
/* Examples, derivations and reusable templates. */
.array{display:flex;flex-wrap:wrap;gap:8px;margin:17px 0;min-width:0}.array-cell{min-width:46px;max-width:100%;text-align:center}.array-cell strong{display:block;min-width:46px;border:1px solid var(--line);border-radius:7px;padding:10px 9px;background:var(--bg);font:16px/1.4 Consolas,monospace;overflow-wrap:anywhere}.array-cell small{display:block;margin-top:4px;color:var(--muted);font-size:9px}.array-cell.active strong{color:var(--accent);border:2px solid var(--accent);padding:9px 8px;background:var(--soft)}.array-cell.found strong{background:#246b48;border-color:#246b48;color:#fff}.sample-output{display:flex;flex-wrap:wrap;gap:8px 24px;align-items:baseline;padding:11px 14px;border:1px solid var(--line);border-radius:7px;background:var(--bg);font-size:12px;overflow-wrap:anywhere}.example-note{margin-top:13px;font-size:13px!important;color:var(--muted)}.input-example{max-width:100%;overflow-x:auto;white-space:pre-wrap;overflow-wrap:anywhere;background:var(--code);border:1px solid var(--line);border-radius:7px;padding:13px 16px;font:13px/1.85 Consolas,"Microsoft YaHei",monospace}.definition{display:grid;grid-template-columns:135px minmax(0,1fr);gap:18px;padding:13px 0;border-bottom:1px solid var(--line)}.definition:last-child{border-bottom:0}.definition strong{font-size:13px;overflow-wrap:anywhere}.definition p{font-size:13px;color:var(--muted)}.source-link{display:block;padding:12px 0;font-size:13px;border-bottom:1px solid var(--line)}.source-link:last-child{border-bottom:0}.source-link small{display:block;margin-top:3px;font-size:11px;color:var(--muted);line-height:1.8}.connection{padding:13px 0;border-bottom:1px solid var(--line)}.connection:last-child{padding-bottom:0;border-bottom:0}.connection strong{display:block;font-size:13px;margin-bottom:4px}.connection p{font-size:13px;color:var(--muted)}.flow{counter-reset:flow}.flow-item{position:relative;counter-increment:flow;padding-left:37px;padding-bottom:22px}.flow-item:last-child{padding-bottom:0}.flow-item:before{content:counter(flow);position:absolute;left:0;top:3px;width:24px;height:24px;display:grid;place-items:center;background:var(--soft);color:var(--accent);border-radius:50%;font:12px/1 Consolas,monospace}.flow-item h3{font-size:15px;margin-bottom:7px}.flow-item p{font-size:14px}.complexity-grid{display:flex;flex-wrap:wrap;gap:16px 35px;padding:7px 0 15px}.complexity{min-width:130px}.complexity small{display:block;font-size:11px;color:var(--muted)}.complexity strong{display:block;font:600 23px/1.7 Consolas,monospace;color:var(--accent)}.template-card{border:1px solid var(--line);background:var(--bg);border-radius:9px;padding:20px 24px;margin:22px 0 25px}.template-heading{display:flex;flex-wrap:wrap;align-items:baseline;gap:7px 15px}.template-heading .card-kicker{margin:0}.template-heading h3{font-size:17px}.template-when{margin:11px 0 0;font-size:13px}.template-when strong{margin-right:13px}.template-steps{counter-reset:template;list-style:none;display:block;padding:0;margin:16px 0}.template-steps li{counter-increment:template;position:relative;padding:3px 0 3px 32px;margin:7px 0;font-size:13px;overflow-wrap:anywhere}.template-steps li:before{content:counter(template);position:absolute;left:0;top:4px;width:22px;height:22px;display:grid;place-items:center;border-radius:50%;background:var(--soft);color:var(--accent);font:11px/1 Consolas,monospace}.template-rule{display:flex;gap:15px;align-items:baseline;border-top:1px solid var(--line);padding-top:13px;font-size:13px}.template-rule>strong{flex:0 0 auto;color:var(--warm)}.template-rule p{margin:0;overflow-wrap:anywhere}.template-cost{margin-top:10px;font-size:12px;color:var(--muted)}
/* Code construction and interactive controls. */
.code-grid{display:grid;grid-template-columns:minmax(0,1.65fr) minmax(240px,1fr);gap:25px;align-items:start}.editor{min-width:0;border:1px solid var(--line);border-radius:9px;overflow:hidden;background:var(--code)}.editor-top{display:flex;align-items:center;gap:10px;padding:10px 12px;border-bottom:1px solid var(--line);background:var(--bg)}.window-dots{display:inline-flex;flex:0 0 auto;gap:4px}.window-dots i{width:6px;height:6px;border-radius:50%;background:#bdc3d3}.editor-title{min-width:0;overflow:hidden;text-overflow:ellipsis;white-space:nowrap;font-size:11px;color:var(--muted)}.lang-switch{display:flex;flex:0 0 auto;gap:4px;margin-left:auto}.lang-switch button{border:1px solid transparent;border-radius:5px;padding:4px 7px;background:transparent;color:var(--muted);font-size:10px;white-space:nowrap}.lang-switch button.active{color:var(--accent);background:var(--surface);border-color:var(--line)}.code-body{padding:16px 0;min-height:240px;max-height:620px;overflow:auto;font:13px/1.95 Consolas,"Cascadia Code",monospace}.code-line{display:flex;align-items:baseline;width:max-content;min-width:100%;padding-right:18px;min-height:1.95em}.code-line.new{background:var(--soft)}.line-num{display:inline-block;flex:0 0 43px;width:43px;padding-right:14px;text-align:right;color:var(--muted);font-size:10px;user-select:none}.code-text{white-space:pre}.kw{color:#6a47ad}.str{color:#99621c}.num{color:#1b7383}.comment{color:#65727f}.caret{display:inline-block;vertical-align:text-bottom;width:1px;height:1.2em;background:var(--accent);margin-left:1px;animation:caret 1.05s steps(2,start) infinite}@keyframes caret{to{visibility:hidden}}.editor-bottom{display:flex;flex-wrap:wrap;align-items:center;justify-content:space-between;gap:6px;padding:8px 13px;border-top:1px solid var(--line);font-size:10px;color:var(--muted)}.controls{display:flex;flex-wrap:wrap;align-items:center;gap:8px;margin-top:13px}.button{display:inline-flex;align-items:center;justify-content:center;gap:5px;min-height:34px;max-width:100%;padding:8px 12px;border:1px solid var(--accent);border-radius:7px;background:var(--accent);color:#fff;font-size:12px;line-height:1.55;text-decoration:none}.button:hover{color:#fff;background:var(--accent-hover);border-color:var(--accent-hover);text-decoration:none}.button.secondary,.button.light{background:var(--surface);border-color:var(--line);color:var(--text)}.button.secondary:hover,.button.light:hover{background:var(--soft);border-color:color-mix(in srgb,var(--accent) 30%,var(--line));color:var(--accent)}.button.light{border-color:transparent;background:transparent}select{min-width:0;max-width:100%;border:1px solid var(--line);border-radius:7px;padding:7px 10px;color:var(--text);background:var(--surface);font-size:12px}.controls .button,.controls select{font-size:11px}.code-caption{padding:0 0 21px}.step-progress{display:flex;flex-wrap:wrap;gap:5px;margin:13px 0}.step-dot{width:20px;height:3px;border-radius:3px;background:var(--line)}.step-dot.done{background:var(--accent)}.step-title{font-size:17px;font-weight:650;line-height:1.6;margin-bottom:12px}.code-caption p{font-size:14px}.caption-detail{border-top:1px solid var(--line);padding-top:14px;margin-top:14px;font-size:12px;color:var(--muted);overflow-wrap:anywhere}.code-summary{margin:0;padding:16px 0;border-bottom:1px solid var(--line)}.code-summary summary{cursor:pointer;color:var(--accent);font-size:13px;line-height:1.85}.code-summary[open] summary{margin-bottom:13px}.code-summary p{font-size:13px}.code-summary pre{max-width:100%;overflow:auto;background:var(--code);border:1px solid var(--line);border-radius:8px;padding:16px 18px;font-size:12px;line-height:1.85;margin:13px 0;tab-size:4}
/* Diagrams, traces, sources and interview notes. */
.concept-diagram{border:1px solid var(--line);border-radius:9px;background:var(--bg);padding:20px;margin:18px 0 22px}.concept-diagram figcaption>p{font-size:12px;color:var(--muted)}.diagram-steps{margin:17px 0 0;padding:0;list-style:none}.diagram-steps li+li{border-top:1px solid var(--line);margin-top:16px;padding-top:16px}.diagram-label{font-size:13px;font-weight:600;color:var(--text);margin-bottom:10px}.diagram-values{display:flex;gap:7px;max-width:100%}.diagram-cell{flex:1;min-width:0;max-width:64px;text-align:center}.diagram-cell strong{display:block;border:1px solid var(--line);background:var(--surface);border-radius:6px;padding:7px 2px;font:15px/1.4 Consolas,monospace;overflow-wrap:anywhere}.diagram-cell small{display:block;font:10px/1.9 Consolas,monospace;color:var(--muted)}.diagram-cell.examining strong{border:2px solid #40875b;padding:6px 1px;color:#155b36;background:#e3f3e9}.diagram-cell.excluded strong{border-style:dashed;border-color:#c3c9d0;color:#687184;background:#eef0f3;text-decoration:line-through}.diagram-cell.matched strong{color:#fff;background:#246b48;border-color:#246b48}.diagram-steps li>p{font-size:12px;margin-top:10px}.diagram-conclusion{border-top:1px solid var(--line);padding-top:13px;margin-top:16px;font-size:13px}.video-link{display:grid;grid-template-columns:30px minmax(0,1fr) 15px;align-items:start;gap:12px;padding:15px 0;border-top:1px solid var(--line)}.video-symbol{width:30px;height:30px;display:grid;place-items:center;background:var(--soft);border-radius:7px;margin-top:4px;font-size:11px}.video-link small{font-size:10px;color:var(--muted)}.video-link strong{display:block;font-size:14px;margin:2px 0 5px}.video-link>span>span{display:block;font-size:12px;color:var(--muted)}.platform-note{font-size:11px!important;color:var(--muted)}.trace-top{display:flex;align-items:baseline;gap:18px;justify-content:space-between;margin-bottom:8px}.trace-top h3{margin:0}.trace-top select{max-width:55%}.frame-label{font-size:11px;color:var(--muted);overflow-wrap:anywhere}.variables{display:grid;grid-template-columns:repeat(auto-fit,minmax(90px,1fr));gap:10px;margin:16px 0}.variable{min-width:0;padding:12px 14px;background:var(--bg);border:1px solid var(--line);border-radius:7px}.variable small{display:block;color:var(--muted);font-size:10px;overflow-wrap:anywhere}.variable strong{display:block;font:600 20px/1.6 Consolas,"Microsoft YaHei",monospace;color:var(--accent);overflow-wrap:anywhere}.trace-caption{min-height:75px;font-size:14px;line-height:1.9;padding:13px 16px;border-left:2px solid var(--accent);background:var(--soft);border-radius:0 7px 7px 0;overflow-wrap:anywhere}.memory{display:flex;flex-wrap:wrap;gap:8px;margin:14px 0}.memory-chip{padding:8px 12px;border:1px solid var(--line);border-radius:7px;background:var(--code);font:13px/1.85 Consolas,"Microsoft YaHei",monospace;overflow-wrap:anywhere;min-width:0;max-width:100%}.memory-empty{color:var(--muted);font-size:12px}.trace-output{font:600 17px/1.8 Consolas,"Microsoft YaHei",monospace;color:var(--accent);overflow-wrap:anywhere}.trace-output:not(:empty){border-top:1px solid var(--line);margin-top:14px;padding-top:14px}.interview-quote{background:var(--soft);border-left:2px solid var(--accent);border-radius:0 7px 7px 0;padding:17px 19px;font-size:14px;line-height:1.95;margin:0 0 22px}.pitfall{padding:14px 0;border-bottom:1px solid var(--line)}.pitfall:last-child{border-bottom:0}.pitfall strong{font-size:13px}.pitfall p{color:var(--muted);margin-top:5px;font-size:13px}textarea{width:100%;min-width:0;min-height:160px;resize:vertical;padding:12px 14px;border:1px solid var(--line);border-radius:9px;background:var(--bg);color:var(--text);font-size:13px;line-height:1.85}.save-note,.card .save-note{color:var(--muted);font-size:11px;margin-top:7px}.read-row{display:flex;flex-wrap:wrap;align-items:center;justify-content:space-between;gap:16px;margin-top:19px;padding-top:17px;border-top:1px solid var(--line)}.read-row p{flex:1 1 320px;font-size:12px;color:var(--muted)}.read-row .button{flex:0 0 auto}
/* Catalog, learning route and resource views share the reading hierarchy. */
.page-heading{padding:22px 26px;background:linear-gradient(115deg,var(--soft),var(--surface) 82%);border:1px solid var(--line);border-radius:16px;margin-bottom:24px}.page-heading h1{margin:7px 0 9px}.page-heading p{color:var(--muted);font-size:13px;line-height:1.8}.catalog-heading,.roadmap-heading{display:flex;align-items:center;justify-content:space-between;gap:23px}.catalog-heading>.button{flex:0 0 auto}.catalog-stats{display:grid;grid-template-columns:repeat(4,minmax(0,1fr));gap:22px;padding:20px 0;margin-bottom:22px;border-bottom:1px solid var(--line)}.catalog-stats>div{display:flex;align-items:baseline;gap:11px}.catalog-stats strong{font:28px/1.4 Consolas,monospace;color:var(--accent)}.catalog-stats span{color:var(--muted);font-size:11px}.catalog-notice{border-left:2px solid var(--accent);background:var(--soft);border-radius:0 7px 7px 0;padding:12px 15px;margin-bottom:25px}.catalog-notice strong{font-size:12px}.catalog-notice p{font-size:11px;line-height:1.8;color:var(--muted);margin-top:3px}.catalog-filters{display:grid;grid-template-columns:minmax(0,1fr) 140px 140px;gap:14px;align-items:end}.catalog-filters label{min-width:0;display:grid;gap:6px;color:var(--muted);font-size:11px}.catalog-filters input,.catalog-filters select{width:100%;height:41px;padding:9px 11px;background:var(--bg);border:1px solid var(--line);border-radius:7px;color:var(--text);font-size:12px;min-width:0}.catalog-count{font-size:11px;color:var(--muted);margin:16px 0 11px}.catalog-grid{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:0 30px;border-top:1px solid var(--line)}.catalog-card{display:flex;flex-direction:column;min-width:0;padding:22px 0;border-bottom:1px solid var(--line)}.catalog-card-top{display:flex;align-items:center;gap:9px;flex-wrap:wrap}.catalog-number{font:18px/1.5 Consolas,monospace;color:var(--accent)}.catalog-date{font-size:10px;color:var(--muted);margin-right:auto}.catalog-badge{font-size:9px;line-height:1.8;color:var(--muted);padding:1px 6px;border-radius:4px;background:var(--bg)}.catalog-badge.read{color:var(--accent);background:var(--soft)}.catalog-badge.backfill{color:var(--warm);background:var(--warm-soft)}.catalog-card h2{font-size:17px;margin:11px 0 8px;line-height:1.55}.catalog-card h2 a{color:var(--text)}.catalog-card h2 a:hover{color:var(--accent)}.catalog-card>p{font-size:13px;color:var(--muted);line-height:1.85;overflow-wrap:anywhere}.catalog-tags{display:flex;flex-wrap:wrap;gap:6px 11px;margin:12px 0 16px;font-size:10px;color:var(--muted)}.catalog-tags span:before{content:"#";color:var(--accent);margin-right:3px}.catalog-card-bottom{margin-top:auto;display:flex;align-items:center;justify-content:space-between;gap:12px}.catalog-card-bottom small{color:var(--muted);font-size:10px}.catalog-card-bottom .button{font-size:10px;padding:6px 10px;min-height:31px}.catalog-empty{grid-column:1/-1;text-align:center;padding:50px 10px}.catalog-empty h2{font-size:19px}.catalog-empty p{font-size:13px;color:var(--muted);margin:10px 0 18px}.catalog-footnote{margin-top:23px;font-size:11px;color:var(--muted)}.resource-grid{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:0 30px}.resource-card{display:flex;flex-direction:column;align-items:flex-start}.resource-card h3{margin-top:5px}.resource-card p{font-size:13px;color:var(--muted);margin-bottom:17px}.resource-card .button{margin-top:auto}.route-count{display:flex;align-items:center;flex:0 0 auto;gap:12px;border-left:1px solid var(--line);padding-left:23px}.route-count strong{font:34px/1.3 Consolas,monospace;color:var(--accent)}.route-count span{color:var(--muted);font-size:11px}.method-chain{display:flex;flex-wrap:wrap;gap:8px;margin:22px 0 30px}.method-chain>span{display:inline-flex;align-items:center;gap:8px;padding:7px 11px;background:var(--soft);border-radius:6px;color:var(--accent);font-size:12px}.method-chain small{font:10px/1.6 Consolas,monospace;color:var(--muted)}.roadmap-layout{display:grid;grid-template-columns:minmax(0,1.3fr) minmax(260px,1fr);gap:32px;align-items:start}.roadmap-timeline{list-style:none;padding:0;margin:0}.roadmap-stage{display:grid;grid-template-columns:31px minmax(0,1fr);gap:14px;position:relative;padding:15px 0 24px}.roadmap-stage:not(:last-child):after{content:"";position:absolute;top:51px;bottom:0;left:15px;width:1px;background:var(--line)}.stage-number{width:31px;height:31px;border:1px solid var(--line);border-radius:50%;background:var(--soft);color:var(--accent);display:grid;place-items:center;font:11px/1 Consolas,monospace}.stage-content{min-width:0;border-bottom:1px solid var(--line);padding:0 0 18px}.stage-heading{display:flex;align-items:baseline;justify-content:space-between;gap:9px;flex-wrap:wrap}.stage-heading h3{font-size:16px}.stage-status{font-size:9px;padding:1px 6px;border-radius:4px;background:var(--soft);color:var(--accent)}.stage-content p{font-size:13px;line-height:1.85;color:var(--muted);margin-top:9px}.stage-content .stage-prerequisite{font-size:11px}.stage-prerequisite strong{margin-right:9px;color:var(--text)}.stage-content p+p{margin-top:5px}.stage-tags{display:flex;flex-wrap:wrap;gap:7px 11px;margin-top:10px;font-size:10px;color:var(--muted)}.stage-tags span:before{content:"#";margin-right:3px;color:var(--accent)}.stage-lessons{display:grid;gap:6px;padding-top:11px;margin-top:11px;border-top:1px solid var(--line)}.stage-lessons a{display:flex;justify-content:space-between;align-items:baseline;gap:10px;font-size:12px}.library-card{padding:19px 0}.library-card h3{font-size:15px;margin-bottom:9px}.library-card p{font-size:12px;color:var(--muted)}.library-boundary{margin:12px 0;font-size:11px;line-height:1.8;color:var(--muted)}.library-boundary strong{display:block;color:var(--warm);font-size:10px;margin-bottom:4px}.library-card .button{font-size:11px}.route-note{color:var(--muted);font-size:11px;margin:17px 0 0;padding:12px 15px;border-left:2px solid var(--accent);background:var(--soft)}
#toast{position:fixed;z-index:100;left:50%;bottom:25px;width:max-content;max-width:calc(100% - 30px);padding:10px 17px;transform:translate(-50%,12px);border-radius:8px;background:var(--text);color:var(--surface);font-size:12px;opacity:0;pointer-events:none;transition:opacity .18s,transform .18s;box-shadow:0 5px 20px #0002}#toast.visible{opacity:1;transform:translate(-50%,0)}.focus-reading .app-shell{grid-template-columns:minmax(0,1fr);max-width:1080px}.focus-reading .sidebar{display:none}.focus-reading .shell{border-left:1px solid var(--line);border-right:1px solid var(--line)}
/* Responsive reading widths and accessible system appearance. */
@media(min-width:1440px){.shell{padding-left:65px;padding-right:65px}}
@media(max-width:1200px){.code-grid{grid-template-columns:minmax(0,1fr)}.code-grid>aside{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:24px}.code-grid>aside>.card{padding-top:0}}
@media(max-width:1100px){.app-shell{grid-template-columns:227px minmax(0,1fr)}.sidebar{padding:26px 15px 20px}.brand{font-size:21px;gap:10px}.brand small{font-size:7px;letter-spacing:1.3px}.shell{padding:26px 30px 30px}.catalog-stats>div{display:block}.catalog-stats span{display:block}.catalog-heading{display:block}.catalog-heading>.button{margin-top:16px}.roadmap-layout{grid-template-columns:minmax(0,1fr)}.catalog-filters{grid-template-columns:minmax(0,1fr) 120px 120px;gap:10px}}
@media(max-width:760px){
  html{scroll-padding-top:66px}body{font-size:14px}.app-shell{display:block}.sidebar{position:static;height:auto;padding:17px 20px 13px;border-right:0;border-bottom:1px solid var(--line);display:flex;flex-direction:row;flex-wrap:wrap;justify-content:space-between;align-items:center;gap:14px}.brand{font-size:20px;gap:9px;letter-spacing:.7px}.brand-mark{width:34px;height:36px;flex-basis:34px;border-radius:9px;font-size:19px}.brand small{font-size:7px;letter-spacing:1px;margin-top:2px}.sidebar-intro,.sidebar-label,.lesson-list,.sidebar-bottom{display:none}.main-nav{display:flex;flex-wrap:wrap;gap:3px;margin:0}.nav-button{font-size:10px;padding:5px 6px;gap:4px}.nav-button>span{font-size:11px}.shell{padding:20px 20px 27px}.topbar{gap:10px;margin-bottom:15px;min-height:31px;font-size:11px}.topbar-actions{gap:5px}.schedule-pill{display:none}#focus-reading{padding:6px 8px;font-size:10px;min-height:31px}#focus-reading svg{width:12px;height:12px}.mobile-course-nav{display:flex;align-items:center;gap:10px;margin-bottom:18px;font-size:10px;color:var(--muted)}.mobile-course-nav label{flex:0 0 auto}.mobile-course-nav select{flex:1;width:100%;min-width:0;padding:7px 8px;font-size:11px;background:var(--bg)}.hero{padding:18px 20px;border-radius:13px}.hero h1,h1{font-size:26px}.hero .eyebrow{font-size:9px}.hero:after{width:175px;height:175px;right:-90px;top:-100px}.lesson-overview{margin:16px 0}.focus-item{font-size:12px;padding:4px 0}.focus-item>strong,.focus-item>span{margin-right:6px}.lesson-actions{gap:7px 12px;margin-top:10px}.lesson-actions a{font-size:10px}.tabs,.lesson-nav{gap:0;justify-content:space-between;padding-top:6px;margin-bottom:25px}.tab,.lesson-nav [data-tab]{font-size:11px;padding:8px 4px 11px;min-height:42px}.lesson-chapter{margin-bottom:30px;scroll-margin-top:68px}.section-head{gap:12px;padding-bottom:12px;margin-bottom:7px}.section-head h2{font-size:19px}.section-head p{font-size:10px;margin-top:4px}.section-step{font-size:9px}.card{padding:20px 0}.card h3{font-size:17px;margin-bottom:11px}.card p,.prose{font-size:13px}.card .small-prose,.small-prose{font-size:11px}.tip{font-size:12px;padding:12px 13px}.tip p{font-size:12px}.definition{grid-template-columns:95px minmax(0,1fr);gap:12px}.definition strong,.definition p{font-size:12px}.source-link{font-size:12px}.source-link small{font-size:10px}.connection p,.connection strong{font-size:12px}.flow-item{padding-left:31px}.flow-item p{font-size:13px}.flow-item h3{font-size:14px}.template-card{padding:17px 15px;margin-top:19px}.template-heading{display:block}.template-heading h3{font-size:16px;margin-top:4px}.template-when,.template-steps li,.template-rule{font-size:12px}.template-rule{display:block}.template-rule p{margin-top:5px}.template-cost{font-size:11px}
  .code-grid{display:block}.code-grid>aside{display:block;margin-top:23px}.code-grid>aside>.card{padding:19px 0}.code-grid>aside>.card:first-child{padding-top:0}.editor-top{gap:7px;padding:9px 10px;flex-wrap:wrap}.window-dots{display:none}.editor-title{font-size:10px;max-width:48%}.lang-switch button{padding:4px 6px;font-size:10px}.code-body{font-size:12px;min-height:210px}.line-num{flex-basis:34px;width:34px;padding-right:10px;font-size:9px}.code-line{padding-right:12px}.editor-bottom{font-size:9px}.editor-bottom>span:last-child{display:none}.controls{gap:7px}.controls .button,.controls select{padding:7px 9px;font-size:10px}.button{font-size:11px;padding:8px 10px}.step-title{font-size:16px}.caption-detail{font-size:12px}.code-summary summary{font-size:12px}.code-summary pre{font-size:11px;padding:13px}.concept-diagram{padding:15px 12px}.diagram-values{gap:5px}.diagram-cell strong{font-size:13px}.diagram-steps li>p{font-size:12px}.trace-top{display:block}.trace-top h3{margin-bottom:10px}.trace-top select{max-width:100%;width:100%;font-size:12px}.variables{grid-template-columns:repeat(auto-fit,minmax(90px,1fr));gap:8px}.variable{padding:10px 11px}.variable strong{font-size:18px}.trace-caption{font-size:13px;padding:12px 14px}.memory-chip{font-size:12px}.interview-quote{font-size:13px;padding:15px 16px}.read-row{gap:13px}.read-row p{flex-basis:100%}.page-heading{padding:19px 20px;border-radius:13px}.page-heading p{font-size:12px}.catalog-stats{grid-template-columns:repeat(2,minmax(0,1fr));gap:18px;padding:15px 0 20px}.catalog-stats>div{display:flex;align-items:baseline;gap:10px}.catalog-stats strong{font-size:25px}.catalog-stats span{font-size:10px}.catalog-filters{grid-template-columns:1fr 1fr;gap:12px}.catalog-search{grid-column:1/-1}.catalog-grid{grid-template-columns:minmax(0,1fr)}.catalog-card h2{font-size:16px}.catalog-card{padding:20px 0}.catalog-card>p{font-size:12px}.catalog-card-bottom small{font-size:10px}.catalog-notice p{font-size:10px}.resource-grid{grid-template-columns:minmax(0,1fr)}.resource-card{padding:20px 0}.roadmap-heading{display:block}.route-count{margin-top:17px;padding:11px 0 0;border-left:0;border-top:1px solid var(--line)}.route-count strong{font-size:27px}.route-count span{font-size:10px}.method-chain{gap:7px;margin:18px 0 25px}.method-chain>span{font-size:11px;padding:6px 9px}.roadmap-stage{gap:12px}.stage-heading h3{font-size:15px}.stage-content p{font-size:12px}.library-card p{font-size:12px}.focus-reading .shell{border:0}footer{margin-top:29px;font-size:9px}footer span{display:block;margin:3px 0 0}
}
@media(max-width:400px){.sidebar{padding:15px 17px 12px}.main-nav{width:100%;justify-content:space-between}.nav-button{padding:6px 8px}.shell{padding-left:17px;padding-right:17px}.hero,.page-heading{padding:18px 17px}.hero h1,h1{font-size:25px}.tabs,.lesson-nav{gap:12px;justify-content:flex-start}.tab,.lesson-nav [data-tab]{font-size:11px;padding-inline:0}.section-step{white-space:normal;text-align:right}.catalog-card-bottom{gap:8px}.catalog-card-bottom .button{padding:6px 8px}}
@media(prefers-color-scheme:dark){:root{--bg:#171c2c;--surface:#1e2436;--text:#e6e9f4;--muted:#a9b2ca;--line:#343c54;--accent:#b1a5ff;--accent-hover:#c6baff;--soft:#302d4b;--code:#171e30;--blue:#28334b;--warm:#edb679;--warm-soft:#3b302b;--mark:#625330;--mark-ink:#fff0be}.brand-mark,.selected .lesson-no,.button,.button:hover{color:#211c3d}.diagram-cell.excluded:not(.matched) strong{border-color:#505967;color:#aab2bf;background:#2b303b}.button.secondary,.button.light{color:var(--text)}.button.secondary:hover,.button.light:hover{color:var(--accent)}.hero:after{border-color:#a89bff08}.kw{color:#c4a2ef}.str{color:#edc28b}.num{color:#81c9d6}.comment{color:#9eafbf}.window-dots i{background:#5e6983}}
@media(prefers-reduced-motion:reduce){*,*:before,*:after{scroll-behavior:auto!important;transition:none!important;animation:none!important}}