@import url('https://fonts.googleapis.com/css2?family=IBM+Plex+Mono:wght@400;500;600&family=IBM+Plex+Sans:wght@400;500;600;700&display=swap'); /* lesson-kit.css — shared styles + base template for PCD interactive lessons. Link from a lesson with: and put class="lk" on . Component classes are prefixed lk-; callouts use .callout. Font: IBM Plex Sans/Mono (swap by editing the @import above + --lk-font/--lk-mono). */ :root{ --lk-font:'IBM Plex Sans',system-ui,-apple-system,Segoe UI,Roboto,sans-serif; --lk-mono:'IBM Plex Mono',ui-monospace,SFMono-Regular,Consolas,monospace; --lk-ac:#2563eb; --lk-ac2:#7c3aed; --lk-text:#1a2233; --lk-muted:#64748b; --lk-bd:#e6e8ee; --lk-bg:#fcfcfd; --lk-soft:#f6f7f9; --lk-code:#f1f3f7; --lk-ok:#10b981; --lk-okbg:#ecfdf5; --lk-warn:#ef4444; --lk-warnbg:#fef2f2; --lk-exam:#f59e0b; --lk-note:#10b981; --lk-hl:#dbeafe; --lk-shadow:0 1px 2px rgba(16,24,40,.04),0 4px 12px rgba(16,24,40,.05); } /* base / reading column */ body.lk{font-family:var(--lk-font);color:var(--lk-text);line-height:1.7; max-width:50rem;margin:0 auto;padding:2.5rem 1.25rem 6rem;background:var(--lk-bg); -webkit-font-smoothing:antialiased;text-rendering:optimizeLegibility} body.lk h1,body.lk h2,body.lk h3,body.lk h4{line-height:1.25;font-weight:700;letter-spacing:-.01em} body.lk h1{font-size:2rem;margin:.1em 0 .35em} body.lk h2{font-size:1.4rem;margin:2.6rem 0 .7rem;padding-bottom:.35rem;border-bottom:2px solid var(--lk-bd)} body.lk h2::before{content:"";display:inline-block;width:.5rem;height:1.05rem;margin-right:.55rem; vertical-align:-1px;background:var(--lk-ac);border-radius:2px} body.lk h3{font-size:1.13rem;margin:1.6rem 0 .4rem;font-weight:600} body.lk h4{font-size:1rem;margin:1.2rem 0 .3rem;font-weight:600} body.lk p,body.lk li{font-size:1.02rem} body.lk a{color:var(--lk-ac);text-underline-offset:2px} body.lk strong{font-weight:600} body.lk code{background:var(--lk-code);padding:.12em .38em;border-radius:5px;font-size:.9em;font-family:var(--lk-mono)} body.lk var{font-style:normal;font-weight:600;color:var(--lk-ac2)} /* header / meta / footer */ .lk-header{margin-bottom:1.75rem;padding-bottom:1.1rem;border-bottom:2px solid var(--lk-bd)} .lk-kicker{font-size:.78rem;font-weight:600;letter-spacing:.08em;text-transform:uppercase;color:var(--lk-ac)} .lk-meta{color:var(--lk-muted);font-size:.88rem;display:flex;gap:1.1rem;flex-wrap:wrap;margin-top:.5rem} .lk-meta a{color:var(--lk-muted)} .lk-foot{margin-top:4.5rem;padding-top:1.5rem;border-top:1px solid var(--lk-bd); font-size:.82rem;color:var(--lk-muted);text-align:center} /* "in this lesson" overview */ .lk-overview{background:linear-gradient(180deg,#f8faff,var(--lk-soft));border:1px solid var(--lk-bd); border-radius:12px;padding:1rem 1.25rem;margin:1.5rem 0;box-shadow:var(--lk-shadow)} .lk-overview h2{border:0;margin:.1rem 0 .5rem;font-size:1.1rem} .lk-overview h2::before{display:none} .lk-overview ul{margin:.3rem 0;padding-left:1.2rem} /* table of contents */ .lk-toc{background:#fff;border:1px solid var(--lk-bd);border-radius:12px;padding:1rem 1.3rem;margin:1.5rem 0;box-shadow:var(--lk-shadow)} .lk-toc h3{margin:.1rem 0 .5rem} .lk-toc ol{margin:0;padding-left:1.4rem;columns:2;column-gap:2rem} .lk-toc li{margin:.15rem 0} .lk-toc a{text-decoration:none} .lk-toc a:hover{text-decoration:underline} /* callouts */ .callout{padding:.9rem 1.05rem;margin:1.4rem 0;border-radius:.6rem;background:var(--lk-soft); border:1px solid var(--lk-bd);border-left:4px solid var(--lk-bd)} .callout .callout-label{display:block;font-weight:700;text-transform:uppercase;font-size:.72rem;letter-spacing:.05em;margin-bottom:.35rem} .callout p:last-child{margin-bottom:0} .callout.idea{border-left-color:var(--lk-ac)} .callout.idea .callout-label{color:var(--lk-ac)} .callout.warn{border-left-color:var(--lk-warn);background:var(--lk-warnbg)} .callout.warn .callout-label{color:var(--lk-warn)} .callout.exam{border-left-color:var(--lk-exam);background:#fffbeb} .callout.exam .callout-label{color:#b45309} .callout.note{border-left-color:var(--lk-note)} .callout.note .callout-label{color:#047857} /* tables */ .lk table,table.lk-table{width:100%;border-collapse:collapse;margin:1.4rem 0;font-size:.95rem; box-shadow:var(--lk-shadow);border-radius:10px;overflow:hidden} .lk th,.lk td{border:1px solid var(--lk-bd);padding:.6rem .8rem;text-align:left;vertical-align:top} .lk th{background:var(--lk-code);font-weight:600} .lk tbody tr:nth-child(even){background:var(--lk-soft)} /* code blocks */ .lk pre{background:#0f172a;color:#e2e8f0;padding:1rem 1.1rem;border-radius:.6rem;overflow-x:auto;margin:1.2rem 0; font-size:.88rem;box-shadow:var(--lk-shadow)} .lk pre code{background:none;padding:0;font-family:var(--lk-mono);font-size:inherit} /* highlight.js: force a readable DARK palette inside our dark code blocks, overriding whatever hljs theme the lesson links (e.g. the light github theme) — fixes dark-on-dark tokens. */ .lk pre code.hljs{background:transparent;color:#e2e8f0;padding:0} .lk pre .hljs-comment,.lk pre .hljs-quote{color:#94a3b8;font-style:italic} .lk pre .hljs-keyword,.lk pre .hljs-selector-tag,.lk pre .hljs-built_in,.lk pre .hljs-type,.lk pre .hljs-literal{color:#93c5fd} .lk pre .hljs-string,.lk pre .hljs-regexp,.lk pre .hljs-addition,.lk pre .hljs-meta .hljs-string{color:#86efac} .lk pre .hljs-number,.lk pre .hljs-symbol,.lk pre .hljs-attr,.lk pre .hljs-attribute,.lk pre .hljs-constant{color:#fbbf24} .lk pre .hljs-title,.lk pre .hljs-title.function_,.lk pre .hljs-section,.lk pre .hljs-name,.lk pre .hljs-selector-id,.lk pre .hljs-selector-class{color:#f0abfc} .lk pre .hljs-variable,.lk pre .hljs-template-variable,.lk pre .hljs-params,.lk pre .hljs-property{color:#e2e8f0} .lk pre .hljs-meta,.lk pre .hljs-doctag{color:#94a3b8} .lk pre .hljs-deletion{color:#fca5a5} .lk pre .hljs-emphasis{font-style:italic} .lk pre .hljs-strong{font-weight:600} /* details / collapsible & quiz */ .lk details{background:#fff;border:1px solid var(--lk-bd);border-radius:.6rem;padding:.8rem 1.05rem;margin:.8rem 0;box-shadow:var(--lk-shadow)} .lk details summary{font-weight:600;cursor:pointer} .lk details[open] summary{margin-bottom:.5rem;color:var(--lk-ac)} .lk-quiz{display:flex;flex-direction:column;gap:.6rem} /* timeline */ .lk-timeline{list-style:none;margin:1.4rem 0;padding-left:1.3rem;border-left:2px solid var(--lk-bd)} .lk-timeline li{position:relative;margin:0 0 1.1rem;padding-left:1rem} .lk-timeline li::before{content:"";position:absolute;left:-1.65rem;top:.5rem;width:.7rem;height:.7rem; border-radius:50%;background:var(--lk-ac);box-shadow:0 0 0 3px #fff,0 0 0 4px var(--lk-bd)} .lk-timeline .lk-tl-when{font-weight:700;color:var(--lk-ac)} /* mermaid centering */ .lk .mermaid{margin:1.6rem 0;text-align:center} /* widget shared shell */ .lk-tabs,.lk-acode,.lk-se,.lk-step{box-shadow:var(--lk-shadow)} /* ---- tabs (data-kit="tabs") ---- */ .lk-tabs{margin:1.4rem 0} .lk-tabs .lk-tablist{display:flex;gap:.4rem;border-bottom:1px solid var(--lk-bd);flex-wrap:wrap} .lk-tabs .lk-tab{font:inherit;cursor:pointer;background:none;border:1px solid transparent;border-bottom:none; padding:.5rem .95rem;border-radius:8px 8px 0 0;color:#475569} .lk-tabs .lk-tab:hover{background:var(--lk-code)} .lk-tabs .lk-tab[aria-selected="true"]{color:var(--lk-ac);border-color:var(--lk-bd);background:#fff;font-weight:600;position:relative;top:1px} .lk-tabs .lk-tab:focus-visible{outline:2px solid var(--lk-ac);outline-offset:2px} .lk-tabs .lk-tabpanel{border:1px solid var(--lk-bd);border-radius:0 8px 8px 8px;padding:1rem 1.1rem;background:#fff} .lk-tabs .lk-tabpanel[hidden]{display:none} /* ---- annotated code ---- */ .lk-acode{border:1px solid var(--lk-bd);border-radius:.6rem;overflow:hidden;margin:1.2rem 0} .lk-acode .lk-ac-code{background:#0f172a;padding:.6rem;margin:0} .lk-acode .lk-ac-line{display:block;width:100%;text-align:left;font:inherit;font-family:var(--lk-mono); font-size:.88rem;background:none;border:none;border-radius:4px;padding:.15rem .55rem;cursor:pointer;white-space:pre;color:#e2e8f0} .lk-acode .lk-ac-line:hover{background:#1e293b} .lk-acode .lk-ac-line[aria-pressed="true"]{background:#1e3a5f;box-shadow:inset 3px 0 0 #60a5fa} .lk-acode .lk-ac-line:focus-visible{outline:2px solid #60a5fa;outline-offset:-2px} .lk-acode .lk-ac-expl{padding:.75rem .95rem;border-top:1px solid var(--lk-bd);background:var(--lk-soft);min-height:1.5em;font-size:.92rem} /* ---- state explorer ---- */ .lk-se{border:1px solid var(--lk-bd);border-radius:.7rem;padding:1.1rem;margin:1.4rem 0;background:#fff} .lk-se .lk-se-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(120px,1fr));gap:.6rem;margin-bottom:1rem} .lk-se .lk-se-node{font:inherit;font-weight:600;cursor:pointer;padding:.7rem .5rem;border:2px solid var(--lk-bd); border-radius:10px;background:#fff;color:var(--lk-text);text-align:center;transition:.12s} .lk-se .lk-se-node:hover{border-color:var(--lk-ac)} .lk-se .lk-se-node:focus-visible{outline:3px solid #93c5fd;outline-offset:2px} .lk-se .lk-se-node[aria-pressed="true"]{background:var(--lk-hl);border-color:var(--lk-ac)} .lk-se .lk-se-node.lk-se-current{box-shadow:0 0 0 3px var(--lk-ac) inset} .lk-se .lk-se-panel{border:1px solid var(--lk-bd);border-radius:10px;padding:.9rem;background:var(--lk-soft)} .lk-se .lk-se-panel h4{margin:0 0 .3rem;color:var(--lk-ac)} .lk-se .lk-se-cur{font-size:.85rem;color:#475569;margin-bottom:.6rem} .lk-se ul.lk-se-trans{list-style:none;padding:0;margin:.4rem 0 0;display:flex;flex-direction:column;gap:.35rem} .lk-se .lk-se-trans button{font:inherit;cursor:pointer;text-align:left;width:100%;padding:.4rem .6rem; border:1px solid var(--lk-bd);border-radius:8px;background:#fff} .lk-se .lk-se-trans button:hover{background:var(--lk-hl);border-color:var(--lk-ac)} .lk-se .lk-se-trans code{background:#eef2ff;padding:0 .25rem;border-radius:4px;color:var(--lk-ac)} /* ---- step simulator ---- */ .lk-step{border:1px solid var(--lk-bd);border-radius:.7rem;padding:1.1rem;margin:1.4rem 0;background:#fff} .lk-step h4{margin:0 0 .25rem;color:#1e3a5f} .lk-step .lk-step-sub{margin:0 0 .7rem;font-size:.85rem;color:var(--lk-muted)} .lk-step .lk-step-cols{display:flex;gap:.6rem;flex-wrap:wrap} .lk-step .lk-step-th{flex:1;min-width:140px;border:1px solid var(--lk-bd);border-radius:8px;padding:.5rem .65rem} .lk-step .lk-step-th h5{margin:0 0 .35rem;font-size:.9rem} .lk-step .lk-step-ins{list-style:none;margin:0;padding:0} .lk-step .lk-step-ins li{font:13px/1.7 var(--lk-mono);padding:.1rem .4rem;border-radius:4px;color:#475569} .lk-step .lk-step-ins li.on{background:#eff6ff;color:var(--lk-ac);font-weight:600} .lk-step .lk-step-ins li.done{color:#94a3b8;text-decoration:line-through} .lk-step .lk-step-ins li.blocked{background:#fef3c7;color:#d97706} .lk-step .lk-step-state{display:flex;gap:.7rem;flex-wrap:wrap;align-items:center;margin:.7rem 0;font-size:.85rem} .lk-step .lk-step-box{border:1px solid #d1d5db;border-radius:6px;padding:.35rem .65rem;background:var(--lk-soft)} .lk-step .lk-step-box b{font-family:var(--lk-mono)} .lk-step .lk-step-verdict{font-size:.88rem;padding:.45rem .7rem;border-radius:6px;margin:.5rem 0;background:var(--lk-soft);min-height:1.3em} .lk-step .lk-step-verdict.ok{background:var(--lk-okbg);color:#065f46} .lk-step .lk-step-verdict.bad{background:var(--lk-warnbg);color:#991b1b} .lk-step .lk-step-btns{display:flex;gap:.4rem;flex-wrap:wrap;margin-top:.6rem} .lk-step .lk-step-btns button{font:inherit;cursor:pointer;padding:.35rem .85rem;border-radius:6px;border:1px solid var(--lk-ac); background:var(--lk-ac);color:#fff;font-size:.85rem;font-weight:600} .lk-step .lk-step-btns button.lk-step-reset{background:#fff;color:var(--lk-muted);border-color:#9ca3af} .lk-step .lk-step-btns button:disabled{opacity:.4;cursor:not-allowed} @media (max-width:640px){ body.lk{padding:1.5rem .9rem 4rem} .lk-toc ol{columns:1} .lk-step .lk-step-cols{flex-direction:column} } @media print{ .lk-step-btns,.lk-se-grid{display:none} a{color:inherit} body.lk{max-width:none} }