/* извлечено из артефакта лекции 1 */
/* ---------- tokens: light is the base, both dark states re-map only tokens ---------- */
:root{
  --paper:#eef1f5;
  --surface:#ffffff;
  --surface-2:#f6f8fa;
  --line:#d3dae3;
  --line-soft:#e4e9ef;
  --ink:#121a25;
  --ink-2:#3d4a5c;
  --ink-3:#6c7a8c;
  --accent:#2f44c9;
  --accent-soft:#e6e9fb;
  --accent-ink:#1e2f96;
  --prime:#0d6b53;
  --prime-soft:#dcefe8;
  --mark:#c0374b;
  --mark-soft:#fae3e6;
  --grid:rgba(18,26,37,.055);
  --shadow:0 1px 2px rgba(16,24,40,.05), 0 8px 24px -12px rgba(16,24,40,.18);
  --radius:10px;
}
@media (prefers-color-scheme: dark){
  :root:not([data-theme="light"]){
    --paper:#0d121a;
    --surface:#141b25;
    --surface-2:#1a2230;
    --line:#2a3545;
    --line-soft:#212b39;
    --ink:#e7ecf3;
    --ink-2:#b3bfd0;
    --ink-3:#8091a5;
    --accent:#8b99ff;
    --accent-soft:#1e2540;
    --accent-ink:#aeb8ff;
    --prime:#42c9a3;
    --prime-soft:#12302a;
    --mark:#ff8095;
    --mark-soft:#33191f;
    --grid:rgba(231,236,243,.05);
    --shadow:0 1px 2px rgba(0,0,0,.4), 0 10px 30px -14px rgba(0,0,0,.7);
  }
}
:root[data-theme="dark"]{
  --paper:#0d121a;
  --surface:#141b25;
  --surface-2:#1a2230;
  --line:#2a3545;
  --line-soft:#212b39;
  --ink:#e7ecf3;
  --ink-2:#b3bfd0;
  --ink-3:#8091a5;
  --accent:#8b99ff;
  --accent-soft:#1e2540;
  --accent-ink:#aeb8ff;
  --prime:#42c9a3;
  --prime-soft:#12302a;
  --mark:#ff8095;
  --mark-soft:#33191f;
  --grid:rgba(231,236,243,.05);
  --shadow:0 1px 2px rgba(0,0,0,.4), 0 10px 30px -14px rgba(0,0,0,.7);
}

*,*::before,*::after{box-sizing:border-box}
body{
  margin:0;
  background:var(--paper);
  background-image:linear-gradient(var(--grid) 1px,transparent 1px),linear-gradient(90deg,var(--grid) 1px,transparent 1px);
  background-size:24px 24px;
  color:var(--ink);
  font-family:"IBM Plex Sans",ui-sans-serif,system-ui,-apple-system,"Segoe UI",sans-serif;
  font-size:16px;
  line-height:1.6;
  -webkit-font-smoothing:antialiased;
}
h1,h2,h3,h4{font-family:Newsreader,ui-serif,Georgia,"Times New Roman",serif;font-weight:500;text-wrap:balance;margin:0;letter-spacing:-.01em}
p{margin:0}
code,kbd,pre,.mono,.num{font-family:"IBM Plex Mono",ui-monospace,SFMono-Regular,Menlo,monospace;font-variant-numeric:tabular-nums}
a{color:var(--accent);text-underline-offset:3px}
:focus-visible{outline:2.5px solid var(--accent);outline-offset:2px;border-radius:4px}
@media (prefers-reduced-motion: reduce){*{animation-duration:.01ms !important;transition-duration:.01ms !important}}

/* ---------- shell ---------- */
.wrap{max-width:1320px;margin:0 auto;padding:0 clamp(16px,3vw,40px) 96px}
.masthead{padding:clamp(36px,6vw,72px) 0 28px;border-bottom:1px solid var(--line)}
.eyebrow{font-size:.72rem;letter-spacing:.16em;text-transform:uppercase;color:var(--ink-3);font-weight:600}
.masthead h1{font-size:clamp(2.3rem,6vw,4rem);line-height:1.02;margin:.28em 0 .3em}
.masthead h1 em{font-style:italic;color:var(--accent)}
.dek{font-size:clamp(1rem,1.6vw,1.13rem);color:var(--ink-2);max-width:62ch}
.facts{display:flex;flex-wrap:wrap;gap:8px;margin-top:22px}
.fact{display:inline-flex;align-items:baseline;gap:7px;border:1px solid var(--line);background:var(--surface);border-radius:999px;padding:5px 13px;font-size:.82rem;color:var(--ink-2)}
.fact b{font-weight:600;color:var(--ink);font-family:"IBM Plex Mono",monospace}

.cols{display:grid;grid-template-columns:1fr;gap:40px;margin-top:36px}
@media(min-width:1060px){.cols{grid-template-columns:15.5rem minmax(0,1fr);gap:52px;align-items:start}}

/* ---------- agenda rail ---------- */
.rail{position:relative}
@media(min-width:1060px){.rail{position:sticky;top:24px;max-height:calc(100vh - 48px);overflow-y:auto;padding-right:6px}}
.rail-h{font-size:.72rem;letter-spacing:.16em;text-transform:uppercase;color:var(--ink-3);font-weight:600;margin-bottom:12px}
.rail ol{list-style:none;margin:0;padding:0;display:flex;flex-direction:column;gap:1px}
.rail a{display:grid;grid-template-columns:1.9rem 1fr auto;gap:8px;align-items:baseline;padding:7px 9px;border-radius:7px;text-decoration:none;color:var(--ink-2);font-size:.87rem;border-left:2px solid transparent;transition:background .15s,color .15s}
.rail a:hover{background:var(--surface);color:var(--ink)}
.rail a.on{background:var(--surface);color:var(--ink);border-left-color:var(--accent);font-weight:500;box-shadow:var(--shadow)}
.rail .n{font-family:"IBM Plex Mono",monospace;font-size:.76rem;color:var(--ink-3)}
.rail a.on .n{color:var(--accent)}
.rail .t{font-size:.72rem;color:var(--ink-3);font-family:"IBM Plex Mono",monospace}
.rail .part{font-size:.68rem;letter-spacing:.14em;text-transform:uppercase;color:var(--ink-3);font-weight:600;margin:16px 0 5px;padding-left:9px}
.rail .part:first-of-type{margin-top:0}

/* ---------- beats ---------- */
.beat{scroll-margin-top:22px;padding-top:8px;margin-bottom:56px}
.beat-head{display:flex;gap:16px;align-items:flex-start;margin-bottom:18px}
.beat-n{flex:none;width:2.6rem;height:2.6rem;border-radius:8px;display:grid;place-items:center;background:var(--surface);border:1px solid var(--line);font-family:"IBM Plex Mono",monospace;font-size:.95rem;font-weight:600;color:var(--accent);box-shadow:var(--shadow)}
.beat-head h2{font-size:clamp(1.5rem,3vw,2rem);line-height:1.15}
.beat-head .sub{font-size:.84rem;color:var(--ink-3);margin-top:3px;display:flex;gap:12px;flex-wrap:wrap;font-family:"IBM Plex Mono",monospace}

.card{background:var(--surface);border:1px solid var(--line);border-radius:var(--radius);box-shadow:var(--shadow)}
.pad{padding:clamp(16px,2.4vw,26px)}
.stack{display:flex;flex-direction:column;gap:18px}
.two{display:grid;grid-template-columns:1fr;gap:18px}
@media(min-width:820px){.two{grid-template-columns:1fr 1fr}}

.say{border-left:3px solid var(--accent);background:var(--accent-soft);border-radius:0 var(--radius) var(--radius) 0;padding:16px 20px}
.say h4{font-family:"IBM Plex Sans",sans-serif;font-size:.7rem;letter-spacing:.14em;text-transform:uppercase;color:var(--accent-ink);font-weight:600;margin-bottom:9px}
.say ul{margin:0;padding-left:19px;display:flex;flex-direction:column;gap:7px;color:var(--ink-2);font-size:.95rem}
.say strong{color:var(--ink);font-weight:600}

.board h4,.demo h4{font-family:"IBM Plex Sans",sans-serif;font-size:.7rem;letter-spacing:.14em;text-transform:uppercase;color:var(--ink-3);font-weight:600;margin-bottom:12px}
.board p+p{margin-top:11px}
.board p{color:var(--ink-2);font-size:.95rem}

pre{margin:0;overflow-x:auto;background:var(--surface-2);border:1px solid var(--line-soft);border-radius:8px;padding:14px 16px;font-size:.85rem;line-height:1.65;color:var(--ink)}
pre .c{color:var(--ink-3);font-style:italic}
pre .k{color:var(--accent);font-weight:500}
pre .s{color:var(--prime)}
.formula{background:var(--surface-2);border:1px solid var(--line-soft);border-radius:8px;padding:13px 16px;font-family:"IBM Plex Mono",monospace;font-size:.93rem;color:var(--ink);overflow-x:auto}
.trap{border-left:3px solid var(--mark);background:var(--mark-soft);border-radius:0 8px 8px 0;padding:13px 17px;font-size:.9rem;color:var(--ink-2)}
.trap b{color:var(--ink);font-weight:600}

table{width:100%;border-collapse:collapse;font-size:.88rem}
.tw{overflow-x:auto;border:1px solid var(--line);border-radius:8px}
.tw table{font-size:.85rem}
th{text-align:left;font-weight:600;font-size:.7rem;letter-spacing:.1em;text-transform:uppercase;color:var(--ink-3);padding:10px 13px;border-bottom:1px solid var(--line);background:var(--surface-2);white-space:nowrap}
td{padding:9px 13px;border-bottom:1px solid var(--line-soft);color:var(--ink-2);vertical-align:top}
tr:last-child td{border-bottom:none}
td.n,th.n{font-family:"IBM Plex Mono",monospace;font-variant-numeric:tabular-nums;text-align:right;white-space:nowrap}
td.k{color:var(--ink);font-weight:500}

/* ---------- controls ---------- */
.ctl{display:flex;flex-wrap:wrap;gap:9px;align-items:center;margin-bottom:16px}
button{font-family:inherit;font-size:.85rem;font-weight:500;padding:7px 15px;border-radius:7px;border:1px solid var(--line);background:var(--surface-2);color:var(--ink);cursor:pointer;transition:background .13s,border-color .13s,transform .06s}
button:hover:not(:disabled){border-color:var(--accent);color:var(--accent)}
button:active:not(:disabled){transform:translateY(1px)}
button:disabled{opacity:.42;cursor:not-allowed}
button.pri{background:var(--accent);border-color:var(--accent);color:#fff}
button.pri:hover:not(:disabled){filter:brightness(1.08);border-color:var(--accent);color:#fff}
:root[data-theme="dark"] button.pri{color:#0d121a}
:root[data-theme="dark"] button.pri:hover:not(:disabled){color:#0d121a}
@media (prefers-color-scheme: dark){
  :root:not([data-theme="light"]) button.pri{color:#0d121a}
  :root:not([data-theme="light"]) button.pri:hover:not(:disabled){color:#0d121a}
}
input[type=text],input[type=number],select{font-family:"IBM Plex Mono",monospace;font-size:.85rem;padding:7px 10px;border-radius:7px;border:1px solid var(--line);background:var(--surface-2);color:var(--ink);min-width:0}
input[type=range]{accent-color:var(--accent);width:100%}
label.f{display:inline-flex;flex-direction:column;gap:4px;font-size:.7rem;letter-spacing:.1em;text-transform:uppercase;color:var(--ink-3);font-weight:600}
.chips{display:flex;flex-wrap:wrap;gap:6px}
.chip{font-size:.76rem;padding:4px 10px;border-radius:999px;border:1px solid var(--line);background:var(--surface-2);color:var(--ink-2);cursor:pointer;font-family:"IBM Plex Mono",monospace}
.chip:hover{border-color:var(--accent);color:var(--accent)}
.seg{display:inline-flex;border:1px solid var(--line);border-radius:8px;overflow:hidden}
.seg button{border:none;border-radius:0;background:var(--surface-2);padding:7px 16px}
.seg button.on{background:var(--accent);color:#fff}
:root[data-theme="dark"] .seg button.on{color:#0d121a}
@media (prefers-color-scheme: dark){:root:not([data-theme="light"]) .seg button.on{color:#0d121a}}

.readout{display:flex;flex-wrap:wrap;gap:10px;margin-top:14px}
.stat{flex:1 1 130px;background:var(--surface-2);border:1px solid var(--line-soft);border-radius:8px;padding:10px 13px}
.stat .lab{font-size:.66rem;letter-spacing:.12em;text-transform:uppercase;color:var(--ink-3);font-weight:600}
.stat .val{font-family:"IBM Plex Mono",monospace;font-size:1.02rem;font-weight:500;color:var(--ink);margin-top:3px;word-break:break-all}
.stat.good .val{color:var(--prime)}
.stat.bad .val{color:var(--mark)}

/* ---------- sieve ---------- */
.sieve{display:grid;gap:3px;grid-template-columns:repeat(auto-fill,minmax(var(--cell,38px),1fr))}
.cell{aspect-ratio:1;display:grid;place-items:center;border-radius:5px;font-family:"IBM Plex Mono",monospace;font-size:calc(var(--cell,38px)*.34);font-weight:500;background:var(--surface-2);border:1px solid var(--line-soft);color:var(--ink-2);transition:background .18s,color .18s,border-color .18s,transform .18s}
.cell.prime{background:var(--prime-soft);border-color:var(--prime);color:var(--prime);font-weight:600}
.cell.comp{background:transparent;border-color:transparent;color:var(--ink-3);opacity:.42;text-decoration:line-through}
.cell.one{opacity:.3}
.cell.p{background:var(--accent);border-color:var(--accent);color:#fff;transform:scale(1.1);z-index:1}
:root[data-theme="dark"] .cell.p{color:#0d121a}
@media (prefers-color-scheme: dark){:root:not([data-theme="light"]) .cell.p{color:#0d121a}}
.cell.hit{background:var(--mark-soft);border-color:var(--mark);color:var(--mark);transform:scale(1.08)}

/* ---------- linear structures ---------- */
.track{display:flex;gap:6px;align-items:center;min-height:74px;padding:12px;background:var(--surface-2);border:1px solid var(--line-soft);border-radius:8px;overflow-x:auto}
.box{flex:none;min-width:52px;height:50px;display:grid;place-items:center;border-radius:7px;background:var(--accent-soft);border:1.5px solid var(--accent);color:var(--accent-ink);font-family:"IBM Plex Mono",monospace;font-weight:600;font-size:1rem;animation:pop .22s ease-out}
@keyframes pop{from{transform:scale(.7);opacity:0}to{transform:scale(1);opacity:1}}
.endcap{flex:none;font-size:.62rem;letter-spacing:.1em;text-transform:uppercase;color:var(--ink-3);font-weight:600;writing-mode:vertical-rl;transform:rotate(180deg)}
.empty{color:var(--ink-3);font-size:.87rem;font-style:italic;padding-left:6px}
.log{margin-top:12px;font-family:"IBM Plex Mono",monospace;font-size:.78rem;color:var(--ink-3);min-height:1.4em}

/* ---------- misc ---------- */
.steps{max-height:290px;overflow:auto;border:1px solid var(--line);border-radius:8px}
.steps table{font-size:.82rem}
.steps th{position:sticky;top:0;z-index:1}
.steps tr.cur td{background:var(--accent-soft)}
.map-row{display:grid;grid-template-columns:2.2rem 1fr;gap:12px;align-items:baseline;padding:11px 0;border-bottom:1px solid var(--line-soft)}
.map-row:last-child{border-bottom:none}
.map-idx{font-family:"IBM Plex Mono",monospace;font-weight:600;color:var(--accent);font-size:.95rem}
.map-name{font-weight:500;color:var(--ink)}
.map-why{font-size:.85rem;color:var(--ink-3)}
.pill{display:inline-block;font-size:.68rem;letter-spacing:.08em;text-transform:uppercase;font-weight:600;padding:2px 8px;border-radius:999px;background:var(--surface-2);border:1px solid var(--line);color:var(--ink-3);margin-left:7px}
.pill.new{background:var(--prime-soft);border-color:var(--prime);color:var(--prime)}
footer{margin-top:64px;padding-top:24px;border-top:1px solid var(--line);color:var(--ink-3);font-size:.83rem;display:flex;flex-wrap:wrap;gap:14px;justify-content:space-between}
.theme-btn{position:fixed;right:18px;bottom:18px;z-index:20;width:42px;height:42px;border-radius:999px;display:grid;place-items:center;background:var(--surface);border:1px solid var(--line);box-shadow:var(--shadow);font-size:1rem;padding:0}

/* ---------- добавлено для многостраничного сайта ---------- */
.pill.key{background:var(--accent-soft);border-color:var(--accent);color:var(--accent-ink)}
.pill.fixed{background:var(--mark-soft);border-color:var(--mark);color:var(--mark)}
.rail a.home{grid-template-columns:1fr;color:var(--ink-3);font-size:.8rem}
footer a{color:var(--accent)}
.idx{display:grid;gap:14px;grid-template-columns:1fr}
@media(min-width:720px){.idx{grid-template-columns:1fr 1fr}}
@media(min-width:1100px){.idx{grid-template-columns:1fr 1fr 1fr}}
.idx a{display:block;text-decoration:none;color:inherit;background:var(--surface);border:1px solid var(--line);border-radius:var(--radius);box-shadow:var(--shadow);padding:18px 20px;transition:border-color .15s,transform .06s}
.idx a:hover{border-color:var(--accent);transform:translateY(-1px)}
.idx .wk{font-family:"IBM Plex Mono",monospace;font-size:.7rem;letter-spacing:.1em;text-transform:uppercase;color:var(--ink-3);font-weight:600}
.idx h3{font-family:Newsreader,serif;font-weight:500;font-size:1.3rem;margin:6px 0 6px;color:var(--ink)}
.idx p{font-size:.86rem;color:var(--ink-2)}
.idx .meta{margin-top:11px;font-family:"IBM Plex Mono",monospace;font-size:.74rem;color:var(--ink-3)}

/* длинный код — свёрнут, раскрывается по клику */
details.code{border:1px solid var(--line-soft);border-radius:8px;background:var(--surface-2)}
details.code>summary{cursor:pointer;list-style:none;display:flex;align-items:center;gap:10px;
  padding:10px 14px;font-family:"IBM Plex Mono",monospace;font-size:.85rem;color:var(--ink)}
details.code>summary::-webkit-details-marker{display:none}
details.code>summary::before{content:"▸";color:var(--accent);transition:transform .15s}
details.code[open]>summary::before{transform:rotate(90deg)}
details.code>summary .lines{margin-left:auto;font-size:.72rem;color:var(--ink-3)}
details.code>summary:hover{color:var(--accent)}
details.code>pre{border:0;border-top:1px solid var(--line-soft);border-radius:0 0 8px 8px}
/* вывод программы */
.out-lbl{font-size:.66rem;letter-spacing:.13em;text-transform:uppercase;color:var(--ink-3);font-weight:600;margin:13px 0 6px}
pre.out{color:var(--ink-2)}