/* Layout: two regions. Left = the slide you read (text, worked example, exercise). Right = the lab, sticky: plane on top, code + output underneath. */
:root{
  --paper:#F2F4F7; --surface:#FFFFFF; --ink:#18202E; --muted:#5B6578; --line:#E1E5EC; --soft:#F6F7FA;
  --grid:#C3CCD9; --grid-ref:#E8EBF0; --accent:#3B4FD8; --accent-soft:#ECEFFE; --accent-ink:#FFFFFF;
  --ihat:#E0522C; --jhat:#0E9A84; --area:rgba(59,79,216,.13); --shape:#18202E;
  --ok:#0E8A5F; --ok-soft:#E2F4EB;
  --code-bg:#151B27; --code-line:rgba(255,255,255,.08); --code-fg:#E5E9F2;
  --tk-kw:#B8A1FF; --tk-num:#FFB374; --tk-str:#9BDB8C; --tk-com:#6F7A90; --tk-fn:#7CC7FF;
  --f-display:"Bricolage Grotesque", "Segoe UI", system-ui, sans-serif;
  --f-body:"IBM Plex Sans", "Segoe UI", system-ui, sans-serif;
  --f-mono:"JetBrains Mono", ui-monospace, "Cascadia Code", Consolas, monospace;
}
@media (prefers-color-scheme: dark){:root:not([data-theme="light"]){
  --paper:#0E1219; --surface:#161C27; --ink:#E7EBF3; --muted:#9AA4B8; --line:#262E3F; --soft:#1C2331;
  --grid:#36425C; --grid-ref:#1F2735; --accent:#8C9BFF; --accent-soft:#232B4A; --accent-ink:#0E1219;
  --ihat:#FF7A52; --jhat:#33D1B4; --area:rgba(140,155,255,.16); --shape:#E7EBF3;
  --ok:#4FD39B; --ok-soft:#16302A; --code-bg:#0B0F16; color-scheme:dark}}
:root[data-theme="dark"]{
  --paper:#0E1219; --surface:#161C27; --ink:#E7EBF3; --muted:#9AA4B8; --line:#262E3F; --soft:#1C2331;
  --grid:#36425C; --grid-ref:#1F2735; --accent:#8C9BFF; --accent-soft:#232B4A; --accent-ink:#0E1219;
  --ihat:#FF7A52; --jhat:#33D1B4; --area:rgba(140,155,255,.16); --shape:#E7EBF3;
  --ok:#4FD39B; --ok-soft:#16302A; --code-bg:#0B0F16; color-scheme:dark}

*{box-sizing:border-box}
[hidden]{display:none!important}
body{background:var(--paper);color:var(--ink);font-family:var(--f-body);font-size:16px;line-height:1.65;
  padding-left:max(20px,env(safe-area-inset-left,0px));padding-right:max(20px,env(safe-area-inset-right,0px));padding-block:18px 40px}
.top{max-width:1380px;margin:0 auto 16px;display:flex;align-items:center;justify-content:space-between;gap:16px;flex-wrap:wrap}
.course{display:flex;align-items:baseline;gap:12px;flex-wrap:wrap}
.course b{font-family:var(--f-display);font-weight:700;font-size:19px;letter-spacing:-.01em}
.course span{color:var(--muted);font-size:14px}
.steps{display:flex;gap:6px;align-items:center;flex-wrap:wrap}
.step{font:inherit;font-size:12px;font-weight:600;font-variant-numeric:tabular-nums;width:28px;height:28px;border-radius:50%;border:1px solid var(--line);background:var(--surface);color:var(--muted);cursor:pointer;display:grid;place-items:center;padding:0}
.step.on{background:var(--accent);border-color:var(--accent);color:var(--accent-ink)}
.step.done:not(.on){background:var(--ok-soft);border-color:var(--ok);color:var(--ok)}
.step:focus-visible,.btn:focus-visible{outline:2px solid var(--accent);outline-offset:2px}

.app{max-width:1380px;margin:0 auto;display:grid;grid-template-columns:minmax(0,1fr) minmax(0,1.1fr);gap:24px;align-items:start}

/* Left: the slide */
.page{background:var(--surface);border:1px solid var(--line);border-radius:16px;padding:36px 44px 28px;min-width:0}
.kicker{font-size:12px;font-weight:600;letter-spacing:.09em;text-transform:uppercase;color:var(--accent);margin-bottom:10px}
.page h1{font-family:var(--f-display);font-weight:700;font-size:clamp(28px,2.6vw,36px);line-height:1.1;letter-spacing:-.02em;margin:0 0 14px;text-wrap:balance}
.lead{font-size:18px;line-height:1.55;margin:0 0 20px;max-width:60ch}
.key{display:flex;align-items:center;justify-content:center;gap:14px;flex-wrap:wrap;background:var(--accent-soft);border-radius:12px;padding:18px 20px;margin:0 0 26px;font-family:var(--f-mono);font-size:16px;text-align:center}
.prose{max-width:64ch}
.prose h2{font-family:var(--f-body);font-size:13px;font-weight:600;letter-spacing:.08em;text-transform:uppercase;color:var(--muted);margin:26px 0 8px}
.prose p{margin:0 0 12px}
.prose ul{margin:0 0 12px;padding-left:20px} .prose li{margin-bottom:6px}
.worked{background:var(--soft);border:1px solid var(--line);border-radius:12px;padding:14px 18px;margin:6px 0 14px;font-size:15px}
.worked .row{font-family:var(--f-mono);font-size:14px;line-height:1.8;overflow-wrap:anywhere}
.mx{display:inline-grid;grid-template-columns:auto auto;gap:0 14px;padding:1px 10px;border-left:2px solid currentColor;border-right:2px solid currentColor;border-radius:6px;font-family:var(--f-mono);font-size:.92em;vertical-align:middle;line-height:1.5}
.vec{display:inline-grid;grid-template-columns:auto;padding:1px 8px;border-left:2px solid currentColor;border-right:2px solid currentColor;border-radius:6px;font-family:var(--f-mono);font-size:.92em;vertical-align:middle;line-height:1.5;text-align:center}
.c1,.i{color:var(--ihat)} .c2,.j{color:var(--jhat)} .i,.j{font-weight:600}
code{font-family:var(--f-mono);font-size:.86em;background:var(--soft);border:1px solid var(--line);padding:1px 5px;border-radius:5px}
a{color:var(--accent)}

.exercise{margin-top:28px;border:1px solid var(--line);border-radius:12px;padding:16px 18px;display:grid;grid-template-columns:auto minmax(0,1fr);gap:4px 14px;align-items:start}
.exercise .tag{grid-row:span 2;font-size:11px;font-weight:600;letter-spacing:.08em;text-transform:uppercase;background:var(--ink);color:var(--surface);padding:4px 8px;border-radius:5px;margin-top:3px}
.exercise .task{font-weight:600}
.exercise .hint{color:var(--muted);font-size:14px}
.exercise.ok{border-color:var(--ok);background:var(--ok-soft)}
.exercise.ok .tag{background:var(--ok);color:var(--surface)}
.exercise.ok .hint{color:var(--ok);font-weight:600}
.nav{display:flex;align-items:center;justify-content:space-between;gap:12px;margin-top:22px;padding-top:18px;border-top:1px solid var(--line)}
.nav .count{font-family:var(--f-mono);font-size:13px;color:var(--muted);font-variant-numeric:tabular-nums}
.btn{font:inherit;font-weight:600;font-size:14px;border-radius:9px;border:1px solid var(--line);background:var(--surface);color:var(--ink);padding:9px 16px;cursor:pointer}
.btn:hover{border-color:var(--muted)} .btn:disabled{opacity:.35;cursor:default}
.btn.primary{background:var(--accent);border-color:var(--accent);color:var(--accent-ink)}

/* Right: the lab */
.lab{position:sticky;top:14px;display:flex;flex-direction:column;gap:14px;min-width:0;height:calc(100vh - 28px);min-height:600px}
.figure{background:var(--surface);border:1px solid var(--line);border-radius:16px;overflow:hidden;flex:1 1 auto;min-height:260px;display:flex;flex-direction:column}
.plane{position:relative;flex:1 1 auto;min-height:0;background:var(--surface)}
.plane canvas{position:absolute;inset:0;width:100%;height:100%;display:block}
.figcap{display:flex;justify-content:space-between;align-items:center;gap:8px 16px;flex-wrap:wrap;padding:10px 16px;border-top:1px solid var(--line);font-size:12.5px;color:var(--muted)}
.legend{display:flex;gap:14px;flex-wrap:wrap}
.legend i{display:inline-block;width:14px;height:3px;border-radius:2px;margin-right:6px;vertical-align:middle}
.readout{display:flex;gap:12px;flex-wrap:wrap;font-family:var(--f-mono);font-size:12px;font-variant-numeric:tabular-nums}
.readout .hi{color:var(--accent)} .readout .good{color:var(--ok);font-weight:600}

.editor-card{background:var(--code-bg);border-radius:16px;overflow:hidden;display:flex;flex-direction:column;flex:none}
.bar{display:flex;align-items:center;gap:10px;padding:9px 10px 9px 16px;border-bottom:1px solid var(--code-line);color:#9AA4B8;font-size:12px}
.bar .file{font-family:var(--f-mono);color:#E5E9F2;margin-right:auto}
.bar .status{display:flex;align-items:center;gap:6px}
.bar .status::before{content:"";width:7px;height:7px;border-radius:50%;background:#E6B450}
.bar .status.ready::before{background:#4FD39B}
.bar .btn{background:transparent;color:#E5E9F2;border-color:rgba(255,255,255,.16);padding:5px 12px;font-size:13px}
.bar .btn.primary{background:#8C9BFF;border-color:#8C9BFF;color:#0B0F16}
.editor{position:relative;display:flex;height:212px;overflow:auto;font-family:var(--f-mono);font-size:13.5px;line-height:1.6}
.gutter{flex:none;padding:12px 10px 12px 14px;color:#4C566B;text-align:right;user-select:none;white-space:pre;font-variant-numeric:tabular-nums}
.code{position:relative;flex:1;min-width:0}
.code pre,.code textarea{margin:0;padding:12px 16px 12px 4px;font:inherit;line-height:inherit;white-space:pre;tab-size:4;border:0}
.code pre{position:absolute;inset:0 auto auto 0;min-width:100%;pointer-events:none;color:var(--code-fg)}
.code textarea{position:relative;display:block;width:100%;resize:none;background:transparent;color:transparent;caret-color:#fff;outline:none;overflow:hidden}
.code textarea::selection{background:rgba(140,155,255,.35);color:transparent}
.tk-kw{color:var(--tk-kw)} .tk-num{color:var(--tk-num)} .tk-str{color:var(--tk-str)} .tk-com{color:var(--tk-com);font-style:italic} .tk-fn{color:var(--tk-fn)}
.outhead{display:flex;align-items:center;justify-content:space-between;padding:6px 16px;border-top:1px solid var(--code-line);font-size:11px;letter-spacing:.08em;text-transform:uppercase;color:#6F7A90}
.outhead button{font:inherit;background:none;border:0;color:#6F7A90;cursor:pointer;letter-spacing:.08em;text-transform:uppercase}
.out{margin:0;padding:4px 16px 14px;font-family:var(--f-mono);font-size:13px;line-height:1.55;color:#C9D1DD;white-space:pre-wrap;overflow:auto;height:92px}
.out .err{color:#FF8B80} .out .sys{color:#6F7A90}
.foot{max-width:1380px;margin:22px auto 0;font-size:12.5px;color:var(--muted)}

@media (max-width:1020px){
  .app{grid-template-columns:minmax(0,1fr)}
  .lab{position:static;height:auto;min-height:0}
  .plane{flex:none;aspect-ratio:1/1;max-width:100%}
  .page{padding:26px 22px 22px}
}
@media (prefers-reduced-motion: reduce){*{transition:none!important}}

/* static-site additions */
.step{text-decoration:none}
a.btn{text-decoration:none;display:inline-block}
a.btn.disabled{opacity:.35;pointer-events:none}
.crumbs{font-size:13px;color:var(--muted)} .crumbs a{color:var(--muted)}
.home{max-width:1080px;margin:0 auto}
.hero{padding:48px 0 28px;display:grid;gap:14px}
.hero h1{font-family:var(--f-display);font-weight:700;font-size:clamp(34px,5vw,56px);line-height:1.03;letter-spacing:-.03em;margin:0;max-width:16ch;text-wrap:balance}
.hero p{font-size:19px;max-width:58ch;margin:0;color:var(--muted)}
.hero .cta{display:flex;gap:10px;flex-wrap:wrap;margin-top:8px}
.cards{display:grid;grid-template-columns:repeat(auto-fill,minmax(280px,1fr));gap:14px;margin:8px 0 32px}
.card{display:block;background:var(--surface);border:1px solid var(--line);border-radius:14px;padding:18px 20px;color:var(--ink);text-decoration:none}
a.card:hover{border-color:var(--accent)}
.card .n{font-family:var(--f-mono);font-size:12px;color:var(--accent)}
.card h3{font-family:var(--f-display);font-size:20px;margin:4px 0 6px;letter-spacing:-.01em}
.card p{margin:0;color:var(--muted);font-size:14.5px}
.card.soon{opacity:.6}
.section-title{font-family:var(--f-display);font-size:24px;margin:24px 0 10px;letter-spacing:-.01em}
.panel{background:var(--surface);border:1px solid var(--line);border-radius:14px;padding:22px 24px;margin:0 0 28px;max-width:72ch}
.panel p{margin:0 0 10px} .panel p:last-child{margin:0}
.signup{background:var(--accent-soft);border-radius:14px;padding:20px 22px;margin-top:22px;display:flex;align-items:center;justify-content:space-between;gap:12px 20px;flex-wrap:wrap}
.signup p{margin:0;max-width:56ch}

/* table view: matrices drawn as text */
.tablebox{position:absolute;inset:0;display:flex;flex-wrap:wrap;align-content:center;justify-content:center;gap:22px 28px;padding:22px;overflow:auto;background:var(--surface)}
.tm{display:flex;flex-direction:column;align-items:center;gap:6px}
.tm-label{font-family:var(--f-mono);font-size:13px;font-weight:600;color:var(--accent)}
.tm-grid{display:grid;gap:4px 14px;padding:6px 12px;border-left:2px solid var(--ink);border-right:2px solid var(--ink);border-radius:8px;font-family:var(--f-mono);font-size:15px;font-variant-numeric:tabular-nums;text-align:right}
.tm-grid .pv{background:var(--accent-soft);color:var(--accent);font-weight:600;border-radius:4px;padding:0 4px;margin:0 -4px}
.tm-dim{font-family:var(--f-mono);font-size:11px;color:var(--muted)}

/* top navigation: course › chapter › lesson, then steps */
.top{position:relative;z-index:20}
.topnav{display:flex;align-items:center;gap:10px 14px;flex-wrap:wrap;min-width:0}
.brand{font-family:var(--f-display);font-weight:700;font-size:19px;letter-spacing:-.01em;color:var(--ink);text-decoration:none;white-space:nowrap}
.crumbnav{display:flex;align-items:center;gap:6px;flex-wrap:wrap;min-width:0}
.crumbnav .sep{color:var(--muted)}
.menu{position:relative}
.menu summary{list-style:none;cursor:pointer;display:flex;align-items:center;gap:6px;font-size:14px;font-weight:500;color:var(--ink);background:var(--surface);border:1px solid var(--line);border-radius:999px;padding:6px 12px;white-space:nowrap}
.menu summary::-webkit-details-marker{display:none}
.menu summary::after{content:"";width:7px;height:7px;border-right:1.5px solid var(--muted);border-bottom:1.5px solid var(--muted);transform:rotate(45deg) translateY(-2px);margin-left:2px}
.menu[open] summary{border-color:var(--accent)}
.menu summary:hover{border-color:var(--muted)}
.menu summary:focus-visible{outline:2px solid var(--accent);outline-offset:2px}
.menu-list{position:absolute;top:calc(100% + 6px);left:0;z-index:30;width:min(360px,calc(100vw - 32px));max-height:min(70vh,560px);overflow:auto;background:var(--surface);border:1px solid var(--line);border-radius:14px;box-shadow:0 12px 32px rgba(15,20,30,.14);padding:8px}
.menu-group{display:flex;flex-direction:column;padding:6px 0;border-bottom:1px solid var(--line)}
.menu-group:last-child{border-bottom:0}
.menu-h{font-size:11px;font-weight:600;letter-spacing:.08em;text-transform:uppercase;color:var(--muted);padding:4px 10px}
.menu-group.on .menu-h{color:var(--accent)}
.menu-item{display:block;padding:7px 10px;border-radius:8px;color:var(--ink);text-decoration:none;font-size:14px;line-height:1.35}
a.menu-item:hover{background:var(--soft)}
.menu-item.on{background:var(--accent-soft);color:var(--accent);font-weight:600}
.menu-item.sub{font-size:13.5px;color:var(--muted)} a.menu-item.sub:hover{color:var(--ink)}
.menu-item.soon{color:var(--muted);opacity:.7}
.step.practice{font-size:14px}
.chapter-title{font-family:var(--f-display);font-size:18px;margin:22px 0 10px;color:var(--muted);letter-spacing:-.01em}
.practice-card{border-style:dashed}
@media (max-width:640px){ .hide-sm{display:none} .brand{font-size:17px} .crumbnav{position:relative} .menu{position:static} .menu-list{left:0} }

/* practice page */
.practice-h{font-family:var(--f-display);font-size:24px;letter-spacing:-.01em;margin:30px 0 12px}
.examples{display:flex;flex-direction:column;gap:14px}
.example{border:1px solid var(--line);border-radius:12px;padding:16px 18px;max-width:72ch}
.example h3{font-family:var(--f-body);font-size:13px;font-weight:600;letter-spacing:.06em;text-transform:uppercase;color:var(--accent);margin:0 0 8px}
.example p{margin:0 0 10px}
.problems{display:flex;flex-direction:column;gap:12px}
.problem{display:grid;grid-template-columns:auto minmax(0,1fr);gap:12px;border:1px solid var(--line);border-radius:12px;padding:14px 16px;max-width:72ch}
.pnum{font-family:var(--f-mono);font-weight:600;font-size:13px;width:28px;height:28px;border-radius:50%;background:var(--accent-soft);color:var(--accent);display:grid;place-items:center}
.pbody p{margin:2px 0 10px}
details.sol summary{list-style:none;cursor:pointer;display:inline-flex;align-items:center;gap:6px;font-size:13.5px;font-weight:600;color:var(--accent);border:1px solid var(--accent);border-radius:8px;padding:5px 12px}
details.sol summary::-webkit-details-marker{display:none}
details.sol summary::before{content:"+";font-family:var(--f-mono)}
details.sol[open] summary::before{content:"−"}
details.sol[open] summary{background:var(--accent-soft)}
details.sol summary:focus-visible{outline:2px solid var(--accent);outline-offset:2px}
.solbody{margin-top:10px;padding:12px 14px;background:var(--soft);border-radius:10px;font-size:15px}
.solbody p{margin:0 0 8px} .solbody p:last-child{margin:0}
details.sol .s-hide{display:none}
details.sol[open] .s-hide{display:inline}
details.sol[open] .s-show{display:none}

/* menu v2: clear chapter > lesson hierarchy */
.menu-list{width:min(400px,calc(100vw - 32px));padding:10px 10px 12px}
.menu-sub{font-size:11px;font-weight:600;letter-spacing:.09em;text-transform:uppercase;color:var(--muted);padding:8px 10px 6px}
.menu-sub:not(:first-child){margin-top:6px;border-top:1px solid var(--line);padding-top:14px}
.ch{padding:4px 0 6px}
.ch-head{display:flex;align-items:center;gap:10px;padding:6px 10px}
.ch-num{flex:none;width:24px;height:24px;border-radius:50%;display:grid;place-items:center;font-family:var(--f-mono);font-size:12px;font-weight:600;background:var(--soft);color:var(--muted);border:1px solid var(--line)}
.ch-title{font-family:var(--f-display);font-weight:700;font-size:16px;letter-spacing:-.01em;color:var(--ink)}
.ch.on .ch-num{background:var(--accent);border-color:var(--accent);color:var(--accent-ink)}
.ch-lessons{display:flex;flex-direction:column;gap:2px;margin:2px 0 0 21px;padding-left:12px;border-left:2px solid var(--line)}
.ch.on .ch-lessons{border-left-color:var(--accent)}
.ch-lessons.flat{margin:0;padding:0 2px;border-left:0}
.ls{display:flex;align-items:baseline;gap:10px;padding:7px 10px;border-radius:9px;color:var(--ink);text-decoration:none;font-size:14.5px;line-height:1.35}
.ls:hover{background:var(--soft)}
.ls-num{flex:none;min-width:58px;font-family:var(--f-mono);font-size:12px;color:var(--muted)}
.slides .ls-num{min-width:18px}
.ls.on{background:var(--accent-soft)}
.ls.on .ls-title{color:var(--accent);font-weight:600}
.ls.on .ls-num{color:var(--accent)}
.ch-later{display:grid;grid-template-columns:1fr 1fr;gap:0 4px}
.ch.soon{padding:0}
.ch.soon .ch-head{padding:5px 10px}
.ch.soon .ch-title{font-family:var(--f-body);font-weight:500;font-size:13.5px;color:var(--muted)}
.ch.soon .ch-num{width:20px;height:20px;font-size:11px}
@media (max-width:420px){ .ch-later{grid-template-columns:1fr} }

.step.practice{width:auto;padding:0 12px;border-radius:999px;font-size:12.5px;font-weight:600;border-color:var(--accent);color:var(--accent)}
.step.practice.on{color:var(--accent-ink)}
.practice-link{display:flex;align-items:center;gap:14px;margin-top:14px;padding:14px 18px;border:1px dashed var(--accent);border-radius:12px;color:var(--ink);text-decoration:none;font-size:14.5px;line-height:1.45;background:var(--surface)}
.practice-link:hover{background:var(--accent-soft)}
.practice-link b{color:var(--accent)}
.pl-icon{flex:none;width:34px;height:34px;border-radius:50%;display:grid;place-items:center;background:var(--accent-soft);color:var(--accent);font-size:16px}
.pl-arrow{margin-left:auto;color:var(--accent);font-size:18px}

/* layout v3 (27 Oct): article on top, then code left + visual right */
.lesson{max-width:1380px;margin:0 auto;display:flex;flex-direction:column;gap:18px}
.lesson .page{padding:40px 56px 34px}
.lesson .prose,.lesson .lead{max-width:72ch}
.lesson .key{max-width:72ch}
.labsec{display:flex;flex-direction:column;gap:14px}
.labsec .exercise{margin-top:0;background:var(--surface)}
.lesson .lab{position:static;height:auto;min-height:0;display:grid;grid-template-columns:minmax(0,1fr) minmax(0,1fr);gap:16px;align-items:start}
.lesson .figure{position:sticky;top:14px;flex:none;display:block;min-height:0}
.lesson .plane{flex:none;aspect-ratio:4/3;max-width:100%}
.lesson .editor{height:auto;min-height:180px;overflow-x:auto;overflow-y:visible}
.lesson .out{height:auto;min-height:72px;max-height:320px}
.after{display:flex;flex-direction:column;gap:12px;background:var(--surface);border:1px solid var(--line);border-radius:16px;padding:6px 24px 18px}
.after .practice-link{margin-top:14px}
.after .nav{border-top:0;margin-top:6px;padding-top:6px}
@media (max-width:1020px){
  .lesson .page{padding:26px 22px 22px}
  .lesson .lab{grid-template-columns:minmax(0,1fr)}
  .lesson .figure{position:static}
  .lesson .plane{aspect-ratio:1/1}
  .after{padding:6px 16px 14px}
}

.lesson .examples,.lesson .problems{max-width:72ch}
.practice-note{margin:-6px 0 12px;color:var(--muted);font-size:14.5px}
.page .practice-h{border-top:1px solid var(--line);padding-top:24px}

/* full-width article (27 Oct): text and boxes use the whole card width, all aligned to the same edges */
.lesson .page .lead,.lesson .page .key,.lesson .page .prose,.lesson .page .prose p,.lesson .page .examples,.lesson .page .problems,.lesson .page .example,.lesson .page .problem,.lesson .page .signup{max-width:none}
.lesson .page .key{justify-content:flex-start;text-align:left}
.lesson .page .prose ul{padding-left:22px}

/* sticky top bar (27 Oct): menus and steps stay visible while scrolling */
.top{position:sticky;top:0;z-index:40;background:var(--paper);padding-block:calc(10px + env(safe-area-inset-top, 0px)) 10px;margin-bottom:12px;box-shadow:0 0 0 100vmax var(--paper);clip-path:inset(0 -100vmax -1px -100vmax);border-bottom:1px solid var(--line)}
.lesson .figure{top:84px}
@media (max-width:640px){ .top{padding-block:calc(8px + env(safe-area-inset-top, 0px)) 8px} }
/* the full-width band is drawn by a pseudo-element, so the open menus are not clipped */
.top{clip-path:none;box-shadow:none;border-bottom:0}
.top::before{content:"";position:absolute;top:0;bottom:0;left:-100vmax;right:-100vmax;background:var(--paper);border-bottom:1px solid var(--line);z-index:-1}
html,body{overflow-x:clip}