:root{
  --google-blue:#4285F4; --google-red:#EA4335; --google-yellow:#FBBC04; --google-green:#34A853;
  --blue-700:#1967D2; --green-700:#1E8E3E; --red-700:#C5221F; --yellow-800:#B06000;
  --grey-900:#202124; --grey-700:#5F6368; --grey-500:#9AA0A6; --grey-300:#DADCE0; --grey-200:#E8EAED; --grey-100:#F1F3F4;
  --surface:#FFFFFF; --surface-alt:#F8F9FA;
  --blue-bg:#E8F0FE; --yellow-bg:#FEF7E0; --green-bg:#E6F4EA; --red-bg:#FCE8E6;
  --radius-sm:8px; --radius-md:16px; --radius-lg:24px;
  --shadow-card:0 1px 2px rgba(60,64,67,.08),0 1px 3px rgba(60,64,67,.10);
  --shadow-lift:0 4px 8px rgba(60,64,67,.10),0 8px 24px rgba(60,64,67,.15);
  --sidebar-w:300px; --content-max:760px;
}
*{margin:0;padding:0;box-sizing:border-box;}
html{scroll-behavior:smooth;}
body{
  font-family:'Google Sans Text',-apple-system,BlinkMacSystemFont,'Segoe UI',Roboto,sans-serif;
  font-size:20px; line-height:1.65; color:var(--grey-900); background:var(--surface);
  -webkit-font-smoothing:antialiased;
}
h1,h2,h3,h4{font-family:'Google Sans',sans-serif;line-height:1.25;color:var(--grey-900);}
a{color:var(--blue-700);text-decoration:none;}
a:hover{text-decoration:underline;}
code{font-family:'Roboto Mono',monospace;font-size:0.9em;background:var(--grey-100);padding:.1em .35em;border-radius:4px;}
strong{font-weight:500;}
ul,ol{margin:0 0 1rem 1.3rem;} li{margin-bottom:.4rem;}

/* Jargon links to glossary */
a.jargon{color:inherit;border-bottom:1px dotted var(--grey-500);}
a.jargon:hover{color:var(--blue-700);border-bottom-color:var(--blue-700);text-decoration:none;}

/* Layout */
.layout{display:flex;max-width:1240px;margin:0 auto;}
.sidebar{
  position:sticky;top:0;align-self:flex-start;height:100vh;width:var(--sidebar-w);flex:0 0 var(--sidebar-w);
  overflow-y:auto;padding:1.75rem 1.25rem;border-right:1px solid var(--grey-200);background:var(--surface-alt);
}
.sidebar .eyebrow{font-size:.8rem;font-weight:500;letter-spacing:.08em;text-transform:uppercase;color:var(--google-blue);}
.sidebar h2{font-size:1.15rem;margin:.15rem 0 1.25rem;}
.toc a{
  display:block;padding:.4rem .6rem;border-radius:var(--radius-sm);color:var(--grey-700);
  font-size:.95rem;line-height:1.35;border-left:3px solid transparent;
}
.toc a:hover{background:var(--grey-100);text-decoration:none;color:var(--grey-900);}
.toc a.active{color:var(--blue-700);background:var(--blue-bg);border-left-color:var(--google-blue);font-weight:500;}
.toc .toc-num{display:inline-block;width:1.5rem;color:var(--grey-500);font-variant-numeric:tabular-nums;}
.toc .toc-group{margin-top:1rem;font-size:.72rem;font-weight:700;letter-spacing:.09em;text-transform:uppercase;color:var(--grey-500);padding:0 .6rem .25rem;}

.main{flex:1 1 auto;min-width:0;padding:2.5rem clamp(1.1rem,4vw,3.5rem);}
.content{max-width:var(--content-max);margin:0 auto;}

/* Topbar (mobile) */
.topbar{display:none;position:sticky;top:0;z-index:40;align-items:center;gap:.75rem;
  padding:.75rem 1rem;background:var(--surface);border-bottom:1px solid var(--grey-200);}
.topbar-title{font-family:'Google Sans';font-weight:500;font-size:1rem;}
.menu-btn{width:2.5rem;height:2.5rem;display:flex;align-items:center;justify-content:center;
  border:1px solid var(--grey-300);border-radius:var(--radius-sm);background:var(--surface);cursor:pointer;color:var(--grey-700);}
.overlay{display:none;position:fixed;inset:0;background:rgba(32,33,36,.45);z-index:45;}

/* Hero */
.hero{margin-bottom:2.5rem;}
.eyebrow{font-size:.85rem;font-weight:500;letter-spacing:.08em;text-transform:uppercase;color:var(--google-blue);margin-bottom:.5rem;}
.hero h1{font-size:2.4rem;letter-spacing:-.01em;margin-bottom:.75rem;}
.lede{font-size:1.2rem;color:var(--grey-700);}
.hero .lede strong{color:var(--grey-900);font-weight:500;}

h2.sec{font-size:1.7rem;margin:3rem 0 1rem;padding-top:1rem;scroll-margin-top:1rem;}
h2.sec .kicker{display:block;font-family:'Google Sans Text';font-size:.8rem;font-weight:700;letter-spacing:.09em;text-transform:uppercase;color:var(--google-blue);margin-bottom:.15rem;}
h3.sub{font-size:1.2rem;margin:1.75rem 0 .6rem;}
p{margin-bottom:1rem;}
.small{font-size:.92rem;color:var(--grey-700);}

/* Fast path chip */
.fastpath{display:flex;flex-wrap:wrap;gap:.6rem;align-items:center;background:var(--surface-alt);
  border:1px solid var(--grey-200);border-radius:var(--radius-md);padding:.9rem 1.1rem;margin:1.5rem 0;font-size:.95rem;}
.fastpath strong{font-family:'Google Sans';}

/* Callouts */
.callout{border-radius:var(--radius-md);padding:1rem 1.15rem;margin:1.25rem 0;border-left:4px solid;font-size:.98rem;}
.callout p:last-child{margin-bottom:0;}
.callout .label{font-family:'Google Sans';font-weight:700;font-size:.8rem;letter-spacing:.05em;text-transform:uppercase;display:block;margin-bottom:.3rem;}
.callout--tip{background:var(--green-bg);border-color:var(--google-green);} .callout--tip .label{color:var(--green-700);}
.callout--key{background:var(--blue-bg);border-color:var(--google-blue);} .callout--key .label{color:var(--blue-700);}
.callout--warn{background:var(--red-bg);border-color:var(--google-red);} .callout--warn .label{color:var(--red-700);}
.callout--note{background:var(--yellow-bg);border-color:var(--google-yellow);} .callout--note .label{color:var(--yellow-800);}

/* Maturity ladder */
.ladder{display:flex;flex-direction:column;gap:.5rem;margin:1.5rem 0;}
.rung{display:flex;gap:1rem;align-items:flex-start;background:var(--surface);border:1px solid var(--grey-200);
  border-radius:var(--radius-md);padding:1rem 1.15rem;box-shadow:var(--shadow-card);}
.rung .lvl{flex:0 0 2.4rem;height:2.4rem;border-radius:50%;display:flex;align-items:center;justify-content:center;
  font-family:'Google Sans';font-weight:700;color:#fff;}
.rung h4{font-size:1.05rem;margin-bottom:.15rem;}
.rung p{margin:0;font-size:.95rem;color:var(--grey-700);}
.rung--0 .lvl{background:var(--grey-500);} .rung--1 .lvl{background:var(--google-red);}
.rung--2 .lvl{background:var(--google-yellow);color:var(--grey-900);} .rung--3 .lvl{background:var(--google-blue);}
.rung--4 .lvl{background:var(--google-green);}

/* Concept cards */
.cards{display:grid;grid-template-columns:repeat(auto-fit,minmax(210px,1fr));gap:.75rem;margin:1.5rem 0;}
.card{background:var(--surface);border:1px solid var(--grey-200);border-radius:var(--radius-md);padding:1rem 1.15rem;box-shadow:var(--shadow-card);}
.card .n{font-family:'Google Sans';font-weight:700;font-size:.78rem;letter-spacing:.06em;text-transform:uppercase;color:var(--google-blue);}
.card h4{font-size:1.02rem;margin:.15rem 0 .3rem;}
.card p{margin:0;font-size:.93rem;color:var(--grey-700);}

/* Step (how-to four-beat) */
.step{border:1px solid var(--grey-200);border-radius:var(--radius-lg);padding:1.5rem;margin:1.5rem 0;box-shadow:var(--shadow-card);}
.step-head{display:flex;gap:.85rem;align-items:center;margin-bottom:.75rem;}
.step-num{flex:0 0 2.2rem;height:2.2rem;border-radius:50%;background:var(--google-blue);color:#fff;
  font-family:'Google Sans';font-weight:700;display:flex;align-items:center;justify-content:center;}
.step-head h3{font-size:1.2rem;margin:0;}
.code-block{position:relative;background:#202124;border-radius:var(--radius-sm);margin:.85rem 0;overflow:hidden;}
.code-block pre{margin:0;padding:1rem 1.1rem;overflow-x:auto;color:#E8EAED;font-family:'Roboto Mono',monospace;font-size:.9rem;line-height:1.6;}
.code-block code{background:none;padding:0;color:inherit;font-size:inherit;}
.copy-btn{position:absolute;top:.55rem;right:.55rem;background:rgba(255,255,255,.1);color:#E8EAED;border:1px solid rgba(255,255,255,.2);
  border-radius:6px;padding:.25rem .6rem;font-size:.78rem;font-family:'Google Sans Text';cursor:pointer;}
.copy-btn:hover{background:rgba(255,255,255,.2);}
.verify{display:flex;gap:.6rem;align-items:flex-start;background:var(--green-bg);border-radius:var(--radius-sm);padding:.7rem .9rem;font-size:.95rem;margin-top:.5rem;}
.verify svg{flex:0 0 1.25rem;margin-top:.15rem;color:var(--green-700);}
.verify b{font-family:'Google Sans';color:var(--green-700);}

/* Good/bad pairs */
.pair{display:grid;grid-template-columns:1fr 1fr;gap:.75rem;margin:1.5rem 0;}
.pair > div{border-radius:var(--radius-md);padding:.9rem 1.1rem;border:1px solid;font-size:.94rem;}
.pair p{margin:0;} .pair p + p{margin-top:.5rem;}
.pair--bad{background:var(--red-bg);border-color:#F3C0BD;}
.pair--good{background:var(--green-bg);border-color:#B7E1C5;}
.pair .tag{font-family:'Google Sans';font-weight:700;font-size:.72rem;letter-spacing:.06em;text-transform:uppercase;display:block;margin-bottom:.35rem;}
.pair--bad .tag{color:var(--red-700);} .pair--good .tag{color:var(--green-700);}

/* Definition-of-done checklist */
.dod{list-style:none;margin:1.25rem 0;padding:0;display:flex;flex-direction:column;gap:.5rem;}
.dod li{display:flex;gap:.6rem;align-items:flex-start;background:var(--surface-alt);border:1px solid var(--grey-200);
  border-radius:var(--radius-sm);padding:.6rem .85rem;font-size:.95rem;margin:0;}
.dod li::before{content:"✓";color:var(--green-700);font-weight:700;flex:0 0 auto;}

/* Glossary */
.gloss{display:grid;grid-template-columns:1fr;gap:.75rem;margin:1.25rem 0;}
.term{background:var(--surface);border:1px solid var(--grey-200);border-radius:var(--radius-md);padding:1rem 1.15rem;scroll-margin-top:1rem;}
.term dt{font-family:'Google Sans';font-weight:700;font-size:1.02rem;margin-bottom:.2rem;}
.term dd{margin:0;font-size:.96rem;color:var(--grey-700);}
.term:target{border-color:var(--google-blue);box-shadow:0 0 0 3px var(--blue-bg);}
.gloss-cat{grid-column:1/-1;font-family:'Google Sans';font-size:.78rem;font-weight:700;letter-spacing:.08em;text-transform:uppercase;color:var(--google-blue);margin-top:1rem;}

/* Resources */
.res{margin:1.25rem 0;}
.res h3{font-size:1.1rem;margin:1.5rem 0 .4rem;}
.res ul{list-style:none;margin:0;padding:0;}
.res li{padding:.45rem 0;border-bottom:1px solid var(--grey-100);font-size:.95rem;}
.res li .meta{color:var(--grey-500);font-size:.85rem;}

details{border:1px solid var(--grey-200);border-radius:var(--radius-md);padding:.4rem 1rem;margin:1.25rem 0;background:var(--surface-alt);}
details summary{cursor:pointer;font-family:'Google Sans';font-weight:500;padding:.6rem 0;color:var(--blue-700);}
details[open] summary{margin-bottom:.5rem;}
details p:last-child{margin-bottom:.4rem;}

.footer{margin-top:4rem;padding-top:1.5rem;border-top:1px solid var(--grey-200);font-size:.9rem;color:var(--grey-500);}

@media (max-width:900px){
  .sidebar{position:fixed;left:0;top:0;z-index:50;transform:translateX(-100%);transition:transform .22s ease;box-shadow:var(--shadow-lift);}
  body.nav-open .sidebar{transform:translateX(0);}
  body.nav-open .overlay{display:block;}
  .topbar{display:flex;}
  .main{padding-top:1.5rem;}
}
@media (max-width:720px){
  body{font-size:18px;}
  .pair{grid-template-columns:1fr;}
  .hero h1{font-size:2rem;}
}

/* ===== Multi-page additions (split-guide.py) ===== */

/* Slim page header on sub-pages */
.pagenav{position:sticky;top:0;z-index:40;display:flex;align-items:center;justify-content:space-between;
  padding:.7rem clamp(1.1rem,4vw,2rem);background:var(--surface);border-bottom:1px solid var(--grey-200);}
.pagenav-home{font-family:'Google Sans';font-weight:500;font-size:1.05rem;color:var(--grey-900);}
.pagenav-contents{font-size:.95rem;color:var(--grey-700);}
.pagenav a:hover{text-decoration:none;color:var(--blue-700);}
/* Breadcrumb next to the wordmark on drill-down pages (patterns/) */
.pagenav-left{display:flex;align-items:baseline;min-width:0;}
.pagenav-crumb{font-size:.95rem;color:var(--grey-700);white-space:nowrap;overflow:hidden;text-overflow:ellipsis;}
.pagenav-crumb::before{content:'›';margin:0 .5rem;color:var(--grey-500);}

/* Category cards on the UX catalogue index */
.catcards{display:grid;grid-template-columns:repeat(auto-fill,minmax(200px,1fr));gap:.75rem;margin:1.5rem 0;}
a.catcard{display:flex;flex-direction:column;gap:.55rem;background:var(--surface);border:1px solid var(--grey-200);
  border-radius:var(--radius-md);padding:1rem 1.15rem;box-shadow:var(--shadow-card);color:inherit;
  transition:box-shadow .15s,border-color .15s;}
a.catcard:hover{text-decoration:none;border-color:var(--google-blue);box-shadow:var(--shadow-lift);}
.catcard-icon{width:38px;height:38px;flex:none;border-radius:50%;background:var(--blue-bg);color:var(--blue-700);
  display:flex;align-items:center;justify-content:center;}
.catcard-icon svg{width:20px;height:20px;}
.catcard h4{font-size:1rem;margin:0;}
.catcard .count{font-family:'Roboto Mono',monospace;font-size:.72rem;font-weight:400;color:var(--grey-500);margin-left:.35rem;}
.catcard p{margin:0;font-size:.88rem;color:var(--grey-700);}

/* Prev/next pager at the bottom of every sub-page */
.pager{display:flex;justify-content:space-between;gap:1rem;margin-top:3.5rem;padding-top:1.25rem;
  border-top:1px solid var(--grey-200);font-family:'Google Sans';font-size:.98rem;}
.pager a{display:block;max-width:48%;}
.pager .pager-next{margin-left:auto;text-align:right;}
.pager .pager-label{display:block;font-size:.75rem;font-weight:700;letter-spacing:.07em;text-transform:uppercase;color:var(--grey-500);}

/* Landing-page table of contents */
.toc-pages{margin:2rem 0;}
.toc-pages .toc-group{font-family:'Google Sans';font-size:.78rem;font-weight:700;letter-spacing:.09em;
  text-transform:uppercase;color:var(--grey-500);margin:1.75rem 0 .5rem;}
.toc-item{display:flex;gap:.9rem;align-items:baseline;padding:.65rem .75rem;border-radius:var(--radius-md);
  color:inherit;border:1px solid transparent;}
.toc-item:hover{background:var(--surface-alt);border-color:var(--grey-200);text-decoration:none;}
.toc-item .toc-num{flex:0 0 1.6rem;color:var(--grey-500);font-variant-numeric:tabular-nums;font-family:'Google Sans';font-weight:700;}
.toc-item strong{font-family:'Google Sans';font-weight:500;display:block;color:var(--grey-900);}
.toc-item .toc-desc{display:block;font-size:.92rem;color:var(--grey-700);}

/* Pattern-catalogue illustrations (SVGs reference vibe-crew theme vars) */
.pattern-illustration{
  --color-border:var(--grey-300);
  --color-surface:var(--surface-alt);
  --color-accent:var(--blue-700);
  --color-accent-bg:var(--blue-bg);
  --font-sans:'Google Sans Text',-apple-system,sans-serif;
  flex-shrink:0;
}
.pattern-illustration svg{width:200px;height:120px;display:block;}
@media (max-width:720px){.pattern-illustration svg{width:160px;height:96px;}}

/* 2×2 rule: a grid of exactly four cards renders 2×2, never 3+1 */
.cards:has(> .card:nth-child(4):last-child){grid-template-columns:repeat(2,1fr);}
@media (max-width:540px){.cards:has(> .card:nth-child(4):last-child){grid-template-columns:1fr;}}

/* Chapter dropdown in the page header (menu built by guide.js) */
.pagenav-right{display:flex;align-items:center;gap:1rem;}
.chapters{position:relative;}
details.chapters{border:0;background:none;padding:0;margin:0;border-radius:0;}
details.chapters[open] summary{margin-bottom:0;}
.chapters summary{list-style:none;cursor:pointer;font-family:'Google Sans';font-size:.92rem;color:var(--grey-700);
  display:flex;align-items:center;gap:.4rem;padding:.32rem .8rem;border:1px solid var(--grey-300);border-radius:999px;background:var(--surface);}
.chapters summary::-webkit-details-marker{display:none;}
.chapters summary::after{content:"▾";font-size:.75em;color:var(--grey-500);}
.chapters summary:hover{background:var(--grey-100);}
.chapters[open] summary{background:var(--grey-100);}
.chapters-menu{position:absolute;right:0;top:calc(100% + .5rem);z-index:60;min-width:20rem;max-height:min(72vh,36rem);overflow-y:auto;
  background:var(--surface);border:1px solid var(--grey-200);border-radius:var(--radius-md);box-shadow:var(--shadow-lift);padding:.5rem;}
.chapters-menu .chapters-group{font-family:'Google Sans';font-size:.7rem;font-weight:700;letter-spacing:.09em;
  text-transform:uppercase;color:var(--grey-500);padding:.6rem .6rem .2rem;}
.chapters-menu a{display:flex;gap:.6rem;align-items:baseline;padding:.4rem .6rem;border-radius:var(--radius-sm);
  color:var(--grey-700);font-size:.92rem;line-height:1.35;}
.chapters-menu a:hover{background:var(--grey-100);text-decoration:none;color:var(--grey-900);}
.chapters-menu a.current{background:var(--blue-bg);color:var(--blue-700);font-weight:500;}
.chapters-menu .toc-num{flex:0 0 1.4rem;color:var(--grey-500);font-variant-numeric:tabular-nums;font-family:'Google Sans';font-weight:700;}
@media (max-width:540px){.chapters-menu{position:fixed;left:.75rem;right:.75rem;top:3.4rem;min-width:0;}}

/* "On this page" mini-TOC (built by guide.js from h3.sub headings) */
.minitoc{background:var(--surface-alt);border:1px solid var(--grey-200);border-radius:var(--radius-md);
  padding:.9rem 1.15rem;margin:1.4rem 0 1.75rem;font-size:.95rem;}
.minitoc .label{font-family:'Google Sans';font-weight:700;font-size:.75rem;letter-spacing:.07em;
  text-transform:uppercase;color:var(--grey-500);display:block;margin-bottom:.45rem;}
.minitoc ol{list-style:none;margin:0;padding:0;display:flex;flex-direction:column;gap:.3rem;counter-reset:minitoc;}
.minitoc li{margin:0;display:flex;gap:.55rem;align-items:baseline;}
.minitoc li::before{counter-increment:minitoc;content:counter(minitoc);flex:0 0 1.1rem;
  color:var(--grey-500);font-family:'Google Sans';font-weight:700;font-size:.8rem;font-variant-numeric:tabular-nums;}
.minitoc a{color:var(--grey-700);}
.minitoc a:hover{color:var(--blue-700);}
h3.sub{scroll-margin-top:4.5rem;}

/* Left rail on wide screens: chapter switcher above the current page's TOC (built by guide.js) */
.pagerail{display:none;}
@media (min-width:1360px){
  .pagerail{display:block;position:fixed;top:4.6rem;width:260px;
    left:max(1rem,calc(50vw - 380px - 300px));z-index:30;}
  .pagerail .chapters{margin-bottom:1.1rem;}
  .pagerail .chapters summary{display:inline-flex;}
  .pagerail .chapters-menu{left:0;right:auto;}
  .content > .minitoc{display:none;}
  .pagenav-right .chapters{display:none;}
}
.pagerail-toc .label{font-family:'Google Sans';font-weight:700;font-size:.72rem;letter-spacing:.08em;
  text-transform:uppercase;color:var(--grey-500);display:block;margin:0 0 .4rem .75rem;}
.pagerail-toc ol{list-style:none;margin:0;padding:0;max-height:calc(100vh - 13rem);overflow-y:auto;}
.pagerail-toc li{margin:0;}
.pagerail-toc a{display:block;padding:.35rem .75rem;border-left:3px solid var(--grey-200);
  color:var(--grey-700);font-size:.9rem;line-height:1.4;}
.pagerail-toc a:hover{background:var(--grey-100);color:var(--grey-900);text-decoration:none;}
.pagerail-toc a.active{color:var(--blue-700);background:var(--blue-bg);border-left-color:var(--google-blue);font-weight:500;}
/* Category switcher in the rail on patterns/ pages — shares the rail's height with "On this page" */
.pagerail-cats{margin-bottom:1.1rem;}
.pagerail-cats ol{max-height:34vh;}
.pagerail-cats~.pagerail-toc ol{max-height:calc(66vh - 16rem);}

/* "For newcomers" explainer box — plain-language backfill for readers without a dev background */
.explain{background:var(--surface-alt);border:1px dashed var(--grey-300);border-radius:var(--radius-md);
  padding:1rem 1.15rem;margin:1.25rem 0;font-size:.95rem;}
.explain .label{font-family:'Google Sans';font-weight:700;font-size:.75rem;letter-spacing:.06em;
  text-transform:uppercase;color:var(--blue-700);display:block;margin-bottom:.35rem;}
.explain .label::before{content:"✱";margin-right:.45rem;color:var(--google-blue);}
.explain p{color:var(--grey-700);}
.explain p:last-child{margin-bottom:0;}

/* ===== Pattern-catalogue pages (generated by scripts/build-patterns.py) ===== */
.pgroup{margin-top:2.5rem;padding-bottom:.35rem;border-bottom:1px solid var(--grey-200);}
.pcard{display:flex;gap:1.25rem;align-items:flex-start;margin:1rem 0;padding:1.15rem 1.25rem;
  background:var(--surface);border:1px solid var(--grey-200);border-radius:var(--radius-md);box-shadow:var(--shadow-card);}
.pcard-body{min-width:0;}
.pcard-name{font-size:1.05rem;margin:0 0 .3rem;}
.pcard-id{font-family:'Roboto Mono',monospace;font-size:.72rem;font-weight:400;color:var(--grey-500);margin-left:.3rem;}
.pcard-desc{margin:0 0 .6rem;font-size:.95rem;}
.pcard-meta{display:grid;gap:.45rem;}
.pmeta{font-size:.9rem;}
.pmeta-label{display:block;font-size:.72rem;font-weight:700;letter-spacing:.06em;text-transform:uppercase;color:var(--grey-500);}
.pmeta p{margin:0;color:var(--grey-700);overflow-wrap:anywhere;}
@media (max-width:720px){.pcard{flex-direction:column;gap:.75rem;}}