/* Hubjo — shared tokens + learner (reader) styles */
:root {
  --paper: #F3F5F7;
  --sheet: #FFFFFF;
  --ink: #16243A;
  --ink-2: #4A5A6E;
  --ink-3: #7A8797;
  --rule: #D3DAE3;
  --teal: #0A6E6A;
  --teal-ink: #064B48;
  --teal-soft: #E1F0EF;
  --hl: #FFE45C;
  --red: #B42318;
  --warn: #FFF4D6;
  --ui: "Public Sans", system-ui, -apple-system, "Segoe UI", sans-serif;
  --read: "Source Serif 4", Georgia, "Times New Roman", serif;
  --radius: 6px;
}
*, *::before, *::after { box-sizing: border-box; }
[hidden] { display: none !important; }
html { -webkit-text-size-adjust: 100%; }
body { margin: 0; background: var(--paper); color: var(--ink); font: 16px/1.5 var(--ui); }
a { color: var(--teal); text-underline-offset: 2px; }
a:hover { color: var(--teal-ink); }
:focus-visible { outline: 3px solid var(--teal); outline-offset: 2px; }
img { max-width: 100%; height: auto; }
.sr-only { position: absolute; width: 1px; height: 1px; overflow: hidden; clip: rect(0 0 0 0); white-space: nowrap; }
.muted { color: var(--ink-2); }
.small { font-size: .875rem; }
.empty { color: var(--ink-2); padding: 1.5rem 0; }

/* Buttons & forms (shared with admin) */
.btn { display: inline-flex; align-items: center; gap: .4rem; font: 500 .9375rem/1 var(--ui); padding: .6rem 1rem;
  border: 1px solid var(--rule); background: var(--sheet); color: var(--ink); border-radius: var(--radius); cursor: pointer; text-decoration: none; }
.btn:hover { border-color: var(--ink-3); color: var(--ink); }
.btn:disabled { opacity: .5; cursor: not-allowed; }
.btn-primary { background: var(--teal); border-color: var(--teal); color: #fff; }
.btn-primary:hover { background: var(--teal-ink); border-color: var(--teal-ink); color: #fff; }
.btn-accent { background: var(--ink); border-color: var(--ink); color: #fff; }
.btn-accent:hover { background: #000; color: #fff; }
.btn-ghost { background: transparent; }
.btn-danger-ghost { background: transparent; color: var(--red); border-color: transparent; }
.btn-danger-ghost:hover { border-color: var(--red); color: var(--red); }
.btn-small { padding: .4rem .7rem; font-size: .8125rem; }
.linklike { background: none; border: 0; padding: 0; font: inherit; color: var(--teal); cursor: pointer; text-decoration: underline; text-underline-offset: 2px; }
.linklike.danger, .danger { color: var(--red); }
label { display: block; font-weight: 500; font-size: .875rem; margin-bottom: .9rem; }
input:not([type=checkbox]):not([type=radio]):not([type=file]), select, textarea {
  display: block; width: 100%; margin-top: .3rem; font: 400 1rem/1.4 var(--ui); color: var(--ink);
  padding: .55rem .7rem; border: 1px solid var(--rule); border-radius: var(--radius); background: var(--sheet); }
textarea { resize: vertical; }
input:focus, select:focus, textarea:focus { outline: none; border-color: var(--teal); box-shadow: 0 0 0 3px var(--teal-soft); }
.form-error { color: var(--red); font-weight: 500; }
.flash { padding: .75rem 1rem; border-radius: var(--radius); margin: 0 0 1rem; border: 1px solid; }
.flash-ok { background: var(--teal-soft); border-color: #B7D9D6; }
.flash-error { background: #FDECEA; border-color: #F3B8B2; color: #7A1A12; }
.flash-warn { background: var(--warn); border-color: #EBD48C; }

/* ---------- Reader ---------- */
.site-head { display: flex; align-items: center; gap: 1.5rem; padding: .9rem clamp(1rem, 4vw, 3rem);
  background: var(--sheet); border-bottom: 1px solid var(--rule); }
.site-head .brand { font: 600 1.35rem/1 var(--read); color: var(--ink); text-decoration: none; }
.site-search { flex: 1; max-width: 420px; }
.site-search input { margin: 0; background: var(--paper); }
.site-head .who { margin-left: auto; display: flex; gap: 1rem; align-items: center; font-size: .9rem; }
.site-head .who form { margin: 0; }
.site-main { max-width: 1100px; margin: 0 auto; padding: 2rem clamp(1rem, 4vw, 3rem) 4rem; }
.site-foot { text-align: center; color: var(--ink-3); font-size: .8rem; padding: 2rem; }

.home-intro { margin: 1rem 0 3rem; max-width: 40rem; }
.home-intro h1 { font: 600 clamp(2rem, 5vw, 3.25rem)/1.1 var(--read); margin: 0 0 .75rem; letter-spacing: -.01em; }
.home-intro p { font: 1.15rem/1.6 var(--read); color: var(--ink-2); margin: 0; }

.pathway { margin-bottom: 3rem; }
.pathway > h2 { font: 600 1.75rem/1.2 var(--read); margin: 0 0 1.25rem; padding-bottom: .5rem; border-bottom: 2px solid var(--ink); }
.pathway > h2 a { color: inherit; text-decoration: none; }
.program-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(230px, 1fr)); gap: 1.5rem 2rem; }
.program { border-left: 3px solid var(--teal); padding-left: 1rem; }
.program h3 { font: 600 1.1rem/1.3 var(--ui); margin: 0 0 .5rem; }
.program h3 a { color: var(--ink); text-decoration: none; }
.program ul { list-style: none; margin: 0; padding: 0; }
.program li { margin: .25rem 0; font-size: .95rem; }

.crumbs { font-size: .85rem; color: var(--ink-3); margin-bottom: 1.5rem; display: flex; flex-wrap: wrap; gap: .4rem; }
.crumbs a { color: var(--ink-2); }
.page-head { max-width: 46rem; margin-bottom: 2rem; }
.page-head .kind { margin: 0 0 .25rem; color: var(--teal); font-weight: 600; font-size: .9rem; }
.page-head h1 { font: 600 clamp(1.8rem, 4vw, 2.6rem)/1.15 var(--read); margin: 0 0 .75rem; }
.lede { font: 1.2rem/1.6 var(--read); color: var(--ink-2); margin: 0; }

.toc { font: 1.1rem/1.5 var(--read); padding-left: 1.5rem; max-width: 46rem; }
.toc > li { margin: .6rem 0; }
.toc-nested > li > a { font-weight: 600; }
.toc ol { font-size: 1rem; margin: .35rem 0 .75rem; padding-left: 1.25rem; list-style: lower-alpha; }

.list-title { font: 600 1.25rem/1.3 var(--ui); margin: 2.5rem 0 1rem; }
.topic-list { padding-left: 1.5rem; max-width: 46rem; }
.topic-list li { margin-bottom: 1.25rem; padding-left: .25rem; }
.topic-list li::marker { color: var(--ink-3); font-weight: 600; }
.topic-list a { font: 600 1.15rem/1.35 var(--read); }
.topic-list p { margin: .25rem 0 0; color: var(--ink-2); }
.topic-list .path { display: block; color: var(--ink-3); font-size: .8rem; }

.topic { max-width: 44rem; }
.topic h1 { font: 600 clamp(1.9rem, 4vw, 2.6rem)/1.15 var(--read); margin: 0 0 1rem; }
.topic > .lede { margin-bottom: 2rem; }

/* The highlighter: key points read like a student's marked-up margin */
.key-points { margin: 0 0 2.25rem; padding: 1.25rem 1.5rem; background: var(--sheet); border: 1px solid var(--rule); border-radius: var(--radius); }
.key-points h2 { font: 600 1rem/1 var(--ui); margin: 0 0 .9rem; color: var(--ink-2); }
.key-points ul { margin: 0; padding-left: 1.1rem; }
.key-points li { margin: .5rem 0; font: 1.05rem/1.55 var(--read); }
.key-points mark { color: inherit; background: linear-gradient(transparent 58%, var(--hl) 58%, var(--hl) 92%, transparent 92%);
  -webkit-box-decoration-break: clone; box-decoration-break: clone; padding: 0 .1em; }

.prose { font: 1.125rem/1.72 var(--read); }
.prose h2, .prose h3, .prose h4 { font-family: var(--ui); line-height: 1.3; margin: 2rem 0 .6rem; }
.prose h2 { font-size: 1.4rem; } .prose h3 { font-size: 1.2rem; } .prose h4 { font-size: 1.05rem; }
.prose p { margin: 0 0 1.1rem; }
.prose ul, .prose ol { padding-left: 1.4rem; margin: 0 0 1.1rem; }
.prose li { margin: .3rem 0; }
.prose blockquote { margin: 1.5rem 0; padding: .25rem 0 .25rem 1.25rem; border-left: 3px solid var(--teal); color: var(--ink-2); }
.prose table { border-collapse: collapse; width: 100%; font: .95rem/1.45 var(--ui); margin: 1.25rem 0; display: block; overflow-x: auto; }
.prose th, .prose td { border: 1px solid var(--rule); padding: .5rem .7rem; text-align: left; vertical-align: top; }
.prose th { background: var(--paper); }
.prose code { font-size: .9em; background: var(--paper); padding: .1em .3em; border-radius: 3px; }
.prose pre { background: var(--paper); padding: 1rem; overflow-x: auto; border-radius: var(--radius); }
.prose .katex-display { overflow-x: auto; overflow-y: hidden; padding: .25rem 0; }
.prose img { display: block; margin: 1.25rem auto; border-radius: 4px; }
.prose iframe { display: block; max-width: 100%; margin: 1.25rem auto; border: 0; }

.pager { display: grid; grid-template-columns: 1fr 1fr; gap: 1rem; max-width: 44rem; margin-top: 3rem; padding-top: 1.5rem; border-top: 1px solid var(--rule); }
.pager a { display: block; text-decoration: none; font: 600 1rem/1.35 var(--read); color: var(--ink); padding: .75rem 1rem; border: 1px solid var(--rule); border-radius: var(--radius); background: var(--sheet); }
.pager a:hover { border-color: var(--teal); }
.pager span { display: block; font: 500 .8rem/1 var(--ui); color: var(--teal); margin-bottom: .35rem; }
.pager .next { text-align: right; grid-column: 2; }

.auth-card { max-width: 380px; margin: 3rem auto; background: var(--sheet); padding: 2rem; border: 1px solid var(--rule); border-radius: var(--radius); }
.auth-card h1 { font: 600 1.6rem/1.2 var(--read); margin: 0 0 1.25rem; }
.auth-card .btn { width: 100%; justify-content: center; margin-top: .5rem; }

@media (max-width: 640px) {
  .site-head { flex-wrap: wrap; }
  .site-search { order: 3; flex-basis: 100%; max-width: none; }
  .pager { grid-template-columns: 1fr; }
  .pager .next { grid-column: 1; }
}
@media (prefers-reduced-motion: reduce) { * { transition: none !important; animation: none !important; } }