/* ============================================================
   Keith Crabb - personal research site
   Dependency-free. System fonts only. Light/dark aware.
   ============================================================ */

:root {
  --mono: ui-monospace, "SFMono-Regular", "JetBrains Mono", Menlo, Consolas,
          "Liberation Mono", monospace;
  --sans: "Inter", system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;

  --bg:         #fbfbfa;
  --surface:    #ffffff;
  --ink:        #16181d;
  --muted:      #5b6371;
  --faint:      #8b919e;
  --rule:       #e3e5ea;
  --accent:     #1f6f8b;
  --accent-ink: #175367;
  --accent-bg:  rgba(31, 111, 139, 0.09);

  --maxw: 62rem;
  --gut: 1.5rem;
}

@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --bg:         #0e1116;
    --surface:    #141a23;
    --ink:        #e5e9ef;
    --muted:      #9aa3b2;
    --faint:      #6d7685;
    --rule:       #222935;
    --accent:     #6fc3dd;
    --accent-ink: #9ad8ec;
    --accent-bg:  rgba(111, 195, 221, 0.12);
  }
}

:root[data-theme="dark"] {
  --bg:         #0e1116;
  --surface:    #141a23;
  --ink:        #e5e9ef;
  --muted:      #9aa3b2;
  --faint:      #6d7685;
  --rule:       #222935;
  --accent:     #6fc3dd;
  --accent-ink: #9ad8ec;
  --accent-bg:  rgba(111, 195, 221, 0.12);
}

*, *::before, *::after { box-sizing: border-box; }

html { -webkit-text-size-adjust: 100%; scroll-behavior: smooth; }
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  * { animation-duration: .01ms !important; transition-duration: .01ms !important; }
}

body {
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  font-family: var(--sans);
  font-size: 16px;
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
}

img { max-width: 100%; height: auto; }

a {
  color: var(--accent-ink);
  text-decoration: none;
  border-bottom: 1px solid var(--accent-bg);
  transition: border-color .15s ease, color .15s ease;
}
a:hover { border-bottom-color: var(--accent); }
a:focus-visible,
button:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 2px;
  border-radius: 2px;
}

.skip {
  position: absolute; left: -9999px;
  background: var(--surface); color: var(--ink);
  padding: .6rem 1rem; z-index: 100;
  font-family: var(--mono); font-size: .8rem;
  border: 1px solid var(--rule);
}
.skip:focus { left: 1rem; top: 1rem; }

.wrap {
  max-width: var(--maxw);
  margin-inline: auto;
  padding-inline: var(--gut);
}

/* ---------- masthead ---------- */

.masthead {
  padding-block: 4.5rem 2.75rem;
  border-bottom: 1px solid var(--rule);
}

.masthead .wrap {
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto;
  align-items: start;
  gap: 0 3rem;
}

.portrait {
  width: 12rem;
  aspect-ratio: 1;
  object-fit: cover;
  border: 1px solid var(--rule);
  border-radius: 3px;
  display: block;
}

.eyebrow {
  font-family: var(--mono);
  font-size: .72rem;
  letter-spacing: .13em;
  text-transform: uppercase;
  color: var(--accent);
  margin: 0 0 1rem;
}

.masthead h1 {
  font-family: var(--mono);
  font-size: clamp(1.9rem, 5.5vw, 2.9rem);
  font-weight: 600;
  letter-spacing: -.02em;
  line-height: 1.1;
  margin: 0 0 .75rem;
}

.role {
  font-family: var(--mono);
  font-size: .9rem;
  color: var(--muted);
  margin: 0 0 1.75rem;
  line-height: 1.8;
}
.role span { display: block; }
.role .org { color: var(--ink); }

.bio {
  max-width: 60ch;
  font-size: 1.02rem;
  margin: 0 0 1.25rem;
}
.bio:last-of-type { margin-bottom: 2rem; }

/* ---------- contact strip ---------- */

.links {
  display: flex;
  flex-wrap: wrap;
  gap: .5rem;
  list-style: none;
  margin: 0;
  padding: 0;
}

.links a {
  display: inline-block;
  font-family: var(--mono);
  font-size: .78rem;
  padding: .4rem .7rem;
  border: 1px solid var(--rule);
  border-radius: 3px;
  color: var(--muted);
  background: var(--surface);
}
.links a:hover {
  color: var(--accent-ink);
  border-color: var(--accent);
  background: var(--accent-bg);
}
.links a::before { content: "\2192\00a0"; color: var(--faint); }

/* ---------- nav ---------- */

.topnav {
  position: sticky;
  top: 0;
  z-index: 20;
  background: var(--bg);
  border-bottom: 1px solid var(--rule);
}

@supports (backdrop-filter: blur(8px)) {
  .topnav {
    background: color-mix(in srgb, var(--bg) 86%, transparent);
    backdrop-filter: saturate(1.6) blur(8px);
  }
}

.topnav .wrap {
  display: flex;
  align-items: center;
  gap: 1rem;
}

.topnav ul {
  display: flex;
  flex: 1;
  flex-wrap: wrap;
  gap: .25rem 1.1rem;
  list-style: none;
  margin: 0;
  padding: .7rem 0;
}

.topnav a {
  font-family: var(--mono);
  font-size: .78rem;
  color: var(--muted);
  border-bottom: none;
  padding-block: .15rem;
}
.topnav a:hover { color: var(--accent-ink); }

.theme-toggle {
  font-family: var(--mono);
  font-size: .72rem;
  letter-spacing: .06em;
  text-transform: uppercase;
  color: var(--muted);
  background: none;
  border: 1px solid var(--rule);
  border-radius: 3px;
  padding: .3rem .55rem;
  cursor: pointer;
  flex-shrink: 0;
}
.theme-toggle:hover { color: var(--accent-ink); border-color: var(--accent); }

/* ---------- sections ---------- */

section { padding-block: 3.25rem; border-bottom: 1px solid var(--rule); }
section:last-of-type { border-bottom: none; }

.sec-head {
  display: flex;
  align-items: baseline;
  gap: .75rem;
  margin: 0 0 1.75rem;
}

.sec-head h2 {
  font-family: var(--mono);
  font-size: .82rem;
  font-weight: 600;
  letter-spacing: .14em;
  text-transform: uppercase;
  color: var(--ink);
  margin: 0;
  flex-shrink: 0;
}

.sec-head::after {
  content: "";
  flex: 1;
  height: 1px;
  background: var(--rule);
}

.lede {
  max-width: 62ch;
  color: var(--muted);
  margin: -.75rem 0 2rem;
}

/* ---------- research areas ---------- */

.areas {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(16rem, 1fr));
  gap: 1px;
  background: var(--rule);
  border: 1px solid var(--rule);
  border-radius: 4px;
  overflow: hidden;
}

.area {
  background: var(--surface);
  padding: 1.4rem 1.35rem 1.5rem;
  display: flex;
  flex-direction: column;
}

.area .idx {
  font-family: var(--mono);
  font-size: .7rem;
  letter-spacing: .1em;
  color: var(--accent);
  display: block;
  margin-bottom: .6rem;
}

.area h3 {
  font-family: var(--mono);
  font-size: .95rem;
  font-weight: 600;
  letter-spacing: -.01em;
  margin: 0 0 .6rem;
  line-height: 1.35;
}

.area p {
  font-size: .92rem;
  color: var(--muted);
  margin: 0 0 .9rem;
}

.area .refs {
  font-family: var(--mono);
  font-size: .72rem;
  color: var(--faint);
  margin: auto 0 0;      /* pin to the bottom so refs line up across cards */
  padding-top: .25rem;
}
.area .refs a { color: var(--faint); border-bottom-color: transparent; }
.area .refs a:hover { color: var(--accent-ink); border-bottom-color: var(--accent); }

/* ---------- publications ---------- */

.year-group { margin-bottom: 2.25rem; }
.year-group:last-child { margin-bottom: 0; }

.year {
  font-family: var(--mono);
  font-size: .75rem;
  letter-spacing: .12em;
  color: var(--faint);
  margin: 0 0 1rem;
}

.pubs { list-style: none; margin: 0; padding: 0; }

.pub {
  display: grid;
  grid-template-columns: 3.25rem 1fr;
  gap: 0 .9rem;
  padding: 1.1rem 0;
  border-top: 1px solid var(--rule);
}
.pub:last-child { border-bottom: 1px solid var(--rule); }

.pub .tag {
  font-family: var(--mono);
  font-size: .72rem;
  color: var(--accent);
  padding-top: .22rem;
}

.pub h3 {
  font-size: 1rem;
  font-weight: 600;
  line-height: 1.45;
  margin: 0 0 .35rem;
}

.pub .authors {
  font-size: .9rem;
  color: var(--muted);
  margin: 0 0 .2rem;
}
.pub .authors .me { color: var(--ink); font-weight: 600; }

.pub .venue {
  font-family: var(--mono);
  font-size: .78rem;
  color: var(--faint);
  margin: 0;
  line-height: 1.6;
}

.pub .pub-links {
  margin: .55rem 0 0;
  display: flex;
  flex-wrap: wrap;
  gap: .5rem;
}
.pub .pub-links a {
  font-family: var(--mono);
  font-size: .72rem;
  color: var(--muted);
  border: 1px solid var(--rule);
  border-radius: 3px;
  padding: .18rem .5rem;
}
.pub .pub-links a:hover { color: var(--accent-ink); border-color: var(--accent); }

/* ---------- generic entry list (software / teaching / notes) ---------- */

.entries { list-style: none; margin: 0; padding: 0; }

.entry {
  padding: 1.15rem 0;
  border-top: 1px solid var(--rule);
}
.entry:last-child { border-bottom: 1px solid var(--rule); }

.entry h3 {
  font-family: var(--mono);
  font-size: .95rem;
  font-weight: 600;
  margin: 0 0 .3rem;
}

.entry .meta {
  font-family: var(--mono);
  font-size: .74rem;
  color: var(--faint);
  margin: 0 0 .5rem;
}

.entry p { font-size: .94rem; color: var(--muted); margin: 0; max-width: 62ch; }

/* ---------- callout / empty state ---------- */

.note {
  border: 1px dashed var(--rule);
  border-radius: 4px;
  padding: 1.1rem 1.25rem;
  background: var(--surface);
  font-size: .92rem;
  color: var(--muted);
  max-width: 62ch;
}
.note strong { color: var(--ink); font-family: var(--mono); font-size: .85rem; }
.note p { margin: 0; }
.note p + p { margin-top: .6rem; }

/* ---------- CV block ---------- */

.cv-rows { list-style: none; margin: 0; padding: 0; }

.cv-row {
  display: grid;
  grid-template-columns: 9rem 1fr;
  gap: .3rem .9rem;
  padding: .95rem 0;
  border-top: 1px solid var(--rule);
}
.cv-row:last-child { border-bottom: 1px solid var(--rule); }

.cv-row .when {
  font-family: var(--mono);
  font-size: .76rem;
  color: var(--faint);
  padding-top: .18rem;
}
.cv-row .what { margin: 0; }
.cv-row .what strong { display: block; font-weight: 600; font-size: .97rem; }
.cv-row .what span { font-size: .9rem; color: var(--muted); }

/* ---------- contact ---------- */

.contact-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(14rem, 1fr));
  gap: 0 1.5rem;
  margin: 0;
}
.contact-grid dt {
  font-family: var(--mono);
  font-size: .72rem;
  letter-spacing: .1em;
  text-transform: uppercase;
  color: var(--faint);
  margin-bottom: .3rem;
}
.contact-grid dd { margin: 0 0 1.25rem; font-size: .94rem; }

/* ---------- footer ---------- */

footer.site {
  border-top: 1px solid var(--rule);
  padding-block: 2rem 3rem;
  font-family: var(--mono);
  font-size: .74rem;
  color: var(--faint);
}
footer.site .wrap {
  display: flex;
  flex-wrap: wrap;
  gap: .5rem 1.5rem;
  justify-content: space-between;
}
footer.site a { color: var(--faint); }

/* ---------- subpage helpers ---------- */

.backlink {
  font-family: var(--mono);
  font-size: .76rem;
  color: var(--muted);
  border-bottom: none;
}
.backlink::before { content: "\2190\00a0"; }

.page-head { padding-block: 3rem 2rem; border-bottom: 1px solid var(--rule); }
.page-head h1 {
  font-family: var(--mono);
  font-size: clamp(1.5rem, 4vw, 2.1rem);
  font-weight: 600;
  letter-spacing: -.02em;
  margin: 1rem 0 .5rem;
}
.page-head p { color: var(--muted); margin: 0; max-width: 62ch; }

.prose { max-width: 68ch; padding-block: 2.5rem 1rem; }
.prose h2 {
  font-family: var(--mono);
  font-size: .82rem;
  letter-spacing: .14em;
  text-transform: uppercase;
  margin: 2.5rem 0 1rem;
}
.prose h2:first-child { margin-top: 0; }

/* Portrait moves above the text before the two columns get cramped. */
@media (max-width: 44rem) {
  .masthead .wrap { grid-template-columns: 1fr; gap: 0; }
  .portrait { width: 9rem; margin-bottom: 1.5rem; order: -1; }
}

@media (max-width: 34rem) {
  .masthead { padding-block: 3rem 2rem; }
  .pub { grid-template-columns: 1fr; gap: .35rem; }
  .pub .tag { padding-top: 0; }
  .cv-row { grid-template-columns: 1fr; }
}