/* ============================================================
   Sarwan Ali — personal site
   Type: Crimson Pro (display) + Source Sans 3 (body) + JetBrains Mono (accents)
   ============================================================ */

@import url('https://fonts.googleapis.com/css2?family=Crimson+Pro:ital,wght@0,400;0,500;0,600;0,700;1,400&family=JetBrains+Mono:wght@400;500&family=Source+Sans+3:wght@300;400;500;600;700&display=swap');

/* ---------- design tokens ---------- */
:root {
  --bg:           #fbfaf7;   /* warm off-white */
  --bg-soft:      #f4f1ea;   /* card / panel */
  --bg-elev:      #ffffff;   /* elevated surfaces */
  --rule:         #d9d4c7;   /* hairline dividers */
  --rule-strong:  #b8b1a1;
  --text:         #1c1a17;   /* near-black, slight warm */
  --text-mute:    #5f594f;   /* muted prose */
  --text-faint:   #8a8273;   /* dates, captions */
  --accent:       #6b3e26;   /* sienna — used sparingly */
  --accent-soft:  #a8693f;
  --link:         #1c1a17;
  --link-hover:   #6b3e26;
  --tag-bg:       #ece6d6;
  --tag-text:     #5f594f;
  --highlight:    #f0d8a8;   /* very light gold for highlight pubs */

  --max-width:    820px;
  --max-width-w:  1120px;
  --gutter:       1.5rem;

  --font-display: 'Crimson Pro', 'EB Garamond', Georgia, serif;
  --font-body:    'Source Sans 3', -apple-system, BlinkMacSystemFont, system-ui, sans-serif;
  --font-mono:    'JetBrains Mono', 'IBM Plex Mono', Menlo, monospace;
}

[data-theme="dark"] {
  --bg:           #14130f;
  --bg-soft:      #1e1c17;
  --bg-elev:      #25221c;
  --rule:         #2e2a22;
  --rule-strong:  #4a4438;
  --text:         #ece6d6;
  --text-mute:    #b4ad9c;
  --text-faint:   #7d7565;
  --accent:       #d4a574;   /* warmer in dark */
  --accent-soft:  #b88a5c;
  --link:         #ece6d6;
  --link-hover:   #d4a574;
  --tag-bg:       #2a2620;
  --tag-text:     #b4ad9c;
  --highlight:    #3a2f1e;
}

/* ---------- reset ---------- */
*, *::before, *::after { box-sizing: border-box; }
html { -webkit-font-smoothing: antialiased; -moz-osx-font-smoothing: grayscale; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: var(--font-body);
  font-size: 17px;
  line-height: 1.6;
  font-weight: 400;
  transition: background 0.2s ease, color 0.2s ease;
}

/* subtle paper texture in light mode */
body::before {
  content: '';
  position: fixed;
  inset: 0;
  pointer-events: none;
  z-index: 0;
  background-image: radial-gradient(rgba(0,0,0,0.018) 1px, transparent 1px);
  background-size: 3px 3px;
  opacity: 1;
}
[data-theme="dark"] body::before {
  background-image: radial-gradient(rgba(255,255,255,0.015) 1px, transparent 1px);
}

main, header, footer, nav { position: relative; z-index: 1; }

/* ---------- typography ---------- */
h1, h2, h3, h4 {
  font-family: var(--font-display);
  font-weight: 600;
  line-height: 1.2;
  letter-spacing: -0.01em;
  margin: 0 0 0.4em 0;
  color: var(--text);
}
h1 { font-size: clamp(2.2rem, 5vw, 3.2rem); font-weight: 700; letter-spacing: -0.02em; }
h2 { font-size: 1.6rem; font-weight: 600; margin-top: 2.5rem; margin-bottom: 1rem; }
h3 { font-size: 1.15rem; font-weight: 600; }

p { margin: 0 0 1rem 0; }
p, li { color: var(--text); }
.muted { color: var(--text-mute); }
.faint { color: var(--text-faint); }

a {
  color: var(--link);
  text-decoration: none;
  border-bottom: 1px solid var(--rule-strong);
  transition: color 0.15s ease, border-color 0.15s ease;
}
a:hover {
  color: var(--link-hover);
  border-bottom-color: var(--link-hover);
}
a.bare, .nav a, .footer a { border-bottom: none; }
a.bare:hover, .nav a:hover, .footer a:hover { color: var(--link-hover); }

em, i { font-style: italic; }
strong, b { font-weight: 600; color: var(--text); }

code, .mono {
  font-family: var(--font-mono);
  font-size: 0.88em;
  letter-spacing: -0.01em;
}

::selection { background: var(--accent); color: var(--bg); }

/* ---------- layout ---------- */
.wrap {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 var(--gutter);
}
.wrap-wide {
  max-width: var(--max-width-w);
  margin: 0 auto;
  padding: 0 var(--gutter);
}

main { padding: 2.5rem 0 5rem 0; }

/* ---------- header / nav ---------- */
.site-header {
  border-bottom: 1px solid var(--rule);
  padding: 1.25rem 0;
  background: var(--bg);
  position: sticky;
  top: 0;
  z-index: 10;
  backdrop-filter: blur(6px);
  background: color-mix(in srgb, var(--bg) 92%, transparent);
}
.site-header .wrap-wide {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1.5rem;
}
.brand {
  font-family: var(--font-display);
  font-size: 1.25rem;
  font-weight: 700;
  letter-spacing: -0.01em;
  border-bottom: none;
}
.brand:hover { color: var(--link-hover); }

.nav {
  display: flex;
  gap: 1.6rem;
  align-items: center;
}
.nav a {
  font-family: var(--font-body);
  font-size: 0.95rem;
  font-weight: 500;
  color: var(--text-mute);
  letter-spacing: 0.01em;
}
.nav a.active {
  color: var(--text);
  position: relative;
}
.nav a.active::after {
  content: '';
  position: absolute;
  left: 0; right: 0; bottom: -6px;
  height: 1px;
  background: var(--accent);
}

.theme-toggle {
  background: none;
  border: 1px solid var(--rule-strong);
  border-radius: 999px;
  padding: 0.35rem 0.7rem;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: var(--text-mute);
  cursor: pointer;
  transition: all 0.15s ease;
  letter-spacing: 0.02em;
}
.theme-toggle:hover { color: var(--text); border-color: var(--text); }

/* ---------- hero ---------- */
.hero {
  display: grid;
  grid-template-columns: 1fr 200px;
  gap: 3rem;
  align-items: start;
  padding: 1rem 0 1.5rem 0;
}
@media (max-width: 640px) {
  .hero { grid-template-columns: 1fr; gap: 1.5rem; }
  .hero-photo { order: -1; max-width: 140px; }
}
.hero-title {
  margin: 0 0 0.25rem 0;
  font-size: clamp(2.4rem, 6vw, 3.4rem);
}
.hero-role {
  font-family: var(--font-display);
  font-style: italic;
  font-weight: 400;
  color: var(--text-mute);
  font-size: 1.25rem;
  margin: 0 0 1.25rem 0;
  line-height: 1.4;
}
.hero-affil {
  font-family: var(--font-mono);
  font-size: 0.85rem;
  color: var(--text-faint);
  letter-spacing: 0.02em;
  margin: 0 0 1.5rem 0;
}
.hero-affil a { color: var(--text-mute); border-bottom-color: var(--rule); }
.hero-photo img {
  width: 100%;
  aspect-ratio: 1;
  object-fit: cover;
  border-radius: 6px;
  filter: grayscale(0.15);
}

.hero-bio p { font-size: 1.05rem; line-height: 1.65; }

/* ---------- social row ---------- */
.socials {
  display: flex;
  flex-wrap: wrap;
  gap: 0.65rem;
  margin: 1.25rem 0 0 0;
  align-items: center;
}
.socials a {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  font-size: 0.85rem;
  color: var(--text-mute);
  border-bottom: none;
  padding: 0.3rem 0.65rem;
  background: var(--bg-soft);
  border-radius: 4px;
  transition: all 0.15s ease;
  font-weight: 500;
}
.socials a:hover {
  background: var(--accent);
  color: var(--bg);
}
.socials .sep {
  color: var(--text-faint);
  font-family: var(--font-mono);
  font-size: 0.75rem;
}

/* ---------- banner / open-to-work strip ---------- */
.notice {
  margin: 2rem 0 0 0;
  padding: 0.85rem 1.1rem;
  border-left: 3px solid var(--accent);
  background: var(--bg-soft);
  font-size: 0.95rem;
  color: var(--text-mute);
}
.notice strong { color: var(--text); }

/* ---------- section heading ---------- */
.section-title {
  display: flex;
  align-items: baseline;
  gap: 0.8rem;
  margin: 3rem 0 1.25rem 0;
  padding-bottom: 0.4rem;
  border-bottom: 1px solid var(--rule);
}
.section-title h2 { margin: 0; }
.section-title .meta {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: var(--text-faint);
  letter-spacing: 0.05em;
  text-transform: uppercase;
  margin-left: auto;
}

/* ---------- publication entry ---------- */
.pub {
  display: grid;
  grid-template-columns: 5rem 1fr;
  gap: 1.25rem;
  padding: 1rem 0;
  border-bottom: 1px solid var(--rule);
}
.pub:last-child { border-bottom: none; }
.pub-year {
  font-family: var(--font-mono);
  font-size: 0.8rem;
  color: var(--text-faint);
  letter-spacing: 0.05em;
  padding-top: 0.25rem;
}
.pub-title {
  font-family: var(--font-display);
  font-size: 1.1rem;
  font-weight: 600;
  line-height: 1.35;
  margin: 0 0 0.25rem 0;
}
.pub-title a { border-bottom: none; }
.pub-title a:hover { color: var(--accent); }
.pub-authors {
  font-size: 0.95rem;
  color: var(--text-mute);
  margin: 0 0 0.3rem 0;
}
.pub-authors .me { color: var(--text); font-weight: 600; }
.pub-venue {
  font-family: var(--font-body);
  font-size: 0.88rem;
  color: var(--text-faint);
  font-style: italic;
  margin: 0 0 0.4rem 0;
}
.pub-venue .venue-name { color: var(--text-mute); font-style: italic; }
.pub-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 0.4rem;
  margin: 0.4rem 0 0 0;
}
.tag {
  font-family: var(--font-mono);
  font-size: 0.7rem;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  background: var(--tag-bg);
  color: var(--tag-text);
  padding: 0.2rem 0.45rem;
  border-radius: 3px;
  border-bottom: none;
}
a.tag:hover { background: var(--accent); color: var(--bg); }
.tag.tag-accent { background: var(--accent); color: var(--bg); }
.tag.tag-status { background: transparent; border: 1px solid var(--rule-strong); color: var(--text-mute); }

.pub.featured {
  background: linear-gradient(to right, var(--highlight) 0%, transparent 30%);
  padding-left: 1rem;
  margin-left: -1rem;
  border-radius: 4px;
  border-bottom: 1px solid var(--rule);
}
[data-theme="dark"] .pub.featured {
  background: linear-gradient(to right, var(--highlight) 0%, transparent 40%);
}
.pub-note {
  font-size: 0.88rem;
  color: var(--text-mute);
  margin: 0.3rem 0 0 0;
  font-style: italic;
}

@media (max-width: 640px) {
  .pub { grid-template-columns: 1fr; gap: 0.4rem; }
  .pub-year { padding-top: 0; }
}

/* ---------- news entry ---------- */
.news {
  display: grid;
  grid-template-columns: 8rem 1fr;
  gap: 1.5rem;
  padding: 0.9rem 0;
  border-bottom: 1px dashed var(--rule);
}
.news:last-child { border-bottom: none; }
.news-date {
  font-family: var(--font-mono);
  font-size: 0.78rem;
  color: var(--text-faint);
  letter-spacing: 0.05em;
  text-transform: uppercase;
  padding-top: 0.15rem;
}
.news-body { font-size: 0.97rem; }
.news-body strong { color: var(--text); }

@media (max-width: 640px) {
  .news { grid-template-columns: 1fr; gap: 0.2rem; }
}

/* ---------- talk / teaching entries ---------- */
.entry {
  padding: 1.1rem 0;
  border-bottom: 1px solid var(--rule);
}
.entry:last-child { border-bottom: none; }
.entry-title {
  font-family: var(--font-display);
  font-size: 1.15rem;
  font-weight: 600;
  margin: 0 0 0.2rem 0;
  line-height: 1.35;
}
.entry-meta {
  font-family: var(--font-mono);
  font-size: 0.78rem;
  color: var(--text-faint);
  letter-spacing: 0.04em;
  margin: 0 0 0.4rem 0;
}
.entry-host { color: var(--text-mute); font-style: italic; }
.entry-desc { font-size: 0.95rem; color: var(--text-mute); }

/* ---------- experience timeline ---------- */
.timeline { margin: 1rem 0; }
.timeline-item {
  display: grid;
  grid-template-columns: 7rem 1fr;
  gap: 1.5rem;
  padding: 0.7rem 0;
  border-bottom: 1px solid var(--rule);
}
.timeline-item:last-child { border-bottom: none; }
.timeline-when {
  font-family: var(--font-mono);
  font-size: 0.78rem;
  color: var(--text-faint);
  letter-spacing: 0.04em;
  padding-top: 0.2rem;
}
.timeline-role {
  font-weight: 600;
  font-size: 1rem;
}
.timeline-where {
  font-style: italic;
  color: var(--text-mute);
  font-size: 0.95rem;
}
.timeline-note {
  font-size: 0.9rem;
  color: var(--text-mute);
  margin-top: 0.2rem;
}

@media (max-width: 640px) {
  .timeline-item { grid-template-columns: 1fr; gap: 0.2rem; }
}

/* ---------- research-topic cards on home ---------- */
.research-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 1rem;
  margin: 1rem 0;
}
.research-card {
  padding: 1.1rem 1.1rem 1rem 1.1rem;
  background: var(--bg-soft);
  border-radius: 4px;
  border-top: 2px solid var(--accent);
}
.research-card h3 {
  font-size: 1rem;
  margin: 0 0 0.4rem 0;
  font-family: var(--font-body);
  font-weight: 600;
  letter-spacing: 0.01em;
}
.research-card p {
  font-size: 0.9rem;
  color: var(--text-mute);
  line-height: 1.5;
  margin: 0;
}

/* ---------- footer ---------- */
.site-footer {
  border-top: 1px solid var(--rule);
  margin-top: 4rem;
  padding: 2rem 0 3rem 0;
  font-size: 0.85rem;
  color: var(--text-faint);
}
.site-footer .wrap-wide {
  display: flex;
  flex-wrap: wrap;
  gap: 1rem;
  justify-content: space-between;
  align-items: center;
}
.site-footer .mono { font-size: 0.78rem; }

/* ---------- utilities ---------- */
.lead { font-size: 1.1rem; line-height: 1.65; color: var(--text); }
.divider {
  border: none;
  height: 1px;
  background: var(--rule);
  margin: 2rem 0;
}
.kbd {
  font-family: var(--font-mono);
  font-size: 0.78rem;
  background: var(--bg-soft);
  border: 1px solid var(--rule);
  border-radius: 3px;
  padding: 0.1rem 0.35rem;
}

/* fade-in for content */
@keyframes rise {
  from { opacity: 0; transform: translateY(6px); }
  to   { opacity: 1; transform: translateY(0); }
}
main > * { animation: rise 0.4s ease-out backwards; }
main > *:nth-child(1) { animation-delay: 0.02s; }
main > *:nth-child(2) { animation-delay: 0.08s; }
main > *:nth-child(3) { animation-delay: 0.14s; }
main > *:nth-child(4) { animation-delay: 0.20s; }
main > *:nth-child(n+5) { animation-delay: 0.26s; }

/* respect reduced motion */
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { animation: none !important; transition: none !important; }
}