/* ==========================================================================
   Chaiyong Ragkhitwetsagul — Personal Website
   Editorial minimal redesign
   ========================================================================== */

/* --- Tokens ---------------------------------------------------------------- */
:root {
  --bg:           #ffffff;
  --bg-alt:       #faf9f7;
  --fg:           oklch(0.18 0.005 60);
  --fg-muted:     oklch(0.45 0.005 60);
  --fg-subtle:    oklch(0.62 0.005 60);
  --line:         oklch(0.91 0.005 60);
  --line-strong:  oklch(0.82 0.005 60);
  --accent:       oklch(0.55 0.14 35);
  --accent-soft:  oklch(0.95 0.03 35);

  --font-sans:    "Geist", "Helvetica Neue", Helvetica, ui-sans-serif, system-ui, sans-serif;
  --font-serif:   "Instrument Serif", "Times New Roman", Georgia, serif;
  --font-mono:    "JetBrains Mono", ui-monospace, "SF Mono", Menlo, monospace;

  --w-content:    1200px;
  --w-prose:      720px;

  --space-1:      0.5rem;
  --space-2:      1rem;
  --space-3:      1.5rem;
  --space-4:      2rem;
  --space-6:      3rem;
  --space-8:      4.5rem;
  --space-10:     6.5rem;

  --radius:       4px;
  --transition:   180ms cubic-bezier(.2,.6,.2,1);
}

/* --- Reset / base --------------------------------------------------------- */
*, *::before, *::after { box-sizing: border-box; }
html { -webkit-font-smoothing: antialiased; -moz-osx-font-smoothing: grayscale; }
body {
  margin: 0;
  font-family: var(--font-sans);
  font-weight: 400;
  font-size: 16px;
  line-height: 1.6;
  color: var(--fg);
  background: var(--bg);
  font-feature-settings: "ss01", "cv11";
  text-rendering: optimizeLegibility;
}

img { max-width: 100%; display: block; }
a { color: inherit; text-decoration: none; }
ul, ol { padding-left: 1.2em; }
button { font: inherit; cursor: pointer; }

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

/* --- Type ----------------------------------------------------------------- */
h1, h2, h3, h4, h5 {
  margin: 0;
  font-weight: 500;
  letter-spacing: -0.02em;
  text-wrap: balance;
  color: var(--fg);
}
h1 { font-size: clamp(2.5rem, 5vw, 4.25rem); line-height: 1.05; letter-spacing: -0.035em; font-weight: 400; }
h2 { font-size: clamp(1.75rem, 3vw, 2.5rem); line-height: 1.1; letter-spacing: -0.03em; font-weight: 400; }
h3 { font-size: 1.25rem; line-height: 1.3; font-weight: 500; }
h4 { font-size: 1.0625rem; line-height: 1.4; font-weight: 500; }
p  { margin: 0 0 1rem; text-wrap: pretty; }

em, .serif {
  font-family: var(--font-serif);
  font-style: italic;
  font-weight: 400;
  letter-spacing: -0.01em;
}

.eyebrow, .label {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  font-weight: 400;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--fg-muted);
}

a.inline, .prose a {
  color: var(--fg);
  background-image: linear-gradient(currentColor, currentColor);
  background-size: 100% 1px;
  background-repeat: no-repeat;
  background-position: 0 100%;
  transition: color var(--transition), background-size var(--transition);
}
a.inline:hover, .prose a:hover { color: var(--accent); }

/* --- Layout helpers ------------------------------------------------------- */
.container, .nav-container, .hero-container {
  width: 100%;
  max-width: var(--w-content);
  margin: 0 auto;
  padding: 0 2rem;
}

section { padding: var(--space-10) 0; }
section + section { border-top: 1px solid var(--line); }

.section-head {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-2);
  margin-bottom: var(--space-6);
}
.section-head .num { color: var(--fg-subtle); }
.section-head .section-title { margin-top: 0.25rem; }
.section-head .section-subtitle {
  max-width: var(--w-prose);
  color: var(--fg-muted);
  font-size: 1.0625rem;
  margin: 0.75rem 0 0;
}

.section-title { font-size: clamp(1.75rem, 3vw, 2.5rem); font-weight: 400; letter-spacing: -0.03em; }
.section-subtitle { color: var(--fg-muted); max-width: var(--w-prose); }

/* --- Navbar --------------------------------------------------------------- */
.navbar {
  position: sticky;
  top: 0;
  z-index: 50;
  background: rgba(255,255,255,0.85);
  backdrop-filter: saturate(180%) blur(12px);
  -webkit-backdrop-filter: saturate(180%) blur(12px);
  border-bottom: 1px solid transparent;
  transition: border-color var(--transition), background-color var(--transition);
}
.navbar.scrolled { border-bottom-color: var(--line); }

.nav-container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 64px;
}

.nav-logo a {
  font-size: 0.95rem;
  font-weight: 500;
  letter-spacing: -0.01em;
  color: var(--fg);
  display: inline-flex;
  align-items: center;
  gap: 0.6rem;
}
.nav-logo a::before {
  content: "";
  width: 22px;
  height: 22px;
  border-radius: 50%;
  background: var(--fg);
  display: inline-block;
}

.nav-menu {
  display: flex;
  gap: 0.25rem;
  margin: 0;
  padding: 0;
  list-style: none;
}
.nav-link {
  position: relative;
  padding: 0.5rem 0.85rem;
  font-size: 0.9rem;
  color: var(--fg-muted);
  border-radius: 999px;
  transition: color var(--transition), background-color var(--transition);
}
.nav-link:hover { color: var(--fg); }
.nav-link.active { color: var(--fg); background: oklch(0.96 0.005 60); }

.hamburger { display: none; flex-direction: column; gap: 4px; background: none; border: 0; padding: 8px; cursor: pointer; }
.hamburger .bar { width: 22px; height: 1.5px; background: var(--fg); transition: var(--transition); }
.hamburger.active .bar:nth-child(1) { transform: translateY(5.5px) rotate(45deg); }
.hamburger.active .bar:nth-child(2) { opacity: 0; }
.hamburger.active .bar:nth-child(3) { transform: translateY(-5.5px) rotate(-45deg); }

/* --- Hero ----------------------------------------------------------------- */
.hero {
  padding: clamp(4rem, 10vw, 8rem) 0 clamp(3rem, 6vw, 5rem);
  border-bottom: 1px solid var(--line);
}
.hero-container { max-width: var(--w-content); }
.hero-content {
  display: grid;
  grid-template-columns: 1.4fr 1fr;
  gap: var(--space-8);
  align-items: end;
}

.hero-text { max-width: 720px; }

.hero-eyebrow {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--fg-muted);
  display: flex;
  align-items: center;
  gap: 0.6rem;
  margin-bottom: var(--space-3);
}
.hero-eyebrow::before {
  content: "";
  width: 1.5rem; height: 1px;
  background: var(--fg-muted);
  display: inline-block;
}

.hero-title {
  font-size: clamp(2.5rem, 6vw, 4.75rem);
  line-height: 1.02;
  letter-spacing: -0.04em;
  font-weight: 400;
  margin-bottom: var(--space-3);
}
.hero-title .highlight {
  font-family: var(--font-serif);
  font-style: italic;
  font-weight: 400;
  letter-spacing: -0.025em;
  color: var(--fg);
}

.hero-subtitle {
  font-size: 1.25rem;
  color: var(--fg);
  margin: 0 0 1rem;
  letter-spacing: -0.01em;
}

.hero-description {
  font-size: 1.0625rem;
  color: var(--fg-muted);
  max-width: 56ch;
  margin: 0 0 var(--space-4);
}

.hero-buttons { display: flex; flex-wrap: wrap; gap: 0.75rem; margin-top: var(--space-3); }

.hero-image {
  position: relative;
  align-self: end;
}
.hero-image .profile-image {
  width: 100%;
  max-width: 360px;
  aspect-ratio: 4/5;
  object-fit: cover;
  border-radius: 2px;
  filter: grayscale(0.15) contrast(1.02);
  margin-left: auto;
}

/* Inner-page hero (research, contact, etc.) */
.research-hero { padding-bottom: clamp(3rem, 5vw, 4rem); }
.research-hero .hero-content { grid-template-columns: 1fr; }
.research-hero .hero-title { max-width: 16ch; }

/* --- Buttons -------------------------------------------------------------- */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.7rem 1.1rem;
  font-size: 0.9rem;
  font-weight: 500;
  letter-spacing: -0.005em;
  border: 1px solid var(--fg);
  border-radius: 999px;
  background: transparent;
  color: var(--fg);
  text-decoration: none;
  transition: all var(--transition);
  white-space: nowrap;
}
.btn:hover { transform: translateY(-1px); }

.btn-primary {
  background: var(--fg);
  color: var(--bg);
}
.btn-primary:hover { background: var(--accent); border-color: var(--accent); }

.btn-secondary {
  background: transparent;
  color: var(--fg);
  border-color: var(--line-strong);
}
.btn-secondary:hover { border-color: var(--fg); }

.btn-small {
  padding: 0.35rem 0.7rem;
  font-size: 0.8rem;
  border-radius: 999px;
  border-color: var(--line-strong);
  color: var(--fg-muted);
  font-weight: 400;
  font-family: var(--font-mono);
  letter-spacing: 0;
}
.btn-small:hover { color: var(--fg); border-color: var(--fg); transform: none; }

/* --- About / prose -------------------------------------------------------- */
.about-content {
  display: grid;
  grid-template-columns: 1fr 1.6fr;
  gap: var(--space-8);
  align-items: start;
}
.about-content .section-title { font-size: clamp(1.5rem, 2.5vw, 2rem); }
.about-text { max-width: var(--w-prose); }
.about-text p {
  font-size: 1.0625rem;
  color: var(--fg);
  line-height: 1.7;
  margin-bottom: 1.1rem;
}
.about-text p:last-child { margin-bottom: 0; }
.about-text a {
  color: var(--fg);
  border-bottom: 1px solid var(--line-strong);
  transition: border-color var(--transition), color var(--transition);
}
.about-text a:hover { color: var(--accent); border-bottom-color: var(--accent); }

/* --- Podcast -------------------------------------------------------------- */
.podcast .podcast-content {
  display: grid;
  grid-template-columns: 1fr 1.4fr;
  gap: var(--space-8);
  align-items: center;
}
.podcast-text .section-title { font-size: clamp(1.5rem, 2.5vw, 2rem); margin-bottom: 1rem; }
.podcast-text p { color: var(--fg-muted); max-width: 40ch; }
.podcast-player iframe { border-radius: 12px; box-shadow: 0 1px 0 var(--line); }

/* --- Research / interest grids (cards) ----------------------------------- */
.research-grid,
.interests-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 0;
  border-top: 1px solid var(--line);
}
.research-card,
.interest-card {
  position: relative;
  padding: var(--space-4) var(--space-3) var(--space-4) 0;
  border-bottom: 1px solid var(--line);
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}
.research-card { padding-right: var(--space-6); }
.research-grid > .research-card:nth-child(odd),
.interests-grid > .interest-card:nth-child(odd) {
  padding-right: var(--space-6);
  border-right: 1px solid var(--line);
  padding-left: 0;
}
.research-grid > .research-card:nth-child(even),
.interests-grid > .interest-card:nth-child(even) {
  padding-left: var(--space-6);
  padding-right: 0;
}

.research-card h3, .interest-card h3 {
  font-size: 1.1875rem;
  font-weight: 500;
  letter-spacing: -0.015em;
  margin: 0.25rem 0 0.5rem;
}
.research-card p, .interest-card p {
  color: var(--fg-muted);
  font-size: 0.975rem;
  line-height: 1.65;
  margin: 0 0 0.6rem;
}
.research-card p:last-child, .interest-card p:last-child { margin-bottom: 0; }
.research-card a, .interest-card a {
  color: var(--fg);
  border-bottom: 1px solid var(--line-strong);
  transition: color var(--transition), border-color var(--transition);
}
.research-card a:hover, .interest-card a:hover {
  color: var(--accent);
  border-bottom-color: var(--accent);
}

.research-icon, .interest-icon {
  font-size: 0.75rem;
  font-family: var(--font-mono);
  color: var(--accent);
  letter-spacing: 0.05em;
  text-transform: uppercase;
  margin-bottom: 0.5rem;
}
.research-icon i, .interest-icon i { display: none; } /* hide font-awesome glyphs for minimalism */
.research-icon::before { content: "—"; color: var(--accent); margin-right: 0.4rem; }
.interest-icon::before { content: "—"; color: var(--accent); margin-right: 0.4rem; }
.research-icon::after { content: attr(data-label); }
.interest-icon::after { content: attr(data-label); }

/* Contact page — show Font Awesome icons instead of mono labels */
#contact-info .interest-icon {
  margin-bottom: 0.75rem;
  font-family: inherit;
}
#contact-info .interest-icon::before,
#contact-info .interest-icon::after { content: none; }
#contact-info .interest-icon i {
  display: inline-block;
  font-size: 1.25rem;
  color: var(--accent);
  line-height: 1;
}

.research-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.6rem;
  margin-top: var(--space-3);
}

/* --- Publications --------------------------------------------------------- */
.publications-container { display: flex; flex-direction: column; }

.year-section {
  display: grid;
  grid-template-columns: 120px 1fr;
  gap: var(--space-4);
  padding: var(--space-4) 0;
  border-top: 1px solid var(--line);
}
.year-section:first-child { border-top: 1px solid var(--line-strong); }

.year-title {
  font-family: var(--font-mono);
  font-size: 0.8rem;
  font-weight: 400;
  letter-spacing: 0.06em;
  color: var(--fg-muted);
  text-transform: uppercase;
  margin: 0.4rem 0 0;
  position: sticky;
  top: 80px;
  align-self: start;
}

.publication-list { display: flex; flex-direction: column; gap: var(--space-3); }

.publication-item {
  padding: 0;
  border: 0;
  background: transparent;
}
.publication-item + .publication-item {
  padding-top: var(--space-3);
  border-top: 1px solid var(--line);
}
.publication-item h4 {
  font-size: 1.0625rem;
  font-weight: 500;
  letter-spacing: -0.015em;
  line-height: 1.4;
  margin: 0 0 0.5rem;
  color: var(--fg);
  text-wrap: pretty;
}
.publication-item .authors {
  font-size: 0.925rem;
  color: var(--fg-muted);
  margin: 0 0 0.3rem;
}
.publication-item .venue {
  font-size: 0.9rem;
  color: var(--fg-subtle);
  margin: 0 0 0.7rem;
  font-family: var(--font-serif);
  font-style: italic;
  letter-spacing: -0.005em;
}
.publication-item .venue .acronym {
  font-family: var(--font-mono);
  font-style: normal;
  font-size: 0.78rem;
  text-transform: none;
  background: var(--bg-alt);
  border: 1px solid var(--line);
  padding: 0.05em 0.45em;
  border-radius: 4px;
  margin: 0 0.15em;
  color: var(--fg);
  letter-spacing: 0;
}
.publication-item .venue strong { font-family: var(--font-sans); font-style: normal; color: var(--accent); }
.publication-links { display: flex; flex-wrap: wrap; gap: 0.4rem; }

/* Academic services list ---------------------------------------------------*/
.services-list {
  display: flex;
  flex-direction: column;
}
.svc-block {
  display: grid;
  grid-template-columns: 180px 1fr;
  gap: var(--space-4);
  padding: var(--space-3) 0;
  border-top: 1px solid var(--line);
}
.svc-block:first-child { border-top: 1px solid var(--line-strong); }
.svc-label {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  text-transform: uppercase;
  letter-spacing: 0.07em;
  color: var(--fg-muted);
  padding-top: 0.4rem;
}
.svc-content {
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
}
.svc-bullets,
.svc-courses,
.svc-items {
  list-style: none;
  padding: 0;
  margin: 0;
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}
.svc-bullets li,
.svc-courses li,
.svc-items li {
  font-size: 0.975rem;
  color: var(--fg);
  line-height: 1.6;
  position: relative;
  padding-left: 1rem;
}
.svc-bullets li::before,
.svc-courses li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.7em;
  width: 0.5rem;
  height: 1px;
  background: var(--fg-subtle);
}
.svc-items li { padding-left: 0; }
.svc-courses a {
  color: var(--fg);
  border-bottom: 1px solid var(--line-strong);
  transition: color var(--transition), border-color var(--transition);
}
.svc-courses a:hover { color: var(--accent); border-bottom-color: var(--accent); }
.svc-host {
  color: var(--fg-muted);
  font-size: 0.875rem;
}
.svc-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 0.35rem;
}
.svc-tag {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  letter-spacing: 0.02em;
  padding: 0.3em 0.7em;
  border-radius: 999px;
  border: 1px solid var(--line);
  background: var(--bg);
  color: var(--fg-muted);
}
.svc-years {
  display: flex;
  flex-direction: column;
  gap: 0.9rem;
}
.svc-year-row {
  display: grid;
  grid-template-columns: 60px 1fr;
  gap: 1rem;
  align-items: start;
}
.svc-year {
  font-family: var(--font-mono);
  font-size: 0.8rem;
  color: var(--fg-muted);
  padding-top: 0.1rem;
}

@media (max-width: 720px) {
  .svc-block { grid-template-columns: 1fr; gap: var(--space-2); }
  .svc-label { padding-top: 0; }
  .svc-year-row { grid-template-columns: 50px 1fr; }
}

/* Filter controls --------------------------------------------------------- */
.pub-controls {
  display: grid;
  grid-template-columns: 1fr auto;
  grid-template-areas:
    "type   search"
    "year   year";
  gap: 0.75rem 1rem;
  align-items: center;
  margin: var(--space-3) 0 var(--space-4);
  padding-bottom: var(--space-3);
  border-bottom: 1px solid var(--line);
}
#pubTypeFilters { grid-area: type; }
#pubYearFilters { grid-area: year; }
.pub-search    { grid-area: search; display: inline-flex; align-items: center; gap: 0.75rem; }

.pub-filters {
  display: flex;
  flex-wrap: wrap;
  gap: 0.35rem;
}
.pf-btn {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  letter-spacing: 0.02em;
  padding: 0.35em 0.75em;
  border-radius: 999px;
  border: 1px solid var(--line);
  background: var(--bg);
  color: var(--fg-muted);
  cursor: pointer;
  transition: all var(--transition);
}
.pf-btn:hover { color: var(--fg); border-color: var(--fg-muted); }
.pf-btn.is-on {
  background: var(--fg);
  color: var(--bg);
  border-color: var(--fg);
}

#pubYearFilters .pf-btn { font-size: 0.72rem; padding: 0.3em 0.65em; }

.pub-search input {
  font: inherit;
  font-size: 0.875rem;
  padding: 0.5em 0.85em;
  border: 1px solid var(--line);
  border-radius: 999px;
  background: var(--bg);
  color: var(--fg);
  width: 260px;
  max-width: 100%;
  outline: none;
  transition: border-color var(--transition), box-shadow var(--transition);
}
.pub-search input::placeholder { color: var(--fg-subtle); }
.pub-search input:focus { border-color: var(--fg); }
.pub-count {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: var(--fg-muted);
  white-space: nowrap;
}

@media (max-width: 720px) {
  .pub-controls {
    grid-template-columns: 1fr;
    grid-template-areas: "type" "year" "search";
  }
  .pub-search input { width: 100%; }
}

/* Group sections (by type) ------------------------------------------------ */
.pub-group { margin-top: var(--space-4); }
.pub-group:first-child { margin-top: 0; }
.pub-group-title {
  font-family: var(--font-mono);
  font-size: 1.125rem;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--fg);
  padding-bottom: 0.55rem;
  border-bottom: 1px solid var(--line-strong);
  margin-bottom: var(--space-3);
  display: flex;
  align-items: baseline;
  gap: 0.6rem;
}
.pub-group-count { color: var(--fg-subtle); }

.pub-empty {
  color: var(--fg-muted);
  font-family: var(--font-serif);
  font-style: italic;
  padding: var(--space-3) 0;
  border-top: 1px solid var(--line);
}

/* Inline year prefix on each paper title */
.publication-item h4 .pub-year-inline {
  font-family: var(--font-mono);
  font-weight: 500;
  font-size: 0.85em;
  color: var(--fg-muted);
  margin-right: 0.5em;
  letter-spacing: 0.02em;
}

/* Search highlight */
.publication-item mark {
  background: oklch(0.93 0.08 90);
  color: var(--fg);
  padding: 0 0.1em;
  border-radius: 2px;
}

/* Load-more (kept hidden when filters are active) */
.year-section.is-hidden { display: none; }
.publications-container.is-expanded .year-section.is-hidden { display: grid; }

.year-section .publication-list,
.year-section > .publication-item { padding-top: 0.4rem; }
/* Direct children publication-items inside year-section without publication-list */
.year-section > .publication-item + .publication-item {
  margin-top: var(--space-3);
  padding-top: var(--space-3);
  border-top: 1px solid var(--line);
}

.load-more-container {
  display: flex;
  justify-content: center;
  margin: var(--space-4) 0 0;
  grid-column: 1 / -1;
}

/* --- Venue summary -------------------------------------------------------- */
.venue-summary { padding-bottom: var(--space-6); }
.venue-stats { margin-top: var(--space-4); }
.venue-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 0.45rem;
}
.venue-tag {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  letter-spacing: 0.02em;
  padding: 0.3em 0.7em;
  border-radius: 999px;
  border: 1px solid var(--line);
  background: var(--bg);
  color: var(--fg-muted);
  transition: all var(--transition);
}
.venue-tag.single { color: var(--fg-muted); }
.venue-tag.low    { color: var(--fg); border-color: var(--line-strong); }
.venue-tag.medium { color: var(--fg); border-color: var(--fg); }
.venue-tag.high   { color: var(--bg); background: var(--fg); border-color: var(--fg); }
.venue-tag:hover  { transform: translateY(-1px); }

/* --- Services grid (teaching philosophy, env, etc.) ---------------------- */
.services-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 0;
  border-top: 1px solid var(--line);
}
.service-card {
  padding: var(--space-4) var(--space-4) var(--space-4) 0;
  border-bottom: 1px solid var(--line);
}
.services-grid > .service-card:nth-child(odd)  { padding-right: var(--space-4); border-right: 1px solid var(--line); }
.services-grid > .service-card:nth-child(even) { padding-left: var(--space-4); padding-right: 0; }
.service-card h3 {
  font-size: 1.05rem;
  font-weight: 500;
  letter-spacing: -0.01em;
  margin: 0 0 0.75rem;
}
.service-card h3 i { display: none; }
.service-card ul {
  list-style: none;
  padding: 0;
  margin: 0;
  display: flex;
  flex-direction: column;
  gap: 0.4rem;
}
.service-card li {
  font-size: 0.95rem;
  color: var(--fg-muted);
  position: relative;
  padding-left: 1.1rem;
}
.service-card li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.7em;
  width: 0.5rem;
  height: 1px;
  background: var(--fg-subtle);
}

/* --- Map / contact -------------------------------------------------------- */
.map-container iframe {
  border-radius: 8px;
  filter: grayscale(0.4) contrast(0.95);
}

/* --- Footer --------------------------------------------------------------- */
.footer {
  margin-top: 0;
  padding: var(--space-8) 0 var(--space-4);
  background: var(--bg);
  border-top: 1px solid var(--line);
}
.footer-content {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr;
  gap: var(--space-6);
  padding-bottom: var(--space-6);
}
.footer-section h3 {
  font-size: 1.0625rem;
  font-weight: 500;
  margin-bottom: 0.5rem;
}
.footer-section h4 {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  font-weight: 400;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--fg-muted);
  margin-bottom: 1rem;
}
.footer-section p { color: var(--fg-muted); margin: 0; }
.footer-section ul {
  list-style: none;
  padding: 0;
  margin: 0;
  display: flex;
  flex-direction: column;
  gap: 0.4rem;
}
.footer-section ul a {
  color: var(--fg-muted);
  font-size: 0.95rem;
  transition: color var(--transition);
}
.footer-section ul a:hover { color: var(--fg); }

.social-links {
  display: flex;
  gap: 0.5rem;
}
.social-links a {
  width: 38px;
  height: 38px;
  border-radius: 50%;
  border: 1px solid var(--line-strong);
  display: inline-flex;
  align-items: center;
  justify-content: center;
  color: var(--fg-muted);
  font-size: 0.95rem;
  transition: all var(--transition);
}
.social-links a:hover { color: var(--bg); background: var(--fg); border-color: var(--fg); }

.footer-bottom {
  padding-top: var(--space-3);
  border-top: 1px solid var(--line);
  display: flex;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 0.5rem;
  color: var(--fg-subtle);
  font-size: 0.825rem;
}
.footer-bottom p { margin: 0; }
.footer-bottom a { color: inherit; text-decoration: underline; text-decoration-color: var(--line-strong); }
.footer-bottom a:hover { color: var(--fg); }

/* --- Back-to-top (script-injected) --------------------------------------- */
.back-to-top {
  position: fixed;
  bottom: 1.5rem;
  right: 1.5rem;
  width: 42px !important;
  height: 42px !important;
  background-color: var(--fg) !important;
  color: var(--bg) !important;
  border: 0;
  border-radius: 50%;
  cursor: pointer;
  display: none;
  align-items: center;
  justify-content: center;
  font-size: 0.85rem !important;
  box-shadow: 0 4px 24px oklch(0.18 0.005 60 / 0.18) !important;
  z-index: 60;
  transition: var(--transition);
}
.back-to-top:hover { background: var(--accent) !important; transform: translateY(-2px); }
.back-to-top.show { display: inline-flex; }

/* --- Home page density tweaks -------------------------------------------- */
.home section { padding: var(--space-6) 0; }
.home .hero {
  padding: clamp(2.5rem, 6vw, 5rem) 0 clamp(2rem, 4vw, 3.5rem);
}
.home .hero-content {
  grid-template-columns: 1.5fr 1fr;
  gap: var(--space-6);
  align-items: center;
}
.home .hero-title {
  font-size: clamp(2.25rem, 4.6vw, 3.75rem);
  line-height: 1.04;
  margin-bottom: var(--space-2);
}
.home .hero-eyebrow { margin-bottom: var(--space-2); }
.home .hero-subtitle { font-size: 1.125rem; margin-bottom: 0.5rem; }
.home .hero-description { font-size: 1rem; margin-bottom: var(--space-3); }
.home .hero-buttons { margin-top: var(--space-2); }
.home .hero-image .profile-image {
  max-width: 280px;
  aspect-ratio: 4/5;
}

.home .section-head { margin-bottom: var(--space-4); gap: 0.25rem; }
.home .section-title { font-size: clamp(1.5rem, 2.5vw, 2rem); }
.home .about-content { grid-template-columns: 0.85fr 1.6fr; gap: var(--space-6); }
.home .about-text p { font-size: 1rem; line-height: 1.65; margin-bottom: 0.85rem; }

.home .podcast .podcast-content { gap: var(--space-6); align-items: center; }
.home .podcast-text p { margin: 0; }

.home .research-card { padding-top: 1.4rem; padding-bottom: 1.4rem; gap: 0.35rem; }
.home .research-card h3 { font-size: 1.0625rem; margin: 0.15rem 0 0.3rem; }
.home .research-card p { font-size: 0.95rem; line-height: 1.6; }
.home .research .research-actions { margin-top: var(--space-4) !important; justify-content: center; }

.home .footer { padding: var(--space-6) 0 var(--space-3); }
.home .footer-content { padding-bottom: var(--space-4); gap: var(--space-4); }

@media (max-width: 900px) {
  .home .hero-content { grid-template-columns: 1fr; gap: var(--space-3); }
  .home .about-content { grid-template-columns: 1fr; gap: var(--space-3); }
}

/* --- Research Interests (research.html) — denser variant ------------------*/
#interests.research-interests { padding: var(--space-6) 0; }
#interests .interests-grid {
  grid-template-columns: repeat(2, 1fr);
  border-top: 1px solid var(--line);
}
#interests .interest-card {
  padding-top: 1.25rem;
  padding-bottom: 1.25rem;
  gap: 0.25rem;
}
#interests .interest-card h3 {
  font-size: 1rem;
  margin: 0.15rem 0 0.3rem;
}
#interests .interest-card p {
  font-size: 0.925rem;
  line-height: 1.55;
  margin-bottom: 0.4rem;
}
#interests .interest-icon { display: none; }

/* --- Courses (teaching.html) — compact list ------------------------------ */
.courses-section { padding: var(--space-6) 0 var(--space-8); }
.courses-section .section-title { margin-bottom: var(--space-4); }

.course-list {
  list-style: none;
  padding: 0;
  margin: 0;
  border-top: 1px solid var(--line);
}
.course-row {
  display: grid;
  grid-template-columns: 7.5rem 1fr 12rem;
  gap: var(--space-4);
  align-items: baseline;
  padding: 1.15rem 0;
  border-bottom: 1px solid var(--line);
  transition: background var(--transition);
}
.course-row:hover { background: var(--bg-alt); }

.course-codes {
  display: flex;
  flex-direction: column;
  gap: 0.15rem;
}
.course-code {
  font-family: var(--font-mono);
  font-size: 0.78rem;
  letter-spacing: 0.04em;
  color: var(--accent);
  font-weight: 500;
}

.course-body { min-width: 0; }
.course-title {
  font-size: 1.0625rem;
  font-weight: 500;
  letter-spacing: -0.015em;
  margin: 0 0 0.2rem;
  color: var(--fg);
}
.link-icon {
  display: inline-block;
  width: 1.25rem;
  margin-right: 0.55rem;
  color: var(--accent);
  font-size: 0.95em;
  text-align: center;
  vertical-align: -0.05em;
}

/* --- Thread "Selected papers" list (index.html research cards) ----------- */
.thread-papers {
  margin-top: 0.75rem;
}
.thread-papers-label {
  font-family: var(--font-mono);
  font-size: 0.7rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--fg-subtle);
  margin: 0 0 0.4rem;
}
.thread-papers ul {
  list-style: none;
  padding: 0;
  margin: 0;
  display: flex;
  flex-direction: column;
  gap: 0.3rem;
}
.thread-papers li {
  font-size: 0.875rem;
  line-height: 1.45;
}
.thread-papers a {
  color: var(--fg);
  border-bottom: 1px solid var(--line-strong);
  transition: color var(--transition), border-color var(--transition);
}
.thread-papers a:hover {
  color: var(--accent);
  border-bottom-color: var(--accent);
}
.thread-papers .paper-venue {
  font-family: var(--font-mono);
  font-size: 0.7rem;
  letter-spacing: 0.03em;
  color: var(--fg-subtle);
  margin-left: 0.4rem;
  white-space: nowrap;
}
.course-topics {
  font-size: 0.925rem;
  line-height: 1.5;
  color: var(--fg-muted);
  margin: 0;
  text-wrap: pretty;
}
.course-meta {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.02em;
  color: var(--fg-subtle);
  margin: 0.35rem 0 0;
}
.course-meta a {
  color: var(--fg-muted);
  border-bottom: 1px solid var(--line-strong);
  transition: color var(--transition), border-color var(--transition);
}
.course-meta a:hover { color: var(--accent); border-bottom-color: var(--accent); }

.course-terms {
  display: flex;
  flex-direction: column;
  align-items: flex-end;
  text-align: right;
  gap: 0.15rem;
}
.terms-count {
  font-family: var(--font-mono);
  font-size: 0.78rem;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  color: var(--fg);
}
.terms-range {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.02em;
  color: var(--fg-subtle);
}

@media (max-width: 720px) {
  .course-row {
    grid-template-columns: 1fr;
    gap: 0.4rem;
    padding: 1rem 0;
  }
  .course-codes { flex-direction: row; gap: 0.75rem; }
  .course-terms {
    flex-direction: row;
    align-items: baseline;
    justify-content: flex-start;
    text-align: left;
    gap: 0.6rem;
  }
}

/* --- Course Evaluations table (teaching.html) ---------------------------- */
.evals-header {
  display: flex;
  align-items: flex-end;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: var(--space-3);
  margin-bottom: var(--space-3);
}
.evals-header .section-title { margin-bottom: 0.25rem; }
.evals-sub {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  letter-spacing: 0.04em;
  color: var(--fg-subtle);
  margin: 0;
  text-transform: uppercase;
}
.evals-summary {
  display: flex;
  gap: var(--space-3);
}
.evals-summary .stat {
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  border-left: 1px solid var(--line);
  padding-left: 0.9rem;
  min-width: 4.5rem;
}
.evals-summary .stat:first-child { border-left: none; padding-left: 0; }
.evals-summary .stat-num {
  font-family: var(--font-sans);
  font-size: 1.5rem;
  font-weight: 400;
  letter-spacing: -0.02em;
  color: var(--fg);
  line-height: 1.1;
}
.evals-summary .stat-label {
  font-family: var(--font-mono);
  font-size: 0.7rem;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--fg-subtle);
  margin-top: 0.15rem;
}

.evals-table-wrap {
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
  overflow-x: auto;
}
.evals-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.875rem;
}
.evals-table thead th {
  font-family: var(--font-mono);
  font-size: 0.7rem;
  font-weight: 500;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--fg-subtle);
  text-align: right;
  padding: 0.75rem 0.7rem;
  border-bottom: 1px solid var(--line);
  background: var(--bg);
}
.evals-table thead .col-code { text-align: left; }
.evals-table tbody tr { transition: background var(--transition); }
.evals-table tbody tr:hover { background: var(--bg-alt); }
.evals-table tbody th.col-code {
  text-align: left;
  font-weight: 400;
  padding: 0.7rem 0.9rem 0.7rem 0;
  border-bottom: 1px solid var(--line);
  vertical-align: middle;
  min-width: 16rem;
}
.evals-table .row-code {
  font-family: var(--font-mono);
  font-size: 0.78rem;
  color: var(--accent);
  font-weight: 500;
  margin-right: 0.6rem;
  letter-spacing: 0.02em;
}
.evals-table .row-title {
  color: var(--fg);
  font-size: 0.9375rem;
}
.evals-table .cell {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  text-align: right;
  padding: 0.55rem 0.7rem;
  border-bottom: 1px solid var(--line);
  color: var(--fg);
  width: 4.25rem;
}
.evals-table .cell-avg {
  font-weight: 500;
  border-left: 1px solid var(--line);
}

/* Heat tiers — warm accent ramp */
.evals-table .tier-na    { color: var(--fg-subtle); background: transparent; }
.evals-table .tier-1     { background: oklch(0.97 0.012 35); }
.evals-table .tier-2     { background: oklch(0.945 0.025 35); }
.evals-table .tier-3     { background: oklch(0.91 0.045 35); }
.evals-table .tier-4     { background: oklch(0.86 0.07  35); color: oklch(0.28 0.08 35); }

.evals-legend {
  display: flex;
  flex-wrap: wrap;
  gap: 0.9rem 1.25rem;
  margin: 0.9rem 0 0;
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  color: var(--fg-subtle);
  align-items: center;
}
.legend-swatch {
  display: inline-block;
  width: 0.85rem;
  height: 0.85rem;
  border-radius: 2px;
  margin-right: 0.4rem;
  vertical-align: -2px;
  border: 1px solid var(--line);
}
.legend-swatch.swatch-1  { background: oklch(0.97 0.012 35); }
.legend-swatch.swatch-2  { background: oklch(0.945 0.025 35); }
.legend-swatch.swatch-3  { background: oklch(0.91 0.045 35); }
.legend-swatch.swatch-4  { background: oklch(0.86 0.07  35); }
.legend-swatch.swatch-na { background: transparent; }

@media (max-width: 720px) {
  .evals-header { flex-direction: column; align-items: flex-start; }
  .evals-summary { gap: var(--space-2); }
  .evals-summary .stat { padding-left: 0.7rem; min-width: 0; }
  .evals-table tbody th.col-code { min-width: 12rem; }
  .evals-table .row-title { font-size: 0.85rem; }
  .evals-table .cell { width: 3.4rem; padding: 0.5rem 0.5rem; }
}

/* --- Research topics (students.html) ------------------------------------- */
.topics-intro {
  max-width: 60ch;
  color: var(--fg-muted);
  margin: 0 0 var(--space-4);
  font-size: 1rem;
}
.topic-group { margin-bottom: var(--space-4); }
.topic-group:last-child { margin-bottom: 0; }
.topic-group-label {
  display: flex;
  align-items: baseline;
  gap: 0.9rem;
  margin: 0 0 0.5rem;
  flex-wrap: wrap;
}
.group-tag {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  font-weight: 500;
  color: var(--accent);
  background: var(--accent-soft);
  padding: 0.18rem 0.55rem;
  border-radius: 2px;
}
.group-tag.group-tag-alt {
  color: var(--fg);
  background: transparent;
  border: 1px solid var(--line-strong);
}
.group-note {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  color: var(--fg-subtle);
}

.course-row .topic-body { padding-right: var(--space-3); }
.course-row .topic-body .course-title { font-size: 1.05rem; }
.course-row .topic-body .course-topics em {
  font-family: var(--font-mono);
  font-style: normal;
  font-size: 0.85em;
  letter-spacing: 0.02em;
  color: var(--fg);
}
.course-row .topic-body .course-topics a {
  color: var(--fg);
  border-bottom: 1px solid var(--line-strong);
  transition: color var(--transition), border-color var(--transition);
}
.course-row .topic-body .course-topics a:hover {
  color: var(--accent);
  border-bottom-color: var(--accent);
}

/* Override the 3-col grid for topic rows (no left codes col) */
#opportunities .course-row,
#research-projects .course-row,
#software-tools .course-row,
#masters-projects .course-row,
#external-links .course-row {
  grid-template-columns: 1fr 15rem;
}
#research-projects .terms-count,
#research-projects .terms-range,
#software-tools .terms-count,
#software-tools .terms-range,
#masters-projects .terms-count,
#masters-projects .terms-range,
#opportunities .terms-count,
#opportunities .terms-range,
#external-links .terms-count,
#external-links .terms-range {
  white-space: nowrap;
}

/* --- Apply / what-you-get strip (students.html) -------------------------- */
.apply-section { padding: var(--space-6) 0 var(--space-8); }
.apply-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--space-6);
  align-items: start;
}
.apply-block .section-title { margin-bottom: var(--space-2); }
.apply-lede {
  color: var(--fg-muted);
  margin: 0 0 0.6rem;
}
.apply-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-direction: column;
  gap: 0.55rem;
}
.apply-list li {
  position: relative;
  padding-left: 1.2rem;
  color: var(--fg-muted);
  font-size: 0.95rem;
  line-height: 1.55;
}
.apply-list li::before {
  content: "—";
  position: absolute;
  left: 0;
  color: var(--accent);
}
.apply-list li strong { color: var(--fg); font-weight: 500; }
.apply-list.compact li { font-size: 0.925rem; }
.apply-actions {
  display: flex;
  gap: 0.75rem;
  flex-wrap: wrap;
  margin-top: var(--space-3);
}

@media (max-width: 720px) {
  #opportunities .course-row,
  #research-projects .course-row,
  #software-tools .course-row,
  #masters-projects .course-row,
  #external-links .course-row { grid-template-columns: 1fr; }
  .apply-grid { grid-template-columns: 1fr; gap: var(--space-4); }
}

/* --- Animations ----------------------------------------------------------- */
.fade-in {
  opacity: 0;
  transform: translateY(8px);
  transition: opacity 600ms ease, transform 600ms cubic-bezier(.2,.6,.2,1);
}
.fade-in.visible { opacity: 1; transform: none; }

/* --- Responsive ----------------------------------------------------------- */
@media (max-width: 900px) {
  .nav-menu {
    position: fixed;
    inset: 64px 0 auto 0;
    flex-direction: column;
    gap: 0;
    background: var(--bg);
    border-bottom: 1px solid var(--line);
    padding: 0.5rem 1rem 1rem;
    transform: translateY(-110%);
    transition: transform var(--transition);
  }
  .nav-menu.active { transform: translateY(0); }
  .nav-link { padding: 0.85rem 0.5rem; width: 100%; border-radius: 0; }
  .hamburger { display: inline-flex; }

  .hero-content { grid-template-columns: 1fr; gap: var(--space-4); }
  .hero-image .profile-image { max-width: 240px; margin: 0; }

  .about-content { grid-template-columns: 1fr; gap: var(--space-4); }
  .podcast .podcast-content { grid-template-columns: 1fr; gap: var(--space-3); }

  .research-grid, .interests-grid, .services-grid {
    grid-template-columns: 1fr;
  }
  .research-grid > .research-card,
  .interests-grid > .interest-card,
  .services-grid > .service-card {
    padding: var(--space-3) 0 !important;
    border-right: 0 !important;
  }

  .year-section { grid-template-columns: 1fr; gap: var(--space-2); }
  .year-title { position: static; }

  .footer-content { grid-template-columns: 1fr; gap: var(--space-4); }
}

@media (max-width: 560px) {
  section { padding: var(--space-8) 0; }
  .container, .nav-container, .hero-container { padding: 0 1.25rem; }
}

/* --- Print ---------------------------------------------------------------- */
@media print {
  .navbar, .footer, .back-to-top, .hamburger, .load-more-container { display: none !important; }
  body { color: #000; }
  a { color: #000; }
}