/* ==========================================================
   SurfReact — design tokens
   Palette drawn from the group's subject: the bulk solid
   (petrol ink), the vacuum/solution side (cool paper), the
   catalyst (teal) and the reacting adsorbate (copper).
   ========================================================== */

:root {
  --ink:    #14262E;   /* bulk solid */
  --deep:   #1F3B46;   /* subsurface layer */
  --paper:  #F4F7F7;   /* gas / solution phase */
  --white:  #FFFFFF;
  --teal:   #0F6B70;   /* catalyst — working accent */
  --copper: #B25A2B;   /* adsorbate — highlight, used sparingly */
  --line:   #D8E0E1;
  --muted:  #55676F;

  --font-display: "Sora", sans-serif;
  --font-body: "IBM Plex Sans", sans-serif;
  --font-mono: "IBM Plex Mono", monospace;

  --measure: 66ch;
  --pad: clamp(1.25rem, 4vw, 3rem);
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth;
     height: 100%; }
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after { animation: none !important; transition: none !important; }
}

body {
  margin: 0;
  font-family: var(--font-body);
  font-size: 1.0625rem;
  line-height: 1.65;
  color: var(--ink);
  background: var(--paper);
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

main {
  flex: 1 0 auto;   /* grows to fill leftover space, shrinks to nothing below its content */
}

a { color: var(--teal); text-decoration-thickness: 1px; text-underline-offset: 3px; }
a:hover { color: var(--copper); }
a:focus-visible,
button:focus-visible,
.nav-button:focus-visible {
  outline: 2px solid var(--copper);
  outline-offset: 3px;
  border-radius: 2px;
}

h1, h2, h3 {
  font-family: var(--font-display);
  line-height: 1.15;
  letter-spacing: -0.015em;
  color: var(--ink);
}

.eyebrow {
  font-family: var(--font-mono);
  font-size: 0.78rem;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--teal);
  margin: 0 0 0.6rem;
}

/* ----------------------------------------------------------
   Header + navigation (menu top right)
   ---------------------------------------------------------- */

.site-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  padding: 1rem var(--pad);
  background: var(--paper);
  border-bottom: 1px solid var(--line);
  position: sticky;
  top: 0;
  z-index: 20;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 0.6rem;
  text-decoration: none;
}

.brand-name {
  font-family: var(--font-display);
  font-weight: 800;
  font-size: 1.25rem;
  color: var(--ink);
}

.nav-list {
  display: flex;
  gap: 1.4rem;
  list-style: none;
  margin: 0;
  padding: 0;
}

.nav-list a {
  font-family: var(--font-mono);
  font-size: 0.85rem;
  text-decoration: none;
  color: var(--ink);
  padding-bottom: 2px;
  border-bottom: 2px solid transparent;
}

.nav-list a:hover { color: var(--teal); }
.nav-list a[aria-current="page"] {
  color: var(--teal);
  border-bottom-color: var(--copper);
}

.nav-toggle { display: none; }
.nav-button { display: none; }

@media (max-width: 860px) {
  .nav-button {
    display: flex;
    flex-direction: column;
    gap: 5px;
    padding: 8px;
    cursor: pointer;
  }
  .nav-button span {
    width: 22px;
    height: 2px;
    background: var(--ink);
  }
  .nav-list {
    display: none;
    position: absolute;
    top: 100%;
    right: 0;
    left: 0;
    flex-direction: column;
    gap: 0;
    background: var(--paper);
    border-bottom: 1px solid var(--line);
    padding: 0.5rem var(--pad) 1rem;
  }
  .nav-list li a {
    display: block;
    padding: 0.7rem 0;
    border-bottom: none;
  }
  .nav-toggle:checked ~ .nav-list { display: flex; }
}
 .has-submenu {
  position: relative;
}

.submenu {
  position: absolute;
  top: 100%;
  left: 0;
  min-width: 12rem;
  margin: 0;
  padding: 0.4rem 0;
  list-style: none;
  background: #fff;                     /* match your header background */
  border: 1px solid rgba(0, 0, 0, .1);
  border-radius: 8px;
  box-shadow: 0 8px 24px rgba(0, 0, 0, .12);
  opacity: 0;
  visibility: hidden;
  transform: translateY(4px);
  transition: opacity .15s ease, transform .15s ease, visibility .15s;
  z-index: 100;
}

.has-submenu:hover > .submenu,
.has-submenu:focus-within > .submenu {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
}

.submenu li { margin: 0; }

.submenu a {
  display: block;
  padding: 0.5rem 1rem;
  white-space: nowrap;
}

.submenu a:hover { background: rgba(0, 0, 0, .05); }

/* ----------------------------------------------------------
   Hero — the interface itself
   ---------------------------------------------------------- */

.hero {
  background: var(--paper);
  padding: clamp(3rem, 7vw, 5.5rem) var(--pad) clamp(1.5rem, 4vw, 3rem);
  text-align: left;
}

.hero-inner {
  max-width: 1100px;
  margin: 0 auto;
}

.hero-split {
  display: grid;
  grid-template-columns: minmax(0, 1.1fr) minmax(0, 1fr);
  gap: clamp(1.5rem, 5vw, 4rem);
  align-items: center;
}

.hero-image img {
  display: block;
  width: 100%;
  height: auto;
  border: 1px solid var(--line);
}

@media (max-width: 760px) {
  .hero-split { grid-template-columns: 1fr; }
  .hero-image { order: 2; }
}

.hero h1 {
  font-size: clamp(2.6rem, 7vw, 4.6rem);
  font-weight: 800;
  margin: 0.2rem 0 1rem;
}

.hero h1 .accent { color: var(--teal); }

.hero .tagline {
  max-width: 46ch;
  font-size: clamp(1.05rem, 2vw, 1.25rem);
  color: var(--muted);
  margin: 0;
}

/* ----------------------------------------------------------
   Sections
   ---------------------------------------------------------- */

.section {
  padding: clamp(2.5rem, 6vw, 4.5rem) var(--pad);
}

.section-inner {
  max-width: 1100px;
  margin: 0 auto;
}

.section-dark {
  background: var(--ink);
  color: #DDE7E8;
}
.section-dark h2 { color: var(--white); }
.section-dark .eyebrow { color: #6FC2C6; }
.section-dark a { color: #8FD4D7; }
.section-dark a:hover { color: #E0A579; }

.section h2 {
  font-size: clamp(1.5rem, 3.2vw, 2.1rem);
  margin: 0 0 1.6rem;
}

/* ----------------------------------------------------------
   Update cards (last three on landing page)
   ---------------------------------------------------------- */

.updates-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 1.25rem;
}

.update-card {
  display: flex;
  flex-direction: column;
  background: #1D323C;
  border: 1px solid #2C4650;
  border-top: 3px solid var(--teal);
  padding: 1.4rem 1.4rem 1.2rem;
}

.update-card time {
  font-family: var(--font-mono);
  font-size: 0.78rem;
  letter-spacing: 0.08em;
  color: #6FC2C6;
}

.update-card h3 {
  font-size: 1.12rem;
  margin: 0.5rem 0 0.6rem;
  color: var(--white);
}

.update-card h3 a {
  color: inherit;
  text-decoration: none;
}
.update-card h3 a:hover { color: #E0A579; }

.update-card p {
  margin: 0 0 1rem;
  font-size: 0.95rem;
  color: #B9C9CD;
  flex-grow: 1;
}

.update-card .more {
  font-family: var(--font-mono);
  font-size: 0.82rem;
}

.all-updates-link {
  margin-top: 1.6rem;
  font-family: var(--font-mono);
  font-size: 0.9rem;
}

/* ----------------------------------------------------------
   Generic pages
   ---------------------------------------------------------- */

.page {
  max-width: calc(var(--measure) + 2 * var(--pad));
  margin: 0 auto;
  padding: clamp(2.5rem, 6vw, 4rem) var(--pad) 4rem;
}

/* Widen content pages that hold lists/grids to match the hero & sections,
   while leaving running-text pages (About, Research, bios) at a readable width. */
.page:has(.member-list, .pub-list, .topics-list, .course-list, .archive-list) {
  max-width: 1100px;
}

/* Keep paragraphs readable even inside those now-wider pages
   (e.g. the intro sentence on the Topics and Teaching pages). */
.prose {
  max-width: var(--measure);
}

.page-header h1 {
  font-size: clamp(2rem, 5vw, 3rem);
  margin: 0 0 1.5rem;
}

.prose h2 {
  font-size: 1.45rem;
  margin: 2.2rem 0 0.8rem;
}

.prose h3 { font-size: 1.15rem; margin: 1.8rem 0 0.5rem; }

.prose ul { padding-left: 1.2rem; }

.prose hr {
  border: none;
  border-top: 1px solid var(--line);
  margin: 2.5rem 0;
}

.back-link { margin-top: 3rem; font-family: var(--font-mono); font-size: 0.9rem; }

/* ----------------------------------------------------------
   Members
   ---------------------------------------------------------- */

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

.member {
  display: grid;
  grid-template-columns: 64px 1fr;
  gap: 1.1rem;
  padding: 1.3rem 0;
  border-bottom: 1px solid var(--line);
}

.member-mark {
  width: 64px;
  height: 64px;
  border-radius: 50%;
  background: var(--deep);
  color: var(--white);
  font-family: var(--font-display);
  font-weight: 700;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.1rem;
}

.member h3 { margin: 0 0 0.15rem; font-size: 1.1rem; }
.member .role {
  font-family: var(--font-mono);
  font-size: 0.8rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--teal);
  margin: 0 0 0.4rem;
}
.member p { margin: 0; font-size: 0.97rem; }

/* ----------------------------------------------------------
   Publications
   ---------------------------------------------------------- */

.pub-section {
  text-transform: uppercase;
  color: var(--teal);
  font-size: 1.15rem;
}

.pub-year {
  font-family: var(--font-mono);
  font-size: 0.9rem;
  letter-spacing: 0.12em;
  color: var(--copper);
  margin: 2.4rem 0 0.6rem;
}

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

.pub-list li {
  padding: 0.9rem 0;
  border-bottom: 1px solid var(--line);
  font-size: 0.98rem;
}

.pub-list .pub-title { font-weight: 600; }
.pub-list .pub-venue { font-style: italic; color: var(--muted); }

/* ----------------------------------------------------------
   Archive
   ---------------------------------------------------------- */

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

.archive-item {
  display: grid;
  grid-template-columns: 9.5rem 1fr;
  gap: 1rem;
  padding: 1.1rem 0;
  border-bottom: 1px solid var(--line);
  align-items: baseline;
}

.archive-item time {
  font-family: var(--font-mono);
  font-size: 0.82rem;
  color: var(--muted);
}

.archive-item h2 {
  font-size: 1.12rem;
  margin: 0 0 0.3rem;
}

.archive-item h2 a { color: var(--ink); text-decoration: none; }
.archive-item h2 a:hover { color: var(--teal); }

.archive-item p { margin: 0; font-size: 0.95rem; color: var(--muted); }

@media (max-width: 560px) {
  .archive-item { grid-template-columns: 1fr; gap: 0.2rem; }
}

/* ----------------------------------------------------------
   Footer
   ---------------------------------------------------------- */

.site-footer {
  background: var(--ink);
  color: #B9C9CD;
  padding: 3rem var(--pad) 2rem;
  font-size: 0.93rem;
  flex-shrink: 0;
}

.footer-grid {
  max-width: 1100px;
  margin: 0 auto;
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 2rem;
}

.footer-title {
  font-family: var(--font-display);
  font-weight: 700;
  color: var(--white);
  margin: 0 0 0.5rem;
}

.site-footer a { color: #8FD4D7; }
.site-footer a:hover { color: #E0A579; }

.footer-note {
  max-width: 1100px;
  margin: 2.5rem auto 0;
  padding-top: 1.2rem;
  border-top: 1px solid #2C4650;
  font-family: var(--font-mono);
  font-size: 0.78rem;
  color: #7A8F96;
}

/* ----------------------------------------------------------
   Featured publications carousel (landing page)
   ---------------------------------------------------------- */

.pub-carousel { max-width: 1100px; }

.pub-slides {
  position: relative;
  min-height: 300px;
}

.pub-slide {
  position: absolute;
  inset: 0;
  display: grid;
  grid-template-columns: minmax(240px, 44%) 1fr;
  gap: 0;
  background: var(--white);
  border: 1px solid var(--line);
  border-left: 4px solid var(--teal);
  text-decoration: none;
  color: var(--ink);
  opacity: 0;
  visibility: hidden;
  transition: opacity 0.5s ease, visibility 0s linear 0.5s;
}

.pub-slide.is-active {
  opacity: 1;
  visibility: visible;
  transition: opacity 0.5s ease;
  position: relative; /* active slide defines the height */
}

.pub-slide:hover { border-left-color: var(--copper); color: var(--ink); }
.pub-slide:hover h3 { color: var(--copper); }

.pub-slide-img {
  background: var(--paper);
  border-right: 1px solid var(--line);
  display: flex;
  align-items: center;
  justify-content: center;
  overflow: hidden;
}

.pub-slide-img img {
  width: 100%;
  height: 100%;
  object-fit: contain;
  display: block;
  padding: 1rem;
  box-sizing: border-box;
}

.pub-slide-text {
  padding: 1.6rem 1.8rem;
  display: flex;
  flex-direction: column;
  justify-content: center;
}

.pub-slide-venue {
  font-family: var(--font-mono);
  font-size: 0.78rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--teal);
  margin: 0 0 0.5rem;
}

.pub-slide-text h3 {
  font-size: clamp(1.05rem, 2vw, 1.3rem);
  margin: 0 0 0.7rem;
  transition: color 0.2s ease;
}

.pub-slide-authors {
  margin: 0;
  font-size: 0.95rem;
  color: var(--muted);
}

.pub-dots {
  display: flex;
  justify-content: center;
  gap: 0.7rem;
  margin-top: 1.1rem;
}

.pub-dot {
  width: 11px;
  height: 11px;
  border-radius: 50%;
  border: 2px solid var(--teal);
  background: transparent;
  padding: 0;
  cursor: pointer;
  transition: background 0.2s ease, transform 0.2s ease;
}

.pub-dot:hover { transform: scale(1.25); }
.pub-dot.is-active { background: var(--teal); }

@media (max-width: 700px) {
  .pub-slide { grid-template-columns: 1fr; }
  .pub-slide-img { border-right: none; border-bottom: 1px solid var(--line); max-height: 200px; }
  .pub-slides { min-height: 420px; }
}

/* ----------------------------------------------------------
   Individual bio pages
   ---------------------------------------------------------- */

.bio-page {
  /* wider than a plain text page: sidebar + text column */
  max-width: calc(var(--measure) + 220px + 3rem + 2 * var(--pad));
}

.bio-grid {
  display: grid;
  grid-template-columns: 220px minmax(0, 1fr);
  gap: 3rem;
  align-items: start;
}

.bio-side {
  position: sticky;
  top: 5.5rem; /* clears the sticky header */
}

.bio-photo {
  display: block;
  width: 100%;
  aspect-ratio: 1 / 1;
  object-fit: cover;
  border: 1px solid var(--line);
}

.bio-photo-fallback {
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--deep);
  color: var(--white);
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 3rem;
}

.bio-role {
  font-family: var(--font-mono);
  font-size: 0.8rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--teal);
  margin: 1rem 0 0.6rem;
}

.bio-links {
  list-style: none;
  margin: 0;
  padding: 0;
  border-top: 1px solid var(--line);
}

.bio-links li {
  border-bottom: 1px solid var(--line);
}

.bio-links a {
  display: block;
  padding: 0.55rem 0;
  font-family: var(--font-mono);
  font-size: 0.85rem;
  text-decoration: none;
}

.bio-links a::after {
  content: " ↗";
  color: var(--muted);
}

.bio-email {
  margin: 0.8rem 0 0;
  font-size: 0.9rem;
  overflow-wrap: anywhere;
}

.bio-skills {
  margin-top: 0.5rem;
  font-size: 0.9rem;
  line-height: 1.5;
  color: #555;
}

@media (max-width: 700px) {
  .bio-grid { grid-template-columns: 1fr; gap: 1.5rem; }
  .bio-side { position: static; max-width: 240px; }
}