/* =========================================================
   Spice level 0 ("none"): the clean academic theme.
   This is also what visitors without JavaScript get.
   ========================================================= */

/* ---------- Tokens ---------- */
:root {
  --bg: #ffffff;
  --text: #1c1f23;
  --muted: #5d6670;
  --rule: #e4e7eb;
  --accent: #1a4f8b;
  --accent-hover: #0f3561;
  --panel: #ffffff;
  --panel-border: #e4e7eb;
  --panel-border-hover: #c9cfd6;
  --shadow: 0 6px 24px rgba(16, 24, 40, 0.08);
  --serif: "Source Serif 4", Georgia, "Times New Roman", serif;
  --sans: "Inter", -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  --container: 960px;
  --gutter: 24px;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #121417;
    --text: #e4e6e9;
    --muted: #9aa2ab;
    --rule: #2a2f35;
    --accent: #8db4f0;
    --accent-hover: #b8d0f6;
    --panel: #ffffff;           /* figures keep their white background */
    --panel-border: #2a2f35;
    --panel-border-hover: #4a525c;
    --shadow: 0 6px 24px rgba(0, 0, 0, 0.45);
  }
}

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

html { -webkit-text-size-adjust: 100%; }

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: var(--serif);
  font-size: 18px;
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

a { color: var(--accent); text-decoration: none; }
a:hover { color: var(--accent-hover); text-decoration: underline; text-underline-offset: 3px; }

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

/* ---------- Header / tabs ---------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 10;
  background: var(--bg);
  border-bottom: 1px solid var(--rule);
}

.site-header .inner {
  max-width: var(--container);
  margin: 0 auto;
  padding: 0 var(--gutter);
  height: 60px;
  display: flex;
  align-items: center;
  gap: 24px;
}

.site-title {
  font-family: var(--serif);
  font-size: 20px;
  font-weight: 600;
  color: var(--text);
  white-space: nowrap;
}
.site-title:hover { color: var(--text); text-decoration: none; }

.site-nav {
  margin-left: auto;
  display: flex;
  align-self: stretch;
  gap: 28px;
  font-family: var(--sans);
  font-size: 15px;
  font-weight: 500;
}

.site-nav a {
  display: flex;
  align-items: center;
  color: var(--muted);
  border-bottom: 2px solid transparent;
  margin-bottom: -1px;            /* sit on top of the header rule */
}
.site-nav a:hover { color: var(--text); text-decoration: none; }
.site-nav a[aria-current="page"] { color: var(--text); border-bottom-color: var(--accent); }

/* ---------- Page ---------- */
main {
  max-width: var(--container);
  margin: 0 auto;
  padding: 56px var(--gutter) 80px;
}

.page-title {
  font-size: 42px;
  font-weight: 600;
  line-height: 1.15;
  letter-spacing: -0.01em;
  margin: 0 0 28px;
}

.section-title {
  font-size: 26px;
  font-weight: 600;
  line-height: 1.3;
  margin: 64px 0 24px;
  padding-bottom: 10px;
  border-bottom: 1px solid var(--rule);
}

/* ---------- Home ---------- */
.about {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 256px;
  grid-template-areas: "bio profile";
  column-gap: 64px;
  align-items: start;
}
.bio { grid-area: bio; }
.profile { grid-area: profile; }

.bio p { margin: 0 0 1.15em; }
.bio p:last-child { margin-bottom: 0; }

.profile {
  font-family: var(--sans);
  font-size: 14.5px;
  line-height: 1.55;
  color: var(--muted);
}

.profile img {
  display: block;
  width: 100%;
  aspect-ratio: 1 / 1;
  object-fit: cover;
  border-radius: 12px;
}

.contact {
  list-style: none;
  margin: 22px 0 0;
  padding: 0;
  display: grid;
  gap: 14px;
}
.contact li,
.btn {
  display: grid;
  grid-template-columns: 16px minmax(0, 1fr);
  column-gap: 12px;
  align-items: start;
}
.ico { display: flex; }
.contact svg,
.btn svg { width: 16px; height: 16px; margin-top: 3px; }
.contact strong { color: var(--text); font-weight: 600; }
.btn { margin-top: 14px; font-weight: 500; }

/* extra home sections (currently commented out in index.html) */
.extra { margin-top: 8px; }
.extra .section-title { margin-top: 64px; }

.news {
  display: grid;
  grid-template-columns: 84px minmax(0, 1fr);
  gap: 12px 24px;
  margin: 0;
}
.news dt {
  grid-column: 1;
  font-family: var(--sans);
  font-size: 14px;
  font-weight: 500;
  color: var(--muted);
  font-variant-numeric: tabular-nums;
  padding-top: 3px;
}
.news dd { grid-column: 2; margin: 0; }
.news .media { display: flex; flex-wrap: wrap; gap: 12px; margin: 14px 0 8px; }
.news .media iframe { width: 100%; max-width: 560px; aspect-ratio: 16 / 9; height: auto; border: 0; border-radius: 8px; }
.news .media img { border-radius: 8px; }

/* ---------- Diagrams ---------- */
.paper {
  padding: 44px 0;
  border-top: 1px solid var(--rule);
}
.paper:first-of-type { border-top: 0; padding-top: 8px; }
.paper:last-of-type { padding-bottom: 0; }

.paper-title {
  font-size: 23px;
  font-weight: 600;
  line-height: 1.3;
  margin: 0 0 6px;
}
.paper-title a { color: var(--text); }
.paper-title a:hover { color: var(--accent); }

.authors {
  font-family: var(--sans);
  font-size: 15px;
  color: var(--muted);
  margin: 0 0 22px;
}
.authors strong { color: var(--text); font-weight: 600; }
.authors em { display: block; font-size: 13.5px; margin-top: 4px; }

.figure { margin: 0 0 24px; }
.figure:last-child { margin-bottom: 0; }

.figure figcaption {
  font-family: var(--sans);
  font-size: 14px;
  font-weight: 500;
  color: var(--muted);
  margin-bottom: 8px;
}

.figure .frame {
  display: flex;
  justify-content: center;
  background: var(--panel);
  border: 1px solid var(--panel-border);
  border-radius: 10px;
  padding: 22px;
  cursor: zoom-in;
  transition: box-shadow 0.2s ease, border-color 0.2s ease;
}
.figure .frame:hover { border-color: var(--panel-border-hover); box-shadow: var(--shadow); }
.figure .frame:focus-visible { outline: 2px solid var(--accent); outline-offset: 2px; }
.figure img { display: block; }

/* ---------- Coauthors ---------- */
.people {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
  column-gap: 48px;
}
.people li { border-bottom: 1px solid var(--rule); }
.person { display: block; padding: 13px 0 12px; color: var(--text); }
.avatar { display: none; }
.person .name { display: block; font-size: 18px; line-height: 1.4; }
.person .site { display: block; font-family: var(--sans); font-size: 13px; color: var(--muted); }
a.person .name { color: var(--accent); }
a.person:hover { text-decoration: none; }
a.person:hover .name { color: var(--accent-hover); text-decoration: underline; text-underline-offset: 3px; }

/* ---------- Enlarged figure ---------- */
.lightbox {
  border: 0;
  padding: 24px;
  border-radius: 12px;
  background: #ffffff;
  max-width: 96vw;
  max-height: 92vh;
  cursor: zoom-out;
}
.lightbox::backdrop { background: rgba(10, 12, 15, 0.82); }
.lightbox img {
  display: block;
  max-width: calc(96vw - 48px);
  max-height: calc(92vh - 48px);
  width: auto;
  height: auto;
}
.lb-close {
  position: absolute;
  top: 6px;
  right: 6px;
  width: 26px;
  height: 26px;
  border: 0;
  border-radius: 50%;
  background: rgba(0, 0, 0, 0.06);
  color: #5d6670;
  font: 500 18px/1 var(--sans);
  cursor: pointer;
}
.lb-close:hover { background: rgba(0, 0, 0, 0.12); color: #1c1f23; }

/* ---------- Spice control: deliberately understated ---------- */
.spice-0 {
  max-width: var(--container);
  margin: 0 auto;
  padding: 0 var(--gutter) 28px;
  display: flex;
  justify-content: flex-end;
  align-items: center;
  gap: 7px;
  font-family: var(--sans);
  font-size: 12px;
  letter-spacing: 0.02em;
  color: var(--muted);
  opacity: 0.45;
  transition: opacity 0.2s ease;
}
.spice-0:hover,
.spice-0:focus-within { opacity: 1; }
.spice-0 .spice-label { margin-right: 3px; }
.spice-dot {
  width: 7px;
  height: 7px;
  padding: 0;
  border: 1px solid currentColor;
  border-radius: 50%;
  background: transparent;
  color: inherit;
  cursor: pointer;
}
.spice-dot[aria-pressed="true"] { background: currentColor; }
.spice-dot:hover { color: var(--text); }
.spice-dot:focus-visible { outline: 2px solid var(--accent); outline-offset: 2px; }

/* ---------- Small screens ---------- */
@media (max-width: 760px) {
  :root { --gutter: 16px; }
  body { font-size: 17px; }
  main { padding-top: 36px; padding-bottom: 56px; }
  .page-title { font-size: 34px; margin-bottom: 22px; }
  .site-title { display: none; }
  .site-nav { gap: 20px; }

  .about {
    grid-template-columns: minmax(0, 1fr);
    grid-template-areas: "profile" "bio";
  }
  .profile { margin-bottom: 32px; }
  .profile img { width: 160px; }

  .paper { padding: 36px 0; }
  .paper-title { font-size: 20px; }
  .figure .frame { padding: 12px; }

  .news { grid-template-columns: minmax(0, 1fr); row-gap: 4px; }
  .news dt, .news dd { grid-column: 1; }
  .news dd { margin-bottom: 14px; }
}

@media (max-width: 380px) {
  .site-nav { gap: 14px; font-size: 14px; }
}