/* =============================================================================
   site.css

   single stylesheet for robelgeda.com.
   zen aesthetic: white background, near-black serif text, generous whitespace,
   rounded apple-style controls. no framework dependencies.
   ============================================================================= */

:root {
  --bg: #ffffff;
  --ink: #1d1d1f;
  --muted: #6e6e73;
  --line: rgba(0, 0, 0, 0.10);
  --line-strong: rgba(0, 0, 0, 0.18);
  --accent: #0071e3;
  --accent-ink: #ffffff;
  --radius: 18px;
  --radius-sm: 12px;
  --nav-h: 64px;
  --maxw: 1040px;
  /* charter first, graceful serif fallback if the webfont is not installed.
     drop charter woff2 files into assets/fonts/ to render charter everywhere
     (see @font-face below); otherwise georgia/serif is used. */
  --serif: "Charter", "Bitstream Charter", "Sitka Text", Cambria, Georgia, "Times New Roman", serif;
}

/* optional self-hosted charter. missing files fail silently and fall back. */
@font-face {
  font-family: "Charter";
  src: url("../fonts/charter_regular.woff2") format("woff2");
  font-weight: 400;
  font-style: normal;
  font-display: swap;
}
@font-face {
  font-family: "Charter";
  src: url("../fonts/charter_italic.woff2") format("woff2");
  font-weight: 400;
  font-style: italic;
  font-display: swap;
}
@font-face {
  font-family: "Charter";
  src: url("../fonts/charter_bold.woff2") format("woff2");
  font-weight: 700;
  font-style: normal;
  font-display: swap;
}

* { box-sizing: border-box; }

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

body {
  margin: 0;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  background: var(--bg);
  color: var(--ink);
  font-family: var(--serif);
  font-size: 19px;
  line-height: 1.6;
  letter-spacing: 0.1px;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

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

h1, h2, h3 { font-weight: 700; line-height: 1.2; letter-spacing: -0.2px; }
h1 { font-size: 2.4rem; margin: 0 0 0.4em; }
h2 { font-size: 1.6rem; margin: 1.8em 0 0.6em; }
h3 { font-size: 1.2rem; margin: 1.4em 0 0.4em; }

p { margin: 0 0 1em; }

img { max-width: 100%; display: block; }

.container {
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 0 24px;
}

/* ---------------------------------------------------------------------------
   navigation: brand left, page list centered, contact right. fixed and
   visible on every page. collapses to a toggle menu on narrow screens.
   --------------------------------------------------------------------------- */
.nav {
  position: fixed;
  top: 0; left: 0; right: 0;
  height: var(--nav-h);
  z-index: 100;
  background: rgba(255, 255, 255, 0.8);
  backdrop-filter: saturate(180%) blur(20px);
  -webkit-backdrop-filter: saturate(180%) blur(20px);
  border-bottom: 1px solid var(--line);
}
/* the bar aligns to the same reading column as the body content */
.nav-inner {
  max-width: var(--maxw);
  height: 100%;
  margin: 0 auto;
  padding: 0 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}
.nav-brand {
  font-size: 1.1rem;
  font-weight: 700;
  color: var(--ink);
  letter-spacing: 0.2px;
  white-space: nowrap;
  flex: 1;
}
.nav-brand:hover { text-decoration: none; }
.nav-menu {
  display: flex;
  align-items: center;
  gap: 30px;
  list-style: none;
  margin: 0;
  padding: 0;
}
.nav-menu a {
  color: var(--ink);
  font-size: 1.02rem;
  padding: 4px 2px;
  border-bottom: 1.5px solid transparent;
}
.nav-menu a:hover { text-decoration: none; opacity: 0.6; }
.nav-menu a[aria-current="page"] { border-bottom-color: var(--ink); }
.nav-right {
  flex: 1;
  display: flex;
  justify-content: flex-end;
}
.nav-right a {
  color: var(--ink);
  font-size: 1.02rem;
}
.nav-right a:hover { text-decoration: none; opacity: 0.6; }

/* contact lives on the right on desktop; it folds into the menu on mobile */
.nav-menu .nav-contact-only { display: none; }

/* mobile toggle (css-only checkbox hack) */
.nav-toggle-cb { display: none; }
.nav-toggle {
  display: none;
  cursor: pointer;
  padding: 8px;
  margin: -8px;
  color: var(--ink);
}
.nav-toggle svg { display: block; }

/* page content sits below the fixed nav */
main { flex: 1 0 auto; padding-top: calc(var(--nav-h) + 48px); padding-bottom: 96px; }

/* ---------------------------------------------------------------------------
   buttons: apple-style pills.
   --------------------------------------------------------------------------- */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-family: var(--serif);
  font-size: 1rem;
  padding: 2px 6px;
  border-radius: 980px;
  border: 1px solid transparent;
  cursor: pointer;
  transition: opacity 0.15s ease, background 0.15s ease;
  white-space: nowrap;
}
.btn:hover { text-decoration: none; }
.btn-primary { opacity: 0.85; }
.btn-primary:hover { opacity: 0.85; }
.btn-ghost { background: transparent; color: var(--ink); border-color: var(--line-strong); }
.btn-ghost:hover { background: rgba(0, 0, 0, 0.04); }

/* ---------------------------------------------------------------------------
   about (landing) page: bio body left, profile panel right.
   --------------------------------------------------------------------------- */
.about {
  display: grid;
  grid-template-columns: 292px 1fr; /*Important*/
  gap: 64px;
  align-items: start;
}
.about-body h1 { margin-top: 0; }
.about-body .lede { font-size: 1.25rem; color: var(--ink); }
.about-body .interests {
  margin-top: 0em;
  padding-top: 0em;
  border-top: 0px solid var(--line);
  color: var(--muted);
  font-size: 1rem;
}

.panel {
  position: sticky;
  top: calc(var(--nav-h) + 48px);
}
.panel .avatar {
  width: 292px;
  height: 329px;
  margin: 0 0 20px;
  border-radius: 3%;
  object-fit: cover;
  background: #f0f0f2;
  border: 1px solid var(--line);
}
.panel .panel-name { font-size: 1.4rem; font-weight: 700; margin: 0; }
.panel .panel-role { color: var(--muted); margin: 4px 0 2px; font-size: 0.98rem; }
.panel .panel-place { color: var(--muted); margin: 0 0 12px; font-size: 0.92rem; }
/* row of icon links, dimmed by default and brightening on hover (apple-style).
   wraps to the next line when the panel is too narrow (phones). */
.panel-links {
  list-style: none;
  margin: 0 0 2px;
  padding: 0;
  display: flex;
  flex-wrap: wrap;
  justify-content: flex-start;
  align-items: center;
  gap: 10px;
  max-width: 292px;
}
.panel-links a {
  position: relative;
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--muted);
  opacity: 0.5;
  transition: opacity 0.2s ease, color 0.2s ease;
}
.panel-links a:hover { opacity: 1; color: var(--accent); text-decoration: none; }
.panel-links svg { width: 22px; height: 22px; flex: none; }
/* custom tooltip built from the link's aria-label */
.panel-links a::after {
  content: attr(aria-label);
  position: absolute;
  bottom: calc(-100% - 10px);
  left: 50%;
  transform: translateX(-50%);
  background: var(--bg);
  color: var(--ink);
  font-size: 1rem;
  line-height: 1;
  padding: 5px 8px;
  border-radius: 6px;
  white-space: nowrap;
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.15s ease;
}
.panel-links a:hover::after { opacity: 1; }

/* ---------------------------------------------------------------------------
   research page: project index on the left, project cards centered.
   --------------------------------------------------------------------------- */
.research {
  display: grid;
  grid-template-columns: 220px 1fr;
  gap: 56px;
  align-items: start;
}
.research-index {
  position: sticky;
  top: calc(var(--nav-h) + 48px);
}
.research-index h2 { margin: 0 0 0.6em; font-size: 1rem; text-transform: uppercase; letter-spacing: 1px; color: var(--muted); }
.research-index ul { list-style: none; margin: 0; padding: 0; }
.research-index li { margin: 0 0 12px; }
.research-index a { color: var(--ink); font-size: 0.98rem; line-height: 1.35; display: block; }
.research-index a:hover { color: var(--accent); text-decoration: none; }

.cards { display: flex; flex-direction: column; gap: 28px; }
.card {
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 28px 30px;
  cursor: pointer;
  scroll-margin-top: calc(var(--nav-h) + 24px);
  transition: box-shadow 0.18s ease, transform 0.18s ease;
}
.card:hover { box-shadow: 0 12px 40px rgba(0, 0, 0, 0.08); transform: translateY(-2px); }
.card:hover h3 { color: var(--accent); }
.card h3 {
  margin: 0 0 6px;
  font-size: 1.4rem;
}
/* badge links and gallery images keep their own pointer behavior */
.card a, .card .gallery img { cursor: pointer; }
.card .meta { color: var(--muted); font-size: 0.9rem; margin: 0 0 14px; }
.card .abstract { margin: 0 0 16px; }
.badges { display: flex; flex-wrap: wrap; gap: 8px; margin: 0 0 16px; }
.badges img { height: 20px; }

/* gallery mode: borderless, edge-to-edge thumbnails (used inside the modal) */
.gallery {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(140px, 1fr));
  gap: 4px;
}
.gallery img, .gallery video {
  width: 100%;
  height: 110px;
  object-fit: cover;
  cursor: zoom-in;
  background: var(--bg);
  display: block;
}

/* card view: large apple-style hero figures. one or two stacked, full width,
   shown whole (no crop) on a neutral panel. overrides the thumbnail grid. */
.card .gallery {
  display: flex;
  flex-direction: column;
  gap: 16px;
  margin-top: 6px;
}
.card .gallery img, .card .gallery video {
  width: 100%;
  height: auto;
  max-height: 480px;
  object-fit: contain;
  background:  var(--bg);
  border-radius: var(--radius-sm);
  padding: 16px;
  cursor: zoom-in;
  display: block;
}

/* ---------------------------------------------------------------------------
   research dialog (modal).
   --------------------------------------------------------------------------- */
.modal {
  position: fixed;
  inset: 0;
  z-index: 200;
  display: none;
  align-items: flex-start;
  justify-content: center;
  padding: 40px 20px;
  background: rgba(0, 0, 0, 0.55);
  /* backdrop blur disabled for performance; re-enable if desired:
     backdrop-filter: blur(4px); -webkit-backdrop-filter: blur(4px); */
  overflow-y: auto;
}
.modal.open { display: flex; }
.modal-box {
  position: relative;
  background: var(--bg);
  border-radius: var(--radius);
  max-width: 760px;
  width: 100%;
  margin: auto 0;
  padding: 26px 44px 48px;
  box-shadow: 0 30px 80px rgba(0, 0, 0, 0.3);
}
/* header strip: prev/next on the left, close on the right. kept in flow (not
   absolute) so it stays put while project bodies of different lengths scroll. */
.modal-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin: 0 0 16px;
}
.modal-step-nav { display: flex; gap: 8px; }
.modal-step, .modal-close {
  width: 34px; height: 34px;
  border: none;
  border-radius: 50%;
  background: rgba(0, 0, 0, 0.06);
  color: var(--ink);
  font-size: 1.3rem;
  line-height: 1;
  cursor: pointer;
}
.modal-close { font-size: 1.2rem; }
.modal-step:hover, .modal-close:hover { background: rgba(0, 0, 0, 0.12); }
.modal-box h2 { margin: 0 0 10px; font-size: 1.9rem; }
.modal-box .meta { color: var(--muted); font-size: 0.95rem; margin: 0 0 18px; }
.modal-box .gallery { margin: 22px 0; }
.modal-box .gallery img, .modal-box .gallery video { height: 150px; }
/* images and videos embedded directly in the dialog body (prose), e.g. gifs */
#modal-body img,
#modal-body video {
  width: 100%;
  height: auto;
  margin: 18px 0;
  border-radius: var(--radius-sm);
  cursor: zoom-in;
}
/* multi-column figure row inside the dialog body: equal columns, one row. */
#modal-body .body-figures {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 14px;
  margin: 18px 0;
}
#modal-body .body-figures.cols-2 { grid-template-columns: repeat(2, 1fr); }
#modal-body .body-figures figure { margin: 0; align-self: start; }
#modal-body .body-figures img,
#modal-body .body-figures video { margin: 0; }
#modal-body figcaption {
  font-size: 0.8rem;
  color: var(--muted);
  line-height: 1.35;
  margin-top: 6px;
}
.modal-section-title { font-size: 0.85rem; text-transform: uppercase; letter-spacing: 1px; color: var(--muted); margin: 26px 0 8px; }
.modal-box ul.presentations { margin: 0; padding-left: 1.2em; color: var(--ink); }

/* ---------------------------------------------------------------------------
   lightbox: full-screen media viewer. images zoom/pan; videos get a fitted
   native player (zoom controls and gestures are suppressed in video mode).
   --------------------------------------------------------------------------- */
.lightbox {
  position: fixed;
  inset: 0;
  z-index: 300;
  display: none;
  background: var(--bg);
}
.lightbox.open { display: block; }
.lb-stage {
  position: absolute;
  inset: 0;
  overflow: hidden;
  cursor: grab;
  touch-action: none; /* we handle pan/pinch ourselves */
  display: flex; /* centers a video; absolute image is unaffected */
  align-items: center;
  justify-content: center;
}
.lb-stage.panning { cursor: grabbing; }
.lb-img {
  position: absolute;
  top: 0; left: 0;
  max-width: none; /* override global img cap so zoom can exceed viewport */
  transform-origin: 0 0;
  user-select: none;
  -webkit-user-drag: none;
  will-change: transform;
  /* subtle edge so a white-background figure reads against the white stage */
  border: 1px solid var(--line);
  box-shadow: 0 10px 40px rgba(0, 0, 0, 0.12);
}
/* video mode: fit the player to the viewport and disable zoom affordances */
.lightbox.video .lb-stage { cursor: default; }
.lightbox.video .lb-img {
  position: static;
  transform: none !important;
  max-width: 94vw;
  max-height: 84vh;
  width: auto;
  height: auto;
  border-radius: var(--radius-sm);
}
.lightbox.video .lb-controls { display: none; }
.lb-close {
  position: absolute;
  top: 16px; right: 18px;
  z-index: 2;
  width: 42px; height: 42px;
  border: none;
  border-radius: 50%;
  background: rgba(0, 0, 0, 0.06);
  color: var(--ink);
  font-size: 1.5rem;
  line-height: 1;
  cursor: pointer;
}
.lb-close:hover { background: rgba(0, 0, 0, 0.12); }
.lb-caption {
  position: absolute;
  bottom: 80px; left: 50%;
  transform: translateX(-50%);
  z-index: 4; /* above the will-change stacking context of the zoomed image */
  max-width: min(90vw, 720px);
  text-align: center;
  color: #fff;
  font-size: 0.92rem;
  line-height: 1.4;
  padding: 8px 16px;
  border-radius: 14px;
  background: rgba(0, 0, 0, 0.55);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  pointer-events: none;
  /* revealed on pointer movement, fades out when idle (see show-caption) */
  opacity: 0;
  transition: opacity 0.25s ease;
}
.lightbox.show-caption .lb-caption { opacity: 1; }
/* an empty caption renders nothing rather than an empty pill */
.lb-caption:empty { display: none; }
.lb-controls {
  position: absolute;
  bottom: 22px; left: 50%;
  transform: translateX(-50%);
  z-index: 2;
  display: flex;
  gap: 6px;
  padding: 6px;
  border-radius: 980px;
  background: rgba(0, 0, 0, 0.06);
  border: 1px solid var(--line);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
}
.lb-controls button {
  min-width: 46px;
  height: 40px;
  padding: 0 16px;
  border: none;
  border-radius: 980px;
  background: transparent;
  color: var(--ink);
  font-family: var(--serif);
  font-size: 1.2rem;
  cursor: pointer;
}
.lb-controls button:hover { background: rgba(0, 0, 0, 0.1); }
.lb-controls .lb-reset { font-size: 0.95rem; }

/* ---------------------------------------------------------------------------
   contact page.
   --------------------------------------------------------------------------- */
.contact { max-width: 620px; margin: 0 auto; text-align: center; }
.contact h1 { margin-bottom: 0.6em; }
.contact-grid {
  display: grid;
  gap: 18px;
  margin: 36px 0;
  text-align: left;
}
.contact-row {
  display: flex;
  align-items: center;
  gap: 16px;
  padding: 18px 22px;
  border: 1px solid var(--line);
  border-radius: var(--radius-sm);
}
.contact-row svg { width: 22px; height: 22px; flex: none; color: var(--muted); }
.contact-row .label { color: var(--muted); font-size: 0.85rem; display: block; }
.contact-row .value { color: var(--ink); }

/* ---------------------------------------------------------------------------
   publications page: a clean, dense reference list. one row per paper, year
   gutter on the left, an ADS button on the right.
   --------------------------------------------------------------------------- */
.pubs { max-width: 840px; margin: 0 auto; }
.pubs-head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 16px;
}
.pubs-head h1 { margin: 0; }
.pubs .lede { color: var(--muted); font-size: 1.05rem; margin: 14px 0 0; }
.pub-group {
  margin: 20px 0 0;
  font-size: 0.82rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--muted);
}
.pub-list { list-style: none; margin: 16px 0 0; padding: 0; }
.pub {
  display: flex;
  align-items: baseline;
  gap: 22px;
  padding: 12px 0;
}
.pub-year {
  flex: none;
  min-width: 46px;
  color: var(--muted);
  font-size: 0.95rem;
  font-variant-numeric: tabular-nums;
}
.pub-main { flex: 1; min-width: 0; }
.pub-title { margin: 0 0 4px; font-size: 1.15rem; line-height: 1.35; }
.pub-title a { color: var(--ink); }
.pub-title a:hover { color: var(--accent); text-decoration: none; }
.pub-authors { margin: 0 0 2px; color: var(--ink); font-size: 0.95rem; }
.pub-venue { margin: 0; color: var(--muted); font-size: 0.92rem; font-style: italic; }

/* ---------------------------------------------------------------------------
   footer.
   --------------------------------------------------------------------------- */
.footer {
  border-top: 1px solid var(--line);
  color: var(--muted);
  font-size: 0.85rem;
  text-align: center;
  padding: 28px 24px;
}
.footer p { margin: 4px 0; }
.footer a { color: inherit; }
.footer a:hover { color: var(--ink); text-decoration: none; }

/* narrow prose column for simple text pages (e.g. colophon) */
.prose { max-width: 680px; margin: 0 auto; }
.prose h1 { margin-top: 0; }
.prose .muted { color: var(--muted); }

/* ---------------------------------------------------------------------------
   responsive.
   --------------------------------------------------------------------------- */
@media (max-width: 860px) {
  body { font-size: 18px; }
  h1 { font-size: 2rem; }

  .nav-toggle { display: inline-flex; }
  .nav-brand { flex: none; }
  .nav-right { display: none; }
  .nav-menu {
    position: absolute;
    top: var(--nav-h);
    left: 0; right: 0;
    flex-direction: column;
    gap: 0;
    background: rgba(255, 255, 255, 0.96);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border-bottom: 1px solid var(--line);
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.25s ease;
  }
  .nav-menu li { width: 100%; text-align: center; }
  .nav-menu a { display: block; padding: 16px; border-bottom: 1px solid var(--line); }
  .nav-menu a[aria-current="page"] { border-bottom-color: var(--line); color: var(--accent); }
  .nav-toggle-cb:checked ~ .nav-menu { max-height: 360px; }
  .nav-menu .nav-contact-only { display: block; }

  .about { grid-template-columns: 1fr; gap: 32px; }
  .panel {
    position: static;
    display: flex;
    flex-direction: column;
    align-items: center;
    text-align: center;
  }
  .panel .avatar { width: 150px; height: 150px; }
  .panel-links {
    justify-content: center;
    gap: 28px;
  }

  .research { grid-template-columns: 1fr; gap: 28px; }
  .research-index {
    position: static;
    border: 1px solid var(--line);
    border-radius: var(--radius);
    padding: 18px 20px;
  }

  .pub { flex-wrap: wrap; gap: 6px 16px; }
  .pub-year { order: -1; }
  .pub-main { flex-basis: 100%; }

  .modal-box { padding: 32px 24px 40px; }
}