/* ==========================================================================
   home.css — homepage: scroll-driven hero, research areas, split sections
   ========================================================================== */

/* full-bleed breakout without a horizontal scrollbar; `clip` keeps sticky working */
body.zl-home { overflow-x: clip; }

/* ---------- hero ----------
   --p : 0 → 1 progress through the sticky stage (set by assets/js/hero.js) */
.zl-hero {
  --p: 0;
  position: relative;
  width: 100vw;
  height: 220vh;
  margin-left: calc(50% - 50vw);
  margin-top: calc(-1 * var(--zl-hero-offset, 0px));
}
.zl-hero__sticky {
  position: sticky;
  top: 0;
  height: 100vh;
  overflow: hidden;
  background: var(--zl-paper);
}
.zl-hero__media { position: absolute; inset: 0; }

.zl-hero__img {
  /* Sized (not cover) so the brain — which starts ~34% into the artwork — never
     reaches left of ~42vw, whatever the screen ratio. The artwork's paper matches
     the stage background, so any spare space above/below is invisible. */
  --zl-ty: -50%;
  position: absolute;
  top: 50%;
  right: 0;
  width: min(88vw, 177.8vh);
  height: auto;
  aspect-ratio: 16 / 9;
  object-fit: cover;
  transform-origin: 60% 46%;
  transform: translateY(calc(var(--zl-ty) - 2% * var(--p))) scale(calc(1 + 0.08 * var(--p)));
  will-change: transform, clip-path;
}
.zl-hero__img--reveal {
  --r: clamp(0, (var(--p) - 0.18) / 0.6, 1);
  clip-path: circle(calc(var(--r) * 100%) at 60% 46%);
}
body.quarto-dark .zl-hero__img {
  filter: invert(0.92) hue-rotate(180deg) brightness(0.95) contrast(0.95);
}

/* paper wash on the left so text always reads, soft edge into the page below */
.zl-hero__veil {
  position: absolute;
  inset: 0;
  pointer-events: none;
  background:
    linear-gradient(90deg, var(--zl-paper) 0%, color-mix(in srgb, var(--zl-paper) 80%, transparent) 30%, transparent 50%),
    linear-gradient(0deg, var(--zl-bg) 0%, transparent 18%);
}

/* phase 1: title */
.zl-hero__title,
.zl-hero__chapters {
  position: absolute;
  left: clamp(1.5rem, 6vw, 7rem);
  max-width: min(32rem, 32vw);
  color: var(--zl-ink);
}
.zl-hero__title {
  --t: clamp(0, (var(--p) - 0.04) / 0.22, 1);
  bottom: 18vh;
  opacity: calc(1 - var(--t));
  transform: translateY(calc(-60px * var(--t)));
  filter: blur(calc(6px * var(--t)));
}
.zl-hero__title h1 {
  margin: 0 0 1.5rem;
  font-size: clamp(3.4rem, 8.5vw, 7.5rem);
  font-weight: 600;
  line-height: 0.92;
  letter-spacing: -0.03em;
  color: var(--zl-ink);
}
.zl-hero__title h1 em {
  font-style: italic;
  font-weight: 400;
  color: var(--zl-accent);
}
.zl-hero__role {
  max-width: 30rem;
  margin: 0;
  font-size: clamp(1.05rem, 1.5vw, 1.3rem);
  line-height: 1.55;
  color: var(--zl-muted);
}

/* phase 2: research chapters */
.zl-hero__chapters {
  --c: clamp(0, (var(--p) - 0.24) / 0.1, 1);
  top: 50%;
  margin: 0;
  padding: 0;
  list-style: none;
  opacity: var(--c);
  transform: translateY(calc(-50% + 40px * (1 - var(--c))));
  pointer-events: none;
}
.zl-hero__chapters li {
  display: grid;
  grid-template-columns: 3rem 1fr;
  column-gap: 0.5rem;
  padding: 1.1rem 0;
  border-top: 1px solid var(--zl-rule);
  opacity: 0.28;
  transition: opacity 0.5s ease, transform 0.5s ease;
}
.zl-hero__chapters li:last-child { border-bottom: 1px solid var(--zl-rule); }
.zl-hero__chapters li.is-active { opacity: 1; transform: translateX(0.75rem); }
.zl-hero__chapters span {
  padding-top: 0.55rem;
  font-family: var(--zl-mono);
  font-size: 0.8rem;
  color: var(--zl-accent);
}
.zl-hero__chapters strong {
  font-family: var(--zl-serif);
  font-size: clamp(1.6rem, 3vw, 2.6rem);
  font-weight: 600;
  line-height: 1.1;
  letter-spacing: -0.015em;
}
.zl-hero__chapters em {
  grid-column: 2;
  margin-top: 0.35rem;
  font-family: var(--zl-mono);
  font-size: 0.78rem;
  font-style: normal;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--zl-muted);
}

/* progress rail + scroll cue */
.zl-hero__progress {
  position: absolute;
  top: 50%;
  right: clamp(1rem, 3vw, 2.5rem);
  width: 1px;
  height: 28vh;
  transform: translateY(-50%);
  background: var(--zl-rule);
}
.zl-hero__progress span {
  position: absolute;
  inset: 0;
  background: var(--zl-accent);
  transform-origin: top;
  transform: scaleY(var(--p));
}
.zl-hero__cue {
  position: absolute;
  left: 50%;
  bottom: 2.25rem;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.75rem;
  transform: translateX(-50%);
  font-family: var(--zl-mono);
  font-size: 0.7rem;
  letter-spacing: 0.3em;
  text-transform: uppercase;
  color: var(--zl-muted);
  text-decoration: none;
  opacity: calc(1 - clamp(0, var(--p) / 0.08, 1));
}
.zl-hero__cue:hover { color: var(--zl-accent); }
.zl-hero__cue::after {
  content: "";
  width: 1px;
  height: 2.75rem;
  background: linear-gradient(currentColor, transparent);
  transform-origin: top;
  animation: zl-cue 2.2s ease-in-out infinite;
}
@keyframes zl-cue {
  0%   { transform: scaleY(0); opacity: 1; }
  60%  { transform: scaleY(1); opacity: 1; }
  100% { transform: scaleY(1); opacity: 0; }
}

@media (max-width: 768px) {
  .zl-hero { height: 200vh; }
  .zl-hero__img {
    --zl-ty: 0%;
    top: 0;
    width: 100%;
    height: 100%;
    aspect-ratio: auto;
    object-position: 60% 45%;
    transform-origin: 60% 45%;
  }
  .zl-hero__veil {
    background: linear-gradient(0deg, var(--zl-bg) 0%, color-mix(in srgb, var(--zl-bg) 80%, transparent) 45%, transparent 70%);
  }
  .zl-hero__title,
  .zl-hero__chapters { right: 1.5rem; max-width: none; }
  .zl-hero__title { bottom: 12vh; }
  .zl-hero__chapters { top: auto; bottom: 8vh; transform: translateY(calc(40px * (1 - var(--c)))); }
  .zl-hero__progress,
  .zl-hero__cue { display: none; }
}

@media (prefers-reduced-motion: reduce) {
  .zl-hero { height: 100vh; }
  .zl-hero__img--reveal,
  .zl-hero__chapters { display: none; }
  .zl-hero__cue::after { animation: none; }
}

/* ---------- sections below the hero ---------- */
.zl-home-body { margin-top: 5rem; }

/* label/heading on the left, content on the right */
.zl-split {
  display: grid;
  grid-template-columns: minmax(0, 4fr) minmax(0, 7fr);
  column-gap: clamp(2rem, 6vw, 6rem);
  margin: 0 0 7rem;
}
.zl-split__head > p:not(:has(.zl-eyebrow)) {
  margin: 0;
  font-family: var(--zl-serif);
  font-size: clamp(1.8rem, 2.6vw, 2.4rem);
  font-weight: 600;
  line-height: 1.2;
  letter-spacing: -0.015em;
  color: var(--zl-ink);
}
.zl-split__head h2 {
  margin: 0;
  padding: 0;
  border: none;
  font-size: clamp(2rem, 3vw, 2.6rem);
}
.zl-split__body > p {
  font-size: 1.15rem;
  line-height: 1.75;
}
.zl-split__body > p:has(.zl-cta) { margin-top: 2rem; }

/* featured / vacancies rows */
.zl-rows { border-top: 1px solid var(--zl-rule); }
.zl-row {
  padding: 1.25rem 0;
  border-bottom: 1px solid var(--zl-rule);
}
.zl-row p { margin: 0; }
.zl-row a {
  font-family: var(--zl-serif);
  font-size: 1.3rem;
  font-weight: 600;
  line-height: 1.3;
  color: var(--zl-ink);
  text-decoration: none;
}
.zl-row a:hover { color: var(--zl-accent); }
.zl-row .zl-row__meta {
  display: block;
  margin-top: 0.4rem;
  font-family: var(--zl-mono);
  font-size: 0.72rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--zl-muted);
}
.zl-row .zl-row__meta strong {
  margin-right: 0.75rem;
  font-weight: 500;
  color: var(--zl-accent);
}

/* ---------- research areas (three editorial columns) ---------- */
.zl-areas { margin: 0 0 7rem; }
.zl-areas__grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  grid-template-rows: repeat(4, auto);
  margin: 0 -2rem; /* equal padding on every column keeps the three images the same size */
  border-top: 1px solid var(--zl-rule);
}
.zl-area {
  /* subgrid: figure / meta / title / text rows line up across the three columns */
  display: grid;
  grid-row: span 4;
  grid-template-rows: subgrid;
  row-gap: 0;
  align-content: start;
  padding: 2rem 2rem 1rem;
  border-left: 1px solid var(--zl-rule);
}
.zl-area:first-child { border-left: none; }
.zl-area__fig {
  margin: 0 0 1.75rem;
  aspect-ratio: 3 / 2;
  overflow: hidden;
}
.zl-area__fig img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  filter: saturate(0.4);
  transition: filter 0.6s ease, transform 0.8s cubic-bezier(.2, .7, .2, 1);
}
.zl-area:hover .zl-area__fig img { filter: saturate(1); transform: scale(1.04); }
body.quarto-dark .zl-area__fig img,
body.quarto-dark .zl-area:hover .zl-area__fig img {
  filter: invert(0.92) hue-rotate(180deg) brightness(0.95);
}
.zl-area__meta {
  display: flex;
  gap: 1rem;
  margin-bottom: 0.75rem;
  font-family: var(--zl-mono);
  font-size: 0.75rem;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--zl-muted);
}
.zl-area__meta span:first-child { color: var(--zl-accent); }
.zl-area h3 {
  margin: 0 0 0.75rem;
  font-size: clamp(1.4rem, 1.75vw, 1.9rem);
  line-height: 1.15;
  letter-spacing: -0.015em;
}
.zl-area h3::after {
  content: "";
  display: block;
  width: 2rem;
  height: 2px;
  margin-top: 0.85rem;
  background: var(--zl-accent);
  transition: width 0.5s ease;
}
.zl-area:hover h3::after { width: 4.5rem; }
.zl-area p {
  margin: 0;
  font-size: 1.05rem;
  line-height: 1.65;
  color: var(--zl-muted);
}

@media (max-width: 900px) {
  .zl-split { grid-template-columns: 1fr; row-gap: 1.5rem; margin-bottom: 4.5rem; }
  .zl-areas { margin-bottom: 4.5rem; }
  .zl-areas__grid { grid-template-columns: 1fr; grid-template-rows: none; margin: 0; }
  .zl-area { display: block; }
  .zl-area,
  .zl-area:first-child {
    padding: 2rem 0 1.5rem;
    border-left: none;
    border-bottom: 1px solid var(--zl-rule);
  }
}