/* ============================================================
   James Liu — jameshliu.me
   Palette: warm paper, deep navy ink, steel-blue accent.
   ============================================================ */

:root{
  --paper:        #faf7f0;
  --paper-tint:   #f5f1e8;
  --paper-card:   #fdfbf6;
  --ink:          #16233a;
  --ink-soft:     #4b5670;
  --ink-faint:    #8b93a5;
  --accent:       #5b7ca6;
  --accent-deep:  #3f5f88;
  --rule:         rgba(22, 35, 58, .13);
  --rule-soft:    rgba(22, 35, 58, .07);

  /* Fraunces carries the voice (optical sizing + a little wonk); Source Serif
     does the reading. Labels borrow Fraunces at small sizes, tracked out. */
  --display: "Fraunces", Georgia, "Times New Roman", serif;
  --serif:   "Source Serif 4", Georgia, "Times New Roman", serif;
  --label:   "Fraunces", Georgia, serif;

  /* Display cut: softened terminals, wonky alternates on. */
  --display-vars: "SOFT" 14, "WONK" 1;
  /* Label cut: sharp and upright, no quirks at small sizes. */
  --label-vars: "SOFT" 0, "WONK" 0;

  --shell: 1560px;
  --pad: clamp(1.5rem, 5vw, 5.5rem);
  --ease: cubic-bezier(.22, .61, .36, 1);
}

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

html{
  -webkit-text-size-adjust:100%;
  scroll-behavior:smooth;
  scroll-padding-top:5.5rem;
  /* Let both faces pick the right optical size for their point size. */
  font-optical-sizing:auto;
}

body{
  margin:0;
  background:var(--paper);
  color:var(--ink);
  font-family:var(--serif);
  font-size:17px;
  line-height:1.68;
  font-weight:400;
  -webkit-font-smoothing:antialiased;
  -moz-osx-font-smoothing:grayscale;
  overflow-x:hidden;
}

/* Subtle paper grain — pure CSS, no assets. */
body::before{
  content:"";
  position:fixed;
  inset:0;
  pointer-events:none;
  z-index:1;
  opacity:.4;
  background-image:
    radial-gradient(circle at 20% 15%, rgba(91,124,166,.05), transparent 45%),
    radial-gradient(circle at 85% 70%, rgba(180,160,120,.06), transparent 50%);
}

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

/* Everything set in Fraunces shares one cut: softened terminals and the
   wonky alternates, which only read at display sizes anyway. */
.monogram svg,
.display,
.section-title,
.node-card,
.theme-num,
.theme h3,
.role-org,
.feature-name,
.pub-title,
.contact-mail{
  font-variation-settings:var(--display-vars);
}

a{ color:inherit; text-decoration:none; }

.shell{
  width:100%;
  max-width:var(--shell);
  margin-inline:auto;
  padding-inline:var(--pad);
}

.skip-link{
  position:absolute; left:-9999px; top:0; z-index:200;
  background:var(--ink); color:var(--paper);
  padding:.75rem 1.25rem; font-size:.85rem;
}
.skip-link:focus{ left:0; }

:focus-visible{
  outline:1px solid var(--accent);
  outline-offset:4px;
}

/* ───────────────────────────── Header ───────────────────────────── */

.site-header{
  position:fixed;
  inset:0 0 auto 0;
  z-index:100;
  padding-block:1.9rem;
  transition:padding .45s var(--ease), background .45s var(--ease), box-shadow .45s var(--ease);
}
.site-header.condensed{
  padding-block:1rem;
  background:rgba(250,247,240,.86);
  backdrop-filter:blur(12px) saturate(1.1);
  -webkit-backdrop-filter:blur(12px) saturate(1.1);
  box-shadow:0 1px 0 var(--rule-soft);
}

.header-inner{
  display:flex;
  align-items:center;
  justify-content:space-between;
  gap:2rem;
}

.monogram{
  display:block;
  width:52px;
  flex:none;
}
.monogram svg{
  width:100%; height:auto; overflow:visible;
  fill:var(--ink);
  font-family:var(--display);
  font-size:46px;
  font-weight:400;
}
.monogram svg text:last-child{ opacity:.9; }
.monogram:hover svg{ fill:var(--accent-deep); }
.monogram svg{ transition:fill .4s var(--ease); }

.nav{
  position:relative;
  display:flex;
  align-items:center;
  gap:clamp(1.4rem, 3vw, 3.1rem);
  font-family:var(--label);
  font-variation-settings:var(--label-vars);
  font-size:.94rem;
  font-weight:500;
  letter-spacing:.015em;
}
.nav a{
  position:relative;
  color:var(--ink);
  padding-block:.25rem;
  opacity:.82;
  transition:opacity .35s var(--ease), color .35s var(--ease);
}
.nav a:hover,
.nav a.active{ opacity:1; color:var(--accent-deep); }

.nav-dot{
  position:absolute;
  bottom:-.55rem;
  width:4px; height:4px;
  border-radius:50%;
  background:var(--accent);
  opacity:0;
  transform:translateX(-50%);
  transition:left .5s var(--ease), opacity .4s var(--ease);
  pointer-events:none;
}
.nav-dot.on{ opacity:1; }

.menu-toggle{
  display:none;
  width:34px; height:24px;
  background:none; border:0; padding:0;
  cursor:pointer;
  flex-direction:column;
  justify-content:center;
  gap:7px;
}
.menu-toggle span{
  display:block; height:1px; width:100%;
  background:var(--ink);
  transition:transform .4s var(--ease), opacity .3s var(--ease);
}
.menu-toggle[aria-expanded="true"] span:first-child{ transform:translateY(4px) rotate(45deg); }
.menu-toggle[aria-expanded="true"] span:last-child{ transform:translateY(-4px) rotate(-45deg); }

/* ────────────────────────────── Hero ────────────────────────────── */

.hero{
  position:relative;
  min-height:100svh;
  display:flex;
  align-items:center;
  padding-block:8rem 5rem;
}

.hero-grid{
  display:grid;
  grid-template-columns:minmax(0,1.04fr) minmax(0,1fr);
  align-items:center;
  gap:clamp(2rem, 5vw, 4.5rem);
}

.eyebrow{
  margin:0 0 1.6rem;
  font-family:var(--label);
  font-variation-settings:var(--label-vars);
  font-size:.74rem;
  font-weight:600;
  letter-spacing:.3em;
  text-transform:uppercase;
  color:var(--accent);
}

.display{
  margin:0;
  font-family:var(--display);
  font-weight:400;
  font-size:clamp(2.4rem, 4.5vw, 4.5rem);
  line-height:1.07;
  letter-spacing:-.022em;
  color:var(--ink);
}
.display em{
  font-style:italic;
  font-weight:400;
}

.rule{
  width:84px;
  height:1px;
  margin:2.6rem 0 1.8rem;
  background:var(--accent);
  opacity:.55;
  transform-origin:left;
}

.lede{
  margin:0;
  font-family:var(--serif);
  font-size:clamp(1.05rem, 1.25vw, 1.22rem);
  font-weight:400;
  color:var(--ink-soft);
  letter-spacing:.01em;
}
.lede em{ font-style:italic; color:var(--ink); }

/* Constellation field */

.hero-canvas{
  position:relative;
  aspect-ratio:1 / .92;
  width:100%;
  cursor:none;
}
#constellation{
  position:absolute;
  inset:0;
  width:100%;
  height:100%;
  display:block;
}

.node-card{
  position:absolute;
  top:0; left:0;
  display:flex;
  flex-direction:column;
  gap:.15rem;
  padding:.65rem .95rem;
  background:rgba(253,251,246,.94);
  border:1px solid var(--rule-soft);
  box-shadow:0 8px 28px rgba(22,35,58,.07);
  font-family:var(--display);
  white-space:nowrap;
  opacity:0;
  transform:translate(0,4px);
  transition:opacity .3s var(--ease), transform .3s var(--ease);
  pointer-events:none;
}
.node-card.on{ opacity:1; transform:translate(0,0); }
.node-card-title{
  font-size:.86rem;
  font-style:italic;
  font-weight:500;
  color:var(--ink);
}
.node-card-sub{
  font-size:.76rem;
  font-style:italic;
  font-weight:400;
  color:var(--ink-faint);
}

.cursor-ring{
  position:absolute;
  top:0; left:0;
  width:34px; height:34px;
  margin:-17px 0 0 -17px;
  border:1px solid rgba(22,35,58,.28);
  border-radius:50%;
  opacity:0;
  transition:opacity .35s var(--ease), width .35s var(--ease), height .35s var(--ease), margin .35s var(--ease);
  pointer-events:none;
}
.cursor-ring.on{ opacity:1; }
.cursor-ring.near{
  width:54px; height:54px; margin:-27px 0 0 -27px;
  border-color:rgba(91,124,166,.5);
}
.cursor-ring::after{
  content:"";
  position:absolute;
  top:50%; left:50%;
  width:3px; height:3px;
  margin:-1.5px 0 0 -1.5px;
  border-radius:50%;
  background:var(--ink);
}

.explore-hint{
  position:absolute;
  right:2%;
  bottom:2%;
  margin:0;
  font-family:var(--serif);
  font-style:italic;
  font-size:.92rem;
  letter-spacing:.06em;
  color:var(--accent);
  opacity:.85;
  pointer-events:none;
}
.hint-rule{
  display:block;
  width:62px; height:1px;
  margin:.6rem 0 0 auto;
  background:var(--accent);
  opacity:.45;
}

.scroll-cue{
  position:absolute;
  left:var(--pad);
  bottom:2.5rem;
  width:1px; height:56px;
  overflow:hidden;
}
.scroll-cue-line{
  position:absolute;
  inset:0;
  background:linear-gradient(var(--accent), transparent);
  animation:cue 2.6s var(--ease) infinite;
}
@keyframes cue{
  0%{ transform:translateY(-100%); }
  60%,100%{ transform:translateY(100%); }
}

/* ──────────────────────────── Sections ──────────────────────────── */

.section{
  position:relative;
  padding-block:clamp(5.5rem, 11vw, 9.5rem);
  border-top:1px solid var(--rule-soft);
}
.section-tint{ background:var(--paper-tint); }

.section-head{
  display:flex;
  align-items:baseline;
  gap:1.4rem;
  margin-bottom:2.6rem;
}
.section-index{
  font-family:var(--label);
  font-variation-settings:var(--label-vars);
  font-size:.72rem;
  font-weight:600;
  letter-spacing:.26em;
  color:var(--accent);
}
.section-title{
  margin:0;
  font-family:var(--display);
  font-weight:400;
  font-size:clamp(1.85rem, 3.2vw, 2.8rem);
  letter-spacing:-.018em;
}


/* About */

.about-grid{
  display:grid;
  grid-template-columns:minmax(0, 1.55fr) minmax(0, 1fr);
  gap:clamp(2.5rem, 7vw, 6rem);
  align-items:start;
}
.about-prose p{
  margin:0 0 1.5rem;
  max-width:58ch;
  color:var(--ink-soft);
  font-size:1.05rem;
}
.about-prose .lead{
  font-family:var(--serif);
  font-size:1.35rem;
  line-height:1.55;
  color:var(--ink);
  margin-bottom:2rem;
}

.about-side{
  padding-top:.5rem;
  border-top:1px solid var(--rule);
}
.side-title{
  margin:1.4rem 0 1.4rem;
  font-family:var(--label);
  font-variation-settings:var(--label-vars);
  font-size:.72rem;
  font-weight:600;
  letter-spacing:.26em;
  text-transform:uppercase;
  color:var(--accent);
}
.side-list{
  list-style:none;
  margin:0 0 2.2rem;
  padding:0;
}
.side-list li{
  display:grid;
  grid-template-columns:6.5rem 1fr;
  gap:1rem;
  padding-block:.85rem;
  border-bottom:1px solid var(--rule-soft);
}
.side-key{
  font-family:var(--label);
  font-variation-settings:var(--label-vars);
  font-size:.74rem;
  letter-spacing:.14em;
  text-transform:uppercase;
  color:var(--ink-faint);
  padding-top:.2rem;
}
.side-val{
  font-family:var(--serif);
  font-size:1rem;
  color:var(--ink);
  line-height:1.45;
}

.text-link{
  display:inline-block;
  font-family:var(--serif);
  font-size:1rem;
  font-style:italic;
  color:var(--accent-deep);
  border-bottom:1px solid rgba(91,124,166,.35);
  padding-bottom:.15rem;
  transition:border-color .35s var(--ease), color .35s var(--ease);
}
.text-link:hover{ border-color:var(--accent-deep); color:var(--ink); }

/* Research themes */

.theme-grid{
  display:grid;
  grid-template-columns:repeat(auto-fit, minmax(255px, 1fr));
  gap:1px;
  background:var(--rule-soft);
  border:1px solid var(--rule-soft);
}
.theme{
  position:relative;
  background:var(--paper-tint);
  padding:2.4rem clamp(1.5rem, 2.4vw, 2.4rem) 2.6rem;
  transition:background .5s var(--ease);
}
.theme:hover{ background:var(--paper-card); }
.theme-num{
  display:block;
  font-family:var(--display);
  font-style:italic;
  font-size:1rem;
  color:var(--accent);
  margin-bottom:1.4rem;
}
.theme h3{
  margin:0 0 1rem;
  font-family:var(--display);
  font-weight:400;
  font-size:1.42rem;
  line-height:1.25;
}
.theme p{
  margin:0 0 1.6rem;
  color:var(--ink-soft);
  font-size:1.02rem;
}
.theme-tags{
  font-family:var(--serif);
  font-style:italic;
  font-size:.9rem;
  color:var(--ink-faint);
}

/* Experience */

.role-list{
  list-style:none;
  margin:0;
  padding:0;
  border-top:1px solid var(--rule);
}
.role{
  display:grid;
  grid-template-columns:14rem minmax(0,1fr);
  gap:clamp(1.5rem, 4vw, 3.5rem);
  padding-block:2.3rem;
  border-bottom:1px solid var(--rule);
}
.role-when{
  display:flex;
  flex-direction:column;
  gap:.5rem;
  padding-top:.45rem;
}
.role-date{
  font-family:var(--label);
  font-variation-settings:var(--label-vars);
  font-size:.74rem;
  letter-spacing:.14em;
  text-transform:uppercase;
  color:var(--accent);
}
.role-place{
  font-family:var(--serif);
  font-style:italic;
  font-size:.92rem;
  color:var(--ink-faint);
}
.role-org{
  margin:0 0 .3rem;
  font-family:var(--display);
  font-weight:400;
  font-size:clamp(1.25rem, 1.9vw, 1.6rem);
  line-height:1.25;
}
.role-unit{
  font-size:.8em;
  color:var(--ink-faint);
}
.role-title{
  margin:0 0 1rem;
  font-family:var(--serif);
  font-style:italic;
  font-size:1.05rem;
  color:var(--ink-soft);
}
.role-text{
  margin:0 0 1.1rem;
  max-width:86ch;
  color:var(--ink-soft);
  font-size:1.02rem;
}
.role-text:last-child{ margin-bottom:0; }

/* Featured project */

.feature{
  display:grid;
  grid-template-columns:minmax(0, 20rem) minmax(0, 1fr);
  gap:clamp(1.5rem, 4vw, 3.5rem);
  padding-block:2.8rem;
  border-block:1px solid var(--rule);
}
.feature-name{
  margin:0 0 .4rem;
  font-family:var(--display);
  font-weight:400;
  font-size:clamp(1.7rem, 2.8vw, 2.3rem);
  line-height:1.15;
}
.feature-sub{
  margin:0;
  font-family:var(--serif);
  font-style:italic;
  font-size:1.05rem;
  color:var(--ink-soft);
}
.feature-desc{
  margin:0 0 1.9rem;
  max-width:62ch;
  font-family:var(--serif);
  font-size:1.15rem;
  line-height:1.6;
  color:var(--ink);
}
.feature-meta{
  display:flex;
  align-items:baseline;
  justify-content:space-between;
  gap:1.5rem;
  flex-wrap:wrap;
  margin:0;
  padding-top:1.4rem;
  border-top:1px solid var(--rule-soft);
}
.feature-tags{
  font-family:var(--serif);
  font-style:italic;
  font-size:.92rem;
  color:var(--ink-faint);
}

/* Publications */

.pub-list{
  list-style:none;
  margin:0 0 2.6rem;
  padding:0;
  counter-reset:pub;
}
.pub{
  position:relative;
  padding:2.2rem 0 2.2rem 4.2rem;
  border-top:1px solid var(--rule);
  counter-increment:pub;
}
.pub:last-child{ border-bottom:1px solid var(--rule); }
.pub::before{
  content:"0" counter(pub);
  position:absolute;
  left:0; top:2.5rem;
  font-size:.72rem;
  letter-spacing:.2em;
  color:var(--accent);
}
.pub-title{
  margin:0 0 .7rem;
  max-width:52ch;
  font-family:var(--display);
  font-weight:400;
  font-size:clamp(1.2rem, 1.9vw, 1.5rem);
  line-height:1.3;
}
.pub-authors,
.pub-venue{
  margin:0 0 .35rem;
  font-family:var(--serif);
  font-size:.98rem;
  color:var(--ink-soft);
}
.pub-venue{ color:var(--ink-faint); font-style:italic; }
/* Own name in the author list. */
.pub-authors em{
  font-style:normal;
  font-weight:500;
  color:var(--ink);
}
.pub-links{
  margin:1rem 0 0;
  font-size:.85rem;
  letter-spacing:.06em;
}
.pub-links a{
  color:var(--accent-deep);
  border-bottom:1px solid rgba(91,124,166,.3);
  padding-bottom:.1rem;
  transition:border-color .35s var(--ease);
}
.pub-links a:hover{ border-color:var(--accent-deep); }
.pub-links .dot{ margin-inline:.75rem; color:var(--ink-faint); }

/* Contact */

.contact-grid{
  display:grid;
  grid-template-columns:minmax(0, 1.4fr) minmax(0, 1fr);
  gap:clamp(2.5rem, 7vw, 6rem);
  align-items:start;
}
.contact-lead{
  margin:0 0 2.4rem;
  max-width:46ch;
  font-family:var(--serif);
  font-size:1.22rem;
  color:var(--ink-soft);
}
.contact-mail{
  display:inline-block;
  font-family:var(--display);
  font-size:clamp(1.4rem, 3vw, 2.3rem);
  color:var(--ink);
  border-bottom:1px solid var(--rule);
  padding-bottom:.35rem;
  transition:color .4s var(--ease), border-color .4s var(--ease);
  word-break:break-word;
}
.contact-mail:hover{ color:var(--accent-deep); border-color:var(--accent); }

.contact-links{
  list-style:none;
  margin:0;
  padding:0;
  border-top:1px solid var(--rule);
}
.contact-links li{ border-bottom:1px solid var(--rule-soft); }
.contact-links a{
  display:flex;
  align-items:center;
  justify-content:space-between;
  padding-block:1.05rem;
  font-family:var(--serif);
  font-size:1.05rem;
  color:var(--ink);
  transition:padding-inline .45s var(--ease), color .4s var(--ease);
}
.contact-links a:hover{ padding-inline:.7rem 0; color:var(--accent-deep); }
.contact-links span{ font-size:.85rem; color:var(--accent); }

/* Footer */

.site-footer{
  padding-block:2.4rem;
  border-top:1px solid var(--rule-soft);
  font-size:.8rem;
  letter-spacing:.08em;
  color:var(--ink-faint);
}
.footer-inner{
  display:flex;
  justify-content:space-between;
  gap:1rem;
  flex-wrap:wrap;
}
.footer-mark{ font-family:var(--serif); font-style:italic; font-size:.92rem; }

/* ──────────────────────── Reveal animation ──────────────────────── */

/* Hidden only when scripting is available to reveal them again. */
.js .reveal{
  opacity:0;
  transform:translateY(18px);
  transition:opacity .9s var(--ease) var(--d, 0s), transform .9s var(--ease) var(--d, 0s);
}
.reveal.in{ opacity:1; transform:none; }

/* ───────────────────────────── Responsive ───────────────────────── */

@media (max-width: 1000px){
  .hero{ min-height:auto; padding-block:7.5rem 4rem; }
  .hero-grid{ grid-template-columns:1fr; }
  .hero-canvas{ order:-1; aspect-ratio:1 / .68; cursor:default; }
  .about-grid,
  .contact-grid{ grid-template-columns:1fr; }
  .role,
  .feature{ grid-template-columns:1fr; gap:1.2rem; }
  .role-when{ flex-direction:row; align-items:baseline; gap:1rem; padding-top:0; }
  .scroll-cue{ display:none; }
}

@media (max-width: 720px){
  .menu-toggle{ display:flex; }
  .nav{
    position:fixed;
    inset:0;
    flex-direction:column;
    justify-content:center;
    gap:1.6rem;
    background:rgba(250,247,240,.97);
    backdrop-filter:blur(14px);
    -webkit-backdrop-filter:blur(14px);
    font-size:1.7rem;
    opacity:0;
    visibility:hidden;
    transition:opacity .45s var(--ease), visibility .45s;
  }
  .nav.open{ opacity:1; visibility:visible; }
  .nav-dot{ display:none; }
  .menu-toggle{ position:relative; z-index:2; }

  /* Let the headline find its own line breaks on narrow screens. */
  .display{ font-size:clamp(2.2rem, 9.6vw, 3.3rem); }
  .display br{ display:none; }
  .section-head{ gap:1rem; }
  .side-list li{ grid-template-columns:1fr; gap:.2rem; }
  .pub{ padding-left:0; }
  .pub::before{ position:static; display:block; margin-bottom:.9rem; }
  .explore-hint{ font-size:.9rem; }
}

@media (prefers-reduced-motion: reduce){
  html{ scroll-behavior:auto; }
  *,*::before,*::after{
    animation-duration:.01ms !important;
    animation-iteration-count:1 !important;
    transition-duration:.01ms !important;
  }
  .reveal,
  .js .reveal{ opacity:1; transform:none; }
}