/* ==========================================================================
   William Hu — personal homepage
   Single stylesheet, no dependencies.

   The knobs you're most likely to want are the variables in :root below —
   change the accent color, max width, or font there and everything follows.
   ========================================================================== */

:root {
  --max-width: 46rem;          /* content column width (~736px) */
  --accent:      #1a5fb4;      /* link color */
  --accent-hover:#0d3d7a;

  --text:        #1a1a1a;
  --text-muted:  #5c5c5c;
  --text-faint:  #8a8a8a;
  --bg:          #ffffff;
  --bg-subtle:   #f6f7f9;
  --border:      #e3e5e8;

  --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", "Helvetica Neue",
               Arial, sans-serif;

  --space:     1rem;
  --radius:    6px;
}

/* Dark mode follows the visitor's OS setting. Delete this block if you
   only ever want the light theme. */
@media (prefers-color-scheme: dark) {
  :root {
    --accent:      #7cb0ee;
    --accent-hover:#a9cbf5;

    --text:        #e8e8e8;
    --text-muted:  #a8a8a8;
    --text-faint:  #7a7a7a;
    --bg:          #16181c;
    --bg-subtle:   #1e2126;
    --border:      #2c3037;
  }
}

/* --------------------------------------------------------------- base -- */

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

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

body {
  margin: 0;
  padding: 0 1.25rem;
  background: var(--bg);
  color: var(--text);
  font-family: var(--font-sans);
  font-size: 1rem;
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
}

main {
  max-width: var(--max-width);
  margin: 0 auto;
}

p { margin: 0 0 1em; }

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

/* Visible focus ring for keyboard users. */
a:focus-visible, :focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 2px;
  border-radius: 2px;
}

.skip-link {
  position: absolute;
  left: -9999px;
}
.skip-link:focus {
  left: 1rem;
  top: 1rem;
  z-index: 10;
  padding: 0.5rem 0.75rem;
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: var(--radius);
}

.muted  { color: var(--text-muted); }

/* ----------------------------------------------------------- headings -- */

h1 {
  margin: 0 0 0.3rem;
  font-size: 2rem;
  line-height: 1.2;
  letter-spacing: -0.02em;
}

/* Secondary name next to the display name, e.g. "William Hu (Haoqi Hu)". */
.alt-name {
  font-size: 1.15rem;
  font-weight: 400;
  color: var(--text-faint);
  letter-spacing: 0;
  white-space: nowrap;
}

h2 {
  margin: 3rem 0 1.15rem;
  padding-bottom: 0.4rem;
  border-bottom: 1px solid var(--border);
  font-size: 1.05rem;
  font-weight: 650;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--text);
}

h3 {
  margin: 0 0 0.35rem;
  font-size: 1.02rem;
  font-weight: 650;
}

/* ---------------------------------------------------------------- nav -- */

.nav {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 1.5rem 0 0;
  display: flex;
  flex-wrap: wrap;
  gap: 1.25rem;
  font-size: 0.9rem;
}

.nav a {
  color: var(--text-muted);
  font-weight: 500;
}
.nav a:hover {
  color: var(--accent);
  text-decoration: none;
}

/* Anchor links land below the top edge instead of flush against it. */
section { scroll-margin-top: 1.5rem; }

/* ------------------------------------------------------------- header -- */

.header {
  display: flex;
  align-items: center;
  gap: 2rem;
  margin: 2.5rem 0 1rem;
}

.avatar {
  flex: none;
  width: 160px;
  height: 160px;
  object-fit: cover;
  border-radius: 50%;
  background: var(--bg-subtle);
  border: 1px solid var(--border);
}

.header-text { min-width: 0; }

.tagline {
  margin: 0 0 0.15rem;
  font-size: 1.05rem;
  color: var(--text-muted);
}

.meta {
  margin: 0 0 0.9rem;
  font-size: 0.92rem;
  color: var(--text-faint);
}

/* Social links row */
.social {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem 0.65rem;
  margin: 0;
  padding: 0;
  list-style: none;
  font-size: 0.9rem;
}

.social a {
  display: inline-block;
  padding: 0.2rem 0.6rem;
  border: 1px solid var(--border);
  border-radius: 999px;
  color: var(--text-muted);
}
.social a:hover {
  border-color: var(--accent);
  color: var(--accent);
  text-decoration: none;
}

/* --------------------------------------------------------------- news -- */

.section-note {
  margin-top: -0.4rem;
  font-size: 0.9rem;
  color: var(--text-muted);
}

/* Currently unused — the News section was removed from index.html because it
   duplicated Experience. Kept so the section can be restored by pasting back a
   <section id="news"> with a <ul class="news-list">. Note that .date below is
   still in use by .timeline, so don't delete that with it. */
.news-list {
  margin: 0;
  padding: 0;
  list-style: none;
  font-size: 0.95rem;

  /* Once the feed gets long it scrolls in place rather than pushing the
     rest of the page down. Sized to show the current entries without
     scrolling — lower it as you add more, or remove it to never scroll. */
  max-height: 22rem;
  overflow-y: auto;
}

.news-list li {
  display: flex;
  gap: 1rem;
  padding: 0.45rem 0;
  border-bottom: 1px solid var(--border);
}
.news-list li:last-child { border-bottom: none; }

.date {
  flex: none;
  width: 6.5rem;
  color: var(--text-faint);
  font-variant-numeric: tabular-nums;
  font-size: 0.88rem;
  padding-top: 0.08rem;
}

/* ------------------------------------ selected work / projects (unused) --

   The Selected Work section was cut from index.html; the draft is parked in
   drafts/selected-work.html. These rules are kept so pasting it back needs no
   CSS changes. Note .links below is still in use by the publications list, so
   don't remove that with the rest.                                         */

.entry {
  padding: 1rem 0;
  border-bottom: 1px solid var(--border);
}
.entry:last-child { border-bottom: none; }

.entry h3 {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 0.75rem;
}

.entry-meta {
  font-size: 0.85rem;
  font-weight: 400;
  color: var(--text-faint);
  font-variant-numeric: tabular-nums;
}

.entry p { margin: 0 0 0.4rem; }

.links {
  font-size: 0.88rem;
  color: var(--text-faint);
}

/* ------------------------------------------------------- publications -- */

/* No bullets or numbers — entries are separated by whitespace alone. Kept as
   a <ul> so screen readers still announce it as a list of N items. */
.pubs {
  margin: 0;
  padding: 0;
  list-style: none;
}

.pubs li {
  margin-bottom: 1.5rem;
  line-height: 1.5;
}

.pubs li:last-child { margin-bottom: 0; }

.pub-title { font-weight: 600; }

.authors {
  font-size: 0.94rem;
  color: var(--text-muted);
}

.venue {
  font-size: 0.9rem;
  font-style: italic;
  color: var(--text-muted);
}

/* Small pill for "Oral", "Best Paper", "Spotlight", etc. */
.award {
  display: inline-block;
  margin-left: 0.4rem;
  padding: 0.05rem 0.45rem;
  border-radius: var(--radius);
  background: var(--bg-subtle);
  border: 1px solid var(--border);
  font-size: 0.75rem;
  font-style: normal;
  letter-spacing: 0.03em;
  color: var(--text-muted);
  vertical-align: 1px;
}

/* --------------------------------------- experience / education lists -- */

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

.timeline li {
  display: flex;
  gap: 1rem;
  padding: 0.7rem 0;
  border-bottom: 1px solid var(--border);
}
.timeline li:last-child { border-bottom: none; }

.timeline .date { width: 8.5rem; }

.timeline .muted { font-size: 0.93rem; }

/* Title progression under an employer, e.g. "Sr. Applied Scientist · AS II". */
.roles {
  font-size: 0.9rem;
  color: var(--text-muted);
}

/* ------------------------------------------------------------- footer -- */

.footer {
  max-width: var(--max-width);
  margin: 4rem auto 0;
  padding: 1.25rem 0 3rem;
  border-top: 1px solid var(--border);
  font-size: 0.85rem;
  color: var(--text-faint);
}
.footer p { margin: 0; }

/* ------------------------------------------------------------- mobile -- */

@media (max-width: 34rem) {
  body { padding: 0 1rem; }

  h1 { font-size: 1.65rem; }

  /* Stack the header and center it. */
  .header {
    flex-direction: column;
    align-items: center;
    text-align: center;
    gap: 1.25rem;
    margin-top: 1.75rem;
  }
  .avatar { width: 130px; height: 130px; }
  .social { justify-content: center; }

  /* Dates move above their content instead of sitting in a side column. */
  .news-list li,
  .timeline li {
    flex-direction: column;
    gap: 0.15rem;
  }
  .date,
  .timeline .date { width: auto; }

  .news-list { max-height: none; }
}

/* -------------------------------------------------------------- print -- */

@media print {
  .nav, .skip-link { display: none; }
  body { color: #000; background: #fff; font-size: 11pt; }
  a { color: #000; text-decoration: underline; }
  .news-list { max-height: none; overflow: visible; }
  section { page-break-inside: avoid; }
}