/* ==========================================================================
   haosun.info — ETH-flavoured academic homepage
   Palette follows the ETH Zurich corporate design; typography pairs
   Inter (UI, headings, metadata) with Source Serif 4 (prose, paper titles).
   ========================================================================== */

:root {
  /* ETH corporate colours */
  --eth-blue:        #215caf;
  --eth-blue-dark:   #16427d;
  --eth-blue-20:     #d3deef;
  --eth-blue-10:     #e9eef7;
  --eth-petrol:      #007894;
  --eth-bronze:      #8e6713;
  --eth-red:         #b7352d;

  /* Surfaces and ink */
  --bg:        #ffffff;
  --bg-soft:   #f6f7f9;
  --bg-raise:  #ffffff;
  --rule:      #e3e6ea;
  --rule-soft: #eef0f3;
  --ink:       #15171a;
  --ink-2:     #43474d;
  --ink-3:     #767b83;

  --accent:      var(--eth-blue);
  --accent-weak: var(--eth-blue-10);
  --badge-bg:    #f4eedf;
  --badge-ink:   var(--eth-bronze);

  /* masthead: ETH-blue tint with a full-strength blue rule on top */
  --bar-bg:       #e9eef7;
  --bar-edge:     #ccd8ea;
  --bar-btn-edge: #c2d1e6;
  --bar-ink:      #16305c;
  --bar-ink-2:    #4b5768;
  --bar-accent:   #215caf;
  --bar-hover:    rgba(33, 92, 175, 0.10);
  --bar-active:   rgba(33, 92, 175, 0.15);

  --sans: "Inter", -apple-system, BlinkMacSystemFont, "Segoe UI", Helvetica, Arial, sans-serif;
  --serif: "Source Serif 4", Charter, "Iowan Old Style", Georgia, serif;

  --wrap: 54rem;
  --nav-h: 3.25rem;
}

:root[data-theme="dark"] {
  --bg:        #131519;
  --bg-soft:   #1a1d23;
  --bg-raise:  #191c21;
  --rule:      #2a2e36;
  --rule-soft: #22262d;
  --ink:       #e7e9ec;
  --ink-2:     #b6bbc3;
  --ink-3:     #888f99;

  --eth-blue-20: #26344b;
  --eth-blue-10: #1b2430;
  --accent:      #7ba7e0;
  --accent-weak: #1b2534;
  --eth-petrol:  #4cb4c8;
  --eth-bronze:  #c9a256;
  --eth-red:     #e0736b;
  --badge-bg:    #2c2517;
  --badge-ink:   #d8b46a;

  --bar-bg:       #1b2230;
  --bar-edge:     #2c3547;
  --bar-btn-edge: #39435a;
  --bar-ink:      #e8edf5;
  --bar-ink-2:    rgba(232, 237, 245, 0.72);
  --bar-accent:   #8ab4e8;
  --bar-hover:    rgba(255, 255, 255, 0.07);
  --bar-active:   rgba(138, 180, 232, 0.16);
  color-scheme: dark;
}

@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --bg:        #131519;
    --bg-soft:   #1a1d23;
    --bg-raise:  #191c21;
    --rule:      #2a2e36;
    --rule-soft: #22262d;
    --ink:       #e7e9ec;
    --ink-2:     #b6bbc3;
    --ink-3:     #888f99;

    --eth-blue-20: #26344b;
    --eth-blue-10: #1b2430;
    --accent:      #7ba7e0;
    --accent-weak: #1b2534;
    --eth-petrol:  #4cb4c8;
    --eth-bronze:  #c9a256;
    --eth-red:     #e0736b;
    --badge-bg:    #2c2517;
    --badge-ink:   #d8b46a;

    --bar-bg:       #1b2230;
    --bar-edge:     #2c3547;
    --bar-btn-edge: #39435a;
    --bar-ink:      #e8edf5;
    --bar-ink-2:    rgba(232, 237, 245, 0.72);
    --bar-accent:   #8ab4e8;
    --bar-hover:    rgba(255, 255, 255, 0.07);
    --bar-active:   rgba(138, 180, 232, 0.16);
    color-scheme: dark;
  }
}

/* --------------------------------------------------------------- reset -- */

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

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

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  * { transition: none !important; }
}

body {
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  font-family: var(--serif);
  font-size: 1.0625rem;
  line-height: 1.62;
  font-variant-numeric: oldstyle-nums proportional-nums;
  text-rendering: optimizeLegibility;
  -webkit-font-smoothing: antialiased;
}

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

p { margin: 0 0 0.9em; }
p:last-child { margin-bottom: 0; }

a {
  color: var(--accent);
  text-decoration: none;
  text-underline-offset: 2px;
  transition: color .12s ease, background-color .12s ease;
}
a:hover { color: var(--eth-blue-dark); text-decoration: underline; }
:root[data-theme="dark"] a:hover { color: #a8c7ec; }
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) a:hover { color: #a8c7ec; }
}

a:focus-visible,
button:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 2px;
  border-radius: 2px;
}

.wrap {
  max-width: var(--wrap);
  margin: 0 auto;
  padding-left: 1.5rem;
  padding-right: 1.5rem;
}

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

.topbar {
  position: sticky;
  top: 0;
  z-index: 50;
  background: var(--bar-bg);
  border-top: 3px solid var(--eth-blue);
  border-bottom: 1px solid var(--bar-edge);
}

.topbar-inner {
  display: flex;
  align-items: center;
  gap: 1rem;
  height: var(--nav-h);
}

.brand {
  font-family: var(--sans);
  font-weight: 700;
  font-size: 0.9375rem;
  letter-spacing: -0.011em;
  color: var(--bar-ink);
  white-space: nowrap;
}
.brand:hover { color: var(--bar-accent); text-decoration: none; }

.topnav {
  display: flex;
  align-items: center;
  justify-content: flex-end;
  gap: 0.25rem;
  min-width: 0;
  flex: 1 1 auto;
  overflow-x: auto;
  -webkit-overflow-scrolling: touch;
  scrollbar-width: none;
  -webkit-mask-image: linear-gradient(to right, transparent 0, #000 1.1rem);
          mask-image: linear-gradient(to right, transparent 0, #000 1.1rem);
}
.topnav::-webkit-scrollbar { display: none; }

.topnav a {
  font-family: var(--sans);
  font-size: 0.8125rem;
  font-weight: 500;
  letter-spacing: 0.005em;
  color: var(--bar-ink-2);
  padding: 0.3rem 0.5rem;
  border-radius: 3px;
  white-space: nowrap;
}
.topnav a:hover {
  color: var(--bar-ink);
  background: var(--bar-hover);
  text-decoration: none;
}
.topnav a.is-active {
  color: var(--bar-accent);
  background: var(--bar-active);
}

.theme-toggle {
  flex: none;
  display: grid;
  place-items: center;
  width: 1.85rem;
  height: 1.85rem;
  margin-left: 0.25rem;
  padding: 0;
  border: 1px solid var(--bar-btn-edge);
  border-radius: 3px;
  background: transparent;
  color: var(--bar-ink-2);
  cursor: pointer;
  transition: border-color .12s ease, color .12s ease, background-color .12s ease;
}
.theme-toggle:hover {
  color: var(--bar-accent);
  border-color: var(--bar-accent);
  background: var(--bar-hover);
}
.theme-toggle svg { width: 15px; height: 15px; }
.icon-moon { display: none; }
:root[data-theme="dark"] .icon-sun { display: none; }
:root[data-theme="dark"] .icon-moon { display: block; }
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) .icon-sun { display: none; }
  :root:not([data-theme="light"]) .icon-moon { display: block; }
}

/* ---------------------------------------------------------------- hero -- */

.hero {
  display: grid;
  grid-template-columns: 200px 1fr;
  gap: 2.25rem;
  align-items: start;
  padding-top: 3.25rem;
  padding-bottom: 2.5rem;
}

.hero-photo img {
  display: block;
  width: 100%;
  border-radius: 3px;
  border: 1px solid var(--rule);
}

.hero h1 {
  margin: -0.15em 0 0.3rem;
  font-family: var(--sans);
  font-size: 2.4rem;
  font-weight: 700;
  letter-spacing: -0.028em;
  line-height: 1.08;
  color: var(--ink);
}

.hero-role {
  font-family: var(--sans);
  font-size: 1rem;
  font-weight: 600;
  letter-spacing: -0.004em;
  color: var(--accent);
  margin-bottom: 0.55rem;
}

.hero-affil {
  color: var(--ink-2);
  font-size: 1rem;
  line-height: 1.5;
  margin-bottom: 0.85rem;
}
.hero-affil a { color: var(--ink-2); text-decoration: underline; text-decoration-color: var(--rule); }
.hero-affil a:hover { color: var(--accent); text-decoration-color: currentColor; }

.hero-contact {
  font-family: var(--sans);
  font-size: 0.8125rem;
  line-height: 1.75;
  color: var(--ink-3);
  margin-bottom: 1rem;
}
.hero-contact a { color: var(--ink-3); }
.hero-contact a:hover { color: var(--accent); }

.linkrow {
  display: flex;
  flex-wrap: wrap;
  gap: 0.4rem;
  margin: 0;
  padding: 0;
  list-style: none;
}
.linkrow a {
  display: inline-flex;
  align-items: center;
  gap: 0.36rem;
  font-family: var(--sans);
  font-size: 0.78125rem;
  font-weight: 500;
  color: var(--ink-2);
  border: 1px solid var(--rule);
  border-radius: 3px;
  padding: 0.26rem 0.6rem;
  background: var(--bg-raise);
}
.linkrow a:hover {
  color: var(--accent);
  border-color: var(--eth-blue-20);
  background: var(--accent-weak);
  text-decoration: none;
}
.linkrow svg { width: 14px; height: 14px; flex: none; }

/* ------------------------------------------------------------ sections -- */

.section {
  padding-bottom: 2.75rem;
  scroll-margin-top: calc(var(--nav-h) + 1.25rem);
}

.section h2 {
  display: flex;
  align-items: center;
  gap: 0.85rem;
  margin: 0 0 1.15rem;
  font-family: var(--sans);
  font-size: 0.78125rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.11em;
  color: var(--accent);
}
.section h2::after {
  content: "";
  flex: 1;
  height: 1px;
  background: var(--rule);
}

h3 {
  margin: 2rem 0 0.9rem;
  font-family: var(--sans);
  font-size: 0.8125rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--ink-3);
}
h3:first-child { margin-top: 0; }

.lede { font-size: 1.09375rem; }

.note {
  margin-top: 1.1rem;
  padding: 0.7rem 0.95rem;
  border-left: 3px solid var(--eth-petrol);
  background: var(--bg-soft);
  border-radius: 0 3px 3px 0;
  font-size: 0.96875rem;
  color: var(--ink-2);
}
.note strong { color: var(--ink); }

/* ----------------------------------------------------------- justified -- */

/* Running prose is justified; hyphenation keeps the word spacing even
   instead of opening rivers. Short list rows (news, talks, awards) stay
   ragged-right, where justifying two-line entries would look worse. */
.lede,
#about p,
.note,
.section > p,
.repo-desc {
  text-align: justify;
  text-justify: inter-word;
  -webkit-hyphens: auto;
      -ms-hyphens: auto;
          hyphens: auto;
  hyphenate-limit-chars: 7 4 3;
}

/* --------------------------------------------------------------- about -- */

.about-grid {
  display: grid;
  grid-template-columns: 1.45fr 1fr;
  column-gap: 2.9rem;
  row-gap: 1.35rem;
  align-items: start;
}

/* the job-market note spans the full content width, under both columns */
.about-grid > .note-full {
  grid-column: 1 / -1;
  margin-top: 0;
}

#about { padding-bottom: 1.8rem; }

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

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

.news li {
  display: grid;
  grid-template-columns: 3.1rem 1fr;
  gap: 0.5rem;
  padding: 0.42rem 0;
  font-size: 0.96875rem;
  line-height: 1.5;
  border-bottom: 1px solid var(--rule-soft);
}
.news li:last-child { border-bottom: 0; }

.news .when {
  font-family: var(--sans);
  font-size: 0.71875rem;
  font-weight: 600;
  letter-spacing: 0.05em;
  color: var(--ink-3);
  padding-top: 0.32em;
  font-variant-numeric: lining-nums tabular-nums;
}

/* ------------------------------------------------------------ research -- */

.themes {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1rem;
  margin-top: 1.5rem;
}

.theme {
  border: 1px solid var(--rule);
  border-top: 2px solid var(--tone, var(--eth-blue));
  border-radius: 0 0 3px 3px;
  background: var(--bg-raise);
  padding: 0.95rem 1.05rem 1.1rem;
}
.theme h4 {
  margin: 0 0 0.4rem;
  font-family: var(--sans);
  font-size: 0.84375rem;
  font-weight: 600;
  letter-spacing: -0.005em;
  color: var(--tone, var(--eth-blue));
}
.theme p {
  margin: 0;
  font-size: 0.9375rem;
  line-height: 1.52;
  color: var(--ink-2);
}
.theme-b { --tone: var(--eth-petrol); }
.theme-c { --tone: var(--eth-bronze); }

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

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

.pub {
  position: relative;
  padding: 0.5rem 0 0.5rem 0.9rem;
  margin-left: -0.9rem;
  border-left: 2px solid transparent;
  transition: border-color .14s ease;
}
.pub + .pub { margin-top: 0.55rem; }
.pub:hover { border-left-color: var(--eth-blue-20); }

.pub-title {
  margin: 0 0 0.12rem;
  font-size: 1.03125rem;
  font-weight: 600;
  line-height: 1.38;
  color: var(--ink);
}
.pub-title a { color: var(--ink); }
.pub-title a:hover { color: var(--accent); text-decoration: none; }

.pub-authors {
  margin: 0 0 0.22rem;
  font-size: 0.9375rem;
  line-height: 1.45;
  color: var(--ink-2);
}
.pub-authors .me { font-weight: 600; color: var(--ink); }

.pub-meta {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 0.45rem;
  margin: 0;
  font-family: var(--sans);
  font-size: 0.8125rem;
  color: var(--ink-3);
}
.venue {
  font-weight: 600;
  letter-spacing: 0.005em;
  color: var(--accent);
}
.venue-note { font-style: italic; }

.badge {
  font-family: var(--sans);
  font-size: 0.6875rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.055em;
  padding: 0.1rem 0.4rem;
  border-radius: 2px;
  background: var(--badge-bg);
  color: var(--badge-ink);
  white-space: nowrap;
}

.pub-links {
  display: flex;
  flex-wrap: wrap;
  gap: 0.3rem;
  margin: 0.42rem 0 0;
  padding: 0;
  list-style: none;
}
.pub-links a {
  display: inline-block;
  font-family: var(--sans);
  font-size: 0.71875rem;
  font-weight: 500;
  letter-spacing: 0.015em;
  color: var(--ink-2);
  border: 1px solid var(--rule);
  border-radius: 2px;
  padding: 0.06rem 0.4rem;
}
.pub-links a:hover {
  color: var(--accent);
  border-color: var(--eth-blue-20);
  background: var(--accent-weak);
  text-decoration: none;
}

/* ------------------------------------------------------------ software -- */

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

.repo {
  display: grid;
  grid-template-columns: 7.5rem 1fr;
  gap: 1.1rem;
  align-items: baseline;
  padding: 0.7rem 0;
  border-bottom: 1px solid var(--rule-soft);
}
.repo:last-child { border-bottom: 0; }

.repo-name {
  font-family: var(--sans);
  font-size: 0.9375rem;
  font-weight: 600;
  letter-spacing: -0.008em;
}
.repo-desc {
  margin: 0;
  font-size: 0.96875rem;
  line-height: 1.5;
  color: var(--ink-2);
}

/* --------------------------------------------------- talks / list rows -- */

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

.rows > li {
  display: grid;
  grid-template-columns: 3.1rem 1fr;
  gap: 0.5rem;
  padding: 0.42rem 0;
  font-size: 0.96875rem;
  line-height: 1.5;
  border-bottom: 1px solid var(--rule-soft);
}
.rows > li:last-child { border-bottom: 0; }

.rows .when {
  font-family: var(--sans);
  font-size: 0.71875rem;
  font-weight: 600;
  letter-spacing: 0.05em;
  color: var(--ink-3);
  padding-top: 0.32em;
  font-variant-numeric: lining-nums tabular-nums;
}
.rows .where {
  display: block;
  font-family: var(--sans);
  font-size: 0.8125rem;
  color: var(--ink-3);
  margin-top: 0.08rem;
}

.two-col {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 2.75rem;
  align-items: start;
}

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

.site-footer {
  margin-top: 1.5rem;
  border-top: 1px solid var(--rule);
  padding: 1.6rem 0 2.75rem;
  font-family: var(--sans);
  font-size: 0.78125rem;
  color: var(--ink-3);
}
.site-footer .wrap {
  display: flex;
  flex-wrap: wrap;
  gap: 0.6rem 1.25rem;
  justify-content: space-between;
}

/* ------------------------------------------------------------ responsive */

@media (max-width: 860px) {
  .about-grid,
  .two-col { grid-template-columns: 1fr; gap: 2rem; }
  .about-grid,
  .two-col { row-gap: 2.25rem; }
  /* stacked, so the desktop column-balancing trim no longer applies */
  #about { padding-bottom: 2.75rem; }
  .themes { grid-template-columns: 1fr; }
}

@media (max-width: 640px) {
  body { font-size: 1.0rem; }
  .wrap { padding-left: 1.15rem; padding-right: 1.15rem; }
  .hero {
    grid-template-columns: 1fr;
    gap: 1.4rem;
    padding-top: 2.25rem;
  }
  .hero-photo { max-width: 152px; }
  .hero h1 { font-size: 2rem; }
  .repo { grid-template-columns: 1fr; gap: 0.2rem; }
  .brand { font-size: 0.875rem; }
  .topbar-inner { gap: 0.5rem; }
  .topnav {
    justify-content: flex-start;
    gap: 0;
    padding-left: 0;
    -webkit-mask-image: linear-gradient(to right, transparent 0, #000 0.45rem, #000 calc(100% - 1.6rem), transparent);
            mask-image: linear-gradient(to right, transparent 0, #000 0.45rem, #000 calc(100% - 1.6rem), transparent);
  }
  .topnav a { padding: 0.3rem 0.36rem; font-size: 0.75rem; }
}

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

@media print {
  .topbar, .theme-toggle, .site-footer { display: none; }
  body { font-size: 10.5pt; }
  a { color: #000; }
}

/* --------------------------------------------------------- inner pages -- */

.page-head {
  padding-top: 3.25rem;
  padding-bottom: 2.25rem;
}
.page-head h1 {
  margin: 0 0 0.6rem;
  font-family: var(--sans);
  font-size: 1.95rem;
  font-weight: 700;
  letter-spacing: -0.024em;
  line-height: 1.14;
  color: var(--ink);
}
.page-head .lede { color: var(--ink-2); }

.rows-wide > li { grid-template-columns: 6.6rem 1fr; gap: 0.85rem; }
.rows-wide > li { padding: 0.62rem 0; }

@media (max-width: 640px) {
  .rows > li,
  .news li { grid-template-columns: 1fr; gap: 0.1rem; }
  .rows .when,
  .news .when { padding-top: 0; }
  .page-head h1 { font-size: 1.7rem; }
}