/* Xiangyu Tao — personal academic site */
:root {
  --bg: #ffffff;
  --text: #252b28;
  --muted: #626963;
  --accent: #14452f;
  --accent-soft: #e3efe7;
  --rule: #e5e8e5;
  --link: #245d43;
  --maxw: 960px;
}

* { box-sizing: border-box; }

html { font-size: 18px; }

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: "Source Serif Pro", "Iowan Old Style", "Palatino Linotype", Palatino, Georgia, serif;
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
}

.wrap {
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 0 1.25rem;
}

/* Header / nav */
header.site {
  border-bottom: 1px solid var(--rule);
  padding: 1.6rem 0;
}
header.site .wrap {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 0.6rem;
}
.site-name {
  font-size: 1.15rem;
  font-weight: 700;
  letter-spacing: 0.01em;
  color: var(--text);
  text-decoration: none;
}
.site-name .zh {
  font-weight: 400;
  color: var(--muted);
  margin-left: 0.45em;
  font-size: 0.95em;
}
nav.main a {
  font-family: -apple-system, "Segoe UI", Helvetica, Arial, sans-serif;
  font-size: 0.85rem;
  letter-spacing: 0;
  text-transform: none;
  color: var(--muted);
  text-decoration: none;
  margin-left: 1.1rem;
}
nav.main a:first-child { margin-left: 0; }
nav.main a:hover { color: var(--accent); }
nav.main a[aria-current="page"] {
  color: var(--accent);
  border-bottom: 2px solid var(--accent);
  padding-bottom: 2px;
}

/* Main content */
main { padding: 3.5rem 0 4rem; }

h1 {
  font-size: clamp(1.9rem, 4vw, 2.35rem);
  line-height: 1.25;
  margin: 0 0 1.1rem;
  font-weight: 700;
}
h2 {
  font-size: 1.25rem;
  margin: 2.8rem 0 1rem;
  font-weight: 700;
}
h2:first-child { margin-top: 0; }

p { margin: 0 0 1.35rem; }

a { color: var(--link); text-decoration-thickness: 1px; text-underline-offset: 2px; }
a:hover { color: #14452f; }

.lede { font-size: 1rem; }

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

.small {
  font-family: -apple-system, "Segoe UI", Helvetica, Arial, sans-serif;
  font-size: 0.85rem;
  color: var(--muted);
}

/* Homepage intro */
.intro { display: grid; grid-template-columns: 188px minmax(0, 1fr); gap: 3rem; align-items: start; }
.intro-text { min-width: 0; }
.intro-text > p { max-width: 65ch; }

/* Publication list */
ol.pubs {
  list-style: none;
  margin: 0;
  padding: 0;
}
ol.pubs li {
  margin: 0 0 1.6rem;
  padding-left: 0;
}
ol.pubs .title { font-weight: 600; }
ol.pubs .venue { font-style: italic; }
.pub-year {
  font-family: -apple-system, "Segoe UI", Helvetica, Arial, sans-serif;
  font-size: 0.8rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--accent);
  border-top: 1px solid var(--rule);
  padding-top: 1.1rem;
  margin: 1.8rem 0 0.9rem;
  font-weight: 600;
}
.award {
  display: inline-block;
  font-family: -apple-system, "Segoe UI", Helvetica, Arial, sans-serif;
  font-size: 0.75rem;
  background: var(--accent-soft);
  color: var(--accent);
  padding: 0.1rem 0.4rem;
  margin-top: 0.25rem;
}

/* News / blog */
ul.news { list-style: none; margin: 0; padding: 0; }
ul.news li {
  display: flex;
  gap: 1rem;
  margin-bottom: 1.25rem;
  align-items: baseline;
}
ul.news .date {
  flex: 0 0 4.8rem;
  font-family: -apple-system, "Segoe UI", Helvetica, Arial, sans-serif;
  font-size: 0.8rem;
  color: var(--muted);
  letter-spacing: 0.02em;
}

article.post h1 { margin-bottom: 0.3rem; }
article.post .post-date { margin-bottom: 1.6rem; }

/* Contact list */
ul.contact { list-style: none; margin: 0; padding: 0; }
ul.contact li { margin-bottom: 1.2rem; }
ul.contact .label {
  display: inline-block;
  width: 6.5rem;
  color: var(--muted);
  font-family: -apple-system, "Segoe UI", Helvetica, Arial, sans-serif;
  font-size: 0.85rem;
}

/* Footer */
footer.site {
  border-top: 1px solid var(--rule);
  padding: 1.2rem 0 2rem;
}
footer.site .wrap {
  display: flex;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 0.5rem;
}

@media (max-width: 540px) {
  html { font-size: 16px; }
  nav.main a { margin-left: 0.8rem; }
  ul.news li { flex-direction: column; gap: 0.1rem; }
}

/* Header logo mark */
.site-name { display: inline-flex; align-items: center; gap: 0.55rem; }
.site-name img.mark { height: 34px; width: auto; display: block; }

/* Quiet project introduction */
.project-card { margin: 0.5rem 0 1.6rem; }
.project-card img.logo { width: min(340px, 100%); height: auto; display: block; margin: 0 0 1.4rem; }
.project-card p { margin-bottom: 0; }

/* Headshot */
.intro img.headshot {
  width: 170px; height: 170px; border-radius: 50%;
  flex: 0 0 auto; border: 0;
}
@media (max-width: 540px) { .intro img.headshot { margin: 0 auto; } }

/* Profile contact icons */
.profile { flex: 0 0 188px; width: 188px; text-align: center; }
.profile .headshot { display: block; margin: 0 auto; }
.profile-links { display: flex; justify-content: center; gap: 4px; margin-top: 0.7rem; }
.profile-links a { display: inline-flex; align-items: center; justify-content: center; width: 44px; height: 44px; border-radius: 50%; color: var(--accent); text-decoration: none; }
.profile-links svg { width: 24px; height: 24px; }
.profile-links a:hover { background: var(--accent-soft); }
.profile-links a:focus-visible { outline: 2px solid var(--accent); outline-offset: 2px; background: var(--accent-soft); }
@media (max-width: 540px) { .profile { margin: 0 auto; } }

/* Compact academic background beneath the profile */
.profile-education { margin-top: 1.6rem; text-align: left; font-family: -apple-system, "Segoe UI", Helvetica, Arial, sans-serif; }
.profile-education h2 { margin: 0 0 0.85rem; font-size: 0.8rem; font-weight: 600; color: var(--text); }
.profile-education ul { list-style: none; margin: 0; padding: 0; }
.profile-education li { margin: 0 0 1.1rem; font-size: 0.8125rem; line-height: 1.55; }
.profile-education strong { display: block; font-weight: 500; }
.profile-education span { display: block; margin-top: 0.2rem; color: var(--muted); }

/* Keep the reading column comfortable on smaller screens. */
@media (max-width: 760px) {
  main { padding-top: 2.5rem; }
  .intro { grid-template-columns: minmax(0, 1fr); gap: 2.5rem; }
  .profile { width: 100%; max-width: 22rem; margin: 0 auto; }
  .profile-education { margin-top: 1.5rem; }
  .profile-education li { font-size: 0.875rem; }
  .project-card img.logo { width: min(300px, 100%); }
}
@media (max-width: 540px) {
  ul.news .date { flex-basis: auto; }
}