:root {
  --text: #1a1a1a;
  --muted: #5a5a5a;
  --accent: #1a4f8b;
  --rule: #e2e2e2;
  --bg: #fdfdfc;
  --max: 720px;
}

* { box-sizing: border-box; }

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

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: "Source Serif 4", Charter, "Iowan Old Style", Georgia, serif;
  font-size: 18px;
  line-height: 1.55;
  font-feature-settings: "kern", "liga", "onum";
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

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

/* Header */
.site-header {
  border-bottom: 1px solid var(--rule);
  padding: 1.25rem 0;
  margin-bottom: 2.5rem;
}
.site-header .container {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  flex-wrap: wrap;
  gap: 0.5rem 1.5rem;
}
.brand {
  font-size: 1.35rem;
  font-weight: 600;
  color: var(--text);
  text-decoration: none;
  letter-spacing: 0.005em;
}
.nav {
  display: flex;
  gap: 1.5rem;
}
.nav a {
  color: var(--muted);
  text-decoration: none;
  font-size: 1rem;
  border-bottom: 1px solid transparent;
  padding-bottom: 2px;
  transition: color 0.15s, border-color 0.15s;
}
.nav a:hover {
  color: var(--text);
}
.nav a.active {
  color: var(--text);
  border-bottom-color: var(--text);
}

/* Sections */
main section {
  margin-bottom: 3rem;
}
h2 {
  font-size: 1.4rem;
  font-weight: 600;
  letter-spacing: 0.005em;
  margin: 0 0 1.25rem 0;
  padding-bottom: 0.4rem;
  border-bottom: 1px solid var(--rule);
}
h3 {
  font-size: 1.15rem;
  font-weight: 600;
  color: var(--text);
  letter-spacing: 0.005em;
  margin: 2rem 0 0.75rem 0;
}

/* Intro */
.intro {
  display: grid;
  grid-template-columns: 1fr auto;
  gap: 2rem;
  align-items: start;
}
.intro p {
  margin-top: 0;
}
.portrait {
  grid-column: 2;
  grid-row: 1 / span 2;
  width: 170px;
  height: auto;
  border-radius: 4px;
  margin-top: 0.25rem;
}
.contact {
  grid-column: 1;
  list-style: none;
  padding: 0;
  margin: 0.5rem 0 0;
}
.contact li {
  margin: 0.25rem 0;
  color: var(--muted);
}

/* Paper lists */
.papers {
  list-style: none;
  padding: 0;
  margin: 0;
}
.papers li {
  margin: 0 0 1.25rem 0;
  text-indent: 0;
}
.papers li a:first-child {
  font-weight: 500;
}

/* Lecture list: each item is a single link, so don't bold the whole line */
.lectures {
  list-style: none;
  padding: 0;
  margin: 0;
}
.lectures li {
  margin: 0.4rem 0;
}
.lectures li a {
  font-weight: 400;
}
.extras {
  display: block;
  color: var(--muted);
  font-size: 0.92rem;
  margin-top: 0.15rem;
}

/* Links */
a {
  color: var(--accent);
  text-decoration: none;
  border-bottom: 1px solid rgba(26, 79, 139, 0.25);
}
a:hover {
  border-bottom-color: var(--accent);
}

/* Mobile */
@media (max-width: 600px) {
  body { font-size: 17px; }
  .intro {
    grid-template-columns: 1fr;
  }
  .portrait {
    grid-column: 1;
    grid-row: auto;
    width: 130px;
    margin-bottom: 0.5rem;
  }
  .contact {
    grid-column: 1;
  }
  .site-header .container {
    flex-direction: column;
    align-items: flex-start;
  }
  h2 { font-size: 1.25rem; }
}