:root {
  --bg: #fafafa;
  --bg-alt: #ffffff;
  --text: #222222;
  --muted: #666666;
  --accent: #254f9d;
  --accent-soft: #e0e8f8;
  --border: #dddddd;
  --link: #254f9d;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", system-ui,
    sans-serif;
  background-color: var(--bg);
  color: var(--text);
  line-height: 1.6;
}

a {
  color: var(--link);
  text-decoration: none;
}

a:hover,
a:focus {
  text-decoration: underline;
}

.container {
  max-width: 900px;
  margin: 0 auto;
  padding: 0 1.25rem;
}

/* Header / nav */

header {
  border-bottom: 1px solid var(--border);
  background-color: var(--bg-alt);
}

.top-nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 1.25rem 0;
  gap: 1.5rem;
}

.brand {
  font-size: 1.1rem;
  font-weight: 600;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  white-space: nowrap;
}

.nav-links {
  display: flex;
  flex-wrap: wrap;
  gap: 0.9rem;
  font-size: 0.92rem;
  text-transform: uppercase;
  letter-spacing: 0.08em;
}

.nav-links a {
  padding-bottom: 0.1rem;
  border-bottom: 1px solid transparent;
}

.nav-links a:hover,
.nav-links a:focus {
  border-color: var(--accent);
  text-decoration: none;
}

.nav-links .active {
  border-color: var(--accent);
}

/* Layout */

main {
  padding: 2rem 0 3rem;
}

.hero {
  display: grid;
  grid-template-columns: minmax(0, 2.2fr) minmax(0, 1.4fr);
  gap: 2rem;
  align-items: center;
  margin-bottom: 2.5rem;
}

/* Reverse hero layout for index: photo left, text right */
.hero-reversed {
  grid-template-columns: minmax(0, 1.4fr) minmax(0, 2.2fr);
}

.hero-text h1 {
  font-size: 2.1rem;
  margin: 0 0 0.35rem;
  font-weight: 600;
}

.hero-text h2 {
  font-size: 1.1rem;
  margin: 0 0 0.4rem;
  font-weight: 500;
  color: var(--muted);
}

.hero-text .affiliation {
  font-size: 0.98rem;
  color: var(--muted);
  margin-bottom: 0.85rem;
}

.hero-text p {
  margin: 0 0 0.75rem;
}

.hero-meta {
  font-size: 0.9rem;
  color: var(--muted);
}

.hero-meta div {
  margin-bottom: 0.25rem;
}

.hero-photo-wrap {
  display: flex;
  justify-content: flex-end;
}

.hero-photo {
  max-width: 260px;
  width: 100%;
  border-radius: 12px;
  box-shadow: 0 10px 30px rgba(0, 0, 0, 0.12);
  overflow: hidden;
  background: #ddd;
}

.hero-photo img {
  display: block;
  width: 100%;
  height: auto;
}

/* Sections */

section {
  padding: 1rem 0 1.5rem;
  border-top: 1px solid var(--border);
}

section:first-of-type {
  border-top: none;
}

section h2 {
  font-size: 1.15rem;
  margin: 0 0 0.8rem;
  text-transform: uppercase;
  letter-spacing: 0.12em;
  font-weight: 600;
}

.two-column {
  display: grid;
  grid-template-columns: minmax(0, 2.4fr) minmax(0, 1.6fr);
  gap: 2rem;
}

.tag-list {
  padding: 0;
  margin: 0.3rem 0 0;
  list-style: none;
  display: flex;
  flex-wrap: wrap;
  gap: 0.4rem 0.8rem;
  font-size: 0.9rem;
}

.tag-list li {
  padding: 0.12rem 0.5rem;
  border-radius: 999px;
  background-color: var(--accent-soft);
  color: var(--accent);
  white-space: nowrap;
}

.pub-list,
.course-list,
.card-list {
  padding-left: 1.1rem;
  margin: 0;
  font-size: 0.95rem;
}

.pub-list li + li,
.course-list li + li,
.card-list li + li {
  margin-top: 0.5rem;
}

.card-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1.1rem;
  margin-top: 0.3rem;
}

.card {
  background-color: var(--bg-alt);
  border-radius: 12px;
  border: 1px solid var(--border);
  padding: 1rem 1.1rem;
}

.card h3 {
  margin: 0 0 0.4rem;
  font-size: 1rem;
}

.card .tagline {
  font-size: 0.88rem;
  color: var(--muted);
  margin-bottom: 0.35rem;
}

.card .why {
  font-size: 0.9rem;
  margin-top: 0.4rem;
}

.cv-link {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  margin-top: 0.7rem;
  padding: 0.45rem 0.85rem;
  border-radius: 999px;
  border: 1px solid var(--accent);
  font-size: 0.88rem;
  text-transform: uppercase;
  letter-spacing: 0.12em;
}

.cv-link:hover,
.cv-link:focus {
  background-color: var(--accent);
  color: #ffffff;
  text-decoration: none;
}

/* External profiles horizontal layout */

.external-links {
  display: flex;
  flex-wrap: wrap;
  gap: 1.5rem;
  font-size: 1rem;
  margin-bottom: 1rem;
}

.external-links a {
  border-bottom: 1px solid transparent;
}

.external-links a:hover,
.external-links a:focus {
  border-color: var(--accent);
  text-decoration: none;
}

/* On My Mind */

.post-list {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1.1rem;
}

.post {
  background-color: var(--bg-alt);
  border-radius: 12px;
  border: 1px solid var(--border);
  padding: 1rem 1.1rem;
}

.post-meta {
  font-size: 0.8rem;
  color: var(--muted);
  text-transform: uppercase;
  letter-spacing: 0.12em;
  margin-bottom: 0.3rem;
}

.post h3 {
  margin: 0 0 0.4rem;
  font-size: 1rem;
}

/* Contact */

.contact-grid {
  display: grid;
  grid-template-columns: minmax(0, 1.6fr) minmax(0, 1.4fr);
  gap: 2rem;
}

.contact-block {
  font-size: 0.95rem;
}

.contact-block h3 {
  margin: 0 0 0.4rem;
  font-size: 0.95rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.12em;
  color: var(--muted);
}

.contact-block p {
  margin: 0.1rem 0;
}

/* Footer */

footer {
  border-top: 1px solid var(--border);
  padding: 1.2rem 0 1.8rem;
  font-size: 0.85rem;
  color: var(--muted);
  text-align: center;
}

/* Responsive */

@media (max-width: 768px) {
  .top-nav {
    flex-direction: column;
    align-items: flex-start;
  }

  .nav-links {
    font-size: 0.85rem;
  }

  .hero,
  .hero-reversed {
    grid-template-columns: minmax(0, 1fr);
  }

  .hero-photo-wrap {
    justify-content: flex-start;
  }

  .two-column,
  .contact-grid {
    grid-template-columns: minmax(0, 1fr);
  }
}