/* Global */
body {
  font-family: 'Roboto', Arial, sans-serif;
  margin: 0;
  padding: 0;
  color: #333;
  background-color: #f9f9f9;
}

a {
  color: #1a4f8b;
}

/* Header */
header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 1rem 2rem;
  background-color: #f8f9fa;
  border-bottom: 1px solid #e0e0e0;
}

.logo {
  font-size: 1.5rem;
  font-weight: 700;
  color: #333;
}

nav ul {
  list-style: none;
  display: flex;
  gap: 2rem;
  margin: 0;
  padding: 0;
}

nav ul li a {
  text-decoration: none;
  color: #333;
  font-weight: 500;
  position: relative;
}

nav ul li a:hover {
  color: #555;
}

nav ul li a.active::after {
  content: "";
  display: block;
  width: 100%;
  height: 2px;
  background-color: #333;
  position: absolute;
  bottom: -3px;
  left: 0;
}

/* Main */
main {
  max-width: 1000px;
  margin: 2rem auto;
  padding: 0 1rem;
}

/* Home page: sidebar + content */
main.home {
  display: flex;
  gap: 2rem;
}

.sidebar {
  flex: 1;
  text-align: center;
}

.sidebar img {
  width: 200px;
  height: 200px;
  border-radius: 20px;
  margin: 0 auto 1rem auto;
  object-fit: cover;
  display: block;
}

.social-links {
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
  text-align: left;
  max-width: 250px;
  margin: 0 auto;
}

.social-links a {
  display: flex;
  align-items: center;
  color: #333;
  text-decoration: none;
}

.social-links a i {
  width: 1.25rem;
  margin-right: 0.5rem;
  text-align: center;
}

.email-link {
  font-size: 0.85rem;
  overflow-wrap: anywhere;
}

/* CONTENT (Right) */
.content {
  flex: 2;
}

.content h2 {
  margin-top: 0;
  margin-bottom: 1rem;
  font-size: 1.5rem;
  text-align: center;
}

.content p {
  margin-bottom: 1rem;
  line-height: 1.6;
  text-align: justify;
}

/* Research & teaching */
.page-title {
  font-size: 2rem;
  font-weight: 500;
  margin-bottom: 1.5rem;
}

.section-heading {
  font-size: 1.5rem;
  margin-top: 2rem;
  margin-bottom: 1rem;
  font-weight: 500;
}

.paper-entry,
.course-entry {
  border-top: 1px solid #ccc;
  padding: 1rem 0;
}

.paper-title,
.course-title {
  font-size: 1.2rem;
  font-weight: 600;
}

.paper-title a {
  color: #333;
}

.paper-title a:hover {
  color: #555;
}

.paper-subtitle,
.course-details {
  font-size: 0.95rem;
  font-style: italic;
  color: #555;
  margin-top: 0.25rem;
}

.paper-note,
.paper-status {
  font-size: 0.9rem;
  color: #555;
  margin-top: 0.25rem;
}

.paper-status {
  color: #666;
}

.paper-award {
  font-size: 0.95rem;
  color: #8a5a00;
  margin-top: 0.25rem;
}

details {
  margin-top: 0.5rem;
}

details summary {
  font-weight: 500;
  font-size: 0.95rem;
  cursor: pointer;
}

details summary:hover {
  color: #555;
}

.paper-content {
  margin-top: 0.5rem;
  font-size: 0.95rem;
  color: #444;
}

.paper-content p {
  text-align: justify;
  hyphens: auto;
  line-height: 1.6;
}

.paper-content ul {
  margin: 0.25rem 0 0;
  padding-left: 1.25rem;
  line-height: 1.6;
}

.paper-links {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  margin-top: 0.75rem;
}

.round-button {
  display: inline-block;
  padding: 0.3rem 0.9rem;
  border: 1px solid #333;
  border-radius: 999px;
  color: #333;
  font-size: 0.85rem;
  text-decoration: none;
}

.round-button:hover {
  background-color: #333;
  color: #fff;
}

/* Footer */
footer {
  text-align: center;
  padding: 1rem;
  margin-top: 3rem;
  background-color: #f8f9fa;
  color: #777;
  border-top: 1px solid #e0e0e0;
}

/* Tablets */
@media (max-width: 768px) {
  header {
    flex-direction: column;
    align-items: flex-start;
  }

  nav ul {
    gap: 1.25rem;
    margin-top: 0.75rem;
  }

  main.home {
    flex-direction: column;
    gap: 1.5rem;
  }

  .paper-title,
  .course-title {
    font-size: 1.1rem;
  }
}

/* Phones */
@media (max-width: 480px) {
  header {
    padding: 1rem;
  }

  .sidebar img {
    width: 150px;
    height: 150px;
  }

  .page-title {
    font-size: 1.6rem;
  }

  .section-heading {
    font-size: 1.25rem;
  }
}