body {
  font-family: sans-serif;
  margin: 0;
  padding: 0;
  background-color: #f5f9f9; /* light background */
  color: #333;
}
header {
  background-color: #2c3e50; /* dark header */
  color: #ecf0f1;
  padding: 1rem;
  text-align: center;
}
header h1 {
  margin: 0.5rem 0;
}
.controls {
  margin-top: 0.5rem;
}
#search {
  padding: 0.5rem;
  width: 60%;
  max-width: 300px;
  margin-right: 1rem;
}
#yearFilter {
  padding: 0.5rem;
}
main {
  padding: 1rem;
}
.year-section {
  margin-bottom: 2rem;
}
.year-section h2 {
  border-bottom: 2px solid #bdc3c7;
  padding-bottom: 0.5rem;
}
.talk-card {
  background-color: #ffffff;
  margin: 1rem 0;
  padding: 1rem;
  border-left: 5px solid #2980b9; /* blue accent */
}
.talk-card h3 {
  margin-top: 0;
}
.talk-card a {
  color: #2980b9;
  text-decoration: none;
}
.talk-card a:hover {
  text-decoration: underline;
}
.talk-card .date {
  font-size: 0.9rem;
  color: #7f8c8d;
}
.talk-card .speakers {
  margin: 0.5rem 0;
}
.talk-card .tags {
  font-size: 0.9rem;
  color: #8e44ad;
}
@media (max-width: 600px) {
  #search {
    width: 100%;
    max-width: none;
    margin: 0 0 0.5rem 0;
  }
  .controls {
    display: flex;
    flex-direction: column;
    align-items: center;
  }
  .talk-card {
    padding: 0.8rem;
  }
}