body {
  font-family: Arial, sans-serif;
  background: #f4f4f4;
  margin: 0;
  padding: 0;
}

header {
  background: #24292e;
  color: white;
  padding: 20px;
  text-align: center;
}

.filters {
  margin-top: 10px;
}

.filter-btn {
  margin: 5px;
  padding: 8px 14px;
  border: none;
  cursor: pointer;
  background: #58a6ff;
  color: white;
  border-radius: 5px;
}

.events {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 20px;
  padding: 20px;
}

.event-card {
  background: white;
  padding: 15px;
  border-radius: 8px;
  box-shadow: 0 2px 10px rgba(0,0,0,0.1);
}

.event-card h3 {
  margin: 0 0 10px;
}

.event-card button {
  background: #1f883d;
  padding: 8px 12px;
  border: none;
  color: white;
  border-radius: 5px;
  cursor: pointer;
}