body {
  margin: 0;
  font-family: sans-serif;
  background: #222;
  color: white;
  display: flex;
  flex-direction: column;
  height: 100vh;
}
header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  background: #333;
  padding: 10px 20px;
  font-size: 1.5em;
  transition: background-color 0.3s ease;
}
header a {
  color: white;
  text-decoration: none;
  font-size: 0.8em;
  padding: 5px 10px;
  border: 1px solid white;
  border-radius: 5px;
}
.scoreboard {
  text-align: center;
  flex: 0;
}
.game-container {
  display: flex;
  flex: 1;
}
.city {
  flex: 1;
  background-size: cover;
  background-position: center;
  position: relative;
  display: flex;
  justify-content: center;
  align-items: center;
  cursor: pointer;
  transition: transform 0.3s ease;
}
.overlay {
  background-color: rgba(0,0,0,0.5);
  padding: 20px;
  border-radius: 10px;
  text-align: center;
}
.city-name { font-size: 2em; font-weight: bold; }
.country-name { font-size: 1.2em; }
.population-display {
  position: absolute;
  top: 10%;
  font-size: 1.2em;
  background: rgba(0,0,0,0.7);
  padding: 5px 10px;
  border-radius: 5px;
  display: none;
}
.end-screen {
  position: absolute;
  top:0;
  left:0;
  width:100%;
  height:100%;
  background: rgba(0,0,0,0.95);
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  font-size: 2em;
  color: white;
  z-index: 10;
  display: none;
}
button {
  margin-top: 20px;
  padding: 10px 20px;
  font-size: 1em;
}