.dropdown {
  position: relative;
  margin-left: 50%; 
  margin-right: 50%;
}

.dropdown-menu {
  position: absolute;
  top: 100%;
  right: 0;
  margin-left: 50%; 
  margin-right: 50%;
}

.flex-container {
  display: flex;
  justify-content: space-evenly;
  flex-direction: row;
  flex-wrap: wrap;
  
}

.flex-container > div {
  background-color: #f1f1f1;
  margin: 10px;
  padding: 10px;
}

#title {
  text-align: center;
  font-family: arial, sans-serif;
}

#students {
  text-align: center;
  font-family: "Trebuchet MS", Arial, Helvetica, sans-serif;
  border-collapse: collapse;
  border: 3px solid #ddd;
  width: 100%;
}

#students td, #students th {
  border: 1px solid #ddd;
  padding: 8px;
}

#students tr:nth-child(even){background-color: #f2f2f2;}

#students tr:hover {background-color: #ddd;}

#students th {
  padding-top: 12px;
  padding-bottom: 12px;
  text-align: center;
  background-color: #4CAF50;
  color: white;
}