h1 {
  color: green;
  text-align: center; 
}

.tabs {
  overflow: hidden;
  border: 1px solid #ccc;
  background-color: #f1f1f1;
}

.tabs button {
  background-color: inherit;
  float: left;
  border: none;
  outline: none;
  cursor: pointer;
  padding: 14px 16px;
  transition: 0.3s;
  font-size: 17px;
}

.tabs button:hover {
  background-color: #ddd;
}

.tabs button.active {
  background-color: #ccc;
}

.tab {
  padding: 6px 12px;
  border: 1px solid #ccc;
  border-top: none;
}
.hidden {
  display: none;
}