html {
    height: 100%;
  }
  body {
    height: 100%;
    width: 100%;
  }
#fő_container {
  display: flex;
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  width: 400px;
}
#container h3{
  align-items: center;
  justify-content: center;
  margin-left: 20px;
  margin-bottom: 15px;
}
#input button {
  margin-top: 15px;
  width: 200px;
  margin-left: 100px;
}
#input input {
  width: 400px;
}
.loader {
  border: 6px solid aliceblue; /* Light grey */
  border-top: 6px solid #ffc107; /* Blue */
  border-radius: 50%;
  width: 50px;
  height: 50px;
  animation: spin 2s linear infinite;
  margin-top: 30px;
  margin-left: 175px;
}

@keyframes spin {
  0% { transform: rotate(0deg); }
  100% { transform: rotate(360deg); }
}