.box_404{
   display: flex;
   flex-direction: column;
   align-items: center;
   justify-content: start;
   height: 500px;
}

.box_404 > p {
  font-size: 3em;
  text-align: center;
  font-weight: 100;
}

.box_404 > h2 {
  text-align: center;
  font-size: 10em;
  font-weight: 100;
}