html,  body{
    display: block;
    margin: 0;
    height: 100%;
    overflow: hidden;
    background-color: #d5d5d5;
}
#box{

    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    margin-bottom: -50%;
    margin-right: -50%;
}
img{
    margin-top: 60px;
    display: block;
    max-height: 600px;
    height: auto;
    width: auto;
    margin-left:auto;
    margin-right: auto;
}
@media(max-width: 650px){
  img{
    max-height: 350px;
  }
}
button{
    background-color: white;
    color: black;
    border: 2px solid #555555;
    border-radius:5px;
    padding: 5px 10px;
    text-align: center;
    text-decoration: none;
    display: inline-block;
    font-size: 16px;
    margin: 4px 2px;
    -webkit-transition-duration: 0.4s; /* Safari */
    transition-duration: 0.4s;
    cursor: pointer;
}
button:hover {
    background-color: #999999;
    color: white
}
a{
    text-decoration: none;
}
#visza{
    margin-top: 15px;
    text-align: center;
    clear: both;
}
.row {
    margin-top:720px ;
    position: absolute;
    left: 50%;
    transform: translate(-50%, 0);
    margin-right: -50%;
    clear: both;
    background-color:green;
}
h3, p {
    clear: both;
    width: 100%;
    height: 10px;
    text-align: center;
}
@media (max-width: 767px){
    button{
       font-size: 12px;
    }

}
#gomb{
    text-decoration: none;
    color: #000000; 
}
#gomb: hover{
    color: #ffffff;
    text-decoration: none;
}