.arkaplan{
   background-color: gray;
   border-radius: 15px;
   margin: 50px 800px;
   text-align: center;
   height: 350px;
}
.un{
   margin: 0px 30px;
   padding: 0px 20px;
   color: darkgrey;
   text-decoration: none;
}
.un:hover{
   color: blue;
}
.giris{
   background-color: red;
   color: white;
   border-radius: 15px;
   padding: 10px 10px;
   text-decoration: none;

}