.background {
  background-image: url(img/858520.jpg);
  position: absolute;
    left: 0;
    top: 0;
    width: 100%;
    height: auto;
    
}

.main{
    text-align: center;
    width: 50%;
    margin: auto;
}
/* nav head */
.nav{
    opacity: 0.8;
    border-radius: 10px;
    height: 100px;
    background-color: white;
    padding: 20px;
    text-align: center;
    box-shadow: 0 10px 22px rgba(0,0,0,0.09), 0 10px 10px rgba(0,0,0,0.09);
}
.headimgl{
    height: 100%;
    float: left;
    margin-left: 60px;
    margin-right: -120px;
}
.headimgr{
    height: 100%;
    float: right;
    margin-right: 60px;
    margin-left: -120px;
}

/* in */

#txt-input{
    opacity: 0.6;
    border-radius: 10px;
    height: 130px;
    padding: 20px;
    margin-top: 40px;
    width: 50%;
    border: 2px solid black;
    box-shadow: 0 10px 22px rgba(0,0,0,0.09), 0 10px 10px rgba(0,0,0,0.09);
}

/* button */

button{
    color: white;
    padding: 10px;
    width: 250px;
    margin-top: 20px;
    background-color: black;
    font-weight: 600;
}
button:hover{
    background-color: red;
}
/* out div */
#output{
    opacity: 0.6;
    border-radius: 10px;
    color: black;
    margin: auto;
    margin-bottom: 20px;
    background-color: white;
    height: 130px;
    width: 50%;
    border: 3px solid black;
    margin-top: 10px;
    padding: 20px;
    box-shadow: 0 10px 22px rgba(0,0,0,0.09), 0 10px 10px rgba(0,0,0,0.09);
}

/* Responsive */

@media only screen and (min-width: 600px){
    
    .main{
        text-align: center;
        width: 70%;
        margin: auto;
        
    }
      
}