@media screen and (min-width: 960px) {
    .opening_message{
        width: 800px;
        margin: 0 auto;
        padding: 2em;
        border-radius:20px;
        background:#20a0ff;
        font-family:"sans-serif";
        justify-content: center;
    }
    h1{
        padding: 20px;
        text-align: center;
        color:#20a0ff;
    }
    .bt1{
        font-size:20px;
        text-align: center;
    }
    .right{
        text-align: right;
    }
    p{
        font-size:30px;
        color:white;
    }
    a{
        text-align: center;
    }        
 }
 
@media screen and (max-width: 480px) {
    .opening_message{
        width: 280px;
        margin: 0 auto;
        padding: 2em;
        border-radius:20px;
        background:#20a0ff;
        font-family:"sans-serif";
        justify-content: center;
    }
    h1{
        font-size:25px;
        padding: 10px;
        text-align: center;
        color:#20a0ff;
    }
    .bt1{
        font-size:15px;
        text-align: center;
    }
    .right{
        text-align: right;
    }
    p{
        font-size:15px;
        color:white;
    }
    a{
        text-align: center;
    }       
}

@media screen and (min-width: 481px) and (max-width: 959px) {
    .opening_message{
        width: 800px;
        margin: 0 auto;
        padding: 2em;
        border-radius:20px;
        background:#20a0ff;
        font-family:"sans-serif";
        justify-content: center;
    }
    h1{
        padding: 20px;
        text-align: center;
        color:#20a0ff;
    }
    .bt1{
        font-size:20px;
        text-align: center;
    }
    .right{
        text-align: right;
    }
    p{
        font-size:30px;
        color:white;
    }
    a{
        text-align: center;
    }      
}