style.css

*{
    margin: 0;
    padding: 0;
}
body{
    height: 100vh;
    background-image: linear-gradient(white,#415b71);
}
.logo{
    display: flex;
    justify-content: center;
    align-items: center;
    margin-bottom: 1px;
}
h1{
    font-style: italic;
    font-size: 60px;
}
#img{
    height: 100px;
    margin-right: 15px;
}
.container{
   border: 4px solid black;
   border-radius: 10px;
   max-width: 955px;
   margin: auto;
   height: 60vh;
   padding: 33px;
   overflow-y: auto;
   margin-bottom: 20px;
}
.message{
    font-family: 'Lucida Sans', 'Lucida Sans Regular', 'Lucida Grande', 'Lucida Sans Unicode', Geneva, Verdana, sans-serif;
    font-weight: 400;
    width:24%;
    padding: 10px;
    margin: 17px 12px;
}
.right{
    background-color: #7c7c7c;
    float: right;
    clear: both;
    border: 2px solid black;
    border-radius: 10px;
}
.left{
    background-color: #7c7c7c;
    float: left;
    clear: both;
    border: 2px solid black;
    border-radius: 10px;
}
.center{
    width: 97%;
    text-align: center;
    clear: both;
    font-family: 'Lucida Sans', 'Lucida Sans Regular', 'Lucida Grande', 'Lucida Sans Unicode', Geneva, Verdana, sans-serif;
    font-weight: bold;
    font-style: italic;
    margin: 0;
}
#form{
    display: flex;
    justify-content: center;
    align-items: center;
    margin: auto;
    text-align: center;
    max-width: 1035px;
    width: 100%;
}
#input{
    width: 80%;
    border: 2px solid black;
    border-radius: 6px;
    height: 34px;
    font-size: 20px;
    font-family: 'Lucida Sans', 'Lucida Sans Regular', 'Lucida Grande', 'Lucida Sans Unicode', Geneva, Verdana, sans-serif;
    font-weight: 400;
}
.btn{
    background-color: black;
    color: white;
    font-weight: bold;
    margin: 10px;
    width: 7%;
    cursor: pointer;
    border: 2px solid black;
    border-radius: 8px;
    height:34px;
}
.btn:active{
    background-color: #343646;
}