*{
    padding: 0;
    margin: 0;
}
body{
    font-family: Arial, Helvetica, sans-serif;
    background:  skyblue;
}
h3{
    text-align: center;
    color: cadetblue;
}
h3::after{
    content: "";
    display: block;
    width: 200px;
    height: 5px;
    background: currentColor;
    margin: 10px auto;
    border-radius: 50px;
}
.content{
    display: flex;
    justify-content: center;
    align-items: center;
    /*margin-top: 10%;*/
}
.content{
    max-width: 100%;
    max-height: 100%;
    height: 650px;
}
.contato{
    width: 100%;
    max-width: 500px;
}
.form{
    display: flex;
    flex-direction: column;
}
.field{
    padding: 10px;
    margin-bottom: 15px;
    border: 1px solid #DDD;
    border-radius: 5px;
    font-family: Arial, Helvetica, sans-serif;
    font-size: 16px;
}
#sub{
    cursor: pointer;
}
.field:invalid{
    color: red;
}
.field:valid{
    color: #000;
}
textarea{
    height: 150px;
}
@media screen and (max-width: 600px) {
    .contato{
        width: 90%;
    }
}