body{
    
    padding: 30px;
    
}
ul{
    font-family: Arial, Helvetica, sans-serif;
    font-size: larger;
    text-transform: uppercase;
    letter-spacing: 4px;
    color: black;
    

}
.divpai{

display: flex;
position: relative;
display: flex;
height: 10px;

}
.divfilho{
    height: 30px;  
}
.imgdiv{
   
    justify-content: center;
    text-align: center;
    margin: auto;
    display: flex;
    height: 600px;
}
.mudarcor{
    background-color: blue;
    opacity: 0,2;
    transition: 0,2;
}
#id-do-elemento:hover 

{ background-color: #000000; 

transition: 0.5s;

opacity: 0.7;

}