Hello Jose, Congratulations on finishing this challenge!
For your .creation-items is not necessary create a class for every element like you do (.creation-item-one, .creation-item-two, etc), the pseudo class :nth-of-type will make this easy for you and help to maintain the html code cleaner.
About the hover effect, your .creation-item:hover::before is ok but you need to create first a .creation-item:before, like this:
.creation-item:before{
content: "";
position: absolute;
top: 0;
left: 0;
width: 0;
height: 100%;
background: rgba(255, 255, 255);
opacity: .7;
transition: all .2s ease-in-out;
cursor: pointer;
}
.creation-item:hover::before {
content: '';
position: absolute;
width: 100%;
}
This one make the transition go from left to right because .creation-item:before width is set to 0 and your .creation-item:hover::before has a widht set to 100%.
U can also set the width to 100%, height to 0% in the.creation-item:before and height to 100% in the .creation-item:hover::before and this will make the transition go from top to bottom.