i’m brand new to html and css, about 3 days but i can’t for the life of me figure out how i remove the boxes around the nav li. even

also my button shapes weird on smaller screens, if you guys have an idea how to fix this would be neat. I’ve searched but can’t find a solution that helps. Thanks!

when i try text-decoration: none; it stays there.

*{
    box-sizing: border-box;
    margin: 0;
    padding: 0;
    background-color: rgba(130, 148, 164, 0.201);
    
}
li,a,button{
    font-family: sans-serif;
    font-weight: 500;
    font-size: 16px;
    color: #ECF0F1;
    text-decoration: none;
}
header{
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 30px 10%;
    
}