How to set height of list items in HTML?

You're missing a semicolon :-)

You can also try setting the line-height property of the li tags to change the position of the text in the element:

.line-height-li {
    line-height: 30px;
}

Just increase the padding-top and padding-bottom as you want. Line height effect other. I found out it by testing it. It work for me.