Clear the gap between unordered lists ul and li in static pages

I wrote a static web page and found that there is an unclear line spacing between ul and li

my css code is as follows

.article ul{
    margin: 17px;
    padding: 5px;
    line-height: 3px;
}
.article ol{
    margin: 17px;
    padding: 5px;
    line-height: 3px;
}
.article li{
    line-height: 3px;
}

my HTML code is as follows

<ul>
<li>Title
<ul>
<li><u>Letter 1</u>
<ul>
<li><u>A</u>
<ul>
<li>Aa, Aaa</li>
</ul></li>
<li><u>B</u>
<ul>
<li>Bb, Bbb</li>
</ul></li>
<li><u>C</u>
<ul>
<li>Cc</li>
</ul></li>
</ul></li>
<li><u>Letter 2</u>
<ul>
<li>Dd</li>
</ul></li>
<li><u>Letter 3</u>
<ul>
<li>Ee</li>
</ul></li>
The picture shown in

Chrome is like this. Now I want to clear the line spacing between Cc and Letter 2. Thanks for your help!

Sep.25,2021

is your .article the outermost ul? Your ul also contains ul, but your style. Article ul is like this, so that all ul will have a padding: 5px, resulting in the gap between you

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