如何删除边框和内部内容之间的空间？

Question

This is from Firefox, and there is no spaceThis is from Android Chrome, and there is no spaceAnd this is from Chrome, and there is space

Here is the white space
i have added green color section code and white box code also

.details section:last-child {
    position: absolute;
    flex-direction: row;
    display: flex;
    width: 100%;
    bottom: 0px;
}

and below is the CSS code

.channel {
    border: 1px solid rgba(130, 130, 130, 0.8);
    margin-bottom: 20px;
    position: relative;
    border-radius: 4px;
    margin-left: 20px;
    height: 266px;
    width: 260px;
}

Answer 1

Have you tried to set the padding to 0px as it is what (should) define the space between the inner content and the border as you can see here when you hit F12 (at least on firefox).

You could do it by adding the following line to your CSS code:

padding: 0px;