How can i set thickness of horizontal rule in html

Question

How can I set thickness of a horizontal rule in html/CSS

Answer 1

.cool_line{ 
    display:block;
    border:none;
    color:white;
    height:1px;
    background:lightgray;
    background: -webkit-gradient(radial, 50% 50%, 0, 50% 50%, 350, from(lightgray), to(#fff));
}

Begin

<hr class='cool_line' />

End