Font weight value is not working properly
<p>I have tried to give a <code>font-weight</code> property to text widgets but it's not working properly, which will show the same bolder appearance for the values 
<code>100,200,300,400 and 500</code> and show a big effect on <code>600</code>. What is this issue? How can I fix it?</p>

<p><div class="snippet" data-lang="js" data-hide="false" data-console="true" data-babel="false">
<div class="snippet-code">
<pre class="snippet-code-css lang-css prettyprint-override"><code>.flip-menu-text {
    text-align: left;
    font-weight: 100;
    line-height: 1.125rem;
    padding: .5625rem 0;
    margin: 0;
    outline: 0;
    border: 0;
    font-size: 14px;
}</code></pre>
<pre class="snippet-code-html lang-html prettyprint-override"><code>&lt;span class="flip-menu-text"&gt;Widgets&lt;/span&gt;</code></pre>
</div>
</div>
</p>