How to make gradual colour change when hover with CSS?
<p>I'm trying to make a gradual background colour change from normal to a hover colour, but, unfortunately, everything I've read and tried didn't work. This is the code I have:</p>

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<pre class="snippet-code-css lang-css prettyprint-override"><code>.button-submit {
     color: #ffffff;
     cursor: pointer;
     display: inline-block;
     line-height: 35px;
     background: #5ea12b;
     padding: 0px 20px;
     vertical-align: middle;
     font-size: 18px;
     min-width: 80px;
     min-height: 35px;
     font-family: Light;
     border: 1px solid transparent;
     margin: 5px;
}
.button-submit:hover {
     background: #5ea12b;
     color: #FFFFFF;
}</code></pre>
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