Unable to edit “Continue reading” button

I’m hoping to edit the Continue reading button inserted by a more tag from the default to something more suited.

In style.css I’ve added the following:

article.post .more-link,
article.page .more-link {
    float: right;
    text-decoration: none;
    padding: 4px 10px;
    border-width: 0px;
    border-style: solid;
    border-color: transparent;
    background: transparent;
    border-radius: 0px;
    font-size: 20px;
    font-weight: bold;
    color: #323232;
}

However this is not taking effect and the default parent theme style continue reading button still displays.

Any idea what’s happening here?