Remove underline

I have been using this CSS code:

.tippy_link {
    color: black;
    text-decoration: none;
    font: bold 1em sans-serif;
}

It reformats the normal blue underlined text “(weitere Infos)” to bold and black text. Only the underline is not taken away.

Also in the HTML code, using the same code for it, the underline is not taken away. Although it does work for the text that appears as a popup.

How do I solve this problem?

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