Reset Css Styles For A Div And All Nested Elements

How can I reset all styles for only a div and all nested elements? I have tried all the below solutions, but none of them are working for me. What am I doing wrong? I have tried us

Solution 1:

You haven't asssigned reset-this class to any div. assign reset-this class to remove-all-styles class div

<div class="dashBackgroundColor">
        <div class="remove-all-styles reset-this">
            <form id="form1" runat="server">
            <div>
                <span>testing</span>
            </div>
            </form>
        </div>
    </div>