р SMALL LETTER ER UTF-8 character with hex code 0440

Using HEX code of SMALL LETTER ER in HTML file

<span> &#x0440; </span>

Using Decimal code of SMALL LETTER ER in HTML file

<span> &#1088; </span>

Using HEX code of SMALL LETTER ER in CSS file for content

span { 
    content: '\0440';
}