Customize WordPress text/html editor area

change_editor_font.php

function change_editor_font(){
    echo "<style type='text/css'>
    #wp-content-editor-container textarea#content {
        font-family: \"Meslo LG M DZ\", Consolas, monospace;
        font-weight: normal;
        font-size: 13px;
        line-height: 1.5em;
        color: #fab00d;
        background-color: #222;
        }
    </style>";
}
add_action("admin_print_styles", "change_editor_font");