Use html input to send http request to change PHP SESSION variable

I have an html table which I want to have a night mode and a day mode. I've built a very basic example of what I'm trying to do below. The boxes in this table will have different colors depending on whether their class is set to "condition_night" or "condition_day". The page will refresh quite often so I'm trying to use the php SESSION object to keep the mode of the page across refreshes. See snippet

<?php

session_start();




    if(isset($_SESSION['MODE']) && $_SESSION['MODE'] === 'night'){
        $mode = 'night';
        } else {
            $mode = 'day';
        };

?>
<style>
    .condition_night {
        background-color: grey;
        color: black;
    }
    .condition_day {
        background-color: blue;
        color: white;
    }
    
</style>
<table>
    <thead>
        <tr>
            <th class="condition_<?=$mode;?>">Person</th>
            <th class="condition_<?=$mode;?>">Score</th>
        </tr>
    </thead>
    <tbody>
        <tr>
            <td>James</td>
            <td>100%</td>
        </tr>
    </tbody>
    
</table>


<input type="button" name="night_mode" class="btn btn-secondary" value="Night Mode" onclick="change_session_day.php;" data-dismiss="modal" style="width: 170px;margin-top: 5px;margin-bottom: 5px;"/>
                        
<input type="button" name="day_mode" class="btn btn-secondary" value="Day Mode" onclick="change_session_day.php;" data-dismiss="modal" style="width: 170px;margin-top: 5px;margin-bottom: 5px;"/>

I am fully aware that the buttons at the bottom of the page won't work I've put them there as an example of what I'm trying to achieve. Is there a way to make the buttons call a separate php script on another page which will change the SESSION['MODE'} variable, then refresh the page so that the new colors are apparent?

The script on the php page would go along the lines of See Snippet

<?php
    
    session_start();
    $_SESSION['MODE']="day";

   //Refresh page here
?>