If elapsed time is longer than 24 hours then

I calculated the elapsed time and I want to echo it with red font if it's longer than 24 hours. This works if its 24:00:00 but if it turns 25:00:00 it doesn't echo it in red anymore.

How can I fix this ?

This is what I have done:

1. I take the timestamp from the Status table, this is in timestamp format.
2. Then I get the current time from the database.
3. I do strtotime() for both values to assure they have the same format.
4. I subtract the Status time from current time so I get the elapsed time.

5. Then I check if the elapsed time is bigger than 24 hours.

   $timestamp            = $status_row['Time'];
   
       $sql_time_difference    = "SELECT TIMEDIFF(NOW(), '$timestamp') as TimeDiff";
       //echo $sql_time_difference;
       $time_select            = mysqli_query($conn, $sql_time_difference);
       $time_row               = mysqli_fetch_assoc($time_select);    
       $time_difference        = $time_row['TimeDiff'];
   
           //echo $time_difference.'<br>';
   
           $time1  = strtotime($time_difference);
           $time2  = strtotime('24:00:00'); 
   
           if ($time_difference >= $time2){
               echo '<b><font color="red">'.$time_difference.'</font></b>';    
           } else {
               echo $time_difference; 
           }