Overflow-hidden on parent container

Well done, some tips:

To increase the distance between the lines, you can add line-height: 25px; inside your .subtitle (25 was an example, test to see what the ideal value is)

The mobile version is different, you can create it with media query, add this at the end of your CSS (or create another file) and change it to match the proposed design, and the changes will only change on small screens, on the desktop it will remain the same version you already made.

@media screen and (max-width: 425px) {
     #card {
         width: 320px;
         ...
     }

     h1 {
        ...
    }

    /* etc */
}