#red_btn
{
 grid-area: red_button;
 width: 4rem;
 height: 4rem;
 background: linear-gradient(180deg, #ff4d4d, #b30000);
 color: white;                /* text color */
 border: 1px solid #800000;
 box-shadow: 0 4px 8px rgba(0,0,0,0.3);
 margin: 2rem;
 padding: 1rem;
 border-radius: 0.25rem;
 cursor: pointer;
}

#red_btn:hover
{
 background-color: #c62828;   /* darker red on hover */
}

#red_btn:disabled
{
 display: none;
}