#container {
    /* Grid layout */
    grid-template-columns:repeat(8, 100px); /* 8 times 100 */
    grid-template-rows:repeat(8, 100px); /* 20 rows all 100px each*/
}

/* Really stupid thing abt the span thing. The final row/columns needs to be +1. Cuz its "end before"*/
#c1 { /*  */
    grid-column:1 / 9;
    grid-row:3 / 5;
}