Hi there,
takes a little bit of custom CSS work, i can point you in the right direction.
1. Within each column you want to add a Group Block ( which you will move the other blocks inside of ). With the Group Block selected, in the settings sidebar > Advanced > Add an Additional CSS class of: column-group
2. Repeat this for each of the columns. The Group block provides you with the option to change its background color.
3. Add this CSS:
/* Add padding to column group */
.column-group {
padding: 30px;
display: flex;
flex-direction: column;
box-sizing: border-box;
}
/* Force buttons to align to the bottom */
.column-group .wp-block-button {
margin-top: auto;
}