mcalc/styles.css

#calculator {
	display: grid;
	grid-template-columns: repeat(4, 1fr);
}

label[for="expr"] {
	display: none;
}

#expr {
	grid-column: 1 / 5;
}

#result {
	grid-column: 1 / 4;
	border: 1px solid gray;
	text-align: right;
}

#modulus-entry {
	grid-column: 4;
	display: flex;
}

#modulus-entry label {
	flex: initial;
}

#modulus {
	flex: auto;
}

#extra-buttons {
	grid-column: 1 / 5;
	display: grid;
	grid-template-columns: subgrid;
}

#main-buttons {
	grid-column: 1 / 5;
	display: grid;
	grid-template-columns: subgrid;
}

#numerals {
	grid-column: 1 / 4;
	display: grid;
	grid-template-columns: subgrid;
}

#operators {
	grid-column: 4;
	grid-row: 1 / 3;
	display: grid;
	grid-template-columns: subgrid;
}