Add flex-grow rule to overlapping columns block style.

assets/sass/05-blocks/columns/_style.scss

@@ -43,36 +43,40 @@
 
 		@include media(laptop) {
 
-			.wp-block-column:nth-child(2n) {
-				margin-left: calc(-2 * var(--global--spacing-horizontal));
-				margin-top: calc(2.5 * var(--global--spacing-horizontal));
-
-				// Provide text-based child blocks with a default background color to ensure they're readable.
-				> p,
-				> h1,
-				> h2,
-				> h3,
-				> h4,
-				> h5,
-				> h6,
-				> ul,
-				> ol,
-				> pre {
-
-					&:not(.has-background) {
-						background-color: var(--global--color-background);
-						padding: var(--global--spacing-unit);
+			.wp-block-column {
+				flex-grow: 1;
+
+				&:nth-child(2n) {
+					margin-left: calc(-2 * var(--global--spacing-horizontal));
+					margin-top: calc(2.5 * var(--global--spacing-horizontal));
+
+					// Provide text-based child blocks with a default background color to ensure they're readable.
+					> p,
+					> h1,
+					> h2,
+					> h3,
+					> h4,
+					> h5,
+					> h6,
+					> ul,
+					> ol,
+					> pre {
+
+						&:not(.has-background) {
+							background-color: var(--global--color-background);
+							padding: var(--global--spacing-unit);
+						}
 					}
-				}
 
-				// Lists should still have their usual left padding.
-				> ul:not(.has-background),
-				> ol:not(.has-background) {
-					padding-left: calc(2 * var(--global--spacing-horizontal));
-				}
+					// Lists should still have their usual left padding.
+					> ul:not(.has-background),
+					> ol:not(.has-background) {
+						padding-left: calc(2 * var(--global--spacing-horizontal));
+					}
 
-				&.is-vertically-aligned-center {
-					margin-top: 0;
+					&.is-vertically-aligned-center {
+						margin-top: 0;
+					}
 				}
 			}
 		}