Header/Footer: Reorganize logo, tweak positioning.

It was moved to `social-links.pcss` in 64629ca, but fits better in `logos.pcss`.

mu-plugins/blocks/global-header-footer/postcss/footer/footer.pcss

@@ -21,8 +21,4 @@
 		/* Create columns automatically, make them equal widths, wrap when needed. */
 		grid-template-columns: repeat( auto-fit, minmax(150px, 1fr) );
 	}
-
-	& .wp-block-image {
-		text-align: left;
-	}
 }

mu-plugins/blocks/global-header-footer/postcss/footer/logos.pcss

@@ -9,6 +9,10 @@
 		flex-wrap: nowrap;
 	}
 
+	& .wp-block-image {
+		text-align: left;
+	}
+
 	& .site-footer__wporg-logo-mark {
 		flex-basis: 65%;
 
@@ -25,4 +29,27 @@
 			flex-basis: 33%;
 		}
 	}
+
+	& .wp-block-image.site-footer__code_is_poetry {
+		flex-basis: 100%;
+		margin-top: 9px;
+		margin-bottom: 0;
+
+		@media (--tablet) {
+			& img {
+				position: absolute;
+				width: 188px;
+				height: 13px;
+				left: calc(50% - (188px / 2)); /* Align horizontally. Width must match width of the image. */
+
+				/*
+				 * Align vertically with W logo and social links.
+				 * This is intentionally not the exact center, since that wouldn't appear perfectly aligned to
+				 * the human eye. It needs to be a little off-center to appear centered.
+				 * Must match the height of the image.
+				 */
+				top: calc( 13px / 1.5 );
+			}
+		}
+	}
 }

mu-plugins/blocks/global-header-footer/postcss/footer/social-links.pcss

@@ -18,7 +18,6 @@
 	min-width: 100px;
 
 	@media (--tablet) {
-		top: -11px; /* Align with W logo. */
 		justify-content: flex-end;
 		flex-basis: 33%;
 		order: 3;
@@ -28,19 +27,4 @@
 		width: 29px;
 		height: 29px;
 	}
-
-	& .wp-block-image.site-footer__code_is_poetry {
-		flex-basis: 100%;
-		margin-top: 9px;
-		margin-bottom: 0;
-
-		@media (--tablet) {
-			position: absolute;
-			top: 0;
-			left: calc(50% - (188px / 2)); /* Must match width of the image. */
-			width: 188px;
-			height: 13px;
-			margin-top: 3px;
-		}
-	}
 }