+/*\
+|*|
+|*| Overall page layout
+|*|
+|*| Assumes: Top-level div with id="page" for all content
+|*|
+\*/
+
+/* Mobile-first: At small sized we have a white background and use the
+ * entire screen width for the page (so the background color of the
+ * body is not visible anywhere). */
+body {
+ background-color: #333738;
+}
+
+#page {
+ background-color: white;
+}
+
+/* We never let the page content get larger than a large fixed width.
+ *
+ * And when the screen is wide enough, we can afford some "wasted"
+ * space on either side of the page content. This starts at 0 for a
+ * 620px wide page up to 50px on either side for a 720px wide page.
+ *
+ * Wider than that and we start to see the background on either side
+ * of the page content.
+ */
+#page {
+ box-sizing: border-box;
+ max-width: 720px;
+ margin-left: auto;
+ margin-right: auto;
+ padding-top: 0;
+ padding-bottom: 0;
+}
+
+@media screen and (min-width: 620px) and (max-width: 720px) {
+ #page {
+ padding-left: calc((100% - 620px)/2);
+ padding-right: calc((100% - 620px)/2);
+ }
+}
+
+@media screen and (min-width: 720px) {
+ #page {
+ padding-left: 50px;
+ padding-right: 50px;
+ }
+}
+
+/* The calculations for height are different. We don't have any
+ * vertical centering, so instead we have only some fixed padding on
+ * the top. Then, the margin which allows the background to be visible
+ * on the top and bottom starts appearing at a viewport height of 648
+ * and tops out at a size of 36px.
+ */
+#page {
+ min-height: 500px;
+ padding-top: 1em;
+}
+
+@media screen and (min-height: 648px) and (max-height: 720px) {
+ #page {
+ margin-top: calc((100vh - 648px)/2);
+ margin-bottom: calc((100vh - 648px)/2);
+ }
+}
+
+@media screen and (min-height: 720px) {
+ #page {
+ margin-top: 36px;
+ margin-bottom: 36px;
+ }
+}
+