diff -r e66bd5c563eb -r b5b5583a3a08 progs/pprint/style.css
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/progs/pprint/style.css	Thu Jul 30 13:50:54 2020 +0100
@@ -0,0 +1,99 @@
+@media print {
+  @page { margin: 0; }
+  body { margin: 1.6cm; }
+}
+
+
+body {
+  font-family: Calibri, Segoe, "Segoe UI", "Gill Sans", "Gill Sans MT", sans-serif;
+}
+
+/* It's supposed to look like a tree diagram */
+.tree, .tree ul, .tree li {
+    list-style: none;
+    margin: 0;
+    padding: 0;
+    position: relative;
+}
+
+.tree {
+    margin: 0 0 1em;
+    text-align: center;
+}
+.tree, .tree ul {
+    display: table;
+}
+.tree ul {
+  width: 100%;
+}
+    .tree li {
+        display: table-cell;
+        padding: .5em 0;
+        vertical-align: top;
+    }
+        /* _________ */
+        .tree li:before {
+            outline: solid 1px #666;
+            content: "";
+            left: 0;
+            position: absolute;
+            right: 0;
+            top: 0;
+        }
+        .tree li:first-child:before {left: 50%;}
+        .tree li:last-child:before {right: 50%;}
+
+        .tree code, .tree span {
+            border: solid .1em #666;
+            border-radius: .2em;
+            display: inline-block;
+            margin: 0 .2em .5em;
+            padding: .2em .5em;
+            position: relative;
+        }
+        /* If the tree represents DOM structure */
+        .tree code {
+            font-family: monaco, Consolas, 'Lucida Console', monospace;
+        }
+
+            /* | */
+            .tree ul:before,
+            .tree code:before,
+            .tree span:before {
+                outline: solid 1px #666;
+                content: "";
+                height: .5em;
+                left: 50%;
+                position: absolute;
+            }
+            .tree ul:before {
+                top: -.5em;
+            }
+            .tree code:before,
+            .tree span:before {
+                top: -.55em;
+            }
+
+/* The root node doesn't connect upwards */
+.tree > li {margin-top: 0;}
+    .tree > li:before,
+    .tree > li:after,
+    .tree > li > code:before,
+    .tree > li > span:before {
+      outline: none;
+    }
+
+
+/* Create two equal columns that floats next to each other */
+.column {
+  float: left;
+  width: 40%;
+  padding: 10px;
+}
+
+/* Clear floats after the columns */
+.row:after {
+  content: "";
+  display: table;
+  clear: both;
+}