Rework everything

www/res/style.css

@@ -1,6 +1,48 @@
 
-html {
+:root {
     font-family: 'Arial', sans-serif;
+    box-sizing: border-box;
+}
+
+body {
+    margin: 3em 0 0 0;
+}
+
+header {
+    position: fixed;
+    top: 0;
+    width: 100%;
+    height: 3em;
+    border-bottom: 1px solid #C0C0C0;
+    background-color: #FFFFFF;
+}
+
+header img {
+    height: 2.5em;
+    margin: 0.25em;
+}
+
+nav {
+    height: 100%;
+}
+
+nav ul {
+    display: flex;
+    list-style-type: none;
+    margin: 0;
+    padding: 0;
+    justify-content: center;
+    align-items: center;
+    height: 100%;
+}
+
+nav li {
+
+}
+
+nav li a {
+    text-decoration: none;
+    padding: 1em;
 }
 
 table td {