Add remaining parts of core template structure

breccia_mapper/static/css/masthead.css

@@ -0,0 +1,39 @@
+header.masthead {
+    position: relative;
+    background: #343a40 no-repeat center;
+    -webkit-background-size: cover;
+    -moz-background-size: cover;
+    -o-background-size: cover;
+    background-size: cover;
+    padding-top: 8rem;
+    padding-bottom: 8rem;
+    min-height: 200px;
+    height: 60vh;
+    z-index: -2;
+}
+
+header.masthead .overlay {
+    position: absolute;
+    background-color: #212529;
+    height: 100%;
+    width: 100%;
+    top: 0;
+    left: 0;
+    opacity: 0.4;
+    z-index: -1;
+}
+
+header.masthead .textbox-container {
+    background-color: rgba(30, 30, 30, 0.2);
+}
+
+@media (min-width: 768px) {
+    header.masthead {
+        padding-top: 1rem;
+        padding-bottom: 12rem;
+    }
+
+    header.masthead h1 {
+        font-size: 3rem;
+    }
+}