feat: Switch header image to webp

* This also makes footer inclusion optional

app/scss/ila.scss

@@ -20,7 +20,7 @@ $danger: #d9534f;
 
 
 header.microblog {
-	background: top / cover no-repeat url('/static/header-3-2.png');
+	background: top / cover no-repeat url('/static/header-3-2.webp');
 	margin: 0 0 15px;
 	padding: 0 15px 3em;
 	font-size: 1.15em;
@@ -301,6 +301,15 @@ nav.flexbox {
 * Admin pages
 */
 
+.login {
+	margin: 5em auto;
+	max-width: 25em;
+	background: $background;
+	border: 1px solid $border;
+	padding: 2em 2em calc(2em - 10px);
+	text-align: center;
+}
+
 .notification.new {
 	background: #5cb85c20;
 }

data/templates/layout.html

@@ -53,7 +53,9 @@
         </div>
     {% endif %}
     {% block content %}{% endblock %}
-    {% include "footer.html" %}
+    {% block footer %}
+        {% include "footer.html" %}
+    {% endblock %}
 </div>
 {% if is_admin %}
 <script src="{{ BASE_URL }}/static/common-admin.js?v={{ JS_HASH }}"></script>

data/templates/login.html

@@ -0,0 +1,23 @@
+{%- import "utils.html" as utils with context -%}
+{% extends "layout.html" %}
+
+{% block head %}
+    <meta name="robots" content="noindex, nofollow">
+{% endblock %}
+
+{% block content %}
+<div class="login">
+    {% if error %}
+        <p class="primary-color">Invalid password.</p>
+    {% endif %}
+    <form class="form" action="{{ BASE_URL }}/admin/login" method="POST">
+        <input type="hidden" name="csrf_token" value="{{ csrf_token }}">
+        <input type="hidden" name="redirect" value="{{ redirect }}">
+        <p><input type="password" placeholder="password" name="password" autofocus class="form-control" /></p>
+        
+        <p><input type="submit" value="login" class="btn btn-primary" /></p>
+    </form>
+</div>
+{% endblock %}
+
+{% block footer %}{% endblock %}