Refresh design for auth and error pages

src/pretix/static/pretixbase/scss/error.scss

@@ -5,16 +5,40 @@
 
 
 body {
-    background: #ececec;
-    text-align: center;
+    background: #fbf7fc;
     padding: 50px 0;
 }
 
 .big-icon {
     font-size: 200px;
-    color: $brand-primary;
+    color: $navbar-inverse-bg;
+    display: block;
+    float: left;
 }
 
-.larger {
-    font-size: 16px;
-}
+.error-details {
+    margin-left: 260px;
+}
+
+.container {
+    width: 90%;
+    max-width: 800px;
+}
+
+.logo {
+    height: 35px;
+    width: auto;
+}
+
+@media(max-width: 600px) {
+    body {
+        text-align: center;
+    }
+    .big-icon {
+        margin: auto;
+        float: none;
+    }
+    .error-details {
+        margin-left: 0;
+    }
+}