xP: indicate hidden buffer lines

xP/public/xP.css

@@ -43,6 +43,9 @@ body {
 	bottom: -1px;
 	background: #ccc;
 }
+button {
+	font: inherit;
+}
 
 .middle {
 	flex: auto;
@@ -111,9 +114,8 @@ body {
 	font-weight: bold;
 }
 .unread {
-	height: 1px;
 	grid-column: span 2;
-	background: #ff5f00;
+	border-top: 1px solid #ff5f00;
 }
 .time {
 	padding: .1em .3em;
@@ -121,6 +123,13 @@ body {
 	color: #bbb;
 	border-right: 1px solid #ccc;
 }
+.time.hidden:after {
+	border-top: .2em dotted #ccc;
+	display: block;
+	width: 50%;
+	margin: 0 auto;
+	content: "";
+}
 .mark {
 	padding-right: .3em;
 	text-align: center;