select button on cards in library view

app/renderer/style.css

@@ -214,8 +214,10 @@ kbd {
 }
 .guide-card {
   position: relative;
-  padding: 14px;
-  min-height: 116px;
+  padding: 16px;
+  min-height: 168px;
+  display: flex;
+  flex-direction: column;
   border: 1px solid var(--border);
   border-radius: var(--radius);
   background: var(--panel);
@@ -223,10 +225,15 @@ kbd {
   cursor: pointer;
 }
 .guide-card:hover { border-color: color-mix(in srgb, var(--accent) 50%, var(--border)); }
+.guide-card.selectable { padding-left: 40px; }
+.guide-card.selected {
+  border-color: var(--accent);
+  background: color-mix(in srgb, var(--accent) 8%, var(--panel));
+}
 .guide-card h4 {
   margin: 0 0 8px;
-  font-size: 14px;
-  line-height: 1.25;
+  font-size: 15px;
+  line-height: 1.3;
   padding-right: 22px;
   word-break: break-word;
 }
@@ -261,9 +268,39 @@ kbd {
   opacity: 1;
   color: #f5a524;
 }
-.guide-card .muted { font-size: 12px; }
+.guide-card .select-check {
+  position: absolute;
+  top: 14px;
+  left: 14px;
+  width: 16px;
+  height: 16px;
+  cursor: pointer;
+}
+.guide-card .muted { font-size: 12px; margin-top: auto; padding-top: 8px; }
 .guide-card .snippet,
 .qa-item .snippet { color: var(--muted); }
+.guide-card .snippet {
+  margin: 0 0 8px;
+  font-size: 12px;
+  line-height: 1.4;
+  display: -webkit-box;
+  -webkit-line-clamp: 3;
+  -webkit-box-orient: vertical;
+  overflow: hidden;
+}
+
+.bulk-bar {
+  display: flex;
+  align-items: center;
+  gap: 8px;
+  flex-wrap: wrap;
+  padding: 8px 12px;
+  margin-bottom: 12px;
+  border: 1px solid var(--border);
+  border-radius: var(--radius);
+  background: var(--panel-2);
+}
+.bulk-bar .spacer { flex: 1; }
 
 .empty-state {
   padding: 60px 20px;