feat: 看板支持A/B组对比下钻 + 全屏 + 删除返回按钮 + 全系统组别(A/B)支持

assets/style.css

@@ -476,3 +476,32 @@ body.fs-on .topbar { padding-top: 8px; padding-bottom: 8px; }
 
 .empty { text-align: center; color: var(--text-3); padding: 40px 0; }
 
+/* 班级卡片：可点击进入该班详情 */
+.class-card.clickable { cursor: pointer; }
+.class-card.clickable:hover { border-color: var(--primary); }
+.grp-tag {
+  display: inline-block; margin-top: 12px; padding: 2px 10px; border-radius: 999px;
+  font-size: 11px; font-weight: 600; color: var(--primary); background: var(--primary-weak);
+}
+
+/* 班级详情头部 */
+.detail-head { display: flex; align-items: center; gap: 14px; flex-wrap: wrap; margin-top: 18px; }
+.detail-head h2 { margin: 0; font-size: 18px; font-weight: 700; }
+
+/* 分组对比：A 在左、B 在右 */
+.group-compare { display: grid; grid-template-columns: 1fr 1fr; gap: 16px; margin-top: 14px; }
+@media (max-width: 860px) { .group-compare { grid-template-columns: 1fr; } }
+.gpanel {
+  background: var(--panel); border: 1px solid var(--border); border-radius: var(--radius);
+  padding: 16px 18px; box-shadow: var(--shadow);
+}
+.gpanel .ghead { display: flex; justify-content: space-between; align-items: baseline; margin-bottom: 2px; }
+.gpanel .ghead strong { font-size: 16px; }
+.gpanel .ghead .rate-num { font-size: 15px; font-weight: 800; }
+
+/* 看板全屏适配 */
+body.fs-on .wrap { max-width: none; padding-top: 14px; }
+body.fs-on .class-grid { grid-template-columns: repeat(auto-fill, minmax(340px, 1fr)); }
+body.fs-on .group-compare { grid-template-columns: 1fr 1fr; }
+body.fs-on .dash-hero { border-radius: var(--radius); }
+