fix: adapt portrait matrix row heights without drift

Co-authored-by: Cursor <cursoragent@cursor.com>

src/pages/clazz/components/ClazzMatrixView.vue

@@ -304,6 +304,8 @@ export default defineComponent({
 <style scoped lang="less">
 @sidebar-width: 1.2rem;
 @cell-width: 1.8rem;
+@portrait-header-height: 0.72rem;
+@portrait-day-row-min-height: 1.16rem;
 
 .matrix-wrapper {
   width: 100%;
@@ -334,9 +336,12 @@ export default defineComponent({
   height: 100%;
   display: flex;
   flex-direction: column;
+  box-sizing: border-box;
   pointer-events: none; /* allow click-through to cells underneath */
 
   .sidebar-corner {
+    height: @portrait-header-height;
+    box-sizing: border-box;
     flex-shrink: 0;
     background: #f7f8fa;
     border-bottom: 1px solid #e8e8e8;
@@ -346,7 +351,8 @@ export default defineComponent({
   }
 
   .sidebar-row {
-    flex: 1;
+    flex: 1 0 @portrait-day-row-min-height;
+    min-height: @portrait-day-row-min-height;
     display: flex;
     flex-direction: column;
     align-items: center;
@@ -387,18 +393,20 @@ export default defineComponent({
   flex-direction: column;
   min-height: 100%;
   min-width: fit-content;
+  box-sizing: border-box;
 }
 
 /* ─── 行：共用 ─── */
 .sr-header {
   display: flex;
+  height: @portrait-header-height;
   flex-shrink: 0;
 }
 
 .sr-row {
   display: flex;
-  flex: 1;
-  min-height: 0;
+  flex: 1 0 @portrait-day-row-min-height;
+  min-height: @portrait-day-row-min-height;
 }
 
 /* ─── Spacer（占位与 sidebar 同宽） ─── */

src/pages/clazz/index.vue

@@ -1265,7 +1265,15 @@ export default defineComponent({
     min-height: 0;
   }
 
+  :deep(.matrix-sidebar) {
+    padding-bottom: calc(0.72rem + env(safe-area-inset-bottom));
+  }
+
   :deep(.matrix-scroll) {
+    box-sizing: border-box;
+  }
+
+  :deep(.scroll-inner) {
     padding-bottom: calc(0.72rem + env(safe-area-inset-bottom));
     box-sizing: border-box;
   }