diff --git a/src/main/java/com/yunhai/userhome/service/impl/AppearanceServiceImpl.java b/src/main/java/com/yunhai/userhome/service/impl/AppearanceServiceImpl.java
index b29b632..1c7c968 100644
--- a/src/main/java/com/yunhai/userhome/service/impl/AppearanceServiceImpl.java
+++ b/src/main/java/com/yunhai/userhome/service/impl/AppearanceServiceImpl.java
@@ -125,7 +125,16 @@ public class AppearanceServiceImpl implements IAppearanceService {
         String avatar = myAvatar;
         try {
             if (theme == null) {
-                theme = schSettingsService.readThemeWithFallback(schId).getValue();
+                // readThemeWithFallback 命中值是 ThemeState JSON（schTheme 端点口径）；oapi 契约统一出
+                // 紧凑编码（init 侧 compactThemeToJson 只认紧凑形态），脏值宽松降 null 不抛
+                String hit = schSettingsService.readThemeWithFallback(schId).getValue();
+                if (hit != null) {
+                    try {
+                        theme = ThemeCodec.encodeThemeState(hit);
+                    } catch (DException e) {
+                        theme = null;
+                    }
+                }
             }
             if (avatar == null) {
                 avatar = schSettingsService.readAvatarWithFallback(schId).getValue();
diff --git a/src/test/java/com/yunhai/userhome/service/AppearanceServiceTest.java b/src/test/java/com/yunhai/userhome/service/AppearanceServiceTest.java
index f1f597d..8585563 100644
--- a/src/test/java/com/yunhai/userhome/service/AppearanceServiceTest.java
+++ b/src/test/java/com/yunhai/userhome/service/AppearanceServiceTest.java
@@ -254,18 +254,19 @@ class AppearanceServiceTest {
     }
 
     @Test
-    @DisplayName("生效值：个人未设 → 学校/平台级联（缺陷 C 修复验证：合成链走 readThemeWithFallback）")
+    @DisplayName("生效值：个人未设 → 学校/平台级联（缺陷 C 修复验证：合成链走 readThemeWithFallback），层间编码统一紧凑形态")
     void effective_fallsToCascade() {
         stubCurrentRole(3);
         when(userAppearanceRepository.findByUserId(10133)).thenReturn(Optional.empty());
+        // 级联命中值是 ThemeState JSON（schTheme 端点口径）——合成层须转回紧凑编码
         when(schSettingsService.readThemeWithFallback(3))
-                .thenReturn(new ISchSettingsService.LayerValue("ink|0|1|1", 0));
+                .thenReturn(new ISchSettingsService.LayerValue("{\"theme\":\"ink\",\"sideDeep\":false,\"gradOn\":true,\"sideFollow\":false}", 0));
         when(schSettingsService.readAvatarWithFallback(3))
                 .thenReturn(new ISchSettingsService.LayerValue("text", 3));
         when(logoRepository.findBySchIdAndType(any(), any())).thenReturn(Collections.emptyList());
 
         Map<String, Object> out = service.getEffectiveAppearance(10133);
-        assertEquals("ink|0|1|1", out.get("theme"), "本校空回落平台档（hitSchId=0）");
+        assertEquals("ink|0|1|0", out.get("theme"), "级联 JSON 转紧凑编码，init 侧才可收敛");
         assertEquals("text", out.get("avatar"), "本校已配直接生效（hitSchId=本校）");
         // 出参只三字段，不外露 my/sch 拆分
         assertTrue(out.containsKey("theme") && out.containsKey("avatar") && out.containsKey("logoUrl"));