diff --git a/src/styles.css b/src/styles.css
index b158bef..c57aee9 100644
--- a/src/styles.css
+++ b/src/styles.css
@@ -423,12 +423,12 @@ button { font-family: inherit; font-size: inherit; color: inherit; }
 .tab-body[data-rail-preview] .ui-fp { flex: 1; }
 .artifact-chip .ac-act { border: none; background: none; }
 
-/* 项目收件箱（CF3/D51）：会话/项目范围分段控件 */
+/* 项目收件箱（CF3/D51）：会话/项目范围分段控件（令牌对齐 DESIGN.md，阶段④合入主线时归一） */
 .inbox-scope {
   display: flex; gap: 4px; padding: 6px 14px 2px;
 }
 .inbox-scope button {
-  border: 1px solid var(--border, #d8d8d8); background: transparent; color: inherit;
-  border-radius: 999px; padding: 2px 12px; font-size: 12px; cursor: pointer; opacity: .72;
+  border: 1px solid var(--border); background: transparent; color: inherit;
+  border-radius: var(--radius-full); padding: 2px 12px; font-size: var(--fs-ui-sm); cursor: pointer; opacity: .72;
 }
-.inbox-scope button.active { opacity: 1; font-weight: 600; background: var(--hover, rgba(0,0,0,.05)); }
+.inbox-scope button.active { opacity: 1; font-weight: 600; background: var(--bg-hover); }