diff --git a/B08_Quantity/B08_Quantity_UI_Hydro.css b/B08_Quantity/B08_Quantity_UI_Hydro.css
index 9d1b50e5f..30cb173d2 100644
--- a/B08_Quantity/B08_Quantity_UI_Hydro.css
+++ b/B08_Quantity/B08_Quantity_UI_Hydro.css
@@ -16,10 +16,10 @@
   margin-bottom: var(--spacing-16);
 }
 
+/* 보조 탭 줄 = 다른 B08 보조 탭(.b08-quantity__tabs) 양식 · [저장] 옆까지 줄을 늘림 */
 .b08-hydro__tabs {
-  display: flex;
-  flex-wrap: wrap;
-  gap: var(--spacing-4);
+  flex: 1 1 auto;
+  min-width: 0;
 }
 
 .b08-hydro__toolbar > .ui-btn {
@@ -63,8 +63,8 @@
 
 .b08-hydro__formula {
   margin: 0 0 0 var(--spacing-8);
-  font-family: "Cambria Math", "Times New Roman", serif;
-  font-size: 15px;
+  font-family: var(--font-body);
+  font-size: var(--text-body-sm);
   color: var(--color-text-secondary);
 }
 
@@ -93,7 +93,7 @@
 
 .b08-hydro__row .b08-hydro__formula {
   margin: 0;
-  font-size: 13px;
+  font-size: var(--text-caption);
 }
 
 .b08-hydro__hint {
@@ -163,7 +163,7 @@
 }
 
 .b08-hydro__pipe text {
-  font-size: 12px;
+  font-size: var(--text-caption);
   fill: var(--color-text-secondary);
 }
 
diff --git a/B08_Quantity/B08_Quantity_UI_Hydro.ts b/B08_Quantity/B08_Quantity_UI_Hydro.ts
index 07367b58b..15880b1bf 100644
--- a/B08_Quantity/B08_Quantity_UI_Hydro.ts
+++ b/B08_Quantity/B08_Quantity_UI_Hydro.ts
@@ -86,7 +86,7 @@ export async function renderHydro(host: HTMLElement, projectId: string): Promise
     }) as HydroInputs;
 
   const tabs = document.createElement("div");
-  tabs.className = "b08-hydro__tabs";
+  tabs.className = "b08-quantity__tabs b08-hydro__tabs";
   tabs.setAttribute("role", "tablist");
   const save = createButton({
     label: "저장",