保存进度！

code/java/后端-用户验证/target/admin-system/css/main_frame.css

@@ -0,0 +1,25 @@
+#app {
+    width: 100vw;
+    height: 100vh;
+    padding: 0px;
+    margin: 0px;
+    display: flex;
+    flex-direction: column;
+}
+
+#header {
+    flex-basis: 50px;
+    border: 1px solid red;
+    max-height: 50px;
+}
+
+#main {
+    flex-grow: 1;
+    border: 1px solid red;
+}
+
+#footer {
+    flex-basis: 100px;
+    max-height: 100px;
+    border: 1px solid red;
+}