add transition, add plane container

src/components/mainPart/mainPart.css

@@ -1,4 +1,4 @@
-.main-part-container {
+.main-part-container {    
     position: relative;
     width: 100%;
     height: 100vh;
@@ -22,6 +22,7 @@
 }
 
 .main-part-header {
+    z-index: 1;
     box-sizing: border-box;
     width: 100%;
     display: flex;
@@ -139,8 +140,48 @@
     display: flex;
     flex-direction: column;
     position: relative;
+    max-width: 600px;
+    gap: 8px;
 }
 
-.main-part-footer-text::before {
+.main-part-footer-text-container {
+    display: flex;
+}
+
+.main-part-footer-text-container::before {    
     content: '*';
+}
+
+.main-part-footer-text {
+    display: flex;
+    flex-direction: column;
+}
+
+.background-container {
+    z-index: 0;
+    position: absolute;
+    top: 0;
+    left: 0;
+    width: 100%;
+    height: 100%;
+    background: rgba(30, 22, 48, 0.8);
+    backdrop-filter: blur(12px);
+}
+
+.show-background-enter {
+    opacity: 0;
+}
+
+.show-background-enter-active {
+    opacity: 1;
+    transition: .3s;
+}
+
+.show-background-exit {
+    opacity: 1;
+}
+
+.show-background-exit-active {
+    opacity: 0;
+    transition: .3s;
 }