refactor: Rename transition class for main content body

- Change class name from 'transition-main-content-body' to 'transition-fade-up'
- Update class name in page.ejs and page.styl files
- Maintain existing transition behavior and styling

layout/page.ejs

@@ -15,7 +15,7 @@
 			<%- partial('components/header/navbar') %>
 		</div>
 
-		<div class="main-content-body transition-main-content-body">
+		<div class="main-content-body transition-fade-up">
 			<% if (is_home() && theme.home.sidebar.enable === true && theme.home.sidebar.position === "left") { %>
 			<%- partial('pages/home/home-sidebar') %>
 			<% } %>

source/css/layout/page.styl

@@ -147,7 +147,7 @@
   transition 0.4s
   opacity 1
 
-.transition-main-content-body
+.transition-fade-up
   transform translateY(0)
   opacity 1
   transition transform 0.4s ease, opacity 0.4s ease
@@ -158,7 +158,7 @@ html.is-changing
     transition opacity 0.4s ease
     opacity 1
 
-  .transition-main-content-body
+  .transition-fade-up
     transition transform 0.4s ease, opacity 0.4s ease
     transform translateY(0)
     opacity 1
@@ -168,6 +168,6 @@ html.is-animating
   .transition-fade
     opacity 0
 
-  .transition-main-content-body
+  .transition-fade-up
     transform translateY(20px)
     opacity 0