fix: flexbox body layout for proper sticky footer, no scrollbar on public pages

public/css/style.css

@@ -20,8 +20,8 @@
 *{margin:0;padding:0;box-sizing:border-box}
 body{
   font-family:'Inter',-apple-system,BlinkMacSystemFont,'Segoe UI','Noto Sans SC',sans-serif;
-  background:var(--g1);color:var(--g8);line-height:1.6;min-height:100vh;
-  -webkit-font-smoothing:antialiased;
+  background:var(--g1);color:var(--g8);line-height:1.6;
+  -webkit-font-smoothing:antialiased;display:flex;flex-direction:column;min-height:100vh;
 }
 .hidden{display:none!important}
 
@@ -306,7 +306,7 @@ tbody tr:last-child td{border-bottom:none}
 .footer-inner{max-width:1280px;margin:0 auto;display:flex;justify-content:center;gap:28px;flex-wrap:wrap}
 .footer-inner a{color:var(--g4);text-decoration:none;transition:color .2s}
 .footer-inner a:hover{color:white}
-#app{min-height:100vh;display:flex;flex-direction:column}
+#app{flex:1;display:flex;flex-direction:column;min-height:0}
 #public-page,#main-layout{flex:1}
 
 /* ===== Install Page ===== */