优化背景色，加深对比度

resources/assets/dcat/sass/dcat-app.scss

@@ -26,6 +26,10 @@ html body {
   color: $font-color;
 }
 
+.content-wrapper {
+  background: $body-bg;
+}
+
 // 字体
 body, .header-navbar, .navigation, .breadcrumb, h1, h2, h3, h4, h5, h6, .h1, .h2, .h3, .h4, .h5, .h6 {
   font-family: $font-family-sans-serif;

resources/assets/dcat/sass/theme/_colors.scss

@@ -92,7 +92,7 @@ $font-color: #414750;
 
 // body背景颜色
 //$body-bg: #f9fafc;
-$body-bg: $dark30;
+$body-bg: lighten($dark40, 2%);
 
 // 灰背景色
 $gray-bg: #f1f1f1;

resources/views/pages/login.blade.php

@@ -1,6 +1,4 @@
 <style>
-    .login-page {background: #f7f7f9;}
-
     .login-box {
         margin-top: -10rem;
         padding: 5px;
@@ -17,7 +15,7 @@
     }
 </style>
 
-<div class="login-page">
+<div class="login-page bg-40">
     <div class="login-box">
         <div class="login-logo mb-2">
             {{ config('admin.name') }}