diff --git a/app/javascript/styles/mastodon-material-dark/theme/_mixins.scss b/app/javascript/styles/mastodon-material-dark/theme/_mixins.scss
index d506b8148..bdfef2e2f 100644
--- a/app/javascript/styles/mastodon-material-dark/theme/_mixins.scss
+++ b/app/javascript/styles/mastodon-material-dark/theme/_mixins.scss
@@ -61,6 +61,13 @@ $shadow-color-3: rgba(0,0,0,.12);
     }
 }
 
+// check background-image value
+@mixin bg-image {
+    @if $bg-image == none {        
+    } @else { background-image: url($bg-image) }
+}
+
+
 @mixin icon-font-style {
     @if $icon-font-style == filled { font-family: "Material Icons" }
     @if $icon-font-style == outlined { font-family: "Material Icons Outlined" }
@@ -151,35 +158,35 @@ $shadow-color-3: rgba(0,0,0,.12);
             @font-face {
                 font-family: "Material Icons";
                 src: local("Material Icons"),
-                     url("../fonts/MaterialIcons-Regular.ttf") format('truetype');
+                     url(".../fonts/MaterialIcons-Regular.ttf") format('truetype');
             }
         }
         @if $icon-font-style == outlined {
             @font-face {
                 font-family: "Material Icons Outlined";
                 src: local("Material Icons Outlined"),
-                     url("../fonts/MaterialIconsOutlined-Regular.otf") format('opentype');
+                     url(".../fonts/MaterialIconsOutlined-Regular.otf") format('opentype');
             }
         }
         @if $icon-font-style == round {
             @font-face {
                 font-family: "Material Icons Round";
                 src: local("Material Icons"),
-                     url("../fonts/MaterialIconsRound-Regular.otf") format('opentype');
+                     url(".../fonts/MaterialIconsRound-Regular.otf") format('opentype');
             }
         }
         @if $icon-font-style == sharp {
             @font-face {
                 font-family: "Material Icons Sharp";
                 src: local("Material Icons Sharp"),
-                     url("../fonts/MaterialIconsSharp-Regular.otf") format('opentype');
+                     url(".../fonts/MaterialIconsSharp-Regular.otf") format('opentype');
             }
         }
         @if $icon-font-style == two-tone {
             @font-face {
                 font-family: "Material Icons Two Tone";
                 src: local("Material Icons Two Tone"),
-                     url("../fonts/MaterialIconsTwoTone-Regular.otf") format('opentype');
+                     url(".../fonts/MaterialIconsTwoTone-Regular.otf") format('opentype');
             }
         }
     }
diff --git a/app/javascript/styles/mastodon-material-dark/theme/base_config.scss b/app/javascript/styles/mastodon-material-dark/theme/base_config.scss
index 13fb4ad75..f36a139ba 100644
--- a/app/javascript/styles/mastodon-material-dark/theme/base_config.scss
+++ b/app/javascript/styles/mastodon-material-dark/theme/base_config.scss
@@ -1,7 +1,7 @@
 @charset "UTF-8";
 
 
-// [important] This file is base file. DO NOT edit this file. If you want to change this file, you should edit "../config.scss".
+// [important] This file is base file. DO NOT edit this file. If you want to change this file, you should edit "../custom_config.scss".
 
 
 // Color scheme
@@ -32,7 +32,7 @@ $name-font-size: 15px;  // mastodon default
 
 
 // Background image
-// If you want to use the local image, please put it in /mastodon-material
+// If you want to use the local image, please put it in "../"
 $bg-image: none;
 //$bg-image: "./image.png";
 //$bg-image: "https://example.com/img/image.png";
diff --git a/app/javascript/styles/mastodon-material-dark/theme/columns.scss b/app/javascript/styles/mastodon-material-dark/theme/columns.scss
index af7776a0c..3f57ea958 100644
--- a/app/javascript/styles/mastodon-material-dark/theme/columns.scss
+++ b/app/javascript/styles/mastodon-material-dark/theme/columns.scss
@@ -202,7 +202,7 @@
 }
 
 .columns-area {
-    background-image: url($bg-image);
+    @include bg-image;
     background-size: contain;
 }
 
diff --git a/app/javascript/styles/mastodon-material-light/theme/_mixins.scss b/app/javascript/styles/mastodon-material-light/theme/_mixins.scss
index d506b8148..bdfef2e2f 100644
--- a/app/javascript/styles/mastodon-material-light/theme/_mixins.scss
+++ b/app/javascript/styles/mastodon-material-light/theme/_mixins.scss
@@ -61,6 +61,13 @@ $shadow-color-3: rgba(0,0,0,.12);
     }
 }
 
+// check background-image value
+@mixin bg-image {
+    @if $bg-image == none {        
+    } @else { background-image: url($bg-image) }
+}
+
+
 @mixin icon-font-style {
     @if $icon-font-style == filled { font-family: "Material Icons" }
     @if $icon-font-style == outlined { font-family: "Material Icons Outlined" }
@@ -151,35 +158,35 @@ $shadow-color-3: rgba(0,0,0,.12);
             @font-face {
                 font-family: "Material Icons";
                 src: local("Material Icons"),
-                     url("../fonts/MaterialIcons-Regular.ttf") format('truetype');
+                     url(".../fonts/MaterialIcons-Regular.ttf") format('truetype');
             }
         }
         @if $icon-font-style == outlined {
             @font-face {
                 font-family: "Material Icons Outlined";
                 src: local("Material Icons Outlined"),
-                     url("../fonts/MaterialIconsOutlined-Regular.otf") format('opentype');
+                     url(".../fonts/MaterialIconsOutlined-Regular.otf") format('opentype');
             }
         }
         @if $icon-font-style == round {
             @font-face {
                 font-family: "Material Icons Round";
                 src: local("Material Icons"),
-                     url("../fonts/MaterialIconsRound-Regular.otf") format('opentype');
+                     url(".../fonts/MaterialIconsRound-Regular.otf") format('opentype');
             }
         }
         @if $icon-font-style == sharp {
             @font-face {
                 font-family: "Material Icons Sharp";
                 src: local("Material Icons Sharp"),
-                     url("../fonts/MaterialIconsSharp-Regular.otf") format('opentype');
+                     url(".../fonts/MaterialIconsSharp-Regular.otf") format('opentype');
             }
         }
         @if $icon-font-style == two-tone {
             @font-face {
                 font-family: "Material Icons Two Tone";
                 src: local("Material Icons Two Tone"),
-                     url("../fonts/MaterialIconsTwoTone-Regular.otf") format('opentype');
+                     url(".../fonts/MaterialIconsTwoTone-Regular.otf") format('opentype');
             }
         }
     }
diff --git a/app/javascript/styles/mastodon-material-light/theme/base_config.scss b/app/javascript/styles/mastodon-material-light/theme/base_config.scss
index 13fb4ad75..f36a139ba 100644
--- a/app/javascript/styles/mastodon-material-light/theme/base_config.scss
+++ b/app/javascript/styles/mastodon-material-light/theme/base_config.scss
@@ -1,7 +1,7 @@
 @charset "UTF-8";
 
 
-// [important] This file is base file. DO NOT edit this file. If you want to change this file, you should edit "../config.scss".
+// [important] This file is base file. DO NOT edit this file. If you want to change this file, you should edit "../custom_config.scss".
 
 
 // Color scheme
@@ -32,7 +32,7 @@ $name-font-size: 15px;  // mastodon default
 
 
 // Background image
-// If you want to use the local image, please put it in /mastodon-material
+// If you want to use the local image, please put it in "../"
 $bg-image: none;
 //$bg-image: "./image.png";
 //$bg-image: "https://example.com/img/image.png";
diff --git a/app/javascript/styles/mastodon-material-light/theme/columns.scss b/app/javascript/styles/mastodon-material-light/theme/columns.scss
index af7776a0c..3f57ea958 100644
--- a/app/javascript/styles/mastodon-material-light/theme/columns.scss
+++ b/app/javascript/styles/mastodon-material-light/theme/columns.scss
@@ -202,7 +202,7 @@
 }
 
 .columns-area {
-    background-image: url($bg-image);
+    @include bg-image;
     background-size: contain;
 }
 
diff --git a/app/javascript/styles/material-black/theme/_mixins.scss b/app/javascript/styles/material-black/theme/_mixins.scss
index d506b8148..bdfef2e2f 100644
--- a/app/javascript/styles/material-black/theme/_mixins.scss
+++ b/app/javascript/styles/material-black/theme/_mixins.scss
@@ -61,6 +61,13 @@ $shadow-color-3: rgba(0,0,0,.12);
     }
 }
 
+// check background-image value
+@mixin bg-image {
+    @if $bg-image == none {        
+    } @else { background-image: url($bg-image) }
+}
+
+
 @mixin icon-font-style {
     @if $icon-font-style == filled { font-family: "Material Icons" }
     @if $icon-font-style == outlined { font-family: "Material Icons Outlined" }
@@ -151,35 +158,35 @@ $shadow-color-3: rgba(0,0,0,.12);
             @font-face {
                 font-family: "Material Icons";
                 src: local("Material Icons"),
-                     url("../fonts/MaterialIcons-Regular.ttf") format('truetype');
+                     url(".../fonts/MaterialIcons-Regular.ttf") format('truetype');
             }
         }
         @if $icon-font-style == outlined {
             @font-face {
                 font-family: "Material Icons Outlined";
                 src: local("Material Icons Outlined"),
-                     url("../fonts/MaterialIconsOutlined-Regular.otf") format('opentype');
+                     url(".../fonts/MaterialIconsOutlined-Regular.otf") format('opentype');
             }
         }
         @if $icon-font-style == round {
             @font-face {
                 font-family: "Material Icons Round";
                 src: local("Material Icons"),
-                     url("../fonts/MaterialIconsRound-Regular.otf") format('opentype');
+                     url(".../fonts/MaterialIconsRound-Regular.otf") format('opentype');
             }
         }
         @if $icon-font-style == sharp {
             @font-face {
                 font-family: "Material Icons Sharp";
                 src: local("Material Icons Sharp"),
-                     url("../fonts/MaterialIconsSharp-Regular.otf") format('opentype');
+                     url(".../fonts/MaterialIconsSharp-Regular.otf") format('opentype');
             }
         }
         @if $icon-font-style == two-tone {
             @font-face {
                 font-family: "Material Icons Two Tone";
                 src: local("Material Icons Two Tone"),
-                     url("../fonts/MaterialIconsTwoTone-Regular.otf") format('opentype');
+                     url(".../fonts/MaterialIconsTwoTone-Regular.otf") format('opentype');
             }
         }
     }
diff --git a/app/javascript/styles/material-black/theme/base_config.scss b/app/javascript/styles/material-black/theme/base_config.scss
index 13fb4ad75..f36a139ba 100644
--- a/app/javascript/styles/material-black/theme/base_config.scss
+++ b/app/javascript/styles/material-black/theme/base_config.scss
@@ -1,7 +1,7 @@
 @charset "UTF-8";
 
 
-// [important] This file is base file. DO NOT edit this file. If you want to change this file, you should edit "../config.scss".
+// [important] This file is base file. DO NOT edit this file. If you want to change this file, you should edit "../custom_config.scss".
 
 
 // Color scheme
@@ -32,7 +32,7 @@ $name-font-size: 15px;  // mastodon default
 
 
 // Background image
-// If you want to use the local image, please put it in /mastodon-material
+// If you want to use the local image, please put it in "../"
 $bg-image: none;
 //$bg-image: "./image.png";
 //$bg-image: "https://example.com/img/image.png";
diff --git a/app/javascript/styles/material-black/theme/columns.scss b/app/javascript/styles/material-black/theme/columns.scss
index af7776a0c..3f57ea958 100644
--- a/app/javascript/styles/material-black/theme/columns.scss
+++ b/app/javascript/styles/material-black/theme/columns.scss
@@ -202,7 +202,7 @@
 }
 
 .columns-area {
-    background-image: url($bg-image);
+    @include bg-image;
     background-size: contain;
 }
 
diff --git a/app/javascript/styles/material-dark/theme/_mixins.scss b/app/javascript/styles/material-dark/theme/_mixins.scss
index d506b8148..bdfef2e2f 100644
--- a/app/javascript/styles/material-dark/theme/_mixins.scss
+++ b/app/javascript/styles/material-dark/theme/_mixins.scss
@@ -61,6 +61,13 @@ $shadow-color-3: rgba(0,0,0,.12);
     }
 }
 
+// check background-image value
+@mixin bg-image {
+    @if $bg-image == none {        
+    } @else { background-image: url($bg-image) }
+}
+
+
 @mixin icon-font-style {
     @if $icon-font-style == filled { font-family: "Material Icons" }
     @if $icon-font-style == outlined { font-family: "Material Icons Outlined" }
@@ -151,35 +158,35 @@ $shadow-color-3: rgba(0,0,0,.12);
             @font-face {
                 font-family: "Material Icons";
                 src: local("Material Icons"),
-                     url("../fonts/MaterialIcons-Regular.ttf") format('truetype');
+                     url(".../fonts/MaterialIcons-Regular.ttf") format('truetype');
             }
         }
         @if $icon-font-style == outlined {
             @font-face {
                 font-family: "Material Icons Outlined";
                 src: local("Material Icons Outlined"),
-                     url("../fonts/MaterialIconsOutlined-Regular.otf") format('opentype');
+                     url(".../fonts/MaterialIconsOutlined-Regular.otf") format('opentype');
             }
         }
         @if $icon-font-style == round {
             @font-face {
                 font-family: "Material Icons Round";
                 src: local("Material Icons"),
-                     url("../fonts/MaterialIconsRound-Regular.otf") format('opentype');
+                     url(".../fonts/MaterialIconsRound-Regular.otf") format('opentype');
             }
         }
         @if $icon-font-style == sharp {
             @font-face {
                 font-family: "Material Icons Sharp";
                 src: local("Material Icons Sharp"),
-                     url("../fonts/MaterialIconsSharp-Regular.otf") format('opentype');
+                     url(".../fonts/MaterialIconsSharp-Regular.otf") format('opentype');
             }
         }
         @if $icon-font-style == two-tone {
             @font-face {
                 font-family: "Material Icons Two Tone";
                 src: local("Material Icons Two Tone"),
-                     url("../fonts/MaterialIconsTwoTone-Regular.otf") format('opentype');
+                     url(".../fonts/MaterialIconsTwoTone-Regular.otf") format('opentype');
             }
         }
     }
diff --git a/app/javascript/styles/material-dark/theme/base_config.scss b/app/javascript/styles/material-dark/theme/base_config.scss
index 13fb4ad75..f36a139ba 100644
--- a/app/javascript/styles/material-dark/theme/base_config.scss
+++ b/app/javascript/styles/material-dark/theme/base_config.scss
@@ -1,7 +1,7 @@
 @charset "UTF-8";
 
 
-// [important] This file is base file. DO NOT edit this file. If you want to change this file, you should edit "../config.scss".
+// [important] This file is base file. DO NOT edit this file. If you want to change this file, you should edit "../custom_config.scss".
 
 
 // Color scheme
@@ -32,7 +32,7 @@ $name-font-size: 15px;  // mastodon default
 
 
 // Background image
-// If you want to use the local image, please put it in /mastodon-material
+// If you want to use the local image, please put it in "../"
 $bg-image: none;
 //$bg-image: "./image.png";
 //$bg-image: "https://example.com/img/image.png";
diff --git a/app/javascript/styles/material-dark/theme/columns.scss b/app/javascript/styles/material-dark/theme/columns.scss
index af7776a0c..3f57ea958 100644
--- a/app/javascript/styles/material-dark/theme/columns.scss
+++ b/app/javascript/styles/material-dark/theme/columns.scss
@@ -202,7 +202,7 @@
 }
 
 .columns-area {
-    background-image: url($bg-image);
+    @include bg-image;
     background-size: contain;
 }
 
diff --git a/app/javascript/styles/material-light/theme/_mixins.scss b/app/javascript/styles/material-light/theme/_mixins.scss
index d506b8148..bdfef2e2f 100644
--- a/app/javascript/styles/material-light/theme/_mixins.scss
+++ b/app/javascript/styles/material-light/theme/_mixins.scss
@@ -61,6 +61,13 @@ $shadow-color-3: rgba(0,0,0,.12);
     }
 }
 
+// check background-image value
+@mixin bg-image {
+    @if $bg-image == none {        
+    } @else { background-image: url($bg-image) }
+}
+
+
 @mixin icon-font-style {
     @if $icon-font-style == filled { font-family: "Material Icons" }
     @if $icon-font-style == outlined { font-family: "Material Icons Outlined" }
@@ -151,35 +158,35 @@ $shadow-color-3: rgba(0,0,0,.12);
             @font-face {
                 font-family: "Material Icons";
                 src: local("Material Icons"),
-                     url("../fonts/MaterialIcons-Regular.ttf") format('truetype');
+                     url(".../fonts/MaterialIcons-Regular.ttf") format('truetype');
             }
         }
         @if $icon-font-style == outlined {
             @font-face {
                 font-family: "Material Icons Outlined";
                 src: local("Material Icons Outlined"),
-                     url("../fonts/MaterialIconsOutlined-Regular.otf") format('opentype');
+                     url(".../fonts/MaterialIconsOutlined-Regular.otf") format('opentype');
             }
         }
         @if $icon-font-style == round {
             @font-face {
                 font-family: "Material Icons Round";
                 src: local("Material Icons"),
-                     url("../fonts/MaterialIconsRound-Regular.otf") format('opentype');
+                     url(".../fonts/MaterialIconsRound-Regular.otf") format('opentype');
             }
         }
         @if $icon-font-style == sharp {
             @font-face {
                 font-family: "Material Icons Sharp";
                 src: local("Material Icons Sharp"),
-                     url("../fonts/MaterialIconsSharp-Regular.otf") format('opentype');
+                     url(".../fonts/MaterialIconsSharp-Regular.otf") format('opentype');
             }
         }
         @if $icon-font-style == two-tone {
             @font-face {
                 font-family: "Material Icons Two Tone";
                 src: local("Material Icons Two Tone"),
-                     url("../fonts/MaterialIconsTwoTone-Regular.otf") format('opentype');
+                     url(".../fonts/MaterialIconsTwoTone-Regular.otf") format('opentype');
             }
         }
     }
diff --git a/app/javascript/styles/material-light/theme/base_config.scss b/app/javascript/styles/material-light/theme/base_config.scss
index 13fb4ad75..f36a139ba 100644
--- a/app/javascript/styles/material-light/theme/base_config.scss
+++ b/app/javascript/styles/material-light/theme/base_config.scss
@@ -1,7 +1,7 @@
 @charset "UTF-8";
 
 
-// [important] This file is base file. DO NOT edit this file. If you want to change this file, you should edit "../config.scss".
+// [important] This file is base file. DO NOT edit this file. If you want to change this file, you should edit "../custom_config.scss".
 
 
 // Color scheme
@@ -32,7 +32,7 @@ $name-font-size: 15px;  // mastodon default
 
 
 // Background image
-// If you want to use the local image, please put it in /mastodon-material
+// If you want to use the local image, please put it in "../"
 $bg-image: none;
 //$bg-image: "./image.png";
 //$bg-image: "https://example.com/img/image.png";
diff --git a/app/javascript/styles/material-light/theme/columns.scss b/app/javascript/styles/material-light/theme/columns.scss
index af7776a0c..3f57ea958 100644
--- a/app/javascript/styles/material-light/theme/columns.scss
+++ b/app/javascript/styles/material-light/theme/columns.scss
@@ -202,7 +202,7 @@
 }
 
 .columns-area {
-    background-image: url($bg-image);
+    @include bg-image;
     background-size: contain;
 }
 
diff --git a/app/javascript/styles/plus/theme/_mixins.scss b/app/javascript/styles/plus/theme/_mixins.scss
index d506b8148..bdfef2e2f 100644
--- a/app/javascript/styles/plus/theme/_mixins.scss
+++ b/app/javascript/styles/plus/theme/_mixins.scss
@@ -61,6 +61,13 @@ $shadow-color-3: rgba(0,0,0,.12);
     }
 }
 
+// check background-image value
+@mixin bg-image {
+    @if $bg-image == none {        
+    } @else { background-image: url($bg-image) }
+}
+
+
 @mixin icon-font-style {
     @if $icon-font-style == filled { font-family: "Material Icons" }
     @if $icon-font-style == outlined { font-family: "Material Icons Outlined" }
@@ -151,35 +158,35 @@ $shadow-color-3: rgba(0,0,0,.12);
             @font-face {
                 font-family: "Material Icons";
                 src: local("Material Icons"),
-                     url("../fonts/MaterialIcons-Regular.ttf") format('truetype');
+                     url(".../fonts/MaterialIcons-Regular.ttf") format('truetype');
             }
         }
         @if $icon-font-style == outlined {
             @font-face {
                 font-family: "Material Icons Outlined";
                 src: local("Material Icons Outlined"),
-                     url("../fonts/MaterialIconsOutlined-Regular.otf") format('opentype');
+                     url(".../fonts/MaterialIconsOutlined-Regular.otf") format('opentype');
             }
         }
         @if $icon-font-style == round {
             @font-face {
                 font-family: "Material Icons Round";
                 src: local("Material Icons"),
-                     url("../fonts/MaterialIconsRound-Regular.otf") format('opentype');
+                     url(".../fonts/MaterialIconsRound-Regular.otf") format('opentype');
             }
         }
         @if $icon-font-style == sharp {
             @font-face {
                 font-family: "Material Icons Sharp";
                 src: local("Material Icons Sharp"),
-                     url("../fonts/MaterialIconsSharp-Regular.otf") format('opentype');
+                     url(".../fonts/MaterialIconsSharp-Regular.otf") format('opentype');
             }
         }
         @if $icon-font-style == two-tone {
             @font-face {
                 font-family: "Material Icons Two Tone";
                 src: local("Material Icons Two Tone"),
-                     url("../fonts/MaterialIconsTwoTone-Regular.otf") format('opentype');
+                     url(".../fonts/MaterialIconsTwoTone-Regular.otf") format('opentype');
             }
         }
     }
diff --git a/app/javascript/styles/plus/theme/base_config.scss b/app/javascript/styles/plus/theme/base_config.scss
index 13fb4ad75..f36a139ba 100644
--- a/app/javascript/styles/plus/theme/base_config.scss
+++ b/app/javascript/styles/plus/theme/base_config.scss
@@ -1,7 +1,7 @@
 @charset "UTF-8";
 
 
-// [important] This file is base file. DO NOT edit this file. If you want to change this file, you should edit "../config.scss".
+// [important] This file is base file. DO NOT edit this file. If you want to change this file, you should edit "../custom_config.scss".
 
 
 // Color scheme
@@ -32,7 +32,7 @@ $name-font-size: 15px;  // mastodon default
 
 
 // Background image
-// If you want to use the local image, please put it in /mastodon-material
+// If you want to use the local image, please put it in "../"
 $bg-image: none;
 //$bg-image: "./image.png";
 //$bg-image: "https://example.com/img/image.png";
diff --git a/app/javascript/styles/plus/theme/columns.scss b/app/javascript/styles/plus/theme/columns.scss
index af7776a0c..3f57ea958 100644
--- a/app/javascript/styles/plus/theme/columns.scss
+++ b/app/javascript/styles/plus/theme/columns.scss
@@ -202,7 +202,7 @@
 }
 
 .columns-area {
-    background-image: url($bg-image);
+    @include bg-image;
     background-size: contain;
 }