diff --git a/internal/theme/common/customcss.go b/internal/theme/common/customcss.go
new file mode 100644
index 0000000..3af457b
--- /dev/null
+++ b/internal/theme/common/customcss.go
@@ -0,0 +1,33 @@
+package common
+
+import (
+	"fmt"
+	"github.com/fthvgb1/wp-go/helper/html"
+	"github.com/fthvgb1/wp-go/internal/pkg/cache"
+	"github.com/fthvgb1/wp-go/internal/wpconfig"
+	"github.com/fthvgb1/wp-go/safety"
+)
+
+var css = safety.NewVar("default")
+
+func (h *Handle) CalCustomCss() (r string) {
+	mods, err := wpconfig.GetThemeMods(h.Theme)
+	if err != nil || mods.CustomCssPostId < 1 {
+		return
+	}
+	post, err := cache.GetPostById(h.C, uint64(mods.CustomCssPostId))
+	if err != nil || post.Id < 1 {
+		return
+	}
+	r = fmt.Sprintf(`<style id="wp-custom-css">%s</style>`, html.StripTags(post.PostContent, ""))
+	return
+}
+
+func (h *Handle) CustomCss() {
+	cs := css.Load()
+	if cs == "default" {
+		cs = h.CalCustomCss()
+		css.Store(cs)
+	}
+	h.GinH["customCss"] = cs
+}
diff --git a/internal/theme/common/detail.go b/internal/theme/common/detail.go
index c5801ca..9decf6b 100644
--- a/internal/theme/common/detail.go
+++ b/internal/theme/common/detail.go
@@ -99,6 +99,7 @@ func (d *DetailHandle) Render() {
 	}
 	d.SiteIcon()
 	d.CustomLogo()
+	d.CustomCss()
 	d.RenderComment()
 	d.CalBodyClass()
 	if d.Templ == "" {
diff --git a/internal/theme/common/index.go b/internal/theme/common/index.go
index 2ebf47f..17d0a07 100644
--- a/internal/theme/common/index.go
+++ b/internal/theme/common/index.go
@@ -114,6 +114,7 @@ func (i *IndexHandle) Render() {
 	i.Pagination()
 	i.SiteIcon()
 	i.CustomLogo()
+	i.CustomCss()
 	i.CalBodyClass()
 	if i.Templ == "" {
 		i.Templ = fmt.Sprintf("%s/posts/index.gohtml", i.Theme)
diff --git a/internal/theme/common/reload.go b/internal/theme/common/reload.go
index ce7d291..27ffc32 100644
--- a/internal/theme/common/reload.go
+++ b/internal/theme/common/reload.go
@@ -3,4 +3,5 @@ package common
 func Reload() {
 	backgroud.Store("default")
 	icon.Store("default")
+	css.Store("default")
 }
diff --git a/internal/theme/twentyfifteen/layout/head.gohtml b/internal/theme/twentyfifteen/layout/head.gohtml
index 9db72e0..4085965 100644
--- a/internal/theme/twentyfifteen/layout/head.gohtml
+++ b/internal/theme/twentyfifteen/layout/head.gohtml
@@ -68,5 +68,8 @@
     {{if .siteIcon}}
         {{.siteIcon|unescaped}}
     {{end}}
+    {{if .customCss}}
+        {{.customCss|unescaped}}
+    {{end}}
 
 {{end}}
\ No newline at end of file