diff --git a/docs/requirements.txt b/docs/requirements.txt
index 2a891db004..c47d196730 100644
--- a/docs/requirements.txt
+++ b/docs/requirements.txt
@@ -1 +1 @@
-sphinx<7
+sphinx<9
diff --git a/docs/source/_themes/metrics/layout.html b/docs/source/_themes/metrics/layout.html
index ab56388451..d1239319b0 100644
--- a/docs/source/_themes/metrics/layout.html
+++ b/docs/source/_themes/metrics/layout.html
@@ -19,7 +19,9 @@
     {%- for cssfile in css_files %}
     <link rel="stylesheet" href="{{ pathto(cssfile, 1) }}" type="text/css"/>
     {%- endfor %}
+    {%- for style in styles -%}
     <link rel="stylesheet" href="{{ pathto('_static/' + style, 1) }}" type="text/css"/>
+    {%- endfor -%}
     {%- if favicon %}
     <link rel="shortcut icon" href="{{ pathto('_static/' + favicon, 1) }}"/>
     {%- endif %}