diff --git a/css/theme/latex.css b/css/theme/latex.css
index 8092317..74c9dcc 100644
--- a/css/theme/latex.css
+++ b/css/theme/latex.css
@@ -1,6 +1,5 @@
 @charset "UTF-8";
 /* tame reveal.js */
-@import url("https://free.bboxtype.com/embedfonts/?family=FiraSans:300,600");
 section {
   min-height: 100vh;
   width: 100vw;
@@ -75,6 +74,16 @@ body {
       box-shadow: 0.2em 0.2em 0.5em 0 rgba(0, 0, 0, 0.3); }
 
 /* content layout */
+@font-face {
+  font-family: 'Fira Sans';
+  src: url("../../lib/font/fira-sans/FiraSans-Regular.ttf");
+  font-weight: 400; }
+
+@font-face {
+  font-family: 'Fira Sans';
+  src: url("../../lib/font/fira-sans/FiraSans-Bold.ttf");
+  font-weight: 700; }
+
 @font-face {
   font-family: 'Fira Code';
   src: url("../../lib/font/fira-code/FiraCode-Regular.otf");
diff --git a/css/theme/source/latex.scss b/css/theme/source/latex.scss
index c14cf71..896b071 100644
--- a/css/theme/source/latex.scss
+++ b/css/theme/source/latex.scss
@@ -33,7 +33,7 @@ body {
     max-width: 100vw;
     overflow: auto;
   }
-  
+
   .layout-content-and-preview {
     grid-template-rows: var(--square) auto;
     grid-template-columns: auto;
@@ -110,7 +110,16 @@ body {
 
 /* content layout */
 
-@import url('https://free.bboxtype.com/embedfonts/?family=FiraSans:300,600');
+@font-face {
+  font-family: 'Fira Sans';
+  src: url('../../lib/font/fira-sans/FiraSans-Regular.ttf');
+  font-weight: 400;
+}
+@font-face {
+  font-family: 'Fira Sans';
+  src: url('../../lib/font/fira-sans/FiraSans-Bold.ttf');
+  font-weight: 700;
+}
 @font-face {
   font-family: 'Fira Code';
   src: url('../../lib/font/fira-code/FiraCode-Regular.otf');
@@ -121,6 +130,7 @@ body {
   src: url('../../lib/font/fira-code/FiraCode-Bold.otf');
   font-weight: 700;
 }
+
 body {
   font-family: 'Fira Sans';
   margin: 0;
diff --git a/lib/font/fira-sans/FiraSans-Black.ttf b/lib/font/fira-sans/FiraSans-Black.ttf
new file mode 100644
index 0000000..b40cf62
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diff --git a/lib/font/fira-sans/FiraSans-BlackItalic.ttf b/lib/font/fira-sans/FiraSans-BlackItalic.ttf
new file mode 100644
index 0000000..30aa806
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diff --git a/lib/font/fira-sans/FiraSans-Bold.ttf b/lib/font/fira-sans/FiraSans-Bold.ttf
new file mode 100644
index 0000000..f5bf9bc
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diff --git a/lib/font/fira-sans/FiraSans-BoldItalic.ttf b/lib/font/fira-sans/FiraSans-BoldItalic.ttf
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index 0000000..7ac379f
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diff --git a/lib/font/fira-sans/FiraSans-ExtraBold.ttf b/lib/font/fira-sans/FiraSans-ExtraBold.ttf
new file mode 100644
index 0000000..f477455
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diff --git a/lib/font/fira-sans/FiraSans-ExtraBoldItalic.ttf b/lib/font/fira-sans/FiraSans-ExtraBoldItalic.ttf
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index 0000000..31b7404
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diff --git a/lib/font/fira-sans/FiraSans-ExtraLight.ttf b/lib/font/fira-sans/FiraSans-ExtraLight.ttf
new file mode 100644
index 0000000..faf1cfb
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diff --git a/lib/font/fira-sans/FiraSans-ExtraLightItalic.ttf b/lib/font/fira-sans/FiraSans-ExtraLightItalic.ttf
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index 0000000..3b35322
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diff --git a/lib/font/fira-sans/FiraSans-Italic.ttf b/lib/font/fira-sans/FiraSans-Italic.ttf
new file mode 100644
index 0000000..f8d4e7e
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diff --git a/lib/font/fira-sans/FiraSans-Light.ttf b/lib/font/fira-sans/FiraSans-Light.ttf
new file mode 100644
index 0000000..63be25f
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diff --git a/lib/font/fira-sans/FiraSans-LightItalic.ttf b/lib/font/fira-sans/FiraSans-LightItalic.ttf
new file mode 100644
index 0000000..ee8ba59
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diff --git a/lib/font/fira-sans/FiraSans-Medium.ttf b/lib/font/fira-sans/FiraSans-Medium.ttf
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index 0000000..efa2e0c
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diff --git a/lib/font/fira-sans/FiraSans-MediumItalic.ttf b/lib/font/fira-sans/FiraSans-MediumItalic.ttf
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index 0000000..817ed64
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diff --git a/lib/font/fira-sans/FiraSans-Regular.ttf b/lib/font/fira-sans/FiraSans-Regular.ttf
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index 0000000..159ccfd
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diff --git a/lib/font/fira-sans/FiraSans-SemiBold.ttf b/lib/font/fira-sans/FiraSans-SemiBold.ttf
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diff --git a/lib/font/fira-sans/FiraSans-SemiBoldItalic.ttf b/lib/font/fira-sans/FiraSans-SemiBoldItalic.ttf
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index 0000000..0d134e5
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diff --git a/lib/font/fira-sans/FiraSans-Thin.ttf b/lib/font/fira-sans/FiraSans-Thin.ttf
new file mode 100644
index 0000000..162ea86
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diff --git a/lib/font/fira-sans/FiraSans-ThinItalic.ttf b/lib/font/fira-sans/FiraSans-ThinItalic.ttf
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index 0000000..6febc77
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