diff --git a/.github/workflows/build.yaml b/.github/workflows/build.yaml
index e218da6b..c5deb29d 100644
--- a/.github/workflows/build.yaml
+++ b/.github/workflows/build.yaml
@@ -33,80 +33,40 @@ jobs:
         with:
           fetch-depth: 0
 
-      - name: Setup pnpm
-        uses: pnpm/action-setup@v3
+      - name: Install nix
+        uses: cachix/install-nix-action@v26
         with:
-          version: latest
-          run_install: true
+          nix_path: "${{ matrix.nixPath }}"
+          extra_nix_config: |
+            experimental-features = nix-command flakes
+            access-tokens = github.com=${{ secrets.GITHUB_TOKEN }}
 
-      - uses: actions/setup-node@v4
-        with:
-          cache: pnpm
-          node-version: current
-
-      - name: Install
-        run: pnpm install
-
-      - name: Install mdBook
-        uses: baptiste0928/cargo-install@v2
-        with:
-          crate: mdbook
-          git: https://github.com/rust-lang/mdBook
-
-      - name: Install mdbook-epub
-        uses: baptiste0928/cargo-install@v2
-        with:
-          crate: mdbook-epub
-          git: https://github.com/Michael-F-Bryan/mdbook-epub
+      - name: Show nixpkgs version
+        run: nix-instantiate --eval -E '(import <nixpkgs> {}).lib.version'
 
-      - name: Install mdbook-typst-pdf
-        uses: baptiste0928/cargo-install@v2
+      - name: Setup cachix
+        uses: cachix/cachix-action@v14
         with:
-          crate: mdbook-typst-pdf
-          git: https://github.com/KaiserY/mdbook-typst-pdf
+          name: cryolitia
+          extraPullNames: nix-community
 
-      - name: Install fonts
-        run: |
-          mkdir -p ~/.local/share/fonts/
-          curl -sL -o Noto_Sans.zip https://fonts.google.com/download?family=Noto%20Sans
-          unzip Noto_Sans.zip -d ~/.local/share/fonts/Noto_Sans
-          curl -sL -o Noto_Sans_SC.zip https://fonts.google.com/download?family=Noto%20Sans%20SC
-          unzip Noto_Sans_SC.zip -d ~/.local/share/fonts/Noto_Sans_SC
-          curl -sL -o Noto_Sans_Mono.zip https://fonts.google.com/download?family=Noto%20Sans%20Mono
-          unzip Noto_Sans_Mono.zip -d ~/.local/share/fonts/Noto_Sans_Mono
-          rm -fv ~/.local/share/fonts/Noto_Sans_Mono/NotoSansMono-VariableFont_wdth,wght.ttf
-          curl -sL -o Noto_Sans_KR.zip https://fonts.google.com/download?family=Noto%20Sans%20KR
-          unzip Noto_Sans_KR.zip -d ~/.local/share/fonts/Noto_Sans_KR
-          curl -sL -o Noto_Sans_Thai.zip https://fonts.google.com/download?family=Noto%20Sans%20Thai
-          unzip Noto_Sans_Thai.zip -d ~/.local/share/fonts/Noto_Sans_Thai
-          rm -fv ~/.local/share/fonts/Noto_Sans_Thai/NotoSansThai-VariableFont_wdth,wght.ttf
-          curl -sL -o Noto_Sans_Arabic.zip https://fonts.google.com/download?family=Noto%20Sans%20Arabic
-          unzip Noto_Sans_Arabic.zip -d ~/.local/share/fonts/Noto_Sans_Arabic
-          curl -sL -o Noto_Sans_Hebrew.zip https://fonts.google.com/download?family=Noto%20Sans%20Hebrew
-          unzip Noto_Sans_Hebrew.zip -d ~/.local/share/fonts/Noto_Sans_Hebrew
-          curl -sL -o Noto_Sans_Devanagari.zip https://fonts.google.com/download?family=Noto%20Sans%20Devanagari
-          unzip Noto_Sans_Devanagari.zip -d ~/.local/share/fonts/Noto_Sans_Devanagari
-          rm -fv ~/.local/share/fonts/Noto_Sans_Devanagari/NotoSansDevanagari-VariableFont_wdth,wght.ttf
-          curl -sL -o Noto_Emoji.zip https://fonts.google.com/download?family=Noto%20Emoji
-          unzip Noto_Emoji.zip -d ~/.local/share/fonts/Noto_Emoji
-          curl -sL -o times_sans_serif.zip https://dl.dafont.com/dl/?f=times_sans_serif
-          unzip times_sans_serif.zip -d ~/.local/share/fonts/times_sans_serif
-          fc-cache -rv
-
-      - name: Install Calibre
-        run: |
-          sudo apt install -y libegl1 libopengl0 libxcb-cursor0
-          sudo -v && wget -nv -O- https://download.calibre-ebook.com/linux-installer.sh | sudo sh /dev/stdin
+      - name: Setup Github Caches
+        uses: DeterminateSystems/magic-nix-cache-action@v4
 
       - name: Build
-        env:
-          NODE_OPTIONS: --max_old_space_size=4096
         run: |
           sed -e "s/BUILD_TIME/$(TZ=Asia/Shanghai date -Isecond)/" -e "s/COMMIT_SHA/${{ github.sha }}/" -i src/about.md
-          pnpm run build
+          NIXPKGS_ALLOW_UNFREE=1 nix build .# --impure -v -L
+
+      - uses: actions/upload-artifact@v4
+        with:
+          path: |
+            result/**/*.epub
+            result/**/*.pdf
+            result/**/*.mobi
 
       - name: Release eBook
         if: github.ref == 'refs/heads/main' && github.event_name != 'pull_request'
         env:
           GITHUB_TOKEN: ${{ github.token }}
-        run: pnpm exec semantic-release
+        run: exit0 || pnpm exec semantic-release
diff --git a/.github/workflows/update-flake.yml b/.github/workflows/update-flake.yml
new file mode 100644
index 00000000..e4398426
--- /dev/null
+++ b/.github/workflows/update-flake.yml
@@ -0,0 +1,47 @@
+name: "Update flake"
+on:
+  workflow_dispatch:
+  schedule:
+    # rebuild everyday at 2:51
+    # TIP: Choose a random time here so not all repositories are build at once:
+    # https://www.random.org/clock-times/?num=1&earliest=01%3A00&latest=08%3A00&interval=5&format=html&rnd=new
+    - cron:  '31 2 * * 5'
+
+permissions:
+  contents: write
+
+jobs:
+  sync-flake:
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Install nix
+        uses: cachix/install-nix-action@v26
+        with:
+          nix_path: nixpkgs=channel:nixpkgs-unstable
+          extra_nix_config: |
+            experimental-features = nix-command flakes
+            access-tokens = github.com=${{ secrets.GITHUB_TOKEN }}
+
+      - name: Checkout
+        uses: actions/checkout@v4
+        with:
+          show-progress: false
+
+      - name: Setup Git
+        run: |
+          git config --global user.name "$GITHUB_ACTOR"
+          git config --global user.email "$GITHUB_ACTOR@users.noreply.github.com"
+          git show -s
+
+      - name: Update flake
+        run: |
+          nix flake update --accept-flake-config
+          nix flake info --accept-flake-config
+
+      - name: Update flake
+        run: |
+          git add .
+          git status
+          git commit -m "flake update: $(date +'%Y-%m-%dT%H:%M:%S')" || exit 0
+          git push
diff --git a/flake.nix b/flake.nix
index 3bc60ab9..ec2598d0 100644
--- a/flake.nix
+++ b/flake.nix
@@ -45,6 +45,7 @@
           , mdbook-epub
           , nur-cryolitia
           , source-han-serif
+          , typst
           }:
 
           stdenvNoCC.mkDerivation
@@ -60,6 +61,7 @@
                 mdbook-epub
                 nur-cryolitia.mdbook-typst-pdf
                 source-han-serif
+                typst
               ];
 
               buildPhase = ''
@@ -73,6 +75,9 @@
                 mkdir -p book/mobi
                 ebook-convert book/epub/药娘的天空.epub book/mobi/药娘的天空.mobi
 
+                export TYPST_FONT_PATHS=${source-han-serif}/share/fonts/opentype/source-han-serif
+                typst compile book/typst-pdf/药娘的天空.typ
+
                 runHook postBuild
               '';
 
diff --git a/theme/template.typ b/theme/template.typ
index 4f7918d3..7c898b1e 100644
--- a/theme/template.typ
+++ b/theme/template.typ
@@ -1,7 +1,7 @@
 #set text(
   lang: "zh",
   font: (
-    "Source Han Serif",
+    "Source Han Serif SC",
   ),
 )