{
  description = "Personal website";

  inputs = {
    nixpkgs.url = "github:NixOS/nixpkgs/nixpkgs-unstable";
    flake-utils.url = "github:numtide/flake-utils";

    # Sub-projects: uncomment and replace URLs when ready
    # project-a = {
    #   url = "path:/path/to/project-a";
    #   inputs.nixpkgs.follows = "nixpkgs";
    # };
    # project-b = {
    #   url = "path:/path/to/project-b";
    #   inputs.nixpkgs.follows = "nixpkgs";
    # };
  };

  outputs = { self, nixpkgs, flake-utils, ... } @ inputs:
    flake-utils.lib.eachSystem [ "x86_64-linux" "aarch64-linux" ] (system:
      let
        pkgs = import nixpkgs { inherit system; };

        # Sub-project outputs — uncomment when inputs above are added
        # subProjectA = inputs.project-a.packages.${system}.default;
        # subProjectB = inputs.project-b.packages.${system}.default;

        site = pkgs.stdenv.mkDerivation {
          name = "personal-site";
          src = pkgs.lib.cleanSource ./.;

          nativeBuildInputs = [ pkgs.emacs-nox ];

          buildPhase = ''
            mkdir -p public
            export HOME=$(mktemp -d)
            emacs --batch --load ./build.el
          '';

          installPhase = ''
            cp -r public/. $out/

            # Sub-project integration: when adding a sub-project, add lines like:
            #   mkdir -p $out/project-a
            #   cp -r <subProjectA-store-path>/. $out/project-a/
          '';
        };

        serve = pkgs.writeShellApplication {
          name = "serve";
          runtimeInputs = [ pkgs.python3 pkgs.psmisc ];
          text = ''
            fuser -k 8080/tcp 2>/dev/null || true
            echo "Serving site at http://localhost:8080"
            python -m http.server --bind 0.0.0.0 8080 -d ${site}
          '';
        };

        tunnel = pkgs.writeShellApplication {
          name = "tunnel";
          runtimeInputs = [ pkgs.python3 pkgs.cloudflared pkgs.qrencode ];
          text = ''
            echo "Starting local server and Cloudflare tunnel..."
            echo ""

            echo "Starting local server on http://localhost:8080..."
            python -m http.server --bind 0.0.0.0 8080 -d ${site} &
            SERVER_PID=$!

            sleep 2

            echo ""
            echo "Starting HTTPS tunnel..."
            echo "Use the QR code below on your device:"
            echo ""

            cloudflared tunnel --url http://localhost:8080 2>&1 | \
              while IFS= read -r line; do
                echo "$line"
                if echo "$line" | grep -q "https://.*trycloudflare.com"; then
                  URL=$(echo "$line" | grep -o "https://[^ ]*trycloudflare.com")
                  echo ""
                  echo "=========================================="
                  echo "TUNNEL URL: $URL"
                  echo "=========================================="
                  echo ""
                  echo "QR Code:"
                  echo ""
                  qrencode -t ANSIUTF8 "$URL"
                  echo ""
                fi
              done

            kill $SERVER_PID 2>/dev/null
          '';
        };

        new-post = pkgs.writeShellApplication {
          name = "new-post";
          runtimeInputs = [ pkgs.coreutils pkgs.gnused ];
          text = ''
            if [ $# -eq 0 ]; then
              echo "Usage: new-post \"Post Title\""
              exit 1
            fi
            title="$*"
            slug=$(echo "$title" | tr '[:upper:]' '[:lower:]' | sed 's/[^a-z0-9]/-/g' | sed 's/-\+/-/g' | sed 's/^-//;s/-$//')
            date=$(date +%Y-%m-%d)
            filename="content/blog/''${date}-''${slug}.org"
            mkdir -p content/blog
            cat > "$filename" <<EOF
#+TITLE: $title
#+DATE: $date

*

EOF
            echo "Created: $filename"
          '';
        };

      in {
        packages.default = site;

        devShells.default = pkgs.mkShell {
          packages = [ new-post ];
        };

        apps = {
          default = {
            type = "app";
            program = "${serve}/bin/serve";
          };
          tunnel = {
            type = "app";
            program = "${tunnel}/bin/tunnel";
          };
        };
      }
    );
}