From 6f2f27a571e9471b69b74ab5d80d53ee916b0c1f Mon Sep 17 00:00:00 2001
From: lzhengqc <lzhengqc@users.noreply.github.com>
Date: Sun, 1 Feb 2026 18:02:20 -0800
Subject: [PATCH 01/10] add fleet and ci

---
 .../{deploy-main.yml => deploy-main.yml.bak}  |  0
 ...{docker-build.yml => docker-build.yml.bak} |  0
 .github/workflows/pr-ci.yaml                  | 47 +++++++++++++++++++
 .../{test-branch.yml => test-branch.yml.bak}  |  0
 fleet.yaml                                    |  4 ++
 k8s/deployment.yaml                           | 19 ++++++++
 k8s/service.yaml                              | 12 +++++
 7 files changed, 82 insertions(+)
 rename .github/workflows/{deploy-main.yml => deploy-main.yml.bak} (100%)
 rename .github/workflows/{docker-build.yml => docker-build.yml.bak} (100%)
 create mode 100644 .github/workflows/pr-ci.yaml
 rename .github/workflows/{test-branch.yml => test-branch.yml.bak} (100%)
 create mode 100644 fleet.yaml
 create mode 100644 k8s/deployment.yaml
 create mode 100644 k8s/service.yaml

diff --git a/.github/workflows/deploy-main.yml b/.github/workflows/deploy-main.yml.bak
similarity index 100%
rename from .github/workflows/deploy-main.yml
rename to .github/workflows/deploy-main.yml.bak
diff --git a/.github/workflows/docker-build.yml b/.github/workflows/docker-build.yml.bak
similarity index 100%
rename from .github/workflows/docker-build.yml
rename to .github/workflows/docker-build.yml.bak
diff --git a/.github/workflows/pr-ci.yaml b/.github/workflows/pr-ci.yaml
new file mode 100644
index 0000000..f94b312
--- /dev/null
+++ b/.github/workflows/pr-ci.yaml
@@ -0,0 +1,47 @@
+name: PR Build & Deploy to k3d via Fleet
+
+on:
+  pull_request:
+    branches: [ main ]
+
+env:
+  REGISTRY: ghcr.io
+  IMAGE_NAME: lzhengqc/visualsubnetcalc
+
+jobs:
+  build-and-deploy:
+    runs-on: ubuntu-latest
+
+    permissions:
+      contents: write
+      packages: write
+
+    steps:
+      - name: Checkout repo
+        uses: actions/checkout@v4
+
+      - name: Login to GHCR
+        uses: docker/login-action@v3
+        with:
+          registry: ghcr.io
+          username: lzhengqc
+          password: ${{ secrets.GITHUB_TOKEN }}
+
+      - name: Build & Push Docker image
+        run: |
+          TAG=pr-${{ github.event.pull_request.number }}
+          docker build -t ghcr.io/lzhengqc/visualsubnetcalc:$TAG .
+          docker push ghcr.io/lzhengqc/visualsubnetcalc:$TAG
+          echo "IMAGE_TAG=$TAG" >> $GITHUB_ENV
+
+      - name: Update Kubernetes manifest
+        run: |
+          sed -i "s|image: .*|image: ghcr.io/lzhengqc/visualsubnetcalc:${IMAGE_TAG}|g" k8s/deployment.yaml
+
+      - name: Commit GitOps change
+        run: |
+          git config user.name "github-actions"
+          git config user.email "actions@github.com"
+          git add k8s/deployment.yaml
+          git commit -m "ci: deploy PR #${{ github.event.pull_request.number }}"
+          git push
\ No newline at end of file
diff --git a/.github/workflows/test-branch.yml b/.github/workflows/test-branch.yml.bak
similarity index 100%
rename from .github/workflows/test-branch.yml
rename to .github/workflows/test-branch.yml.bak
diff --git a/fleet.yaml b/fleet.yaml
new file mode 100644
index 0000000..faf8964
--- /dev/null
+++ b/fleet.yaml
@@ -0,0 +1,4 @@
+namespace: default
+
+kustomize:
+  dir: k8s
\ No newline at end of file
diff --git a/k8s/deployment.yaml b/k8s/deployment.yaml
new file mode 100644
index 0000000..6606eed
--- /dev/null
+++ b/k8s/deployment.yaml
@@ -0,0 +1,19 @@
+apiVersion: apps/v1
+kind: Deployment
+metadata:
+  name: visualsubnetcalc
+spec:
+  replicas: 1
+  selector:
+    matchLabels:
+      app: visualsubnetcalc
+  template:
+    metadata:
+      labels:
+        app: visualsubnetcalc
+    spec:
+      containers:
+        - name: visualsubnetcalc
+          image: ghcr.io/lzhengqc/visualsubnetcalc:latest
+          ports:
+            - containerPort: 8080
\ No newline at end of file
diff --git a/k8s/service.yaml b/k8s/service.yaml
new file mode 100644
index 0000000..69cdf6f
--- /dev/null
+++ b/k8s/service.yaml
@@ -0,0 +1,12 @@
+apiVersion: v1
+kind: Service
+metadata:
+  name: visualsubnetcalc
+spec:
+  type: ClusterIP
+  selector:
+    app: visualsubnetcalc
+  ports:
+    - name: http
+      port: 80
+      targetPort: 8080
\ No newline at end of file

From 53730250efc0b65a12522cb31c31168c3874eb02 Mon Sep 17 00:00:00 2001
From: lzhengqc <lzhengqc@users.noreply.github.com>
Date: Sun, 1 Feb 2026 18:16:17 -0800
Subject: [PATCH 02/10] test pr

---
 .github/workflows/pr-ci.yaml | 2 +-
 README.md                    | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/.github/workflows/pr-ci.yaml b/.github/workflows/pr-ci.yaml
index f94b312..c80be41 100644
--- a/.github/workflows/pr-ci.yaml
+++ b/.github/workflows/pr-ci.yaml
@@ -44,4 +44,4 @@ jobs:
           git config user.email "actions@github.com"
           git add k8s/deployment.yaml
           git commit -m "ci: deploy PR #${{ github.event.pull_request.number }}"
-          git push
\ No newline at end of file
+          git push
diff --git a/README.md b/README.md
index 7ffc816..77bca3a 100644
--- a/README.md
+++ b/README.md
@@ -1,5 +1,5 @@
 # Visual Subnet Calculator - [visualsubnetcalc.com](https://visualsubnetcalc.com)
-
+tst1
 ![demo.gif](src%2Fdemo.gif)
 
 Visual Subnet Calculator is a modernized tool based on the original work by [davidc](https://github.com/davidc/subnets).

From 424c0295e83a30341e60007e52cdc090d4a8641f Mon Sep 17 00:00:00 2001
From: lzhengqc <lzhengqc@users.noreply.github.com>
Date: Sun, 1 Feb 2026 18:23:04 -0800
Subject: [PATCH 03/10] update pr ci

---
 .github/workflows/pr-ci.yaml | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/.github/workflows/pr-ci.yaml b/.github/workflows/pr-ci.yaml
index c80be41..9298c87 100644
--- a/.github/workflows/pr-ci.yaml
+++ b/.github/workflows/pr-ci.yaml
@@ -42,6 +42,10 @@ jobs:
         run: |
           git config user.name "github-actions"
           git config user.email "actions@github.com"
+
           git add k8s/deployment.yaml
-          git commit -m "ci: deploy PR #${{ github.event.pull_request.number }}"
-          git push
+          git commit -m "ci: deploy PR #${{ github.event.pull_request.number }}" || echo "No changes to commit"
+
+          git push origin HEAD:${{ github.head_ref }}
+
+

From 4071cbc35a56920b54aff3bbd470121324e99b34 Mon Sep 17 00:00:00 2001
From: lzhengqc <lzhengqc@users.noreply.github.com>
Date: Sun, 1 Feb 2026 18:26:04 -0800
Subject: [PATCH 04/10] one more

---
 .github/workflows/pr-ci.yaml | 11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

diff --git a/.github/workflows/pr-ci.yaml b/.github/workflows/pr-ci.yaml
index 9298c87..9459548 100644
--- a/.github/workflows/pr-ci.yaml
+++ b/.github/workflows/pr-ci.yaml
@@ -43,9 +43,16 @@ jobs:
           git config user.name "github-actions"
           git config user.email "actions@github.com"
 
+          # Fetch the real PR branch
+          git fetch origin ${{ github.head_ref }}
+
+          # Rebase CI changes on top of PR branch
+          git checkout -B ci-temp HEAD
+          git rebase origin/${{ github.head_ref }}
+
           git add k8s/deployment.yaml
           git commit -m "ci: deploy PR #${{ github.event.pull_request.number }}" || echo "No changes to commit"
 
-          git push origin HEAD:${{ github.head_ref }}
-
+          # Push safely back to PR branch
+          git push origin HEAD:${{ github.head_ref }} --force-with-lease
 

From dad214f0602eb50a3f3fdd9261b36e52b11707d7 Mon Sep 17 00:00:00 2001
From: lzhengqc <lzhengqc@users.noreply.github.com>
Date: Sun, 1 Feb 2026 18:33:06 -0800
Subject: [PATCH 05/10] ci only

---
 .github/workflows/pr-ci.yaml | 41 +++++-------------------------------
 1 file changed, 5 insertions(+), 36 deletions(-)

diff --git a/.github/workflows/pr-ci.yaml b/.github/workflows/pr-ci.yaml
index 9459548..bd6009e 100644
--- a/.github/workflows/pr-ci.yaml
+++ b/.github/workflows/pr-ci.yaml
@@ -1,24 +1,17 @@
-name: PR Build & Deploy to k3d via Fleet
+name: PR Build Image
 
 on:
   pull_request:
     branches: [ main ]
 
-env:
-  REGISTRY: ghcr.io
-  IMAGE_NAME: lzhengqc/visualsubnetcalc
-
 jobs:
-  build-and-deploy:
+  build:
     runs-on: ubuntu-latest
-
     permissions:
-      contents: write
       packages: write
 
     steps:
-      - name: Checkout repo
-        uses: actions/checkout@v4
+      - uses: actions/checkout@v4
 
       - name: Login to GHCR
         uses: docker/login-action@v3
@@ -27,32 +20,8 @@ jobs:
           username: lzhengqc
           password: ${{ secrets.GITHUB_TOKEN }}
 
-      - name: Build & Push Docker image
+      - name: Build & Push PR image
         run: |
           TAG=pr-${{ github.event.pull_request.number }}
           docker build -t ghcr.io/lzhengqc/visualsubnetcalc:$TAG .
-          docker push ghcr.io/lzhengqc/visualsubnetcalc:$TAG
-          echo "IMAGE_TAG=$TAG" >> $GITHUB_ENV
-
-      - name: Update Kubernetes manifest
-        run: |
-          sed -i "s|image: .*|image: ghcr.io/lzhengqc/visualsubnetcalc:${IMAGE_TAG}|g" k8s/deployment.yaml
-
-      - name: Commit GitOps change
-        run: |
-          git config user.name "github-actions"
-          git config user.email "actions@github.com"
-
-          # Fetch the real PR branch
-          git fetch origin ${{ github.head_ref }}
-
-          # Rebase CI changes on top of PR branch
-          git checkout -B ci-temp HEAD
-          git rebase origin/${{ github.head_ref }}
-
-          git add k8s/deployment.yaml
-          git commit -m "ci: deploy PR #${{ github.event.pull_request.number }}" || echo "No changes to commit"
-
-          # Push safely back to PR branch
-          git push origin HEAD:${{ github.head_ref }} --force-with-lease
-
+          docker push ghcr.io/lzhengqc/visualsubnetcalc:$TAG
\ No newline at end of file

From 4371811b66f55c5f8497e33ffa0cf9b83a981bba Mon Sep 17 00:00:00 2001
From: lzhengqc <lzhengqc@users.noreply.github.com>
Date: Sun, 1 Feb 2026 18:39:08 -0800
Subject: [PATCH 06/10] add more

---
 .github/workflows/merge-deploy.yaml | 42 +++++++++++++++++++++++++++++
 fleet.yaml                          |  4 ---
 k8s/deployment.yaml                 | 19 -------------
 k8s/service.yaml                    | 12 ---------
 4 files changed, 42 insertions(+), 35 deletions(-)
 create mode 100644 .github/workflows/merge-deploy.yaml
 delete mode 100644 fleet.yaml
 delete mode 100644 k8s/deployment.yaml
 delete mode 100644 k8s/service.yaml

diff --git a/.github/workflows/merge-deploy.yaml b/.github/workflows/merge-deploy.yaml
new file mode 100644
index 0000000..04d125b
--- /dev/null
+++ b/.github/workflows/merge-deploy.yaml
@@ -0,0 +1,42 @@
+name: Deploy on Merge to Main
+
+on:
+  push:
+    branches: [ main ]
+
+jobs:
+  deploy:
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Checkout app repo
+        uses: actions/checkout@v4
+
+      - name: Set image tag
+        run: |
+          TAG=$(git rev-parse --short HEAD)
+          echo "IMAGE_TAG=$TAG" >> $GITHUB_ENV
+
+      - name: Build & Push Release Image
+        uses: docker/build-push-action@v5
+        with:
+          push: true
+          tags: ghcr.io/lzhengqc/visualsubnetcalc:${{ env.IMAGE_TAG }}
+
+      - name: Checkout GitOps repo
+        uses: actions/checkout@v4
+        with:
+          repository: lzhengqc/visualsubnetcalc-gitops
+          token: ${{ secrets.GITOPS_TOKEN }}
+          path: gitops
+
+      - name: Update GitOps deployment
+        run: |
+          sed -i "s|image: .*|image: ghcr.io/lzhengqc/visualsubnetcalc:${IMAGE_TAG}|g" \
+            gitops/k8s/deployment.yaml
+
+          cd gitops
+          git config user.name "github-actions"
+          git config user.email "actions@github.com"
+          git commit -am "deploy: visualsubnetcalc ${IMAGE_TAG}"
+          git push
\ No newline at end of file
diff --git a/fleet.yaml b/fleet.yaml
deleted file mode 100644
index faf8964..0000000
--- a/fleet.yaml
+++ /dev/null
@@ -1,4 +0,0 @@
-namespace: default
-
-kustomize:
-  dir: k8s
\ No newline at end of file
diff --git a/k8s/deployment.yaml b/k8s/deployment.yaml
deleted file mode 100644
index 6606eed..0000000
--- a/k8s/deployment.yaml
+++ /dev/null
@@ -1,19 +0,0 @@
-apiVersion: apps/v1
-kind: Deployment
-metadata:
-  name: visualsubnetcalc
-spec:
-  replicas: 1
-  selector:
-    matchLabels:
-      app: visualsubnetcalc
-  template:
-    metadata:
-      labels:
-        app: visualsubnetcalc
-    spec:
-      containers:
-        - name: visualsubnetcalc
-          image: ghcr.io/lzhengqc/visualsubnetcalc:latest
-          ports:
-            - containerPort: 8080
\ No newline at end of file
diff --git a/k8s/service.yaml b/k8s/service.yaml
deleted file mode 100644
index 69cdf6f..0000000
--- a/k8s/service.yaml
+++ /dev/null
@@ -1,12 +0,0 @@
-apiVersion: v1
-kind: Service
-metadata:
-  name: visualsubnetcalc
-spec:
-  type: ClusterIP
-  selector:
-    app: visualsubnetcalc
-  ports:
-    - name: http
-      port: 80
-      targetPort: 8080
\ No newline at end of file

From d6676d5a9f50350273313eef1645f3c4ef61cae2 Mon Sep 17 00:00:00 2001
From: lzhengqc <lzhengqc@users.noreply.github.com>
Date: Sun, 1 Feb 2026 18:48:37 -0800
Subject: [PATCH 07/10] add latest tag

---
 .github/workflows/pr-ci.yaml | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/.github/workflows/pr-ci.yaml b/.github/workflows/pr-ci.yaml
index bd6009e..ff31a56 100644
--- a/.github/workflows/pr-ci.yaml
+++ b/.github/workflows/pr-ci.yaml
@@ -24,4 +24,7 @@ jobs:
         run: |
           TAG=pr-${{ github.event.pull_request.number }}
           docker build -t ghcr.io/lzhengqc/visualsubnetcalc:$TAG .
+          # add latest tag for testing purpose
+          docker tag ghcr.io/lzhengqc/visualsubnetcalc:$TAG ghcr.io/lzhengqc/visualsubnetcalc:latest
+          docker push ghcr.io/lzhengqc/visualsubnetcalc:latest
           docker push ghcr.io/lzhengqc/visualsubnetcalc:$TAG
\ No newline at end of file

From 03acf7c13063f1a83fdbca85debf2f83cc4c26f5 Mon Sep 17 00:00:00 2001
From: lzhengqc <lzhengqc@users.noreply.github.com>
Date: Sun, 1 Feb 2026 18:54:51 -0800
Subject: [PATCH 08/10] enabled persist state

---
 dist/index.html |   5 +++
 dist/js/main.js | 112 +++++++++++++++++++++++++++++++++++++++++++++++-
 server.js       |  54 +++++++++++++++++++++++
 3 files changed, 169 insertions(+), 2 deletions(-)
 create mode 100644 server.js

diff --git a/dist/index.html b/dist/index.html
index 401293e..42464b1 100644
--- a/dist/index.html
+++ b/dist/index.html
@@ -99,6 +99,8 @@ <h1>Visual Subnet Calculator</h1>
             <div style="height:1.5rem"></div>
             <div>
                 <button id="btn_go" class="btn btn-success mb-0 mt-auto" type="button">Go</button>
+                <button id="btn_save_file" class="btn btn-outline-primary mb-0 ms-2 mt-auto" type="button">Save</button>
+                <button id="btn_load_file" class="btn btn-outline-secondary mb-0 ms-2 mt-auto" type="button">Load</button>
                 <div class="dropdown d-inline">
                     <button class="btn btn-secondary dropdown-toggle" type="button" data-bs-toggle="dropdown" aria-expanded="false">
                         Tools
@@ -179,6 +181,9 @@ <h3 class="modal-title" id="notifyModalLabel">Warning!</h3>
         </div>
     </div>
 
+        <!-- Hidden file input for loading configurations -->
+        <input type="file" id="hiddenFileInput" style="display: none;" accept=".json" aria-label="Load configuration file">
+
     <div class="modal fade" id="importExportModal" tabindex="-1" aria-hidden="true">
         <div class="modal-dialog modal-xl modal-dialog-centered">
             <div class="modal-content" role="alertdialog" aria-labelledby="importExportModalLabel" aria-describedby="importExportModalDescription">
diff --git a/dist/js/main.js b/dist/js/main.js
index d4b96a5..0326726 100644
--- a/dist/js/main.js
+++ b/dist/js/main.js
@@ -83,6 +83,7 @@ $('#calcbody').on('click', '.row_address, .row_range, .row_usable, .row_hosts, .
         // We could re-render here, but there is really no point, keep performant and just change the background color now
         //renderTable();
         $(this).closest('tr').css('background-color', inflightColor)
+        saveConfigToLocalStorage(exportConfig(false)); // Auto-save when color is set
     }
 })
 
@@ -144,6 +145,83 @@ $('#dropdown_oci').click(function() {
 $('#importBtn').on('click', function() {
     importConfig(JSON.parse($('#importExportArea').val()))
 })
+// Save configuration to a JSON file
+$('#btn_save_file').on('click', function(e) {
+    e.preventDefault();
+    const config = exportConfig(false);
+    const jsonString = JSON.stringify(config, null, 2);
+    
+    // Save to disk via API
+    fetch('/api/config/save', {
+        method: 'POST',
+        headers: { 'Content-Type': 'application/json' },
+        body: jsonString
+    }).catch(err => console.warn('API save failed (offline?), using local save:', err));
+    
+    // Also download file to user's computer
+    const blob = new Blob([jsonString], { type: 'application/json' });
+    const url = URL.createObjectURL(blob);
+    const link = document.createElement('a');
+    link.href = url;
+    link.download = `subnet-config-${new Date().toISOString().split('T')[0]}.json`;
+    document.body.appendChild(link);
+    link.click();
+    document.body.removeChild(link);
+    URL.revokeObjectURL(url);
+    
+    // Save to localStorage too
+    saveConfigToLocalStorage(config);
+})
+
+// Load configuration from a JSON file
+$('#btn_load_file').on('click', function(e) {
+    e.preventDefault();
+    $('#hiddenFileInput').click();
+})
+
+$('#hiddenFileInput').on('change', function(e) {
+    const file = e.target.files[0];
+    if (!file) return;
+    
+    const reader = new FileReader();
+    reader.onload = function(event) {
+        try {
+            const config = JSON.parse(event.target.result);
+            importConfig(config);
+            // Auto-save to localStorage after successful load
+            saveConfigToLocalStorage(config);
+            $('#input_form').removeClass('was-validated');
+            show_warning_modal('<div>Configuration loaded successfully!</div>');
+        } catch (error) {
+            show_warning_modal('<div>Error loading configuration file: ' + error.message + '</div>');
+        }
+    };
+    reader.readAsText(file);
+    // Reset the input so the same file can be loaded again
+    this.value = '';
+})
+
+// Save configuration to localStorage
+function saveConfigToLocalStorage(config) {
+    try {
+        localStorage.setItem('visualSubnetCalc_config', JSON.stringify(config));
+    } catch (e) {
+        console.warn('Failed to save configuration to localStorage:', e);
+    }
+}
+
+// Load configuration from localStorage
+function loadConfigFromLocalStorage() {
+    try {
+        const stored = localStorage.getItem('visualSubnetCalc_config');
+        if (stored) {
+            return JSON.parse(stored);
+        }
+    } catch (e) {
+        console.warn('Failed to load configuration from localStorage:', e);
+    }
+    return null;
+}
 
 $('#bottom_nav #colors_word_open').on('click', function() {
     $('#bottom_nav #color_palette').removeClass('d-none');
@@ -207,6 +285,8 @@ function reset() {
     }
     maxNetSize = parseInt($('#netsize').val())
     renderTable(operatingMode);
+        // Auto-save configuration to localStorage
+        saveConfigToLocalStorage(exportConfig(false));
 }
 
 function changeBaseNetwork(newBaseNetwork) {
@@ -228,6 +308,7 @@ $('#calcbody').on('click', 'td.split,td.join', function(event) {
     mutate_subnet_map(this.dataset.mutateVerb, this.dataset.subnet, '')
     this.dataset.subnet = sortIPCIDRs(this.dataset.subnet)
     renderTable(operatingMode);
+    saveConfigToLocalStorage(exportConfig(false));
 })
 
 $('#calcbody').on('keyup', 'td.note input', function(event) {
@@ -236,6 +317,7 @@ $('#calcbody').on('keyup', 'td.note input', function(event) {
     clearTimeout(noteTimeout);
     noteTimeout = setTimeout(function(element) {
         mutate_subnet_map('note', element.dataset.subnet, '', element.value)
+        saveConfigToLocalStorage(exportConfig(false));
     }, delay, this);
 })
 
@@ -243,6 +325,7 @@ $('#calcbody').on('focusout', 'td.note input', function(event) {
     // HTML DOM Data elements! Yay! See the `data-*` attributes of the HTML tags
     clearTimeout(noteTimeout);
     mutate_subnet_map('note', this.dataset.subnet, '', this.value)
+    saveConfigToLocalStorage(exportConfig(false));
 })
 
 
@@ -823,7 +906,32 @@ $( document ).ready(function() {
 
     let autoConfigResult = processConfigUrl();
     if (!autoConfigResult) {
-        reset();
+        // Try to auto-load from disk via API first (persistent across browser restarts)
+        fetch('/api/config/load')
+            .then(response => response.ok ? response.json() : null)
+            .then(diskConfig => {
+                if (diskConfig) {
+                    importConfig(diskConfig);
+                } else {
+                    // Fall back to localStorage
+                    const storedConfig = loadConfigFromLocalStorage();
+                    if (storedConfig) {
+                        importConfig(storedConfig);
+                    } else {
+                        reset();
+                    }
+                }
+            })
+            .catch(err => {
+                console.warn('API load failed (offline?), trying localStorage:', err);
+                // Fall back to localStorage if API fails
+                const storedConfig = loadConfigFromLocalStorage();
+                if (storedConfig) {
+                    importConfig(storedConfig);
+                } else {
+                    reset();
+                }
+            });
     }
 });
 
@@ -973,7 +1081,7 @@ function importConfig(text) {
     subnetMap = sortIPCIDRs(text['subnets']);
     operatingMode = text['operating_mode'] || 'Standard'
     switchMode(operatingMode);
-
+    renderTable(operatingMode);
 }
 
 function sortIPCIDRs(obj) {
diff --git a/server.js b/server.js
new file mode 100644
index 0000000..9cb41f2
--- /dev/null
+++ b/server.js
@@ -0,0 +1,54 @@
+const express = require('express');
+const path = require('path');
+const fs = require('fs');
+
+const app = express();
+const PORT = process.env.PORT || 8080;
+const CONFIG_DIR = '/app/config';
+const CONFIG_FILE = path.join(CONFIG_DIR, 'last-config.json');
+
+// Ensure config directory exists
+if (!fs.existsSync(CONFIG_DIR)) {
+  fs.mkdirSync(CONFIG_DIR, { recursive: true });
+}
+
+// Middleware
+app.use(express.json());
+app.use(express.static(path.join(__dirname, 'dist')));
+
+// API: Save configuration to disk
+app.post('/api/config/save', (req, res) => {
+  try {
+    const config = req.body;
+    fs.writeFileSync(CONFIG_FILE, JSON.stringify(config, null, 2));
+    res.json({ success: true, message: 'Configuration saved to disk' });
+  } catch (error) {
+    console.error('Error saving config:', error);
+    res.status(500).json({ success: false, error: error.message });
+  }
+});
+
+// API: Load configuration from disk
+app.get('/api/config/load', (req, res) => {
+  try {
+    if (fs.existsSync(CONFIG_FILE)) {
+      const config = fs.readFileSync(CONFIG_FILE, 'utf-8');
+      res.json(JSON.parse(config));
+    } else {
+      res.status(404).json({ success: false, error: 'No saved configuration found' });
+    }
+  } catch (error) {
+    console.error('Error loading config:', error);
+    res.status(500).json({ success: false, error: error.message });
+  }
+});
+
+// Serve index.html for root path
+app.get('/', (req, res) => {
+  res.sendFile(path.join(__dirname, 'dist', 'index.html'));
+});
+
+// Start server
+app.listen(PORT, () => {
+  console.log(`Visual Subnet Calculator server running on port ${PORT}`);
+});

From 983939097e5c926479aa5c905d13d2d14faafb02 Mon Sep 17 00:00:00 2001
From: lzhengqc <lzhengqc@users.noreply.github.com>
Date: Sun, 1 Feb 2026 19:09:32 -0800
Subject: [PATCH 09/10] Update merge-deploy.yaml

---
 .github/workflows/merge-deploy.yaml | 21 +++++++++++++++++----
 1 file changed, 17 insertions(+), 4 deletions(-)

diff --git a/.github/workflows/merge-deploy.yaml b/.github/workflows/merge-deploy.yaml
index 04d125b..d0ab40b 100644
--- a/.github/workflows/merge-deploy.yaml
+++ b/.github/workflows/merge-deploy.yaml
@@ -1,13 +1,19 @@
-name: Deploy on Merge to Main
+name: Deploy on PR Merge
 
 on:
-  push:
+  pull_request:
+    types: [closed]
     branches: [ main ]
 
 jobs:
   deploy:
+    if: github.event.pull_request.merged == true
     runs-on: ubuntu-latest
 
+    permissions:
+      contents: write
+      packages: write
+
     steps:
       - name: Checkout app repo
         uses: actions/checkout@v4
@@ -17,7 +23,14 @@ jobs:
           TAG=$(git rev-parse --short HEAD)
           echo "IMAGE_TAG=$TAG" >> $GITHUB_ENV
 
-      - name: Build & Push Release Image
+      - name: Login to GHCR
+        uses: docker/login-action@v3
+        with:
+          registry: ghcr.io
+          username: lzhengqc
+          password: ${{ secrets.GITHUB_TOKEN }}
+
+      - name: Build & Push Image
         uses: docker/build-push-action@v5
         with:
           push: true
@@ -39,4 +52,4 @@ jobs:
           git config user.name "github-actions"
           git config user.email "actions@github.com"
           git commit -am "deploy: visualsubnetcalc ${IMAGE_TAG}"
-          git push
\ No newline at end of file
+          git push

From 27e5a7ff0dcf81d91e30cb8b64071e0da5e352f0 Mon Sep 17 00:00:00 2001
From: lzhengqc <lzhengqc@users.noreply.github.com>
Date: Sun, 1 Feb 2026 23:43:52 -0800
Subject: [PATCH 10/10] revert readme change

---
 README.md | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/README.md b/README.md
index 77bca3a..7ffc816 100644
--- a/README.md
+++ b/README.md
@@ -1,5 +1,5 @@
 # Visual Subnet Calculator - [visualsubnetcalc.com](https://visualsubnetcalc.com)
-tst1
+
 ![demo.gif](src%2Fdemo.gif)
 
 Visual Subnet Calculator is a modernized tool based on the original work by [davidc](https://github.com/davidc/subnets).