nextjs upgrade

This PR contains the following updates:

| Package | Type | Update | Change |
|---|---|---|---|
| [eslint-plugin-react-hooks](https://react.dev/) ([source](https://github.com/facebook/react/tree/HEAD/packages/eslint-plugin-react-hooks)) | devDependencies | pin | [`^5.2.0` -> `5.2.0`](https://renovatebot.com/diffs/npm/eslint-plugin-react-hooks/5.2.0/5.2.0) |
| [pnpm/action-setup](https://github.com/pnpm/action-setup) | action | pinDigest |  -> `a7487c7` |

Add the preset `:preserveSemverRanges` to your config if you don't want to pin your dependencies.

---

### Configuration

📅 **Schedule**: Branch creation - "every weekend" (UTC), Automerge - At any time (no schedule defined).

🚦 **Automerge**: Disabled by config. Please merge this manually once you are satisfied.

♻ **Rebasing**: Whenever PR is behind base branch, or you tick the rebase/retry checkbox.

👻 **Immortal**: This PR will be recreated if closed unmerged. Get [config help](https://github.com/renovatebot/renovate/discussions) if that's undesired.

---

 - [ ] <!-- rebase-check -->If you want to rebase/retry this PR, check this box

---

This PR has been generated by [Renovate Bot](https://github.com/renovatebot/renovate).
<!--renovate-debug:eyJjcmVhdGVkSW5WZXIiOiI0MS4zMS4xIiwidXBkYXRlZEluVmVyIjoiNDEuMzEuMSIsInRhcmdldEJyYW5jaCI6Im1haW4iLCJsYWJlbHMiOltdfQ==-->

Reviewed-on: #7
Co-authored-by: Renovate Bot <renovatebot@schulze.network>
Co-committed-by: Renovate Bot <renovatebot@schulze.network>

.gitea/workflows/check.yml

@@ -0,0 +1,31 @@
+name: Lint
+
+on:
+  pull_request:
+  push:
+    branches:
+      - "**" # matches every branch
+
+jobs:
+  lint_and_typecheck:
+    name: Lint and Typecheck
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4
+
+      - name: Install pnpm
+        uses: pnpm/action-setup@a7487c7e89a18df4991f7f222e4898a00d66ddda # v4
+
+      - name: Setup Node.js
+        uses: actions/setup-node@49933ea5288caeca8642d1e84afbd3f7d6820020 # v4
+        with:
+          node-version: 22
+          cache: "pnpm"
+
+      - name: Install dependencies
+        run: pnpm install
+
+      - name: Run check
+        run: pnpm run check

README.md

@@ -1,3 +1,108 @@
-# fire
+![InvestingFIRE logo](/src/app/apple-icon.png)
 
-FIRE calculator
+# InvestingFIRE 🔥 — The #1 Interactive FIRE Calculator
+
+**InvestingFIRE** is a responsive web application for calculating your path to Financial Independence and Early Retirement (FIRE). It features a year-by-year projection engine that simulates both accumulation (savings and investment growth) and retirement (withdrawals) phases, allowing users to:
+
+- Input starting capital, monthly savings, expected annual growth rate, inflation rate, current age, desired retirement age, life expectancy, and desired monthly retirement allowance.
+- View a dynamic chart displaying projected portfolio balance and monthly allowance over time.
+- Instantly see their estimated “FIRE number” (required capital at retirement), how long their capital will last, and compare results to the “4% rule.”
+- Adjust assumptions live, with all calculations and visualizations updating automatically.
+- Access explanatory content about FIRE methodology, key variables, and additional community resources, all on a single, consolidated page.
+
+The project’s code is structured using React/Next.js with TypeScript, focusing on user experience, modern UI components, and clarity of financial assumptions.
+
+---
+
+## 🚀 Features at a Glance
+
+- **⚡️ Real-Time Projections:** Every field updates the chart _as you type_. Experiment with savings, growth rates, inflation, or retirement age and see your future instantly.
+- **📈 Interactive Chart:** Dual-area plots for portfolio value and future monthly spending, plus reference lines for FIRE milestones and “4% rule” legends.
+- **🧠 Education Baked In:** Contextual tooltips, deep-dive sections on how FIRE works, FAQs, and must-read resources included.
+- **🔎 Detailed Methodology:** Not just a 25x rule — runs a full, year-by-year simulation with inflation-adjusted withdrawals and optional 4%-rule overlays.
+- **👌 Modern UX:** Typing, sliding, or clicking feels _good_. Responsive on all devices.
+
+---
+
+## 🧰 How It Works
+
+The calculator models your FIRE journey in two phases:
+
+1. **Accumulation:**
+   - Your starting capital is grown by your expected CAGR (~7% by default).
+   - Monthly savings are added for each year until retirement.
+   - Every variable can be adjusted live (capital, savings, age, growth, inflation, spending, target retirement).
+
+2. **Retirement:**
+   - Your balance continues to grow by CAGR.
+   - Each year, an inflation-adjusted monthly allowance is withdrawn.
+   - The simulation runs until your selected life expectancy, showing the possibility of portfolio depletion.
+
+**Key Outputs:**
+
+- 🔥 “FIRE Number”: Portfolio value at your defined retirement age
+- 📊 Interactive projection chart: See how your nest egg and withdrawals evolve over time
+- 4️⃣ “4% Rule” overlays: Compare dynamic results to classic rule-of-thumb
+
+---
+
+## 🌟 Try It For Yourself
+
+To run locally:
+
+1. **Clone the repo**
+   ```bash
+   git clone https://git.schulze.network/schulze/fire.git
+   cd fire
+   ```
+2. **Install dependencies**
+   ```bash
+   pnpm install
+   ```
+3. **Run the app**
+   ```bash
+   pnpm run dev
+   ```
+4. Visit [http://localhost:3000](http://localhost:3000) and unleash the fire.
+
+Deployed version: [https://investingfire.com](https://investingfire.com)
+
+---
+
+## ✏️ Inputs & Variables
+
+- **Starting Capital** — How much you’ve already invested
+- **Monthly Savings** — What you’ll add each month
+- **Current Age & Retirement Age** — Your FI timeline
+- **Life Expectancy** — How long do you want income to last?
+- **Expected Growth Rate (CAGR)** — Portfolio annual % return, before inflation
+- **Inflation Rate** — Cost of living increases
+- **Desired Monthly Allowance** — Your lifestyle, today’s dollars
+
+As you adjust these, all projections update instantly _without needing to hit “Calculate.”_
+
+Try many “what ifs” fast.
+
+---
+
+## 👩‍💻 Contributing
+
+Pull requests are welcome! Open issues for bugs, new features, or debate about safe withdrawal rates and tax assumptions.
+
+---
+
+## 📄 License
+
+[GPL-3.0](./LICENSE)
+
+---
+
+## 🥇 Why Use InvestingFIRE?
+
+- You want the truth — not just a 4% fantasy.
+- You want to learn, not just punch in numbers.
+- You want clarity, speed, and modern UI.
+- You want to show your friends the best FIRE tool on the web.
+
+Enjoy the _rocket ride_ to financial independence.  
+**InvestingFIRE — Know your number. Change your future.**

package.json

@@ -6,14 +6,12 @@
   "scripts": {
     "build": "next build",
     "check": "next lint && tsc --noEmit",
-    "dev": "next dev --turbo",
+    "dev": "next dev --turbopack",
     "format:check": "prettier --check \"**/*.{ts,tsx,js,jsx,mdx}\" --cache",
     "format:write": "prettier --write \"**/*.{ts,tsx,js,jsx,mdx}\" --cache",
-    "lint": "next lint",
     "lint:fix": "next lint --fix",
     "preview": "next build && next start",
-    "start": "next start",
-    "typecheck": "tsc --noEmit"
+    "start": "next start"
   },
   "dependencies": {
     "@hookform/resolvers": "^5.0.1",
@@ -22,37 +20,38 @@
     "@radix-ui/react-select": "^2.2.2",
     "@radix-ui/react-slider": "^1.3.2",
     "@radix-ui/react-slot": "^1.2.0",
-    "@t3-oss/env-nextjs": "^0.12.0",
+    "@t3-oss/env-nextjs": "^0.13.0",
     "class-variance-authority": "^0.7.1",
     "clsx": "^2.1.1",
-    "lucide-react": "^0.503.0",
-    "next": "^15.2.3",
+    "lucide-react": "^0.525.0",
+    "next": "^15.4.1",
     "next-plausible": "^3.12.4",
     "react": "^19.0.0",
     "react-dom": "^19.0.0",
     "react-hook-form": "^7.56.1",
     "recharts": "^2.15.3",
     "tailwind-merge": "^3.2.0",
-    "zod": "^3.24.3"
+    "zod": "^4.0.0"
   },
   "devDependencies": {
-    "@eslint/eslintrc": "^3.3.1",
-    "@tailwindcss/postcss": "^4.0.15",
-    "@types/node": "^20.14.10",
-    "@types/react": "^19.0.0",
-    "@types/react-dom": "^19.0.0",
-    "eslint": "^9.23.0",
-    "eslint-config-next": "^15.2.3",
-    "postcss": "^8.5.3",
-    "prettier": "^3.5.3",
-    "prettier-plugin-tailwindcss": "^0.6.11",
-    "tailwindcss": "^4.0.15",
-    "tw-animate-css": "^1.2.8",
-    "typescript": "^5.8.2",
-    "typescript-eslint": "^8.27.0"
+    "@eslint/eslintrc": "3.3.1",
+    "@tailwindcss/postcss": "4.1.11",
+    "@types/node": "22.16.3",
+    "@types/react": "19.1.8",
+    "@types/react-dom": "19.1.6",
+    "eslint": "9.31.0",
+    "eslint-config-next": "15.4.1",
+    "eslint-plugin-react-hooks": "5.2.0",
+    "postcss": "8.5.6",
+    "prettier": "3.6.2",
+    "prettier-plugin-tailwindcss": "0.6.14",
+    "tailwindcss": "4.1.11",
+    "tw-animate-css": "1.3.5",
+    "typescript": "5.8.3",
+    "typescript-eslint": "8.36.0"
   },
   "ct3aMetadata": {
     "initVersion": "7.39.3"
   },
-  "packageManager": "npm@11.2.0"
+  "packageManager": "pnpm@10.13.1"
 }

pnpm-workspace.yaml

@@ -0,0 +1,6 @@
+ignoredBuiltDependencies:
+  - unrs-resolver
+
+onlyBuiltDependencies:
+  - '@tailwindcss/oxide'
+  - sharp

public/wgu5fuk8d5j5wp3pjtta9vrw8d9by9qk.txt

@@ -0,0 +1 @@
+wgu5fuk8d5j5wp3pjtta9vrw8d9by9qk

renovate.json

@@ -0,0 +1,11 @@
+{
+  "extends": ["config:best-practices", ":semanticCommits"],
+  "$schema": "https://docs.renovatebot.com/renovate-schema.json",
+  "packageRules": [
+    {
+      "matchUpdateTypes": ["minor", "patch", "pin", "digest"],
+      "automerge": true,
+      "automergeType": "branch"
+    }
+  ]
+}

src/app/components/BackgroundPattern.tsx

@@ -0,0 +1,157 @@
+"use client";
+import { useState, useEffect } from "react";
+import {
+  type LucideIcon,
+  HandCoins,
+  Bitcoin,
+  Coins,
+  DollarSign,
+  Euro,
+  IndianRupee,
+  JapaneseYen,
+  PiggyBank,
+  PoundSterling,
+  Wallet,
+  Banknote,
+  ChartCandlestick,
+  CirclePercent,
+  CreditCard,
+  Gem,
+  Receipt,
+  ShoppingBasket,
+  Rocket,
+  RockingChair,
+  Sparkles,
+  ChartPie,
+  ChartBar,
+  BarChart3,
+  ChartLine,
+  TrendingDown,
+  TrendingUp,
+  Vault,
+  Landmark,
+  Briefcase,
+  Handshake,
+  Shield,
+  Lock,
+  CalendarRange,
+  Hourglass,
+  Sprout,
+  Target,
+} from "lucide-react";
+
+export default function MultiIconPattern({ opacity = 0.2, spacing = 160 }) {
+  const [width, setWidth] = useState(0);
+  const [height, setHeight] = useState(0);
+  const [rows, setRows] = useState(0);
+  const [columns, setColumns] = useState(0);
+
+  useEffect(() => {
+    const updateDimensions = () => {
+      if (window.innerWidth > width + spacing * 2) {
+        setWidth(window.innerWidth);
+      }
+      if (window.innerHeight > height + spacing * 2) {
+        setHeight(window.innerHeight);
+      }
+    };
+
+    updateDimensions();
+    window.addEventListener("resize", updateDimensions);
+
+    return () => {
+      window.removeEventListener("resize", updateDimensions);
+    };
+  }, [height, width, spacing]);
+
+  useEffect(() => {
+    setColumns(Math.ceil(width / spacing) + 3);
+  }, [width, spacing]);
+
+  useEffect(() => {
+    setRows(Math.ceil(height / spacing) + 3);
+  }, [height, spacing]);
+
+  // Explicitly type the array as LucideIcon[]
+  const iconComponents: LucideIcon[] = [
+    HandCoins,
+    Bitcoin,
+    Coins,
+    DollarSign,
+    Euro,
+    IndianRupee,
+    JapaneseYen,
+    PiggyBank,
+    PoundSterling,
+    Wallet,
+    Banknote,
+    ChartCandlestick,
+    CirclePercent,
+    CreditCard,
+    Gem,
+    Receipt,
+    ShoppingBasket,
+    Rocket,
+    RockingChair,
+    Sparkles,
+    ChartPie,
+    ChartBar,
+    BarChart3,
+    ChartLine,
+    TrendingDown,
+    TrendingUp,
+    Vault,
+    Landmark,
+    Briefcase,
+    Handshake,
+    Shield,
+    Lock,
+    CalendarRange,
+    Hourglass,
+    Sprout,
+    Target,
+  ];
+
+  const renderIcons = ({
+    rows,
+    columns,
+  }: {
+    rows: number;
+    columns: number;
+  }) => {
+    const icons = [];
+    for (let y = 0; y < rows; y++) {
+      for (let x = 0; x < columns; x++) {
+        // Pick a random icon component from the array
+        const randomIndex = Math.floor(Math.random() * iconComponents.length);
+        const IconComponent = iconComponents[randomIndex]!;
+
+        // Slightly randomize size and position for more organic feel
+        const size = 28 + Math.floor(Math.random() * 8);
+        const xOffset = Math.floor(Math.random() * (spacing / 1.618));
+        const yOffset = Math.floor(Math.random() * (spacing / 1.618));
+
+        icons.push(
+          <IconComponent
+            key={`icon-${x}-${y}`}
+            size={size}
+            className="text-primary fixed"
+            style={{
+              left: `${x * spacing + xOffset}px`,
+              top: `${y * spacing + yOffset}px`,
+              opacity: opacity,
+              transform: `rotate(${Math.round((Math.random() - 0.5) * 30)}deg)`,
+            }}
+          />,
+        );
+      }
+    }
+    return icons;
+  };
+
+  return (
+    <div className="absolute h-full w-full">
+      {width > 0 && renderIcons({ rows, columns })}
+    </div>
+  );
+}

src/app/components/FireCalculatorForm.tsx

@@ -73,12 +73,16 @@ interface YearlyData {
   age: number;
   year: number;
   balance: number;
+  untouchedBalance: number;
   phase: "accumulation" | "retirement";
   monthlyAllowance: number;
+  untouchedMonthlyAllowance: number;
 }
 
 interface CalculationResult {
   fireNumber: number | null;
+  fireNumber4percent: number | null;
+  retirementAge4percent: number | null;
   yearlyData: YearlyData[];
   error?: string;
 }
@@ -101,8 +105,8 @@ const tooltipRenderer = ({
     return (
       <div className="bg-background border p-2 shadow-sm">
         <p className="font-medium">{`Year: ${data.year.toString()} (Age: ${data.age.toString()})`}</p>
-        <p className="text-chart-1">{`Balance: ${formatNumber(data.balance)}`}</p>
-        <p className="text-chart-2">{`Monthly allowance: ${formatNumber(data.monthlyAllowance)}`}</p>
+        <p className="text-orange-500">{`Balance: ${formatNumber(data.balance)}`}</p>
+        <p className="text-red-600">{`Monthly allowance: ${formatNumber(data.monthlyAllowance)}`}</p>
         <p>{`Phase: ${data.phase === "accumulation" ? "Accumulation" : "Retirement"}`}</p>
       </div>
     );
@@ -113,9 +117,10 @@ const tooltipRenderer = ({
 export default function FireCalculatorForm() {
   const [result, setResult] = useState<CalculationResult | null>(null);
   const irlYear = new Date().getFullYear();
+  const [showing4percent, setShowing4percent] = useState(false);
 
   // Initialize form with default values
-  const form = useForm<FormValues>({
+  const form = useForm<z.input<typeof formSchema>, undefined, FormValues>({
     resolver: zodResolver(formSchema),
     defaultValues: {
       startingCapital: 50000,
@@ -123,7 +128,7 @@ export default function FireCalculatorForm() {
       currentAge: 25,
       cagr: 7,
       desiredMonthlyAllowance: 3000,
-      inflationRate: 2,
+      inflationRate: 2.3,
       lifeExpectancy: 84,
       retirementAge: 55,
     },
@@ -149,8 +154,10 @@ export default function FireCalculatorForm() {
       age: age,
       year: irlYear,
       balance: startingCapital,
+      untouchedBalance: startingCapital,
       phase: "accumulation",
-      monthlyAllowance: initialMonthlyAllowance,
+      monthlyAllowance: 0,
+      untouchedMonthlyAllowance: initialMonthlyAllowance,
     });
 
     // Calculate accumulation phase (before retirement)
@@ -175,13 +182,18 @@ export default function FireCalculatorForm() {
         newBalance =
           previousYearData.balance * annualGrowthRate - inflatedAllowance * 12;
       }
-
+      const untouchedBalance =
+        previousYearData.untouchedBalance * annualGrowthRate +
+        monthlySavings * 12;
+      const allowance = phase === "retirement" ? inflatedAllowance : 0;
       yearlyData.push({
         age: currentAge,
         year: year,
         balance: newBalance,
+        untouchedBalance: untouchedBalance,
         phase: phase,
-        monthlyAllowance: inflatedAllowance,
+        monthlyAllowance: allowance,
+        untouchedMonthlyAllowance: inflatedAllowance,
       });
     }
 
@@ -192,9 +204,23 @@ export default function FireCalculatorForm() {
     );
     const retirementData = yearlyData[retirementIndex];
 
+    const [fireNumber4percent, retirementAge4percent] = (() => {
+      for (const yearData of yearlyData) {
+        if (
+          yearData.untouchedBalance >
+          (yearData.untouchedMonthlyAllowance * 12) / 0.04
+        ) {
+          return [yearData.untouchedBalance, yearData.age];
+        }
+      }
+      return [0, 0];
+    })();
+
     if (retirementIndex === -1 || !retirementData) {
       setResult({
         fireNumber: null,
+        fireNumber4percent: null,
+        retirementAge4percent: null,
         error: "Could not calculate retirement data",
         yearlyData: yearlyData,
       });
@@ -202,6 +228,8 @@ export default function FireCalculatorForm() {
       // Set the result
       setResult({
         fireNumber: retirementData.balance,
+        fireNumber4percent: fireNumber4percent,
+        retirementAge4percent: retirementAge4percent,
         yearlyData: yearlyData,
       });
     }
@@ -230,11 +258,18 @@ export default function FireCalculatorForm() {
                         <Input
                           placeholder="e.g., 10000"
                           type="number"
-                          {...field}
-                          onChange={(value) => {
-                            field.onChange(value);
+                          value={field.value as number | string | undefined}
+                          onChange={(e) => {
+                            field.onChange(
+                              e.target.value === ""
+                                ? undefined
+                                : Number(e.target.value),
+                            );
                             void form.handleSubmit(onSubmit)();
                           }}
+                          onBlur={field.onBlur}
+                          name={field.name}
+                          ref={field.ref}
                         />
                       </FormControl>
                       <FormMessage />
@@ -251,11 +286,18 @@ export default function FireCalculatorForm() {
                         <Input
                           placeholder="e.g., 500"
                           type="number"
-                          {...field}
-                          onChange={(value) => {
-                            field.onChange(value);
+                          value={field.value as number | string | undefined}
+                          onChange={(e) => {
+                            field.onChange(
+                              e.target.value === ""
+                                ? undefined
+                                : Number(e.target.value),
+                            );
                             void form.handleSubmit(onSubmit)();
                           }}
+                          onBlur={field.onBlur}
+                          name={field.name}
+                          ref={field.ref}
                         />
                       </FormControl>
                       <FormMessage />
@@ -272,11 +314,18 @@ export default function FireCalculatorForm() {
                         <Input
                           placeholder="e.g., 30"
                           type="number"
-                          {...field}
-                          onChange={(value) => {
-                            field.onChange(value);
+                          value={field.value as number | string | undefined}
+                          onChange={(e) => {
+                            field.onChange(
+                              e.target.value === ""
+                                ? undefined
+                                : Number(e.target.value),
+                            );
                             void form.handleSubmit(onSubmit)();
                           }}
+                          onBlur={field.onBlur}
+                          name={field.name}
+                          ref={field.ref}
                         />
                       </FormControl>
                       <FormMessage />
@@ -293,11 +342,18 @@ export default function FireCalculatorForm() {
                         <Input
                           placeholder="e.g., 90"
                           type="number"
-                          {...field}
-                          onChange={(value) => {
-                            field.onChange(value);
+                          value={field.value as number | string | undefined}
+                          onChange={(e) => {
+                            field.onChange(
+                              e.target.value === ""
+                                ? undefined
+                                : Number(e.target.value),
+                            );
                             void form.handleSubmit(onSubmit)();
                           }}
+                          onBlur={field.onBlur}
+                          name={field.name}
+                          ref={field.ref}
                         />
                       </FormControl>
                       <FormMessage />
@@ -315,11 +371,18 @@ export default function FireCalculatorForm() {
                           placeholder="e.g., 7"
                           type="number"
                           step="0.1"
-                          {...field}
-                          onChange={(value) => {
-                            field.onChange(value);
+                          value={field.value as number | string | undefined}
+                          onChange={(e) => {
+                            field.onChange(
+                              e.target.value === ""
+                                ? undefined
+                                : Number(e.target.value),
+                            );
                             void form.handleSubmit(onSubmit)();
                           }}
+                          onBlur={field.onBlur}
+                          name={field.name}
+                          ref={field.ref}
                         />
                       </FormControl>
                       <FormMessage />
@@ -337,11 +400,18 @@ export default function FireCalculatorForm() {
                           placeholder="e.g., 2"
                           type="number"
                           step="0.1"
-                          {...field}
-                          onChange={(value) => {
-                            field.onChange(value);
+                          value={field.value as number | string | undefined}
+                          onChange={(e) => {
+                            field.onChange(
+                              e.target.value === ""
+                                ? undefined
+                                : Number(e.target.value),
+                            );
                             void form.handleSubmit(onSubmit)();
                           }}
+                          onBlur={field.onBlur}
+                          name={field.name}
+                          ref={field.ref}
                         />
                       </FormControl>
                       <FormMessage />
@@ -360,11 +430,18 @@ export default function FireCalculatorForm() {
                         <Input
                           placeholder="e.g., 2000"
                           type="number"
-                          {...field}
-                          onChange={(value) => {
-                            field.onChange(value);
+                          value={field.value as number | string | undefined}
+                          onChange={(e) => {
+                            field.onChange(
+                              e.target.value === ""
+                                ? undefined
+                                : Number(e.target.value),
+                            );
                             void form.handleSubmit(onSubmit)();
                           }}
+                          onBlur={field.onBlur}
+                          name={field.name}
+                          ref={field.ref}
                         />
                       </FormControl>
                       <FormMessage />
@@ -378,16 +455,18 @@ export default function FireCalculatorForm() {
                   name="retirementAge"
                   render={({ field }) => (
                     <FormItem>
-                      <FormLabel>Retirement Age: {field.value}</FormLabel>
+                      <FormLabel>
+                        Retirement Age: {field.value as number}
+                      </FormLabel>
                       <FormControl>
                         <Slider
                           name="retirementAge"
-                          value={[field.value]}
+                          value={[field.value as number]}
                           min={25}
                           max={75}
                           step={1}
-                          onValueChange={(value) => {
-                            field.onChange(...value);
+                          onValueChange={(value: number[]) => {
+                            field.onChange(value[0]);
                             void form.handleSubmit(onSubmit)();
                           }}
                           className="py-4"
@@ -430,10 +509,10 @@ export default function FireCalculatorForm() {
                             offset: -10,
                           }}
                         />
-                        {/* Left Y axis */}
+                        {/* Right Y axis */}
                         <YAxis
-                          yAxisId={"left"}
-                          orientation="left"
+                          yAxisId={"right"}
+                          orientation="right"
                           tickFormatter={(value: number) => {
                             if (value >= 1000000) {
                               return `${(value / 1000000).toPrecision(3)}M`;
@@ -447,11 +526,13 @@ export default function FireCalculatorForm() {
                             return value.toString();
                           }}
                           width={30}
+                          stroke="var(--color-orange-500)"
+                          tick={{}}
                         />
-                        {/* Right Y axis */}
+                        {/* Left Y axis */}
                         <YAxis
-                          yAxisId="right"
-                          orientation="right"
+                          yAxisId="left"
+                          orientation="left"
                           tickFormatter={(value: number) => {
                             if (value >= 1000000) {
                               return `${(value / 1000000).toPrecision(3)}M`;
@@ -461,6 +542,7 @@ export default function FireCalculatorForm() {
                             return value.toString();
                           }}
                           width={30}
+                          stroke="var(--color-red-600)"
                         />
                         <ChartTooltip content={tooltipRenderer} />
                         <defs>
@@ -473,12 +555,12 @@ export default function FireCalculatorForm() {
                           >
                             <stop
                               offset="5%"
-                              stopColor="var(--chart-1)"
+                              stopColor="var(--color-orange-500)"
                               stopOpacity={0.8}
                             />
                             <stop
                               offset="95%"
-                              stopColor="var(--chart-1)"
+                              stopColor="var(--color-orange-500)"
                               stopOpacity={0.1}
                             />
                           </linearGradient>
@@ -487,43 +569,55 @@ export default function FireCalculatorForm() {
                           type="monotone"
                           dataKey="balance"
                           name="balance"
-                          stroke="var(--chart-1)"
+                          stroke="var(--color-orange-500)"
                           fill="url(#fillBalance)"
                           fillOpacity={0.9}
                           activeDot={{ r: 6 }}
-                          yAxisId={"left"}
+                          yAxisId={"right"}
                           stackId={"a"}
                         />
                         <Area
-                          type="monotone"
+                          type="step"
                           dataKey="monthlyAllowance"
                           name="allowance"
-                          stroke="var(--chart-2)"
+                          stroke="var(--color-red-600)"
                           fill="none"
                           activeDot={{ r: 6 }}
-                          yAxisId="right"
-                          stackId={"a"}
+                          yAxisId="left"
                         />
                         {result.fireNumber && (
                           <ReferenceLine
                             y={result.fireNumber}
-                            stroke="var(--chart-3)"
-                            strokeWidth={1}
-                            strokeDasharray="2 2"
+                            stroke="var(--primary)"
+                            strokeWidth={2}
+                            strokeDasharray="2 1"
                             label={{
                               value: "FIRE Number",
                               position: "insideBottomRight",
                             }}
-                            yAxisId={"left"}
+                            yAxisId={"right"}
+                          />
+                        )}
+                        {result.fireNumber4percent && showing4percent && (
+                          <ReferenceLine
+                            y={result.fireNumber4percent}
+                            stroke="var(--secondary)"
+                            strokeWidth={1}
+                            strokeDasharray="1 1"
+                            label={{
+                              value: "4%-Rule FIRE Number",
+                              position: "insideBottomLeft",
+                            }}
+                            yAxisId={"right"}
                           />
                         )}
                         <ReferenceLine
                           x={
                             irlYear +
-                            (form.getValues("retirementAge") -
-                              form.getValues("currentAge"))
+                            (Number(form.getValues("retirementAge")) -
+                              Number(form.getValues("currentAge")))
                           }
-                          stroke="var(--chart-2)"
+                          stroke="var(--primary)"
                           strokeWidth={2}
                           label={{
                             value: "Retirement",
@@ -531,11 +625,36 @@ export default function FireCalculatorForm() {
                           }}
                           yAxisId={"left"}
                         />
+                        {result.retirementAge4percent && showing4percent && (
+                          <ReferenceLine
+                            x={
+                              irlYear +
+                              (result.retirementAge4percent -
+                                Number(form.getValues("currentAge")))
+                            }
+                            stroke="var(--secondary)"
+                            strokeWidth={1}
+                            label={{
+                              value: "4%-Rule Retirement",
+                              position: "insideBottomLeft",
+                            }}
+                            yAxisId={"left"}
+                          />
+                        )}
                       </AreaChart>
                     </ChartContainer>
                   </CardContent>
                 </Card>
               )}
+              {result && (
+                <Button
+                  onClick={() => setShowing4percent(!showing4percent)}
+                  variant={showing4percent ? "secondary" : "default"}
+                  size={"sm"}
+                >
+                  {showing4percent ? "Hide" : "Show"} 4%-Rule
+                </Button>
+              )}
             </form>
           </Form>
         </CardContent>
@@ -574,11 +693,45 @@ export default function FireCalculatorForm() {
                 </CardHeader>
                 <CardContent>
                   <p className="text-3xl font-bold">
-                    {form.getValues("lifeExpectancy") -
-                      form.getValues("retirementAge")}
+                    {Number(form.getValues("lifeExpectancy")) -
+                      Number(form.getValues("retirementAge"))}
                   </p>
                 </CardContent>
               </Card>
+              {showing4percent && (
+                <>
+                  <Card>
+                    <CardHeader>
+                      <CardTitle>4%-Rule FIRE Number</CardTitle>
+                      <CardDescription className="text-xs">
+                        Capital needed for 4% of it to be greater than your
+                        yearly allowance
+                      </CardDescription>
+                    </CardHeader>
+                    <CardContent>
+                      <p className="text-3xl font-bold">
+                        {formatNumber(result.fireNumber4percent)}
+                      </p>
+                    </CardContent>
+                  </Card>
+
+                  <Card>
+                    <CardHeader>
+                      <CardTitle>4%-Rule Retirement Duration</CardTitle>
+                      <CardDescription className="text-xs">
+                        Years to enjoy your financial independence if you follow
+                        the 4% rule
+                      </CardDescription>
+                    </CardHeader>
+                    <CardContent>
+                      <p className="text-3xl font-bold">
+                        {Number(form.getValues("lifeExpectancy")) -
+                          (result.retirementAge4percent ?? 0)}
+                      </p>
+                    </CardContent>
+                  </Card>
+                </>
+              )}
             </>
           )}
         </div>

src/app/layout.tsx

@@ -1,15 +1,17 @@
 import "@/styles/globals.css";
 import PlausibleProvider from "next-plausible";
-import { type Metadata } from "next";
+import { type Metadata, type Viewport } from "next";
 import { Geist } from "next/font/google";
 import { WebVitals } from "./components/web-vitals";
 
+export const viewport: Viewport = {
+  themeColor: [{ color: "oklch(0.97 0.0228 95.96)" }],
+};
+
 export const metadata: Metadata = {
-  title:
-    "InvestingFIRE Calculator | Plan Your Financial Independence & Early Retirement",
+  title: "InvestingFIRE | Finance and Retirement Calculator",
   description:
-    "Achieve Financial Independence, Retire Early (FIRE) with the InvestingFIRE calculator. Get personalized projections and investing advice to plan your journey.",
-  icons: [{ rel: "icon", url: "/favicon.ico" }],
+    "Achieve Financial Independence & Early Retirement! Plan your FIRE journey with the InvestingFIRE calculator and get personalized projections in buttersmooth graphs.",
 };
 
 const geist = Geist({
@@ -24,17 +26,16 @@ export default function RootLayout({
     <html lang="en" className={geist.variable}>
       <head>
         <meta name="apple-mobile-web-app-title" content="FIRE" />
-      </head>
         <PlausibleProvider
           domain="investingfire.com"
           customDomain="https://analytics.schulze.network"
           selfHosted={true}
           enabled={true}
           trackOutboundLinks={true}
-      >
+        />
+      </head>
       <WebVitals />
       <body>{children}</body>
-      </PlausibleProvider>
     </html>
   );
 }

src/app/page.tsx

@@ -7,13 +7,17 @@ import {
   AccordionTrigger,
 } from "@/components/ui/accordion";
 import Footer from "./components/footer";
+import BackgroundPattern from "./components/BackgroundPattern";
 
 export default function HomePage() {
   return (
     <main className="text-primary-foreground to-destructive from-secondary flex min-h-screen flex-col items-center bg-gradient-to-b p-2">
-      <div className="mx-auto flex flex-col items-center justify-center gap-4 text-center">
+      <BackgroundPattern />
+      <div className="z-10 mx-auto flex flex-col items-center justify-center gap-4 text-center">
         <div className="mt-8 flex flex-row flex-wrap items-center justify-center gap-4 align-middle">
           <Image
+            priority
+            unoptimized
             src="/investingfire_logo_no-bg.svg"
             alt="InvestingFIRE Logo"
             width={100}
@@ -32,7 +36,7 @@ export default function HomePage() {
       </div>
 
       {/* Added SEO Content Sections */}
-      <div className="mx-auto max-w-2xl py-12 text-left">
+      <div className="z-10 mx-auto max-w-2xl py-12 text-left">
         <section className="mb-12">
           <h2 className="mb-4 text-3xl font-bold">
             What Is FIRE? Understanding Financial Independence and Early
@@ -247,7 +251,7 @@ export default function HomePage() {
             financial independence and smart investing.
           </p>
 
-          <div className="bg-secondary/20 my-8 rounded-md p-4 text-lg">
+          <div className="bg-foreground my-8 rounded-md p-4 text-lg">
             <p className="font-semibold">Getting Started with FIRE:</p>
             <ol className="ml-6 list-decimal space-y-1">
               <li>

src/app/robots.ts

@@ -0,0 +1,11 @@
+import type { MetadataRoute } from "next";
+
+export default function robots(): MetadataRoute.Robots {
+  return {
+    rules: {
+      userAgent: "*",
+      allow: "/",
+    },
+    sitemap: "https://investingfire.com/sitemap.xml",
+  };
+}

src/app/sitemap.ts

@@ -0,0 +1,13 @@
+import { BASE_URL } from "@/lib/constants";
+import { type MetadataRoute } from "next";
+
+export default function sitemap(): MetadataRoute.Sitemap {
+  return [
+    {
+      url: BASE_URL,
+      lastModified: new Date(),
+      changeFrequency: "yearly",
+      priority: 1,
+    },
+  ];
+}

src/lib/constants.ts

@@ -0,0 +1 @@
+export const BASE_URL = "https://investingfire.com/";