Useless Polymath

A React suite for practicing technical, mathematical, and cryptographic skills to impress absolutely nobody at parties.

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Modules

The application is structured into isolated domains, each containing a Tool (calculator/converter), a Practice mode (drills), and a Guide.

Chronometry

• Doomsday Algorithm: Calculate the day of the week for any date mentally.
• Time Zones: Offset calculations and UTC conversions.
• Moon Phases: Algorithmic calculation of the moon's age (0-29).
• Calendar Ordinals: Day-of-year calculations.

Logic & Electronics

• Binary/Hex: Base conversion drills (Decimal ↔ Binary ↔ Hex).
• Bitwise Operations: Visualizing AND, OR, XOR, NOT, and bit shifting.
• Resistor Codes: Reading 4-band and 5-band electronic resistors.
• Roman Numerals: Standard and non-standard conversion logic.

Cryptography

• Ciphers: Caesar Cipher (ROT-N).
• Encodings: Morse Code, Braille, Semaphore flags.
• NATO Alphabet: Phonetic spelling drills.

Networks

• Subnetting: IPv4 CIDR, Network ID, and Broadcast address calculations.
• Storage Units: Bit/Byte conversion (Base 2 vs Base 10).
• Color Theory: RGB to Hex conversion logic.
• ASCII: Character code lookups.

Algorithms & Science

• Validation: Luhn Algorithm (Credit Cards) and EAN-13 (Barcodes).
• Science: Periodic Table data and Thermodynamics (C/F/K) conversion.
• Financial: Rule of 72 (Interest rate doubling).

Technical Stack

• Core: React 19, TypeScript, Vite.
• State/Persistence: Dexie.js (IndexedDB wrapper) for persisting user statistics and progress.
• Styling: SCSS Modules (*.module.scss) for component-scoped styles.
• Localization: i18next with lazy-loading backends (English, Spanish, Italian).
• Linting: ESLint (Flat Config).