Generate responsive CSS calc() functions visually. Mix units like pixels, percentages, and viewport values. Perfect for building fluid, responsive layouts fast.
AI Generation Prompt
CSS Calc() Builder Specification
Overview
A clean, professional, single-file browser utility that allows developers to visually construct calc() expressions. It simplifies the complexity of mixing units (px, %, rem, vh, vw, em, pt) by providing a live visual preview and a ready-to-copy CSS snippet.
Technical Architecture
- Architecture: Single-file HTML/CSS/JS (Vanilla).
- Sandbox Constraints:
- Strictly No Storage: Do NOT use
localStorage,sessionStorage, orcookies. Use only in-memory JavaScript variables. - No Popups: Do not use
alert(),confirm(), orprompt(). All user interaction must be handled via custom DOM overlays/modals. - Iframe Compatibility: The app must function within a sandboxed
nullorigin iframe.
- Strictly No Storage: Do NOT use
UI Layout
1. Header
- Simple, minimalist title: "CSS Calc() Builder".
- Short subtitle: "Visually mix units for responsive layouts.".
2. Main Builder Area
- Input Rows: A vertical stack of rows where each row represents a unit + operator (e.g.,
[Value Input] [Unit Select] [Operator Select]). - Add/Remove Controls: "+" button to add a new step, "-" to remove.
- Preview Box: A visual container (a gray/blue square) that dynamically resizes based on the current calculation string applied to
widthorheight.
3. Output Section
- Result Display: A prominent code block showing the full
calc(...)string. - Copy Button: A primary action button with a smooth transition, triggering a "Copied!" toast notification.
Design System & Aesthetics
- Palette: Clean "SaaS Light" mode.
- Background:
#f8fafc - Primary Surface:
#ffffff - Accent (Primary Action):
#3b82f6(Blue) - Border:
#e2e8f0 - Text:
#1e293b(Primary),#64748b(Secondary)
- Background:
- Typography: Inter or System Sans-Serif.
- Transitions: All interactions (adding/removing rows) must use
transition: all 0.2s ease-in-out. - Shadows: Soft, diffused drop shadows (e.g.,
box-shadow: 0 4px 6px -1px rgb(0 0 0 / 0.1)) on containers.
Key Features
- Dynamic Preview: Real-time visual box resizing using JavaScript to update the element's style property via
calc(). - Unit Support: Dropdown for:
px,%,vh,vw,rem,em,pt. - Operator Logic: Support for
+,-,*,/. - Input Validation: Ensure users cannot perform illegal operations (e.g., multiplying two lengths, which is invalid in CSS).
- Responsive Design: The UI stack must shift from a side-by-side builder/preview layout on desktop to a stacked layout on mobile.
Implementation Guidelines for Developer
- CDN Usage: Use Tailwind CSS (via CDN) for rapid, consistent styling.
- State Management: Keep the entire app state in a single JavaScript object (e.g.,
const state = { steps: [...] }). - DOM Updates: Use vanilla DOM API (e.g.,
document.createElement,innerHTML) to render the list of calculation steps. - No External Dependencies: Avoid heavy frameworks. If icons are needed, use a light SVG icon library via CDN.
Spread the word
Files being used
Frequently Asked Questions
Everything you need to know about using this application.
What is the CSS calc() function and why should I use it?
The CSS calc() function is a powerful tool that allows you to perform mathematical calculations directly within your CSS property values. It enables you to mix different units, such as adding a fixed pixel value to a percentage-based width, making it an essential tool for creating flexible and truly responsive web designs that adapt seamlessly to various screen sizes. By utilizing this function, you avoid the rigid constraints of fixed-width layouts. This tool simplifies the process by providing a visual interface to construct these expressions, ensuring your math is correct and your layout remains stable across all devices.
Does this tool save my settings or design progress?
No, this tool does not save any data. It is built as a stateless, client-side application running entirely within your browser's sandboxed environment. We do not use cookies, local storage, or server-side databases, ensuring your privacy and session anonymity. Because of this architecture, any calculations or configurations you create will be cleared upon refreshing the page. We recommend copying your generated code snippet using the integrated copy-to-clipboard button before navigating away from the page.
How do I implement the code generated by this builder?
Once you have built your expression, the application generates a ready-to-use CSS code snippet. Simply click the 'Copy to Clipboard' button to save the code to your system. You can then paste this directly into your CSS files, such as inside width, height, margin, or padding declarations. The generated output follows standard CSS syntax, making it compatible with all modern browsers. It is formatted to be clean and readable, ensuring it fits perfectly into your existing stylesheet or utility class framework.
Is this tool compatible with mobile devices?
Yes, this tool is designed to be fully mobile-responsive. The interface automatically adapts to your screen size, whether you are working on a desktop, tablet, or smartphone, providing a consistent and user-friendly experience across all platforms. All UI elements, including the builder controls and the real-time preview box, are optimized for touch interactions and smaller viewports. You can comfortably build and test your CSS calc() strings on the go, making it a highly portable utility for web developers.
