When to Use
TRIGGER when:
- Adding Tailwind to a Capacitor app (Vite, Angular, Next static export, etc.)
- Upgrading Tailwind v3 -> v4, or a v4 install produces no styles
tailwind.config.jsedits have no effect (v4 is CSS-first)- Colors / gradients broken or transparent on older iOS devices
- Safe-area, dark mode, platform-specific, or touch-target utilities
Do not use:
- Konsta UI setup/components:
konsta-ui - Ionic components and
--ion-*variables:ionic-design - SystemBars / Android edge-to-edge / status bar plugin:
safe-area-handling - Inputs hidden by keyboard:
capacitor-keyboard - Adding Capacitor to a framework:
framework-to-capacitor
Version facts (October 2026)
tailwindcss4.x islatest(4.3.x); 3.4.x onv3-lts.- v4 is configured in CSS.
tailwind.config.jsis not read unless you add@config "./tailwind.config.js";. - v4 targets Safari 16.4+, Chrome 111+, Firefox 128+ (uses
@property,color-mix(), cascade layers, oklch). - Capacitor 8 supports iOS 15+, Capacitor 9 iOS 16+. WKWebView = the device's Safari version. Devices on iOS 15.x - 16.3 render v4 styles incorrectly. Android System WebView auto-updates, so Chrome 111+ is usually met (Capacitor 9 minSdk 26).
Decision: if the iOS deployment target (or real user base) includes iOS < 16.4, ask the user: stay on Tailwind 3.4, or raise the minimum OS. Do not silently ship v4.
Workflow
- Inspect:
npm ls tailwindcss,tailwind.config.*,postcss.config.*, bundler config, main CSS file,ios/App/App.xcodeprojIPHONEOS_DEPLOYMENT_TARGET, presence of Ionic or Konsta. - New install (below) or upgrade: references/v3-to-v4.md.
- Mobile utilities (safe areas, platform variants, touch, dark mode): references/mobile-patterns.md.
- Verify (below).
Only load a reference when its topic is in play.
Install (Vite: React, Vue, Svelte, Solid)
npm i tailwindcss @tailwindcss/vite
// vite.config.ts
import { defineConfig } from 'vite';
import tailwindcss from '@tailwindcss/vite';
export default defineConfig({ plugins: [tailwindcss() /* + framework plugin */] });
/* src/styles.css */
@import "tailwindcss";
@custom-variant dark (&:where(.dark, .dark *));
@custom-variant ios (&:where(.plt-ios, .plt-ios *));
@custom-variant android (&:where(.plt-android, .plt-android *));
@theme {
--color-brand: oklch(0.55 0.2 265);
--font-sans: system-ui, -apple-system, "Roboto", sans-serif;
}
@utility pt-safe { padding-top: env(safe-area-inset-top); }
@utility pb-safe { padding-bottom: env(safe-area-inset-bottom); }
@utility px-safe { padding-left: env(safe-area-inset-left); padding-right: env(safe-area-inset-right); }
Other toolchains: PostCSS (Angular, webpack, Next) -> npm i tailwindcss @tailwindcss/postcss and postcss.config.mjs { plugins: { "@tailwindcss/postcss": {} } }; standalone -> @tailwindcss/cli. Angular CLI 17+ reads .postcssrc.json.
// main.ts: platform class for ios:/android: variants
import { Capacitor } from '@capacitor/core';
document.documentElement.classList.add(`plt-${Capacitor.getPlatform()}`); // plt-ios | plt-android | plt-web
Add viewport-fit=cover to the viewport meta or the safe-area utilities resolve to 0.
Traps
- Content detection is automatic in v4 (respects
.gitignore). Classes innode_modulesor outside the project root need@source "../path";. Dynamic class names (`bg-${color}-500`) are never generated; map to full class strings. - v4
hover:only applies on devices with(hover: hover), so sticky hover on touch is solved by default. Useactive:for press feedback. - v4 defaults changed: border color is
currentColor,ringis 1px,shadow-sm/shadowandrounded-sm/roundedscales shifted,outline-none->outline-hidden. The upgrade tool renames most; review visually. - Ionic + Tailwind: Preflight resets Ionic typography. Import Tailwind without Preflight (
@layer theme, base, components, utilities; @import "tailwindcss/theme.css" layer(theme); @import "tailwindcss/utilities.css" layer(utilities);) or load Ionic CSS after Tailwind. - Konsta UI v5 already imports Tailwind theme pieces via
konsta/<fw>/theme.css; followkonsta-uiinstead of duplicating setup. - Do not use
100vhfor full-screen layouts; useh-dvh(v4 hasdvh/svh/lvhutilities) or a flex shell. - Android WebView < 140 reports safe-area
env()as 0; Capacitor 8 SystemBars injects--safe-area-inset-*. For Android robustness, use@utility pt-safe { padding-top: var(--safe-area-inset-top, env(safe-area-inset-top)); }(seesafe-area-handling).
Verification
npm run buildsucceeds; built CSS contains your utilities:grep -c "pt-safe" dist/assets/*.css.npx cap syncand run on: oldest supported iOS version (check colors, gradients, shadows render), current iPhone, Android 15/16.- Toggle dark mode class and OS appearance; check
ios:/android:variants by inspecting<html class>. - Leftovers after upgrade:
grep -rn "@tailwind base\|@tailwind components\|@tailwind utilities\|require('tailwindcss')" src postcss.config.* 2>/dev/nullreturns nothing.
Error Handling
| Error / symptom | Cause | Fix |
|---|---|---|
[postcss] It looks like you're trying to use tailwindcss directly as a PostCSS plugin. The PostCSS plugin has moved to a separate package |
v3-style PostCSS config with v4 | Use @tailwindcss/postcss (or @tailwindcss/vite) |
| No styles at all | Missing @import "tailwindcss" or bundler plugin |
Add both |
Cannot apply unknown utility class in @apply |
Custom class not defined via @utility, or CSS module / Vue <style> without theme reference |
Define with @utility; add @reference "../styles.css"; in the scoped style |
tailwind.config.js theme changes ignored |
v4 does not auto-load JS config | Move to @theme, or add @config |
| Transparent/missing colors on some iPhones | iOS < 16.4 lacks features v4 uses | Raise min iOS or stay on 3.4 |
dark: follows OS, ignores toggle |
Default dark variant is media-based | Add @custom-variant dark (&:where(.dark, .dark *)); |
| Upgrade tool fails: requires Node | @tailwindcss/upgrade needs Node 20+ |
Upgrade Node (Capacitor 9 needs 24+ anyway) |
Resources
- Tailwind v4 install (Vite): https://tailwindcss.com/docs/installation/using-vite
- Upgrade guide: https://tailwindcss.com/docs/upgrade-guide
- Theme variables: https://tailwindcss.com/docs/theme
- Browser support: https://tailwindcss.com/docs/compatibility
- Dark mode: https://tailwindcss.com/docs/dark-mode