다크 모드 전략
미디어 전략(prefers-color-scheme)과 클래스 전략(html에 dark 클래스를 토글하는 방식)을 비교하고 각각을 사용할 상황을 배웁니다.
다크 모드 전략은(는) CoddyKit의 무료 Tailwind CSS Academy 강의입니다. 이것은 4개 중 1번째 강의입니다. 아래에서 전체 강의를 무료로 읽을 수 있으며, 내장 코드 에디터와 24/7 AI 튜터와 함께 브라우저에서 직접 실습할 수 있습니다. 이 강의는 Tailwind CSS Academy 학습 경로의 일부이며, 진행 상황이 웹과 CoddyKit 앱에 동기화됩니다. Tailwind CSS Academy 강의에는 총 4개의 강의가 포함되어 있습니다.
이 강의의 일부는 아직 번역되지 않았으며 영어로 표시됩니다.
Why Dark Mode Matters
Dark mode has become a first-class feature expectation in modern web apps. Users prefer it for reducing eye strain in low-light environments, and it can extend battery life on OLED screens. Tailwind CSS makes implementing dark mode straightforward with a built-in dark variant. Before writing a single class, you need to choose between two strategies: the media strategy and the class strategy.
The Media Strategy Explained
The media strategy relies on the browser's prefers-color-scheme CSS media query. When the user sets their operating system to dark mode, Tailwind automatically activates all dark: prefixed utilities. This requires zero JavaScript — the browser handles everything. It is the simplest approach but offers no user toggle within your app itself.
/* Tailwind uses this media query under the hood */
@media (prefers-color-scheme: dark) {
/* dark: utilities are applied here */
}Enabling Media Strategy in Config
In Tailwind v3, the media strategy is not the default. You must explicitly configure it in tailwind.config.js by setting darkMode to 'media'. Once enabled, every utility prefixed with dark: will activate automatically when the OS reports dark mode preference. This is ideal for simple sites that do not need a manual toggle.
// tailwind.config.js
module.exports = {
darkMode: 'media',
content: ['./src/**/*.{html,js}'],
theme: {
extend: {},
},
plugins: [],
};The Class Strategy Explained
The class strategy gives you programmatic control over dark mode. Instead of relying on the OS preference, Tailwind activates dark styles whenever a dark class is present on a parent element — usually the <html> tag. This lets users toggle dark mode manually inside your app, regardless of their system setting. Most modern apps prefer this strategy.
<!-- Light mode: no dark class -->
<html>
<body class="bg-white text-gray-900">...</body>
</html>
<!-- Dark mode: dark class applied -->
<html class="dark">
<body class="bg-white dark:bg-gray-900 dark:text-white">...</body>
</html>Enabling Class Strategy in Config
Set darkMode to 'class' in your config file to enable the class strategy. Tailwind v3 uses 'class' as a common default for apps that need user-controlled theming. With this setting active, dark: variants only apply when the ancestor element carries the dark class — giving you full control over when dark styles activate.
// tailwind.config.js
module.exports = {
darkMode: 'class',
content: ['./src/**/*.{html,js}'],
theme: {
extend: {},
},
plugins: [],
};Media vs Class: Key Differences
Choosing between the two strategies depends on your use case. The media strategy is automatic and requires no JavaScript — perfect for static sites and documentation. The class strategy requires JavaScript to toggle the class but allows user preference within the app that can override the OS setting. It also enables you to persist the preference in localStorage.
media— OS-driven, zero JSclass— app-driven, JS toggle required
Selector Strategy in Tailwind v3.3+
Tailwind v3.3 introduced a third option: selector strategy, where you pass a custom CSS selector string instead of 'class'. This is useful when your dark mode is driven by a data-theme attribute or a specific wrapper class other than dark. For example, setting darkMode: ['class', '[data-theme="dark"]'] activates dark utilities when that attribute is present on any ancestor.
// tailwind.config.js (v3.3+)
module.exports = {
darkMode: ['class', '[data-theme="dark"]'],
// ...
};Writing Dark Variant Classes
Once a dark mode strategy is configured, applying dark styles is just a matter of prefixing any utility with dark:. You can apply dark: to colors, backgrounds, borders, shadows, and even hover states. Tailwind will generate the correct CSS selectors or media queries automatically. Always define both light and dark versions side-by-side on the same element.
<div class="bg-white dark:bg-gray-900 text-gray-800 dark:text-gray-100 p-6 rounded-lg shadow dark:shadow-gray-700">
<h2 class="text-xl font-bold">Card Title</h2>
<p class="text-gray-600 dark:text-gray-300 mt-2">Card content here.</p>
</div>Dark Mode Scoping
With the class strategy, the dark class can be placed on any ancestor element, not just <html>. This allows partial dark mode — you can make a single section of your page dark while leaving the rest light. This is useful for themed panels, sidebars, or preview components that need a different visual treatment than the main page.
<div class="bg-gray-100 p-8">
<p>This section is always light.</p>
<div class="dark bg-gray-900 text-white p-4 mt-4 rounded">
<p>This inner section is always dark.</p>
</div>
</div>Combining Dark with Other Variants
Tailwind's variant system is composable. You can stack dark: with other variants like hover:, focus:, and responsive breakpoints. The order of prefixes matters: write responsive prefixes first, then state variants, then dark — for example md:hover:dark:bg-gray-700. This makes it possible to build highly specific, context-aware styles without any custom CSS.
<button class="
bg-blue-600 text-white
hover:bg-blue-700
dark:bg-blue-500
dark:hover:bg-blue-400
focus:ring-2 focus:ring-blue-300
dark:focus:ring-blue-700
px-4 py-2 rounded
">
Click Me
</button>When to Use Each Strategy
Use the media strategy when your audience is technical (developer tools, docs sites) and automatically respecting OS preference is enough. Use the class strategy when building consumer apps where users expect an in-app toggle. Use the selector strategy when your theming system uses a design-token-driven data-theme attribute or you are integrating with an existing theming library that manages its own class names.
Quick Check
Test your understanding of Tailwind CSS dark mode strategies from this lesson.
Lesson Recap
In this lesson you learned: the media strategy uses the OS prefers-color-scheme preference automatically, the class strategy requires a dark class on an ancestor element and enables JavaScript toggling, and the selector strategy allows custom attribute-based dark mode triggers. Next up we explore how to apply the dark: variant across colors, backgrounds, and components.
자주 묻는 질문
“다크 모드 전략” 강의는 무료인가요?
네 — “다크 모드 전략” 전체 내용을 이 웹사이트에서 무료로 읽을 수 있습니다. 인터랙티브하게 실습하려면(내장 코드 에디터와 24/7 AI 튜터), CoddyKit PRO로 업그레이드하면 Tailwind CSS Academy 강의 전체를 잠금 해제할 수 있습니다. Tailwind CSS Academy 강의에는 총 4개의 강의가 포함되어 있습니다.
“다크 모드 전략”에서 뭘 배우나요?
미디어 전략(prefers-color-scheme)과 클래스 전략(html에 dark 클래스를 토글하는 방식)을 비교하고 각각을 사용할 상황을 배웁니다. 브라우저에서 직접 실행하는 실습 코드로 Tailwind CSS Academy을(를) 배우며, 24/7 AI 튜터가 강의를 진행하면서 질문에 답변해줍니다.
Tailwind CSS Academy을(를) 시작하는 데 경험이 필요한가요?
사전 경험은 필요하지 않습니다. CoddyKit의 Tailwind CSS Academy은(는) 초급자부터 고급 학습자까지를 위해 구성되어 있으므로, 여기서 시작하거나 처음부터 시작할 수 있으며 자신의 속도대로 진행할 수 있습니다. 이것은 4개 중 1번째 강의입니다.
“다크 모드 전략” 강의는 얼마나 걸리나요?
대부분의 CoddyKit 강의는 약 5~10분이 소요됩니다. 각 강의는 간결하고 인터랙티브하여 꾸준한 진행이 가능하며, 웹과 앱에서 중단한 부분부터 바로 시작할 수 있습니다.
이 Tailwind CSS Academy 강의에서 코드를 작성하고 실행할 수 있나요?
네. 모든 Tailwind CSS Academy 강의에는 내장 코드 에디터가 포함되어 있으므로, 브라우저에서 바로 실제 코드를 작성하고 실행한 후 즉시 AI 피드백을 받을 수 있습니다 — 로컬 설정이 필요 없습니다.