자주 사용하는 CDN

<!-- jQuery CDN -->
<script src="https://code.jquery.com/jquery-3.5.1.min.js"></script>

<!-- jQuery UI CDN -->
<script src="https://code.jquery.com/ui/1.12.1/jquery-ui.min.js"></script>

/* Google Web Fonts CDN */
@import url('https://fonts.googleapis.com/css?family=Noto+Sans+KR:300,400,500,700,900&display=swap');
font-family: 'Noto Sans KR', sans-serif;

/* Google Web Font */
@import url('https://fonts.googleapis.com/css?family=Raleway&display=swap');
font-family: 'Raleway', sans-serif;

/* Google Web Font */
@import url('https://fonts.googleapis.com/css?family=Montserrat:300,400,500&display=swap');
font-family: 'Montserrat', sans-serif;

/* Google Web Font */
@import url('https://fonts.googleapis.com/css2?family=Roboto:wght@100;300;400;500;700;900&display=swap');
font-family: 'Roboto', sans-serif;

/* Google Web Font */
@import url('https://fonts.googleapis.com/css2?family=Source+Sans+Pro:wght@300;400;600;700;900&display=swap');
font-family: 'Source Sans Pro', sans-serif;

/* Noonnu Korean Fonts */
@font-face {
  font-family: 'GmarketSansLight';
  src: url('https://cdn.jsdelivr.net/gh/projectnoonnu/noonfonts_2001@1.1/GmarketSansLight.woff') format('woff');
  font-weight: normal;
  font-style: normal;
}

/* Fontawesome 4.7 */
@import url('https://stackpath.bootstrapcdn.com/font-awesome/4.7.0/css/font-awesome.min.css');

/* XEION CDN */
@import url('http://cdn.jsdelivr.net/npm/xeicon@2.3.3/xeicon.min.css');

<!-- Featherlight.js CDN -->
<script src="https://cdnjs.cloudflare.com/ajax/libs/featherlight/1.7.13/featherlight.min.js"></script>
<link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/featherlight/1.7.13/featherlight.min.css">

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■ Reference URL

FontAwesome 4.7 CheatSheet
https://fontawesome.bootstrapcheatsheets.com/

FontAwesome 4.7 Official Website
https://fontawesome.com/v4.7.0/icons/

XEICON Ver2.3.3
https://xpressengine.github.io/XEIcon/

Web Gradients
https://webgradients.com/

W3 Schools Color Picker
https://www.w3schools.com/colors/colors_picker.asp

Flat UI colors
https://flatuicolors.com/

Social Colors
https://www.materialui.co/socialcolors

눈누 한글 폰트
https://noonnu.cc/