## HTML/CSS, <s>183</s> <s>180</s> <s>163</s> <s>161</s> 160 bytes

<!-- begin snippet: js hide: false console: true babel: false -->

<!-- language: lang-css -->

    a{display:inline-flex;vertical-align:top;overflow:hidden;width:1ch}c{animation:c 1s steps(4)infinite}@keyframes c{to{margin-left:-4ch

<!-- language: lang-html -->

    <pre>Loading... <a><c>|/-\

<!-- end snippet -->

Edit: Saved 3 bytes thanks to @betseg. Saved 17 bytes thanks to @manatwork. Saved 1 byte thanks to @Daniel.