react.js

// Import dependencies
import React, { Component } from 'react'

// Import styles
import styles from './Panes.scss'

class Panes extends Component  {
  render() {
    return (
      <div className={styles.Panes}>
        {this.props.children}
      </div>
    )
  }
}

// Export component
export default Panes

// --- Instead of ---

<div class="panes">
  <div id="template-slot"></div>
</div>

// Note: A bit of a 'skewed' example of course, but I found it funny when I just wrote it and thought about it.