Vue

HTML

<div id="app">
  <ol>
    <li v-for="(todo, key) in todos" :key="key" @click="clickHandler(key)">{{ todo.text }}</li>
  </ol>
</div>

CSS

li {
  padding: 10px;
}

Vue

new Vue({
  el: "#app",
  data: {
    todos: [
      { text: "Learn JavaScript" },
      { text: "Learn Vue" },
      { text: "Play around in JSFiddle" },
      { text: "Build something awesome" }
    ]
  },
  methods: {
  	clickHandler (index) {
    console.log(index)
    	let todos = document.querySelectorAll('li')
			todos[index].style.backgroundColor = '#ff0000'
      this.todos.splice(index, 1)
    }
  }
})