How to apply CSS styles in continuation classes

Question

When the .checked class exists, I need to insert the text-decoration: line-through; style into the .todo-name

(I never understood if it could be done with css, but in case I could also use js as a last chance)

<label class="checkbox-container" for="0"><span class="todo-name">Todo</span>
    <input onclick="updateStatus(this)" type="checkbox" id="0" checked="">
    <span class="checkmark checked"></span>
</label>

<!--This content does not have .checked and should not change-->
<label class="checkbox-container" for="0"><span class="todo-name">Todo</span>
    <input onclick="updateStatus(this)" type="checkbox" id="0">
    <span class="checkmark"></span>
</label>

<style>
/*.todo-name{text-decoration: line-through;}*/


/*Not working*/
/*
.checkbox-container .checked ~ .todo-name {
  text-decoration: line-through;
}
.checkbox-container:not(.checked) .todo-name {text-decoration: line-through;}
*/
</style>

Codepen Project

The final result should be like this

Answer 1

You have encountered several problems. As mentioned in the comments, if you don't want to use JavaScript, you should use pseudo-classes. : is checked in this example.

Next, you'll use the CSS selector ~, which selects sibling elements after this element rather than before it. So trying to select .todo-name using the selector #0:checked ~ .todo-name will not work because the name appears before the checkbox.

Below is an example of a working version.

input:checked ~ .todo-name {
    text-decoration: line-through;  
}

    
    Todo



    
    Todo