css select sibling

/*The adjacent sibling combinator (+) separates two 
selectors and matches the second element only if 
it immediately follows the first element, and
both are children of the same parent element.*/

li:first-of-type + li {
  color: red;
}

<ul>
  <li>One</li> // The sibling 
  <li>Two</li> // This adjacent sibling will be red
  <li>Three</li>
</ul>

/* Paragraphs that come immediately after any image */
img + p {
  font-weight: bold;
}

/*
Adjecent Sibling Selector
-------------------------
example: Select all <p> tags that immediatly follows after <div> tag
*/
div + p {
  background-color: yellow;
}

/*
General Sibling Selector
-------------------------
example: Select all <p> tags that has a sibling with a <div> tag
*/
div ~ p {
  background-color: yellow;
}