Custom Radio Button images dont work in php but they work in html

Question

As shown in the picture above its working without issues in html, but when switching to php it wont work as shown in picture below..

Code: HTML/PHP

<label>
              <input type="radio" name="test" value="big">
              <img src="assets/icon-paper.svg" width="150">
            </label>

Code: CSS

[type=radio] { 
  position: absolute;
  opacity: 0;
  width: 0;
  height: 0;
}

/* IMAGE STYLES */
[type=radio] + img {
  cursor: pointer;
  margin-left: 91px;
}

/* CHECKED STYLES */
[type=radio]:checked + img {
  outline: 0.6px solid orange;
}