Why Radio button is not changing the image when checked?

Question

<input type="radio" name="gender" value="pack1" >
<input type="radio" name="gender" value="pack2">
<input type="radio" name="gender" value="pack3">

CSS

input {content: url("https://images.clickfunnels.com/43/7b14e04a2311e7a86d4de9d8397df3/yes4.png");
}
input [type="radio"]:checked {content: url("https://images.clickfunnels.com/43/ac0ff04a2311e79e9859f99317b8f7/yes3.png");
}

Answer 1

Delete the extra space character

input[type="radio"]:checked {content: url("https://images.clickfunnels.com/43/ac0ff04a2311e79e9859f99317b8f7/yes3.png");
}

Answer 2

Whoa!!! Thanks a million, man, Helped a lottttttt....