How to make opacity only for background?

Question

I have a form and I need to add the background with opacity to that. Unfortunately opacity takes the form as well. How to remove opacity from the form and have it only for background?

.container {
    width: 100%;
    height: 100%;
    position: fixed;
    visibility: visible;
    display: block;
    background-color: green;
    top: 0;
    left: 0;
    opacity: 0.5;
   }
    
.form {
    width: 150px;
    height: 200px;
    background-color: blue;
    display: flex;
    flex-direction: column;
    justify-content: center;
    color: black;
    align-items: center;
    margin: 0 auto;
    margin-top: 10px;
    border-radius: 8px;
    z-index: 2;
    opacity: 1; 
 }

<div class="container">
<div class="form">
<p>text</p>
<p>text</p>
<p>text</p>
</div>
</div>

Answer 1

Hi if your background does not has any Images. Then easily you can apply opacity on it background. Here is some example you can use ->

background-color: #00ff0055;
/*-- The value after six digit is your alpha color or opacity of background.--*/
background-color: #0f05; /*-- Same as previous one.--*/
background-color: rgba(0,255,0,.5); /*-- a extend for alpha color--*/

Hope this help you.