.bg, .inner { box-sizing: border-box;}

.bg {
/* for plain background */
background: #FE82B624;

/* vv for image background. remove if want plain */
background-image:url(https://i.imgur.com/Wy0Pm6R.jpg);
background-size:cover;

padding:12px; /* make number bigger/smaller for a bigger/smaller border */
width:100%;
border:1px solid black;
}

.inner {
background: #FFF;
color: #000;
padding:5px;
border:1px solid black;
height:200px; /* set height to "height:fit-content;" to expand with text size */
overflow-y:auto; /* remove overflow if you don't want a scroll */
}