animation-styles.css

body {
    background-color: bisque;
    margin: 0;
}

button {
    background-color: yellowgreen;
    width: 100px;
    height: 40px;
    margin: 10px;
}

button:hover {
    background-color: yellow
}

.wrapper {
    height: 400px;
    width: 400px;
    border: 2px solid coral;
    margin: 1rem;
}

.box {
    background-color: navy;
    width: 100px;
    height: 100px;
    position: relative;
}

.btn-block {
    width: 100%;
    background-color: lightgoldenrodyellow;
    margin: 10px 0;
    padding: 10px;
}

.text {
    width: 400px;
    height: 350px;
    overflow: scroll;
    margin: 0 auto;
    margin-top: 50px;
    padding: 10px;
    border: 5px solid white;
    background-color: wheat;
    /* with box-sizing property padding & border
    will include in the offset w/h */
    box-sizing: border-box;
}

.btn-text > button {
    display: block;
    margin: 0 auto;
    margin-top: 20px;
}