body {
    padding: 0;
    margin: 0;
}

#app {
    position: relative;
    display: flex;
    width: 100vw;
    padding-top: 100px;
}

.wrapper {
    flex: 1;
    position: relative;
    height: 300px;
    margin: 100px auto 0;
    border: 1px solid blue;
    overflow: hidden;
}

.container > p {
    padding: 10px;
    margin: 0;
    border: 1px solid gray;
}

button {
    position: absolute;
    top: 10px;
    left: 50%;
}