* {
    box-sizing: border-box;
}
.demo-content {
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    justify-content: center;
    height: auto;
}
.button {
    background: none;
    border: none;
    padding: 15px 40px;
    border-radius: 100px;
    font-size: 18px;
    text-decoration: none;
    color: white;
    transition: box-shadow 0.25s ease-in-out;
}
.button:not(:last-child) {
    margin-right: 30px;
}
.button:hover, .button:focus, .button:active {
    outline: none;
    cursor: pointer;
    box-shadow: 3px 3px 15px rgba(0,0,0,0.3);
}
.button--one {
    background-color: #6453f7;
}
.button--two {
    background-color: #f3b60f;
}
.button--three {
    background-color: #272727;
}