html,
body {
    height: 100%;
    margin: 0;
}

.container {
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    height: 100%;
    background-color: #f5f5f5;
}

.text {
    font-size: 24px;
    margin: 0 0 20px 0;
}

.btn {
    padding: 8px 16px;
    margin: 0 5px;
    cursor: pointer;
}

.btn-group {
    display: flex;
}