* {
    padding: 0;
    margin: 0;
    box-sizing: border-box;
}

body, html {
    width: 100%;
    height: 100%;
    display: flex;
    justify-content: center;
    align-items: center;
}

.container {
    display: grid;
    grid-template-columns: repeat(5, 1fr);
    gap: 15px;
}

.btn {
    width: 80px;
    height: 80px;
    border-radius: 6px;
    border: 4px solid rgb(56, 128, 216);
    cursor: pointer;
    display: flex;
    justify-content: center;
    align-items: center;
}

.btn .content {
    border-radius: 50%;
    border: 2px solid rgb(126, 163, 209);
    width: 90%;
    height: 90%;
}

.btn.active {
    animation: btn_key .5s;
    .content{
        animation: btn_content .5s;
    }
}

@keyframes btn_key {
    50% {
        scale: .7;
    }
}

@keyframes btn_content {
    50% {
        rotate: y 180deg;
    }
}