@import url('https://fonts.googleapis.com/css2?family=Roboto:wght@300,400,500,700&display=swap');
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: 'Roboto', sans-serif;
}
body {
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    background: #202020;
    overflow: hidden;
}
.container {
    /* border: 2px solid yellow; */
    position: absolute;
    width: 100%;
    height: 100%;
    display: flex;
    justify-content: center;
    align-items: center;
}
button {
    position: relative;
    z-index: 1;
    margin: 10px;
    border: none;
    outline: none;
    background: #fff;
    font-size: 1.2em;
    padding: 15px 30px;
    cursor: pointer;
    box-shadow: 10px 10px 30px rgba(0,0,0,0.25);
    /* display: none; */
}
.block {
    /* border: 2px solid rebeccapurple; */
    position: absolute;
    width: 50px;
    height: 50px;
    background: #fff;
    box-shadow: 10px 10px 30px rgba(0,0,0,0.25);
}
.block:nth-child(3n + 2) {
    background: #444;
    border: 0.5px solid white;
    box-shadow: 10px 10px 30px rgba(0,0,0,1.25);
}
.block:nth-child(3n + 3) {
    /* background: #ff9213; */
    background: rgb(212, 119, 57);
    border: 0.5px solid rgb(234, 104, 28);
    box-shadow: 10px 10px 30px rgba(0,0,0,5);
}

/* https://www.youtube.com/watch?v=M8G6SAmckxA */