* {
    box-sizing: border-box;
}

body {
    font-family: 'Open Sans', sans-serif;
    text-align: center;
}

hr {
    border-style: solid;
    border-color: #eee;
}

#game-field {
    display: flex;
    flex-wrap: wrap;
    max-width: 1024px;
    margin: 0 auto;
}

.card {
    background-color: #4d3bee;
    color: transparent;
    border: 5px solid white;
    width: 20%;
    height: 150px;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    border-radius: 20%;
    user-select: none;
    -webkit-user-select: none;
    -moz-user-select: none;
    -ms-user-select: none;
}

.card:hover {
    background-color: #0b0169;
}

.card.revealed {
    background: rgb(245, 225, 45);
    color: rgb(0, 0, 0);
}