* {
    box-sizing: border-box;
    padding: 0;
    margin: 0;
    font-family: sans-serif;
}

body {
    overflow: hidden;
}

.content {
    position: relative;
    width: 100vw;
    height: 100vh;
}

.cover-container {
    width: 100%;
    height: 100%;
    background-image: url(./assets/bg01.jpg);
    background-repeat: no-repeat;
    background-size: cover;
}

#game-box {
    display: none;
}

#game-over-box {
    display: none;
}

button {
    background: none;
    border: none;
}

#btn-play {
    position: absolute;
    background-image: url(./assets/play-game.png);
    background-size: cover;
    width: 277px;
    height: 81px;
    left: 50%;
    top: 50%;
    margin-left: -138.5px;
    margin-top: -40.5px;
    cursor: pointer;
}

#btn-restart {
    position: absolute;
    background-image: url(./assets/btn-restart.png);
    background-size: cover;
    width: 100px;
    height: 83px;
    left: 50%;
    top: 50%;
    margin-left: -50px;
    margin-top: -41.5px;
    cursor: pointer;
}

#score {
    position: absolute;
    left: 50%;
    top: 50%;
    width: 100px;
    height: 80px;
    margin-top: -80px;
    margin-left: -50px;
    text-align: center;
    font-size: large;
    color: red;
}