* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    user-select: none;
}

:root {
    --shadow: 0 10px 25px rgba(41, 48, 65, 0.08);
}

body {
    background-color: rgb(54, 44, 42);
}

.start-menu {
    position: absolute;
    inset: 0;
    background: rgba(0, 0, 0, 0.4);
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    gap: 20px;
    z-index: 10;
}

.start-menu h1 {
    color: white;
    font-size: 48px;
    font-family: Arial, Helvetica, sans-serif;
}

.start-menu button {
    padding: 12px 24px;
    font-size: 20px;
    border: none;
    border-radius: 50px;
    cursor: pointer;
    font-size: 900;
}

#start-btn {
    background-color: rgba(40, 77, 187, 0.5);
    color: white;
}

#restart-btn {
    background-color: rgba(255, 0, 0, 0.5);
    color: white;
}

.start-menu.hidden {
    display: none;
}

.game-board {
    width: 100vw;
    height: 80vh;
    border-bottom: 15px solid rgb(35, 160, 35);
    margin: 0 auto;
    position: relative;
    overflow: hidden;
    background: linear-gradient(#87ceeb, #e0f6ff);
}

.pipe {
    position: absolute;
    bottom: 0;
    width: 80px;
    animation: pipe-animation 2.8s infinite linear;
    animation-play-state: paused;
}

@keyframes pipe-animation {
    from {
        right: -80px;
    }
    to {
        right: 100%;
    }
}

.mario {
    width: 150px;
    position: absolute;
    bottom: 0px;
}

.jump {
    animation: jump 700ms ease-out;
}

@keyframes jump {
    0% {bottom: 0;}
    30% {bottom: 150px;}
    40% {bottom: 170px;}
    50% {bottom: 180px;}
    60% {bottom: 170px;}
    70% {bottom: 150px;}
    100% {bottom: 0;}
}

.clouds {
    position: absolute;
    width: 550px;
    animation: clouds-animation 10s infinite linear;
}

@keyframes clouds-animation {
    from {
        right: -550px;
    }
    to {
        right: 100%;
    }
}