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

header {
    background-color: #000;
    color: #fff;
    padding: 20px;
}

nav {
    font-size: 16px;
    justify-content: space-between;
    align-items: center;
    /* width: 100%; */
    margin-top: 3px;
}

nav ul {
    list-style: none;
    display: flex;
    justify-content: space-around;
    width: 100%;
}

nav ul li a {
    color: #fff;
    text-decoration: none;
    padding: 10px;
    border-radius: 10px;
    border: 3px solid transparent; /* Add this line */
    transition: background-color 0.3s ease;
}

nav ul li a:hover {
    background-color: #ffffff;
    color: #000;
    padding: 10px;
    border-radius: 10px;
}

html, body {
    height: 100%;
    margin: 0;
    padding: 0;
}

body {
    display: flex;
    flex-direction: column;
    background-color: #000;
    color: #fff;
    font-size: 24px;
}

.container {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    height: 100%;
}

#score {
    position: absolute;
    font-size: 36px;
    color: #fff;
    margin-top: -400px;
}

#game {
    width: 700px;
    height: 200px;
    border: 1px solid #000;
    margin-top: -50px;
}

#character {
    width : 75px;
    height : 75px;
    background-color : #fff;
    border-radius: 50%;
    position: relative;
    top : 150px;
    left : 0;
    right : 75px;
}

.animate {
    animation: jump 500ms;
}

@keyframes jump {
    0% {
        top : 150px;
    }
    30% {
        top : 100px;
    }
    70% {
        top : 100px;
    }
    100% {
        top : 150px;
    }
}

#block {
    width : 25px;
    height : 25px;
    background-color : #0000ff;
    position: relative;
    top : 125px;
    left : 675px;
}

@keyframes block {
    0% {
        left : 675px;
    }
    100% {
        left : 0;
    }
}

#resetButton {
    position: relative;
    background-color: #fff;
    border: none;
    border-radius: 10px;
    color: #000;
    cursor: pointer;
    margin-top: 100px;
    font-size: 24px;
    padding: 10px 20px;
    transition: background-color 0.3s ease-in-out;
}

#resetButton:hover {
    background-color: #000;
    color: #fff;
}

.instructions {
    position: relative;
    text-align: center;
    top: -100px;
}

.instructions p {
    padding: 10px;
}

/* Small screens */
@media only screen and (max-width: 768px) {
    header {
        padding: 10px;
        font-size: 12px;
    }

    nav {
        font-size: 12px;
    }

    nav ul li a {
        padding: 5px;
        border-radius: 5px;
    }

    nav ul li a:hover {
        padding: 5px;
        border-radius: 5px;
        }

    body {
        font-size: 14px;
        line-height: 1.5;
        }

    #score {
        font-size: 18px;
    }

    #resetButton {
        font-size: 18px;
        padding: 5px 10px;
    }

    #game {
        width: 300px;
    }

    #block {
        left: 275px;
    }

    @keyframes block {
        0% {
            left : 275px;
        }
        100% {
            left : 0;
        }
    }

    .animate {
        animation: jump 700ms;
    }
}