style.css

* {
    font-family: system-ui, sans-serif;
}

body {
    padding: 30px 20px;
    background-color: #d7d7d7;
    overflow-x: hidden;
}

body.dark {
    background-color: #000;
    user-select: none;
    cursor: none;
}

body a {
    color: black;
}

#content {
    max-width: 768px;
    margin: auto;
}

header {
    display: flex;
    justify-content: space-between;
    margin-bottom: 30px;
}

header h1 {
    margin: 0;
}

button#toggle {
    max-height: 50px;
    background-color: transparent;
    border: 2px solid black;
    border-radius: 5px;
    padding: 10px 30px;
    cursor: pointer;
    color: black;
}

body.dark #cursor {
    width: 150px;
    height: 150px;
    background-color: white;
    position: absolute;
    left: -40px;
    top: -40px;
    z-index: -10;
    border-radius: 50%;
    box-shadow: 0 0 30px 40px #fff;
    border: none;
}