header .darkmodeSwitch {
    position: fixed;
    left: 2rem;
    top: 1.5rem;
    width: 3rem;
    height: 1.5rem;
    border-radius: 500px;
    border: 2px solid #fff;
    background-color: transparent;
    cursor: pointer;
    appearance: none;
    z-index: 999;
}

header .darkmodeSwitch::before {
    content: '';
    position: absolute;
    left: 3px;
    top: 50%;
    width: 1rem;
    height: 1rem;
    background-color: #fff;
    border-radius: 50%;
    transform: translateY(-50%);
}

header .darkmodeSwitch.active::before {
    left: auto;
    right: 4px;
}