.setting-container {
    position: relative;
    z-index: 5;
}

.darkness-setting {
    height: 40px;
    width: 40px;
    line-height: 40px;
    font-size: 1em;
    border-radius: 50%;
    background-color: rgba(0, 0, 0, 0.5);
    color: white;
    text-align: center;
    margin: 1vh 1vh 0 0;
    float: right;
    cursor: pointer;
    border-radius: 50%;
    border: 2px solid black;
    transition: border 0.2s ease;
}

.darkness-setting:hover {
    border: 2px solid grey;
}



.darkness-setting:hover+.tooltip {
    opacity: 1;
}

.tooltip {
    float: right;
    margin: 1vh 1vh 0 0;
    transform-origin: top right;
    min-width: 120px;
    padding: 1rem;
    border-radius: 0.4rem;
    background: black;
    color: white;
    opacity: 0;
    transition: opacity 0.4s ease;
}

.tooltip:hover {
    opacity: 1;
}