body {
    margin: 0;
    padding: 0;
    background-color: #0F111A;
}

.header {
    font-family: "Nabla";
    font-size: 100px;
    display: flex;
    justify-content: center;
}

.btn {
    display: flex;
    justify-content: center;
}

#mode {
    font-size: 36px;
    background: #1E293B;
    padding: 10px;
    border: none;
    cursor: pointer;
    border-radius: 100%;
}