#main-header {
    z-index: 5;
    position: sticky;
    top: 0;
    width: 100%;
    padding: .3rem 2.5rem;
    backdrop-filter: blur(10px);
    mix-blend-mode: difference;
}

#main-header-nav {
    width: 100%;
    justify-content: space-between;
    align-items: center;
}

#main-header-nav ul {
    /* backdrop-filter: blur(10px); */
    border-radius: 2rem;
    align-items: center;
    margin: 0;
    padding: 0;
}

#main-header-nav li {
    margin: 1rem;
}

#main-header-nav li a:not(.btn) {
    color: var(--bg-light);
    /* mix-blend-mode: difference; */
}

#main-header-nav .contact-btn {
    margin: 0 !important;
    border: solid 1px var(--bg-light);
}

/* menu hamburger toggle */
#menuToggle {
    display: block;
    position: absolute;
    top: 0;
    left: 0;
    z-index: 1;
    -webkit-user-select: none;
    user-select: none;
    padding: 1rem;
}

#menuToggle input {
    display: block;
    width: 3.5rem;
    height: 3.5rem;
    position: absolute;
    top: -7px;
    left: -5px;
    cursor: pointer;
    opacity: 0;
    z-index: 2;
    -webkit-touch-callout: none;
}

#menuToggle span {
    display: block;
    width: 33px;
    height: 4px;
    margin-bottom: 5px;
    position: relative;
    background: #cdcdcd;
    border-radius: 3px;
    z-index: 1;
    transform-origin: 4px 0px;
    transition: transform 0.5s cubic-bezier(0.77, 0.2, 0.05, 1.0),
        background 0.5s cubic-bezier(0.77, 0.2, 0.05, 1.0),
        opacity 0.55s ease;
}

#menuToggle span:first-child {
    transform-origin: 0% 0%;
}

#menuToggle span:nth-last-child(2) {
    transform-origin: 0% 100%;
}

#menuToggle input:checked~span {
    opacity: 1;
    transform: rotate(45deg) translate(-.5rem, -1rem);
    background: var(--bg-light);
}

#menuToggle input:checked~span:nth-last-child(3) {
    opacity: 0;
    transform: rotate(0deg) scale(0.2, 0.2);
}

#menuToggle input:checked~span:nth-last-child(2) {
    opacity: 1;
    transform: rotate(-45deg) translate(-.2rem, .8rem);
}

@media only screen and (max-width: 900px) {
    .fullul {
        height: 95vh;
        justify-content: start;
        font-size: 2rem;
        padding: 7vh 0 !important;
        gap: 2rem;
    }

    #main-header {
        padding: 0;
        backdrop-filter: unset;
        background-color: var(--text-dark);
        mix-blend-mode: unset;
    }
}