:root {
    --duration: 1s;
    --nav-duration: calc(var(--duration) / 3);
    --ease: cubic-bezier(0.215, 0.61, 0.355, 1);
    --space: 0.5rem;
    --line-height: 5.5;
}

* {
    box-sizing: border-box;
}

.main-navigation-toggle {
    position: fixed;
    height: 1px;
    width: 1px;
    overflow: hidden;
    clip: rect(1px, 1px, 1px, 1px);
    white-space: nowrap;
}

.main-navigation-toggle+label,
.main-impressum-toggle+label {
    position: fixed;
    top: calc(var(--space) * 1.5);
    right: calc(var(--space) * 2);
    cursor: pointer;
    z-index: 4;
}

.icon--menu-toggle {
    --size: calc(1rem + 3vmin);
    display: flex;
    align-items: center;
    justify-content: center;
    width: var(--size);
    height: var(--size);
    stroke-width: 0.15rem;
}

.icon-group {
    transform: translateX(0);
    transition: transform var(--nav-duration) var(--ease);
}

.icon--menu {
    stroke: var(--color-secondary);
}

.icon--close {
    stroke: var(--color-secondary);
    transform: translateX(-100%);
}

.main-navigation {
    position: fixed;
    top: 0;
    left: 0;
    display: flex;
    align-items: center;
    width: 100%;
    height: 100%;
    transform: translateX(-100%);
    transition: transform var(--nav-duration);
    z-index: 3;
}

.main-navigation:after {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-color: var(--color-primary);
    transform-origin: 0 50%;
    z-index: -1;
}

.main-navigation ul {
    font-size: 1rem;
    text-transform: uppercase;
    font-family: var(--font-heading);
    letter-spacing: 0.04rem;
    width: 100%;
}

.main-navigation li {
    --border-size: 0.06rem;
    display: flex;
    align-items: center;
    position: relative;
    overflow: hidden;
    margin: 0.6rem auto;
}

.main-navigation li:after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 100%;
    height: var(--border-size);
    background-color: var(--color-secondary);
    transform-origin: 0 50%;
    transform: translateX(-100%) skew(15deg);
}

.main-navigation li:hover a {
    letter-spacing: 0.09em;
    color: var(--color-four);
}

.main-navigation a {
    display: inline-block;
    width: 100%;
    max-width: 800px;
    margin: 0 auto;
    color: var(--color-secondary);
    line-height: 1;
    text-decoration: none;
    user-select: none;
    padding: var(--space) calc(var(--space) * 2) calc(var(--space) + var(--border-size) / 2);
    transform: translateY(100%);
    transition: all 0.3s ease;
}

.main-navigation-toggle:checked~label .icon--menu-toggle .icon-group {
    transform: translateX(100%);
}

.main-navigation-toggle:checked~.main-content {
    transform: translateX(10%);
}

.main-navigation-toggle:checked~.main-navigation {
    transition-duration: 0s;
    transform: translateX(0);
}

.main-navigation-toggle:checked~.main-navigation:after {
    animation: nav-bg var(--nav-duration) var(--ease) forwards;
}

.main-navigation-toggle:checked~.main-navigation li:after {
    animation: nav-line var(--duration) var(--ease) forwards;
}

.main-navigation-toggle:checked~.main-navigation a {
    animation: link-appear calc(var(--duration) * 1.5) var(--ease) forwards;
}

.main-navigation-toggle:checked~.main-navigation li:nth-child(1):after,
.main-navigation-toggle:checked~.main-navigation li:nth-child(1) a {
    animation-delay: calc((var(--duration) / 2) * 1 * 0.125);
}

.main-navigation-toggle:checked~.main-navigation li:nth-child(2):after,
.main-navigation-toggle:checked~.main-navigation li:nth-child(2) a {
    animation-delay: calc((var(--duration) / 2) * 2 * 0.125);
}

.main-navigation-toggle:checked~.main-navigation li:nth-child(3):after,
.main-navigation-toggle:checked~.main-navigation li:nth-child(3) a {
    animation-delay: calc((var(--duration) / 2) * 3 * 0.125);
}

.main-navigation-toggle:checked~.main-navigation li:nth-child(4):after,
.main-navigation-toggle:checked~.main-navigation li:nth-child(4) a {
    animation-delay: calc((var(--duration) / 2) * 4 * 0.125);
}

.main-navigation-toggle:checked~.main-navigation li:nth-child(5):after,
.main-navigation-toggle:checked~.main-navigation li:nth-child(5) a {
    animation-delay: calc((var(--duration) / 2) * 5 * 0.125);
}

.main-navigation-toggle:checked~.main-navigation li:nth-child(6):after,
.main-navigation-toggle:checked~.main-navigation li:nth-child(6) a {
    animation-delay: calc((var(--duration) / 2) * 6 * 0.125);
}

.main-navigation-toggle:checked~.main-navigation li:nth-child(7):after,
.main-navigation-toggle:checked~.main-navigation li:nth-child(7) a {
    animation-delay: calc((var(--duration) / 2) * 7 * 0.125);
}

.main-navigation-toggle:checked~.main-navigation li:nth-child(8):after,
.main-navigation-toggle:checked~.main-navigation li:nth-child(8) a {
    animation-delay: calc((var(--duration) / 2) * 8 * 0.125);
}

.main-navigation-toggle:checked~.main-navigation li:nth-child(9):after,
.main-navigation-toggle:checked~.main-navigation li:nth-child(9) a {
    animation-delay: calc((var(--duration) / 2) * 9 * 0.125);
}

.main-navigation-toggle:checked~.main-navigation li:nth-child(10):after,
.main-navigation-toggle:checked~.main-navigation li:nth-child(10) a {
    animation-delay: calc((var(--duration) / 2) * 10 * 0.125);
}

@keyframes nav-bg {
    from {
        transform: translateX(-100%) skewX(-15deg);
    }
    to {
        transform: translateX(0);
    }
}

@keyframes nav-line {
    0% {
        transform: scaleX(0);
        transform-origin: 0 50%;
    }
    35% {
        transform: scaleX(1.001);
        transform-origin: 0 50%;
    }
    65% {
        transform: scaleX(1.001);
        transform-origin: 100% 50%;
    }
    100% {
        transform: scaleX(0);
        transform-origin: 100% 50%;
    }
}

@keyframes link-appear {
    0%,
    25% {
        transform: translateY(100%);
    }
    50%,
    100% {
        transform: translateY(0);
    }
}