:root {
    --screen-width: 100vw;
    --screen-height: 100vh;
    --header-bg-color: #673ab7;
    --splash-bg-color: #368887;
}

.nav__toggle {
    display: inline-block;
    position: absolute;
    z-index: 10;
    padding: 0;
    border: 0;
    background: transparent;
    outline: 0;
    right: 15px;
    top: 6px;
    cursor: pointer;
    border-radius: 50%;
    transition: background-color 0.15s linear;
}
.nav__toggle:hover, .nav__toggle:focus {
    background-color: rgba(0, 0, 0, .5);
}

.nav h1 {
    position: absolute;
    top: 23px;
    left: 22px;
}

.nav__menu {
    display: flex;
    flex-direction: column;
    justify-content: center;
    height: 560px;
    position: relative;
    z-index: 5;
    visibility: hidden;
}
.nav__item {
    opacity: 0;
    transition: all 0.3s cubic-bezier(0, 0.995, 0.99, 1) 0.3s;
}
.nav__item:nth-child(1) {
    transform: translateY(-40px);
}
.nav__item:nth-child(2) {
    transform: translateY(-80px);
}
.nav__item:nth-child(3) {
    transform: translateY(-120px);
}
.nav__item:nth-child(4) {
    transform: translateY(-160px);
}
.nav__item:nth-child(5) {
    transform: translateY(-200px);
}
.nav__item:nth-child(6) {
    transform: translateY(-240px);
}
.nav__link {
    color: white;
    display: block;
    text-align: center;
    text-transform: uppercase;
    letter-spacing: 1px;
    font-size: 1.25rem;
    text-decoration: none;
    padding: 1rem;
}
.nav__link:hover, .nav__link:focus {
    outline: 0;
    background-color: rgba(0, 0, 0, 0.2);
}
.menuicon {
    display: block;
    cursor: pointer;
    color: white;
    transform: rotate(0deg);
    transition: 0.3s cubic-bezier(0.165, 0.84, 0.44, 1);
}
.menuicon__bar, .menuicon__circle {
    fill: none;
    stroke: currentColor;
    stroke-width: 3;
    stroke-linecap: round;
}
.menuicon__bar {
    transform: rotate(0deg);
    transform-origin: 50% 50%;
    transition: transform 0.25s ease-in-out;
}
.menuicon__circle {
    transition: stroke-dashoffset 0.3s linear 0.1s;
    stroke-dashoffset: 144.513262038;
    stroke-dasharray: 144.513262038;
}
.splash {
    position: absolute;
    top: 40px;
    right: 40px;
    width: 1px;
    height: 1px;
    z-index: 3;
}
.splash::after {
    content: "";
    display: block;
    position: absolute;
    border-radius: 50%;
    background-color: var(--splash-bg-color);
    width: 284vmax;
    height: 284vmax;
    top: -142vmax;
    left: -142vmax;
    transform: scale(0);
    transform-origin: 50% 50%;
    transition: transform 0.5s cubic-bezier(0.755, 0.05, 0.855, 0.06);
    will-change: transform;
}
.nav:target > .splash::after, .nav--open > .splash::after {
    transform: scale(1);
}
.nav:target .menuicon, .nav--open .menuicon {
    color: white;
    transform: rotate(180deg);
}
.nav:target .menuicon__circle, .nav--open .menuicon__circle {
    stroke-dashoffset: 0;
}
.nav:target .menuicon__bar:nth-child(1), .nav--open .menuicon__bar:nth-child(1), .nav:target .menuicon__bar:nth-child(4), .nav--open .menuicon__bar:nth-child(4) {
    opacity: 0;
}
.nav:target .menuicon__bar:nth-child(2), .nav--open .menuicon__bar:nth-child(2) {
    transform: rotate(45deg);
    color: white;
}
.nav:target .menuicon__bar:nth-child(3), .nav--open .menuicon__bar:nth-child(3) {
    transform: rotate(-45deg);
    color: white;
}
.nav:target .nav__menu, .nav--open .nav__menu {
    visibility: visible;
}
.nav:target .nav__item, .nav--open .nav__item {
    opacity: 1;
    transform: translateY(0);
}
.viewport {
    width: var(--screen-width);
    height: var(--screen-height);
    margin: 0 auto;
    position: relative;
    overflow: hidden;
}
.header {
    height: 60px;
    background-color: white;
}
.main {
    padding: 20px;
}