:root {
    box-sizing: border-box;
}
*, *::before, *::after {
    box-sizing: inherit;
}
body {
    background-color: hsl(200, 80%, 30%);
    background-image: radial-gradient( hsl(200, 80%,30%), hsl(210, 80%, 20%));
    color: #fff;
    font-family: Raleway, Arial, Helvetica, sans-serif;
    line-height: 1.4;
    margin: 0;
    min-height: 100vh;

}
h1, h2, h3 {
    font-family: Alfa Slab One, serif;
    font-weight: 400;
}
main {
    display: block;
}
img {
    max-width: 100%;
}
.page-header {
    margin: 0;
    padding: 1rem;
}
/* nav */
.nav-links {
    display: flex;
    justify-content: space-between;
    margin-top: 0;
    margin-bottom: 1rem;
    padding: 0 1rem;
    list-style: none;
}
.nav-links > li + li {
    margin-left: 0;

}
.nav-links > li > a {
    display: block;
    padding: .8em 0;
    color: #fff;
    font-size: .8rem;
    text-decoration: none;
    text-transform: uppercase;
    letter-spacing: .06em;
}
.nav-links__icon {
    height: 1.5em;
    width: 1.5em;
    vertical-align: -.2em;
}
.nav-links > li > a:hover {
    color: hsl(40, 100%, 70%);
}
/* cards */
.flyin-grid {
    margin: 0 1rem;
    perspective: 500px;
}
.card {
    margin-bottom: 1em;
    padding: .5em;
    background-color: #fff;
    color: hsl(210, 15%, 20%);
    box-shadow: .2em .5em 1em rgba(0, 0, 0, 0.3);
}
/* card animation */
.flyin-grid__item {
    animation: fly-in 600ms ease-in;
    animation-fill-mode: backwards;
}
.flyin-grid__item:nth-child(2) {
    animation-delay: .15s;
}
.flyin-grid__item:nth-child(3) {
    animation-delay: .3s;
}
.flyin-grid__item:nth-child(4) {
    animation-delay: .45s;
}
@keyframes fly-in {
    0% {
        transform: translateZ(-800px) rotate(90deg);
    }
    50% {
        transform: translateZ(-160px) rotateY(87deg);
    }
    100% {
        transform: translateZ(0) rotateY(0);
    }
}
/* shake animation */
.shake {
    font-size: .8em;
    text-align: center;
    animation: shake 1.5s linear infinite ;
}
@keyframes shake {
    0%, 100% {
        transform: translateX(0);
    }
    10%, 30%, 50%, 70% {
        transform: translateX(-.4em);
    }
    20%, 40%, 60% {
        transform: translateX(.4em);
    }
    80% {
        transform: translateX(.3em);
    }
    90% {
        transform: translateX(-.3em);
    }
}
@media (min-width: 30em){
    .page-header {
        padding: 2rem 2rem 3rem;
    }
    /* nav */
    .main-nav {
        position: fixed;
        top: 8.25rem;
        left: 0;
        z-index: 10;
        background-color: transparent;
        border-top-right-radius: .5em;
        border-bottom-right-radius: .5em;
    }
    .main-nav:hover {
        background-color: rgba(0, 0, 0, 0.6);
    }
    .nav-links {
        display: block;
        padding: 1em;
        margin-bottom: 0;
    }
    .nav-links > li + li {
        margin-left: 0;
    }
    .nav-links__label {
        display: inline-block;
        margin-left: 1em;
        padding-right: 1em;
        opacity: 0;
        transform: translate(-1em);
        transition: transform .4s cubic-bezier(0.2,0.9,0.3,1.3), 
        opacity .4s linear;
    }
    .nav-links:hover .nav-links__label,
    .nav-links:focus > .nav-links__label {
        opacity: 1;
        transform: translate(0);
    }
    .nav-links > li:nth-child(2) .nav-links__label {
        transition-delay: .1s;
    }
    .nav-links > li:nth-child(3) .nav-links__label {
        transition-delay: .2s;
    }
    .nav-links > li:nth-child(4) .nav-links__label {
        transition-delay: .3s;
    }
    .nav-links > li:nth-child(5) .nav-links__label {
        transition-delay: .4s;
    }
    .nav-links__icon {
        transition: transform 0.2s ease-out;
    }
    .nav-links a:hover > .nav-links__icon,
    .nav-links a:focus > .nav-links__icon {
        transform: scale(1.3);
    }
    /* card */
    .flyin-grid {
        display: flex;
        flex-wrap: wrap;
        margin: 0 5rem;
    }
    .flyin-grid__item {
        flex: 1 1 300px;
        margin-left: .5em;
        margin-right: .5em;
        max-width: 600px;
    }
    .flyin-grid {
        display: grid;
        grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
        gap: 2em;
    }
    .flyin-grid__item {
        max-width: initial;
        margin: 0;
    }
}