:root {
    --color-primary-100: #e6feff;
    --color-primary-200: #bef8fd;
    --color-primary-300: #87eaf2;
    --color-primary-400: #54d1d8;
    --color-primary-500: #38bec9;
    --color-primary-600: #2cb1bc;
    --color-primary-700: #14919b;
    --color-primary-800: #0e7c86;
    --color-primary-900: #0a6c74;
    --color-primary-950: #044e54;

    --color-base-100: #f0f4f8;
    --color-base-200: #d9e2ec;
    --color-base-300: #bcccdc;
    --color-base-400: #9fb3c8;
    --color-base-500: #829ab1;
    --color-base-600: #627d98;
    --color-base-700: #486581;
    --color-base-800: #334e68;
    --color-base-900: #243b53;
    --color-base-950: #102a43;

    --color-indigo-100: #e0e8f9;
    --color-indigo-200: #bef0f7;
    --color-indigo-300: #98aeeb;
    --color-indigo-400: #7b93db;
    --color-indigo-500: #647acb;
    --color-indigo-600: #4c63b6;
    --color-indigo-700: #4055a8;
    --color-indigo-800: #35469c;
    --color-indigo-900: #2d3a8c;
    --color-indigo-950: #19216c;

    --color-pink-100: #ffe0f0;
    --color-pink-200: #fab8d9;
    --color-pink-300: #f191c1;
    --color-pink-400: #e668a7;
    --color-pink-500: #da4a91;
    --color-pink-600: #c42d78;
    --color-pink-700: #ad2167;
    --color-pink-800: #9b1b5a;
    --color-pink-900: #781244;
    --color-pink-950: #5c0b33;

    --color-yellow-100: #fffaeb;
    --color-yellow-200: #fcefc7;
    --color-yellow-300: #f8e3a3;
    --color-yellow-400: #f9da8b;
    --color-yellow-500: #f7d070;
    --color-yellow-600: #e9b949;
    --color-yellow-700: #c99a2e;
    --color-yellow-800: #a27c1a;
    --color-yellow-900: #7c5e10;
    --color-yellow-950: #513c06;

    --color-red-100: #ffeeee;
    --color-red-200: #facdcd;
    --color-red-300: #f29b9b;
    --color-red-400: #e66a6a;
    --color-red-500: #d64545;
    --color-red-600: #ba2525;
    --color-red-700: #a61b1b;
    --color-red-800: #911111;
    --color-red-900: #780a0a;
    --color-red-950: #610404;
}

html, body {
    margin: 0;
    padding: 0;
    font-family: 'Roboto', sans-serif;
    background-color: var(--color-base-400);
    color: var(--color-base-900);
}

.op-listing-header {
    font-size: 1.5rem;
    font-weight: bold;
    margin: 1rem 2rem;
}

.op-listing {
    list-style: none;
    display: flex;
    flex-direction: row;
    flex-wrap: wrap;
    justify-content: space-between;
    gap: 1rem;
    margin: 1rem 0;
    padding: 0;
    --op-index: 0;
}

ul:has(.op-elem) {
    margin: 0 2rem;
}

.op-elem {
    display: block;
    width: 30%;
    flex-grow: 1;
    padding: 1em;
    background-color: var(--color-base-100);
    border-radius: 3px;
    box-shadow: 0 4px 6px -1px var(--color-primary-800),
                0 2px 4px -2px var(--color-primary-800);
    height: 100px;
    animation: slide-bottom 0.5s cubic-bezier(0.250, 0.460, 0.450, 0.940) both;
    animation-delay: calc(var(--op-index) * 40ms);
}

.op-elem > a {
    text-decoration: none;
    color: var(--color-base-900);
    font-weight: bold;
    font-size: 1.2em;
    position: relative;
    animation: slide-bottom 0.5s cubic-bezier(0.250, 0.460, 0.450, 0.940) both;
}

.op-elem > a::after {
    display: block;
    z-index: -5;
    position: absolute;
    content: "";
    width: 100%;
    height: 4px;
    bottom: -2px;
    left: 0;
    border-right-color: red;
    border-right-width: 10rem;
    background-color: var(--color-primary-500);
    transition: all 0.5s ease-out allow-discrete;
}

@keyframes slide-bottom {
    0% {
        -webkit-transform: translateY(-30px);
        transform: translateY(-30px);
    }
    100% {
        -webkit-transform: translateY(0);
        transform: translateY(0);
    }
}

.op-elem:hover {
    --line-percent: 100%;
}

@media (max-width: 768px) {
    .op-elem {
        width: 100%;
    }
}