:root {
    --unit: 5px;
    --text-input-border-width: calc(0.2 * var(--unit));
    --button-height: calc(4 * var(--unit));

    --header-height: calc(7 * var(--unit));
    --header-gap: calc(2 * var(--unit));

    --main-gap: calc(5 * var(--unit));
    --window-height: calc(18 * var(--unit));
    --window-width: calc(26 * var(--unit));
    --window-border-width: calc(0.2 * var(--unit));

    --footer-height: calc(3 * var(--unit));

    --item-list-duration: 150ms;
    --text-input-border-duration: 300ms;
    --window-duration: 300ms;

    --main-theme-color: #d101ca;
    --gradient-height: 2%;
    --background-filter: invert(9%) sepia(9%) saturate(4212%) hue-rotate(224deg)
        brightness(96%) contrast(110%);
    --header-bg-color: #222222;
    --main-font-color: #fffe;
    --main-bg-color: #160829;
    --window-mask-bg-color: #fff1;
    --footer-bg-color: #111111;
    --footer-font-color: #a0a0a0aa;
}

*,
*::before,
*::after {
    box-sizing: border-box;
}

.hexagon {
    position: relative;
    margin-inline: calc(var(--button-height) / 3);
}

.hexagon::before,
.hexagon::after {
    content: "";
    position: absolute;
    width: 0;
    height: 0;
    top: 0;
    border: solid transparent;
    border-width: calc(var(--hexagon-height) / 2)
        calc(var(--hexagon-height) / 3);
}

.hexagon::before {
    right: 100%;
    border-right-color: var(--hexagon-bg-color);
}

.hexagon::after {
    left: 100%;
    border-left-color: var(--hexagon-bg-color);
}

.colored-text {
    color: var(--main-theme-color);
}

.text-input-box {
    position: relative;
}

.text-input-box > .border,
.text-input-box > .border-placeholder {
    transition:
        opacity var(--item-list-duration),
        transform var(--text-input-border-duration);
    position: absolute;
    width: calc(100% + var(--button-height) / 3 * 2);
    margin: 0;
    bottom: 0;
    opacity: 0.5;
    border: var(--text-input-border-width) solid transparent;
    border-bottom-color: var(--main-font-color);
    z-index: 1;
}

.text-input-box > .border {
    transform: scale(0, 1);
}

.btn {
    min-width: calc(10 * var(--unit));
    text-decoration: none;
    display: grid;
    place-items: center;
    justify-self: stretch;
    background-color: var(--main-theme-color);
    --hexagon-bg-color: var(--main-theme-color);
    --hexagon-height: var(--button-height);
    cursor: pointer;
    user-select: auto;
}

.text-input,
.btn {
    font-size: calc(var(--button-height) / 2);
    height: var(--button-height);
    color: inherit;
    font-weight: inherit;
    font-family: inherit;
    border: none;
    outline: none;
}

.btn.inverted-colors {
    background-color: var(--main-font-color);
    --hexagon-bg-color: var(--main-font-color);
    color: var(--main-theme-color);
}

.btn {
    transition: opacity var(--item-list-duration);
}

.btn:not(.no-hover):hover {
    opacity: 0.6;
}

.text-input:focus ~ .border {
    opacity: 1;
    transform: none;
}

body {
    margin: 0;
    font-family: Arial, Helvetica, sans-serif;
    color: var(--main-font-color);
    font-weight: 600;
    background: linear-gradient(
        var(--header-bg-color),
        var(--main-theme-color) var(--gradient-height),
        var(--main-theme-color) calc(100% - var(--gradient-height)),
        var(--header-bg-color)
    );
}

.root-container {
    display: grid;
    min-height: calc(100vh + var(--footer-height));
    grid-template-rows: var(--header-height) 1fr var(--footer-height);
}

.main-bg {
    position: fixed;
    width: 100%;
    height: 100%;
    background: url("./img/background.png");
    background-size: calc(5 * var(--unit));
    z-index: -1;
    filter: var(--background-filter);
}

.main-bg::before {
    z-index: 1;
    inset: 0;
    background-color: #d101ca;
}

header {
    display: grid;
    grid-template-rows: var(--header-height);
    grid-template-columns: 1fr auto 1fr;
    align-items: center;
    background-color: var(--header-bg-color);
    position: sticky;
    top: 0;
    z-index: 2;
}

.logo-box {
    display: grid;
    grid-auto-flow: column;
    justify-content: start;
    align-items: center;
}

.title {
    font-size: calc(3 * var(--unit));
    margin-left: var(--header-gap);
}

.search-box {
    display: grid;
    grid-auto-flow: column;
}

.search-bar-box {
    --hexagon-bg-color: var(--main-theme-color);
    --hexagon-height: var(--button-height);
}

.search-bar-box::after {
    border-top-color: var(--main-theme-color);
    border-bottom-color: var(--main-theme-color);
}

.search-bar {
    display: block;
    background-color: var(--main-theme-color);
    width: calc(30 * var(--unit));
    padding-left: var(--unit);
}

.search-list {
    margin-left: calc(0.8 * var(--unit));
}

.menu {
    display: grid;
    grid-auto-flow: column;
    justify-content: end;
}

.right-menu-btn {
    margin-right: calc(var(--header-gap) + var(--button-height) / 3);
}

.list-container {
    display: grid;
    position: relative;
    margin-right: var(--header-gap);
}

.list-container > .btn {
    transition:
        transform var(--item-list-duration),
        opacity var(--item-list-duration);
    z-index: 2;
    cursor: auto;
    transition-delay: calc(var(--items-quantity) * var(--item-list-duration));
}

.list {
    list-style-type: none;
    padding: 0;
    margin: 0;
    transition: height calc(var(--items-quantity) * var(--item-list-duration));
    height: var(--button-height);
    width: 100%;
    overflow: hidden;
    top: 0;
    position: absolute;
}

.list-item {
    transition: transform
        calc(var(--items-quantity) * var(--item-list-duration));
    display: grid;
    place-items: center;
    background-color: var(--main-bg-color);
    --hexagon-bg-color: var(--main-bg-color);
    --hexagon-height: var(--button-height);
    transform: translateY(
        calc((var(--items-quantity) - 1) * var(--button-height) * -1)
    );
}

.list-item > .btn {
    margin-inline: 0;
    z-index: 1;
}

.list-container:hover > .btn {
    transform: translateX(calc(100% * var(--direction)));
    opacity: 1;
    transition-delay: 0ms;
}

.list-container:hover > .list {
    height: calc(var(--items-quantity) * var(--button-height));
    transition-delay: var(--item-list-duration);
}

.list-container:hover > .list > .list-item {
    transform: none;
    transition-delay: var(--item-list-duration);
}

main {
    background-color: var(--main-bg-color);
    display: grid;
    grid-template-columns: repeat(auto-fill, var(--window-width));
    grid-template-rows: repeat(auto-fill, var(--window-height));
    justify-content: center;
    justify-items: center;

    gap: var(--main-gap);
    padding: var(--main-gap);
    align-content: start;
}

.window {
    height: var(--window-height);
    width: var(--window-width);
    display: grid;
    grid-template-rows: 1fr calc(
            var(--button-height) + var(--window-border-width)
        );
    cursor: pointer;
    text-decoration: none;
}

.window-img {
    border: var(--window-border-width) solid var(--main-theme-color);
    background-color: var(--main-theme-color);
    overflow: hidden;
    position: relative;
}

.window-img > img {
    height: 100%;
    width: 100%;
}

.window-title {
    display: grid;
    justify-items: stretch;
    border: var(--window-border-width) solid var(--main-theme-color);
    border-top: none;
}

.window-img::after {
    content: "";
    position: absolute;
    inset: var(--window-border-width);
    background-color: var(--window-mask-bg-color);
    pointer-events: none;
    opacity: 0;
}

.window-img::after {
    transition: opacity var(--window-duration);
}

.window:hover > .window-img::after {
    opacity: 1;
}

.window > .window-img > img {
    transition: transform var(--window-duration);
}

.window:hover > .window-img > img {
    transform: scale(1.1);
}

.window :is(.window-title, .window-img),
.window::before,
.window::after {
    transition: border var(--window-duration);
}

.window:hover :is(.window-title, .window-img),
.window:hover::before,
.window:hover::after {
    border-color: var(--main-font-color);
}

.octagon-border {
    position: relative;
    overflow: hidden;
}

.octagon-border::before,
.octagon-border::after {
    content: "";
    z-index: 1;
    position: absolute;
    height: calc(var(--button-height) * 1.8);
    width: calc(var(--button-height) * 1.8);
    background-color: var(--main-bg-color);
    border: var(--window-border-width) solid var(--main-theme-color);
    top: calc(-1 * (var(--window-border-width) + var(--button-height)));
    transform: rotate(45deg);
}

.octagon-border::before {
    left: calc(-1 * (var(--window-border-width) + var(--button-height)));
}

.octagon-border::after {
    right: calc(-1 * (var(--window-border-width) + var(--button-height)));
}

footer {
    background-color: var(--footer-bg-color);
    color: var(--footer-font-color);
    display: grid;
    place-items: center;
    font-size: var(--unit);
}

@media screen and (min-width: 800px) {
    .root-container {
        width: 90%;
        margin-inline: auto;
    }

    :root {
        --unit: 7px;
    }
}

@media screen and (min-width: 1000px) {
    .root-container {
        width: 80%;
    }

    :root {
        --unit: 8px;
    }
}

@media screen and (min-width: 1300px) {
    :root {
        --unit: 10px;
    }
}