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

html {
    scroll-behavior: smooth;
}

.window {
    border: 2px solid var(--lt_dark);
    margin-bottom: 12px;
    background-color: var(--lt_black);
    padding: 6px;
}

.window-title {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 4px 8px;
    background-image: linear-gradient(to right, var(--lt_blue), var(--lt_lavender));

    font-size: 16px;
    text-transform: uppercase;
}

.window-content {
    padding: 8px;
}

.window-title::after {
    content: "";
    display: block;

    width: 12px;
    height: 12px;

    background-image: url(../images/ui/ui-close.png);
    background-size: contain;
    background-repeat: no-repeat;
    background-position: center;

    image-rendering: pixelated;
}

.highlight-text {
    color: var(--lt_yellow);
}

a {
    text-decoration: none;
    color: var(--lt_lavender_l);
}

a:hover {
    color: var(--lt_peach);
}

.external-link::after {
    content: "";
    display: inline-block;
    width: 8px;
    height: 8px;
    margin-left: 6px;
    background-image: url("../images/ui/external-link-export.png");
    background-size: contain;
    background-repeat: no-repeat;
    background-position: center;
}

/* Parallax effect */
.parallax {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100vh;
    overflow: hidden;
    z-index: -5;
    background-color: var(--lt_dark);
}

.parallax-layer {
    position: absolute;
    top: 0;
    left: 0;

    width: 200%;
    height: 100%;

    background-position: 0 0;
    background-size: 50%;

    background-repeat: repeat-x;

    image-rendering: pixelated;
}

.par_layer1 {
    background-image: url("../images/par_layer1.png");
    animation: parScroll 25s linear infinite;
}

.par_layer2 {
    background-image: url("../images/par_layer2.png");
    animation: parScroll 40s linear infinite;
}

.par_layer3 {
    background-image: url("../images/par_layer3.png");
    animation: parScroll 70s linear infinite;
}

.par_layer4 {
    background-image: url("../images/par_layer4.png");
    animation: parScroll 120s linear infinite;
}

@keyframes parScroll {
    from {
        transform: translateX(0);
    }
    to {
        transform: translateX(-50%);
    }
}

/* General element settings */

body {
    font-family: "Lexend Deca", sans-serif;
    font-weight: 400;
    font-style: normal;
    font-size: 16px;
    color: var(--lt_white);
    background-color: var(--lt_dark);
}

/* Custom cursors */
body {
    cursor:
        url("../images/ui/ui-cursor-normal.png") 0 0,
        auto;
}

a,
button,
.project-card,
.nav-topic,
.nav-topic:hover {
    cursor:
        url("../images/ui/ui-cursor-click.png") 0 0,
        pointer;
}

main {
    position: relative;

    margin-left: auto;
    margin-right: auto;

    padding-left: 30px;
    padding-right: 30px;

    width: 100%;
    max-width: 1000px;

    background-color: var(--lt_darkest);
    min-height: 100vh;

    box-shadow: 0px 2px 6px var(--lt_shadow);
}

header {
    display: flex;
    flex-direction: column;
    align-items: center;
    padding: 25px 0px;
    background: var(--lt_darkest);
}

.header-content {
    image-rendering: pixelated;
    text-align: center;
    margin-bottom: 6px;
}

.header-content p {
    font-size: 20px;
    margin: 12px;
}

.wave-text span {
    display: inline-block;
    animation: wave 3s ease-in-out infinite;
}

@keyframes wave {
    0%,
    100% {
        transform: translateY(0);
    }
    50% {
        transform: translateY(-2px);
    }
}

.header-content img {
    width: 342px;
}

/* Navigation Topics */
.header-nav {
    display: flex;
    justify-content: center;
    gap: 24px;
    width: 100%;
    background-color: var(--lt_mutedblue);
    border: 2px solid var(--lt_blue_l);
}

.nav-topic {
    position: relative;
}

.nav-link {
    display: flex;
    align-items: center;
    gap: 10px;
    padding: 4px 15px;
    text-decoration: none;
}

.nav-icon {
    width: 32px;
    height: 32px;
    image-rendering: pixelated;
}

.nav-label {
    color: var(--lt_white);
    font-size: 18px;
    font-weight: 500;
    transition: color 0.2s ease;
}

.nav-link:hover .nav-label {
    color: var(--lt_peach);
}

/* Dropdown menu */
.dropdown-menu {
    position: absolute;
    top: 100%;
    left: 0;
    background-color: var(--lt_dark);
    width: 150px;
    opacity: 0;
    max-height: 0;
    overflow: hidden;
    transition:
        opacity 0.1s ease,
        max-height 0.3s ease;
    z-index: 10;

    /* Reposition to avoid clipping with border. */
    top: calc(100% + 2px);
}

.nav-topic:hover .dropdown-menu {
    opacity: 1;
    max-height: 200px;
}

.dropdown-item {
    display: block;
    padding: 12px 15px;
    color: var(--lt_white);
    text-decoration: none;

    opacity: 0;
    transform: translate3d(0, -6px, 0);

    transition:
        opacity 0.15s ease,
        transform 0.4s ease;
}

.nav-topic:hover .dropdown-item {
    opacity: 1;
    transform: translate3d(0, 0, 0);
}
.nav-topic:hover .dropdown-item:nth-child(1) {
    transition-delay: 0s;
}

.nav-topic:hover .dropdown-item:nth-child(2) {
    transition-delay: 0.05s;
}

.nav-topic:hover .dropdown-item:nth-child(3) {
    transition-delay: 0.1s;
}

.dropdown-item:hover {
    color: var(--lt_peach);
}

/* Responsive Design */
@media (max-width: 768px) {
    main {
        padding-left: 15px;
        padding-right: 15px;
    }

    .header-content img {
        width: 100%;
        max-width: 300px;
    }

    .header-nav {
        flex-wrap: wrap;
        gap: 10px;
        justify-content: center;
    }

    .nav-topic {
        padding: 4px 10px;
    }

    .nav-label {
        font-size: 16px;
    }

    .window-title {
        font-size: 14px;
    }

    .window-content {
        padding: 6px;
    }
}

@media (max-width: 480px) {
    body {
        font-size: 14px;
    }

    .header-nav {
        flex-direction: column;
        gap: 5px;
    }

    .nav-topic {
        justify-content: center;
    }

    .window-title {
        font-size: 14px;
    }

    .window-content {
        padding: 6px;
    }
}

#backToTopBtn {
    position: fixed;
    bottom: 32px;
    right: 32px;

    width: 48px;
    height: 48px;

    background: none;
    border: none;
    padding: 0;
    cursor: pointer;

    z-index: 9999;

    opacity: 0;
    pointer-events: none;

    transition:
        opacity 0.1s ease,
        transform 0.2s ease;
}

#backToTopBtn img {
    width: 100%;
    height: 100%;
    image-rendering: pixelated;
}

/* Visible state */
#backToTopBtn.visible {
    opacity: 1;
    pointer-events: auto;
}

/* Hover feedback */
#backToTopBtn:hover {
    transform: translateY(-4px);
}