:root {
 /* Core Colors */
 --color-text-primary: #424242;
 --color-background-light: rgba(242, 242, 242, 0.8);
 --color-background-header: rgba(232, 232, 232, 0.95);
 --color-text-dark: #212121;
 --color-text-link: #757575;
 --color-background-white: rgba(250, 250, 250, 0.9);
 --color-background-hover: rgba(219, 219, 219, 0.7);
 --color-border-light: rgba(204, 204, 204, 0.3);
 --color-background-footer: #212121;
 --color-text-white: #FAFAFA;
 --color-background-modal-overlay: rgba(33, 33, 33, 0.4);
 --color-background-modal: rgba(250, 250, 250, 0.98);
 --color-background-scrollbar-track: rgba(232, 232, 232, 0.5);
 --color-background-scrollbar-thumb: rgba(140, 140, 140, 0.5);
 --color-background-scrollbar-thumb-hover: #757575;
 --color-shadow-light: rgba(33, 33, 33, 0.08);
 --color-shadow-medium: rgba(33, 33, 33, 0.15);

 /* Accent Colors */
 --color-accent-primary: #616161;
 --color-accent-secondary: #E0E0E0;
 --color-accent-success: #66BB6A;
 --color-accent-warning: #FFA726;
 --color-accent-error: #EF5350;
    /* Glass Effect Colors */
    --color-glass-background: rgba(247, 251, 250, 0.7);
    --color-glass-border: rgba(255, 255, 255, 0.2);
    --color-glass-shadow: rgba(26, 77, 65, 0.1);

    /* Enhanced Shadows */
    --shadow-light: 0 2px 8px rgba(26, 77, 65, 0.08);
    --shadow-medium: 0 4px 12px rgba(26, 77, 65, 0.12);
    --shadow-large: 0 8px 24px rgba(26, 77, 65, 0.16);
    --shadow-glass: 0 8px 32px rgba(26, 77, 65, 0.1);
    --shadow-inset: inset 0 2px 4px rgba(26, 77, 65, 0.05);
    --shadow-close-button: 0 2px 8px rgba(26, 77, 65, 0.15);

    /* Font Sizes */
    --font-size-body: 1.25rem;
    --font-size-hero-title-large: 4rem;
    --font-size-hero-title-medium: 3rem;
    --font-size-hero-title-small: 2rem;
    --font-size-hero-subtitle-large: 2rem;
    --font-size-hero-subtitle-medium: 1.5rem;
    --font-size-hero-subtitle-small: 1.2rem;
    --font-size-sticky-header: 1.5rem;
    --font-size-sticky-header-small: 1.2rem;
    --font-size-secondary-column-header: 1.3rem;
    --font-size-secondary-column-item: 1rem;
    --font-size-modal-title: 1.5rem;

    /* Spacing */
    --spacing-tiny: 0.5rem;
    --spacing-small: 1rem;
    --spacing-medium: 2rem;
    --spacing-large: 3rem;
    --spacing-xlarge: 4rem;

    /* Border Radius */
    --border-radius-small: 8px;
    --border-radius-medium: 15px;
    --border-radius-large: 24px;
    --border-radius-round: 50%;
    --border-radius-pill: 9999px;

    /* Z-Index */
    --z-index-modal: 2000;
    --z-index-sticky-header: 1000;
    --z-index-default: 1;
    --z-index-dropdown: 1500;
    --z-index-tooltip: 1800;

    /* Transitions */
    --transition-speed-fast: 200ms;
    --transition-speed-medium: 300ms;
    --transition-speed-slow: 500ms;
    --transition-easing: cubic-bezier(0.4, 0, 0.2, 1);
    --transition-bounce: cubic-bezier(0.68, -0.55, 0.265, 1.55);

    /* Grid */
    --grid-columns-desktop: repeat(3, 1fr);
    --grid-columns-tablet: repeat(2, 1fr);
    --grid-columns-mobile: 1fr;
    --grid-gap-desktop: 2rem;
    --grid-gap-mobile: 1rem;

    /* Scrollbar */
    --scrollbar-width: 8px;
    --scrollbar-radius: 4px;
    --scrollbar-track-color: rgba(226, 238, 233, 0.5);
    --scrollbar-thumb-color: rgba(91, 140, 127, 0.5);
    --scrollbar-thumb-hover-color: #00B894;

    /* Dimensions */
    --modal-width-desktop: 50%;
    --modal-width-tablet: 70%;
    --modal-width-mobile: 90%;
    --modal-height-desktop: 70vh;
    --modal-height-mobile: 80vh;

    /* Blur Effects */
    --blur-small: 4px;
    --blur-medium: 8px;
    --blur-large: 16px;

    /* Border Styles */
    --border-width-thin: 1px;
    --border-width-medium: 2px;
    --border-width-thick: 4px;
    --border-style-glass: 1px solid var(--color-glass-border);
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: "Roboto", serif;
    font-optical-sizing: auto;
    color: var(--color-text-primary);
    background-color: var(--color-background-light);
    font-size: var(--font-size-body);
}

/* Full-screen header */
.hero-header {
    height: 100vh;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    background-color: var(--color-background-header);
    padding: var(--spacing-medium);
    background-image: url("../images/header-bg-50.png");
}

.hero-title {
    font-size: var(--font-size-hero-title-medium);
    margin-bottom: var(--spacing-small);
    text-align: center;
}

.hero-subtitle {
    font-size: var(--font-size-hero-subtitle-medium);
    margin-bottom: var(--spacing-medium);
    text-align: center;
}

.hero-gif {
    width: 150px;
    height: 150px;
}

/* Sticky header */
.sticky-header {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    background-color: var(--color-background-white);
    padding: var(--spacing-medium);
    display: flex;
    justify-content: space-between;
    align-items: center;
    box-shadow: var(--shadow-light);
    opacity: 0;
    transform: translateY(-100%);
    z-index: var(--z-index-sticky-header);
}

.sticky-title {
    font-size: var(--font-size-sticky-header);
}

.nav-links {
    display: flex;
    gap: var(--spacing-medium);
}

.navBtn{
    cursor: pointer;
}

/* link styles */
.nav-links a, .un {
    text-decoration: none;
    color: var(--color-text-link);
    display: inline-block;
}

.nav-links a::after, .un::after {
    content: '';
    width: 0px;
    height: 2px;
    display: block;
    background: var(--color-text-dark);
    transition: var(--transition-speed-fast);
}

.nav-links a:hover::after, .un:hover::after {
    width: 100%;
}

/* Main content */
.main-content {
    display: flex;
    padding: var(--spacing-medium);
    opacity: 0;
    max-width: 1800px;
    margin: 0 auto;
    flex-wrap: wrap;
}

.primary-column {
    width: 80%;
    padding-right: var(--spacing-medium);
    padding-bottom: 3em;
    min-height: 100vh;
}

.text-content p {
    margin-bottom: var(--spacing-small);
    line-height: 1.6;
}

.grid-container {
    display: grid;
    grid-template-columns: var(--grid-columns-desktop);
    gap: var(--grid-gap-desktop);
    margin-top: var(--spacing-medium);
    position: relative;
    z-index: var(--z-index-default);
}

.grid-item {
    position: relative;
    overflow: hidden;
    padding: 0;
    border-radius: var(--border-radius-medium);
    cursor: pointer;
}

.grid-item-thumbnail {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: transform var(--transition-speed-medium) var(--transition-easing);
}

.grid-item:hover .grid-item-thumbnail {
    transform: scale(1.1);
}


.subTitle{
    font-size: var(--font-size-secondary-column-header);
    font-weight: bold;
    color: var(--color-text-dark);
    padding-top: var(--spacing-large);
}


/* right column for skills  */
.secondary-column {
    width: 20%;
    border-radius: var(--border-radius-small);
    padding: var(--spacing-medium);
}

.secondary-column ul {
    list-style: none;
    padding: 0;
    margin: 0;
}

.secondary-column li {
    padding: var(--spacing-tiny) 0;
    border-bottom: 1px solid var(--color-border-light);
    transition: background-color var(--transition-speed-medium) var(--transition-easing);
}

.secondary-column li:last-child {
    border-bottom: none;
}

.secondary-column li:hover {
    background-color: var(--color-background-hover);
}

.secondary-column li:first-child {
    font-size: var(--font-size-secondary-column-header);
    font-weight: bold;
    color: var(--color-text-dark);
    text-transform: uppercase;
    letter-spacing: 1px;
    border-bottom: 2px solid var(--color-text-dark);
    margin-bottom: var(--spacing-tiny);
    padding-bottom: var(--spacing-tiny);
}

/* Footer */
footer {
    background-color: var(--color-background-footer);
    color: var(--color-text-white);
    padding: var(--spacing-medium);
    text-align: center;
    position: relative;
    z-index: var(--z-index-default);
    background-image: url("../images/header-bg-30.png");
}

/* Modal Styles */
.modal-overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-color: var(--color-background-modal-overlay);
    display: none;
    justify-content: center;
    align-items: center;
    z-index: var(--z-index-modal);
    opacity: 0;
}

.modal {
    width: var(--modal-width-desktop);
    height: var(--modal-height-desktop);
    background-color: var(--color-background-modal);
    border-radius: var(--border-radius-medium);
    display: flex;
    flex-direction: column;
    position: relative;
    overflow: hidden;
}

.modal-image {
    width: 100%;
    height: 50%;
    object-fit: cover;
    object-position: center;
    background-color: #f0f0f0;
}

.modal-content {
    padding: var(--spacing-medium);
    height: 50%;
    display: flex;
    flex-direction: column;
    justify-content: space-between;
    overflow-y: auto;
    max-height: 100%;
}

.modal-content::-webkit-scrollbar {
    width: var(--scrollbar-width);
}

.modal-content::-webkit-scrollbar-track {
    background: var(--color-background-scrollbar-track);
}

.modal-content::-webkit-scrollbar-thumb {
    background: var(--color-background-scrollbar-thumb);
    border-radius: var(--scrollbar-radius);
}

.modal-content::-webkit-scrollbar-thumb:hover {
    background: var(--color-background-scrollbar-thumb-hover);
}

.modal-title {
    font-size: var(--font-size-modal-title);
    margin-bottom: var(--spacing-small);
}

.modal-text {
    line-height: 1.6;
    margin-bottom: var(--spacing-medium);
}

.close-button {
    position: absolute;
    top: var(--spacing-small);
    right: var(--spacing-small);
    background-color: var(--color-background-white);
    border: none;
    width: 32px;
    height: 32px;
    border-radius: var(--border-radius-round);
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: var(--font-size-modal-title);
    box-shadow: var(--shadow-close-button);
    z-index: calc(var(--z-index-modal) + 1);
}

/* Media Queries */
@media screen and (min-width: 1920px) {
    .main-content {
        padding: var(--spacing-large) var(--spacing-xlarge);
    }

    .hero-title {
        font-size: var(--font-size-hero-title-large);
    }

    .hero-subtitle {
        font-size: var(--font-size-hero-subtitle-large);
    }

    .grid-container {
        gap: var(--grid-gap-desktop);
    }
}

@media screen and (max-width: 1023px) {
    .main-content {
        flex-direction: column;
    }

    .primary-column {
        width: 100%;
        padding-right: 0;
        margin-bottom: var(--spacing-medium);
    }

    .secondary-column {
        width: 100%;
        margin-top: 0;
    }

    .grid-container {
        grid-template-columns: var(--grid-columns-tablet);
        margin-bottom: var(--spacing-medium);
    }

    .modal {
        width: var(--modal-width-tablet);
    }
}

@media screen and (max-width: 767px) {
    .hero-title {
        font-size: var(--font-size-hero-title-small);
    }

    .hero-subtitle {
        font-size: var(--font-size-hero-subtitle-small);
    }

    .sticky-header {
        padding: var(--spacing-tiny) var(--spacing-small);
        flex-direction: column;
        gap: var(--spacing-tiny);
    }

    .sticky-title {
        font-size: var(--font-size-sticky-header-small);
    }

    .nav-links {
        gap: var(--spacing-small);
    }

    .main-content {
        padding: var(--spacing-small);
    }

    .grid-container {
        grid-template-columns: var(--grid-columns-mobile);
        gap: var(--grid-gap-mobile);
    }

    .modal {
        width: var(--modal-width-mobile);
        height: var(--modal-height-mobile);
    }

    .modal-content {
        padding: var(--spacing-small);
    }
}