/* ==========================================
   ROOT VARIABLES & DESIGN TOKENS (LIGHT GLASSMORPHISM)
   ========================================== */
@import url('https://fonts.googleapis.com/css2?family=Inter:wght@300;400;500;600;700;800&family=Space+Grotesk:wght@500;600;700&display=swap');

:root {
    /* Background & Glass Surfaces */
    --color-bg-base: #f8fafc;
    --color-glass-surface: rgba(255, 255, 255, 0.3);
    --color-glass-surface-hover: rgba(255, 255, 255, 0.45);
    --color-glass-border: rgba(255, 255, 255, 0.4);
    --color-glass-border-strong: rgba(255, 255, 255, 0.7);

    /* Text Colors - High Contrast for Readability */
    --color-text-main: #0f172a;
    --color-text-muted: #475569;
    --color-text-light: #64748b;

    /* Brand & Accent Colors - Pastel & Vibrant for Light Mode */
    --color-primary: #3b82f6;
    --color-secondary: #8b5cf6;
    --color-accent: #10b981;

    /* Orb Colors for Animated Background */
    --orb-color-1: rgba(59, 130, 246, 0.4);
    /* Blue */
    --orb-color-2: rgba(139, 92, 246, 0.4);
    /* Purple */
    --orb-color-3: rgba(16, 185, 129, 0.3);
    /* Green */

    /* Typography */
    --font-sans: 'Inter', system-ui, -apple-system, sans-serif;
    --font-display: 'Space Grotesk', sans-serif;

    /* Shadows */
    --shadow-glass: 0 8px 32px 0 rgba(31, 38, 135, 0.07);
    --shadow-glass-hover: 0 12px 40px 0 rgba(31, 38, 135, 0.12);

    /* Layout */
    --container-width: 1200px;
    --border-radius-sm: 8px;
    --border-radius-md: 16px;
    --border-radius-lg: 24px;
    --border-radius-pill: 9999px;

    /* Semantic Theme Backgrounds */
    --bg-nav: rgba(255, 255, 255, 0.6);
    --bg-nav-mobile: rgba(255, 255, 255, 0.95);
    --bg-btn-secondary-hover: rgba(255, 255, 255, 0.9);
    --bg-preloader: rgba(255, 255, 255, 0.4);
}

/* ==========================================
   DARK THEME OVERRIDE
   ========================================== */
[data-theme="dark"] {
    --color-bg-base: #0f172a;
    --color-glass-surface: rgba(255, 255, 255, 0.03);
    --color-glass-surface-hover: rgba(255, 255, 255, 0.08);
    --color-glass-border: rgba(255, 255, 255, 0.1);
    --color-glass-border-strong: rgba(255, 255, 255, 0.2);

    --color-text-main: #f8fafc;
    --color-text-muted: #cbd5e1;
    --color-text-light: #94a3b8;

    --orb-color-1: rgba(59, 130, 246, 0.3);
    --orb-color-2: rgba(139, 92, 246, 0.3);
    --orb-color-3: rgba(16, 185, 129, 0.2);

    --shadow-glass: 0 8px 32px 0 rgba(0, 0, 0, 0.4);
    --shadow-glass-hover: 0 12px 40px 0 rgba(0, 0, 0, 0.6);

    /* Semantic Theme Backgrounds */
    --bg-nav: rgba(15, 23, 42, 0.6);
    --bg-nav-mobile: rgba(15, 23, 42, 0.95);
    --bg-btn-secondary-hover: rgba(51, 65, 85, 0.9);
    --bg-preloader: rgba(15, 23, 42, 0.6);
}

/* ==========================================
   RESET & BASE STYLES
   ========================================== */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-sans);
    background-color: var(--color-bg-base);
    color: var(--color-text-main);
    line-height: 1.6;
    overflow-x: hidden;
    position: relative;
}

a {
    text-decoration: none;
    color: inherit;
}

.container {
    max-width: var(--container-width);
    margin: 0 auto;
    padding: 0 2rem;
}

/* ==========================================
   ANIMATED BACKGROUND (AURORA ORBS)
   ========================================== */
.animated-background {
    position: fixed;
    top: 0;
    left: 0;
    width: 100vw;
    height: 100vh;
    z-index: -1;
    overflow: hidden;
    background-color: var(--color-bg-base);
}

.gradient-orb {
    position: absolute;
    border-radius: 50%;
    filter: blur(80px);
    opacity: 0.8;
    will-change: transform;
    transition: transform 0.3s ease-out;
}

.orb-1 {
    width: 600px;
    height: 600px;
    background: var(--orb-color-1);
    top: -100px;
    left: -100px;
    animation-delay: 0s;
}

.orb-2 {
    width: 500px;
    height: 500px;
    background: var(--orb-color-2);
    bottom: 10%;
    right: -50px;
    animation-delay: -5s;
    animation-duration: 25s;
}

.orb-3 {
    width: 400px;
    height: 400px;
    background: var(--orb-color-3);
    top: 40%;
    left: 30%;
    animation-delay: -10s;
    animation-duration: 30s;
}

@keyframes float {
    0% {
        transform: translate(0, 0) scale(1);
    }

    33% {
        transform: translate(30px, -50px) scale(1.1);
    }

    66% {
        transform: translate(-20px, 20px) scale(0.9);
    }

    100% {
        transform: translate(0, 0) scale(1);
    }
}

/* ==========================================
   GLASSMORPHISM UTILITIES
   ========================================== */
.glass-panel {
    background: var(--color-glass-surface);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border: 1px solid var(--color-glass-border);
    box-shadow: var(--shadow-glass);
    border-radius: var(--border-radius-lg);
    transition: all 0.3s ease;
}

.glass-panel:hover {
    background: var(--color-glass-surface-hover);
    border-color: var(--color-glass-border-strong);
    box-shadow: var(--shadow-glass-hover);
}

.gradient-text {
    background: linear-gradient(135deg, var(--color-primary), var(--color-secondary));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

/* ==========================================
   NAVIGATION
   ========================================== */
.nav-container {
    position: fixed;
    top: 1rem;
    left: 50%;
    transform: translateX(-50%);
    width: 90%;
    max-width: var(--container-width);
    z-index: 100;

    background: var(--bg-nav);
    backdrop-filter: blur(16px);
    -webkit-backdrop-filter: blur(16px);
    border: 1px solid var(--color-glass-border);
    border-radius: var(--border-radius-pill);
    box-shadow: var(--shadow-glass);
    padding: 0.5rem 1.5rem;
}

.nav-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.nav-logo {
    display: flex;
    align-items: center;
    gap: 0.75rem;
}

.logo-icon {
    height: 32px;
    width: 32px;
}

.logo-text {
    font-family: var(--font-display);
    font-weight: 700;
    font-size: 1.25rem;
    letter-spacing: -0.5px;
}

.nav-menu {
    display: flex;
    gap: 1.5rem;
    list-style: none;
}

.nav-link {
    font-size: 0.875rem;
    font-weight: 500;
    color: var(--color-text-muted);
    padding: 0.5rem 0.75rem;
    border-radius: var(--border-radius-pill);
    transition: all 0.2s ease;
}

.nav-link:hover,
.nav-link.active {
    color: var(--color-primary);
    background: rgba(59, 130, 246, 0.1);
}

.mobile-menu-toggle {
    display: none;
}

/* ==========================================
   SECTIONS & HEADERS
   ========================================== */
section {
    padding: 5rem 0 2rem;
}

.section-header {
    text-align: center;
    margin-bottom: 4rem;
}

.section-tag {
    display: inline-block;
    padding: 0.25rem 1rem;
    background: rgba(59, 130, 246, 0.1);
    color: var(--color-primary);
    border-radius: var(--border-radius-pill);
    font-size: 0.875rem;
    font-weight: 600;
    margin-bottom: 1rem;
}

.section-title {
    font-family: var(--font-display);
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: 0.5rem;
}

.section-subtitle {
    color: var(--color-text-muted);
    font-size: 1.125rem;
}

/* ==========================================
   HERO SECTION
   ========================================== */
.hero-section {
    min-height: 100vh;
    display: flex;
    align-items: center;
    padding-top: 6rem;
}

.hero-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 4rem;
    align-items: center;
}

.hero-title {
    font-family: var(--font-display);
    font-size: 4rem;
    line-height: 1.1;
    font-weight: 800;
    margin-bottom: 1rem;
    letter-spacing: -1px;
}

.hero-subtitle {
    font-size: 1.5rem;
    color: var(--color-text-muted);
    font-weight: 500;
    margin-bottom: 1.5rem;
}

.hero-description {
    font-size: 1.125rem;
    color: var(--color-text-muted);
    margin-bottom: 2rem;
    max-width: 500px;
}

.social-links {
    display: flex;
    gap: 1rem;
    margin-bottom: 2rem;
}

.social-link {
    width: 48px;
    height: 48px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.25rem;
    color: var(--color-text-main);
    background: var(--color-glass-surface);
    border: 1px solid var(--color-glass-border);
    backdrop-filter: blur(10px);
    transition: all 0.3s ease;
}

.social-link:hover {
    color: white;
    background: var(--color-primary);
    transform: translateY(-3px);
}

.hero-stats {
    display: flex;
    gap: 2rem;
    margin-bottom: 2rem;
    padding: 1.5rem;
    background: var(--color-glass-surface);
    backdrop-filter: blur(10px);
    border: 1px solid var(--color-glass-border);
    border-radius: var(--border-radius-lg);
}

.stat-value {
    font-family: var(--font-display);
    font-size: 2rem;
    font-weight: 700;
    color: var(--color-primary);
}

.stat-label {
    font-size: 0.875rem;
    color: var(--color-text-muted);
    font-weight: 500;
}

.hero-cta {
    display: flex;
    gap: 1rem;
}

.btn {
    padding: 0.75rem 1.5rem;
    border-radius: var(--border-radius-pill);
    font-weight: 600;
    font-size: 1rem;
    transition: all 0.3s ease;
    border: none;
    cursor: pointer;
    display: inline-block;
}

.btn-primary {
    background: linear-gradient(135deg, var(--color-primary), var(--color-secondary));
    color: white;
    box-shadow: 0 4px 15px rgba(59, 130, 246, 0.3);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(59, 130, 246, 0.4);
}

.btn-secondary {
    background: var(--color-glass-surface);
    color: var(--color-text-main);
    border: 1px solid var(--color-glass-border);
    backdrop-filter: blur(10px);
}

.btn-secondary:hover {
    background: var(--bg-btn-secondary-hover);
}

/* Profile Image */
.hero-visual {
    position: relative;
    min-height: 400px;
    /* Prevent collapse when profile floats */
}

.profile-card {
    position: relative;
    width: 400px;
    height: 400px;
    margin: 0 auto;
    transition: all 0.6s cubic-bezier(0.4, 0, 0.2, 1);
    z-index: 90;
    border-radius: 50%;
}

/* Floating Companion Mode */
.profile-card.floating-companion {
    position: fixed;
    bottom: 4rem;
    left: calc(100% - 120px - 5vw);
    /* Pushed further to the right edge */
    width: 120px;
    height: 120px;
    margin: 0;
    box-shadow: 0 15px 35px rgba(0, 0, 0, 0.2);
    transition: all 1s cubic-bezier(0.25, 1, 0.5, 1);
    /* Slower, smoother glide */
}

.profile-card.floating-companion.companion-left-side {
    left: 5vw;
    /* Keeps avatar near the left edge, out of the way of content */
}

.profile-card.floating-companion .floating-badge {
    opacity: 0;
    pointer-events: none;
    transform: scale(0.5);
    transition: all 0.3s ease;
}

/* Micro-animations */
@keyframes companionBounce {

    0%,
    100% {
        transform: translateY(0);
    }

    50% {
        transform: translateY(-15px) scale(1.05);
    }
}

@keyframes companionSpin {
    0% {
        transform: rotate(0deg);
    }

    100% {
        transform: rotate(360deg);
    }
}

.profile-card.companion-bounce {
    animation: companionBounce 0.5s ease-out;
}

.profile-card.companion-spin .profile-ring {
    animation: companionSpin 1s cubic-bezier(0.4, 0, 0.2, 1);
    border-color: var(--color-accent) transparent var(--color-primary) transparent;
}

/* Companion Speech Bubble */
.companion-speech-bubble {
    position: absolute;
    bottom: 110%;
    right: 50%;
    transform: translateX(50%) translateY(10px) scale(0.9);
    background: var(--color-glass-surface);
    backdrop-filter: blur(10px);
    border: 1px solid var(--color-glass-border);
    color: var(--color-text-main);
    padding: 0.75rem 1.25rem;
    border-radius: 20px;
    font-size: 0.875rem;
    font-weight: 500;
    white-space: normal;
    width: max-content;
    max-width: 220px;
    text-align: center;
    opacity: 0;
    pointer-events: none;
    transition: all 0.4s cubic-bezier(0.175, 0.885, 0.32, 1.275);
    box-shadow: var(--shadow-glass);
    z-index: 10;
}

.companion-speech-bubble::after {
    content: '';
    position: absolute;
    top: 100%;
    left: 50%;
    transform: translateX(-50%);
    border-width: 8px;
    border-style: solid;
    border-color: var(--color-glass-border) transparent transparent transparent;
}

.profile-card.floating-companion .companion-speech-bubble.show-bubble {
    opacity: 1;
    transform: translateX(50%) translateY(0) scale(1);
}

.profile-image {
    width: 100%;
    height: 100%;
    border-radius: 50%;
    position: relative;
    background: transparent !important;
    box-shadow: none !important;
    border: 3px solid var(--color-glass-border);
    clip-path: circle(50% at 50% 50%);
}

.profile-avatar-img {
    width: 100%;
    height: 100%;
    border-radius: 50%;
    object-fit: cover;
    background: transparent !important;
    clip-path: circle(50% at 50% 50%);
}

.profile-ring {
    display: none !important;
}

.floating-badge {
    position: absolute;
    background: var(--color-glass-surface);
    backdrop-filter: blur(10px);
    border: 1px solid var(--color-glass-border);
    padding: 0.5rem 1rem;
    border-radius: var(--border-radius-pill);
    font-size: 0.875rem;
    font-weight: 600;
    display: flex;
    align-items: center;
    gap: 0.5rem;
    box-shadow: var(--shadow-glass);
    animation: float 6s infinite ease-in-out alternate;
}

.badge-1 {
    top: 10%;
    left: -5%;
    animation-delay: 0s;
}

.badge-2 {
    bottom: 20%;
    left: -10%;
    animation-delay: -2s;
}

.badge-3 {
    bottom: 10%;
    right: -5%;
    animation-delay: -4s;
}

/* ==========================================
   ABOUT SECTION
   ========================================== */
.about-content {
    display: grid;
    grid-template-columns: 3fr 2fr;
    gap: 2rem;
}

.about-card,
.about-education {
    background: var(--color-glass-surface);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border: 1px solid var(--color-glass-border);
    border-radius: var(--border-radius-lg);
    padding: 2.5rem;
    box-shadow: var(--shadow-glass);
}

.about-card h3,
.about-education h3 {
    font-family: var(--font-display);
    font-size: 1.5rem;
    margin-bottom: 1.5rem;
    color: var(--color-primary);
}

.about-card p {
    margin-bottom: 1rem;
    color: var(--color-text-muted);
}

.about-card b {
    color: var(--color-text-main);
}

.education-item {
    margin-bottom: 1.5rem;
    padding-left: 1.5rem;
    border-left: 2px solid var(--color-primary);
    position: relative;
}

.education-item::before {
    content: '';
    position: absolute;
    left: -6px;
    top: 0;
    width: 10px;
    height: 10px;
    border-radius: 50%;
    background: var(--color-primary);
}

.education-year {
    font-size: 0.875rem;
    font-weight: 700;
    color: var(--color-primary);
    margin-bottom: 0.25rem;
}

.education-content h4 {
    font-size: 1.125rem;
    font-weight: 600;
}

.education-content p {
    font-size: 0.875rem;
    color: var(--color-text-muted);
}

/* ==========================================
   EXPERIENCE SECTION (TIMELINE)
   ========================================== */
.experience-timeline {
    max-width: 800px;
    margin: 0 auto;
    position: relative;
}

.experience-timeline::before {
    content: '';
    position: absolute;
    left: 20px;
    top: 0;
    height: 100%;
    width: 2px;
    background: rgba(59, 130, 246, 0.2);
}

.timeline-item {
    position: relative;
    padding-left: 60px;
    margin-bottom: 3rem;
}

.timeline-marker {
    position: absolute;
    left: 12px;
    top: 0;
    width: 18px;
    height: 18px;
    border-radius: 50%;
    background: var(--color-bg-base);
    border: 4px solid var(--color-primary);
    box-shadow: 0 0 0 4px rgba(59, 130, 246, 0.2);
}

.timeline-content {
    background: var(--color-glass-surface);
    backdrop-filter: blur(20px);
    border: 1px solid var(--color-glass-border);
    border-radius: var(--border-radius-lg);
    padding: 2rem;
    box-shadow: var(--shadow-glass);
    transition: transform 0.3s ease;
}

.timeline-content:hover {
    transform: translateY(-5px);
}

.timeline-header {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    margin-bottom: 1rem;
}

.timeline-company h3 {
    font-family: var(--font-display);
    font-size: 1.25rem;
    color: var(--color-primary);
}

.timeline-location {
    font-size: 0.875rem;
    color: var(--color-text-muted);
}

.timeline-period {
    font-size: 0.875rem;
    font-weight: 600;
    background: rgba(59, 130, 246, 0.1);
    color: var(--color-primary);
    padding: 0.25rem 0.75rem;
    border-radius: var(--border-radius-pill);
}

.timeline-role {
    font-size: 1.125rem;
    font-weight: 600;
    margin-bottom: 1rem;
}

.timeline-achievements {
    padding-left: 1.25rem;
    margin-bottom: 1.5rem;
    color: var(--color-text-muted);
}

.timeline-achievements li {
    margin-bottom: 0.5rem;
}

.timeline-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
}

.tag {
    font-size: 0.75rem;
    font-weight: 500;
    padding: 0.25rem 0.75rem;
    background: rgba(0, 0, 0, 0.05);
    border-radius: var(--border-radius-pill);
    color: var(--color-text-main);
}

/* ==========================================
   SKILLS SECTION
   ========================================== */
.skills-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 2rem;
}

.skill-category {
    background: var(--color-glass-surface);
    backdrop-filter: blur(20px);
    border: 1px solid var(--color-glass-border);
    border-radius: var(--border-radius-lg);
    padding: 2rem;
    box-shadow: var(--shadow-glass);
}

.skill-category-header {
    display: flex;
    align-items: center;
    gap: 1rem;
    margin-bottom: 1.5rem;
}

.skill-icon {
    font-size: 1.5rem;
}

.skill-category-header h3 {
    font-family: var(--font-display);
    font-size: 1.25rem;
}

.skill-items {
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

.skill-item span {
    display: block;
    font-size: 0.875rem;
    font-weight: 500;
    margin-bottom: 0.5rem;
}

.skill-bar {
    height: 8px;
    background: rgba(0, 0, 0, 0.05);
    border-radius: var(--border-radius-pill);
    overflow: hidden;
}

.skill-progress {
    height: 100%;
    background: linear-gradient(90deg, var(--color-primary), var(--color-secondary));
    border-radius: var(--border-radius-pill);
}

/* ==========================================
   GITHUB / PROJECTS SECTION
   ========================================== */
.hidden {
    display: none !important;
}

@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(10px);
    }

    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.project-filters {
    display: flex;
    justify-content: center;
    gap: 1rem;
    margin-bottom: 3rem;
    flex-wrap: wrap;
}

.filter-btn {
    padding: 0.5rem 1.25rem;
    border: 1px solid var(--color-glass-border);
    background: var(--color-glass-surface);
    color: var(--color-text-main);
    border-radius: var(--border-radius-pill);
    font-size: 0.875rem;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.2s;
    backdrop-filter: blur(10px);
}

.filter-btn.active,
.filter-btn:hover {
    background: var(--color-primary);
    color: white;
    border-color: var(--color-primary);
}

.github-grid,
.downloads-grid,
.certifications-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    gap: 2rem;
}

.github-card,
.download-card,
.cert-card {
    background: var(--color-glass-surface);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border: 1px solid var(--color-glass-border);
    border-radius: var(--border-radius-lg);
    padding: 2rem;
    box-shadow: var(--shadow-glass);
    transition: all 0.3s ease;
    display: flex;
    flex-direction: column;
}

.github-card:hover,
.download-card:hover,
.cert-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-glass-hover);
    border-color: rgba(59, 130, 246, 0.3);
}

.github-card-header,
.download-card-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 1rem;
}

.github-icon,
.download-icon {
    font-size: 1.5rem;
    color: var(--color-primary);
}

.github-card h3,
.download-card h3,
.cert-card h3 {
    font-family: var(--font-display);
    font-size: 1.25rem;
    margin-bottom: 0.75rem;
}

.github-card p,
.download-card p {
    color: var(--color-text-muted);
    font-size: 0.875rem;
    margin-bottom: 1.5rem;
    flex-grow: 1;
}

.github-footer,
.download-footer {
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: 1rem;
    border-top: 1px solid rgba(0, 0, 0, 0.05);
    padding-top: 1rem;
}

.github-language,
.file-type {
    font-size: 0.75rem;
    font-weight: 600;
    color: var(--color-primary);
    background: rgba(59, 130, 246, 0.1);
    padding: 0.25rem 0.5rem;
    border-radius: var(--border-radius-sm);
    white-space: nowrap;
}

.github-link {
    font-size: 0.875rem;
    font-weight: 600;
    color: var(--color-primary);
    white-space: nowrap;
}

.download-link {
    font-size: 0.875rem;
    font-weight: 600;
    color: white;
    background: var(--color-primary);
    padding: 0.35rem 0.75rem;
    border-radius: var(--border-radius-pill);
    transition: all 0.2s ease;
    white-space: nowrap;
}

.download-link:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(59, 130, 246, 0.3);
}

.github-cta {
    text-align: center;
    margin-top: 3rem;
}

.version-badge {
    background: rgba(0, 0, 0, 0.05);
    padding: 0.25rem 0.5rem;
    border-radius: var(--border-radius-sm);
    font-size: 0.75rem;
    font-weight: 600;
}

.checksum-value code {
    display: block;
    background: rgba(0, 0, 0, 0.05);
    padding: 0.5rem;
    border-radius: var(--border-radius-sm);
    font-size: 0.75rem;
    margin-top: 0.5rem;
    word-break: break-all;
}

.footer-actions {
    display: flex;
    align-items: center;
    gap: 1rem;
    flex-wrap: wrap;
}

.vt-link {
    font-size: 0.875rem;
    color: var(--color-accent);
    font-weight: 600;
    display: flex;
    align-items: center;
    gap: 0.25rem;
    white-space: nowrap;
}

/* ==========================================
   CERTIFICATIONS & PUBLICATIONS
   ========================================== */
.cert-badge {
    width: 48px;
    height: 48px;
    background: rgba(59, 130, 246, 0.1);
    color: var(--color-primary);
    border-radius: 12px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.5rem;
    margin-bottom: 1rem;
}

.cert-issuer {
    color: var(--color-text-muted);
    font-size: 0.875rem;
    font-weight: 500;
}

.cert-note {
    font-size: 0.75rem;
    color: var(--color-text-muted);
    margin-top: 0.5rem;
    border-top: 1px solid rgba(0, 0, 0, 0.05);
    padding-top: 0.5rem;
}

.publications-section {
    margin-top: 4rem;
}

.publications-section h3 {
    font-family: var(--font-display);
    font-size: 1.5rem;
    text-align: center;
    margin-bottom: 2rem;
}

.publications-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 2rem;
}

.publication-item {
    background: var(--color-glass-surface);
    backdrop-filter: blur(20px);
    border: 1px solid var(--color-glass-border);
    padding: 1.5rem;
    border-radius: var(--border-radius-lg);
    display: flex;
    gap: 1rem;
    align-items: flex-start;
}

.publication-icon {
    font-size: 1.5rem;
}

.publication-content h4 {
    font-size: 1rem;
    margin-bottom: 0.25rem;
}

.publication-content p {
    font-size: 0.875rem;
    color: var(--color-text-muted);
}

/* ==========================================
   CONTACT SECTION
   ========================================== */
.contact-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 1.5rem;
}

.contact-card {
    display: flex;
    flex-direction: column;
    align-items: center;
    text-align: center;
    background: var(--color-glass-surface);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border: 1px solid var(--color-glass-border);
    border-radius: var(--border-radius-lg);
    padding: 3rem 2rem;
    transition: all 0.3s ease;
}

.contact-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-glass-hover);
}

.contact-card-icon {
    font-size: 2rem;
    color: var(--color-primary);
    margin-bottom: 1rem;
}

.contact-card h3 {
    font-family: var(--font-display);
    font-size: 1.25rem;
    margin-bottom: 0.5rem;
}

.contact-card-action {
    font-weight: 600;
    color: var(--color-primary);
    margin-bottom: 0.5rem;
}

.contact-card-desc {
    font-size: 0.75rem;
    color: var(--color-text-muted);
}

/* ==========================================
   FOOTER
   ========================================== */
.footer {
    padding: 4rem 0 2rem;
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border-top: 1px solid var(--color-glass-border);
}

.footer-content {
    text-align: center;
}

.footer-logo {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
    margin-bottom: 1rem;
}

.footer-tagline {
    color: var(--color-text-muted);
    margin-bottom: 2rem;
}

.footer-links {
    display: flex;
    justify-content: center;
    gap: 1.5rem;
    flex-wrap: wrap;
    margin-bottom: 2rem;
}

.footer-links a {
    font-size: 0.875rem;
    font-weight: 500;
    color: var(--color-text-main);
}

.footer-links a:hover {
    color: var(--color-primary);
}

.footer-copyright {
    font-size: 0.875rem;
    color: var(--color-text-muted);
}

/* ==========================================
   RESPONSIVE DESIGN
   ========================================== */
@media (max-width: 1024px) {
    .nav-menu {
        display: flex;
        flex-direction: column;
        position: absolute;
        top: 100%;
        left: 0;
        right: 0;
        background: var(--bg-nav-mobile);
        backdrop-filter: blur(20px);
        -webkit-backdrop-filter: blur(20px);
        padding: 1rem;
        border-radius: var(--border-radius-lg);
        border: 1px solid var(--color-glass-border);
        box-shadow: var(--shadow-glass);
        gap: 0.5rem;
        opacity: 0;
        visibility: hidden;
        transform: translateY(0);
        transition: all 0.3s ease;
    }

    .nav-menu.active {
        opacity: 1;
        visibility: visible;
        transform: translateY(10px);
    }

    .mobile-menu-toggle {
        display: flex;
        flex-direction: column;
        gap: 4px;
        background: none;
        border: none;
        cursor: pointer;
        padding: 0.5rem;
        z-index: 101;
    }

    .mobile-menu-toggle span {
        display: block;
        width: 24px;
        height: 2px;
        background-color: var(--color-text-main);
        transition: all 0.3s ease;
    }

    .mobile-menu-toggle.active span:nth-child(1) {
        transform: translateY(6px) rotate(45deg);
    }

    .mobile-menu-toggle.active span:nth-child(2) {
        opacity: 0;
    }

    .mobile-menu-toggle.active span:nth-child(3) {
        transform: translateY(-6px) rotate(-45deg);
    }

    .hero-content {
        grid-template-columns: 1fr;
        text-align: center;
        gap: 2rem;
    }

    .hero-description {
        margin: 0 auto 2rem;
    }

    .social-links {
        justify-content: center;
    }

    .hero-stats {
        justify-content: center;
    }

    .hero-cta {
        justify-content: center;
    }

    .about-content {
        grid-template-columns: 1fr;
    }

    .contact-grid {
        grid-template-columns: repeat(2, 1fr);
    }

    .publications-grid {
        grid-template-columns: 1fr;
    }
}

@media (max-width: 768px) {
    .hero-title {
        font-size: 3rem;
    }

    .skills-grid {
        grid-template-columns: 1fr;
    }

    .contact-grid {
        grid-template-columns: 1fr;
    }

    .footer-links {
        gap: 1rem;
    }
}

/* ==========================================
   PRELOADER
   ========================================== */
#preloader {
    position: fixed;
    inset: 0;
    z-index: 9999;
    background-color: var(--color-bg-base);
    display: flex;
    justify-content: center;
    align-items: center;
    transition: opacity 0.5s ease, visibility 0.5s ease;
}

.preloader-content {
    text-align: center;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 1.5rem;
}

.preloader-logo {
    display: flex;
    align-items: center;
    gap: 0.75rem;
}

.preloader-spinner {
    width: 40px;
    height: 40px;
    border: 3px solid rgba(59, 130, 246, 0.2);
    border-radius: 50%;
    border-top-color: var(--color-primary);
    animation: spin 1s linear infinite;
}

.preloader-status {
    font-size: 0.875rem;
    color: var(--color-text-muted);
    font-weight: 500;
    letter-spacing: 0.5px;
}

@keyframes spin {
    to {
        transform: rotate(360deg);
    }
}