/* ===================================
   CSS Variables & Design Tokens
   =================================== */
:root {
    /* Colors - Light Theme */
    --bg-primary: #f5f7fa;
    --bg-secondary: #ffffff;
    --bg-tertiary: #e8ecf1;
    --text-primary: #1a1a2e;
    --text-secondary: #6b7280;
    --text-tertiary: #9ca3af;

    /* Brand Colors */
    --brand-primary: #6366f1;
    --brand-secondary: #8b5cf6;
    --brand-accent: #ec4899;

    /* Gradients */
    --gradient-primary: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    --gradient-circle: linear-gradient(135deg, #a78bfa 0%, #ec4899 100%);

    /* Shadows */
    --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px rgba(0, 0, 0, 0.07);
    --shadow-lg: 0 10px 15px rgba(0, 0, 0, 0.1);
    --shadow-xl: 0 20px 25px rgba(0, 0, 0, 0.15);

    /* Typography */
    --font-primary: 'Poppins', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    --font-secondary: 'Inter', var(--font-primary);

    /* Border Radius */
    --radius-sm: 0.5rem;
    --radius-md: 0.75rem;
    --radius-lg: 1rem;
    --radius-xl: 1.5rem;
    --radius-full: 9999px;

    /* Transitions */
    --transition-fast: 150ms ease;
    --transition-base: 250ms ease;
    --transition-slow: 350ms ease;
}

/* Dark Theme */
[data-theme="dark"] {
    --bg-primary: #1a1d2e;
    --bg-secondary: #22283a;
    --bg-tertiary: #2d3548;
    --text-primary: #ffffff;
    --text-secondary: #e5e7eb;
    --text-tertiary: #b8bcc8;
}

/* ===================================
   Reset & Base Styles
   =================================== */
*,
*::before,
*::after {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
    font-size: 16px;
}

body {
    font-family: var(--font-primary);
    background: linear-gradient(-45deg, #fafbff, #f0f4ff, #e8ecff, #fef3ff);
    background-size: 400% 400%;
    animation: gradientShift 15s ease infinite;
    color: var(--text-primary);
    line-height: 1.6;
    overflow-x: hidden;
    transition: background-color var(--transition-base), color var(--transition-base);
}

[data-theme="dark"] body {
    background: linear-gradient(-45deg, #16213e, #1a2332, #1e2a3a, #1a2332);
    background-size: 400% 400%;
    animation: gradientShift 15s ease infinite;
}

@keyframes gradientShift {
    0% {
        background-position: 0% 50%;
    }

    50% {
        background-position: 100% 50%;
    }

    100% {
        background-position: 0% 50%;
    }
}

.container {
    max-width: 1400px;
    margin: 0 auto;
    padding: 0 2rem;
}

/* ===================================
   Navigation
   =================================== */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    background: rgba(255, 255, 255, 0.85);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border-bottom: 2px solid transparent;
    border-image: linear-gradient(90deg, #667eea, #764ba2, #ec4899, #f59e0b) 1;
    transition: all var(--transition-base);
    box-shadow: 0 4px 30px rgba(99, 102, 241, 0.1);
}

[data-theme="dark"] .navbar {
    background: rgba(26, 26, 46, 0.85);
    border-image: linear-gradient(90deg, #667eea, #764ba2, #ec4899, #f59e0b) 1;
    box-shadow: 0 4px 30px rgba(99, 102, 241, 0.2);
}

.nav-content {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 1rem 0;
}

.logo {
    font-size: 1.5rem;
    font-weight: 700;
    background: var(--gradient-primary);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    text-decoration: none;
    letter-spacing: -0.5px;
}

.nav-menu {
    display: flex;
    list-style: none;
    gap: 2rem;
    align-items: center;
}

.nav-link {
    text-decoration: none;
    color: var(--text-secondary);
    font-weight: 500;
    font-size: 0.95rem;
    position: relative;
    transition: color var(--transition-base);
}

.nav-link::after {
    content: '';
    position: absolute;
    bottom: -4px;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--gradient-primary);
    transition: width var(--transition-base);
}

.nav-link:hover,
.nav-link.active {
    color: var(--brand-primary);
}

.nav-link:hover::after,
.nav-link.active::after {
    width: 100%;
}

.nav-right {
    display: flex;
    align-items: center;
    gap: 1rem;
}

.theme-toggle {
    width: 40px;
    height: 40px;
    border-radius: var(--radius-full);
    background: var(--bg-tertiary);
    border: none;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    transition: all var(--transition-base);
    position: relative;
}

.theme-toggle:hover {
    transform: scale(1.1);
    box-shadow: var(--shadow-md);
}

[data-theme="dark"] .theme-toggle {
    background: rgba(99, 102, 241, 0.2);
    border: 1px solid rgba(99, 102, 241, 0.3);
}

[data-theme="dark"] .theme-toggle:hover {
    background: rgba(99, 102, 241, 0.3);
    border-color: rgba(99, 102, 241, 0.5);
}

[data-theme="dark"] .sun-icon {
    color: #fbbf24;
}

.sun-icon,
.moon-icon {
    position: absolute;
    transition: all var(--transition-base);
}

[data-theme="light"] .sun-icon {
    opacity: 0;
    transform: rotate(90deg);
}

[data-theme="dark"] .moon-icon {
    opacity: 0;
    transform: rotate(-90deg);
}

.mobile-toggle {
    display: none;
    flex-direction: column;
    gap: 5px;
    background: none;
    border: none;
    cursor: pointer;
    padding: 0.5rem;
}

.mobile-toggle span {
    width: 25px;
    height: 2px;
    background: var(--text-primary);
    transition: all var(--transition-base);
}

/* ===================================
   Hero Section
   =================================== */
.hero {
    min-height: 100vh;
    display: flex;
    align-items: center;
    position: relative;
    padding-top: 80px;
    overflow: hidden;
}

.hero-content {
    display: flex;
    flex-direction: column;
    align-items: center;
    text-align: center;
    gap: 3rem;
    position: relative;
    z-index: 2;
    max-width: 900px;
    margin: 0 auto;
}

.hero-text {
    animation: fadeInUp 0.8s ease-out;
    display: flex;
    flex-direction: column;
    align-items: center;
}

.hero-greeting {
    font-size: 1.25rem;
    color: var(--text-secondary);
    margin-bottom: 0.5rem;
    font-weight: 400;
}

.hero-name {
    font-size: 3.5rem;
    font-weight: 700;
    line-height: 1.1;
    margin-bottom: 1.5rem;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 40%, #ec4899 70%, #f59e0b 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    filter: drop-shadow(0 0 20px rgba(99, 102, 241, 0.3));
}


.hero-role {
    font-size: 1.5rem;
    color: var(--brand-primary);
    margin-bottom: 1.5rem;
    font-weight: 400;
    min-height: 2.5rem;
}

.typewriter {
    color: var(--brand-primary);
}

.cursor {
    animation: blink 1s infinite;
    color: var(--brand-primary);
}

@keyframes blink {

    0%,
    50% {
        opacity: 1;
    }

    51%,
    100% {
        opacity: 0;
    }
}

.hero-description {
    font-size: 1.05rem;
    color: var(--text-secondary);
    line-height: 1.8;
    margin-bottom: 2rem;
    max-width: 650px;
}

.hero-buttons {
    display: flex;
    gap: 1rem;
    flex-wrap: wrap;
    margin-bottom: 2rem;
    justify-content: center;
}

.btn {
    padding: 0.875rem 1.75rem;
    border-radius: var(--radius-lg);
    font-weight: 600;
    font-size: 1rem;
    text-decoration: none;
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    transition: all var(--transition-base);
    border: 2px solid transparent;
    cursor: pointer;
    font-family: var(--font-primary);
}

.btn-primary {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 50%, #ec4899 100%);
    background-size: 200% auto;
    color: white;
    box-shadow: 0 8px 25px rgba(99, 102, 241, 0.4);
    position: relative;
    overflow: hidden;
}

.btn-primary::before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg, transparent, rgba(255, 255, 255, 0.3), transparent);
    transition: left 0.5s;
}

.btn-primary:hover {
    transform: translateY(-3px) scale(1.02);
    box-shadow: 0 12px 35px rgba(99, 102, 241, 0.5);
    background-position: right center;
}

.btn-primary:hover::before {
    left: 100%;
}

.btn-secondary {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 50%, #ec4899 100%);
    background-size: 200% auto;
    color: white;
    box-shadow: 0 8px 25px rgba(99, 102, 241, 0.4);
    position: relative;
    overflow: hidden;
}

.btn-secondary::before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg, transparent, rgba(255, 255, 255, 0.3), transparent);
    transition: left 0.5s;
}

.btn-secondary:hover {
    transform: translateY(-3px) scale(1.02);
    box-shadow: 0 12px 35px rgba(99, 102, 241, 0.5);
    background-position: right center;
}

.btn-secondary:hover::before {
    left: 100%;
}

.btn-outline {
    background: transparent;
    color: var(--brand-primary);
    border-color: var(--brand-primary);
    border-width: 2px;
    position: relative;
    overflow: hidden;
}

.btn-outline::before {
    content: '';
    position: absolute;
    top: 50%;
    left: 50%;
    width: 0;
    height: 0;
    border-radius: 50%;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 50%, #ec4899 100%);
    transition: width 0.4s, height 0.4s, top 0.4s, left 0.4s;
    transform: translate(-50%, -50%);
    z-index: -1;
}

.btn-outline:hover {
    color: white;
    border-color: transparent;
    transform: translateY(-3px);
    box-shadow: 0 10px 30px rgba(99, 102, 241, 0.4);
}

.btn-outline:hover::before {
    width: 300px;
    height: 300px;
}


.social-links {
    display: flex;
    gap: 1rem;
    justify-content: center;
}

.social-link {
    width: 52px;
    height: 52px;
    border-radius: var(--radius-lg);
    background: var(--bg-secondary);
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--text-primary);
    transition: all var(--transition-base);
    text-decoration: none;
    box-shadow: var(--shadow-md);
    position: relative;
    overflow: hidden;
}

.social-link::before {
    content: '';
    position: absolute;
    inset: 0;
    background: var(--gradient-primary);
    opacity: 0;
    transition: opacity var(--transition-base);
}

.social-link svg {
    position: relative;
    z-index: 1;
    transition: all var(--transition-base);
}

.social-link:nth-child(1):hover {
    background: linear-gradient(135deg, #333 0%, #000 100%);
    color: white;
    transform: translateY(-6px) rotate(5deg);
    box-shadow: 0 15px 40px rgba(0, 0, 0, 0.3);
}

.social-link:nth-child(2):hover {
    background: linear-gradient(135deg, #0077b5 0%, #00a0dc 100%);
    color: white;
    transform: translateY(-6px) rotate(-5deg);
    box-shadow: 0 15px 40px rgba(0, 119, 181, 0.4);
}

.social-link:nth-child(3):hover {
    background: linear-gradient(135deg, #ea4335 0%, #fbbc05 50%, #34a853 100%);
    color: white;
    transform: translateY(-6px) rotate(5deg);
    box-shadow: 0 15px 40px rgba(234, 67, 53, 0.4);
}

/* Scroll Indicator */
.scroll-indicator {
    position: absolute;
    bottom: 2.5rem;
    left: 50%;
    transform: translateX(-50%);
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: 0.35rem;
    font-size: 0.7rem;
    font-weight: 600;
    animation: bounce 2s infinite;
    letter-spacing: 1px;
}

.scroll-indicator span {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 50%, #ec4899 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    text-transform: uppercase;
}

.scroll-indicator svg {
    color: var(--brand-primary);
    filter: drop-shadow(0 0 6px rgba(99, 102, 241, 0.3));
    width: 16px;
    height: 16px;
}

@keyframes bounce {

    0%,
    100% {
        transform: translateX(-50%) translateY(0);
    }

    50% {
        transform: translateX(-50%) translateY(-12px);
    }
}

/* Background */
.hero-bg {
    position: absolute;
    inset: 0;
    overflow: hidden;
    z-index: 0;
}

.gradient-orb {
    position: absolute;
    border-radius: 50%;
    filter: blur(120px);
    opacity: 0.3;
    animation: moveOrb 20s ease-in-out infinite;
}

.orb-1 {
    width: 700px;
    height: 700px;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    top: -350px;
    right: -250px;
}

.orb-2 {
    width: 600px;
    height: 600px;
    background: linear-gradient(135deg, #f093fb 0%, #f5576c 100%);
    bottom: -300px;
    left: -200px;
    animation-delay: 5s;
}

.orb-1::after,
.orb-2::after {
    content: '';
    position: absolute;
    inset: 0;
    border-radius: 50%;
    background: inherit;
    filter: blur(60px);
    opacity: 0.5;
}

@keyframes moveOrb {

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

    33% {
        transform: translate(50px, -50px) scale(1.1) rotate(120deg);
    }

    66% {
        transform: translate(-50px, 50px) scale(0.9) rotate(240deg);
    }
}

/* Animations */
@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }

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

@keyframes fadeInRight {
    from {
        opacity: 0;
        transform: translateX(30px);
    }

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

/* ===================================
   Responsive Design
   =================================== */
@media (max-width: 1024px) {
    .hero-name {
        font-size: 3rem;
    }
}

@media (max-width: 768px) {
    .container {
        padding: 0 1.5rem;
    }

    .nav-menu {
        position: fixed;
        top: 70px;
        left: -100%;
        flex-direction: column;
        background: var(--bg-secondary);
        width: 100%;
        padding: 2rem;
        box-shadow: var(--shadow-xl);
        transition: left var(--transition-base);
        gap: 1.5rem;
        align-items: center;
        text-align: center;
    }

    .nav-menu.active {
        left: 0;
    }

    .mobile-toggle {
        display: flex;
    }

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

    .hero-text {
        padding-right: 0;
        display: flex;
        flex-direction: column;
        align-items: center;
    }

    .hero-name {
        font-size: 2.5rem;
    }

    .hero-role {
        font-size: 1.25rem;
    }

    .hero-description {
        font-size: 1rem;
        max-width: 100%;
    }

    .hero-buttons {
        flex-direction: column;
        width: 100%;
        gap: 1rem;
    }

    .btn {
        width: 100%;
        justify-content: center;
    }
}

@media (max-width: 480px) {
    .hero-name {
        font-size: 2rem;
    }

    .hero-greeting {
        font-size: 1.1rem;
    }

    .hero-role {
        font-size: 1.1rem;
    }
}

/* ===================================
   Projects Section
   =================================== */
.projects-section {
    padding: 6rem 0;
    position: relative;
}

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

.section-title {
    font-size: 2.5rem;
    font-weight: 700;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 50%, #ec4899 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    margin-bottom: 1rem;
}

.title-underline {
    width: 80px;
    height: 4px;
    background: linear-gradient(90deg, #667eea, #764ba2, #ec4899);
    margin: 0 auto;
    border-radius: var(--radius-full);
}

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

.project-card {
    background: var(--bg-secondary);
    border-radius: var(--radius-xl);
    padding: 2.5rem;
    box-shadow: var(--shadow-lg);
    transition: all var(--transition-slow);
    position: relative;
    overflow: hidden;
    border: 1px solid transparent;
}

.project-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 4px;
    background: linear-gradient(90deg, #667eea, #764ba2, #ec4899);
    transform: scaleX(0);
    transform-origin: left;
    transition: transform var(--transition-slow);
}

.project-card:hover {
    transform: translateY(-8px);
    box-shadow: 0 20px 40px rgba(99, 102, 241, 0.2);
    border-color: rgba(99, 102, 241, 0.2);
}

.project-card:hover::before {
    transform: scaleX(1);
}

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

.project-icon {
    width: 60px;
    height: 60px;
    min-width: 60px;
    border-radius: var(--radius-lg);
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    box-shadow: 0 8px 20px rgba(99, 102, 241, 0.3);
    transition: all var(--transition-base);
}

.project-card:hover .project-icon {
    transform: scale(1.1) rotate(5deg);
    box-shadow: 0 12px 30px rgba(99, 102, 241, 0.4);
}

.project-title {
    font-size: 1.4rem;
    font-weight: 700;
    color: var(--text-primary);
    line-height: 1.3;
    flex: 1;
}

.project-summary {
    font-size: 1rem;
    color: var(--text-secondary);
    font-style: italic;
    margin-bottom: 1.5rem;
    line-height: 1.6;
}

.project-description {
    margin-bottom: 1.5rem;
}

.project-features {
    list-style: none;
    padding: 0;
    margin: 0;
}

.project-features li {
    position: relative;
    padding-left: 1.5rem;
    margin-bottom: 1rem;
    color: var(--text-secondary);
    line-height: 1.7;
}

.project-features li::before {
    content: '▹';
    position: absolute;
    left: 0;
    color: var(--brand-primary);
    font-size: 1.2rem;
    font-weight: bold;
}

.project-links {
    display: flex;
    gap: 1rem;
    margin: 1.5rem 0;
    flex-wrap: wrap;
}

.project-link {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.75rem 1.5rem;
    background: var(--bg-tertiary);
    color: var(--text-primary);
    text-decoration: none;
    border-radius: var(--radius-lg);
    font-weight: 600;
    font-size: 0.9rem;
    transition: all var(--transition-base);
    border: 2px solid transparent;
    position: relative;
    overflow: hidden;
}

.project-link::before {
    content: '';
    position: absolute;
    inset: 0;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    opacity: 0;
    transition: opacity var(--transition-base);
}

.project-link svg {
    position: relative;
    z-index: 1;
    transition: transform var(--transition-base);
}

.project-link span {
    position: relative;
    z-index: 1;
}

.project-link:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 20px rgba(99, 102, 241, 0.3);
    border-color: var(--brand-primary);
}

.project-link:hover::before {
    opacity: 1;
}

.project-link:hover {
    color: white;
}

.project-link:hover svg {
    transform: scale(1.1);
}

.project-link-disabled {
    opacity: 0.5;
    cursor: not-allowed;
    pointer-events: none;
}

.project-link-demo {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    box-shadow: 0 4px 15px rgba(99, 102, 241, 0.3);
}

.project-link-demo::before {
    background: linear-gradient(135deg, #764ba2 0%, #ec4899 100%);
}

.project-link-demo:hover {
    box-shadow: 0 8px 25px rgba(99, 102, 241, 0.4);
}

.project-tech {

    display: flex;
    flex-wrap: wrap;
    gap: 0.75rem;
    margin-top: 1.5rem;
}

.tech-tag {
    padding: 0.5rem 1rem;
    background: linear-gradient(135deg, rgba(99, 102, 241, 0.1) 0%, rgba(139, 92, 246, 0.1) 100%);
    color: var(--brand-primary);
    border-radius: var(--radius-full);
    font-size: 0.85rem;
    font-weight: 600;
    border: 1px solid rgba(99, 102, 241, 0.2);
    transition: all var(--transition-base);
}

.tech-tag:hover {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(99, 102, 241, 0.3);
}

/* Dark theme adjustments for projects */
[data-theme="dark"] .project-card {
    background: var(--bg-secondary);
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.3);
    border: 1px solid rgba(99, 102, 241, 0.2);
}

[data-theme="dark"] .project-card:hover {
    box-shadow: 0 20px 50px rgba(99, 102, 241, 0.3);
    border-color: rgba(99, 102, 241, 0.4);
}

[data-theme="dark"] .tech-tag {
    background: linear-gradient(135deg, rgba(99, 102, 241, 0.2) 0%, rgba(139, 92, 246, 0.2) 100%);
    border-color: rgba(99, 102, 241, 0.4);
    color: #b8b5ff;
}

/* ===================================
   Certifications Section
   =================================== */
.certifications-section {
    padding: 6rem 0;
    background: var(--bg-primary);
}

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

.certification-card {
    background: var(--bg-secondary);
    border-radius: var(--radius-xl);
    padding: 3rem 2rem;
    box-shadow: var(--shadow-lg);
    transition: all var(--transition-slow);
    position: relative;
    overflow: hidden;
    border: 1px solid transparent;
    display: flex;
    flex-direction: column;
    align-items: center;
    text-align: center;
    gap: 1.25rem;
}

.certification-card:hover {
    transform: translateY(-8px);
    box-shadow: 0 20px 40px rgba(0, 0, 0, 0.15);
    border-color: rgba(99, 102, 241, 0.3);
}

.certification-icon-circle {
    width: 90px;
    height: 90px;
    min-width: 90px;
    border-radius: 50%;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    box-shadow: 0 10px 30px rgba(99, 102, 241, 0.4);
    transition: all var(--transition-base);
    margin-bottom: 0.5rem;
}

.certification-card:hover .certification-icon-circle {
    transform: scale(1.1);
    box-shadow: 0 15px 40px rgba(99, 102, 241, 0.5);
}

.certification-name {
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--text-primary);
    line-height: 1.4;
    margin: 0;
}

.certification-org {
    font-size: 1rem;
    color: var(--text-secondary);
    font-weight: 500;
    margin: 0;
}

.certification-date {
    font-size: 1.1rem;
    color: var(--brand-primary);
    font-weight: 700;
    letter-spacing: 0.5px;
    margin: 0;
}

.verify-btn {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.75rem 1.75rem;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    border-radius: var(--radius-lg);
    text-decoration: none;
    font-weight: 600;
    font-size: 0.95rem;
    transition: all var(--transition-base);
    box-shadow: 0 4px 15px rgba(99, 102, 241, 0.3);
    margin-top: 0.5rem;
}

.verify-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(99, 102, 241, 0.4);
    background: linear-gradient(135deg, #764ba2 0%, #667eea 100%);
}

.verify-btn svg {
    width: 16px;
    height: 16px;
}

/* Dark theme adjustments for certifications */
[data-theme="dark"] .certification-card {
    background: var(--bg-secondary);
    backdrop-filter: blur(10px);
    border: 1px solid rgba(99, 102, 241, 0.2);
}

[data-theme="dark"] .certification-card:hover {
    background: var(--bg-tertiary);
    border-color: rgba(99, 102, 241, 0.4);
}

/* ===================================
   Publications Section
   =================================== */
.publications-section {
    padding: 6rem 0;
    background: var(--bg-secondary);
}

.publications-list {
    margin-top: 3rem;
    display: flex;
    flex-direction: column;
    gap: 2rem;
}

.publication-card {
    background: var(--bg-primary);
    border-radius: var(--radius-xl);
    padding: 2.5rem;
    box-shadow: var(--shadow-lg);
    transition: all var(--transition-slow);
    border: 1px solid transparent;
    display: flex;
    align-items: flex-start;
    gap: 2rem;
}

.publication-card:hover {
    transform: translateY(-4px);
    box-shadow: 0 20px 40px rgba(0, 0, 0, 0.15);
    border-color: rgba(99, 102, 241, 0.3);
}

.publication-icon {
    width: 60px;
    height: 60px;
    min-width: 60px;
    border-radius: var(--radius-lg);
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    box-shadow: 0 8px 20px rgba(99, 102, 241, 0.3);
    transition: all var(--transition-base);
}

.publication-card:hover .publication-icon {
    transform: scale(1.1);
    box-shadow: 0 12px 30px rgba(99, 102, 241, 0.4);
}

.publication-content {
    flex: 1;
}

.publication-title {
    font-size: 1.3rem;
    font-weight: 700;
    color: var(--text-primary);
    line-height: 1.4;
    margin-bottom: 0.75rem;
}

.publication-venue {
    font-size: 1rem;
    color: var(--text-secondary);
    line-height: 1.6;
    margin-bottom: 0.5rem;
}

.publication-doi {
    font-size: 0.9rem;
    color: var(--brand-primary);
    font-weight: 600;
    font-family: 'Courier New', monospace;
}

.publication-btn {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.75rem 1.5rem;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    border-radius: var(--radius-lg);
    text-decoration: none;
    font-weight: 600;
    font-size: 0.95rem;
    transition: all var(--transition-base);
    box-shadow: 0 4px 15px rgba(99, 102, 241, 0.3);
    align-self: flex-start;
}

.publication-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(99, 102, 241, 0.4);
    background: linear-gradient(135deg, #764ba2 0%, #667eea 100%);
}

.publication-btn svg {
    width: 16px;
    height: 16px;
}

/* Dark theme adjustments for publications */
[data-theme="dark"] .publication-card {
    background: var(--bg-secondary);
    backdrop-filter: blur(10px);
    border: 1px solid rgba(99, 102, 241, 0.2);
}

[data-theme="dark"] .publication-card:hover {
    background: var(--bg-tertiary);
    border-color: rgba(99, 102, 241, 0.4);
}

/* ===================================
   Achievements Section
   =================================== */
.achievements-section {
    padding: 6rem 0;
    background: var(--bg-primary);
}

.achievements-list {
    margin-top: 3rem;
    display: flex;
    flex-direction: column;
    gap: 2rem;
}

.achievement-card {
    background: var(--bg-secondary);
    border-radius: var(--radius-xl);
    padding: 2.5rem;
    box-shadow: var(--shadow-lg);
    transition: all var(--transition-slow);
    border: 1px solid transparent;
    display: flex;
    align-items: center;
    gap: 2rem;
}

.achievement-card:hover {
    transform: translateY(-4px);
    box-shadow: 0 20px 40px rgba(0, 0, 0, 0.15);
    border-color: rgba(99, 102, 241, 0.3);
}

.achievement-icon {
    width: 60px;
    height: 60px;
    min-width: 60px;
    border-radius: var(--radius-lg);
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    box-shadow: 0 8px 20px rgba(99, 102, 241, 0.3);
    transition: all var(--transition-base);
}

.achievement-card:hover .achievement-icon {
    transform: scale(1.1) rotate(5deg);
    box-shadow: 0 12px 30px rgba(99, 102, 241, 0.4);
}

.achievement-content {
    flex: 1;
}

.achievement-title {
    font-size: 1.3rem;
    font-weight: 700;
    color: var(--text-primary);
    line-height: 1.4;
    margin: 0;
}

.achievement-date {
    font-size: 1rem;
    color: var(--brand-primary);
    font-weight: 600;
    white-space: nowrap;
}

/* Dark theme adjustments for achievements */
[data-theme="dark"] .achievement-card {
    background: var(--bg-secondary);
    backdrop-filter: blur(10px);
    border: 1px solid rgba(99, 102, 241, 0.2);
}

[data-theme="dark"] .achievement-card:hover {
    background: var(--bg-tertiary);
    border-color: rgba(99, 102, 241, 0.4);
}

/* ===================================
   Contact Section
   =================================== */
.contact-section {
    padding: 6rem 0 3rem;
    background: var(--bg-secondary);
}

.contact-description {
    text-align: center;
    font-size: 1.1rem;
    color: var(--text-secondary);
    max-width: 700px;
    margin: 1rem auto 4rem;
    line-height: 1.7;
}

.contact-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 2.5rem;
    margin-bottom: 4rem;
}

.contact-card {
    background: var(--bg-primary);
    border-radius: var(--radius-xl);
    padding: 3rem 2rem;
    text-align: center;
    box-shadow: var(--shadow-lg);
    transition: all var(--transition-slow);
    border: 1px solid transparent;
}

.contact-card:hover {
    transform: translateY(-8px);
    box-shadow: 0 20px 40px rgba(0, 0, 0, 0.15);
    border-color: rgba(99, 102, 241, 0.3);
}

.contact-card-icon {
    width: 70px;
    height: 70px;
    margin: 0 auto 1.5rem;
    border-radius: var(--radius-lg);
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    box-shadow: 0 10px 30px rgba(99, 102, 241, 0.3);
    transition: all var(--transition-base);
}

.contact-card:hover .contact-card-icon {
    transform: scale(1.1);
    box-shadow: 0 15px 40px rgba(99, 102, 241, 0.4);
}

.contact-card h3 {
    font-size: 1.3rem;
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: 0.75rem;
}

.contact-card a {
    color: var(--text-secondary);
    text-decoration: none;
    font-size: 1rem;
    transition: all var(--transition-base);
    word-break: break-word;
}

.contact-card a:hover {
    color: var(--brand-primary);
}

.contact-footer {
    margin-top: 4rem;
    padding-top: 2.5rem;
    border-top: 1px solid rgba(0, 0, 0, 0.1);
    text-align: center;
}

.copyright {
    color: var(--text-secondary);
    font-size: 0.95rem;
    margin: 0;
}

/* Dark theme adjustments for contact */
[data-theme="dark"] .contact-card {
    background: var(--bg-secondary);
    backdrop-filter: blur(10px);
    border: 1px solid rgba(99, 102, 241, 0.2);
}

[data-theme="dark"] .contact-card:hover {
    background: var(--bg-tertiary);
    border-color: rgba(99, 102, 241, 0.4);
}

[data-theme="dark"] .contact-footer {
    border-top-color: rgba(99, 102, 241, 0.2);
}

/* Responsive adjustments for projects */
@media (max-width: 1200px) {
    .projects-grid {
        grid-template-columns: repeat(2, 1fr);
    }

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

@media (max-width: 768px) {
    .projects-grid {
        grid-template-columns: 1fr;
        gap: 2rem;
    }

    .certifications-grid {
        grid-template-columns: 1fr;
        gap: 2rem;
    }

    .section-title {
        font-size: 2rem;
        text-align: center;
    }

    .section-header {
        text-align: center;
        margin-bottom: 3rem;
    }

    .project-header {
        flex-direction: column;
        align-items: center;
        text-align: center;
        gap: 1.5rem;
    }

    .project-title {
        font-size: 1.25rem;
    }

    .project-summary {
        font-size: 0.95rem;
        text-align: center;
    }

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

    .certification-card {
        text-align: center;
    }

    .certification-name {
        font-size: 1.15rem;
    }

    .certification-icon-circle {
        width: 80px;
        height: 80px;
        min-width: 80px;
        margin: 0 auto;
    }

    .publication-card {
        flex-direction: column;
        align-items: center;
        text-align: center;
        gap: 1.5rem;
    }

    .publication-info {
        text-align: center;
    }

    .publication-title {
        font-size: 1.2rem;
    }

    .achievement-card {
        flex-direction: column;
        align-items: center;
        text-align: center;
        gap: 1.5rem;
        padding: 2.5rem 1.5rem;
    }

    .achievement-info {
        text-align: center;
    }

    .achievement-title {
        font-size: 1.25rem;
    }

    .contact-grid {
        grid-template-columns: 1fr;
        gap: 2rem;
    }
}

@media (max-width: 480px) {
    .projects-section {
        padding: 4rem 0;
    }

    .certifications-section {
        padding: 4rem 0;
    }

    .publications-section {
        padding: 4rem 0;
    }

    .achievements-section {
        padding: 4rem 0;
    }

    .contact-section {
        padding: 4rem 0 2rem;
    }

    .project-card {
        padding: 1.5rem;
    }

    .certification-card {
        padding: 2rem 1.5rem;
    }

    .publication-card {
        padding: 1.5rem;
    }

    .achievement-card {
        padding: 1.5rem;
        flex-direction: column;
        align-items: flex-start;
    }

    .contact-card {
        padding: 2rem 1.5rem;
    }

    .contact-description {
        font-size: 1rem;
    }

    .section-title {
        font-size: 1.75rem;
    }

    .project-header {
        flex-direction: column;
        align-items: flex-start;
    }

    .project-icon {
        width: 50px;
        height: 50px;
        min-width: 50px;
    }

    .certification-icon-circle {
        width: 70px;
        height: 70px;
        min-width: 70px;
    }

    .publication-icon {
        width: 50px;
        height: 50px;
        min-width: 50px;
    }

    .achievement-icon {
        width: 50px;
        height: 50px;
        min-width: 50px;
    }

    .contact-card-icon {
        width: 60px;
        height: 60px;
    }

    .project-title {
        font-size: 1.1rem;
    }

    .certification-name {
        font-size: 1rem;
    }

    .publication-title {
        font-size: 1.1rem;
    }

    .achievement-title {
        font-size: 1.1rem;
    }

    .contact-card h3 {
        font-size: 1.2rem;
    }

    .contact-card a {
        font-size: 0.95rem;
    }

    .project-summary {
        font-size: 0.9rem;
    }

    .verify-btn {
        padding: 0.65rem 1.5rem;
        font-size: 0.9rem;
    }

    .publication-btn {
        padding: 0.65rem 1.5rem;
        font-size: 0.9rem;
    }
}