@import url('https://fonts.googleapis.com/css2?family=Inter:wght@300;400;500;600;700&family=Space+Grotesk:wght@400;500;600;700&display=swap');

:root {
    /* Color Palette */
    --bg-darker: #080c14;
    --bg-dark: #0f172a;
    --bg-card: rgba(30, 41, 59, 0.4);
    --border-color: rgba(255, 255, 255, 0.08);
    --border-glow: rgba(16, 185, 129, 0.2);
    
    --primary: #10b981; /* Emerald/Lithium green */
    --primary-glow: rgba(16, 185, 129, 0.5);
    --secondary: #06b6d4; /* Electric Cyan */
    --secondary-glow: rgba(6, 182, 212, 0.5);
    
    --text-primary: #f8fafc;
    --text-secondary: #94a3b8;
    --text-muted: #64748b;
    
    /* Typography */
    --font-header: 'Space Grotesk', sans-serif;
    --font-body: 'Inter', sans-serif;
    
    /* Layout & Transition */
    --transition-smooth: all 0.4s cubic-bezier(0.16, 1, 0.3, 1);
    --transition-fast: all 0.2s ease;
    --radius-lg: 16px;
    --radius-md: 12px;
    --radius-sm: 8px;
}

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

body {
    background-color: var(--bg-darker);
    background-image: 
        radial-gradient(at 0% 0%, rgba(16, 185, 129, 0.08) 0px, transparent 50%),
        radial-gradient(at 100% 100%, rgba(6, 182, 212, 0.08) 0px, transparent 50%),
        linear-gradient(180deg, var(--bg-darker) 0%, var(--bg-dark) 100%);
    color: var(--text-primary);
    font-family: var(--font-body);
    line-height: 1.6;
    overflow-x: hidden;
    min-height: 100vh;
}

/* Custom Scrollbar */
::-webkit-scrollbar {
    width: 8px;
}
::-webkit-scrollbar-track {
    background: var(--bg-darker);
}
::-webkit-scrollbar-thumb {
    background: rgba(255, 255, 255, 0.1);
    border-radius: var(--radius-sm);
}
::-webkit-scrollbar-thumb:hover {
    background: var(--primary);
}

/* Background Canvas Container */
#particles-js {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: 0;
    pointer-events: none;
}

header {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    z-index: 100;
    background: rgba(8, 12, 20, 0.6);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border-bottom: 1px solid var(--border-color);
    transition: var(--transition-smooth);
}

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 20px 24px;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo {
    font-family: var(--font-header);
    font-weight: 700;
    font-size: 1.5rem;
    color: var(--text-primary);
    text-decoration: none;
    display: flex;
    align-items: center;
    gap: 8px;
}

.logo-dot {
    width: 10px;
    height: 10px;
    background: linear-gradient(135deg, var(--primary), var(--secondary));
    border-radius: 50%;
    box-shadow: 0 0 10px var(--primary-glow);
    display: inline-block;
    animation: pulse 2s infinite;
}

nav ul {
    display: flex;
    gap: 32px;
    list-style: none;
}

nav a {
    color: var(--text-secondary);
    text-decoration: none;
    font-family: var(--font-header);
    font-size: 0.95rem;
    font-weight: 500;
    transition: var(--transition-fast);
    position: relative;
    padding: 4px 0;
}

nav a:hover, nav a.active {
    color: var(--text-primary);
}

nav a::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 0;
    height: 2px;
    background: linear-gradient(90deg, var(--primary), var(--secondary));
    transition: var(--transition-smooth);
}

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

.menu-toggle {
    display: none;
    background: none;
    border: none;
    cursor: pointer;
    padding: 4px;
}

.menu-toggle span {
    display: block;
    width: 24px;
    height: 2px;
    background: var(--text-primary);
    margin: 6px 0;
    transition: var(--transition-fast);
}

main {
    position: relative;
    z-index: 10;
    max-width: 1200px;
    margin: 0 auto;
    padding: 120px 24px 80px 24px;
}

/* Sections */
section {
    padding: 80px 0;
    border-bottom: 1px solid var(--border-color);
}

section:last-of-type {
    border-bottom: none;
}

.section-title {
    font-family: var(--font-header);
    font-size: 2.25rem;
    font-weight: 700;
    margin-bottom: 16px;
    display: inline-block;
    position: relative;
    letter-spacing: -0.02em;
}

.section-title::after {
    content: '';
    display: block;
    width: 50px;
    height: 4px;
    background: linear-gradient(90deg, var(--primary), var(--secondary));
    border-radius: 2px;
    margin-top: 8px;
}

.section-desc {
    color: var(--text-secondary);
    font-size: 1.1rem;
    max-width: 600px;
    margin-bottom: 48px;
}

/* Hero Section */
.hero-wrapper {
    display: grid;
    grid-template-columns: 1.2fr 0.8fr;
    gap: 64px;
    align-items: center;
}

.hero-content {
    display: flex;
    flex-direction: column;
}

.badge {
    align-self: flex-start;
    display: flex;
    align-items: center;
    gap: 8px;
    padding: 8px 16px;
    background: rgba(16, 185, 129, 0.1);
    border: 1px solid rgba(16, 185, 129, 0.25);
    border-radius: 50px;
    color: var(--primary);
    font-family: var(--font-header);
    font-size: 0.85rem;
    font-weight: 600;
    margin-bottom: 24px;
    box-shadow: 0 0 15px rgba(16, 185, 129, 0.05);
}

.badge-dot {
    width: 8px;
    height: 8px;
    background-color: var(--primary);
    border-radius: 50%;
    animation: blink 1.5s infinite;
}

.hero-title {
    font-family: var(--font-header);
    font-size: 3.5rem;
    font-weight: 700;
    line-height: 1.15;
    margin-bottom: 16px;
    letter-spacing: -0.03em;
}

.gradient-text {
    background: linear-gradient(135deg, var(--primary) 0%, var(--secondary) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

.hero-subtitle {
    font-size: 1.5rem;
    font-weight: 500;
    color: var(--text-secondary);
    margin-bottom: 24px;
    display: flex;
    align-items: center;
    gap: 12px;
}

.hero-desc {
    color: var(--text-secondary);
    font-size: 1.1rem;
    margin-bottom: 40px;
    max-width: 580px;
}

.hero-ctas {
    display: flex;
    gap: 16px;
    flex-wrap: wrap;
}

.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    padding: 14px 28px;
    border-radius: var(--radius-md);
    font-family: var(--font-header);
    font-weight: 600;
    font-size: 1rem;
    text-decoration: none;
    transition: var(--transition-smooth);
    cursor: pointer;
}

.btn-primary {
    background: linear-gradient(135deg, var(--primary) 0%, var(--secondary) 100%);
    color: #080c14;
    border: none;
    box-shadow: 0 4px 20px rgba(16, 185, 129, 0.2);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 24px rgba(16, 185, 129, 0.35);
}

.btn-secondary {
    background: var(--bg-card);
    color: var(--text-primary);
    border: 1px solid var(--border-color);
}

.btn-secondary:hover {
    background: rgba(255, 255, 255, 0.05);
    border-color: rgba(255, 255, 255, 0.15);
    transform: translateY(-2px);
}

/* Profile Image Glowing Container */
.hero-image-container {
    position: relative;
    display: flex;
    justify-content: center;
    align-items: center;
}

.profile-frame {
    position: relative;
    width: 320px;
    height: 320px;
    border-radius: 50%;
    padding: 8px;
    background: linear-gradient(135deg, var(--primary) 0%, var(--secondary) 100%);
    box-shadow: 0 0 40px rgba(16, 185, 129, 0.2);
    animation: morph 8s ease-in-out infinite;
}

.profile-img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    border-radius: 50%;
    border: 4px solid var(--bg-darker);
    background-color: var(--bg-dark);
}

/* Animated decorative background grid behind photo */
.hero-image-decorations {
    position: absolute;
    width: 110%;
    height: 110%;
    pointer-events: none;
    background-image: 
        radial-gradient(rgba(16, 185, 129, 0.15) 1.5px, transparent 1.5px),
        radial-gradient(rgba(6, 182, 212, 0.15) 1.5px, transparent 1.5px);
    background-size: 20px 20px;
    background-position: 0 0, 10px 10px;
    mask-image: radial-gradient(circle, black 40%, transparent 70%);
    -webkit-mask-image: radial-gradient(circle, black 40%, transparent 70%);
    z-index: -1;
}

/* About / Biography Section */
.about-grid {
    display: grid;
    grid-template-columns: 0.9fr 1.1fr;
    gap: 48px;
}

.about-visual {
    display: flex;
    flex-direction: column;
    gap: 24px;
}

/* Battery Charging Animation Card */
.energy-card {
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    padding: 32px;
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    position: relative;
    overflow: hidden;
    box-shadow: inset 0 0 20px rgba(255, 255, 255, 0.02);
}

.energy-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 24px;
}

.energy-title {
    font-family: var(--font-header);
    font-size: 1.2rem;
    font-weight: 600;
}

.battery-icon {
    width: 50px;
    height: 24px;
    border: 2px solid var(--text-secondary);
    border-radius: 4px;
    padding: 2px;
    position: relative;
    display: flex;
}

.battery-icon::after {
    content: '';
    position: absolute;
    right: -6px;
    top: 5px;
    width: 4px;
    height: 10px;
    background: var(--text-secondary);
    border-radius: 0 2px 2px 0;
}

.battery-level {
    height: 100%;
    width: 85%;
    background: linear-gradient(90deg, var(--primary), var(--secondary));
    border-radius: 2px;
    animation: charge 4s ease-in-out infinite;
}

.energy-stat {
    margin-top: 16px;
}

.energy-stat-number {
    font-family: var(--font-header);
    font-size: 2.5rem;
    font-weight: 700;
    color: var(--primary);
    line-height: 1;
}

.energy-stat-label {
    color: var(--text-secondary);
    font-size: 0.85rem;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    margin-top: 4px;
}

.education-card {
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    padding: 32px;
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    display: flex;
    align-items: center;
    gap: 24px;
}

.edu-icon-container {
    width: 64px;
    height: 64px;
    background: rgba(255, 255, 255, 0.03);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--secondary);
    font-size: 1.75rem;
}

.edu-details h4 {
    font-family: var(--font-header);
    font-size: 1.15rem;
    font-weight: 600;
}

.edu-school {
    color: var(--text-secondary);
    font-size: 0.95rem;
}

.edu-year {
    color: var(--text-muted);
    font-size: 0.85rem;
    margin-top: 4px;
}

.about-text p {
    color: var(--text-secondary);
    font-size: 1.05rem;
    margin-bottom: 24px;
}

.about-text p:last-child {
    margin-bottom: 0;
}

.highlight {
    color: var(--text-primary);
    font-weight: 500;
}

/* Key Expertise Section */
.expertise-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 24px;
}

.expertise-card {
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    padding: 32px;
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    transition: var(--transition-smooth);
    position: relative;
    overflow: hidden;
}

.expertise-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: linear-gradient(180deg, rgba(16, 185, 129, 0.05) 0%, transparent 100%);
    opacity: 0;
    transition: var(--transition-smooth);
}

.expertise-card:hover {
    transform: translateY(-6px);
    border-color: var(--border-glow);
    box-shadow: 0 10px 30px rgba(16, 185, 129, 0.05);
}

.expertise-card:hover::before {
    opacity: 1;
}

.expertise-icon {
    width: 48px;
    height: 48px;
    border-radius: var(--radius-md);
    background: rgba(16, 185, 129, 0.08);
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--primary);
    font-size: 1.25rem;
    margin-bottom: 24px;
    border: 1px solid rgba(16, 185, 129, 0.15);
    transition: var(--transition-smooth);
}

.expertise-card:hover .expertise-icon {
    color: #080c14;
    background: var(--primary);
    box-shadow: 0 0 15px var(--primary-glow);
    border-color: var(--primary);
}

.expertise-card h3 {
    font-family: var(--font-header);
    font-size: 1.35rem;
    font-weight: 600;
    margin-bottom: 12px;
}

.expertise-card p {
    color: var(--text-secondary);
    font-size: 0.95rem;
}

.skills-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
    margin-top: 20px;
}

.skill-tag {
    background: rgba(255, 255, 255, 0.03);
    border: 1px solid var(--border-color);
    padding: 4px 10px;
    border-radius: 50px;
    font-size: 0.75rem;
    color: var(--text-secondary);
    transition: var(--transition-fast);
}

.expertise-card:hover .skill-tag {
    border-color: rgba(16, 185, 129, 0.2);
    color: var(--text-primary);
}

/* Publications Section */
.publications-list {
    display: flex;
    flex-direction: column;
    gap: 24px;
}

.pub-card {
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    padding: 32px;
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    transition: var(--transition-smooth);
    display: grid;
    grid-template-columns: auto 1fr;
    gap: 32px;
    align-items: start;
}

.pub-card:hover {
    border-color: rgba(6, 182, 212, 0.3);
    box-shadow: 0 10px 30px rgba(6, 182, 212, 0.03);
    transform: translateX(4px);
}

.pub-number {
    font-family: var(--font-header);
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--secondary);
    background: rgba(6, 182, 212, 0.08);
    border: 1px solid rgba(6, 182, 212, 0.15);
    width: 48px;
    height: 48px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
}

.pub-details {
    display: flex;
    flex-direction: column;
}

.pub-tag {
    align-self: flex-start;
    padding: 2px 8px;
    border-radius: 4px;
    background: rgba(6, 182, 212, 0.1);
    color: var(--secondary);
    font-size: 0.75rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    margin-bottom: 12px;
}

.pub-title {
    font-family: var(--font-header);
    font-size: 1.25rem;
    font-weight: 600;
    line-height: 1.4;
    margin-bottom: 8px;
}

.pub-authors {
    color: var(--text-secondary);
    font-size: 0.95rem;
    margin-bottom: 8px;
}

.pub-authors span.me {
    color: var(--text-primary);
    font-weight: 600;
    text-decoration: underline;
    text-decoration-color: var(--secondary);
}

.pub-meta {
    display: flex;
    gap: 16px;
    color: var(--text-muted);
    font-size: 0.85rem;
    align-items: center;
}

.pub-journal {
    font-style: italic;
    color: var(--text-secondary);
}

.pub-link {
    display: inline-flex;
    align-items: center;
    gap: 4px;
    color: var(--secondary);
    text-decoration: none;
    font-weight: 500;
    transition: var(--transition-fast);
}

.pub-link:hover {
    color: var(--text-primary);
}

/* Contact Section & Footer */
.contact-wrapper {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 64px;
}

.contact-info {
    display: flex;
    flex-direction: column;
}

.contact-card-grid {
    display: flex;
    flex-direction: column;
    gap: 20px;
    margin-top: 32px;
}

.contact-item {
    display: flex;
    align-items: center;
    gap: 20px;
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    padding: 20px 24px;
    border-radius: var(--radius-md);
    transition: var(--transition-fast);
    text-decoration: none;
    color: inherit;
}

.contact-item:hover {
    border-color: var(--border-glow);
    background: rgba(16, 185, 129, 0.03);
}

.contact-icon {
    width: 48px;
    height: 48px;
    border-radius: 50%;
    background: rgba(255, 255, 255, 0.03);
    border: 1px solid var(--border-color);
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--primary);
    font-size: 1.2rem;
    transition: var(--transition-fast);
}

.contact-item:hover .contact-icon {
    background: var(--primary);
    color: #080c14;
    box-shadow: 0 0 12px var(--primary-glow);
    border-color: var(--primary);
}

.contact-lbl {
    font-size: 0.85rem;
    color: var(--text-muted);
}

.contact-val {
    font-family: var(--font-header);
    font-weight: 600;
    font-size: 1.05rem;
}

/* Premium Form */
.contact-form {
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    padding: 40px;
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
}

.form-group {
    margin-bottom: 24px;
}

.form-group label {
    display: block;
    margin-bottom: 8px;
    font-size: 0.85rem;
    font-weight: 500;
    color: var(--text-secondary);
}

.form-group input, .form-group textarea {
    width: 100%;
    padding: 14px 18px;
    background: rgba(8, 12, 20, 0.4);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    color: var(--text-primary);
    font-family: var(--font-body);
    font-size: 0.95rem;
    transition: var(--transition-fast);
}

.form-group input:focus, .form-group textarea:focus {
    outline: none;
    border-color: var(--primary);
    box-shadow: 0 0 10px rgba(16, 185, 129, 0.1);
}

footer {
    padding: 40px 0;
    border-top: 1px solid var(--border-color);
    text-align: center;
    color: var(--text-muted);
    font-size: 0.9rem;
}

/* Animations */
@keyframes pulse {
    0%, 100% {
        transform: scale(1);
        opacity: 1;
        box-shadow: 0 0 10px var(--primary-glow);
    }
    50% {
        transform: scale(1.1);
        opacity: 0.8;
        box-shadow: 0 0 20px var(--primary-glow);
    }
}

@keyframes blink {
    0%, 100% { opacity: 1; }
    50% { opacity: 0.4; }
}

@keyframes morph {
    0%, 100% {
        border-radius: 50%;
    }
    50% {
        border-radius: 42% 58% 50% 50% / 45% 45% 55% 55%;
    }
}

@keyframes charge {
    0% {
        width: 10%;
        opacity: 0.6;
    }
    50% {
        width: 100%;
        opacity: 1;
        background: linear-gradient(90deg, var(--primary), var(--secondary));
    }
    90% {
        width: 100%;
        opacity: 1;
    }
    100% {
        width: 10%;
        opacity: 0.6;
    }
}

/* Animations on Scroll utility */
.reveal {
    opacity: 0;
    transform: translateY(30px);
    transition: opacity 0.8s ease, transform 0.8s cubic-bezier(0.16, 1, 0.3, 1);
}

.reveal.active {
    opacity: 1;
    transform: translateY(0);
}

/* Responsive Design */
@media (max-width: 992px) {
    .hero-wrapper {
        grid-template-columns: 1fr;
        text-align: center;
        gap: 48px;
    }
    .hero-content {
        align-items: center;
    }
    .badge {
        align-self: center;
    }
    .hero-ctas {
        justify-content: center;
    }
    .about-grid {
        grid-template-columns: 1fr;
    }
    .contact-wrapper {
        grid-template-columns: 1fr;
        gap: 48px;
    }
}

@media (max-width: 768px) {
    .nav-container {
        padding: 16px 20px;
    }
    nav ul {
        display: none; /* Mobile navigation toggle handled in script.js */
        position: absolute;
        top: 100%;
        left: 0;
        width: 100%;
        flex-direction: column;
        background: rgba(8, 12, 20, 0.95);
        backdrop-filter: blur(16px);
        border-bottom: 1px solid var(--border-color);
        padding: 24px;
        gap: 20px;
    }
    nav ul.open {
        display: flex;
    }
    .menu-toggle {
        display: block;
    }
    .hero-title {
        font-size: 2.75rem;
    }
    .profile-frame {
        width: 260px;
        height: 260px;
    }
    .pub-card {
        grid-template-columns: 1fr;
        gap: 16px;
    }
    .pub-number {
        width: 40px;
        height: 40px;
        font-size: 1.2rem;
    }
}