/* CSS Reset and Base Styles */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    --primary-color: #2563eb;
    --secondary-color: #1e40af;
    --accent-color: #3b82f6;
    --text-color: #1f2937;
    --bg-color: #ffffff;
    --card-bg: #f8fafc;
    --border-color: #e5e7eb;
    --shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
    --transition: all 0.3s ease;
}

[data-theme="dark"] {
    --text-color: #f3f4f6;
    --bg-color: #111827;
    --card-bg: #1f2937;
    --border-color: #374151;
    --shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.3);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.3);
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Inter', sans-serif;
    line-height: 1.6;
    color: var(--text-color);
    background-color: var(--bg-color);
    transition: var(--transition);
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 1rem;
}

/* Navigation */
.navbar {
    position: fixed;
    top: 0;
    width: 100%;
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    z-index: 1000;
    transition: var(--transition);
}

[data-theme="dark"] .navbar {
    background: rgba(17, 24, 39, 0.95);
}

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 1rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.nav-logo {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--primary-color);
}

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

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

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

.nav-link::after {
    content: '';
    position: absolute;
    bottom: -5px;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--primary-color);
    transition: var(--transition);
}

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

.hamburger {
    display: none;
    flex-direction: column;
    cursor: pointer;
}

.bar {
    width: 25px;
    height: 3px;
    background: var(--text-color);
    margin: 3px 0;
    transition: var(--transition);
}

/* Hero Section */
.hero {
    min-height: 100vh;
    display: flex;
    align-items: center;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    position: relative;
    overflow: hidden;
}

.hero::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: url('data:image/svg+xml,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 100 100"><defs><pattern id="grain" patternUnits="userSpaceOnUse" width="100" height="100"><circle cx="50" cy="50" r="2" fill="rgba(255,255,255,0.1)"/></pattern></defs><rect width="100" height="100" fill="url(%23grain)"/></svg>');
    animation: grain 8s steps(10) infinite;
}

@keyframes grain {
    0%, 100% { transform: translate(0, 0); }
    10% { transform: translate(-5%, -5%); }
    20% { transform: translate(-10%, 5%); }
    30% { transform: translate(5%, -10%); }
    40% { transform: translate(-5%, 15%); }
    50% { transform: translate(-10%, 5%); }
    60% { transform: translate(15%, 0); }
    70% { transform: translate(0, 10%); }
    80% { transform: translate(-15%, 0); }
    90% { transform: translate(10%, 5%); }
}

.hero-content {
    max-width: 1200px;
    margin: 0 auto;
    padding: 2rem;
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 3rem;
    align-items: center;
    position: relative;
    z-index: 2;
}

.hero-title {
    font-size: 3.5rem;
    font-weight: 700;
    margin-bottom: 1rem;
    animation: fadeInUp 1s ease;
}

.hero-subtitle {
    font-size: 1.5rem;
    margin-bottom: 2rem;
    opacity: 0.9;
    animation: fadeInUp 1s ease 0.2s both;
}

.hero-contact p {
    margin: 0.5rem 0;
    display: flex;
    align-items: center;
    gap: 0.5rem;
    animation: fadeInUp 1s ease 0.4s both;
}

.hero-buttons {
    display: flex;
    gap: 1rem;
    margin-top: 2rem;
    animation: fadeInUp 1s ease 0.6s both;
}

.btn {
    padding: 0.75rem 1.5rem;
    border: none;
    border-radius: 0.5rem;
    text-decoration: none;
    font-weight: 600;
    transition: var(--transition);
    cursor: pointer;
    display: inline-block;
}

.btn-primary {
    background: var(--primary-color);
    color: white;
}

.btn-primary:hover {
    background: var(--secondary-color);
    transform: translateY(-2px);
}

.btn-secondary {
    background: transparent;
    color: white;
    border: 2px solid white;
}

.btn-secondary:hover {
    background: white;
    color: var(--primary-color);
}

.btn-outline {
    background: transparent;
    color: var(--primary-color);
    border: 2px solid var(--primary-color);
}

.btn-outline:hover {
    background: var(--primary-color);
    color: white;
}

.hero-image {
    display: flex;
    justify-content: center;
    align-items: center;
    animation: fadeInRight 1s ease 0.8s both;
}

.profile-placeholder {
    width: 300px;
    height: 300px;
    border-radius: 50%;
    background: rgba(255, 255, 255, 0.1);
    backdrop-filter: blur(10px);
    display: flex;
    align-items: center;
    justify-content: center;
    border: 3px solid rgba(255, 255, 255, 0.2);
}

.profile-placeholder i {
    font-size: 8rem;
    color: rgba(255, 255, 255, 0.3);
}

.scroll-indicator {
    position: absolute;
    bottom: 2rem;
    left: 50%;
    transform: translateX(-50%);
    animation: bounce 2s infinite;
}

@keyframes bounce {
    0%, 20%, 50%, 80%, 100% {
        transform: translateX(-50%) translateY(0);
    }
    40% {
        transform: translateX(-50%) translateY(-10px);
    }
    60% {
        transform: translateX(-50%) translateY(-5px);
    }
}

/* Section Styles */
section {
    padding: 5rem 0;
}

.section-title {
    font-size: 2.5rem;
    text-align: center;
    margin-bottom: 3rem;
    color: var(--text-color);
    position: relative;
}

.section-title::after {
    content: '';
    position: absolute;
    bottom: -10px;
    left: 50%;
    transform: translateX(-50%);
    width: 50px;
    height: 3px;
    background: var(--primary-color);
}

/* About Section */
.about-content {
    max-width: 800px;
    margin: 0 auto;
    text-align: center;
}

.research-interests {
    list-style: none;
    margin-top: 2rem;
}

.research-interests li {
    margin: 1rem 0;
    padding: 1rem;
    background: var(--card-bg);
    border-radius: 0.5rem;
    display: flex;
    align-items: center;
    gap: 1rem;
    transition: var(--transition);
}

.research-interests li:hover {
    transform: translateX(10px);
    box-shadow: var(--shadow);
}

/* Publications Section */
.publications-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
    margin-top: 2rem;
}

.publication-card {
    background: var(--card-bg);
    padding: 2rem;
    border-radius: 1rem;
    box-shadow: var(--shadow);
    transition: var(--transition);
    border: 1px solid var(--border-color);
}

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

.publication-journal {
    color: var(--primary-color);
    font-weight: 500;
    margin: 1rem 0;
}

.publication-links {
    display: flex;
    gap: 1rem;
    margin-top: 1rem;
}

/* Conference Section */
.conference-list {
    display: grid;
    gap: 1.5rem;
    margin-top: 2rem;
}

.conference-item {
    background: var(--card-bg);
    padding: 1.5rem;
    border-radius: 0.5rem;
    border-left: 4px solid var(--primary-color);
    transition: var(--transition);
}

.conference-item:hover {
    transform: translateX(10px);
    box-shadow: var(--shadow);
}

.conference-role {
    color: var(--primary-color);
    font-weight: 600;
    margin-top: 0.5rem;
}

/* Education Timeline */
.timeline {
    position: relative;
    max-width: 800px;
    margin: 2rem auto;
    padding: 2rem 0;
}

.timeline::before {
    content: '';
    position: absolute;
    left: 50%;
    top: 0;
    bottom: 0;
    width: 2px;
    background: var(--primary-color);
    transform: translateX(-50%);
}

.timeline-item {
    position: relative;
    margin-bottom: 3rem;
    width: 50%;
    padding: 0 2rem;
}

.timeline-item:nth-child(odd) {
    left: 0;
}

.timeline-item:nth-child(even) {
    left: 50%;
}

.timeline-content {
    background: var(--card-bg);
    padding: 1.5rem;
    border-radius: 0.5rem;
    box-shadow: var(--shadow);
    transition: var(--transition);
}

.timeline-content:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
}

.timeline-period {
    color: var(--primary-color);
    font-weight: 600;
    margin-bottom: 0.5rem;
}

/* Experience Section */
.experience-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
    margin-top: 2rem;
}

.experience-card {
    background: var(--card-bg);
    padding: 2rem;
    border-radius: 1rem;
    box-shadow: var(--shadow);
    transition: var(--transition);
    border: 1px solid var(--border-color);
}

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

.experience-period {
    color: var(--primary-color);
    font-weight: 600;
    margin: 0.5rem 0;
}

/* Projects Section */
.projects-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
    margin-top: 2rem;
}

.project-card {
    perspective: 1000px;
    height: 200px;
}

.project-front,
.project-back {
    position: absolute;
    width: 100%;
    height: 100%;
    backface-visibility: hidden;
    border-radius: 1rem;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    padding: 2rem;
    transition: transform 0.6s ease;
}

.project-front {
    background: var(--card-bg);
    box-shadow: var(--shadow);
}

.project-back {
    background: var(--primary-color);
    color: white;
    transform: rotateY(180deg);
}

.project-card:hover .project-front {
    transform: rotateY(180deg);
}

.project-card:hover .project-back {
    transform: rotateY(0deg);
}

/* Skills Section */
.skills-categories {
    display: grid;
    gap: 2rem;
    margin-top: 2rem;
}

.skill-category {
    background: var(--card-bg);
    padding: 2rem;
    border-radius: 1rem;
    box-shadow: var(--shadow);
}

.skill-list {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
    margin-top: 1rem;
}

.skill-tag {
    background: var(--primary-color);
    color: white;
    padding: 0.5rem 1rem;
    border-radius: 2rem;
    font-size: 0.9rem;
    transition: var(--transition);
}

.skill-tag:hover {
    transform: scale(1.05);
    box-shadow: var(--shadow);
}

/* Achievements Section */
.achievements-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
    margin-top: 2rem;
}

.achievement-card {
    background: var(--card-bg);
    padding: 2rem;
    border-radius: 1rem;
    text-align: center;
    box-shadow: var(--shadow);
    transition: var(--transition);
}

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

/* Failures Section */
.failures-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
    margin-top: 2rem;
}

.failure-card {
    background: var(--card-bg);
    padding: 2rem;
    border-radius: 1rem;
    box-shadow: var(--shadow);
    transition: var(--transition);
    border: 1px solid var(--border-color);
    position: relative;
    overflow: hidden;
}

.failure-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 4px;
    height: 100%;
    background: linear-gradient(to bottom, #ef4444, #f59e0b);
}

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

.failure-card h3 {
    color: #ef4444;
    margin-bottom: 1rem;
}

.learning-point {
    margin-top: 1.5rem;
    padding: 1rem;
    background: rgba(239, 68, 68, 0.1);
    border-radius: 0.5rem;
    border-left: 3px solid #f59e0b;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.learning-point i {
    color: #f59e0b;
    font-size: 1.2rem;
}

.learning-point span {
    color: var(--text-color);
    font-weight: 500;
}

/* Contact Section */
.contact-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 3rem;
    margin-top: 2rem;
}

.contact-info {
    background: var(--card-bg);
    padding: 2rem;
    border-radius: 1rem;
    box-shadow: var(--shadow);
}

.contact-form {
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

.contact-form input,
.contact-form textarea {
    padding: 1rem;
    border: 1px solid var(--border-color);
    border-radius: 0.5rem;
    background: var(--card-bg);
    color: var(--text-color);
    transition: var(--transition);
}

.contact-form input:focus,
.contact-form textarea:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.1);
}

/* Footer */
.footer {
    background: var(--card-bg);
    padding: 2rem 0;
    text-align: center;
    border-top: 1px solid var(--border-color);
}

/* 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: 768px) {
    .hero-content {
        grid-template-columns: 1fr;
        text-align: center;
        gap: 2rem;
    }

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

    .hero-subtitle {
        font-size: 1.2rem;
    }

    .nav-menu {
        position: fixed;
        left: -100%;
        top: 70px;
        flex-direction: column;
        background: var(--bg-color);
        width: 100%;
        text-align: center;
        transition: 0.3s;
        box-shadow: var(--shadow);
        padding: 2rem 0;
    }

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

    .hamburger {
        display: flex;
    }

    .hamburger.active .bar:nth-child(2) {
        opacity: 0;
    }

    .hamburger.active .bar:nth-child(1) {
        transform: translateY(8px) rotate(45deg);
    }

    .hamburger.active .bar:nth-child(3) {
        transform: translateY(-8px) rotate(-45deg);
    }

    .timeline::before {
        left: 20px;
    }

    .timeline-item {
        width: 100%;
        padding-left: 50px;
        padding-right: 0;
    }

    .timeline-item:nth-child(even) {
        left: 0;
    }

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

    .publications-grid,
    .experience-grid,
    .projects-grid,
    .achievements-grid {
        grid-template-columns: 1fr;
    }
}

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

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

    .btn {
        padding: 0.6rem 1.2rem;
        font-size: 0.9rem;
    }

    .profile-placeholder {
        width: 200px;
        height: 200px;
    }

    .profile-placeholder i {
        font-size: 5rem;
    }
}

/* Theme Toggle Button */
.theme-toggle {
    position: fixed;
    bottom: 2rem;
    right: 2rem;
    background: var(--primary-color);
    color: white;
    width: 50px;
    height: 50px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    box-shadow: var(--shadow-lg);
    z-index: 1000;
    transition: var(--transition);
}

.theme-toggle:hover {
    transform: scale(1.1);
}