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

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    line-height: 1.6;
    color: #333;
    background: linear-gradient(135deg, #f5f5f5 0%, #e8e8e8 100%);
    min-height: 100vh;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

/* Navigation */
nav {
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    padding: 1rem 0;
    box-shadow: 0 2px 20px rgba(0, 0, 0, 0.1);
}

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

.logo {
    font-size: 1.5rem;
    font-weight: 700;
    color: #4a4a4a;
    text-decoration: none;
}

.nav-links {
    display: flex;
    gap: 2rem;
}

.nav-links a {
    text-decoration: none;
    color: #333;
    font-weight: 500;
    transition: color 0.3s ease;
    position: relative;
}

.nav-links a:hover {
    color: #4a4a4a;
}

.nav-links a.active {
    color: #4a4a4a;
}

.nav-links a::after {
    content: '';
    position: absolute;
    bottom: -5px;
    left: 0;
    width: 0;
    height: 2px;
    background: #4a4a4a;
    transition: width 0.3s ease;
}

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

.hero {
  padding: 120px 0 60px;
  text-align: center;
  color: white;
}

.hero-text {
  max-width: 700px;
  margin: 0 auto;
  color: #333;
}

.hero h1 {
  font-size: 3.5rem;
  margin-bottom: 1rem;
  font-weight: 700;
  text-shadow: 2px 2px 4px rgba(0, 0, 0, 0.3);
}

.hero p {
  font-size: 1.3rem;
  margin: 0 auto;
  text-shadow: 1px 1px 2px rgba(0, 0, 0, 0.3);
}

/* Main Content */
.main-content {
    background: white;
    margin: 40px 20px;
    border-radius: 20px;
    padding: 60px 0;
    box-shadow: 0 20px 40px rgba(0, 0, 0, 0.1);
}

.intro-section {
    text-align: center;
    margin-bottom: 60px;
}

.intro-section h2 {
    font-size: 2.5rem;
    margin-bottom: 1.5rem;
    color: #333;
}

.intro-section p {
    font-size: 1.1rem;
    line-height: 1.8;
    max-width: 800px;
    margin: 0 auto;
    color: #666;
}

/* Featured Image */
.featured-image {
    text-align: center;
    margin: 60px 0;
}

.featured-image img {
    width: 150px;
    height: 150px;
    object-fit: cover;
    display: block;
    border-radius: 50%;
    border: 3px solid #f9f9f9;
    box-shadow: 0 8px 20px rgba(0, 0, 0, 0.2);
}

.featured-image img:hover {
    transform: translateY(-5px);
}

/* Social Links */
.social-links {
    display: flex;
    justify-content: center;
    gap: 1.5rem;
    margin-top: 40px;
}

.social-btn {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    padding: 12px 24px;
    text-decoration: none;
    border-radius: 50px;
    font-weight: 600;
    transition: all 0.3s ease;
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.1);
}

.social-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(0, 0, 0, 0.2);
}

.linkedin {
    background: #0077b5;
    color: white;
}

.github {
    background: #333;
    color: white;
}

.blog {
    background: #6b6b6b;
    color: white;
}

/* Quick Preview Cards */
.preview-cards {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 30px;
    margin-top: 60px;
}

.card {
    background: #f8f9fa;
    padding: 30px;
    border-radius: 15px;
    border: none;
    text-align: center;
    transition: transform 0.3s ease;
}

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

.card h3 {
    color: #333;
    margin-bottom: 15px;
    font-size: 1.3rem;
}

.card p {
    color: #666;
    line-height: 1.6;
}

.card-icon {
    font-size: 2.5rem;
    margin-bottom: 20px;
    color: #4a4a4a;
}

/* About Page Styles */
.about-section {
    display: grid;
    grid-template-columns: 1fr 2fr;
    gap: 60px;
    align-items: start;
    margin-bottom: 80px;
}

.profile-card {
    background: #f8f9fa;
    padding: 40px;
    border-radius: 20px;
    text-align: center;
    position: sticky;
    top: 140px;
}

.profile-image {
    width: 200px;
    height: 200px;
    border-radius: 50%;
    margin: 0 auto 20px;
    background: linear-gradient(135deg, #4a4a4a, #6b6b6b);
    display: block;
    align-items: center;
    justify-content: center;
    font-size: 4rem;
    color: white;
    font-weight: bold;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.2);
    object-fit: cover;
}

.profile-card h2 {
    font-size: 1.8rem;
    margin-bottom: 10px;
    color: #333;
}

.profile-card .title {
    color: #4a4a4a;
    font-weight: 600;
    margin-bottom: 20px;
}

.profile-card .location {
    color: #666;
    margin-bottom: 30px;
}

.about-content h3 {
    font-size: 2rem;
    margin-bottom: 20px;
    color: #333;
}

.about-content p {
    font-size: 1.1rem;
    line-height: 1.8;
    margin-bottom: 20px;
    color: #666;
}

/* Skills Section */
.skills-section {
    margin-bottom: 80px;
}

.skills-section h3 {
    font-size: 2rem;
    margin-bottom: 40px;
    color: #333;
    text-align: center;
}

.skills-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 30px;
}

.skill-category {
    background: #f8f9fa;
    padding: 30px;
    border-radius: 15px;
    text-align: center;
}

.skill-category h4 {
    font-size: 1.3rem;
    margin-bottom: 20px;
    color: #333;
}

.skill-category .icon {
    font-size: 3rem;
    margin-bottom: 20px;
    color: #4a4a4a;
}

.skill-list {
    display: flex;
    flex-wrap: wrap;
    gap: 10px;
    justify-content: center;
}

.skill-tag {
    background: #4a4a4a;
    color: white;
    padding: 5px 15px;
    border-radius: 20px;
    font-size: 0.9rem;
    font-weight: 500;
}

/* Education & Experience Timeline */
.timeline-section {
    margin-bottom: 80px;
}

.timeline-section h3 {
    font-size: 2rem;
    margin-bottom: 40px;
    color: #333;
    text-align: center;
}

.timeline {
    position: relative;
    padding-left: 30px;
}

.timeline::before {
    content: '';
    position: absolute;
    left: 15px;
    top: 0;
    bottom: 0;
    width: 2px;
    background: #4a4a4a;
}

.timeline-item {
    position: relative;
    background: #f8f9fa;
    padding: 30px;
    border-radius: 15px;
    margin-bottom: 30px;
    margin-left: 30px;
}

.timeline-item::before {
    content: '';
    position: absolute;
    left: -45px;
    top: 30px;
    width: 16px;
    height: 16px;
    background: #4a4a4a;
    border-radius: 50%;
    border: 3px solid white;
}

.timeline-item h4 {
    font-size: 1.3rem;
    margin-bottom: 10px;
    color: #333;
}

.timeline-item .period {
    color: #4a4a4a;
    font-weight: 600;
    margin-bottom: 15px;
}

.timeline-item p {
    color: #666;
    line-height: 1.6;
}

/* Interests Section */
.interests-section {
    text-align: center;
}

.interests-section h3 {
    font-size: 2rem;
    margin-bottom: 40px;
    color: #333;
}

.interests-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 20px;
}

.interest-item {
    background: #f8f9fa;
    padding: 20px;
    border-radius: 15px;
    transition: transform 0.3s ease;
}

.interest-item:hover {
    transform: translateY(-5px);
}

.interest-item .icon {
    font-size: 2.5rem;
    margin-bottom: 15px;
    color: #4a4a4a;
}

.interest-item h4 {
    font-size: 1.1rem;
    color: #333;
}

/* Contact Button */
.contact-btn {
    display: inline-block;
    background: #4a4a4a;
    color: white;
    padding: 15px 30px;
    text-decoration: none;
    border-radius: 50px;
    font-weight: 600;
    margin-top: 30px;
    transition: all 0.3s ease;
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.1);
}

.contact-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(0, 0, 0, 0.2);
}

/* Filter Buttons */
.filter-section {
    text-align: center;
    margin-bottom: 50px;
}

.filter-buttons {
    display: flex;
    justify-content: center;
    gap: 15px;
    flex-wrap: wrap;
    margin-top: 30px;
}

.filter-btn {
    padding: 10px 25px;
    border: 2px solid #4a4a4a;
    background: transparent;
    color: #4a4a4a;
    border-radius: 25px;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
}

.filter-btn:hover,
.filter-btn.active {
    background: #4a4a4a;
    color: white;
    transform: translateY(-2px);
}

/* Projects Grid */
.projects-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
    gap: 30px;
    margin-bottom: 60px;
}

.project-card {
    background: white;
    border-radius: 20px;
    overflow: hidden;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.1);
    transition: all 0.3s ease;
    opacity: 1;
    transform: scale(1);
}

.project-card:hover {
    transform: translateY(-10px);
    box-shadow: 0 20px 40px rgba(0, 0, 0, 0.15);
}

.project-card.hidden {
    opacity: 0;
    transform: scale(0.8);
    pointer-events: none;
}

.project-image {
    height: 200px;
    background: linear-gradient(135deg, #4a4a4a, #6b6b6b);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 3rem;
    color: white;
    position: relative;
    overflow: hidden;
}

.project-image img {
    width: 100%;
    height: 100%;
    object-fit: cover;
}

.project-status {
    position: absolute;
    top: 15px;
    right: 15px;
    padding: 5px 12px;
    border-radius: 15px;
    font-size: 0.8rem;
    font-weight: 600;
}

.status-completed {
    background: #28a745;
    color: white;
}

.status-in-progress {
    background: #ffc107;
    color: #333;
}

.status-concept {
    background: #6c757d;
    color: white;
}

.project-content {
    padding: 25px;
}

.project-title {
    font-size: 1.4rem;
    font-weight: 700;
    color: #333;
    margin-bottom: 10px;
}

.project-description {
    color: #666;
    line-height: 1.6;
    margin-bottom: 20px;
}

.project-tech {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
    margin-bottom: 20px;
}

.tech-tag {
    background: #f8f9fa;
    color: #4a4a4a;
    padding: 4px 12px;
    border-radius: 15px;
    font-size: 0.8rem;
    font-weight: 500;
    border: 1px solid #e9ecef;
}

.project-links {
    display: flex;
    gap: 15px;
}

.project-link {
    display: inline-flex;
    align-items: center;
    gap: 5px;
    padding: 8px 16px;
    text-decoration: none;
    border-radius: 20px;
    font-weight: 600;
    font-size: 0.9rem;
    transition: all 0.3s ease;
}

.link-demo {
    background: #4a4a4a;
    color: white;
}

.link-demo:hover {
    background: #3a3a3a;
    transform: translateY(-1px);
}

.link-github {
    background: #f8f9fa;
    color: #333;
    border: 1px solid #e9ecef;
}

.link-github:hover {
    background: #e9ecef;
    transform: translateY(-1px);
}

/* Research Categories */
.category-nav {
    display: flex;
    justify-content: center;
    gap: 20px;
    margin-bottom: 50px;
    flex-wrap: wrap;
}

.category-btn {
    padding: 12px 30px;
    border: 2px solid #4a4a4a;
    background: transparent;
    color: #4a4a4a;
    border-radius: 30px;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
    text-decoration: none;
    display: inline-block;
}

.category-btn:hover,
.category-btn.active {
    background: #4a4a4a;
    color: white;
    transform: translateY(-2px);
}

/* Featured Research */
.featured-research { 
    background: linear-gradient(135deg, #4a4a4a, #6b6b6b);
    border-radius: 20px;
    padding: 40px;
    color: white;
    margin-bottom: 60px;
}

.featured-research h3 {
    font-size: 2rem;
    margin-bottom: 15px;
}

.featured-research .research-meta {
    display: flex;
    gap: 20px;
    margin-bottom: 20px;
    flex-wrap: wrap;
}

.featured-research .meta-item {
    background: rgba(255, 255, 255, 0.2);
    padding: 5px 15px;
    border-radius: 15px;
    font-size: 0.9rem;
}

.featured-research p {
    font-size: 1.1rem;
    margin-bottom: 25px;
    opacity: 0.9;
    line-height: 1.6;
}

.featured-research .research-actions {
    display: flex;
    gap: 15px;
    flex-wrap: wrap;
}

.research-btn {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 10px 20px;
    background: rgba(255, 255, 255, 0.2);
    color: white;
    text-decoration: none;
    border-radius: 25px;
    font-weight: 600;
    transition: all 0.3s ease;
    backdrop-filter: blur(10px);
}

.research-btn:hover {
    background: rgba(255, 255, 255, 0.3);
    transform: translateY(-1px);
}

/* Research Grid */
.research-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(400px, 1fr));
    gap: 30px;
    margin-bottom: 60px;
}

.research-card {
    background: white;
    border-radius: 20px;
    padding: 30px;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.1);
    transition: all 0.3s ease;
    opacity: 1;
    transform: scale(1);
}

.research-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 20px 40px rgba(0, 0, 0, 0.15);
}

.research-card.hidden {
    opacity: 0;
    transform: scale(0.8);
    pointer-events: none;
}

.research-header {
    display: flex;
    align-items: flex-start;
    gap: 20px;
    margin-bottom: 20px;
}

.research-icon {
    width: 60px;
    height: 60px;
    background: linear-gradient(135deg, #4a4a4a, #6b6b6b);
    border-radius: 15px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.5rem;
    color: white;
    flex-shrink: 0;
}

.research-title {
    font-size: 1.3rem;
    font-weight: 700;
    color: #333;
    margin-bottom: 8px;
    line-height: 1.3;
}

.research-meta {
    display: flex;
    gap: 15px;
    margin-bottom: 15px;
    flex-wrap: wrap;
}

.meta-item {
    background: #f8f9fa;
    color: #4a4a4a;
    padding: 4px 12px;
    border-radius: 12px;
    font-size: 0.8rem;
    font-weight: 600;
    border: 1px solid #e9ecef;
}

.research-abstract {
    color: #666;
    line-height: 1.6;
    margin-bottom: 20px;
}

.research-keywords {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
    margin-bottom: 20px;
}

.keyword-tag {
    background: #4a4a4a;
    color: white;
    padding: 4px 10px;
    border-radius: 12px;
    font-size: 0.8rem;
    font-weight: 500;
}

.research-actions {
    display: flex;
    gap: 12px;
    flex-wrap: wrap;
}

.action-btn {
    display: inline-flex;
    align-items: center;
    gap: 5px;
    padding: 8px 15px;
    text-decoration: none;
    border-radius: 20px;
    font-weight: 600;
    font-size: 0.9rem;
    transition: all 0.3s ease;
}

.btn-primary {
    background: #4a4a4a;
    color: white;
}

.btn-primary:hover {
    background: #3a3a3a;
    transform: translateY(-1px);
}

.btn-secondary {
    background: #f8f9fa;
    color: #333;
    border: 1px solid #e9ecef;
}

.btn-secondary:hover {
    background: #e9ecef;
    transform: translateY(-1px);
}

/* Research Areas Section */
.research-areas {
    margin-bottom: 60px;
}

.research-areas h3 {
    font-size: 2rem;
    margin-bottom: 30px;
    color: #333;
    text-align: center;
}

.areas-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 25px;
}

.area-card {
    background: #f8f9fa;
    padding: 25px;
    border-radius: 15px;
    text-align: center;
    transition: transform 0.3s ease;
}

.area-card:hover {
    transform: translateY(-3px);
}

.area-icon {
    font-size: 2.5rem;
    margin-bottom: 15px;
    color: #4a4a4a;
}

.area-title {
    font-size: 1.2rem;
    font-weight: 600;
    color: #333;
    margin-bottom: 10px;
}

.area-description {
    color: #666;
    font-size: 0.9rem;
    line-height: 1.5;
}

/* Responsive Design */
@media (max-width: 768px) {
    .nav-links {
        gap: 1rem;
    }

    .hero h1 {
        font-size: 2.5rem;
    }

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

    .hero-wrapper {
        flex-direction: column;
        text-align: center;
    }

    .hero-text {
        min-width: auto;
    }

    .social-links {
        flex-direction: column;
        align-items: center;
    }

    .preview-cards {
        grid-template-columns: 1fr;
    }

    .about-section {
        grid-template-columns: 1fr;
        gap: 40px;
    }

    .profile-card {
        position: static;
    }

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

    .timeline {
        padding-left: 20px;
    }

    .timeline-item {
        margin-left: 20px;
    }

    .interests-grid {
        grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
    }
    .projects-grid {
        grid-template-columns: 1fr;
    }

    .filter-buttons {
        gap: 10px;
    }

    .filter-btn {
        padding: 8px 20px;
        font-size: 0.9rem;
    }

    .featured-project {
        padding: 30px 20px;
    }

    .project-links {
        flex-direction: column;
    }

}