:root {
            --primary: #2563eb;
            --primary-dark: #1d4ed8;
            --secondary: #374151;
            --accent: #10b981;
            --light: #f3f4f6;
            --dark: #1f2937;
            --text: #374151;
            --text-light: #6b7280;
            --white: #ffffff;
            --shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
            --transition: all 0.3s ease;
        }
        
        * {
            margin: 0;
            padding: 0;
            box-sizing: border-box;
        }
        
        body {
            font-family: 'Inter', sans-serif;
            line-height: 1.6;
            color: var(--text);
            background-color: var(--white);
            scroll-behavior: smooth;
        }
        
        a {
            text-decoration: none;
            color: var(--primary);
            transition: var(--transition);
        }
        
        a:hover {
            color: var(--primary-dark);
        }
        
        .container {
            width: 90%;
            max-width: 1200px;
            margin: 0 auto;
            padding: 0 20px;
        }
        
        /* ===== UNIFIED BUTTON STYLES ===== */
        .btn {
            display: inline-block;
            padding: 10px 20px;
            background-color: var(--primary);
            color: var(--white);
            border-radius: 6px;
            font-weight: 500;
            transition: var(--transition);
            border: none;
            cursor: pointer;
            box-shadow: var(--shadow);
            text-decoration: none;
            font-size: 0.9rem;
            text-align: center;
        }
        
        .btn:hover {
            background-color: var(--primary-dark);
            color: var(--white);
            transform: translateY(-2px);
        }
        
        .btn-outline {
            background-color: transparent;
            border: 2px solid var(--primary);
            color: var(--primary);
        }
        
        .btn-outline:hover {
            background-color: var(--primary);
            color: var(--white);
        }
        
        /* Specific styles for contact form button only */
        .contact-form-container .btn {
            padding: 14px 28px;
            font-weight: 600;
            font-size: 1rem;
            width: 100%;
        }
        
        /* Hero section buttons - keep their specific layout */
        .hero-buttons .btn {
            width: auto;
        }
        
        /* Project links buttons - keep their specific layout */
        .project-links .btn {
            width: auto;
        }
        
        .section {
            padding: 80px 0;
        }
        
        .section-title {
            font-size: 2.5rem;
            font-weight: 700;
            margin-bottom: 1rem;
            color: var(--dark);
            text-align: center;
        }
        
        .section-subtitle {
            font-size: 1.2rem;
            color: var(--text-light);
            text-align: center;
            margin-bottom: 3rem;
            max-width: 700px;
            margin-left: auto;
            margin-right: auto;
        }
        
        /* Header & Navigation */
        header {
            position: fixed;
            top: 0;
            left: 0;
            width: 100%;
            z-index: 1000;
            background-color: rgba(255, 255, 255, 0.95);
            box-shadow: var(--shadow);
            padding: 15px 0;
        }
        
        .nav-container {
            display: flex;
            justify-content: space-between;
            align-items: center;
        }
        
        .logo {
            font-size: 1.8rem;
            font-weight: 700;
            color: var(--dark);
        }
        
        .logo span {
            color: var(--primary);
        }
        
        .nav-menu {
            display: flex;
            list-style: none;
        }
        
        .nav-item {
            margin-left: 2rem;
        }
        
        .nav-link {
            color: var(--text);
            font-weight: 500;
            position: relative;
        }
        
        .nav-link::after {
            content: '';
            position: absolute;
            bottom: -5px;
            left: 0;
            width: 0;
            height: 2px;
            background-color: var(--primary);
            transition: var(--transition);
        }
        
        .nav-link:hover::after {
            width: 100%;
        }
        
        .header-social {
            display: flex;
            align-items: center;
            margin-left: 2rem;
        }
        
        .social-icon {
            width: 36px;
            height: 36px;
            border-radius: 50%;
            background-color: var(--light);
            display: flex;
            align-items: center;
            justify-content: center;
            color: var(--primary);
            margin-left: 10px;
            transition: var(--transition);
        }
        
        .social-icon:hover {
            background-color: var(--primary);
            color: var(--white);
            transform: translateY(-3px);
        }
        
        .hamburger {
            display: none;
            cursor: pointer;
        }

    .timeline {
    position: relative;
    margin: 2rem auto;
    padding: 2rem 0;
    width: 80%;
    }

    .timeline::before {
    content: '';
    position: absolute;
    top: 0;
    left: 50%;
    transform: translateX(-50%);
    width: 3px;
    height: 100%;
    background: var(--primary);
    }

    .timeline-item {
    position: relative;
    width: 50%;
    padding: 1rem 2rem;
    }

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

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

    .timeline-item::before {
    content: '';
    position: absolute;
    top: 1.2rem;
    left: 100%;
    transform: translateX(-50%);
    width: 16px;
    height: 16px;
    background: var(--primary);
    border-radius: 50%;
    }

    .timeline-item:nth-child(even)::before {
    left: 0;
    transform: translateX(-50%);
    }

    .timeline-date {
    font-weight: 700;
    color: var(--primary);
    margin-bottom: 0.3rem;
    padding-left: 10px;
    padding-right: 10px;
    display: inline-block;
    }

    .timeline-content h3 {
    font-size: 1.2rem;
    font-weight: 600;
    margin: 0;
    color: var(--dark);
    }

    .timeline-content .company {
    font-size: 0.95rem;
    color: var(--text-light);
    }

        /* Hero Section */
        .hero {
            padding-top: 150px;
            padding-bottom: 80px;
            background: linear-gradient(135deg, #f0f4ff 0%, #e6f0ff 100%);
            position: relative;
            overflow: hidden;
        }
        
        .hero::before {
            content: '';
            position: absolute;
            top: -100px;
            right: -100px;
            width: 400px;
            height: 400px;
            border-radius: 50%;
            background: rgba(37, 99, 235, 0.1);
            z-index: 0;
        }
        
        .hero::after {
            content: '';
            position: absolute;
            bottom: -100px;
            left: -100px;
            width: 300px;
            height: 300px;
            border-radius: 50%;
            background: rgba(16, 185, 129, 0.1);
            z-index: 0;
        }
        
        .hero-content {
            position: relative;
            z-index: 1;
            display: grid;
            grid-template-columns: 60% 40%;
            gap: 40px;
            align-items: center;
        }
        
        .hero-text h1 {
            font-size: 3.5rem;
            font-weight: 800;
            margin-bottom: 1.5rem;
            color: var(--dark);
            line-height: 1.2;
        }
        
        .hero-text h1 span {
            color: var(--primary);
        }
        
        .hero-text p {
            font-size: 1.2rem;
            margin-bottom: 2rem;
            color: var(--text-light);
        }
        
        .hero-buttons {
            display: flex;
            gap: 15px;
        }
        
        .hero-image {
            position: relative;
            text-align: center;
        }
        
        .hero-image img {
            width: 320px;
            height: 320px;
            border-radius: 50%;
            object-fit: cover;
            border: 5px solid var(--white);
            box-shadow: var(--shadow);
        }
        
        /* About Section */
        .about-grid {
            display: grid;
            grid-template-columns: 1fr 1fr;
            gap: 50px;
            align-items: center;
        }
        
        .about-content h2 {
            font-size: 2.5rem;
            margin-bottom: 1.5rem;
            color: var(--dark);
        }
        
        .about-content p {
            margin-bottom: 1.5rem;
            color: var(--text);
        }
        
        .about-skills {
            display: flex;
            flex-wrap: wrap;
            gap: 12px;
            margin-top: 1.5rem;
            margin-bottom: 2rem;  
        }

        .skill-tag {
            padding: 8px 18px;
            border-radius: 30px;
            font-size: 0.9rem;
            font-weight: 600;
            color: var(--primary);
            background: rgba( var(--primary-rgb), 0.1);
            border: 1px solid var(--primary);
            transition: all 0.3s ease;
            cursor: default;
        }

        .skill-tag:hover {
            background: var(--primary);
            color: #fff;
            transform: translateY(-3px);
            box-shadow: 0 5px 15px rgba(var(--primary-rgb), 0.4);
        }
        
        /* Experience Section */
        .experience-container {
            max-width: 900px;
            margin: 0 auto;
        }
        
        .experience-item {
            display: grid;
            grid-template-columns: 200px 1fr;
            gap: 30px;
            margin-bottom: 40px;
            padding: 25px;
            border-radius: 10px;
            background-color: var(--white);
            box-shadow: var(--shadow);
        }
        
        .experience-date {
            font-weight: 600;
            color: var(--primary);
        }
        
        .experience-content h3 {
            font-size: 1.3rem;
            margin-bottom: 8px;
            color: var(--dark);
        }
        
        .experience-content .company {
            font-weight: 600;
            color: var(--text-light);
            margin-bottom: 12px;
            display: block;
        }
        
        .experience-content ul {
            padding-left: 20px;
            color: var(--text);
        }
        
        .experience-content li {
            margin-bottom: 8px;
        }

        /* Project Tabs */
        .project-tabs {
            display: flex;
            justify-content: center;
            margin-bottom: 40px;
            border-bottom: 2px solid var(--light);
            padding-bottom: 10px;
        }
        
        .project-tab-btn {
            padding: 12px 24px;
            background: none;
            border: none;
            font-size: 1.2rem;
            font-weight: 600;
            color: var(--text-light);
            cursor: pointer;
            transition: var(--transition);
            position: relative;
            margin: 0 10px;
        }
        
        .project-tab-btn:after {
            content: '';
            position: absolute;
            bottom: -12px;
            left: 0;
            width: 0;
            height: 3px;
            background-color: var(--primary);
            transition: var(--transition);
        }
        
        .project-tab-btn.active {
            color: var(--primary);
        }
        
        .project-tab-btn.active:after {
            width: 100%;
        }
        
        .project-tab-btn:hover {
            color: var(--primary);
        }

        /* Projects Grid */
        .projects-grid {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
            gap: 30px;
        }
        
        .project-card {
            background-color: var(--white);
            border-radius: 10px;
            overflow: hidden;
            box-shadow: var(--shadow);
            transition: var(--transition);
            display: flex;
            flex-direction: column;
            height: 100%;
            padding-bottom: 15px;
        }
        
        .project-card:hover {
            transform: translateY(-5px);
            box-shadow: 0 10px 20px rgba(0, 0, 0, 0.1);
        }
        
        .project-img {
            width: 100%;
            height: 200px;
            object-fit: cover;
        }

        .project-links {
            display: flex;
            justify-content: center;
            gap: 1rem;
            margin-top: 5px;
        }

        .project-content {
            padding: 20px;
            display: flex;
            flex-direction: column;
            flex-grow: 1;
        }
        
        .project-title {
            font-size: 1.2rem;
            font-weight: 600;
            margin-bottom: 8px;
            color: var(--dark);
        }
        
        .project-desc {
            color: var(--text-light);
            margin-bottom: 8px;
            font-size: 0.95rem;
            flex-grow: 1;
        }
        
        .project-tags {
            display: flex;
            flex-wrap: wrap;
            gap: 8px;
            margin-bottom: 12px;
            justify-content: center;
        }
        
        .project-tag {
            padding: 4px 10px;
            background-color: var(--light);
            border-radius: 4px;
            font-size: 0.8rem;
            color: var(--text);
        }
        
        /* Tab content */
        .project-tab-content {
            display: none;
        }
        
        .project-tab-content.active {
            display: block;
        }
        
        @media (max-width: 768px) {
            .project-tabs {
                flex-direction: column;
                align-items: center;
            }
            
            .project-tab-btn {
                margin: 5px 0;
                width: 200px;
            }
            
            .projects-grid {
                grid-template-columns: 1fr;
            }
            
            .project-links {
                flex-direction: column;
            }
        }
        

        /* Research Tabs */
        .research-tabs {
            display: flex;
            justify-content: center;
            margin-bottom: 40px;
            border-bottom: 2px solid var(--light);
            padding-bottom: 10px;
            flex-wrap: wrap;
        }
        
        .research-tab-btn {
            padding: 12px 24px;
            background: none;
            border: none;
            font-size: 1.2rem;
            font-weight: 600;
            color: var(--text-light);
            cursor: pointer;
            transition: var(--transition);
            position: relative;
            margin: 0 10px;
        }
        
        .research-tab-btn:after {
            content: '';
            position: absolute;
            bottom: -12px;
            left: 0;
            width: 0;
            height: 3px;
            background-color: var(--primary);
            transition: var(--transition);
        }
        
        .research-tab-btn.active {
            color: var(--primary);
        }
        
        .research-tab-btn.active:after {
            width: 100%;
        }
        
        .research-tab-btn:hover {
            color: var(--primary);
        }
        
        /* Research Grid */
        .research-grid {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
            gap: 30px;
        }
        
        .research-card {
            background-color: var(--white);
            border-radius: 10px;
            padding: 25px;
            box-shadow: var(--shadow);
            transition: var(--transition);
            display: flex;
            flex-direction: column;
            height: 100%;
            padding-bottom: 15px;
        }
        
        .research-card:hover {
            transform: translateY(-5px);
            box-shadow: 0 10px 20px rgba(0, 0, 0, 0.1);
        }
        
        .research-category-tag {
            display: inline-block;
            padding: 4px 12px;
            background-color: rgba(16, 185, 129, 0.1);
            color: var(--accent);
            border-radius: 20px;
            font-size: 0.8rem;
            font-weight: 600;
            margin-bottom: 12px;
        }
        
        .research-title {
            font-size: 1.2rem;
            font-weight: 600;
            margin-bottom: 8px;
            color: var(--dark);
            line-height: 1.4;
        }
        
        .research-desc {
            color: var(--text-light);
            margin-bottom: 8px;
            font-size: 0.95rem;
            flex-grow: 1;
        }
        
        /* Blog Tabs */
        .blog-tabs {
            display: flex;
            justify-content: center;
            margin-bottom: 40px;
            border-bottom: 2px solid var(--light);
            padding-bottom: 10px;
        }
        
        .blog-tab-btn {
            padding: 12px 24px;
            background: none;
            border: none;
            font-size: 1.2rem;
            font-weight: 600;
            color: var(--text-light);
            cursor: pointer;
            transition: var(--transition);
            position: relative;
            margin: 0 10px;
        }
        
        .blog-tab-btn:after {
            content: '';
            position: absolute;
            bottom: -12px;
            left: 0;
            width: 0;
            height: 3px;
            background-color: var(--primary);
            transition: var(--transition);
        }
        
        .blog-tab-btn.active {
            color: var(--primary);
        }
        
        .blog-tab-btn.active:after {
            width: 100%;
        }
        
        .blog-tab-btn:hover {
            color: var(--primary);
        }

        /* Blog Grid */
        .blogs-grid {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
            gap: 30px;
        }
        
        .blog-card {
            background-color: var(--white);
            border-radius: 10px;
            overflow: hidden;
            box-shadow: var(--shadow);
            transition: var(--transition);
            display: flex;
            flex-direction: column;
            height: 100%;
            padding-bottom: 15px;
        }
        
        .blog-card:hover {
            transform: translateY(-5px);
            box-shadow: 0 10px 20px rgba(0, 0, 0, 0.1);
        }
        
        .blog-img {
            width: 100%;
            height: 200px;
            object-fit: cover;
        }
        
        .blog-content {
            padding: 20px;
            display: flex;
            flex-direction: column;
            flex-grow: 1;
        }
        
        .blog-category {
            display: inline-block;
            padding: 4px 12px;
            background-color: rgba(37, 99, 235, 0.1);
            color: var(--primary);
            border-radius: 20px;
            font-size: 0.8rem;
            font-weight: 600;
            margin-bottom: 12px;
        }
        
        .blog-title {
            font-size: 1.2rem;
            font-weight: 600;
            margin-bottom: 8px;
            color: var(--dark);
            line-height: 1.4;
        }
        
        .blog-desc {
            color: var(--text-light);
            margin-bottom: 8px;
            font-size: 0.95rem;
            flex-grow: 1;
        }
        
        /* Tab content */
        .research-tab-content {
            display: none;
        }
        
        .research-tab-content.active {
            display: block;
        }
        
        .blog-tab-content {
            display: none;
        }
        
        .blog-tab-content.active {
            display: block;
        }
        
        @media (max-width: 768px) {
            .research-tabs, .blog-tabs {
                flex-direction: column;
                align-items: center;
            }
            
            .research-tab-btn, .blog-tab-btn {
                margin: 5px 0;
                width: 200px;
            }
            
            .research-grid, .blogs-grid {
                grid-template-columns: 1fr;
            }
        }

        /* Contact Form */
        .contact-form-container {
            background-color: var(--white);
            padding: 40px;
            border-radius: 12px;
            box-shadow: var(--shadow);
            max-width: 600px;
            margin: 0 auto;
        }
        
        .form-header {
            text-align: center;
            margin-bottom: 30px;
        }
        
        .form-icon {
            font-size: 2.5rem;
            color: var(--primary);
            margin-bottom: 15px;
        }
        
        .form-title {
            font-size: 1.8rem;
            margin-bottom: 10px;
            color: var(--dark);
        }
        
        .form-subtitle {
            color: var(--text-light);
            margin-bottom: 20px;
        }
        
        .form-group {
            margin-bottom: 20px;
        }
        
        .form-label {
            display: block;
            margin-bottom: 8px;
            font-weight: 500;
            color: var(--dark);
        }
        
        .form-control {
            width: 100%;
            padding: 14px 16px;
            border: 1px solid #ddd;
            border-radius: 8px;
            font-family: 'Inter', sans-serif;
            font-size: 1rem;
            transition: var(--transition);
        }
        
        .form-control:focus {
            border-color: var(--primary);
            outline: none;
            box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.1);
        }
        
        textarea.form-control {
            min-height: 150px;
            resize: vertical;
        }
        
        .form-footer {
            text-align: center;
            margin-top: 20px;
            color: var(--text-light);
            font-size: 0.9rem;
        }
        
        .form-footer a {
            color: var(--primary);
            text-decoration: none;
        }
        
        .form-footer a:hover {
            text-decoration: underline;
        }
        
        @media (max-width: 768px) {
            .contact-form-container {
                padding: 30px 20px;
            }
            
            .section-title {
                font-size: 2rem;
            }
            
            .form-title {
                font-size: 1.5rem;
            }
        }
        
        /* Footer */
        footer {
            background-color: var(--dark);
            color: var(--white);
            padding: 60px 0 30px;
        }
        
        .footer-grid {
            display: grid;
            grid-template-columns: 2fr 1fr 1fr;
            gap: 40px;
            margin-bottom: 40px;
        }
        
        .footer-logo {
            font-size: 1.8rem;
            font-weight: 700;
            color: var(--white);
            margin-bottom: 1rem;
            display: inline-block;
        }
        
        .footer-desc {
            color: #d1d5db;
            margin-bottom: 1.5rem;
        }
        
        .social-links {
            display: flex;
            gap: 15px;
        }
        
        .social-link {
            width: 40px;
            height: 40px;
            border-radius: 50%;
            background-color: rgba(255, 255, 255, 0.1);
            display: flex;
            align-items: center;
            justify-content: center;
            color: var(--white);
            transition: var(--transition);
        }
        
        .social-link:hover {
            background-color: var(--primary);
            transform: translateY(-3px);
        }
        
        .footer-heading {
            font-size: 1.2rem;
            font-weight: 600;
            margin-bottom: 1.5rem;
            color: var(--white);
        }
        
        .footer-links {
            list-style: none;
        }
        
        .footer-links li {
            margin-bottom: 12px;
        }
        
        .footer-links a {
            color: #d1d5db;
            transition: var(--transition);
        }
        
        .footer-links a:hover {
            color: var(--white);
        }
        
        .copyright {
            text-align: center;
            padding-top: 30px;
            border-top: 1px solid rgba(255, 255, 255, 0.1);
            color: #9ca3af;
        }
        
        /* Responsive Design */
        @media (max-width: 992px) {
            .hero-content,
            .about-grid,
            .contact-container {
                grid-template-columns: 1fr;
            }
            
            .footer-grid {
                grid-template-columns: 1fr 1fr;
            }
            
            .experience-item {
                grid-template-columns: 1fr;
            }
        }
        
        @media (max-width: 768px) {
            .section {
                padding: 60px 0;
            }
            
            .section-title {
                font-size: 2rem;
            }
            
            .hero-text h1 {
                font-size: 2.5rem;
            }
            
            .nav-menu {
                position: fixed;
                top: 80px;
                right: -100%;
                background-color: var(--white);
                width: 80%;
                height: 100vh;
                flex-direction: column;
                padding: 40px 20px;
                box-shadow: -5px 0 15px rgba(0, 0, 0, 0.1);
                transition: 0.4s;
            }
            
            .nav-menu.active {
                right: 0;
            }
            
            .nav-item {
                margin: 15px 0;
            }
            
            .header-social {
                display: none;
            }
            
            .hamburger {
                display: block;
            }
            
            .footer-grid {
                grid-template-columns: 1fr;
            }
        }
        
        @media (max-width: 576px) {
            .hero-buttons {
                flex-direction: column;
            }
            
            .btn {
                width: 100%;
                text-align: center;
            }
            
            .research-grid,
            .blogs-grid {
                grid-template-columns: 1fr;
            }
        }