:root {
            --primary: #6a0dad;
            --secondary: #ffffff;
            --dark: #121212;
            --light-dark: #1e1e1e;
        }

        * {
            margin: 0;
            padding: 0;
            box-sizing: border-box;
            font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
        }

        html {
            overflow-x: hidden;
        }

        body {
            background: linear-gradient(135deg, #f5f5f5 0%, #e8d9ff 50%, #f5f5f5 100%);
            background-attachment: fixed;
            background-color: var(--secondary);
            color: var(--dark);
            line-height: 1.6;

            overflow-x: hidden;
            max-width: 100vw;
        }

        /* animation classes */
        .fade-in {
            opacity: 0;
            transform: translateY(30px);
            transition: opacity 0.6s ease-out, transform 0.6s ease-out;
        }

        .slide-in-up {
            opacity: 0;
            transform: translateY(10px);
            transition: opacity 0.6s ease, transform 0.5s ease;
        }

        .slide-in-up.visible {
            opacity: 1;
            transform: translateY(0);
        }

        .fade-in.visible {
            opacity: 1;
            transform: translateY(0);
        }

        .slide-in-left {
            opacity: 0;
            transform: translateX(-200px);
            transition: opacity 0.6s ease, transform 1s ease;
        }

        .slide-in-left.visible {
            opacity: 1;
            transform: translateX(0);
        }

        .slide-in-right {
            opacity: 0;
            transform: translateX(200px);
            transition: opacity 0.6s ease, transform 1s ease;
        }

        .slide-in-right.visible {
            opacity: 1;
            transform: translateX(0);
        }

        /* navigation */
        header {
            background-color: var(--secondary);
            box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
            position: fixed;
            width: 100%;
            max-width: 100vw;
            top: 0;
            left: 0;
            right: 0;
            top: 0;
            z-index: 1000;
            transition: all 0.5s ease;
            overflow-x: hidden;
            /* to prevent horizontal overflow */
        }

        header.shrink {
            padding: 1rem 0;
        }

        header.shrink nav {
            padding: 0 5%;
        }

        nav {
            display: flex;
            justify-content: space-between;
            align-items: center;
            padding: 1rem 5%;
            max-width: 1200px;
            margin: 0 auto;
            width: 100%;
            /* Ensure full width */
        }

        /* stefen logo */
        .logo img {
            max-height: 40px;
            max-width: 150px;
        }

        .nav-links {
            display: flex;
            list-style: none;
        }

        .nav-links li {
            margin-left: 2rem;
        }

        .nav-links a {
            color: var(--dark);
            text-decoration: none;
            font-weight: 500;
            transition: color 0.3s;
        }

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

        .mobile-menu-btn {
            display: none;
            background: none;
            border: none;
            font-size: 1.5rem;
            color: var(--dark);
            cursor: pointer;
        }

        /* all section base size */
        section {
            padding: 4rem 5%;
            min-height: 100vh;
            max-width: 1200px;
            margin: 0 auto;
        }

        /* home section */
        #home {
            display: flex;
            align-items: center;
            justify-content: space-between;
            flex-wrap: wrap;
        }

        .home-content {
            flex: 1;
            min-width: 300px;
        }

        .home-image {
            flex: 1;
            min-width: 300px;
            text-align: center;
        }

        .home-image img {
            max-width: 70%;
            border-radius: 50%;
            box-shadow: 0 5px 15px var(--primary);
        }

        h1 {
            font-size: 2.5rem;
            margin-bottom: 1rem;
            color: var(--primary);
        }

        h2 {
            font-size: 2rem;
            margin-bottom: 2rem;
            color: var(--primary);
            text-align: center;
        }

        p {
            margin-bottom: 1.5rem;
            color: var(--dark);
            font-size: 1.1rem;
        }

        .btn {
            display: inline-block;
            background-color: var(--primary);
            color: var(--secondary);
            padding: 0.8rem 1.5rem;
            border-radius: 5px;
            text-decoration: none;
            font-weight: 500;
            transition: background-color 0.3s;
            border: none;
            cursor: pointer;
        }

        .btn:hover {
            background-color: #5a0788;
        }

        /* skills section */
        .skills-container {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(350px, 3fr));
            gap: 2rem;
            margin-top: 2rem;
        }

        .skill-card {
            /* background-color: var(--secondary); */
            padding: 1rem;
            border-radius: 10px;
            box-shadow: 0 5px 15px rgba(0, 0, 0, 0.05);
            text-align: center;
            transition: transform 0.3s, box-shadow 0.3s;

        }

        /* .skill-card:hover {
            transform: translateY(-10px);
            box-shadow: 0 15px 30px rgba(0, 0, 0, 0.1);
        } */

        .skill-card i {
            font-size: 3rem;
            margin-bottom: 1rem;
            color: var(--primary);
        }

        .skill-card img {
            max-height: 80px;
            max-width: 80px;
            margin-top: 10px;
            border-radius: 10px;
            padding: 5px;
            transition: transform 0.3s, box-shadow 0.3s;
        }

        .skill-card img:hover {
            transform: translateY(-10px);
            box-shadow: 0 15px 30px rgba(0, 0, 0, 0.1);
        }

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

        .project-card {
            background-color: var(--secondary);
            border-radius: 10px;
            overflow: hidden;
            box-shadow: 0 5px 15px rgba(0, 0, 0, 0.05);
            transition: transform 0.3s, box-shadow 0.3s;
        }

        .project-card:hover {
            transform: translateY(-10px);
            box-shadow: 0 15px 30px rgba(0, 0, 0, 0.1);
        }

        .project-image {
            height: 200px;
            overflow: hidden;
        }

        .project-image img {
            width: 100%;
            height: 100%;
            object-fit: cover;
            transition: transform 0.3s;
        }

        .project-card:hover .project-image img {
            transform: scale(1.1);
        }

        .project-info {
            padding: 1.5rem;
        }

        .project-info h3 {
            margin-bottom: 0.5rem;
            color: var(--primary);
        } */


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

        .timeline::after {
            content: '';
            position: absolute;
            width: 2px;
            background-color: var(--primary);
            top: 0;
            bottom: 0;
            left: 50%;
            margin-left: -1px;
        }

        .timeline-item {
            padding: 10px 40px;
            position: relative;
            width: 50%;
            box-sizing: border-box;
            z-index: 999;
        }

        .timeline-item::after {
            content: '';
            position: absolute;
            width: 20px;
            height: 20px;
            background-color: var(--secondary);
            border: 4px solid var(--primary);
            border-radius: 50%;
            top: 15px;
            z-index: 1;
        }

        .left {
            left: 0;
        }

        .right {
            left: 50%;
        }

        .left::after {
            right: -10px;
        }

        .right::after {
            left: -10px;
        }

        .timeline-content {
            padding: 20px;
            background-color: var(--secondary);
            border-radius: 10px;
            box-shadow: 0 5px 15px rgba(0, 0, 0, 0.05);
        }

        .timeline-content p {
            font-size: 1rem;
        }


        /* footer section */
        footer {
            background-color: var(--dark);
            color: var(--secondary);
            text-align: center;
            padding: 2rem 5%;
        }

        footer p {
            color: var(--secondary)
        }

        .social-links {
            margin: 1rem 0;
        }

        .social-links a {
            color: var(--secondary);
            margin: 0 0.5rem;
            font-size: 1.5rem;
            transition: color 0.3s;
        }

        .social-links a:hover {
            color: var(--primary);
        }


        /* tablet size */
        @media screen and (max-width: 768px) {
            .nav-links {
                display: none;
                flex-direction: column;
                /* width: 100%; */
                position: fixed;
                top:80px;
                left: 0;
                right: 0;
                background-color: var(--secondary);
                padding: 1rem 5%;
                box-shadow: 0 5px 15px rgba(0, 0, 0, 0.1);
                max-height: calc(100vh - 70px);
                overflow-y: auto;
                z-index: 999;
            }

            .nav-links.active {
                display: flex;
            }

            .nav-links li {
                margin: 1rem 0;
                text-align: center;
            }

            .mobile-menu-btn {
                display: block;
            }

            .timeline::after {
                left: 31px;
            }

            .timeline-item {
                width: 100%;
                padding-left: 70px;
                padding-right: 25px;
            }

            .timeline-item::after {
                left: 21px;
            }

            .left,
            .right {
                left: 0;
            }

            /* hidden profile in tablet size */
            .home-image {
                display: none;

            }

            .home-content p {
                text-align: justify;
            }
        }



        /* phone size */
        @media screen and (max-width: 640px) {

            /* hidden profile in phone size */
            .home-image {
                display: none;
            }

            .home-content h1 {
                text-align: center;
            }

            .home-content p {
                text-align: justify;
                padding: 0px 20px 0px 20px;
                
            }

            .home-content .home-button {
                justify-content: center;
                text-align: center;
                padding: 20px;
                
            }
        }