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

        body {
            font-family: 'Arial', sans-serif;
            line-height: 1.6;
            color: #333;
            background: #fff;
            overflow-x: hidden;
        }

        :root {
            --primary-blue: #007bff;
            --primary-purple: #6f42c1;
            --primary-teal: #20c997;
            --gradient-1: linear-gradient(135deg, #007bff 0%, #6f42c1 100%);
            --gradient-2: linear-gradient(135deg, #20c997 0%, #007bff 100%);
            --gradient-3: linear-gradient(135deg, #6f42c1 0%, #20c997 100%);
        }

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

        /* Header */
        header {
            background: #fff;
            box-shadow: 0 2px 10px rgba(0,0,0,0.1);
            position: fixed;
            width: 100%;
            top: 0;
            z-index: 1000;
            transition: all 0.3s ease;
        }

        nav {
            display: flex;
            justify-content: space-between;
            align-items: center;
            padding: 1rem 0;
        }

        .logo {
            font-size: 1.5rem;
            font-weight: bold;
            color: #000;
            text-decoration: none;
            transition: color 0.3s ease;
        }

        .logo:hover {
            background: var(--gradient-1);
            -webkit-background-clip: text;
            -webkit-text-fill-color: transparent;
            background-clip: text;
        }

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

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

        .nav-links a::after {
            content: '';
            position: absolute;
            bottom: -5px;
            left: 0;
            width: 0;
            height: 2px;
            background: var(--gradient-1);
            transition: width 0.3s ease;
        }

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

        .nav-links a:hover {
            color: #000;
        }

        /* Hero Section */
        .hero {
            height: 100vh;
            display: flex;
            align-items: center;
            justify-content: center;
            text-align: center;
            background: linear-gradient(135deg, #f8f9fa 0%, #fff 50%, #f8f9fa 100%);
            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="grid" width="10" height="10" patternUnits="userSpaceOnUse"><path d="M 10 0 L 0 0 0 10" fill="none" stroke="%23e9ecef" stroke-width="0.5"/></pattern></defs><rect width="100" height="100" fill="url(%23grid)"/></svg>');
            opacity: 0.3;
        }

        .hero::after {
            content: '';
            position: absolute;
            top: 10%;
            left: 10%;
            width: 200px;
            height: 200px;
            background: var(--gradient-1);
            border-radius: 50%;
            opacity: 0.1;
            animation: float 6s ease-in-out infinite;
        }

        .floating-shapes {
            position: absolute;
            width: 100%;
            height: 100%;
            pointer-events: none;
            z-index: 1;
        }

        .shape {
            position: absolute;
            opacity: 0.1;
            animation: float 8s ease-in-out infinite;
        }

        .shape:nth-child(1) {
            top: 20%;
            right: 20%;
            width: 100px;
            height: 100px;
            background: var(--gradient-2);
            border-radius: 30% 70% 70% 30% / 30% 30% 70% 70%;
            animation-delay: -2s;
        }

        .shape:nth-child(2) {
            bottom: 20%;
            left: 20%;
            width: 150px;
            height: 150px;
            background: var(--gradient-3);
            border-radius: 50% 50% 50% 50% / 60% 60% 40% 40%;
            animation-delay: -4s;
        }

        .shape:nth-child(3) {
            top: 60%;
            right: 10%;
            width: 80px;
            height: 80px;
            background: var(--primary-teal);
            border-radius: 20% 80% 80% 20% / 20% 20% 80% 80%;
            animation-delay: -1s;
        }

        .hero-content {
            z-index: 2;
            position: relative;
        }

        .hero h1 {
            font-size: 3.5rem;
            margin-bottom: 1rem;
            color: #000;
            opacity: 0;
            animation: fadeInUp 1s ease 0.5s forwards;
        }

        .hero .subtitle {
            font-size: 1.2rem;
            color: #666;
            margin-bottom: 2rem;
            opacity: 0;
            animation: fadeInUp 1s ease 0.7s forwards;
        }

        .hero .description {
            font-size: 1rem;
            color: #888;
            max-width: 600px;
            margin: 0 auto 2rem;
            opacity: 0;
            animation: fadeInUp 1s ease 0.9s forwards;
        }

        .cta-button {
            display: inline-block;
            padding: 12px 30px;
            background: var(--gradient-1);
            color: #fff;
            text-decoration: none;
            border-radius: 25px;
            transition: all 0.3s ease;
            opacity: 0;
            animation: fadeInUp 1s ease 1.1s forwards;
            position: relative;
            overflow: hidden;
        }

        .cta-button::before {
            content: '';
            position: absolute;
            top: 0;
            left: -100%;
            width: 100%;
            height: 100%;
            background: linear-gradient(90deg, transparent, rgba(255,255,255,0.3), transparent);
            transition: left 0.5s ease;
        }

        .cta-button:hover::before {
            left: 100%;
        }

        .cta-button:hover {
            transform: translateY(-2px);
            box-shadow: 0 10px 25px rgba(0,123,255,0.3);
        }

        /* Skills Section */
        .skills {
            padding: 100px 0;
            background: #fff;
        }

        .section-title {
            text-align: center;
            font-size: 2.5rem;
            margin-bottom: 3rem;
            color: #000;
            position: relative;
        }

        .section-title::after {
            content: '';
            position: absolute;
            bottom: -10px;
            left: 50%;
            transform: translateX(-50%);
            width: 50px;
            height: 3px;
            background: var(--gradient-1);
            border-radius: 2px;
        }

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

        .skill-category {
            background: #f9f9f9;
            padding: 2rem;
            border-radius: 15px;
            text-align: center;
            transition: all 0.3s ease;
            border: 1px solid #eee;
            position: relative;
            overflow: hidden;
        }

        .skill-category::before {
            content: '';
            position: absolute;
            top: 0;
            left: 0;
            right: 0;
            height: 3px;
            background: var(--gradient-1);
            transform: translateX(-100%);
            transition: transform 0.3s ease;
        }

        .skill-category:hover::before {
            transform: translateX(0);
        }

        .skill-category:hover {
            transform: translateY(-5px);
            box-shadow: 0 15px 35px rgba(0,123,255,0.1);
        }

        .skill-category:nth-child(2)::before {
            background: var(--gradient-2);
        }

        .skill-category:nth-child(3)::before {
            background: var(--gradient-3);
        }

        .skill-category h3 {
            font-size: 1.5rem;
            margin-bottom: 1rem;
            color: #000;
        }

        .skill-tags {
            display: flex;
            flex-wrap: wrap;
            gap: 0.5rem;
            justify-content: center;
        }

        .skill-tag {
            background: var(--gradient-1);
            color: #fff;
            padding: 0.3rem 0.8rem;
            border-radius: 20px;
            font-size: 0.9rem;
            transition: all 0.3s ease;
            position: relative;
            overflow: hidden;
        }

        .skill-tag::before {
            content: '';
            position: absolute;
            top: 0;
            left: -100%;
            width: 100%;
            height: 100%;
            background: linear-gradient(90deg, transparent, rgba(255,255,255,0.2), transparent);
            transition: left 0.5s ease;
        }

        .skill-tag:hover::before {
            left: 100%;
        }

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

        .skill-category:nth-child(2) .skill-tag {
            background: var(--gradient-2);
        }

        .skill-category:nth-child(3) .skill-tag {
            background: var(--gradient-3);
        }

        /* Projects Section */
        .projects {
            padding: 100px 0;
            background: #f8f9fa;
        }

        .projects-grid {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
            gap: 2rem;
            margin-top: 2rem;
        }

        .project-card {
            background: #fff;
            border-radius: 15px;
            overflow: hidden;
            box-shadow: 0 5px 25px rgba(0,0,0,0.1);
            transition: all 0.3s ease;
            position: relative;
        }

        .project-card::before {
            content: '';
            position: absolute;
            top: 0;
            left: 0;
            right: 0;
            height: 4px;
            background: var(--gradient-1);
            transform: scaleX(0);
            transition: transform 0.3s ease;
        }

        .project-card:hover::before {
            transform: scaleX(1);
        }

        .project-card:hover {
            transform: translateY(-8px);
            box-shadow: 0 15px 40px rgba(0,123,255,0.15);
        }

        .project-card:nth-child(2n)::before {
            background: var(--gradient-2);
        }

        .project-card:nth-child(3n)::before {
            background: var(--gradient-3);
        }

        .project-header {
            padding: 1.5rem;
            background: linear-gradient(135deg, #f8f9fa 0%, #fff 100%);
        }

        .project-title {
            font-size: 1.3rem;
            font-weight: bold;
            margin-bottom: 0.5rem;
            color: #000;
        }

        .project-status {
            display: inline-block;
            padding: 0.2rem 0.8rem;
            border-radius: 20px;
            font-size: 0.8rem;
            font-weight: 500;
            margin-bottom: 1rem;
        }

        .status-working {
            background: rgba(32, 201, 151, 0.1);
            color: var(--primary-teal);
            border: 1px solid rgba(32, 201, 151, 0.3);
        }

        .status-completed {
            background: rgba(0, 123, 255, 0.1);
            color: var(--primary-blue);
            border: 1px solid rgba(0, 123, 255, 0.3);
        }

        .project-description {
            color: #666;
            line-height: 1.6;
            margin-bottom: 1rem;
        }

        .project-tech {
            display: flex;
            flex-wrap: wrap;
            gap: 0.5rem;
        }

        .tech-tag {
            background: #f1f3f4;
            color: #333;
            padding: 0.2rem 0.6rem;
            border-radius: 12px;
            font-size: 0.8rem;
            border: 1px solid #e1e5e9;
        }

        .project-body {
            padding: 0 1.5rem 1.5rem;
        }

        /* About Section */
        .about {
            padding: 100px 0;
            background: #fff;
        }

        .about-content {
            display: grid;
            grid-template-columns: 1fr 2fr;
            gap: 3rem;
            align-items: center;
        }

        .about-text {
            font-size: 1.1rem;
            line-height: 1.8;
            color: #555;
        }

        .about-image {
            text-align: center;
        }

        .profile-placeholder {
            width: 200px;
            height: 200px;
            background: var(--gradient-1);
            border-radius: 50%;
            display: inline-flex;
            align-items: center;
            justify-content: center;
            font-size: 3rem;
            color: #fff;
            margin-bottom: 1rem;
            animation: profilePulse 3s ease-in-out infinite;
            /* Thêm background image từ gravatar */
            background-image: url('avatar.png');
            background-size: cover;
            background-position: center;
        }

        /* Contact Section */
        .contact {
            padding: 100px 0;
            background: #f8f9fa;
            text-align: center;
        }

        .contact-info {
            display: flex;
            justify-content: center;
            gap: 2rem;
            margin-top: 2rem;
            flex-wrap: wrap;
        }

        .contact-item {
            background: #fff;
            padding: 1.5rem;
            border-radius: 15px;
            transition: all 0.3s ease;
            border: 1px solid #eee;
            position: relative;
            overflow: hidden;
        }

        .contact-item::before {
            content: '';
            position: absolute;
            top: 0;
            left: 0;
            right: 0;
            height: 3px;
            background: var(--gradient-1);
            transform: translateX(-100%);
            transition: transform 0.3s ease;
        }

        .contact-item:hover::before {
            transform: translateX(0);
        }

        .contact-item:hover {
            transform: translateY(-5px);
            box-shadow: 0 10px 30px rgba(0,123,255,0.1);
        }

        .contact-item:nth-child(2)::before {
            background: var(--gradient-2);
        }

        .contact-item:nth-child(3)::before {
            background: var(--gradient-3);
        }

        .contact-item h4 {
            margin-bottom: 0.5rem;
            color: #000;
        }

        .contact-item p {
            color: #666;
        }

        /* Footer */
        footer {
            background: linear-gradient(135deg, #000 0%, #333 100%);
            color: #fff;
            text-align: center;
            padding: 2rem 0;
            position: relative;
            overflow: hidden;
        }

        footer::before {
            content: '';
            position: absolute;
            top: 0;
            left: 0;
            right: 0;
            height: 2px;
            background: var(--gradient-1);
        }

        /* Animations */
        @keyframes fadeInUp {
            from {
                opacity: 0;
                transform: translateY(30px);
            }
            to {
                opacity: 1;
                transform: translateY(0);
            }
        }

        @keyframes float {
            0%, 100% {
                transform: translateY(0px) rotate(0deg);
            }
            50% {
                transform: translateY(-20px) rotate(180deg);
            }
        }

        @keyframes profilePulse {
            0%, 100% {
                transform: scale(1);
                box-shadow: 0 0 0 0 rgba(0, 123, 255, 0.7);
            }
            50% {
                transform: scale(1.05);
                box-shadow: 0 0 0 10px rgba(0, 123, 255, 0);
            }
        }

        /* Mobile Responsiveness */
        @media (max-width: 768px) {
            .nav-links {
                display: none;
            }

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

            .hero .subtitle {
                font-size: 1rem;
            }

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

            .about-content {
                grid-template-columns: 1fr;
                text-align: center;
            }

            .contact-info {
                flex-direction: column;
                align-items: center;
            }

            .contact-item {
                width: 100%;
                max-width: 300px;
            }
        }

        @media (max-width: 480px) {
            .container {
                padding: 0 15px;
            }

            .hero h1 {
                font-size: 2rem;
            }

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