:root {
    --primary: #2c3e50;
    --secondary: #3498db;
    --accent: #e74c3c;
    --light: #ecf0f1;
    --dark: #1a252f;
    --text: #333;
    --text-light: #7f8c8d;
    --background: #f9f9f9;
    --transition: all 0.3s ease;
}

/* Theme: Forest Calm */
.theme-forest {
    --primary: #2e4600;
    --secondary: #486b00;
    --accent: #a2c523;
    --light: #f0f5e4;
    --dark: #1b2e0e;
    --text: #2e4600;
    --text-light: #6e8b3d;
    --background: #f0f5e4;
}

/* Theme: Default (Fallback) */
.theme-default {
    --primary: #2c3e50;
    --secondary: #3498db;
    --accent: #e74c3c;
    --light: #ecf0f1;
    --dark: #1a252f;
    --text: #333;
    --text-light: #7f8c8d;
    --background: #f9f9f9;
}

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

/* Base Typography & Layout */
body {
    font-family: Georgia, serif;
    line-height: 1.6;
    color: var(--text);
    background-color: var(--background);
    overflow-x: hidden;
}

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

section {
    padding: 80px 0;
    background-color: var(--background);
}

/* Header & Navigation */
header {
    background-color: white;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
    position: fixed;
    width: 100%;
    top: 0;
    z-index: 1000;
}

nav {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 20px 0;
}

.logo {
    font-size: 1.8rem;
    font-weight: 700;
    color: var(--primary);
}

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

.nav-links li {
    margin-left: 30px;
}

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

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

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

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

.hamburger {
    display: none;
    cursor: pointer;
}

.hamburger div {
    width: 25px;
    height: 3px;
    background-color: var(--primary);
    margin: 5px;
    transition: var(--transition);
}

/* Hero Section */
#hero {
    height: 100vh;
    display: flex;
    align-items: center;
    background: linear-gradient(rgba(0,0,0,0.7), rgba(0,0,0,0.7)),
        url('https://source.unsplash.com/1600x900/?programming') no-repeat center center/cover;
    color: white;
    text-align: center;
    padding-top: 60px;
}

.hero-content {
    max-width: 800px;
    margin: 0 auto;
}

.hero-content h1 {
    font-size: 3.5rem;
    margin-bottom: 20px;
    animation: fadeInDown 1s ease;
}

.hero-content p {
    font-size: 1.2rem;
    margin-bottom: 30px;
    animation: fadeIn 1.5s ease;
}

.btn {
    display: inline-block;
    background: var(--secondary);
    color: white;
    padding: 12px 30px;
    border-radius: 50px;
    text-decoration: none;
    font-weight: 500;
    transition: var(--transition);
    animation: fadeInUp 1s ease;
}

.btn:hover {
    background: var(--primary);
    transform: translateY(-3px);
    box-shadow: 0 10px 20px rgba(0, 0, 0, 0.2);
}

/* Section Titles */
.section-title {
    text-align: center;
    margin-bottom: 60px;
}

.section-title h2 {
    font-size: 2.5rem;
    color: var(--primary);
    position: relative;
    display: inline-block;
    padding-bottom: 15px;
}

.section-title h2::after {
    content: '';
    position: absolute;
    width: 70px;
    height: 3px;
    background-color: var(--secondary);
    bottom: 0;
    left: 50%;
    transform: translateX(-50%);
}

        .about-content {
            display: flex;
            align-items: center;
            gap: 50px;
        }

        .about-image {
    flex: 1;
    border-radius: 10px;
    overflow: hidden;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.1);
    transition: var(--transition);
}

.about-image img {
    width: auto;
    height: auto;
    object-fit: cover;
    transition: var(--transition);
}

.about-image:hover {
    transform: translateY(-10px);
    box-shadow: 0 15px 30px rgba(0, 0, 0, 0.2);
}

.about-image:hover img {
    transform: scale(1.05);
}


        .about-text {
            flex: 1;
        }

        .about-text h3 {
            font-size: 1.8rem;
            margin-bottom: 20px;
            color: var(--primary);
        }

        .about-text p {
            margin-bottom: 20px;
            color: var(--text-light);
        }

        .about-text ul {
            list-style: none;
            padding-left: 0;
        }
        .about-text ul li {
            margin-bottom: 10px;
            color: var(--text);
            font-size: 1rem;
        }
        .about-text ul li i {
            color: var(--secondary);
            margin-right: 10px;
        }
        
        /* Skills Section */
        #skills {
            background-color: #f5f7fa;
        }

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

        .skill-card {
            background-color: white;
            padding: 30px;
            border-radius: 10px;
            text-align: center;
            box-shadow: 0 5px 15px rgba(0,0,0,0.05);
            transition: var(--transition);
        }

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

        .skill-card i {
            font-size: 3rem;
            color: var(--secondary);
            margin-bottom: 20px;
        }

        .skill-card h3 {
            font-size: 1.3rem;
            margin-bottom: 15px;
            color: var(--primary);
        }

        .skill-card p {
            color: var(--text-light);
            font-size: 0.9rem;
        }

        /* Projects Section */
        #projects {
            background-color: white;
        }

        .projects-grid {
            display: grid;
            grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
            gap: 30px;
        }

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

        .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: var(--transition);
        }

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

        .project-info {
            padding: 20px;
        }

        .project-info h3 {
            font-size: 1.3rem;
            margin-bottom: 10px;
            color: var(--primary);
        }

        .project-info p {
            color: var(--text-light);
            margin-bottom: 20px;
            font-size: 0.9rem;
        }

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

        .project-links a {
            color: var(--secondary);
            text-decoration: none;
            font-weight: 500;
            transition: var(--transition);
        }

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

        /* Achievement Section */
        .achievement-list,
        .certification-list {
           list-style: none;
           padding-left: 0;
           margin-top: 1rem;
        }

        .achievement-list li,
        .certification-list li {
           padding: 0.5rem 0;
           font-size: 1rem;
           border-bottom: 1px solid #eee;
        }

        .achievement-list li:last-child,
        .certification-list li:last-child {
            border-bottom: none;
        }

        /* Education Section */
        #education {
            background-color: #f5f7fa;
        }

        .education-grid {
            display: grid;
            grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
            gap: 30px;
        }

        .education-item {
            background-color: white;
            padding: 20px;
            border-radius: 10px;
            box-shadow: 0 5px 15px rgba(0,0,0,0.05);
            transition: var(--transition);
        }

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

        .education-grid {
           display: grid;
           grid-template-columns: 1fr;
           gap: 1.5rem;
        }

        .education-item h4 {
            font-size: 1.2rem;
            color: var(--primary);
            margin-bottom: 0.5rem;
        }

        .education-item p {
            color: var(--text-light);
            margin-bottom: 0.5rem;
        }

        .education-item h3 {
           margin: 0.3rem 0;
           font-weight: 600;
           font-size: 1.5rem;
           color: var(--primary);
        }

        .education-item span {
            font-size: 0.9rem;
            color: var(--text-light);
        }
        
        /* Contact Section */
        #contact {
            background-color: #f5f7fa;
        }

        .contact-container {
            display: flex;
            gap: 50px;
        }

        .contact-info {
            flex: 1;
        }

        .contact-info h3 {
            font-size: 1.8rem;
            margin-bottom: 20px;
            color: var(--primary);
        }

        .contact-info p {
            margin-bottom: 30px;
            color: var(--text-light);
        }

        .contact-links {
            display: flex;
            flex-direction: column;
            gap: 15px;
        }

        .contact-links a {
            display: flex;
            align-items: center;
            color: var(--text);
            text-decoration: none;
            transition: var(--transition);
        }

        .contact-links a:hover {
            color: var(--secondary);
        }

        .contact-links i {
            margin-right: 10px;
            color: var(--secondary);
        }

        .contact-form {
            flex: 1;
            background-color: white;
            padding: 30px;
            border-radius: 10px;
            box-shadow: 0 5px 15px rgba(0,0,0,0.05);
        }

        .form-group {
            margin-bottom: 20px;
        }

        .form-group label {
            display: block;
            margin-bottom: 8px;
            color: var(--primary);
            font-weight: 500;
        }

        .form-group input,
        .form-group textarea {
            width: 100%;
            padding: 12px;
            border: 1px solid #ddd;
            border-radius: 5px;
            font-family: inherit;
            transition: var(--transition);
        }

        .form-group input:focus,
        .form-group textarea:focus {
            border-color: var(--secondary);
            outline: none;
            box-shadow: 0 0 0 3px rgba(52, 152, 219, 0.2);
        }

        .form-group textarea {
            height: 150px;
            resize: vertical;
        }

        .btn-submit {
            background-color: var(--secondary);
            color: white;
            padding: 12px 30px;
            border-radius: 50px;
            border: none;
            cursor: pointer;
            font-weight: 500;
            transition: var(--transition);
        }
        .btn-submit:hover {
            background-color: var(--primary);
            transform: translateY(-3px);
            box-shadow: 0 10px 20px rgba(0,0,0,0.2);
        }

        /* Footer */
        footer {
            background-color: var(--dark);
            color: white;
            padding: 40px 0;
            text-align: center;
        }

        .footer-content {
            display: flex;
            flex-direction: column;
            align-items: center;
        }

        .social-links {
            display: flex;
            gap: 20px;
            margin-bottom: 20px;
        }

        .social-links a {
            color: white;
            font-size: 1.5rem;
            transition: var(--transition);
        }

        .social-links a:hover {
            color: var(--secondary);
            transform: translateY(-5px);
        }

        .footer-text {
            font-size: 0.9rem;
            color: var(--text-light);
        }

        /* Scroll to Top Button */
        .scroll-to-top {
            position: fixed;
            bottom: 20px;
            right: 20px;
            background-color: var(--secondary);
            color: white;
            width: 50px;
            height: 50px;
            border-radius: 50%;
            display: flex;
            justify-content: center;
            align-items: center;
            text-decoration: none;
            opacity: 0;
            visibility: hidden;
            transition: var(--transition);
            z-index: 999;
        }
        .scroll-to-top.visible {
            opacity: 1;
            visibility: visible;
        }
        .scroll-to-top:hover {
            background-color: var(--primary);
            transform: translateY(-5px);
        }
        .scroll-to-top i {
            font-size: 1.5rem;
        }

        /* Back to Top Button */
        .back-to-top {
            position: fixed;
            bottom: 30px;
            right: 30px;
            background-color: var(--secondary);
            color: white;
            width: 50px;
            height: 50px;
            border-radius: 50%;
            display: flex;
            justify-content: center;
            align-items: center;
            text-decoration: none;
            opacity: 0;
            visibility: hidden;
            transition: var(--transition);
            z-index: 999;
        }

        .back-to-top.visible {
            opacity: 1;
            visibility: visible;
        }

        .back-to-top:hover {
            background-color: var(--primary);
            transform: translateY(-5px);
        }

        .back-to-top i {
            font-size: 1.5rem;
        }

      /* Animations */
@keyframes fadeIn {
    from { opacity: 0; }
    to { opacity: 1; }
}

@keyframes fadeInDown {
    from { opacity: 0; transform: translateY(-30px); }
    to { opacity: 1; transform: translateY(0); }
}

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

/* Responsive Design */
@media (max-width: 992px) {
    .about-content,
    .contact-container {
        flex-direction: column;
    }
}

@media (max-width: 768px) {
    .nav-links {
        position: absolute;
        top: 80px;
        left: 0;
        right: 0;
        background-color: white;
        flex-direction: column;
        align-items: center;
        padding: 20px 0;
        box-shadow: 0 5px 15px rgba(0, 0, 0, 0.1);
        transform: translateY(-150%);
        transition: var(--transition);
        z-index: 999;
    }

    .nav-links.active {
        transform: translateY(0);
    }

    .nav-links li {
        margin: 15px 0;
    }

    .hamburger {
        display: block;
    }

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

    .section-title h2 {
        font-size: 2rem;
    }
}

@media (max-width: 576px) {
    .skills-grid,
    .projects-grid {
        grid-template-columns: 1fr;
    }

    .contact-form {
        padding: 20px;
    }

    .form-group input,
    .form-group textarea {
        padding: 10px;
    }

    .footer-text {
        font-size: 0.8rem;
    }

    .social-links a {
        font-size: 1.2rem;
    }
}

@media (max-width: 400px) {
    .hero-content h1 {
        font-size: 2rem;
    }

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

    .btn {
        padding: 10px 20px;
        font-size: 0.9rem;
    }

    .footer-content {
        padding: 20px;
    }
}

@media (max-width: 320px) {
    .hero-content h1 {
        font-size: 1.8rem;
    }

    .btn {
        padding: 8px 15px;
        font-size: 0.8rem;
    }

    .social-links a {
        font-size: 0.9rem;
    }

    .footer-content {
        padding: 10px;
    }
}

/* Theme Switcher */
.theme-switcher {
    position: relative;
    top: 20px;
    right: 20px;
    display: flex;
    gap: 10px;
}

.theme-switcher button {
    background-color: var(--secondary);
    color: white;
    border: none;
    padding: 10px 15px;
    border-radius: 5px;
    cursor: pointer;
    transition: var(--transition);
}

.theme-switcher button:hover {
    background-color: var(--primary);
}

.theme-switcher button:focus {
    outline: none;
    box-shadow: 0 0 0 3px rgba(52, 152, 219, 0.2);
}

.theme-switcher button.active {
    background-color: var(--primary);
}

.theme-switcher button.active:hover {
    background-color: var(--secondary);
}