:root {
    --bg-color-light: #f8f9fa;
    --text-color-light: #212529;
    --card-bg-light: #ffffff;
    --header-bg-light: rgba(255, 255, 255, 0.85);
    --primary-color-light: #fd7e14;
    --primary-hover-light: #e86100;

    --bg-color-dark: #0a192f;
    --text-color-dark: #ccd6f6;
    --card-bg-dark: #112240;
    --header-bg-dark: rgba(17, 34, 64, 0.85);
    --primary-color-dark: #fd7e14;
    --primary-hover-dark: #ff9a4a;

    --bg-color: var(--bg-color-light);
    --text-color: var(--text-color-light);
    --card-bg: var(--card-bg-light);
    --header-bg: var(--header-bg-light);
    --primary-color: var(--primary-color-light);
    --primary-hover: var(--primary-hover-light);

    --font-family: 'Inter', sans-serif;
    --transition-speed: 0.25s ease-in-out;
}

body.dark-theme {
    --bg-color: var(--bg-color-dark);
    --text-color: var(--text-color-dark);
    --card-bg: var(--card-bg-dark);
    --header-bg: var(--header-bg-dark);
    --primary-color: var(--primary-color-dark);
    --primary-hover: var(--primary-hover-dark);
}

body {
    font-family: var(--font-family);
    margin: 0;
    background-color: var(--bg-color);
    color: var(--text-color);
    transition: background-color var(--transition-speed), color var(--transition-speed);
}

html {
    scroll-behavior: smooth;
}

a {
    text-decoration: none;
    color: var(--primary-color);
    transition: color var(--transition-speed);
}

img {
    max-width: 100%;
    height: auto;
    display: block;
}

.header {
    background-color: var(--header-bg);
    backdrop-filter: blur(10px);
    box-shadow: 0 2px 4px rgba(0,0,0,0.05);
    position: fixed;
    width: 100%;
    top: 0;
    z-index: 1000;
    transition: background-color var(--transition-speed);
}

.navbar {
    display: flex;
    justify-content: space-between;
    align-items: center;
    max-width: 1100px;
    margin: 0 auto;
    padding: 0 20px;
    height: 70px;
}

.nav-logo {
    font-weight: 700;
    font-size: 1.5rem;
    color: var(--text-color);
}

.nav-menu {
    display: flex;
    list-style: none;
    margin: 0;
    padding: 0;
    gap: 30px;
    flex-wrap: wrap;
}

.nav-link {
    color: var(--text-color);
    font-weight: 500;
    transition: color var(--transition-speed);
}

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

.theme-switcher {
    display: flex;
    align-items: center;
}

.switch-label {
    cursor: pointer;
    position: relative;
    display: inline-block;
    width: 50px;
    height: 26px;
}

.switch-label input {
    opacity: 0;
    width: 0;
    height: 0;
}

.slider {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background-color: #ccc;
    border-radius: 26px;
    transition: var(--transition-speed);
}

.slider:before {
    position: absolute;
    content: "";
    height: 20px;
    width: 20px;
    left: 3px;
    bottom: 3px;
    background-color: white;
    border-radius: 50%;
    transition: var(--transition-speed);
}

input:checked + .slider {
    background-color: var(--primary-color);
}

input:checked + .slider:before {
    transform: translateX(24px);
}

section {
    padding: 35px 25px;
    max-width: 1000px;
    margin: 0 auto;
    text-align: center;
}

h1, h2, h3 {
    color: var(--text-color);
    font-weight: 700;
}

h1 { font-size: 3rem; margin-bottom: 1rem; }
h2 { font-size: 2.5rem; margin-bottom: 30px; }
.hero p { font-size: 1.1rem; color: var(--text-color); opacity: 0.8; }

.hero {
    padding-top: 120px;
    padding-bottom: 120px;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    justify-content: center;
    box-sizing: border-box;
}

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

.btn {
    display: inline-block;
    padding: 12px 28px;
    background-color: var(--primary-color);
    color: #fff;
    border: 2px solid var(--primary-color);
    border-radius: 8px;
    font-weight: 500;
    transition: all var(--transition-speed);
}

.btn:hover {
    background-color: var(--primary-hover);
    border-color: var(--primary-hover);
    transform: translateY(-3px);
    box-shadow: 0 4px 15px rgba(0,0,0,0.2);
}

.btn-secondary {
    display: inline-block;
    padding: 12px 28px;
    border: 2px solid var(--text-color);
    color: var(--text-color);
    background-color: transparent;
    border-radius: 8px;
    font-weight: 500;
    transition: all var(--transition-speed);
}

.btn-secondary:hover {
    background-color: var(--text-color);
    color: var(--bg-color);
    transform: translateY(-3px);
    box-shadow: 0 4px 15px rgba(0,0,0,0.2);
}

.about {
    background-color: var(--card-bg);
    border-radius: 12px;
    padding: 40px;
    box-shadow: 0 8px 30px rgba(0,0,0,0.08);
    max-width: 800px;
    padding-top: 70px;
    margin-top: -70px;
}

.about p {
    font-size: 1.1rem;
    line-height: 1.7;
    opacity: 0.8;
}

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

.about-photo-container {
    flex-shrink: 0;
}

.about-photo {
    width: 300px;
    height: 300px;
    border-radius: 50%;
    object-fit: cover;
    object-position: 50% 30%;
    border: 5px solid var(--card-bg);
    box-shadow: 0 10px 30px rgba(0,0,0,0.15);
}

.technologies {
    padding-top: 100px;
    margin-top: -70px;
    padding-bottom: 50px;
}

.tech-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(100px, 1fr));
    gap: 20px;
    justify-items: center;
}

.tech-item {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 12px;
    transition: transform var(--transition-speed);
    position: relative;
}

.tech-item img {
    width: 60px;
    height: 60px;
}

.tech-item span {
    font-size: 0.9rem;
    font-weight: 500;
    opacity: 0.8;
}

.tech-item:hover {
    transform: translateY(-8px);
}

.learning-badge {
    position: absolute;
    top: -5px;
    right: -5px;
    background: #ffc107;
    color: #333;
    font-size: 0.6rem;
    padding: 2px 6px;
    border-radius: 4px;
    font-weight: bold;
    box-shadow: 0 2px 4px rgba(0,0,0,0.2);
    z-index: 10;
}

.projects {
    padding-top: 100px; 
    margin-top: -70px;
}

.project-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 25px;
    text-align: left;
}

.project-card {
    background-color: var(--card-bg);
    border-radius: 12px;
    box-shadow: 0 8px 30px rgba(0,0,0,0.08);
    overflow: hidden;
    transition: transform var(--transition-speed), box-shadow var(--transition-speed), border-color var(--transition-speed);
    display: flex;
    flex-direction: column;
    border: 1px solid transparent;
}

.project-card:hover {
    transform: translateY(-10px);
    box-shadow: 0 12px 40px rgba(0,0,0,0.12);
    border-color: var(--primary-color);
}

.project-card img {
    width: 100%;
    height: 220px;
    object-fit: cover;
}

.project-content {
    padding: 25px;
    display: flex;
    flex-direction: column;
    flex-grow: 1;
}

.project-content h3 {
    margin-top: 0;
    margin-bottom: 10px;
}

.project-content p {
    flex-grow: 1;
    margin-bottom: 20px;
    font-size: 0.95rem;
    line-height: 1.6;
    opacity: 0.8;
}

.project-links {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-top: auto;
}

.project-links .btn-secondary {
    padding: 8px 18px;
    border-color: var(--primary-color);
    color: var(--primary-color);
    font-size: 0.9rem;
    font-weight: 500;
}

.project-links .btn-secondary:hover {
    background-color: var(--primary-color);
    color: #fff;
}

.github-icon {
    width: 28px;
    height: 28px;
    color: var(--text-color);
    transition: color var(--transition-speed), transform var(--transition-speed);
}

.github-link:hover .github-icon {
    color: var(--primary-color);
    transform: scale(1.1);
}

.certificates {
    padding-top: 100px;
    margin-top: -70px;
}

.certificate-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 25px;
    text-align: left;
}

.certificate-card {
    background-color: var(--card-bg);
    border-radius: 12px;
    box-shadow: 0 8px 30px rgba(0,0,0,0.08);
    transition: transform var(--transition-speed), box-shadow var(--transition-speed), border-color var(--transition-speed);
    display: flex;
    flex-direction: column;
    border: 1px solid transparent;
    justify-content: center;
    min-height: 180px;
    padding: 25px;
    box-sizing: border-box;
}

.certificate-card:hover {
    transform: translateY(-10px);
    box-shadow: 0 12px 40px rgba(0,0,0,0.12);
    border-color: var(--primary-color);
}

.certificate-card h3 {
    margin-top: 0;
}
.certificate-card p {
    font-size: 0.9rem;
    opacity: 0.7;
    margin-bottom: 15px;
}
.certificate-card a {
    font-weight: 500;
}

.contact {
    padding-top: 100px;
    margin-top: -70px;
}

.footer {
    text-align: center;
    padding: 30px 20px;
    margin-top: 40px;
    border-top: 1px solid rgba(128, 128, 128, 0.2);
    font-size: 0.9rem;
}

.contact-form {
    display: flex;
    flex-direction: column;
    gap: 15px;
    max-width: 700px;
    margin: 30px auto 0 auto;
    text-align: left;
}

.contact-form input,
.contact-form textarea {
    width: 100%;
    padding: 12px;
    font-family: var(--font-family);
    font-size: 1rem;
    color: var(--text-color);
    background-color: var(--card-bg);
    border: 2px solid rgba(128, 128, 128, 0.2);
    border-radius: 8px;
    transition: border-color var(--transition-speed);
    box-sizing: border-box;
}

.contact-form input:focus,
.contact-form textarea:focus {
    outline: none;
    border-color: var(--primary-color);
}

.contact-form textarea {
    resize: vertical;
}

.contact-form button {
    align-self: flex-start;
    cursor: pointer;
}

@media (max-width: 900px) {
    .navbar {
        height: auto;
        flex-wrap: wrap;
        justify-content: center;
        padding-top: 10px;
        padding-bottom: 10px;
        gap: 15px;
    }
    .nav-menu {
        gap: 20px;
        justify-content: center;
        width: 100%;
        order: 3;
    }
    .nav-logo {
        order: 1;
    }
    .theme-switcher {
        order: 2;
    }
}

@media (max-width: 768px) {
    h1 { font-size: 2.5rem; }
    h2 { font-size: 2rem; }
    section { padding: 30px 20px; }
    
    .hero {
        padding-top: 100px;
        padding-bottom: 80px;
        text-align: center;
    }
    .hero-buttons {
        flex-direction: column;
        align-items: center;
        gap: 20px;
    }
    .btn, .btn-secondary {
        width: 80%;
        max-width: 320px;
        text-align: center;
    }
    .about {
        padding: 30px;
        padding-top: 90px;
    }
    .about-container {
        flex-direction: column;
        text-align: center;
        gap: 30px;
    }
    .about-photo {
        width: 220px;
        height: 220px;
    }
    .project-grid {
        grid-template-columns: 1fr;
    }
    .certificate-grid {
        grid-template-columns: 1fr;
    }
    .contact-form button {
        align-self: stretch;
    }

    .technologies, .projects, .certificates, .contact {
        padding-top: 90px; 
    }
}

@media (max-width: 480px) {
    .navbar {
        padding: 15px;
        justify-content: space-between;
    }
    .nav-menu {
        gap: 15px;
    }
    .nav-link {
        font-size: 0.9rem;
    }
    h1 { font-size: 2.1rem; }
    h2 { font-size: 1.75rem; }
    h3 { font-size: 1.25rem; }
    section { padding: 25px 15px; }
    
    .hero {
        padding-top: 80px;
        padding-bottom: 60px;
    }
    .hero p {
        font-size: 1rem;
    }
    .btn, .btn-secondary {
        width: 100%;
        max-width: none;
    }
    .about {
        padding: 25px;
        padding-top: 85px;
    }
    .about-photo {
        width: 180px;
        height: 180px;
    }
    .about p {
        font-size: 1rem;
    }
    .project-content {
        padding: 20px;
    }
    .tech-grid {
        gap: 30px;
        grid-template-columns: repeat(auto-fit, minmax(80px, 1fr));
    }
    
    .technologies, .projects, .certificates, .contact {
        padding-top: 85px; 
    }
}