:root {
    --primary-color: #0a66c2;
    --secondary-color: #2977c9;
    --accent-color: #f3f6f9;
    --text-color: #333;
    --light-text: #666;
    --white: #fff;
    --dark-bg: #1a1a2e;
    --dark-text: #e6e6e6;
    --transition: all 0.3s ease;
    --shadow: 0 5px 15px rgba(0, 0, 0, 0.1);
    --border-radius: 8px;
}

/* Dark Mode Variables */
.dark-mode {
    --primary-color: #4f8fda;
    --secondary-color: #60a5fa;
    --accent-color: #213043;
    --text-color: #e6e6e6;
    --light-text: #b0b0b0;
    --white: #1e293b;
    --shadow: 0 5px 15px rgba(0, 0, 0, 0.5);
}

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

body {
    font-family: 'Segoe UI', Roboto, 'Helvetica Neue', sans-serif;
    line-height: 1.6;
    color: var(--text-color);
    background-color: #f9fafc;
    transition: var(--transition);
    scroll-behavior: smooth;
}

body.dark-mode {
    background-color: var(--dark-bg);
    color: var(--dark-text);
}

h1, h2, h3, h4 {
    font-weight: 700;
    line-height: 1.2;
    margin-bottom: 1rem;
    color: var(--text-color);
}

p {
    margin-bottom: 1rem;
    color: var(--light-text);
}

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

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

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 1.5rem;
}

.btn {
    display: inline-block;
    background-color: var(--primary-color);
    color: var(--white);
    padding: 0.75rem 1.5rem;
    border-radius: var(--border-radius);
    font-weight: 600;
    transition: var(--transition);
    border: none;
    cursor: pointer;
    text-align: center;
}

.btn:hover {
    background-color: white;
    transform: translateY(-3px);
    box-shadow: var(--shadow);
}

.btn-outline {
    background-color: transparent;
    border: 2px solid var(--primary-color);
    color: var(--primary-color);
}

.btn-outline:hover {
    background-color: var(--primary-color);
    color: var(--white);
}

section {
    padding: 5rem 0;
}

.section-title {
    text-align: center;
    margin-bottom: 3rem;
    position: relative;
}

.section-title h2 {
    font-size: 2.5rem;
    display: inline-block;
    position: relative;
    z-index: 1;
}

.section-title h2::after {
    content: "";
    position: absolute;
    bottom: -10px;
    left: 50%;
    transform: translateX(-50%);
    width: 70px;
    height: 4px;
    background-color: var(--primary-color);
    border-radius: 4px;
}

/* Header Styles */
header {
    background-color: var(--white);
    box-shadow: var(--shadow);
    position: fixed;
    width: 100%;
    top: 0;
    z-index: 1000;
    transition: var(--transition);
}

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

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

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

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

.nav-links a {
    color: var(--text-color);
    font-weight: 500;
    position: relative;
}

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

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

.toggle-mode {
    background: none;
    border: none;
    color: var(--text-color);
    font-size: 1.2rem;
    cursor: pointer;
    margin-left: 1.5rem;
    transition: var(--transition);
}

.toggle-mode:hover {
    color: var(--primary-color);
}

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

/* Hero Section */
.hero {
    padding-top: 120px;
    padding-bottom: 3rem;
    background-color: var(--accent-color);
    position: relative;
    overflow: hidden;
}

.hero-content {
    display: flex;
    align-items: center;
    flex-wrap: wrap;
    gap: 3rem;
}

.hero-text {
    flex: 1;
    min-width: 300px;
}

.hero-image {
    flex: 1;
    min-width: 300px;
    display: flex;
    justify-content: center;
}

.hero-image img {
    width: 300px;
    height: 300px;
    object-fit: cover;
    border-radius: 50%;
    border: 5px solid var(--white);
    box-shadow: var(--shadow);
    transition: var(--transition);
}

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

.hero-title {
    font-size: 3rem;
    margin-bottom: 1rem;
}

.hero-subtitle {
    font-size: 1.5rem;
    color: var(--primary-color);
    margin-bottom: 1.5rem;
}

.hero-description {
    margin-bottom: 2rem;
    font-size: 1.1rem;
}

.hero-cta {
    display: flex;
    gap: 1rem;
}

.social-links {
    display: flex;
    gap: 1rem;
    margin-top: 2rem;
}

.social-links a {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 40px;
    height: 40px;
    background-color: var(--white);
    color: var(--primary-color);
    border-radius: 50%;
    transition: var(--transition);
    box-shadow: var(--shadow);
}

.social-links a:hover {
    background-color: var(--primary-color);
    color: var(--white);
    transform: translateY(-3px);
}

/* About Section */
.about {
    background-color: var(--white);
}

.about-content {
    display: flex;
    flex-wrap: wrap;
    gap: 3rem;
    align-items: center;
}

.about-text {
    flex: 2;
    min-width: 300px;
}

.about-stats {
    flex: 1;
    min-width: 300px;
}

.stat-item {
    text-align: center;
    margin-bottom: 2rem;
}

.stat-number {
    font-size: 2.5rem;
    font-weight: 700;
    color: var(--primary-color);
    margin-bottom: 0.5rem;
}

.stat-title {
    font-size: 1rem;
    color: var(--light-text);
}

/* Skills Section */
.skills {
    background-color: var(--accent-color);
}

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

.skill-category {
    background-color: var(--white);
    border-radius: var(--border-radius);
    padding: 2rem;
    box-shadow: var(--shadow);
    transition: var(--transition);
}

.skill-category:hover {
    transform: translateY(-5px);
}

.skill-category h3 {
    font-size: 1.5rem;
    margin-bottom: 1.5rem;
    color: var(--primary-color);
}

.skill-list {
    list-style: none;
}

.skill-item {
    margin-bottom: 1.5rem;
}

.skill-info {
    display: flex;
    justify-content: space-between;
    margin-bottom: 0.5rem;
}

.skill-name {
    font-weight: 600;
}

.skill-level {
    color: var(--primary-color);
}

.progress-bar {
    width: 100%;
    height: 8px;
    background-color: #e4e8ed;
    border-radius: 4px;
    overflow: hidden;
}

.progress {
    height: 100%;
    background-color: var(--primary-color);
    border-radius: 4px;
    width: 0;
    transition: width 1.5s ease-in-out;
}

/* Experience Section */
.experience {
    background-color: var(--white);
}

.timeline {
    position: relative;
    max-width: 800px;
    margin: 0 auto;
}

.timeline::after {
    content: '';
    position: absolute;
    width: 2px;
    background-color: #e4e8ed;
    top: 0;
    bottom: 0;
    left: 50%;
    margin-left: -1px;
}

.timeline-item {
    padding: 1rem 2rem;
    position: relative;
    background-color: inherit;
    width: 50%;
    box-sizing: border-box;
    margin-bottom: 2rem;
}

.timeline-item::after {
    content: '';
    position: absolute;
    width: 20px;
    height: 20px;
    right: -10px;
    background-color: var(--white);
    border: 4px solid var(--primary-color);
    top: 15px;
    border-radius: 50%;
    z-index: 1;
}

.timeline-item.left {
    left: 0;
}

.timeline-item.right {
    left: 50%;
}

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

.timeline-content {
    padding: 1.5rem;
    background-color: var(--white);
    border-radius: var(--border-radius);
    box-shadow: var(--shadow);
    transition: var(--transition);
}

.timeline-content:hover {
    box-shadow: 0 8px 25px rgba(0, 0, 0, 0.15);
}

.timeline-date {
    color: var(--primary-color);
    font-weight: 600;
    margin-bottom: 0.5rem;
    display: inline-block;
}

.timeline-title {
    margin-bottom: 0.5rem;
    font-size: 1.2rem;
}

/* Projects Section */
.projects {
    background-color: var(--accent-color);
}

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

.project-card {
    background-color: var(--white);
    border-radius: var(--border-radius);
    overflow: hidden;
    box-shadow: var(--shadow);
    transition: var(--transition);
}

.project-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 15px 30px rgba(0, 0, 0, 0.15);
}

.project-image {
    width: 100%;
    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-content {
    padding: 1.5rem;
}

.project-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
    margin: 1rem 0;
}

.tag {
    display: inline-block;
    padding: 0.25rem 0.75rem;
    background-color: #f0f4f8;
    color: var(--primary-color);
    border-radius: 20px;
    font-size: 0.85rem;
    font-weight: 500;
    transition: var(--transition);
}

.project-card:hover .tag {
    background-color: #e4ecf7;
}

.project-links {
    display: flex;
    gap: 1rem;
    margin-top: 1rem;
}

.project-links a {
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

/* Certifications Section */
.certifications {
    background-color: var(--white);
}

.certificates-container {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: 1.5rem;
}

.certificate-card {
    background-color: var(--white);
    border: 1px solid #e4e8ed;
    border-radius: var(--border-radius);
    padding: 1.5rem;
    width: 300px;
    display: flex;
    flex-direction: column;
    align-items: center;
    box-shadow: var(--shadow);
    transition: var(--transition);
}

.certificate-card:hover {
    transform: translateY(-5px);
}

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

.certificate-title {
    font-size: 1.2rem;
    text-align: center;
    margin-bottom: 0.5rem;
}

.certificate-issuer {
    color: var(--light-text);
    text-align: center;
    font-size: 0.9rem;
}

/* Contact Section */
.contact {
    background-color: var(--accent-color);
}

.contact-container {
    display: flex;
    flex-wrap: wrap;
    gap: 3rem;
}

.contact-info {
    flex: 1;
    min-width: 300px;
}

.contact-form {
    flex: 2;
    min-width: 300px;
}

.contact-item {
    display: flex;
    align-items: center;
    margin-bottom: 1.5rem;
}

.contact-icon {
    width: 50px;
    height: 50px;
    background-color: var(--white);
    color: var(--primary-color);
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: 50%;
    margin-right: 1rem;
    font-size: 1.2rem;
    box-shadow: var(--shadow);
}

.form-group {
    margin-bottom: 1.5rem;
}

.form-control {
    width: 100%;
    padding: 0.75rem 1rem;
    border: 1px solid #e4e8ed;
    border-radius: var(--border-radius);
    font-family: inherit;
    font-size: 1rem;
    color: var(--text-color);
    transition: var(--transition);
}

.form-control:focus {
    outline: none;
    border-color: var(--primary-color);
}

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

/* Footer */
footer {
    background-color: var(--white);
    padding: 2rem 0;
    text-align: center;
}

.footer-text {
    margin-bottom: 1rem;
}

.footer-links {
    display: flex;
    justify-content: center;
    gap: 1.5rem;
    margin-bottom: 1rem;
}

.footer-links a {
    color: var(--light-text);
    transition: var(--transition);
}

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

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

/* Utilities */
.text-primary {
    color: var(--primary-color);
}

/* Animations */
.fade-in {
    opacity: 0;
    transform: translateY(20px);
    transition: opacity 0.6s ease-in-out, transform 0.6s ease-in-out;
}

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

/* Back to top button */
.back-to-top {
    position: fixed;
    bottom: 20px;
    right: 20px;
    width: 50px;
    height: 50px;
    background-color: var(--primary-color);
    color: var(--white);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.2rem;
    z-index: 99;
    opacity: 0;
    visibility: hidden;
    transition: var(--transition);
    box-shadow: var(--shadow);
}

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

.back-to-top:hover {
    background-color: var(--secondary-color);
    transform: translateY(-3px);
}

/* Mobile Styling */
@media screen and (max-width: 768px) {
    .navbar {
        padding: 1rem;
    }

    .menu-btn {
        display: block;
    }

    .nav-links {
        position: absolute;
        top: 100%;
        left: 0;
        flex-direction: column;
        background-color: var(--white);
        width: 100%;
        padding: 1rem 0;
        box-shadow: var(--shadow);
        clip-path: polygon(0 0, 100% 0, 100% 0, 0 0);
        transition: var(--transition);
    }

    .nav-links.active {
        clip-path: polygon(0 0, 100% 0, 100% 100%, 0 100%);
    }

    .nav-links li {
        margin: 0;
        width: 100%;
        text-align: center;
    }

    .nav-links a {
        display: block;
        padding: 0.75rem 0;
    }

    .nav-links a::after {
        display: none;
    }

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

    .hero-subtitle {
        font-size: 1.2rem;
    }

    .hero-cta {
        flex-direction: column;
    }

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

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

    .timeline-item::after {
        left: 15px;
        right: auto;
    }

    .timeline-item.right {
        left: 0;
    }
}