/* Base Styles */
:root {
    --primary-color: #2c3e50;
    --secondary-color: #3498db;
    --accent-color: #e74c3c;
    --light-color: #ecf0f1;
    --dark-color: #2c3e50;
    --text-color: #333;
    --sidebar-width: 300px;
    --transition-speed: 0.3s;
}

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

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    line-height: 1.6;
    color: var(--text-color);
    background-color: #f5f5f5;
}

.container {
    display: flex;
    min-height: 100vh;
}

/* Sidebar Styles */
.sidebar {
    width: var(--sidebar-width);
    background-color: var(--primary-color);
    color: white;
    position: fixed;
    height: 100vh;
    overflow-y: auto;
    transition: all var(--transition-speed);
}

.profile {
    padding: 2rem;
    text-align: center;
    border-bottom: 1px solid rgba(255, 255, 255, 0.1);
}

.profile-img {
    width: 150px;
    height: 150px;
    border-radius: 50%;
    overflow: hidden;
    margin: 0 auto 1rem;
    border: 4px solid var(--secondary-color);
}

.profile-img img {
    width: 100%;
    height: 100%;
    object-fit: cover;
}

.profile h1 {
    font-size: 1.5rem;
    margin-bottom: 0.5rem;
}

.title {
    font-size: 0.9rem;
    color: var(--secondary-color);
    margin-bottom: 1rem;
}

.contact-info {
    margin-bottom: 1rem;
    font-size: 0.9rem;
}

.contact-info p {
    margin-bottom: 0.5rem;
}

.contact-info i {
    margin-right: 0.5rem;
    color: var(--secondary-color);
}

.social-links {
    display: flex;
    justify-content: center;
    gap: 1rem;
    margin-bottom: 2rem;
}

.social-links a {
    color: white;
    font-size: 1.2rem;
    transition: color var(--transition-speed);
}

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

nav ul {
    list-style: none;
}

nav ul li {
    margin-bottom: 0.5rem;
}

nav ul li a {
    display: block;
    padding: 0.5rem;
    color: white;
    text-decoration: none;
    border-radius: 4px;
    transition: background-color var(--transition-speed);
}

nav ul li a:hover, nav ul li a.active {
    background-color: rgba(52, 152, 219, 0.2);
}

/* Main Content Styles */
.content {
    flex: 1;
    margin-left: var(--sidebar-width);
    padding: 2rem;
}

.section {
    display: none;
    animation: fadeIn 0.5s ease-in-out;
    margin-bottom: 3rem;
}

.section.active {
    display: block;
}

@keyframes fadeIn {
    from { opacity: 0; transform: translateY(20px); }
    to { opacity: 1; transform: translateY(0); }
}

h2 {
    font-size: 2rem;
    margin-bottom: 1.5rem;
    color: var(--primary-color);
    border-bottom: 2px solid var(--secondary-color);
    padding-bottom: 0.5rem;
}

h2::after {
    content: '';
    position: absolute;
    left: 0;
    bottom: 0;
    width: 50px;
    height: 3px;
    background-color: var(--secondary-color);
}

p {
    margin-bottom: 1rem;
}

/* Skills Section */
.skills-container {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(250px, 1fr));
    gap: 1.5rem;
}

.skill-category {
    background-color: white;
    border-radius: 8px;
    padding: 1.5rem;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
}

.skill-category h3 {
    margin-bottom: 1rem;
    color: var(--secondary-color);
    border-bottom: 1px solid #eee;
    padding-bottom: 0.5rem;
}

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

.skill-list li {
    margin-bottom: 0.5rem;
    position: relative;
    padding-left: 1.5rem;
}

.skill-list li::before {
    content: '•';
    color: var(--secondary-color);
    position: absolute;
    left: 0;
    font-weight: bold;
}

/* Projects Section */
.projects-filter {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
    margin-bottom: 1.5rem;
}

.filter-btn {
    background-color: var(--light-color);
    border: none;
    padding: 0.5rem 1rem;
    border-radius: 4px;
    cursor: pointer;
    transition: all var(--transition-speed);
}

.filter-btn:hover, .filter-btn.active {
    background-color: var(--secondary-color);
    color: white;
}

.projects-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    gap: 1.5rem;
}

.project-card {
    background-color: white;
    border-radius: 8px;
    overflow: hidden;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
    transition: transform var(--transition-speed);
}

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

.project-img {
    position: relative;
    height: 200px;
    overflow: hidden;
    background-color: #f5f5f5;
    background-image: url('images/default-image.jpg');
    background-size: cover;
    background-position: center;
}

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

.project-card:hover .project-img img {
    transform: scale(1.05);
}

.project-info {
    padding: 1.5rem;
}

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

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

.project-tags span {
    background-color: var(--light-color);
    padding: 0.25rem 0.5rem;
    border-radius: 4px;
    font-size: 0.8rem;
}

.project-link {
    display: inline-block;
    color: var(--secondary-color);
    text-decoration: none;
    font-weight: bold;
    margin-top: 0.5rem;
}

.project-link:hover {
    color: var(--accent-color);
}

.project-link i {
    margin-left: 0.25rem;
    transition: transform var(--transition-speed);
}

.project-link:hover i {
    transform: translateX(3px);
}

.project-links {
    display: flex;
    flex-wrap: wrap;
    gap: 1rem;
    margin-top: 0.5rem;
}

.project-links .project-link {
    display: inline-block;
    color: #3498db;
    text-decoration: none;
    font-weight: bold;
    padding: 0.25rem 0.5rem;
    border: 1px solid #3498db;
    border-radius: 4px;
    transition: all 0.3s;
}

.project-links .project-link:hover {
    background-color: #3498db;
    color: white;
}

.project-links .project-link i {
    margin-left: 0.25rem;
    transition: transform 0.3s;
}

.project-links .project-link:hover i {
    transform: translateX(3px);
}

/* Timeline for Education and Experience */
.timeline-item {
    position: relative;
    padding-left: 2rem;
    margin-bottom: 2rem;
    border-left: 2px solid var(--secondary-color);
}

.timeline-content {
    background-color: white;
    padding: 1.5rem;
    border-radius: 8px;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
}

.timeline-content h3 {
    margin-bottom: 0.5rem;
    color: var(--primary-color);
}

.institution {
    font-weight: 500;
    color: var(--secondary-color);
    margin-bottom: 0.5rem;
}

.period {
    font-style: italic;
    color: #777;
    margin-bottom: 1rem;
}

.timeline-content ul {
    padding-left: 1.5rem;
}

.timeline-content ul li {
    margin-bottom: 0.5rem;
}

/* Achievements Section */
.achievements-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    gap: 1.5rem;
}

.achievement-card {
    display: flex;
    align-items: center;
    background-color: white;
    padding: 1.5rem;
    border-radius: 8px;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
}

.achievement-icon {
    font-size: 2rem;
    color: var(--secondary-color);
    margin-right: 1rem;
}

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

/* Research Section Styles */
.research-item {
    background-color: white;
    border-radius: 8px;
    padding: 1.5rem;
    margin-bottom: 2rem;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
}

.research-item h3 {
    color: var(--primary-color);
    margin-bottom: 0.5rem;
}

.research-item .institution {
    font-weight: 500;
    color: var(--secondary-color);
    margin-bottom: 1rem;
}

.research-highlights {
    margin-top: 1rem;
}

.research-highlights h4 {
    font-size: 1rem;
    margin-bottom: 0.5rem;
    color: var(--primary-color);
}

.research-highlights ul {
    padding-left: 1.5rem;
}

.research-highlights ul li {
    margin-bottom: 0.5rem;
}

/* Responsive Design */
@media (max-width: 992px) {
    .sidebar {
        width: 250px;
    }
    
    .content {
        margin-left: 250px;
    }
}

@media (max-width: 768px) {
    .container {
        flex-direction: column;
    }
    
    .sidebar {
        width: 100%;
        height: auto;
        position: relative;
    }
    
    .content {
        margin-left: 0;
    }
    
    .profile {
        padding: 1rem;
    }
    
    .profile-img {
        width: 100px;
        height: 100px;
    }
    
    nav ul {
        display: flex;
        flex-wrap: wrap;
    }
    
    nav ul li {
        flex: 1 0 50%;
        border-bottom: none;
    }
    
    nav ul li a {
        padding: 0.75rem 1rem;
        text-align: center;
    }
    
    nav ul li a:hover, nav ul li a.active {
        padding-left: 1rem;
    }
    
    .skills-container, .projects-grid, .achievements-grid {
        grid-template-columns: 1fr;
    }
}

@media (max-width: 576px) {
    .skills-container,
    .projects-grid,
    .achievements-grid {
        grid-template-columns: 1fr;
    }
    
    nav ul li {
        flex: 1 0 100%;
    }
}