:root {
    --background: #ffffff;
    --foreground: #333333;
    --primary: #3498db;
    --secondary: #f1f5f9;
    --accent: #e74c3c;
    --muted: #94a3b8;
    --card: #ffffff;
    --card-hover: #f1f5f9;
}

.dark-mode {
    --background: #1a202c;
    --foreground: #e2e8f0;
    --primary: #4299e1;
    --secondary: #2d3748;
    --accent: #f56565;
    --muted: #718096;
    --card: #2d3748;
    --card-hover: #4a5568;
}

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

body {
    font-family: 'Arial', sans-serif;
    line-height: 1.6;
    color: var(--foreground);
    background-color: var(--background);
    transition: background-color 0.3s, color 0.3s;
}

.container {
    width: 90%;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

/* Navigation */
#navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    background-color: var(--background);
    padding: 1rem 0;
    z-index: 1000;
    transition: background-color 0.3s, box-shadow 0.3s;
}

#navbar.scrolled {
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
}

#navbar .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo {
    font-size: 1.5rem;
    font-weight: bold;
    color: var(--primary);
    text-decoration: none;
}

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

.nav-links li {
    margin-left: 1.5rem;
}

.nav-links a {
    color: var(--foreground);
    text-decoration: none;
    transition: color 0.3s;
}

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

#theme-toggle {
    background: none;
    border: none;
    cursor: pointer;
    color: var(--foreground);
}

#theme-toggle svg {
    width: 24px;
    height: 24px;
}

#theme-toggle .moon {
    display: none;
}

.dark-mode #theme-toggle .sun {
    display: none;
}

.dark-mode #theme-toggle .moon {
    display: inline;
}

/* Hero Section */
#hero {
    padding: 100px 0;
    background: linear-gradient(135deg, var(--primary) 0%, var(--accent) 100%);
    color: #ffffff;
}

.hero-content {
    text-align: center;
    margin-bottom: 2rem;
}

.name {
    font-size: 3rem;
    margin-bottom: 0.5rem;
    animation: fadeIn 1s ease-out;
}

.degree {
    font-size: 1.5rem;
    margin-bottom: 1.5rem;
    animation: fadeIn 1s ease-out 0.5s both;
}

.cta-button {
    display: inline-block;
    padding: 0.8rem 1.5rem;
    background-color: #ffffff;
    color: var(--primary);
    text-decoration: none;
    border-radius: 5px;
    font-weight: bold;
    transition: background-color 0.3s, color 0.3s;
    animation: fadeIn 1s ease-out 1s both;
}

.cta-button:hover {
    background-color: var(--accent);
    color: #ffffff;
}

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

.profile-img {
    width: 200px;
    height: 200px;
    border-radius: 50%;
    object-fit: cover;
    border: 4px solid #ffffff;
    animation: float 6s ease-in-out infinite;
}

/* Sections */
section {
    padding: 80px 0;
}

h2 {
    font-size: 2.5rem;
    margin-bottom: 2rem;
    text-align: center;
}

/* About Section */
.about-content {
    display: flex;
    align-items: center;
    gap: 2rem;
}

.about-text {
    flex: 1;
}

.about-image {
    flex: 1;
}

.about-image img {
    width: 100%;
    border-radius: 10px;
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.1);
}

/* Bio Section */
#bio {
    background-color: var(--secondary);
}

.bio-content {
    display: flex;
    gap: 2rem;
}

.bio-card {
    flex: 1;
    background-color: var(--card);
    padding: 2rem;
    border-radius: 10px;
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.1);
    transition: transform 0.3s, box-shadow 0.3s;
}

.bio-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 20px rgba(0, 0, 0, 0.15);
}

.bio-card h3 {
    font-size: 1.5rem;
    margin-bottom: 1rem;
    color: var(--primary);
}

/* Education Section */
.education-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
}

.education-card {
    background-color: var(--card);
    padding: 2rem;
    border-radius: 10px;
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.1);
    transition: transform 0.3s, box-shadow 0.3s;
}

.education-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 20px rgba(0, 0, 0, 0.15);
}

.education-card h3 {
    font-size: 1.3rem;
    margin-bottom: 0.5rem;
    color: var(--primary);
}

.education-card .school {
    font-weight: bold;
    margin-bottom: 0.5rem;
}

.education-card .concentration {
    font-style: italic;
    color: var(--muted);
    margin-bottom: 0.5rem;
}

/* Projects Section */
.projects-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
}

.project-card {
    background-color: var(--card);
    border-radius: 10px;
    overflow: hidden;
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.1);
    transition: transform 0.3s, box-shadow 0.3s;
}

.project-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 20px rgba(0, 0, 0, 0.15);
}

.project-card img {
    width: 100%;
    height: 200px;
    object-fit: cover;
}

.project-info {
    padding: 1.5rem;
}

.project-year {
    font-size: 0.9rem;
    color: var(--muted);
}

.project-info h3 {
    font-size: 1.3rem;
    margin: 0.5rem 0;
}

.project-info a {
    color: var(--primary);
    text-decoration: none;
    transition: color 0.3s;
}

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

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

/* Back to Top Button */
#back-to-top {
    position: fixed;
    bottom: 20px;
    right: 20px;
    background-color: var(--primary);
    color: #ffffff;
    width: 50px;
    height: 50px;
    border-radius: 50%;
    display: flex;
    justify-content: center;
    align-items: center;
    cursor: pointer;
    opacity: 0;
    visibility: hidden;
    transition: opacity 0.3s, visibility 0.3s;
}

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

#back-to-top:hover {
    background-color: var(--accent);
}

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

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

/* Responsive Design */
@media (max-width: 768px) {
    .about-content, .bio-content {
        flex-direction: column;
    }

    .nav-links {
        display: none;
    }

    .hero-content {
        padding: 0 1rem;
    }

    .name {
        font-size: 2.5rem;
    }

    .degree {
        font-size: 1.2rem;
    }
}