/* Define CSS Variables for Colors */
:root {
    --background-color: #000000;       /* Black */
    --secondary-background: #1A1A1A;   /* Dark Gray */
    --text-color: #FFFFFF;             /* White */
    --secondary-text-color: #CCCCCC;   /* Light Gray */
    --accent-color: #FFFFFF;           /* White */
    --secondary-accent: #DDDDDD;       /* Very Light Gray */
    --hover-color: #BBBBBB;            /* Medium Gray */
    --border-color: #333333;           /* Darker Gray */
}

/* Apply Background and Text Colors */
body {
    background-color: var(--background-color);
    color: var(--text-color);
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    font-size: 14px; /* Reduced base font size */
    line-height: 1.6;
    margin: 0;
    padding: 0;
    padding-bottom: 60px; /* Add padding to prevent footer overlap */
}

/* Navigation Tabs */
.main-nav {
    position: fixed;
    top: 0;
    width: 100%;
    background-color: var(--background-color);
    z-index: 1000;
    border-bottom: 1px solid var(--border-color);
}

.main-nav ul {
    list-style: none;
    display: flex;
    justify-content: center;
    margin: 0;
    padding: 10px 0;
}

.main-nav li {
    margin: 0 10px;
}

.main-nav .nav-link {
    color: var(--secondary-text-color);
    text-decoration: none;
    font-size: 16px; /* Reduced font size */
    padding: 6px 12px;
    transition: color 0.3s ease;
}

.main-nav .nav-link:hover,
.main-nav .nav-link.active {
    color: var(--hover-color);
}

/* Section Styling */
.section {
    padding: 80px 20px 40px 20px;
    max-width: 1000px;
    margin: 0 auto;
}

.bio-section {
    margin-top: 60px;
}

.bio-container {
    display: flex;
    align-items: flex-start;
    gap: 20px;
    flex-wrap: nowrap;
}

.profile-container {
    flex: 0 0 200px;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 10px;
}

.profile-photo {
    width: 150px;
    height: auto;
    border-radius: 10px;
    object-fit: cover;
    border: 2px solid var(--border-color);
}

.additional-info {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 8px;
}

.description {
    font-style: italic;
    color: var(--secondary-text-color);
    text-align: center;
    font-size: 14px;
}

.location {
    display: flex;
    align-items: center;
    font-size: 14px;
    color: var(--secondary-text-color);
}

.location-icon {
    margin-right: 5px;
    width: 16px;
    height: 16px;
    fill: var(--accent-color);
}

/* Bio Content */
.bio-content {
    flex: 1;
    max-width: 700px;
}

.bio-content h2,
.research-section h2,
.projects-section h2 {
    margin-bottom: 15px;
    font-size: 24px; /* Reduced font size */
    color: var(--accent-color);
    text-align: center;
}

.bio-content p {
    font-size: 14px; /* Reduced font size */
    margin-bottom: 15px;
    color: var(--text-color);
}

/* Research Papers Section */
.research-section {
    /* No changes needed here; it inherits from .section */
}

.research-paper {
    display: flex;
    align-items: flex-start;
    margin-bottom: 25px;
    /* Removed max-width to match the Bio section */
    /* Removed margin-left and margin-right auto */
    width: 100%; /* Ensures it takes full width of the parent */
}

.paper-image {
    width: 450px;
    height: 150px; /* Adjusted height */
    object-fit: cover;
    margin-right: 15px;
    border-radius: 10px;
}

.paper-details {
    flex: 1;
}

.paper-details h3 {
    margin-top: 0;
    font-size: 18px; /* Reduced font size */
    color: var(--accent-color);
}

.paper-details h3 a {
    color: var(--accent-color);
    text-decoration: none;
}

.paper-details h3 a:hover {
    color: var(--hover-color);
}

.paper-details p {
    margin: 4px 0;
    font-size: 14px; /* Reduced font size */
    color: var(--text-color);
}

/* Projects Section */
.projects-section {
    /* Inherits from .section */
}

.project {
    display: flex;
    align-items: flex-start;
    margin-bottom: 25px;
    background-color: var(--secondary-background);
    padding: 15px;
    border-radius: 10px;
    flex-wrap: wrap;
    /* Removed max-width to match the Bio section */
    width: 100%; /* Ensures it takes full width of the parent */
}

.project-image {
    width: 120px;
    height: 120px;
    object-fit: cover;
    border-radius: 10px;
    margin-right: 15px;
    flex-shrink: 0;
}

.project-description {
    flex: 1;
}

.project-description h3 {
    margin-bottom: 8px;
    font-size: 18px; /* Reduced font size */
    color: var(--accent-color);
}

.project-description .project-icon {
    margin-right: 5px;
    width: 18px;
    height: 18px;
    fill: var(--accent-color);
}

.project-description p {
    font-size: 14px; /* Reduced font size */
    color: var(--text-color);
}

/* Footer Styling */
.footer {
    position: fixed;
    bottom: 0;
    width: 100%;
    background-color: var(--background-color);
    color: var(--secondary-text-color);
    text-align: center;
    padding: 8px 0;
    border-top: 1px solid var(--border-color);
    z-index: 1000;
}

.footer-social-links {
    display: flex;
    justify-content: center;
    align-items: center;
    gap: 15px;
}

.footer-social-links a {
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--secondary-text-color);
    text-decoration: none;
    font-size: 14px; /* Reduced font size */
    transition: color 0.3s ease;
}

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

.footer-social-icon {
    margin-right: 5px;
    width: 18px;
    height: 18px;
    fill: var(--secondary-text-color);
    transition: fill 0.3s ease;
}

.footer-social-links a:hover .footer-social-icon {
    fill: var(--hover-color);
}

/* Responsive Design */
@media (max-width: 768px) {
    .bio-container {
        flex-direction: column;
        align-items: center;
    }

    .profile-container {
        width: 100%;
    }

    .bio-content {
        width: 100%;
        text-align: center;
    }

    .research-paper,
    .project {
        flex-direction: column;
        align-items: center;
        text-align: center;
    }

    .paper-image,
    .project-image {
        margin-right: 0;
        margin-bottom: 15px;
    }
}

/* Optional: Focus States for Accessibility */
.nav-link:focus,
.footer-social-links a:focus {
    outline: 2px solid var(--hover-color);
    outline-offset: 2px;
}