/* Modern CSS Reset */
*,
*::before,
*::after {
    box-sizing: border-box;
}

* {
    margin: 0;
}

html {
    scroll-behavior: smooth;
}

body {
    line-height: 1.5;
    -webkit-font-smoothing: antialiased;
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    background: #f8fafc;
    min-height: 100vh;
    color: #2c3e50;
}

img,
picture,
video,
canvas,
svg {
    display: block;
    max-width: 100%;
}

input,
button,
textarea,
select {
    font: inherit;
}

p,
h1,
h2,
h3,
h4,
h5,
h6 {
    overflow-wrap: break-word;
}

/* CSS Variables for Modern Design System */
:root {
    --primary-color: #1e40af;
    --primary-dark: #1e3a8a;
    --secondary-color: #64748b;
    --accent-color: #0ea5e9;
    --text-primary: #1e293b;
    --text-secondary: #64748b;
    --bg-primary: #ffffff;
    --bg-secondary: #f8fafc;
    --bg-accent: #f1f5f9;
    --border-color: #e2e8f0;
    --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.05);
    --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.1), 0 2px 4px -2px rgb(0 0 0 / 0.1);
    --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.1), 0 4px 6px -4px rgb(0 0 0 / 0.1);
    --border-radius: 8px;
    --transition: all 0.2s ease-in-out;
}

/* Accessibility */
.skip-link {
    position: absolute;
    top: -40px;
    left: 6px;
    z-index: 999;
    background: var(--text-primary);
    color: white;
    padding: 8px 16px;
    text-decoration: none;
    border-radius: var(--border-radius);
    font-weight: 500;
    transition: var(--transition);
}

.skip-link:focus {
    top: 0;
}

a:focus,
button:focus {
    outline: 2px solid var(--primary-color);
    outline-offset: 2px;
}

/* Layout */
#layout_wrapper_outer {
    background: transparent;
    min-height: 100vh;
    padding: 1rem 0;
}

#layout_wrapper {
    max-width: 1200px;
    margin: 0 auto;
    background: var(--bg-primary);
    border-radius: 12px;
    box-shadow: var(--shadow-md);
    overflow: hidden;
    min-height: calc(100vh - 2rem);
}


/* Modern Header */
.modern-header {
    background: var(--bg-primary);
    border-bottom: 1px solid var(--border-color);
    color: var(--text-primary);
    padding: 2rem;
    position: relative;
}

.header-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: 2rem;
}

.profile-section {
    display: flex;
    align-items: center;
    gap: 1.5rem;
}

#site_title h1 {
    font-size: 2.5rem;
    font-weight: 600;
    margin-bottom: 0.5rem;
    color: var(--text-primary);
}

#site_title .title {
    font-size: 1.1rem;
    font-weight: 500;
    color: var(--text-secondary);
    margin-bottom: 0.25rem;
}

#site_title .position {
    font-size: 1rem;
    color: var(--text-secondary);
    margin-bottom: 0.25rem;
}

#site_title .institution {
    font-size: 0.9rem;
    color: var(--text-secondary);
}

.quick-contact {
    display: flex;
    flex-direction: column;
    gap: 0.75rem;
}

.contact-btn,
.scholar-btn {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.75rem 1.25rem;
    background: var(--primary-color);
    color: white;
    text-decoration: none;
    border-radius: var(--border-radius);
    font-weight: 500;
    transition: var(--transition);
    border: 1px solid var(--primary-color);
}

.contact-btn:hover,
.scholar-btn:hover {
    background: var(--primary-dark);
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}


/* Modern Navigation */
#navigation {
    background: var(--bg-secondary);
    border-bottom: 1px solid var(--border-color);
    padding: 0;
}

#nav1 ul {
    display: flex;
    justify-content: center;
    gap: 0;
    list-style: none;
    margin: 0;
    padding: 0;
}

#nav1 li {
    position: relative;
}

#nav1 a {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    padding: 1rem 1.5rem;
    color: var(--text-secondary);
    text-decoration: none;
    font-weight: 500;
    transition: var(--transition);
    border-bottom: 3px solid transparent;
}

#nav1 a:hover {
    color: var(--primary-color);
    background: rgba(37, 99, 235, 0.05);
}

#nav1 li.current_page_item a {
    color: var(--primary-color);
    background: rgba(37, 99, 235, 0.1);
    border-bottom-color: var(--primary-color);
}

#nav1 a i {
    font-size: 1.1rem;
}

/* Sub-navigation */
#nav2,
#nav3 {
    background: var(--bg-accent);
    padding: 0.5rem 0;
    border-bottom: 1px solid var(--border-color);
}

#nav2 ul,
#nav3 ul {
    display: flex;
    justify-content: center;
    gap: 0;
    list-style: none;
    margin: 0;
    padding: 0;
    flex-wrap: wrap;
}

#nav2 a,
#nav3 a {
    padding: 0.5rem 1rem;
    color: var(--text-secondary);
    text-decoration: none;
    font-size: 0.9rem;
    transition: var(--transition);
    border-radius: var(--border-radius);
    margin: 0 0.25rem;
}

#nav2 a:hover,
#nav3 a:hover {
    color: var(--primary-color);
    background: rgba(37, 99, 235, 0.1);
}

#nav2 li.current_page_item a,
#nav3 li.current_page_item a {
    color: var(--primary-color);
    background: rgba(37, 99, 235, 0.15);
    font-weight: 500;
}

/* Main Content */
#main {
    padding: 2rem;
}

#content {
    padding: 0;
}

/* Modern Cards Layout */
.cards-container {
    display: grid;
    gap: 1.5rem;
    margin-bottom: 2rem;
}

.card {
    background: var(--bg-primary);
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius);
    box-shadow: var(--shadow-sm);
    transition: var(--transition);
    overflow: hidden;
}

.card:hover {
    box-shadow: var(--shadow-md);
    transform: translateY(-2px);
}

.card-header {
    background: var(--bg-secondary);
    padding: 1rem 1.5rem;
    border-bottom: 1px solid var(--border-color);
}

.card-header h2 {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-size: 1.25rem;
    font-weight: 600;
    color: var(--text-primary);
    margin: 0;
}

.card-header i {
    color: var(--primary-color);
    font-size: 1.1rem;
}

.card-body {
    padding: 1.5rem;
}

/* Paragraph spacing for card bodies and thesis abstracts */
.card-body p,
.thesis-abstract p {
    margin-bottom: 1rem;
}

.card-body p:last-child,
.thesis-abstract p:last-child {
    margin-bottom: 0;
}

/* Interest Grid */
.interest-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 1rem;
}

.interest-item {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    padding: 0.75rem;
    background: var(--bg-secondary);
    border-radius: var(--border-radius);
    transition: var(--transition);
}

.interest-item:hover {
    background: rgba(37, 99, 235, 0.05);
    transform: translateX(4px);
}

.interest-item i {
    color: var(--primary-color);
    font-size: 1.2rem;
    min-width: 20px;
}

.interest-item span {
    font-weight: 500;
    color: var(--text-primary);
}

/* Profile Grid */
.profile-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 0.75rem;
}

.profile-link {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    padding: 0.75rem 1rem;
    background: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius);
    text-decoration: none;
    color: var(--text-primary);
    font-weight: 500;
    transition: var(--transition);
}

.profile-link:hover {
    background: var(--primary-color);
    color: white;
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

.profile-link i {
    font-size: 1.1rem;
    min-width: 16px;
}

/* Education List */
.education-info h4 {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-size: 1.1rem;
    font-weight: 600;
    color: var(--text-primary);
    margin: 1rem 0 0.75rem 0;
}

.education-info h4 i {
    color: var(--primary-color);
}

.education-list {
    list-style: none;
    padding: 0;
    margin: 0;
}

.education-list li {
    padding: 0.5rem 0;
    color: var(--text-secondary);
    border-bottom: 1px solid var(--border-color);
}

.education-list li:last-child {
    border-bottom: none;
}

/* Images */
img.alignright {
    float: right;
    margin: 0 0 1rem 1.5rem;
    border-radius: var(--border-radius);
    box-shadow: var(--shadow-sm);
    max-width: 200px;
}

/* Contact Information */
.contact-methods {
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

.contact-item {
    display: flex;
    align-items: flex-start;
    gap: 1rem;
    padding: 1rem;
    background: var(--bg-secondary);
    border-radius: var(--border-radius);
}

.contact-item i {
    color: var(--primary-color);
    font-size: 1.2rem;
    margin-top: 0.2rem;
    min-width: 20px;
}

.contact-details a {
    color: var(--primary-color);
    text-decoration: none;
    font-weight: 500;
}

.contact-details a:hover {
    text-decoration: underline;
}

/* Posts and Articles */
.post {
    background: var(--bg-primary);
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius);
    box-shadow: var(--shadow-sm);
    margin-bottom: 1.5rem;
}

.post_title {
    background: var(--bg-secondary);
    padding: 1rem 1.5rem;
    border-bottom: 1px solid var(--border-color);
}

.post_title h2 {
    font-size: 1.25rem;
    font-weight: 600;
    color: var(--text-primary);
    margin: 0;
}

.post_body {
    padding: 1.5rem;
}

.post_meta {
    background: transparent;
    border: none;
    padding: 0;
    font-style: normal;
}

/* Bibliography Styles */
.header {
    font-size: 1.2rem;
    font-weight: 600;
    color: var(--primary-color);
    padding: 1.5rem 0 0.75rem 0;
    border-bottom: 2px solid var(--border-color);
    margin-bottom: 1rem;
}

.bibref {
    font-size: 0.85rem;
    color: var(--text-secondary);
    margin-bottom: 0.5rem;
}

.bibline {
    padding: 1rem;
    background: var(--bg-secondary);
    border-radius: var(--border-radius);
    margin-bottom: 1rem;
    border-left: 4px solid var(--primary-color);
}

.purebibtex {
    background: var(--bg-accent);
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius);
    padding: 1rem;
    font-family: 'Monaco', 'Menlo', monospace;
    font-size: 0.85rem;
    margin: 1rem 0;
    overflow-x: auto;
}

/* Thesis Information */
.thesis-info {
    background: linear-gradient(135deg, rgba(37, 99, 235, 0.05), rgba(116, 75, 162, 0.05));
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius);
    padding: 1.5rem;
    margin-bottom: 1.5rem;
}

.thesis-abstract {
    text-align: justify;
    line-height: 1.6;
    color: var(--text-secondary);
}

/* Error Messages */
.error-message {
    background: #fef2f2;
    color: #dc2626;
    border: 1px solid #fecaca;
    border-radius: var(--border-radius);
    padding: 1rem;
    margin: 1rem 0;
    border-left: 4px solid #dc2626;
}

/* Utility Classes */
.clearer {
    clear: both;
    display: block;
    height: 0;
    font-size: 0;
    line-height: 0;
}

/* Responsive Design */
@media (max-width: 768px) {
    #layout_wrapper {
        margin: 0 1rem;
        border-radius: 12px;
        min-height: calc(100vh - 2rem);
    }
    
    .modern-header {
        padding: 1.5rem;
    }
    
    .header-content {
        flex-direction: column;
        text-align: center;
        gap: 1.5rem;
    }
    
    .profile-section {
        flex-direction: column;
        text-align: center;
    }
    
    #site_title h1 {
        font-size: 2rem;
    }
    
    .quick-contact {
        flex-direction: row;
        justify-content: center;
    }
    
    #nav1 ul {
        flex-direction: column;
        align-items: center;
    }
    
    #nav1 a {
        padding: 0.75rem 1rem;
        justify-content: center;
        min-width: 120px;
    }
    
    /* Sub-navigation mobile styles */
    #nav2 ul,
    #nav3 ul {
        flex-direction: column;
        align-items: center;
        gap: 0.25rem;
        padding: 0.5rem;
    }
    
    #nav2 a,
    #nav3 a {
        padding: 0.5rem 1rem;
        margin: 0.1rem 0;
        min-width: 200px;
        max-width: 90vw;
        text-align: center;
        display: block;
        white-space: nowrap;
        overflow: hidden;
        text-overflow: ellipsis;
    }
    
    #main {
        padding: 1rem;
    }
    
    .cards-container {
        gap: 1rem;
    }
    
    .card-body {
        padding: 1rem;
    }
    
    .interest-grid {
        grid-template-columns: 1fr;
        gap: 0.75rem;
    }
    
    .profile-grid {
        grid-template-columns: 1fr;
    }
    
    img.alignright {
        float: none;
        display: block;
        margin: 0 auto 1rem auto;
        max-width: 150px;
    }
    
    .contact-item {
        flex-direction: column;
        align-items: flex-start;
        gap: 0.5rem;
    }
    
    .contact-item i {
        margin-top: 0;
    }
}

@media (max-width: 600px) and (min-width: 481px) {
    /* Medium mobile/small tablet styles */
    #nav2 ul,
    #nav3 ul {
        flex-wrap: wrap;
        justify-content: center;
        gap: 0.5rem;
    }
    
    #nav2 a,
    #nav3 a {
        padding: 0.4rem 0.8rem;
        font-size: 0.85rem;
        min-width: 140px;
        margin: 0.2rem;
    }
}

@media (max-width: 480px) {
    #layout_wrapper {
        margin: 0 0.5rem;
        border-radius: 8px;
    }
    
    .modern-header {
        padding: 1rem;
    }
    
    #site_title h1 {
        font-size: 1.75rem;
    }
    
    .contact-btn,
    .scholar-btn {
        padding: 0.5rem 1rem;
        font-size: 0.9rem;
    }
    
    #nav1 a {
        padding: 0.5rem 0.75rem;
        font-size: 0.9rem;
    }
    
    /* Sub-navigation mobile styles for very small screens */
    #nav2,
    #nav3 {
        padding: 0.25rem 0;
    }
    
    #nav2 a,
    #nav3 a {
        padding: 0.4rem 0.8rem;
        font-size: 0.8rem;
        min-width: 160px;
        max-width: 85vw;
        margin: 0.1rem 0;
        white-space: normal;
        line-height: 1.3;
        text-align: center;
    }
    
    .card-header {
        padding: 0.75rem 1rem;
    }
    
    .card-body {
        padding: 0.75rem;
    }
    
    .interest-item {
        padding: 0.5rem;
    }
    
    .profile-link {
        padding: 0.5rem 0.75rem;
        font-size: 0.9rem;
    }
}

/* Dark mode support (optional) */
@media (prefers-color-scheme: dark) {
    :root {
        --bg-primary: #1e293b;
        --bg-secondary: #334155;
        --bg-accent: #475569;
        --text-primary: #f1f5f9;
        --text-secondary: #cbd5e1;
        --border-color: #475569;
    }
    
    body {
        background: #0f172a;
    }
}

/* Loading animations */
@keyframes fadeIn {
    from { opacity: 0; transform: translateY(10px); }
    to { opacity: 1; transform: translateY(0); }
}

.spa-section {
    animation: fadeIn 0.3s ease-out;
}

/* Smooth transitions for section changes */
.spa-section[style*="display: none"] {
    display: none !important;
}

.spa-section:not([style*="display: none"]) {
    display: block;
    animation: fadeIn 0.3s ease-out;
}