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

:root {
    --primary-color: #d4af37;
    --primary-dark: #b8941f;
    --secondary-color: #f4d03f;
    --text-primary: #000000;
    --text-secondary: #4a4a4a;
    --text-light: #808080;
    --bg-primary: #ffffff;
    --bg-secondary: #f5f5f5;
    --bg-accent: #e8e8e8;
    --border-color: #d0d0d0;
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
    --transition: all 0.3s ease;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    line-height: 1.6;
    color: var(--text-primary);
    background-color: var(--bg-primary);
    overflow-x: hidden;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 2rem;
}

/* App Layout */
.app-layout {
    display: flex;
    min-height: 100vh;
}

/* Sidebar Navigation */
.sidebar {
    width: 250px;
    background: white;
    border-right: 1px solid var(--border-color);
    position: fixed;
    left: 0;
    top: 0;
    height: 100vh;
    display: flex;
    flex-direction: column;
    z-index: 1000;
    box-shadow: var(--shadow-sm);
}

.sidebar-logo {
    font-size: 1.75rem;
    font-weight: 700;
    color: var(--primary-color);
    padding: 2rem 1.5rem;
    border-bottom: 1px solid var(--border-color);
}

.sidebar-nav {
    display: flex;
    flex-direction: column;
    padding: 1rem 0;
    flex: 1;
}

.sidebar-btn {
    padding: 1rem 1.5rem;
    background: none;
    border: none;
    font-size: 1rem;
    font-weight: 500;
    color: var(--text-secondary);
    cursor: pointer;
    transition: var(--transition);
    text-align: left;
    font-family: inherit;
    border-left: 3px solid transparent;
    margin: 0.25rem 0;
}

.sidebar-btn:hover {
    color: var(--primary-color);
    background: var(--bg-accent);
}

.sidebar-btn.active {
    color: var(--primary-color);
    background: var(--bg-accent);
    border-left-color: var(--primary-color);
    font-weight: 600;
}

/* Main Content Area */
.main-content {
    flex: 1;
    margin-left: 250px;
    min-height: 100vh;
    width: calc(100% - 250px);
}

/* Page Header */
.page-header {
    background: linear-gradient(135deg, #d4af37 0%, #b8941f 100%);
    color: white;
    padding: 2.5rem 2rem;
    border-bottom: 1px solid var(--border-color);
}

.header-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: 1.5rem;
}

.header-name-section {
    flex: 1;
    min-width: 200px;
}

.page-title {
    font-size: 2rem;
    font-weight: 700;
    margin-bottom: 0.5rem;
    line-height: 1.2;
}

.page-subtitle {
    font-size: 1rem;
    opacity: 0.9;
    font-weight: 400;
}

.header-icons {
    display: flex;
    gap: 2rem;
    align-items: center;
}

.header-icon {
    color: white;
    opacity: 0.9;
    transition: var(--transition);
    display: flex;
    align-items: center;
    justify-content: center;
    width: 50px;
    height: 50px;
    border-radius: 50%;
    background: rgba(255, 255, 255, 0.1);
    padding: 0.5rem;
}

.header-icon:hover {
    opacity: 1;
    background: rgba(255, 255, 255, 0.2);
    transform: translateY(-2px);
}

.header-icon svg {
    width: 28px;
    height: 28px;
}

.tab-content {
    display: none;
    padding: 2rem 0;
    animation: fadeIn 0.3s ease;
}

.tab-content.active {
    display: block;
}

@keyframes fadeIn {
    from {
        opacity: 0;
    }
    to {
        opacity: 1;
    }
}

/* Home Tab */
#home {
    padding: 2rem 0;
}

.welcome-text {
    font-size: 1.1rem;
    color: var(--text-secondary);
    line-height: 1.8;
    margin-bottom: 3rem;
    text-align: center;
}

.about-section {
    margin-bottom: 3rem;
}

.about-section .section-title {
    margin-bottom: 2rem;
}

.home-buttons {
    display: flex;
    gap: 1rem;
    justify-content: center;
    flex-wrap: wrap;
    margin-top: 3rem;
}

.btn {
    padding: 0.875rem 2rem;
    border-radius: 8px;
    text-decoration: none;
    font-weight: 600;
    transition: var(--transition);
    display: inline-block;
    border: 2px solid transparent;
    cursor: pointer;
    font-family: inherit;
    font-size: 1rem;
}

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

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
}

.btn-secondary {
    background: transparent;
    color: white;
    border-color: white;
}

.btn-secondary:hover {
    background: white;
    color: var(--primary-color);
    transform: translateY(-2px);
}

/* Section Styles */
.section-title {
    font-size: clamp(2rem, 4vw, 2.5rem);
    font-weight: 700;
    text-align: center;
    margin-bottom: 3rem;
    color: var(--text-primary);
}

/* About Tab */
.about {
    background: var(--bg-secondary);
}

.about-content {
    display: flex;
    flex-direction: column;
    gap: 2rem;
}

.about-intro-wrapper {
    display: flex;
    gap: 3rem;
    align-items: flex-start;
}

.profile-image-container {
    display: flex;
    justify-content: center;
    flex-shrink: 0;
}

.profile-image {
    width: 200px;
    height: 200px;
    border-radius: 50%;
    object-fit: cover;
    border: 4px solid var(--primary-color);
    box-shadow: var(--shadow-md);
}

.about-text {
    flex: 1;
}

.about-text p {
    margin-bottom: 1.5rem;
    color: var(--text-secondary);
    font-size: 1.1rem;
    line-height: 1.8;
}

.about-skills {
    width: 100%;
}

.about-skills h3 {
    font-size: 1.5rem;
    margin-bottom: 1.5rem;
    color: var(--text-primary);
}

.skills-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 1rem;
}

.skill-item {
    padding: 1rem;
    background: #e8e8e8;
    border-radius: 8px;
    text-align: center;
    font-weight: 500;
    box-shadow: var(--shadow-sm);
    transition: var(--transition);
}

.skill-item:hover {
    transform: translateY(-3px);
    box-shadow: var(--shadow-md);
    color: var(--primary-color);
}

/* Academic Tab */
.academic {
    background: var(--bg-primary);
}

.academic-section {
    margin-bottom: 4rem;
}

.subsection-title {
    font-size: 1.75rem;
    font-weight: 600;
    margin-bottom: 2rem;
    color: var(--text-primary);
    padding-left: 1rem;
    border-left: 4px solid var(--primary-color);
}

/* Timeline */
.timeline {
    position: relative;
    padding-left: 2rem;
}

.timeline::before {
    content: '';
    position: absolute;
    left: 0;
    top: 0;
    bottom: 0;
    width: 2px;
    background: var(--border-color);
}

.timeline-item {
    position: relative;
    margin-bottom: 3rem;
    padding-left: 2rem;
}

.timeline-marker {
    position: absolute;
    left: -1.5rem;
    top: 0.5rem;
    width: 12px;
    height: 12px;
    border-radius: 50%;
    background: var(--primary-color);
    border: 3px solid white;
    box-shadow: var(--shadow-md);
}

.timeline-content h4 {
    font-size: 1.25rem;
    font-weight: 600;
    margin-bottom: 0.5rem;
    color: var(--text-primary);
}

.timeline-institution {
    font-weight: 500;
    color: var(--primary-color);
    margin-bottom: 0.25rem;
}

.timeline-date {
    color: var(--text-secondary);
    font-size: 0.9rem;
    margin-bottom: 0.75rem;
}

.timeline-description {
    color: var(--text-secondary);
    line-height: 1.7;
}

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

.research-card {
    background: white;
    padding: 2rem;
    border-radius: 12px;
    box-shadow: var(--shadow-md);
    transition: var(--transition);
    border: 1px solid var(--border-color);
}

.research-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-xl);
}

.research-header {
    display: flex;
    justify-content: space-between;
    align-items: start;
    margin-bottom: 1rem;
    gap: 1rem;
}

.research-header h4 {
    font-size: 1.25rem;
    font-weight: 600;
    color: var(--text-primary);
    flex: 1;
}

.research-role {
    font-size: 0.875rem;
    color: var(--primary-color);
    font-weight: 500;
    white-space: nowrap;
}

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

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

.research-description {
    color: var(--text-secondary);
    line-height: 1.7;
    margin-bottom: 1rem;
}

.research-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
}

.tag {
    padding: 0.375rem 0.875rem;
    background: var(--bg-accent);
    border-radius: 20px;
    font-size: 0.875rem;
    color: var(--text-secondary);
}

/* Publications */
.publications-list {
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
}

.publication-item {
    display: flex;
    gap: 1.5rem;
    background: white;
    padding: 2rem;
    border-radius: 12px;
    box-shadow: var(--shadow-md);
    transition: var(--transition);
    border: 1px solid var(--border-color);
}

.publication-item:hover {
    transform: translateX(5px);
    box-shadow: var(--shadow-lg);
}

.publication-icon {
    font-size: 2rem;
    flex-shrink: 0;
}

.publication-content h4 {
    font-size: 1.25rem;
    font-weight: 600;
    margin-bottom: 0.5rem;
    color: var(--text-primary);
}

.publication-authors {
    color: var(--text-secondary);
    margin-bottom: 0.5rem;
}

.publication-venue {
    color: var(--primary-color);
    font-weight: 500;
    margin-bottom: 1rem;
}

.publication-links {
    display: flex;
    gap: 1rem;
    flex-wrap: wrap;
}

.publication-link {
    color: var(--primary-color);
    text-decoration: none;
    font-weight: 500;
    padding: 0.375rem 0.875rem;
    border: 1px solid var(--primary-color);
    border-radius: 6px;
    transition: var(--transition);
    font-size: 0.875rem;
}

.publication-link:hover {
    background: var(--primary-color);
    color: white;
}

/* Awards */
.awards-list {
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
}

.award-item {
    display: flex;
    gap: 1.5rem;
    background: white;
    padding: 2rem;
    border-radius: 12px;
    box-shadow: var(--shadow-md);
    transition: var(--transition);
    border: 1px solid var(--border-color);
}

.award-item:hover {
    transform: translateX(5px);
    box-shadow: var(--shadow-lg);
}

.award-icon {
    font-size: 2rem;
    flex-shrink: 0;
}

.award-content h4 {
    font-size: 1.25rem;
    font-weight: 600;
    margin-bottom: 0.5rem;
    color: var(--text-primary);
}

.award-content p {
    color: var(--text-secondary);
    margin-bottom: 0.5rem;
}

.award-description {
    color: var(--text-secondary);
    line-height: 1.7;
}

/* Projects Tab */
.projects {
    background: var(--bg-secondary);
}

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

.under-construction {
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 300px;
    padding: 3rem 2rem;
}

.construction-text {
    font-size: 2rem;
    font-weight: 600;
    color: var(--text-secondary);
    text-align: center;
}

.project-card {
    background: white;
    border-radius: 12px;
    overflow: hidden;
    box-shadow: var(--shadow-md);
    transition: var(--transition);
    border: 1px solid var(--border-color);
    display: flex;
    flex-direction: column;
}

.project-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-xl);
}

.project-image {
    width: 100%;
    min-height: 200px;
    background: linear-gradient(135deg, #d4af37 0%, #b8941f 100%);
    display: flex;
    align-items: center;
    justify-content: center;
    overflow: hidden;
}

.project-img {
    width: 100%;
    height: auto;
    object-fit: contain;
    display: block;
}

.project-placeholder {
    color: white;
    font-weight: 500;
    opacity: 0.8;
}

.project-content {
    padding: 2rem;
    flex: 1;
    display: flex;
    flex-direction: column;
}

.project-title {
    font-size: 1.5rem;
    font-weight: 600;
    margin-bottom: 1rem;
    color: var(--text-primary);
}

.project-description {
    color: var(--text-secondary);
    line-height: 1.7;
    margin-bottom: 1.5rem;
    flex: 1;
}

.project-tech {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
    margin-bottom: 1.5rem;
}

.tech-tag {
    padding: 0.375rem 0.875rem;
    background: var(--bg-accent);
    border-radius: 20px;
    font-size: 0.875rem;
    color: var(--text-secondary);
    font-weight: 500;
}

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

.project-link {
    color: var(--primary-color);
    text-decoration: none;
    font-weight: 600;
    padding: 0.5rem 1.25rem;
    border: 2px solid var(--primary-color);
    border-radius: 6px;
    transition: var(--transition);
    font-size: 0.9rem;
}

.project-link:hover {
    background: var(--primary-color);
    color: white;
    transform: translateY(-2px);
}

/* Contact Tab */
.contact {
    background: var(--bg-primary);
}

.contact-description {
    text-align: center;
    color: var(--text-secondary);
    font-size: 1.1rem;
    margin-bottom: 3rem;
    max-width: 600px;
    margin-left: auto;
    margin-right: auto;
}

.contact-icons {
    display: flex;
    justify-content: center;
    gap: 2rem;
    align-items: center;
    flex-wrap: wrap;
}

.contact-icon-link {
    color: var(--primary-color);
    transition: var(--transition);
    display: flex;
    align-items: center;
    justify-content: center;
    width: 50px;
    height: 50px;
    border-radius: 50%;
    background: var(--bg-accent);
    border: 2px solid var(--primary-color);
}

.contact-icon-link:hover {
    background: var(--primary-color);
    color: white;
    transform: translateY(-3px);
    box-shadow: var(--shadow-md);
}

.contact-icon-link svg {
    width: 24px;
    height: 24px;
}

.contact-content {
    max-width: 800px;
    margin: 0 auto;
}

.contact-info {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
}

.contact-item {
    display: flex;
    gap: 1.5rem;
    align-items: start;
    padding: 2rem;
    background: white;
    border-radius: 12px;
    box-shadow: var(--shadow-md);
    transition: var(--transition);
    border: 1px solid var(--border-color);
}

.contact-item:hover {
    transform: translateY(-3px);
    box-shadow: var(--shadow-lg);
}

.contact-icon {
    font-size: 2rem;
    flex-shrink: 0;
}

.contact-item h4 {
    font-size: 1.1rem;
    font-weight: 600;
    margin-bottom: 0.5rem;
    color: var(--text-primary);
}

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

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

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

.footer p {
    margin-bottom: 0.5rem;
}

/* Responsive Design */
@media (max-width: 768px) {
    .sidebar {
        width: 200px;
    }

    .main-content {
        margin-left: 200px;
        width: calc(100% - 200px);
    }

    .sidebar-logo {
        font-size: 1.5rem;
        padding: 1.5rem 1rem;
    }

    .sidebar-btn {
        padding: 0.875rem 1rem;
        font-size: 0.9rem;
    }

    .header-content {
        flex-direction: column;
        align-items: flex-start;
    }

    .header-icons {
        width: 100%;
        justify-content: flex-start;
    }

    .about-intro-wrapper {
        flex-direction: column;
        align-items: center;
        gap: 2rem;
    }

    .about-content {
        grid-template-columns: 1fr;
    }

    .skills-grid {
        grid-template-columns: 1fr;
    }

    .research-grid {
        grid-template-columns: 1fr;
    }

    .projects-grid {
        grid-template-columns: 1fr;
    }

    .contact-info {
        grid-template-columns: 1fr;
    }

    .hero-buttons {
        flex-direction: column;
        align-items: center;
    }

    .btn {
        width: 100%;
        max-width: 300px;
        text-align: center;
    }

    .container {
        padding: 0 1rem;
    }

    .tab-content {
        padding: 2rem 0;
    }
}

@media (max-width: 480px) {
    .sidebar {
        width: 70px;
    }

    .main-content {
        margin-left: 70px;
        width: calc(100% - 70px);
    }

    .sidebar-logo {
        font-size: 1.25rem;
        padding: 1rem 0.5rem;
        text-align: center;
    }

    .sidebar-btn {
        padding: 1rem 0.5rem;
        font-size: 0.75rem;
        text-align: center;
        border-left: none;
        border-bottom: 3px solid transparent;
    }

    .sidebar-btn.active {
        border-left: none;
        border-bottom-color: var(--primary-color);
    }

    #home {
        padding: 2rem 1rem;
    }

    .timeline {
        padding-left: 1.5rem;
    }

    .timeline-item {
        padding-left: 1.5rem;
    }

    .timeline-marker {
        left: -1.25rem;
    }
}