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

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Arial', 'Helvetica', sans-serif;
    line-height: 1.6;
    color: #333;
    background-color: #fff;
}

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

/* ===== Language Toggle ===== */
.language-toggle {
    position: fixed;
    top: 20px;
    right: 20px;
    z-index: 1000;
    display: flex;
    background: rgba(255, 255, 255, 0.95);
    border-radius: 20px;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
    backdrop-filter: blur(10px);
}

.lang-btn {
    background: transparent;
    border: none;
    padding: 8px 16px;
    cursor: pointer;
    border-radius: 20px;
    font-weight: 600;
    font-size: 14px;
    color: #666;
    transition: all 0.3s ease;
}

.lang-btn.active {
    background: #2c5aa0;
    color: white;
}

.lang-btn:hover {
    background: #2c5aa0;
    color: white;
}

/* ===== Header ===== */
.header {
    background: linear-gradient(135deg, #2c5aa0 0%, #1e4080 100%);
    color: white;
    padding: 35px 0 25px;
    text-align: center;
    min-height: 140px;
    display: flex;
    align-items: center;
}

.header-content {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 25px;
    width: 100%;
}

.profile-section {
    display: flex;
    align-items: center;
    gap: 20px;
    text-align: left;
}

.profile-image {
    flex-shrink: 0;
    width: 90px;
    height: 90px;
}

.profile-image img {
    width: 90px;
    height: 90px;
    border-radius: 50%;
    border: 3px solid rgba(255, 255, 255, 0.2);
    object-fit: cover;
    transition: transform 0.3s ease;
}

.profile-image img:hover {
    transform: scale(1.05);
}

.profile-info {
    min-width: 420px;
    min-height: 90px;
    display: flex;
    flex-direction: column;
    justify-content: center;
    transition: all 0.3s ease;
}

.profile-info h1 {
    font-size: 2rem;
    font-weight: 700;
    margin-bottom: 5px;
    line-height: 1.2;
    min-height: 2.4rem;
    display: flex;
    align-items: center;
    transition: all 0.3s ease;
}

.profile-info h2 {
    font-size: 1rem;
    font-weight: 400;
    margin-bottom: 4px;
    opacity: 0.9;
    line-height: 1.2;
    min-height: 1.2rem;
    display: flex;
    align-items: center;
    transition: all 0.3s ease;
}

.profile-info h3 {
    font-size: 0.9rem;
    font-weight: 400;
    opacity: 0.8;
    line-height: 1.2;
    min-height: 1.08rem;
    display: flex;
    align-items: center;
    transition: all 0.3s ease;
}

/* ===== Navigation ===== */
.navbar {
    background: white;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
    position: sticky;
    top: 0;
    z-index: 999;
}

.nav-menu {
    display: flex;
    list-style: none;
    justify-content: center;
    padding: 0;
    margin: 0;
}

.nav-item {
    margin: 0;
}

.nav-link {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 6px;
    padding: 12px 12px;
    text-decoration: none;
    color: #666;
    font-weight: 500;
    font-size: 0.9rem;
    transition: all 0.3s ease;
    border-bottom: 2px solid transparent;
    white-space: nowrap;
    width: 90px;
    text-align: center;
}

/* Specific widths for different nav items */
.nav-link[data-section="about"] {
    width: 85px;
}

.nav-link[data-section="experience"] {
    width: 100px;
}

.nav-link[data-section="research"] {
    width: 100px;
}

.nav-link[data-section="publications"] {
    width: 115px;
}

.nav-link[data-section="recognition"] {
    width: 105px;
}

.nav-link[data-section="teaching"] {
    width: 95px;
}

.nav-link:hover,
.nav-link.active {
    color: #2c5aa0;
    border-bottom-color: #2c5aa0;
    background: rgba(44, 90, 160, 0.05);
}

.nav-link i {
    font-size: 14px;
}

.mobile-menu-toggle {
    display: none;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    cursor: pointer;
    padding: 15px;
    color: #666;
}

/* ===== Main Content ===== */
.main-content {
    padding: 25px 0 40px;
    min-height: calc(100vh - 300px);
}

.content-section {
    display: none;
    animation: fadeIn 0.5s ease-in-out;
}

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

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

.section-title {
    font-size: 1.8rem;
    font-weight: 700;
    color: #2c5aa0;
    margin-bottom: 25px;
    text-align: center;
    position: relative;
}

.section-title::after {
    content: '';
    position: absolute;
    bottom: -8px;
    left: 50%;
    transform: translateX(-50%);
    width: 50px;
    height: 3px;
    background: #2c5aa0;
    border-radius: 2px;
}

/* ===== About Section ===== */
.about-content {
    display: grid;
    gap: 25px;
    max-width: 1000px;
    margin: 0 auto;
}

.bio-section {
    background: #f8f9fa;
    padding: 20px;
    border-radius: 8px;
    border-left: 4px solid #2c5aa0;
}

.bio-text {
    font-size: 1rem;
    line-height: 1.6;
    color: #444;
}

.contact-info {
    background: white;
    padding: 20px;
    border-radius: 8px;
    box-shadow: 0 2px 12px rgba(0, 0, 0, 0.1);
}

.contact-info h3 {
    font-size: 1.2rem;
    color: #2c5aa0;
    margin-bottom: 15px;
    font-weight: 600;
}

.contact-item {
    display: flex;
    align-items: center;
    gap: 10px;
    margin-bottom: 12px;
    font-size: 0.95rem;
}

.contact-item i {
    color: #2c5aa0;
    width: 18px;
    text-align: center;
}

.research-overview {
    background: white;
    padding: 20px;
    border-radius: 8px;
    box-shadow: 0 2px 12px rgba(0, 0, 0, 0.1);
}

.research-overview h3 {
    font-size: 1.2rem;
    color: #2c5aa0;
    margin-bottom: 20px;
    font-weight: 600;
}

.research-list {
    list-style: none;
    padding: 0;
}

.research-list li {
    padding: 15px 0;
    border-bottom: 1px solid #eee;
    position: relative;
    padding-left: 20px;
    line-height: 1.6;
}

.research-list li:before {
    content: '▶';
    color: #2c5aa0;
    position: absolute;
    left: 0;
    top: 15px;
}

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

/* ===== Timeline Styles ===== */
.timeline {
    position: relative;
    padding-left: 25px;
}

.timeline::before {
    content: '';
    position: absolute;
    left: 12px;
    top: 0;
    bottom: 0;
    width: 2px;
    background: #2c5aa0;
}

.timeline-item {
    position: relative;
    margin-bottom: 20px;
    background: white;
    padding: 18px;
    border-radius: 8px;
    box-shadow: 0 2px 12px rgba(0, 0, 0, 0.1);
    margin-left: 25px;
}

.timeline-item::before {
    content: '';
    position: absolute;
    left: -35px;
    top: 22px;
    width: 10px;
    height: 10px;
    background: #2c5aa0;
    border-radius: 50%;
    border: 3px solid white;
}

.timeline-year {
    background: #2c5aa0;
    color: white;
    padding: 3px 10px;
    border-radius: 12px;
    font-size: 0.85rem;
    font-weight: 600;
    display: inline-block;
    margin-right: 10px;
    margin-bottom: 0;
    vertical-align: middle;
}

.timeline-header {
    display: flex;
    align-items: center;
    margin-bottom: 6px;
}

.timeline-title {
    font-size: 1.1rem;
    font-weight: 600;
    color: #333;
    margin-bottom: 0;
    flex: 1;
}

.timeline-subtitle {
    color: #666;
    font-style: italic;
    margin-bottom: 10px;
    font-size: 0.9rem;
}

.timeline-content {
    color: #555;
    line-height: 1.5;
    font-size: 0.95rem;
}

/* ===== Cards ===== */
.card {
    background: white;
    border-radius: 8px;
    padding: 18px;
    box-shadow: 0 2px 12px rgba(0, 0, 0, 0.1);
    margin-bottom: 15px;
    transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.card:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.15);
}

.card h3 {
    color: #2c5aa0;
    font-size: 1.1rem;
    margin-bottom: 12px;
    font-weight: 600;
}

.card p {
    color: #555;
    line-height: 1.5;
    margin-bottom: 8px;
    font-size: 0.95rem;
}

/* ===== Publication Styles ===== */
.publication-year {
    background: #f8f9fa;
    padding: 12px 16px;
    margin: 15px 0;
    border-left: 3px solid #2c5aa0;
    border-radius: 0 6px 6px 0;
}

.publication-year h3 {
    color: #2c5aa0;
    font-size: 1.2rem;
    font-weight: 600;
}

.publication-section {
    margin-bottom: 25px;
}

.publication-section h3 {
    color: #2c5aa0;
    font-size: 1.1rem;
    font-weight: 600;
    margin-bottom: 15px;
    padding-bottom: 8px;
    border-bottom: 2px solid #e9ecef;
}

.publication-item {
    background: white;
    padding: 15px;
    margin-bottom: 12px;
    border-radius: 6px;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.08);
    border-left: 3px solid #e9ecef;
    transition: all 0.2s ease;
}

.publication-item:hover {
    border-left-color: #2c5aa0;
    box-shadow: 0 3px 12px rgba(0, 0, 0, 0.12);
}

.publication-item.highlight {
    border-left-color: #28a745;
    background: linear-gradient(to right, #f8fff9, #ffffff);
}

.publication-title {
    font-weight: 600;
    color: #333;
    margin-bottom: 6px;
    font-size: 1rem;
    line-height: 1.3;
}

.publication-authors {
    color: #666;
    margin-bottom: 4px;
    font-size: 0.9rem;
}

.publication-venue {
    color: #2c5aa0;
    font-style: italic;
    font-size: 0.9rem;
    margin-bottom: 4px;
}

.publication-details {
    color: #777;
    font-size: 0.85rem;
    margin-top: 4px;
    font-style: italic;
}

.publication-note {
    color: #28a745;
    font-size: 0.85rem;
    margin-top: 6px;
    padding: 4px 8px;
    background: #f8fff9;
    border-radius: 4px;
    border-left: 3px solid #28a745;
}

/* ===== Award/Achievement Styles ===== */
.achievement-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 18px;
    margin-top: 15px;
}

.achievement-item {
    background: white;
    padding: 18px;
    border-radius: 8px;
    box-shadow: 0 2px 12px rgba(0, 0, 0, 0.1);
    border-top: 3px solid #2c5aa0;
    transition: transform 0.2s ease;
}

.achievement-item:hover {
    transform: translateY(-2px);
}

.achievement-icon {
    font-size: 1.8rem;
    color: #2c5aa0;
    margin-bottom: 12px;
}

.achievement-title {
    font-size: 1.1rem;
    font-weight: 600;
    color: #333;
    margin-bottom: 8px;
}

.achievement-description {
    color: #666;
    line-height: 1.5;
    font-size: 0.95rem;
}

/* ===== Footer ===== */
.footer {
    background: #2c5aa0;
    color: white;
    text-align: center;
    padding: 30px 0;
    margin-top: 60px;
}

.footer p {
    margin-bottom: 5px;
    opacity: 0.9;
}

/* ===== Utility Classes ===== */
.text-center {
    text-align: center;
}

.mb-20 {
    margin-bottom: 20px;
}

.mb-30 {
    margin-bottom: 30px;
}

.highlight {
    background: #fff3cd;
    padding: 2px 6px;
    border-radius: 4px;
    font-weight: 600;
}

/* ===== Loading States ===== */
.loading {
    display: flex;
    justify-content: center;
    align-items: center;
    padding: 40px;
    font-style: italic;
    color: #666;
}

/* ===== Responsive Design Preparation ===== */
@media (max-width: 768px) {
    .container {
        padding: 0 15px;
    }
    
    .profile-section {
        flex-direction: column;
        text-align: center;
        gap: 20px;
    }
    
    .header-content {
        flex-direction: column;
        gap: 20px;
    }
    
    .profile-info h1 {
        font-size: 2rem;
    }
}