/* Simple Professional Animations - Light Mode Only */

/* Variables */
:root {
    --bg-color: #ffffff;
    --bg-secondary: #f8fafc;
    --text-color: #1f2937;
    --text-secondary: #6b7280;
    --accent-color: #2563eb;
    --shadow: rgba(0, 0, 0, 0.1);
    --gradient-blue: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    --gradient-purple: linear-gradient(135deg, #f093fb 0%, #f5576c 100%);
    --gradient-green: linear-gradient(135deg, #4facfe 0%, #00f2fe 100%);
    --gradient-orange: linear-gradient(135deg, #43e97b 0%, #38f9d7 100%);
}

/* Dark Mode Toggle Button - Removed */

/* Apply colors */
body {
    background-color: var(--bg-color);
    color: var(--text-color);
    transition: background-color 0.3s ease, color 0.3s ease;
}

.navbar {
    background: rgba(255, 255, 255, 0.95);
    transition: all 0.3s ease;
}

/* Simple fade-in animation */
.fade-in {
    opacity: 0;
    transform: translateY(20px);
    transition: all 0.6s ease;
}

.fade-in.visible {
    opacity: 1;
    transform: translateY(0);
}

/* Simple slide animations */
.slide-left {
    opacity: 0;
    transform: translateX(-30px);
    transition: all 0.6s ease;
}

.slide-left.visible {
    opacity: 1;
    transform: translateX(0);
}

.slide-right {
    opacity: 0;
    transform: translateX(30px);
    transition: all 0.6s ease;
}

.slide-right.visible {
    opacity: 1;
    transform: translateX(0);
}

/* Professional hover effects */
.card-hover {
    transition: all 0.3s ease;
}

.card-hover:hover {
    transform: translateY(-5px);
}

.education-content:hover,
.experience-content:hover {
    transform: translateY(-5px);
    box-shadow: 0 8px 25px rgba(0, 0, 0, 0.15);
}

/* Simplified flip cards */
.flip-card {
    opacity: 0;
    transform: translateY(30px);
    transition: all 0.6s ease;
}

.flip-card.visible {
    opacity: 1;
    transform: translateY(0);
}



.flip-card-inner {
    transition: transform 0.6s ease;
}

/* Section backgrounds */
.about, .courses, .opportunities, .students {
    background-color: var(--bg-secondary);
    transition: background-color 0.3s ease;
}

.education, .experience {
    background-color: var(--bg-color);
    transition: background-color 0.3s ease;
    position: relative;
}

/* Modern Interactive Timeline */
.timeline-container {
    position: relative;
    max-width: 800px;
    margin: 0 auto;
    padding: 2rem 0;
}

.timeline-progress {
    position: absolute;
    left: 50%;
    top: 0;
    bottom: 0;
    width: 6px;
    background: #e5e7eb;
    transform: translateX(-50%);
    border-radius: 3px;
    overflow: hidden;
}

.timeline-progress::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 0;
    background: linear-gradient(180deg, #2563eb, #60a5fa, #3b82f6);
    border-radius: 3px;
    animation: progressFill 3s ease-out forwards;
    animation-delay: 0.5s;
}

@keyframes progressFill {
    to { height: 100%; }
}

.timeline-item {
    position: relative;
    margin-bottom: 4rem;
    opacity: 0;
    transform: translateY(50px);
    transition: all 0.8s cubic-bezier(0.175, 0.885, 0.32, 1.275);
}

.timeline-item.visible {
    opacity: 1;
    transform: translateY(0);
}

.timeline-item:nth-child(odd) {
    padding-right: 55%;
}

.timeline-item:nth-child(even) {
    padding-left: 55%;
}

.timeline-content {
    background: white;
    border: 1px solid #e5e7eb;
    border-radius: 20px;
    padding: 2rem;
    box-shadow: 0 8px 30px rgba(0, 0, 0, 0.1);
    position: relative;
    transition: all 0.3s ease;
    border-left: 5px solid #2563eb;
}

.timeline-content:hover {
    transform: translateY(-8px);
    box-shadow: 0 15px 40px rgba(37, 99, 235, 0.2);
}

.timeline-dot {
    position: absolute;
    left: 50%;
    top: 2rem;
    width: 20px;
    height: 20px;
    background: #2563eb;
    border: 4px solid white;
    border-radius: 50%;
    transform: translateX(-50%);
    z-index: 10;
    box-shadow: 0 0 0 4px #2563eb;
    animation: dotPulse 2s infinite;
}

@keyframes dotPulse {
    0%, 100% { transform: translateX(-50%) scale(1); }
    50% { transform: translateX(-50%) scale(1.2); }
}

.timeline-item:nth-child(odd) .timeline-content::after {
    content: '';
    position: absolute;
    right: -15px;
    top: 2rem;
    width: 0;
    height: 0;
    border-left: 15px solid white;
    border-top: 10px solid transparent;
    border-bottom: 10px solid transparent;
}

.timeline-item:nth-child(even) .timeline-content::after {
    content: '';
    position: absolute;
    left: -15px;
    top: 2rem;
    width: 0;
    height: 0;
    border-right: 15px solid white;
    border-top: 10px solid transparent;
    border-bottom: 10px solid transparent;
}

.timeline-year {
    display: inline-block;
    background: linear-gradient(135deg, #2563eb, #3b82f6);
    color: white !important;
    padding: 0.6rem 1.2rem;
    border-radius: 25px;
    font-size: 0.9rem;
    font-weight: 600;
    margin-bottom: 1.5rem;
    box-shadow: 0 4px 15px rgba(37, 99, 235, 0.3);
}

.timeline-content h3 {
    color: #1f2937 !important;
    margin-bottom: 0.8rem;
    font-size: 1.3rem;
    font-weight: 600;
}

.timeline-content h4 {
    color: #2563eb !important;
    margin-bottom: 1rem;
    font-size: 1.1rem;
}

.timeline-content p {
    color: #6b7280 !important;
    margin-bottom: 0.8rem;
    line-height: 1.7;
}

.timeline-content .specialization {
    font-style: italic;
    color: #8b5cf6 !important;
    background: rgba(139, 92, 246, 0.1);
    padding: 0.3rem 0.8rem;
    border-radius: 15px;
    font-size: 0.85rem;
    display: inline-block;
    margin-bottom: 1rem;
}

/* Professional Gradient Cards */
.stat-item {
    background: var(--gradient-blue);
    color: white;
    border: none;
    border-radius: 16px;
    transition: all 0.3s ease;
}

.flip-card-front {
    background: var(--gradient-blue) !important;
    color: white;
}

.flip-card-back {
    background: var(--gradient-purple) !important;
    color: white;
}

.lab-card, .project-card {
    background: white;
    color: #1f2937;
    border: 1px solid #e5e7eb;
    border-radius: 16px;
    padding: 2rem;
    margin-bottom: 1.5rem;
    transition: all 0.3s ease;
    border-left: 4px solid #2563eb;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
}

.course-category {
    background: white;
    color: #1f2937;
    border: 1px solid #e5e7eb;
    border-radius: 16px;
    transition: all 0.3s ease;
    border-left: 4px solid #2563eb;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
}

.opportunity-card {
    background: white;
    color: #1f2937;
    border: 1px solid #e5e7eb;
    border-radius: 16px;
    transition: all 0.3s ease;
    border-left: 4px solid #2563eb;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
}

.award-card {
    background: linear-gradient(135deg, #ffd89b 0%, #19547b 100%);
    color: white;
    border: none;
    border-radius: 16px;
    transition: all 0.3s ease;
}

.research-item {
    background: white;
    color: #1f2937;
    border: 1px solid #e5e7eb;
    border-radius: 16px;
    transition: all 0.3s ease;
    border-left: 4px solid #2563eb;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
}

/* Text colors */
.section-title, .about-header h3, .course-category h3, .lab-card h3, .project-card h3, .research-item h3 {
    color: var(--text-color);
}

.about-text p, .course-category p, .lab-card p, .project-card p, .research-item p {
    color: var(--text-secondary);
}

.course-category h4, .lab-card h4, .project-card h4 {
    color: var(--text-color);
}

.course-category .course-item h4 {
    color: #2563eb;
}

.stat-number {
    color: white;
}

.stat-label {
    color: rgba(255, 255, 255, 0.8);
}

.research-number {
    background: #2563eb;
    color: white !important;
    display: flex;
    align-items: center;
    justify-content: center;
    width: 50px;
    height: 50px;
    border-radius: 50%;
    font-weight: 600;
    font-size: 1.1rem;
    flex-shrink: 0;
}

.research-item {
    display: flex;
    align-items: flex-start;
    gap: 1.5rem;
}

.research-content {
    flex: 1;
}

.research-images {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
    margin-bottom: 3rem;
}

.research-image-item {
    opacity: 0;
    transform: translateY(30px);
    transition: all 0.6s ease;
}

.research-image-item.visible {
    opacity: 1;
    transform: translateY(0);
}

.research-img {
    width: 100%;
    height: 250px;
    object-fit: cover;
    border-radius: 15px;
    box-shadow: 0 8px 25px rgba(0, 0, 0, 0.15);
    transition: all 0.3s ease;
}

.research-img:hover {
    transform: scale(1.05);
    box-shadow: 0 15px 35px rgba(0, 0, 0, 0.2);
}

.research-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
    gap: 2rem;
    max-width: 1000px;
    margin: 0 auto;
}

.contact-info h3 {
    color: var(--text-color);
}

.contact-info p, .office-address p {
    color: var(--text-secondary);
}

.contact-link {
    color: var(--text-color);
}

.opportunity-card h3 {
    color: #1f2937;
}

.opportunity-card p {
    color: #6b7280;
}

.motor-list li, .converter-list li {
    color: #374151;
}

.motor-list li::before {
    content: '⚙️';
}

.converter-list li::before {
    content: '🔧';
}

/* Card layouts */
.labs-content, .projects-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
    gap: 2rem;
}

.project-card h3, .lab-card h3 {
    margin-bottom: 1rem;
    font-size: 1.3rem;
}

.project-card p, .lab-card p {
    margin-bottom: 1rem;
    opacity: 0.9;
}

.project-card ul, .lab-card ul {
    list-style: none;
    padding: 0;
    margin: 0;
}

.project-card li, .lab-card li {
    padding: 0.5rem 0;
    position: relative;
    padding-left: 1.5rem;
}

.project-card li::before, .lab-card li::before {
    content: '✓';
    position: absolute;
    left: 0;
    color: #2563eb;
}

.project-status {
    display: inline-block;
    background: #2563eb;
    color: white;
    padding: 0.3rem 0.8rem;
    border-radius: 20px;
    font-size: 0.8rem;
    margin-top: 1rem;
}

/* Accent colors */
.nav-link:hover, .position {
    color: var(--accent-color);
}

.education-year, .experience-period {
    color: white !important;
}

.research-number, .award-year {
    color: var(--accent-color);
}

/* Simple stagger animation */
.stagger-item {
    opacity: 0;
    transform: translateY(20px);
    transition: all 0.6s ease;
}

.stagger-item:nth-child(1) { transition-delay: 0.1s; }
.stagger-item:nth-child(2) { transition-delay: 0.2s; }
.stagger-item:nth-child(3) { transition-delay: 0.3s; }
.stagger-item:nth-child(4) { transition-delay: 0.4s; }
.stagger-item:nth-child(5) { transition-delay: 0.5s; }
.stagger-item:nth-child(6) { transition-delay: 0.6s; }

.stagger-item.visible {
    opacity: 1;
    transform: translateY(0);
}

/* Simplified button hover */
.cta-button:hover {
    transform: translateY(-2px);
}

.social-link:hover {
    transform: translateY(-2px);
}

/* Professional navigation */
.nav-link:hover {
    transform: none;
}

.nav-link::after {
    transition: width 0.3s ease;
}

/* Mobile responsiveness */
@media (max-width: 768px) {
    .timeline-item:nth-child(odd),
    .timeline-item:nth-child(even) {
        padding-left: 0;
        padding-right: 0;
    }
    
    .timeline-content {
        margin-left: 3rem;
        margin-right: 0;
    }
    
    .timeline-progress {
        left: 1.5rem;
        transform: none;
    }
    
    .timeline-dot {
        left: 1.5rem;
        transform: translateX(-50%);
    }
    
    .timeline-content::after {
        display: none;
    }
    
    .labs-content, .projects-content {
        grid-template-columns: 1fr;
    }
}responsiveness */
@media (max-width: 768px) {
    .education-item:nth-child(odd),
    .education-item:nth-child(even),
    .experience-item:nth-child(odd),
    .experience-item:nth-child(even) {
        padding-left: 0;
        padding-right: 0;
    }
    
    .education-item:nth-child(odd) .education-content,
    .education-item:nth-child(even) .education-content,
    .experience-item:nth-child(odd) .experience-content,
    .experience-item:nth-child(even) .experience-content {
        margin-left: 2rem;
        margin-right: 0;
        text-align: left;
    }
    
    .education-timeline::before, .experience-timeline::before {
        left: 1rem;
    }
    

    
    .education-content::after, .experience-content::after {
        display: none;
    }
    
    .education-content::before, .experience-content::before {
        left: -6px !important;
        right: auto !important;
    }
    
    .labs-content, .projects-content {
        grid-template-columns: 1fr;
    }
}