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

body {
    font-family: 'Inter', sans-serif;
    line-height: 1.6;
    color: #1f2937;
    background: linear-gradient(135deg, #f0f9ff 0%, #ffffff 50%, #eef2ff 100%);
    min-height: 100vh;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 1rem;
}

/* Header Styles */
.header {
    background: rgba(255, 255, 255, 0.8);
    backdrop-filter: blur(12px);
    border-bottom: 1px solid rgba(229, 231, 235, 0.5);
    position: sticky;
    top: 0;
    z-index: 1000;
    transition: all 0.3s ease;
}

.header-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem 0;
}

.logo-section {
    display: flex;
    align-items: center;
    gap: 0.75rem;
}

.logo-icon {
    background: linear-gradient(135deg, #2563eb, #4f46e5);
    padding: 0.5rem;
    border-radius: 0.5rem;
    color: white;
    display: flex;
    align-items: center;
    justify-content: center;
}

.logo-icon i {
    width: 2rem;
    height: 2rem;
}

.logo-title {
    font-size: 1.5rem;
    font-weight: 700;
    background: linear-gradient(135deg, #2563eb, #4f46e5);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.logo-subtitle {
    font-size: 0.875rem;
    color: #6b7280;
}

.nav {
    display: flex;
    gap: 2rem;
}

.nav-link {
    color: #374151;
    text-decoration: none;
    font-weight: 500;
    transition: color 0.3s ease;
    position: relative;
}

.nav-link:hover {
    color: #2563eb;
}

.nav-link::after {
    content: '';
    position: absolute;
    bottom: -0.25rem;
    left: 0;
    width: 0;
    height: 2px;
    background: linear-gradient(135deg, #2563eb, #4f46e5);
    transition: width 0.3s ease;
}

.nav-link:hover::after {
    width: 100%;
}

.mobile-menu-btn {
    display: none;
    background: none;
    border: none;
    color: #374151;
    cursor: pointer;
    padding: 0.5rem;
}

.mobile-menu {
    display: none;
    position: fixed;
    top: 100%;
    left: 0;
    right: 0;
    background: white;
    border-bottom: 1px solid #e5e7eb;
    padding: 1rem;
    z-index: 999;
    transform: translateY(-100%);
    transition: transform 0.3s ease;
}

.mobile-menu.active {
    transform: translateY(0);
}

.mobile-nav-link {
    display: block;
    padding: 0.75rem 0;
    color: #374151;
    text-decoration: none;
    font-weight: 500;
    border-bottom: 1px solid #f3f4f6;
}

.mobile-nav-link:hover {
    color: #2563eb;
}

/* Hero Section */
.hero {
    padding: 5rem 0;
    text-align: center;
}

.hero-content {
    max-width: 4xl;
    margin: 0 auto;
}

.hero-badge {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    background: #f1f5f9;
    color: #475569;
    padding: 0.5rem 1rem;
    border-radius: 9999px;
    font-size: 0.875rem;
    font-weight: 500;
    margin-bottom: 2rem;
}

.hero-badge i {
    width: 1rem;
    height: 1rem;
    color: #ef4444;
}

.hero-title {
    font-size: clamp(2.5rem, 5vw, 4rem);
    font-weight: 700;
    color: #1f2937;
    margin-bottom: 1.5rem;
    line-height: 1.1;
}

.gradient-text {
    background: linear-gradient(135deg, #2563eb, #4f46e5);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.hero-description {
    font-size: 1.25rem;
    color: #6b7280;
    margin-bottom: 2rem;
    max-width: 48rem;
    margin-left: auto;
    margin-right: auto;
    line-height: 1.6;
}

.hero-buttons {
    display: flex;
    flex-direction: column;
    gap: 1rem;
    align-items: center;
}

@media (min-width: 640px) {
    .hero-buttons {
        flex-direction: row;
        justify-content: center;
    }
}

/* Button Styles */
.btn {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.75rem 1.5rem;
    border-radius: 0.5rem;
    font-weight: 600;
    text-decoration: none;
    border: none;
    cursor: pointer;
    transition: all 0.3s ease;
    font-size: 1rem;
}

.btn i {
    width: 1.25rem;
    height: 1.25rem;
}

.btn-primary {
    background: linear-gradient(135deg, #2563eb, #4f46e5);
    color: white;
}

.btn-primary:hover {
    background: linear-gradient(135deg, #1d4ed8, #4338ca);
    transform: translateY(-2px);
    box-shadow: 0 10px 25px rgba(37, 99, 235, 0.3);
}

.btn-secondary {
    background: white;
    color: #374151;
    border: 1px solid #d1d5db;
}

.btn-secondary:hover {
    background: #f9fafb;
    border-color: #9ca3af;
    transform: translateY(-2px);
    box-shadow: 0 10px 25px rgba(0, 0, 0, 0.1);
}

.btn-book {
    background: #2563eb;
    color: white;
    width: 100%;
}

.btn-book:hover {
    background: #1d4ed8;
    transform: translateY(-2px);
}

.btn-video {
    background: #7c3aed;
    color: white;
    width: 100%;
}

.btn-video:hover {
    background: #6d28d9;
    transform: translateY(-2px);
}

.btn-full {
    width: 100%;
}

/* Section Styles */
section {
    padding: 5rem 0;
}

.section-header {
    text-align: center;
    margin-bottom: 4rem;
}

.section-title {
    font-size: 2.5rem;
    font-weight: 700;
    color: #1f2937;
    margin-bottom: 1rem;
}

.section-description {
    font-size: 1.25rem;
    color: #6b7280;
    max-width: 48rem;
    margin: 0 auto 1rem;
}

.section-divider {
    width: 6rem;
    height: 0.25rem;
    background: linear-gradient(135deg, #2563eb, #4f46e5);
    margin: 0 auto;
    border-radius: 9999px;
}

/* About Section */
.about {
    background: rgba(255, 255, 255, 0.5);
}

.about-content {
    display: grid;
    gap: 3rem;
    align-items: start;
}

@media (min-width: 1024px) {
    .about-content {
        grid-template-columns: 1fr 1fr;
    }
}

.about-card {
    background: linear-gradient(135deg, #dbeafe, #e0e7ff);
    padding: 2rem;
    border-radius: 1rem;
    box-shadow: 0 10px 25px rgba(0, 0, 0, 0.1);
}

.about-name {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    margin-bottom: 1rem;
}

.about-name i {
    width: 2rem;
    height: 2rem;
    color: #2563eb;
}

.about-name h3 {
    font-size: 1.5rem;
    font-weight: 700;
    color: #1f2937;
}

.about-degree {
    font-size: 1.125rem;
    font-weight: 500;
    color: #374151;
    margin-bottom: 1.5rem;
}

.about-description {
    color: #374151;
    line-height: 1.6;
    margin-bottom: 1.5rem;
}

.philosophy h4 {
    font-size: 1.125rem;
    font-weight: 600;
    color: #1f2937;
    margin-bottom: 0.75rem;
}

.philosophy-list {
    list-style: none;
}

.philosophy-list li {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    margin-bottom: 0.5rem;
    color: #374151;
}

.bullet {
    width: 0.5rem;
    height: 0.5rem;
    background: #2563eb;
    border-radius: 50%;
    flex-shrink: 0;
}

.about-features {
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
}

.feature-card {
    background: white;
    padding: 1.5rem;
    border-radius: 0.75rem;
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.1);
    display: flex;
    gap: 1rem;
    transition: all 0.3s ease;
}

.feature-card:hover {
    transform: translateY(-4px);
    box-shadow: 0 10px 25px rgba(0, 0, 0, 0.15);
}

.feature-icon {
    background: #dbeafe;
    padding: 0.75rem;
    border-radius: 0.5rem;
    flex-shrink: 0;
}

.feature-icon i {
    width: 1.5rem;
    height: 1.5rem;
    color: #2563eb;
}

.feature-content h4 {
    font-weight: 600;
    color: #1f2937;
    margin-bottom: 0.5rem;
}

.feature-content p {
    color: #6b7280;
    line-height: 1.5;
}

/* Materials Section */
.materials-grid {
    display: grid;
    gap: 2rem;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
}

.material-card {
    background: white;
    padding: 2rem;
    border-radius: 1rem;
    text-align: center;
    transition: all 0.3s ease;
    border: 1px solid transparent;
    position: relative;
    overflow: hidden;
}

.material-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    opacity: 0;
    transition: opacity 0.3s ease;
    border-radius: 1rem;
}

.material-card:hover {
    transform: translateY(-8px);
    box-shadow: 0 20px 40px rgba(0, 0, 0, 0.15);
}

.material-card:hover::before {
    opacity: 1;
}

.engineering {
    background: linear-gradient(135deg, #dbeafe, #bfdbfe);
}

.machine-learning {
    background: linear-gradient(135deg, #dcfce7, #bbf7d0);
}

.ai {
    background: linear-gradient(135deg, #f3e8ff, #e9d5ff);
}

.deep-learning {
    background: linear-gradient(135deg, #fed7aa, #fdba74);
}

.material-icon {
    width: 4rem;
    height: 4rem;
    margin: 0 auto 1.5rem;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: transform 0.3s ease;
}

.material-card:hover .material-icon {
    transform: scale(1.1);
}

.engineering .material-icon {
    background: #2563eb;
    color: white;
}

.machine-learning .material-icon {
    background: #16a34a;
    color: white;
}

.ai .material-icon {
    background: #7c3aed;
    color: white;
}

.deep-learning .material-icon {
    background: #ea580c;
    color: white;
}

.material-icon i {
    width: 2rem;
    height: 2rem;
}

.material-title {
    font-size: 1.25rem;
    font-weight: 700;
    color: #1f2937;
    margin-bottom: 1rem;
}

.material-description {
    color: #374151;
    line-height: 1.5;
    margin-bottom: 1.5rem;
}

.material-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
    justify-content: center;
}

.tag {
    background: rgba(255, 255, 255, 0.8);
    color: #374151;
    padding: 0.25rem 0.75rem;
    border-radius: 9999px;
    font-size: 0.875rem;
    font-weight: 500;
}

/* Books Section */
.books {
    background: rgba(255, 255, 255, 0.5);
}

.books-grid {
    display: grid;
    gap: 3rem;
    grid-template-columns: repeat(auto-fit, minmax(400px, 1fr));
}

.book-card {
    background: white;
    border-radius: 1rem;
    overflow: hidden;
    box-shadow: 0 10px 25px rgba(0, 0, 0, 0.1);
    transition: all 0.3s ease;
}

.book-card:hover {
    transform: translateY(-8px);
    box-shadow: 0 20px 40px rgba(0, 0, 0, 0.15);
}

.book-image {
    aspect-ratio: 16/9;
    background: linear-gradient(135deg, #dbeafe, #bfdbfe);
    display: flex;
    align-items: center;
    justify-content: center;
}

.book-image i {
    width: 6rem;
    height: 6rem;
    color: #2563eb;
}

.book-card:nth-child(2) .book-image {
    background: linear-gradient(135deg, #e0e7ff, #c7d2fe);
}

.book-card:nth-child(2) .book-image i {
    color: #4f46e5;
}

.book-content {
    padding: 2rem;
}

.book-title {
    font-size: 1.5rem;
    font-weight: 700;
    color: #1f2937;
    margin-bottom: 0.5rem;
}

.book-subtitle {
    font-size: 1.125rem;
    color: #6b7280;
    margin-bottom: 1rem;
}

.book-description {
    color: #374151;
    line-height: 1.5;
    margin-bottom: 1.5rem;
}

/* Videos Section */
.videos-grid {
    display: grid;
    gap: 3rem;
    grid-template-columns: repeat(auto-fit, minmax(400px, 1fr));
}

.video-card {
    background: white;
    border-radius: 1rem;
    overflow: hidden;
    box-shadow: 0 10px 25px rgba(0, 0, 0, 0.1);
    transition: all 0.3s ease;
}

.video-card:hover {
    transform: translateY(-8px);
    box-shadow: 0 20px 40px rgba(0, 0, 0, 0.15);
}

.video-image {
    aspect-ratio: 16/9;
    background: linear-gradient(135deg, #dcfce7, #bbf7d0);
    display: flex;
    align-items: center;
    justify-content: center;
}

.video-image i {
    width: 6rem;
    height: 6rem;
    color: #16a34a;
}

.video-card:nth-child(2) .video-image {
    background: linear-gradient(135deg, #f3e8ff, #e9d5ff);
}

.video-card:nth-child(2) .video-image i {
    color: #7c3aed;
}

.video-content {
    padding: 2rem;
}

.video-title {
    font-size: 1.5rem;
    font-weight: 700;
    color: #1f2937;
    margin-bottom: 0.5rem;
}

.video-subtitle {
    font-size: 1.125rem;
    color: #6b7280;
    margin-bottom: 1rem;
}

.video-description {
    color: #374151;
    line-height: 1.5;
    margin-bottom: 1.5rem;
}

/* Contact Section */
.contact {
    background: linear-gradient(135deg, #f9fafb, #f3f4f6);
}

.contact-content {
    display: grid;
    gap: 3rem;
    grid-template-columns: repeat(auto-fit, minmax(400px, 1fr));
}

.contact-info {
    display: flex;
    flex-direction: column;
    gap: 2rem;
}

.contact-item {
    background: white;
    padding: 2rem;
    border-radius: 0.75rem;
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.1);
    display: flex;
    gap: 1rem;
}

.contact-icon {
    background: #dbeafe;
    padding: 0.75rem;
    border-radius: 0.5rem;
    flex-shrink: 0;
}

.contact-icon i {
    width: 1.5rem;
    height: 1.5rem;
    color: #2563eb;
}

.contact-item:nth-child(2) .contact-icon {
    background: #e0e7ff;
}

.contact-item:nth-child(2) .contact-icon i {
    color: #4f46e5;
}

.contact-details h4 {
    font-weight: 600;
    color: #1f2937;
    margin-bottom: 0.5rem;
}

.contact-details p {
    color: #6b7280;
    line-height: 1.5;
}

.contact-details a {
    color: #4f46e5;
    text-decoration: none;
    transition: color 0.3s ease;
}

.contact-details a:hover {
    color: #3730a3;
}

.contact-form {
    background: white;
    padding: 2rem;
    border-radius: 0.75rem;
    box-shadow: 0 10px 25px rgba(0, 0, 0, 0.1);
}

.contact-form h3 {
    font-size: 1.25rem;
    font-weight: 600;
    color: #1f2937;
    margin-bottom: 1.5rem;
}

.form-group {
    margin-bottom: 1rem;
}

.form-group label {
    display: block;
    font-weight: 500;
    color: #374151;
    margin-bottom: 0.5rem;
}

.form-group input,
.form-group textarea {
    width: 100%;
    padding: 0.75rem 1rem;
    border: 2px solid #e5e7eb;
    border-radius: 0.5rem;
    font-size: 1rem;
    transition: border-color 0.3s ease;
}

.form-group input:focus,
.form-group textarea:focus {
    outline: none;
    border-color: #2563eb;
    box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.1);
}

.form-group textarea {
    resize: vertical;
    min-height: 100px;
}

.form-message {
    margin-top: 1rem;
    padding: 1rem;
    border-radius: 0.5rem;
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-weight: 500;
}

.form-message.success {
    background: #d1fae5;
    color: #065f46;
    border: 1px solid #a7f3d0;
}

.form-message.error {
    background: #fee2e2;
    color: #991b1b;
    border: 1px solid #fecaca;
}

/* Footer */
.footer {
    background: #1f2937;
    color: white;
    padding: 3rem 0 1.5rem;
}

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

.footer-logo {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    margin-bottom: 1rem;
}

.footer-logo-icon {
    background: linear-gradient(135deg, #2563eb, #4f46e5);
    padding: 0.5rem;
    border-radius: 0.5rem;
    display: flex;
    align-items: center;
    justify-content: center;
}

.footer-logo-icon i {
    width: 1.5rem;
    height: 1.5rem;
    color: white;
}

.footer-logo h3 {
    font-size: 1.25rem;
    font-weight: 700;
}

.footer-description {
    color: #9ca3af;
    line-height: 1.5;
}

.footer-section h4 {
    font-weight: 600;
    margin-bottom: 1rem;
}

.footer-links {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.footer-links a {
    color: #9ca3af;
    text-decoration: none;
    transition: color 0.3s ease;
}

.footer-links a:hover {
    color: white;
}

.footer-contact {
    color: #9ca3af;
}

.footer-contact p {
    margin-bottom: 0.25rem;
}

.footer-divider {
    height: 1px;
    background: #374151;
    margin: 2rem 0;
}

.footer-bottom {
    text-align: center;
    color: #9ca3af;
}

/* Responsive Design */
@media (max-width: 768px) {
    .nav {
        display: none;
    }
    
    .mobile-menu-btn {
        display: block;
    }
    
    .mobile-menu {
        display: block;
    }
    
    .hero {
        padding: 3rem 0;
    }
    
    .hero-title {
        font-size: 2.5rem;
    }
    
    .hero-description {
        font-size: 1.125rem;
    }
    
    section {
        padding: 3rem 0;
    }
    
    .section-title {
        font-size: 2rem;
    }
    
    .section-description {
        font-size: 1.125rem;
    }
    
    .materials-grid {
        grid-template-columns: 1fr;
    }
    
    .books-grid,
    .videos-grid {
        grid-template-columns: 1fr;
    }
    
    .contact-content {
        grid-template-columns: 1fr;
    }
    
    .footer-content {
        grid-template-columns: 1fr;
        text-align: center;
    }
}

@media (max-width: 480px) {
    .container {
        padding: 0 0.75rem;
    }
    
    .hero-title {
        font-size: 2rem;
    }
    
    .about-card,
    .contact-form {
        padding: 1.5rem;
    }
    
    .material-card {
        padding: 1.5rem;
    }
    
    .book-content,
    .video-content {
        padding: 1.5rem;
    }
}

/* Smooth Scrolling */
html {
    scroll-behavior: smooth;
}

/* Loading Animation */
@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.fade-in-up {
    animation: fadeInUp 0.6s ease-out;
}

/* Hover Effects */
.material-card:hover,
.book-card:hover,
.video-card:hover,
.feature-card:hover {
    animation: none;
}

/* Focus States */
.btn:focus,
input:focus,
textarea:focus {
    outline: 2px solid #2563eb;
    outline-offset: 2px;
}

/* Video Modal Styles */
.modal {
    display: none;
    position: fixed;
    z-index: 10000;
    left: 0;
    top: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(0, 0, 0, 0.8);
    backdrop-filter: blur(5px);
}

.modal-content {
    position: relative;
    background-color: #fff;
    margin: 5% auto;
    padding: 0;
    width: 90%;
    max-width: 800px;
    border-radius: 12px;
    box-shadow: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 10px 10px -5px rgba(0, 0, 0, 0.04);
    animation: modalSlideIn 0.3s ease-out;
}

.close {
    position: absolute;
    top: 15px;
    right: 20px;
    color: #fff;
    font-size: 28px;
    font-weight: bold;
    cursor: pointer;
    z-index: 10001;
    background: rgba(0, 0, 0, 0.5);
    border-radius: 50%;
    width: 40px;
    height: 40px;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all 0.3s ease;
}

.close:hover {
    background: rgba(0, 0, 0, 0.8);
    transform: scale(1.1);
}

.video-container {
    position: relative;
    padding-bottom: 56.25%; /* 16:9 aspect ratio */
    height: 0;
    overflow: hidden;
    border-radius: 0 0 12px 12px;
}

.video-container iframe {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    border: none;
}

@keyframes modalSlideIn {
    from {
        opacity: 0;
        transform: translateY(-50px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* Print Styles */
@media print {
    .header,
    .footer,
    .mobile-menu {
        display: none;
    }
    
    body {
        background: white;
    }
    
    .hero,
    .about,
    .materials,
    .books,
    .videos,
    .contact {
        background: white;
        box-shadow: none;
    }
}