/* SourceKode Modern CSS - Coursera Inspired Design */

/* CSS Variables for consistent theming */
:root {
    --primary-color: #0056d3;
    --primary-dark: #004bb8;
    --primary-light: #e6f2ff;
    --secondary-color: #00c896;
    --warning-color: #f4b942;
    --danger-color: #e74c3c;
    --dark-color: #1a1a1a;
    --gray-100: #f8f9fa;
    --gray-200: #e9ecef;
    --gray-300: #dee2e6;
    --gray-400: #ced4da;
    --gray-500: #adb5bd;
    --gray-600: #6c757d;
    --gray-700: #495057;
    --gray-800: #343a40;
    --gray-900: #212529;
    --font-family-primary: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    --border-radius: 8px;
    --border-radius-lg: 12px;
    --box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
    --box-shadow-lg: 0 10px 30px rgba(0, 0, 0, 0.15);
    --transition: all 0.3s ease;
}

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

body {
    font-family: var(--font-family-primary);
    font-size: 16px;
    line-height: 1.6;
    color: var(--gray-800);
    background-color: #ffffff;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

html {
    scroll-behavior: smooth;
}

/* Typography */
h1, h2, h3, h4, h5, h6 {
    font-weight: 600;
    line-height: 1.3;
    color: var(--gray-900);
}

.display-4 {
    font-weight: 700;
    line-height: 1.2;
}

.display-5 {
    font-weight: 700;
    line-height: 1.2;
}

.lead {
    font-size: 1.125rem;
    font-weight: 400;
    line-height: 1.6;
}

/* Custom Button Styles */
.btn {
    font-weight: 500;
    border-radius: var(--border-radius);
    padding: 0.75rem 1.5rem;
    transition: var(--transition);
    border: none;
    text-decoration: none;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    font-size: 0.95rem;
}

.btn-lg {
    padding: 1rem 2rem;
    font-size: 1.1rem;
    border-radius: var(--border-radius-lg);
}

.btn-primary {
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--primary-dark) 100%);
    color: white;
    box-shadow: 0 4px 15px rgba(0, 86, 211, 0.3);
}

.btn-primary:hover {
    background: linear-gradient(135deg, var(--primary-dark) 0%, #003a9e 100%);
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(0, 86, 211, 0.4);
    color: white;
}

.btn-outline-primary {
    border: 2px solid var(--primary-color);
    color: var(--primary-color);
    background-color: transparent;
}

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

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

.btn-light:hover {
    background-color: var(--gray-100);
    color: var(--primary-color);
    transform: translateY(-2px);
}

.btn-outline-light {
    border: 2px solid white;
    color: white;
    background-color: transparent;
}

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

/* Navigation Styles */
.navbar {
    padding: 1rem 0;
    transition: var(--transition);
    background-color: rgba(255, 255, 255, 0.95) !important;
    backdrop-filter: blur(10px);
}

.navbar-brand img {
    transition: var(--transition);
}

.navbar-nav .nav-link {
    font-weight: 500;
    color: var(--gray-700) !important;
    padding: 0.75rem 1rem !important;
    margin: 0 0.25rem;
    border-radius: var(--border-radius);
    transition: var(--transition);
}

.navbar-nav .nav-link:hover,
.navbar-nav .nav-link.active {
    color: var(--primary-color) !important;
    background-color: var(--primary-light);
}

/* Mega Menu Styles */
.mega-menu {
    border: none;
    box-shadow: var(--box-shadow-lg);
    border-radius: var(--border-radius-lg);
    padding: 2rem;
    margin-top: 0.5rem;
    min-width: 800px;
}

.mega-menu .dropdown-header {
    font-weight: 600;
    color: var(--primary-color);
    font-size: 0.9rem;
    text-transform: uppercase;
    letter-spacing: 0.5px;
    margin-bottom: 1rem;
}

.mega-menu .dropdown-item {
    padding: 0.75rem 0;
    font-weight: 400;
    color: var(--gray-700);
    transition: var(--transition);
    border-radius: var(--border-radius);
    margin-bottom: 0.25rem;
}

.mega-menu .dropdown-item:hover {
    background-color: var(--primary-light);
    color: var(--primary-color);
    padding-left: 1rem;
}

/* Hero Section */
.hero-section {
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--primary-dark) 50%, #002d7a 100%);
    position: relative;
    overflow: hidden;
}

.hero-section::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: url('data:image/svg+xml,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 1000 1000"><polygon fill="rgba(255,255,255,0.05)" points="0,1000 1000,0 1000,1000"/></svg>');
    pointer-events: none;
}

.min-vh-75 {
    min-height: 75vh;
}

.hero-image img {
    border-radius: var(--border-radius-lg);
    transition: var(--transition);
}

.hero-image img:hover {
    transform: scale(1.02);
}

.counter-item h3 {
    font-size: 2.5rem;
    font-weight: 700;
}

/* Background Gradients */
.bg-gradient-primary {
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--primary-dark) 100%);
}

/* Company Logos */
.company-logos {
    gap: 2rem;
}

.company-logo {
    height: 40px;
    width: auto;
    opacity: 0.7;
    transition: var(--transition);
    filter: grayscale(100%);
}

.company-logo:hover {
    opacity: 1;
    filter: grayscale(0%);
    transform: scale(1.1);
}

/* Course Cards */
.course-card {
    background: white;
    border-radius: var(--border-radius-lg);
    box-shadow: var(--box-shadow);
    transition: var(--transition);
    border: none;
    overflow: hidden;
}

.course-card:hover {
    transform: translateY(-8px);
    box-shadow: var(--box-shadow-lg);
}

.course-image {
    position: relative;
    overflow: hidden;
}

.course-image img {
    width: 100%;
    height: 200px;
    object-fit: cover;
    transition: var(--transition);
}

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

.course-badge {
    position: absolute;
    top: 1rem;
    left: 1rem;
    background: linear-gradient(135deg, var(--warning-color) 0%, #e67e22 100%);
    color: white;
    padding: 0.25rem 0.75rem;
    border-radius: 20px;
    font-size: 0.75rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.course-meta {
    font-size: 0.875rem;
    color: var(--gray-600);
}

.duration {
    display: flex;
    align-items: center;
}

.rating {
    display: flex;
    align-items: center;
    gap: 0.25rem;
}

.price .current-price {
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--primary-color);
}

.price .original-price {
    font-size: 0.9rem;
    color: var(--gray-500);
    text-decoration: line-through;
    margin-left: 0.5rem;
}

/* Tab Styles */
.nav-pills .nav-link {
    border-radius: 25px;
    padding: 0.75rem 1.5rem;
    margin: 0 0.25rem;
    color: var(--gray-600);
    background-color: transparent;
    border: 2px solid var(--gray-300);
    transition: var(--transition);
    font-weight: 500;
}

.nav-pills .nav-link.active,
.nav-pills .nav-link:hover {
    background-color: var(--primary-color);
    color: white;
    border-color: var(--primary-color);
    transform: translateY(-2px);
}

/* Feature Cards */
.feature-card {
    background: white;
    padding: 2rem;
    border-radius: var(--border-radius-lg);
    transition: var(--transition);
    border: 1px solid var(--gray-200);
}

.feature-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--box-shadow-lg);
    border-color: var(--primary-light);
}

.feature-icon {
    width: 80px;
    height: 80px;
    background: linear-gradient(135deg, var(--primary-light) 0%, #cce7ff 100%);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto;
}

.feature-icon i {
    font-size: 2rem;
    color: var(--primary-color);
}

/* Testimonial Cards */
.testimonial-card {
    background: white;
    border-radius: var(--border-radius-lg);
    box-shadow: var(--box-shadow);
    border: none;
    overflow: hidden;
    transition: var(--transition);
}

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

.testimonial-content {
    padding: 2rem;
}

.author-image {
    width: 50px;
    height: 50px;
    border-radius: 50%;
    object-fit: cover;
}

/* Demo Form Card */
.demo-form-card {
    max-width: 500px;
    margin: 0 auto;
}

.demo-features .feature-item {
    font-size: 1.1rem;
}

.demo-features i {
    color: var(--secondary-color);
    font-size: 1.25rem;
}

/* Contact Section */
.contact-item {
    margin-bottom: 1rem;
}

.contact-item i {
    color: var(--primary-color);
    width: 20px;
}

.social-links a {
    width: 45px;
    height: 45px;
    background-color: rgba(255, 255, 255, 0.1);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: var(--transition);
}

.social-links a:hover {
    background-color: var(--primary-color);
    transform: translateY(-3px);
}

/* Scroll to Top Button */
.scroll-to-top {
    position: fixed;
    bottom: 30px;
    right: 30px;
    width: 50px;
    height: 50px;
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--primary-dark) 100%);
    color: white;
    border: none;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    box-shadow: var(--box-shadow-lg);
    transition: var(--transition);
    opacity: 0;
    visibility: hidden;
    z-index: 1000;
}

.scroll-to-top.show {
    opacity: 1;
    visibility: visible;
}

.scroll-to-top:hover {
    transform: translateY(-3px);
    box-shadow: 0 15px 35px rgba(0, 86, 211, 0.4);
}

/* Form Styles */
.form-control,
.form-select {
    border: 2px solid var(--gray-300);
    border-radius: var(--border-radius);
    padding: 0.75rem 1rem;
    font-weight: 400;
    transition: var(--transition);
    background-color: white;
}

.form-control:focus,
.form-select:focus {
    border-color: var(--primary-color);
    box-shadow: 0 0 0 0.2rem rgba(0, 86, 211, 0.25);
    outline: none;
}

.form-control-lg,
.form-select-lg {
    padding: 1rem 1.25rem;
    font-size: 1rem;
}

/* 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;
}

/* Counter Animation */
@keyframes countUp {
    from {
        transform: translateY(10px);
        opacity: 0;
    }
    to {
        transform: translateY(0);
        opacity: 1;
    }
}

.counter-animate {
    animation: countUp 0.5s ease-out;
}

/* Responsive Design */
@media (max-width: 1199.98px) {
    .mega-menu {
        min-width: 700px;
        padding: 1.5rem;
    }
}

@media (max-width: 991.98px) {
    .navbar-collapse {
        background: white;
        padding: 1rem;
        border-radius: var(--border-radius-lg);
        margin-top: 1rem;
        box-shadow: var(--box-shadow-lg);
    }
    
    .mega-menu {
        position: static !important;
        transform: none !important;
        width: 100% !important;
        min-width: auto;
        box-shadow: none;
        padding: 1rem 0;
    }
    
    .hero-section {
        text-align: center;
    }
    
    .display-4 {
        font-size: 2.5rem;
    }
    
    .counter-item h3 {
        font-size: 2rem;
    }
}

@media (max-width: 767.98px) {
    .container {
        padding-left: 1rem;
        padding-right: 1rem;
    }
    
    .display-4 {
        font-size: 2rem;
    }
    
    .display-5 {
        font-size: 1.75rem;
    }
    
    .lead {
        font-size: 1rem;
    }
    
    .btn-lg {
        padding: 0.875rem 1.5rem;
        font-size: 1rem;
    }
    
    .hero-section {
        padding: 3rem 0;
    }
    
    .feature-card {
        padding: 1.5rem;
    }
    
    .testimonial-content {
        padding: 1.5rem;
    }
    
    .company-logos {
        gap: 1rem;
    }
    
    .company-logo {
        height: 30px;
    }
    
    .course-image img {
        height: 180px;
    }
    
    .scroll-to-top {
        bottom: 20px;
        right: 20px;
        width: 45px;
        height: 45px;
    }
}

@media (max-width: 575.98px) {
    .display-4 {
        font-size: 1.75rem;
    }
    
    .display-5 {
        font-size: 1.5rem;
    }
    
    .course-image img {
        height: 160px;
    }
    
    .feature-icon {
        width: 60px;
        height: 60px;
    }
    
    .feature-icon i {
        font-size: 1.5rem;
    }
    
    .counter-item h3 {
        font-size: 1.75rem;
    }
    
    .demo-form-card {
        margin-top: 2rem;
    }
}

/* Accessibility Improvements */
@media (prefers-reduced-motion: reduce) {
    * {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
    }
}

/* High Contrast Mode Support */
@media (prefers-contrast: high) {
    .btn-outline-primary {
        border-width: 3px;
    }
    
    .form-control:focus,
    .form-select:focus {
        border-width: 3px;
    }
}

/* Dark Mode Support (Optional) */
@media (prefers-color-scheme: dark) {
    :root {
        --gray-100: #1a1a1a;
        --gray-200: #2a2a2a;
        --gray-800: #e9ecef;
        --gray-900: #f8f9fa;
    }
}

/* Print Styles */
@media print {
    .navbar,
    .scroll-to-top,
    .btn {
        display: none !important;
    }
    
    .hero-section {
        background: white !important;
        color: black !important;
    }
    
    body {
        font-size: 12pt;
        line-height: 1.4;
    }
}

/* Performance Optimizations */
.img-fluid {
    height: auto;
    max-width: 100%;
}

/* Smooth transitions for better UX */
* {
    transition-property: transform, opacity, background-color, border-color, box-shadow;
    transition-duration: 0.3s;
    transition-timing-function: ease;
}

/* Focus styles for better accessibility */
.btn:focus,
.form-control:focus,
.form-select:focus,
.nav-link:focus {
    outline: 2px solid var(--primary-color);
    outline-offset: 2px;
}

/* Custom scrollbar for webkit browsers */
::-webkit-scrollbar {
    width: 8px;
}

::-webkit-scrollbar-track {
    background: var(--gray-200);
}

::-webkit-scrollbar-thumb {
    background: var(--primary-color);
    border-radius: 4px;
}

::-webkit-scrollbar-thumb:hover {
    background: var(--primary-dark);
}

/* ============================================
   LOADING ANIMATIONS & PAGE TRANSITIONS
   ============================================ */

/* Page Loader */
.page-loader {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--primary-dark) 100%);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 9999;
    transition: opacity 0.5s ease, visibility 0.5s ease;
}

.page-loader.fade-out {
    opacity: 0;
    visibility: hidden;
}

.loader-content {
    text-align: center;
    color: white;
}

.spinner {
    width: 60px;
    height: 60px;
    border: 4px solid rgba(255, 255, 255, 0.3);
    border-top-color: white;
    border-radius: 50%;
    animation: spin 1s linear infinite;
    margin: 0 auto 20px;
}

@keyframes spin {
    to { transform: rotate(360deg); }
}

/* Fade In Animation */
@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* Slide In Animation */
@keyframes slideInLeft {
    from {
        opacity: 0;
        transform: translateX(-50px);
    }
    to {
        opacity: 1;
        transform: translateX(0);
    }
}

@keyframes slideInRight {
    from {
        opacity: 0;
        transform: translateX(50px);
    }
    to {
        opacity: 1;
        transform: translateX(0);
    }
}

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

/* Scale Animation */
@keyframes scaleIn {
    from {
        opacity: 0;
        transform: scale(0.9);
    }
    to {
        opacity: 1;
        transform: scale(1);
    }
}

/* Pulse Animation */
@keyframes pulse {
    0%, 100% {
        transform: scale(1);
    }
    50% {
        transform: scale(1.05);
    }
}

/* Bounce Animation */
@keyframes bounce {
    0%, 100% {
        transform: translateY(0);
    }
    50% {
        transform: translateY(-10px);
    }
}

/* Fade-in classes for content */
.animate-fade-in {
    animation: fadeIn 0.8s ease-out forwards;
}

.animate-slide-left {
    animation: slideInLeft 0.8s ease-out forwards;
}

.animate-slide-right {
    animation: slideInRight 0.8s ease-out forwards;
}

.animate-slide-up {
    animation: slideInUp 0.8s ease-out forwards;
}

.animate-scale {
    animation: scaleIn 0.6s ease-out forwards;
}

/* Stagger animation delays */
.delay-100 { animation-delay: 0.1s; }
.delay-200 { animation-delay: 0.2s; }
.delay-300 { animation-delay: 0.3s; }
.delay-400 { animation-delay: 0.4s; }
.delay-500 { animation-delay: 0.5s; }

/* Course Card Hover Animation */
.course-card {
    animation: fadeIn 0.6s ease-out;
    transition: all 0.3s ease;
}

.course-card:hover {
    animation: pulse 1s ease infinite;
}

/* Counter Animation */
.counter-item h3 {
    display: inline-block;
}

.counter-item.counting h3 {
    animation: pulse 0.5s ease;
}

/* Skeleton Loading for Images */
.skeleton {
    background: linear-gradient(90deg, 
        var(--gray-200) 25%, 
        var(--gray-300) 50%, 
        var(--gray-200) 75%
    );
    background-size: 200% 100%;
    animation: skeleton-loading 1.5s ease-in-out infinite;
}

@keyframes skeleton-loading {
    0% {
        background-position: 200% 0;
    }
    100% {
        background-position: -200% 0;
    }
}

/* Smooth Reveal on Scroll */
.reveal {
    opacity: 0;
    transform: translateY(30px);
    transition: all 0.8s ease;
}

.reveal.active {
    opacity: 1;
    transform: translateY(0);
}

/* Hero Section Animation */
.hero-section h1 {
    animation: slideInLeft 1s ease-out;
}

.hero-section p {
    animation: slideInLeft 1.2s ease-out;
}

.hero-section .btn {
    animation: slideInUp 1.4s ease-out;
}

.hero-image img {
    animation: slideInRight 1.2s ease-out;
}

/* Navigation Animation */
.navbar {
    animation: slideInUp 0.5s ease-out;
}

/* Company Logos Animation */
.company-logo {
    transition: all 0.3s ease;
    animation: fadeIn 1s ease-out;
}

.company-logo:hover {
    transform: scale(1.1) translateY(-5px);
}

/* Testimonial Card Animation */
.testimonial-card {
    animation: scaleIn 0.8s ease-out;
    transition: all 0.3s ease;
}

.testimonial-card:hover {
    transform: translateY(-10px);
}

/* Stats Counter Animation */
.stat-item {
    animation: slideInUp 1s ease-out;
}

/* Form Focus Animation */
.form-control:focus,
.form-select:focus {
    animation: pulse 0.3s ease;
}

/* Button Ripple Effect */
@keyframes ripple {
    0% {
        transform: scale(0);
        opacity: 1;
    }
    100% {
        transform: scale(4);
        opacity: 0;
    }
}

.btn-primary::before {
    content: '';
    position: absolute;
    top: 50%;
    left: 50%;
    width: 0;
    height: 0;
    border-radius: 50%;
    background: rgba(255, 255, 255, 0.5);
    transform: translate(-50%, -50%);
    transition: width 0.6s, height 0.6s;
}

.btn-primary:active::before {
    width: 300px;
    height: 300px;
}

/* Loading Bar at Top */
.loading-bar {
    position: fixed;
    top: 0;
    left: 0;
    width: 0;
    height: 3px;
    background: linear-gradient(90deg, var(--primary-color), var(--secondary-color));
    z-index: 9999;
    transition: width 0.3s ease;
}

.loading-bar.active {
    width: 100%;
}