/* User App Styles */
:root {
    --primary-color: #6366f1;
    --secondary-color: #8b5cf6;
    --accent-color: #ec4899;
    --dark-color: #1f2937;
    --light-color: #f8fafc;
    --success-color: #10b981;
    --warning-color: #f59e0b;
    --bangla-font: 'Noto Sans Bengali', sans-serif;
    --english-font: 'Poppins', sans-serif;
}

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

body {
    font-family: var(--english-font);
    background: linear-gradient(135deg, #f5f7fa 0%, #c3cfe2 100%);
    color: var(--dark-color);
    line-height: 1.6;
    min-height: 100vh;
    padding-bottom: 80px; /* Space for WhatsApp button */
}

/* Top Banner */
.top-banner {
    width: 100%;
    height: 180px;
    overflow: hidden;
    background: linear-gradient(90deg, var(--primary-color), var(--secondary-color));
}

.top-banner img {
    width: 100%;
    height: 100%;
    object-fit: cover;
}

/* Header */
.main-header {
    background: white;
    padding: 1rem;
    box-shadow: 0 2px 10px rgba(0,0,0,0.1);
    text-align: center;
}

.logo-container {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 15px;
    margin-bottom: 10px;
}

.logo {
    width: 50px;
    height: 50px;
    border-radius: 12px;
    object-fit: contain;
}

.logo-container h1 {
    font-size: 2.2rem;
    background: linear-gradient(90deg, var(--primary-color), var(--accent-color));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    font-weight: 700;
}

.tagline {
    display: flex;
    flex-direction: column;
    gap: 5px;
}

.tagline .bangla {
    font-family: var(--bangla-font);
    font-size: 1.1rem;
    color: var(--dark-color);
}

.tagline .english {
    font-size: 0.9rem;
    color: #666;
}

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

/* Welcome Section */
.welcome-section {
    background: white;
    border-radius: 20px;
    padding: 25px;
    margin: 25px auto;
    text-align: center;
    box-shadow: 0 8px 30px rgba(0,0,0,0.08);
    border: 2px solid rgba(99, 102, 241, 0.1);
}

.welcome-section h2 {
    color: var(--primary-color);
    font-size: 2rem;
    margin-bottom: 15px;
}

.mixed-text {
    font-size: 1.1rem;
    color: #444;
    line-height: 1.8;
}

.highlight {
    background: linear-gradient(120deg, rgba(99, 102, 241, 0.2) 0%, rgba(99, 102, 241, 0) 100%);
    padding: 0 8px;
    border-radius: 6px;
    font-weight: 600;
    color: var(--primary-color);
}

/* Categories */
.categories {
    display: flex;
    flex-wrap: wrap;
    gap: 10px;
    justify-content: center;
    margin: 30px 0;
}

.category-btn {
    padding: 10px 20px;
    border: 2px solid var(--primary-color);
    background: white;
    color: var(--primary-color);
    border-radius: 50px;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
    font-family: var(--english-font);
}

.category-btn:hover {
    background: var(--primary-color);
    color: white;
    transform: translateY(-3px);
    box-shadow: 0 5px 15px rgba(99, 102, 241, 0.3);
}

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

/* Courses Grid */
.courses-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: 25px;
    margin-top: 30px;
}

.course-card {
    background: white;
    border-radius: 20px;
    overflow: hidden;
    box-shadow: 0 10px 30px rgba(0,0,0,0.08);
    transition: all 0.3s ease;
    cursor: pointer;
    position: relative;
}

.course-card:hover {
    transform: translateY(-10px);
    box-shadow: 0 20px 40px rgba(0,0,0,0.15);
}

.course-thumbnail {
    width: 100%;
    height: 180px;
    object-fit: cover;
    border-bottom: 3px solid var(--primary-color);
}

.course-content {
    padding: 20px;
}

.course-title {
    font-size: 1.3rem;
    font-weight: 700;
    color: var(--dark-color);
    margin-bottom: 10px;
    min-height: 60px;
}

.course-category {
    display: inline-block;
    padding: 5px 12px;
    background: rgba(99, 102, 241, 0.1);
    color: var(--primary-color);
    border-radius: 20px;
    font-size: 0.85rem;
    font-weight: 600;
    margin-bottom: 15px;
}

.course-description {
    color: #666;
    font-size: 0.95rem;
    margin-bottom: 15px;
    display: -webkit-box;
    -webkit-line-clamp: 3;
    -webkit-box-orient: vertical;
    overflow: hidden;
}

.view-course-btn {
    display: block;
    width: 100%;
    padding: 12px;
    background: var(--primary-color);
    color: white;
    border: none;
    border-radius: 10px;
    font-weight: 600;
    cursor: pointer;
    transition: background 0.3s ease;
    text-align: center;
    text-decoration: none;
}

.view-course-btn:hover {
    background: var(--secondary-color);
}

/* Loading Animation */
.loading-courses {
    grid-column: 1 / -1;
    text-align: center;
    padding: 50px;
}

.spinner {
    width: 60px;
    height: 60px;
    border: 5px solid rgba(99, 102, 241, 0.2);
    border-top-color: var(--primary-color);
    border-radius: 50%;
    margin: 0 auto 20px;
    animation: spin 1s linear infinite;
}

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

/* Ads Container */
.ads-container {
    max-width: 1200px;
    margin: 40px auto;
    padding: 0 20px;
}

.banner-ad {
    width: 100%;
    height: 120px;
    background: linear-gradient(90deg, #ff6b6b, #ffa726);
    border-radius: 15px;
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    font-weight: bold;
    font-size: 1.2rem;
    box-shadow: 0 5px 15px rgba(255, 107, 107, 0.3);
    position: relative;
    overflow: hidden;
}

.banner-ad::before {
    content: "AD";
    position: absolute;
    top: 5px;
    right: 10px;
    background: rgba(0,0,0,0.2);
    padding: 2px 8px;
    border-radius: 10px;
    font-size: 0.8rem;
}

/* Ad Overlay (Interstitial) */
.ad-overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0,0,0,0.9);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 9999;
}

.ad-content {
    background: white;
    width: 90%;
    max-width: 400px;
    border-radius: 20px;
    overflow: hidden;
    box-shadow: 0 20px 60px rgba(0,0,0,0.3);
}

.ad-header {
    background: var(--primary-color);
    color: white;
    padding: 15px;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.close-ad {
    background: none;
    border: none;
    color: white;
    font-size: 2rem;
    cursor: pointer;
    line-height: 1;
    display: none;
}

.ad-body {
    padding: 30px;
    text-align: center;
}

.ad-countdown {
    width: 60px;
    height: 60px;
    background: var(--primary-color);
    color: white;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.8rem;
    font-weight: bold;
    margin: 20px auto;
    animation: pulse 1s infinite;
}

@keyframes pulse {
    0%, 100% { transform: scale(1); }
    50% { transform: scale(1.1); }
}

/* Footer */
.main-footer {
    background: var(--dark-color);
    color: white;
    padding: 40px 20px 20px;
    margin-top: 50px;
}

.footer-content {
    max-width: 1200px;
    margin: 0 auto;
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 30px;
}

.footer-logo {
    text-align: center;
}

.footer-logo-img {
    width: 60px;
    height: 60px;
    margin-bottom: 10px;
}

.footer-logo h3 {
    color: white;
    margin-bottom: 5px;
    font-size: 1.5rem;
}

.footer-logo .bangla {
    font-family: var(--bangla-font);
    color: #ccc;
    font-size: 0.9rem;
}

.footer-info {
    display: flex;
    flex-direction: column;
    gap: 15px;
}

.footer-info p {
    display: flex;
    align-items: center;
    gap: 10px;
    color: #ccc;
}

.footer-info i {
    color: var(--primary-color);
    font-size: 1.2rem;
}

.developer-credit {
    text-align: center;
    padding-top: 20px;
    border-top: 1px solid #444;
    grid-column: 1 / -1;
}

.credit-text {
    font-size: 1.1rem;
    color: var(--primary-color);
    font-weight: 600;
    margin-bottom: 5px;
}

.copyright {
    color: #888;
    font-size: 0.9rem;
}

/* WhatsApp Floating Button */
.whatsapp-float {
    position: fixed;
    bottom: 25px;
    right: 25px;
    width: 60px;
    height: 60px;
    background: #25D366;
    color: white;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 2rem;
    box-shadow: 0 5px 20px rgba(37, 211, 102, 0.4);
    text-decoration: none;
    z-index: 1000;
    transition: all 0.3s ease;
    animation: float 3s ease-in-out infinite;
}

.whatsapp-float:hover {
    transform: scale(1.1);
    box-shadow: 0 8px 25px rgba(37, 211, 102, 0.6);
    animation: none;
}

@keyframes float {
    0%, 100% { transform: translateY(0); }
    50% { transform: translateY(-10px); }
}

/* Responsive Design */
@media (max-width: 768px) {
    .top-banner {
        height: 140px;
    }
    
    .logo-container h1 {
        font-size: 1.8rem;
    }
    
    .courses-grid {
        grid-template-columns: repeat(auto-fill, minmax(250px, 1fr));
        gap: 20px;
    }
    
    .welcome-section h2 {
        font-size: 1.6rem;
    }
    
    .mixed-text {
        font-size: 1rem;
    }
    
    .whatsapp-float {
        width: 55px;
        height: 55px;
        font-size: 1.8rem;
        bottom: 20px;
        right: 20px;
    }
}

@media (max-width: 480px) {
    .categories {
        overflow-x: auto;
        justify-content: flex-start;
        padding-bottom: 10px;
    }
    
    .category-btn {
        flex-shrink: 0;
    }
    
    .courses-grid {
        grid-template-columns: 1fr;
    }
}