/* ===================================
   Dog Training Academy - Styles
   =================================== */

/* CSS Variables */
:root {
    --primary-color: #5B8DEE;
    --primary-dark: #4A7BD8;
    --secondary-color: #FF9F43;
    --text-dark: #2C3E50;
    --text-light: #6C757D;
    --bg-light: #F8F9FA;
    --bg-white: #FFFFFF;
    --border-color: #E9ECEF;
    --shadow-sm: 0 2px 4px rgba(0, 0, 0, 0.08);
    --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 8px 24px rgba(0, 0, 0, 0.12);
    --radius-sm: 8px;
    --radius-md: 12px;
    --radius-lg: 16px;
    --spacing-xs: 8px;
    --spacing-sm: 12px;
    --spacing-md: 20px;
    --spacing-lg: 32px;
    --spacing-xl: 48px;
}

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Roboto', 'Helvetica Neue', Arial, sans-serif;
    line-height: 1.6;
    color: var(--text-dark);
    background-color: var(--bg-light);
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

img {
    max-width: 100%;
    height: auto;
    display: block;
}

a {
    text-decoration: none;
    color: inherit;
    transition: all 0.3s ease;
}

/* ===================================
   Main Header
   =================================== */

.main-header {
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--primary-dark) 100%);
    color: white;
    padding: var(--spacing-xl) var(--spacing-md) var(--spacing-lg);
    text-align: center;
    box-shadow: var(--shadow-md);
}

.training-header-top {
    max-width: 1200px;
    margin: 0 auto;
    padding-bottom: var(--spacing-md);
}

.back-to-home {
    display: inline-flex;
    align-items: center;
    gap: var(--spacing-xs);
    color: white;
    font-weight: 600;
    padding: var(--spacing-sm) var(--spacing-md);
    border-radius: var(--radius-sm);
    background: rgba(255, 255, 255, 0.1);
    transition: all 0.3s ease;
    border: 1px solid rgba(255, 255, 255, 0.2);
}

.back-to-home:hover {
    background: rgba(255, 255, 255, 0.2);
    transform: translateX(-4px);
}

.back-to-home svg {
    width: 20px;
    height: 20px;
}

.header-content {
    max-width: 800px;
    margin: 0 auto var(--spacing-lg);
}

.main-title {
    font-size: 2.5rem;
    font-weight: 800;
    margin-bottom: var(--spacing-sm);
    letter-spacing: -0.5px;
}

.main-subtitle {
    font-size: 1.125rem;
    opacity: 0.95;
    font-weight: 400;
}

/* Category Navigation */
.category-nav {
    display: flex;
    gap: var(--spacing-sm);
    justify-content: center;
    flex-wrap: wrap;
    max-width: 800px;
    margin: 0 auto;
}

.nav-category {
    padding: var(--spacing-sm) var(--spacing-md);
    background: rgba(255, 255, 255, 0.2);
    border-radius: var(--radius-lg);
    font-weight: 600;
    font-size: 0.9rem;
    backdrop-filter: blur(10px);
    border: 1px solid rgba(255, 255, 255, 0.3);
    transition: all 0.3s ease;
}

.nav-category:hover {
    background: rgba(255, 255, 255, 0.3);
    transform: translateY(-2px);
}

/* ===================================
   Main Container
   =================================== */

.main-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: var(--spacing-xl) var(--spacing-md);
}

/* ===================================
   Category Section
   =================================== */

.category-section {
    margin-bottom: var(--spacing-xl);
    scroll-margin-top: 20px;
}

.category-header {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
    margin-bottom: var(--spacing-lg);
    padding: var(--spacing-md);
    background: white;
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-sm);
}

.category-icon {
    width: 60px;
    height: 60px;
    border-radius: var(--radius-md);
    overflow: hidden;
    flex-shrink: 0;
    background: var(--bg-light);
}

.category-icon img {
    width: 100%;
    height: 100%;
    object-fit: cover;
}

.category-title {
    font-size: 1.75rem;
    font-weight: 700;
    color: var(--text-dark);
    flex: 1;
}

.category-count {
    color: var(--text-light);
    font-size: 0.9rem;
    font-weight: 500;
    padding: 6px 12px;
    background: var(--bg-light);
    border-radius: var(--radius-sm);
}

/* ===================================
   Lessons Grid
   =================================== */

.lessons-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
    gap: var(--spacing-md);
}

/* Lesson Card */
.lesson-card {
    background: white;
    border-radius: var(--radius-lg);
    overflow: hidden;
    box-shadow: var(--shadow-sm);
    transition: all 0.3s ease;
    display: flex;
    flex-direction: column;
    cursor: pointer;
}

.lesson-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-lg);
}

.lesson-card-image {
    width: 100%;
    height: 200px;
    overflow: hidden;
    background: var(--bg-light);
}

.lesson-card-image img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: transform 0.3s ease;
}

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

.lesson-card-content {
    padding: var(--spacing-md);
    flex: 1;
    display: flex;
    flex-direction: column;
}

.lesson-card-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: var(--spacing-sm);
}

.lesson-number {
    font-size: 0.85rem;
    font-weight: 700;
    color: var(--secondary-color);
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.lesson-badge {
    font-size: 0.75rem;
    font-weight: 700;
    padding: 4px 10px;
    border-radius: var(--radius-sm);
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.lesson-badge.free {
    background: #D4EDDA;
    color: #155724;
}

.lesson-badge.premium {
    background: var(--primary-color);
    color: white;
}

.lesson-card-title {
    font-size: 1.125rem;
    font-weight: 600;
    color: var(--text-dark);
    line-height: 1.4;
}

/* ===================================
   Lesson Detail Page
   =================================== */

.lesson-header {
    background: white;
    box-shadow: var(--shadow-sm);
    position: sticky;
    top: 0;
    z-index: 100;
}

.lesson-nav {
    max-width: 1200px;
    margin: 0 auto;
    padding: var(--spacing-md);
}

.back-link {
    display: inline-flex;
    align-items: center;
    gap: var(--spacing-xs);
    color: var(--text-dark);
    font-weight: 600;
    padding: var(--spacing-sm) var(--spacing-md);
    border-radius: var(--radius-sm);
    transition: all 0.3s ease;
}

.back-link:hover {
    background: var(--bg-light);
    color: var(--primary-color);
}

.back-link svg {
    width: 20px;
    height: 20px;
}

/* Lesson Container */
.lesson-container {
    max-width: 800px;
    margin: 0 auto;
    padding: var(--spacing-lg) var(--spacing-md);
}

.lesson-content {
    background: white;
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-md);
    overflow: hidden;
}

/* Lesson Title Section */
.lesson-title-section {
    padding: var(--spacing-lg) var(--spacing-lg) var(--spacing-md);
    border-bottom: 1px solid var(--border-color);
}

.lesson-meta {
    display: flex;
    gap: var(--spacing-sm);
    align-items: center;
    margin-bottom: var(--spacing-md);
}

.lesson-category {
    font-size: 0.9rem;
    font-weight: 600;
    color: var(--primary-color);
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.lesson-title {
    font-size: 2rem;
    font-weight: 700;
    color: var(--text-dark);
    line-height: 1.3;
}

/* Lesson Body */
.lesson-body {
    padding: var(--spacing-lg);
}

.lesson-image-container {
    margin: var(--spacing-md) 0;
    border-radius: var(--radius-md);
    overflow: hidden;
}

.lesson-image {
    width: 100%;
    height: auto;
    display: block;
}

.lesson-text-content {
    margin: var(--spacing-md) 0;
}

.lesson-text-content h1 {
    font-size: 1.75rem;
    font-weight: 700;
    color: var(--text-dark);
    margin: var(--spacing-lg) 0 var(--spacing-md);
    line-height: 1.3;
}

.lesson-text-content h2 {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--text-dark);
    margin: var(--spacing-lg) 0 var(--spacing-md);
    line-height: 1.3;
}

.lesson-text-content h3 {
    font-size: 1.25rem;
    font-weight: 600;
    color: var(--text-dark);
    margin: var(--spacing-md) 0 var(--spacing-sm);
}

.lesson-text-content p {
    font-size: 1.0625rem;
    line-height: 1.7;
    color: var(--text-dark);
    margin-bottom: var(--spacing-md);
}

.lesson-text-content ul,
.lesson-text-content ol {
    margin: var(--spacing-md) 0;
    padding-left: var(--spacing-lg);
}

.lesson-text-content li {
    font-size: 1.0625rem;
    line-height: 1.7;
    margin-bottom: var(--spacing-sm);
}

/* Lesson Footer */
.lesson-footer {
    padding: var(--spacing-lg);
    border-top: 1px solid var(--border-color);
    background: var(--bg-light);
}

.lesson-navigation {
    display: flex;
    gap: var(--spacing-md);
    justify-content: space-between;
}

.nav-btn {
    flex: 1;
    padding: var(--spacing-md) var(--spacing-lg);
    background: var(--primary-color);
    color: white;
    font-weight: 600;
    text-align: center;
    border-radius: var(--radius-md);
    transition: all 0.3s ease;
}

.nav-btn:hover {
    background: var(--primary-dark);
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

.nav-btn.prev::before {
    content: '← ';
}

.nav-btn.next::after {
    content: ' →';
}

/* ===================================
   Footer
   =================================== */

.main-footer {
    text-align: center;
    padding: var(--spacing-lg) var(--spacing-md);
    color: var(--text-light);
    font-size: 0.9rem;
    border-top: 1px solid var(--border-color);
    background: white;
}

.footer-links {
    display: flex;
    justify-content: center;
    align-items: center;
    flex-wrap: wrap;
    gap: 10px;
}

.footer-link {
    color: var(--text-light);
    text-decoration: none;
    transition: color 0.3s ease;
}

.footer-link:hover {
    color: var(--primary-color);
}

.footer-separator {
    color: var(--border-color);
}

/* ===================================
   Responsive Design
   =================================== */

@media (max-width: 768px) {
    .main-title {
        font-size: 2rem;
    }
    
    .main-subtitle {
        font-size: 1rem;
    }
    
    .back-to-home span {
        display: inline;
    }
    
    .category-nav {
        gap: var(--spacing-xs);
    }
    
    .nav-category {
        padding: var(--spacing-xs) var(--spacing-sm);
        font-size: 0.85rem;
    }
    
    .lessons-grid {
        grid-template-columns: 1fr;
        gap: var(--spacing-sm);
    }
    
    .category-header {
        flex-direction: column;
        text-align: center;
        gap: var(--spacing-sm);
    }
    
    .category-title {
        font-size: 1.5rem;
    }
    
    .lesson-title {
        font-size: 1.5rem;
    }
    
    .lesson-text-content h1 {
        font-size: 1.5rem;
    }
    
    .lesson-text-content h2 {
        font-size: 1.25rem;
    }
    
    .lesson-navigation {
        flex-direction: column;
    }
    
    .footer-links {
        flex-direction: column;
        gap: 5px;
    }
    
    .footer-separator {
        display: none;
    }
}

@media (max-width: 480px) {
    :root {
        --spacing-md: 16px;
        --spacing-lg: 24px;
        --spacing-xl: 32px;
    }
    
    .main-header {
        padding: var(--spacing-lg) var(--spacing-sm);
    }
    
    .main-title {
        font-size: 1.75rem;
    }
    
    .back-to-home {
        padding: var(--spacing-xs) var(--spacing-sm);
        font-size: 0.9rem;
    }
    
    .back-to-home span {
        display: none;
    }
    
    .back-to-home svg {
        width: 24px;
        height: 24px;
    }
    
    .lesson-card-image {
        height: 180px;
    }
}

/* ===================================
   Animations
   =================================== */

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

.lesson-card,
.category-section {
    animation: fadeIn 0.5s ease-out;
}

/* ===================================
   Print Styles
   =================================== */

@media print {
    .main-header,
    .lesson-header,
    .lesson-footer,
    .main-footer,
    .lesson-navigation {
        display: none;
    }
    
    .lesson-content {
        box-shadow: none;
    }
}

/* ===================================
   Accessibility
   =================================== */

.visually-hidden {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    white-space: nowrap;
    border: 0;
}

/* Focus styles */
a:focus,
button:focus {
    outline: 2px solid var(--primary-color);
    outline-offset: 2px;
}

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