@import url('https://fonts.googleapis.com/css2?family=Quicksand:wght@300;400;500;600;700&display=swap');

/* ===============================================
   Inner English - Lesson Styles CSS
   Color Palette: Teal & Blue Focus with Accents
   =============================================== */

:root {
    /* Main Colors - Teal & Blue */
    --primary-teal: #14b8a6;
    --primary-teal-dark: #0f766e;
    --primary-blue: #3b82f6;
    --primary-blue-dark: #1e40af;
    --secondary-teal: #5eead4;
    --secondary-blue: #93c5fd;
    
    /* Accent Colors */
    --accent-purple: #8b5cf6;
    --accent-pink: #ec4899;
    --accent-yellow: #f59e0b;
    --accent-green: #10b981;
    --accent-cyan: #06b6d4;
    --accent-indigo: #6366f1;
    
    /* Text Colors */
    --text-primary: #0f172a;
    --text-secondary: #475569;
    --text-light: #94a3b8;
    
    /* Background Colors */
    --bg-primary: #ffffff;
    --bg-secondary: #f8fafc;
    --bg-tertiary: #f1f5f9;
    --border-light: #e2e8f0;
    --border-medium: #cbd5e1;
    
    /* Gradients */
    --gradient-primary: linear-gradient(135deg, var(--primary-teal) 0%, var(--primary-blue) 100%);
    --gradient-secondary: linear-gradient(135deg, var(--secondary-teal) 0%, var(--secondary-blue) 100%);
    --gradient-accent: linear-gradient(135deg, var(--accent-purple) 0%, var(--accent-pink) 100%);
    
    /* Spacing & Layout */
    --max-width: 1200px;
    --border-radius: 12px;
    --border-radius-lg: 20px;
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
    --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 10px 10px -5px rgba(0, 0, 0, 0.04);
    
    /* Animation */
    --transition-fast: 0.15s ease;
    --transition-base: 0.3s ease;
    --transition-slow: 0.5s ease;
}

/* ===============================================
   Reset & Base Styles
   =============================================== */

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Quicksand', sans-serif;
    line-height: 1.6;
    color: var(--text-primary);
    background: var(--bg-primary);
    overflow-x: hidden;
}

body.A1 {
    background: linear-gradient(135deg, var(--bg-secondary) 0%, var(--bg-primary) 100%);
    min-height: 100vh;
}






main {
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 120px 2rem 2rem;
    position: relative;
}

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

.content::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 6px;
    background: var(--gradient-primary);
}

/* ===============================================
   Image Banner
   =============================================== */

.image-banner {
    width: 100%;
    background: var(--gradient-secondary);
    padding: 2rem;
    text-align: center;
    position: relative;
    overflow: hidden;
}

.image-banner::before {
    content: '';
    position: absolute;
    top: -50%;
    left: -50%;
    width: 200%;
    height: 200%;
    background: radial-gradient(circle, rgba(20, 184, 166, 0.1) 0%, transparent 70%);
    animation: float 6s ease-in-out infinite;
}

.image-banner img {
    max-width: 100%;
    height: auto;
    border-radius: var(--border-radius);
    box-shadow: var(--shadow-md);
    position: relative;
    z-index: 2;
}

/* ===============================================
   Navigation Elements
   =============================================== */

.lesson-navigation {
    padding: 1.5rem 2rem;
    background: var(--bg-tertiary);
    display: flex;
    justify-content: flex-end;
    border-bottom: 1px solid var(--border-light);
}

.next-lesson {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    background: var(--gradient-primary);
    color: white;
    text-decoration: none;
    padding: 0.75rem 1.5rem;
    margin-left: 2%;
    border-radius: var(--border-radius);
    font-weight: 600;
    transition: var(--transition-base);
    box-shadow: var(--shadow-sm);
}

.next-lesson:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
    color: white;
}

.next-lesson i {
    font-size: 1.2rem;
    transition: var(--transition-base);
}

.next-lesson:hover i {
    transform: translateX(3px);
}


.prev-lesson {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    background: var(--gradient-primary);
    color: white;
    text-decoration: none;
    margin-right: 2%;
    padding: 0.75rem 1.5rem;
    border-radius: var(--border-radius);
    font-weight: 600;
    transition: var(--transition-base);
    box-shadow: var(--shadow-sm);
}

.prev-lesson:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
    color: white;
}

.prev-lesson i {
    font-size: 1.2rem;
    transition: var(--transition-base);
}

.prev-lesson:hover i {
    transform: translateX(3px);
}


/* ===============================================
   Typography & Content
   =============================================== */

.content h1 {
    font-size: 4rem;
    font-weight: 700;
    color: var(--text-primary);
    margin: 2rem;
    text-align: center;
    position: relative;
}

.content h1::after {
    content: '';
    position: absolute;
    width: 80px;
    height: 4px;
    background: var(--gradient-primary);
    bottom: -10px;
    left: 50%;
    transform: translateX(-50%);
    border-radius: 2px;
}

.content h2 {
    font-size: 1.8rem;
    font-weight: 600;
    color: var(--primary-blue);
    margin: 2rem;
    margin-bottom: 1rem;
    position: relative;
    padding-left: 1rem;
}

.content h2::before {
    content: '';
    position: absolute;
    left: 0;
    top: 0;
    bottom: 0;
    width: 4px;
    background: var(--gradient-primary);
    border-radius: 2px;
}

.content h3 {
    font-size: 1.4rem;
    font-weight: 600;
    color: var(--accent-purple);
    margin: 2rem;
    margin-bottom: 0.8rem;
    margin-top: 1.5rem;
}

.content p {
    font-size: 1.1rem;
    line-height: 1.7;
    color: var(--text-secondary);
    margin: 0 2rem 1.5rem;
    text-align: justify;
}

/* ===============================================
   Special Text Elements
   =============================================== */

/* Example sentences */
t {
    display: block;
    background: linear-gradient(135deg, #f0f9ff 0%, #e0f2fe 100%);
    border: 1px solid var(--secondary-blue);
    border-left: 4px solid var(--primary-blue);
    border-radius: var(--border-radius);
    padding: 1rem 1.5rem;
    margin: 1rem 2rem;
    font-family: 'Georgia', serif;
    font-size: 1.1rem;
    color: var(--primary-blue-dark);
    box-shadow: var(--shadow-sm);
    position: relative;
    overflow: hidden;
}

t::before {
    content: '"';
    position: absolute;
    top: -10px;
    left: 10px;
    font-size: 3rem;
    color: var(--secondary-blue);
    opacity: 0.5;
}

t b {
    background: var(--gradient-primary);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    font-weight: 700;
}

/* Descriptive text */
d {
    background: linear-gradient(135deg, var(--accent-green), var(--accent-cyan));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    font-weight: 600;
    font-style: italic;
    position: relative;
}

d::after {
    content: '';
    position: absolute;
    bottom: -2px;
    left: 0;
    right: 0;
    height: 2px;
    background: var(--accent-green);
    opacity: 0.3;
}

/* Connector text */
c {
    background: var(--accent-yellow);
    color: white;
    padding: 2px 6px;
    border-radius: 4px;
    font-weight: 600;
    font-size: 0.9em;
    box-shadow: var(--shadow-sm);
    white-space: nowrap;
}



/* Footer text */
f {
    display: block;
    background: var(--gradient-accent);
    color: white;
    padding: 1.5rem;
    margin: 2rem;
    border-radius: var(--border-radius);
    text-align: center;
    font-weight: 500;
    font-size: 1.1rem;
    box-shadow: var(--shadow-lg);
}

f a {
    color: white;
    text-decoration: underline;
    font-weight: 600;
}

f a:hover {
    text-decoration: none;
    text-shadow: 0 0 5px rgba(255, 255, 255, 0.5);
}

/* ===============================================
   Table Styles
   =============================================== */

table {
    width: 100%;
    max-width: 600px;
    margin: 2rem auto;
    border-collapse: collapse;
    border-radius: var(--border-radius);
    overflow: hidden;
    box-shadow: var(--shadow-lg);
    background: white;
}

table th,
table td {
    padding: 1rem 1.5rem;
    text-align: center;
    border-bottom: 1px solid var(--border-light);
}

table th {
    background: var(--gradient-primary);
    color: white;
    font-weight: 700;
    font-size: 1.1rem;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

table td {
    background: var(--bg-secondary);
    color: var(--text-primary);
    font-weight: 600;
    font-size: 1.1rem;
    transition: var(--transition-base);
}

table tr:hover td {
    background: var(--secondary-teal);
    color: var(--primary-teal-dark);
    transform: scale(1.02);
}

table tr:last-child td {
    border-bottom: none;
}

/* ===============================================
   Exercise Link & Button Styles
   =============================================== */

.exercise-link-container {
    text-align: center;
    margin: 3rem 2rem;
}

.exercise-link {
    display: inline-block;
    background: var(--gradient-primary);
    color: white;
    text-decoration: none;
    padding: 1.25rem 3rem;
    border-radius: var(--border-radius-lg);
    font-weight: 700;
    font-size: 1.2rem;
    transition: var(--transition-base);
    box-shadow: var(--shadow-lg);
    position: relative;
    overflow: hidden;
    text-transform: uppercase;
    letter-spacing: 1px;
}

.exercise-link::before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg, transparent, rgba(255, 255, 255, 0.2), transparent);
    transition: var(--transition-base);
}

.exercise-link:hover::before {
    left: 100%;
}

.exercise-link:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-xl);
    color: white;
}

/* ===============================================
   Image Lesson Styles
   =============================================== */

.image-lesson {
    text-align: center;
    margin: 2rem;
    padding: 1.5rem;
    background: var(--bg-tertiary);
    border-radius: var(--border-radius);
    border: 2px dashed var(--border-medium);
}

.image-lesson img {
    max-width: 100%;
    height: auto;
    border-radius: var(--border-radius);
    box-shadow: var(--shadow-md);
    transition: var(--transition-base);
}

.image-lesson img:hover {
    transform: scale(1.05);
    box-shadow: var(--shadow-lg);
}

/* ===============================================
   Responsive Video Container
   =============================================== */

.responsive-iframe-container {
    position: relative;
    width: 100%;
    padding-bottom: 56.25%; /* 16:9 aspect ratio */
    height: 0;
    overflow: hidden;
    margin: 2rem;
    border-radius: var(--border-radius);
    box-shadow: var(--shadow-lg);
    background: var(--bg-secondary);
}

.responsive-iframe-container iframe {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    border-radius: var(--border-radius);
}

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

@keyframes float {
    0%, 100% { transform: translateY(0px) rotate(0deg); }
    50% { transform: translateY(-10px) rotate(5deg); }
}

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

@keyframes slideInUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.animate-in {
    animation: slideInUp 0.6s ease forwards;
}

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

@media (max-width: 768px) {
    .header {
        padding: 1rem;
        flex-direction: row;
        gap: 1rem;
    }
    
    .title {
        font-size: 1.2rem;
        position: static;
        transform: none;
        order: 2;
        flex: 1;
        text-align: center;
    }
    
    .menu-btn {
        order: 1;
        padding: 0.6rem 1rem;
        font-size: 0.9rem;
    }
    
    .language-switch {
        order: 3;
        flex-direction: column;
        align-items: center;
    }
    
    .language-switch a {
        padding: 0.6rem 1rem;
        font-size: 0.9rem;
        width: 100%;
        text-align: center;
    }
    
    main {
        padding: 20px 1rem 2rem;
    }
    
    .content h1 {
        font-size: 2rem;
        margin: 1.5rem 1rem;
    }
    
    .content h2 {
        font-size: 1.5rem;
        margin: 1.5rem 1rem 0.8rem;
    }
    
    .content h3 {
        font-size: 1.2rem;
        margin: 1.2rem 1rem 0.6rem;
    }
    
    .content p,
    t,
    f {
        margin: 1rem;
        font-size: 1rem;
    }
    
    .image-banner {
        padding: 1rem;
    }
    
    .lesson-navigation {
        padding: 1rem;
        justify-content: center;
    }
    
    .next-lesson {
        padding: 0.6rem 1.2rem;
        font-size: 0.9rem;
    }
    
    table th,
    table td {
        padding: 0.8rem;
        font-size: 0.9rem;
    }
    
    .exercise-link {
        padding: 1rem 2rem;
        font-size: 1rem;
    }
    
    .responsive-iframe-container {
        margin: 1rem;
    }
    
    .image-lesson {
        margin: 1rem;
        padding: 1rem;
    }
}

@media (max-width: 480px) {
    .header {
        padding: 0.8rem;
    }
    
    .title {
        font-size: 1rem;
    }
    
    .menu-btn {
        padding: 0.5rem 0.8rem;
        font-size: 0.8rem;
    }
    
    .language-switch a {
        padding: 0.5rem 0.8rem;
        font-size: 0.8rem;
    }
    
    main {
        padding: 20px 0.5rem 1rem;
    }
    
    .content h1 {
        font-size: 1.7rem;
    }
    
    .content h2 {
        font-size: 1.3rem;
    }
    
    .content p,
    t,
    f {
        margin: 0.8rem;
        font-size: 0.95rem;
    }
    
    table {
        font-size: 0.8rem;
    }
    
    table th,
    table td {
        padding: 0.6rem 0.4rem;
    }
    
    .exercise-link {
        padding: 0.9rem 1.5rem;
        font-size: 0.9rem;
    }
}

/* ===============================================
   Hover Effects & Micro-interactions
   =============================================== */

.content {
    transition: var(--transition-slow);
}

.content:hover {
    box-shadow: var(--shadow-xl);
}

/* Smooth scrolling enhancements */
@media (prefers-reduced-motion: no-preference) {
    * {
        scroll-behavior: smooth;
    }
}

/* Focus states for accessibility */
.menu-btn:focus,
.language-switch a:focus,
.next-lesson:focus,
.exercise-link:focus {
    outline: 3px solid var(--accent-cyan);
    outline-offset: 2px;
}

/* Print styles */
@media print {
    .header,
    .lesson-navigation,
    .exercise-link-container,
    .responsive-iframe-container {
        display: none;
    }
    
    main {
        padding: 0;
    }
    
    .content {
        box-shadow: none;
        border: 1px solid var(--border-medium);
    }
    
    body {
        background: white;
    }
}