/* ============================================
   WordMaster - Professional Vocabulary Platform
   Comprehensive Stylesheet
   ============================================ */

/* ============================================
   CSS Variables & Theme
   ============================================ */
:root {
    /* Colors */
    --primary: #667eea;
    --primary-dark: #5568d3;
    --secondary: #764ba2;
    --accent: #48bb78;
    --danger: #f56565;
    --warning: #ed8936;
    --info: #4299e1;

    /* Neutrals */
    --bg-primary: #ffffff;
    --bg-secondary: #f7fafc;
    --bg-tertiary: #edf2f7;
    --text-primary: #2d3748;
    --text-secondary: #4a5568;
    --text-tertiary: #718096;
    --border: #e2e8f0;

    /* Gradients */
    --gradient-primary: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    --gradient-success: linear-gradient(135deg, #48bb78, #38a169);
    --gradient-danger: linear-gradient(135deg, #f56565, #e53e3e);

    /* Spacing */
    --spacing-xs: 0.25rem;
    --spacing-sm: 0.5rem;
    --spacing-md: 1rem;
    --spacing-lg: 1.5rem;
    --spacing-xl: 2rem;
    --spacing-2xl: 3rem;

    /* Border Radius */
    --radius-sm: 0.375rem;
    --radius-md: 0.5rem;
    --radius-lg: 0.75rem;
    --radius-xl: 1rem;
    --radius-2xl: 1.5rem;

    /* Shadows */
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
    --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1);
    --shadow-2xl: 0 25px 50px -12px rgba(0, 0, 0, 0.25);

    /* Transitions */
    --transition-fast: 150ms ease-in-out;
    --transition-base: 250ms ease-in-out;
    --transition-slow: 350ms ease-in-out;
}

/* Dark Mode Variables */
body.dark-mode {
    --bg-primary: #1a202c;
    --bg-secondary: #2d3748;
    --bg-tertiary: #4a5568;
    --text-primary: #f7fafc;
    --text-secondary: #e2e8f0;
    --text-tertiary: #cbd5e0;
    --border: #4a5568;
}

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
    line-height: 1.6;
    color: var(--text-primary);
    background: var(--gradient-primary);
    min-height: 100vh;
    transition: background-color var(--transition-base);
}

body.dark-mode {
    background: linear-gradient(135deg, #1a202c 0%, #2d3748 100%);
}

/* ============================================
   Typography
   ============================================ */
h1, h2, h3, h4, h5, h6 {
    font-weight: 700;
    line-height: 1.2;
    color: var(--text-primary);
}

h1 { font-size: 2.5rem; }
h2 { font-size: 2rem; }
h3 { font-size: 1.75rem; }
h4 { font-size: 1.5rem; }
h5 { font-size: 1.25rem; }
h6 { font-size: 1rem; }

p {
    margin-bottom: var(--spacing-md);
}

a {
    color: var(--primary);
    text-decoration: none;
    transition: color var(--transition-fast);
}

a:hover {
    color: var(--primary-dark);
}

/* ============================================
   Layout
   ============================================ */
.main-container {
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

.container {
    max-width: 1400px;
    margin: 0 auto;
    padding: 0 var(--spacing-xl);
    width: 100%;
}

/* ============================================
   Header
   ============================================ */
.app-header {
    background: rgba(255, 255, 255, 0.98);
    backdrop-filter: blur(20px);
    border-bottom: 1px solid var(--border);
    padding: var(--spacing-lg) var(--spacing-xl);
    position: sticky;
    top: 0;
    z-index: 1000;
    box-shadow: var(--shadow-md);
}

body.dark-mode .app-header {
    background: rgba(45, 55, 72, 0.98);
}

.header-content {
    max-width: 1400px;
    margin: 0 auto;
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: var(--spacing-lg);
}

.logo-section {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
}

.logo {
    width: 48px;
    height: 48px;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: transform var(--transition-fast);
}

.logo:hover {
    transform: scale(1.05);
}

.brand-info h1 {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: 0.2rem;
}

.brand-tagline {
    font-size: 0.875rem;
    color: var(--text-secondary);
    font-weight: 400;
}

.header-actions {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
}

.date-display {
    background: var(--gradient-primary);
    color: white;
    padding: 0.75rem 1.5rem;
    border-radius: 50px;
    font-weight: 500;
    font-size: 0.9rem;
    box-shadow: var(--shadow-md);
}

.dark-mode-toggle {
    width: 44px;
    height: 44px;
    border-radius: 50%;
    border: 2px solid var(--border);
    background: var(--bg-primary);
    font-size: 1.25rem;
    cursor: pointer;
    transition: all var(--transition-fast);
    display: flex;
    align-items: center;
    justify-content: center;
}

.dark-mode-toggle:hover {
    transform: scale(1.1);
    box-shadow: var(--shadow-md);
}

/* ============================================
   Navigation
   ============================================ */
.main-nav {
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid var(--border);
    padding: var(--spacing-md) 0;
    position: sticky;
    top: 80px;
    z-index: 900;
}

body.dark-mode .main-nav {
    background: rgba(45, 55, 72, 0.95);
}

.nav-content {
    max-width: 1400px;
    margin: 0 auto;
    padding: 0 var(--spacing-xl);
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: var(--spacing-lg);
    flex-wrap: wrap;
}

.view-buttons {
    display: flex;
    gap: var(--spacing-sm);
    flex-wrap: wrap;
}

.view-btn {
    padding: 0.625rem 1.25rem;
    border: 2px solid transparent;
    background: var(--bg-secondary);
    color: var(--text-primary);
    border-radius: 50px;
    font-weight: 500;
    font-size: 0.9rem;
    cursor: pointer;
    transition: all var(--transition-fast);
}

.view-btn:hover {
    background: var(--bg-tertiary);
    transform: translateY(-2px);
}

.view-btn.active {
    background: var(--gradient-primary);
    color: white;
    box-shadow: var(--shadow-md);
}

.nav-actions {
    display: flex;
    gap: var(--spacing-sm);
}

.nav-action-btn {
    padding: 0.625rem 1.25rem;
    background: var(--gradient-primary);
    color: white;
    border: none;
    border-radius: 50px;
    font-weight: 500;
    font-size: 0.9rem;
    cursor: pointer;
    transition: all var(--transition-fast);
}

.nav-action-btn:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
}

/* ============================================
   Main Content
   ============================================ */
.app-main {
    flex: 1;
    padding: var(--spacing-2xl) 0;
}

.section-title {
    font-size: 1.75rem;
    font-weight: 700;
    color: white;
    margin-bottom: var(--spacing-lg);
    text-align: center;
    text-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
}

/* ============================================
   Dashboard Section
   ============================================ */
.dashboard-section {
    margin-bottom: var(--spacing-2xl);
}

.stats-section {
    background: rgba(255, 255, 255, 0.1);
    backdrop-filter: blur(10px);
    border-radius: var(--radius-2xl);
    padding: var(--spacing-xl);
    border: 1px solid rgba(255, 255, 255, 0.2);
    box-shadow: var(--shadow-xl);
}

.stats-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
    gap: var(--spacing-xl);
    margin-bottom: var(--spacing-lg);
}

.stat-item {
    text-align: center;
    color: white;
}

.stat-number {
    display: block;
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: var(--spacing-sm);
}

.stat-label {
    font-size: 0.95rem;
    opacity: 0.9;
    font-weight: 500;
}

.progress-bar-container {
    background: rgba(255, 255, 255, 0.2);
    border-radius: 50px;
    height: 12px;
    overflow: hidden;
    margin-top: var(--spacing-lg);
}

.progress-bar {
    height: 100%;
    background: var(--gradient-success);
    border-radius: 50px;
    transition: width 0.5s ease-in-out;
    box-shadow: 0 0 10px rgba(72, 187, 120, 0.5);
}

/* ============================================
   Filters Section
   ============================================ */
.filters-section {
    margin-bottom: var(--spacing-2xl);
}

.filters-container {
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    border-radius: var(--radius-2xl);
    padding: var(--spacing-xl);
    box-shadow: var(--shadow-lg);
    display: grid;
    grid-template-columns: 2fr 1fr 1fr;
    gap: var(--spacing-lg);
    align-items: end;
}

body.dark-mode .filters-container {
    background: rgba(45, 55, 72, 0.95);
}

.search-box {
    grid-column: span 1;
}

.search-input {
    width: 100%;
    padding: 0.875rem 1.25rem;
    border: 2px solid var(--border);
    border-radius: 50px;
    font-size: 1rem;
    font-family: inherit;
    background: var(--bg-primary);
    color: var(--text-primary);
    transition: all var(--transition-fast);
}

.search-input:focus {
    outline: none;
    border-color: var(--primary);
    box-shadow: 0 0 0 3px rgba(102, 126, 234, 0.1);
}

.filter-group {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-sm);
}

.filter-group label {
    font-size: 0.875rem;
    font-weight: 600;
    color: var(--text-secondary);
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.filter-select {
    padding: 0.875rem 1.25rem;
    border: 2px solid var(--border);
    border-radius: var(--radius-lg);
    font-size: 0.95rem;
    font-family: inherit;
    background: var(--bg-primary);
    color: var(--text-primary);
    cursor: pointer;
    transition: all var(--transition-fast);
}

.filter-select:focus {
    outline: none;
    border-color: var(--primary);
    box-shadow: 0 0 0 3px rgba(102, 126, 234, 0.1);
}

/* ============================================
   Words Grid
   ============================================ */
.words-section {
    margin-bottom: var(--spacing-2xl);
}

.words-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(380px, 1fr));
    gap: var(--spacing-xl);
}

/* ============================================
   Word Card
   ============================================ */
.word-card {
    background: var(--bg-primary);
    backdrop-filter: blur(10px);
    border-radius: var(--radius-2xl);
    padding: var(--spacing-xl);
    box-shadow: var(--shadow-lg);
    border: 1px solid var(--border);
    transition: all var(--transition-base);
    position: relative;
    overflow: hidden;
}

.word-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 4px;
    background: var(--gradient-primary);
}

.word-card:hover {
    transform: translateY(-8px);
    box-shadow: var(--shadow-2xl);
}

.word-card.learned {
    border-color: var(--accent);
}

.word-card.learned::before {
    background: var(--gradient-success);
}

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

.word-badge {
    padding: 0.375rem 0.875rem;
    border-radius: 50px;
    font-size: 0.75rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.word-badge.beginner {
    background: rgba(72, 187, 120, 0.1);
    color: #2f855a;
}

.word-badge.intermediate {
    background: rgba(66, 153, 225, 0.1);
    color: #2c5282;
}

.word-badge.advanced {
    background: rgba(159, 122, 234, 0.1);
    color: #553c9a;
}

.favorite-btn {
    width: 40px;
    height: 40px;
    border-radius: 50%;
    border: 2px solid var(--border);
    background: var(--bg-primary);
    font-size: 1.5rem;
    cursor: pointer;
    transition: all var(--transition-fast);
    color: var(--text-tertiary);
}

.favorite-btn:hover {
    transform: scale(1.1);
    border-color: var(--warning);
}

.favorite-btn.active {
    color: #ed8936;
    border-color: #ed8936;
    background: rgba(237, 137, 54, 0.1);
}

.word-title {
    font-size: 2rem;
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: var(--spacing-sm);
}

.pronunciation {
    font-size: 1rem;
    color: var(--text-secondary);
    font-style: italic;
    margin-bottom: var(--spacing-sm);
}

.part-of-speech {
    font-size: 0.875rem;
    color: var(--text-tertiary);
    font-weight: 500;
    text-transform: capitalize;
    margin-bottom: var(--spacing-lg);
}

/* ============================================
   Audio Section
   ============================================ */
.audio-section {
    display: flex;
    gap: var(--spacing-sm);
    margin-bottom: var(--spacing-lg);
    flex-wrap: wrap;
}

.pronunciation-button {
    background: var(--gradient-primary);
    color: white;
    border: none;
    padding: 0.625rem 1.25rem;
    border-radius: 50px;
    font-weight: 500;
    font-size: 0.875rem;
    cursor: pointer;
    transition: all var(--transition-fast);
}

.pronunciation-button:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

.pronunciation-button.playing {
    background: var(--gradient-success);
    animation: pulse-audio 1.5s infinite;
}

@keyframes pulse-audio {
    0%, 100% { opacity: 1; }
    50% { opacity: 0.7; }
}

/* ============================================
   Definition, Example, Meaning
   ============================================ */
.definition,
.example,
.bengali-meaning {
    margin-bottom: var(--spacing-lg);
    padding: var(--spacing-md) var(--spacing-lg);
    border-radius: var(--radius-lg);
}

.definition {
    background: rgba(102, 126, 234, 0.05);
    border-left: 4px solid var(--primary);
}

.example {
    background: rgba(237, 137, 54, 0.05);
    border-left: 4px solid var(--warning);
}

.bengali-meaning {
    background: rgba(72, 187, 120, 0.05);
    border-left: 4px solid var(--accent);
}

.definition-label,
.example-label,
.meaning-label {
    font-size: 0.75rem;
    color: var(--text-tertiary);
    text-transform: uppercase;
    letter-spacing: 0.5px;
    font-weight: 600;
    margin-bottom: var(--spacing-xs);
}

.definition-text,
.example-text {
    color: var(--text-primary);
    font-size: 0.95rem;
    line-height: 1.6;
}

.bengali-text {
    font-size: 1.25rem;
    font-weight: 600;
    color: var(--text-primary);
}

/* ============================================
   Synonyms
   ============================================ */
.synonyms {
    display: flex;
    flex-wrap: wrap;
    gap: var(--spacing-sm);
    margin-bottom: var(--spacing-lg);
    align-items: center;
}

.syn-label {
    font-size: 0.875rem;
    font-weight: 600;
    color: var(--text-secondary);
}

.syn-tag {
    padding: 0.375rem 0.75rem;
    background: var(--bg-secondary);
    border: 1px solid var(--border);
    border-radius: 50px;
    font-size: 0.825rem;
    color: var(--text-secondary);
}

/* ============================================
   Word Actions
   ============================================ */
.word-actions {
    display: flex;
    gap: var(--spacing-sm);
    margin-top: var(--spacing-lg);
    padding-top: var(--spacing-lg);
    border-top: 1px solid var(--border);
}

.action-btn {
    flex: 1;
    padding: 0.75rem 1.25rem;
    border: 2px solid var(--border);
    border-radius: var(--radius-lg);
    font-weight: 600;
    font-size: 0.875rem;
    cursor: pointer;
    transition: all var(--transition-fast);
    background: var(--bg-primary);
    color: var(--text-primary);
}

.action-btn:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

.learn-btn {
    background: var(--gradient-success);
    color: white;
    border: none;
}

.share-btn:hover {
    border-color: var(--info);
    color: var(--info);
}

.learned-badge {
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 0.75rem;
    background: rgba(72, 187, 120, 0.1);
    color: var(--accent);
    border-radius: var(--radius-lg);
    font-weight: 600;
    font-size: 0.875rem;
}

/* ============================================
   No Results
   ============================================ */
.no-results {
    text-align: center;
    padding: var(--spacing-2xl);
    color: white;
}

.no-results-icon {
    font-size: 4rem;
    margin-bottom: var(--spacing-lg);
}

.no-results h3 {
    color: white;
    margin-bottom: var(--spacing-sm);
}

.no-results p {
    color: rgba(255, 255, 255, 0.8);
}

/* ============================================
   Quiz Container
   ============================================ */
.quiz-container {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0, 0, 0, 0.8);
    backdrop-filter: blur(10px);
    z-index: 2000;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: var(--spacing-xl);
}

.quiz-header {
    display: flex;
    justify-content: space-between;
    margin-bottom: var(--spacing-xl);
    color: white;
    font-weight: 600;
}

.quiz-question {
    background: var(--bg-primary);
    padding: var(--spacing-2xl);
    border-radius: var(--radius-2xl);
    margin-bottom: var(--spacing-xl);
    text-align: center;
}

.quiz-question h2 {
    font-size: 2.5rem;
    margin-bottom: var(--spacing-md);
}

.quiz-pronunciation {
    font-size: 1.25rem;
    color: var(--text-secondary);
    font-style: italic;
}

.quiz-options {
    display: grid;
    gap: var(--spacing-md);
}

.quiz-option {
    padding: var(--spacing-lg);
    background: var(--bg-primary);
    border: 2px solid var(--border);
    border-radius: var(--radius-xl);
    font-size: 1rem;
    cursor: pointer;
    transition: all var(--transition-fast);
    text-align: left;
}

.quiz-option:hover {
    transform: translateX(8px);
    border-color: var(--primary);
    box-shadow: var(--shadow-lg);
}

.quiz-results {
    background: var(--bg-primary);
    padding: var(--spacing-2xl);
    border-radius: var(--radius-2xl);
    text-align: center;
    max-width: 500px;
}

.quiz-final-score {
    margin: var(--spacing-2xl) 0;
}

.score-circle {
    width: 150px;
    height: 150px;
    border-radius: 50%;
    background: var(--gradient-primary);
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto var(--spacing-lg);
}

.score-percentage {
    font-size: 2.5rem;
    font-weight: 700;
    color: white;
}

/* ============================================
   Modal
   ============================================ */
.modal {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0, 0, 0, 0.7);
    backdrop-filter: blur(10px);
    z-index: 2000;
    padding: var(--spacing-xl);
    overflow-y: auto;
}

.modal-content {
    background: var(--bg-primary);
    max-width: 600px;
    margin: 2rem auto;
    border-radius: var(--radius-2xl);
    box-shadow: var(--shadow-2xl);
}

.modal-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: var(--spacing-xl);
    border-bottom: 1px solid var(--border);
}

.modal-close {
    width: 40px;
    height: 40px;
    border-radius: 50%;
    border: none;
    background: var(--bg-secondary);
    font-size: 1.5rem;
    cursor: pointer;
    transition: all var(--transition-fast);
}

.modal-close:hover {
    background: var(--bg-tertiary);
    transform: scale(1.1);
}

.modal-body {
    padding: var(--spacing-xl);
}

.export-options {
    display: grid;
    gap: var(--spacing-md);
}

.export-btn {
    display: flex;
    align-items: center;
    gap: var(--spacing-lg);
    padding: var(--spacing-lg);
    background: var(--bg-secondary);
    border: 2px solid var(--border);
    border-radius: var(--radius-xl);
    cursor: pointer;
    transition: all var(--transition-fast);
    text-align: left;
}

.export-btn:hover {
    border-color: var(--primary);
    transform: translateY(-4px);
    box-shadow: var(--shadow-lg);
}

.export-icon {
    font-size: 2rem;
}

.export-btn h3 {
    font-size: 1.125rem;
    margin-bottom: 0.25rem;
}

.export-btn p {
    font-size: 0.875rem;
    color: var(--text-secondary);
    margin: 0;
}

/* ============================================
   Notifications
   ============================================ */
.notification {
    position: fixed;
    bottom: var(--spacing-xl);
    right: var(--spacing-xl);
    padding: var(--spacing-lg) var(--spacing-xl);
    background: var(--bg-primary);
    border-radius: var(--radius-xl);
    box-shadow: var(--shadow-2xl);
    z-index: 3000;
    transform: translateY(100px);
    opacity: 0;
    transition: all var(--transition-base);
    border-left: 4px solid var(--info);
}

.notification.show {
    transform: translateY(0);
    opacity: 1;
}

.notification-success {
    border-left-color: var(--accent);
}

.notification-error {
    border-left-color: var(--danger);
}

/* ============================================
   Footer
   ============================================ */
.app-footer {
    background: rgba(45, 55, 72, 0.95);
    color: white;
    padding: var(--spacing-2xl) 0;
    margin-top: var(--spacing-2xl);
}

.footer-content {
    max-width: 1400px;
    margin: 0 auto;
    padding: 0 var(--spacing-xl);
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: var(--spacing-2xl);
}

.footer-section h3 {
    color: white;
    margin-bottom: var(--spacing-md);
}

.footer-section h4 {
    color: white;
    font-size: 1.125rem;
    margin-bottom: var(--spacing-md);
}

.footer-section p {
    color: rgba(255, 255, 255, 0.8);
    margin-bottom: var(--spacing-sm);
}

.footer-section ul {
    list-style: none;
}

.footer-section li {
    margin-bottom: var(--spacing-sm);
}

.footer-section a {
    color: rgba(255, 255, 255, 0.8);
    transition: color var(--transition-fast);
}

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

.footer-bottom {
    text-align: center;
    padding-top: var(--spacing-xl);
    margin-top: var(--spacing-xl);
    border-top: 1px solid rgba(255, 255, 255, 0.1);
}

.footer-bottom p {
    color: rgba(255, 255, 255, 0.6);
    margin: 0;
}

/* ============================================
   Loading Indicator
   ============================================ */
.loading-overlay {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0, 0, 0, 0.8);
    backdrop-filter: blur(10px);
    z-index: 9999;
    display: flex;
    align-items: center;
    justify-content: center;
}

.spinner-container {
    text-align: center;
    color: white;
}

.spinner {
    width: 50px;
    height: 50px;
    border: 3px solid rgba(255, 255, 255, 0.3);
    border-top-color: white;
    border-radius: 50%;
    animation: spin 1s linear infinite;
    margin: 0 auto var(--spacing-md);
}

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

/* ============================================
   Responsive Design
   ============================================ */
@media (max-width: 1024px) {
    .words-grid {
        grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
    }

    .filters-container {
        grid-template-columns: 1fr;
    }

    .search-box {
        grid-column: span 1;
    }
}

@media (max-width: 768px) {
    .header-content {
        flex-direction: column;
        gap: var(--spacing-md);
    }

    .nav-content {
        flex-direction: column;
    }

    .view-buttons {
        width: 100%;
        justify-content: center;
    }

    .words-grid {
        grid-template-columns: 1fr;
    }

    .stats-grid {
        grid-template-columns: repeat(2, 1fr);
    }

    h1 { font-size: 2rem; }
    h2 { font-size: 1.75rem; }
    h3 { font-size: 1.5rem; }

    .word-title {
        font-size: 1.75rem;
    }

    .footer-content {
        grid-template-columns: 1fr;
    }
}

@media (max-width: 480px) {
    .container {
        padding: 0 var(--spacing-md);
    }

    .view-btn {
        font-size: 0.825rem;
        padding: 0.5rem 1rem;
    }

    .word-card {
        padding: var(--spacing-lg);
    }

    .audio-section {
        flex-direction: column;
    }

    .pronunciation-button {
        width: 100%;
    }

    .word-actions {
        flex-direction: column;
    }

    .stats-grid {
        grid-template-columns: 1fr;
    }
}

/* ============================================
   Print Styles
   ============================================ */
@media print {
    .app-header,
    .main-nav,
    .filters-section,
    .app-footer,
    .word-actions,
    .favorite-btn,
    .audio-section {
        display: none;
    }

    .word-card {
        break-inside: avoid;
        page-break-inside: avoid;
    }
}