/* Reset and base styles */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    /* Material Design Color Palette */
    --primary-color: #1976d2;
    --primary-light: #42a5f5;
    --primary-dark: #1565c0;
    --secondary-color: #dc004e;
    --surface-color: #ffffff;
    --background-color: #fafafa;
    --on-surface: #212121;
    --on-surface-variant: #757575;
    --outline: #e0e0e0;
    --outline-variant: #eeeeee;
    --shadow: rgba(0, 0, 0, 0.12);
    --shadow-dark: rgba(0, 0, 0, 0.24);
    
    /* Typography */
    --font-family: 'Roboto', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    --font-size-h1: 2.125rem;
    --font-size-h2: 1.5rem;
    --font-size-h3: 1.25rem;
    --font-size-body: 0.875rem;
    --font-size-caption: 0.75rem;
    
    /* Spacing */
    --spacing-xs: 4px;
    --spacing-sm: 8px;
    --spacing-md: 16px;
    --spacing-lg: 24px;
    --spacing-xl: 32px;
    --spacing-xxl: 48px;
    
    /* Border radius */
    --border-radius-sm: 4px;
    --border-radius-md: 8px;
    --border-radius-lg: 12px;
    --border-radius-xl: 16px;
    
    /* Elevation */
    --elevation-1: 0 1px 3px var(--shadow), 0 1px 2px var(--shadow);
    --elevation-2: 0 2px 6px var(--shadow), 0 1px 2px var(--shadow-dark);
    --elevation-3: 0 4px 8px var(--shadow), 0 2px 4px var(--shadow-dark);
    --elevation-4: 0 6px 12px var(--shadow), 0 2px 6px var(--shadow-dark);
}

/* Dark theme */
[data-theme="dark"] {
    --surface-color: #121212;
    --background-color: #0d1117;
    --on-surface: #e1e4e8;
    --on-surface-variant: #8b949e;
    --outline: #30363d;
    --outline-variant: #21262d;
    --shadow: rgba(0, 0, 0, 0.3);
    --shadow-dark: rgba(0, 0, 0, 0.5);
}

body {
    font-family: var(--font-family);
    background-color: var(--background-color);
    color: var(--on-surface);
    line-height: 1.6;
    font-size: var(--font-size-body);
    transition: background-color 0.3s ease, color 0.3s ease;
}

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

/* Header */
.header {
    background-color: var(--surface-color);
    border-bottom: 1px solid var(--outline);
    position: sticky;
    top: 0;
    z-index: 100;
    box-shadow: var(--elevation-1);
}

.header .container {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: var(--spacing-md);
    min-height: 64px;
}

.logo {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    text-decoration: none;
    color: var(--primary-color);
}

.logo .material-icons {
    font-size: 32px;
}

.logo h1 {
    font-size: 1.25rem;
    font-weight: 500;
    margin: 0;
}

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

.nav-link {
    text-decoration: none;
    color: var(--on-surface);
    font-weight: 500;
    padding: var(--spacing-sm) var(--spacing-md);
    border-radius: var(--border-radius-md);
    transition: background-color 0.2s ease;
}

.nav-link:hover {
    background-color: var(--outline-variant);
}

/* Main Tool Section */
.main-tool {
    padding: var(--spacing-xxl) 0;
    background: linear-gradient(135deg, #f5f7fa 0%, #c3cfe2 100%);
}

[data-theme="dark"] .main-tool {
    background: linear-gradient(135deg, #0d1117 0%, #161b22 100%);
}

.tool-header {
    text-align: center;
    margin-bottom: var(--spacing-xl);
}

.tool-header h2 {
    font-size: var(--font-size-h1);
    font-weight: 400;
    color: var(--primary-color);
    margin-bottom: var(--spacing-sm);
}

.tool-header p {
    font-size: 1rem;
    color: var(--on-surface-variant);
    max-width: 600px;
    margin: 0 auto;
}

.tool-container {
    display: grid;
    grid-template-columns: 1fr 250px;
    gap: var(--spacing-xl);
    max-width: 1200px;
    margin: 0 auto;
}

/* Text Input Section */
.text-input-section {
    background-color: var(--surface-color);
    border-radius: var(--border-radius-lg);
    overflow: hidden;
    box-shadow: var(--elevation-2);
}

.input-header {
    padding: var(--spacing-md);
    border-bottom: 1px solid var(--outline);
    background-color: var(--outline-variant);
}

.toolbar {
    display: flex;
    gap: var(--spacing-xs);
}

.btn {
    border: none;
    background: transparent;
    cursor: pointer;
    border-radius: var(--border-radius-sm);
    transition: all 0.2s ease;
    font-family: inherit;
}

.btn-icon {
    padding: var(--spacing-sm);
    color: var(--on-surface-variant);
    display: flex;
    align-items: center;
    justify-content: center;
}

.btn-icon:hover {
    background-color: var(--outline);
    color: var(--primary-color);
    transform: translateY(-1px);
}

.btn-icon .material-icons {
    font-size: 20px;
}

.text-area {
    width: 100%;
    min-height: 400px;
    padding: var(--spacing-lg);
    border: none;
    outline: none;
    font-family: var(--font-family);
    font-size: 1rem;
    line-height: 1.6;
    background-color: var(--surface-color);
    color: var(--on-surface);
    resize: none;
    box-shadow: none;
    border-top: none;
    border-bottom: none;
}

.text-area::placeholder {
    color: var(--on-surface-variant);
    opacity: 0.7;
}

/* Stats Panel */
.stats-panel {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-lg);
}

.stats-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--spacing-md);
}

.stat-card {
    background-color: var(--surface-color);
    border-radius: var(--border-radius-lg);
    padding: var(--spacing-lg);
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
    box-shadow: var(--elevation-1);
    transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.stat-card:hover {
    transform: translateY(-2px);
    box-shadow: var(--elevation-3);
}

.stat-icon {
    background-color: var(--primary-color);
    color: white;
    padding: var(--spacing-sm);
    border-radius: var(--border-radius-md);
    display: flex;
    align-items: center;
    justify-content: center;
}

.stat-icon .material-icons {
    font-size: 24px;
}

.stat-info {
    flex: 1;
}

.stat-value {
    font-size: 1.5rem;
    font-weight: 500;
    color: var(--on-surface);
    line-height: 1.2;
}

.stat-label {
    font-size: var(--font-size-caption);
    color: var(--on-surface-variant);
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

/* Word Density Panel */
.word-density-panel {
    background-color: var(--surface-color);
    border-radius: var(--border-radius-lg);
    padding: var(--spacing-lg);
    box-shadow: var(--elevation-1);
    width: 100%;
}

.word-density-panel h3 {
    font-size: var(--font-size-h3);
    font-weight: 500;
    margin-bottom: var(--spacing-md);
    color: var(--on-surface);
}

.density-list {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-sm);
    max-height: 250px;
    overflow-y: auto;
}

.density-item {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: var(--spacing-md) var(--spacing-lg);
    background-color: var(--outline-variant);
    border-radius: var(--border-radius-md);
    font-size: var(--font-size-body);
    transition: background-color 0.2s ease, transform 0.2s ease;
}

.density-item:hover {
    background-color: var(--outline);
    transform: translateY(-1px);
}

.density-word {
    font-weight: 500;
    color: var(--primary-color);
    flex: 1;
    margin-right: var(--spacing-md);
}

.density-count {
    font-weight: 500;
    color: var(--on-surface);
    white-space: nowrap;
}

.density-percentage {
    background-color: var(--primary-color);
    color: white;
    padding: 4px 8px;
    border-radius: var(--border-radius-sm);
    font-size: var(--font-size-caption);
    font-weight: 500;
    min-width: 50px;
    text-align: center;
}

/* Content Section */
.content-section {
    padding: var(--spacing-xxl) 0;
    background-color: var(--surface-color);
}

.content-wrapper {
    max-width: 800px;
    margin: 0 auto;
}

.seo-content {
    line-height: 1.8;
}

.seo-content h2 {
    font-size: var(--font-size-h2);
    font-weight: 400;
    color: var(--primary-color);
    margin: var(--spacing-xl) 0 var(--spacing-lg);
}

.seo-content h3 {
    font-size: var(--font-size-h3);
    font-weight: 500;
    color: var(--on-surface);
    margin: var(--spacing-lg) 0 var(--spacing-md);
}

.seo-content h4 {
    font-size: 1rem;
    font-weight: 500;
    color: var(--primary-color);
    margin: var(--spacing-md) 0 var(--spacing-sm);
}

.seo-content p {
    margin-bottom: var(--spacing-md);
    color: var(--on-surface);
}

.seo-content strong {
    color: var(--primary-color);
    font-weight: 500;
}

/* FAQ Section */
.faq-section {
    margin-top: var(--spacing-lg);
}

.faq-item {
    border: 1px solid var(--outline);
    border-radius: var(--border-radius-md);
    margin-bottom: var(--spacing-md);
    overflow: hidden;
}

.faq-item h4 {
    background-color: var(--outline-variant);
    padding: var(--spacing-md);
    margin: 0;
    cursor: pointer;
    transition: background-color 0.2s ease;
}

.faq-item h4:hover {
    background-color: var(--outline);
}

.faq-item p {
    padding: var(--spacing-md);
    margin: 0;
    border-top: 1px solid var(--outline);
}

/* Footer */
.footer {
    background-color: var(--on-surface);
    color: var(--surface-color);
    padding: var(--spacing-xxl) 0 var(--spacing-lg);
}

.footer-content {
    display: grid;
    grid-template-columns: 2fr 1fr 1fr 1fr;
    gap: var(--spacing-xl);
    margin-bottom: var(--spacing-xl);
}

.footer-section h3,
.footer-section h4 {
    margin-bottom: var(--spacing-md);
    color: var(--surface-color);
}

.footer-section p {
    color: var(--outline-variant);
    line-height: 1.6;
}

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

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

.footer-section ul li a {
    color: var(--outline-variant);
    text-decoration: none;
    transition: color 0.2s ease;
}

.footer-section ul li a:hover {
    color: var(--surface-color);
}

.footer-bottom {
    border-top: 1px solid var(--outline);
    padding-top: var(--spacing-lg);
    text-align: center;
    color: var(--outline-variant);
}

/* Social Media Styles */
.social-media {
    margin-top: var(--spacing-lg);
}

.social-media h4 {
    margin-bottom: var(--spacing-sm);
    font-size: var(--font-size-body);
    font-weight: 500;
}

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

.social-btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 40px;
    height: 40px;
    border-radius: 50%;
    text-decoration: none;
    transition: all 0.3s ease;
    cursor: pointer;
}

.social-btn .material-icons {
    font-size: 20px;
    color: white;
}

.social-btn.facebook {
    background-color: #1877f2;
}

.social-btn.facebook:hover {
    background-color: #166fe5;
    transform: translateY(-2px);
}

.social-btn.twitter {
    background-color: #000000;
}

.social-btn.twitter:hover {
    background-color: #333333;
    transform: translateY(-2px);
}

.social-btn.instagram {
    background: linear-gradient(45deg, #f09433 0%, #e6683c 25%, #dc2743 50%, #cc2366 75%, #bc1888 100%);
}

.social-btn.instagram:hover {
    opacity: 0.9;
    transform: translateY(-2px);
}

.social-btn.pinterest {
    background-color: #bd081c;
}

.social-btn.pinterest:hover {
    background-color: #a50719;
    transform: translateY(-2px);
}

/* Fullscreen mode */
.fullscreen-mode {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    z-index: 1000;
    background-color: var(--surface-color);
    display: flex;
    flex-direction: column;
}

.fullscreen-mode .text-area {
    flex: 1;
    min-height: auto;
    border-radius: 0;
}

.fullscreen-mode .input-header {
    flex-shrink: 0;
}

/* Responsive Design */
@media (max-width: 1024px) {
    .tool-container {
        grid-template-columns: 1fr;
        gap: var(--spacing-lg);
    }
    
    .stats-grid {
        grid-template-columns: repeat(3, 1fr);
    }
}

@media (max-width: 768px) {
    .container {
        padding: 0 var(--spacing-sm);
    }
    
    .header .container {
        padding: var(--spacing-sm);
    }
    
    .logo h1 {
        font-size: 1rem;
    }
    
    .nav {
        gap: var(--spacing-sm);
    }
    
    .nav-link {
        padding: var(--spacing-xs) var(--spacing-sm);
        font-size: var(--font-size-caption);
    }
    
    .tool-header h2 {
        font-size: 1.5rem;
    }
    
    .main-tool {
        padding: var(--spacing-lg) 0;
    }
    
    .stats-grid {
        grid-template-columns: 1fr 1fr;
        gap: var(--spacing-sm);
    }
    
    .stat-card {
        padding: var(--spacing-md);
        flex-direction: column;
        text-align: center;
    }
    
    .stat-value {
        font-size: 1.25rem;
    }
    
    .text-area {
        min-height: 300px;
        font-size: 16px; /* Prevent zoom on iOS */
    }
    
    .footer-content {
        grid-template-columns: 1fr;
        gap: var(--spacing-lg);
        text-align: center;
    }
    
    .social-buttons {
        justify-content: center;
    }
}

@media (max-width: 480px) {
    .tool-header {
        margin-bottom: var(--spacing-lg);
    }
    
    .toolbar {
        flex-wrap: wrap;
    }
    
    .stats-grid {
        grid-template-columns: 1fr;
    }
    
    .content-section {
        padding: var(--spacing-lg) 0;
    }
}

/* Print styles */
@media print {
    .header,
    .toolbar,
    .footer {
        display: none;
    }
    
    .main-tool {
        background: none;
    }
    
    .text-area {
        border: 1px solid #000;
        min-height: auto;
    }
}

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

/* Focus states for keyboard navigation */
.btn:focus,
.nav-link:focus {
    outline: 2px solid var(--primary-color);
    outline-offset: 2px;
}

.text-area:focus {
    outline: none;
    border: none;
    box-shadow: none;
}

/* Loading animation */
.loading {
    opacity: 0.7;
    pointer-events: none;
}

/* Success/Error states */
.success {
    color: #4caf50;
}

.error {
    color: #f44336;
}

/* Copy feedback */
.copy-feedback {
    position: fixed;
    top: 20px;
    right: 20px;
    background-color: var(--primary-color);
    color: white;
    padding: var(--spacing-sm) var(--spacing-md);
    border-radius: var(--border-radius-md);
    z-index: 1001;
    animation: slideIn 0.3s ease;
}

@keyframes slideIn {
    from {
        transform: translateX(100%);
        opacity: 0;
    }
    to {
        transform: translateX(0);
        opacity: 1;
    }
}