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

:root {
    /* Colors - Modern 2025 Palette */
    --color-primary: #2D3748;
    --color-accent: #4299E1;
    --color-success: #48BB78;
    --color-warning: #ED8936;
    --color-error: #F56565;
    --color-bg: #F7FAFC;
    --color-surface: #FFFFFF;
    --color-text: #1A202C;
    --color-text-muted: #718096;
    --color-border: #E2E8F0;
    --color-border-hover: #CBD5E0;
    
    /* Typography */
    --font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    --font-mono: 'JetBrains Mono', 'Fira Code', Consolas, monospace;
    
    /* 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;
    
    /* 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), 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);
    
    /* Transitions */
    --transition-fast: 0.15s ease-out;
    --transition-normal: 0.25s ease-out;
    --transition-slow: 0.35s ease-out;
}

body {
    font-family: var(--font-family);
    background-color: var(--color-bg);
    color: var(--color-text);
    line-height: 1.6;
    font-size: 16px;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

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

/* Header */
.header {
    background: linear-gradient(135deg, var(--color-primary) 0%, #4A5568 100%);
    color: white;
    padding: var(--spacing-2xl) 0;
    position: relative;
    overflow: hidden;
}

.header::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: url("data:image/svg+xml,%3Csvg width='60' height='60' viewBox='0 0 60 60' xmlns='http://www.w3.org/2000/svg'%3E%3Cg fill='none' fill-rule='evenodd'%3E%3Cg fill='%23ffffff' fill-opacity='0.03'%3E%3Ccircle cx='30' cy='30' r='2'/%3E%3C/g%3E%3C/g%3E%3C/svg%3E") repeat;
    pointer-events: none;
}

.header-content {
    position: relative;
    z-index: 1;
    text-align: center;
}

.logo {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: var(--spacing-md);
    margin-bottom: var(--spacing-lg);
}

.logo-icon {
    font-size: 2.5rem;
    animation: sparkle 2s ease-in-out infinite;
}

@keyframes sparkle {
    0%, 100% { transform: scale(1) rotate(0deg); }
    50% { transform: scale(1.1) rotate(5deg); }
}

.logo-text {
    font-size: 2.5rem;
    font-weight: 700;
    letter-spacing: -0.025em;
}

.tagline {
    font-size: 1.25rem;
    opacity: 0.9;
    font-weight: 400;
    max-width: 600px;
    margin: 0 auto;
}

/* Main Content */
.main {
    padding: var(--spacing-2xl) 0;
    min-height: calc(100vh - 300px);
}

/* Stats Bar */
.stats-bar {
    display: flex;
    justify-content: center;
    gap: var(--spacing-2xl);
    margin-bottom: var(--spacing-2xl);
    padding: var(--spacing-lg);
    background: var(--color-surface);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-sm);
    border: 1px solid var(--color-border);
}

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

.stat-label {
    display: block;
    font-size: 0.875rem;
    color: var(--color-text-muted);
    margin-bottom: var(--spacing-xs);
    font-weight: 500;
}

.stat-value {
    display: block;
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--color-accent);
    font-family: var(--font-mono);
}

/* Text Areas */
.text-areas {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--spacing-xl);
    margin-bottom: var(--spacing-2xl);
}

.text-area-container {
    background: var(--color-surface);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-md);
    border: 1px solid var(--color-border);
    overflow: hidden;
    transition: all var(--transition-normal);
}

.text-area-container:hover {
    box-shadow: var(--shadow-lg);
    border-color: var(--color-border-hover);
}

.text-area-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: var(--spacing-lg);
    border-bottom: 1px solid var(--color-border);
    background: linear-gradient(to right, #f8fafc, #ffffff);
}

.text-area-title {
    font-size: 1.125rem;
    font-weight: 600;
    color: var(--color-text);
}

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

.action-btn {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 32px;
    height: 32px;
    border: none;
    background: transparent;
    color: var(--color-text-muted);
    border-radius: var(--radius-sm);
    cursor: pointer;
    transition: all var(--transition-fast);
}

.action-btn:hover {
    background: var(--color-border);
    color: var(--color-text);
    transform: translateY(-1px);
}

.text-area-wrapper {
    position: relative;
}

.text-area {
    width: 100%;
    height: 300px;
    padding: var(--spacing-lg);
    border: none;
    outline: none;
    resize: vertical;
    font-family: var(--font-mono);
    font-size: 0.875rem;
    line-height: 1.6;
    background: transparent;
    color: #1A202C !important;
    transition: all var(--transition-normal);
    display: block !important;
    visibility: visible !important;
    opacity: 1 !important;
}

.text-area:focus {
    background: #fafbfc;
}

.text-area::placeholder {
    color: var(--color-text-muted);
    opacity: 0.7;
}

.text-area-footer {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: var(--spacing-sm) var(--spacing-lg);
    background: #f8fafc;
    border-top: 1px solid var(--color-border);
    font-size: 0.75rem;
    color: var(--color-text-muted);
}

.char-counter {
    font-family: var(--font-mono);
}

.changes-indicator {
    font-weight: 500;
    color: var(--color-success);
}

/* Options Panel */
.options-panel {
    background: var(--color-surface);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-md);
    border: 1px solid var(--color-border);
    padding: var(--spacing-xl);
    margin-bottom: var(--spacing-2xl);
}

.options-title {
    font-size: 1.25rem;
    font-weight: 600;
    margin-bottom: var(--spacing-lg);
    color: var(--color-text);
}

.options-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: var(--spacing-lg);
}

.option-item {
    display: flex;
    align-items: flex-start;
    gap: var(--spacing-md);
    cursor: pointer;
    padding: var(--spacing-md);
    border-radius: var(--radius-md);
    transition: all var(--transition-fast);
    border: 1px solid transparent;
}

.option-item:hover {
    background: #f8fafc;
    border-color: var(--color-border);
}

.option-item input[type="checkbox"] {
    display: none;
}

.option-checkbox {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 20px;
    height: 20px;
    border: 2px solid var(--color-border);
    border-radius: var(--radius-sm);
    background: var(--color-surface);
    transition: all var(--transition-fast);
    flex-shrink: 0;
    margin-top: 2px;
}

.option-checkbox::after {
    content: '✓';
    color: white;
    font-size: 12px;
    font-weight: bold;
    opacity: 0;
    transform: scale(0.5);
    transition: all var(--transition-fast);
}

.option-item input[type="checkbox"]:checked + .option-checkbox {
    background: var(--color-accent);
    border-color: var(--color-accent);
}

.option-item input[type="checkbox"]:checked + .option-checkbox::after {
    opacity: 1;
    transform: scale(1);
}

.option-content {
    flex: 1;
}

.option-label {
    display: block;
    font-weight: 500;
    color: var(--color-text);
    margin-bottom: var(--spacing-xs);
}

.option-description {
    display: block;
    font-size: 0.875rem;
    color: var(--color-text-muted);
    line-height: 1.4;
}

/* Action Section */
.action-section {
    text-align: center;
    margin-bottom: var(--spacing-2xl);
}

.humanize-btn {
    display: inline-flex;
    align-items: center;
    gap: var(--spacing-md);
    padding: var(--spacing-lg) var(--spacing-2xl);
    background: linear-gradient(135deg, var(--color-accent) 0%, #3182CE 100%);
    color: white;
    border: none;
    border-radius: var(--radius-lg);
    font-size: 1.125rem;
    font-weight: 600;
    cursor: pointer;
    transition: all var(--transition-normal);
    box-shadow: var(--shadow-md);
    position: relative;
    overflow: hidden;
    min-width: 200px;
    justify-content: center;
}

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

.humanize-btn:active {
    transform: translateY(0);
}

.humanize-btn.loading {
    pointer-events: none;
}

.humanize-btn.loading .btn-text {
    opacity: 0.7;
}

.btn-icon {
    font-size: 1.25rem;
    animation: sparkle 2s ease-in-out infinite;
}

.btn-loader {
    display: none;
    width: 20px;
    height: 20px;
    border: 2px solid rgba(255, 255, 255, 0.3);
    border-top: 2px solid white;
    border-radius: 50%;
    animation: spin 1s linear infinite;
}

.humanize-btn.loading .btn-loader {
    display: block;
}

@keyframes spin {
    0% { transform: rotate(0deg); }
    100% { transform: rotate(360deg); }
}

.action-note {
    margin: var(--spacing-lg) 0;
    color: var(--color-text-muted);
    font-size: 0.875rem;
}

.auto-process-toggle {
    display: inline-flex;
    align-items: center;
    gap: var(--spacing-md);
    cursor: pointer;
    font-size: 0.875rem;
    color: var(--color-text);
}

.auto-process-toggle input[type="checkbox"] {
    display: none;
}

.toggle-slider {
    position: relative;
    width: 44px;
    height: 24px;
    background: var(--color-border);
    border-radius: 12px;
    transition: all var(--transition-normal);
}

.toggle-slider::after {
    content: '';
    position: absolute;
    top: 2px;
    left: 2px;
    width: 20px;
    height: 20px;
    background: white;
    border-radius: 50%;
    transition: all var(--transition-normal);
    box-shadow: var(--shadow-sm);
}

.auto-process-toggle input[type="checkbox"]:checked + .toggle-slider {
    background: var(--color-accent);
}

.auto-process-toggle input[type="checkbox"]:checked + .toggle-slider::after {
    transform: translateX(20px);
}

/* Footer */
.footer {
    background: var(--color-surface);
    border-top: 1px solid var(--color-border);
    padding: var(--spacing-xl) 0;
    margin-top: auto;
}

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

.footer-text {
    color: var(--color-text-muted);
    font-size: 0.875rem;
    margin-bottom: var(--spacing-sm);
}

.footer-text a {
    color: var(--color-accent);
    text-decoration: none;
    font-weight: 500;
}

.footer-text a:hover {
    text-decoration: underline;
}

.footer-note {
    color: var(--color-text-muted);
    font-size: 0.75rem;
}

/* Toast Notifications */
.toast-container {
    position: fixed;
    bottom: 1.25rem;
    right: 1.25rem;
    z-index: 1000;
    display: flex;
    flex-direction: column;
    gap: var(--spacing-sm);
    pointer-events: none;
}

.toast {
    padding: var(--spacing-md) var(--spacing-lg);
    border-radius: var(--radius-md);
    box-shadow: var(--shadow-lg);
    color: white;
    font-weight: 500;
    font-size: 0.875rem;
    animation: fadeIn var(--transition-normal) ease-out forwards;
    max-width: 280px;
    min-width: 200px;
    word-wrap: break-word;
    box-sizing: border-box;
    line-height: 1.4;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

.toast.success {
    background: var(--color-success);
}

.toast.error {
    background: var(--color-error);
}

.toast.info {
    background: var(--color-accent);
}

@keyframes fadeIn {
    from {
        opacity: 0;
        transform: scale(0.9);
    }
    to {
        opacity: 1;
        transform: scale(1);
    }
}

@keyframes fadeOut {
    from {
        opacity: 1;
        transform: scale(1);
    }
    to {
        opacity: 0;
        transform: scale(0.9);
    }
}

/* Responsive Design */
@media (max-width: 768px) {
    .container {
        padding: 0 var(--spacing-md);
    }
    
    .header {
        padding: var(--spacing-xl) 0;
    }
    
    .logo-text {
        font-size: 2rem;
    }
    
    .tagline {
        font-size: 1.125rem;
    }
    
    .stats-bar {
        flex-direction: column;
        gap: var(--spacing-lg);
        text-align: center;
    }
    
    .text-areas {
        grid-template-columns: 1fr;
        gap: var(--spacing-lg);
    }
    
    .text-area {
        height: 250px;
    }
    
    .options-grid {
        grid-template-columns: 1fr;
        gap: var(--spacing-md);
    }
    
    .humanize-btn {
        width: 100%;
        max-width: 300px;
    }
    
    .toast-container {
        left: var(--spacing-md);
        right: var(--spacing-md);
    }
    
    .toast {
        max-width: none;
    }
}

@media (max-width: 480px) {
    .text-area-header {
        flex-direction: column;
        gap: var(--spacing-sm);
        align-items: flex-start;
    }
    
    .text-area-actions {
        align-self: flex-end;
    }
    
    .option-item {
        padding: var(--spacing-sm);
    }
    
    .options-panel {
        padding: var(--spacing-lg);
    }
}

/* Dark mode support */
@media (prefers-color-scheme: dark) {
    :root {
        --color-bg: #1A202C;
        --color-surface: #2D3748;
        --color-text: #F7FAFC;
        --color-text-muted: #A0AEC0;
        --color-border: #4A5568;
        --color-border-hover: #718096;
    }
    
    .text-area:focus {
        background: #2a3441;
    }
    
    .text-area-footer {
        background: #2a3441;
    }
    
    .option-item:hover {
        background: #2a3441;
    }
}

/* Print styles */
@media print {
    .header,
    .options-panel,
    .action-section,
    .footer,
    .toast-container {
        display: none;
    }
    
    .text-areas {
        grid-template-columns: 1fr;
        gap: var(--spacing-lg);
    }
    
    .text-area-container {
        box-shadow: none;
        border: 1px solid #ccc;
    }
}