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

:root {
    /* Color Palette */
    --primary-color: #2563eb;
    --primary-hover: #1d4ed8;
    --primary-light: #dbeafe;
    --secondary-color: #64748b;
    --success-color: #059669;
    --warning-color: #d97706;
    --error-color: #dc2626;
    
    /* Background Colors */
    --bg-primary: #ffffff;
    --bg-secondary: #f8fafc;
    --bg-tertiary: #f1f5f9;
    --bg-dark: #0f172a;
    
    /* Text Colors */
    --text-primary: #0f172a;
    --text-secondary: #475569;
    --text-muted: #64748b;
    --text-white: #ffffff;
    
    /* Border Colors */
    --border-color: #e2e8f0;
    --border-focus: #2563eb;
    --border-error: #dc2626;
    
    /* Shadows */
    --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.05);
    --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.1);
    --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.1), 0 4px 6px -4px rgb(0 0 0 / 0.1);
    --shadow-xl: 0 20px 25px -5px rgb(0 0 0 / 0.1), 0 8px 10px -6px rgb(0 0 0 / 0.1);
    
    /* Fonts */
    --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    --font-devanagari: 'Noto Sans Devanagari', 'Mangal', 'Arial Unicode MS', sans-serif;
    
    /* Spacing */
    --spacing-xs: 0.5rem;
    --spacing-sm: 0.75rem;
    --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;
    
    /* Transitions */
    --transition-fast: 150ms ease-in-out;
    --transition-normal: 300ms ease-in-out;
    --transition-slow: 500ms ease-in-out;
}

/* Base Typography */
html {
    font-size: 16px;
    line-height: 1.6;
    scroll-behavior: smooth;
}

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

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

/* Header */
.header {
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--primary-hover) 100%);
    color: var(--text-white);
    padding: var(--spacing-lg) 0;
    position: sticky;
    top: 0;
    z-index: 100;
    box-shadow: var(--shadow-md);
}

.header-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: var(--spacing-md);
}

.logo h1 {
    font-size: 1.75rem;
    font-weight: 700;
    margin-bottom: var(--spacing-xs);
}

.tagline {
    font-family: var(--font-devanagari);
    font-size: 1rem;
    opacity: 0.9;
}

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

.nav-link {
    color: var(--text-white);
    text-decoration: none;
    font-weight: 500;
    padding: var(--spacing-xs) var(--spacing-md);
    border-radius: var(--radius-md);
    transition: var(--transition-fast);
    position: relative;
}

.nav-link:hover {
    background-color: rgba(255, 255, 255, 0.1);
    transform: translateY(-1px);
}

/* Hero Section */
.hero {
    background: linear-gradient(135deg, var(--bg-secondary) 0%, var(--bg-tertiary) 100%);
    padding: var(--spacing-2xl) 0;
    text-align: center;
}

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

.hero-title {
    font-size: 2.5rem;
    font-weight: 800;
    color: var(--text-primary);
    margin-bottom: var(--spacing-lg);
    line-height: 1.2;
}

.hero-description {
    font-size: 1.125rem;
    color: var(--text-secondary);
    margin-bottom: var(--spacing-2xl);
    max-width: 600px;
    margin-left: auto;
    margin-right: auto;
}

.hero-stats {
    display: flex;
    justify-content: center;
    gap: var(--spacing-2xl);
    flex-wrap: wrap;
}

.stat {
    text-align: center;
}

.stat-number {
    display: block;
    font-size: 2rem;
    font-weight: 700;
    color: var(--primary-color);
}

.stat-label {
    font-size: 0.875rem;
    color: var(--text-secondary);
    font-weight: 500;
}

/* Converter Section */
.converter-section {
    padding: var(--spacing-2xl) 0;
    background-color: var(--bg-primary);
}

.converter-container {
    background-color: var(--bg-secondary);
    border-radius: var(--radius-xl);
    padding: var(--spacing-2xl);
    box-shadow: var(--shadow-lg);
    border: 1px solid var(--border-color);
}

.converter-header {
    text-align: center;
    margin-bottom: var(--spacing-2xl);
}

.converter-header h3 {
    font-size: 1.875rem;
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: var(--spacing-sm);
}

.converter-header p {
    font-size: 1.125rem;
    color: var(--text-secondary);
}

.converter-grid {
    display: grid;
    grid-template-columns: 1fr auto 1fr;
    gap: var(--spacing-lg);
    align-items: start;
}

.input-section,
.output-section {
    background-color: var(--bg-primary);
    border-radius: var(--radius-lg);
    padding: var(--spacing-lg);
    border: 2px solid var(--border-color);
    transition: var(--transition-normal);
}

.input-section:focus-within,
.output-section:focus-within {
    border-color: var(--border-focus);
    box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.1);
}

.section-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: var(--spacing-md);
    flex-wrap: wrap;
    gap: var(--spacing-sm);
}

.section-header h4 {
    font-size: 1.125rem;
    font-weight: 600;
    color: var(--text-primary);
}

.section-actions {
    display: flex;
    gap: var(--spacing-xs);
    flex-wrap: wrap;
}

/* Text Areas */
.text-area {
    width: 100%;
    min-height: 300px;
    padding: var(--spacing-md);
    border: 2px solid var(--border-color);
    border-radius: var(--radius-md);
    font-size: 1rem;
    line-height: 1.6;
    resize: vertical;
    transition: var(--transition-normal);
    background-color: var(--bg-primary);
}

.text-area:focus {
    outline: none;
    border-color: var(--border-focus);
    box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.1);
}

.krutidev-font {
    font-family: 'Kruti Dev 010', var(--font-devanagari);
}

.unicode-font {
    font-family: var(--font-devanagari);
}

.text-info {
    display: flex;
    justify-content: space-between;
    margin-top: var(--spacing-sm);
    font-size: 0.875rem;
    color: var(--text-muted);
}

/* Convert Section */
.convert-section {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: var(--spacing-md);
    padding: var(--spacing-lg) 0;
}

.convert-btn {
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--primary-hover) 100%);
    color: var(--text-white);
    border: none;
    padding: var(--spacing-lg) var(--spacing-xl);
    border-radius: var(--radius-lg);
    font-size: 1.125rem;
    font-weight: 600;
    cursor: pointer;
    transition: var(--transition-normal);
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    box-shadow: var(--shadow-md);
    min-width: 200px;
    justify-content: center;
}

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

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

.convert-btn:disabled {
    opacity: 0.6;
    cursor: not-allowed;
    transform: none;
}

.convert-icon {
    font-size: 1.25rem;
}

.swap-btn {
    background-color: var(--bg-primary);
    border: 2px solid var(--border-color);
    color: var(--text-secondary);
    padding: var(--spacing-sm);
    border-radius: 50%;
    cursor: pointer;
    transition: var(--transition-fast);
    width: 48px;
    height: 48px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.25rem;
}

.swap-btn:hover {
    border-color: var(--primary-color);
    color: var(--primary-color);
    transform: rotate(180deg);
}

/* Buttons */
.btn-secondary {
    background-color: var(--bg-primary);
    border: 1px solid var(--border-color);
    color: var(--text-secondary);
    padding: var(--spacing-xs) var(--spacing-sm);
    border-radius: var(--radius-sm);
    font-size: 0.875rem;
    cursor: pointer;
    transition: var(--transition-fast);
    display: flex;
    align-items: center;
    gap: var(--spacing-xs);
}

.btn-secondary:hover {
    background-color: var(--bg-tertiary);
    border-color: var(--primary-color);
    color: var(--primary-color);
}

.btn-action {
    background-color: var(--bg-primary);
    border: 2px solid var(--border-color);
    color: var(--text-secondary);
    padding: var(--spacing-sm) var(--spacing-md);
    border-radius: var(--radius-md);
    font-size: 0.875rem;
    cursor: pointer;
    transition: var(--transition-fast);
    display: flex;
    align-items: center;
    gap: var(--spacing-xs);
}

.btn-action:hover {
    border-color: var(--primary-color);
    color: var(--primary-color);
    background-color: var(--primary-light);
}

/* Quick Actions */
.quick-actions {
    display: flex;
    justify-content: center;
    gap: var(--spacing-md);
    margin-top: var(--spacing-xl);
    flex-wrap: wrap;
}

/* Features Section */
.features-section {
    background-color: var(--bg-secondary);
    padding: var(--spacing-2xl) 0;
}

.section-header {
    text-align: center;
    margin-bottom: var(--spacing-2xl);
}

.section-header h3 {
    font-size: 2rem;
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: var(--spacing-sm);
}

.section-header p {
    font-size: 1.125rem;
    color: var(--text-secondary);
    max-width: 600px;
    margin: 0 auto;
}

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

.feature-card {
    background-color: var(--bg-primary);
    padding: var(--spacing-xl);
    border-radius: var(--radius-lg);
    text-align: center;
    box-shadow: var(--shadow-md);
    border: 1px solid var(--border-color);
    transition: var(--transition-normal);
}

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

.feature-icon {
    font-size: 2.5rem;
    margin-bottom: var(--spacing-md);
}

.feature-card h4 {
    font-size: 1.25rem;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: var(--spacing-sm);
}

.feature-card p {
    color: var(--text-secondary);
    line-height: 1.6;
}

/* Help Section */
.help-section {
    padding: var(--spacing-2xl) 0;
    background-color: var(--bg-primary);
}

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

.steps {
    margin: var(--spacing-xl) 0;
}

.step {
    display: flex;
    gap: var(--spacing-lg);
    margin-bottom: var(--spacing-xl);
}

.step-number {
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--primary-hover) 100%);
    color: var(--text-white);
    width: 48px;
    height: 48px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 600;
    font-size: 1.125rem;
    flex-shrink: 0;
}

.step-content h4 {
    font-size: 1.25rem;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: var(--spacing-xs);
}

.step-content p {
    color: var(--text-secondary);
    line-height: 1.6;
}

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

.faq h4 {
    font-size: 1.5rem;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: var(--spacing-lg);
}

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

.faq-item summary {
    background-color: var(--bg-secondary);
    padding: var(--spacing-md);
    font-weight: 600;
    cursor: pointer;
    transition: var(--transition-fast);
}

.faq-item summary:hover {
    background-color: var(--bg-tertiary);
}

.faq-item p {
    padding: var(--spacing-md);
    color: var(--text-secondary);
    background-color: var(--bg-primary);
    line-height: 1.6;
}

.help-sidebar {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-lg);
}

.help-card {
    background-color: var(--bg-secondary);
    padding: var(--spacing-lg);
    border-radius: var(--radius-lg);
    border: 1px solid var(--border-color);
}

.help-card h4 {
    font-size: 1.125rem;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: var(--spacing-md);
}

.help-card ul {
    list-style: none;
}

.help-card li {
    color: var(--text-secondary);
    margin-bottom: var(--spacing-xs);
    padding-left: var(--spacing-md);
    position: relative;
}

.help-card li:before {
    content: '•';
    color: var(--primary-color);
    position: absolute;
    left: 0;
    font-weight: bold;
}

/* Footer */
.footer {
    background-color: var(--bg-dark);
    color: var(--text-white);
    padding: var(--spacing-2xl) 0 var(--spacing-lg);
}

.footer-content {
    margin-bottom: var(--spacing-xl);
}

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

.footer-brand h4 {
    font-size: 1.25rem;
    font-weight: 600;
    margin-bottom: var(--spacing-sm);
}

.footer-brand p {
    color: rgba(255, 255, 255, 0.7);
    line-height: 1.6;
}

.link-group h5 {
    font-size: 1rem;
    font-weight: 600;
    margin-bottom: var(--spacing-md);
}

.link-group a {
    display: block;
    color: rgba(255, 255, 255, 0.7);
    text-decoration: none;
    margin-bottom: var(--spacing-xs);
    transition: var(--transition-fast);
}

.link-group a:hover {
    color: var(--text-white);
}

.footer-bottom {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding-top: var(--spacing-lg);
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    flex-wrap: wrap;
    gap: var(--spacing-md);
}

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

/* Loading Indicator */
.loading-indicator {
    position: fixed;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    background-color: var(--bg-primary);
    padding: var(--spacing-xl);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-xl);
    display: none;
    align-items: center;
    gap: var(--spacing-md);
    z-index: 1000;
}

.loading-indicator.show {
    display: flex;
}

.spinner {
    width: 24px;
    height: 24px;
    border: 3px solid var(--border-color);
    border-top: 3px solid var(--primary-color);
    border-radius: 50%;
    animation: spin 1s linear infinite;
}

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

/* Toast Notifications */
.toast-container {
    position: fixed;
    top: var(--spacing-lg);
    right: var(--spacing-lg);
    z-index: 1001;
    display: flex;
    flex-direction: column;
    gap: var(--spacing-sm);
}

.toast {
    background-color: var(--bg-primary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    padding: var(--spacing-md);
    box-shadow: var(--shadow-lg);
    min-width: 300px;
    max-width: 400px;
    transform: translateX(100%);
    transition: var(--transition-normal);
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
}

.toast.show {
    transform: translateX(0);
}

.toast.success {
    border-left: 4px solid var(--success-color);
}

.toast.error {
    border-left: 4px solid var(--error-color);
}

.toast.warning {
    border-left: 4px solid var(--warning-color);
}

.toast-icon {
    font-size: 1.25rem;
    flex-shrink: 0;
}

.toast-content {
    flex: 1;
}

.toast-title {
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 2px;
}

.toast-message {
    font-size: 0.875rem;
    color: var(--text-secondary);
}

/* Responsive Design */
@media (max-width: 1024px) {
    .converter-grid {
        grid-template-columns: 1fr;
        gap: var(--spacing-xl);
    }
    
    .convert-section {
        order: 2;
    }
    
    .output-section {
        order: 3;
    }
    
    .help-content {
        grid-template-columns: 1fr;
        gap: var(--spacing-xl);
    }
    
    .footer-main {
        grid-template-columns: 1fr;
        gap: var(--spacing-lg);
        text-align: center;
    }
}

@media (max-width: 768px) {
    .hero-title {
        font-size: 2rem;
    }
    
    .hero-stats {
        gap: var(--spacing-lg);
    }
    
    .converter-container {
        padding: var(--spacing-lg);
    }
    
    .text-area {
        min-height: 200px;
    }
    
    .section-header {
        flex-direction: column;
        align-items: flex-start;
    }
    
    .quick-actions {
        flex-direction: column;
        align-items: center;
    }
    
    .features-grid {
        grid-template-columns: 1fr;
    }
    
    .footer-bottom {
        flex-direction: column;
        text-align: center;
    }
    
    .toast {
        min-width: auto;
        width: calc(100vw - 2rem);
        max-width: none;
        margin: 0 var(--spacing-md);
    }
}

@media (max-width: 480px) {
    .container {
        padding: 0 var(--spacing-sm);
    }
    
    .hero {
        padding: var(--spacing-xl) 0;
    }
    
    .converter-section {
        padding: var(--spacing-xl) 0;
    }
    
    .converter-container {
        padding: var(--spacing-md);
    }
    
    .hero-title {
        font-size: 1.75rem;
    }
    
    .nav {
        flex-direction: column;
        gap: var(--spacing-sm);
        width: 100%;
    }
    
    .header-content {
        flex-direction: column;
        text-align: center;
    }
}

/* Print Styles */
@media print {
    .header,
    .nav,
    .quick-actions,
    .footer,
    .loading-indicator,
    .toast-container {
        display: none !important;
    }
    
    .converter-container {
        box-shadow: none;
        border: 1px solid var(--border-color);
    }
    
    .text-area {
        border: 1px solid var(--border-color);
        background-color: transparent;
    }
}

/* High Contrast Mode */
@media (prefers-contrast: high) {
    :root {
        --border-color: #000000;
        --text-secondary: #000000;
        --bg-secondary: #ffffff;
    }
}

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

/* Focus Styles for Accessibility */
*:focus {
    outline: 2px solid var(--primary-color);
    outline-offset: 2px;
}

button:focus,
.btn-secondary:focus,
.btn-action:focus {
    outline: 2px solid var(--primary-color);
    outline-offset: 2px;
}

/* Custom Scrollbar */
::-webkit-scrollbar {
    width: 8px;
}

::-webkit-scrollbar-track {
    background: var(--bg-tertiary);
}

::-webkit-scrollbar-thumb {
    background: var(--border-color);
    border-radius: var(--radius-sm);
}

::-webkit-scrollbar-thumb:hover {
    background: var(--text-muted);
}