/**
 * Wikimathics - Enhanced Glass Morphism Styles
 * Method Explainer UI with beautiful visitor counter
 */

/* ============================================
   RESET & VARIABLES
   ============================================ */
*, *::before, *::after {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

:root {
    /* Glass morphism colors */
    --bg-primary: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    --glass-bg: rgba(255, 255, 255, 0.1);
    --glass-border: rgba(255, 255, 255, 0.2);
    --glass-shadow: rgba(0, 0, 0, 0.1);
    --glass-hover-bg: rgba(255, 255, 255, 0.15);
    
    /* Text colors */
    --text-primary: #ffffff;
    --text-secondary: rgba(255, 255, 255, 0.9);
    --text-tertiary: rgba(255, 255, 255, 0.7);
    
    /* Accent colors */
    --accent-primary: #fbbf24;
    --accent-secondary: #60a5fa;
    --accent-success: #34d399;
    --accent-error: #f87171;
    --accent-info: #a78bfa;
    
    /* Spacing */
    --spacing-xs: 0.25rem;
    --spacing-sm: 0.5rem;
    --spacing-md: 1rem;
    --spacing-lg: 1.5rem;
    --spacing-xl: 2rem;
    --spacing-2xl: 3rem;
    
    /* Typography */
    --font-sans: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    --font-mono: 'SF Mono', Monaco, 'Cascadia Code', 'Courier New', monospace;
    
    /* Border radius */
    --radius-sm: 0.5rem;
    --radius-md: 0.75rem;
    --radius-lg: 1rem;
    --radius-xl: 1.5rem;
    --radius-full: 9999px;
    
    /* Transitions */
    --transition-fast: 150ms cubic-bezier(0.4, 0, 0.2, 1);
    --transition-normal: 250ms cubic-bezier(0.4, 0, 0.2, 1);
    --transition-slow: 350ms cubic-bezier(0.4, 0, 0.2, 1);
    
    /* Blur effect */
    --blur-amount: 20px;
    --blur-light: 10px;
}

/* ============================================
   BASE STYLES
   ============================================ */
html {
    font-size: 16px;
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-sans);
    background: var(--bg-primary);
    background-attachment: fixed;
    color: var(--text-primary);
    line-height: 1.6;
    min-height: 100vh;
    overflow-x: hidden;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

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

/* ============================================
   GLASS PANELS
   ============================================ */
.glass-panel {
    background: var(--glass-bg);
    backdrop-filter: blur(var(--blur-amount));
    -webkit-backdrop-filter: blur(var(--blur-amount));
    border: 1px solid var(--glass-border);
    border-radius: var(--radius-lg);
    box-shadow: 0 8px 32px var(--glass-shadow);
    transition: transform var(--transition-normal), box-shadow var(--transition-normal);
}

.glass-panel:hover {
    transform: translateY(-2px);
    box-shadow: 0 12px 40px var(--glass-shadow);
}

.glass-chip {
    background: var(--glass-bg);
    backdrop-filter: blur(var(--blur-light));
    -webkit-backdrop-filter: blur(var(--blur-light));
    border: 1px solid var(--glass-border);
    border-radius: var(--radius-full);
    padding: var(--spacing-sm) var(--spacing-md);
    font-size: 0.875rem;
    transition: all var(--transition-fast);
}

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

/* ============================================
   HEADER
   ============================================ */
.app-header {
    padding: var(--spacing-lg) var(--spacing-xl);
    margin: var(--spacing-lg);
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: var(--spacing-md);
}

.header-content {
    flex: 1;
    min-width: 250px;
}

.app-title {
    font-size: 2.5rem;
    font-weight: 700;
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    margin-bottom: var(--spacing-xs);
}

.math-symbol {
    font-size: 3rem;
    background: linear-gradient(135deg, var(--accent-primary), var(--accent-secondary));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.app-subtitle {
    font-size: 1.125rem;
    color: var(--text-secondary);
    font-weight: 300;
}

.header-controls {
    display: flex;
    align-items: center;
    gap: var(--spacing-lg);
    flex-wrap: wrap;
}

/* ============================================
   VISITOR COUNTER (Enhanced Glassmorphism)
   ============================================ */
.visitor-counter {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    padding: var(--spacing-sm) var(--spacing-lg);
    background: linear-gradient(
        135deg,
        rgba(255, 255, 255, 0.12) 0%,
        rgba(255, 255, 255, 0.08) 100%
    );
    border: 1.5px solid rgba(255, 255, 255, 0.25);
    border-radius: var(--radius-full);
    backdrop-filter: blur(15px);
    -webkit-backdrop-filter: blur(15px);
    box-shadow: 
        0 4px 16px rgba(0, 0, 0, 0.12),
        inset 0 1px 2px rgba(255, 255, 255, 0.2);
    transition: all var(--transition-normal);
    position: relative;
    overflow: hidden;
}

.visitor-counter::before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: linear-gradient(
        90deg,
        transparent,
        rgba(255, 255, 255, 0.15),
        transparent
    );
    transition: left 0.5s;
}

.visitor-counter:hover {
    transform: translateY(-1px);
    border-color: rgba(255, 255, 255, 0.35);
    box-shadow: 
        0 6px 24px rgba(0, 0, 0, 0.15),
        inset 0 1px 3px rgba(255, 255, 255, 0.25);
}

.visitor-counter:hover::before {
    left: 100%;
}

.counter-icon {
    font-size: 1.25rem;
    filter: drop-shadow(0 2px 4px rgba(0, 0, 0, 0.2));
}

.counter-label {
    font-size: 0.875rem;
    font-weight: 500;
    color: var(--text-secondary);
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.counter-value {
    font-size: 1.25rem;
    font-weight: 700;
    background: linear-gradient(135deg, #fbbf24, #f59e0b);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    min-width: 50px;
    text-align: center;
    filter: drop-shadow(0 2px 8px rgba(251, 191, 36, 0.3));
}

.counter-value.pulse {
    animation: pulse 1s ease-in-out;
}

@keyframes pulse {
    0%, 100% { transform: scale(1); }
    50% { transform: scale(1.15); }
}

.loading-dots {
    display: inline-block;
    animation: dots 1.4s infinite;
}

@keyframes dots {
    0%, 20% { content: '.'; }
    40% { content: '..'; }
    60%, 100% { content: '...'; }
}

/* ============================================
   LANGUAGE SWITCHER
   ============================================ */
.language-switcher {
    display: flex;
    gap: var(--spacing-xs);
    background: var(--glass-bg);
    padding: var(--spacing-xs);
    border-radius: var(--radius-full);
    border: 1px solid var(--glass-border);
}

.lang-btn {
    background: transparent;
    border: none;
    color: var(--text-secondary);
    padding: var(--spacing-sm) var(--spacing-md);
    border-radius: var(--radius-full);
    cursor: pointer;
    font-weight: 600;
    font-size: 0.875rem;
    transition: all var(--transition-fast);
}

.lang-btn:hover {
    background: var(--glass-hover-bg);
    color: var(--text-primary);
}

.lang-btn.active {
    background: var(--accent-primary);
    color: #1f2937;
}

/* ============================================
   MAIN GRID
   ============================================ */
.main-grid {
    display: grid;
    grid-template-columns: 280px 1fr 280px;
    gap: var(--spacing-lg);
    padding: 0 var(--spacing-lg) var(--spacing-lg);
    flex: 1;
}

@media (max-width: 1200px) {
    .main-grid {
        grid-template-columns: 260px 1fr;
    }
    .info-panel {
        display: none;
    }
}

@media (max-width: 768px) {
    .main-grid {
        grid-template-columns: 1fr;
    }
    .sidebar {
        order: 2;
    }
}

/* ============================================
   SIDEBAR
   ============================================ */
.sidebar {
    padding: var(--spacing-lg);
    max-height: calc(100vh - 200px);
    overflow-y: auto;
    position: sticky;
    top: var(--spacing-lg);
}

.sidebar-header h2 {
    font-size: 1.25rem;
    margin-bottom: var(--spacing-md);
}

.search-box {
    position: relative;
    margin-bottom: var(--spacing-lg);
}

.search-box input {
    width: 100%;
    padding: var(--spacing-sm) var(--spacing-md);
    padding-right: 2.5rem;
    background: rgba(255, 255, 255, 0.08);
    border: 1px solid var(--glass-border);
    border-radius: var(--radius-md);
    color: var(--text-primary);
    font-size: 0.875rem;
    transition: all var(--transition-fast);
}

.search-box input:focus {
    outline: none;
    background: rgba(255, 255, 255, 0.12);
    border-color: var(--accent-primary);
}

.search-box input::placeholder {
    color: var(--text-tertiary);
}

.search-icon {
    position: absolute;
    right: var(--spacing-md);
    top: 50%;
    transform: translateY(-50%);
    opacity: 0.6;
}

/* Method Categories */
.method-category {
    margin-bottom: var(--spacing-lg);
}

.category-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: var(--spacing-sm) 0;
    margin-bottom: var(--spacing-sm);
}

.category-header h3 {
    font-size: 0.875rem;
    text-transform: uppercase;
    letter-spacing: 0.5px;
    color: var(--accent-primary);
    font-weight: 600;
}

.category-count {
    background: rgba(251, 191, 36, 0.2);
    color: var(--accent-primary);
    padding: 0.125rem 0.5rem;
    border-radius: var(--radius-sm);
    font-size: 0.75rem;
    font-weight: 600;
}

.methods-list {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-xs);
}

.method-btn {
    width: 100%;
    text-align: left;
    padding: var(--spacing-sm) var(--spacing-md);
    background: transparent;
    border: 1px solid transparent;
    border-radius: var(--radius-md);
    color: var(--text-secondary);
    font-size: 0.875rem;
    cursor: pointer;
    transition: all var(--transition-fast);
}

.method-btn:hover {
    background: var(--glass-hover-bg);
    border-color: var(--glass-border);
    color: var(--text-primary);
    transform: translateX(4px);
}

.method-btn.selected {
    background: var(--accent-primary);
    color: #1f2937;
    font-weight: 600;
}

/* ============================================
   MAIN CONTENT
   ============================================ */
.main-content {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-lg);
}

/* Welcome Section */
.welcome-section {
    padding: var(--spacing-2xl);
    text-align: center;
}

.welcome-content h2 {
    font-size: 1.875rem;
    margin-bottom: var(--spacing-lg);
}

.info-steps {
    list-style: none;
    counter-reset: step-counter;
    margin: var(--spacing-xl) 0;
    text-align: left;
    max-width: 600px;
    margin-left: auto;
    margin-right: auto;
}

.info-steps li {
    counter-increment: step-counter;
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
    padding: var(--spacing-md);
    margin-bottom: var(--spacing-md);
    background: rgba(255, 255, 255, 0.05);
    border-radius: var(--radius-md);
}

.info-steps li::before {
    content: counter(step-counter);
    background: var(--accent-primary);
    color: #1f2937;
    width: 2rem;
    height: 2rem;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 700;
    flex-shrink: 0;
}

.welcome-note {
    margin-top: var(--spacing-xl);
    padding: var(--spacing-lg);
    background: rgba(96, 165, 250, 0.1);
    border: 1px solid rgba(96, 165, 250, 0.3);
    border-radius: var(--radius-md);
    text-align: left;
}

.welcome-note strong {
    color: var(--accent-secondary);
}

/* Options Section */
.options-section {
    padding: var(--spacing-xl);
}

.options-section h3 {
    font-size: 1.5rem;
    margin-bottom: var(--spacing-lg);
}

.selected-method-display {
    margin-bottom: var(--spacing-xl);
}

.selected-method-card {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
    padding: var(--spacing-lg);
    background: linear-gradient(135deg, rgba(251, 191, 36, 0.15), rgba(251, 191, 36, 0.05));
    border: 2px solid rgba(251, 191, 36, 0.3);
    border-radius: var(--radius-lg);
}

.method-icon {
    font-size: 2.5rem;
    filter: drop-shadow(0 4px 8px rgba(251, 191, 36, 0.3));
}

.method-info h4 {
    font-size: 1.25rem;
    margin-bottom: var(--spacing-xs);
}

.method-category {
    color: var(--text-tertiary);
    font-size: 0.875rem;
}

.options-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: var(--spacing-lg);
    margin-bottom: var(--spacing-xl);
}

.option-group label:first-child {
    display: block;
    font-weight: 600;
    margin-bottom: var(--spacing-sm);
    color: var(--text-secondary);
}

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

.radio-label {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    padding: var(--spacing-sm) var(--spacing-md);
    background: rgba(255, 255, 255, 0.05);
    border: 1px solid transparent;
    border-radius: var(--radius-md);
    cursor: pointer;
    transition: all var(--transition-fast);
}

.radio-label:hover {
    background: rgba(255, 255, 255, 0.1);
    border-color: var(--glass-border);
}

.radio-label input[type="radio"] {
    appearance: none;
    width: 1.25rem;
    height: 1.25rem;
    border: 2px solid var(--glass-border);
    border-radius: 50%;
    position: relative;
    cursor: pointer;
}

.radio-label input[type="radio"]:checked {
    border-color: var(--accent-primary);
}

.radio-label input[type="radio"]:checked::after {
    content: '';
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    width: 0.625rem;
    height: 0.625rem;
    background: var(--accent-primary);
    border-radius: 50%;
}

/* Compare Section */
.compare-section {
    margin-bottom: var(--spacing-xl);
}

.compare-section label {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    cursor: pointer;
    margin-bottom: var(--spacing-md);
}

.compare-section input[type="checkbox"] {
    appearance: none;
    width: 1.25rem;
    height: 1.25rem;
    border: 2px solid var(--glass-border);
    border-radius: var(--radius-sm);
    cursor: pointer;
    position: relative;
}

.compare-section input[type="checkbox"]:checked {
    background: var(--accent-primary);
    border-color: var(--accent-primary);
}

.compare-section input[type="checkbox"]:checked::after {
    content: '✓';
    position: absolute;
    color: #1f2937;
    font-weight: 700;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
}

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

.methods-chips {
    display: flex;
    flex-wrap: wrap;
    gap: var(--spacing-sm);
}

.compare-chip {
    padding: var(--spacing-sm) var(--spacing-md);
    background: rgba(255, 255, 255, 0.05);
    border: 1px solid var(--glass-border);
    border-radius: var(--radius-full);
    color: var(--text-secondary);
    font-size: 0.875rem;
    cursor: pointer;
    transition: all var(--transition-fast);
}

.compare-chip:hover {
    background: rgba(255, 255, 255, 0.1);
    border-color: var(--accent-secondary);
}

.compare-chip.selected {
    background: var(--accent-secondary);
    color: #1f2937;
    font-weight: 600;
}

/* Buttons */
.btn-primary {
    width: 100%;
    padding: var(--spacing-md) var(--spacing-xl);
    background: var(--accent-primary);
    color: #1f2937;
    border: none;
    border-radius: var(--radius-md);
    font-size: 1.125rem;
    font-weight: 700;
    cursor: pointer;
    transition: all var(--transition-normal);
    display: flex;
    align-items: center;
    justify-content: center;
    gap: var(--spacing-sm);
}

.btn-primary:hover:not(:disabled) {
    transform: translateY(-2px);
    box-shadow: 0 8px 24px rgba(251, 191, 36, 0.4);
}

.btn-primary:disabled {
    opacity: 0.6;
    cursor: not-allowed;
}

.btn-loader {
    display: inline-block;
    animation: spin 1s linear infinite;
}

@keyframes spin {
    from { transform: rotate(0deg); }
    to { transform: rotate(360deg); }
}

/* ============================================
   RESULTS SECTION
   ============================================ */
.results-section {
    margin-top: var(--spacing-lg);
}

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

.results-header h2 {
    font-size: 1.875rem;
}

.btn-clear {
    background: rgba(248, 113, 113, 0.2);
    border: 1px solid rgba(248, 113, 113, 0.3);
    color: var(--accent-error);
    width: 2.5rem;
    height: 2.5rem;
    border-radius: 50%;
    cursor: pointer;
    font-size: 1.25rem;
    transition: all var(--transition-fast);
}

.btn-clear:hover {
    background: var(--accent-error);
    color: white;
}

/* Method Explanation Card */
.method-explanation-card {
    padding: var(--spacing-2xl);
}

.method-header {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    margin-bottom: var(--spacing-xl);
    padding-bottom: var(--spacing-lg);
    border-bottom: 1px solid var(--glass-border);
}

.method-title-group h3 {
    font-size: 2rem;
    margin-bottom: var(--spacing-xs);
}

.method-meta {
    display: flex;
    gap: var(--spacing-sm);
    flex-wrap: wrap;
}

.meta-badge {
    padding: var(--spacing-xs) var(--spacing-md);
    background: rgba(255, 255, 255, 0.1);
    border: 1px solid var(--glass-border);
    border-radius: var(--radius-full);
    font-size: 0.75rem;
    font-weight: 600;
}

.method-section {
    margin-bottom: var(--spacing-xl);
}

.method-section h4 {
    font-size: 1.25rem;
    margin-bottom: var(--spacing-md);
    color: var(--accent-primary);
}

.section-content {
    padding: var(--spacing-md);
    background: rgba(255, 255, 255, 0.03);
    border-radius: var(--radius-md);
    line-height: 1.8;
}

.math-content {
    font-family: var(--font-mono);
    background: rgba(255, 255, 255, 0.05);
}

/* Chips */
.chips-container {
    display: flex;
    flex-wrap: wrap;
    gap: var(--spacing-sm);
}

.chip {
    padding: var(--spacing-xs) var(--spacing-md);
    background: rgba(96, 165, 250, 0.15);
    border: 1px solid rgba(96, 165, 250, 0.3);
    border-radius: var(--radius-full);
    font-size: 0.875rem;
}

/* Lists */
.check-list, .examples-list {
    list-style: none;
    padding-left: 0;
}

.check-list li, .examples-list li {
    padding: var(--spacing-sm) var(--spacing-md);
    margin-bottom: var(--spacing-sm);
    background: rgba(255, 255, 255, 0.03);
    border-radius: var(--radius-md);
}

.recipe-list {
    list-style: none;
    counter-reset: recipe;
}

.recipe-list li {
    counter-increment: recipe;
    padding: var(--spacing-md);
    margin-bottom: var(--spacing-md);
    background: rgba(255, 255, 255, 0.05);
    border-left: 3px solid var(--accent-primary);
    border-radius: var(--radius-md);
    display: flex;
    gap: var(--spacing-md);
}

.step-number {
    background: var(--accent-primary);
    color: #1f2937;
    width: 1.75rem;
    height: 1.75rem;
    border-radius: 50%;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    font-weight: 700;
    flex-shrink: 0;
}

.step-number::before {
    content: counter(recipe);
}

/* Worked Sample */
.worked-sample-section {
    background: linear-gradient(135deg, rgba(52, 211, 153, 0.1), rgba(52, 211, 153, 0.05));
    border: 1px solid rgba(52, 211, 153, 0.2);
    padding: var(--spacing-lg);
    border-radius: var(--radius-lg);
}

.sample-problem {
    padding: var(--spacing-md);
    background: rgba(0, 0, 0, 0.2);
    border-radius: var(--radius-md);
    margin-bottom: var(--spacing-md);
    font-style: italic;
}

.sample-solution {
    padding: var(--spacing-md);
}

.sample-final {
    margin-top: var(--spacing-md);
    padding: var(--spacing-md);
    background: rgba(52, 211, 153, 0.15);
    border-radius: var(--radius-md);
}

/* Pitfalls */
.pitfalls-section {
    background: linear-gradient(135deg, rgba(248, 113, 113, 0.1), rgba(248, 113, 113, 0.05));
    border: 1px solid rgba(248, 113, 113, 0.2);
    padding: var(--spacing-lg);
    border-radius: var(--radius-lg);
}

.pitfalls-list {
    list-style: none;
}

.pitfalls-list li {
    padding: var(--spacing-md);
    margin-bottom: var(--spacing-sm);
    background: rgba(248, 113, 113, 0.1);
    border-left: 3px solid var(--accent-error);
    border-radius: var(--radius-md);
}

/* Comparison Table */
.comparison-table table {
    width: 100%;
    border-collapse: collapse;
    margin-top: var(--spacing-md);
}

.comparison-table th,
.comparison-table td {
    padding: var(--spacing-md);
    text-align: left;
    border: 1px solid var(--glass-border);
}

.comparison-table th {
    background: rgba(255, 255, 255, 0.1);
    font-weight: 600;
}

.comparison-table td div {
    margin-bottom: var(--spacing-sm);
}

.comparison-table td div:last-child {
    margin-bottom: 0;
}

/* History */
.history-section {
    background: linear-gradient(135deg, rgba(167, 139, 250, 0.1), rgba(167, 139, 250, 0.05));
    border: 1px solid rgba(167, 139, 250, 0.2);
    padding: var(--spacing-lg);
    border-radius: var(--radius-lg);
}

.history-figures {
    margin-top: var(--spacing-md);
    padding: var(--spacing-md);
    background: rgba(167, 139, 250, 0.1);
    border-radius: var(--radius-md);
}

.timeline {
    list-style: none;
    margin-top: var(--spacing-md);
}

.timeline li {
    padding: var(--spacing-sm) var(--spacing-md);
    padding-left: var(--spacing-xl);
    margin-bottom: var(--spacing-sm);
    border-left: 2px solid var(--accent-info);
    position: relative;
}

.timeline li::before {
    content: '';
    position: absolute;
    left: -0.375rem;
    top: var(--spacing-sm);
    width: 0.625rem;
    height: 0.625rem;
    background: var(--accent-info);
    border-radius: 50%;
}

/* Error Card */
.error-card {
    padding: var(--spacing-2xl);
    text-align: center;
}

.error-icon {
    font-size: 4rem;
    margin-bottom: var(--spacing-md);
}

.error-message {
    color: var(--accent-error);
    font-size: 1.125rem;
}

/* ============================================
   INFO PANEL
   ============================================ */
.info-panel {
    padding: var(--spacing-lg);
    max-height: calc(100vh - 200px);
    overflow-y: auto;
    position: sticky;
    top: var(--spacing-lg);
}

.info-content h3 {
    font-size: 1.25rem;
    margin-bottom: var(--spacing-md);
}

.placeholder-text {
    color: var(--text-tertiary);
    font-size: 0.875rem;
}

.related-methods-list {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-sm);
}

.related-method-btn {
    width: 100%;
    text-align: left;
    padding: var(--spacing-sm) var(--spacing-md);
    background: rgba(255, 255, 255, 0.05);
    border: 1px solid var(--glass-border);
    border-radius: var(--radius-md);
    color: var(--text-secondary);
    font-size: 0.875rem;
    cursor: pointer;
    transition: all var(--transition-fast);
}

.related-method-btn:hover {
    background: var(--glass-hover-bg);
    color: var(--text-primary);
    transform: translateX(4px);
}

/* ============================================
   FOOTER
   ============================================ */
.app-footer {
    margin: var(--spacing-2xl) var(--spacing-lg) var(--spacing-lg);
    padding: var(--spacing-lg);
    text-align: center;
    border-top: 1px solid var(--glass-border);
}

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

.footer-content p {
    color: var(--text-tertiary);
    font-size: 0.875rem;
}

.copyright {
    font-size: 0.75rem;
}

/* ============================================
   SCROLLBAR
   ============================================ */
::-webkit-scrollbar {
    width: 0.5rem;
}

::-webkit-scrollbar-track {
    background: rgba(255, 255, 255, 0.05);
}

::-webkit-scrollbar-thumb {
    background: rgba(255, 255, 255, 0.2);
    border-radius: var(--radius-full);
}

::-webkit-scrollbar-thumb:hover {
    background: rgba(255, 255, 255, 0.3);
}

/* ============================================
   RTL SUPPORT
   ============================================ */
[dir="rtl"] {
    direction: rtl;
}

[dir="rtl"] .method-btn:hover,
[dir="rtl"] .related-method-btn:hover {
    transform: translateX(-4px);
}

[dir="rtl"] .search-icon {
    right: auto;
    left: var(--spacing-md);
}

/* ============================================
   RESPONSIVE
   ============================================ */
@media (max-width: 768px) {
    .app-header {
        flex-direction: column;
        text-align: center;
    }
    
    .app-title {
        font-size: 2rem;
        justify-content: center;
    }
    
    .header-controls {
        width: 100%;
        justify-content: center;
    }
    
    .visitor-counter {
        order: -1;
    }
    
    .method-explanation-card {
        padding: var(--spacing-lg);
    }
    
    .method-header {
        flex-direction: column;
        gap: var(--spacing-md);
    }
    
    .options-grid {
        grid-template-columns: 1fr;
    }
}

@media (max-width: 480px) {
    :root {
        font-size: 14px;
    }
    
    .app-title {
        font-size: 1.75rem;
    }
    
    .math-symbol {
        font-size: 2rem;
    }
}