:root {
    /* Primary Colors - Blue Theme */
    --primary-50: #eff6ff;
    --primary-100: #dbeafe;
    --primary-200: #bfdbfe;
    --primary-300: #93c5fd;
    --primary-400: #60a5fa;
    --primary-500: #3b82f6;
    --primary-600: #2563eb;
    --primary-700: #1d4ed8;
    --primary-800: #1e40af;
    --primary-900: #1e3a8a;

    /* Secondary Colors - Emerald Theme */
    --secondary-50: #ecfdf5;
    --secondary-100: #d1fae5;
    --secondary-200: #a7f3d0;
    --secondary-300: #6ee7b7;
    --secondary-400: #34d399;
    --secondary-500: #10b981;
    --secondary-600: #059669;
    --secondary-700: #047857;
    --secondary-800: #065f46;
    --secondary-900: #064e3b;

    /* Accent Colors - Amber Theme */
    --accent-50: #fffbeb;
    --accent-100: #fef3c7;
    --accent-200: #fde68a;
    --accent-300: #fcd34d;
    --accent-400: #fbbf24;
    --accent-500: #f59e0b;
    --accent-600: #d97706;
    --accent-700: #b45309;
    --accent-800: #92400e;
    --accent-900: #78350f;

    /* Status Colors */
    --success: #22c55e;
    --warning: #f59e0b;
    --error: #ef4444;
    --info: #3b82f6;

    /* Neutral Colors */
    --gray-50: #f9fafb;
    --gray-100: #f3f4f6;
    --gray-200: #e5e7eb;
    --gray-300: #d1d5db;
    --gray-400: #9ca3af;
    --gray-500: #6b7280;
    --gray-600: #4b5563;
    --gray-700: #374151;
    --gray-800: #1f2937;
    --gray-900: #111827;

    /* Surface Colors */
    --surface-primary: #ffffff;
    --surface-secondary: var(--gray-50);
    --surface-tertiary: var(--gray-100);
    --surface-elevated: #ffffff;
    
    /* Text Colors */
    --text-primary: var(--gray-900);
    --text-secondary: var(--gray-700);
    --text-tertiary: var(--gray-500);
    --text-quaternary: var(--gray-400);
    --text-inverse: #ffffff;

    /* Border Colors */
    --border-primary: var(--gray-200);
    --border-secondary: var(--gray-300);
    --border-focus: var(--primary-500);
    --border-error: var(--error);

    /* Shadows */
    --shadow-xs: 0 1px 2px 0 rgb(0 0 0 / 0.05);
    --shadow-sm: 0 1px 3px 0 rgb(0 0 0 / 0.1), 0 1px 2px -1px rgb(0 0 0 / 0.1);
    --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.1), 0 2px 4px -2px 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);
    --shadow-2xl: 0 25px 50px -12px rgb(0 0 0 / 0.25);

    /* Spacing Scale */
    --space-px: 1px;
    --space-0: 0;
    --space-1: 0.25rem;
    --space-2: 0.5rem;
    --space-3: 0.75rem;
    --space-4: 1rem;
    --space-5: 1.25rem;
    --space-6: 1.5rem;
    --space-8: 2rem;
    --space-10: 2.5rem;
    --space-12: 3rem;
    --space-16: 4rem;
    --space-20: 5rem;
    --space-24: 6rem;
    --space-32: 8rem;

    /* Border Radius */
    --radius-none: 0;
    --radius-sm: 0.375rem;
    --radius-md: 0.5rem;
    --radius-lg: 0.75rem;
    --radius-xl: 1rem;
    --radius-2xl: 1.25rem;
    --radius-3xl: 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);

    /* Z-Index Scale */
    --z-dropdown: 1000;
    --z-sticky: 1020;
    --z-fixed: 1030;
    --z-modal-backdrop: 1040;
    --z-modal: 1050;
    --z-popover: 1060;
    --z-tooltip: 1070;
    --z-toast: 1080;
}

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

html {
    scroll-behavior: smooth;
    -webkit-text-size-adjust: 100%;
}

body {
    font-family: 'Tajawal', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    line-height: 1.6;
    color: var(--text-primary);
    background: var(--gray-50);
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    overflow-x: hidden;
}

/* Enhanced Hero Section */
.hero-section {
    position: relative;
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    background: linear-gradient(135deg, var(--primary-600) 0%, var(--primary-700) 50%, var(--secondary-600) 100%);
    overflow: hidden;
}

.hero-background {
    position: absolute;
    inset: 0;
    pointer-events: none;
}

.floating-letters {
    position: absolute;
    width: 100%;
    height: 100%;
}

.floating-letter {
    position: absolute;
    color: rgba(255, 255, 255, 0.1);
    font-size: clamp(2rem, 8vw, 6rem);
    font-weight: 700;
    font-family: 'Amiri', serif;
    animation: float 20s infinite linear;
    pointer-events: none;
}

.floating-letter:nth-child(1) { top: 10%; left: 10%; animation-delay: 0s; }
.floating-letter:nth-child(2) { top: 20%; right: 15%; animation-delay: -3s; }
.floating-letter:nth-child(3) { top: 60%; left: 20%; animation-delay: -6s; }
.floating-letter:nth-child(4) { top: 80%; right: 25%; animation-delay: -9s; }
.floating-letter:nth-child(5) { top: 40%; left: 80%; animation-delay: -12s; }
.floating-letter:nth-child(6) { top: 70%; right: 60%; animation-delay: -15s; }

@keyframes float {
    0%, 100% { transform: translateY(0) rotate(0deg); }
    25% { transform: translateY(-20px) rotate(5deg); }
    50% { transform: translateY(-40px) rotate(-5deg); }
    75% { transform: translateY(-20px) rotate(3deg); }
}

.hero-container {
    position: relative;
    z-index: 2;
    text-align: center;
    max-width: 48rem;
    padding: var(--space-8);
}

.hero-content {
    backdrop-filter: blur(20px);
    background: rgba(255, 255, 255, 0.1);
    border: 1px solid rgba(255, 255, 255, 0.2);
    border-radius: var(--radius-3xl);
    padding: var(--space-12);
    box-shadow: var(--shadow-2xl);
}

.hero-icon {
    width: 5rem;
    height: 5rem;
    background: rgba(255, 255, 255, 0.2);
    border-radius: var(--radius-full);
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto var(--space-6);
    backdrop-filter: blur(10px);
}

.hero-icon i {
    font-size: 2.5rem;
    color: white;
}

.hero-title {
    font-family: 'Amiri', serif;
    font-size: clamp(2rem, 5vw, 3.5rem);
    font-weight: 700;
    color: white;
    margin-bottom: var(--space-4);
    text-shadow: 0 2px 4px rgba(0, 0, 0, 0.3);
}

.hero-description {
    font-size: 1.25rem;
    color: rgba(255, 255, 255, 0.9);
    margin-bottom: var(--space-8);
    font-weight: 400;
}

.hero-stats {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: var(--space-6);
    margin-top: var(--space-8);
}

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

.stat-number {
    display: block;
    font-size: 2rem;
    font-weight: 900;
    color: white;
    font-family: 'Tajawal', sans-serif;
}

.stat-label {
    display: block;
    font-size: 0.875rem;
    color: rgba(255, 255, 255, 0.8);
    font-weight: 500;
    margin-top: var(--space-1);
}

.stat-divider {
    width: 1px;
    height: 3rem;
    background: rgba(255, 255, 255, 0.3);
}

/* Main Container */
.main-container {
    max-width: 75rem;
    margin: -6rem auto 0;
    padding: 0 var(--space-4);
    position: relative;
    z-index: 10;
}

/* Enhanced Tab Navigation */
.tab-navigation {
    margin-bottom: var(--space-8);
}

.tab-nav-wrapper {
    display: flex;
    background: var(--surface-primary);
    border-radius: var(--radius-2xl);
    padding: var(--space-2);
    box-shadow: var(--shadow-lg);
    border: 1px solid var(--border-primary);
    gap: var(--space-1);
    overflow-x: auto;
    scrollbar-width: none;
    -ms-overflow-style: none;
}

.tab-nav-wrapper::-webkit-scrollbar {
    display: none;
}

.tab-nav-item {
    flex: 1;
    min-width: 12rem;
    display: flex;
    align-items: center;
    gap: var(--space-3);
    padding: var(--space-4);
    border: none;
    background: transparent;
    border-radius: var(--radius-xl);
    cursor: pointer;
    transition: var(--transition-normal);
    text-align: right;
}

.tab-nav-item:hover {
    background: var(--gray-100);
    transform: translateY(-1px);
}

.tab-nav-item.active {
    background: linear-gradient(135deg, var(--primary-500) 0%, var(--primary-600) 100%);
    color: white;
    box-shadow: var(--shadow-md);
}

.tab-icon {
    width: 2.5rem;
    height: 2.5rem;
    border-radius: var(--radius-lg);
    display: flex;
    align-items: center;
    justify-content: center;
    background: rgba(255, 255, 255, 0.1);
    backdrop-filter: blur(10px);
    flex-shrink: 0;
}

.tab-nav-item:not(.active) .tab-icon {
    background: var(--gray-200);
    color: var(--text-secondary);
}

.tab-icon i {
    font-size: 1.125rem;
}

.tab-content {
    flex: 1;
}

.tab-title {
    display: block;
    font-size: 1rem;
    font-weight: 600;
    margin-bottom: var(--space-1);
}

.tab-desc {
    display: block;
    font-size: 0.75rem;
    opacity: 0.8;
}

.tab-nav-item:not(.active) .tab-title,
.tab-nav-item:not(.active) .tab-desc {
    color: var(--text-secondary);
}

/* Tab Content Container */
.tab-content-container {
    margin-bottom: var(--space-16);
}

.tab-pane {
    display: none;
    animation: fadeInUp 0.5s ease-out;
}

.tab-pane.active {
    display: block;
}

@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(2rem);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* Search Panel */
.search-panel {
    background: var(--surface-primary);
    border-radius: var(--radius-2xl);
    box-shadow: var(--shadow-xl);
    border: 1px solid var(--border-primary);
    overflow: hidden;
}

.panel-header {
    background: linear-gradient(135deg, var(--secondary-500) 0%, var(--secondary-600) 100%);
    padding: var(--space-8);
    display: flex;
    align-items: center;
    gap: var(--space-4);
    position: relative;
    overflow: hidden;
}

.panel-header::before {
    content: '';
    position: absolute;
    inset: 0;
    background: url('data:image/svg+xml,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 60 60"><defs><pattern id="dots" width="15" height="15" patternUnits="userSpaceOnUse"><circle cx="7.5" cy="7.5" r="1" fill="rgba(255,255,255,0.1)"/></pattern></defs><rect width="60" height="60" fill="url(%23dots)"/></svg>');
    opacity: 0.3;
}

.panel-icon {
    width: 3.5rem;
    height: 3.5rem;
    background: rgba(255, 255, 255, 0.2);
    border-radius: var(--radius-xl);
    display: flex;
    align-items: center;
    justify-content: center;
    backdrop-filter: blur(10px);
    position: relative;
    z-index: 1;
    flex-shrink: 0;
}

.panel-icon i {
    font-size: 1.5rem;
    color: white;
}

.panel-title {
    color: white;
    position: relative;
    z-index: 1;
}

.panel-title h2 {
    font-family: 'Amiri', serif;
    font-size: 1.5rem;
    font-weight: 700;
    margin-bottom: var(--space-2);
}

.panel-title p {
    font-size: 1rem;
    opacity: 0.9;
    font-weight: 400;
}

/* Section Styles */
.quick-select-section,
.advanced-section {
    padding: var(--space-8);
}

.quick-select-section {
    border-bottom: 1px solid var(--border-primary);
}

.section-heading {
    display: flex;
    align-items: center;
    gap: var(--space-3);
    font-size: 1.25rem;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: var(--space-6);
}

.section-heading i {
    color: var(--primary-500);
    font-size: 1.125rem;
}

/* Letters Grid */
.letters-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(4rem, 1fr));
    gap: var(--space-3);
    max-width: 100%;
}

.letter-btn {
    aspect-ratio: 1;
    background: var(--surface-primary);
    border: 2px solid var(--border-primary);
    border-radius: var(--radius-xl);
    padding: var(--space-2);
    cursor: pointer;
    transition: var(--transition-normal);
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    position: relative;
    overflow: hidden;
    min-height: 4rem;
}

.letter-btn::before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg, transparent, rgba(255, 255, 255, 0.2), transparent);
    transition: left var(--transition-slow);
}

.letter-btn:hover {
    transform: translateY(-3px) scale(1.05);
    border-color: var(--primary-500);
    box-shadow: var(--shadow-lg);
    background: linear-gradient(135deg, var(--primary-500) 0%, var(--primary-600) 100%);
}

.letter-btn:hover::before {
    left: 100%;
}

.letter-btn:hover .letter,
.letter-btn:hover .name {
    color: white;
}

.letter-btn:active {
    transform: translateY(-1px) scale(1.02);
}

.letter-btn .letter {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: var(--space-1);
    transition: var(--transition-normal);
    font-family: 'Amiri', serif;
}

.letter-btn .name {
    font-size: 0.625rem;
    color: var(--text-tertiary);
    font-weight: 500;
    transition: var(--transition-normal);
    text-align: center;
    line-height: 1.2;
}

/* Search Form */
.search-form {
    background: var(--surface-secondary);
    border-radius: var(--radius-2xl);
    padding: var(--space-8);
    border: 1px solid var(--border-primary);
}

.form-description {
    color: var(--text-secondary);
    line-height: 1.6;
    margin-bottom: var(--space-6);
    font-size: 0.9375rem;
}

.example-tag {
    display: flex;
    align-items: center;
    gap: var(--space-2);
    margin-top: var(--space-3);
    padding: var(--space-3) var(--space-4);
    background: var(--accent-100);
    color: var(--accent-700);
    border-radius: var(--radius-lg);
    font-size: 0.875rem;
    font-weight: 500;
    border: 1px solid var(--accent-200);
}

.example-tag i {
    color: var(--accent-600);
    font-size: 0.75rem;
}

/* Input Group */
.input-group {
    display: flex;
    gap: var(--space-4);
    align-items: flex-end;
}

.input-wrapper {
    position: relative;
    flex: 1;
}

.form-input {
    width: 100%;
    padding: var(--space-4) var(--space-4) var(--space-4) var(--space-12);
    border: 2px solid var(--border-primary);
    border-radius: var(--radius-xl);
    font-size: 1rem;
    font-weight: 400;
    background: var(--surface-primary);
    transition: var(--transition-normal);
    outline: none;
    color: var(--text-primary);
}

.form-input:focus {
    border-color: var(--border-focus);
    box-shadow: 0 0 0 4px rgba(59, 130, 246, 0.1);
}

.form-input::placeholder {
    color: var(--text-quaternary);
}

.input-icon {
    position: absolute;
    left: var(--space-4);
    top: 50%;
    transform: translateY(-50%);
    color: var(--text-tertiary);
    transition: var(--transition-normal);
    pointer-events: none;
}

.form-input:focus + .input-icon {
    color: var(--primary-500);
}

/* Buttons */
.search-btn {
    border: none;
    border-radius: var(--radius-xl);
    padding: var(--space-4) var(--space-6);
    font-weight: 600;
    cursor: pointer;
    transition: var(--transition-normal);
    display: flex;
    align-items: center;
    gap: var(--space-2);
    font-size: 0.9375rem;
    white-space: nowrap;
    outline: none;
    position: relative;
    overflow: hidden;
}

.search-btn.primary {
    background: linear-gradient(135deg, var(--accent-500) 0%, var(--accent-600) 100%);
    color: white;
    box-shadow: var(--shadow-md);
}

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

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

.search-btn.large {
    padding: var(--space-5) var(--space-8);
    font-size: 1.0625rem;
}

.search-btn.secondary {
    background: var(--surface-primary);
    color: var(--text-secondary);
    border: 2px solid var(--border-primary);
}

.search-btn.secondary:hover {
    background: var(--surface-secondary);
    border-color: var(--border-secondary);
}

.search-btn.danger {
    background: var(--error);
    color: white;
}

.search-btn.danger:hover {
    background: #dc2626;
    transform: translateY(-1px);
}

/* Dual Input Container */
.dual-input-container {
    display: flex;
    flex-direction: column;
    gap: var(--space-6);
}

.dual-input-group {
    display: flex;
    align-items: flex-end;
    gap: var(--space-6);
}

.dual-input-section {
    flex: 1;
}

.input-label {
    display: flex;
    align-items: center;
    gap: var(--space-2);
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: var(--space-3);
    font-size: 0.9375rem;
}

.input-label i {
    color: var(--primary-500);
    font-size: 0.875rem;
}

.connector-element {
    display: flex;
    flex-direction: column;
    align-items: center;
    margin-bottom: var(--space-4);
}

.connector-line {
    width: 2px;
    height: 2rem;
    background: linear-gradient(to bottom, var(--primary-300), var(--secondary-300));
    margin-bottom: var(--space-2);
}

.connector-icon {
    width: 2.5rem;
    height: 2.5rem;
    background: var(--surface-primary);
    border: 2px solid var(--border-primary);
    border-radius: var(--radius-full);
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--text-tertiary);
}

/* Results Section */
.results-section {
    margin: var(--space-16) auto;
    max-width: 75rem;
    padding: 0 var(--space-4);
    animation: slideInUp 0.6s ease-out;
}

@keyframes slideInUp {
    from {
        opacity: 0;
        transform: translateY(3rem);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.results-container {
    background: var(--surface-primary);
    border-radius: var(--radius-2xl);
    box-shadow: var(--shadow-xl);
    border: 1px solid var(--border-primary);
    overflow: hidden;
}

.results-header {
    background: linear-gradient(135deg, var(--info) 0%, var(--primary-700) 100%);
    padding: var(--space-8);
    color: white;
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: var(--space-4);
    position: relative;
    overflow: hidden;
}

.results-header::before {
    content: '';
    position: absolute;
    inset: 0;
    background: url('data:image/svg+xml,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 40 40"><defs><pattern id="grid" width="8" height="8" patternUnits="userSpaceOnUse"><path d="M 8 0 L 0 0 0 8" fill="none" stroke="rgba(255,255,255,0.1)" stroke-width="1"/></pattern></defs><rect width="40" height="40" fill="url(%23grid)"/></svg>');
    opacity: 0.3;
}

.results-title-section {
    display: flex;
    align-items: center;
    gap: var(--space-4);
    flex: 1;
    position: relative;
    z-index: 1;
}

.results-icon {
    width: 3rem;
    height: 3rem;
    background: rgba(255, 255, 255, 0.2);
    border-radius: var(--radius-lg);
    display: flex;
    align-items: center;
    justify-content: center;
    backdrop-filter: blur(10px);
    flex-shrink: 0;
}

.results-icon i {
    font-size: 1.25rem;
}

.results-info {
    flex: 1;
}

.results-title {
    font-family: 'Amiri', serif;
    font-size: 1.75rem;
    font-weight: 700;
    margin-bottom: var(--space-2);
}

.results-meta {
    display: flex;
    align-items: center;
    gap: var(--space-4);
}

.results-count {
    background: rgba(255, 255, 255, 0.2);
    padding: var(--space-1) var(--space-3);
    border-radius: var(--radius-lg);
    font-weight: 600;
    backdrop-filter: blur(10px);
    font-size: 0.875rem;
}

.results-time {
    font-size: 0.8125rem;
    opacity: 0.8;
}

.results-actions {
    display: flex;
    align-items: center;
    gap: var(--space-3);
    position: relative;
    z-index: 1;
}

.action-btn {
    padding: var(--space-2) var(--space-4);
    border: 1px solid rgba(255, 255, 255, 0.3);
    background: rgba(255, 255, 255, 0.1);
    color: white;
    border-radius: var(--radius-lg);
    cursor: pointer;
    transition: var(--transition-normal);
    display: flex;
    align-items: center;
    gap: var(--space-2);
    font-size: 0.8125rem;
    backdrop-filter: blur(10px);
}

.action-btn:hover {
    background: rgba(255, 255, 255, 0.2);
    border-color: rgba(255, 255, 255, 0.5);
}

.action-btn.danger:hover {
    background: rgba(239, 68, 68, 0.3);
    border-color: rgba(239, 68, 68, 0.5);
}

.results-body {
    padding: var(--space-8);
}

.length-group {
    background: var(--surface-secondary);
    border-radius: var(--radius-2xl);
    padding: var(--space-6);
    margin-bottom: var(--space-6);
    border: 1px solid var(--border-primary);
    box-shadow: var(--shadow-sm);
}

.length-group:last-child {
    margin-bottom: 0;
}

.length-header {
    display: flex;
    align-items: center;
    gap: var(--space-4);
    margin-bottom: var(--space-4);
}

.length-title {
    font-size: 1.1875rem;
    font-weight: 600;
    color: var(--text-primary);
    font-family: 'Amiri', serif;
}

.word-count-badge {
    background: linear-gradient(135deg, var(--success) 0%, var(--secondary-500) 100%);
    color: white;
    padding: var(--space-1) var(--space-3);
    border-radius: var(--radius-full);
    font-size: 0.8125rem;
    font-weight: 600;
}

.words-list {
    background: var(--surface-primary);
    padding: var(--space-6);
    border-radius: var(--radius-xl);
    font-size: 1.0625rem;
    line-height: 2.2;
    text-align: justify;
    border-right: 4px solid var(--primary-500);
    color: var(--text-primary);
    font-family: 'Tajawal', sans-serif;
    font-weight: 500;
}

.no-results {
    text-align: center;
    padding: var(--space-16);
    color: var(--text-tertiary);
}

.no-results i {
    font-size: 4rem;
    margin-bottom: var(--space-4);
    color: var(--text-quaternary);
}

.no-results h3 {
    font-size: 1.5rem;
    margin-bottom: var(--space-2);
    color: var(--text-secondary);
}

.no-results p {
    font-size: 1rem;
}

/* Loading Overlay */
.loading-overlay {
    position: fixed;
    inset: 0;
    background: rgba(0, 0, 0, 0.7);
    backdrop-filter: blur(8px);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: var(--z-modal);
}

.loading-container {
    background: var(--surface-primary);
    padding: var(--space-12);
    border-radius: var(--radius-3xl);
    text-align: center;
    box-shadow: var(--shadow-2xl);
    border: 1px solid var(--border-primary);
    max-width: 20rem;
}

.loading-animation {
    margin-bottom: var(--space-6);
    position: relative;
}

.loading-spinner {
    width: 3rem;
    height: 3rem;
    border: 4px solid var(--border-primary);
    border-top: 4px solid var(--primary-500);
    border-radius: var(--radius-full);
    animation: spin 1s linear infinite;
    margin: 0 auto var(--space-4);
}

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

.loading-dots {
    display: flex;
    justify-content: center;
    gap: var(--space-2);
}

.loading-dots span {
    width: 0.5rem;
    height: 0.5rem;
    background: var(--primary-500);
    border-radius: var(--radius-full);
    animation: bounce 1.4s infinite ease-in-out both;
}

.loading-dots span:nth-child(1) { animation-delay: -0.32s; }
.loading-dots span:nth-child(2) { animation-delay: -0.16s; }

@keyframes bounce {
    0%, 80%, 100% { transform: scale(0); }
    40% { transform: scale(1); }
}

.loading-title {
    font-size: 1.25rem;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: var(--space-2);
}

.loading-subtitle {
    color: var(--text-secondary);
    font-size: 0.9375rem;
}

/* Notification Toast */
.notification-toast {
    position: fixed;
    top: var(--space-6);
    right: var(--space-6);
    background: var(--surface-primary);
    border-radius: var(--radius-xl);
    padding: var(--space-4);
    box-shadow: var(--shadow-lg);
    border: 1px solid var(--border-primary);
    display: flex;
    align-items: center;
    gap: var(--space-3);
    z-index: var(--z-toast);
    transform: translateX(120%);
    transition: transform var(--transition-slow);
    max-width: 20rem;
}

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

.toast-icon {
    width: 2rem;
    height: 2rem;
    background: var(--success);
    border-radius: var(--radius-lg);
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    flex-shrink: 0;
}

.toast-content {
    flex: 1;
}

.toast-title {
    font-weight: 600;
    color: var(--text-primary);
    font-size: 0.875rem;
    margin-bottom: var(--space-1);
}

.toast-message {
    color: var(--text-secondary);
    font-size: 0.8125rem;
}

.toast-close {
    background: none;
    border: none;
    color: var(--text-tertiary);
    cursor: pointer;
    padding: var(--space-1);
    border-radius: var(--radius-md);
    transition: var(--transition-fast);
}

.toast-close:hover {
    background: var(--surface-secondary);
    color: var(--text-secondary);
}

/* Responsive Design */
@media (max-width: 1024px) {
    .main-container {
        margin-top: -4rem;
        padding: 0 var(--space-3);
    }
    
    .hero-container {
        padding: var(--space-6);
    }
    
    .hero-content {
        padding: var(--space-8);
    }
}

@media (max-width: 768px) {
    .hero-title {
        font-size: 2rem;
    }
    
    .hero-description {
        font-size: 1rem;
    }
    
    .hero-stats {
        flex-direction: column;
        gap: var(--space-4);
    }
    
    .stat-divider {
        width: 3rem;
        height: 1px;
    }
    
    .tab-nav-wrapper {
        overflow-x: auto;
        padding: var(--space-1);
    }
    
    .tab-nav-item {
        min-width: 10rem;
        padding: var(--space-3);
    }
    
    .tab-title {
        font-size: 0.875rem;
    }
    
    .tab-desc {
        display: none;
    }
    
    .panel-header {
        flex-direction: column;
        text-align: center;
        padding: var(--space-6);
        gap: var(--space-3);
    }
    
    .panel-title h2 {
        font-size: 1.25rem;
    }
    
    .quick-select-section,
    .advanced-section {
        padding: var(--space-6);
    }
    
    .letters-grid {
        grid-template-columns: repeat(auto-fill, minmax(3rem, 1fr));
        gap: var(--space-2);
    }
    
    .letter-btn {
        min-height: 3rem;
        padding: var(--space-2);
    }
    
    .letter-btn .letter {
        font-size: 1.125rem;
    }
    
    .letter-btn .name {
        font-size: 0.5625rem;
    }
    
    .input-group {
        flex-direction: column;
        align-items: stretch;
    }
    
    .dual-input-group {
        flex-direction: column;
        gap: var(--space-4);
    }
    
    .connector-element {
        align-self: center;
        margin: 0;
    }
    
    .connector-line {
        width: 3rem;
        height: 2px;
        background: linear-gradient(to right, var(--primary-300), var(--secondary-300));
        margin-bottom: var(--space-2);
    }
    
    .results-header {
        flex-direction: column;
        align-items: stretch;
        gap: var(--space-4);
    }
    
    .results-title-section {
        flex-direction: column;
        text-align: center;
    }
    
    .results-actions {
        justify-content: center;
    }
    
    .results-title {
        font-size: 1.5rem;
    }
}

@media (max-width: 640px) {
    .main-container {
        padding: 0 var(--space-2);
    }
    
    .hero-content {
        padding: var(--space-6);
    }
    
    .hero-icon {
        width: 4rem;
        height: 4rem;
    }
    
    .hero-icon i {
        font-size: 2rem;
    }
    
    .tab-nav-item {
        min-width: 8rem;
        padding: var(--space-3);
    }
    
    .tab-icon {
        width: 2rem;
        height: 2rem;
    }
    
    .tab-icon i {
        font-size: 1rem;
    }
    
    .tab-title {
        font-size: 0.8125rem;
    }
    
    .section-heading {
        font-size: 1.125rem;
    }
    
    .search-btn {
        padding: var(--space-4) var(--space-5);
        font-size: 0.875rem;
    }
    
    .results-body {
        padding: var(--space-6);
    }
    
    .length-group {
        padding: var(--space-4);
    }
    
    .loading-container {
        padding: var(--space-8);
        margin: var(--space-4);
    }
    
    .notification-toast {
        top: var(--space-4);
        right: var(--space-4);
        left: var(--space-4);
        max-width: none;
    }
}

@media (max-width: 480px) {
    .letters-grid {
        grid-template-columns: repeat(auto-fill, minmax(2.5rem, 1fr));
        gap: var(--space-1);
    }
    
    .letter-btn {
        min-height: 2.5rem;
        padding: var(--space-1);
    }
    
    .letter-btn .letter {
        font-size: 1rem;
    }
    
    .letter-btn .name {
        font-size: 0.5rem;
    }
    
    .search-form {
        padding: var(--space-6);
    }
    
    .form-input {
        padding: var(--space-3) var(--space-3) var(--space-3) var(--space-10);
    }
}

/* Accessibility Improvements */
@media (prefers-reduced-motion: reduce) {
    *,
    *::before,
    *::after {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
    }
    
    .floating-letter {
        animation: none;
    }
}

@media (prefers-contrast: high) {
    :root {
        --border-primary: #000000;
        --text-tertiary: #000000;
        --text-quaternary: #333333;
    }
}

/* Focus States for Accessibility */
.letter-btn:focus,
.search-btn:focus,
.form-input:focus,
.tab-nav-item:focus {
    outline: 2px solid var(--primary-500);
    outline-offset: 2px;
}

/* Scrollbar Styling */
::-webkit-scrollbar {
    width: 0.5rem;
    height: 0.5rem;
}

::-webkit-scrollbar-track {
    background: var(--surface-secondary);
    border-radius: var(--radius-sm);
}

::-webkit-scrollbar-thumb {
    background: var(--border-secondary);
    border-radius: var(--radius-sm);
    border: 2px solid var(--surface-secondary);
}

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

/* Print Styles */
@media print {
    .hero-section,
    .tab-navigation,
    .loading-overlay,
    .notification-toast {
        display: none;
    }
    
    .results-section {
        margin: 0;
        box-shadow: none;
        border: 1px solid #000;
    }
    
    .results-header {
        background: #f5f5f5 !important;
        color: #000 !important;
    }
    
    .words-list {
        font-size: 12pt;
        line-height: 1.5;
    }
}