@import url('https://fonts.googleapis.com/css2?family=Inter:wght@200;300;400;500;600;700;800;900&display=swap');
        :root {
            --primary-1: #ff006e;
            --primary-2: #8338ec;
            --primary-3: #3a86ff;
            --primary-4: #06ffa5;
            --primary-5: #ffbe0b;
            
            --bg-primary: #0a0a0f;
            --bg-secondary: #1a1a2e;
            --bg-tertiary: #16213e;
            --bg-glass: rgba(255, 255, 255, 0.08);
            --bg-glass-hover: rgba(255, 255, 255, 0.15);
            
            --text-primary: #ffffff;
            --text-secondary: rgba(255, 255, 255, 0.8);
            --text-muted: rgba(255, 255, 255, 0.6);
            --text-accent: var(--primary-4);
            --glow-primary: 0 0 30px rgba(255, 0, 110, 0.3);
            --glow-secondary: 0 0 40px rgba(131, 56, 236, 0.4);
            --glow-accent: 0 0 25px rgba(6, 255, 165, 0.5);
            --blur-strong: 20px;
            --blur-medium: 12px;
            --container-max: 1400px;
            --radius-xl: 32px;
            --radius-lg: 24px;
            --radius-md: 16px;
            --spacing-xl: 64px;
            --spacing-lg: 48px;
            --spacing-md: 32px;
            --spacing-sm: 24px;
        }
        * {
            box-sizing: border-box;
            margin: 0;
            padding: 0;
        }
        
        html, body {
            height: 100%;
            font-family: 'Inter', system-ui, -apple-system, sans-serif;
            background: var(--bg-primary);
            color: var(--text-primary);
            overflow-x: hidden;
            scroll-behavior: smooth;
        }
        
        body {
            background: 
                radial-gradient(circle at 20% 80%, rgba(255, 0, 110, 0.15) 0%, transparent 50%),
                radial-gradient(circle at 80% 20%, rgba(131, 56, 236, 0.15) 0%, transparent 50%),
                radial-gradient(circle at 40% 40%, rgba(58, 134, 255, 0.1) 0%, transparent 50%),
                linear-gradient(135deg, #0a0a0f 0%, #1a1a2e 50%, #16213e 100%);
            background-attachment: fixed;
            min-height: 100vh;
            padding: var(--spacing-md) var(--spacing-sm);
            position: relative;
        }
        body::before {
            content: '';
            position: fixed;
            top: 0;
            left: 0;
            width: 100%;
            height: 100%;
            pointer-events: none;
            z-index: -1;
            background-image: 
                radial-gradient(2px 2px at 20px 30px, rgba(255, 0, 110, 0.3), transparent),
                radial-gradient(2px 2px at 40px 70px, rgba(6, 255, 165, 0.2), transparent),
                radial-gradient(1px 1px at 90px 40px, rgba(131, 56, 236, 0.4), transparent),
                radial-gradient(1px 1px at 130px 80px, rgba(255, 190, 11, 0.3), transparent);
            background-repeat: repeat;
            background-size: 200px 200px;
            animation: particleFloat 20s linear infinite;
        }
        @keyframes particleFloat {
            0% { transform: translate(0, 0) rotate(0deg); }
            33% { transform: translate(30px, -30px) rotate(120deg); }
            66% { transform: translate(-20px, 20px) rotate(240deg); }
            100% { transform: translate(0, 0) rotate(360deg); }
        }
        .container {
            max-width: var(--container-max);
            margin: 0 auto;
            padding: 0 var(--spacing-sm);
        }
        .header {
            text-align: center;
            margin-bottom: var(--spacing-xl);
            padding: var(--spacing-lg) 0;
            position: relative;
        }
        .header::before {
            content: '';
            position: absolute;
            top: 50%;
            left: 50%;
            transform: translate(-50%, -50%);
            width: 600px;
            height: 600px;
            background: radial-gradient(circle, rgba(255, 0, 110, 0.1) 0%, transparent 70%);
            border-radius: 50%;
            filter: blur(40px);
            z-index: -1;
        }
        .header h1 {
            font-size: clamp(2.5rem, 8vw, 6rem);
            font-weight: 900;
            line-height: 0.9;
            letter-spacing: -0.04em;
            margin-bottom: var(--spacing-sm);
            background: linear-gradient(
                135deg,
                var(--primary-1) 0%,
                var(--primary-2) 25%,
                var(--primary-3) 50%,
                var(--primary-4) 75%,
                var(--primary-5) 100%
            );
            background-size: 300% 300%;
            -webkit-background-clip: text;
            -webkit-text-fill-color: transparent;
            background-clip: text;
            animation: gradientShift 8s ease-in-out infinite;
            filter: drop-shadow(0 0 20px rgba(255, 0, 110, 0.5));
        }
        @keyframes gradientShift {
            0%, 100% { background-position: 0% 50%; }
            50% { background-position: 100% 50%; }
        }
        .header p {
            font-size: clamp(1.1rem, 2.5vw, 1.8rem);
            font-weight: 300;
            color: var(--text-secondary);
            max-width: 800px;
            margin: 0 auto;
            line-height: 1.4;
        }
        .tabs {
            display: flex;
            justify-content: center;
            gap: 8px;
            margin-bottom: var(--spacing-xl);
            flex-wrap: wrap;
            padding: 16px;
            background: var(--bg-glass);
            backdrop-filter: blur(var(--blur-medium));
            border-radius: 60px;
            border: 1px solid rgba(255, 255, 255, 0.1);
            max-width: 1000px;
            margin-left: auto;
            margin-right: auto;
        }
        .tab-button {
            position: relative;
            padding: 16px 28px;
            border-radius: 50px;
            border: none;
            background: transparent;
            color: var(--text-secondary);
            font-size: 1rem;
            font-weight: 600;
            cursor: pointer;
            transition: all 0.4s cubic-bezier(0.23, 1, 0.32, 1);
            overflow: hidden;
            min-width: 140px;
        }
        .tab-button::before {
            content: '';
            position: absolute;
            inset: 0;
            background: linear-gradient(135deg, var(--primary-1), var(--primary-2), var(--primary-3));
            border-radius: inherit;
            opacity: 0;
            transition: opacity 0.4s ease;
            z-index: -1;
        }
        .tab-button::after {
            content: '';
            position: absolute;
            inset: 2px;
            background: var(--bg-primary);
            border-radius: inherit;
            opacity: 0;
            transition: opacity 0.4s ease;
            z-index: -1;
        }
        .tab-button:hover {
            color: var(--text-primary);
            transform: translateY(-2px);
            box-shadow: var(--glow-primary);
        }
        .tab-button:hover::before,
        .tab-button:hover::after {
            opacity: 1;
        }
        .tab-button.active {
            color: var(--text-primary);
            background: linear-gradient(135deg, var(--primary-1), var(--primary-2));
            box-shadow: var(--glow-primary);
            transform: translateY(-2px);
        }
        .tab-button.active::before,
        .tab-button.active::after {
            opacity: 0;
        }
        .content-section {
            background: var(--bg-glass);
            backdrop-filter: blur(var(--blur-strong));
            border-radius: var(--radius-xl);
            padding: var(--spacing-xl);
            margin-bottom: var(--spacing-lg);
            border: 1px solid rgba(255, 255, 255, 0.1);
            display: none;
            animation: sectionFadeIn 0.8s cubic-bezier(0.23, 1, 0.32, 1);
            position: relative;
            overflow: hidden;
        }
        .content-section::before {
            content: '';
            position: absolute;
            top: 0;
            left: 0;
            right: 0;
            height: 1px;
            background: linear-gradient(90deg, transparent, var(--primary-4), transparent);
        }
        .content-section.active {
            display: block;
        }
        @keyframes sectionFadeIn {
            from {
                opacity: 0;
                transform: translateY(40px) scale(0.95);
            }
            to {
                opacity: 1;
                transform: translateY(0) scale(1);
            }
        }
        .content-section h2 {
            font-size: clamp(1.8rem, 4vw, 3rem);
            font-weight: 800;
            text-align: center;
            margin-bottom: var(--spacing-lg);
            background: linear-gradient(135deg, var(--primary-4), var(--primary-3));
            -webkit-background-clip: text;
            -webkit-text-fill-color: transparent;
            background-clip: text;
        }
        .vocabulary-grid {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
            gap: var(--spacing-md);
            margin-bottom: var(--spacing-lg);
        }
        .vocab-card {
            position: relative;
            padding: var(--spacing-md);
            border-radius: var(--radius-lg);
            background: linear-gradient(135deg, var(--bg-secondary), var(--bg-tertiary));
            border: 1px solid rgba(255, 255, 255, 0.1);
            cursor: pointer;
            transition: all 0.5s cubic-bezier(0.23, 1, 0.32, 1);
            transform-style: preserve-3d;
            overflow: hidden;
        }
        .vocab-card::before {
            content: '';
            position: absolute;
            inset: 0;
            background: linear-gradient(135deg, var(--primary-1), var(--primary-2), var(--primary-3));
            border-radius: inherit;
            opacity: 0;
            transition: opacity 0.5s ease;
            z-index: -1;
        }
        .vocab-card:hover {
            transform: translateY(-12px) rotateX(5deg) rotateY(5deg);
            box-shadow: 
                0 25px 50px rgba(0, 0, 0, 0.3),
                var(--glow-secondary);
        }
        .vocab-card:hover::before {
            opacity: 0.1;
        }
        .native-word {
            font-size: 2rem;
            font-weight: 900;
            color: var(--text-primary);
            margin-bottom: 8px;
            letter-spacing: -0.02em;
        }
        .pronunciation {
            font-size: 1.1rem;
            color: var(--text-accent);
            font-style: italic;
            margin-bottom: 12px;
            font-weight: 500;
        }
        .english-translation {
            font-size: 1.2rem;
            color: var(--text-secondary);
            font-weight: 600;
            margin-bottom: 16px;
        }
        .quiz-container {
            text-align: center;
            max-width: 1000px;
            margin: 0 auto;
        }
        .score {
            font-size: 1.5rem;
            font-weight: 800;
            color: var(--primary-4);
            margin-bottom: var(--spacing-md);
            text-shadow: var(--glow-accent);
        }
        .quiz-question {
            background: linear-gradient(135deg, var(--bg-secondary), var(--bg-tertiary));
            border-radius: var(--radius-lg);
            padding: var(--spacing-lg);
            margin-bottom: var(--spacing-md);
            font-size: clamp(1.2rem, 3vw, 1.8rem);
            font-weight: 700;
            color: var(--text-primary);
            border: 1px solid rgba(255, 255, 255, 0.1);
            position: relative;
            overflow: hidden;
            min-height: 100px;
        }
        .quiz-question::before {
            content: '';
            position: absolute;
            top: 0;
            left: -100%;
            width: 100%;
            height: 100%;
            background: linear-gradient(90deg, transparent, rgba(255, 255, 255, 0.1), transparent);
            animation: questionShimmer 3s infinite;
        }
        @keyframes questionShimmer {
            0% { left: -100%; }
            100% { left: 100%; }
        }
        .quiz-options {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
            gap: 20px;
            margin-bottom: var(--spacing-md);
        }
        .quiz-option {
            padding: 24px;
            border-radius: var(--radius-md);
            background: var(--bg-glass);
            backdrop-filter: blur(var(--blur-medium));
            border: 2px solid rgba(255, 255, 255, 0.1);
            color: var(--text-primary);
            font-size: 1.1rem;
            font-weight: 600;
            cursor: pointer;
            transition: all 0.4s cubic-bezier(0.23, 1, 0.32, 1);
            position: relative;
            overflow: hidden;
        }
        .quiz-option::before {
            content: '';
            position: absolute;
            inset: 0;
            background: linear-gradient(135deg, var(--primary-3), var(--primary-4));
            opacity: 0;
            transition: opacity 0.4s ease;
            z-index: -1;
        }
        .quiz-option:hover {
            transform: translateY(-4px);
            border-color: var(--primary-3);
            box-shadow: 0 15px 40px rgba(58, 134, 255, 0.3);
        }
        .quiz-option:hover::before {
            opacity: 0.1;
        }
        .quiz-option.correct {
            background: linear-gradient(135deg, rgba(6, 255, 165, 0.2), rgba(6, 255, 165, 0.1));
            border-color: var(--primary-4);
            box-shadow: var(--glow-accent);
        }
        .quiz-option.incorrect {
            background: linear-gradient(135deg, rgba(255, 0, 110, 0.2), rgba(255, 0, 110, 0.1));
            border-color: var(--primary-1);
            box-shadow: var(--glow-primary);
        }
        .quiz-feedback {
            padding: 20px;
            border-radius: var(--radius-md);
            font-weight: 700;
            font-size: 1.2rem;
            margin: var(--spacing-sm) 0;
            min-height: 70px;
        }
        .quiz-feedback.correct {
            background: linear-gradient(135deg, rgba(6, 255, 165, 0.2), rgba(6, 255, 165, 0.1));
            color: var(--primary-4);
            border: 1px solid var(--primary-4);
        }
        .quiz-feedback.incorrect {
            background: linear-gradient(135deg, rgba(255, 0, 110, 0.2), rgba(255, 0, 110, 0.1));
            color: var(--primary-1);
            border: 1px solid var(--primary-1);
        }
        .next-question-btn {
            padding: 16px 32px;
            border-radius: 50px;
            border: none;
            background: linear-gradient(135deg, var(--primary-2), var(--primary-1));
            color: var(--text-primary);
            font-size: 1.1rem;
            font-weight: 700;
            cursor: pointer;
            transition: all 0.4s ease;
            box-shadow: var(--glow-secondary);
            position: relative;
            overflow: hidden;
        }
        
        .next-question-btn:hover {
            transform: translateY(-3px) scale(1.05);
            box-shadow: 
                var(--glow-secondary),
                0 15px 40px rgba(131, 56, 236, 0.4);
        }
        
        .phrases-list {
            display: grid;
            gap: 24px;
            margin-bottom: var(--spacing-lg);
        }
        
        .phrase-item {
            background: var(--bg-glass);
            backdrop-filter: blur(var(--blur-medium));
            border-radius: var(--radius-lg);
            padding: var(--spacing-md);
            border: 1px solid rgba(255, 255, 255, 0.1);
            cursor: pointer;
            transition: all 0.4s cubic-bezier(0.23, 1, 0.32, 1);
            position: relative;
        }
        
        .phrase-item:hover {
            transform: translateX(12px) scale(1.02);
            border-color: var(--primary-4);
            box-shadow: 0 20px 60px rgba(6, 255, 165, 0.15);
        }
        
        .phrase-native {
            font-size: 1.5rem;
            font-weight: 800;
            color: var(--text-primary);
            margin-bottom: 8px;
        }
        
        .phrase-pronunciation {
            font-size: 1rem;
            color: var(--text-accent);
            font-style: italic;
            margin-bottom: 12px;
        }
        
        .phrase-english {
            font-size: 1.1rem;
            color: var(--text-secondary);
            font-weight: 600;
        }
        
        .grammar-section {
            margin-bottom: var(--spacing-lg);
        }
        
        .grammar-title {
            font-size: 1.5rem;
            font-weight: 800;
            color: var(--primary-5);
            margin-bottom: 16px;
            position: relative;
            padding-bottom: 8px;
        }
        
        .grammar-title::after {
            content: '';
            position: absolute;
            bottom: 0;
            left: 0;
            width: 60px;
            height: 3px;
            background: linear-gradient(135deg, var(--primary-5), var(--primary-1));
            border-radius: 2px;
        }
        
        .grammar-content {
            color: var(--text-secondary);
            line-height: 1.7;
            font-size: 1.1rem;
        }
        
        .example {
            background: var(--bg-glass);
            backdrop-filter: blur(var(--blur-medium));
            border-radius: var(--radius-md);
            padding: 24px;
            margin-top: 20px;
            border-left: 4px solid var(--primary-4);
            position: relative;
        }
        
        .alphabet-table {
            display: grid;
            grid-template-columns: 1fr 1fr 1fr 2fr;
            gap: 2px;
            background: var(--bg-primary);
            border-radius: var(--radius-lg);
            overflow: hidden;
            border: 1px solid rgba(255, 255, 255, 0.1);
        }
        
        .alphabet-cell.alphabet-header {
            background: linear-gradient(135deg, var(--primary-2), var(--primary-1));
            color: var(--text-primary);
            font-weight: 800;
            font-size: 1.1rem;
            padding: 20px 16px;
        }
        
        .alphabet-cell {
            background: var(--bg-glass);
            backdrop-filter: blur(var(--blur-medium));
            padding: 16px 12px;
            text-align: center;
            transition: all 0.3s ease;
            border: 1px solid rgba(255, 255, 255, 0.05);
        }
        
        .alphabet-cell:hover:not(.alphabet-header) {
            background: var(--bg-glass-hover);
            border-color: var(--primary-4);
            transform: scale(1.02);
        }
        
        .alphabet-letter {
            font-size: 1.4rem;
            font-weight: 900;
            color: var(--primary-4);
            text-shadow: var(--glow-accent);
        }
        
        /* Controls */
        .controls {
            max-width: 1000px;
            margin: 16px auto 40px;
            display: flex;
            gap: 12px;
            align-items: center;
            justify-content: center;
        }
        .search-input {
            flex: 1;
            min-width: 200px;
            padding: 10px 14px;
            border-radius: 999px;
            border: 1px solid rgba(255, 255, 255, 0.06);
            background: rgba(255, 255, 255, 0.02);
            color: var(--text-primary);
            font-size: 1rem;
        }
        .search-input::placeholder { 
            color: rgba(255,255,255,0.45); 
        }
        .controls .tab-button {
            min-width: auto;
            padding: 10px 14px; 
            border-radius: 40px; 
            font-weight:700; 
        }
        
        /* Modal Styles */
        #progressModal {
            position: fixed;
            inset: 0;
            background: rgba(0, 0, 0, 0.6);
            display: none; /* Controlled by aria-hidden */
            align-items: center;
            justify-content: center;
            z-index: 9999;
        }
        #progressModal[aria-hidden="false"] {
            display: flex;
        }
        .modal-content {
            width: 90%;
            max-width: 760px;
            border-radius: 16px;
            padding: 24px;
            background: linear-gradient(135deg, rgba(20, 20, 30, 0.95), rgba(10, 10, 20, 0.95));
            border: 1px solid rgba(255, 255, 255, 0.06);
            animation: sectionFadeIn 0.5s cubic-bezier(0.23, 1, 0.32, 1);
        }
        .modal-header {
            margin-bottom: 12px;
            font-size: 1.5rem;
        }
        .modal-body {
            max-height: 60vh;
            overflow-y: auto;
            color: var(--text-secondary);
        }
        .modal-footer {
            text-align: right;
            margin-top: 12px;
        }

        /* Favorite / copy buttons on vocab cards */
        .card-controls { 
            position: absolute; 
            top: 12px; 
            right: 12px; 
            display:flex; 
            gap:8px; 
            align-items:center; 
        }
        .small-ghost-btn {
            width:36px; 
            height:36px; 
            border-radius:50%; 
            border:none; 
            display:inline-flex; 
            align-items:center; 
            justify-content:center;
            background: rgba(255,255,255,0.03); 
            color:var(--text-primary); 
            cursor:pointer; 
            transition:transform .15s;
        }
        .small-ghost-btn:hover { 
            transform:scale(1.08); 
            box-shadow: 0 6px 18px rgba(0,0,0,0.4); 
        }
        .small-ghost-btn.faved { 
            background: linear-gradient(135deg,var(--primary-4),var(--primary-3)); 
            color:var(--bg-primary); 
            box-shadow: var(--glow-accent); 
        }
        
        @media (max-width: 1200px) {
            .vocabulary-grid {
                grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
                gap: 24px;
            }
        }
        
        @media (max-width: 968px) {
            .tabs {
                border-radius: var(--radius-lg);
                flex-direction: column;
                align-items: center;
                gap: 12px;
            }
            
            .tab-button {
                width: 100%;
                max-width: 300px;
            }
            
            .alphabet-table {
                grid-template-columns: 1fr 1fr;
            }
        }
        
        @media (max-width: 640px) {
            body {
                padding: var(--spacing-sm) 16px;
            }
            
            .container {
                padding: 0;
            }
            
            .content-section {
                padding: var(--spacing-md);
                border-radius: var(--radius-lg);
            }
            
            .vocabulary-grid {
                grid-template-columns: 1fr;
            }
            
            .quiz-options {
                grid-template-columns: 1fr;
            }
            
            .alphabet-table {
                grid-template-columns: 1fr;
            }
        }
        
        @media (prefers-reduced-motion: reduce) {
            * {
                animation-duration: 0.01ms !important;
                animation-iteration-count: 1 !important;
                transition-duration: 0.01ms !important;
            }
            
            body::before {
                animation: none;
            }
        }
        
        .tab-button:focus-visible,
        .quiz-option:focus-visible,
        .next-question-btn:focus-visible,
        .search-input:focus-visible,
        .small-ghost-btn:focus-visible {
            outline: none;
            box-shadow: 0 0 0 2px var(--bg-primary), 0 0 0 4px var(--primary-3);
        }
        
        @media (prefers-contrast: high) {
            :root {
                --bg-glass: rgba(255, 255, 255, 0.15);
                --text-secondary: rgba(255, 255, 255, 0.9);
            }
        }