*,*:before,*:after{box-sizing:border-box}:root{font-family:Inter,system-ui,Avenir,Helvetica,Arial,sans-serif;line-height:1.5;font-weight:400;color-scheme:light dark;--color-bg: #ffffff;--color-text: #213547;--color-text-muted: #64748b;--color-primary: #6366f1;--color-primary-hover: #4f46e5;--color-border: #e2e8f0;--color-input-bg: #f8fafc;--transition-speed: .2s;background-color:var(--color-bg);color:var(--color-text);font-synthesis:none;text-rendering:optimizeLegibility;-webkit-font-smoothing:antialiased;-moz-osx-font-smoothing:grayscale}[data-theme=dark]{--color-bg: #09090b;--color-text: #f8fafc;--color-text-muted: #94a3b8;--color-primary: #818cf8;--color-primary-hover: #6366f1;--color-border: #27272a;--color-input-bg: #18181b}body{margin:0;min-width:320px;min-height:100vh;background-color:var(--color-bg);color:var(--color-text);transition:background-color var(--transition-speed),color var(--transition-speed)}#root{width:100%}button{background-color:transparent;border:1px solid transparent;padding:.6em 1.2em;font-size:1em;font-weight:500;font-family:inherit;cursor:pointer;transition:border-color .25s,background-color .25s;color:var(--color-text);border-radius:8px}button:hover{background-color:var(--color-border)}button:focus,button:focus-visible{outline:4px auto -webkit-focus-ring-color}.icon-btn{padding:8px;border-radius:50%;display:flex;align-items:center;justify-content:center}.input-large{font-size:2rem;padding:1rem;width:100%;max-width:600px;background:transparent;border:none;border-bottom:2px solid var(--color-border);color:var(--color-text);text-align:center;outline:none;transition:border-color var(--transition-speed)}.input-large:focus{border-bottom-color:var(--color-primary)}.fade-in{animation:fadeIn .3s ease-in}:root{--color-surface: #ffffff}[data-theme=dark]{--color-surface: #18181b}.main-container{width:100%;max-width:1200px;margin:0 auto;padding:2rem;position:relative}.quiz-container{display:flex;flex-direction:column;gap:2rem;width:100%;max-width:1000px;margin:0 auto;padding:2rem;background-color:var(--surface);border-radius:var(--radius-lg);box-shadow:var(--shadow-md);min-height:400px}.quiz-header{display:flex;align-items:center;justify-content:space-between;margin-bottom:1rem}.icon-btn.back-home{padding:.5rem;color:var(--text-secondary)}.icon-btn.back-home:hover{color:var(--primary);background:var(--surface-hover)}.progress{font-weight:500;color:var(--text-secondary)}.score-badge{background:var(--primary);color:#fff;padding:.25rem .75rem;border-radius:999px;font-weight:600;font-size:.875rem}.question-card{text-align:center;flex:1;display:flex;flex-direction:column;justify-content:center}.question-word{font-size:2.5rem;font-weight:700;color:var(--text-primary);margin-bottom:2rem}.options-grid{display:grid;grid-template-columns:1fr 1fr;gap:1rem}.option-btn{padding:1.5rem;font-size:1.125rem;background:var(--background);border:1px solid var(--border);border-radius:var(--radius-md);color:var(--text-primary);cursor:pointer;transition:all .2s}.option-btn:hover:not(:disabled){border-color:var(--primary);background:var(--surface-hover);transform:translateY(-2px)}.option-btn:disabled{cursor:default}.option-btn.correct{background:#10b981;color:#fff;border-color:#10b981}.option-btn.incorrect{background:#ef4444;color:#fff;border-color:#ef4444}.results{text-align:center;justify-content:center;align-items:center}.score-display{margin:2rem 0}.score-number{font-size:4rem;font-weight:800;color:var(--primary)}.actions{display:flex;gap:1rem;justify-content:center}.primary-btn{display:flex;align-items:center;gap:.5rem;background:var(--primary);color:#fff;padding:.75rem 1.5rem;border-radius:var(--radius-md);font-weight:600;border:none;cursor:pointer;transition:background .2s}.primary-btn:hover{background:var(--primary-dark)}.secondary-btn{display:flex;align-items:center;gap:.5rem;background:var(--surface-hover);color:var(--text-primary);padding:.75rem 1.5rem;border-radius:var(--radius-md);font-weight:600;border:none;cursor:pointer;transition:background .2s}.secondary-btn:hover{background:var(--border)}.loading,.error{align-items:center;justify-content:center;text-align:center;color:var(--text-secondary)}@media(max-width:640px){.options-grid{grid-template-columns:1fr}}.study-container{max-width:600px;margin:2rem auto;padding:1rem;text-align:center}.study-card{background:var(--color-surface);border-radius:12px;padding:2rem;box-shadow:0 4px 6px -1px #0000001a,0 2px 4px -1px #0000000f;min-height:400px;display:flex;flex-direction:column;justify-content:center;align-items:center;border:1px solid var(--color-border)}.study-word h2{font-size:2.5rem;margin-bottom:2rem;color:var(--color-text)}.btn-reveal{background:var(--color-primary);color:#fff;border:none;padding:.75rem 2rem;font-size:1.1rem;border-radius:8px;cursor:pointer;transition:background .2s}.btn-reveal:hover{background:var(--color-primary-hover)}.study-answer{animation:fadeIn .3s ease-in;width:100%}.translation{font-size:2rem;color:var(--color-primary);margin-bottom:1rem}.example{font-style:italic;color:var(--color-text-muted);margin-bottom:2rem}.rating-buttons{display:grid;grid-template-columns:repeat(3,1fr);gap:.5rem;margin-top:2rem}.btn-rate{padding:.75rem;border:1px solid var(--color-border);border-radius:8px;background:var(--color-input-bg);cursor:pointer;transition:all .2s;display:flex;flex-direction:column;align-items:center;gap:.25rem}.btn-rate:hover{transform:translateY(-2px);box-shadow:0 2px 4px #0000001a;background:var(--color-border)}.rate-emoji{font-size:1.5rem}.rate-label{font-size:.8rem;color:var(--color-text-muted)}.progress{margin-top:auto;padding-top:2rem;color:var(--color-text-muted);font-size:.9rem}.study-finished{text-align:center;margin-top:3rem;padding:2rem}@keyframes fadeIn{0%{opacity:0;transform:translateY(10px)}to{opacity:1;transform:translateY(0)}}@media(max-width:480px){.rating-buttons{grid-template-columns:repeat(2,1fr)}}