:root{--bg-deep: #0a0a0a;--bg-charcoal: #141414;--bg-card: #181818;--bg-card-hover: #1f1f1f;--bg-card-subtle: #121212;--border-muted: #262626;--border-subtle: #1e1e1e;--border-active: #00e5ff;--border-gold: #ffd700;--text-primary: #f5f5f5;--text-muted: #a3a3a3;--text-dim: #737373;--accent-cyan: #00e5ff;--accent-cyan-glow: rgba(0, 229, 255, .15);--accent-cyan-border: rgba(0, 229, 255, .4);--accent-gold: #ffd700;--accent-gold-glow: rgba(255, 215, 0, .15);--state-wrong: #8b3a3a;--state-wrong-bg: rgba(139, 58, 58, .12);--state-wrong-border: #9b4444;--font-sans: "Outfit", -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;--font-mono: "JetBrains Mono", monospace;--radius-sm: 6px;--radius-md: 10px;--radius-lg: 16px;--radius-full: 9999px;--transition-fast: .15s ease;--transition-normal: .25s cubic-bezier(.16, 1, .3, 1)}*{box-sizing:border-box;margin:0;padding:0}body{background-color:var(--bg-deep);color:var(--text-primary);font-family:var(--font-sans);line-height:1.6;-webkit-font-smoothing:antialiased;min-height:100vh;overflow-x:hidden}body:before{content:"";position:fixed;top:0;left:0;width:100%;height:100%;background:radial-gradient(circle at 50% 0%,#151d20 0%,transparent 60%),radial-gradient(circle at 100% 100%,#121516 0%,transparent 40%);pointer-events:none;z-index:-1}.app-container{max-width:860px;margin:0 auto;padding:2.5rem 1.5rem 5rem}.app-header{margin-bottom:2.5rem;padding-bottom:1.5rem;border-bottom:1px solid var(--border-muted)}.header-top{display:flex;align-items:center;justify-content:space-between;margin-bottom:.75rem}.brand-badge{display:inline-flex;align-items:center;gap:.5rem;font-size:.75rem;text-transform:uppercase;letter-spacing:.1em;color:var(--accent-cyan);background:var(--accent-cyan-glow);border:1px solid var(--accent-cyan-border);padding:.25rem .75rem;border-radius:var(--radius-full);font-weight:600}.lesson-badge{display:inline-flex;align-items:center;gap:.4rem;font-size:.75rem;text-transform:uppercase;letter-spacing:.08em;color:var(--accent-gold);background:var(--accent-gold-glow);border:1px solid rgba(255,215,0,.3);padding:.25rem .75rem;border-radius:var(--radius-full);font-weight:600}.app-title{font-size:2rem;font-weight:700;color:var(--text-primary);letter-spacing:-.02em;margin-bottom:.25rem}.app-subtitle{color:var(--text-muted);font-size:.95rem}.progress-card{background:var(--bg-charcoal);border:1px solid var(--border-muted);border-radius:var(--radius-md);padding:1rem 1.25rem;margin-bottom:2rem;display:flex;align-items:center;justify-content:space-between;gap:1.5rem}.progress-info{display:flex;flex-direction:column;gap:.2rem}.progress-label{font-size:.8rem;text-transform:uppercase;letter-spacing:.05em;color:var(--text-muted)}.progress-score{font-size:1.25rem;font-weight:700;color:var(--accent-gold)}.progress-bar-track{flex:1;height:6px;background:#202020;border-radius:var(--radius-full);overflow:hidden}.progress-bar-fill{height:100%;background:linear-gradient(90deg,var(--accent-cyan),var(--accent-gold));border-radius:var(--radius-full);transition:width .4s ease}.theory-card{background:var(--bg-card);border:1px solid var(--border-muted);border-radius:var(--radius-lg);padding:1.5rem;margin-bottom:2.5rem;box-shadow:0 4px 20px #0006}.theory-header{display:flex;align-items:center;justify-content:space-between;cursor:pointer;-webkit-user-select:none;user-select:none}.theory-title-group{display:flex;align-items:center;gap:.75rem}.theory-title{font-size:1.1rem;font-weight:600;color:var(--text-primary)}.theory-body{margin-top:1rem;padding-top:1rem;border-top:1px solid var(--border-subtle);color:#d1d1d1;font-size:.95rem;line-height:1.7;white-space:pre-wrap}.section-title{font-size:1.3rem;font-weight:600;margin-bottom:1.5rem;display:flex;align-items:center;gap:.5rem}.exercise-card{background:var(--bg-card);border:1px solid var(--border-muted);border-radius:var(--radius-lg);padding:1.75rem;margin-bottom:1.75rem;transition:border-color var(--transition-fast)}.exercise-card:focus-within{border-color:var(--accent-cyan-border)}.exercise-meta{display:flex;align-items:center;justify-content:space-between;margin-bottom:1rem}.exercise-type-tag{font-size:.7rem;text-transform:uppercase;letter-spacing:.08em;padding:.2rem .5rem;border-radius:var(--radius-sm);background:#242424;color:var(--text-muted);font-weight:600}.exercise-question{font-size:1.15rem;font-weight:500;color:var(--text-primary);margin-bottom:1.25rem;line-height:1.5}.options-grid{display:flex;flex-direction:column;gap:.75rem}.option-btn{display:flex;align-items:flex-start;justify-content:space-between;width:100%;padding:1rem 1.25rem;border-radius:var(--radius-md);border:1px solid var(--border-muted);background:var(--bg-charcoal);color:var(--text-primary);font-family:inherit;font-size:1rem;text-align:left;cursor:pointer;transition:all var(--transition-fast);position:relative}.option-btn:hover:not(:disabled){background:var(--bg-card-hover);border-color:#383838}.option-btn:focus-visible{outline:none;border-color:var(--accent-cyan);box-shadow:0 0 0 2px var(--accent-cyan-glow)}.option-btn.selected-correct{border-color:var(--accent-cyan);background:#00e5ff12}.option-btn.selected-wrong{border-color:var(--state-wrong-border);background:var(--state-wrong-bg)}.option-btn.highlighted-correct{border-color:var(--accent-cyan);background:#00e5ff0a}.option-text-wrapper{display:flex;flex-direction:column;gap:.4rem;flex:1}.option-label{font-weight:500;display:flex;align-items:center;gap:.5rem}.option-explanation{font-size:.85rem;line-height:1.45;padding-top:.35rem}.explanation-correct{color:#55d6e6}.explanation-wrong{color:#e09898}.written-form{display:flex;flex-direction:column;gap:1rem}.written-textarea{width:100%;min-height:90px;padding:.9rem 1rem;border-radius:var(--radius-md);border:1px solid var(--border-muted);background:var(--bg-charcoal);color:var(--text-primary);font-family:inherit;font-size:1rem;resize:vertical;transition:border-color var(--transition-fast)}.written-textarea:focus{outline:none;border-color:var(--accent-cyan);box-shadow:0 0 0 2px var(--accent-cyan-glow)}.written-actions{display:flex;justify-content:flex-end}.btn-cyan{display:inline-flex;align-items:center;justify-content:center;gap:.6rem;background:var(--accent-cyan);color:#050505;font-weight:600;font-size:.95rem;border:none;border-radius:var(--radius-md);padding:.75rem 1.4rem;cursor:pointer;transition:all var(--transition-fast)}.btn-cyan:hover:not(:disabled){background:#2fe9ff;box-shadow:0 0 15px #00e5ff59}.btn-cyan:disabled{opacity:.5;cursor:not-allowed}.loading-arch-container{display:inline-flex;align-items:center;justify-content:center}.rotating-arch{width:22px;height:22px;border:2.5px solid transparent;border-top-color:var(--accent-cyan);border-right-color:var(--accent-cyan);border-radius:50%;animation:spinArch .8s linear infinite}@keyframes spinArch{0%{transform:rotate(0)}to{transform:rotate(360deg)}}.evaluation-feedback-box{margin-top:1.25rem;padding:1.2rem;border-radius:var(--radius-md);border:1px solid var(--border-muted);background:var(--bg-charcoal);display:flex;flex-direction:column;gap:.6rem;animation:fadeIn .3s ease}.evaluation-feedback-box.correct{border-color:var(--accent-cyan-border);background:#00e5ff0d}.evaluation-feedback-box.incorrect{border-color:var(--state-wrong-border);background:var(--state-wrong-bg)}.feedback-header{display:flex;align-items:center;gap:.5rem;font-weight:600;font-size:.95rem}.feedback-header.correct{color:var(--accent-cyan)}.feedback-header.incorrect{color:#ff9f9f}.feedback-body{font-size:.9rem;line-height:1.6;color:#e5e5e5}.state-screen{text-align:center;padding:5rem 1.5rem;max-width:540px;margin:0 auto}.state-icon-wrapper{display:inline-flex;align-items:center;justify-content:center;width:72px;height:72px;border-radius:50%;background:var(--bg-charcoal);border:1px solid var(--border-muted);color:var(--accent-cyan);margin-bottom:1.5rem;box-shadow:0 0 25px #00e5ff1a}.state-title{font-size:1.75rem;font-weight:700;margin-bottom:.75rem}.state-message{color:var(--text-muted);font-size:1rem;line-height:1.6}@keyframes fadeIn{0%{opacity:0;transform:translateY(6px)}to{opacity:1;transform:translateY(0)}}