:root{--bg-primary: #1a1a2e;--bg-secondary: #16213e;--bg-tertiary: #0f3460;--bg-chat: #1e1e3a;--text-primary: #e8e8e8;--text-secondary: #a0a0b8;--accent-primary: #e94560;--accent-secondary: #533483;--accent-success: #4ecca3;--accent-warning: #f0a500;--user-bubble: #0f3460;--ai-bubble: #1a1a3e;--border-color: #2a2a4a;--input-bg: #16213e;--button-hover: #c73650;--shadow: 0 4px 20px rgba(0, 0, 0, .3)}*{margin:0;padding:0;box-sizing:border-box}body{font-family:Segoe UI,Inter,system-ui,-apple-system,sans-serif;background:var(--bg-primary);color:var(--text-primary);min-height:100vh;overflow:hidden}#root{height:100vh;display:flex;flex-direction:column}.app-container{display:flex;height:100vh;overflow:hidden}.sidebar{width:280px;min-width:280px;background:var(--bg-secondary);border-right:1px solid var(--border-color);display:flex;flex-direction:column;padding:16px;gap:12px;overflow-y:auto}.sidebar-header{display:flex;align-items:center;gap:10px;padding-bottom:16px;border-bottom:1px solid var(--border-color)}.sidebar-header h2{font-size:1.1rem;font-weight:600;color:var(--accent-primary)}.sidebar-logo{font-size:1.8rem}.btn{padding:10px 16px;border:none;border-radius:8px;cursor:pointer;font-size:.9rem;font-weight:500;transition:all .2s;display:flex;align-items:center;gap:8px;justify-content:center}.btn-primary{background:var(--accent-primary);color:#fff}.btn-primary:hover{background:var(--button-hover);transform:translateY(-1px)}.btn-secondary{background:var(--bg-tertiary);color:var(--text-primary)}.btn-secondary:hover{background:#1a4a80}.btn-outline{background:transparent;border:1px solid var(--border-color);color:var(--text-primary)}.btn-outline:hover{border-color:var(--accent-primary);color:var(--accent-primary)}.btn-small{padding:6px 12px;font-size:.8rem}.btn-full{width:100%}.btn-danger{background:transparent;border:1px solid var(--accent-primary);color:var(--accent-primary)}.btn-danger:hover{background:var(--accent-primary);color:#fff}.conversation-list{flex:1;overflow-y:auto;display:flex;flex-direction:column;gap:6px}.conversation-item{padding:10px 12px;border-radius:8px;cursor:pointer;transition:all .2s;border:1px solid transparent;font-size:.85rem;color:var(--text-secondary);white-space:nowrap;overflow:hidden;text-overflow:ellipsis}.conversation-item:hover{background:var(--bg-tertiary);border-color:var(--border-color)}.conversation-item.active{background:var(--bg-tertiary);border-color:var(--accent-primary);color:var(--text-primary)}.main-area{flex:1;display:flex;flex-direction:column;overflow:hidden}.chat-header{padding:16px 24px;background:var(--bg-secondary);border-bottom:1px solid var(--border-color);display:flex;align-items:center;justify-content:space-between;gap:12px}.chat-header h3{font-size:1rem;font-weight:500;white-space:nowrap;overflow:hidden;text-overflow:ellipsis}.chat-header-actions{display:flex;gap:8px}.messages-container{flex:1;overflow-y:auto;padding:20px 24px;display:flex;flex-direction:column;gap:16px;background:var(--bg-chat)}.message-bubble{max-width:75%;padding:12px 16px;border-radius:16px;line-height:1.5;font-size:.95rem;animation:fadeIn .3s ease;position:relative}@keyframes fadeIn{0%{opacity:0;transform:translateY(8px)}to{opacity:1;transform:translateY(0)}}.message-user{align-self:flex-end;background:var(--user-bubble);border-bottom-right-radius:4px;margin-left:auto}.message-ai{align-self:flex-start;background:var(--ai-bubble);border:1px solid var(--border-color);border-bottom-left-radius:4px}.message-role{font-size:.7rem;text-transform:uppercase;letter-spacing:.5px;color:var(--accent-primary);margin-bottom:4px;font-weight:600}.message-time{font-size:.7rem;color:var(--text-secondary);margin-top:6px;text-align:right}.correction-tag{display:inline-block;background:#f0a50033;border:1px solid var(--accent-warning);border-radius:12px;padding:2px 8px;font-size:.75rem;color:var(--accent-warning);margin-top:6px;cursor:pointer}.correction-detail{margin-top:8px;padding:8px 12px;background:#f0a5001a;border-radius:8px;font-size:.8rem;color:var(--accent-warning);border-left:3px solid var(--accent-warning)}.typing-indicator{align-self:flex-start;display:flex;gap:4px;padding:12px 16px;background:var(--ai-bubble);border:1px solid var(--border-color);border-radius:16px 16px 16px 4px}.typing-dot{width:8px;height:8px;border-radius:50%;background:var(--text-secondary);animation:typingBounce 1.4s infinite ease-in-out}.typing-dot:nth-child(1){animation-delay:0s}.typing-dot:nth-child(2){animation-delay:.2s}.typing-dot:nth-child(3){animation-delay:.4s}@keyframes typingBounce{0%,80%,to{transform:scale(.6);opacity:.4}40%{transform:scale(1);opacity:1}}.input-area{padding:16px 24px;background:var(--bg-secondary);border-top:1px solid var(--border-color);display:flex;gap:10px;align-items:flex-end}.input-wrapper{flex:1;display:flex;gap:8px;align-items:flex-end}.message-input{flex:1;padding:12px 16px;border-radius:12px;border:1px solid var(--border-color);background:var(--input-bg);color:var(--text-primary);font-size:.95rem;resize:none;min-height:44px;max-height:120px;font-family:inherit;line-height:1.4;transition:border-color .2s}.message-input:focus{outline:none;border-color:var(--accent-primary)}.message-input::placeholder{color:var(--text-secondary)}.send-btn{width:44px;height:44px;border-radius:12px;border:none;background:var(--accent-primary);color:#fff;cursor:pointer;font-size:1.2rem;display:flex;align-items:center;justify-content:center;transition:all .2s;flex-shrink:0}.send-btn:hover{background:var(--button-hover);transform:scale(1.05)}.send-btn:disabled{opacity:.5;cursor:not-allowed;transform:none}.voice-btn{width:44px;height:44px;border-radius:50%;border:2px solid var(--border-color);background:transparent;color:var(--text-secondary);cursor:pointer;font-size:1.2rem;display:flex;align-items:center;justify-content:center;transition:all .2s;flex-shrink:0}.voice-btn:hover{border-color:var(--accent-primary);color:var(--accent-primary)}.voice-btn.listening{border-color:var(--accent-primary);background:var(--accent-primary);color:#fff;animation:pulse 1.5s infinite}@keyframes pulse{0%{box-shadow:0 0 #e9456080}70%{box-shadow:0 0 0 12px #e9456000}to{box-shadow:0 0 #e9456000}}.grammar-panel{position:fixed;right:0;top:0;bottom:0;width:380px;background:var(--bg-secondary);border-left:1px solid var(--border-color);display:flex;flex-direction:column;padding:20px;gap:16px;z-index:100;box-shadow:var(--shadow);animation:slideIn .3s ease}@keyframes slideIn{0%{transform:translate(100%)}to{transform:translate(0)}}.grammar-panel-header{display:flex;justify-content:space-between;align-items:center;padding-bottom:12px;border-bottom:1px solid var(--border-color)}.grammar-panel-header h3{font-size:1rem;color:var(--accent-primary)}.grammar-content{flex:1;overflow-y:auto;display:flex;flex-direction:column;gap:12px}.grammar-question{padding:12px;background:var(--bg-chat);border-radius:8px;border:1px solid var(--border-color)}.grammar-answer-input{width:100%;padding:10px 12px;border-radius:8px;border:1px solid var(--border-color);background:var(--input-bg);color:var(--text-primary);font-size:.9rem;font-family:inherit}.grammar-feedback{padding:12px;border-radius:8px;font-size:.85rem;line-height:1.5}.grammar-feedback.correct{background:#4ecca326;border:1px solid var(--accent-success);color:var(--accent-success)}.grammar-feedback.incorrect{background:#e9456026;border:1px solid var(--accent-primary);color:var(--accent-primary)}.score-display{text-align:center;padding:16px;font-size:1.2rem}.score-number{font-size:2.5rem;font-weight:700;color:var(--accent-success)}.topic-selector{display:flex;flex-wrap:wrap;gap:8px;padding:8px 0}.topic-chip{padding:6px 14px;border-radius:20px;border:1px solid var(--border-color);background:transparent;color:var(--text-secondary);cursor:pointer;font-size:.8rem;transition:all .2s}.topic-chip:hover{border-color:var(--accent-primary);color:var(--accent-primary)}.topic-chip.selected{background:var(--accent-primary);border-color:var(--accent-primary);color:#fff}.settings-overlay{position:fixed;top:0;right:0;bottom:0;left:0;background:#0009;z-index:200;display:flex;align-items:center;justify-content:center}.settings-panel{background:var(--bg-secondary);border:1px solid var(--border-color);border-radius:16px;padding:24px;width:90%;max-width:500px;max-height:80vh;overflow-y:auto}.settings-panel h3{margin-bottom:20px;color:var(--accent-primary)}.form-group{margin-bottom:16px}.form-group label{display:block;margin-bottom:6px;font-size:.85rem;color:var(--text-secondary)}.form-group input,.form-group select,.form-group textarea{width:100%;padding:10px 12px;border-radius:8px;border:1px solid var(--border-color);background:var(--input-bg);color:var(--text-primary);font-size:.9rem;font-family:inherit}.form-group input:focus,.form-group select:focus,.form-group textarea:focus{outline:none;border-color:var(--accent-primary)}.settings-actions{display:flex;gap:10px;justify-content:flex-end;margin-top:20px}::-webkit-scrollbar{width:6px}::-webkit-scrollbar-track{background:transparent}::-webkit-scrollbar-thumb{background:var(--border-color);border-radius:3px}::-webkit-scrollbar-thumb:hover{background:var(--text-secondary)}.welcome-screen{flex:1;display:flex;flex-direction:column;align-items:center;justify-content:center;gap:20px;padding:40px;text-align:center}.welcome-screen h1{font-size:2rem;color:var(--accent-primary)}.welcome-screen p{color:var(--text-secondary);max-width:500px;line-height:1.6}.welcome-actions{display:flex;gap:12px;flex-wrap:wrap;justify-content:center}@media (max-width: 768px){.sidebar{display:none}.grammar-panel{width:100%}.message-bubble{max-width:90%}}