:root{--text: #222;--text-muted: #666;--link: #0066cc;--bg: #fff;--bg-alt: #f5f5f5;--border: #ddd;--error: #c00;--success: #060}.dark-mode{--text: #e0e0e0;--text-muted: #999;--link: #6699ff;--bg: #121212;--bg-alt: #1e1e1e;--border: #444;--error: #ff6666;--success: #6f6}*{box-sizing:border-box}body{font-family:-apple-system,BlinkMacSystemFont,Segoe UI,Roboto,Helvetica Neue,Arial,sans-serif;font-size:16px;line-height:1.6;color:var(--text);background:var(--bg);margin:0;padding:20px}:focus{outline:none}:focus-visible{outline:1px dotted var(--text-muted);outline-offset:2px}a{color:var(--link);text-decoration:none}a:hover{text-decoration:underline}h1,h2,h3,h4{margin:0 0 1rem;line-height:1.3}p{margin:0 0 1rem}ul{list-style:none;padding:0;margin:0}input,select,textarea{font-family:inherit;font-size:inherit;padding:6px 10px;border:1px solid var(--border);border-radius:3px;background:var(--bg);color:var(--text)}input:disabled,select:disabled,textarea:disabled{opacity:.6;cursor:not-allowed}button{font-family:inherit;font-size:14px;padding:6px 12px;border:1px solid var(--border);border-radius:3px;background:var(--bg);color:var(--text);cursor:pointer}button:hover:not(:disabled){background:var(--bg-alt)}button:disabled{opacity:.5;cursor:not-allowed}.hidden{display:none!important}.container{max-width:900px;margin:0 auto}.flex-row{display:flex;gap:10px;align-items:center}.flex-col{display:flex;flex-direction:column;gap:10px}.page-header{display:flex;align-items:center;gap:20px;padding:10px 0 20px;border-bottom:1px solid var(--border);margin-bottom:20px}.page-header-logo{height:36px;width:auto}.page-header h2{margin:0;flex:1}.nav-links{display:flex;gap:20px;font-size:14px}.nav-links a,.nav-links button{background:none;border:none;padding:0;color:var(--text);cursor:pointer;font-size:14px}.nav-links a:hover,.nav-links button:hover{color:var(--link)}.nav-links .disabled{color:var(--text-muted);cursor:not-allowed}.auth-links{display:flex;gap:15px;margin-top:15px}.auth-links a,.auth-links button{background:none;border:none;padding:0;color:var(--link);cursor:pointer;font-size:14px}form{display:flex;flex-direction:column;gap:10px;max-width:300px}form input{width:100%}form button[type=submit]{align-self:flex-start}.chat-box{border:1px solid var(--border);border-radius:4px;padding:15px;height:400px;overflow-y:auto;background:var(--bg);margin-bottom:15px}.message{margin-bottom:15px;padding:10px;border-radius:4px}.message.user{background:var(--bg-alt)}.message.assistant{background:var(--bg);border:1px solid var(--border)}.message.error{background:#fff0f0;border:1px solid var(--error);color:var(--error)}.dark-mode .message.error{background:#2a1a1a}.message strong{display:block;margin-bottom:5px;color:var(--text-muted);font-size:14px}.chat-input{display:flex;gap:10px}.chat-input input{flex:1}.topic-list{display:flex;flex-direction:column;gap:8px}.topic-item{padding:12px 15px;border:1px solid var(--border);border-radius:4px;cursor:pointer;display:flex;align-items:center;gap:10px}.topic-item:hover{background:var(--bg-alt)}.topic-item .status{font-size:12px;color:var(--text-muted)}.topic-item.started{border-left:3px solid var(--success)}.topic-item.not-started{border-left:3px solid var(--text-muted)}.topic-content{padding:15px;border:1px solid var(--border);border-radius:4px;background:var(--bg-alt);margin-bottom:20px}.vocab-item{padding:12px 15px;border:1px solid var(--border);border-radius:4px;margin-bottom:8px;background:var(--bg)}.vocab-item h3{margin:0 0 5px;font-size:1rem}.vocab-details{font-size:14px;color:var(--text-muted)}.vocab-actions{margin-top:10px;display:flex;gap:8px}.dashboard-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(280px,1fr));gap:20px;margin-bottom:20px}.dashboard-card{padding:20px;border:1px solid var(--border);border-radius:4px;background:var(--bg)}.dashboard-card h3{margin:0 0 15px;font-size:1rem;color:var(--text-muted)}.stat-value{font-size:2rem;font-weight:700}.review-card{padding:30px;border:1px solid var(--border);border-radius:4px;text-align:center;background:var(--bg);margin:20px 0}.flashcard-word{font-size:1.5rem;margin-bottom:20px}.flashcard-translation{font-size:1.2rem;color:var(--text-muted);margin-bottom:10px}.flashcard-example{font-size:.9rem;color:var(--text-muted);font-style:italic}.review-buttons{display:flex;gap:15px;justify-content:center;margin-top:20px}.review-stats{display:flex;gap:20px;justify-content:center;margin-top:15px;font-size:14px;color:var(--text-muted)}.srs-settings{padding:20px;border:1px solid var(--border);border-radius:4px;background:var(--bg-alt);margin:20px 0}.settings-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(200px,1fr));gap:15px;margin-top:15px}.setting-item label{display:block;margin-bottom:5px;font-size:14px;color:var(--text-muted)}.setting-item input{width:100%}.modal{position:fixed;top:0;left:0;width:100%;height:100%;background:rgba(0,0,0,.5);display:flex;justify-content:center;align-items:center;z-index:1000}.modal-content{background:var(--bg);padding:30px;border-radius:4px;max-width:500px;width:90%}.modal-buttons{display:flex;gap:10px;justify-content:flex-end;margin-top:20px}.toggle-container{display:flex;gap:15px;align-items:center}.toggle-switch{display:flex;align-items:center;gap:8px;font-size:14px}.toggle-switch input[type=checkbox]{width:18px;height:18px;cursor:pointer}.language-controls{padding:15px;border:1px solid var(--border);border-radius:4px;margin-bottom:20px;background:var(--bg-alt)}.language-stats{display:grid;grid-template-columns:repeat(auto-fit,minmax(150px,1fr));gap:15px;margin-top:15px}.vocabulary-section{padding:20px;border:1px solid var(--border);border-radius:4px;margin:20px 0;background:var(--bg)}.vocabulary-section h3{margin:0 0 15px}#batch-words{width:100%;min-height:100px;margin-bottom:15px}.conversation-history{border:1px solid var(--border);border-radius:4px;padding:15px;margin-top:20px}.conversation-history h3{margin:0 0 15px}.conversation-item{padding:10px;border-bottom:1px solid var(--border);cursor:pointer}.conversation-item:last-child{border-bottom:none}.conversation-item:hover{background:var(--bg-alt)}.loading{color:var(--text-muted);padding:20px;text-align:center}.session-summary{text-align:left;margin:20px 0}.summary-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(120px,1fr));gap:15px;margin-top:10px}.summary-item{text-align:center}.summary-label{font-size:12px;color:var(--text-muted)}.summary-value{font-size:1.5rem;font-weight:700}@media (max-width: 600px){body{padding:15px}.page-header{flex-direction:column;align-items:flex-start;gap:15px}.nav-links{flex-wrap:wrap;gap:15px}.dashboard-grid{grid-template-columns:1fr}.review-buttons,.auth-links{flex-direction:column;gap:10px}}