.language-selector-overlay{position:fixed;top:0;left:0;width:100%;height:100%;background-color:#000000b3;display:flex;justify-content:center;align-items:center;z-index:1000}.language-selector-modal{background-color:#fff;padding:2rem;border-radius:8px;text-align:center}.dark-mode .language-selector-modal{background-color:#2d3748;color:#fff}.language-buttons button{background-color:#4a90e2;color:#fff;border:none;padding:10px 20px;margin:5px;border-radius:5px;cursor:pointer;font-size:1rem}.language-buttons button:hover{background-color:#357abd}.suggestion-buttons{margin-top:15px;display:flex;flex-wrap:wrap;gap:10px}.suggestion-buttons button{background-color:transparent;border:1px solid #4a90e2;color:#4a90e2;padding:8px 12px;border-radius:20px;cursor:pointer;transition:background-color .3s,color .3s}.suggestion-buttons button:hover{background-color:#4a90e2;color:#fff}.dark-mode .suggestion-buttons button{border-color:#63b3ed;color:#63b3ed}.dark-mode .suggestion-buttons button:hover{background-color:#63b3ed;color:#1a202c}:root{--primary-color: #4a6fa5;--secondary-color: #166d67;--text-color: #333;--bg-color: #f5f5f5;--sidebar-bg: #ffffff;--message-user-bg: #e3f2fd;--message-ai-bg: #f1f1f1;--input-bg: #ffffff;--border-color: #e0e0e0;--shadow-color: rgba(0, 0, 0, .1)}.dark{--primary-color: #5d8acd;--secondary-color: #1da598;--text-color: #e0e0e0;--bg-color: #121212;--sidebar-bg: #1e1e1e;--message-user-bg: #2d3a4b;--message-ai-bg: #2a2a2a;--input-bg: #2d2d2d;--border-color: #444;--shadow-color: rgba(0, 0, 0, .3)}*{box-sizing:border-box;margin:0;padding:0}body{font-family:Segoe UI,Tahoma,Geneva,Verdana,sans-serif;line-height:1.6;color:var(--text-color);background-color:var(--bg-color)}.material-icons{font-family:Material Icons;font-weight:400;font-style:normal;font-size:24px;line-height:1;letter-spacing:normal;text-transform:none;display:inline-block;white-space:nowrap;word-wrap:normal;direction:ltr;-webkit-font-feature-settings:"liga";-webkit-font-smoothing:antialiased}.app-container{display:flex;height:100vh;transition:background-color .3s ease;width:100%}.sidebar{width:300px;background-color:var(--sidebar-bg);border-right:1px solid var(--border-color);display:flex;flex-direction:column;transition:transform .3s ease;z-index:100}.main-content{flex:1;display:flex;flex-direction:column;overflow:hidden;height:100vh;transition:background-color .3s ease;width:100%}.book-sidebar{width:300px;background-color:var(--sidebar-bg);border-left:1px solid var(--border-color);display:flex;flex-direction:column;transition:transform .3s ease;z-index:100}.mobile-menu-btn{display:none;top:10px;left:10px;background:none;color:#fff;border:none;border-radius:50%;width:40px;height:40px;z-index:1000;cursor:pointer}.mobile-overlay{position:fixed;top:0;left:0;right:0;bottom:0;background-color:#00000080;z-index:99}@media (min-width: 768px){.close-btn{display:none}}@media (max-width: 768px){.mobile-menu-btn{display:block}.close-btn{display:none}.sidebar,.book-sidebar{position:fixed;top:0;bottom:0;transform:translate(-100%)}.sidebar.mobile-visible{transform:translate(0)}.book-sidebar{right:0;left:auto;transform:translate(100%)}.book-sidebar.mobile-visible{transform:translate(0)}}.sidebar-header{padding:20px;border-bottom:1px solid var(--border-color)}.new-chat-btn{display:flex;align-items:center;justify-content:center;width:100%;padding:10px;margin-top:10px;background-color:var(--primary-color);color:#fff;border:none;border-radius:4px;cursor:pointer;transition:background-color .2s}.new-chat-btn:hover{background-color:var(--secondary-color)}.chat-list{flex:1;overflow-y:auto;padding:10px 0}.chat-item{display:flex;align-items:center;padding:12px 20px;cursor:pointer;transition:background-color .2s}.chat-item:hover{background-color:#0000000d}.chat-item.active{background-color:#0000001a}.chat-title{flex:1;margin-left:10px;white-space:nowrap;overflow:hidden;text-overflow:ellipsis}.delete-chat{background:none;border:none;color:#888;cursor:pointer;opacity:0;transition:opacity .2s}.chat-item:hover .delete-chat{opacity:1}.sidebar-footer{padding:15px;border-top:1px solid var(--border-color)}.theme-toggle{display:flex;align-items:center;justify-content:center;width:100%;padding:8px;background:none;border:1px solid var(--border-color);border-radius:4px;color:var(--text-color);cursor:pointer}.chat-container{display:flex;flex-direction:column;height:100vh}.chat-header{padding:15px 20px;border-bottom:1px solid var(--border-color);display:flex;justify-content:space-between;align-items:center}.book-btn{display:flex;align-items:center;background-color:var(--primary-color);color:#fff;border:none;border-radius:4px;padding:8px 12px;cursor:pointer}.messages-container{flex:1;overflow-y:auto;padding:20px}.message{margin-bottom:20px;max-width:80%}.message.user{margin-left:auto}.message.assistant{margin-right:auto}.message-content{padding:12px 16px;border-radius:8px;background-color:var(--message-user-bg)}.message.assistant .message-content{background-color:var(--message-ai-bg)}.message-header{display:flex;align-items:center;margin-bottom:8px;font-weight:700}.message-header span:first-child{margin-right:8px}.message-text{line-height:1.6}.message-text code{background-color:#0000001a;padding:2px 4px;border-radius:3px;font-family:monospace}.input-container{display:flex;padding:15px;border-top:1px solid var(--border-color)}.input-container textarea{flex:1;padding:12px;border:1px solid var(--border-color);border-radius:4px;resize:none;min-height:50px;max-height:150px;background-color:var(--input-bg);color:var(--text-color)}.send-btn{margin-left:10px;background-color:var(--primary-color);color:#fff;border:none;border-radius:4px;width:50px;cursor:pointer}.typing-indicator{display:flex;padding:10px 0}.typing-indicator span{height:8px;width:8px;margin:0 2px;background-color:var(--text-color);border-radius:50%;display:inline-block;opacity:.4}.typing-indicator span:nth-child(1){animation:typing 1s infinite}.typing-indicator span:nth-child(2){animation:typing 1s infinite .2s}.typing-indicator span:nth-child(3){animation:typing 1s infinite .4s}@keyframes typing{0%{opacity:.4;transform:translateY(0)}50%{opacity:1;transform:translateY(-5px)}to{opacity:.4;transform:translateY(0)}}.book-sidebar-header{padding:20px;border-bottom:1px solid var(--border-color);display:flex;justify-content:space-between;align-items:center}.close-btn{background:none;border:none;color:var(--text-color);cursor:pointer}.chapters-container{flex:1;overflow-y:auto;padding:15px}.chapter-item{margin-bottom:10px}.chapter-btn{width:100%;padding:10px;text-align:left;background-color:var(--primary-color);color:#fff;border:none;border-radius:4px;cursor:pointer;transition:background-color .2s;font-size:1.15rem}.chapter-btn:hover{background-color:var(--secondary-color)}.subchapters{margin-top:5px;margin-left:15px}.subchapter-btn{width:100%;padding:8px;text-align:left;background-color:#0000001a;color:var(--text-color);border:none;border-radius:4px;margin-top:5px;cursor:pointer;transition:background-color .2s;font-size:1.15rem}.subchapter-btn:hover{background-color:#0003}.welcome-screen{display:flex;flex-direction:column;align-items:center;justify-content:center;height:100vh;text-align:center;padding:20px}.welcome-screen h1{margin-bottom:20px;color:var(--primary-color)}.welcome-screen p{margin-bottom:30px;max-width:500px}.generating-chapters{display:flex;align-items:center;padding:10px;color:var(--text-color)}.generating-chapters .material-icons{margin-right:10px;animation:spin 1s linear infinite}@keyframes spin{0%{transform:rotate(0)}to{transform:rotate(360deg)}}.no-chats-placeholder{display:flex;flex-direction:column;justify-content:center;align-items:center;height:100%;text-align:center;color:var(--text-color-primary);padding:2rem}.no-chats-placeholder .book-icon{font-size:6rem;color:var(--primary-color);opacity:.7}.no-chats-placeholder h2{margin-top:1.5rem;font-size:1.8rem;font-weight:600}.no-chats-placeholder p{margin-top:.5rem;font-size:1.1rem;max-width:400px;color:var(--text-color-secondary)}.new-chat-btn-main{margin-top:2rem;padding:12px 24px;border-radius:8px;border:none;background-color:var(--primary-color);color:#fff;font-size:1rem;font-weight:500;display:flex;align-items:center;gap:8px;cursor:pointer;transition:background-color .3s ease}.new-chat-btn-main:hover{transform:scale(.98)}.lightmenu{color:#000}.darkmenu{color:#fff}.message-header *{margin-right:1rem;color:var(--primary-color)}