:root{--primary-bg: #ffffff;--secondary-bg: #f7f7f8;--text-color: #111111;--text-secondary: #666666;--border-color: #f4f4f4;--accent-color: #ff4d6b;--sidebar-width: 260px;--header-height: 64px}body{margin:0;padding:0;font-family:-apple-system,BlinkMacSystemFont,Inter,Segoe UI,Roboto,Helvetica Neue,sans-serif;background-color:var(--primary-bg);color:var(--text-color);overflow-x:hidden;-webkit-font-smoothing:antialiased}.app-container.app{display:flex;height:100vh;width:100vw;overflow:hidden}.sidebar{position:fixed;top:0;left:0;height:100vh;width:var(--sidebar-width);background-color:var(--primary-bg);border-right:1px solid var(--border-color);display:flex;flex-direction:column;z-index:10}.sidebar.open{width:var(--sidebar-width)}.sidebar.collapsed{width:var(--sidebar-collapsed)}.user-profile{display:flex;align-items:center;gap:12px;padding:16px;border-bottom:none}.avatar{width:32px;height:32px;border-radius:50%}.new-chat-btn{display:flex;align-items:center;gap:8px;margin:16px;padding:8px 12px;border:1px solid var(--border-color);border-radius:20px;background:none;color:var(--text-color);font-size:14px;cursor:pointer;width:calc(100% - 32px)}.new-chat-btn:hover{background-color:var(--secondary-bg)}.sidebar-header h2{margin:0;font-size:1.25rem;white-space:nowrap;opacity:1;transition:opacity .2s ease}.sidebar.collapsed .sidebar-header h2{opacity:0;width:0;overflow:hidden}.menu-toggle{background:none;border:none;color:var(--sidebar-text);cursor:pointer;padding:.5rem;border-radius:4px;display:flex;align-items:center;justify-content:center}.menu-toggle:hover{background-color:var(--sidebar-hover)}.sidebar-footer{border-top:none;padding:16px}.footer-btn{display:flex;align-items:center;gap:8px;width:100%;padding:8px 0;border:none;background:none;color:var(--text-secondary);font-size:14px;text-align:left;cursor:pointer}.footer-btn:hover{color:var(--text-color)}.nav-item{display:flex;align-items:center;gap:.75rem;width:70%;padding:.75rem 1rem;border:none;background:none;color:var(--sidebar-text);text-align:left;border-radius:4px;cursor:pointer;transition:background-color .2s ease;white-space:nowrap}.nav-item:hover{background-color:var(--sidebar-hover)}.nav-item.active{background-color:var(--sidebar-hover);font-weight:500}.nav-icon{flex-shrink:0;font-size:1.25rem}.main-content{margin-left:var(--sidebar-width);width:calc(100% - var(--sidebar-width));min-height:100vh;display:flex;flex-direction:column;transition:margin-left .3s ease,width .3s ease}.sidebar.collapsed+.main-content{margin-left:var(--sidebar-collapsed);width:calc(100% - var(--sidebar-collapsed))}.chat-header{padding:0;height:var(--header-height);border-bottom:1px solid var(--border-color);display:flex;align-items:center;justify-content:space-between;background-color:var(--primary-bg);position:sticky;top:0;z-index:20}.model-select{margin-left:24px;position:relative;z-index:30}.model-list{position:absolute;top:100%;left:0;right:0;margin-top:4px;background:white;border:1px solid var(--border-color);border-radius:8px;box-shadow:0 4px 12px #0000001a;overflow:hidden}.model-option{padding:10px 12px;font-size:13px;cursor:pointer;transition:all .15s ease}.model-option:hover:not(.disabled){background:var(--secondary-bg)}.model-option.selected{background:var(--secondary-bg);font-weight:500}.model-option.disabled{opacity:.5;cursor:not-allowed;font-style:italic}.model-dropdown{font-size:13px;color:var(--text-color);font-weight:500;padding:8px 32px 8px 12px;background:var(--secondary-bg);border-radius:8px;border:1px solid transparent;cursor:pointer;width:100%;text-align:left;background-image:url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='16' height='16' viewBox='0 0 24 24' fill='none' stroke='currentColor' stroke-width='2' stroke-linecap='round' stroke-linejoin='round'%3E%3Cpolyline points='6 9 12 15 18 9'%3E%3C/polyline%3E%3C/svg%3E");background-repeat:no-repeat;background-position:right 8px center;transition:all .15s ease;outline:none}.model-dropdown:focus{border-color:var(--accent-color)}.model-dropdown.open{border-color:var(--accent-color);background-color:#fff}.model-dropdown::-ms-expand{display:none}.model-dropdown::-webkit-scrollbar{width:8px}.model-dropdown::-webkit-scrollbar-track{background:transparent}.model-dropdown::-webkit-scrollbar-thumb{background-color:var(--border-color);border-radius:4px}select.model-dropdown{-webkit-appearance:none;-moz-appearance:none}select.model-dropdown::-ms-expand{display:none}select.model-dropdown option{background:white;color:var(--text-color);padding:12px;font-size:13px;border:none;outline:none}select.model-dropdown option:hover{background:var(--secondary-bg)}select.model-dropdown option:checked{background:var(--secondary-bg);color:var(--text-color)}select.model-dropdown option:disabled{color:var(--text-secondary);font-style:italic;background:white}.model-dropdown:hover{background-color:var(--secondary-bg);border-color:var(--border-color)}.model-dropdown:focus{border-color:var(--accent-color);background-color:#fff}.model-dropdown option{color:var(--text-color);background:white;padding:12px;font-size:13px;z-index:30;position:relative;border-radius:6px}.model-dropdown option:checked{background:var(--secondary-bg);color:var(--text-color)}.model-dropdown option:disabled{color:var(--text-secondary);font-style:italic}.header-actions{display:flex;gap:12px;margin-right:48px}.header-btn{padding:6px 12px;border:1px solid var(--border-color);border-radius:20px;background:none;color:var(--text-color);font-size:14px;cursor:pointer}.header-btn.share-btn{background-color:var(--accent-color);border-color:var(--accent-color);color:#fff}.header-btn:hover{background-color:var(--secondary-bg)}.header-btn.share-btn:hover{opacity:.9;background-color:var(--accent-color)}.mobile-menu-toggle{display:none;background:none;border:none;font-size:1.25rem;margin-right:1rem;cursor:pointer}.main-content{margin-left:var(--sidebar-width);width:calc(100% - var(--sidebar-width));display:flex;flex-direction:column;min-height:100vh;position:relative;overflow-y:auto}.chat-container{flex:1;width:100%;max-width:1200px;margin:0 auto;padding:24px 32px 100px;display:flex;flex-direction:column;box-sizing:border-box}.chat-header h1{margin:0;font-size:1.25rem;font-weight:500;flex:1;text-align:center}.chat-messages{flex:1;overflow-y:auto;padding:8px 0;width:100%;box-sizing:border-box;max-width:960px;margin:0 auto}.date-label{padding:0 24px;margin:24px 0 8px;font-size:11px;font-weight:500;color:var(--text-secondary);text-transform:uppercase;letter-spacing:.5px}.chat-item{display:block;width:calc(100% - 48px);margin:1px 24px;padding:8px 12px;border:none;background:none;text-align:left;color:var(--text-color);font-size:13px;cursor:pointer;line-height:1.4;border-radius:10px;transition:all .15s ease;white-space:nowrap;overflow:hidden;text-overflow:ellipsis;opacity:.9}.chat-item:hover,.chat-item.active{opacity:1;background-color:var(--secondary-bg);transform:translate(2px)}.welcome-message{text-align:center;margin:auto;padding:32px;max-width:600px}.welcome-message h2{margin-bottom:16px;font-size:24px;font-weight:500;color:var(--text-color)}.welcome-message p{color:var(--text-secondary);font-size:16px;line-height:1.5}.loading-indicator{align-self:flex-start;margin:12px 0;font-size:14px;color:var(--text-secondary);opacity:.7;padding-left:32px}.loading-dots:after{display:inline-block;animation:dots 1.4s steps(4,end) infinite;content:""}@keyframes dots{0%{content:""}25%{content:"."}50%{content:".."}75%{content:"..."}to{content:""}}.input-wrapper{position:fixed;bottom:0;left:var(--sidebar-width);right:0;padding:24px;background-color:var(--primary-bg);border-top:1px solid var(--border-color);z-index:100}.chat-input-container{display:flex;align-items:center;max-width:800px;margin:0 auto;width:100%;position:relative}.chat-input{width:100%;padding:16px 48px 16px 16px;border:1px solid var(--border-color);border-radius:30px;font-size:14px;line-height:20px;outline:none;transition:border-color .2s ease}.chat-input:focus{border-color:#000}.send-button{position:absolute;right:12px;top:50%;transform:translateY(-50%);padding:4px;background:none;border:none;color:#666;cursor:pointer;display:flex;align-items:center;justify-content:center;transition:color .2s ease}.send-button:hover:not(:disabled){color:#000}.send-button:disabled{opacity:.5;cursor:not-allowed}@media (max-width: 768px){.input-wrapper{left:0;padding:16px}.sidebar{transform:translate(-100%);width:80%;max-width:300px}.sidebar.open{transform:translate(0)}.main-content{margin-left:0!important;width:100%!important}.mobile-menu-toggle{display:block}.chat-container{padding:0 1rem 1rem}.welcome-message h2{font-size:1.5rem}}.chat-message{display:flex;width:100%;padding:4px 0;box-sizing:border-box}.message-content{max-width:65%;padding:12px 16px;border-radius:12px;font-size:14px;line-height:1.5;white-space:pre-wrap;margin:0;box-shadow:0 1px 2px #0000000d}.chat-message.user{justify-content:flex-end}.chat-message.user .message-content{background-color:#e3f2fd;color:#000;border-bottom-right-radius:4px;margin-left:auto}.chat-message.bot .message-content{background-color:#f5f5f5;color:#000;border-bottom-left-radius:4px;margin-right:auto}.error-message{color:#ff4d4f;font-style:italic}.message.error .message-content{background-color:#ffebee;color:#c62828}*{box-sizing:border-box;margin:0;padding:0}body{font-family:-apple-system,BlinkMacSystemFont,Segoe UI,Roboto,Oxygen,Ubuntu,Cantarell,Open Sans,Helvetica Neue,sans-serif;-webkit-font-smoothing:antialiased;-moz-osx-font-smoothing:grayscale}code{font-family:source-code-pro,Menlo,Monaco,Consolas,Courier New,monospace}