:root{--bg-main: #212121;--bg-sidebar: #171717;--bg-surface: #2f2f2f;--bg-hover: #424242;--border-color: rgba(255, 255, 255, .1);--text-primary: #ececec;--text-muted: #b4b4b4;--accent: #10a37f;--accent-hover: #1a7f64;--sidebar-width: 260px;--header-height: 56px;--input-max-height: 200px}*{box-sizing:border-box;margin:0;padding:0}body,html{height:100%;width:100%;font-family:Inter,-apple-system,sans-serif;background-color:var(--bg-main);color:var(--text-primary);overflow:hidden}.app-container{display:flex;height:100vh;width:100vw;overflow:hidden}.sidebar{width:var(--sidebar-width);background-color:var(--bg-sidebar);display:flex;flex-direction:column;flex-shrink:0;transition:transform .3s ease;z-index:100}.sidebar-header{padding:12px}.btn-new-chat{display:flex;align-items:center;justify-content:space-between;width:100%;padding:10px 12px;border-radius:8px;background:transparent;color:var(--text-primary);border:none;font-weight:500;font-size:14px;cursor:pointer;transition:background .2s}.btn-new-chat:hover{background:var(--bg-hover)}.new-chat-icon-container{display:flex;align-items:center;gap:12px}.sidebar-history{flex:1;overflow-y:auto;padding:0 12px}.history-item{padding:10px;border-radius:8px;font-size:14px;color:var(--text-primary);cursor:pointer;white-space:nowrap;overflow:hidden;text-overflow:ellipsis;margin-bottom:4px}.history-item:hover{background:var(--bg-hover)}.history-item.active{background:var(--bg-hover);font-weight:600}.sidebar-footer{padding:12px}.auth-card{display:flex;align-items:center;justify-content:space-between;padding:10px 12px;border-radius:8px;cursor:pointer;text-decoration:none;color:var(--text-primary);transition:background .2s}.auth-card:hover{background:var(--bg-hover)}.auth-profile{display:flex;align-items:center;gap:12px;font-size:14px;font-weight:600}.avatar{width:32px;height:32px;border-radius:50%;object-fit:cover}.chat-area{flex:1;display:flex;flex-direction:column;background:var(--bg-main);position:relative;min-width:0}.chat-header{height:var(--header-height);padding:0 16px;display:flex;align-items:center;justify-content:space-between}.model-selector-wrapper{display:flex;align-items:center;gap:8px;padding:8px 12px;border-radius:8px;cursor:pointer;color:var(--text-muted);font-size:18px;font-weight:600}.model-selector-wrapper:hover{background:var(--bg-surface);color:var(--text-primary)}.btn-icon{background:transparent;border:none;color:var(--text-muted);cursor:pointer;padding:8px;border-radius:6px;display:flex;align-items:center;justify-content:center}.btn-icon:hover{color:var(--text-primary);background:var(--bg-surface)}.mobile-only{display:none}.messages-container{flex:1;overflow-y:auto;display:flex;flex-direction:column;scroll-behavior:smooth;padding:0 24px}.chat-content-inner{max-width:800px;margin:0 auto;width:100%}.empty-state{display:flex;flex-direction:column;align-items:center;justify-content:center;height:60vh;text-align:center;color:var(--text-muted)}.empty-logo{width:48px;height:48px;border-radius:24px;background:#fff;display:flex;align-items:center;justify-content:center;margin-bottom:24px;color:#171717}.message-row{display:flex;width:100%;margin-bottom:24px}.message-row.user{justify-content:flex-end}.message-row.ai{justify-content:flex-start}.message-bubble{max-width:80%;display:flex;gap:16px}.message-bubble.user .msg-content{background:var(--bg-surface);padding:12px 16px;border-radius:24px;color:var(--text-primary);font-size:15px;line-height:1.6}.message-bubble.ai{width:100%;max-width:100%}.msg-avatar{width:32px;height:32px;border-radius:16px;display:flex;align-items:center;justify-content:center;flex-shrink:0;border:1px solid var(--border-color)}.msg-avatar.ai{background:#fff;color:#171717;border:none}.msg-content.ai-text{flex:1;font-size:16px;line-height:1.6;color:var(--text-primary);min-width:0;padding-top:4px}.msg-content p{margin-bottom:12px}.msg-content p:last-child{margin-bottom:0}.msg-content pre{background:#000;padding:12px;border-radius:8px;overflow-x:auto;margin:12px 0}.msg-content code{font-family:monospace;background:#ffffff1a;padding:2px 4px;border-radius:4px}.msg-content pre code{background:transparent;padding:0}.msg-content img{max-width:100%;border-radius:8px;margin-top:12px}.input-container{padding:0 24px 24px;width:100%}.input-box-wrapper{max-width:800px;margin:0 auto;background:var(--bg-surface);border:1px solid var(--border-color);border-radius:24px;padding:10px 16px;display:flex;align-items:flex-end;gap:12px}.input-box-wrapper:focus-within{border-color:#ffffff4d}textarea{flex:1;background:transparent;border:none;color:var(--text-primary);font-family:inherit;font-size:16px;line-height:1.5;resize:none;max-height:var(--input-max-height);outline:none;padding:6px 0}textarea::placeholder{color:var(--text-muted)}.send-btn{background:#fff;color:#171717;border:none;border-radius:50%;width:32px;height:32px;display:flex;align-items:center;justify-content:center;cursor:pointer;flex-shrink:0;margin-bottom:2px;transition:opacity .2s}.send-btn:disabled{background:var(--bg-hover);color:var(--text-muted);cursor:not-allowed}.send-btn:not(:disabled):hover{opacity:.8}.input-footer{text-align:center;font-size:12px;color:var(--text-muted);margin-top:12px}.input-footer a{color:var(--text-primary);text-decoration:underline}.modal{position:fixed;top:0;left:0;right:0;bottom:0;background:#0009;display:flex;align-items:center;justify-content:center;z-index:1000;-webkit-backdrop-filter:blur(2px);backdrop-filter:blur(2px)}.modal.hidden{display:none}.modal-content{background:var(--bg-main);border:1px solid var(--border-color);padding:32px;border-radius:16px;width:100%;max-width:400px;text-align:center;box-shadow:0 20px 40px #00000080}.modal-content h3{margin-bottom:12px}.modal-content p{color:var(--text-muted);margin-bottom:24px}.modal-actions{display:flex;gap:12px;justify-content:center}.btn-primary{background:#fff;color:#171717;border:none;padding:10px 16px;border-radius:6px;font-weight:600;text-decoration:none;cursor:pointer}.btn-ghost{background:transparent;color:var(--text-primary);border:1px solid var(--border-color);padding:10px 16px;border-radius:6px;font-weight:600;cursor:pointer}@media (max-width: 768px){.sidebar{position:absolute;top:0;bottom:0;left:0;transform:translate(-100%);width:280px}.sidebar.open{transform:translate(0)}.mobile-only{display:block}.chat-area{width:100%}.mobile-overlay{position:fixed;top:0;left:0;right:0;bottom:0;background:#00000080;z-index:99;display:none}.mobile-overlay.active{display:block}}.sr-only{position:absolute;width:1px;height:1px;padding:0;margin:-1px;overflow:hidden;clip:rect(0,0,0,0);white-space:nowrap;border:0}