*{box-sizing:border-box} :root{color-scheme:light;--bg:#fff;--sidebar:#f9f9f9;--hover:#ececec;--text:#0d0d0d;--muted:#676767;--line:#e5e5e5;--card:#fff;--accent:#10a37f;--shadow:0 8px 28px rgba(0,0,0,.14)}html[data-theme=dark]{color-scheme:dark;--bg:#212121;--sidebar:#171717;--hover:#2f2f2f;--text:#ececec;--muted:#b4b4b4;--line:#424242;--card:#2f2f2f;--shadow:0 8px 28px rgba(0,0,0,.38)}html,body{height:100%;margin:0}body{font:14px/1.5 ui-sans-serif,-apple-system,BlinkMacSystemFont,"Segoe UI","PingFang SC","Microsoft YaHei",sans-serif;background:var(--bg);color:var(--text);overflow:hidden}button,input,textarea{font:inherit;color:inherit}.hidden{display:none!important}.app{height:100%;display:flex}.sidebar{width:260px;flex:0 0 260px;background:var(--sidebar);display:flex;flex-direction:column;padding:10px;transition:margin .22s ease;z-index:30}.app.sidebar-collapsed .sidebar{margin-left:-260px}.sidebar-header{display:flex;gap:5px}.new-chat-btn,.footer-btn{border:0;background:transparent;border-radius:9px;height:44px;padding:0 10px;display:flex;align-items:center;gap:10px;cursor:pointer;text-align:left}.new-chat-btn{flex:1;font-weight:600}.new-chat-btn:hover,.footer-btn:hover,.icon-btn:hover,.chat-row:hover{background:var(--hover)}.icon-btn{border:0;background:transparent;border-radius:9px;width:40px;height:40px;display:grid;place-items:center;cursor:pointer}.chat-list{flex:1;overflow-y:auto;padding-top:18px}.chat-day{font-size:12px;color:var(--muted);padding:8px}.chat-row{height:42px;border-radius:9px;padding:0 8px;display:flex;align-items:center;cursor:pointer;gap:4px}.chat-row.active{background:var(--hover)}.chat-title{white-space:nowrap;overflow:hidden;text-overflow:ellipsis;flex:1}.chat-actions{display:none;gap:1px}.chat-row:hover .chat-actions,.chat-row.active .chat-actions{display:flex}.mini-btn{width:27px;height:27px;border:0;background:transparent;border-radius:6px;cursor:pointer;color:var(--muted)}.mini-btn:hover{background:var(--card);color:var(--text)}.sidebar-footer{border-top:1px solid var(--line);padding-top:8px}.footer-btn{width:100%}.main{min-width:0;position:relative;flex:1;display:flex;flex-direction:column;background:var(--bg)}.topbar{height:56px;flex:0 0 56px;display:flex;align-items:center;padding:0 14px;position:relative;z-index:20}.model-picker{position:relative}.model-btn{border:0;background:transparent;border-radius:10px;padding:8px 10px;font-size:18px;font-weight:600;display:flex;align-items:center;gap:6px;cursor:pointer}.model-btn:hover{background:var(--hover)}.model-menu{position:absolute;top:45px;left:0;width:280px;max-height:min(480px,70vh);overflow:auto;background:var(--card);border:1px solid var(--line);box-shadow:var(--shadow);border-radius:14px;padding:7px}.model-option{border:0;background:transparent;width:100%;border-radius:9px;padding:10px;display:flex;align-items:center;justify-content:space-between;cursor:pointer;text-align:left}.model-option:hover,.model-option.active{background:var(--hover)}.model-option strong{display:block}.model-option small{color:var(--muted)}.badge{font-size:11px;border:1px solid var(--line);border-radius:6px;padding:1px 5px}.topbar-right{margin-left:auto}.chat-container{flex:1;min-height:0;overflow-y:auto;scroll-behavior:smooth}.welcome{min-height:100%;display:grid;place-items:center;padding-bottom:100px}.welcome-title{font-size:32px;letter-spacing:-.7px;margin:0;font-weight:600}.messages{width:min(768px,100%);margin:auto;padding:18px 18px 180px}.message{margin:18px 0;display:flex;flex-direction:column}.message.user{align-items:flex-end}.bubble{max-width:85%;word-break:break-word}.user .bubble{background:var(--hover);border-radius:20px;padding:10px 16px}.assistant .bubble{max-width:100%;font-size:15px;line-height:1.75}.bubble p{margin:.4em 0 1em}.bubble p:last-child{margin-bottom:.4em}.bubble h1,.bubble h2,.bubble h3{line-height:1.3;margin:1.2em 0 .5em}.bubble ul,.bubble ol{padding-left:25px}.bubble blockquote{border-left:3px solid var(--line);margin:1em 0;padding-left:12px;color:var(--muted)}.bubble a{color:#0b7dda}.bubble code{font-family:ui-monospace,SFMono-Regular,Menlo,monospace;background:var(--hover);padding:2px 5px;border-radius:5px}.code-wrap{margin:14px 0;border:1px solid var(--line);border-radius:10px;overflow:hidden;background:#0d0d0d;color:#eee}.code-head{height:38px;display:flex;align-items:center;justify-content:space-between;padding:0 12px;background:#242424;color:#b4b4b4;font-size:12px}.copy-code{border:0;background:transparent;color:#ddd;cursor:pointer}.code-wrap pre{margin:0;padding:14px;overflow:auto}.code-wrap code{padding:0;background:none;color:inherit}.message-tools{display:flex;gap:3px;margin-top:6px;opacity:0;transition:.15s}.message:hover .message-tools{opacity:1}.tool-btn{border:0;background:transparent;color:var(--muted);border-radius:7px;padding:5px 8px;cursor:pointer}.tool-btn:hover{background:var(--hover);color:var(--text)}.typing:after{content:'●';display:inline-block;animation:blink 1s infinite;color:var(--muted)}@keyframes blink{50%{opacity:.2}}.composer-wrap{position:absolute;left:0;right:0;bottom:0;padding:18px max(16px,calc((100% - 768px)/2));background:linear-gradient(transparent,var(--bg) 24%)}.composer{background:var(--card);border:1px solid var(--line);box-shadow:0 2px 12px rgba(0,0,0,.08);border-radius:27px;display:flex;align-items:flex-end;padding:10px 10px 10px 18px}.composer:focus-within{border-color:#b7b7b7}.composer textarea{border:0;outline:0;resize:none;background:transparent;max-height:180px;min-height:24px;line-height:24px;flex:1;padding:3px 8px 3px 0}.send-btn{border:0;border-radius:50%;background:var(--text);color:var(--bg);width:34px;height:34px;display:grid;place-items:center;cursor:pointer;flex:0 0 34px}.send-btn:disabled{opacity:.2;cursor:default}.send-btn.stop svg{display:none}.send-btn.stop:after{content:'';width:10px;height:10px;border-radius:2px;background:currentColor}.disclaimer{text-align:center;font-size:12px;color:var(--muted);margin:7px 0 -9px}.login-overlay{position:fixed;inset:0;z-index:100;background:var(--bg);display:grid;place-items:center;padding:20px}.login-card{width:min(390px,100%);text-align:center}.login-logo{color:var(--text);margin-bottom:18px}.login-card h1{font-size:28px;margin:0 0 6px}.login-sub{color:var(--muted);margin:0 0 24px}.login-card input{width:100%;height:54px;border:1px solid var(--line);border-radius:9px;background:var(--bg);padding:0 14px;outline:0}.login-card input:focus{border-color:var(--accent);box-shadow:0 0 0 1px var(--accent)}.login-card button{width:100%;height:52px;margin-top:12px;border:0;border-radius:9px;background:var(--accent);color:white;font-weight:600;cursor:pointer}.login-error{color:#d00;font-size:13px;text-align:left;margin-top:7px}.mobile-backdrop{display:none}
@media(max-width:700px){.sidebar{position:fixed;inset:0 auto 0 0;width:280px;box-shadow:var(--shadow)}.app.sidebar-collapsed .sidebar{margin-left:-290px}.app:not(.sidebar-collapsed):after{content:'';position:fixed;inset:0;background:rgba(0,0,0,.35);z-index:25}.topbar{padding:0 8px}.model-btn{font-size:16px}.welcome-title{font-size:26px}.messages{padding:5px 13px 155px}.bubble{max-width:92%}.composer-wrap{padding:16px 10px 10px}.disclaimer{font-size:10px}.collapse-btn{display:grid}}@media(min-width:701px){.app:not(.sidebar-collapsed) #open-sidebar-btn{display:none}}.composer-tool{border:0;background:transparent;border-radius:50%;width:34px;height:34px;display:grid;place-items:center;cursor:pointer;flex:0 0 34px;color:var(--muted);margin-right:7px}.composer-tool:hover{background:var(--hover);color:var(--text)}.composer-tool.active{background:#e7f5ff;color:#0877d1}.image-grid{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:8px;margin-top:8px;max-width:680px}.image-card{position:relative;border-radius:16px;overflow:hidden;background:var(--hover);min-height:240px}.image-card.single{grid-column:1/-1}.image-card img{display:block;width:100%;height:auto;object-fit:cover}.image-card.loading{aspect-ratio:1;background:linear-gradient(100deg,var(--hover) 20%,var(--card) 40%,var(--hover) 60%);background-size:200% 100%;animation:shimmer 1.4s infinite}.image-actions{position:absolute;right:10px;bottom:10px;display:flex;gap:6px;opacity:0;transition:.15s}.image-card:hover .image-actions{opacity:1}.image-action{border:1px solid rgba(255,255,255,.35);background:rgba(20,20,20,.75);backdrop-filter:blur(8px);color:#fff;border-radius:9px;padding:7px 10px;text-decoration:none;cursor:pointer}.image-caption{color:var(--muted);font-size:12px;margin-top:8px}.image-status{display:flex;align-items:center;gap:9px;color:var(--muted);padding:8px 0}.image-status:before{content:'';width:16px;height:16px;border:2px solid var(--line);border-top-color:var(--text);border-radius:50%;animation:spin .8s linear infinite}@keyframes shimmer{to{background-position:-200% 0}}@keyframes spin{to{transform:rotate(360deg)}}
/* ChatGPT-style multimodal composer */
.composer{position:relative;padding:10px}.composer textarea{padding:5px 8px}.composer-tool{margin-right:0}.attach-btn{border:1px solid var(--line)}.mic-btn{margin-right:4px}.mic-btn.recording{color:#e5484d;background:#ffe9ea;animation:micpulse 1.2s infinite}.attach-menu{position:absolute;left:0;bottom:48px;width:238px;padding:7px;background:var(--card);border:1px solid var(--line);border-radius:16px;box-shadow:var(--shadow);z-index:40}.attach-menu button{width:100%;height:46px;border:0;background:transparent;border-radius:10px;display:flex;align-items:center;gap:13px;padding:0 12px;cursor:pointer;text-align:left}.attach-menu button:hover,.attach-menu button.active{background:var(--hover)}.attach-menu svg{width:21px;height:21px;fill:none;stroke:currentColor;stroke-width:1.8}.upload-preview{max-width:768px;margin:0 auto 8px}.upload-chip{position:relative;width:250px;max-width:100%;height:64px;background:var(--card);border:1px solid var(--line);border-radius:14px;padding:7px;display:flex;gap:9px;align-items:center;box-shadow:0 2px 8px rgba(0,0,0,.07)}.upload-chip img{width:48px;height:48px;object-fit:cover;border-radius:9px}.upload-chip div{min-width:0;display:flex;flex-direction:column}.upload-chip strong{white-space:nowrap;overflow:hidden;text-overflow:ellipsis;font-size:13px}.upload-chip small{color:var(--muted)}.upload-chip button{position:absolute;right:-7px;top:-7px;width:22px;height:22px;border:1px solid var(--line);background:var(--card);border-radius:50%;cursor:pointer}.sent-attachment{display:flex;align-items:center;gap:8px;margin-bottom:7px;font-size:12px;color:var(--muted)}.sent-attachment img{width:120px;max-height:120px;object-fit:cover;border-radius:12px}@keyframes micpulse{50%{box-shadow:0 0 0 5px rgba(229,72,77,.12)}}