:root{--bg: #fcfcfc;--sidebar: #f9f9f9;--border: #e5e5e5;--text: #0d0d0d;--muted: #5d5d5d;--faint: #b4b4b4;--hover: #ececec;--composer: #ffffff;--user-bubble: #f0f0f0;--send: #0d0d0d;--send-disabled: #a5c8fb;font-family:ui-sans-serif,-apple-system,Segoe UI,Roboto,Helvetica Neue,Arial,sans-serif;color:var(--text)}*{box-sizing:border-box}html,body{margin:0;height:100%;background:var(--bg)}button{font:inherit;color:inherit;cursor:pointer;background:none;border:0}svg{width:20px;height:20px;fill:none;stroke:currentColor;stroke-width:1.7;stroke-linecap:round;stroke-linejoin:round}.app{display:flex;height:100vh;height:100dvh}.sidebar{width:332px;flex-shrink:0;background:var(--sidebar);border-right:1px solid var(--border);display:flex;flex-direction:column;padding:8px;transition:margin-left .2s ease}.app.collapsed .sidebar{margin-left:-332px}.sidebar-top{display:flex;align-items:center;justify-content:space-between;padding:6px 0 14px}.brand{font-weight:600;font-size:18px}.sidebar-icons{display:flex;gap:4px}.icon-btn{width:36px;height:36px;display:inline-flex;align-items:center;justify-content:center;border-radius:8px;color:var(--muted)}.icon-btn:hover{background:var(--hover)}.nav{display:flex;flex-direction:column;gap:2px}.nav-item{display:flex;align-items:center;gap:10px;padding:8px 10px;border-radius:10px;font-size:14px;text-align:left}.nav-item svg{width:18px;height:18px}.nav-item:hover,.nav-item.active{background:var(--hover)}.history{flex:1;overflow-y:auto;margin-top:18px}.history-title{font-size:13px;color:var(--muted);padding:6px 10px}.history ul{list-style:none;margin:0;padding:0}.history li button{width:100%;text-align:left;padding:8px 10px;border-radius:10px;font-size:14px;white-space:nowrap;overflow:hidden;text-overflow:ellipsis}.history li button:hover,.history li button.active{background:var(--hover)}.user{display:flex;align-items:center;gap:10px;padding:10px 6px 4px}.avatar{width:32px;height:32px;border-radius:50%;background:#e3e3e3;color:var(--muted);display:flex;align-items:center;justify-content:center;font-size:14px;font-weight:600}.user-name{font-size:13px;font-weight:600;color:var(--muted)}.user-plan{font-size:12px;color:var(--faint)}.main{flex:1;min-width:0;display:flex;flex-direction:column;position:relative}.topbar{height:56px;flex-shrink:0;display:flex;align-items:center;justify-content:center;position:relative;padding:0 12px}.topbar #reset{position:absolute;right:12px}.open-sidebar{position:absolute;left:12px;display:none}.app.collapsed .open-sidebar{display:inline-flex}.mode-toggle{display:flex;background:#efefef;border-radius:999px;padding:3px}.mode{padding:6px 44px;border-radius:999px;font-size:14px;font-weight:600;color:var(--faint)}.mode.active{background:#fff;color:var(--muted);box-shadow:0 1px 2px #0000000f}.conversation{flex:1;overflow-y:auto;display:none}.app.chatting .conversation{display:block}.messages{max-width:768px;margin:0 auto;padding:24px 24px 40px;display:flex;flex-direction:column;gap:24px}.msg{font-size:16px;line-height:1.65;white-space:pre-wrap;word-wrap:break-word}.msg.user{align-self:flex-end;max-width:70%;background:var(--user-bubble);padding:10px 18px;border-radius:22px}.msg.assistant{align-self:stretch}.msg.error{color:#c0392b}.typing{display:inline-flex;gap:4px;padding:6px 0}.typing span{width:7px;height:7px;border-radius:50%;background:#9b9b9b;animation:blink 1.2s infinite}.typing span:nth-child(2){animation-delay:.2s}.typing span:nth-child(3){animation-delay:.4s}@keyframes blink{0%,80%,to{opacity:.25}40%{opacity:1}}.composer-wrap{flex:1;display:flex;flex-direction:column;align-items:center;justify-content:center;padding:0 16px 18vh}.app.chatting .composer-wrap{flex:0;padding:0 16px 20px}.welcome{font-size:24px;font-weight:400;margin:0 0 28px}.app.chatting .welcome{display:none}.composer{width:100%;max-width:768px;display:flex;align-items:flex-end;gap:6px;background:var(--composer);border:1px solid var(--border);border-radius:28px;padding:8px 8px 8px 10px;box-shadow:0 4px 24px #0000000a,0 0 0 40px #fafafa66}.composer textarea{flex:1;resize:none;border:0;outline:0;background:transparent;font:inherit;font-size:16px;line-height:24px;padding:6px 4px;max-height:200px;color:var(--text)}.composer textarea::placeholder{color:var(--muted)}.send{width:36px;height:36px;border-radius:50%;flex-shrink:0;background:var(--send);color:#fff;display:inline-flex;align-items:center;justify-content:center}.send:disabled{background:var(--send-disabled);cursor:default}.send svg{stroke-width:2.2}@media(max-width:768px){.sidebar{position:absolute;z-index:10;height:100%;width:280px;box-shadow:4px 0 20px #00000014}.app.collapsed .sidebar{margin-left:-280px;box-shadow:none}.mode{padding:6px 24px}.msg.user{max-width:85%}}