:root{--bg: #ffffff;--fg: #202124;--fg-muted: #5f6368;--input-bg: #ffffff;--border: #dfe1e5;--border-focus: #1a73e8;--accent: #1a73e8;--bubble-user: #1a73e8;--bubble-user-fg: #ffffff;--bubble-ai: #f1f3f4;--bubble-ai-fg: #202124;--hover: #f8f9fa;--shadow: 0 1px 6px rgba(32, 33, 36, .28)}@media(prefers-color-scheme:dark){:root{--bg: #202124;--fg: #e8eaed;--fg-muted: #9aa0a6;--input-bg: #303134;--border: #5f6368;--border-focus: #8ab4f8;--accent: #8ab4f8;--bubble-user: #8ab4f8;--bubble-user-fg: #202124;--bubble-ai: #303134;--bubble-ai-fg: #e8eaed;--hover: #3c4043;--shadow: 0 1px 6px rgba(0, 0, 0, .4)}}*{box-sizing:border-box}html,body,#root{margin:0;padding:0;height:100%}body{font-family:-apple-system,BlinkMacSystemFont,Segoe UI,Roboto,Helvetica Neue,Arial,PingFang SC,Microsoft YaHei,sans-serif;background:var(--bg);color:var(--fg);-webkit-font-smoothing:antialiased}.login-page{min-height:100vh;display:flex;flex-direction:column;align-items:center;justify-content:center;padding:24px;gap:28px}.login-page .logo{font-size:clamp(56px,14vw,96px);font-weight:600;letter-spacing:4px;color:var(--fg);text-align:center}.login-form{width:100%;max-width:420px;display:flex;flex-direction:column;gap:16px}.field input{width:100%;padding:14px 18px;font-size:16px;border:1px solid var(--border);border-radius:24px;background:var(--input-bg);color:var(--fg);outline:none;transition:box-shadow .15s}.field input:focus{box-shadow:var(--shadow);border-color:var(--border-focus)}.btn{padding:12px 20px;font-size:15px;border:none;border-radius:24px;cursor:pointer;background:var(--accent);color:#fff;transition:opacity .15s}@media(prefers-color-scheme:dark){.btn{color:#202124}}.btn:disabled{opacity:.6;cursor:not-allowed}.btn-secondary{background:var(--hover);color:var(--fg)}.login-error{color:#d93025;font-size:14px;text-align:center}.chat-page{height:100vh;display:flex;flex-direction:column}.chat-header{display:flex;align-items:center;justify-content:space-between;padding:10px 16px;border-bottom:1px solid var(--border);font-size:15px;font-weight:600;flex-shrink:0}.chat-header .brand{letter-spacing:2px}.chat-header .user{display:flex;align-items:center;gap:10px;font-weight:400;color:var(--fg-muted)}.chat-header .user .email{font-size:13px}.logout{background:var(--hover);color:var(--fg);padding:6px 12px;border-radius:16px;cursor:pointer;border:1px solid var(--border);font-size:13px}.chat-body{flex:1;display:flex;min-height:0}.conv-list{width:220px;border-right:1px solid var(--border);overflow-y:auto;padding:12px 8px;flex-shrink:0;display:flex;flex-direction:column;gap:4px}.conv-item{padding:8px 12px;border-radius:8px;cursor:pointer;font-size:14px;color:var(--fg);white-space:nowrap;overflow:hidden;text-overflow:ellipsis}.conv-item:hover{background:var(--hover)}.conv-item.active{background:var(--border)}.conv-list .empty{font-size:13px;color:var(--fg-muted);padding:12px;text-align:center}.chat-main{flex:1;display:flex;flex-direction:column;min-width:0}.chat-hero{flex:1;display:flex;flex-direction:column;align-items:center;justify-content:center;gap:20px;padding:20px}.chat-hero .logo{font-size:clamp(44px,10vw,72px);font-weight:600;letter-spacing:4px}.chat-hero .subtitle{color:var(--fg-muted);font-size:15px}.messages{flex:1;overflow-y:auto;padding:20px 24px;display:flex;flex-direction:column;gap:14px}.message-row{display:flex;gap:10px;align-items:flex-start}.message-row .role{min-width:56px;text-align:right;font-size:12px;font-weight:600;color:var(--fg-muted);padding-top:10px;flex-shrink:0}.message-row.user{flex-direction:row-reverse}.message-row.user .role{text-align:left}.bubble{max-width:76%;padding:12px 16px;border-radius:16px;font-size:15px;line-height:1.6;white-space:pre-wrap;word-break:break-word}.bubble.user{background:var(--bubble-user);color:var(--bubble-user-fg);border-bottom-right-radius:4px}.bubble.ai{background:var(--bubble-ai);color:var(--bubble-ai-fg);border-bottom-left-radius:4px}.bubble .thinking{color:var(--fg-muted)}.composer{padding:12px 16px 20px;flex-shrink:0}.composer .box{max-width:760px;margin:0 auto;display:flex;gap:8px;border:1px solid var(--border);border-radius:28px;padding:6px 6px 6px 18px;background:var(--input-bg);transition:box-shadow .15s}.composer .box:focus-within{box-shadow:var(--shadow);border-color:var(--border-focus)}.composer textarea{flex:1;border:none;background:transparent;color:var(--fg);font-size:16px;resize:none;outline:none;padding:10px 0;font-family:inherit;min-height:24px;max-height:160px}.composer .send{background:var(--accent);color:#fff;border:none;border-radius:50%;width:42px;height:42px;cursor:pointer;flex-shrink:0;font-size:18px}@media(prefers-color-scheme:dark){.composer .send{color:#202124}}.composer .send:disabled{opacity:.5;cursor:not-allowed}@media(max-width:640px){.conv-list{width:100%;max-height:120px;border-right:none;border-bottom:1px solid var(--border);flex-direction:row;overflow-x:auto}.conv-item{flex-shrink:0;white-space:nowrap}.chat-body{flex-direction:column}.bubble{max-width:88%}.message-row .role{min-width:40px}}