*{margin:0;padding:0;box-sizing:border-box}
:root{--bg:#1a1a2e;--bg2:#16213e;--bg3:#0f3460;--text:#e0e0e0;--text2:#a0a0b0;--accent:#4fc3f7;--user-bg:#1e3a5f;--ai-bg:#252540;--input-bg:#2a2a4a;--border:#333355;--hover:#2a2a4a;--sidebar-w:260px;--code-bg:#1e1e2e}
[data-theme="light"]{--bg:#f5f5f5;--bg2:#ffffff;--bg3:#e8e8e8;--text:#1a1a2e;--text2:#555;--accent:#1976d2;--user-bg:#e3f2fd;--ai-bg:#f8f8ff;--input-bg:#fff;--border:#ddd;--hover:#eee;--code-bg:#f4f4f4}
body{font-family:-apple-system,BlinkMacSystemFont,'Segoe UI',Roboto,sans-serif;background:var(--bg);color:var(--text);height:100vh;overflow:hidden}
.app{display:flex;height:100vh}
.sidebar{width:var(--sidebar-w);background:var(--bg2);border-right:1px solid var(--border);display:flex;flex-direction:column;transition:transform .3s}
.sidebar.hidden{transform:translateX(calc(-1 * var(--sidebar-w)))}
.new-chat-btn{margin:12px;padding:12px;background:var(--accent);color:#fff;border:none;border-radius:8px;cursor:pointer;font-size:14px;font-weight:600;transition:opacity .2s}
.new-chat-btn:hover{opacity:.85}
.chat-history{flex:1;overflow-y:auto;padding:8px}
.chat-history-item{padding:10px 12px;margin:2px 0;border-radius:6px;cursor:pointer;font-size:14px;font-weight:500;color:var(--text);display:flex;justify-content:space-between;align-items:center;gap:8px;min-width:0}
.chat-history-item .chat-history-title{min-width:0;overflow:hidden;text-overflow:ellipsis;white-space:nowrap;flex:1}
.chat-history-item:hover,.chat-history-item.active{background:var(--hover);color:var(--text)}
.chat-history-item .delete-btn{display:inline-flex;align-items:center;justify-content:center;background:none;border:none;color:var(--text2);cursor:pointer;font-size:18px;padding:2px 6px;border-radius:4px;flex-shrink:0}
.chat-history-item .delete-btn:hover{color:#e74c3c;background:rgba(231,76,60,.15)}
.sidebar-footer{padding:12px;border-top:1px solid var(--border)}
.theme-toggle{width:100%;padding:8px;background:var(--input-bg);color:var(--text);border:1px solid var(--border);border-radius:6px;cursor:pointer;font-size:14px;font-weight:600}
.chat-area{flex:1;display:flex;flex-direction:column;min-width:0}
.chat-header{display:flex;align-items:center;gap:12px;padding:12px 20px;border-bottom:1px solid var(--border);background:var(--bg2);isolation:isolate;flex-wrap:wrap}
.chat-header .header-logo-wrap,.welcome .welcome-logo-wrap{background:var(--bg2);display:inline-flex;align-items:center;line-height:0}
.login-logo-wrap{background:var(--bg2);display:block;margin:0 auto 16px;line-height:0}
.chat-header .header-logo{height:36px;width:auto;object-fit:contain;flex-shrink:0;display:block}
[data-theme="light"] .chat-header .header-logo,[data-theme="light"] .welcome .welcome-logo,.login-logo{filter:brightness(1.12);mix-blend-mode:multiply}
[data-theme="dark"] .chat-header .header-logo,[data-theme="dark"] .welcome .welcome-logo{mix-blend-mode:multiply}
.chat-header h1{font-size:18px;font-weight:700;flex:1;color:var(--text)}
.chat-header .header-link{color:var(--accent);font-size:13px;text-decoration:none}
.chat-header .header-link:hover{text-decoration:underline}
.header-auth{display:flex;align-items:center;gap:12px}
.system-stats{display:flex;align-items:center;gap:10px;padding:6px 10px;background:var(--bg3);border-radius:8px;font-size:12px;font-weight:600;color:var(--text);flex-shrink:0}
.system-stats .stat{display:inline-flex;align-items:center;gap:4px}
.system-stats .stat-icon{opacity:.9;font-size:14px}
.tools-list{font-size:12px;color:var(--text);flex-shrink:0;padding:5px 12px;background:var(--accent);color:#fff;border-radius:6px;font-weight:600;margin-right:4px}
.welcome .guest-hint{color:var(--accent);font-size:14px;margin-top:12px}
.sidebar-toggle{background:none;border:none;color:var(--text);font-size:20px;cursor:pointer;display:none}
.model-select{padding:8px 12px;background:var(--input-bg);color:var(--text);border:1px solid var(--border);border-radius:6px;font-size:14px;font-weight:600;max-width:300px}
.model-fixed-label{font-size:14px;font-weight:600;color:var(--text);max-width:200px;overflow:hidden;text-overflow:ellipsis;white-space:nowrap}
.messages{flex:1;overflow-y:auto;padding:20px;scroll-behavior:smooth}
.welcome{text-align:center;margin-top:20vh;color:var(--text);isolation:isolate}
.welcome .welcome-logo-wrap{margin:0 auto 16px}
.welcome .welcome-logo{display:block;margin:0 auto;max-height:88px;width:auto}
.welcome h2{font-size:26px;font-weight:700;margin-bottom:8px;color:var(--text)}
.message{max-width:800px;margin:0 auto 16px;padding:16px 20px;border-radius:12px;line-height:1.6;font-size:15px;animation:fadeIn .3s}
@keyframes fadeIn{from{opacity:0;transform:translateY(8px)}to{opacity:1;transform:translateY(0)}}
.message.user{background:var(--user-bg);margin-left:auto;max-width:700px;border-bottom-right-radius:4px}
.message.user .msg-user-image{margin-bottom:8px}
.message.user .msg-user-image img{max-width:100%;max-height:min(360px,50vh);width:auto;height:auto;border-radius:8px;display:block;object-fit:contain}
.message.user .msg-user-text:empty{display:none}
.message.assistant{background:var(--ai-bg);border-bottom-left-radius:4px}
.message.assistant .thinking{color:var(--text2);font-style:italic;opacity:.7}
.message pre{background:var(--code-bg);padding:12px;border-radius:8px;overflow-x:auto;margin:8px 0;position:relative}
.message pre code{font-family:'Fira Code',monospace;font-size:13px}
.message code:not(pre code){background:var(--code-bg);padding:2px 6px;border-radius:4px;font-size:13px}
.message p{margin:6px 0}
.message ul,.message ol{margin:6px 0 6px 20px}
.message table{border-collapse:collapse;margin:8px 0;width:100%}
.message th,.message td{border:1px solid var(--border);padding:6px 10px;text-align:left;font-size:13px}
.message th{background:var(--bg3)}
.message a{color:var(--accent)}
.message .code-actions{position:absolute;top:6px;right:6px;display:flex;gap:4px}
.message .copy-code,.message .save-code{background:var(--bg3);color:var(--text2);border:1px solid var(--border);border-radius:4px;padding:2px 8px;font-size:11px;cursor:pointer}
.message .copy-code:hover,.message .save-code:hover{color:var(--text)}
.message.assistant{padding-bottom:44px}
.message.assistant .msg-save{position:absolute;bottom:8px;right:8px;background:var(--accent);color:#fff;border:none;border-radius:6px;padding:4px 10px;font-size:12px;font-weight:600;cursor:pointer;opacity:.9}
.message.assistant .msg-save:hover{opacity:1}
.message .msg-usage{margin:8px 0 0;font-size:11px;color:var(--text2);opacity:.85}
.typing-indicator{display:flex;align-items:center;gap:8px}
.typing-indicator .typing-label{font-size:13px;font-weight:600;color:var(--text2);margin-right:4px}
.typing-indicator span:not(.typing-label){display:inline-block;width:6px;height:6px;border-radius:50%;background:var(--accent);margin:0 2px;animation:bounce .6s infinite alternate}
.typing-indicator span:not(.typing-label):nth-child(2){animation-delay:.2s}
.typing-indicator span:not(.typing-label):nth-child(3){animation-delay:.4s}
@keyframes bounce{to{opacity:.3;transform:translateY(-4px)}}
.input-area{padding:12px 20px 16px;border-top:1px solid var(--border);background:var(--bg2)}
.processing-status{max-width:800px;margin:0 auto 8px;padding:8px 14px;background:var(--bg3);border:1px solid var(--accent);border-radius:8px;font-size:13px;font-weight:600;color:var(--accent);display:flex;align-items:center;gap:8px}
.processing-status .status-dot{width:8px;height:8px;border-radius:50%;background:var(--accent);animation:statusPulse 1.2s infinite}
@keyframes statusPulse{0%,100%{opacity:1;transform:scale(1)}50%{opacity:.5;transform:scale(1.2)}}
.input-wrapper{max-width:800px;margin:0 auto;display:flex;align-items:flex-end;gap:8px;background:var(--input-bg);border:1px solid var(--border);border-radius:12px;padding:8px 12px}
.input-wrapper:focus-within{border-color:var(--accent)}
.attach-btn{background:none;border:none;color:var(--text2);cursor:pointer;width:36px;height:36px;border-radius:8px;display:flex;align-items:center;justify-content:center;flex-shrink:0;transition:color .2s,background .2s}
.attach-btn:hover{color:var(--accent);background:var(--hover)}
.attach-btn.recording{color:#e74c3c;background:rgba(231,76,60,.18)}
.stt-lang-label{align-self:center;flex-shrink:0;margin:0}
.stt-lang-select{max-width:118px;font-size:12px;padding:6px 8px;border-radius:8px;border:1px solid var(--border);background:var(--input-bg);color:var(--text);cursor:pointer;line-height:1.2}
.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}
#userInput{flex:1;background:none;border:none;color:var(--text);font-size:15px;resize:none;max-height:150px;outline:none;font-family:inherit;line-height:1.5;min-width:0}
#sendBtn,#stopBtn{background:var(--accent);border:none;color:#fff;width:36px;height:36px;border-radius:8px;cursor:pointer;display:flex;align-items:center;justify-content:center;flex-shrink:0;transition:opacity .2s}
.attached-file-chip{max-width:800px;margin:0 auto 6px;padding:6px 10px;background:var(--input-bg);border:1px solid var(--border);border-radius:8px;font-size:12px;color:var(--text2);display:flex;align-items:center;gap:8px}
.attached-file-chip .attached-name{flex:1;overflow:hidden;text-overflow:ellipsis;white-space:nowrap}
.attached-file-chip .attached-remove{background:none;border:none;color:var(--text2);cursor:pointer;padding:2px 6px;font-size:14px;border-radius:4px}
.attached-file-chip .attached-remove:hover{color:#e74c3c;background:rgba(231,76,60,.15)}
#sendBtn:hover,#stopBtn:hover{opacity:.8}
#stopBtn{background:#e74c3c}
.disclaimer{text-align:center;font-size:11px;color:var(--text2);margin-top:8px}
.messages::-webkit-scrollbar{width:6px}
.messages::-webkit-scrollbar-thumb{background:var(--border);border-radius:3px}
.modal-overlay{position:fixed;inset:0;background:rgba(0,0,0,.6);display:flex;align-items:center;justify-content:center;z-index:100;padding:20px}
.modal-box{background:var(--bg2);border:1px solid var(--border);border-radius:12px;padding:24px;max-width:360px;width:100%}
.save-format-modal{max-width:420px}
.save-format-options{display:flex;flex-wrap:wrap;gap:8px;margin:16px 0}
.format-btn{padding:10px 16px;background:var(--input-bg);color:var(--text);border:1px solid var(--border);border-radius:8px;cursor:pointer;font-size:14px;font-weight:600;transition:background .2s,border-color .2s}
.format-btn:hover{background:var(--accent);border-color:var(--accent);color:#fff}
.format-btn-copy{background:var(--accent);color:#fff;border-color:var(--accent)}
.format-btn-copy:hover{opacity:.9}
.format-hint{font-size:12px;color:var(--text2);margin-top:8px}
.modal-box h3{font-size:18px;margin-bottom:16px}
.modal-box input{width:100%;padding:10px 12px;margin-bottom:10px;background:var(--input-bg);border:1px solid var(--border);border-radius:8px;color:var(--text);font-size:14px}
.modal-box input:focus{outline:none;border-color:var(--accent)}
.modal-error{color:#e74c3c;font-size:13px;margin-bottom:8px;min-height:20px}
.modal-actions{display:flex;gap:10px;margin-top:16px;justify-content:flex-end}
.btn-secondary{background:var(--input-bg);color:var(--text);border:1px solid var(--border)}
@media(max-width:768px){
  .sidebar{position:fixed;z-index:10;height:100vh;transform:translateX(calc(-1 * var(--sidebar-w)))}
  .sidebar.show{transform:translateX(0)}
  .sidebar-toggle{display:block}
}