*{margin:0;padding:0;box-sizing:border-box}body{font-family:-apple-system,BlinkMacSystemFont,Segoe UI,Roboto,sans-serif;background:#f5f5f5;color:#1a1a1a;height:100vh;overflow:hidden}.hidden{display:none!important}#login-screen{display:flex;align-items:center;justify-content:center;height:100vh;background:linear-gradient(135deg,#667eea,#764ba2)}.login-card{background:#fff;padding:3rem;border-radius:12px;text-align:center;box-shadow:0 4px 24px #00000026;max-width:400px}.login-card h1{font-size:1.8rem;margin-bottom:.5rem}.login-card p{color:#666;margin-bottom:2rem}.btn-primary{background:#4f46e5;color:#fff;border:none;padding:.75rem 1.5rem;border-radius:8px;font-size:1rem;cursor:pointer;transition:background .2s}.btn-primary:hover{background:#4338ca}.btn-primary:disabled{opacity:.5;cursor:not-allowed}#chat-screen{display:flex;height:100vh}#sidebar{width:280px;background:#1e1e2e;color:#cdd6f4;display:flex;flex-direction:column;flex-shrink:0}.sidebar-header{display:flex;align-items:center;justify-content:space-between;padding:1rem;border-bottom:1px solid #313244}.sidebar-header h2{font-size:1rem;font-weight:600}.sidebar-header button{background:#313244;color:#cdd6f4;border:none;width:32px;height:32px;border-radius:6px;font-size:1.2rem;cursor:pointer}.sidebar-header button:hover{background:#45475a}#conversation-list{flex:1;overflow-y:auto;padding:.5rem}.conversation-item{display:flex;align-items:center;padding:.6rem .8rem;border-radius:6px;cursor:pointer;margin-bottom:2px}.conversation-item:hover{background:#313244}.conversation-item.active{background:#45475a}.conv-title{flex:1;overflow:hidden;text-overflow:ellipsis;white-space:nowrap;font-size:.875rem}.conv-delete{background:none;border:none;color:#6c7086;font-size:1.1rem;cursor:pointer;padding:0 4px;opacity:0;transition:opacity .15s}.conversation-item:hover .conv-delete{opacity:1}.conv-delete:hover{color:#f38ba8}.sidebar-footer{padding:.75rem 1rem;border-top:1px solid #313244;display:flex;align-items:center;justify-content:space-between;font-size:.8rem}.sidebar-footer span{overflow:hidden;text-overflow:ellipsis;white-space:nowrap}#logout-btn{background:none;border:none;color:#6c7086;cursor:pointer;font-size:.8rem;flex-shrink:0}#logout-btn:hover{color:#cdd6f4}#chat-main{flex:1;display:flex;flex-direction:column;background:#fff}#messages{flex:1;overflow-y:auto;padding:1.5rem}.welcome{text-align:center;color:#999;margin-top:30vh;font-size:1.1rem}.message{margin-bottom:1.5rem;max-width:800px}.message-label{font-size:.75rem;font-weight:600;text-transform:uppercase;color:#666;margin-bottom:.25rem}.message-body{line-height:1.6;white-space:pre-wrap;word-wrap:break-word}.message.user .message-body{background:#f0f0f0;padding:.75rem 1rem;border-radius:8px}.message.assistant .message-body{padding:.75rem 0}.message-body.error{color:#dc2626}#chat-form{display:flex;gap:.75rem;padding:1rem 1.5rem;border-top:1px solid #e5e5e5;background:#fff}#chat-input{flex:1;border:1px solid #d4d4d4;border-radius:8px;padding:.75rem;font-size:.95rem;font-family:inherit;resize:none;outline:none;max-height:150px}#chat-input:focus{border-color:#4f46e5;box-shadow:0 0 0 2px #4f46e526}#send-btn{align-self:flex-end}