:root{--primary-color:#2563eb;--border-color:#e5e7eb;--background-color:#fff;--surface-color:#f8fafc;--text-color:#111827;--muted-color:#6b7280;--user-message:#2563eb;--assistant-message:#f1f5f9}*{box-sizing:border-box}body{color:var(--text-color);background:var(--background-color);margin:0;font-family:Inter,Arial,sans-serif}.chat-window{border:1px solid var(--border-color);border-radius:12px;flex-direction:column;height:100%;display:flex;overflow:hidden}.chat-header{border-bottom:1px solid var(--border-color);padding:16px;font-weight:600}.chat-body{flex:1;padding:20px;overflow-y:auto}.chat-message{border-radius:10px;max-width:70%;margin-bottom:10px;padding:10px 14px}.chat-message.user{background:var(--user-message);color:#fff;margin-left:auto}.chat-message.assistant{background:var(--assistant-message);margin-right:auto}.chat-input{border-top:1px solid var(--border-color);padding:10px;display:flex}.chat-input input{flex:1;padding:10px}.chat-input button{padding:10px 20px}.typing-indicator{color:var(--muted-color);font-style:italic}