:root{--primary-color: #007bff;--background-light: #f8f9fa;--text-dark: #333;--text-muted: #6c757d;--border-radius: 16px;--message-spacing: 12px;--animation-duration: .3s}*{margin:0;padding:0;box-sizing:border-box}body{font-family:-apple-system,BlinkMacSystemFont,Segoe UI,Roboto,Helvetica Neue,Arial,sans-serif;line-height:1.5;color:var(--text-dark);background:linear-gradient(135deg,#667eea,#764ba2);min-height:100vh;padding:20px}.chat-container{max-width:800px;margin:0 auto;background:#fff;border-radius:20px;box-shadow:0 20px 60px #0000001a;overflow:hidden}.chat-history{display:flex;flex-direction:column;gap:var(--message-spacing);padding:24px;max-height:600px;overflow-y:auto}.message-item{display:flex;flex-direction:column;animation:messageAppear var(--animation-duration) ease-out}.message-own{align-items:flex-end}.message-own .message-header{order:2;margin-top:4px}.message-own .message-bubble{background:linear-gradient(135deg,var(--primary-color),#0056b3);color:#fff;border-bottom-right-radius:4px}.message-response{align-items:flex-start}.message-response .message-header{order:2;margin-top:4px}.message-response .message-bubble{background:var(--background-light);color:var(--text-dark);border-bottom-left-radius:4px}.message-header{display:flex;gap:8px;font-size:12px;color:var(--text-muted)}.message-author{font-weight:600}.message-time{opacity:.8}.message-bubble{max-width:70%;padding:12px 16px;border-radius:var(--border-radius);word-wrap:break-word;position:relative;box-shadow:0 2px 8px #0000001a;transition:all var(--animation-duration) ease}.message-bubble:hover{transform:translateY(-1px);box-shadow:0 4px 16px #00000026}.message-typing{align-items:flex-start}.typing-indicator{display:flex;align-items:center;gap:8px;padding:12px 16px;background:var(--background-light);border-radius:var(--border-radius);border-bottom-left-radius:4px;max-width:70%;font-style:italic;color:var(--text-muted);animation:pulse 1.5s ease-in-out infinite}.typing-dots{display:flex;gap:4px}.typing-dots span{width:6px;height:6px;background:var(--text-muted);border-radius:50%;animation:typingDot 1.4s ease-in-out infinite}.typing-dots span:nth-child(1){animation-delay:0ms}.typing-dots span:nth-child(2){animation-delay:.2s}.typing-dots span:nth-child(3){animation-delay:.4s}@keyframes messageAppear{0%{opacity:0;transform:translateY(20px)}to{opacity:1;transform:translateY(0)}}@keyframes pulse{0%,to{opacity:1}50%{opacity:.7}}@keyframes typingDot{0%,20%{transform:scale(1);opacity:1}50%{transform:scale(1.5);opacity:.7}to{transform:scale(1);opacity:1}}@media(max-width:768px){.chat-container{margin:10px;border-radius:16px}.chat-history{padding:16px}.message-bubble{max-width:85%;font-size:14px}}.chat-history::-webkit-scrollbar{width:6px}.chat-history::-webkit-scrollbar-track{background:transparent}.chat-history::-webkit-scrollbar-thumb{background:#ccc;border-radius:3px}.chat-history::-webkit-scrollbar-thumb:hover{background:#999}