:root{--bg-primary:#f8fafc;--bg-secondary:#fff;--bg-message-user:#007aff;--bg-message-other:#e5e7eb;--bg-message-ai:#f0f9ff;--text-primary:#1f2937;--text-secondary:#6b7280;--text-message-user:#fff;--text-message-other:#1f2937;--border-light:#e5e7eb;--shadow-sm:0 1px 2px 0 rgba(0,0,0,.05);--shadow-md:0 4px 6px -1px rgba(0,0,0,.1),0 2px 4px -2px rgba(0,0,0,.1);--radius:12px;--radius-sm:8px}*{box-sizing:border-box;margin:0;padding:0}body{font-family:-apple-system,BlinkMacSystemFont,Segoe UI,Roboto,Helvetica Neue,Arial,sans-serif;background-color:var(--bg-primary);color:var(--text-primary);line-height:1.5;-webkit-font-smoothing:antialiased;-moz-osx-font-smoothing:grayscale}button{cursor:pointer;border:none;outline:none;transition:all .2s ease}button:hover{transform:translateY(-1px)}button:active{transform:translateY(0)}input{outline:none;border:none;font-family:inherit}::-webkit-scrollbar{width:6px}::-webkit-scrollbar-track{background:transparent}::-webkit-scrollbar-thumb{background:#cbd5e1;border-radius:3px}::-webkit-scrollbar-thumb:hover{background:#94a3b8}@keyframes typing{0%,60%,to{transform:translateY(0);opacity:.4}30%{transform:translateY(-10px);opacity:1}}