*{margin:0;padding:0;box-sizing:border-box}body{font-family:-apple-system,BlinkMacSystemFont,Segoe UI,PingFang SC,Hiragino Sans GB,Microsoft YaHei,Helvetica Neue,Helvetica,Arial,sans-serif;background:linear-gradient(135deg,#667eea,#764ba2);min-height:100vh}#app{min-height:100vh;display:flex;align-items:center;justify-content:center;padding:20px;width:100%}