*{margin:0;padding:0;box-sizing:border-box}body,html{height:100%;font-family:PingFang SC,Microsoft YaHei,sans-serif;-webkit-font-smoothing:antialiased;-moz-osx-font-smoothing:grayscale;background-color:#f5f5f5}#app{height:100%;display:flex;flex-direction:column}.container{max-width:600px;margin:0 auto;padding:0 20px;width:100%}.btn{padding:12px 20px;border:none;border-radius:8px;font-size:16px;font-weight:500;cursor:pointer;transition:all .3s ease}.btn-primary{background-color:#4caf50;color:#fff}.btn-primary:hover{background-color:#3e8e41}.btn-secondary{background-color:#f1f1f1;color:#333}.btn-secondary:hover{background-color:#ddd}