占位设置，空格导致无效

//占位设置，空格导致无效
var btnSty = "height:30px;margin-top:6px;color: red;" //无效设置
var btnSty = "height:30px;margin-top:6px;color:red;" //有效设置
li.innerHTML = `<button data-id = ${id} style=${btnSty}>下一级</button>`;