.txt1::-webkit-input-placeholder::before {
color:#c2c3c3;
content:"Hey Brad,\A Tell us what's on your mind";
}
.txt1::-moz-input-placeholder::before {
color:#c2c3c3;
content:"Hey Brad,\A Tell us what's on your mind";
}
占位符在 Firefox 中不起作用,Chrome 很好