这将仅为桌面(和大型平板电脑)隐藏占位符：
@media (min-width:1025px) and (min-width:1281px) {
::-webkit-input-placeholder { /* WebKit browsers */
color: transparent;
}
:-moz-placeholder { /* Mozilla Firefox 4 to 18 */
color: transparent;
}
::-moz-placeholder { /* Mozilla Firefox 19+ */
color: transparent;
}
:-ms-input-placeholder { /* Internet Explorer 10+ */
color: transparent;
}
textarea::-webkit-input-placeholder { /* WebKit browsers */
color: transparent;
}
textarea:-moz-placeholder { /* Mozilla Firefox 4 to 18 */
color: transparent;
}
textarea::-moz-placeholder { /* Mozilla Firefox 19+ */
color: transparent;
}
textarea:-ms-input-placeholder { /* Internet Explorer 10+ */
color: transparent;
}
}
This input has no placeholder on Desktops