// 扭动
.animate-wiggle(@animation_name: animation-wiggle, @duration: 1s, @loop: infinite) {
    .animation(@animation_name @duration @loop);

    & when (@prefix = true) {
        @-webkit-keyframes @animation_name { .keyframes('-webkit-'); }
        @-moz-keyframes @animation_name { .keyframes('-moz-'); }
    }

    @keyframes @animation_name { .keyframes; }

    .keyframes(@prefix: '') {
        @pf: e('@{prefix}');
        0%   { @{pf}transform: skewX(9deg); }
        10%  { @{pf}transform: skewX(-8deg); }
        20%  { @{pf}transform: skewX(7deg); }
        30%  { @{pf}transform: skewX(-6deg); }
        40%  { @{pf}transform: skewX(5deg); }
        50%  { @{pf}transform: skewX(-4deg); }
        60%  { @{pf}transform: skewX(3deg); }
        70%  { @{pf}transform: skewX(-2deg); }
        80%  { @{pf}transform: skewX(1deg); }
        90%  { @{pf}transform: skewX(0deg); }
        100% { @{pf}transform: skewX(0deg); }
    }
}