#alertMessage{
    z-index:9999999;
    position: absolute;
    top: 20%;
    left: 50%;
    -webkit-transform: translate(-50%, -50%);
    -moz-transform: translate(-50%, -50%);
    -ms-transform: translate(-50%, -50%);
    -o-transform: translate(-50%, -50%);
    transform: translate(-50%, -50%);
     background: #FFD700;
     width:400px;
    height:50px;
    text-align: center;
    font-size:20px;
    display: none;
}

#logout:hover{
    background-color: #000080;
}
#logout:active {
    background-color: #FFFF00;
}

/* 按钮的样式 */
.btn{
    height: 30px;
    width: 130px;
    border: 0;
    background-color:#000188;
    box-shadow:0 0 1px #272727,
    0 0 10px 2px #3C3C3C,
    0 0 10px  4px #4F4F4F;
    border-radius: 4px;
    font-family: Calibri;
    font-weight: 800;
    font-size: 12px;
    color: aqua;
    cursor: pointer;
}
.btn:hover{
    animation: buttonEffect 0.4s linear;
    transition-timing-function: linear;
}

.btn:active{
    transform: scale(1.2);
    bottom: -3px;
    transition-timing-function: ease-in-out;
}
@keyframes buttonEffect {
    0%{background: radial-gradient(ellipse 20px 8px,white,blue,black);}
    20%{background: radial-gradient(ellipse 30px 12px,white,blue,black);}
    40%{background: radial-gradient(ellipse 40px 16px,white,blue,black);}
    60%{background: radial-gradient(ellipse 50px 20px,white,blue,black);}
    80%{background: radial-gradient(ellipse 60px 24px,red,red,black);}
    100%{background: radial-gradient(ellipse 70px 280px,red,red,black);}
}

.ml-80px {
  margin-left: 25%;
}