body {
    margin: 0;
    padding: 0;
    font: 14px Microsoft YaHei, Verdana, Arial, Helvetica, sans-serif, "宋体", "黑体";
    line-height: 1.8em;
    text-align: left;
    border: 0;
    background: linear-gradient(to right, #1a1a1a, #001122, #012027, #001122, #1a1a1a);
    background-size: cover;
    background-blend-mode: difference;
}

.login-container, .register-container {
    margin-top: 100px;
    padding: 20px;
    color: #000000;
    background-color: #F4F7F7;
    border-radius: 5px;
    box-shadow: 0 0 10px rgba(0, 0, 0, 0.5);
    opacity: 0.9;
}

.register-container {
    margin-bottom: 20px;
}

.text-right {
    position: absolute;
    right: 20px;
}

.btn-primary {
    background-color: #0AB4F7;
    border-color: #F4F7F7;
}

.btn-primary:hover,
.btn-primary:active,
.btn-primary:focus {
    background-color: #086DF2;
    border-color: #F4F7F7;
}

.tip-msg {
    color: darkred;
    height: 20px;
    text-align: center;
}

.login-bg {
    position: fixed;
    margin: 0px auto;
    z-index: -1;
}

.login-bg .center {
    top: 50vh;
    position: absolute;
    animation: move-bg 15s cubic-bezier(0.4, 0, 0.35, 1) 0s infinite alternate-reverse forwards;
}

@keyframes move-bg {
    0% {
        transform: scale(1.1);
    }
    100% {
        transform: scale(1);
    }
}