body {
    margin: 0;
    padding: 0;
    font-family: sans-serif;
    background: url(../images/背景.jpg) no-repeat;
    /* background-color: transparent; */
}

.login-box {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    width: 400px;
    padding: 40px;
    /* background: rgba(26, 61, 34, 0.6); */
    background: rgba(54, 53, 53, 0.6);
    box-sizing: border-box;
    box-shadow: 0 15px 25px rgba(0, 0, 0, .5);
    border-radius: 10px;
}

.login-box h2 {
    margin: 0 0 30px;
    padding: 0;
    text-align: center;
    color: #fff;
}

.login-box .login-field {
    position: relative;
}

.login-box .login-field input {
    width: 100%;
    padding: 10px 0;
    font-size: 16px;
    color: #fff;
    margin-bottom: 30px;
    border: none;
    border-bottom: 1px solid #fff;
    outline: none;
    background: transparent;
}

.login-box .login-field label {
    position: absolute;
    top: 0;
    left: 0;
    letter-spacing: 1px;
    padding: 10px 0;
    font-size: 16px;
    color: #fff;
    pointer-events: none;
    transition: .5s;
}

.login-box .login-field input:focus~label,
.login-box .login-field input:valid~label {
    top: -23px;
    left: 0;
    font-size: 12px;
}

.login-box button {
    background: transparent;
    border: none;
    outline: none;
    color: #fff;
    background: #03a9f4;
    padding: 10px 146px;
    cursor: pointer;
    border-radius: 5px;
}

.login-box .return {
    background: transparent;
    border: none;
    outline: none;
    color: #fff;
    font-size: 5px;
    padding: 14px 148px;
    cursor: pointer;
    border-radius: 5px;
}

.login-box .return-zc,
.login-box .return-wjmm {
    background: transparent;
    border: none;
    outline: none;
    color: #fff;
    font-size: 5px;
    padding: 14px 20px;
    cursor: pointer;
    border-radius: 5px;
}

.login-box .return-zc {
    float: left;
}

.login-box .return-wjmm {
    float: right;
}