html,body {
    height: 100%;
}

body {
    display: -ms-flexbox;
    display: flex;
    -ms-flex-align: center;
    align-items: center;
    padding-top: 30px;
    padding-bottom: 10px;
    flex-direction: column;
    background: url(../images/nebula.jpg);
}
.friend-links{
    text-align:center;
    display:inline-block;
    color:white;
}
.friend-links img{
    height:45px;
    margin:0 10px;
}
.is-invalid .form-label-group input{
    border-color: #e3342f;
    padding-right: calc(1.6em + 0.75rem);
    background-image: url("data:image/svg+xml,%3csvg xmlns='http://www.w3.org/2000/svg' width='12' height='12' fill='none' stroke='%23e3342f' viewBox='0 0 12 12'%3e%3ccircle cx='6' cy='6' r='4.5'/%3e%3cpath stroke-linejoin='round' d='M5.8 3.6h.4L6 6.5z'/%3e%3ccircle cx='6' cy='8.2' r='.6' fill='%23e3342f' stroke='none'/%3e%3c/svg%3e");
    background-repeat: no-repeat;
    background-position: right calc(0.4em + 0.1875rem) center;
    background-size: calc(0.8em + 0.375rem) calc(0.8em + 0.375rem);
}
.is-invalid .form-label-group .invalid-feedback{
    display: block !important;
}
.form-signin {
    width: 100%;
    max-width: 420px;
    padding: 15px;
    margin: auto;
    background: rgba(24, 23, 23,0.8);
    box-sizing: border-box;
    box-shadow: 0 15px 25px rgb(0 0 0 / 60%);
    border-radius: 10px;
}
.form-signin .title,.remember{
    color: #fff !important;
}
.form-signin .title{
    cursor: pointer;
    color: #fff;
    letter-spacing: 2px;
    font-family: 宋体;
}

.form-label-group {
    position: relative;
    margin-bottom: 1rem;
}

.form-label-group input,
.form-label-group label {
    height: 3.125rem;
    padding: .75rem;
}

.form-label-group label {
    position: absolute;
    top: 0;
    left: 0;
    display: block;
    width: 100%;
    margin-bottom: 0; /* Override default `<label>` margin */
    line-height: 1.5;
    color: #495057;
    pointer-events: none;
    cursor: text; /* Match the input under the label */
    border: 1px solid transparent;
    border-radius: .25rem;
    transition: all .1s ease-in-out;
}

.form-label-group input::-webkit-input-placeholder {
color: transparent;
}

.form-label-group input::-moz-placeholder {
color: transparent;
}

.form-label-group input:-ms-input-placeholder {
color: transparent;
}

.form-label-group input::-ms-input-placeholder {
color: transparent;
}

.form-label-group input::placeholder {
color: transparent;
}

.form-label-group input:not(:-moz-placeholder-shown) {
padding-top: 1.25rem;
padding-bottom: .25rem;
}

.form-label-group input:not(:-ms-input-placeholder) {
padding-top: 1.25rem;
padding-bottom: .25rem;
}

.form-label-group input:not(:placeholder-shown) {
padding-top: 1.25rem;
padding-bottom: .25rem;
}

.form-label-group input:not(:-moz-placeholder-shown) ~ label {
padding-top: .25rem;
padding-bottom: .25rem;
font-size: 12px;
color: #777;
}

.form-label-group input:not(:-ms-input-placeholder) ~ label {
padding-top: .25rem;
padding-bottom: .25rem;
font-size: 12px;
color: #777;
}

.form-label-group input:not(:placeholder-shown) ~ label {
padding-top: .25rem;
padding-bottom: .25rem;
font-size: 12px;
color: #777;
}

.form-label-group input:-webkit-autofill ~ label {
    padding-top: .25rem;
    padding-bottom: .25rem;
    font-size: 12px;
    color: #777;
}

/* Fallback for Edge
-------------------------------------------------- */
@supports (-ms-ime-align: auto) {
    .form-label-group {
        display: -ms-flexbox;
        display: flex;
        -ms-flex-direction: column-reverse;
        flex-direction: column-reverse;
    }

    .form-label-group label {
        position: static;
    }

    .form-label-group input::-ms-input-placeholder {
        color: #777;
    }
}
.bd-placeholder-img {
    font-size: 1.125rem;
    text-anchor: middle;
    -webkit-user-select: none;
    -moz-user-select: none;
    -ms-user-select: none;
    user-select: none;
  }

@media (min-width: 768px) {
    .bd-placeholder-img-lg {
      font-size: 3.5rem;
   }
}