.modal {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    z-index: 1050;
    width: 100%;
    height: 100%;
    overflow: hidden;
    background: rgba(0, 0, 0, 0.7); /* 半透明背景 */
}

    .modal.fade .modal-dialog {
        transform: translateY(-50%);
        transition: transform 0.3s ease-out;
    }

    .modal.show .modal-dialog {
        transform: translateY(0);
    }

/* 居中 modal */
.modal-dialog {
    display: flex;
    align-items: center;
    justify-content: center;
    min-height: 100vh; /* 确保 modal 在整个屏幕高度中居中 */
    margin: 0 auto;
}

/* 适配手机和桌面 */
@media (max-width: 768px) {
    .modal-dialog {
        width: 90%; /* 手机端稍微缩小 modal 宽度 */
    }
}

@media (min-width: 769px) {
    .modal-dialog {
        width: 600px; /* 桌面端 modal 宽度 */
    }
}

.modal-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.modal-header .close {
    margin: 0;
    padding: 0;
    font-size: 1.5rem;
    border: none;
    background: none;
    cursor: pointer;
    opacity: 0.7;
    transition: opacity 0.3s ease;
}

.modal-header .close:hover {
    opacity: 1;
}

.modal-footer {
    display: flex;
    justify-content: flex-end; /* 按钮靠右对齐 */
    gap: 10px; /* 按钮之间的间距 */
    padding-top: 15px;
    padding-bottom: 15px;
    border-top: 1px solid #e5e5e5;
}

.modal-footer .btn {
    min-width: 100px; /* 让按钮大小一致 */
}


/* modal 内容 */
.modal-content {
    width: 100%;
    max-width: 600px;
    background-color: #fff;
    border-radius: .3rem;
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.5);
    padding: 15px;
}

/* 修正 backdrop 遮罩层 */
.modal-backdrop {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(0, 0, 0, 0.5);
}

.close {
  float: right;
  font-size: 21px;
  font-weight: bold;
  line-height: 1;
  color: #000000;
  text-shadow: 0 1px 0 #ffffff;
  opacity: 0.2;
  filter: alpha(opacity=20);
}
.close:hover,
.close:focus {
  color: #000000;
  text-decoration: none;
  cursor: pointer;
  opacity: 0.5;
  filter: alpha(opacity=50);
}
button.close {
  padding: 0;
  cursor: pointer;
  background: transparent;
  border: 0;
  -webkit-appearance: none;
}

.btn {
    display: inline-block;
    padding: 6px 12px;
    margin-bottom: 0;
    font-size: 14px;
    font-weight: 400;
    line-height: 1.42857143;
    text-align: center;
    white-space: nowrap;
    vertical-align: middle;
    -ms-touch-action: manipulation;
    touch-action: manipulation;
    cursor: pointer;
    -webkit-user-select: none;
    -moz-user-select: none;
    -ms-user-select: none;
    user-select: none;
    background-image: none;
    border: 1px solid transparent;
    border-radius: 4px;
}

.btn-close {
    color: #fff;
    background-color: #000;
    border-color: #000;
}

.form-control {
    display: block;
    width: 100%;
    height: calc(1.5em + .75rem + 2px);
    padding: .375rem .75rem;
    font-size: 1rem;
    font-weight: 400;
    line-height: 1.5;
    color: #495057;
    background-color: #fff;
    background-clip: padding-box;
    border: 1px solid #ced4da;
    border-radius: .25rem;
    transition: border-color .15s ease-in-out, box-shadow .15s ease-in-out;
}

.form-group .form-control + .form-control {
    margin-top: 5px !important; /* 让后一个 TextBox 有 10px 间距 */
}