game/css/training/modal.css

.modal__backdrop {
    position: fixed;
    top: 0;
    right: 0;
    bottom: 0;
    left: 0;
    /*background: rgba(0, 0, 0, 0.5);*/
    opacity: 0;
    z-index: -1;
    pointer-events: none;
    transition: opacity0 .2s ease-in;
}

.modal__content {
    position: relative;
    width: auto;
    margin: 10px;
    transition: opacity 0.3s ease-in;
    display: flex;
    flex-direction: column;
    background-color: #fff;
    background-clip: padding-box;
    border: 1px solid rgba(0, 0, 0, 0.2);
    border-radius: 0.3rem;
    box-shadow: 0 0 7px 0 rgba(0, 0, 0, 0.3);
}

@media (min-width: 576px) {
    .modal__content {
        max-width: 500px;
        margin: 50px auto;
    }
}

.modal__show .modal__backdrop,
.modal__show .modal__content {
    opacity: 1;
    z-index: 1050;
    pointer-events: auto;
    overflow-y: auto;
}

.modal__header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 15px;
    border-bottom: 1px solid #eceeef;
}

.modal__title {
    margin-top: 0;
    margin-bottom: 0;
    line-height: 1.5;
    font-size: 1.25rem;
    font-weight: 500;
}

.modal__btn-close {
    float: right;
    font-family: sans-serif;
    font-size: 24px;
    font-weight: 700;
    line-height: 1;
    color: #000;
    text-shadow: 0 1px 0 #fff;
    opacity: 0.5;
    text-decoration: none;
}

.modal__btn-close:focus,
.modal__btn-close:hover {
    color: #000;
    text-decoration: none;
    cursor: pointer;
    opacity: 0.75;
}

.modal__body {
    position: relative;
    flex: 1 1 auto;
    padding: 15px;
    overflow: auto;
}

.modal__footer {
    display: flex;
    align-items: center;
    justify-content: flex-end;
    padding: 1rem;
    border-top: 1px solid #e9ecef;
    border-bottom-right-radius: 0.3rem;
    border-bottom-left-radius: 0.3rem;
}