* {
    margin: 0;
    padding: 0
}

body {
    display: -webkit-box;
    display: -ms-flexbox;
    display: flex;
    -webkit-box-pack: center;
    -ms-flex-pack: center;
    justify-content: center
}

button.btn,
button.btn:focus {
    background: #ffd200;
    color: #e31837;
    -webkit-box-shadow: 0 4px 0 #fca503;
    box-shadow: 0 4px 0 #fca503;
    font-weight: 600;
    font-size: 20px;
    cursor: pointer;
    border-radius: 5em;
    padding: 2px 20px;
    -webkit-transition: 0.1s;
    -o-transition: 0.1s;
    transition: 0.1s
}

button.btn:active,
button.btn:hover {
    background: #b9071e;
    -webkit-box-shadow: 0 4px 0 #6b020c;
    box-shadow: 0 4px 0 #6b020c;
    color: #FFF
}

#game_board {
    /* position: relative; */
    /* display: -webkit-box; */
    display: -ms-flexbox;
    display: flex;
    /* -webkit-box-orient: vertical; */
    /* -webkit-box-direction: normal; */
    -ms-flex-direction: column;
    flex-direction: column;
    /* -webkit-box-pack: center; */
    -ms-flex-pack: center;
    justify-content: center;
    width: 100%;
    height: 100%;
    /* margin: auto; */
    /* padding: 0.5%; */
    /* z-index: 1; */
    position: absolute;
}

#game_board .row_board {
    display: -webkit-box;
    display: -ms-flexbox;
    display: flex;
    -webkit-box-orient: horizontal;
    -webkit-box-direction: normal;
    -ms-flex-direction: row;
    flex-direction: row;
    -webkit-box-pack: center;
    -ms-flex-pack: center;
    justify-content: center;
    width: 100%;
    height: 100%;
    margin: 0.5% 0
}

#game_board .row_board .card_board {
    position: relative;
    width: 100%;
    height: 100%;
    margin: 0 0.5%;
    -webkit-perspective: 700;
    perspective: 700
}

#game_board .row_board .card_board>input[type=checkbox] {
    display: none
}

#game_board .row_board .card_board .content_card {
    position: relative;
    width: 100%;
    height: 100%;
    -webkit-transform-style: preserve-3d;
    transform-style: preserve-3d;
    -webkit-transition: 1s;
    -o-transition: 1s;
    transition: 1s;
    cursor: pointer
}

#game_board .row_board .card_board .content_card .face_card {
    width: 100%;
    height: 100%;
    -webkit-backface-visibility: hidden;
    backface-visibility: hidden;
    position: absolute
}

#game_board .row_board .card_board .content_card .face_card img {
    width: 100%;
    height: 100%;
    border-radius: 14px;
}

#game_board .row_board .card_board .content_card .face_card:last-child {
    -webkit-transform: rotateY(180deg);
    transform: rotateY(180deg)
}

#game_board .row_board .card_board>input[type=checkbox]:checked~.content_card {
    -webkit-transform: rotateY(180deg);
    transform: rotateY(180deg)
}

#game_board .row_board .card_board .open_card {
    -webkit-transform: rotateY(180deg) !important;
    transform: rotateY(180deg) !important
}

#game_board .row_board .card_board .close_card {
    -webkit-transform: rotateY(0deg);
    transform: rotateY(0deg)
}

.welcome_fade {
    background: rgba(0, 0, 0, 0.6);
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100vh;
    z-index: 2000;
    display: -webkit-box;
    display: -ms-flexbox;
    display: flex;
    -webkit-box-orient: vertical;
    -webkit-box-direction: normal;
    -ms-flex-direction: column;
    flex-direction: column;
    -webkit-box-pack: center;
    -ms-flex-pack: center;
    justify-content: center
}

.welcome_fade .content_welcome {
    position: relative;
    margin: auto;
    display: -webkit-box;
    display: -ms-flexbox;
    display: flex;
    -webkit-box-orient: vertical;
    -webkit-box-direction: normal;
    -ms-flex-direction: column;
    flex-direction: column;
    -webkit-box-pack: center;
    -ms-flex-pack: center;
    justify-content: center
}

.welcome_fade .content_welcome img {
    margin: auto;
    max-width: 600px;
    width: 90%;
    height: auto
}

.welcome_fade .content_welcome button.btn,
.welcome_fade .content_welcome button.btn:focus {
    position: absolute;
    margin: auto;
    bottom: 13%;
    left: 50%;
    -webkit-transform: translateX(-50%) translateY(-50%);
    -ms-transform: translateX(-50%) translateY(-50%);
    transform: translateX(-50%) translateY(-50%)
}

@media (max-width:475px) {
    .welcome_fade .content_welcome button.btn {
        bottom: 8%
    }
}