@font-face {
    font-family: 'kleenexSans';
    src: url('./font/KleenexSans-Medium.otf');
  }
  /*@font-face {
    font-family: 'kleenexSans';
    src: url('./font/KleenexSans-Bold.otf');
    font-weight: bold;
  }*/


body {
    background: url('./img/fondo.png');    
    background-size: cover;
    background-position: center;
    font-family: 'kleenexSans';
}

.logo_Kleenex {
    width: 169px;
    display: block;
    margin: auto;
    background: url(./img/fondo_logo.png);
    background-size: 100% 100%;
    background-repeat: no-repeat;
    padding: 10px;
    padding-bottom: 20px;
    z-index: 5;
    position: relative;
    filter: drop-shadow(0px -4px 4px #fff);
}
.imgInstrucciones {
    display: block;
    width: 100%;
    margin-top: -48px;
    filter: drop-shadow(0px 2px 2px #fff);
}
.instrucciones {
    background: url(./img/fondo_instrucciones.png);
    background-size: 100% 100%;
    background-position: center;
    color: #fff;
    padding: 50px 10px;
    margin-top: -50px;
    z-index: 4;
    position: relative;
    filter: drop-shadow(2px 4px 6px #fff);    
}
.instrucciones li {
    display: block;
    padding: 0px 20px;
}
.btn-iniciar {
    width: 100px !important;
    display: block;
    margin: auto;
    margin-top: -55px;
    z-index: 5;
    position: relative;
    filter: drop-shadow(0px 4px 2px #fff);
}
.btn-iniciar.v2 {
    margin-top: -73px;
    filter: drop-shadow(0px 2px 1px #fff);
}
.btn-volver {
    width: 100px !important;
    display: block;
    margin: auto;        
    position: relative;
    filter: drop-shadow(0px 4px 2px #000);
}
.bg-opacy {
    min-height: 100vh;
    background-color: #00000087;
}

.board {
    width: 540px;
    height: 440px;
    margin: auto;
    display: flex;
    flex-wrap: wrap;
    perspective: 1000px;
}

.titulo {
    background: #00599c;
}

.btn-primary {
    background-color: #00599c;
}

.time {
    width: 520px;
    margin: auto;   
    perspective: 1000px;
    text-align: center;
    color: #fff;
    font-size: 1.5rem;
}

.cards {
    width: calc(25% - 10px);
    height: calc(25% - 10px);
    margin: 5px;
    position: relative;
    transform: scale(1);
    transform-style: preserve-3d;
    transition: transform .5s;
    box-shadow: 2px 2px 4px 2px #000000d6;
    border-radius: 10px;
}

.cards:active {
    transform: scale(0.97);
    transition: transform .2s;
}

.cards.flip {
    transform: rotateY(180deg);
}

.front-face,
.back-face {
    width: 100%;
    height: 100%;
    padding: 20px;
    position: absolute;
    border-radius: 5px;
    background: #00599c;
    backface-visibility: hidden;
    object-fit: contain;
}
.front-face {
    padding: 10px !important;
}

img.back-face {
    padding: 0;
    object-fit: fill !important;
}

.front-face {
    transform: rotateY(180deg);
}