:root{
  --text-color: #DBE4EF;
  --card-front-color: #144480;
  --card-back-color: #00F4BF;
}

/* box sizing global */
*,
*::before,
*::after { box-sizing: border-box; }

body{
  margin: 0;
  font-family: 'Bai Jamjuree', sans-serif;
  background: url('img/bg-desktop.webp') no-repeat center/cover;
  color: var(--text-color);
  margin-bottom: 20px;
}

/* GRID do container (confere com id="container") */
#container {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 20px;
    padding: 20px;
}

/* cada card */
.cartao{
  width: 100%;
  height: 20rem;
  perspective: 1000px; /* necessário para flip 3D */
  margin: 0;
}

/* wrapper das faces */
.cartao__conteudo {
    position: relative;
    height: 100%;
    transform-style: preserve-3d;
    transition: transform 0.6s ease;
}

/* título */
.cartao__conteudo h3{
  position: absolute;
  top: 0.6rem;
  left: 0.6rem;
  margin: 0;
  padding: 0.4rem 0.6rem;
  border-radius: 6px;
  border: 1px solid var(--text-color);
  font-size: 0.95rem;
  color: var(--text-color);
  background: rgba(0,0,0,0.06);
  z-index: 2;
  backface-visibility: hidden;
}

/* texto base */
.cartao__conteudo p{
  margin: 0;
  padding: 2rem;
  padding-top: 4rem;
  font-size: 1rem;
  line-height: 1.3;
  text-align: center;
}

/* frente e verso ocupam todo o espaço */
.cartao__conteudo__pergunta,
.cartao__conteudo__resposta{
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  backface-visibility: hidden; /* evita texto espelhado visível */
  display: flex;
  align-items: center;
  justify-content: center;
  box-sizing: border-box;
  padding: 2rem;
}

/* estilos específicos */
.cartao__conteudo__pergunta {
    background-color: var(--card-front-color);
    color: var(--text-color);
}

.cartao__conteudo__resposta {
    background-color: rgba(0, 244, 191, 0.2);
    border: 4px solid var(--card-back-color);
    color: var(--card-back-color);
    transform: rotateY(180deg);
}

/* classe que o JS trocará: is-flipped */
.cartao.is-flipped .cartao__conteudo{
  transform: rotateY(180deg);
}

/* footer */
footer{
  background: #000;
  color: #fff;
  position: fixed;
  bottom: 0;
  left: 0;
  right: 0;
  height: 2.2rem;
  display: flex;
  align-items: center;
  justify-content: center;
}

footer p{
  margin: 0;
  font-size: 0.65rem;
}

/* mobile */
@media (max-width: 560px){
  body{ background: url('img/bg-mobile.webp') no-repeat center/cover; }
  .cartao{ height: 16rem; }
  .cartao__conteudo p{ font-size: 3.2vw; padding-top: 5vw; }
  .cartao__conteudo h3{ font-size: 3.5vw; }
}