@import url("https://fonts.googleapis.com/css2?family=Instrument+Serif:ital@0;1&display=swap");

:root {
  --bg: #0f0f0f;
  --fg: #fff;
  --card-1: #b2b2b2;
  --card-2: #ce2017;
}

* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

body {
  font-family: "Instrument Serif", sans-serif;
}

img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

h1 {
  font-size: 4rem;
  font-weight: 500;
  line-height: 1;
}

p {
  font-size: 2rem;
  font-weight: 500;
  line-height: 1;
}

section {
  position: relative;
  width: 100%;
  height: 100svh;
  padding: 2rem;
  background-color: var(--bg);
  color: var(--fg);
}

.intro,
.outro {
  text-align: center;
  align-content: center;
}

.intro h1,
.outro h1 {
  width: 30%;
  margin: 0 auto;
}

.sticky {
  position: relative;
  display: flex;
  justify-content: center;
  align-items: center;
}

.sticky-header {
  position: absolute;
  top: 20%;
  left: 50%;
  transform: translate(-50%, -50%);
}

.sticky-header h1 {
  position: relative;
  text-align: center;
  will-change: transform, opacity;
  transform: translateY(40px);
  opacity: 0;
}

.card-container {
  position: relative;
  width: 62%;
  display: flex;
  perspective: 1000px;
  transform: translateY(40px);
  will-change: width;
}

.card {
  position: relative;
  flex: 1;
  aspect-ratio: 5/7;
  transform-style: preserve-3d;
  transform-origin: top;
}

#card-1 {
  border-radius: 20px 0 0 20px;
}

#card-2 {
  border-radius: 0 20px 20px 0;
}

.card-front,
.card-back {
  position: absolute;
  width: 100%;
  height: 100%;
  backface-visibility: hidden;
  border-radius: inherit;
  overflow: hidden;
}

.card-back {
  display: flex;
  justify-content: center;
  align-items: center;
  text-align: center;
  transform: rotateY(180deg);
  padding: 2rem;
}

.card-back span {
  position: absolute;
  top: 2rem;
  left: 2rem;
  opacity: 0.4;
}

#card-1 .card-back {
  background-color: var(--card-1);
  color: var(--bg);
}

#card-2 .card-back {
  background-color: var(--card-2);
}

@media (max-width: 1000px) {
  h1 {
    font-size: 3rem;
  }

  .intro h1,
  .outro h1 {
    width: 100%;
  }

  .sticky {
    height: max-content;
    padding: 4rem 2rem;
    flex-direction: column;
  }

  .sticky-header {
    position: relative;
    top: 0;
    left: 0;
    transform: none;
    margin-bottom: 4rem;
  }

  .sticky-header h1 {
    opacity: 1;
  }

  .card-container {
    width: 100%;
    flex-direction: column;
    gap: 2rem;
  }

  .card {
    width: 100%;
    max-width: 400px;
    margin: 0 auto;
    border-radius: 20px !important;
  }

  #card-1,
  #card-2,
  .card-back {
    transform: none;
  }
}