:root {
  --intro-ink: #111111;
  --intro-muted: rgba(17, 17, 17, 0.58);
  --intro-glass: rgba(255, 255, 255, 0.42);
  --intro-glass-strong: rgba(255, 255, 255, 0.72);
  --intro-line: rgba(17, 17, 17, 0.08);
}

html,
body {
  min-height: 100%;
  background: #ffffff;
}

body.intro-body {
  margin: 0;
  overflow: hidden;
  color: var(--intro-ink);
  font-family: "Noto Sans KR", sans-serif;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
  background:
    radial-gradient(circle at 20% 18%, rgba(0, 0, 0, 0.025), transparent 24%),
    radial-gradient(circle at 78% 26%, rgba(0, 0, 0, 0.02), transparent 22%),
    radial-gradient(circle at 50% 80%, rgba(0, 0, 0, 0.018), transparent 28%),
    linear-gradient(180deg, #ffffff 0%, #fbfbfb 100%);
}

.intro-page {
  position: relative;
  min-height: 100svh;
  isolation: isolate;
}

.intro-page::before {
  content: "";
  position: absolute;
  inset: -12%;
  z-index: 0;
  pointer-events: none;
  background:
    radial-gradient(circle at 50% 44%, rgba(0, 0, 0, 0.03), transparent 34%),
    radial-gradient(circle at 14% 74%, rgba(0, 0, 0, 0.02), transparent 26%),
    radial-gradient(circle at 86% 70%, rgba(0, 0, 0, 0.02), transparent 28%);
  filter: blur(24px);
}

.intro-brand {
  position: fixed;
  top: clamp(20px, 2.8vw, 36px);
  left: clamp(20px, 2.8vw, 36px);
  z-index: 4;
  font-size: 0.92rem;
  font-weight: 600;
  letter-spacing: -0.03em;
  color: rgba(17, 17, 17, 0.85);
}

.intro-hero {
  position: relative;
  z-index: 2;
  min-height: 100svh;
  display: grid;
  place-items: center;
  padding:
    clamp(92px, 14vh, 128px)
    clamp(20px, 4vw, 48px)
    clamp(36px, 6vh, 56px);
}

.intro-copy {
  position: relative;
  z-index: 3;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: clamp(18px, 2.5vw, 26px);
  max-width: min(920px, calc(100vw - 40px));
  text-align: center;
}

.intro-kicker {
  margin: 0;
  font-size: clamp(0.75rem, 1.2vw, 0.95rem);
  font-weight: 600;
  letter-spacing: 0.22em;
  text-transform: uppercase;
  color: var(--intro-muted);
}

.intro-title {
  margin: 0;
  display: flex;
  flex-direction: column;
  gap: 0.16em;
  font-family: "Noto Sans KR", sans-serif;
  font-size: clamp(1.9rem, 4.8vw, 4.1rem);
  line-height: 0.94;
  letter-spacing: -0.06em;
  font-weight: 500;
  text-wrap: balance;
}

.intro-title span {
  display: block;
}

.intro-cta {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.75rem;
  min-width: min(100%, 240px);
  padding: 15px 22px;
  border: 1px solid rgba(17, 17, 17, 0.08);
  border-radius: 999px;
  text-decoration: none;
  color: var(--intro-ink);
  background: var(--intro-glass);
  box-shadow:
    0 12px 36px rgba(0, 0, 0, 0.08),
    inset 0 1px 0 rgba(255, 255, 255, 0.82);
  backdrop-filter: blur(20px) saturate(180%);
  -webkit-backdrop-filter: blur(20px) saturate(180%);
  font-size: clamp(0.95rem, 1.8vw, 1rem);
  font-weight: 600;
  letter-spacing: -0.02em;
  transition:
    transform 0.24s ease,
    background-color 0.24s ease,
    box-shadow 0.24s ease,
    border-color 0.24s ease;
}

.intro-cta:hover,
.intro-cta:focus-visible {
  transform: translateY(-2px);
  background: var(--intro-glass-strong);
  border-color: rgba(17, 17, 17, 0.12);
  box-shadow:
    0 18px 44px rgba(0, 0, 0, 0.1),
    inset 0 1px 0 rgba(255, 255, 255, 0.9);
  outline: none;
}

.intro-cta__arrow {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  transition: transform 0.24s ease;
}

.intro-cta:hover .intro-cta__arrow,
.intro-cta:focus-visible .intro-cta__arrow {
  transform: translateX(2px);
}

.intro-stage {
  position: absolute;
  inset: 0;
  z-index: 1;
  pointer-events: none;
  overflow: hidden;
}

.intro-float-item {
  position: absolute;
  left: var(--x);
  top: var(--y);
  width: var(--size);
  margin: 0;
  transform: translateY(calc(-1 * var(--drop-start))) scale(0.76, 1.18) rotate(calc(var(--rotation) - 6deg));
  opacity: 0;
  will-change: transform, opacity, filter;
  animation:
    intro-drop var(--drop-duration) cubic-bezier(0.18, 0.9, 0.18, 1) var(--drop-delay) forwards,
    intro-float var(--float-duration) ease-in-out calc(var(--drop-delay) + var(--drop-duration)) infinite alternate;
  filter:
    drop-shadow(0 20px 24px rgba(0, 0, 0, 0.12))
    drop-shadow(0 0 22px var(--shadow-color));
}

.intro-float-item img {
  display: block;
  width: 100%;
  height: auto;
  user-select: none;
  -webkit-user-drag: none;
}

@keyframes intro-drop {
  0% {
    opacity: 0;
    transform: translateY(calc(-1 * var(--drop-start))) scale(0.76, 1.18) rotate(calc(var(--rotation) - 6deg));
    filter:
      blur(10px)
      drop-shadow(0 20px 24px rgba(0, 0, 0, 0.12))
      drop-shadow(0 0 22px var(--shadow-color));
  }

  50% {
    opacity: 1;
    filter:
      blur(0)
      drop-shadow(0 20px 24px rgba(0, 0, 0, 0.12))
      drop-shadow(0 0 22px var(--shadow-color));
  }

  68% {
    transform: translateY(0) scale(1.1, 0.84) rotate(var(--rotation));
  }

  80% {
    transform: translateY(-16px) scale(0.96, 1.04) rotate(calc(var(--rotation) + 2deg));
  }

  92% {
    transform: translateY(6px) scale(1.02, 0.98) rotate(calc(var(--rotation) - 1deg));
  }

  100% {
    opacity: 1;
    transform: translateY(0) scale(1) rotate(var(--rotation));
  }
}

@keyframes intro-float {
  from {
    transform: translateY(0) rotate(var(--rotation));
  }

  to {
    transform: translateY(-14px) rotate(calc(var(--rotation) + 1.5deg));
  }
}

@media (max-width: 1024px) {
  .intro-copy {
    max-width: min(760px, calc(100vw - 32px));
  }
}

@media (max-width: 768px) {
  .intro-brand {
    top: 20px;
    left: 20px;
    font-size: 0.86rem;
  }

  .intro-hero {
    padding:
      88px 20px 34px;
  }

  .intro-copy {
    gap: 18px;
    max-width: min(560px, calc(100vw - 28px));
  }

  .intro-title {
    font-size: clamp(1.9rem, 7.8vw, 3rem);
    line-height: 0.96;
    font-weight: 600;
  }

  .intro-cta {
    min-width: min(100%, 190px);
    padding: 10px 0px;
    font-size: 0.88rem;
    gap: 0.6rem;
  }
}

@media (max-width: 480px) {
  .intro-kicker {
    letter-spacing: 0.16em;
  }

  .intro-title {
    font-size: clamp(1.7rem, 7.4vw, 2.6rem);
    font-weight: 600;
  }

  .intro-float-item {
    filter:
      drop-shadow(0 16px 18px rgba(0, 0, 0, 0.11))
      drop-shadow(0 0 18px var(--shadow-color));
  }

  .intro-cta {
    min-width: min(100%, 170px);
    padding: 10px 0px;
    font-size: 0.84rem;
    gap: 0.5rem;
  }
}

@media (prefers-reduced-motion: reduce) {
  .intro-cta,
  .intro-cta__arrow {
    transition: none;
  }

  .intro-float-item {
    animation: none;
    opacity: 1;
    transform: none;
    filter:
      drop-shadow(0 16px 18px rgba(0, 0, 0, 0.1))
      drop-shadow(0 0 14px var(--shadow-color));
  }
}