/* 全画面イントロ（LP 初回表示）— theme-ocean / ks-background と併用
   粒子（canvas）が周辺からロゴへ収束 → .is-revealed でロゴ・文言をフェードイン → 拡散して退場 */

.lp-intro {
  --lp-intro-ease: cubic-bezier(0.22, 1, 0.36, 1);
  position: fixed;
  inset: 0;
  z-index: 10000;
  display: flex;
  align-items: center;
  justify-content: center;
  overflow: hidden;
  background:
    radial-gradient(ellipse 90% 70% at 12% 8%, rgba(90, 164, 192, 0.22), transparent 55%),
    radial-gradient(ellipse 85% 65% at 88% 12%, rgba(63, 135, 165, 0.18), transparent 52%),
    radial-gradient(ellipse 80% 60% at 50% 100%, rgba(143, 188, 203, 0.16), transparent 50%),
    linear-gradient(180deg, #fffbf8 0%, #f2f8f8 45%, #e7f1f2 100%);
  opacity: 1;
  visibility: visible;
  transition:
    opacity 0.82s var(--lp-intro-ease),
    visibility 0.82s var(--lp-intro-ease);
}

.lp-intro.is-exiting {
  opacity: 0;
  visibility: hidden;
  pointer-events: none;
}

body.lp-intro-active {
  overflow: hidden;
}

/* 粒子収束キャンバス（inner より背面） */
.lp-intro__particles {
  position: absolute;
  inset: 0;
  z-index: 0;
  width: 100%;
  height: 100%;
  pointer-events: none;
}

.lp-intro__inner {
  position: relative;
  z-index: 1;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 1.35rem;
  width: min(92vw, 28rem);
  padding: 1.5rem;
  text-align: center;
}

.lp-intro__glow {
  position: absolute;
  inset: -40%;
  z-index: -1;
  border-radius: 50%;
  background: radial-gradient(circle, rgba(90, 164, 192, 0.28) 0%, transparent 68%);
  animation: lp-intro-glow 2.4s ease-in-out infinite;
}

/* ロゴ・タグライン・ステップは粒子の収束完了（.is-revealed）に同期して表示 */
.lp-intro__logo {
  display: block;
  width: min(72vw, 18.5rem);
  height: auto;
  opacity: 0;
  transform: scale(0.9) translateY(12px);
  filter: drop-shadow(0 12px 28px rgba(31, 79, 99, 0.18));
}

.lp-intro.is-revealed .lp-intro__logo {
  animation: lp-intro-logo-in 0.55s var(--lp-intro-ease) forwards;
}

.lp-intro__tagline {
  margin: 0;
  font-family: 'Noto Sans JP', sans-serif;
  font-size: clamp(0.95rem, 2.8vw, 1.08rem);
  font-weight: 700;
  line-height: 1.55;
  letter-spacing: 0.02em;
  color: #1f4f63;
  opacity: 0;
  transform: translateY(10px);
}

.lp-intro.is-revealed .lp-intro__tagline {
  animation: lp-intro-tag-in 0.5s var(--lp-intro-ease) 0.1s forwards;
}

.lp-intro__steps {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 0.45rem;
  margin: 0;
  padding: 0;
  list-style: none;
  opacity: 0;
}

.lp-intro.is-revealed .lp-intro__steps {
  animation: lp-intro-tag-in 0.5s var(--lp-intro-ease) 0.18s forwards;
}

.lp-intro__step {
  padding: 0.32rem 0.62rem;
  border-radius: 999px;
  font-family: 'Noto Sans JP', sans-serif;
  font-size: 0.72rem;
  font-weight: 700;
  letter-spacing: 0.03em;
  color: #2b6f8b;
  background: rgba(255, 255, 255, 0.72);
  border: 1px solid rgba(63, 135, 165, 0.28);
  box-shadow: 0 6px 16px rgba(31, 79, 99, 0.08);
  opacity: 0.45;
  transform: scale(0.96);
  transition:
    opacity 0.35s ease,
    transform 0.35s var(--lp-intro-ease),
    background 0.35s ease,
    color 0.35s ease;
}

.lp-intro__step.is-active {
  opacity: 1;
  transform: scale(1);
  color: #fff;
  background: linear-gradient(145deg, #5aa4c0, #3f87a5 48%, #2f6f8b);
  border-color: rgba(43, 111, 139, 0.35);
}

/* スキップボタン */
.lp-intro__skip {
  position: absolute;
  right: clamp(1rem, 4vw, 2rem);
  bottom: clamp(1.25rem, 5vh, 2.25rem);
  z-index: 2;
  padding: 0.45rem 1.1rem;
  border-radius: 999px;
  border: 1px solid rgba(63, 135, 165, 0.35);
  background: rgba(255, 255, 255, 0.6);
  color: #2b6f8b;
  font-family: 'Noto Sans JP', sans-serif;
  font-size: 0.78rem;
  font-weight: 600;
  letter-spacing: 0.04em;
  cursor: pointer;
  transition: background 0.2s ease, color 0.2s ease;
}

.lp-intro__skip:hover {
  background: rgba(255, 255, 255, 0.9);
  color: #1f4f63;
}

.lp-intro__skip:focus-visible {
  outline: 2px solid #3f87a5;
  outline-offset: 2px;
}

.lp-intro__ring {
  position: absolute;
  inset: 0;
  pointer-events: none;
}

.lp-intro__ring::before {
  content: '';
  position: absolute;
  top: 50%;
  left: 50%;
  width: min(88vmin, 34rem);
  height: min(88vmin, 34rem);
  transform: translate(-50%, -50%) scale(0.35);
  border-radius: 50%;
  border: 1px solid rgba(90, 164, 192, 0.35);
  opacity: 0;
}

@media (max-width: 640px) {
  .lp-intro__inner {
    transform: translateY(-5vh);
  }
}

.lp-intro.is-exiting .lp-intro__ring::before {
  animation: lp-intro-ring-out 0.82s var(--lp-intro-ease) forwards;
}

@keyframes lp-intro-logo-in {
  to {
    opacity: 1;
    transform: scale(1) translateY(0);
  }
}

@keyframes lp-intro-tag-in {
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@keyframes lp-intro-glow {
  0%, 100% { transform: scale(0.96); opacity: 0.75; }
  50% { transform: scale(1.04); opacity: 1; }
}

@keyframes lp-intro-ring-out {
  0% {
    opacity: 0.85;
    transform: translate(-50%, -50%) scale(0.35);
  }
  100% {
    opacity: 0;
    transform: translate(-50%, -50%) scale(2.4);
  }
}

@media (prefers-reduced-motion: reduce) {
  .lp-intro,
  .lp-intro__logo,
  .lp-intro__tagline,
  .lp-intro__steps,
  .lp-intro__glow {
    animation: none !important;
    transition: none !important;
  }

  .lp-intro__logo,
  .lp-intro__tagline,
  .lp-intro__steps {
    opacity: 1;
    transform: none;
  }
}