.page {
  position: relative;
  width: 100%;
  height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  overflow: hidden;
  background: var(--color-bg-page);
  z-index: 2;
}

/* ── Layer 5: Content ── */
.content {
  position: relative;
  z-index: 10;
  display: flex;
  flex-direction: column;
  align-items: center;
  text-align: center;
  animation: fadeUp 1.2s ease-out both;
}

@keyframes fadeUp {
  from {
    opacity: 0;
    transform: translateY(30px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.logo {
  width: 80px;
  height: 80px;
  margin-bottom: 28px;
  filter: drop-shadow(0 0 40px var(--color-mint-accent-glow));
  animation: fadeUp 1.2s ease-out 0.1s both;
}

.title {
  font-family: 'Space Grotesk', sans-serif;
  font-size: 48px;
  font-weight: 300;
  color: var(--color-text-primary);
  letter-spacing: 0.1em;
  margin-bottom: 12px;
  line-height: 1.1;
  animation: fadeUp 1.2s ease-out 0.2s both;
}

.tagline {
  font-family: 'Space Grotesk', sans-serif;
  font-size: 14px;
  font-weight: 300;
  color: var(--color-text-on-glass-soft);
  letter-spacing: 0.15em;
  margin-bottom: 48px;
  animation: fadeUp 1.2s ease-out 0.3s both;
}

/* ── Buttons ── */
.actions {
  display: flex;
  gap: 24px;
  align-items: flex-start;
  animation: fadeUp 1.2s ease-out 0.4s both;
}

.btnGroup {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 8px;
}

.btnPrimary,
.btnGhost {
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 14px 32px;
  border-radius: 10px;
  cursor: pointer;
  transition: all 0.3s;
  backdrop-filter: var(--bf-glass-sm);
  -webkit-backdrop-filter: var(--bf-glass-sm);
}

.btnPrimary {
  background: var(--color-mint-accent-bg);
  border: 1px solid var(--color-mint-accent-border);
}

.btnPrimary .btnName {
  font-family: 'Space Grotesk', sans-serif;
  font-size: 15px;
  font-weight: 500;
  color: var(--color-mint-accent);
}

.btnPrimary:hover {
  background: var(--color-mint-accent-bg-hover);
  box-shadow: 0 0 30px var(--color-mint-accent-glow);
}

.btnGhost {
  background: var(--color-bg-glass);
  border: 1px solid var(--color-border-card);
  /* V2: 玻璃顶边白高光 */
  box-shadow: inset 0 1px 0 var(--color-inset-highlight);
}

.btnGhost .btnName {
  font-family: 'Space Grotesk', sans-serif;
  font-size: 15px;
  font-weight: 500;
  color: var(--color-text-on-glass);
}

.btnGhost:hover {
  background: var(--color-bg-glass-strong);
}

.btnGhost:hover .btnName {
  color: var(--color-text-primary);
}

/* Sub-text below buttons */
.btnSub {
  font-family: 'Space Grotesk', sans-serif;
  font-size: 12px;
  font-weight: 300;
  color: var(--color-mint-accent);
  opacity: 0.65;
}

.btnSubGhost {
  font-family: 'Space Grotesk', sans-serif;
  font-size: 12px;
  font-weight: 300;
  color: var(--color-text-tertiary);
}

/* ── Easter egg ── */
.easter {
  position: absolute;
  bottom: 36px;
  left: 0;
  right: 0;
  z-index: 10;
  font-family: 'Space Grotesk', sans-serif;
  font-size: 13px;
  font-weight: 300;
  font-style: italic;
  color: var(--color-text-quaternary);
  opacity: 0.45;
  letter-spacing: 0.05em;
  cursor: default;
  transition: color 2s ease, opacity 2s ease;
  white-space: nowrap;
  text-align: center;
  animation: fadeUp 1.2s ease-out 0.8s both;
}

.easter:hover {
  color: var(--color-text-tertiary);
  opacity: 1;
}

/* ── Air Spark full-screen overlay ── */
.sparkOverlay {
  position: fixed;
  inset: 0;
  z-index: 100;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  background: var(--color-overlay-soft);
  backdrop-filter: blur(30px);
  -webkit-backdrop-filter: blur(30px);
  animation: sparkBgIn 0.5s ease-out both;
}

@keyframes sparkBgIn {
  from {
    backdrop-filter: blur(0px);
    -webkit-backdrop-filter: blur(0px);
    background: rgba(0, 0, 0, 0);
  }
  to {
    backdrop-filter: blur(30px);
    -webkit-backdrop-filter: blur(30px);
    background: var(--color-overlay-soft);
  }
}

.sparkContent {
  display: flex;
  flex-direction: column;
  align-items: center;
  animation: sparkTextIn 0.4s ease-out 0.1s both;
}

@keyframes sparkTextIn {
  from {
    opacity: 0;
    transform: scale(0.9);
  }
  to {
    opacity: 1;
    transform: scale(1);
  }
}

.sparkTitle {
  font-family: 'Space Grotesk', sans-serif;
  font-size: clamp(40px, 5vw, 64px);
  font-weight: 300;
  color: var(--color-text-primary);
  line-height: 1.2;
  text-align: center;
}

.sparkEmoji {
  font-size: 0.6em;
  vertical-align: baseline;
}

.sparkSub {
  font-family: 'Space Grotesk', sans-serif;
  font-size: 16px;
  font-weight: 300;
  color: var(--color-text-secondary);
  margin-top: 20px;
}

/* ── Music button — bottom right ── */
.musicBtn {
  position: absolute;
  bottom: 25px;
  right: 32px;
  z-index: 10;
  width: 36px;
  height: 36px;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 0;
  background: none;
  border: none;
  outline: none;
  appearance: none;
  -webkit-appearance: none;
  -webkit-tap-highlight-color: transparent;
  user-select: none;
  -webkit-user-select: none;
  color: var(--color-text-quaternary);
  cursor: pointer;
  transition: color 0.3s;
  animation: fadeUp 1.2s ease-out 0.8s both;
}

.musicBtn:hover {
  color: var(--color-text-tertiary);
}


/* ── Responsive ── */
@media (max-width: 768px) {
  .logo {
    width: 60px;
    height: 60px;
  }

  .title {
    font-size: 32px;
  }

  .tagline {
    font-size: 12px;
    margin-bottom: 36px;
  }

  .actions {
    flex-direction: column;
    gap: 16px;
  }

  .btnPrimary,
  .btnGhost {
    min-width: 200px;
  }

  .easter {
    font-size: 11px;
    bottom: 24px;
  }

  .musicBtn {
    bottom: 24px;
    right: 20px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .content,
  .logo,
  .title,
  .tagline,
  .actions,
  .easter,
  .sparkOverlay,
  .sparkContent,
  .musicBtn {
    animation: none !important;
    opacity: 1 !important;
    transform: none !important;
  }

}
