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

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

body {
  font-family: "Segoe UI", "PingFang SC", "Microsoft YaHei", sans-serif;
  color: #1a2b3c;
  overflow-x: hidden;
  background: #e8f3ff;
}

.page-bg {
  position: fixed;
  inset: 0;
  z-index: 0;
  background-image: var(--bg-pc);
  background-size: cover;
  background-position: center center;
  background-repeat: no-repeat;
}

.nav-wrap {
  position: relative;
  z-index: 1;
  min-height: 100vh;
  min-height: 100dvh;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: clamp(24px, 5vh, 64px) 16px;
}

.nav-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: clamp(28px, 4.5vw, 72px) clamp(36px, 6vw, 96px);
  width: min(720px, 88vw);
  justify-items: center;
}

.nav-item {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 12px;
  text-decoration: none;
  color: inherit;
  width: 100%;
  max-width: 140px;
  transition: transform 0.22s ease;
}

.nav-item:hover {
  transform: translateY(-4px);
}

.nav-item:active {
  transform: scale(0.97);
}

.nav-icon {
  width: clamp(72px, 12vw, 120px);
  aspect-ratio: 1;
  border-radius: 26%;
  overflow: hidden;
  background: rgba(255, 255, 255, 0.55);
  box-shadow:
    0 10px 28px rgba(40, 90, 160, 0.18),
    0 2px 6px rgba(40, 90, 160, 0.08);
}

.nav-icon img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
}

.nav-label {
  font-size: clamp(14px, 1.6vw, 18px);
  font-weight: 600;
  letter-spacing: 0.02em;
  text-align: center;
  color: #1e2f45;
  text-shadow: 0 1px 0 rgba(255, 255, 255, 0.65);
}

@media (max-width: 768px) {
  .page-bg {
    background-image: var(--bg-mobile);
  }

  .nav-grid {
    width: min(360px, 92vw);
    gap: 28px 22px;
  }

  .nav-icon {
    width: clamp(68px, 22vw, 96px);
    border-radius: 24%;
  }

  .nav-label {
    font-size: 14px;
  }

  .nav-item {
    max-width: 110px;
    gap: 10px;
  }
}