.product-nav {
  position: fixed;
  inset: 14px auto 14px 12px;
  z-index: 24;
  width: 64px;
  padding: 10px 7px;
  display: flex;
  flex-direction: column;
  align-items: stretch;
  gap: 8px;
  border: 1px solid rgba(155, 204, 227, .32);
  border-radius: 20px;
  background: linear-gradient(165deg, rgba(19, 51, 76, .92), rgba(5, 25, 44, .96));
  box-shadow: 0 18px 48px rgba(0, 9, 24, .3), inset 0 1px rgba(255, 255, 255, .08);
  backdrop-filter: blur(22px) saturate(135%);
}
.product-nav-brand,
.product-nav-item {
  min-height: 48px;
  display: flex;
  align-items: center;
  justify-content: center;
  flex-direction: column;
  gap: 4px;
  border-radius: 14px;
  color: #9ab7c9;
  text-decoration: none;
  -webkit-tap-highlight-color: transparent;
}
.product-nav-brand { margin-bottom: 8px; }
.product-nav-brand span {
  width: 38px;
  height: 38px;
  display: grid;
  place-items: center;
  border-radius: 13px;
  color: #fff;
  background: linear-gradient(145deg, #172c40, #061625);
  box-shadow: 3px 2px 0 #1bd0d2, -2px -1px 0 #fe416a;
  font-size: 14px;
  font-weight: 900;
}
.product-nav-item { position: relative; transition: color .18s ease, background .18s ease, transform .18s ease; }
.product-nav-item > span { font-size: 19px; line-height: 1; }
.product-nav-item small { font-size: 9px; font-weight: 750; white-space: nowrap; }
.product-nav-item:hover,
.product-nav-item:focus-visible { color: #e9fbff; background: rgba(84, 185, 217, .12); outline: 0; }
.product-nav-item.active { color: #fff; background: linear-gradient(145deg, rgba(30, 155, 190, .72), rgba(10, 104, 139, .82)); box-shadow: 0 8px 20px rgba(5, 115, 154, .28), inset 0 1px rgba(255,255,255,.15); }
.with-product-nav .app-shell { width: calc(100vw - 104px); margin-left: 90px; }

@media (max-width: 1040px) and (min-width: 761px) {
  .product-nav { inset: 8px auto 8px 8px; width: 58px; border-radius: 17px; }
  .with-product-nav .app-shell { width: calc(100vw - 82px); margin-left: 74px; }
}

@media (max-width: 760px) {
  :root { --mobile-nav-height: 56px; }
  .product-nav {
    inset: auto 0 0;
    width: 100%;
    min-width: 0;
    max-width: 100%;
    box-sizing: border-box;
    height: calc(var(--mobile-nav-height) + env(safe-area-inset-bottom));
    padding: 5px max(10px, env(safe-area-inset-right)) calc(5px + env(safe-area-inset-bottom)) max(10px, env(safe-area-inset-left));
    display: grid;
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 8px;
    border-width: 1px 0 0;
    border-radius: 0;
    background: rgba(5, 27, 47, .96);
  }
  .product-nav-brand { display: none; }
  .product-nav-item { min-height: 44px; width: 100%; min-width: 0; max-width: 100%; flex-direction: row; gap: 7px; border-radius: 12px; }
  .product-nav-item > span { font-size: 16px; }
  .product-nav-item small { font-size: 10px; }
  .with-product-nav .app-shell {
    position: fixed;
    top: var(--mobile-viewport-offset-top, 0px);
    width: 100vw;
    max-width: 100vw;
    height: calc(var(--mobile-viewport-height, 100dvh) - var(--mobile-nav-height) - env(safe-area-inset-bottom));
    margin: 0;
    overflow: hidden;
  }
  .mobile-keyboard-open.with-product-nav .app-shell { height: var(--mobile-viewport-height, 100dvh); }
  .mobile-keyboard-open .product-nav { visibility: hidden; pointer-events: none; transform: translateY(100%); }
  .with-product-nav .toast { bottom: calc(var(--mobile-nav-height) + 10px + env(safe-area-inset-bottom)); }
  .mobile-keyboard-open.with-product-nav .toast { bottom: 10px; }
}

@media (max-width: 375px) {
  :root { --mobile-nav-height: 52px; }
  .product-nav { padding: 3px max(8px, env(safe-area-inset-right)) calc(3px + env(safe-area-inset-bottom)) max(8px, env(safe-area-inset-left)); gap: 5px; }
  .product-nav-item { gap: 5px; border-radius: 10px; }
  .product-nav-item > span { font-size: 15px; }
  .product-nav-item small { font-size: 10px; }
}