.install-app-button {
  position: fixed;
  left: 20px;
  bottom: 20px;
  z-index: 95;
  display: inline-flex;
  align-items: center;
  gap: 9px;
  min-height: 50px;
  padding: 0 16px;
  border: 0;
  border-radius: 999px;
  background: #0f777d;
  color: #fff;
  font: inherit;
  font-weight: 700;
  box-shadow: 0 12px 28px rgba(0,0,0,.22);
  cursor: pointer;
  opacity: 0;
  visibility: hidden;
  pointer-events: none;
  transform: translateY(10px);
  transition: opacity .24s ease, visibility .24s ease, transform .24s ease, box-shadow .18s ease;
}

.install-app-button:hover {
  transform: translateY(-2px);
  box-shadow: 0 15px 32px rgba(0,0,0,.26);
}

.install-app-button:focus-visible {
  outline: 3px solid rgba(15,119,125,.35);
  outline-offset: 3px;
}

.install-app-button svg {
  width: 21px;
  height: 21px;
  fill: currentColor;
}

.install-app-button.is-visible {
  opacity: 1;
  visibility: visible;
  pointer-events: auto;
  transform: translateY(0);
}

.install-help {
  position: fixed;
  inset: 0;
  z-index: 120;
  display: none;
  place-items: center;
  padding: 20px;
  background: rgba(0,0,0,.5);
}

.install-help.is-visible {
  display: grid;
}

.install-help__card {
  width: min(420px, 100%);
  border-radius: 18px;
  background: #fff;
  color: #18383b;
  padding: 24px;
  box-shadow: 0 24px 70px rgba(0,0,0,.28);
}

.install-help__card h2 {
  margin: 0 0 10px;
  font-size: 1.35rem;
}

.install-help__card p {
  margin: 0 0 14px;
  line-height: 1.5;
}

.install-help__card button {
  width: 100%;
  min-height: 44px;
  border: 0;
  border-radius: 999px;
  background: #0f777d;
  color: #fff;
  font: inherit;
  font-weight: 700;
  cursor: pointer;
}

@media (max-width: 600px) {
  .install-app-button {
    left: 14px;
    bottom: 14px;
    min-height: 48px;
    padding: 0 14px;
  }
}