.install-overlay {
  position: fixed;
  z-index: 140;
  top: var(--app-visual-top, 0px);
  left: 50%;
  bottom: auto;
  width: min(100%, var(--content-max-width));
  height: var(--app-visual-height, 100dvh);
  transform: translateX(-50%);
  background: var(--overlay-install);
  backdrop-filter: blur(var(--overlay-blur, 3px));
  display: flex;
  align-items: flex-end;
  justify-content: center;
  overflow: hidden;
  touch-action: none;
  overscroll-behavior: none;
}
.install-sheet {
  width: 100%;
  max-height: min(calc(var(--app-visual-height, 100dvh) - 10px), 760px);
  background: var(--surface);
  border: 1px solid var(--border);
  border-bottom: 0;
  border-radius: 27px 27px 0 0;
  padding: 0;
  box-shadow: var(--shadow);
  transform: translateY(var(--drag-y, 0px));
  transition: transform 0.22s ease;
  display: flex;
  flex-direction: column;
  overflow: hidden;
  touch-action: none;
  overscroll-behavior: contain;
}
.install-sheet.dragging {
  transition: none;
}
.install-sheet-header {
  display: grid;
  grid-template-columns: 1fr 44px;
  align-items: center;
  gap: 12px;
  padding: 2px 16px 12px;
  border-bottom: 1px solid var(--border);
  background: var(--surface);
}
.install-sheet-header h2 {
  margin: 2px 0 0;
  font-size: 1.16rem;
}
.install-card {
  display: grid;
  grid-template-columns: 72px 1fr;
  align-items: center;
  gap: 14px;
  padding: 15px;
  border: 1px solid var(--border);
  border-radius: 20px;
  background: var(--surface-2);
}
.install-card img {
  width: 72px;
  height: 72px;
  border-radius: 20px;
}
.install-card strong,
.install-card span {
  display: block;
}
.install-card span {
  margin-top: 5px;
  color: var(--muted);
  line-height: 1.4;
}
.install-instruction {
  margin: 14px 2px;
  padding: 14px;
  border-radius: 16px;
  background: var(--accent-soft);
  color: var(--text);
  line-height: 1.45;
}
.install-actions {
  display: grid;
  gap: 9px;
}
.about-actions {
  display: grid;
  gap: 9px;
  margin-top: 16px;
}

.install-sheet-body {
  flex: 1 1 auto;
  min-height: 0;
  overflow-y: auto;
  overflow-x: hidden;
  -webkit-overflow-scrolling: touch;
  overscroll-behavior: contain;
  touch-action: pan-y;
  padding: 16px 18px 18px;
  scrollbar-width: none;
}
.install-sheet-body::-webkit-scrollbar { display:none; }
body.keyboard-open .install-sheet-body { padding-bottom: 14px; }