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

html, body {
  height: 100%;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  background-color: #F2F2F7;
  color: #1c1c1e;
  -webkit-tap-highlight-color: transparent;
}

main {
  min-height: 100%;
  padding: 20px;
  padding-bottom: calc(100px + env(safe-area-inset-bottom));
}

/* Floating Action Button */
.fab {
  position: fixed;
  bottom: calc(28px + env(safe-area-inset-bottom));
  left: calc(28px + env(safe-area-inset-left));
  width: 48px;
  height: 48px;
  border-radius: 50%;
  background-color: #007AFF;
  color: white;
  border: none;
  font-size: 28px;
  font-weight: 300;
  line-height: 1;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  box-shadow: 0 4px 12px rgba(0, 122, 255, 0.35);
  z-index: 100;
  transition: transform 0.15s ease, box-shadow 0.15s ease;
}

.fab:active {
  transform: scale(0.92);
  box-shadow: 0 2px 6px rgba(0, 122, 255, 0.3);
}