.study-return-link {
  position: fixed;
  z-index: 1000;
  left: 50%;
  bottom: calc(16px + env(safe-area-inset-bottom, 0px));
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 44px;
  max-width: calc(100vw - 32px);
  box-sizing: border-box;
  padding: 10px 20px;
  transform: translateX(-50%);
  border: 1px solid #26a69a;
  border-radius: 24px;
  background: #1a3326;
  box-shadow: 0 4px 20px rgba(0, 0, 0, .3);
  color: #e8f5e9;
  font: 700 13px/1.4 'JetBrains Mono', monospace;
  letter-spacing: .2px;
  text-align: center;
  text-decoration: none;
}

.study-return-link:hover {
  background: #244735;
  color: #fff;
}

.study-return-link:focus-visible {
  outline: 3px solid #26a69a;
  outline-offset: 3px;
}