TrueFocus

.focus-container {
  position: relative;
  display: flex;
  gap: 1em;
  justify-content: center;
  align-items: center;
  flex-wrap: wrap;
  outline: none;
  user-select: none;
}

.focus-word {
  position: relative;
  font-size: 3rem;
  font-weight: 900;
  cursor: pointer;
  transition:
    filter 0.3s ease,
    color 0.3s ease;
  outline: none;
  user-select: none;
}

.focus-word.active {
  filter: blur(0);
}

.focus-frame {
  position: absolute;
  top: 0;
  left: 0;
  pointer-events: none;
  box-sizing: content-box;
  border: none;
}

.corner {
  position: absolute;
  width: 1rem;
  height: 1rem;
  border: 3px solid var(--border-color, #fff);
  filter: drop-shadow(0px 0px 4px var(--border-color, #fff));
  border-radius: 3px;
  transition: none;
}

.top-left {
  top: -10px;
  left: -10px;
  border-right: none;
  border-bottom: none;
}

.top-right {
  top: -10px;
  right: -10px;
  border-left: none;
  border-bottom: none;
}

.bottom-left {
  bottom: -10px;
  left: -10px;
  border-right: none;
  border-top: none;
}

.bottom-right {
  bottom: -10px;
  right: -10px;
  border-left: none;
  border-top: none;
}