style.css

* {
  box-sizing: border-box;
}

.box {
  border-radius: 20px;
  box-shadow: 0 0.5rem 1rem rgba(0, 0, 0, 0.15);
}

@media screen and (min-width: 600px) {
  .box {
    width: 80% !important;
  }
}

.time {
  font-weight: 600;
  font-size: 20px;
}

.answers p:hover {
  background-color: antiquewhite;
  cursor: pointer;
}

button.disabled {
  cursor: not-allowed;
}

.check_1 {
  width: 18px;
  min-width: 18px;
  height: 18px;
}

.check_2 {
  width: 8px;
  height: 8px;
}

.answer.checked .check_1 {
  background-color: forestgreen !important;
}

.wrapper button {
  border-style: none;
  letter-spacing: 3px;
  outline: none;
  position: relative;
  overflow: hidden;
  transition: all 0.5s;
}

.wrapper button span {
  position: absolute;
}

.wrapper button span:nth-child(1) {
  height: 3px;
  width: 200px;
  top: 0px;
  left: -200px;
  background: linear-gradient(to right, rgba(0, 0, 0, 0), #f6e58d);
  border-top-right-radius: 1px;
  border-bottom-right-radius: 1px;
  animation: span1 2s linear infinite;
  animation-delay: 1s;
}

@keyframes span1 {
  0% {
    left: -200px;
  }
  100% {
    left: 200px;
  }
}

.wrapper button span:nth-child(2) {
  height: 70px;
  width: 3px;
  top: -70px;
  right: 0px;
  background: linear-gradient(to bottom, rgba(0, 0, 0, 0), #f6e58d);
  border-bottom-left-radius: 1px;
  border-bottom-right-radius: 1px;
  animation: span2 2s linear infinite;
  animation-delay: 2s;
}

@keyframes span2 {
  0% {
    top: -70px;
  }
  100% {
    top: 70px;
  }
}

.wrapper button span:nth-child(3) {
  height: 3px;
  width: 200px;
  right: -200px;
  bottom: 0px;
  background: linear-gradient(to left, rgba(0, 0, 0, 0), #f6e58d);
  border-top-left-radius: 1px;
  border-bottom-left-radius: 1px;
  animation: span3 2s linear infinite;
  animation-delay: 3s;
}

@keyframes span3 {
  0% {
    right: -200px;
  }
  100% {
    right: 200px;
  }
}

.wrapper button span:nth-child(4) {
  height: 70px;
  width: 3px;
  bottom: -70px;
  left: 0px;
  background: linear-gradient(to top, rgba(0, 0, 0, 0), #f6e58d);
  border-top-right-radius: 1px;
  border-top-left-radius: 1px;
  animation: span4 2s linear infinite;
  animation-delay: 4s;
}

@keyframes span4 {
  0% {
    bottom: -70px;
  }
  100% {
    bottom: 70px;
  }
}

@media screen and (max-width: 600px) {
  .title,
  .questionNumber {
    font-size: 20px;
  }

  .question,
  .check-question {
    font-size: 16px;
  }

  .answer h6,
  .check-answer h6 {
    font-size: 13px;
  }
}