*,
*:before,
*:after {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
  font-size: 100%;
}

body {
  animation: colorchange 15s infinite alternate;
  cursor: pointer;
}

h1 {
  margin-bottom:20px;
  text-align: center; 
}

h1:hover {
  color:white;
}

.invitation h2 {
  margin-top: 20px; 
  text-align: center;
}

.diploma {
  background-color: #ffffcc;
  width: 50%;
  border: 15px;
  border-radius: 50px;
    padding: 50px;
    margin: 20px;
    box-shadow: 0 4px 8px 0 rgba(0, 0, 0, 0.2), 0 6px 20px 0 rgba(0, 0, 0, 0.19);
  font-family: sans-serif;
  font-size: 22px;
  line-height: 1.5;
  text-align: center; 
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  z-index: -1;

}

.invitation {
  background-color: #ffffe6;
  width: 50%;
  border: 15px;
  border-radius: 50px;
  padding: 50px;
  margin: 20px;
  box-shadow: 0 4px 8px 0 rgba(0, 0, 0, 0.2), 0 6px 20px 0 rgba(0, 0, 0, 0.19);
  font-family: 'Noto Sans KR', sans-serif;
  font-size: 22px;
  line-height: 1.5;
  text-align: center; 
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  z-index: 1;
  display: none;

}

button {
  border-radius: 20px;
  background-color: black;
  color: white;
  padding: 10px;
  position: absolute;
  bottom: 20%;
  left: 50%;
  transform: translateX(-50%);
  z-index: 0;
}

.invitation img {
  width: 50%;
  margin-top: 30px;
  margin-bottom: 30px;
}

.invitation p {
  font-size: 15px;
}

strong {
  animation: blink 1s infinite alternate;
  cursor: pointer;
}

@keyframes colorchange {
  0% {
    background-color: #800000;
  } 20% {
    background-color: #00394d;
  } 40% {
    background-color: #004d00;
  } 60%{
    background-color: #e6e600;
  } 80%{
    background-color: #000000;
  } 100%
}

@keyframes blink {
  0% {
    opacity: 0;
  } 100% {
    opacity: 100;
  } 
}