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

html {
  font-size: 16px;
}


body {
  font-family: "Pretendard", sans-serif;
  font-weight: 400;
  font-size: 1rem;
  line-height: 1.375;
  word-break: keep-all; 
  background-color: white;
  letter-spacing: 0.015rem;
  padding: 0;
  margin: 0;
}

.introduction {
  position: relative;
  max-width: 100%; 
  margin: 1rem auto 2rem auto;
  padding: 2rem;
  text-align: left;
  line-height: 1.375;
  box-sizing: border-box; 
  overflow-wrap: break-word; 
}

.lang-switch{
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 1rem;
  white-space: nowrap;     
}

.lang-switch .name{
  overflow: hidden;        
  text-overflow: ellipsis; 
  min-width: 0;           
  flex: 1 1 auto;          
}

.lang-link{
  flex: 0 0 auto;          
  margin-left: auto;       
  text-decoration: none;
  color: dimgray;
  opacity: .8;
  transition: opacity .2s ease;
}

.intro-header {
  letter-spacing: 0.035rem;
  line-height: 1.625;
}

.lang-link:hover{ 
  opacity: 1; 
}

a {
  text-decoration: none;
  color: blue;
  cursor: pointer;
  animation: blink 5s infinite linear;
}

@keyframes blink {
  0% { opacity: .25; }
  100% { opacity: 1; }
}

.no-wrap {
  white-space: nowrap;
}

@media (max-width: 360px){
  .lang-switch{ 
    font-size: 0.9rem; 
  }
}

@media screen and (max-width: 768px) and (orientation: portrait) {
  html, body {
    overflow: hidden;
    height: 100%;
  }

  .introduction {
    max-width: 95%;
    padding: 1.5rem;
    font-size: 0.825rem;
    line-height: 1.375;
  }
}

@media screen and (max-width: 768px) and (orientation: landscape) {
  .introduction {
    max-width: 95%;
    padding: 1.5rem;
    font-size: 0.75rem;
    line-height: 1.375;
  }
}

@media screen and (min-width: 900px) {
  .introduction {
    line-height: 1.375;
    padding-left: 3rem;
    padding-right: 3rem;
    font-size: clamp(16px, 1vw, 18px); 
    max-width: 45%; 
  }
}