body {
  margin: 0;
  padding: 0;
  font-family: "Helvetica", "Arial", sans-serif;
  text-align: center;
  background-color: #1f3350;
  color: #f0f8ff;
}

.container {
  max-width: 768px;
  margin: auto;
  padding: 40px 20px;
  background: #ffffff;
  box-shadow: 0 0 10px rgba(0,0,0,0.1);
  border-radius: 10px;
  margin-top: 50px;
}

header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 1.5rem 2rem;
  background-color: #1f3350;
}

.logo {
  font-size: 1.8rem;
  font-weight: bold;
}

nav a {
  color: #d6e4f0;
  text-decoration: none;
  margin-left: 2rem;
  font-size: 1rem;
}

.main-section {
  position: relative;
  padding: 2rem 2rem;
  background-color: #1f3350;
  text-align: left;
  overflow: hidden;
}

.letter-r { color: #4dabf7; }
.letter-t { color: #4dabf7; }
.letter-c { color: #4dabf7; }

.circle-bg {
  position: absolute;
  bottom: 0;
  left: 0;
  width: 100%;
  height: 15%;
  background-color: #fff;
  z-index: 0;
  border-top-left-radius: 60px;
  border-top-right-radius: 60px;
}

.main-section h1 {
  font-size: 4rem;
  margin-bottom: 1rem;
}

.main-section p {
  font-size: 1.2rem;
  color: #cbdced;
}

.circles {
  display: flex;
  justify-content: center;
  gap: 7rem;
  margin-top: 4rem;
  flex-wrap: wrap;
  overflow-x: auto;
  padding-bottom: 1rem;
  scroll-snap-type: x mandatory;
  -webkit-overflow-scrolling: touch;
}

.circle {
  flex: 0 0 auto;
  scroll-snap-align: start;
  width: 310px;
  height: 310px;
  border-radius: 50%;
  background-color: #c2eff4;
  position: relative;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: flex-end;
  overflow: hidden;
  box-sizing: border-box;
}

.circle-img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  border-radius: 50%;
  position: absolute;
  top: 0;
  left: 0;
  z-index: 0;
  opacity: 1;
  filter: contrast(0.9) brightness(0.9) saturate(1.0);
}

.circle-text {
  position: relative;
  z-index: 1;
  color: #ffffff;
  font-size: 1.2rem;
  font-weight: bold;
  margin-bottom: 1.1rem;
  text-align: center;
  background: none;
  padding: 0;
  border-radius: 0;
}

.footer {
  background-color: #ffffff;
  color: #1f3350;
  text-align: center;
  padding: 2rem;
}

.company-info {
  font-size: 12px;
  text-align: left;
  margin-bottom: 10px;
}

.company-info p {
  margin: 5px 0;
}

.back-to-top {
  position: fixed;
  bottom: 20px;
  right: 20px;
  display: none;
  border-radius: 0 !important;
}

#contact {
  top: 0;
  margin-bottom: 20px;
}

#contact h2 {
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  color: black;
  margin-left: 400px;
}

#contact h2 .overview {
  font-size: 24px;
  color: blue;
  margin-bottom: 10px;
}

#contact h2 .summary {
  font-size: 34px;
  color: black;
  font-weight: bold;
}

#contact .contact-info {
  text-align: left;
  padding: 1rem 25rem;
  font-size: 1rem;
  color: #333;
}

.logo-link {
  text-decoration: none;
  color: inherit;
  font-weight: bold;
}

@media screen and (max-width: 1024px) {
  .main-section h1 {
    font-size: 3rem;
  }

  .circles {
    gap: 5rem;
  }

  #contact h2 {
    margin-left: 100px;
  }
}

@media screen and (max-width: 768px) {
  .main-section h1 {
    font-size: 2.5rem;
    text-align: left;
  }

  .main-section p {
    font-size: 1rem;
    text-align: left;
  }

  .circles {
    flex-wrap: nowrap;
    overflow-x: auto;
    justify-content: center;
    gap: 1rem;
	overflow-x: visible;
    padding-bottom: 1rem;
    scroll-snap-type: x mandatory;
  }

  .circle {
    width: 180px;
    height: 180px;
    flex-shrink: 1;
    scroll-snap-align: start;
  }

  nav a {
    margin-left: 1rem;
    font-size: 0.95rem;
  }

  #contact h2 {
    margin-left: 20px;
    align-items: center;
    text-align: center;
  }

  #contact h2 .overview {
    font-size: 20px;
  }

  #contact h2 .summary {
    font-size: 28px;
  }
}

@media screen and (max-width: 480px) {
  header {
    flex-direction: column;
    align-items: flex-start;
  }

  nav a {
    display: block;
    margin: 0.5rem 0;
  }

  .circles {
    display: flex;
    flex-wrap: nowrap;                /* 줄바꿈 방지 */
    overflow-x: auto;                 /* 가로 스크롤 허용 */
    justify-content: flex-start;
    gap: 1rem;
    padding-bottom: 1rem;
    scroll-snap-type: x mandatory;
    -webkit-overflow-scrolling: touch;
  }

  .circle {
    width: 160px;                     /* 3개가 보일 수 있는 크기 */
    height: 160px;
    flex: 0 0 auto;
    scroll-snap-align: start;
  }

  .main-section {
    padding: 1rem;
    text-align: center;
  }

  .main-section h1 {
    font-size: 2rem;
  }

  .main-section p {
    font-size: 0.95rem;
  }
}

.responsive-img {
  max-width: 100%;
  height: auto;
  display: block;
  margin: 0 auto;
}