html {
  font-size: 16px;
}

*,
*::before,
*::after {
  box-sizing: border-box;
}

body {
  margin: 0;
  color: #1d1d1d;
  font-family: Arial, Helvetica, sans-serif;
  background: #ffffff;
}

a {
  color: inherit;
  text-decoration: none;
}

img {
  display: block;
  max-width: 100%;
}

button {
  font: inherit;
}

.clearfix::after {
  content: "";
  display: table;
  clear: both;
}

.site-wrap {
  width: min(1180px, calc(100vw - 32px));
  margin: 0 auto;
}

#site-header {
  padding: 28px 0 18px;
}

.hdr-content {
  margin-bottom: 14px;
}

.logo {
  margin: 0;
}

.logo a {
  display: inline-block;
}

.logo img {
  width: min(335px, 72vw);
  height: auto;
}

.navigation {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
  padding: 14px 0;
  border-top: 1px solid #dfdfdf;
  border-bottom: 1px solid #dfdfdf;
}

.menu,
.social,
.child,
.share ul {
  list-style: none;
  margin: 0;
  padding: 0;
}

.menu,
.social {
  display: flex;
  align-items: center;
  gap: 22px;
}

.parent > a,
.social a,
.menu-button {
  display: inline-block;
  font-size: 0.875rem;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: #525252;
}

.menu-button {
  border: 0;
  padding: 0;
  background: transparent;
  cursor: pointer;
}

.first-child {
  position: relative;
  display: none;
}

.child {
  position: absolute;
  top: calc(100% + 10px);
  left: 0;
  min-width: 180px;
  padding: 8px 0;
  background: #ffffff;
  border: 1px solid #dedede;
  box-shadow: 0 14px 30px rgba(0, 0, 0, 0.08);
  display: none;
  z-index: 10;
}

.child.opened {
  display: block;
}

.child li a {
  display: block;
  padding: 10px 16px;
  font-size: 0.875rem;
  color: #444444;
}

.site-container {
  padding: 38px 0 18px;
}

.slide-detail-content {
  position: relative;
}

.feature-frame {
  width: min(100%, 980px);
  margin: 0 auto;
  aspect-ratio: 16 / 10;
  overflow: hidden;
  border: 1px solid #e2e2e2;
  background: #f6f6f6;
}

.feature-frame img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  object-position: center;
}

.slider-txt {
  padding: 28px 0 0;
}

.desc-header {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 24px;
}

.course-name {
  margin: 0 0 8px;
  font-size: 0.875rem;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: #8a5d35;
}

.title {
  margin: 0;
  font-family: Georgia, "Times New Roman", serif;
  font-size: clamp(2.1rem, 3vw, 3rem);
  font-weight: 400;
  line-height: 1.08;
  color: #1c1c1c;
}

.share {
  display: flex;
  align-items: center;
  gap: 14px;
}

.share > p {
  margin: 0;
  font-size: 0.8125rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: #7b7b7b;
}

.share ul {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.share-action {
  display: inline-block;
  border: 1px solid #d9d9d9;
  padding: 10px 14px;
  background: #ffffff;
  color: #444444;
  font-size: 0.8125rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  cursor: pointer;
}

.desc {
  max-width: 820px;
  padding-top: 16px;
}

.brief,
.page-note p,
#site-footer p {
  margin: 0;
  color: #666666;
  font-size: 1rem;
  line-height: 1.8;
}

.page-note {
  padding: 24px 0 12px;
}

#site-footer {
  padding: 24px 0 36px;
  border-top: 1px solid #dfdfdf;
}

#site-footer p {
  color: #4d4d4d;
}

@media (max-width: 860px) {
  .navigation {
    align-items: flex-start;
    flex-direction: column;
  }

  .menu {
    width: 100%;
    justify-content: space-between;
    gap: 16px;
  }

  .first-child {
    display: block;
  }

  .menu .parent:not(.first-child) {
    display: none;
  }

  .social {
    gap: 16px;
  }

  .feature-frame {
    width: 100%;
    aspect-ratio: 4 / 3;
  }

  .desc-header,
  .share {
    align-items: flex-start;
    flex-direction: column;
  }
}

@media (max-width: 540px) {
  .site-wrap {
    width: min(100vw - 20px, 1180px);
  }

  #site-header {
    padding-top: 20px;
  }

  .navigation {
    padding: 12px 0;
  }

  .share ul {
    gap: 6px;
  }

  .share-action {
    padding: 9px 12px;
  }
}