.hdr {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: var(--hdr-h);
  z-index: 100;
  background: var(--white);
}
.hdr__inner {
  height: 100%;
  display: flex;
  align-items: center;
}

.hdr__logo {
  display: flex;
  flex: 0 0 auto;
}
.hdr__logo-full {
  display: block;
  width: 211px;
  height: 29px;
}
.hdr__logo-mark {
  display: none;
}

.hdr__title {
  flex: 1;
  margin: 0;
  text-align: center;
  font-size: 20px;
  line-height: 36px;
  font-weight: 600;
  color: var(--ink);
}
.hdr__year {
  color: var(--primary);
}

.lang {
  position: relative;
  flex: 0 0 auto;
}
.lang__btn {
  display: flex;
  align-items: center;
  gap: 10px;
  height: 24px;
  cursor: pointer;
  list-style: none;
}
.lang__btn::-webkit-details-marker {
  display: none;
}
.lang__globe {
  display: block;
  margin-left: -0.5px;
  margin-right: 1.03px;
}
.lang__label {
  font-size: 16px;
  line-height: 24px;
  font-weight: 700;
  color: var(--ink);
  white-space: nowrap;
}
.lang__caret {
  display: block;
  transition: transform 0.2s ease;
}
.lang[open] .lang__caret {
  transform: rotate(180deg);
}

.lang__menu {
  position: absolute;
  top: calc(100% + 8px);
  right: 0;
  z-index: 20;
  min-width: 100%;
  padding: 4px 0;
  background: var(--white);
  border: 1px solid var(--line);
  border-radius: 8px;
  box-shadow: 0 4px 12px rgb(0 0 0 / 8%);
}

.lang::details-content {
  opacity: 0;
  transform: translateY(-6px);
  transition:
    opacity 0.2s ease,
    transform 0.2s ease,
    content-visibility 0.2s allow-discrete;
}
.lang[open]::details-content {
  opacity: 1;
  transform: translateY(0);
}
.lang__item {
  display: block;
  padding: 6px 16px;
  font-size: 16px;
  line-height: 24px;
  color: var(--ink);
  white-space: nowrap;
  cursor: pointer;
  transition: color 0.2s ease;
}
.lang__item.is-active {
  color: var(--primary);
  cursor: default;
}
a.lang__item:hover,
a.lang__item:focus-visible {
  color: var(--primary);
}

.nav__burger {
  display: none;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
  width: 40px;
  height: 40px;
  padding: 9px 8px;
  background: none;
  border: 0;
  cursor: pointer;
}
.nav__burger span {
  display: block;
  width: 100%;
  height: 2px;
  background: var(--primary);
  border-radius: 2px;
}

@media (max-width: 767px) {
  .hdr {
    height: var(--hdr-h-mobile);
  }
  .hdr__inner {
    gap: 4px;
  }
  .hdr__logo-full {
    display: none;
  }
  .hdr__logo-mark {
    display: block;
    width: 43px;
    height: 29px;
  }
  .hdr__title {
    text-align: left;
    font-family: var(--font-alt);
    font-size: 18px;
    line-height: 24px;
    font-weight: 500;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
  }
  .nav__burger {
    margin-right: -8px;
  }
  .lang {
    display: none;
  }
  .nav__burger {
    display: flex;
  }
}

.banner {
  display: flex;
  align-items: stretch;
  height: 520px;
}

.banner__content {
  flex: 0 0 977px;
  display: flex;
  align-items: flex-start;
  gap: 0;
  padding-left: 376px;
  box-sizing: border-box;
  background-color: var(--primary);
  background-size: cover;
  background-position: center;
}

.banner--do .banner__content {
  background-image: url("../assets/images/banner-bg-do.jpg");
}

.banner__num {
  flex: 0 0 112px;
  margin-top: 196px;
  font-family: var(--font-num);
  font-weight: 400;
  font-size: 84px;
  line-height: 128px;
  letter-spacing: -0.03em;
  color: var(--white);
}

@media (min-width: 768px) {
  body[data-chapter="3"] .banner__num,
  body[data-chapter="4"] .banner__num,
  body[data-chapter="5"] .banner__num,
  body[data-chapter="6"] .banner__num {
    flex-basis: 132px;
  }
}

.banner__text {
  flex: 0 0 auto;
  max-width: 489px;
  padding-top: 227px;
}
@media (min-width: 768px) {
  body[data-chapter="3"] .banner__text,
  body[data-chapter="4"] .banner__text,
  body[data-chapter="5"] .banner__text,
  body[data-chapter="6"] .banner__text {
    max-width: 469px;
  }
}
.banner__chapter {
  font-size: 36px;
  line-height: 42px;
  font-weight: 500;
  letter-spacing: -0.01em;
  color: var(--white);
  margin-bottom: 24px;
}

@media (min-width: 768px) {
  html[lang="vi"] body[data-chapter="5"] .banner__chapter {
    max-width: 420px;
  }
}

.banner__list {
  display: flex;
  flex-direction: column;
  gap: 8px;
  width: 352px;
}
.banner__item {
  font-size: 18px;
  line-height: 24px;
  font-weight: 500;
  color: var(--white);
}

.banner__img {
  flex: 1 1 auto;
  display: block;
  width: 100%;
  height: 100%;
  object-fit: cover;
}

@media (max-width: 767px) {
  .banner {
    flex-direction: column;
    height: auto;
  }
  .banner__img {
    order: -1;
    flex: 0 0 auto;
    height: 185px;
  }

  .banner__content {
    flex: 1 1 auto;
    flex-direction: column;
    align-items: stretch;
    justify-content: flex-start;
    gap: 0;
    padding: 16px;
  }
  .banner--do .banner__content {
    background-image: url("../assets/images/banner-bg-do-mobile.jpg");
  }
  .banner__num {
    flex: 0 0 auto;
    align-self: stretch;
    margin-top: 0;
    font-size: 48px;
    line-height: 56px;
    text-align: left;
  }
  .banner__text {
    flex: 0 0 auto;
    max-width: none;
    padding-top: 12px;
  }
  .banner__chapter {
    font-size: var(--h3-size);
    line-height: var(--h3-lh);
    letter-spacing: var(--h3-ls);
    font-weight: 600;
    margin-bottom: 16px;
    white-space: normal;
  }
  .banner__list {
    width: 100%;
  }
}