.option-b {
  font-family: "Noto Sans KR", sans-serif;
  background: var(--steel-bg);
}

.b-header {
  position: relative;
  z-index: 80;
  height: 66px;
  color: #ffffff;
  background: var(--steel-ink);
  border-bottom: 1px solid rgba(255, 255, 255, 0.14);
}

.b-header__inner {
  display: flex;
  height: 100%;
  align-items: center;
  justify-content: space-between;
  gap: 26px;
}

.b-brand {
  display: inline-flex;
  min-height: 44px;
  align-items: center;
  gap: 11px;
  min-width: 180px;
  font-size: 16px;
  font-weight: 800;
}

.b-brand__lines {
  display: grid;
  width: 27px;
  gap: 4px;
}

.b-brand__lines span {
  height: 3px;
  background: var(--steel-tint);
}

.b-brand__lines span:nth-child(2) {
  width: 19px;
}

.b-nav {
  display: flex;
  align-items: center;
  gap: 6px;
}

.b-nav a {
  display: inline-flex;
  min-height: 44px;
  align-items: center;
  padding: 0 13px;
  color: rgba(255, 255, 255, 0.72);
  border-bottom: 2px solid transparent;
  font-size: 13px;
  font-weight: 600;
}

.b-nav a:hover,
.b-nav a[aria-current="page"] {
  color: #ffffff;
  border-bottom-color: var(--steel-tint);
}

.b-header__contact {
  display: inline-flex;
  min-height: 42px;
  align-items: center;
  gap: 7px;
  padding: 0 13px;
  color: var(--steel-ink);
  background: var(--steel-tint);
  border-radius: 5px;
  font-size: 13px;
  font-weight: 800;
}

.b-menu-button {
  display: none;
  width: 44px;
  height: 44px;
  align-items: center;
  justify-content: center;
  color: #ffffff;
  background: transparent;
  border: 1px solid rgba(255, 255, 255, 0.28);
  border-radius: 5px;
}

.b-hero {
  position: relative;
  min-height: 450px;
  display: flex;
  align-items: center;
  overflow: hidden;
  color: #ffffff;
  background: var(--steel-ink) url("assets/coil.jpg") center 46% / cover no-repeat;
}

.b-hero::before {
  position: absolute;
  inset: 0;
  background: rgba(9, 30, 64, 0.76);
  content: "";
}

.b-hero__content {
  position: relative;
  z-index: 1;
  padding-block: 58px 80px;
}

.b-hero__path {
  display: flex;
  align-items: center;
  gap: 8px;
  margin: 0 0 24px;
  color: var(--steel-tint);
  font-size: 12px;
  font-weight: 700;
}

.b-hero h1 {
  max-width: 680px;
  margin: 0;
  color: #ffffff;
  font-size: 50px;
  font-weight: 800;
  line-height: 1.18;
}

.b-hero__lead {
  max-width: 660px;
  margin: 20px 0 0;
  color: rgba(255, 255, 255, 0.78);
  font-size: 16px;
  line-height: 1.75;
}

.b-hero__actions {
  display: flex;
  gap: 10px;
  margin-top: 28px;
  flex-wrap: wrap;
}

.b-index-nav {
  position: relative;
  z-index: 4;
  margin-top: -28px;
}

.b-index-nav__inner {
  display: grid;
  grid-template-columns: 180px repeat(3, minmax(0, 1fr));
  min-height: 92px;
  background: #ffffff;
  border: 1px solid var(--steel-line);
  border-radius: 8px;
  box-shadow: 0 16px 36px rgba(15, 40, 84, 0.11);
  overflow: hidden;
}

.b-index-nav__label {
  display: flex;
  align-items: center;
  padding: 20px;
  color: #ffffff;
  background: var(--steel-primary);
  font-size: 14px;
  font-weight: 800;
}

.b-index-link {
  display: flex;
  min-width: 0;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  padding: 20px;
  border-right: 1px solid var(--steel-line);
  font-size: 14px;
  font-weight: 800;
}

.b-index-link:last-child {
  border-right: 0;
}

.b-index-link:hover {
  color: var(--steel-primary);
  background: #f5fbfe;
}

.b-catalog {
  padding: 90px 0 96px;
}

.b-catalog__header {
  display: flex;
  align-items: end;
  justify-content: space-between;
  gap: 40px;
  margin-bottom: 34px;
}

.b-catalog__header h2 {
  margin: 0;
  color: var(--steel-ink);
  font-size: 34px;
  font-weight: 800;
  line-height: 1.25;
}

.b-catalog__header p {
  max-width: 490px;
  margin: 0;
  color: var(--steel-muted);
  font-size: 14px;
  line-height: 1.75;
  text-align: right;
}

.b-tabs {
  display: flex;
  gap: 0;
  border-bottom: 1px solid #bac8d7;
  overflow-x: auto;
}

.b-tab {
  position: relative;
  min-width: 130px;
  min-height: 52px;
  padding: 0 22px;
  color: var(--steel-muted);
  background: transparent;
  border: 0;
  font-size: 15px;
  font-weight: 700;
  white-space: nowrap;
}

.b-tab::after {
  position: absolute;
  right: 0;
  bottom: -1px;
  left: 0;
  height: 3px;
  background: var(--steel-primary);
  content: "";
  transform: scaleX(0);
}

.b-tab[aria-selected="true"] {
  color: var(--steel-primary);
}

.b-tab[aria-selected="true"]::after {
  transform: scaleX(1);
}

.b-panel {
  display: none;
  padding-top: 32px;
}

.b-panel[data-active="true"] {
  display: block;
}

.b-panel__layout {
  display: grid;
  grid-template-columns: minmax(260px, 0.72fr) minmax(0, 1.28fr);
  gap: 34px;
}

.b-panel__media {
  position: relative;
  min-height: 330px;
  overflow: hidden;
  border-radius: 8px;
}

.b-panel__media img {
  width: 100%;
  height: 100%;
  min-height: 330px;
  object-fit: cover;
}

.b-panel__media p {
  position: absolute;
  right: 12px;
  bottom: 12px;
  left: 12px;
  margin: 0;
  padding: 10px 12px;
  color: var(--steel-ink);
  background: rgba(255, 255, 255, 0.92);
  border-radius: 4px;
  font-size: 11px;
  line-height: 1.5;
}

.b-panel__content {
  min-width: 0;
}

.b-panel__summary {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 28px;
  margin-bottom: 22px;
}

.b-panel__summary h3 {
  margin: 0;
  color: var(--steel-ink);
  font-size: 25px;
  font-weight: 800;
}

.b-panel__summary p {
  max-width: 420px;
  margin: 0;
  color: var(--steel-muted);
  font-size: 14px;
  line-height: 1.7;
}

.b-item-list {
  border-top: 2px solid var(--steel-ink);
}

.b-item {
  display: grid;
  grid-template-columns: minmax(110px, 0.55fr) minmax(0, 1fr) auto;
  min-height: 74px;
  align-items: center;
  gap: 18px;
  padding: 13px 8px;
  border-bottom: 1px solid var(--steel-line);
}

.b-item strong {
  color: var(--steel-ink);
  font-size: 14px;
}

.b-item span {
  color: var(--steel-muted);
  font-size: 13px;
  line-height: 1.6;
}

.b-item button {
  display: inline-flex;
  min-height: 40px;
  align-items: center;
  gap: 6px;
  padding: 0 10px;
  color: var(--steel-primary);
  background: transparent;
  border: 1px solid var(--steel-line);
  border-radius: 5px;
  font-size: 12px;
  font-weight: 800;
}

.b-item button:hover {
  border-color: var(--steel-primary);
}

.b-specs {
  padding: 88px 0;
  background: #ffffff;
}

.b-specs__grid {
  display: grid;
  grid-template-columns: minmax(240px, 0.62fr) minmax(0, 1.38fr);
  gap: 72px;
}

.b-specs h2 {
  margin: 0;
  color: var(--steel-ink);
  font-size: 32px;
  font-weight: 800;
  line-height: 1.3;
}

.b-specs__intro p {
  margin: 16px 0 0;
  color: var(--steel-muted);
  font-size: 14px;
  line-height: 1.75;
}

.b-specs__list {
  border-top: 2px solid var(--steel-ink);
}

.b-spec {
  border-bottom: 1px solid var(--steel-line);
}

.b-spec summary {
  display: flex;
  min-height: 66px;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
  padding: 12px 6px;
  color: var(--steel-ink);
  cursor: pointer;
  font-size: 15px;
  font-weight: 800;
  list-style: none;
}

.b-spec summary::-webkit-details-marker {
  display: none;
}

.b-spec summary .steel-icon {
  transition: transform 180ms ease;
}

.b-spec[open] summary .steel-icon {
  transform: rotate(45deg);
}

.b-spec__body {
  padding: 0 38px 24px 6px;
  color: var(--steel-muted);
  font-size: 14px;
  line-height: 1.8;
}

.b-spec__body p {
  margin: 0;
}

.b-company {
  padding: 88px 0;
  background: var(--steel-tint);
}

.b-company__grid {
  display: grid;
  grid-template-columns: minmax(0, 0.9fr) minmax(0, 1.1fr);
  gap: 58px;
  align-items: center;
}

.b-company__media img {
  width: 100%;
  height: auto;
  aspect-ratio: 16 / 10;
  object-fit: cover;
  border-radius: 8px;
}

.b-company h2 {
  margin: 0;
  color: var(--steel-ink);
  font-size: 32px;
  font-weight: 800;
  line-height: 1.3;
}

.b-company__copy {
  margin: 18px 0 0;
  color: #38516f;
  font-size: 15px;
  line-height: 1.85;
}

.b-company__data {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  margin-top: 28px;
  border-top: 1px solid rgba(15, 40, 84, 0.28);
}

.b-company__data div {
  padding: 18px 12px 18px 0;
  border-bottom: 1px solid rgba(15, 40, 84, 0.28);
}

.b-company__data div:nth-child(even) {
  padding-left: 20px;
  border-left: 1px solid rgba(15, 40, 84, 0.28);
}

.b-company__data span,
.b-company__data strong {
  display: block;
}

.b-company__data span {
  color: #4a6380;
  font-size: 11px;
  font-weight: 700;
}

.b-company__data strong {
  margin-top: 6px;
  color: var(--steel-ink);
  font-size: 14px;
}

.b-inquiry {
  padding: 92px 0 100px;
  background: var(--steel-bg);
}

.b-inquiry__head {
  display: flex;
  align-items: end;
  justify-content: space-between;
  gap: 40px;
  padding-bottom: 28px;
  border-bottom: 2px solid var(--steel-ink);
}

.b-inquiry__head h2 {
  margin: 0;
  color: var(--steel-ink);
  font-size: 34px;
  font-weight: 800;
}

.b-inquiry__head p {
  max-width: 480px;
  margin: 0;
  color: var(--steel-muted);
  font-size: 14px;
  line-height: 1.7;
  text-align: right;
}

.b-inquiry__body {
  display: grid;
  grid-template-columns: 230px minmax(0, 1fr);
  gap: 52px;
  padding-top: 34px;
}

.b-inquiry__aside {
  padding-right: 28px;
  border-right: 1px solid var(--steel-line);
}

.b-inquiry__aside h3 {
  margin: 0;
  color: var(--steel-ink);
  font-size: 16px;
  font-weight: 800;
}

.b-inquiry__aside ol {
  display: grid;
  gap: 16px;
  margin: 20px 0 0;
  padding: 0;
  list-style: none;
}

.b-inquiry__aside li {
  display: flex;
  align-items: center;
  gap: 10px;
  color: var(--steel-muted);
  font-size: 13px;
}

.b-inquiry__aside b {
  display: grid;
  width: 26px;
  height: 26px;
  place-items: center;
  color: var(--steel-primary);
  background: var(--steel-tint);
  border-radius: 4px;
  font-size: 11px;
}

.b-footer {
  padding: 36px 0;
  color: rgba(255, 255, 255, 0.62);
  background: var(--steel-ink);
  font-size: 12px;
}

.b-footer__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 30px;
}

.b-footer strong {
  color: #ffffff;
  font-size: 15px;
}

.b-footer p {
  margin: 6px 0 0;
}

@media (max-width: 940px) {
  .b-nav,
  .b-header__contact {
    position: fixed;
    top: 66px;
    right: 0;
    left: 0;
    display: none;
  }

  .b-nav[data-open="true"] {
    display: grid;
    padding: 16px 22px 20px;
    background: var(--steel-ink);
    border-bottom: 1px solid rgba(255, 255, 255, 0.18);
  }

  .b-nav a {
    padding-inline: 0;
  }

  .b-menu-button {
    display: inline-flex;
  }

  .b-index-nav__inner {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

  .b-index-nav__label {
    display: none;
  }

  .b-panel__layout,
  .b-specs__grid,
  .b-company__grid {
    grid-template-columns: 1fr;
    gap: 36px;
  }

  .b-panel__media {
    min-height: 280px;
  }

  .b-panel__media img {
    min-height: 280px;
    max-height: 390px;
  }
}

@media (max-width: 720px) {
  .b-hero {
    min-height: 470px;
  }

  .b-hero h1 {
    font-size: 40px;
  }

  .b-index-nav {
    margin-top: -20px;
  }

  .b-index-nav__inner {
    grid-template-columns: 1fr;
  }

  .b-index-link {
    min-height: 62px;
    border-right: 0;
    border-bottom: 1px solid var(--steel-line);
  }

  .b-index-link:last-child {
    border-bottom: 0;
  }

  .b-catalog,
  .b-specs,
  .b-company,
  .b-inquiry {
    padding: 72px 0;
  }

  .b-catalog__header,
  .b-inquiry__head {
    align-items: flex-start;
    flex-direction: column;
    gap: 16px;
  }

  .b-catalog__header p,
  .b-inquiry__head p {
    text-align: left;
  }

  .b-panel__summary {
    flex-direction: column;
    gap: 12px;
  }

  .b-item {
    grid-template-columns: 1fr auto;
  }

  .b-item span {
    grid-column: 1 / -1;
    grid-row: 2;
  }

  .b-inquiry__body {
    grid-template-columns: 1fr;
    gap: 34px;
  }

  .b-inquiry__aside {
    padding-right: 0;
    padding-bottom: 28px;
    border-right: 0;
    border-bottom: 1px solid var(--steel-line);
  }

  .b-inquiry__aside ol {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }
}

@media (max-width: 480px) {
  .b-brand {
    min-width: 0;
  }

  .b-hero {
    min-height: 490px;
    background-position: 58% center;
  }

  .b-hero__content {
    padding-block: 50px 76px;
  }

  .b-hero h1 {
    font-size: 36px;
  }

  .b-hero__actions {
    display: grid;
  }

  .b-hero__actions .steel-btn {
    width: 100%;
  }

  .b-catalog__header h2,
  .b-specs h2,
  .b-company h2,
  .b-inquiry__head h2 {
    font-size: 28px;
  }

  .b-panel__media,
  .b-panel__media img {
    min-height: 230px;
  }

  .b-item {
    gap: 8px 12px;
  }

  .b-company__data {
    grid-template-columns: 1fr;
  }

  .b-company__data div:nth-child(even) {
    padding-left: 0;
    border-left: 0;
  }

  .b-inquiry__aside ol {
    grid-template-columns: 1fr;
  }

  .b-footer__inner {
    align-items: flex-start;
    flex-direction: column;
  }
}