.option-a {
  font-family: "Pretendard", "Noto Sans KR", sans-serif;
}

.a-header {
  position: relative;
  z-index: 80;
  height: 74px;
  background: #ffffff;
  border-bottom: 1px solid var(--steel-line);
}

.a-header__inner {
  display: flex;
  height: 100%;
  align-items: center;
  justify-content: space-between;
  gap: 32px;
}

.a-brand {
  display: inline-flex;
  min-height: 44px;
  align-items: center;
  gap: 12px;
  color: var(--steel-ink);
  font-size: 19px;
  font-weight: 800;
}

.a-brand__mark {
  display: grid;
  width: 34px;
  height: 34px;
  place-items: center;
  color: #ffffff;
  background: var(--steel-ink);
  border-radius: 6px;
}

.a-nav {
  display: flex;
  align-items: center;
  gap: 28px;
}

.a-nav a:not(.steel-btn) {
  position: relative;
  min-height: 44px;
  display: inline-flex;
  align-items: center;
  color: #34445d;
  font-size: 15px;
  font-weight: 600;
}

.a-nav a:not(.steel-btn)::after {
  position: absolute;
  right: 0;
  bottom: 4px;
  left: 0;
  height: 2px;
  background: var(--steel-primary);
  content: "";
  transform: scaleX(0);
  transform-origin: left;
  transition: transform 180ms ease;
}

.a-nav a:not(.steel-btn):hover::after {
  transform: scaleX(1);
}

.a-menu-button {
  display: none;
  width: 46px;
  height: 46px;
  align-items: center;
  justify-content: center;
  padding: 0;
  color: var(--steel-ink);
  background: #ffffff;
  border: 1px solid var(--steel-line);
  border-radius: 7px;
}

.a-hero {
  position: relative;
  min-height: 620px;
  display: flex;
  align-items: center;
  overflow: hidden;
  color: #ffffff;
  background: var(--steel-ink) url("assets/hero-beams.jpg") center 52% / cover no-repeat;
}

.a-hero::before {
  position: absolute;
  inset: 0;
  background: rgba(7, 22, 49, 0.66);
  content: "";
}

.a-hero__content {
  position: relative;
  z-index: 1;
  padding-block: 74px 90px;
}

.a-hero__eyebrow {
  display: flex;
  align-items: center;
  gap: 12px;
  margin: 0 0 22px;
  color: var(--steel-tint);
  font-size: 14px;
  font-weight: 700;
}

.a-hero__eyebrow::before {
  width: 38px;
  height: 2px;
  background: var(--steel-tint);
  content: "";
}

.a-hero h1 {
  max-width: 760px;
  margin: 0;
  color: #ffffff;
  font-size: 60px;
  font-weight: 800;
  line-height: 1.12;
}

.a-hero__lead {
  max-width: 610px;
  margin: 24px 0 0;
  color: rgba(255, 255, 255, 0.84);
  font-size: 19px;
  line-height: 1.75;
}

.a-hero__actions {
  display: flex;
  gap: 12px;
  margin-top: 34px;
  flex-wrap: wrap;
}

.a-hero__facts {
  display: flex;
  gap: 28px;
  margin: 38px 0 0;
  padding: 0;
  list-style: none;
}

.a-hero__facts li {
  display: flex;
  align-items: center;
  gap: 9px;
  color: rgba(255, 255, 255, 0.78);
  font-size: 14px;
  font-weight: 600;
}

.a-intro {
  padding: 72px 0 82px;
  background: var(--steel-surface);
}

.a-intro__top {
  display: grid;
  grid-template-columns: minmax(0, 0.82fr) minmax(0, 1.18fr);
  gap: 80px;
  align-items: end;
  margin-bottom: 46px;
}

.a-intro__top h2 {
  margin: 0;
  color: var(--steel-ink);
  font-size: 40px;
  font-weight: 800;
  line-height: 1.25;
}

.a-intro__copy {
  margin: 0;
  color: var(--steel-muted);
  font-size: 17px;
  line-height: 1.85;
}

.a-products {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 18px;
}

.a-product {
  min-height: 250px;
  padding: 30px;
  background: var(--steel-bg);
  border: 1px solid var(--steel-line);
  border-radius: 12px;
  transition: border-color 180ms ease, transform 180ms ease;
}

.a-product:hover {
  border-color: var(--steel-accent);
  transform: translateY(-4px);
}

.a-product__icon {
  display: grid;
  width: 46px;
  height: 46px;
  place-items: center;
  color: var(--steel-primary);
  background: var(--steel-tint);
  border-radius: 8px;
}

.a-product h3 {
  margin: 28px 0 10px;
  color: var(--steel-ink);
  font-size: 23px;
  font-weight: 800;
}

.a-product p {
  margin: 0;
  color: var(--steel-muted);
  font-size: 15px;
  line-height: 1.75;
}

.a-product a {
  display: inline-flex;
  min-height: 44px;
  align-items: center;
  gap: 7px;
  margin-top: 18px;
  color: var(--steel-primary);
  font-size: 14px;
  font-weight: 800;
}

.a-process {
  padding: 96px 0;
  background: var(--steel-bg);
}

.a-process__steps {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  border-top: 1px solid var(--steel-line);
  border-bottom: 1px solid var(--steel-line);
}

.a-step {
  position: relative;
  min-height: 232px;
  padding: 34px 38px 30px 0;
}

.a-step + .a-step {
  padding-left: 38px;
  border-left: 1px solid var(--steel-line);
}

.a-step__number {
  display: block;
  color: var(--steel-accent);
  font-size: 14px;
  font-weight: 800;
}

.a-step h3 {
  margin: 36px 0 12px;
  color: var(--steel-ink);
  font-size: 22px;
  font-weight: 800;
}

.a-step p {
  margin: 0;
  color: var(--steel-muted);
  font-size: 15px;
  line-height: 1.75;
}

.a-about {
  padding: 104px 0;
}

.a-about__grid {
  display: grid;
  grid-template-columns: minmax(0, 1.05fr) minmax(0, 0.95fr);
  gap: 78px;
  align-items: center;
}

.a-about__media {
  position: relative;
  aspect-ratio: 4 / 3;
  overflow: hidden;
  border-radius: 12px;
}

.a-about__media img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.a-about__caption {
  position: absolute;
  right: 18px;
  bottom: 18px;
  max-width: 240px;
  margin: 0;
  padding: 12px 14px;
  color: var(--steel-ink);
  background: rgba(255, 255, 255, 0.92);
  border-radius: 6px;
  font-size: 12px;
  line-height: 1.55;
}

.a-about h2 {
  margin: 0;
  color: var(--steel-ink);
  font-size: 40px;
  font-weight: 800;
  line-height: 1.25;
}

.a-about__copy {
  margin: 20px 0 0;
  color: var(--steel-muted);
  font-size: 17px;
  line-height: 1.85;
}

.a-about__list {
  display: grid;
  gap: 0;
  margin: 30px 0 0;
  padding: 0;
  border-top: 1px solid var(--steel-line);
  list-style: none;
}

.a-about__list li {
  display: flex;
  min-height: 52px;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
  border-bottom: 1px solid var(--steel-line);
  font-size: 14px;
}

.a-about__list span:first-child {
  color: var(--steel-muted);
}

.a-about__list strong {
  color: var(--steel-ink);
  font-weight: 700;
}

.a-contact {
  padding: 100px 0;
  background: var(--steel-ink);
}

.a-contact__grid {
  display: grid;
  grid-template-columns: minmax(0, 0.75fr) minmax(0, 1.25fr);
  gap: 72px;
  align-items: start;
}

.a-contact__copy {
  position: sticky;
  top: 40px;
}

.a-contact .steel-eyebrow {
  color: var(--steel-tint);
}

.a-contact h2 {
  margin: 0;
  color: #ffffff;
  font-size: 42px;
  font-weight: 800;
  line-height: 1.25;
}

.a-contact__lead {
  margin: 20px 0 0;
  color: rgba(255, 255, 255, 0.72);
  font-size: 16px;
  line-height: 1.8;
}

.a-contact__points {
  display: grid;
  gap: 14px;
  margin: 34px 0 0;
  padding: 0;
  list-style: none;
}

.a-contact__points li {
  display: flex;
  align-items: center;
  gap: 12px;
  color: rgba(255, 255, 255, 0.84);
  font-size: 14px;
}

.a-contact__form {
  padding: 34px;
  background: #ffffff;
  border-radius: 12px;
}

.a-contact__form h3 {
  margin: 0 0 8px;
  color: var(--steel-ink);
  font-size: 24px;
  font-weight: 800;
}

.a-contact__form > p {
  margin: 0 0 28px;
  color: var(--steel-muted);
  font-size: 14px;
  line-height: 1.65;
}

.a-footer {
  padding: 42px 0;
  background: #081a39;
}

.a-footer__inner {
  display: flex;
  align-items: flex-end;
  justify-content: space-between;
  gap: 32px;
}

.a-footer__brand {
  margin: 0;
  color: #ffffff;
  font-size: 18px;
  font-weight: 800;
}

.a-footer p:not(.a-footer__brand) {
  margin: 9px 0 0;
  color: rgba(255, 255, 255, 0.54);
  font-size: 12px;
  line-height: 1.7;
}

.a-footer__links {
  display: flex;
  gap: 20px;
  color: rgba(255, 255, 255, 0.72);
  font-size: 13px;
}

.a-footer__links a {
  display: inline-flex;
  min-height: 44px;
  align-items: center;
}

@media (max-width: 960px) {
  .a-nav {
    position: fixed;
    top: 74px;
    right: 0;
    left: 0;
    display: none;
    padding: 22px 24px 28px;
    background: #ffffff;
    border-bottom: 1px solid var(--steel-line);
    box-shadow: 0 16px 30px rgba(15, 40, 84, 0.12);
  }

  .a-nav[data-open="true"] {
    display: grid;
    gap: 4px;
  }

  .a-nav .steel-btn {
    margin-top: 10px;
  }

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

  .a-intro__top,
  .a-about__grid,
  .a-contact__grid {
    grid-template-columns: 1fr;
    gap: 42px;
  }

  .a-contact__copy {
    position: static;
  }
}

@media (max-width: 760px) {
  .a-hero {
    min-height: 600px;
    align-items: flex-end;
  }

  .a-hero__content {
    padding-block: 72px 66px;
  }

  .a-hero h1 {
    font-size: 44px;
  }

  .a-hero__lead {
    font-size: 17px;
  }

  .a-hero__facts {
    gap: 12px 22px;
    flex-wrap: wrap;
  }

  .a-intro {
    padding: 64px 0 72px;
  }

  .a-intro__top {
    gap: 22px;
  }

  .a-intro__top h2,
  .a-about h2,
  .a-contact h2 {
    font-size: 34px;
  }

  .a-products,
  .a-process__steps {
    grid-template-columns: 1fr;
  }

  .a-product {
    min-height: 0;
  }

  .a-step,
  .a-step + .a-step {
    min-height: 0;
    padding: 28px 0;
    border-left: 0;
  }

  .a-step + .a-step {
    border-top: 1px solid var(--steel-line);
  }

  .a-step h3 {
    margin-top: 18px;
  }

  .a-process,
  .a-about,
  .a-contact {
    padding: 76px 0;
  }

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

@media (max-width: 480px) {
  .a-header {
    height: 68px;
  }

  .a-nav {
    top: 68px;
  }

  .a-brand {
    font-size: 17px;
  }

  .a-brand__mark {
    width: 32px;
    height: 32px;
  }

  .a-hero {
    min-height: 590px;
    background-position: 59% center;
  }

  .a-hero h1 {
    font-size: 38px;
  }

  .a-hero__lead {
    font-size: 16px;
  }

  .a-hero__actions {
    display: grid;
  }

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

  .a-hero__facts {
    display: grid;
  }

  .a-about__caption {
    position: static;
    max-width: none;
    background: var(--steel-bg);
    border-radius: 0 0 8px 8px;
  }

  .a-about__media {
    aspect-ratio: auto;
    overflow: visible;
  }

  .a-about__media img {
    height: auto;
    aspect-ratio: 4 / 3;
    border-radius: 8px 8px 0 0;
  }

  .a-contact__form {
    padding: 24px 20px;
  }
}