:root {
  --ink: #10201f;
  --muted: #5a6664;
  --line: #dce8e6;
  --paper: #ffffff;
  --wash: #f3f8f7;
  --teal: #0f766e;
  --teal-dark: #073f3b;
  --amber: #d89a17;
  --graphite: #1b2423;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  color: var(--ink);
  background: var(--paper);
  font-family: "Noto Sans KR", "Apple SD Gothic Neo", "Malgun Gothic", Arial, sans-serif;
  line-height: 1.6;
}

body.nav-open {
  overflow: hidden;
}

a {
  color: inherit;
}

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

.site-header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 20;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  min-height: 76px;
  padding: 16px 56px;
  color: #ffffff;
  background: rgba(8, 29, 28, 0.34);
  border-bottom: 1px solid rgba(255, 255, 255, 0.2);
  backdrop-filter: blur(14px);
}

.site-header.is-solid,
.site-header.is-scrolled,
.site-header.is-open {
  color: var(--ink);
  background: rgba(255, 255, 255, 0.96);
  border-bottom-color: var(--line);
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  font-size: 1.25rem;
  font-weight: 800;
  text-decoration: none;
}

.brand img {
  width: 38px;
  height: 38px;
  object-fit: contain;
  background: transparent;
  border: 0;
}

.site-nav {
  display: flex;
  align-items: center;
  gap: 22px;
  font-size: 0.96rem;
  font-weight: 700;
}

.site-nav a,
.nav-menu-trigger {
  color: inherit;
  background: transparent;
  border: 0;
  font: inherit;
  font-weight: inherit;
  text-decoration: none;
  cursor: pointer;
}

.site-nav a:hover,
.nav-menu-trigger:hover {
  color: var(--amber);
}

.nav-menu {
  position: relative;
}

.nav-submenu {
  position: absolute;
  top: calc(100% + 12px);
  right: 0;
  min-width: 190px;
  display: grid;
  gap: 2px;
  padding: 8px;
  color: var(--ink);
  background: #ffffff;
  border: 1px solid var(--line);
  box-shadow: 0 18px 42px rgba(16, 32, 31, 0.16);
  opacity: 0;
  visibility: hidden;
  transform: translateY(-6px);
  transition: opacity 0.16s ease, transform 0.16s ease, visibility 0.16s ease;
}

.nav-menu:hover .nav-submenu,
.nav-menu:focus-within .nav-submenu {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
}

.nav-submenu a {
  padding: 10px 12px;
  color: var(--ink);
  white-space: nowrap;
  border-bottom: 0;
}

.nav-toggle {
  display: none;
  width: 44px;
  height: 44px;
  padding: 10px;
  border: 1px solid currentColor;
  background: transparent;
  color: inherit;
}

.nav-toggle span {
  display: block;
  width: 100%;
  height: 2px;
  margin: 5px 0;
  background: currentColor;
}

.hero {
  position: relative;
  min-height: 84vh;
  display: flex;
  align-items: center;
  padding: 132px 56px 80px;
  color: #ffffff;
  background-image: url("../img/ai-education-hero.png");
  background-position: center center;
  background-size: cover;
  overflow: hidden;
}

.hero::before {
  content: "";
  position: absolute;
  inset: 0;
  background: rgba(4, 26, 25, 0.46);
}

.hero-copy {
  position: relative;
  width: min(720px, 100%);
}

.eyebrow {
  margin: 0 0 14px;
  color: var(--amber);
  font-size: 0.83rem;
  font-weight: 800;
  letter-spacing: 0;
}

.hero h1 {
  margin: 0;
  font-size: 5rem;
  line-height: 1;
  font-weight: 900;
  letter-spacing: 0;
}

.hero-lead {
  max-width: 670px;
  margin: 28px 0 0;
  font-size: 1.35rem;
  line-height: 1.65;
  color: rgba(255, 255, 255, 0.94);
}

.hero-actions,
.contact-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 34px;
}

.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 48px;
  padding: 13px 20px;
  font-weight: 800;
  text-decoration: none;
  border: 1px solid currentColor;
}

.button-primary {
  color: #ffffff;
  background: var(--teal);
  border-color: var(--teal);
}

.button-primary:hover {
  background: var(--teal-dark);
  border-color: var(--teal-dark);
}

.button-secondary {
  color: inherit;
  background: rgba(255, 255, 255, 0.14);
  border-color: rgba(255, 255, 255, 0.55);
}

.button-secondary:hover {
  background: rgba(255, 255, 255, 0.24);
}

.signal-band {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 1px;
  background: var(--line);
  border-bottom: 1px solid var(--line);
}

.signal {
  min-height: 128px;
  padding: 28px 34px;
  background: #ffffff;
}

.signal strong,
.signal span {
  display: block;
}

.signal strong {
  margin-bottom: 8px;
  font-size: 1.12rem;
}

.signal span {
  color: var(--muted);
}

.section {
  padding: 104px 56px;
}

.section-heading {
  max-width: 860px;
  margin-bottom: 44px;
}

.section h2,
.contact-section h2 {
  margin: 0;
  font-size: 2.85rem;
  line-height: 1.22;
  letter-spacing: 0;
}

.section-lead,
.contact-copy p {
  max-width: 720px;
  margin: 24px 0 0;
  color: var(--muted);
  font-size: 1.08rem;
}

.intro {
  background: var(--paper);
}

.capability-grid {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 18px;
}

.capability,
.field-grid article {
  min-height: 250px;
  padding: 28px;
  border: 1px solid var(--line);
  background: #ffffff;
}

.capability span {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 42px;
  height: 42px;
  margin-bottom: 36px;
  color: #ffffff;
  background: var(--teal);
  font-weight: 900;
}

.capability h3,
.field-grid h3 {
  margin: 0 0 14px;
  font-size: 1.26rem;
}

.capability p,
.field-grid p {
  margin: 0;
  color: var(--muted);
}

.split {
  display: grid;
  grid-template-columns: minmax(0, 0.9fr) minmax(360px, 1fr);
  gap: 56px;
  align-items: start;
  color: #ffffff;
  background: var(--graphite);
}

.split .section-lead {
  color: rgba(255, 255, 255, 0.74);
}

.solution-list {
  display: grid;
  gap: 14px;
}

.solution-item {
  display: grid;
  grid-template-columns: 180px 1fr;
  gap: 18px;
  align-items: center;
  min-height: 82px;
  padding: 20px 22px;
  background: rgba(255, 255, 255, 0.08);
  border: 1px solid rgba(255, 255, 255, 0.18);
  text-decoration: none;
}

.solution-item strong {
  color: #ffffff;
  font-size: 1.05rem;
}

.solution-item span {
  color: rgba(255, 255, 255, 0.76);
}

.solution-page-main {
  padding-top: 76px;
}

.solution-page-hero {
  padding-top: 92px;
  padding-bottom: 72px;
}

.solution-page-hero h1 {
  max-width: 900px;
  margin: 0;
  font-size: clamp(2.45rem, 5vw, 4.8rem);
  line-height: 1.05;
  letter-spacing: 0;
}

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

.solution-page-card {
  min-height: 240px;
  padding: 28px;
  background: #ffffff;
  border: 1px solid var(--line);
}

.solution-page-card h2 {
  margin: 0 0 14px;
  font-size: 1.26rem;
  line-height: 1.32;
}

.solution-page-card p {
  margin: 0;
  color: var(--muted);
}

.site-link-list {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 28px;
}

.about-doc-grid {
  display: grid;
  grid-template-columns: repeat(5, minmax(0, 1fr));
  gap: 16px;
}

.about-lead-section {
  padding-top: 58px;
  padding-bottom: 24px;
}

.about-lead-section h1 {
  margin: 0;
  font-size: clamp(2rem, 4vw, 3.6rem);
  line-height: 1.1;
  letter-spacing: 0;
}

.about-history-section {
  padding-top: 22px;
  padding-bottom: 34px;
  background: #ffffff;
}

.about-history-heading {
  display: flex;
  align-items: end;
  justify-content: space-between;
  gap: 24px;
  margin-bottom: 18px;
}

.about-history-heading h2 {
  margin: 0;
  font-size: 1.55rem;
  line-height: 1.25;
}

.about-history-timeline {
  display: grid;
  grid-template-columns: 1fr;
  gap: 10px;
}

.about-history-timeline article {
  position: relative;
  min-height: 0;
  padding: 15px 18px 14px;
  background: #ffffff;
  border: 1px solid var(--line);
}

.about-history-timeline article::before {
  content: "";
  position: absolute;
  top: 0;
  left: 18px;
  right: 18px;
  height: 3px;
  background: var(--teal);
}

.about-history-timeline span {
  display: inline-flex;
  margin-bottom: 8px;
  color: var(--teal);
  font-size: 0.78rem;
  font-weight: 900;
}

.about-history-timeline h3 {
  margin: 0 0 10px;
  font-size: 1rem;
  line-height: 1.35;
}

.about-history-timeline p {
  margin: 0;
  color: var(--muted);
  font-size: 0.86rem;
  line-height: 1.42;
}

.about-doc-card {
  display: flex;
  flex-direction: column;
  min-width: 0;
}

.about-doc-card h2 {
  min-height: 34px;
  margin: 0 0 8px;
  font-size: 0.82rem;
  line-height: 1.25;
}

.about-doc-section {
  padding-top: 18px;
}

.about-doc-logo {
  min-height: 38px;
  display: flex;
  align-items: center;
  gap: 12px;
  margin-bottom: 8px;
  padding: 7px 8px;
  background: #ffffff;
  border: 1px solid var(--line);
}

.about-doc-logo img {
  max-width: min(100%, 260px);
  max-height: 28px;
  object-fit: contain;
}

.about-doc-logo.is-pair {
  justify-content: space-between;
}

.about-doc-logo.is-pair img {
  max-width: 48%;
}

.about-doc-frame {
  width: 100%;
  height: clamp(190px, 30vh, 260px);
  min-height: 0;
  overflow: hidden;
  background: #ffffff;
  border: 1px solid var(--line);
}

.about-doc-frame img,
.about-doc-frame object {
  display: block;
  width: 100%;
  height: 100%;
  object-fit: contain;
  background: #ffffff;
  border: 0;
}

.about-doc-frame object {
  pointer-events: none;
}

.about-doc-card-note {
  display: flex;
  flex-direction: column;
}

.about-doc-text-panel {
  min-height: 0;
  height: clamp(190px, 30vh, 260px);
  display: flex;
  flex-direction: column;
  justify-content: center;
  gap: 14px;
  padding: 24px 18px;
  color: var(--ink);
  background: #ffffff;
  border: 1px solid var(--line);
}

.about-doc-text-panel strong {
  font-size: 0.95rem;
  line-height: 1.45;
}

.about-doc-text-panel span {
  display: inline-flex;
  width: fit-content;
  padding: 8px 11px;
  color: #14532d;
  font-size: 0.82rem;
  font-weight: 800;
  line-height: 1.25;
  background: #ecfdf5;
  border: 1px solid #bbf7d0;
}

.logo-cloud {
  padding: 48px 56px;
  background: #ffffff;
  border-top: 1px solid var(--line);
}

.logo-cloud-inner {
  display: grid;
  gap: 28px;
}

.logo-group h2 {
  margin: 0 0 14px;
  color: var(--ink);
  font-size: 1rem;
}

.logo-list {
  display: grid;
  grid-template-columns: repeat(5, minmax(0, 1fr));
  gap: 12px;
}

.logo-card {
  min-height: 92px;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 16px;
  color: var(--ink);
  background: #ffffff;
  border: 1px solid var(--line);
  text-align: center;
  font-weight: 900;
}

.logo-card img {
  max-width: 100%;
  max-height: 54px;
  object-fit: contain;
}

.partner-logo {
  font-size: 1.05rem;
  letter-spacing: 0;
}

.field {
  background: var(--wash);
}

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

.field-grid article {
  background: #ffffff;
}

.contact-section {
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto;
  gap: 36px;
  align-items: center;
  padding: 78px 56px;
  color: #ffffff;
  background: var(--teal-dark);
}

.contact-copy p {
  color: rgba(255, 255, 255, 0.76);
}

.contact-section .button-secondary {
  color: #ffffff;
}

.site-footer {
  display: grid;
  grid-template-columns: minmax(180px, 0.6fr) minmax(0, 1.7fr);
  gap: 30px;
  align-items: start;
  padding: 28px 56px;
  color: var(--muted);
  background: #ffffff;
  border-top: 1px solid var(--line);
}

.footer-summary {
  display: grid;
  gap: 8px;
}

.footer-summary strong {
  color: var(--ink);
  font-size: 1.05rem;
}

.site-footer a {
  color: var(--teal);
  font-weight: 800;
  text-decoration: none;
}

.business-disclosure h2 {
  margin: 0 0 16px;
  color: var(--ink);
  font-size: 1rem;
}

.business-list {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 10px 24px;
  margin: 0;
}

.business-list div {
  min-width: 0;
}

.business-list dt {
  color: var(--ink);
  font-size: 0.82rem;
  font-weight: 800;
}

.business-list dd {
  margin: 2px 0 0;
  overflow-wrap: anywhere;
  font-size: 0.9rem;
}

.business-required-note {
  margin: 16px 0 0;
  font-size: 0.82rem;
  color: var(--muted);
}

@media (max-width: 1180px) {
  .site-header,
  .hero,
  .section,
  .contact-section,
  .site-footer {
    padding-left: 32px;
    padding-right: 32px;
  }

  .capability-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .solution-page-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .about-history-timeline {
    grid-template-columns: 1fr;
  }

  .about-doc-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .split,
  .contact-section {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 860px) {
  .site-header {
    min-height: 68px;
    padding-top: 12px;
    padding-bottom: 12px;
  }

  .nav-toggle {
    display: block;
  }

  .site-nav {
    position: fixed;
    top: 68px;
    left: 0;
    right: 0;
    display: none;
    flex-direction: column;
    align-items: stretch;
    gap: 0;
    padding: 12px 24px 24px;
    color: var(--ink);
    background: #ffffff;
    border-bottom: 1px solid var(--line);
  }

  .site-nav.is-open {
    display: flex;
  }

  .site-nav a,
  .nav-menu-trigger {
    padding: 14px 0;
    border-bottom: 1px solid var(--line);
  }

  .nav-menu {
    display: grid;
  }

  .nav-submenu {
    position: static;
    min-width: 0;
    padding: 0 0 0 14px;
    margin-left: 6px;
    background: transparent;
    border: 0;
    border-left: 2px solid var(--line);
    box-shadow: none;
    opacity: 1;
    visibility: visible;
    transform: none;
  }

  .nav-submenu a {
    padding: 12px 0;
  }

  .hero {
    min-height: 82vh;
    padding-top: 112px;
    background-position: 58% center;
  }

  .hero h1 {
    font-size: 3.5rem;
  }

  .hero-lead {
    font-size: 1.12rem;
  }

  .signal-band,
  .field-grid {
    grid-template-columns: 1fr;
  }

  .signal {
    min-height: auto;
    padding: 22px 32px;
  }

  .section {
    padding-top: 76px;
    padding-bottom: 76px;
  }

  .section h2,
  .contact-section h2 {
    font-size: 2.18rem;
  }

  .solution-item {
    grid-template-columns: 1fr;
    gap: 6px;
  }

  .site-footer {
    grid-template-columns: 1fr;
  }

  .business-list {
    grid-template-columns: 1fr;
  }

  .logo-list {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

@media (max-width: 620px) {
  .site-header,
  .hero,
  .section,
  .contact-section,
  .site-footer {
    padding-left: 20px;
    padding-right: 20px;
  }

  .brand span {
    font-size: 1.08rem;
  }

  .hero h1 {
    font-size: 2.85rem;
  }

  .hero-actions,
  .contact-actions {
    display: grid;
    grid-template-columns: 1fr;
  }

  .button {
    width: 100%;
  }

  .capability-grid {
    grid-template-columns: 1fr;
  }

  .solution-page-grid {
    grid-template-columns: 1fr;
  }

  .about-history-heading {
    display: block;
  }

  .about-history-timeline {
    grid-template-columns: 1fr;
  }

  .about-history-timeline article {
    min-height: auto;
  }

  .about-doc-frame,
  .about-doc-frame img,
  .about-doc-frame object,
  .about-doc-text-panel {
    height: 240px;
    min-height: 0;
  }

  .capability,
  .field-grid article {
    min-height: auto;
    padding: 24px;
  }

  .site-footer {
    gap: 24px;
  }

  .logo-cloud {
    padding-left: 20px;
    padding-right: 20px;
  }

  .logo-list {
    grid-template-columns: 1fr;
  }
}