:root {
  --navy: #173547;
  --navy-soft: #416174;
  --cream: #effafa;
  --paper: #fbfffe;
  --white: #ffffff;
  --coral: #ff7b72;
  --coral-soft: #ffe7e4;
  --cobalt: #168bab;
  --cobalt-soft: #dff8f8;
  --mint: #9edfeb;
  --mint-soft: #e8fbfd;
  --muted: #607480;
  --line: 2px solid var(--navy);
  --shadow: 7px 8px 0 var(--navy);
  --radius-lg: 30px;
  --radius-md: 18px;
}

* {
  box-sizing: border-box;
}

html {
  min-width: 320px;
  scroll-behavior: smooth;
  background: var(--cream);
}

body {
  min-width: 320px;
  min-height: 100vh;
  margin: 0;
  color: var(--navy);
  font-family:
    Pretendard, "Apple SD Gothic Neo", "Noto Sans KR", system-ui,
    -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  word-break: keep-all;
  background:
    radial-gradient(circle at 9% 9%, rgba(104, 213, 234, 0.52) 0 5px, transparent 6px),
    radial-gradient(circle at 92% 19%, rgba(255, 123, 114, 0.38) 0 6px, transparent 7px),
    linear-gradient(rgba(23, 53, 71, 0.045) 1px, transparent 1px),
    linear-gradient(90deg, rgba(23, 53, 71, 0.045) 1px, transparent 1px),
    var(--cream);
  background-size: 48px 48px, 64px 64px, 32px 32px, 32px 32px, auto;
}

a {
  color: var(--cobalt);
  font-weight: 850;
  text-decoration-thickness: 1.5px;
  text-underline-offset: 4px;
}

a:hover {
  color: var(--navy);
}

a:focus-visible,
summary:focus-visible {
  outline: 3px solid var(--cobalt);
  outline-offset: 3px;
}

.skip-link {
  position: fixed;
  top: 10px;
  left: 10px;
  z-index: 100;
  padding: 11px 15px;
  color: var(--white);
  font-weight: 900;
  text-decoration: none;
  background: var(--navy);
  border-radius: 10px;
  transform: translateY(-160%);
}

.skip-link:focus {
  color: var(--white);
  transform: translateY(0);
}

.page-shell {
  width: min(980px, calc(100% - 40px));
  margin: 0 auto;
  padding: 24px 0 44px;
}

.site-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  min-height: 54px;
  margin-bottom: clamp(64px, 10vw, 112px);
}

.brand {
  display: inline-flex;
  flex: 0 0 auto;
  gap: 11px;
  align-items: center;
  color: var(--navy);
  text-decoration: none;
}

.brand:hover {
  color: var(--navy);
}

.brand-mark {
  display: grid;
  width: 43px;
  height: 43px;
  place-items: center;
  font-size: 24px;
  font-weight: 950;
  background: var(--coral);
  border: var(--line);
  border-radius: 13px;
  box-shadow: 3px 3px 0 var(--navy);
  transform: rotate(-5deg);
}

.brand-copy {
  display: grid;
  font-size: 18px;
  font-weight: 950;
  line-height: 1;
  letter-spacing: -0.055em;
}

.brand-copy small {
  margin-top: 5px;
  color: var(--muted);
  font-size: 9px;
  font-weight: 900;
  letter-spacing: 0.18em;
}

.site-nav {
  display: flex;
  flex-wrap: wrap;
  justify-content: flex-end;
  gap: 8px 18px;
}

.site-nav a {
  color: var(--muted);
  font-size: 13px;
  text-decoration: none;
}

.site-nav a:hover,
.site-nav a[aria-current="page"] {
  color: var(--navy);
  text-decoration: underline;
}

.hero {
  position: relative;
  margin-bottom: 48px;
}

.hero::after {
  position: absolute;
  top: 6px;
  right: 0;
  width: clamp(70px, 12vw, 112px);
  aspect-ratio: 1;
  content: "";
  background: var(--mint);
  border: var(--line);
  border-radius: 47% 53% 58% 42%;
  opacity: 0.72;
  transform: rotate(17deg);
}

.error-hero::after {
  background: var(--coral);
}

.eyebrow {
  display: inline-flex;
  margin: 0 0 19px;
  padding: 8px 13px;
  color: var(--navy);
  font-size: 11px;
  font-weight: 950;
  letter-spacing: 0.12em;
  background: var(--mint);
  border: 1.5px solid var(--navy);
  border-radius: 999px;
  transform: rotate(-1deg);
}

h1,
h2,
h3,
p {
  margin-top: 0;
}

h1 {
  position: relative;
  z-index: 1;
  max-width: 790px;
  margin-bottom: 22px;
  font-size: clamp(43px, 8.2vw, 78px);
  font-weight: 950;
  line-height: 1.02;
  letter-spacing: -0.075em;
}

.hero-copy {
  position: relative;
  z-index: 1;
  max-width: 720px;
  margin-bottom: 0;
  color: var(--muted);
  font-size: clamp(16px, 2vw, 20px);
  font-weight: 650;
  line-height: 1.75;
  letter-spacing: -0.02em;
}

.meta-strip {
  position: relative;
  z-index: 1;
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-top: 25px;
}

.meta-strip span {
  padding: 8px 12px;
  color: var(--navy-soft);
  font-size: 12px;
  font-weight: 850;
  background: rgba(255, 253, 247, 0.92);
  border: 1.5px solid var(--navy);
  border-radius: 999px;
}

.article-card {
  padding: clamp(26px, 5vw, 54px);
  background: var(--paper);
  border: var(--line);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow);
}

.article-section {
  scroll-margin-top: 24px;
}

.article-section + .article-section {
  margin-top: 60px;
  padding-top: 52px;
  border-top: 1.5px dashed rgba(16, 33, 63, 0.48);
}

h2 {
  margin-bottom: 18px;
  font-size: clamp(26px, 4vw, 36px);
  font-weight: 950;
  line-height: 1.2;
  letter-spacing: -0.055em;
}

h3 {
  margin-bottom: 10px;
  font-size: 18px;
  font-weight: 950;
  line-height: 1.35;
  letter-spacing: -0.035em;
}

.article-card p,
.article-card li,
.definition-list dd {
  color: #4e596a;
  font-size: 15px;
  line-height: 1.82;
  letter-spacing: -0.01em;
}

.article-card p:last-child,
.article-card li:last-child {
  margin-bottom: 0;
}

.article-card ul,
.article-card ol:not(.route-list) {
  display: grid;
  gap: 10px;
  margin: 16px 0 0;
  padding-left: 23px;
}

.route-list {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 12px;
  margin: 26px 0 0;
  padding: 0;
  list-style: none;
  counter-reset: route;
}

.route-list li {
  position: relative;
  display: flex;
  gap: 14px;
  align-items: center;
  min-height: 104px;
  padding: 17px;
  background: var(--white);
  border: 1.5px solid var(--navy);
  border-radius: var(--radius-md);
}

.route-list li::after {
  position: absolute;
  right: -13px;
  z-index: 2;
  width: 13px;
  height: 2px;
  content: "";
  background: var(--navy);
}

.route-list li:nth-child(2n)::after,
.route-list li:last-child::after {
  display: none;
}

.route-list > li > span {
  display: grid;
  flex: 0 0 auto;
  width: 43px;
  height: 43px;
  place-items: center;
  color: var(--navy);
  font-size: 12px;
  font-weight: 950;
  background: var(--mint);
  border: 1.5px solid var(--navy);
  border-radius: 50%;
}

.route-list li:nth-child(3n + 2) > span {
  background: var(--coral-soft);
}

.route-list li:nth-child(3n) > span {
  background: var(--cobalt-soft);
}

.route-list strong,
.route-list small {
  display: block;
}

.route-list strong {
  color: var(--navy);
  font-size: 16px;
  font-weight: 950;
  line-height: 1.35;
}

.route-list small {
  margin-top: 5px;
  color: var(--muted);
  font-size: 12px;
  line-height: 1.55;
}

.info-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 13px;
  margin-top: 24px;
}

.info-box {
  padding: 22px;
  background: var(--white);
  border: 1.5px solid var(--navy);
  border-radius: var(--radius-md);
}

.info-box:nth-child(4n + 1) {
  box-shadow: inset 0 5px 0 var(--coral);
}

.info-box:nth-child(4n + 2) {
  box-shadow: inset 0 5px 0 var(--mint);
}

.info-box:nth-child(4n + 3) {
  box-shadow: inset 0 5px 0 var(--cobalt);
}

.info-box:nth-child(4n) {
  box-shadow: inset 0 5px 0 var(--navy);
}

.info-box p {
  margin: 0;
  font-size: 14px;
}

.definition-list {
  display: grid;
  gap: 0;
  margin: 21px 0 0;
  border: 1.5px solid var(--navy);
  border-radius: var(--radius-md);
  overflow: hidden;
}

.definition-list > div {
  display: grid;
  grid-template-columns: minmax(150px, 0.3fr) minmax(0, 1fr);
  gap: 20px;
  padding: 18px 20px;
  background: var(--white);
}

.definition-list > div:nth-child(even) {
  background: var(--mint-soft);
}

.definition-list > div + div {
  border-top: 1px solid rgba(16, 33, 63, 0.35);
}

.definition-list dt {
  color: var(--navy);
  font-size: 14px;
  font-weight: 950;
}

.definition-list dd {
  min-width: 0;
  margin: 0;
  font-size: 14px;
  overflow-wrap: anywhere;
}

.notice {
  margin: 23px 0 0;
  padding: 20px 22px;
  color: #613428;
  font-size: 14px;
  font-weight: 720;
  line-height: 1.72;
  background: var(--coral-soft);
  border-left: 6px solid var(--coral);
  border-radius: 0 15px 15px 0;
}

.notice.is-blue {
  color: #223661;
  background: var(--cobalt-soft);
  border-left-color: var(--cobalt);
}

.site-footer {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 28px;
  margin-top: 76px;
  padding: 29px 0 7px;
  border-top: 1.5px solid var(--navy);
}

.footer-copy strong,
.footer-copy span {
  display: block;
}

.footer-copy strong {
  margin-bottom: 6px;
  font-size: 14px;
}

.footer-copy span {
  color: var(--muted);
  font-size: 12px;
  line-height: 1.6;
}

.footer-links {
  display: flex;
  flex-wrap: wrap;
  justify-content: flex-end;
  gap: 12px 18px;
}

.footer-links a {
  color: var(--navy);
  font-size: 12px;
}

@media (max-width: 760px) {
  .site-header {
    display: grid;
    margin-bottom: 62px;
  }

  .site-nav {
    justify-content: flex-start;
  }

  .hero::after {
    top: -8px;
    opacity: 0.52;
  }

  .route-list,
  .info-grid {
    grid-template-columns: 1fr;
  }

  .route-list li::after {
    right: auto;
    bottom: -13px;
    left: 37px;
    width: 2px;
    height: 13px;
  }

  .route-list li:nth-child(2n)::after {
    display: block;
  }

  .route-list li:last-child::after {
    display: none;
  }

  .definition-list > div {
    grid-template-columns: 1fr;
    gap: 7px;
  }
}

@media (max-width: 560px) {
  .page-shell {
    width: min(100% - 24px, 980px);
    padding-top: max(16px, env(safe-area-inset-top));
    padding-bottom: max(28px, env(safe-area-inset-bottom));
  }

  .brand-mark {
    width: 38px;
    height: 38px;
    font-size: 21px;
  }

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

  h1 {
    max-width: 92%;
    font-size: clamp(40px, 13.5vw, 59px);
  }

  .article-card {
    padding: 26px 19px;
    border-radius: 23px;
    box-shadow: 4px 5px 0 var(--navy);
  }

  .article-section + .article-section {
    margin-top: 46px;
    padding-top: 42px;
  }

  .route-list li {
    min-height: 96px;
    padding: 15px;
  }

  .site-footer {
    display: grid;
  }

  .footer-links {
    justify-content: flex-start;
  }
}

@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }

  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }
}