:root {
  --blue-900: #0b2f5f;
  --blue-800: #124274;
  --blue-700: #0068b6;
  --blue-100: #e7f2fb;
  --blue-050: #f3f8fc;
  --ink: #152238;
  --muted: #5f6f84;
  --line: #d6e0ea;
  --paper: #ffffff;
  --band: #f6f9fc;
  --accent: #c9302c;
  --shadow: 0 18px 45px rgba(11, 47, 95, 0.09);
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  color: var(--ink);
  background: var(--paper);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "Noto Sans SC", "Microsoft YaHei", Arial, sans-serif;
  line-height: 1.65;
}

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

a {
  color: inherit;
  text-decoration: none;
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 20;
  display: grid;
  grid-template-columns: auto 1fr auto;
  align-items: center;
  gap: 24px;
  min-height: 74px;
  padding: 14px clamp(18px, 4vw, 52px);
  background: rgba(255, 255, 255, 0.94);
  border-bottom: 1px solid var(--line);
  backdrop-filter: blur(14px);
}

.brand img {
  width: 118px;
  height: 46px;
  object-fit: contain;
}

.header-title {
  color: var(--blue-900);
  font-weight: 800;
  font-size: clamp(16px, 1.7vw, 22px);
}

.main-nav {
  display: flex;
  flex-wrap: wrap;
  justify-content: flex-end;
  gap: 6px;
  color: var(--blue-800);
  font-size: 14px;
  font-weight: 700;
}

.main-nav a {
  padding: 8px 10px;
  border-radius: 6px;
}

.main-nav a:hover,
.main-nav a:focus-visible {
  color: var(--paper);
  background: var(--blue-700);
  outline: none;
}

.header-actions {
  display: flex;
  align-items: center;
  justify-content: flex-end;
  gap: 8px;
}

.lang-toggle {
  padding: 7px 12px;
  border: 1px solid var(--blue-700);
  border-radius: 6px;
  background: var(--paper);
  color: var(--blue-800);
  font: inherit;
  font-size: 13px;
  font-weight: 800;
  cursor: pointer;
  white-space: nowrap;
}

.lang-toggle:hover,
.lang-toggle:focus-visible {
  background: var(--blue-700);
  color: var(--paper);
  outline: none;
}

.nav-toggle {
  display: none;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
  width: 42px;
  height: 38px;
  padding: 0 9px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--paper);
  cursor: pointer;
}

.nav-toggle span {
  display: block;
  height: 2px;
  border-radius: 2px;
  background: var(--blue-900);
  transition: transform 0.2s ease, opacity 0.2s ease;
}

.site-header.nav-open .nav-toggle span:nth-child(1) {
  transform: translateY(7px) rotate(45deg);
}

.site-header.nav-open .nav-toggle span:nth-child(2) {
  opacity: 0;
}

.site-header.nav-open .nav-toggle span:nth-child(3) {
  transform: translateY(-7px) rotate(-45deg);
}

body.lang-ko .only-zh,
body.lang-zh .only-ko {
  display: none;
}

.hero {
  display: grid;
  grid-template-columns: minmax(0, 1.4fr) minmax(280px, 0.6fr);
  gap: clamp(24px, 5vw, 72px);
  align-items: center;
  padding: clamp(54px, 7vw, 96px) clamp(18px, 4vw, 52px);
  background:
    linear-gradient(125deg, rgba(11, 47, 95, 0.93), rgba(0, 104, 182, 0.88)),
    url("assets/pdf-images/turbine-layout-map.png") center / cover no-repeat;
  color: var(--paper);
}

.eyebrow {
  margin: 0 0 10px;
  color: var(--blue-700);
  font-size: 12px;
  font-weight: 900;
  letter-spacing: 0;
  text-transform: uppercase;
}

.hero .eyebrow {
  color: #9dd2ff;
}

.hero h1 {
  margin: 0;
  max-width: 880px;
  font-size: clamp(34px, 5vw, 66px);
  line-height: 1.12;
  letter-spacing: 0;
}

.hero-lead {
  max-width: 790px;
  margin: 22px 0 0;
  color: rgba(255, 255, 255, 0.88);
  font-size: clamp(16px, 1.7vw, 20px);
}

.hero-badges {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-top: 28px;
}

.hero-badges span {
  padding: 9px 12px;
  border: 1px solid rgba(255, 255, 255, 0.28);
  border-radius: 6px;
  background: rgba(255, 255, 255, 0.12);
  font-weight: 800;
}

.hero-panel {
  display: grid;
  gap: 12px;
}

.hero-panel div {
  padding: 20px;
  border: 1px solid rgba(255, 255, 255, 0.22);
  border-radius: 8px;
  background: rgba(255, 255, 255, 0.13);
}

.hero-panel strong {
  display: block;
  font-size: 31px;
  line-height: 1.15;
}

.hero-panel span {
  display: block;
  margin-top: 4px;
  color: rgba(255, 255, 255, 0.82);
  font-size: 14px;
}

.section {
  padding: clamp(58px, 7vw, 92px) clamp(18px, 4vw, 52px);
}

.section > * {
  max-width: 1180px;
  margin-left: auto;
  margin-right: auto;
}

.band {
  background: var(--band);
}

.section-heading {
  margin-bottom: 30px;
}

.section-heading h2 {
  margin: 0;
  color: var(--blue-900);
  font-size: clamp(28px, 3.4vw, 44px);
  line-height: 1.2;
  letter-spacing: 0;
}

.section-heading p:last-child {
  max-width: 800px;
  margin: 12px 0 0;
  color: var(--muted);
  font-size: 16px;
}

.overview-grid {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 14px;
}

.metric-card,
.route-grid article,
.wind-stats article {
  min-height: 116px;
  padding: 18px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--paper);
  box-shadow: 0 10px 28px rgba(11, 47, 95, 0.06);
}

.metric-card.wide {
  grid-column: span 2;
}

.metric-card span,
.route-grid span,
.wind-stats span {
  display: block;
  color: var(--muted);
  font-size: 13px;
  font-weight: 800;
}

.metric-card strong,
.route-grid strong,
.wind-stats strong {
  display: block;
  margin-top: 8px;
  color: var(--blue-900);
  font-size: 18px;
  line-height: 1.4;
}

.letter {
  max-width: 1000px;
  margin: 0 auto;
  padding: clamp(24px, 4vw, 46px);
  border: 1px solid var(--line);
  border-radius: 10px;
  background: var(--paper);
  box-shadow: var(--shadow);
}

.letter p {
  margin: 0 0 16px;
  color: var(--ink);
  font-size: 16px;
}

.letter p:last-child {
  margin-bottom: 0;
}

.role-list {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 10px;
  margin: 10px 0 22px;
  padding: 0;
  list-style: none;
}

.role-list li {
  padding: 12px 14px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--blue-050);
  color: var(--blue-900);
  font-weight: 800;
  text-align: center;
}

.letter-sign {
  margin-top: 22px !important;
  padding-top: 18px;
  border-top: 1px solid var(--line);
  color: var(--blue-900);
  font-weight: 800;
  line-height: 1.7;
}

.source-figure {
  margin-top: 28px;
}

.source-figure img,
.gallery figure,
.page-thumb {
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--paper);
  box-shadow: var(--shadow);
}

.source-figure img {
  width: 100%;
  overflow: hidden;
}

.source-figure.compact img {
  max-height: 720px;
  object-fit: contain;
  background: var(--paper);
}

.source-figure.large img {
  min-height: 360px;
  object-fit: cover;
}

figcaption {
  margin-top: 10px;
  color: var(--muted);
  font-size: 13px;
}

.route-grid,
.wind-stats {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 14px;
  margin-top: 22px;
}

.coordinate-layout {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(320px, 0.78fr);
  gap: 24px;
  align-items: start;
}

.table-wrap {
  overflow-x: auto;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--paper);
  box-shadow: var(--shadow);
}

table {
  width: 100%;
  min-width: 520px;
  border-collapse: collapse;
  font-size: 15px;
}

th,
td {
  padding: 11px 14px;
  border-bottom: 1px solid var(--line);
  text-align: left;
  white-space: nowrap;
}

th {
  color: var(--blue-900);
  background: var(--blue-100);
  font-size: 13px;
  text-transform: uppercase;
}

tbody tr:nth-child(even) {
  background: #f9fbfd;
}

tbody tr:last-child td {
  border-bottom: 0;
}

.notice {
  margin-bottom: 18px;
  padding: 12px 14px;
  border-left: 4px solid var(--accent);
  border-radius: 6px;
  background: #fff7f7;
  color: #8a1f1b;
  font-size: 13px;
  font-weight: 800;
}

.wind-stats {
  grid-template-columns: repeat(3, minmax(0, 1fr));
  margin-bottom: 24px;
}

.gallery {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 18px;
}

.gallery figure {
  margin: 0;
  overflow: hidden;
}

.gallery figure:first-child {
  grid-column: span 2;
}

.gallery img {
  width: 100%;
  height: 100%;
  max-height: 760px;
  object-fit: contain;
  background: #fff;
}

.gallery figcaption {
  padding: 0 14px 14px;
}

.site-footer {
  display: grid;
  justify-items: center;
  gap: 6px;
  padding: 34px 18px 42px;
  color: var(--muted);
  text-align: center;
  border-top: 1px solid var(--line);
  background: var(--blue-050);
}

.site-footer img {
  width: 132px;
  height: 52px;
  object-fit: contain;
}

.site-footer p {
  margin: 0;
  font-size: 13px;
}

.kr-note {
  color: var(--blue-800);
}

.footer-contact {
  color: var(--blue-900);
  font-weight: 800;
}

@media (max-width: 980px) {
  .hero {
    grid-template-columns: 1fr;
  }

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

/* 모바일: 햄버거 메뉴 */
@media (max-width: 860px) {
  .site-header {
    position: sticky;
    grid-template-columns: auto 1fr auto;
  }

  .nav-toggle {
    display: flex;
  }

  .main-nav {
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    display: none;
    flex-direction: column;
    align-items: stretch;
    gap: 2px;
    padding: 10px clamp(18px, 4vw, 52px) 16px;
    background: rgba(255, 255, 255, 0.98);
    border-bottom: 1px solid var(--line);
    box-shadow: var(--shadow);
    backdrop-filter: blur(14px);
  }

  .site-header.nav-open .main-nav {
    display: flex;
  }

  .main-nav a {
    padding: 10px 12px;
  }

  .lang-toggle {
    margin-top: 8px;
    align-self: flex-start;
  }
}

/* 모바일: PC 축소판 레이아웃 유지 */
@media (max-width: 600px) {
  body {
    font-size: 14px;
  }

  .header-title {
    font-size: 15px;
  }

  .hero {
    padding: 40px 18px;
  }

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

  .hero-panel strong {
    font-size: 24px;
  }

  .section {
    padding: 40px 16px;
  }

  .overview-grid,
  .route-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 10px;
  }

  .wind-stats {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 8px;
  }

  .gallery {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 10px;
  }

  .gallery figure:first-child {
    grid-column: span 2;
  }

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

  .metric-card,
  .route-grid article,
  .wind-stats article {
    min-height: 0;
    padding: 12px;
  }

  .metric-card span,
  .route-grid span,
  .wind-stats span {
    font-size: 11px;
  }

  .metric-card strong,
  .route-grid strong,
  .wind-stats strong {
    font-size: 14px;
    margin-top: 5px;
  }

  .letter p {
    font-size: 14px;
  }

  .source-figure.large img {
    min-height: 200px;
  }

  th,
  td {
    padding: 8px 9px;
    font-size: 12px;
  }
}