:root {
  --gpk-bg: #FFFFFF;
  --gpk-surface: #ffffff;
  --gpk-surface-soft: #F4F7FB;
  --gpk-navy: #1B4D8F;
  --gpk-teal: #C9A227;
  --gpk-ink: #2A2E35;
  --gpk-line: #DCE3EC;
  --gpk-shadow: 0 28px 64px rgba(11, 59, 90, 0.16);
  --gpk-radius: 28px;
  --gpk-space-24: 24px;
  --gpk-space-32: 32px;
  --gpk-space-88: 88px;
}

*,
*::before,
*::after {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body.gpk-body {
  margin: 0;
  font-family: "PT Sans", Arial, sans-serif;
  font-size: 18px;
  line-height: 1.65;
  color: var(--gpk-ink);
  background:
    radial-gradient(circle at top, rgba(18, 152, 185, 0.18), transparent 34%),
    linear-gradient(180deg, #f6fbfd 0%, var(--gpk-bg) 100%);
}

a {
  color: var(--gpk-navy);
  text-decoration-color: rgba(18, 152, 185, 0.45);
}

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

.gpk-shell {
  width: min(1260px, calc(100vw - 32px));
  margin: 0 auto;
}

.gpk-main {
  padding-top: 88px;
}

.gpk-section {
  padding-top: var(--gpk-space-32);
  padding-bottom: var(--gpk-space-88);
}

.gpk-kicker,
.gpk-brand__eyebrow,
.gpk-footer__eyebrow {
  display: inline-block;
  font-size: 0.78rem;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: rgba(16, 42, 58, 0.68);
}

.gpk-header {
  position: fixed;
  inset: 0 0 auto 0;
  z-index: 20;
  background: rgba(255, 255, 255, 0.8);
  backdrop-filter: blur(18px);
  border-bottom: 1px solid rgba(215, 228, 236, 0.75);
  box-shadow: 0 16px 40px rgba(11, 59, 90, 0.06);
}

.gpk-header__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  min-height: 88px;
}

.gpk-brand {
  display: flex;
  align-items: center;
  gap: 14px;
  color: var(--gpk-navy);
  text-decoration: none;
}

.gpk-brand__mark {
  display: grid;
  place-items: center;
  width: 48px;
  height: 48px;
  border-radius: 18px;
  background: linear-gradient(145deg, rgba(18, 152, 185, 0.88), rgba(11, 59, 90, 0.95));
  color: #fff;
  font-family: "PT Sans", Arial, sans-serif;
  font-weight: 800;
  letter-spacing: 0.08em;
  box-shadow: 0 14px 24px rgba(11, 59, 90, 0.24);
}

.gpk-brand__copy {
  display: flex;
  flex-direction: column;
  gap: 2px;
}

.gpk-brand__title {
  font-family: "PT Sans", Arial, sans-serif;
  font-weight: 700;
  font-size: 1.05rem;
}

.gpk-nav {
  flex: 1;
}

.gpk-menu,
.gpk-submenu,
.gpk-breadcrumbs__list {
  list-style: none;
  margin: 0;
  padding: 0;
}

.gpk-menu {
  display: flex;
  justify-content: center;
  gap: 8px;
  flex-wrap: wrap;
}

.gpk-menu__item > a,
.gpk-dropdown summary,
.gpk-mobile__link {
  display: inline-flex;
  align-items: center;
  min-height: 46px;
  padding: 0 16px;
  border-radius: 16px;
  font-family: "PT Sans", Arial, sans-serif;
  font-size: 0.92rem;
  font-weight: 600;
  color: rgba(16, 42, 58, 0.84);
  text-decoration: none;
  transition: transform 180ms ease, background-color 180ms ease, color 180ms ease;
}

.gpk-menu__item > a:hover,
.gpk-dropdown summary:hover,
.gpk-mobile__link:hover {
  color: var(--gpk-navy);
  background: rgba(18, 152, 185, 0.12);
  transform: translateY(-1px);
}

.gpk-dropdown {
  position: relative;
}

.gpk-dropdown summary {
  cursor: pointer;
  list-style: none;
}

.gpk-dropdown summary::-webkit-details-marker {
  display: none;
}

.gpk-submenu {
  position: absolute;
  top: calc(100% + 10px);
  left: 0;
  min-width: 240px;
  padding: 12px;
  border: 1px solid rgba(215, 228, 236, 0.95);
  border-radius: 20px;
  background: rgba(255, 255, 255, 0.97);
  box-shadow: var(--gpk-shadow);
}

.gpk-submenu li + li {
  margin-top: 6px;
}

.gpk-submenu a {
  display: block;
  padding: 10px 12px;
  border-radius: 14px;
  text-decoration: none;
  color: var(--gpk-ink);
}

.gpk-submenu a:hover {
  background: rgba(18, 152, 185, 0.08);
}

.gpk-dropdown:not([open]) .gpk-submenu {
  display: none;
}

.gpk-header__meta {
  display: flex;
  align-items: center;
  gap: 12px;
}

.gpk-header__pill {
  padding: 10px 14px;
  border-radius: 999px;
  background: rgba(11, 59, 90, 0.08);
  font-size: 0.85rem;
  color: rgba(16, 42, 58, 0.78);
}

.gpk-nav-toggle {
  display: none;
  border: 0;
  border-radius: 16px;
  background: var(--gpk-navy);
  color: #fff;
  min-height: 46px;
  padding: 0 16px;
  font-family: "PT Sans", Arial, sans-serif;
  font-weight: 700;
}

.gpk-mobile {
  display: none;
  border-top: 1px solid rgba(215, 228, 236, 0.75);
  background: rgba(255, 255, 255, 0.96);
}

.gpk-mobile.is-open {
  display: block;
}

.gpk-mobile__item {
  padding: 10px 0;
}

.gpk-dropdown--mobile .gpk-submenu {
  position: static;
  margin-top: 8px;
  min-width: 0;
  box-shadow: none;
}

.gpk-home-hero {
  min-height: 520px;
  padding: 72px 0 88px;
  background-size: cover;
  background-position: center;
}

.gpk-home-hero__card {
  max-width: 680px;
  padding: 42px;
  border: 1px solid rgba(255, 255, 255, 0.16);
  border-radius: 32px;
  background: rgba(255, 255, 255, 0.12);
  color: #fff;
  box-shadow: 0 24px 54px rgba(0, 0, 0, 0.2);
}

.gpk-home-hero__card h1,
.gpk-article-hero h1,
.gpk-static-hero h1,
.gpk-content-article__header h1 {
  margin: 12px 0 0;
  font-family: "PT Sans", Arial, sans-serif;
  font-size: clamp(2.6rem, 4.3vw, 3.7rem);
  line-height: 1.04;
  font-weight: 800;
}

.gpk-home-hero__card p,
.gpk-article-hero__copy p,
.gpk-static-hero p,
.gpk-content-article__summary {
  margin-top: 18px;
  max-width: 52ch;
  font-size: 1.05rem;
}

.gpk-chip-cloud {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

.gpk-chip {
  display: inline-flex;
  align-items: center;
  min-height: 38px;
  padding: 0 14px;
  border-radius: 999px;
  background: rgba(11, 59, 90, 0.08);
  color: var(--gpk-navy);
  text-decoration: none;
  transition: transform 180ms ease, background-color 180ms ease;
}

.gpk-chip:hover {
  background: rgba(18, 152, 185, 0.14);
  transform: translateY(-1px);
}

.gpk-chip--light {
  background: rgba(255, 255, 255, 0.18);
  color: #fff;
}

.gpk-home-grid {
  display: grid;
  grid-template-columns: minmax(0, 1.75fr) minmax(280px, 0.7fr);
  gap: 32px;
  align-items: start;
}

.gpk-service-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 18px;
}

.gpk-service-card,
.gpk-listing-card,
.gpk-category-card,
.gpk-mini-card,
.gpk-alert-card,
.gpk-side-panel,
.gpk-panel,
.gpk-article-panel,
.gpk-sidebar,
.gpk-error-card {
  border: 1px solid var(--gpk-line);
  border-radius: var(--gpk-radius);
  background: rgba(255, 255, 255, 0.96);
  box-shadow: var(--gpk-shadow);
}

.gpk-service-card,
.gpk-listing-card {
  display: flex;
  flex-direction: column;
  gap: 12px;
  min-height: 184px;
  padding: var(--gpk-space-24);
  text-decoration: none;
}

.gpk-service-card:hover,
.gpk-listing-card:hover,
.gpk-category-card:hover,
.gpk-mini-card:hover {
  transform: translateY(-4px);
  box-shadow: 0 30px 56px rgba(11, 59, 90, 0.18);
}

.gpk-service-card__badge {
  display: inline-grid;
  place-items: center;
  width: 42px;
  height: 42px;
  border-radius: 14px;
  background: linear-gradient(145deg, rgba(18, 152, 185, 0.16), rgba(11, 59, 90, 0.18));
  font-family: "PT Sans", Arial, sans-serif;
  font-weight: 700;
}

.gpk-service-card strong,
.gpk-listing-card strong,
.gpk-category-card h2,
.gpk-mini-card h3,
.gpk-sidebar__link,
.gpk-alert-card strong {
  font-family: "PT Sans", Arial, sans-serif;
  color: var(--gpk-navy);
}

.gpk-service-card small,
.gpk-listing-card a {
  color: rgba(16, 42, 58, 0.68);
}

.gpk-panel,
.gpk-side-panel,
.gpk-sidebar,
.gpk-article-panel,
.gpk-error-card {
  padding: 26px;
}

.gpk-panel--watermark {
  display: grid;
  place-items: center;
  min-height: 240px;
  background:
    linear-gradient(135deg, rgba(18, 152, 185, 0.12), rgba(11, 59, 90, 0.08));
  text-align: center;
  font-family: "PT Sans", Arial, sans-serif;
}

.gpk-alert-card {
  padding: 24px;
  background: linear-gradient(160deg, #C9A227, #A8131A);
  color: #fff;
}

.gpk-alert-card span {
  display: block;
  opacity: 0.82;
  text-transform: uppercase;
  letter-spacing: 0.18em;
  font-size: 0.72rem;
}

.gpk-side-panel + .gpk-side-panel,
.gpk-alert-card + .gpk-side-panel {
  margin-top: 18px;
}

.gpk-article-hero,
.gpk-static-hero {
  display: grid;
  grid-template-columns: minmax(0, 1.2fr) minmax(260px, 0.85fr);
  gap: 28px;
  align-items: stretch;
  margin-bottom: 28px;
}

.gpk-article-hero__copy,
.gpk-static-hero > div:first-child {
  padding: 30px;
  border-radius: var(--gpk-radius);
  background: linear-gradient(155deg, rgba(255, 255, 255, 0.98), rgba(239, 248, 252, 0.92));
  border: 1px solid var(--gpk-line);
  box-shadow: var(--gpk-shadow);
}

.gpk-article-hero__media,
.gpk-static-hero__media {
  overflow: hidden;
  border-radius: var(--gpk-radius);
  min-height: 320px;
  background: linear-gradient(160deg, rgba(11, 59, 90, 0.18), rgba(18, 152, 185, 0.24));
  box-shadow: var(--gpk-shadow);
}

.gpk-article-hero__media img,
.gpk-static-hero__media img,
.gpk-content-main-image img,
.gpk-figure img,
.gpk-gallery__item img,
.gpk-category-card img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.gpk-content-grid {
  display: grid;
  grid-template-columns: minmax(0, 1.7fr) minmax(260px, 0.75fr);
  gap: 28px;
  align-items: start;
}

.gpk-sidebar {
  display: flex;
  flex-direction: column;
  gap: 18px;
}

.gpk-sidebar__stack {
  display: grid;
  gap: 10px;
}

.gpk-sidebar__link {
  display: block;
  padding: 12px 14px;
  border-radius: 16px;
  text-decoration: none;
  background: rgba(18, 152, 185, 0.08);
}

.gpk-sidebar__link:hover {
  background: rgba(18, 152, 185, 0.14);
}

.gpk-prose {
  display: grid;
  gap: 18px;
}

.gpk-prose__heading {
  margin: 0;
  font-family: "PT Sans", Arial, sans-serif;
  color: var(--gpk-navy);
}

.gpk-prose__heading--1,
.gpk-prose__heading--2 {
  font-size: clamp(1.75rem, 3vw, 2.2rem);
}

.gpk-prose__heading--3 {
  font-size: 1.45rem;
}

.gpk-prose__paragraph {
  color: var(--gpk-ink);
}

.gpk-table-shell {
  overflow-x: auto;
  border-radius: 22px;
  border: 1px solid var(--gpk-line);
}

.gpk-table {
  width: 100%;
  border-collapse: collapse;
  background: #fff;
}

.gpk-table th,
.gpk-table td {
  padding: 14px 16px;
  border-bottom: 1px solid rgba(215, 228, 236, 0.7);
  vertical-align: top;
}

.gpk-table thead th {
  background: rgba(11, 59, 90, 0.92);
  color: #fff;
  text-align: left;
}

.gpk-list {
  margin: 0;
  padding-left: 1.2rem;
}

.gpk-list li + li {
  margin-top: 0.55rem;
}

.gpk-gallery {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
  gap: 16px;
}

.gpk-gallery--wide {
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
}

.gpk-gallery__item {
  overflow: hidden;
  min-height: 200px;
  border-radius: 24px;
  background: rgba(255, 255, 255, 0.98);
  border: 1px solid var(--gpk-line);
  box-shadow: var(--gpk-shadow);
}

.gpk-figure {
  overflow: hidden;
  border-radius: 22px;
  background: rgba(255, 255, 255, 0.98);
  border: 1px solid var(--gpk-line);
  box-shadow: var(--gpk-shadow);
}

.gpk-figure--float {
  float: right;
  max-width: min(360px, 45%);
  margin: 0 0 18px 18px;
}

.gpk-breadcrumbs {
  padding-top: 12px;
}

.gpk-breadcrumbs__list {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  align-items: center;
  color: rgba(16, 42, 58, 0.66);
  font-size: 0.92rem;
}

.gpk-breadcrumbs__list li {
  display: inline-flex;
  align-items: center;
  gap: 10px;
}

.gpk-breadcrumbs__list li:not(:first-child)::before {
  content: "/";
  opacity: 0.45;
}

.gpk-mini-card,
.gpk-category-card {
  padding: 22px;
}

.gpk-category-grid {
  display: grid;
  grid-template-columns: repeat(var(--gpk-grid-columns, 3), minmax(0, 1fr));
  gap: 20px;
  margin-top: 28px;
}

.gpk-category-card--horizontal {
  display: grid;
  grid-template-columns: 180px minmax(0, 1fr);
  gap: 18px;
  align-items: stretch;
}

.gpk-category-card--minimal img {
  display: none;
}

.gpk-listing-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 18px;
  margin-top: 24px;
}

.gpk-content-article {
  padding: 30px;
  border-radius: 32px;
  background: rgba(255, 255, 255, 0.98);
  border: 1px solid var(--gpk-line);
  box-shadow: var(--gpk-shadow);
}

.gpk-content-article__meta {
  display: flex;
  flex-wrap: wrap;
  gap: 14px;
  margin-top: 18px;
  font-size: 0.92rem;
  color: rgba(16, 42, 58, 0.7);
}

.gpk-content-layout {
  margin-top: 28px;
}

.gpk-content-layout--with-side {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 260px;
  gap: 24px;
}

.gpk-content-layout--reverse {
  grid-template-columns: 260px minmax(0, 1fr);
}

.gpk-content-layout__aside--desktop {
  position: sticky;
  top: 110px;
  align-self: start;
}

.gpk-content-main-image {
  overflow: hidden;
  margin: 0 0 22px;
  border-radius: 24px;
}

.gpk-toc {
  margin: 22px 0;
  padding: 18px;
  border-radius: 24px;
  background: rgba(18, 152, 185, 0.08);
  border: 1px solid rgba(18, 152, 185, 0.14);
}

.gpk-toc ul {
  margin: 0;
  padding-left: 1rem;
}

.gpk-toc li + li {
  margin-top: 0.55rem;
}

.gpk-toc--mobile {
  display: none;
}

.gpk-blockquote {
  margin: 0;
  padding: 18px 22px;
  border-left: 4px solid var(--gpk-teal);
  border-radius: 0 22px 22px 0;
  background: rgba(18, 152, 185, 0.08);
}

.gpk-code {
  overflow-x: auto;
  padding: 18px;
  border-radius: 20px;
  background: #143A6B;
  color: #d8edf7;
}

.gpk-rule {
  border: 0;
  border-top: 1px solid rgba(215, 228, 236, 0.95);
  margin: 10px 0;
}

.gpk-footer {
  padding: 48px 0;
  background:
    linear-gradient(180deg, rgba(7, 32, 49, 0.98), rgba(11, 59, 90, 0.98));
  color: rgba(255, 255, 255, 0.86);
}

.gpk-footer a {
  color: #fff;
  text-decoration: none;
}

.gpk-footer__brand strong {
  display: block;
  margin-top: 10px;
  font-family: "PT Sans", Arial, sans-serif;
  font-size: 1.15rem;
}

.gpk-footer__links {
  display: grid;
  gap: 10px;
}

.gpk-scrolled .gpk-header {
  box-shadow: 0 20px 50px rgba(11, 59, 90, 0.1);
}

@media (max-width: 1024px) {
  .gpk-home-grid,
  .gpk-content-grid,
  .gpk-article-hero,
  .gpk-static-hero,
  .gpk-content-layout--with-side,
  .gpk-content-layout--reverse {
    grid-template-columns: 1fr;
  }

  .gpk-content-layout__aside--desktop {
    display: none;
  }

  .gpk-toc--mobile {
    display: block;
  }

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

@media (max-width: 820px) {
  .gpk-nav--desktop,
  .gpk-header__pill {
    display: none;
  }

  .gpk-nav-toggle {
    display: inline-flex;
    align-items: center;
    justify-content: center;
  }

  .gpk-home-hero {
    min-height: 420px;
    padding-top: 36px;
  }

  .gpk-home-hero__card,
  .gpk-panel,
  .gpk-side-panel,
  .gpk-sidebar,
  .gpk-article-panel,
  .gpk-error-card,
  .gpk-content-article {
    padding: 22px;
  }
}

@media (max-width: 640px) {
  body.gpk-body {
    font-size: 16px;
  }

  .gpk-shell {
    width: min(100vw - 20px, 1260px);
  }

  .gpk-main {
    padding-top: 78px;
  }

  .gpk-header__inner {
    min-height: 78px;
  }

  .gpk-brand__mark {
    width: 42px;
    height: 42px;
  }

  .gpk-home-hero__card h1,
  .gpk-article-hero h1,
  .gpk-static-hero h1,
  .gpk-content-article__header h1 {
    font-size: 2.4rem;
  }

  .gpk-service-grid,
  .gpk-listing-grid,
  .gpk-category-grid {
    grid-template-columns: 1fr;
  }

  .gpk-category-card--horizontal {
    grid-template-columns: 1fr;
  }

  .gpk-figure--float {
    float: none;
    max-width: none;
    margin-left: 0;
  }
}

@media print {
  .gpk-header,
  .gpk-footer,
  .gpk-nav-toggle,
  .gpk-mobile,
  .gpk-sidebar,
  .gpk-chip-cloud {
    display: none !important;
  }

  body.gpk-body {
    background: #fff;
    color: #000;
    font-size: 12pt;
  }

  .gpk-main {
    padding-top: 0;
  }

  .gpk-panel,
  .gpk-article-panel,
  .gpk-content-article,
  .gpk-service-card,
  .gpk-listing-card,
  .gpk-category-card {
    box-shadow: none;
    border-color: #bbb;
  }
}

/* Typographic scale (specs.md): h1 40/700 h2 30/700 h3 22/600 h4 18/600 body 16/400 small 13/400 */
body{font-size:16px;font-weight:400}
h1{font-size:40px;font-weight:700}
h2{font-size:30px;font-weight:700}
h3{font-size:22px;font-weight:600}
h4{font-size:18px;font-weight:600}
small{font-size:13px;font-weight:400}
@media(max-width:768px){h1{font-size:30px}h2{font-size:24px}}