@font-face {
  font-family: 'Nebula Sans Book';
  src: url('../fonts/nebula-sans/NebulaSans-Book.woff2') format('woff2');
  font-weight: 400;
}

@font-face {
  font-family: 'Nebula Sans Book';
  src: url('../fonts/nebula-sans/NebulaSans-Bold.woff2') format('woff2');
  font-weight: 700;
}

@font-face {
  font-family: 'Ubuntu';
  src: url('../fonts/ubuntu/Ubuntu-Regular.woff') format('woff');
  font-weight: 400;
}

:root {
  --font-mono: 'IBM Plex Mono', 'Courier New', monospace;
  --font-body: 'Nebula Sans Book', Helvetica, Arial, sans-serif;
  --font-heading: 'Ubuntu', sans-serif;

  --font-size-base: 1rem; /* 16px */
  --line-height-base: 1.6; /* 25.6px */
  --rhythm: 1.6rem;
  --scale-ratio: 1.618;

  /* Widths */
  --page-width: 1200px; /* TODO: make -sm -md -lg versions for diferent viewports */
  --hamburger-width: 396px;

  /* Border radius */
  --rounding: 3px;

  /* Modular scale */
  --font-size-xs: 0.75rem;  /* 12px - hard minimum */
  --font-size-sm: 0.875rem; /* 14px - use for metadata */
  --font-size-md: var(--font-size-base); /* 16px */
  --font-size-lg: calc(var(--font-size-base) * var(--scale-ratio)); /* ~25.9px */
  --font-size-xl: calc(var(--font-size-lg) * var(--scale-ratio));   /* ~42px */
  --font-size-xxl: calc(var(--font-size-xl) * var(--scale-ratio));  /* ~68px */

  /* Colours */
  --brand-primary-blue: rgb(0, 26, 87);
  --brand-primary-green: rgb(0,63,63);
  --brand-primary-teal: rgb(0,166,221);
  --brand-secondary-blue: rgb(0, 88, 125);
  --brand-secondary-teal: rgb(0,162,154);
  --brand-tertiary-yellow: rgb(243,146,0);
  --brand-tertiary-red: rgb(136,12,82);

  --black: rgb(17, 17, 17);
  --white: rgb(255,255,255);

  --grey-100: rgb(247, 249, 251);
  --grey-200: rgb(239, 242, 246);
  --grey-300: rgb(230, 233, 237);
  --grey-400: rgb(221, 224, 228);
  --grey-600: rgb(135, 139, 145);
  --grey-800: rgb(87, 87, 94);
}

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

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  font-family: var(--font-body);
  font-size: var(--font-size-base);
  line-height: var(--line-height-base);
  color: var(--black);
  background-color: var(--white);
  min-height: 100vh;
  display: flex;
  flex-flow: column nowrap;
  justify-content: space-between;
}

/*********************/
/* LAYOUT COMPONENTS */
/*********************/

.container,
.container-left-aside,
.container-right-aside,
.main-nav,
.breadcrumb__container,
.hamburger__container,
.footer__container,
.hero__content {
  padding-inline: var(--rhythm);
  max-width: var(--page-width);
  margin-inline: auto;
}

.container-right-aside,
.container-left-aside {
  display: grid;
  column-gap: calc(var(--rhythm) * 2);
}

.container-right-aside {
  grid-template-areas: "main aside";
  grid-template-columns: 3fr 1fr;
}

.container-left-aside {
  grid-template-areas: "aside main";
  grid-template-columns: 1fr 3fr;
}

.container-left-aside > aside,
.container-right-aside > aside {
  grid-area: aside;
}

/***************************/
/* FUNDAMENTAL PAGE LAYOUT */
/***************************/

body > header {
  background: var(--grey-200);
}

body > main {
  flex-grow: 1;
}

body > main > .container:first-child,
body > main > .container-left-aside:first-child,
body > main > .container-right-aside:first-child {
  margin-block-start: var(--rhythm);
}

body > main > .container:last-child,
body > main > .container-left-aside:last-child,
body > main > .container-right-aside:last-child {
  margin-block-end: var(--rhythm);
}

/*****************/
/* ACCESSIBILITY */
/*****************/

*:focus {
  outline: 4px solid var(--brand-secondary-blue);
}

/************************/
/* STYLED HTML ELEMENTS */
/************************/

a {
  color: var(--black);
}

a:hover {
  text-decoration: none;
}

h1, h2, h3, h4, h5 {
  font-family: var(--font-heading);
  font-weight: 400;
  color: var(--brand-secondary-blue);
  line-height: 1.2;
  margin-block: calc(var(--rhythm) * 2) var(--rhythm);
}

.container > h3:first-child {
  margin-block-start: calc(var(--rhythm) * 1.5);
}

h2 {
  font-size: var(--font-size-xl);
}

h3 {
  font-size: var(--font-size-lg);
}

p, ul, ol, blockquote, table, img {
  margin-block-end: var(--rhythm);
}

hr, .divider {
  width: 100%;
  display: block;
  border: 0;
  border-bottom: 1px solid var(--grey-200);
  margin-block: var(--rhythm);
}

.divider--lg {
  margin-block: calc(var(--rhythm) * 2);
}

/********************/
/* REUSABLE LAYOUTS */
/********************/

/* Grids */

.grid {
  display: grid;
  gap: var(--rhythm);
}

.grid--center {
  align-items: center;
}

.grid--left {
  grid-template-columns: 34% 1fr;
}

.grid--right {
  grid-template-columns: 1fr 34%;
}

.grid--2 {
  grid-template-columns: 1fr 1fr;
}

.grid--3 {
  grid-template-columns: 1fr 1fr 1fr;
}

/* Centered contents */

.centered {
  display: flex;
  flex-flow: row nowrap;
  justify-content: center;
  align-items: center;
}

/***************************/
/* BEM REUSABLE COMPONENTS */
/***************************/

/* Main navigation (in the header) */

.main-nav {
  display: grid;
  grid-template-areas:
    "brand region region"
    "brand text-nav icon-nav";
  grid-template-columns: auto 1fr auto;
  grid-template-rows: auto 1fr;
  align-items: center;
  padding-block: 1.2rem;
}

.main-nav__brand {
  grid-area: brand;
}

.main-nav__brand-image {
  max-height: 98px;
  margin: 0;
}

.main-nav__region {
  grid-area: region;
  margin-inline-start: auto;
  position: relative;
}

.main-nav__region ::marker {
  content: none;
}

.main-nav__region-list {
  position: absolute;
  top: 100%;
  right: 0;
  background: var(--grey-300);
  padding: .8rem 0;
  margin-block: .6rem 0;
  min-width: 180px;
}

.main-nav__region-link {
  display: block;
  text-decoration: none;
  padding: .4rem 1.2rem;
}

.main-nav__current-region {
  font-size: var(--font-size-xs);
  cursor: pointer;
}

.main-nav__current-region::after {
  content: "⌄";
  vertical-align: text-bottom;
}

.main-nav__list {
  grid-area: text-nav;
  list-style: none;
  display: flex;
  flex-flow: row wrap;
  margin-block: 0;
  margin-inline-start: auto;
  padding: 0;
  font-size: var(--font-size-sm);
}

.main-nav__item {
  text-transform: uppercase;
}

.main-nav__item:not(:last-child)::after {
  content: "|";
  display: inline-block;
  margin-inline: .8rem;
  color: var(--grey-600);
}

.main-nav__link {
  text-decoration: none;
}

.main-nav__link:hover {
  text-decoration: underline;
}

.main-nav__icon-list {
  grid-area: icon-nav;
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-flow: row wrap;
  column-gap: 1.2rem;
  margin-inline-start: 1.6rem;
}

.main-nav__icon-link {
  text-decoration: none;
  font-size: var(--font-size-lg);
  display: inline-flex;
  align-items: center;
  justify-content: center;
}

/* Breadcrumb navigation (below the header)  */

.breadcrumb {
  grid-area: breadcrumb;
  background: var(--grey-400);
  padding-block: .6rem;
}

.breadcrumb__list {
  list-style: none;
  padding: 0;
  margin: 0;
  display: flex;
  flex-flow: row wrap;
}

.breadcrumb__item {
  text-transform: uppercase;
  font-size: var(--font-size-sm);
  color: var(--grey-800);
}

.breadcrumb__item:not(:last-child)::after {
  content: "›";
  display: inline-block;
  margin-inline: .6rem;
}

.breadcrumb__link {
  text-decoration: none;
  vertical-align: middle;
  color: var(--grey-800);
}

.breadcrumb__link:hover {
  text-decoration: underline;
}

/* Hamburger menu (popout) */

.hamburger {
  display: none;
  position: fixed;
  top: 0;
  right: 0;
  height: 100vh;
  background: var(--grey-300);
  width: var(--hamburger-width);
  overflow: auto;
  z-index: 99;
}

.hamburger--open {
  display: block;
}

.hamburger__container {
  margin: 1.6rem;
}

.hamburger__list {
  margin: calc(var(--rhythm) * 2) 0 0 0;
  padding: 0;
  list-style: none;
  display: flex;
  flex-flow: column nowrap;
  row-gap: .6rem;
}

.hamburger__item--right {
  margin-inline-start: auto;
}

.hamburger__link {
  text-decoration: none;
}

.hamburger__link:hover {
  text-decoration: underline;
}

.hamburger__link--lg {
  font-size: var(--font-size-lg);
}

/* Page footer */

.footer {
  background: var(--grey-600);
  color: var(--white);
  font-size: var(--font-size-sm);
  padding-block: var(--rhythm) calc(var(--rhythm) * 1.5);
}

.footer__container {
  display: grid;
  grid-template-areas:
    "left right"
    "nav copy";
  grid-template-columns: 1fr 1fr;
  grid-template-rows: 1fr auto;
  column-gap: 1.6rem;
  row-gap: .8rem;
}

.footer__left {
  grid-area: left;
  font-size: var(--font-size-lg);
}

.footer__right {
  grid-area: right;
  margin-inline-start: auto;
  font-size: var(--font-size-lg);
}

.footer__nav {
  grid-area: nav;
}

.footer__nav-list {
  list-style: none;
  padding: 0;
  margin: 0;
  display: flex;
  flex-flow: row wrap;
}

.footer__nav-item:not(:last-child)::after {
  content: "|";
  display: inline-block;
  margin-inline: .8rem;
}

.footer__nav-item a {
  color: var(--white);
}

.footer__copy {
  grid-area: copy;
  margin-block: 0;
  margin-inline-start: auto;
}

/* Hero component */

.hero {
  min-height: 260px;
  background-color: var(--grey-300);
  background-size: cover;
  background-position: 50% 50%;
  display: flex;
  flex-flow: column nowrap;
  justify-content: flex-end;
  align-items: stretch;
  position: relative;
}

.hero::after {
  content: '';
  position: absolute;
  height: 100%;
  width: 100%;
  background: linear-gradient(to bottom, rgba(0, 0, 0, 0), rgba(0, 0, 0, 0.7));
}

.hero__content {
  width: 100%;
  padding-block-end: 1.2rem;
  position: relative;
  z-index: 2;
}

.hero__title {
  margin: 0;
  color: var(--white);
  font-size: var(--font-size-xl);
  font-family: var(--font-heading);
}

.hero__tagline {
  margin-top: .8rem;
  color: var(--white);
  font-size: var(--font-size-sm);
}

@media(min-width: 576px) {
  .hero__tagline {
    width: 66%;
    text-wrap: pretty;
  }
}

.hero__tagline > *:first-child {
  margin-block-start: 0;
}

.hero__tagline > *:last-child {
  margin-block-end: 0;
}

/* Article page */

.article > h3 {
  padding-bottom: 0.75rem;
  border-bottom: 1px solid var(--grey-200);
}

.article__header {
  padding-inline-start: var(--rhythm);
  margin-block-start: var(--rhythm);
  border-inline-start: 4px solid var(--brand-secondary-blue);
}

.article__eyebrow {
  font-size: var(--font-size-sm);
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.article__eyebrow a {
  color: var(--grey-800);
  text-decoration: none;
}

.article__eyebrow a:hover {
  text-decoration: underline;
}

.article__title {
  margin-block: 0 var(--rhythm);
  hyphens: auto;
  overflow-wrap: break-word;
  word-break: break-word;
  text-wrap: balance;
}

.article__title:has(+ .article__meta) {
  margin-block-end: 0;
}

.article__meta {
  color: var(--grey-800);
  font-size: var(--font-size-sm);
}

.article__meta a {
  color: var(--grey-800);
}

@supports (text-wrap: pretty) {
  .article__content p,
  .article__content li {
    text-wrap: pretty;
  }
}

/* Article page sidebar */

.article-aside {
  font-size: var(--font-size-sm);
}

.article-aside__author picture {
  margin-block-end: var(--rhythm);
}

.article-aside__author img {
  max-width: 100%;
  height: auto;
  margin: 0;
  outline: 2px solid rgba(255, 255, 255, 0.55);
  outline-offset: calc(var(--font-size-base) * -1);
}

/* Icons */

.icon {
  align-items: center;
  justify-content: center;
  display: inline-flex;
  flex-shrink: 0;
  transition: color .2s ease-in-out;
}

.icon--xs {
  width: .785rem;
  height: .785rem;
}

.icon--sm {
  width: 1rem;
  height: 1rem;
}

.icon--md {
  width: 1.2rem;
  height: 1.2rem;
}

.icon--lg {
  width: 1.4rem;
  height: 1.4rem;
}

.icon--xl {
  width: 1.8rem;
  height: 1.8rem;
}

/* Cards */

.cards {
  display: grid;
  grid-template-columns: 1fr;
  column-gap: calc(var(--rhythm) / 2);
  row-gap: calc(var(--rhythm) / 2);
  align-items: start;
  margin-block-start: var(--rhythm);
}

.cards--nomedia {
  align-items: stretch;
}

@media(min-width: 576px) {
  .cards {
    grid-template-columns: 1fr 1fr;
  }

  .cards--row {
    grid-template-columns: 1fr;
  }
}

@media(min-width: 768px) {
  .cards {
    grid-template-columns: 1fr 1fr 1fr;
  }

  .cards--row {
    grid-template-columns: 1fr 1fr;
    column-gap: var(--rhythm);
  }
}

.card {
  display: grid;
  grid-template-areas:
    "image"
    "content";
}

a:has(> .card) {
  text-decoration: none;
}

.cards--row .card {
  grid-template-areas: "image content";
  grid-template-columns: 48% 1fr;
  column-gap: calc(var(--rhythm) / 2);
}

.cards--nomedia .card {
  display: block;
  background: var(--grey-100);
  border: 1px solid var(--grey-300);
  border-radius: var(--rounding);
  padding: calc(var(--rhythm) / 2);
  min-height: 140px;
}

.cards--nomedia a > .card {
  height: 100%;
}

.card__media {
  background: var(--grey-400);
  grid-area: image;
  display: flex;
  height: 190px;
}

@media(min-width: 576px) {
  .card__media {
    max-width: 420px;
  }
}

.cards--row .card__media {
  height: 150px;
}

.card__media img {
  width: 100%;
  height: 100%;
  margin: 0;
}

.card__content {
  grid-area: content;
  padding-block-start: 1rem;
}

.cards--nomedia .card__content {
  padding: 0;
}

.cards--row .card__content {
  padding-block-start: .4rem;
}

.card__title {
  font-size: var(--font-size-md);
  color: var(--black);
  margin-block: 0 .8rem;
}

.cards--nomedia .card__title {
  margin-block: 0 .4rem;
}

.card__title .icon {
  display: block;
  margin-block-end: .4rem;
  margin-inline: .2rem;
}

.card__body {
  font-size: var(--font-size-sm);
  margin: 0;
  color: var(--grey-800);
}

.card__body > :first-child {
  margin-block-start: 0;
}

.card__body > :last-child {
  margin-block-end: 0;
}

.card__actions {
  margin-block-start: var(--rhythm);
  display: flex;
  flex-flow: row nowrap;
  font-size: var(--font-size-sm);
  color: var(--grey-800);
}

.card__action--left {
  margin-inline-end: auto;
}

.card__action--end {
  margin-inline-start: auto;
}

/* Tab-like navigation */

.tabs {
  margin: 0;
  padding: 0;
  display: flex;
  flex-flow: row wrap;
  align-items: center;
  list-style: none;
  column-gap: 1rem;
  row-gap: .4rem;
  margin-block-start: var(--rhythm);
}

@media (min-width: 576px) {
  .tabs {
    padding-inline-end: 4rem;
    width: fit-content;
    border-bottom: 1px solid var(--grey-400);
  }

  .tabs__item {
    transform: translateY(1px);
  }
}

.tabs__item {
  border-bottom: 3px solid var(--grey-400);
}

.tabs__item--current {
  border-color: var(--grey-600);
  color: var(--black);
  cursor: default;
}

.tabs__link {
  text-decoration: none;
  color: var(--grey-800);
  display: block;
}

/* Table of contents */

.table-of-contents {
  --toc-spacing: .4rem;

  font-size: var(--font-size-sm);
}

.table-of-contents__title {
  font-size: var(--font-size-md);
  text-transform: uppercase;
}

.table-of-contents__list,
.table-of-contents__sublist {
  margin: 0;
}

.table-of-contents__list {
  counter-reset: heading;
  padding: 0;
}

.table-of-contents__sublist {
  margin-block-start: var(--toc-spacing);
  counter-reset: subheading;
  padding-inline-start: 1.8rem;
}

.table-of-contents__item,
.table-of-contents__subitem {
  display: block;
}

.table-of-contents__item {
  counter-increment: heading;
  margin-block-end: calc(var(--toc-spacing) * 2);
}

.table-of-contents__item::before {
  content: counter(heading) ". ";
}

.table-of-contents__subitem {
  counter-increment: subheading;
  margin-block-end: var(--toc-spacing);
}

.table-of-contents__subitem::before {
  content: counter(heading) "." counter(subheading) ". ";
}

/* Information display */

.info {
  display: flex;
  flex-flow: row wrap;
  column-gap: var(--rhythm);
  row-gap: calc(var(--rhythm) / 2);
}

.info__item {
  font-size: var(--font-size-sm);
}

.info__header {
  font-weight: bold;
  margin: 0;
  padding: 0;
}

.info__body {
  margin: 0;
  padding: 0;
}

/* Call to action button */

.cta-button {
  background: var(--grey-200);
  display: inline-block;
  padding: 1.2rem 1.8rem;
  text-decoration: none;
  color: var(--grey-800);
  text-align: center;
}

.cta-button:hover {
  background: var(--grey-300);
}