:root {
  --width: 36;
  --rounding: 4px;
  --table-width: 316px;
  --accent: #f8c040;
  --background: #eee;
  --content-background: #fff;
  --content-text: #000;
  --heading-background: #aaa;
  --heading-text: #fff;
  --selected-background: #fffc;
  --help-background: #aaa;
  --help-text: #fff;
  --graph-line: #bbb;
  --graph-highlight: #0001;
  --key-line: #999;
  --unit-opacity: 0.4;
  --table-stripe: #f8f8f8;
}

@media (prefers-color-scheme:dark) {
  :root {
    --background: #000;
    --content-background: #222;
    --content-text: #eee;
    --heading-background: #444;
    --selected-background: #222c;
    --help-background: #888;
    --help-text: #000;
    --graph-line: #444;
    --graph-highlight: #fff1;
    --key-line: #666;
    --unit-opacity: 0.6;
    --table-stripe: #181818;
  }
}

html {
  height: 100%;
  font-family: 'Poppins', sans-serif;
  font-weight: 300;
  font-size: clamp(18px, calc(100vw / var(--width)), 20px);
  font-feature-settings: 'tnum';
  line-height: 1.5;
  -webkit-text-size-adjust: none;
  text-size-adjust: none;
}

body {
  display: grid;
  grid-template-rows: max-content 1fr max-content;
  height: 100%;
  margin: 0;
  background: var(--background);
  color: var(--content-text);
}

header {
  padding: 1.25rem 0 0;
}

header nav {
  display: grid;
  grid-template-columns: 1fr auto 1fr;
  grid-auto-flow: dense;
  gap: 0.25rem;
  align-items: center;
}

header nav > a {
  grid-column: 2;
  display: grid;
  place-content: center;
  width: 2.5rem;
  height: 2.5rem;
  border-radius: 50%;
  background: var(--content-text);
  transition: background-color 0.2s;
}

header nav > a:hover {
  background: var(--accent);
}

header nav svg {
  height: 1.6rem;
  fill: var(--content-background);
}

header nav div,
footer nav {
  display: grid;
  grid-auto-flow: column;
  justify-content: center;
}

header nav div {
  justify-content: right;
}

header nav div + div {
  justify-content: left;
}

nav a {
  display: block;
  position: relative;
  padding: 0.2rem 0.75rem 0.3rem;
  border-radius: 1rem;
  color: inherit;
  font-weight: 400;
  font-variant: small-caps;
  text-transform: lowercase;
  text-decoration: none;
  transition: color 0.2s;
}

nav a.section,
nav a:hover {
  color: var(--accent);
}

nav a + a::after {
  content: '';
  display: block;
  position: absolute;
  top: 0.85rem;
  left: -0.175rem;
  width: 0.35rem;
  height: 0.35rem;
  border-radius: 50%;
  background: var(--accent);
}

footer {
  padding: 1rem 0 1.5rem;
  text-align: center;
}

footer div {
  padding: 1rem 1.25rem 0.25rem;
}

footer span {
  white-space: nowrap;
}

main {
  display: grid;
  gap: 1rem;
  justify-content: center;
  padding: 1rem;
  font-size: 16px;
  line-height: 1.25;
}

main > * {
  max-width: 1280px;
}

section {
  box-sizing: border-box;
  padding: 1rem;
  border-radius: var(--rounding);
  background: var(--content-background);
  color: var(--content-text);
}

h1 {
  margin: 0 0 0.5rem;
  font-size: 2rem;
  font-weight: 400;
  line-height: 1.1;
}

h2 {
  font-size: 1.1rem;
  font-weight: 400;
  line-height: 1;
}

main h2 {
  margin: -1rem -1rem 1rem;
  padding: 0.75rem 1rem;
  border-radius: var(--rounding) var(--rounding) 0 0;
  background: var(--heading-background);
  color: var(--heading-text);
}

h3 {
  margin: 2rem 0 1rem;
  padding: 0;
  font-size: 1rem;
  font-weight: 300;
  text-align: center;
}

h3:first-of-type {
  margin-top: 0;
}

p {
  margin: 0;
  font-size: 1rem;
  line-height: 1.5;
}

p + p {
  margin-top: 1rem;
}

table {
  border-collapse: collapse;
}

a {
  color: var(--accent);
  text-decoration-color: transparent;
  text-decoration-thickness: 0.1em;
  text-underline-offset: 0.15em;
  transition: text-decoration-color 0.2s;
}

a:hover {
  text-decoration-color: var(--accent);
}

img {
  vertical-align: bottom;
}

/* colours */

.generation  { color: #aaa; }
.price       { color: #000; }
.emissions   { color: #000; }
.demand      { color: #000; }
.fossils     { color: #c45; }
.renewables  { color: #5b5; }
.others      { color: #27c; }
.transfers   { color: #aaa; }
.coal        { color: #a35; }
.gas         { color: #e94; }
.solar       { color: #ed0; }
.wind        { color: #9d5; }
.hydro       { color: #2cb; }
.nuclear     { color: #09c; }
.biomass     { color: #36b; }
.belgium     { color: #817; }
.denmark     { color: #c66; }
.france      { color: #e94; }
.ireland     { color: #ed0; }
.netherlands { color: #9d5; }
.norway      { color: #2cb; }
.pumped      { color: #09c; }
.battery     { color: #639; }

@media (prefers-color-scheme:dark) {
  .generation  { color: #888; }
  .price       { color: #eee; }
  .emissions   { color: #eee; }
  .demand      { color: #eee; }
  .transfers   { color: #888; }
}

/* columns */

.columns {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1rem;
}

@media screen and (max-width:959px) {
  .columns {
    grid-template-columns: 1fr;
  }
}

/* introduction */

#introduction {
  text-align: center;
}

/* status */

#status {
  font-size: 1rem;
}

dl {
  display: grid;
  grid-template-columns: 1fr 1fr 1fr;
  gap: 0.5em;
  align-items: center;
  justify-items: center;
  margin: 0 -1em;
}

dt,
dd {
  margin: 0;
  line-height: 1;
  white-space: nowrap;
}

dt {
  grid-row: 1;
}

dd {
  grid-row: 2;
  font-size: 1.2em;
}

dd abbr {
  opacity: var(--unit-opacity);
}

dt:nth-child(1),
dd:nth-child(2) {
  grid-column: 1;
}

dt:nth-child(3),
dd:nth-child(4) {
  grid-column: 2;
}

dt:nth-child(5),
dd:nth-child(6) {
  grid-column: 3;
}

[data-operator]::before {
  content: '=';
  grid-area: 1 / 1 / 3 / 3;
  font-size: 1.25rem;
}

[data-operator]::after {
  content: attr(data-operator);
  grid-area: 1 / 2 / 3 / 4;
  font-size: 1.25rem;
}

/* latest */

#latest {
  display: grid;
  grid-template-columns: 1fr 1fr 1fr;
  grid-template-areas: "generation fossils transfers" "generation renewables transfers" "generation others storage";
  gap: 1rem;
}

@media screen and (max-width:1199px) {
  #latest {
    grid-template-columns: 1fr 1fr;
    grid-template-areas: "generation fossils" "generation renewables" "generation others" "transfers storage";
  }
}

@media screen and (max-width:779px) {
  #latest {
    grid-template-columns: 1fr;
    grid-template-areas: "generation" "fossils" "renewables" "others" "transfers" "storage";
  }
}

#latest section {
  margin: 0;
}

#generation {
  grid-area: generation;
}

#fossils {
  grid-area: fossils;
}

#renewables {
  grid-area: renewables;
}

#others {
  grid-area: others;
}

#transfers {
  grid-area: transfers;
}

#storage {
  grid-area: storage;
}

.sources {
  width: 100%;
  margin: 0;
}

.sources.transfers {
  color: inherit;
}

.sources td {
  vertical-align: top;
}

.sources td:nth-child(1) {
  padding: 0 0 1em;
  background: transparent;
}

.sources td:nth-child(1)::after {
  content: '';
  display: block;
  box-sizing: border-box;
  width: 1em;
  height: 1em;
  margin-top: 2px;
  background: currentcolor;
}

.sources.transfers td:nth-child(1)::after {
  border: 2px solid;
  background: transparent;
}

.sources td:nth-child(2) {
  width: 100%;
  padding: 0 0 1em 0.5em;
}

.sources td:nth-child(3),
.sources td:nth-child(4) {
  padding: 0 0 1em 0.75em;
  text-align: right;
  white-space: nowrap;
}

.sources td:nth-child(1),
.sources td:nth-child(3),
.sources td:nth-child(4) {
  width: 0;
}

.sources td:nth-child(3)::after {
  content: 'GW';
  opacity: var(--unit-opacity);
}

.sources td:nth-child(4)::after {
  content: '%';
  opacity: var(--unit-opacity);
}

.sources tr:last-child td {
  padding-bottom: 0;
}

[data-help] {
  display: inline-block;
  width: 1em;
  height: 1em;
  border-radius: 50%;
  background: var(--help-background);
  color: var(--help-text);
  font-weight: 400;
  font-variant: small-caps;
  line-height: 1;
  text-align: center;
  cursor: pointer;
}

[data-help]:after {
  content: '?';
  position: relative;
  top: -1px;
}

#fossils h2 {
  background: #c45;
}

#renewables h2 {
  background: #5b5;
}

#others h2 {
  background: #27c;
}

/* tabs */

[role="tablist"] {
  display: grid;
  grid-template-columns: 1fr 1fr 1fr 1fr;
  position: sticky;
  top: 0;
  z-index: 1;
  margin: -1rem -1rem 1rem;
}

[role="tablist"] h2 {
  margin: 0;
  border-radius: 0;
  text-align: center;
  -webkit-user-select: none;
  user-select: none;
}

[role="tablist"] h2:first-child {
  border-top-left-radius: var(--rounding);
}

[role="tablist"] h2:last-child {
  border-top-right-radius: var(--rounding);
}

h2[aria-selected="true"] {
  -webkit-backdrop-filter: saturate(180%) blur(20px);
  backdrop-filter: saturate(180%) blur(20px);
  background: var(--selected-background);
  color: var(--content-text);
}

h2[aria-selected="false"] {
  cursor: pointer;
}

@media screen and (max-width:34rem) {
  [role="tablist"] h2 {
    text-transform: capitalize;
  }

  [role="tablist"] span {
    display: none;
  }
}

[role="tabpanel"] {
  display: grid;
  grid-template-columns: 1fr var(--table-width) 1fr;
  grid-template-areas: "pie status demand" "pie equation demand" "pie table demand" "price table generation" "emissions table transfers";
  gap: 1rem 3rem;
}

[role="tabpanel"]:nth-child(n + 3) {
  display: none;
}

[role="tabpanel"] > div {
  min-width: 0;
}

[role="tabpanel"] > :nth-child(1) { grid-area: status; }
[role="tabpanel"] > :nth-child(2) { grid-area: equation; }
[role="tabpanel"] > :nth-child(3) { grid-area: pie; }
[role="tabpanel"] > :nth-child(4) { grid-area: table; }
[role="tabpanel"] > :nth-child(5) { grid-area: price; }
[role="tabpanel"] > :nth-child(6) { grid-area: emissions; }
[role="tabpanel"] > :nth-child(7) { grid-area: demand; }
[role="tabpanel"] > :nth-child(8) { grid-area: generation; }
[role="tabpanel"] > :nth-child(9) { grid-area: transfers; }

[role="tabpanel"] > :is(:nth-child(1),:nth-child(2)) {
  padding-bottom: 1rem;
}

[role="tabpanel"] > :is(:nth-child(1),:nth-child(2),:nth-child(4)) {
  width: 100%;
  max-width: var(--table-width);
  justify-self: center;
}

[role="tabpanel"] > :nth-child(3) {
  align-self: center;
  justify-self: center;
}

@media screen and (max-width:1023px) {
  [role="tabpanel"] {
    grid-template-columns: var(--table-width) 1fr;
    grid-template-areas: "pie price" "status emissions" "equation emissions" "table emissions" "table demand" "table generation" "table transfers";
  }
}

@media screen and (max-width:767px) {
  [role="tabpanel"] {
    grid-template-columns: 1fr;
    grid-template-areas: none;
  }

  [role="tabpanel"] > :nth-child(n) {
    grid-area: auto;
  }

  [role="tabpanel"] > :is(:nth-child(3),:nth-child(4)) {
    padding-bottom: 1rem;
  }
}

/* dialogs */

dialog::backdrop {
  background: rgba(0,0,0,0.5);
}

dialog[open] {
  display: grid;
  grid-template-columns: 1fr 1.5rem;
  grid-template-rows: 1.5rem min-content; /* required to stop Safari stretching the dialog to the viewport height */
  gap: 1rem;
  width: 24rem;
  max-width: calc(100vw - 6rem);
  padding: 1rem;
  border: 0;
  border-radius: var(--rounding);
  background: var(--content-background);
  color: var(--content-text)
}

dialog h2 {
  margin: 0;
  font-size: 1.5rem;
}

dialog div {
  grid-area: 2 / 1 / 3 / 3;
  max-height: calc(100vh - 8.5rem);
  max-height: calc(100dvh - 8.5rem);
  overflow: auto;
}

dialog p + p {
  margin-top: 1rem;
}

dialog button {
  padding: 0;
  border: 0;
  outline: 0;
  background: transparent;
  cursor: pointer;
}

dialog button::-moz-focus-inner {
  padding: 0;
  border: 0;
}

dialog svg {
  display: block;
  width: 1.5rem;
  height: 1.5rem;
}

dialog path {
  stroke: var(--content-text);
  stroke-width: 4;
}

/* pie charts */

.pie-chart-container {
  display: grid;
  align-content: center;
  justify-content: center;
  max-width: 330px;
  aspect-ratio: 1;
  margin: 0 auto 1rem;
}

.pie-chart {
  display: grid;
  max-width: 300px;
  font-size: 16px;
}

.pie-chart > div,
.pie-chart > svg {
  grid-row: 1 / 2;
  grid-column: 1 / 2;
}

.pie-chart > div {
  display: grid;
  justify-items: center;
  align-content: center;
  text-align: center;
}

.pie-chart > div > div:nth-child(1) {
  padding-top: 1.25em;
}

.pie-chart > div > div:nth-child(2) {
  display: block;
  width: 33%;
  height: 2px;
  margin: 0.25em 0;
  background: currentcolor;
}

.pie-chart > svg {
  width: 100%; /* required to stop Safari shrinking the pie chart to the width of the text */
}

.pie-chart > svg > path {
  fill: currentcolor;
  stroke: var(--content-background);
  stroke-width: 2;
  vector-effect: non-scaling-stroke;
}

/* graphs */

.graph {
  --graph-height: 250px;
  --axis-width: 40px;
  --axis-height: 64px;
  --axis-gap: 10px;
  --key-padding: 8px;
  display: grid;
  grid-template: auto var(--axis-height) /  var(--axis-width) 1fr;
  gap: calc(var(--axis-gap) - 0.5em) var(--axis-gap);
  position: relative;
  font-size: 12px;
  line-height: 1;
}

.graph > div {
  display: grid;
  text-align: right;
}

.graph > :nth-child(1) {
  grid-area: 1 / 1 / 2 / 3;
  grid-template-columns: var(--axis-width) 1fr;
  column-gap: var(--axis-gap);
  align-content: space-between;
}

.graph > :nth-child(1) > :nth-child(even) {
  margin-top: calc(0.5em - 1px);
  border-top: 1px solid var(--graph-line);
}

.graph > :nth-child(2) {
  grid-area: 2 / 2 / 3 / 3;
  grid-auto-flow: column;
  justify-content: space-around;
}

.graph > :nth-child(2) > div {
  writing-mode: vertical-lr;
  transform: rotate(180deg);
}

.graph svg {
  grid-area: 1 / 2 / 2 / 3;
  width: 100%;
  height: var(--graph-height);
  margin: 0.5em 0;
}

polyline {
  fill: transparent;
  stroke: currentcolor;
  stroke-width: 2.5;
  vector-effect: non-scaling-stroke;
}

.graph rect {
  fill: transparent;
}

.graph rect:hover {
  fill: var(--graph-highlight);
}

.graph svg + div {
  position: absolute;
  top: calc(var(--graph-height) / 2 + 0.5em);
  width: max-content;
  max-width: calc(100vw / 2 - 4 * var(--key-padding));
  padding: var(--key-padding);
  background: var(--content-background);
  color: var(--content-text);
  border: 1px solid var(--key-line);
  border-radius: var(--rounding);
  text-align: left;
  transform: translateY(-50%);
  pointer-events: none;
}

.graph svg + div > div {
  margin-bottom: var(--key-padding);
  font-size: 16px;
  font-weight: 400;
  text-align: center;
}

.graph svg + div td:nth-child(1)::after {
  margin-top: 0;
}

.graph svg + div td:nth-child(3) {
  white-space: nowrap;
}

.graph svg + div td:nth-child(3)::after {
  content: none;
}

.visits-graph {
  margin: 1rem 0;
}

/* wind milestones */

.wind-milestones {
  margin: 0.75rem auto 0;
  font-size: 1rem;
}

.wind-milestones tr:nth-child(even){
  background: var(--table-stripe);
  border: solid var(--background);
  border-width: 2px 0;
}

.wind-milestones th,
.wind-milestones td {
  padding: 0.25rem 0.5rem;
}

.wind-milestones th {
  font-weight: 400;
  text-align: left;
}