/* Decentralised Water Grid: Network Plan design system.
   Language of a water-utility network drawing: a drawing sheet with a title block,
   navy drawing ink, and the blue used for potable-water mains.
   Every font size and every margin, padding and gap uses the tokens below (see CLAUDE.md). */

@font-face { font-family: "Public Sans"; src: url("fonts/public-sans-latin-400-normal.woff2") format("woff2"); font-weight: 400; font-display: swap; }
@font-face { font-family: "Public Sans"; src: url("fonts/public-sans-latin-600-normal.woff2") format("woff2"); font-weight: 600; font-display: swap; }
@font-face { font-family: "Public Sans"; src: url("fonts/public-sans-latin-800-normal.woff2") format("woff2"); font-weight: 800; font-display: swap; }

:root {
  /* Colour */
  --paper: #FFFFFF;
  --band: #F2F4F7;
  --plan: #E7EFF9;
  --ink: #0B1F33;
  --muted: #55606E;
  --rule: #D5DAE1;
  --main: #0057B8;      /* potable-water main */

  /* Type */
  --sans: "Public Sans", "Segoe UI", Arial, sans-serif;

  /* Type scale (desktop / mobile) */
  --fs-display: clamp(38px, 3.4vw + 23px, 72px);
  --fs-h2: clamp(22px, 0.6vw + 19.5px, 28px);
  --fs-h3: 19px;
  --fs-lead: clamp(19px, 0.2vw + 18px, 21px);
  --fs-body: 17px;
  --fs-small: 15px;
  --fs-caption: 14px;
  --fs-micro: 12px;

  /* Spacing scale */
  --s-1: 4px;
  --s-2: 8px;
  --s-3: 12px;
  --s-4: 16px;
  --s-5: 24px;
  --s-6: 32px;
  --s-7: 48px;
  --s-8: 72px;
  --s-9: 96px;

  --wrap: 1240px;
  --pad: clamp(var(--s-4), 4vw, var(--s-7));
  --tap: 44px;
  --ease: cubic-bezier(0.2, 0, 0, 1);
}

*, *::before, *::after { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; scroll-padding-top: var(--s-8); }
body { margin: 0; background: var(--paper); color: var(--ink); font-family: var(--sans); font-size: var(--fs-body); line-height: 1.6; }
a { color: var(--main); text-underline-offset: 0.18em; }
a[href^="mailto:"] { overflow-wrap: anywhere; }   /* long addresses may break on narrow phones */
:focus-visible { outline: 3px solid var(--main); outline-offset: 2px; }
button { font: inherit; }
.skip { position: absolute; left: -9999px; background: var(--ink); color: var(--paper); padding: var(--s-2) var(--s-4); z-index: 10; }
.skip:focus { left: var(--s-3); top: var(--s-3); }
.wrap { max-width: var(--wrap); margin: 0 auto; padding: 0 var(--pad); }

/* ---------- Header: solid ink bar ---------- */
.bar { position: sticky; top: 0; z-index: 5; background: var(--ink); color: var(--paper); }
.bar .wrap { display: flex; align-items: center; justify-content: space-between; gap: var(--s-5); min-height: calc(var(--s-7) + var(--s-4)); flex-wrap: wrap; }
.brand { color: var(--paper); text-decoration: none; font-weight: 800; font-size: var(--fs-h3); letter-spacing: 0.01em; }
.bar nav { display: flex; gap: var(--s-5); flex-wrap: wrap; align-items: center; font-size: var(--fs-small); }
.bar nav a { color: var(--paper); text-decoration: none; padding: var(--s-2) 0; border-bottom: 2px solid transparent; }
.bar nav a:hover { border-bottom-color: var(--paper); }
.bar nav a.cta { background: var(--main); padding: var(--s-2) var(--s-4); border-radius: 3px; border: 0; }
.bar nav a.cta:hover { background: var(--paper); color: var(--ink); }

/* ---------- Hero ---------- */
.hero { padding: var(--s-7) 0 0; }
.hero h1 { font-weight: 800; font-size: var(--fs-display); line-height: 1.04; letter-spacing: -0.02em; margin: 0 0 var(--s-5); max-width: 16ch; }
.hero .lede { font-size: var(--fs-lead); line-height: 1.55; max-width: 62ch; margin: 0 0 var(--s-4); }
.actions { display: flex; flex-wrap: wrap; gap: var(--s-3); margin-top: var(--s-5); }
.btn { display: inline-flex; align-items: center; justify-content: center; text-align: center; min-height: var(--s-7); font-weight: 600; font-size: var(--fs-body); line-height: 1.25; text-decoration: none; padding: var(--s-2) var(--s-5); border-radius: 3px; border: 2px solid var(--ink); }
.btn--primary { background: var(--main); border-color: var(--main); color: var(--paper); }
.btn--primary:hover { background: var(--ink); border-color: var(--ink); }
.btn--secondary { color: var(--ink); background: var(--paper); }
.btn--secondary:hover { background: var(--band); }

/* ---------- Drawing sheet (signature) ---------- */
.drawing { margin: var(--s-7) 0 0; background: var(--plan); border: 2px solid var(--ink); }
.drawing svg { display: block; width: 100%; height: auto; }
.fig-note { font-size: var(--fs-caption); color: var(--muted); margin: var(--s-3) 0 0; max-width: 80ch; }
.fig-note b { color: var(--ink); }
.key { list-style: none; padding: 0; margin: var(--s-3) 0 0; display: flex; flex-wrap: wrap; gap: var(--s-2) var(--s-5); font-size: var(--fs-caption); color: var(--muted); }
.key li { display: flex; align-items: center; gap: var(--s-2); }
.key svg { width: 22px; height: 14px; flex: none; }

/* ---------- Sections: number column + content ---------- */
.part { border-top: 2px solid var(--ink); margin-top: var(--s-8); padding-top: var(--s-5); display: grid; grid-template-columns: 240px minmax(0, 1fr); column-gap: var(--s-7); }
.part__head { align-self: start; position: sticky; top: var(--s-9); }
.part__no { display: block; font-weight: 800; font-size: var(--fs-h2); line-height: 1.2; color: var(--main); }
.part__head h2 { font-size: var(--fs-h2); font-weight: 800; line-height: 1.2; margin: var(--s-1) 0 0; }
.part__body { min-width: 0; }
.part__body > p, .part__body > ul { max-width: 70ch; margin: 0 0 var(--s-4); }
.part__body > ul { padding-left: 1.2em; }
.part__body li { margin-bottom: var(--s-2); }
.part__body h3 { font-size: var(--fs-h3); font-weight: 800; margin: var(--s-6) 0 var(--s-3); }
.big { font-size: var(--fs-lead); line-height: 1.45; font-weight: 600; max-width: 46ch; }
.pull { margin: var(--s-6) 0; padding: var(--s-5); background: var(--plan); font-size: var(--fs-lead); line-height: 1.4; font-weight: 600; max-width: 48ch; }
.pull p { margin: 0; }
.note { background: var(--band); padding: var(--s-4) var(--s-5); font-size: var(--fs-small); max-width: 70ch; }

/* ---------- Tables ---------- */
.table-wrap { overflow-x: auto; margin: var(--s-5) 0 var(--s-3); }
table { width: 100%; border-collapse: collapse; font-size: var(--fs-small); line-height: 1.5; }
thead th { background: var(--band); text-align: left; font-weight: 600; padding: var(--s-3) var(--s-4); border-bottom: 2px solid var(--ink); }
tbody th, tbody td { text-align: left; vertical-align: top; padding: var(--s-3) var(--s-4); border-bottom: 1px solid var(--rule); }
tbody th { font-weight: 600; width: 26%; }
table.vs thead th:last-child, table.vs tbody td:last-child { background: var(--plan); }
table.vs thead th:last-child { color: var(--main); }

/* ---------- Sequences: modes, design steps, phases ---------- */
.cards { list-style: none; padding: 0; margin: var(--s-5) 0; display: grid; gap: var(--s-4); }
.cards--3 { grid-template-columns: repeat(3, minmax(0, 1fr)); }
.cards--4 { grid-template-columns: repeat(4, minmax(0, 1fr)); }
.cards > li { border: 1px solid var(--rule); padding: var(--s-5); margin: 0; background: var(--paper); }
.cards .tag, .seq .tag { display: block; font-weight: 800; font-size: var(--fs-h2); line-height: 1; color: var(--main); margin-bottom: var(--s-3); }
.cards h3 { font-size: var(--fs-h3); font-weight: 800; line-height: 1.3; margin: 0 0 var(--s-2); }
.cards p { font-size: var(--fs-small); line-height: 1.5; margin: 0 0 var(--s-2); }
.cards .out { color: var(--muted); }

.seq { list-style: none; padding: 0; margin: var(--s-5) 0; display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); border-top: 1px solid var(--rule); border-left: 1px solid var(--rule); }
.seq > li { margin: 0; padding: var(--s-4) var(--s-5); border-right: 1px solid var(--rule); border-bottom: 1px solid var(--rule); }
.seq h4 { font-size: var(--fs-body); font-weight: 800; margin: 0 0 var(--s-2); }
.seq p { font-size: var(--fs-small); line-height: 1.5; margin: 0; }

/* ---------- Layout catalogue ---------- */
.geoms { list-style: none; padding: 0; margin: var(--s-5) 0; display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: var(--s-4); }
.geoms li { margin: 0; border: 1px solid var(--rule); }
.geoms svg { display: block; width: 100%; height: auto; background: var(--plan); border-bottom: 1px solid var(--rule); }
.geoms div { padding: var(--s-3) var(--s-4) var(--s-4); }
.geoms h3 { font-size: var(--fs-h3); font-weight: 800; margin: 0 0 var(--s-1); }
.geoms p { font-size: var(--fs-small); line-height: 1.45; margin: 0 0 var(--s-2); }
.geoms .app { color: var(--muted); }

.sister { margin-top: var(--s-6); padding: var(--s-5); background: var(--ink); color: var(--paper); display: grid; grid-template-columns: minmax(0, 1fr) auto; gap: var(--s-4) var(--s-6); align-items: center; }
.sister p { margin: 0; max-width: 60ch; }
.sister .btn { background: var(--paper); color: var(--ink); border-color: var(--paper); }
.sister p a { color: var(--paper); }

/* ---------- Footer: one line, same pattern as Spektral-Q ---------- */
.foot { margin-top: var(--s-9); border-top: 2px solid var(--ink); }
.foot__inner { display: flex; flex-wrap: wrap; justify-content: space-between; gap: var(--s-4) var(--s-7); padding-top: var(--s-5); padding-bottom: var(--s-7); }
.foot p { margin: 0; font-size: var(--fs-caption); color: var(--muted); }

/* ---------- Mobile menu: a sections sheet dropping from the bar (same pattern as Spektral-Q) ---------- */
.menu-btn { display: none; }
.menu {
  margin: 0; inset: 0 0 auto; width: 100%; max-width: none; max-height: 100dvh; overflow-y: auto;
  padding: 0 var(--pad) var(--s-5); border: 0; background: var(--paper); color: var(--ink);
}
.menu::backdrop { background: rgba(11, 31, 51, 0.45); }
.menu[open] { animation: menu-drop 0.25s var(--ease); }
@keyframes menu-drop { from { transform: translateY(-12px); opacity: 0; } }
.menu__head {
  display: flex; justify-content: space-between; align-items: center; min-height: calc(var(--s-7) + var(--s-2));
  margin: 0 calc(-1 * var(--pad)); padding: 0 var(--pad); background: var(--ink); color: var(--paper); font-size: var(--fs-h3); font-weight: 800;
}
.menu__close, .menu-btn {
  font-weight: 600; font-size: var(--fs-small); color: var(--paper); background: transparent;
  border: 1px solid rgba(255, 255, 255, 0.4); border-radius: 3px; min-height: var(--tap); padding: 0 var(--s-4); cursor: pointer;
}
.menu ol { list-style: none; margin: 0; padding: 0; }
.menu li + li { border-top: 1px solid var(--rule); }
.menu a { display: flex; gap: var(--s-4); align-items: center; min-height: var(--s-7); color: var(--ink); text-decoration: none; font-size: var(--fs-body); font-weight: 600; }
.menu a span { font-weight: 800; color: var(--main); min-width: 2.8em; }
.menu__also { margin: var(--s-3) 0 0; padding-top: var(--s-3); border-top: 2px solid var(--ink); font-size: var(--fs-small); color: var(--muted); }
.menu .menu__also a { display: inline-flex; min-height: var(--tap); color: var(--main); font-size: var(--fs-small); }

/* ---------- Motion ---------- */
.appear { opacity: 0; animation: appear 0.45s var(--ease) forwards; }
@keyframes appear { to { opacity: 1; } }
@media (prefers-reduced-motion: reduce) { .appear, .menu[open] { animation: none; opacity: 1; } }

/* ---------- Tablet ---------- */
@media (max-width: 980px) {
  .part { grid-template-columns: minmax(0, 1fr); }
  .part__head { position: static; margin-bottom: var(--s-4); display: flex; gap: var(--s-3); align-items: baseline; }
  .part__head h2 { margin: 0; }
  .cards--3, .cards--4, .geoms, .seq { grid-template-columns: repeat(2, minmax(0, 1fr)); }
}
@media (max-width: 820px) {
  .bar .wrap { flex-wrap: nowrap; }
  .bar nav { display: none; }
  .menu-btn { display: inline-flex; align-items: center; gap: var(--s-2); }
  .menu-btn__bars, .menu-btn__bars::before, .menu-btn__bars::after { display: block; width: 18px; height: 2px; background: var(--paper); position: relative; }
  .menu-btn__bars::before, .menu-btn__bars::after { content: ""; position: absolute; left: 0; }
  .menu-btn__bars::before { top: -6px; }
  .menu-btn__bars::after { top: 6px; }
}

/* ---------- Phone ---------- */
@media (max-width: 640px) {
  .bar .wrap { min-height: calc(var(--s-7) + var(--s-2)); }
  .brand { font-size: var(--fs-body); line-height: 1.2; }
  /* The plan shrinks to the screen width; labels grow just enough to read at phone scale. */
  .fig-scroll text { font-size: 30px; }
  .hero { padding-top: var(--s-6); }
  .btn { width: 100%; }
  /* Phones: sections are separated by space only; lines appear only between items of one list or table. */
  .part { margin-top: var(--s-7); padding-top: 0; border-top: 0; }
  .cards--3, .cards--4, .geoms, .seq, .sister { grid-template-columns: minmax(0, 1fr); }
  .geoms svg { height: 150px; }
  /* Tables stack on phones: the row heading on top, its content full width below. Words never break. */
  table, tbody, tr, th, td { display: block; }
  thead { position: absolute; width: 1px; height: 1px; overflow: hidden; clip-path: inset(50%); }
  tbody tr { padding: var(--s-4) 0; }
  tbody tr + tr { border-top: 1px solid var(--rule); }
  tbody th, tbody td { width: auto; padding: 0; border: 0; }
  tbody th { margin-bottom: var(--s-1); font-size: var(--fs-body); }
  /* The comparison keeps two columns on phones: a column header that sticks under the bar, then each
     property as a full-width heading over its two values side by side. */
  .table-wrap--vs { overflow: visible; }
  table.vs thead {
    position: sticky; top: calc(var(--s-7) + var(--s-2)); z-index: 1; width: auto; height: auto; overflow: visible; clip-path: none;
    background: var(--paper); padding: var(--s-2) 0;
  }
  table.vs thead tr, table.vs tbody tr { display: grid; grid-template-columns: 1fr 1fr; gap: var(--s-2); }
  table.vs thead th { padding: var(--s-2) var(--s-3); font-size: var(--fs-caption); border: 0; background: var(--band); }
  table.vs thead th:first-child { display: none; }
  table.vs thead th:last-child { background: var(--plan); }
  table.vs tbody th { grid-column: 1 / -1; margin: 0; }
  table.vs tbody td { padding: var(--s-3); font-size: var(--fs-small); background: var(--band); }
  table.vs tbody td:last-child { background: var(--plan); }
}

/* ---------- Print ---------- */
/* ---------- Copy deterrent: no selection except contact and legal lines ---------- */
html { -webkit-user-select: none; user-select: none; -webkit-touch-callout: none; }
.allow-select { -webkit-user-select: text; user-select: text; }
img, svg { -webkit-user-drag: none; }

/* ---------- Print: not available ---------- */
@media print {
  body > * { display: none !important; }
  body::before { content: "The Decentralised Water Grid Operating Model is not available in print. Please read it online at decentralisedwatergrid.com."; display: block; padding: 20mm; font-family: var(--sans); font-size: 12pt; color: #0B1F33; }
}