/* =========================================================================
   Filters and water treatment: template-filters.php (/billi-filters/).
   Scoped to .fl, mobile first, min-width media queries only (640 / 768 /
   900 / 1200). The house recipe from the 18 Sep 2026 spec
   (docs/superpowers/specs/2026-09-18-support-and-content-pages-design.md),
   plus what this page needs: horizontal product cards, the comparison
   table and a download row.

   Bands: navy split hero, white intro, grey filters, white comparison, the
   navy "change your filter" band, Green Grey help band above the navy footer.
   ========================================================================= */

.fl {
	--fl-navy: #181d46;      /* Billi Blue */
	--fl-lightblue: #90cdeb; /* primary button on dark, accents */
	--fl-grey: #eaeaea;      /* borders, rules */
	--fl-band-grey: #f5f5f5;
	--fl-band-tint: #f1f5f5; /* Green Grey */
	--fl-text: #000;
	--fl-muted: #75757b;
	--fl-gutter: 20px;

	font-family: var(--font-din);
	color: var(--fl-text);
	line-height: 1.5;
}

@media (min-width: 900px) {
	.fl { --fl-gutter: 40px; }
}

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

/* framework.css sets a global img { width: 100% }: width must be reset. */
.fl img {
	max-width: 100%;
	width: auto;
	height: auto;
	display: block;
}

.fl-container {
	width: 100%;
	max-width: 1436px; /* 1356px content + 2 x 40px */
	margin: 0 auto;
	padding-left: var(--fl-gutter);
	padding-right: var(--fl-gutter);
}

.fl-visually-hidden {
	position: absolute;
	width: 1px;
	height: 1px;
	margin: -1px;
	padding: 0;
	overflow: hidden;
	clip: rect(0 0 0 0);
	clip-path: inset(50%);
	white-space: nowrap;
	border: 0;
}


/* ---- Sections ------------------------------------------------------------ */

.fl-section { padding: 48px 0; }

@media (min-width: 900px) {
	.fl-section { padding: 80px 0; }
}

.fl-section--grey { background: var(--fl-band-grey); }
.fl-section--tint { background: var(--fl-band-tint); }
.fl-section--navy { background: var(--fl-navy); color: #fff; }

.fl .fl-section-heading {
	margin: 0 0 12px;
	font-size: 26px;
	font-weight: 600;
	line-height: 1.18;
	color: var(--fl-navy);
	text-transform: none;
	letter-spacing: normal;
}

.fl-section--navy .fl-section-heading { color: #fff; }

.fl-section-intro {
	margin: 0;
	max-width: 66ch;
	font-size: 17px;
	line-height: 1.55;
	color: var(--fl-muted);
}

.fl-section-head { margin-bottom: 28px; }

@media (min-width: 900px) {
	.fl .fl-section-heading { font-size: 34px; }
	.fl-section-head { margin-bottom: 40px; }
}


/* ---- WYSIWYG output --------------------------------------------------------
   Base rules sit inside :where() so band overrides win. */

:where(.fl) .fl-text > :first-child { margin-top: 0; }
:where(.fl) .fl-text > :last-child { margin-bottom: 0; }
:where(.fl) .fl-text p { margin: 0 0 0.85em; }

:where(.fl) .fl-text :is(h2, h3, h4) {
	margin: 1.4em 0 0.5em;
	font-size: 20px;
	font-weight: 600;
	line-height: 1.25;
	color: var(--fl-navy);
}

:where(.fl) .fl-text :is(ul, ol) { margin: 0 0 0.9em; padding-left: 1.15em; }
:where(.fl) .fl-text li { margin: 0 0 0.45em; }

:where(.fl) .fl-text a {
	color: inherit;
	text-decoration: underline;
	text-underline-offset: 2px;
}

.fl-section--navy .fl-text { color: rgba(255, 255, 255, 0.85); }
.fl-section--navy .fl-text :is(h2, h3, h4) { color: #fff; }
.fl-section--navy .fl-text a { color: var(--fl-lightblue); }


/* ---- Buttons ---------------------------------------------------------------
   desktop.css has a global a:hover { opacity: .7 }: every button opts out. */

/* 16px on a 1.5 line with 12px padding: 48px tall, the size the homepage,
   Why Billi, Specify Billi and the sector pages use. position: relative
   keeps the visually hidden file details and new-tab notes inside their
   button. */
.fl .fl-btn {
	position: relative;
	display: inline-flex;
	align-items: center;
	justify-content: center;
	gap: 8px;
	min-height: 48px;
	padding: 12px 28px;
	border: 0;
	border-radius: 2px;
	font-size: 16px;
	font-weight: 600;
	line-height: 1.5;
	text-align: center;
	text-decoration: none;
	cursor: pointer;
	transition: background-color 0.2s ease, color 0.2s ease, box-shadow 0.2s ease;
}

.fl .fl-btn:hover,
.fl .fl-btn:focus-visible { opacity: 1; }

.fl .fl-btn svg {
	width: 16px;
	height: 16px;
	flex: 0 0 auto;
}

.fl .fl-btn--navy { background: var(--fl-navy); color: #fff; }

.fl .fl-btn--navy:hover,
.fl .fl-btn--navy:focus-visible {
	background: #fff;
	color: var(--fl-navy);
	box-shadow: inset 0 0 0 1px var(--fl-navy);
}

.fl .fl-btn--light { background: var(--fl-lightblue); color: var(--fl-navy); }

.fl .fl-btn--light:hover,
.fl .fl-btn--light:focus-visible { background: #fff; color: var(--fl-navy); }

.fl .fl-btn--ghost {
	background: transparent;
	color: #fff;
	box-shadow: inset 0 0 0 1px rgba(255, 255, 255, 0.6);
}

.fl .fl-btn--ghost:hover,
.fl .fl-btn--ghost:focus-visible {
	background: #fff;
	color: var(--fl-navy);
	box-shadow: none;
}

.fl .fl-btn--outline {
	background: transparent;
	color: var(--fl-navy);
	box-shadow: inset 0 0 0 1px var(--fl-navy);
}

.fl .fl-btn--outline:hover,
.fl .fl-btn--outline:focus-visible { background: var(--fl-navy); color: #fff; }

/* framework.css removes focus outlines sitewide. Navy on light grounds,
   white on navy. */
.fl :is(a, button, summary, input, select, textarea, [tabindex]):focus-visible {
	outline: 2px solid var(--fl-navy);
	outline-offset: 3px;
}

.fl :is(.fl-hero, .fl-section--navy) :is(a, button):focus-visible { outline-color: #fff; }


/* ---- Hero ------------------------------------------------------------------
   Navy, copy left, the two cartridges from Billi's filter banner right. The
   banner is 2560x463 with the cartridges and the splash in its right half and
   a blank left half, so it is cropped to that half rather than stretched
   behind the copy. The title is an h1: typography.css gives it DM Serif
   Display at 400. Never set its weight or family here. */

.fl-hero {
	background: var(--fl-navy);
	color: #fff;
}

.fl-hero__inner {
	padding-top: 48px;
	padding-bottom: 48px;
}

.fl-hero--split .fl-hero__inner {
	display: grid;
	grid-template-columns: minmax(0, 1fr);
	gap: 32px;
	align-items: center;
}

.fl-hero__content,
.fl-hero__panel { min-width: 0; }

.fl-hero__content { max-width: 640px; }

.fl-hero__eyebrow {
	margin: 0 0 12px;
	color: var(--fl-lightblue);
	font-size: 14px;
	font-weight: 600;
	letter-spacing: 0.08em;
	text-transform: uppercase;
}

.fl .fl-hero__title {
	margin: 0;
	color: #fff;
	font-size: 34px;
	line-height: 1.12;
}

.fl-hero__intro {
	margin: 16px 0 0;
	max-width: 56ch;
	color: rgba(255, 255, 255, 0.9);
	font-size: 17px;
	line-height: 1.5;
}

.fl-hero__actions {
	display: flex;
	flex-wrap: wrap;
	gap: 12px;
	margin-top: 28px;
}

.fl-hero__actions:empty { display: none; }

/* The panel's height sets the crop: the picture is drawn at 5.5 times the
   height, so 236px tall needs a 1300px candidate and 364px a 2000px one
   (the img's sizes attribute says so). */
.fl-hero__panel {
	position: relative;
	height: 236px;
	overflow: hidden;
	border-radius: 4px;
	background: #e6f5fc;
}

.fl .fl-hero__img {
	position: absolute;
	inset: 0;
	width: 100%;
	height: 100%;
	max-width: none;
	object-fit: cover;
	/* The cartridges sit between about 57% and 79% of the banner's width;
	   73% keeps that span centred whether the panel shows a fifth or a
	   quarter of the picture. */
	object-position: 73% 50%;
}

@media (min-width: 900px) {
	.fl-hero__inner { padding-top: 72px; padding-bottom: 72px; }

	.fl-hero--split .fl-hero__inner {
		grid-template-columns: minmax(0, 1.15fr) minmax(0, 0.85fr);
		gap: 64px;
	}

	.fl .fl-hero__title { font-size: 52px; }
	.fl-hero__intro { font-size: 18px; }
	.fl-hero__panel { height: 364px; }
}


/* ---- Introduction: the BWT partnership beside why filtered water -------------- */

.fl-intro__inner {
	display: grid;
	grid-template-columns: minmax(0, 1fr);
	gap: 32px;
}

@media (min-width: 900px) {
	.fl-intro__inner {
		grid-template-columns: minmax(0, 1.1fr) minmax(0, 0.9fr);
		gap: 64px;
	}
}

.fl-intro__lede,
.fl-intro__why { min-width: 0; }

.fl-intro__lede {
	max-width: 62ch;
	font-size: 18px;
	line-height: 1.6;
}

@media (min-width: 900px) {
	.fl-intro__lede { font-size: 19px; }
}

.fl-intro__why {
	padding-top: 24px;
	border-top: 2px solid var(--fl-navy);
	font-size: 16px;
	line-height: 1.6;
}

.fl .fl-intro__heading {
	margin: 0 0 10px;
	font-size: 22px;
	font-weight: 600;
	line-height: 1.25;
	color: var(--fl-navy);
}


/* ---- Filter cards ---------------------------------------------------------------
   Product cut-outs on white, so the picture sits in a white box with
   `contain` and nothing is cropped off the cartridge. */

.fl-filters__grid {
	display: grid;
	grid-template-columns: minmax(0, 1fr);
	gap: 20px;
}

@media (min-width: 1100px) {
	.fl-filters__grid { grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 28px; }
}

.fl-filter {
	position: relative;
	display: grid;
	grid-template-columns: minmax(0, 1fr);
	min-width: 0;
	overflow: hidden;
	border: 1px solid var(--fl-grey);
	border-radius: 4px;
	background: #fff;
	transition: border-color 0.2s ease, box-shadow 0.2s ease;
}

.fl-filter:hover {
	border-color: var(--fl-navy);
	box-shadow: 0 6px 24px rgba(24, 29, 70, 0.08);
}

@media (min-width: 640px) {
	.fl-filter { grid-template-columns: 200px minmax(0, 1fr); }
}

@media (min-width: 900px) {
	.fl-filter { grid-template-columns: 240px minmax(0, 1fr); }
}

.fl-filter__media {
	display: flex;
	align-items: center;
	justify-content: center;
	padding: 20px;
	background: #fff;
}

.fl .fl-filter__img {
	width: 100%;
	max-width: 200px;
	height: auto;
	aspect-ratio: 1 / 1;
	object-fit: contain;
}

.fl-filter__body {
	display: flex;
	flex-direction: column;
	min-width: 0;
	padding: 4px 24px 24px;
}

@media (min-width: 640px) {
	.fl-filter__body { padding: 28px 28px 28px 8px; }
}

.fl-filter__code {
	margin: 0 0 6px;
	font-size: 13px;
	font-weight: 600;
	letter-spacing: 0.08em;
	color: var(--fl-muted);
}

.fl .fl-filter__title {
	margin: 0;
	font-size: 21px;
	font-weight: 600;
	line-height: 1.2;
	color: var(--fl-navy);
	text-transform: none;
}

/* One stretched link per card; desktop.css sets a { font-weight: 600 } and
   fades links on hover. */
.fl .fl-filter__link {
	color: inherit;
	font-weight: inherit;
	text-decoration: none;
}

.fl .fl-filter__link::after {
	content: '';
	position: absolute;
	inset: 0;
	border-radius: 4px;
}

.fl .fl-filter__link:hover { opacity: 1; }
.fl .fl-filter__link:focus-visible { outline: none; }
.fl .fl-filter__link:focus-visible::after { outline: 2px solid var(--fl-navy); outline-offset: 3px; }

.fl-filter__summary {
	margin: 8px 0 0;
	font-size: 16px;
	line-height: 1.5;
	color: var(--fl-text);
}

.fl-filter__specs {
	margin: 14px 0 0;
	padding: 0;
	list-style: none;
}

.fl-filter__specs li {
	position: relative;
	margin: 0 0 6px;
	padding-left: 18px;
	font-size: 15px;
	line-height: 1.45;
	color: var(--fl-muted);
}

.fl-filter__specs li::before {
	content: '';
	position: absolute;
	left: 2px;
	top: 0.6em;
	width: 6px;
	height: 6px;
	border-radius: 50%;
	background: var(--fl-lightblue);
}

.fl-filter__more {
	display: inline-flex;
	align-items: center;
	gap: 6px;
	margin-top: auto;
	padding-top: 16px;
	font-size: 15px;
	font-weight: 600;
	color: var(--fl-navy);
}

.fl-filter__more span {
	border-bottom: 1px solid currentColor;
	padding-bottom: 2px;
}

.fl .fl-filter__more svg {
	width: 16px;
	height: 16px;
	transition: transform 0.2s ease;
}

.fl-filter:hover .fl-filter__more svg { transform: translateX(3px); }


/* ---- Comparison table -------------------------------------------------------------
   Bordered wrapper that scrolls sideways on a phone rather than squashing the
   columns. Ticks and crosses are Feather's check and x, with the words for
   screen readers. */

/* position: relative makes the wrapper the containing block for the
   visually hidden "Included" spans, which are absolutely positioned: without
   it they escape the scroll box and widen the whole page on a phone. */
.fl-table-wrap {
	position: relative;
	overflow-x: auto;
	border: 1px solid var(--fl-grey);
	border-radius: 4px;
	-webkit-overflow-scrolling: touch;
}

/* desktop.css styles every table cell (width 33.33%, a 3px white border,
   upper-case th at 27px), so each of those is reset here. Fixed layout: the
   filter column takes its share and the five capabilities split the rest. */
.fl-table {
	width: 100%;
	min-width: 640px;
	margin: 0;
	table-layout: fixed;
	border: 0;
	border-collapse: collapse;
	font-size: 15px;
	line-height: 1.35;
}

.fl-table :is(th, td) {
	width: auto;
	padding: 16px 12px;
	border: 0;
	border-bottom: 1px solid var(--fl-grey);
	font-size: 15px;
	font-weight: 400;
	text-align: center;
	text-transform: none;
	letter-spacing: normal;
	vertical-align: middle;
}

.fl-table thead th:first-child { width: 30%; }

.fl-table tbody tr:last-child :is(th, td) { border-bottom: 0; }

/* The row carries the navy too, so fractional column widths cannot open
   hairline gaps between the header cells. */
.fl-table thead tr { background: var(--fl-navy); }

.fl-table thead th {
	background: var(--fl-navy);
	color: #fff;
	font-size: 14px;
	font-weight: 600;
	line-height: 1.3;
}

.fl-table :is(thead th:first-child, tbody th) { text-align: left; }

.fl-table tbody th {
	min-width: 180px;
	font-size: 16px;
	font-weight: 600;
	color: var(--fl-navy);
}

.fl-table__code {
	display: block;
	margin-top: 2px;
	font-size: 13px;
	font-weight: 400;
	letter-spacing: 0.06em;
	color: var(--fl-muted);
}

.fl-table td svg {
	display: inline-block;
	width: 22px;
	height: 22px;
	vertical-align: middle;
}

.fl-table__yes { color: var(--fl-navy); }
.fl-table__no { color: #b5b8c2; }

@media (min-width: 900px) {
	.fl-table :is(th, td) { padding: 18px 20px; }
}


/* ---- Download row ------------------------------------------------------------------ */

.fl-download {
	display: flex;
	flex-wrap: wrap;
	align-items: center;
	gap: 16px 20px;
	margin-top: 28px;
	padding: 20px;
	border-radius: 4px;
	background: var(--fl-band-tint);
}

@media (min-width: 900px) {
	.fl-download { margin-top: 40px; padding: 24px 28px; }
}

.fl-download__icon {
	flex: 0 0 auto;
	display: flex;
	align-items: center;
	justify-content: center;
	width: 48px;
	height: 48px;
	border-radius: 4px;
	background: #fff;
	color: var(--fl-navy);
}

.fl .fl-download__icon svg {
	width: 26px;
	height: 26px;
	display: block;
}

.fl-download__body {
	flex: 1 1 280px;
	min-width: 0;
}

.fl .fl-download__title {
	margin: 0;
	font-size: 19px;
	font-weight: 600;
	line-height: 1.25;
	color: var(--fl-navy);
}

.fl-download__text {
	margin: 4px 0 0;
	font-size: 15px;
	line-height: 1.5;
	color: var(--fl-muted);
}

.fl-download__meta {
	margin: 6px 0 0;
	font-size: 13px;
	font-weight: 600;
	letter-spacing: 0.06em;
	color: var(--fl-navy);
}

.fl .fl-download__btn { width: 100%; }

@media (min-width: 640px) {
	.fl .fl-download__btn { width: auto; }
}


/* ---- Changing the filter (navy) ----------------------------------------------------- */

.fl-change__inner {
	display: grid;
	grid-template-columns: minmax(0, 1fr);
	gap: 32px;
	align-items: center;
}

@media (min-width: 900px) {
	.fl-change__inner {
		grid-template-columns: minmax(0, 0.8fr) minmax(0, 1.2fr);
		gap: 64px;
	}

	.fl-change--plain .fl-change__inner { grid-template-columns: minmax(0, 1fr); }
}

.fl-change__media,
.fl-change__body { min-width: 0; }

.fl-change__body {
	max-width: 66ch;
	font-size: 16px;
	line-height: 1.6;
}

/* 784x1000 portrait: capped so it cannot outgrow the copy, and never drawn
   wider than its own pixels. */
.fl .fl-change__img {
	width: 100%;
	max-height: 360px;
	object-fit: cover;
	object-position: 50% 60%;
	border-radius: 4px;
}

@media (min-width: 900px) {
	.fl .fl-change__img { max-height: 540px; }
}

.fl-change__actions { margin: 28px 0 0; }


/* ---- Help band --------------------------------------------------------------------- */

.fl-help__inner {
	display: flex;
	flex-direction: column;
	gap: 24px;
}

@media (min-width: 900px) {
	.fl-help__inner {
		flex-direction: row;
		align-items: center;
		justify-content: space-between;
		gap: 48px;
	}
}

.fl-help__body { min-width: 0; max-width: 68ch; }

.fl-help .fl-section-heading { margin-bottom: 10px; }

.fl-help__text {
	margin: 0;
	font-size: 17px;
	line-height: 1.55;
	color: var(--fl-muted);
}

.fl-help__actions {
	display: flex;
	flex-wrap: wrap;
	gap: 12px;
	flex: 0 0 auto;
}

@media (prefers-reduced-motion: reduce) {
	.fl-filter,
	.fl .fl-filter__more svg { transition: none; }
	.fl-filter:hover .fl-filter__more svg { transform: none; }
}