/* Emberlith, concept launch site: everything below the hero.
   Loaded without blocking the first paint (see index.html).
   Tokens and base styles live in core.css.
   Rule of the house: only hot things glow, and panels are square, like plant equipment. */

/* ---------- Sections ---------- */
.section { position: relative; padding-block: var(--section); }
.section-head { max-width: 780px; margin-bottom: clamp(44px, 6vw, 80px); }
.section-head .section-lede { max-width: 56ch; margin-top: var(--s-5); }

/* The problem, in one plain paragraph. */
.statement { padding-block: clamp(96px, 13vw, 200px) clamp(40px, 5vw, 64px); }
.statement-text {
  margin: 0;
  max-width: 26ch;
  font-family: var(--font-display);
  font-weight: 400;
  font-size: clamp(1.875rem, 1.1rem + 3.1vw, 3.75rem);
  line-height: 1.12;
  letter-spacing: -.02em;
  text-wrap: pretty;
}

/* ---------- How it works ---------- */
.how-grid {
  display: grid;
  grid-template-columns: minmax(0, 1.05fr) minmax(0, .95fr);
  gap: clamp(40px, 6vw, 104px);
  align-items: start;
}
.how-visual { position: sticky; top: calc(var(--header) + 32px); }
.how-card {
  padding: clamp(16px, 2vw, 24px);
  border: 1px solid var(--line);
  border-radius: var(--r-3);
  background: var(--bg-1);
}
.how-card-head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  padding: 4px 4px 14px;
  font-size: .75rem;
  font-weight: 500;
  letter-spacing: .14em;
  text-transform: uppercase;
  color: var(--amber);
}
.how-progress { display: flex; gap: 6px; }
.how-progress i { width: 28px; height: 3px; background: var(--line-2); }
.how-card :is(.s1, .s2, .s3) { display: none; }
.how-card[data-state="1"] .s0, .how-card[data-state="2"] .s0, .how-card[data-state="3"] .s0 { display: none; }
.how-card[data-state="1"] .s1, .how-card[data-state="2"] .s2, .how-card[data-state="3"] .s3 { display: inline; }
.how-card[data-state="0"] .how-progress i,
.how-card[data-state="1"] .how-progress i:nth-child(-n+1),
.how-card[data-state="2"] .how-progress i:nth-child(-n+2),
.how-card[data-state="3"] .how-progress i { background: var(--flame); }
.how-readout {
  display: grid;
  margin-top: 12px;
  padding: 12px 4px 2px;
  border-top: 1px solid var(--line);
  font-size: .9375rem;
  color: var(--fg-2);
}
/* All four lines share one cell, so the card is as tall as the longest and never
   changes height between states (which would shift the page under it). */
.how-card .how-readout > span { display: block; grid-area: 1 / 1; visibility: hidden; }
.how-card[data-state="0"] .how-readout .s0, .how-card[data-state="1"] .how-readout .s1,
.how-card[data-state="2"] .how-readout .s2, .how-card[data-state="3"] .how-readout .s3 { visibility: visible; }

/* The diagram: the same machine as the hero and the datasheet, in the same line language. */
.how-diagram { width: 100%; height: auto; }
.how-diagram .hd-ground { stroke: var(--line-2); stroke-width: 1.5; }
.how-diagram .hd-stroke { fill: none; stroke: #8a7968; stroke-width: 1.5; stroke-linecap: round; stroke-linejoin: round; }
.how-diagram .hd-thin { stroke-width: 1; }
.how-diagram .hd-solid { fill: #15110d; stroke: #8a7968; stroke-width: 1.5; stroke-linejoin: round; }
.how-diagram .hd-building { fill: #15110d; stroke: #8a7968; stroke-width: 1.5; stroke-linejoin: round; }
.how-diagram .hd-blade { fill: #8a7968; }
.how-diagram .hd-hub { fill: var(--fg-2); }
.how-diagram .hd-panel { fill: #232a2f; stroke: var(--steel); stroke-width: 1; stroke-linejoin: round; }
.how-diagram .hd-rotor { transform-origin: 48px 163px; }
.how-diagram .hd-label { fill: var(--fg-2); font-family: var(--font-text); font-size: 14px; font-weight: 450; }
.how-diagram .hd-sub { fill: var(--fg-3); font-family: var(--font-text); font-size: 12px; }
.how-diagram .hd-wire { fill: none; stroke: #4a3d33; stroke-width: 2.5; stroke-linejoin: round; }
.how-diagram .hd-pipe { fill: none; stroke: #3d3128; stroke-width: 8; stroke-linejoin: round; }
.how-diagram .hd-port { fill: #0c0907; }
.how-diagram .hd-flow { fill: none; stroke-width: 3; stroke-linecap: round; stroke-dasharray: 1 11; opacity: 0; }
.how-diagram .hd-flow-power { stroke: var(--amber); }
.how-diagram .hd-flow-air { stroke: var(--flame); stroke-width: 2.5; stroke-linecap: butt; stroke-dasharray: 6 8; }
.how-diagram .hd-flow-steam { stroke: #fff3e2; }
.how-diagram .hd-tag { opacity: 0; transition: opacity .4s; }
.how-diagram .hd-tag rect { fill: var(--bg-3); stroke: var(--amber); }
.how-diagram .hd-tag text { fill: var(--hot); font-family: var(--font-text); font-size: 12.5px; font-weight: 500; }
.how-diagram .hd-plinth { fill: #1a1512; stroke: #4a3d33; }
.how-diagram .hd-shell { fill: none; stroke: #9a8a7b; stroke-width: 2.5; }
.how-diagram .hd-inner { fill: none; stroke: #4a3d33; stroke-width: 1; }
.how-diagram .hd-cold { fill: #2b1a12; }
/* The charge front: a cold cover slides over a fixed heat gradient, so the colour bands never stretch.
   Its top edge sits at 72 + (share of the stack that's hot) × 260. */
.how-diagram .hd-cover { transform: translateY(280px); transition: transform 1.2s var(--ease-out); }
.how-diagram .hd-rod { fill: none; stroke: #1a0f0a; stroke-width: 2.5; }
.how-diagram .hd-rod-glow { fill: none; stroke: #ff9a3d; stroke-width: 8; opacity: 0; }
.how-diagram .hd-caps { fill: #6f6153; }
.how-diagram .hd-temp { fill: var(--hot); font-family: var(--font-display); font-size: 22px; opacity: 0; transition: opacity .4s; }
.how-diagram .hd-gauge circle { fill: #15110d; stroke: #8a7968; stroke-width: 1.5; }
.how-diagram .hd-needle { stroke: var(--hot); stroke-width: 1.5; stroke-linecap: round; transform-origin: 394px 287px; transform: rotate(50deg); }
.how-diagram .hd-smoke circle { fill: #6f6153; opacity: 0; transform-box: fill-box; transform-origin: center; }
.how-diagram .hd-boiler { fill: #15110d; stroke: #8a7968; stroke-width: 1.5; }
.how-diagram .hd-burner { fill: var(--flame); }
.how-diagram .hd-boiler-off { opacity: 0; }

/* State 0: no JavaScript, the whole cycle at once, running on stored heat. */
[data-state="0"] .hd-flow { opacity: .9; }
[data-state="0"] .hd-temp, [data-state="0"] .hd-tag { opacity: 1; }
/* State 1: charging. The rods run white-hot and the front moves down, one way, then cuts back. */
[data-state="1"] .hd-flow-power { opacity: 1; animation: flow .9s linear infinite; }
[data-state="1"] .hd-tag { opacity: 1; }
[data-state="1"] .hd-rod { stroke: #fff3dc; }
[data-state="1"] .hd-rod-glow { opacity: .35; }
[data-state="1"] .hd-cover { transition: none; animation: charge 5s var(--ease-out) infinite; }
[data-state="1"] .hd-rotor { animation: spin 4s linear infinite; }
/* State 2: holding at 94%. */
[data-state="2"] .hd-cover { transform: translateY(316px); }
[data-state="2"] .hd-temp { opacity: 1; }
/* Before Emberlith takes over, the plant still burns gas. */
[data-state="1"] .hd-smoke circle, [data-state="2"] .hd-smoke circle { animation: smoke 2.4s var(--ease-out) infinite; }
.hd-smoke circle:nth-child(2) { animation-delay: .8s !important; }
.hd-smoke circle:nth-child(3) { animation-delay: 1.6s !important; }
/* State 3: delivering. The store drains, air runs down the duct, steam runs to the plant. */
[data-state="3"] .hd-cover { transition: none; animation: drain 4.8s linear infinite; }
[data-state="3"] .hd-flow-air, [data-state="3"] .hd-flow-steam { opacity: 1; animation: flow .9s linear infinite; }
[data-state="3"] .hd-flow-air { animation-name: flow-air; }
[data-state="3"] .hd-burner, [data-state="0"] .hd-burner { fill: #4a3d33; }
[data-state="3"] .hd-boiler-on, [data-state="0"] .hd-boiler-on { opacity: 0; }
[data-state="3"] .hd-boiler-off, [data-state="0"] .hd-boiler-off { opacity: 1; }

@keyframes flow { to { stroke-dashoffset: -24; } }
@keyframes flow-air { to { stroke-dashoffset: -28; } }
@keyframes charge { 0% { transform: translateY(150px); } 70%, 100% { transform: translateY(311px); } }
@keyframes drain { 0% { transform: translateY(316px); } 83%, 100% { transform: translateY(228px); } }
@keyframes spin { to { transform: rotate(360deg); } }
@keyframes smoke {
  0% { opacity: 0; transform: translateY(6px) scale(.6); }
  25% { opacity: .5; }
  100% { opacity: 0; transform: translate(4px, -30px) scale(1.6); }
}

.how-steps { margin: 0; padding: 0; list-style: none; }
.how-step {
  position: relative;
  display: flex;
  flex-direction: column;
  justify-content: center;
  min-height: 64vh;
  padding: 40px 0 40px 32px;
}
.how-step::before {
  content: "";
  position: absolute;
  left: 0; top: 0; bottom: 0;
  width: 1px;
  background: var(--line-2);
}
.how-step::after {
  content: "";
  position: absolute;
  left: -1px; top: 18%; bottom: 18%;
  width: 3px;
  background: var(--flame);
  visibility: hidden;
}
.how-step.is-active::after, .no-js .how-step::after { visibility: visible; }
.how-num {
  font-family: var(--font-display);
  font-size: 1.125rem;
  color: var(--fg-3);
  font-variant-numeric: tabular-nums;
  margin-bottom: 14px;
}
.how-step.is-active .how-num { color: var(--amber); }
.how-step .h3 { font-family: var(--font-display); font-weight: 400; font-size: clamp(1.875rem, 1.4rem + 1.4vw, 2.625rem); line-height: 1.05; letter-spacing: -.02em; }
.how-step p { margin-top: 16px; max-width: 46ch; color: var(--fg-2); }
/* One tabular spec line per step, like a line off the datasheet. */
.how-step .step-spec {
  display: flex;
  flex-wrap: wrap;
  margin-top: 24px;
  padding-top: 12px;
  border-top: 1px solid var(--line);
  font-size: .875rem;
  color: var(--fg-3);
  font-variant-numeric: tabular-nums;
}
.step-spec span { padding-right: 16px; margin-right: 16px; border-right: 1px solid var(--line-2); }
.step-spec span:last-child { border-right: 0; margin-right: 0; }
.step-spec b { font-weight: 500; color: var(--fg); }

/* ---------- A day on the grid ---------- */
.day { background: var(--bg-1); border-block: 1px solid var(--line); }
.daychart {
  margin: 0;
  padding: clamp(20px, 3vw, 40px);
  border: 1px solid var(--line-2);
  border-radius: var(--r-3);
  background: var(--bg);
}
/* The headline sits on the chart like the title of a trading screen. */
.daychart-head {
  display: grid;
  grid-template-columns: minmax(0, 1.25fr) minmax(0, 1fr);
  gap: 12px 48px;
  align-items: end;
  padding-bottom: clamp(20px, 2.4vw, 28px);
  margin-bottom: clamp(20px, 2.4vw, 28px);
  border-bottom: 1px solid var(--line-2);
}
.daychart-title {
  margin: 0;
  max-width: 22ch;
  font-family: var(--font-display);
  font-weight: 400;
  font-size: clamp(1.875rem, 1.3rem + 1.9vw, 3rem);
  line-height: 1.05;
  letter-spacing: -.02em;
  text-wrap: balance;
}
.daychart-lede { max-width: 44ch; color: var(--fg-2); }
.lanes {
  display: grid;
  grid-template-columns: 200px minmax(0, 1fr);
  column-gap: 56px;
  position: relative;
  touch-action: pan-y pinch-zoom; /* a sideways drag scrubs the day, see initDay */
}
.lane { display: contents; }
.lane-head {
  grid-column: 1;
  display: flex;
  flex-direction: column;
  gap: 4px;
  padding: 14px 0 20px;
  border-top: 1px solid var(--line);
}
.lane-price .lane-head, .lane-price .plot { border-top: 0; }
.lane-title { font-size: .75rem; font-weight: 500; letter-spacing: .14em; text-transform: uppercase; color: var(--fg-3); }
.lane-value {
  font-family: var(--font-display);
  font-size: 1.5rem;
  line-height: 1.15;
  color: var(--fg);
  font-variant-numeric: tabular-nums;
}
.lane-note { font-size: .8125rem; color: var(--fg-3); }
.lane-note.is-on { color: var(--amber); }
.plot {
  grid-column: 2;
  position: relative;
  height: 180px;
  margin-bottom: 20px;
  border-top: 1px solid var(--line);
}
.lane-store .plot { height: 110px; }
.lane-steam .plot { height: 44px; }
.plot svg { width: 100%; height: 100%; overflow: visible; }
.plot path, .plot line { vector-effect: non-scaling-stroke; }
.plot .win { fill: rgba(255, 122, 31, .09); }
.plot .win.is-on { fill: rgba(255, 122, 31, .18); }
.plot .win-rule { stroke: var(--amber); stroke-width: 2; fill: none; }
.plot .grid { stroke: var(--line); stroke-width: 1; fill: none; }
.plot .zero { stroke: var(--line-2); stroke-width: 1; fill: none; }
.plot .threshold { stroke: var(--amber); stroke-width: 1; stroke-dasharray: 4 5; fill: none; opacity: .75; }
.plot .price-line { fill: none; stroke: var(--steel); stroke-width: 2; stroke-linejoin: round; }
.plot .store-area { fill: rgba(255, 122, 31, .16); }
.plot .store-line { fill: none; stroke: var(--flame); stroke-width: 2; stroke-linejoin: round; }
.plot .steam-line { fill: none; stroke: var(--hot); stroke-width: 1.5; }
.plot .steam-ticks { fill: none; stroke: var(--fg-3); stroke-width: 1; }
.tick {
  /* In the gutter left of the plot (right of it on phones), never on the line. */
  position: absolute;
  right: calc(100% + 12px);
  top: var(--y);
  line-height: 1.3;
  transform: translateY(-50%);
  font-size: .6875rem;
  color: var(--fg-3);
  font-variant-numeric: tabular-nums;
}
.win-label, .dip-label {
  position: absolute;
  top: 10px;
  left: var(--x);
  padding-left: 8px;
  font-size: .6875rem;
  font-weight: 500;
  letter-spacing: .12em;
  text-transform: uppercase;
  color: var(--amber);
  white-space: nowrap;
}
.dip-label { top: auto; bottom: 2px; color: var(--hot); letter-spacing: .04em; text-transform: none; font-size: .75rem; }
.ph, .ph-dot { position: absolute; top: 0; left: 0; display: none; pointer-events: none; will-change: transform; }
.daychart.is-live .ph, .daychart.is-live .ph-dot { display: block; }
.ph { bottom: 0; width: 1px; margin-left: -.5px; background: rgba(255, 232, 196, .55); }
.ph-dot {
  width: 10px; height: 10px;
  margin: -5px 0 0 -5px;
  border-radius: 50%;
  background: var(--hot);
  box-shadow: 0 0 0 2px var(--bg);
}
/* Labels sit on their hour: centred on 06:00, 12:00 and 18:00, held inside at the ends. */
.axis {
  grid-column: 2;
  position: relative;
  height: 1.2em;
  margin-top: -8px;
  font-size: .75rem;
  color: var(--fg-3);
  font-variant-numeric: tabular-nums;
}
.axis span { position: absolute; top: 0; left: var(--x); transform: translateX(-50%); }
.axis span:first-child { transform: none; }
.axis span:last-child { transform: translateX(-100%); }
.scrub {
  display: flex;
  align-items: center;
  gap: 16px;
  margin-top: 28px;
  padding-top: 20px;
  border-top: 1px solid var(--line);
}
.scrub[hidden] { display: none; }
.scrub-time {
  min-width: 3.4em;
  font-family: var(--font-display);
  font-size: 1.75rem;
  line-height: 1;
  color: var(--hot);
  font-variant-numeric: tabular-nums;
  text-align: right;
}
.daychart-note {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  gap: 8px 32px;
  margin-top: 20px;
  font-size: .8125rem;
  color: var(--fg-3);
}
.legend { display: inline-flex; align-items: center; gap: 10px; color: var(--fg-2); }
.lg-win { width: 18px; height: 12px; background: rgba(255, 122, 31, .18); border-top: 2px solid var(--amber); }

/* Sliders, shared by the chart and the calculator: a flat fill and a plain thumb. */
.range {
  --p: 50%;
  -webkit-appearance: none;
  appearance: none;
  flex: 1;
  width: 100%;
  height: 32px;
  margin: 0;
  background: transparent;
  cursor: pointer;
  touch-action: pan-y;
}
.range::-webkit-slider-runnable-track {
  height: 4px;
  background: linear-gradient(90deg, var(--flame) var(--p), var(--edge) var(--p));
}
.range::-moz-range-track { height: 4px; background: var(--edge); }
.range::-moz-range-progress { height: 4px; background: var(--flame); }
.range::-webkit-slider-thumb {
  -webkit-appearance: none;
  width: 20px; height: 20px;
  margin-top: -8px;
  border: 0;
  border-radius: 50%;
  background: var(--hot);
  box-shadow: 0 0 0 2px var(--bg);
}
.range::-moz-range-thumb {
  width: 20px; height: 20px;
  border: 0;
  border-radius: 50%;
  background: var(--hot);
  box-shadow: 0 0 0 2px var(--bg);
}
/* Touch: a 44px tall hit area and a bigger thumb on the same slim track. */
@media (pointer: coarse) {
  .range { height: 44px; }
  .range::-webkit-slider-thumb { width: 24px; height: 24px; margin-top: -10px; }
  .range::-moz-range-thumb { width: 24px; height: 24px; }
}
.range:focus-visible { outline: none; }
.range:focus-visible::-webkit-slider-thumb { box-shadow: 0 0 0 2px var(--bg), 0 0 0 4px var(--amber); }
.range:focus-visible::-moz-range-thumb { box-shadow: 0 0 0 2px var(--bg), 0 0 0 4px var(--amber); }

/* ---------- Heat as a service: a sample bill ---------- */
.service-grid {
  display: grid;
  grid-template-columns: minmax(0, 5fr) minmax(0, 7fr);
  gap: clamp(40px, 6vw, 104px);
  align-items: start;
}
.service-copy .section-lede { margin-top: var(--s-5); max-width: 44ch; }
.bill {
  margin: 0;
  justify-self: end;
  width: 100%;
  max-width: 640px;
  padding: clamp(22px, 3vw, 40px);
  border-radius: 2px;
  background: #f3eadf;
  color: #22170f;
  font-size: .9375rem;
  font-variant-numeric: tabular-nums;
}
.bill-top { display: flex; justify-content: space-between; align-items: center; gap: 16px; padding-bottom: 16px; border-bottom: 2px solid #22170f; }
.bill-brand { display: flex; align-items: center; gap: 8px; font-family: var(--font-display); font-size: 1.25rem; line-height: 1; white-space: nowrap; }
.bill-brand svg { width: 18px; height: 18px; fill: #b3300e; }
.bill-sample { flex: none; padding: 3px 8px; border: 1.5px solid #b3300e; color: #b3300e; font-size: .75rem; font-weight: 600; letter-spacing: .16em; text-transform: uppercase; }
.bill-title { margin: 22px 0 2px; font-size: 1.125rem; font-weight: 550; letter-spacing: -.01em; }
.bill-meta { font-size: .875rem; color: #6b5a4c; }
.bill-lines { width: 100%; margin-top: 20px; border-collapse: collapse; }
.bill-lines th, .bill-lines td { padding: 12px 0; border-top: 1px solid #d8cbbb; text-align: left; vertical-align: top; font-weight: 400; }
.bill-lines td { padding-left: 16px; text-align: right; white-space: nowrap; }
.bill small { display: block; margin-top: 2px; font-size: .8125rem; color: #6b5a4c; }
.bill-lines tfoot th, .bill-lines tfoot td { border-top: 2px solid #22170f; font-weight: 600; font-size: 1.0625rem; }
.bill-compare { margin: 20px 0 0; padding: 14px 16px; background: #e9dccb; }
.bill-compare div { display: flex; justify-content: space-between; gap: 16px; }
.bill-compare div + div { margin-top: 10px; padding-top: 10px; border-top: 1px solid #cdbca8; }
.bill-compare dd { margin: 0; white-space: nowrap; }
.bill-compare small { color: #5f4f42; }
.bill-kept dt, .bill-kept dd { font-weight: 600; color: #8f1d0b; }
.bill-fine { margin-top: 18px; font-size: .8125rem; line-height: 1.5; color: #6b5a4c; }

/* ---------- Calculator ---------- */
.calc-panel {
  display: grid;
  grid-template-columns: minmax(0, 5fr) minmax(0, 7fr);
  border: 1px solid var(--line-2);
  border-radius: var(--r-3);
  background: var(--bg-1);
  overflow: hidden;
}
.panel-title {
  display: flex;
  align-items: baseline;
  flex-wrap: wrap;
  gap: 10px;
  margin: 0 0 28px;
  font-size: .75rem;
  font-weight: 500;
  letter-spacing: .14em;
  line-height: 1.4;
  text-transform: uppercase;
  color: var(--fg-3);
}
.tag { letter-spacing: .1em; color: var(--fg-2); }
.tag::before { content: "· "; }
.calc-inputs { padding: clamp(24px, 3vw, 44px); border-right: 1px solid var(--line); }
.field-range + .field-range { margin-top: 32px; }
.range-row { display: flex; align-items: baseline; justify-content: space-between; gap: 16px; margin-bottom: 10px; }
.range-row label { font-size: 1rem; color: var(--fg); font-weight: 400; }
.range-row output {
  font-family: var(--font-display);
  font-size: 1.625rem;
  line-height: 1;
  color: var(--hot);
  font-variant-numeric: tabular-nums;
  white-space: nowrap;
}
.range-hint { margin-top: 6px; font-size: .8125rem; color: var(--fg-3); }
.calc-results {
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  padding: clamp(24px, 3vw, 44px);
  background: var(--bg-2);
}
.result-hero { width: 100%; padding-bottom: 28px; border-bottom: 1px solid var(--line-2); }
.result-label { font-size: .9375rem; color: var(--fg-2); }
.result-big {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 0 .3em;
  margin-top: 6px;
  font-family: var(--font-display);
  font-size: clamp(2.75rem, 1.6rem + 4vw, 5.25rem);
  line-height: 1;
  letter-spacing: -.03em;
  color: var(--hot);
  font-variant-numeric: tabular-nums;
}
.result-to { font-style: italic; font-size: .5em; color: var(--fg-3); letter-spacing: 0; }
.result-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 24px;
  width: 100%;
  margin: 24px 0 32px;
}
.result-grid div { display: flex; flex-direction: column; gap: 6px; }
.result-grid dt { font-size: .8125rem; color: var(--fg-3); line-height: 1.35; }
.result-grid dd { margin: 0; font-family: var(--font-display); font-size: 1.75rem; line-height: 1.05; letter-spacing: -.015em; font-variant-numeric: tabular-nums; }
.result-grid .unit { display: block; margin-top: 4px; font-family: var(--font-text); font-size: .8125rem; letter-spacing: 0; color: var(--fg-2); }
.assumptions { grid-column: 1 / -1; padding: clamp(24px, 3vw, 44px); border-top: 1px solid var(--line); }
.assumptions ul {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 14px 40px;
  margin: 0 0 20px;
  padding: 0;
  list-style: none;
  font-size: .9375rem;
  color: var(--fg-2);
}
.assumptions li { position: relative; padding-left: 20px; }
.assumptions li::before {
  content: "";
  position: absolute;
  left: 0; top: .68em;
  width: 8px; height: 1px;
  background: var(--amber);
}
.assumptions b { color: var(--fg); font-weight: 450; }

/* ---------- Specs: a datasheet ---------- */
.sheet-head {
  display: grid;
  grid-template-columns: minmax(0, 1.12fr) minmax(0, .88fr);
  gap: 16px clamp(32px, 5vw, 88px);
  align-items: end;
  margin-bottom: clamp(32px, 4vw, 56px);
  padding-bottom: 20px;
  border-bottom: 2px solid var(--fg-3);
}
.sheet-title { display: flex; align-items: baseline; flex-wrap: wrap; gap: 8px 24px; margin: 0; font-weight: 400; }
.sheet-model { font-family: var(--font-display); font-size: var(--t-h2); line-height: .95; letter-spacing: -.025em; }
.sheet-rev { font-size: .75rem; font-weight: 500; letter-spacing: .16em; text-transform: uppercase; color: var(--fg-3); }
.sheet-lede { max-width: 40ch; font-size: var(--t-lede); line-height: 1.5; color: var(--fg-2); }
.specs-grid {
  display: grid;
  grid-template-columns: minmax(0, 1.12fr) minmax(0, .88fr);
  gap: clamp(32px, 5vw, 88px);
  align-items: start;
}
.drawing-wrap {
  margin: 0;
  padding: clamp(12px, 1.6vw, 20px);
  border: 1px solid var(--line-2);
  border-radius: 2px;
  background: var(--bg-1);
}
.drawing { width: 100%; height: auto; }
.drawing polygon { stroke: #6e5d4f; stroke-width: .8; stroke-linejoin: round; }
.drawing .ground { fill: #080605; stroke: none; opacity: .85; }
/* Lit from the top left: the roof brightest, the right-hand faces in shadow. */
.drawing .f-z { fill: #3a3028; }
.drawing .f-y { fill: #2a221b; }
.drawing .f-x { fill: #15100c; }
.drawing .top-edge { stroke: #7d6b5b; stroke-width: 1; }
.drawing .seam { stroke: #3a2f26; stroke-width: .7; stroke-linecap: round; }
.drawing .plinth { fill: #1a1512; }
.drawing .skin { fill: #5a4b3f; stroke: none; }
.drawing .insul { fill: url(#hatch); stroke: #3a2f26; }
.drawing .brick { fill: url(#brickHeat); stroke: none; }
.drawing .brick-B { opacity: .84; }
.drawing .joints { stroke: none; }
.drawing .rod { stroke: #fff3dc; stroke-width: 1.4; stroke-linecap: round; transition: stroke .15s; }
.drawing .cap { stroke: #9a8a7b; stroke-width: 2.2; stroke-linecap: round; }
.drawing .edge { stroke: #8a7766; stroke-width: 1; }
.drawing .flange { fill: #3a2f26; }
.drawing .person { fill: #8a7968; }
.drawing .person polygon { stroke: none; }
.drawing .sb-a { fill: var(--fg-3); }
.drawing .sb-b { fill: none; stroke: var(--fg-3); stroke-width: .8; }
.drawing .dim { fill: none; stroke: var(--fg-3); stroke-width: .8; }
.drawing .dim-arrow { fill: var(--fg-3); stroke: none; }
.drawing .dim-text, .drawing .tb-text { fill: var(--fg-2); font-family: var(--font-text); font-size: 11px; }
.drawing .frame { fill: none; stroke: var(--line-2); stroke-width: 1; }
.drawing .tb { fill: var(--bg-1); stroke: var(--line-2); stroke-width: 1; }
.drawing .zone { fill: var(--fg-3); font-family: var(--font-text); font-size: 8px; text-anchor: middle; dominant-baseline: central; }
/* Landscape phones and touch tablets show the full sheet, where the zone letters come out
   around 6px: they're grid references, so they give way there as on portrait phones. */
@media (pointer: coarse) and (max-width: 1023px) { .drawing .zone { display: none; } }
.drawing .tb-text { font-size: 8.5px; letter-spacing: .06em; fill: var(--fg-3); }
.drawing .tb-title { fill: var(--fg); font-size: 9px; letter-spacing: .04em; } /* fits inside the title block */
.drawing .callout circle { stroke-width: 1; }
.drawing .callout .dot { fill: var(--amber); stroke: none; }
.drawing .num { transform-box: fill-box; transform-origin: center; }
.drawing .callout text {
  font-family: var(--font-text);
  font-size: 12px;
  font-weight: 600;
  text-anchor: middle;
  dominant-baseline: central;
}
/* Point at a line of the key and its callout lights up. */
.drawing[data-hl="1"] [data-n="1"], .drawing[data-hl="2"] [data-n="2"], .drawing[data-hl="3"] [data-n="3"],
.drawing[data-hl="4"] [data-n="4"], .drawing[data-hl="5"] [data-n="5"], .drawing[data-hl="6"] [data-n="6"],
.drawing[data-hl="7"] [data-n="7"] { --hl-line: var(--hot); --hl-fill: var(--flame); --hl-text: #1a0b04; --hl-w: 1.5; }
.drawing .callout line { stroke: var(--hl-line, var(--fg-3)); stroke-width: var(--hl-w, .8); }
.drawing .callout .num circle { fill: var(--hl-fill, var(--bg)); stroke: var(--hl-fill, var(--amber)); }
.drawing .callout text { fill: var(--hl-text, var(--hot)); }
/* The rods start cold and light one after another the first time the drawing scrolls in. */
.drawing-wrap.is-cold .rod { stroke: #3a2f26; }
.drawing-wrap figcaption { margin-top: 16px; padding: 16px 8px 4px; border-top: 1px solid var(--line); }
.drawing-key {
  columns: 2;
  column-gap: 32px;
  margin: 0 0 14px;
  padding: 0;
  list-style: none;
  counter-reset: key;
  font-size: .875rem;
  color: var(--fg-2);
}
.drawing-key li {
  counter-increment: key;
  display: flex;
  gap: 10px;
  align-items: baseline;
  padding: 4px 0;
  break-inside: avoid;
}

/* The line whose callout is lit (by pointing, or by a tap on a touch screen). */
.drawing-key li.is-hl { color: var(--fg); }
@media (hover: hover) { .drawing-key li:hover { color: var(--fg); } }
@media (pointer: coarse) { .drawing-key li { padding-block: 10px; } }
.drawing-key li::before {
  content: counter(key);
  flex: none;
  display: inline-grid;
  place-items: center;
  width: 20px; height: 20px;
  border: 1px solid var(--amber);
  border-radius: 50%;
  font-size: .6875rem;
  font-weight: 600;
  color: var(--hot);
  transform: translateY(-1px);
}
.drawing-key li.is-hl::before { border-color: var(--flame); background: var(--flame); color: #1a0b04; }
.spec { width: 100%; table-layout: fixed; border-collapse: collapse; font-variant-numeric: tabular-nums; }
.spec caption {
  padding: 28px 0 10px;
  font-size: .75rem;
  font-weight: 500;
  letter-spacing: .16em;
  text-align: left;
  text-transform: uppercase;
  color: var(--amber);
}
.spec:first-child caption { padding-top: 0; }
.spec th[scope="row"], .spec td { padding: 13px 0; border-top: 1px solid var(--line); vertical-align: top; text-align: left; }
.spec th[scope="row"] { width: 44%; padding-right: 16px; font-weight: 350; color: var(--fg-2); }
.spec td { color: var(--fg); }
.spec td b { color: var(--hot); font-weight: 500; }

/* ---------- Pilots ---------- */
.pilots { background: var(--bg-1); border-block: 1px solid var(--line); }
.plant {
  display: grid;
  grid-template-columns: minmax(0, 5fr) minmax(0, 6fr);
  gap: clamp(32px, 5vw, 80px);
  padding: clamp(24px, 3vw, 44px);
  border: 1px solid var(--line-2);
  border-radius: var(--r-3);
  background: var(--bg);
}
.plant-status { display: flex; align-items: center; gap: 10px; font-size: .75rem; font-weight: 500; letter-spacing: .12em; text-transform: uppercase; color: var(--amber); }
.plant-status i { flex: none; width: 8px; height: 8px; background: var(--flame); }
.plant-name {
  margin: 20px 0 6px;
  font-family: var(--font-display);
  font-weight: 400;
  font-size: clamp(2.25rem, 1.6rem + 1.8vw, 3.25rem);
  line-height: 1;
  letter-spacing: -.02em;
}
.plant-where { color: var(--fg-2); font-size: .9375rem; }
.plant-facts { margin: 28px 0 0; }
.plant-facts div {
  display: grid;
  grid-template-columns: 92px minmax(0, 1fr);
  gap: 12px;
  padding: 12px 0;
  border-top: 1px solid var(--line);
  font-size: .9375rem;
}
.plant-facts dt { color: var(--fg-3); }
.plant-facts dd { margin: 0; }
.plant-quote { margin: 28px 0 0; padding-left: 18px; border-left: 2px solid var(--line-2); }
.plant-quote p { max-width: 36ch; font-family: var(--font-display); font-size: clamp(1.25rem, 1.1rem + .5vw, 1.5rem); line-height: 1.3; letter-spacing: -.01em; }
.plant-quote footer { margin-top: 10px; font-size: .875rem; color: var(--fg-3); }
.plant-chart { display: flex; flex-direction: column; margin: 0; }
.plant-chart-title { margin-bottom: 40px; font-size: .75rem; font-weight: 500; letter-spacing: .12em; line-height: 1.5; text-transform: uppercase; color: var(--fg-3); }
.bars-wrap { position: relative; flex: 1; min-height: 240px; margin-left: 40px; }
.bars {
  position: absolute;
  inset: 0 0 26px;
  display: grid;
  grid-template-columns: repeat(24, minmax(0, 1fr));
  gap: 3px;
  align-items: end;
  border-bottom: 1px solid var(--edge);
}
.bars i { display: block; height: calc(var(--h) * 100%); background: #7a6b5d; }
.bars i.is-zero { height: 2px; background: var(--flame); }
.bars-y { position: absolute; right: calc(100% + 8px); font-size: .6875rem; color: var(--fg-3); white-space: nowrap; line-height: 1; font-variant-numeric: tabular-nums; }
.bars-y-top { top: 0; }
.bars-y-zero { bottom: 26px; transform: translateY(50%); }
.bars-y-top::after { content: ""; position: absolute; left: calc(100% + 4px); top: 50%; width: 4px; height: 1px; background: var(--edge); }
.bars-mark { position: absolute; top: -18px; bottom: 26px; left: var(--x); border-left: 1px dashed var(--amber); }
.bars-mark b { position: absolute; top: 0; left: 8px; font-size: .75rem; font-weight: 500; color: var(--amber); white-space: nowrap; line-height: 1; }
.bars-note { position: absolute; bottom: 48px; left: var(--x); transform: translateX(-50%); font-size: .6875rem; color: var(--fg-3); white-space: nowrap; }
.bars-note::after { content: ""; position: absolute; left: 50%; top: calc(100% + 3px); height: 8px; border-left: 1px solid var(--edge); }
.bars-note-end { transform: translateX(calc(-100% + 8px)); }
.bars-note-end::after { left: auto; right: 8px; }
.bars-x { position: absolute; left: 0; right: 0; bottom: 0; height: 18px; font-size: .6875rem; color: var(--fg-3); }
.bars-x span { position: absolute; left: var(--x); top: 4px; }
.bars-legend { display: flex; flex-wrap: wrap; gap: 6px 20px; margin-top: 16px; margin-left: 40px; font-size: .8125rem; color: var(--fg-2); }
.bars-legend span { display: inline-flex; align-items: center; gap: 8px; }
.bars-legend i { width: 12px; height: 10px; background: #7a6b5d; }
.bars-legend .lg-brick { height: 2px; background: var(--flame); }
.cores { display: inline-flex; gap: 3px; margin-left: 8px; vertical-align: -1px; }
.cores i { width: 5px; height: 13px; background: linear-gradient(180deg, var(--hot), var(--flame) 55%, var(--ember-600)); }
.cores.is-cold i { background: var(--line-2); }
/* The rest of the list: a commissioning log, ruled like the datasheet. */
.log { width: 100%; margin-top: clamp(40px, 5vw, 64px); border-collapse: collapse; font-size: .9375rem; }
.log caption { padding-bottom: 12px; text-align: left; font-size: .75rem; font-weight: 500; letter-spacing: .14em; text-transform: uppercase; color: var(--fg-3); }
.log thead th { padding: 0 16px 10px 0; border-bottom: 1px solid var(--line-2); text-align: left; font-size: .75rem; font-weight: 500; letter-spacing: .12em; text-transform: uppercase; color: var(--fg-3); }
.log tbody th, .log td { padding: 18px 20px 18px 0; border-bottom: 1px solid var(--line); text-align: left; vertical-align: top; font-weight: 400; }
.log tbody th { width: 32%; }
.log tbody th b { display: block; font-family: var(--font-display); font-weight: 400; font-size: 1.5rem; line-height: 1.1; letter-spacing: -.01em; }
.log tbody th span { display: block; margin-top: 4px; font-size: .875rem; color: var(--fg-2); }
.log td { color: var(--fg-2); }
.log-status { display: inline-flex; gap: 10px; align-items: baseline; color: var(--fg); }
.log-status i { flex: none; width: 8px; height: 8px; border: 1.5px solid var(--fg-3); }
.log-status.is-soon i { border-color: var(--flame); }

/* ---------- Team ---------- */
.team-grid {
  display: grid;
  grid-template-columns: minmax(0, 4fr) minmax(0, 8fr);
  gap: 24px clamp(32px, 6vw, 96px);
  align-items: start;
}
.founders {
  max-width: 34ch;
  font-family: var(--font-display);
  font-size: clamp(1.5rem, 1.2rem + 1vw, 2.125rem);
  line-height: 1.25;
  letter-spacing: -.012em;
  text-wrap: pretty;
}
.founders b { font-weight: 400; color: var(--hot); }
.crew { margin: 40px 0 0; padding: 0; list-style: none; border-top: 1px solid var(--line-2); }
.crew li {
  display: grid;
  grid-template-columns: 10rem 10rem minmax(0, 1fr);
  gap: 4px 24px;
  padding: 16px 0;
  border-bottom: 1px solid var(--line);
  font-size: .9375rem;
}
.crew-name { font-weight: 500; }
.crew-role { color: var(--fg-3); }
.crew-bio { color: var(--fg-2); }
.hiring { margin-top: 32px; max-width: 60ch; color: var(--fg-2); }
.hiring b { color: var(--fg); font-weight: 500; }

/* ---------- FAQ ---------- */
.faq-grid {
  display: grid;
  grid-template-columns: minmax(0, 5fr) minmax(0, 7fr);
  gap: clamp(32px, 6vw, 96px);
  align-items: start;
}
.faq-title {
  position: sticky;
  top: calc(var(--header) + 32px);
  max-width: 14ch;
  margin: 0;
  text-wrap: balance;
  font-family: var(--font-display);
  font-weight: 400;
  font-size: clamp(1.75rem, 1.4rem + 1.2vw, 2.5rem);
  line-height: 1.08;
  letter-spacing: -.018em;
}
.faq-list { border-bottom: 1px solid var(--line); }
.faq-list details { border-top: 1px solid var(--line); }
.faq-list summary {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  padding: 22px 0;
  font-size: clamp(1.0625rem, 1rem + .3vw, 1.25rem);
  font-weight: 400;
  line-height: 1.35;
  cursor: pointer;
  list-style: none;
}
.faq-list summary::-webkit-details-marker { display: none; }
@media (hover: hover) { .faq-list summary:hover { color: var(--hot); } }
.faq-list summary:focus-visible { outline-offset: 4px; }
/* A plain plus that loses its upright when open. */
.faq-list summary i { position: relative; flex: none; width: 14px; height: 14px; }
.faq-list summary i::before, .faq-list summary i::after {
  content: "";
  position: absolute;
  top: 50%; left: 0;
  width: 14px; height: 1.5px;
  margin-top: -.75px;
  background: var(--amber);
}
.faq-list summary i::after { transform: rotate(90deg); }
.faq-list details[open] summary i::after { display: none; }
.faq-a { padding: 0 48px 26px 0; color: var(--fg-2); max-width: 62ch; }

/* ---------- Assessment ---------- */
.cta { padding-bottom: clamp(112px, 12vw, 176px); }
.cta-grid {
  position: relative;
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(0, 1fr);
  gap: clamp(40px, 6vw, 104px);
  align-items: start;
}
.h2-xl { font-size: clamp(2.75rem, 1.6rem + 4.4vw, 5.75rem); line-height: .98; }
.cta-copy .section-lede { margin-top: var(--s-5); max-width: 44ch; }
.ticks { margin: 32px 0 0; padding: 0; list-style: none; }
.ticks li {
  position: relative;
  padding: 12px 0 12px 32px;
  border-top: 1px solid var(--line);
  color: var(--fg);
}
.ticks li:last-child { border-bottom: 1px solid var(--line); }
.ticks li::before {
  content: "";
  position: absolute;
  left: 2px; top: 1.05em;
  width: 12px; height: 7px;
  border-left: 1.5px solid var(--amber);
  border-bottom: 1.5px solid var(--amber);
  transform: rotate(-45deg);
}
.form-card {
  position: relative;
  padding: clamp(24px, 3vw, 40px);
  border: 1px solid var(--line-2);
  border-radius: var(--r-3);
  background: var(--bg-2);
}
.form-card .panel-title { color: var(--fg); letter-spacing: .12em; }
.form-grid { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 20px 16px; margin-bottom: 24px; }
.field-wide { grid-column: 1 / -1; }
.field label { display: block; margin-bottom: 8px; font-size: .875rem; color: var(--fg-2); }
.optional { margin-left: 6px; font-size: .75rem; color: var(--fg-3); }
.field input, .field textarea {
  display: block;
  width: 100%;
  min-height: 50px;
  padding: 12px 14px;
  border: 1px solid var(--edge);
  border-radius: var(--r-2);
  background: var(--bg);
  color: var(--fg);
  font-size: 1rem;
  font-weight: 350;
}
.field textarea { resize: vertical; min-height: 96px; }
.field input::placeholder { color: var(--fg-3); opacity: 1; }
@media (hover: hover) { .field input:hover, .field textarea:hover { border-color: #8d7d6e; } }
.field input:focus-visible, .field textarea:focus-visible {
  outline: none;
  border-color: var(--amber);
  box-shadow: 0 0 0 1px var(--amber);
}
.field [aria-invalid="true"] { border-color: var(--error); }
.field-hint { margin-top: 6px; font-size: .8125rem; color: var(--fg-3); }
.field-hint.is-carried { color: var(--amber); }
.field-error { margin-top: 6px; font-size: .8125rem; color: var(--error); }
.field-error::before { content: "! "; font-weight: 700; }
.input-unit { position: relative; }
.input-unit input { padding-right: 52px; }
.unit-suffix { position: absolute; right: 14px; top: 50%; transform: translateY(-50%); color: var(--fg-3); font-size: .875rem; pointer-events: none; }
.input-unit input::-webkit-outer-spin-button, .input-unit input::-webkit-inner-spin-button { -webkit-appearance: none; margin: 0; }
.input-unit input[type="number"] { -moz-appearance: textfield; appearance: textfield; }
.form-fine { margin-top: 14px; }
.form-success { text-align: left; }
.form-success:focus { outline: none; }
.form-success[hidden] { display: none; }
.success-mark { width: 56px; height: 56px; margin-bottom: 24px; fill: none; stroke: var(--amber); stroke-width: 1.5; stroke-linecap: round; stroke-linejoin: round; }
.success-mark circle { stroke: var(--line-2); }
.success-mark path { stroke-dasharray: 32; stroke-dashoffset: 32; animation: tick .7s .2s var(--ease-out) forwards; }
@keyframes tick { to { stroke-dashoffset: 0; } }
.form-success .panel-title { display: block; font-family: var(--font-display); font-size: 2rem; letter-spacing: -.015em; text-transform: none; color: var(--fg); margin-bottom: 14px; }
.form-success p { color: var(--fg-2); max-width: 44ch; }
.form-success .fine { margin-top: 14px; }
.form-success .btn { margin-top: 28px; }

/* ---------- Footer ---------- */
.site-footer { border-top: 1px solid var(--line); padding-block: 64px 112px; background: var(--bg); }
.footer-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(0, 1fr) minmax(0, 1.3fr);
  gap: 40px;
}
.footer-brand p { margin-top: 14px; color: var(--fg-3); font-size: .9375rem; }
.footer-nav { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 24px; }
.footer-nav ul { margin: 0; padding: 0; list-style: none; display: grid; gap: 10px; align-content: start; }
.footer-nav a { color: var(--fg-2); font-size: .9375rem; text-decoration: none; }
@media (hover: hover) { .footer-nav a:hover { color: var(--fg); } }
.footer-legal { font-size: .875rem; color: var(--fg-3); display: grid; gap: 12px; }
.footer-legal b { color: var(--fg-2); font-weight: 500; }
.footer-legal a { color: var(--fg-2); text-underline-offset: 3px; }
@media (hover: hover) { .footer-legal a:hover { color: var(--fg); } }

/* ---------- Responsive: sections ---------- */
@media (max-width: 1180px) {
  .assumptions ul { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .result-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .result-grid div:last-child { grid-column: 1 / -1; }
  .plant { grid-template-columns: minmax(0, 1fr); }
  .bars-wrap { flex: none; height: 220px; }
  .crew li { grid-template-columns: 10rem minmax(0, 1fr); }
  .crew-bio { grid-column: 2; }
}

@media (max-width: 1023px) {
  .how-grid, .specs-grid, .faq-grid, .cta-grid, .service-grid, .team-grid, .sheet-head, .daychart-head { grid-template-columns: minmax(0, 1fr); }
  .faq-title { position: static; max-width: none; margin-bottom: 8px; }
  .calc-panel { grid-template-columns: minmax(0, 1fr); }
  .calc-inputs { border-right: 0; border-bottom: 1px solid var(--line); }
  .footer-grid { grid-template-columns: minmax(0, 1fr) minmax(0, 1fr); }
  .footer-legal { grid-column: 1 / -1; }
  .site-footer { padding-bottom: 64px; } /* no floating badge down here below 960px */
  /* The diagram rides along at the top while the steps scroll under it. The mask runs
     well below the card, so a heading never shows half-cut under its bottom edge. */
  .how-visual { top: calc(var(--header) + 8px); z-index: 2; }
  .how-visual::before {
    content: "";
    position: absolute;
    inset: -12px calc(var(--gutter) * -1) -56px;
    z-index: -1;
    background: linear-gradient(180deg, var(--bg) calc(100% - 56px), rgba(12, 9, 7, 0));
  }
  .how-card { max-width: 560px; margin-inline: auto; }
  .how-steps { position: relative; z-index: 1; }
  .how-step { min-height: 52vh; padding-block: 32px 48px; }
  .bill { max-width: none; }
  /* The first charging window is too narrow for its word below 1024px: the amber top rule
     and the legend name the windows instead. */
  .win-label { display: none; }
}

@media (max-width: 1023px) and (max-height: 620px) {
  .how-visual { position: static; }
  .how-visual::before { display: none; }
}

@media (max-width: 719px) {
  /* Panels run edge to edge on a phone: the chart, the calculator, the drawing, the
     Brekkeby panel and the form get the whole width, and what's inside them lines up
     with the page's own margin. The bill stays a sheet of paper, and the diagram card
     floats over the steps. */
  .daychart, .calc-panel, .drawing-wrap, .plant, .form-card {
    margin-inline: calc(var(--gutter) * -1);
    border-inline: 0;
    border-radius: 0;
  }
  .daychart, .form-card { padding-inline: var(--gutter); }
  .calc-inputs, .calc-results, .assumptions { padding-inline: var(--gutter); }
  .drawing-wrap { padding: 8px 6px 16px; }
  .drawing-wrap figcaption { padding: 16px calc(var(--gutter) - 6px) 0; }
  .how-card { padding: 12px 12px 10px; }
  .how-card-head { padding-bottom: 8px; }
  .how-diagram .hd-label { font-size: 19px; }
  .how-diagram .hd-sub { font-size: 15px; }
  .how-diagram .hd-tag text { font-size: 15px; }
  .how-readout { margin-top: 6px; padding-top: 10px; font-size: .875rem; }
  .how-step { min-height: 46vh; padding-left: 24px; }
  .step-spec span { padding-right: 12px; margin-right: 12px; }
  .lanes { grid-template-columns: minmax(0, 1fr); }
  .lane-head { grid-column: 1; flex-direction: row; align-items: baseline; justify-content: space-between; padding: 12px 0 10px; }
  .lane-title { white-space: nowrap; letter-spacing: .1em; }
  .lane-value { font-size: 1.125rem; text-align: right; white-space: nowrap; }
  .lane-note { display: none; }
  .tick { right: auto; left: calc(100% + 8px); font-size: .75rem; }
  .range-row output { font-size: 1.375rem; }
  .plot { grid-column: 1; border-top: 0; height: 132px; margin: 0 40px 8px 0; }
  .lane-store .plot { height: 84px; }
  .lane-steam .plot { height: 36px; }
  .axis { grid-column: 1; margin: 0 40px 0 0; }
  .dip-label { font-size: .75rem; }
  .scrub { gap: 12px; }
  .scrub-time { font-size: 1.375rem; }
  .bill { padding: 20px 16px 22px; font-size: .875rem; }
  .bill-brand { font-size: 1.125rem; }
  .bill-compare { padding: 12px; }
  .result-grid { grid-template-columns: minmax(0, 1fr) minmax(0, 1fr); gap: 20px 16px; }
  .result-grid dd { font-size: 1.5rem; }
  .calc-results .btn { width: 100%; white-space: normal; text-wrap: balance; text-align: center; padding-block: 12px; }
  .assumptions ul { grid-template-columns: minmax(0, 1fr); }
  .drawing-key { columns: 1; }
  /* The drawing on a phone: the sheet keeps its frame, the zone letters and the title
     block (both too small to read here; the caption says what it is) give way, and
     the dimensions, the scale bar and the callouts are set bigger. */
  .drawing .zone, .drawing .title-block .tb, .drawing .title-block .frame, .drawing .title-block .tb-title, .drawing .title-block .tb-rev { display: none; }
  .drawing .dim-text { font-size: 18px; }
  .drawing .title-block .sb-text { font-size: 18px; fill: var(--fg-2); }
  .drawing .num { transform: scale(1.5); }
  .spec th[scope="row"], .spec td { padding-block: 12px; font-size: .9375rem; }
  .spec th[scope="row"] { width: 42%; padding-right: 12px; }
  .plant { padding: 24px var(--gutter); }
  .bars-wrap { height: 200px; min-height: 0; margin-left: 34px; }
  .bars { gap: 2px; }
  .bars-legend { margin-left: 0; }
  .bars-mark b, .bars-y, .bars-note, .bars-x { font-size: .75rem; }
  .log thead { display: none; }
  .log caption { display: block; }
  .log, .log tbody, .log tr, .log th, .log td { display: block; width: auto !important; }
  .log tbody tr { padding: 16px 0; border-bottom: 1px solid var(--line); }
  .log tbody th, .log td { padding: 0; border: 0; }
  .log tbody th { margin-bottom: 10px; }
  .log td { display: grid; grid-template-columns: 72px minmax(0, 1fr); column-gap: 12px; padding: 4px 0; }
  .log td::before { content: attr(data-label); color: var(--fg-3); }
  .crew li { grid-template-columns: minmax(0, 1fr); gap: 2px; }
  .crew-bio { grid-column: auto; margin-top: 4px; }
  .form-grid { grid-template-columns: minmax(0, 1fr); }
  .faq-a { padding-right: 0; }
  .footer-grid { grid-template-columns: minmax(0, 1fr); gap: 32px; }
  .footer-legal { grid-column: auto; }
  /* 44px to tap. */
  .footer-nav { row-gap: 0; }
  .footer-nav ul { gap: 0; }
  .footer-nav a { display: flex; align-items: center; min-height: 44px; }
  .footer-legal a { display: inline-block; padding-block: 12px; margin-block: -12px; }
}

/* Touch screens of any size: chart labels at 12px, footer links 44px to tap. */
@media (pointer: coarse) {
  .tick, .win-label, .bars-mark b, .bars-y, .bars-note, .bars-x { font-size: .75rem; }
  .footer-nav ul { gap: 0; }
  .footer-nav a { display: flex; align-items: center; min-height: 44px; }
  .footer-legal a { display: inline-block; padding-block: 12px; margin-block: -12px; }
}

/* The diagram's labels on the narrowest phones: 12px on screen (the plant's state and
   the price tag 11px), with the row of names nudged up to make room under it. */
@media (max-width: 479px) {
  .how-diagram .hd-label { font-size: 21px; transform: translateY(-5px); }
  .how-diagram .hd-sub { font-size: 19.5px; transform: translateY(-2px); }
  .how-diagram .hd-tag { transform: scale(1.4); transform-origin: 168px 108px; }
}

@media (prefers-reduced-motion: reduce) {
  [data-state="1"] .hd-cover { transform: translateY(260px); }
  [data-state="3"] .hd-cover { transform: translateY(260px); }
  .hd-smoke circle { display: none; }
  .success-mark path { stroke-dashoffset: 0; }
}