:root {
  color-scheme: light;
  --ink: #0b1f33;
  --paper: #f7f5ef;
  --blue: #075bc7;
  --cyan: #19c6d3;
  --yellow: #ffd84a;
  --muted: #536474;
  --line: #c9d2d9;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body { margin: 0; min-width: 320px; color: var(--ink); background: var(--paper); }
button, input, select { font: inherit; }
a { color: inherit; }
input:focus-visible, select:focus-visible, a:focus-visible { outline: 4px solid var(--yellow); outline-offset: 3px; }

.calculator-main { min-height: 100vh; }
.calculator-intro { display: grid; grid-template-columns: 1.15fr .85fr; gap: clamp(2rem, 6vw, 6rem); align-items: end; padding: clamp(2rem, 4vw, 3rem) max(1.25rem, calc((100vw - 1320px) / 2)); background: var(--ink); color: white; }
.calculator-intro h1 { max-width: 760px; margin: 0; font-size: clamp(2.7rem, 4.3vw, 4.5rem); line-height: .88; letter-spacing: -.06em; }
.calculator-intro > p { max-width: 620px; margin: 0; color: #d8e8f2; font-size: 1.08rem; }
.calculator-workspace { max-width: 1320px; margin: 0 auto; padding: clamp(2rem, 5vw, 4.5rem) 1.25rem; display: grid; grid-template-columns: minmax(0, 1.05fr) minmax(360px, .95fr); gap: clamp(1.5rem, 4vw, 3.5rem); align-items: start; }
.calculator-fields { display: grid; gap: 1rem; }
.calculator-preset { display: grid; gap: .2rem; padding: 1rem 1.1rem; border: 2px solid var(--ink); background: var(--cyan); color: var(--ink); }
.calculator-preset strong { font-size: 1rem; }
.calculator-preset span { font-size: .82rem; font-weight: 700; }
.calculator-preset a { color: var(--ink); font-weight: 950; }
.calculator-fields fieldset { min-width: 0; margin: 0; padding: 1.3rem; border: 2px solid var(--ink); background: white; }
.calculator-fields legend { padding: 0 .5rem; font-weight: 950; font-size: 1.08rem; }
.calc-field-grid { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: .9rem; }
.calc-field { display: grid; gap: .4rem; align-content: start; color: var(--ink); font-size: .85rem; font-weight: 850; }
.calc-field > span:first-child { min-height: 2.7rem; }
.calc-field small { display: block; color: var(--muted); font-size: .75rem; font-weight: 650; }
.calc-field-wide { grid-column: 1 / -1; }
.calc-field input:not([type="range"]), .calc-field select { width: 100%; min-height: 50px; border: 2px solid #83909a; border-radius: .35rem; background: white; padding: .7rem .8rem; color: var(--ink); }
.calc-field input[readonly] { border-color: var(--blue); background: #eaf7fa; color: var(--ink); cursor: not-allowed; font-weight: 950; }
.money-input { position: relative; display: block; }
.money-input b { position: absolute; top: 50%; left: .85rem; transform: translateY(-50%); color: var(--muted); }
.money-input input { padding-left: 1.8rem !important; }
.calc-range { width: 100%; min-height: 44px; accent-color: var(--blue); cursor: pointer; }
.water-reading { display: flex; justify-content: space-between; gap: .8rem; margin-top: 1rem; padding: .75rem .85rem; background: #eaf7fa; border-left: 4px solid var(--cyan); font-size: .78rem; }
.water-reading span { color: var(--muted); text-align: right; }
.appliance-comparison { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); margin-top: 1rem; border: 2px solid var(--ink); background: #eaf7fa; }
.appliance-comparison div { padding: .75rem .8rem; }
.appliance-comparison div + div { border-left: 1px solid var(--line); }
.appliance-comparison span { display: block; min-height: 2.2rem; color: var(--muted); font-size: .7rem; font-weight: 850; text-transform: uppercase; }
.appliance-comparison strong { display: block; font-size: 1rem; }
.appliance-life-note { margin: .65rem 0 0; color: var(--muted); font-size: .75rem; }
.reading-grid { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: .7rem; }
.calculator-results { position: sticky; top: 1rem; padding: clamp(1.5rem, 4vw, 3rem); border: 2px solid var(--ink); background: var(--yellow); box-shadow: 14px 14px 0 var(--cyan); }
.calculator-results h2 { margin: 0 0 1.7rem; }
.calculator-results h2 > span { display: block; font-size: clamp(4rem, 8vw, 7.8rem); line-height: .78; letter-spacing: -.075em; }
.calculator-results h2 small { display: block; margin-top: .7rem; font-size: 1rem; letter-spacing: 0; }
.result-metrics { display: grid; grid-template-columns: repeat(3, 1fr); margin-bottom: 2rem; border-block: 2px solid var(--ink); }
.result-metrics div { padding: .9rem .75rem; }
.result-metrics div + div { border-left: 1px solid rgba(11,31,51,.35); }
.result-metrics span { display: block; min-height: 2.5rem; font-size: .7rem; font-weight: 850; text-transform: uppercase; letter-spacing: .04em; }
.result-metrics strong { display: block; font-size: 1.15rem; }
.savings-breakdown h3 { margin: 0 0 1rem; font-size: 1.1rem; }
.breakdown-row { margin-bottom: .85rem; }
.breakdown-row > div { display: flex; justify-content: space-between; gap: 1rem; margin-bottom: .25rem; font-size: .83rem; }
.breakdown-row i { display: block; height: 8px; overflow: hidden; background: rgba(11,31,51,.14); }
.breakdown-row i b { display: block; width: 0; height: 100%; background: var(--blue); transition: width .25s ease; }
.result-boundary { margin: 1.5rem 0; padding: 1rem; background: white; border-left: 4px solid var(--ink); }
.result-boundary strong { display: block; font-size: .86rem; }
.result-boundary p { margin: .3rem 0 0; color: var(--muted); font-size: .78rem; }
.calculator-cta { display: block; text-align: center; text-decoration: none; box-shadow: none; }
.calculator-method { background: white; padding: clamp(1.5rem, 4vw, 3rem) max(1.25rem, calc((100vw - 1180px) / 2)); }
.method-disclosure { border: 2px solid var(--ink); background: white; }
.method-disclosure summary { display: flex; justify-content: space-between; align-items: center; gap: 1rem; padding: 1.15rem 1.25rem; cursor: pointer; font-weight: 950; list-style: none; }
.method-disclosure summary::-webkit-details-marker { display: none; }
.method-disclosure summary::after { content: "+"; display: grid; width: 2rem; height: 2rem; place-items: center; flex: 0 0 auto; border-radius: 50%; background: var(--cyan); font-size: 1.35rem; line-height: 1; }
.method-disclosure[open] summary::after { content: "−"; }
.method-disclosure summary small { margin-left: auto; color: var(--muted); font-size: .8rem; font-weight: 700; }
.method-grid { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); border-top: 1px solid var(--line); }
.method-grid article { padding: 1.35rem; }
.method-grid article:nth-child(even) { border-left: 1px solid var(--line); }
.method-grid article:nth-child(n+3) { border-top: 1px solid var(--line); }
.method-grid strong { font-size: 1.05rem; }
.method-grid p { margin: .4rem 0 0; color: var(--muted); font-size: .9rem; }
.calculator-sources { margin: 0; padding: 1rem 1.25rem; border-top: 1px solid var(--line); color: var(--muted); font-size: .78rem; }
.calculator-sources a { color: var(--blue); font-weight: 800; }

@media (max-width: 900px) {
  .calculator-intro, .calculator-workspace { grid-template-columns: 1fr; }
  .calculator-results { position: static; }
}

@media (max-width: 580px) {
  .calc-field-grid, .reading-grid, .method-grid, .result-metrics { grid-template-columns: 1fr; }
  .calc-field-wide { grid-column: auto; }
  .result-metrics div + div { border-left: 0; border-top: 1px solid rgba(11,31,51,.35); }
  .result-metrics span, .appliance-comparison span { min-height: 0; }
  .appliance-comparison { grid-template-columns: 1fr; }
  .appliance-comparison div + div { border-top: 1px solid var(--line); border-left: 0; }
  .method-grid article:nth-child(even) { border-left: 0; }
  .method-grid article + article { border-top: 1px solid var(--line); }
}

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { scroll-behavior: auto !important; transition: none !important; }
}