:root {
  color-scheme: light;
  --ink: #16323a;
  --muted: #4f656c;
  --line: #d8e3e3;
  --paper: #f5f8f7;
  --white: #fff;
  --accent: #12675e;
  --accent-dark: #0a504a;
  --wash: #e8f5f1;
  --radius: 1rem;
  font: 16px/1.55 system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
}

*, *::before, *::after { box-sizing: border-box; }
html { scroll-padding-top: 1rem; }
body { margin: 0; background: var(--paper); color: var(--ink); }
a { color: var(--accent-dark); text-underline-offset: .2em; }
button, input { font: inherit; }
button { cursor: pointer; }
:focus-visible { outline: 3px solid #208277; outline-offset: 3px; }
[hidden] { display: none !important; }
.wrap { width: min(100% - 4rem, 76rem); margin-inline: auto; }
.sr-only { position: absolute; width: 1px; height: 1px; padding: 0; margin: -1px; overflow: hidden; clip-path: inset(50%); white-space: nowrap; }
.skip-link { position: absolute; top: .5rem; left: .5rem; transform: translateY(-200%); padding: .5rem 1rem; background: var(--white); z-index: 2; }
.skip-link:focus { transform: none; }

.site-header { background: var(--white); border-bottom: 1px solid var(--line); }
.header-inner { min-height: 4.65rem; display: flex; align-items: center; justify-content: space-between; gap: 1rem; }
.brand { display: inline-flex; align-items: center; gap: .65rem; color: var(--ink); text-decoration: none; font-size: 1.12rem; font-weight: 720; line-height: 1.1; letter-spacing: -.035em; }
.brand img { flex: none; }
.brand small { display: block; margin-top: .2rem; color: var(--muted); font-size: .72rem; font-weight: 540; letter-spacing: 0; }
.header-inner nav { display: flex; align-items: center; gap: clamp(1rem, 3vw, 2.4rem); }
.header-inner nav a { color: var(--ink); font-size: .87rem; font-weight: 620; text-decoration: none; }
.header-inner nav a:hover { color: var(--accent); text-decoration: underline; }

.hero {
  position: relative;
  isolation: isolate;
  overflow: hidden;
  display: grid;
  grid-template-columns: minmax(0, 1.33fr) minmax(0, 1fr);
  align-items: center;
  gap: 1rem;
  margin-top: 1.75rem;
  padding: clamp(2.2rem, 4.4vw, 4.2rem);
  border-radius: 1.35rem;
  background: radial-gradient(ellipse at 100% 85%, #1b5f65, transparent 62%), linear-gradient(120deg, #0b303b, #124550);
  color: #f4fcfa;
}
.eyebrow { margin: 0 0 .55rem; color: var(--accent-dark); font-size: .7rem; font-weight: 750; letter-spacing: .13em; text-transform: uppercase; }
.hero .eyebrow { display: flex; align-items: center; gap: .55rem; color: #b0e8de; margin-bottom: 1rem; }
.signal { width: .5rem; height: .5rem; border-radius: 50%; background: #82e4d1; box-shadow: 0 0 0 4px #78d7ca29; }
h1, h2, h3, h4, p { overflow-wrap: break-word; }
h1 { margin: 0; font-size: clamp(2.5rem, 5.05vw, 4.8rem); font-weight: 690; letter-spacing: -.063em; line-height: 1.02; }
.hero-intro { max-width: 46ch; margin: 1.15rem 0 1.6rem; color: #d7ebe9; font-size: clamp(.95rem, 1.3vw, 1.12rem); }
.hero-link { display: inline-flex; gap: .8rem; align-items: center; padding: .67rem .95rem; border: 1px solid #9cebdc; border-radius: .45rem; background: #a5ebdc; color: #0e383b; text-decoration: none; font-size: .85rem; font-weight: 720; }
.hero-link:hover { background: #caf6ed; }
.hero-link:focus-visible { outline-color: #e4fff9; }
.hero-art { display: block; width: 100%; height: auto; }

.toolkit { margin-top: 2.7rem; }
.section-header { display: flex; justify-content: space-between; align-items: end; gap: 1rem; margin-bottom: 1.05rem; }
h2 { margin: 0; font-size: clamp(1.55rem, 3.2vw, 2.2rem); line-height: 1.15; letter-spacing: -.045em; }
.metric-badge { padding: .32rem .65rem; border: 1px solid #badbd4; border-radius: 2rem; background: var(--wash); color: var(--accent-dark); font-size: .73rem; font-weight: 680; white-space: nowrap; }

.workspace { display: grid; grid-template-columns: minmax(15rem, .78fr) minmax(0, 2.22fr); align-items: start; gap: 1.2rem; }
.directory, .calculator { background: var(--white); border: 1px solid var(--line); border-radius: var(--radius); }
.directory { padding: .85rem; }
.search { display: flex; align-items: center; gap: .5rem; padding: .45rem .6rem; background: var(--paper); color: var(--muted); border: 1px solid var(--line); border-radius: .46rem; }
.search:focus-within { border-color: var(--accent); box-shadow: 0 0 0 1px var(--accent); }
.search svg { flex: none; }
.search input { min-width: 0; width: 100%; border: 0; outline: 0; background: transparent; color: var(--ink); font-size: .86rem; }
.search input::placeholder { color: var(--muted); }
.category { margin-top: .9rem; }
.category h3 { margin: 0 0 .3rem; padding-inline: .5rem; color: var(--muted); font-size: .65rem; letter-spacing: .1em; text-transform: uppercase; }
.tool-option { display: flex; align-items: center; gap: .55rem; width: 100%; min-height: 2.5rem; padding: .34rem .5rem; border: 1px solid transparent; border-radius: .43rem; background: transparent; color: var(--ink); font-size: .82rem; font-weight: 630; line-height: 1.3; text-align: left; }
.tool-option:hover { background: var(--paper); }
.tool-option[aria-current="true"] { border-color: #c0e3da; background: var(--wash); color: var(--accent-dark); }
.tool-number { flex: none; color: var(--muted); font-size: .64rem; font-weight: 650; font-variant-numeric: tabular-nums; }
.search-status { margin: .8rem .25rem .25rem; color: var(--muted); font-size: .8rem; }

.calculator { min-width: 0; padding: clamp(1rem, 2.7vw, 2rem); }
.calculator-header { margin-bottom: 1.25rem; }
.calculator-header h3 { margin: 0; font-size: clamp(1.35rem, 3vw, 2rem); line-height: 1.12; letter-spacing: -.035em; }
.calculator-header h3:focus { outline: none; }
.calculator-header > p:last-child { max-width: 68ch; margin: .5rem 0 0; color: var(--muted); font-size: .92rem; }
.calculator-body { display: grid; grid-template-columns: minmax(0, 1.2fr) minmax(0, .8fr); align-items: start; gap: 1.15rem; }
.fields { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: .75rem; }
.field { min-width: 0; }
.field label { display: block; min-height: 1.2rem; margin-bottom: .28rem; font-size: .79rem; font-weight: 670; }
.field-control { display: flex; align-items: stretch; background: var(--white); border: 1px solid #bdcdcf; border-radius: .44rem; }
.field-control:focus-within { border-color: var(--accent); box-shadow: 0 0 0 1px var(--accent); }
.field-control:has([aria-invalid="true"]) { border-color: #b63d2c; }
.field-control input { width: 100%; min-width: 0; padding: .48rem .55rem; border: 0; outline: 0; border-radius: inherit; background: transparent; color: var(--ink); font-size: .92rem; font-variant-numeric: tabular-nums; }
.field-unit { display: grid; place-items: center; flex: none; padding: .38rem .4rem; background: var(--paper); border-left: 1px solid var(--line); border-radius: 0 .39rem .39rem 0; color: var(--muted); font-size: .67rem; white-space: nowrap; }
.field-hint { margin: .25rem 0 0; color: var(--muted); font-size: .7rem; }
.form-error { margin: .65rem 0 0; color: #9a3023; font-size: .8rem; font-weight: 650; }
.actions { display: flex; align-items: center; flex-wrap: wrap; gap: .5rem .75rem; margin-top: 1rem; }
.calculate, .reset { min-height: 2.5rem; border-radius: .44rem; font-size: .82rem; font-weight: 700; }
.calculate { display: inline-flex; align-items: center; gap: .65rem; padding: .45rem .75rem; border: 1px solid var(--accent); background: var(--accent); color: white; }
.calculate:hover { border-color: var(--accent-dark); background: var(--accent-dark); }
.reset { padding: .45rem .25rem; border: 1px solid transparent; background: transparent; color: var(--accent-dark); }
.reset:hover { text-decoration: underline; }

.results { padding: .9rem; border: 1px solid #c6e2dc; border-radius: .65rem; background: var(--wash); }
.results h4 { margin: 0; font-size: .78rem; letter-spacing: .08em; text-transform: uppercase; }
.result-status { margin: .25rem 0 0; color: var(--muted); font-size: .74rem; }
.results dl { margin: .5rem 0 0; }
.results dl:empty { display: none; }
.result-row { padding: .47rem 0; border-bottom: 1px solid #c6e2dc; }
.result-row:last-child { border: 0; padding-bottom: 0; }
.result-row dt { color: var(--muted); font-size: .72rem; }
.result-row dd { margin: .03rem 0 0; color: var(--ink); font-size: 1.22rem; font-variant-numeric: tabular-nums; font-weight: 680; line-height: 1.2; overflow-wrap: anywhere; }
.result-unit { color: var(--muted); font-size: .72rem; font-weight: 610; white-space: nowrap; }

.method { margin-top: 1.25rem; padding-top: .85rem; border-top: 1px solid var(--line); }
.method summary { width: fit-content; color: var(--ink); font-size: .87rem; font-weight: 700; cursor: pointer; }
.method-body { margin-top: .55rem; }
.formula { margin: 0; padding: .65rem .75rem; border-radius: .4rem; background: var(--paper); color: var(--ink); font: .78rem/1.55 ui-monospace, Consolas, monospace; white-space: pre-wrap; overflow-wrap: anywhere; }
.notes { margin: .55rem 0 .35rem; color: var(--muted); font-size: .79rem; white-space: pre-line; }
.method a { font-size: .79rem; font-weight: 650; }
.about { display: grid; grid-template-columns: minmax(0, .8fr) minmax(0, 1.2fr); gap: 1rem 3rem; margin: 2.75rem 0 0; padding: clamp(1.25rem, 4vw, 2.5rem); border: 1px solid var(--line); border-radius: var(--radius); background: var(--white); }
.about-copy { color: var(--muted); font-size: .9rem; }
.about-copy p { margin: 0; }
.about-copy p + p { margin-top: .55rem; }
.site-footer { display: flex; justify-content: space-between; align-items: center; gap: .75rem; margin-top: 1.3rem; padding-block: 1.2rem; color: var(--muted); font-size: .78rem; }
.site-footer a { text-decoration: none; }
.site-footer a:hover { text-decoration: underline; }

@media (max-width: 63rem) {
  .hero-break { display: none; }
  .calculator-body { grid-template-columns: 1fr; }
  .results dl { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: .25rem .75rem; }
  .result-row, .result-row:last-child { border: 0; padding: .3rem 0; }
}
@media (max-width: 47rem) {
  .wrap { width: calc(100% - 2rem); }
  .header-inner { min-height: 4rem; }
  .hero { grid-template-columns: 1fr; gap: .65rem; margin-top: 1rem; padding: 1.4rem; }
  .hero-art { max-height: 10rem; }
  .toolkit { margin-top: 1.75rem; }
  .workspace, .about { grid-template-columns: 1fr; }
  .workspace { gap: .8rem; }
  .category-list { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: .1rem; }
  .about { margin-top: 1.75rem; }
}
@media (max-width: 23rem) {
  .header-inner nav { gap: .6rem; }
  .brand small, .footer-detail { display: none; }
  .section-header { align-items: start; flex-direction: column; gap: .4rem; }
  .fields { grid-template-columns: 1fr; }
}