/* ============================================================
   Water Softener Size Calculator — YourBizTools
   Vanilla CSS, mobile-first. Restrained blue/teal/neutral palette.
   ============================================================ */

:root {
  --blue: #0b5c8a;
  --blue-dark: #084767;
  --teal: #0f8f8f;
  --teal-dark: #0a6f6f;
  --accent: #0f6f8f;
  --ink: #12222b;
  --body: #34464f;
  --muted: #5c6b73;
  --line: #dce4e8;
  --bg: #f4f7f9;
  --card: #ffffff;
  --soft-bg: #eef5f8;
  --warn-bg: #fff6e6;
  --warn-line: #e6b34d;
  --warn-ink: #7a4e00;
  --ok-bg: #e9f6ee;
  --ok-line: #4caf7d;
  --focus: #0f6f8f;
  --radius: 12px;
  --radius-sm: 8px;
  --shadow: 0 1px 3px rgba(18,34,43,.08), 0 8px 24px rgba(18,34,43,.06);
  --maxw: 1080px;
  --font: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  * { animation-duration: .001ms !important; transition-duration: .001ms !important; }
}

body {
  margin: 0;
  font-family: var(--font);
  color: var(--body);
  background: var(--bg);
  line-height: 1.6;
  font-size: 17px;
  -webkit-font-smoothing: antialiased;
}

h1, h2, h3 { color: var(--ink); line-height: 1.25; }
h1 { font-size: 2rem; margin: 0 0 .5rem; }
h2 { font-size: 1.5rem; }
h3 { font-size: 1.15rem; }

a { color: var(--blue); }
a:hover { color: var(--blue-dark); }

code {
  background: var(--soft-bg);
  padding: .12em .4em;
  border-radius: 4px;
  font-size: .92em;
  color: var(--ink);
}

.container { width: 100%; max-width: var(--maxw); margin: 0 auto; padding: 0 1rem; }

/* Skip link */
.skip-link {
  position: absolute; left: -999px; top: 0; z-index: 100;
  background: var(--ink); color: #fff; padding: .6rem 1rem; border-radius: 0 0 8px 0;
}
.skip-link:focus { left: 0; color: #fff; }

/* Focus visibility */
:focus-visible {
  outline: 3px solid var(--focus);
  outline-offset: 2px;
  border-radius: 4px;
}

/* ============ HEADER ============ */
.site-header {
  position: sticky; top: 0; z-index: 50;
  background: rgba(255,255,255,.95);
  backdrop-filter: saturate(160%) blur(6px);
  border-bottom: 1px solid var(--line);
}
.header-inner { display: flex; align-items: center; justify-content: space-between; min-height: 60px; gap: 1rem; }
.logo { display: inline-flex; align-items: center; gap: .5rem; text-decoration: none; color: var(--blue-dark); }
.logo-mark { color: var(--teal); flex: none; }
.logo-text { font-weight: 800; font-size: 1.15rem; letter-spacing: -.01em; color: var(--ink); }
.logo-accent { color: var(--teal); }
.main-nav { display: flex; gap: 1.25rem; flex-wrap: wrap; }
.main-nav a { text-decoration: none; color: var(--body); font-weight: 600; font-size: .95rem; }
.main-nav a:hover { color: var(--blue); }

/* ============ BREADCRUMB ============ */
.breadcrumb { background: #fff; border-bottom: 1px solid var(--line); font-size: .88rem; }
.breadcrumb ol { list-style: none; display: flex; flex-wrap: wrap; gap: .4rem; margin: 0; padding: .6rem 0; }
.breadcrumb li { color: var(--muted); }
.breadcrumb li + li::before { content: "/"; margin-right: .4rem; color: var(--line); }
.breadcrumb a { text-decoration: none; }
.breadcrumb [aria-current="page"] { color: var(--ink); font-weight: 600; }

/* ============ HERO ============ */
.hero {
  background: linear-gradient(160deg, var(--blue) 0%, var(--teal) 100%);
  color: #fff; padding: 2.75rem 0 2.25rem;
}
.hero h1 { color: #fff; }
.hero-lead { max-width: 62ch; color: #eaf6fb; margin: 0 0 1.25rem; }
.hero-points { list-style: none; margin: 0; padding: 0; display: grid; gap: .5rem; }
.hero-points li { display: flex; align-items: center; gap: .55rem; color: #f2fbff; font-weight: 600; font-size: .97rem; }
.hero-points svg { color: #cdfff0; flex: none; }

/* ============ LAYOUT ============ */
.layout-grid { display: grid; gap: 1.5rem; padding-top: 1.75rem; padding-bottom: 1.75rem; grid-template-columns: 1fr; }
@media (min-width: 900px) { .layout-grid { grid-template-columns: 1fr 1fr; align-items: start; } }

.card {
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  padding: 1.5rem;
}
.card-sub { color: var(--muted); margin-top: 0; font-size: .95rem; }

/* ============ FORM ============ */
.field { margin-bottom: 1.15rem; }
.field label, .field-legend { display: block; font-weight: 700; color: var(--ink); margin-bottom: .35rem; font-size: .97rem; }
.field-row { display: grid; gap: 1.15rem; grid-template-columns: 1fr; }
@media (min-width: 520px) { .field-row { grid-template-columns: 1.2fr 1fr; } }

input[type="number"], select {
  width: 100%;
  padding: .6rem .7rem;
  font-size: 1rem;
  font-family: inherit;
  color: var(--ink);
  background: #fff;
  border: 1.5px solid var(--line);
  border-radius: var(--radius-sm);
}
input[type="number"]:focus, select:focus { border-color: var(--accent); }
input[aria-invalid="true"] { border-color: #c0392b; background: #fff5f4; }

.help { font-size: .82rem; color: var(--muted); margin: .35rem 0 0; }
.error { font-size: .85rem; color: #c0392b; margin: .35rem 0 0; font-weight: 600; }

.radio-group { display: grid; gap: .4rem; }
.radio { display: flex; align-items: center; gap: .55rem; font-weight: 500; color: var(--body); cursor: pointer; }
.radio input { width: auto; accent-color: var(--accent); }

/* ============ BUTTONS ============ */
.btn-row { display: flex; flex-wrap: wrap; gap: .6rem; margin-top: 1rem; }
.btn {
  font: inherit; font-weight: 700; cursor: pointer;
  border: 1.5px solid transparent; border-radius: var(--radius-sm);
  padding: .65rem 1.15rem; font-size: .97rem;
  transition: background .15s, color .15s, border-color .15s;
}
.btn-primary { background: var(--blue); color: #fff; }
.btn-primary:hover { background: var(--blue-dark); }
.btn-secondary { background: #fff; color: var(--blue-dark); border-color: var(--line); }
.btn-secondary:hover { border-color: var(--accent); color: var(--blue); }
.copy-status { align-self: center; font-size: .88rem; color: var(--teal-dark); font-weight: 600; }

/* ============ RESULTS ============ */
.results-card { border-top: 4px solid var(--teal); }
.result-highlight {
  background: var(--soft-bg);
  border: 1px solid var(--line);
  border-radius: var(--radius-sm);
  padding: 1rem 1.15rem; margin: .5rem 0 1rem;
  display: flex; flex-direction: column; gap: .15rem;
}
.result-highlight-label { font-size: .85rem; color: var(--muted); font-weight: 600; text-transform: uppercase; letter-spacing: .03em; }
.result-highlight-value { font-size: 1.75rem; font-weight: 800; color: var(--blue-dark); }

.result-grid { display: grid; grid-template-columns: 1fr; gap: 0; margin: 1rem 0; }
@media (min-width: 520px) { .result-grid { grid-template-columns: 1fr 1fr; } }
.result-grid > div { padding: .6rem .1rem; border-bottom: 1px solid var(--line); }
.result-grid dt { font-size: .82rem; color: var(--muted); font-weight: 600; margin: 0; }
.result-grid dd { margin: .1rem 0 0; font-size: 1.05rem; font-weight: 700; color: var(--ink); }

.result-explain h3, .result-limits h3 { margin-bottom: .35rem; }
.result-explain p { margin-top: 0; }
.result-limits { background: var(--soft-bg); border-radius: var(--radius-sm); padding: .9rem 1rem; margin-top: 1rem; }
.result-limits p { margin: 0; font-size: .92rem; }

.btn-row-results { border-top: 1px solid var(--line); padding-top: 1rem; }

/* ============ WARNINGS ============ */
.warnings { display: grid; gap: .6rem; margin-bottom: 1rem; }
.warnings:empty { display: none; }
.warn {
  display: flex; gap: .6rem; align-items: flex-start;
  background: var(--warn-bg); border: 1px solid var(--warn-line);
  border-radius: var(--radius-sm); padding: .7rem .85rem;
  color: var(--warn-ink); font-size: .9rem;
}
.warn svg { flex: none; color: var(--warn-line); margin-top: 2px; }
.warn.info { background: var(--ok-bg); border-color: var(--ok-line); color: #1f5b3d; }
.warn.info svg { color: var(--ok-line); }
.warn strong { display: block; }

/* ============ SECTIONS ============ */
.section { padding: 2rem 1rem; }
.section > p, .section li { max-width: 72ch; }
.method-steps { max-width: 72ch; }
.method-steps li { margin-bottom: .6rem; }
.callout {
  background: var(--soft-bg); border-left: 4px solid var(--teal);
  padding: .9rem 1.1rem; border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
  max-width: 72ch;
}

/* ============ COMPARE / AFFILIATE ============ */
.affiliate-disclosure {
  background: var(--soft-bg); border: 1px dashed var(--line);
  border-radius: var(--radius-sm); padding: .8rem 1rem; font-size: .9rem;
  max-width: 72ch; color: var(--body);
}
.compare-grid { display: grid; gap: 1rem; grid-template-columns: 1fr; margin-top: 1.25rem; }
@media (min-width: 720px) { .compare-grid { grid-template-columns: repeat(3, 1fr); } }
.compare-card {
  background: var(--card); border: 1px solid var(--line);
  border-radius: var(--radius); padding: 1.2rem; box-shadow: var(--shadow);
}
.compare-card h3 { margin-top: 0; }
.compare-meta { color: var(--muted); font-size: .9rem; margin: 0 0 .75rem; }
.compare-placeholder {
  font-size: .88rem; color: var(--body); font-style: italic;
  background: var(--soft-bg); padding: .7rem .8rem; border-radius: var(--radius-sm); margin: 0;
}

/* ============ FAQ ============ */
.faq { display: grid; gap: .6rem; max-width: 72ch; }
.faq details {
  background: var(--card); border: 1px solid var(--line);
  border-radius: var(--radius-sm); padding: .5rem .9rem;
}
.faq summary {
  cursor: pointer; font-weight: 700; color: var(--ink);
  padding: .35rem 0; list-style: none;
}
.faq summary::-webkit-details-marker { display: none; }
.faq summary::after { content: "+"; float: right; color: var(--teal); font-weight: 800; }
.faq details[open] summary::after { content: "\2212"; }
.faq details p { margin: .3rem 0 .6rem; }

/* ============ CTA ============ */
.cta-band { background: var(--ink); color: #fff; padding: 2.25rem 0; margin-top: 1rem; text-align: center; }
.cta-band h2 { color: #fff; }
.cta-band p { color: #cdd8de; max-width: 60ch; margin: .5rem auto 1.25rem; }
.cta-band .btn-primary { background: var(--teal); }
.cta-band .btn-primary:hover { background: var(--teal-dark); }

/* ============ FOOTER ============ */
.site-footer { background: #0c1a21; color: #b9c6cd; padding: 2rem 0 1.5rem; }
.footer-inner { display: flex; flex-wrap: wrap; gap: 1.25rem; justify-content: space-between; align-items: flex-start; }
.footer-brand .logo-text { color: #fff; }
.footer-tagline { font-size: .9rem; margin: .35rem 0 0; color: #92a3ac; }
.footer-links { display: flex; flex-wrap: wrap; gap: 1rem; }
.footer-links a { color: #cdd8de; text-decoration: none; font-size: .92rem; }
.footer-links a:hover { color: #fff; text-decoration: underline; }
.footer-legal { border-top: 1px solid #1c2c34; margin-top: 1.25rem; padding-top: 1.25rem; font-size: .82rem; color: #8ea0a8; }
.footer-legal p { margin: .4rem 0; max-width: 80ch; }
.affiliate-disclosure-footer { color: #a7b6bd; }
.copyright { color: #6f828b; }

/* ============ LEGAL PAGES ============ */
.legal { max-width: 800px; margin: 2rem auto; padding: 0 1rem; }
.legal h1 { margin-bottom: .25rem; }
.legal .updated { color: var(--muted); font-size: .9rem; margin-top: 0; }
.legal h2 { font-size: 1.2rem; margin-top: 1.75rem; }
.legal ul { max-width: 72ch; }

/* ============ 404 ============ */
.notfound { text-align: center; padding: 4rem 1rem; }
.notfound .code { font-size: 4rem; font-weight: 800; color: var(--teal); margin: 0; }

/* ============ PRINT ============ */
@media print {
  .no-print, .site-header, .breadcrumb, .hero, .main-nav,
  .cta-band, .site-footer, #calc-form, .calc-card, .btn-row,
  .section, .compare-grid, .affiliate-disclosure, .faq { display: none !important; }
  body { background: #fff; font-size: 12pt; color: #000; }
  .layout-grid { display: block; padding: 0; }
  .results-card { border: none; box-shadow: none; padding: 0; }
  .result-highlight { border: 1px solid #000; }
  .card { break-inside: avoid; }
}