/* ==========================================================================
   Anion Gap Calculator — Design System
   Clean. Modern. No gradients. Beautiful typography.
   ========================================================================== */

/* ---------- Design Tokens ---------- */
:root {
  /* Color — calm, trustworthy, modern */
  --color-bg: #ffffff;
  --color-bg-soft: #f8f9fb;
  --color-bg-card: #ffffff;
  --color-border: #e6e8ec;
  --color-border-strong: #d0d4db;

  --color-text: #1a1d23;
  --color-text-soft: #565d6b;
  --color-text-muted: #8a91a0;

  --color-primary: #2563eb;        /* clean blue */
  --color-primary-hover: #1d4ed8;
  --color-primary-soft: #eff4ff;

  --color-success: #059669;
  --color-success-soft: #ecfdf5;
  --color-success-border: #a7f3d0;

  --color-warning: #d97706;
  --color-warning-soft: #fffbeb;
  --color-warning-border: #fde68a;

  --color-danger: #dc2626;
  --color-danger-soft: #fef2f2;
  --color-danger-border: #fecaca;

  --color-accent: #0d9488;          /* teal for subtle accents */

  /* Typography */
  --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  --font-serif: 'Newsreader', Georgia, 'Times New Roman', serif;
  --font-mono: 'JetBrains Mono', 'SF Mono', Consolas, monospace;

  /* Spacing scale */
  --space-1: 0.25rem;
  --space-2: 0.5rem;
  --space-3: 0.75rem;
  --space-4: 1rem;
  --space-5: 1.5rem;
  --space-6: 2rem;
  --space-7: 3rem;
  --space-8: 4rem;
  --space-9: 6rem;

  /* Radii */
  --radius-sm: 8px;
  --radius: 12px;
  --radius-lg: 16px;
  --radius-full: 9999px;

  /* Shadows — soft, never heavy */
  --shadow-xs: 0 1px 2px rgba(16, 24, 40, 0.04);
  --shadow-sm: 0 1px 3px rgba(16, 24, 40, 0.06), 0 1px 2px rgba(16, 24, 40, 0.04);
  --shadow: 0 4px 12px rgba(16, 24, 40, 0.06), 0 1px 3px rgba(16, 24, 40, 0.04);
  --shadow-md: 0 8px 24px rgba(16, 24, 40, 0.08);

  /* Layout */
  --container: 1120px;
  --container-narrow: 720px;
}

/* ---------- Reset ---------- */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; -webkit-text-size-adjust: 100%; }
body {
  font-family: var(--font-sans);
  font-size: 1rem;
  line-height: 1.65;
  color: var(--color-text);
  background: var(--color-bg);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  text-rendering: optimizeLegibility;
}
img, svg { display: block; max-width: 100%; }
a { color: var(--color-primary); text-decoration: none; transition: color 0.15s ease; }
a:hover { color: var(--color-primary-hover); text-decoration: underline; }
button { font-family: inherit; cursor: pointer; border: none; background: none; }
input { font-family: inherit; }

/* ---------- Layout helpers ---------- */
.container { width: 100%; max-width: var(--container); margin: 0 auto; padding: 0 var(--space-5); }
.container-narrow { max-width: var(--container-narrow); }
.section { padding: var(--space-8) 0; }
.section-sm { padding: var(--space-7) 0; }

/* ---------- Header ---------- */
.site-header {
  position: sticky; top: 0; z-index: 50;
  background: rgba(255, 255, 255, 0.88);
  backdrop-filter: saturate(180%) blur(12px);
  -webkit-backdrop-filter: saturate(180%) blur(12px);
  border-bottom: 1px solid var(--color-border);
}
.site-header__inner {
  display: flex; align-items: center; justify-content: space-between;
  height: 64px;
}
.brand {
  display: flex; align-items: center; gap: var(--space-3);
  font-weight: 700; font-size: 1.05rem; color: var(--color-text);
  letter-spacing: -0.01em;
}
.brand:hover { text-decoration: none; color: var(--color-text); }
.brand__mark {
  width: 34px; height: 34px;
  background: var(--color-primary);
  color: #fff;
  border-radius: var(--radius-sm);
  display: grid; place-items: center;
  font-family: var(--font-mono); font-weight: 700; font-size: 0.95rem;
  letter-spacing: -0.02em;
}
.brand__name { font-family: var(--font-sans); }
.brand__name b { color: var(--color-primary); font-weight: 700; }

.main-nav { display: flex; align-items: center; gap: var(--space-5); }
.main-nav a {
  color: var(--color-text-soft); font-size: 0.92rem; font-weight: 500;
  padding: var(--space-2) 0;
}
.main-nav a:hover { color: var(--color-text); text-decoration: none; }
.nav-cta {
  background: var(--color-primary); color: #fff !important;
  padding: var(--space-2) var(--space-4) !important;
  border-radius: var(--radius-sm);
  font-weight: 600 !important;
}
.nav-cta:hover { background: var(--color-primary-hover); }

/* ---------- Hero ---------- */
.hero { padding: var(--space-9) 0 var(--space-7); text-align: center; }
.hero__eyebrow {
  display: inline-flex; align-items: center; gap: var(--space-2);
  background: var(--color-primary-soft); color: var(--color-primary);
  font-size: 0.82rem; font-weight: 600;
  padding: var(--space-1) var(--space-3);
  border-radius: var(--radius-full);
  margin-bottom: var(--space-5);
  letter-spacing: 0.01em;
}
.hero__eyebrow::before { content: ""; width: 6px; height: 6px; border-radius: 50%; background: var(--color-primary); }
.hero h1 {
  font-size: clamp(2.2rem, 5vw, 3.25rem);
  line-height: 1.1;
  letter-spacing: -0.03em;
  font-weight: 800;
  color: var(--color-text);
  max-width: 760px; margin: 0 auto var(--space-4);
}
.hero h1 em {
  font-family: var(--font-serif);
  font-style: italic;
  font-weight: 500;
  color: var(--color-primary);
}
.hero__lede {
  font-family: var(--font-serif);
  font-size: 1.2rem;
  line-height: 1.55;
  color: var(--color-text-soft);
  max-width: 600px; margin: 0 auto var(--space-6);
}

/* ---------- Calculator card ---------- */
.calc-card {
  max-width: 560px; margin: 0 auto;
  background: var(--color-bg-card);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-md);
  padding: var(--space-6);
}
.calc-card__header {
  display: flex; align-items: baseline; justify-content: space-between;
  margin-bottom: var(--space-5);
  padding-bottom: var(--space-4);
  border-bottom: 1px solid var(--color-border);
}
.calc-card__title { font-size: 1.15rem; font-weight: 700; letter-spacing: -0.01em; }
.calc-card__formula {
  font-family: var(--font-mono); font-size: 0.82rem;
  color: var(--color-text-muted);
}

.calc-grid { display: grid; gap: var(--space-4); margin-bottom: var(--space-5); }
.calc-field { display: flex; flex-direction: column; gap: var(--space-2); }
.calc-field__label {
  display: flex; align-items: baseline; justify-content: space-between;
  font-size: 0.88rem; font-weight: 600; color: var(--color-text);
}
.calc-field__symbol {
  font-family: var(--font-mono);
  color: var(--color-text-muted); font-weight: 500;
}
.calc-field__unit { font-size: 0.78rem; color: var(--color-text-muted); font-weight: 400; }
.calc-input {
  width: 100%;
  font-size: 1.05rem;
  padding: var(--space-3) var(--space-4);
  background: var(--color-bg-soft);
  border: 1.5px solid var(--color-border);
  border-radius: var(--radius-sm);
  transition: border-color 0.15s ease, background 0.15s ease, box-shadow 0.15s ease;
  color: var(--color-text);
  font-variant-numeric: tabular-nums;
}
.calc-input:focus {
  outline: none;
  border-color: var(--color-primary);
  background: #fff;
  box-shadow: 0 0 0 4px var(--color-primary-soft);
}
.calc-input::placeholder { color: var(--color-text-muted); }

.calc-options {
  display: flex; align-items: center; gap: var(--space-2);
  margin-bottom: var(--space-5);
  padding-top: var(--space-3);
  border-top: 1px dashed var(--color-border);
}
.calc-toggle {
  display: inline-flex; align-items: center; gap: var(--space-2);
  font-size: 0.85rem; color: var(--color-text-soft); cursor: pointer;
  user-select: none;
}
.calc-toggle input { display: none; }
.calc-toggle__switch {
  width: 36px; height: 20px; border-radius: var(--radius-full);
  background: var(--color-border-strong); position: relative;
  transition: background 0.2s ease;
}
.calc-toggle__switch::after {
  content: ""; position: absolute; top: 2px; left: 2px;
  width: 16px; height: 16px; border-radius: 50%;
  background: #fff; box-shadow: var(--shadow-xs);
  transition: transform 0.2s ease;
}
.calc-toggle input:checked + .calc-toggle__switch { background: var(--color-primary); }
.calc-toggle input:checked + .calc-toggle__switch::after { transform: translateX(16px); }

/* Result */
.calc-result {
  padding: var(--space-5);
  border-radius: var(--radius);
  border: 1.5px solid var(--color-border);
  background: var(--color-bg-soft);
  transition: all 0.3s ease;
}
.calc-result.is-normal { background: var(--color-success-soft); border-color: var(--color-success-border); }
.calc-result.is-high { background: var(--color-danger-soft); border-color: var(--color-danger-border); }
.calc-result.is-low { background: var(--color-warning-soft); border-color: var(--color-warning-border); }
.calc-result.is-empty { opacity: 0.55; }
.calc-result__label {
  font-size: 0.8rem; font-weight: 600; text-transform: uppercase;
  letter-spacing: 0.06em; color: var(--color-text-muted); margin-bottom: var(--space-1);
}
.calc-result__value {
  font-family: var(--font-mono);
  font-size: 2.4rem; font-weight: 700; line-height: 1;
  color: var(--color-text); letter-spacing: -0.02em;
  font-variant-numeric: tabular-nums;
}
.calc-result__unit { font-size: 0.95rem; color: var(--color-text-muted); font-weight: 500; margin-left: var(--space-2); }
.calc-result__badge {
  display: inline-flex; align-items: center; gap: var(--space-2);
  margin-top: var(--space-3);
  padding: var(--space-1) var(--space-3);
  border-radius: var(--radius-full);
  font-size: 0.82rem; font-weight: 600;
}
.is-normal .calc-result__badge { background: var(--color-success); color: #fff; }
.is-high .calc-result__badge { background: var(--color-danger); color: #fff; }
.is-low .calc-result__badge { background: var(--color-warning); color: #fff; }
.calc-result__interp {
  margin-top: var(--space-3);
  font-family: var(--font-serif);
  font-size: 0.95rem; line-height: 1.5;
  color: var(--color-text-soft);
}
.calc-result__corrected {
  margin-top: var(--space-3); padding-top: var(--space-3);
  border-top: 1px dashed var(--color-border);
  font-size: 0.88rem; color: var(--color-text-soft);
}
.calc-result__corrected b { color: var(--color-text); font-family: var(--font-mono); }

.calc-actions { display: flex; gap: var(--space-3); margin-top: var(--space-4); }
.btn {
  display: inline-flex; align-items: center; gap: var(--space-2);
  padding: var(--space-2) var(--space-4);
  border-radius: var(--radius-sm);
  font-size: 0.88rem; font-weight: 600;
  transition: all 0.15s ease;
}
.btn--ghost { color: var(--color-text-soft); border: 1px solid var(--color-border); background: #fff; }
.btn--ghost:hover { border-color: var(--color-border-strong); color: var(--color-text); }

/* ---------- Trust strip ---------- */
.trust {
  display: flex; flex-wrap: wrap; align-items: center; justify-content: center;
  gap: var(--space-6);
  padding: var(--space-6) 0;
  border-top: 1px solid var(--color-border);
  border-bottom: 1px solid var(--color-border);
  color: var(--color-text-muted);
  font-size: 0.85rem;
}
.trust__item { display: inline-flex; align-items: center; gap: var(--space-2); }
.trust__item svg { color: var(--color-accent); }

/* ---------- Section heads ---------- */
.section-head { text-align: center; max-width: 640px; margin: 0 auto var(--space-7); }
.section-head h2 {
  font-size: clamp(1.6rem, 3.5vw, 2.1rem);
  font-weight: 700; letter-spacing: -0.02em; line-height: 1.2;
  margin-bottom: var(--space-3);
}
.section-head p {
  font-family: var(--font-serif);
  font-size: 1.1rem; color: var(--color-text-soft); line-height: 1.5;
}

/* ---------- Pillar content (prose) ---------- */
.prose {
  font-family: var(--font-serif);
  font-size: 1.1rem; line-height: 1.75; color: var(--color-text);
}
.prose p { margin-bottom: var(--space-4); }
.prose h2 { font-family: var(--font-sans); font-size: 1.5rem; font-weight: 700; letter-spacing: -0.01em; margin: var(--space-6) 0 var(--space-3); color: var(--color-text); }
.prose h3 { font-family: var(--font-sans); font-size: 1.2rem; font-weight: 600; margin: var(--space-5) 0 var(--space-2); }
.prose ul, .prose ol { margin: 0 0 var(--space-4) var(--space-5); }
.prose li { margin-bottom: var(--space-2); }
.prose strong { color: var(--color-text); font-weight: 600; }
.prose code { font-family: var(--font-mono); font-size: 0.92em; background: var(--color-bg-soft); padding: 0.1em 0.4em; border-radius: 4px; }

/* ---------- Hub grid (explore all tools) ---------- */
.hub-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
  gap: var(--space-4);
}
.hub-card {
  display: block;
  padding: var(--space-5);
  background: #fff;
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  transition: all 0.2s ease;
  color: var(--color-text);
}
.hub-card:hover {
  border-color: var(--color-primary);
  box-shadow: var(--shadow);
  text-decoration: none;
  transform: translateY(-2px);
}
.hub-card__icon {
  width: 40px; height: 40px;
  border-radius: var(--radius-sm);
  background: var(--color-primary-soft);
  color: var(--color-primary);
  display: grid; place-items: center;
  margin-bottom: var(--space-3);
}
.hub-card__title { font-weight: 700; font-size: 1rem; margin-bottom: var(--space-1); letter-spacing: -0.01em; }
.hub-card__desc { font-size: 0.9rem; color: var(--color-text-soft); line-height: 1.5; }

/* Cluster section */
.cluster { margin-bottom: var(--space-7); }
.cluster__head {
  display: flex; align-items: center; gap: var(--space-3);
  margin-bottom: var(--space-4);
  padding-bottom: var(--space-3);
  border-bottom: 1px solid var(--color-border);
}
.cluster__num {
  width: 28px; height: 28px; border-radius: var(--radius-sm);
  background: var(--color-text); color: #fff;
  display: grid; place-items: center;
  font-family: var(--font-mono); font-size: 0.82rem; font-weight: 700;
}
.cluster__title { font-size: 1.1rem; font-weight: 700; letter-spacing: -0.01em; }
.cluster__count { font-size: 0.82rem; color: var(--color-text-muted); margin-left: auto; }

/* ---------- Featured band ---------- */
.featured { background: var(--color-bg-soft); }
.featured-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(220px, 1fr));
  gap: var(--space-4);
}
.featured-card {
  padding: var(--space-5);
  background: #fff;
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  color: var(--color-text);
  transition: all 0.2s ease;
}
.featured-card:hover { border-color: var(--color-primary); box-shadow: var(--shadow-sm); text-decoration: none; transform: translateY(-1px); }
.featured-card__tag { font-size: 0.75rem; font-weight: 600; text-transform: uppercase; letter-spacing: 0.05em; color: var(--color-primary); margin-bottom: var(--space-2); }
.featured-card__title { font-weight: 700; font-size: 1.02rem; margin-bottom: var(--space-1); letter-spacing: -0.01em; }
.featured-card__desc { font-size: 0.88rem; color: var(--color-text-soft); line-height: 1.45; }

/* ---------- CTA band ---------- */
.cta-band { text-align: center; }
.cta-band h2 { font-size: clamp(1.7rem, 4vw, 2.3rem); font-weight: 800; letter-spacing: -0.02em; margin-bottom: var(--space-3); }
.cta-band p { font-family: var(--font-serif); font-size: 1.1rem; color: var(--color-text-soft); margin-bottom: var(--space-5); }
.btn--primary {
  display: inline-flex; align-items: center; gap: var(--space-2);
  background: var(--color-primary); color: #fff;
  padding: var(--space-3) var(--space-6);
  border-radius: var(--radius-sm);
  font-weight: 600; font-size: 1rem;
  transition: background 0.15s ease;
}
.btn--primary:hover { background: var(--color-primary-hover); color: #fff; text-decoration: none; }

/* ---------- Footer ---------- */
.site-footer {
  background: #fafbfc;
  border-top: 1px solid var(--color-border);
  padding: var(--space-7) 0 var(--space-5);
  margin-top: var(--space-8);
}
.footer-grid {
  display: grid;
  grid-template-columns: 2fr repeat(3, 1fr);
  gap: var(--space-6);
  margin-bottom: var(--space-6);
}
.footer-brand p { font-size: 0.88rem; color: var(--color-text-soft); margin-top: var(--space-3); max-width: 320px; line-height: 1.5; }
.footer-col h4 { font-size: 0.78rem; font-weight: 700; text-transform: uppercase; letter-spacing: 0.06em; color: var(--color-text-muted); margin-bottom: var(--space-3); }
.footer-col ul { list-style: none; display: flex; flex-direction: column; gap: var(--space-2); }
.footer-col a { font-size: 0.9rem; color: var(--color-text-soft); }
.footer-col a:hover { color: var(--color-text); text-decoration: none; }
.footer-bottom {
  display: flex; flex-wrap: wrap; align-items: center; justify-content: space-between;
  gap: var(--space-3);
  padding-top: var(--space-5);
  border-top: 1px solid var(--color-border);
  font-size: 0.82rem; color: var(--color-text-muted);
}
.disclaimer {
  font-size: 0.8rem; color: var(--color-text-muted);
  line-height: 1.5;
  padding: var(--space-3) var(--space-4);
  background: #fff;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  margin-top: var(--space-4);
}
.disclaimer strong { color: var(--color-text-soft); }

/* ---------- Article / subpage header ---------- */
.page-hero {
  padding: var(--space-7) 0 var(--space-5);
  border-bottom: 1px solid var(--color-border);
  background: var(--color-bg-soft);
}
.page-hero__eyebrow {
  font-size: 0.82rem; font-weight: 600; text-transform: uppercase;
  letter-spacing: 0.08em; color: var(--color-primary);
  margin-bottom: var(--space-2);
}
.page-hero h1 {
  font-size: clamp(1.8rem, 4vw, 2.6rem);
  font-weight: 800; letter-spacing: -0.025em; line-height: 1.15;
  margin-bottom: var(--space-3);
}
.page-hero p { font-family: var(--font-serif); font-size: 1.15rem; color: var(--color-text-soft); max-width: 640px; line-height: 1.5; }

/* ---------- Breadcrumb ---------- */
.breadcrumb {
  display: flex; align-items: center; flex-wrap: wrap; gap: var(--space-2);
  font-size: 0.82rem; color: var(--color-text-muted);
  margin-bottom: var(--space-4);
}
.breadcrumb a { color: var(--color-text-muted); }
.breadcrumb a:hover { color: var(--color-primary); }
.breadcrumb__sep { opacity: 0.5; }

/* ---------- Related links widget (supplementary to in-body bridges) ---------- */
.related {
  margin-top: var(--space-7);
  padding-top: var(--space-6);
  border-top: 1px solid var(--color-border);
}
.related h3 { font-size: 0.78rem; text-transform: uppercase; letter-spacing: 0.06em; color: var(--color-text-muted); margin-bottom: var(--space-3); }
.related-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(200px,1fr)); gap: var(--space-3); }
.related a {
  display: block; padding: var(--space-3) var(--space-4);
  border: 1px solid var(--color-border); border-radius: var(--radius-sm);
  font-size: 0.92rem; font-weight: 600; color: var(--color-text);
}
.related a:hover { border-color: var(--color-primary); color: var(--color-primary); text-decoration: none; }

/* ---------- Prose tables (clinical reference) ---------- */
.prose table { width: 100%; border-collapse: collapse; font-family: var(--font-sans); font-size: 0.95rem; margin: var(--space-4) 0; }
.prose th { text-align: left; padding: var(--space-3); font-weight: 700; border-bottom: 2px solid var(--color-border-strong); background: var(--color-bg-soft); }
.prose td { padding: var(--space-3); border-bottom: 1px solid var(--color-border); }
.prose tr:last-child td { border-bottom: none; }

/* ---------- Callout / clinical pearl ---------- */
.callout {
  border-left: 3px solid var(--color-primary);
  background: var(--color-primary-soft);
  padding: var(--space-4) var(--space-5);
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
  margin: var(--space-5) 0;
}
.callout strong { display: block; margin-bottom: var(--space-1); color: var(--color-primary); }
.callout--warning { border-color: var(--color-warning); background: var(--color-warning-soft); }
.callout--warning strong { color: var(--color-warning); }
.callout p { font-family: var(--font-sans); font-size: 0.95rem; margin: 0; color: var(--color-text-soft); }

/* ---------- Key-value summary box (for case studies) ---------- */
.kv-box {
  display: grid; grid-template-columns: repeat(auto-fill, minmax(140px,1fr));
  gap: 1px; background: var(--color-border);
  border: 1px solid var(--color-border); border-radius: var(--radius-sm);
  overflow: hidden; margin: var(--space-5) 0;
}
.kv-box__item { background: #fff; padding: var(--space-3) var(--space-4); }
.kv-box__label { font-size: 0.78rem; color: var(--color-text-muted); text-transform: uppercase; letter-spacing: 0.05em; }
.kv-box__value { font-family: var(--font-mono); font-size: 1.1rem; font-weight: 700; color: var(--color-text); }

/* ---------- Mnemonic cards ---------- */
.mnemonic-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(150px,1fr)); gap: var(--space-3); margin: var(--space-5) 0; }
.mnemonic-card {
  padding: var(--space-4); border: 1px solid var(--color-border); border-radius: var(--radius);
  background: #fff;
}
.mnemonic-card__letter {
  width: 36px; height: 36px; border-radius: var(--radius-sm);
  background: var(--color-primary); color: #fff;
  display: grid; place-items: center;
  font-family: var(--font-mono); font-weight: 700; font-size: 1.1rem;
  margin-bottom: var(--space-2);
}
.mnemonic-card__word { font-weight: 700; font-size: 0.95rem; margin-bottom: var(--space-1); }
.mnemonic-card__note { font-size: 0.82rem; color: var(--color-text-soft); line-height: 1.4; }

/* ---------- Delta ratio visual band ---------- */
.delta-band {
  position: relative; height: 40px; border-radius: var(--radius-sm);
  background: linear-gradient(to right, #fef3c7 0%, #fde68a 20%, #fcd34d 40%, #6ee7b7 60%, #6ee7b7 80%, #93c5fd 90%, #60a5fa 100%);
  margin: var(--space-4) 0; overflow: hidden;
}
.delta-band__marker {
  position: absolute; top: 0; bottom: 0; width: 3px; background: var(--color-text);
  transition: left 0.4s ease;
}
.delta-band__marker::after {
  content: attr(data-value); position: absolute; top: -22px; left: 50%; transform: translateX(-50%);
  font-family: var(--font-mono); font-size: 0.78rem; font-weight: 700; white-space: nowrap;
  background: var(--color-text); color: #fff; padding: 1px 6px; border-radius: 4px;
}
.delta-band__labels { display: flex; justify-content: space-between; font-size: 0.72rem; color: var(--color-text-muted); margin-top: var(--space-1); }

/* ---------- FAQ item ---------- */
.faq-item { border-bottom: 1px solid var(--color-border); padding: var(--space-4) 0; }
.faq-item__question { font-weight: 700; font-size: 1.05rem; cursor: pointer; display: flex; justify-content: space-between; align-items: center; }
.faq-item__answer { margin-top: var(--space-3); }

/* ---------- Mobile ---------- */
@media (max-width: 768px) {
  .main-nav { display: none; }
  .hero { padding: var(--space-7) 0 var(--space-6); }
  .footer-grid { grid-template-columns: 1fr 1fr; }
  .footer-brand { grid-column: 1 / -1; }
  .calc-result__value { font-size: 2rem; }
}

/* Mobile menu toggle */
.menu-toggle { display: none; }
@media (max-width: 768px) {
  .menu-toggle {
    display: inline-flex; align-items: center; justify-content: center;
    width: 40px; height: 40px; border-radius: var(--radius-sm);
    color: var(--color-text);
  }
  .menu-toggle:hover { background: var(--color-bg-soft); }
}

/* Focus visibility for a11y */
:focus-visible { outline: 2px solid var(--color-primary); outline-offset: 2px; border-radius: 4px; }

/* Selection */
::selection { background: var(--color-primary-soft); color: var(--color-primary-hover); }

/* ---------- Images / Figures ---------- */
.prose__figure {
  margin: var(--space-6) auto;
  text-align: center;
  max-width: 720px;
}
.prose__figure img {
  width: 100%;
  max-width: 720px;
  height: auto;
  border-radius: var(--radius);
  border: 1px solid var(--color-border);
  box-shadow: var(--shadow-sm);
}
.prose__figure figcaption {
  font-size: 0.85rem;
  color: var(--color-text-muted);
  margin-top: var(--space-2);
  font-family: var(--font-sans);
  line-height: 1.4;
  padding: 0 var(--space-2);
}
@media (max-width: 768px) {
  .prose__figure { margin-left: 0; margin-right: 0; }
  .prose__figure img { max-width: 100%; }
}