/* ==========================================================================
   Statistics PT+DK Cluster — style.css
   Cluster: statistics-calculators
   Updated: 2026-06-10
   Personality: Academico-moderno e editorialmente preciso. Caderno de
   pesquisa em interface SaaS. Serifa confiavel nos titulos, monospace
   tabular nos numeros, azul-profundo institucional aquecido por um
   verde-cal "calculate". Stripe Docs meets Wolfram Alpha.
   ========================================================================== */

@import url('https://fonts.googleapis.com/css2?family=Source+Serif+4:opsz,wght@8..60,400;8..60,600;8..60,700&family=Inter:wght@400;500;600;700&family=JetBrains+Mono:wght@400;500;700&display=swap');

/* ============================================================
   Design tokens
   ============================================================ */
:root {
  /* Brand palette */
  --c-primary:        #1E3A8A;
  --c-primary-dark:   #1E3A8A;
  --c-primary-darker: #172554;
  --c-primary-soft:   #EEF2FF;
  --c-primary-soft2:  #DDE3F7;

  --c-secondary:      #475569;
  --c-accent:         #10B981;
  --c-accent-soft:    #ECFDF5;

  /* Ink + paper */
  --c-ink:            #0B1220;
  --c-text:           #1F2937;
  --c-muted:          #5B6473;
  --c-paper:          #FBFBF7;
  --c-paper-alt:      #F4F4EE;
  --c-bg:             #FBFBF7;
  --c-soft:           #F4F4EE;
  --c-softer:         #ECECE3;
  --c-line:           #E4E3D8;
  --c-border:         #E4E3D8;

  /* Status colors */
  --c-success:        #047857;
  --c-success-strong: #065F46;
  --c-success-bg:     #ECFDF5;
  --c-success-border: #A7F3D0;

  --c-danger:         #B91C1C;
  --c-danger-bg:      #FEF2F2;
  --c-danger-border:  #FECACA;

  --c-warning:        #B45309;
  --c-warning-bg:     #FFFBEB;
  --c-warning-border: #FDE68A;

  /* Spacing scale (4px) */
  --sp-1: 4px;
  --sp-2: 8px;
  --sp-3: 12px;
  --sp-4: 16px;
  --sp-5: 24px;
  --sp-6: 32px;
  --sp-7: 48px;
  --sp-8: 64px;
  --sp-9: 96px;

  /* Radii */
  --r-xs:   4px;
  --r-sm:   8px;
  --r-md:   12px;
  --r-lg:   18px;
  --r-xl:   24px;
  --r-full: 999px;

  /* Legacy alias (preserved class names use these) */
  --radius-sm: var(--r-sm);
  --radius:    var(--r-md);
  --radius-lg: var(--r-lg);

  /* Shadows — tinted blue, never pure grey */
  --sh-0: 0 1px 0 rgba(11, 18, 32, .04);
  --sh-1: 0 1px 2px rgba(23, 37, 84, .06), 0 1px 1px rgba(23, 37, 84, .04);
  --sh-2: 0 4px 14px rgba(23, 37, 84, .07), 0 2px 4px rgba(23, 37, 84, .04);
  --sh-3: 0 18px 40px rgba(23, 37, 84, .10), 0 4px 10px rgba(23, 37, 84, .05);
  --sh-result: 0 0 0 1px rgba(16, 185, 129, .20), 0 12px 32px rgba(16, 185, 129, .10);
  --sh-focus: 0 0 0 3px rgba(30, 58, 138, .22);

  /* Legacy shadow aliases */
  --shadow-sm: var(--sh-1);
  --shadow:    var(--sh-2);
  --shadow-lg: var(--sh-3);

  /* Layout */
  --container:     1180px;
  --narrow:        720px;
  --header-h:      72px;
  --sticky-offset: 88px;

  /* Typography stacks */
  --font-heading: 'Source Serif 4', 'Source Serif Pro', 'Lora', Georgia, 'Times New Roman', serif;
  --font-body:    'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
  --font-mono:    'JetBrains Mono', 'SF Mono', 'SFMono-Regular', ui-monospace, Menlo, Consolas, 'Liberation Mono', monospace;
  --font: var(--font-body);

  /* Motion */
  --ease: cubic-bezier(.2, 0, 0, 1);
  --t-fast: 120ms var(--ease);
  --t-base: 180ms var(--ease);
  --t-slow: 320ms var(--ease);
}

/* ============================================================
   Reset
   ============================================================ */
*, *::before, *::after { box-sizing: border-box; }
* { margin: 0; }
html {
  -webkit-text-size-adjust: 100%;
  scroll-behavior: smooth;
  text-size-adjust: 100%;
}
body {
  font-family: var(--font-body);
  font-size: 1.0625rem;
  line-height: 1.65;
  color: var(--c-text);
  background: var(--c-paper);
  font-feature-settings: 'kern', 'liga', 'calt';
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  text-rendering: optimizeLegibility;
  min-height: 100vh;
}
img, svg, video, canvas { display: block; max-width: 100%; }
svg { fill: currentColor; }
button { font: inherit; color: inherit; background: none; border: 0; cursor: pointer; }
input, select, textarea { font: inherit; color: inherit; }
hr { border: 0; border-top: 1px solid var(--c-border); margin-block: var(--sp-5); }

/* ============================================================
   Typography
   ============================================================ */
h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-heading);
  font-weight: 600;
  color: var(--c-ink);
  line-height: 1.18;
  letter-spacing: -0.018em;
  font-feature-settings: 'kern', 'liga', 'onum';
}
h1 {
  font-size: clamp(2.1rem, 5.2vw, 3.1rem);
  letter-spacing: -0.022em;
  font-weight: 700;
  line-height: 1.1;
}
h2 {
  font-size: clamp(1.55rem, 3.4vw, 2rem);
  letter-spacing: -0.018em;
  line-height: 1.2;
}
h3 { font-size: 1.22rem; letter-spacing: -0.012em; }
h4 { font-size: 1.06rem; letter-spacing: -0.008em; }
h5 { font-size: 0.98rem; }
h6 { font-size: 0.92rem; text-transform: uppercase; letter-spacing: 0.08em; color: var(--c-muted); }

p { margin: 0; }
small { font-size: 0.92rem; color: var(--c-muted); }

a {
  color: var(--c-primary);
  text-decoration: none;
  transition: color var(--t-fast);
}
a:hover { color: var(--c-primary-darker); text-decoration: underline; text-underline-offset: 3px; }

strong, b { color: var(--c-ink); font-weight: 600; }
em, i { font-style: italic; }

blockquote {
  border-left: 3px solid var(--c-primary);
  background: var(--c-paper-alt);
  padding: var(--sp-4) var(--sp-5);
  border-radius: 0 var(--r-md) var(--r-md) 0;
  margin-block: var(--sp-5);
  font-family: var(--font-heading);
  font-style: italic;
  color: var(--c-ink);
}

ul, ol { padding-left: 1.3rem; }
li { margin-top: var(--sp-1); }
li::marker { color: var(--c-primary); }

code, kbd, samp {
  font-family: var(--font-mono);
  font-size: 0.94em;
  font-feature-settings: 'tnum', 'zero', 'ss01';
  background: var(--c-paper-alt);
  border: 1px solid var(--c-border);
  border-radius: var(--r-xs);
  padding: 0.1em 0.35em;
  color: var(--c-ink);
}
pre {
  font-family: var(--font-mono);
  background: var(--c-paper-alt);
  border: 1px solid var(--c-border);
  border-radius: var(--r-md);
  padding: var(--sp-4);
  overflow-x: auto;
  font-size: 0.94rem;
  line-height: 1.55;
}
pre code { background: transparent; border: 0; padding: 0; }

/* Tabular numbers everywhere they matter */
.num,
.tabular,
[data-num],
.metric__value,
.result__hero-value,
.result__hero-pvalue {
  font-variant-numeric: tabular-nums slashed-zero;
  font-feature-settings: 'tnum', 'zero', 'ss01';
}

sub, sup { font-size: 0.72em; line-height: 0; vertical-align: baseline; position: relative; }
sup { top: -0.5em; }
sub { bottom: -0.25em; }

::selection { background: color-mix(in srgb, var(--c-primary) 22%, transparent); color: var(--c-ink); }

/* ============================================================
   Focus ring (accessibility-first)
   ============================================================ */
:focus { outline: none; }
:focus-visible {
  outline: 3px solid var(--c-primary-darker);
  outline-offset: 2px;
  border-radius: inherit;
}

/* ============================================================
   Layout primitives
   ============================================================ */
.container {
  width: 100%;
  max-width: var(--container);
  margin-inline: auto;
  padding-inline: var(--sp-4);
}
.narrow {
  max-width: var(--narrow);
  margin-inline: auto;
}
.section { padding-block: var(--sp-7); }
.section--soft { background: var(--c-paper-alt); }
.section--tint { background: var(--c-primary-soft); }

.stack > * + * { margin-top: var(--sp-4); }
.cluster {
  display: flex; flex-wrap: wrap; gap: var(--sp-3);
  align-items: center;
}
.grid {
  display: grid;
  gap: var(--sp-4);
}

.skip-link {
  position: absolute; left: -999px; top: 0;
  background: var(--c-primary-darker); color: #fff;
  padding: var(--sp-3) var(--sp-4);
  border-radius: 0 0 var(--r-sm) 0;
  z-index: 200;
  font-weight: 600;
}
.skip-link:focus { left: 0; }

/* ============================================================
   Site header
   ============================================================ */
.site-header {
  position: sticky; top: 0; z-index: 100;
  background: color-mix(in srgb, var(--c-paper) 88%, transparent);
  backdrop-filter: saturate(180%) blur(10px);
  -webkit-backdrop-filter: saturate(180%) blur(10px);
  border-bottom: 1px solid var(--c-border);
}
.site-header__inner {
  display: flex; align-items: center; justify-content: space-between;
  gap: var(--sp-4); min-height: var(--header-h);
}

.brand {
  display: inline-flex; align-items: center; gap: var(--sp-2);
  font-family: var(--font-heading);
  font-weight: 700; font-size: 1.12rem;
  color: var(--c-ink);
  letter-spacing: -0.012em;
}
.brand:hover { text-decoration: none; color: var(--c-ink); }
.brand__mark {
  width: 34px; height: 34px; flex: none;
  border-radius: var(--r-sm);
  overflow: hidden;
}
.brand__name { display: inline; }
.brand__name span { color: var(--c-primary); font-style: italic; }

/* Nav toggle (mobile) */
.nav-toggle {
  display: inline-flex; align-items: center; justify-content: center;
  width: 44px; height: 44px;
  border: 1px solid var(--c-border);
  border-radius: var(--r-sm);
  background: var(--c-paper);
  cursor: pointer;
  transition: border-color var(--t-fast), background var(--t-fast);
}
.nav-toggle:hover { border-color: var(--c-primary); background: var(--c-primary-soft); }
.nav-toggle svg { width: 22px; height: 22px; color: var(--c-ink); }
.nav-toggle__close { display: none; }
.nav-toggle[aria-expanded="true"] .nav-toggle__open { display: none; }
.nav-toggle[aria-expanded="true"] .nav-toggle__close { display: block; }

/* Main nav */
.main-nav { display: none; }
.main-nav.is-open {
  display: block;
  position: absolute; left: 0; right: 0; top: 100%;
  background: var(--c-paper);
  border-bottom: 1px solid var(--c-border);
  box-shadow: var(--sh-2);
  padding-block: var(--sp-2);
}
.main-nav ul {
  list-style: none; padding: var(--sp-2) var(--sp-4) var(--sp-4); margin: 0;
  display: flex; flex-direction: column; gap: var(--sp-1);
}
.main-nav a {
  display: block;
  padding: var(--sp-3) var(--sp-3);
  border-radius: var(--r-sm);
  color: var(--c-ink);
  font-weight: 500;
  font-size: 0.98rem;
  transition: background var(--t-fast), color var(--t-fast);
}
.main-nav a:hover {
  background: var(--c-paper-alt);
  color: var(--c-primary-darker);
  text-decoration: none;
}
.main-nav a.is-active {
  color: var(--c-primary-darker);
  background: var(--c-primary-soft);
  font-weight: 600;
}
.main-nav .nav-cta {
  margin-top: var(--sp-2);
  background: var(--c-primary);
  color: #fff;
  text-align: center;
  font-weight: 600;
}
.main-nav .nav-cta:hover { background: var(--c-primary-darker); color: #fff; }

/* ============================================================
   Buttons
   ============================================================ */
.btn {
  display: inline-flex; align-items: center; justify-content: center;
  gap: var(--sp-2);
  font-family: var(--font-body);
  font-size: 0.98rem;
  font-weight: 600;
  letter-spacing: -0.005em;
  padding: 0.78rem 1.25rem;
  min-height: 44px;
  border-radius: var(--r-md);
  border: 1px solid transparent;
  cursor: pointer;
  text-align: center;
  text-decoration: none;
  transition:
    background var(--t-fast),
    color var(--t-fast),
    border-color var(--t-fast),
    box-shadow var(--t-fast),
    transform var(--t-fast);
  white-space: nowrap;
}
.btn:hover { text-decoration: none; }
.btn:active { transform: translateY(1px); }
.btn:disabled, .btn[disabled] { opacity: 0.55; cursor: not-allowed; }

.btn--primary {
  background: var(--c-primary);
  color: #fff;
  box-shadow: var(--sh-1);
}
.btn--primary:hover { background: var(--c-primary-darker); color: #fff; box-shadow: var(--sh-2); }

.btn--ghost {
  background: var(--c-paper);
  color: var(--c-primary-darker);
  border-color: var(--c-border);
}
.btn--ghost:hover {
  background: var(--c-primary-soft);
  border-color: var(--c-primary);
  color: var(--c-primary-darker);
}

.btn--light {
  background: #fff;
  color: var(--c-primary-darker);
  border-color: transparent;
  box-shadow: var(--sh-1);
}
.btn--light:hover { background: var(--c-paper-alt); color: var(--c-primary-darker); }

.btn--accent {
  background: var(--c-accent);
  color: #fff;
}
.btn--accent:hover { background: color-mix(in srgb, var(--c-accent) 80%, var(--c-ink)); color: #fff; }

.btn--block { width: 100%; }
.btn--lg {
  padding: 0.95rem 1.5rem;
  font-size: 1.02rem;
  min-height: 52px;
}
.btn--sm {
  padding: 0.5rem 0.85rem;
  font-size: 0.9rem;
  min-height: 36px;
}

/* ============================================================
   Hero (editorial)
   ============================================================ */
.hero {
  background: var(--c-paper);
  padding-block: clamp(var(--sp-6), 7vw, var(--sp-8)) var(--sp-7);
  border-bottom: 1px solid var(--c-border);
  position: relative;
}
.hero__eyebrow {
  display: inline-flex; align-items: center; gap: var(--sp-2);
  font-family: var(--font-mono);
  font-weight: 500; font-size: 0.78rem;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--c-primary-darker);
  background: var(--c-primary-soft);
  border: 1px solid color-mix(in srgb, var(--c-primary) 18%, transparent);
  padding: 0.3rem 0.75rem;
  border-radius: var(--r-full);
  margin-bottom: var(--sp-4);
}
.hero h1 {
  font-size: clamp(2.1rem, 5.2vw, 3.1rem);
  letter-spacing: -0.022em;
  color: var(--c-ink);
  max-width: 18ch;
}
.hero p.lead {
  font-size: 1.12rem;
  color: var(--c-text);
  margin-top: var(--sp-4);
  max-width: 60ch;
  line-height: 1.6;
}
.hero p.lead strong { color: var(--c-ink); font-weight: 600; }

.hero__actions {
  display: flex; flex-wrap: wrap; gap: var(--sp-3);
  margin-top: var(--sp-6);
}
.hero__ai-link {
  margin-top: var(--sp-5);
  font-size: 0.98rem;
  color: var(--c-muted);
}
.hero__ai-link a {
  color: var(--c-primary-darker);
  font-weight: 500;
  border-bottom: 1px dashed color-mix(in srgb, var(--c-primary) 35%, transparent);
}
.hero__ai-link a:hover { text-decoration: none; border-bottom-color: var(--c-primary); }
.hero__ai-link strong { color: var(--c-primary-darker); font-weight: 700; }

.hero__badges {
  display: flex; flex-wrap: wrap; gap: var(--sp-3) var(--sp-5);
  margin-top: var(--sp-6);
  color: var(--c-muted);
  font-size: 0.92rem;
  font-weight: 500;
  font-family: var(--font-mono);
  font-feature-settings: 'tnum';
}
.hero__badges span { display: inline-flex; align-items: center; gap: var(--sp-2); }
.hero__badges svg {
  width: 16px; height: 16px;
  color: var(--c-accent);
  flex: none;
}

/* Hero stat — giant editorial number (decorative add) */
.hero__stat {
  display: inline-flex; align-items: baseline; gap: var(--sp-3);
  margin-top: var(--sp-5);
  font-family: var(--font-mono);
  font-feature-settings: 'tnum', 'zero', 'ss01';
}
.hero__stat strong {
  font-family: var(--font-heading);
  font-style: italic;
  font-size: clamp(2.8rem, 6vw, 4.2rem);
  font-weight: 600;
  color: var(--c-ink);
  line-height: 1;
  letter-spacing: -0.03em;
}
.hero__stat em {
  font-family: var(--font-body);
  font-style: normal;
  color: var(--c-muted);
  font-size: 0.95rem;
}

/* ============================================================
   Page head (compact, flat, no gradient)
   ============================================================ */
.page-head {
  background: var(--c-paper-alt);
  padding-block: var(--sp-6) var(--sp-6);
  border-bottom: 1px solid var(--c-border);
}
.page-head h1 {
  font-size: clamp(1.7rem, 4.4vw, 2.4rem);
  letter-spacing: -0.02em;
  margin-top: var(--sp-3);
  color: var(--c-ink);
}
.page-head p.lead {
  font-size: 1.06rem;
  color: var(--c-text);
  margin-top: var(--sp-3);
  max-width: 68ch;
  line-height: 1.6;
}

/* ============================================================
   Breadcrumb (mono uppercase tracked)
   ============================================================ */
.breadcrumb {
  font-family: var(--font-mono);
  font-size: 0.78rem;
  color: var(--c-muted);
  text-transform: uppercase;
  letter-spacing: 0.08em;
}
.breadcrumb ol {
  list-style: none; padding: 0;
  display: flex; flex-wrap: wrap; gap: var(--sp-2);
}
.breadcrumb li { margin: 0; }
.breadcrumb li::after {
  content: "/";
  margin-left: var(--sp-2);
  color: var(--c-border);
}
.breadcrumb li:last-child::after { content: ""; }
.breadcrumb a {
  color: var(--c-muted);
}
.breadcrumb a:hover { color: var(--c-primary-darker); text-decoration: none; }

/* ============================================================
   Section titles
   ============================================================ */
.section-title {
  text-align: center;
  margin-bottom: var(--sp-6);
  max-width: 60ch;
  margin-inline: auto;
}
.section-title h2 {
  font-size: clamp(1.55rem, 3.4vw, 2rem);
  color: var(--c-ink);
}
.section-title p {
  color: var(--c-muted);
  margin-top: var(--sp-3);
  font-size: 1.02rem;
  line-height: 1.6;
}

/* ============================================================
   Card grids (calculator cards, guide cards)
   ============================================================ */
.card-grid {
  display: grid;
  gap: var(--sp-4);
  grid-template-columns: 1fr;
}

.card {
  display: flex;
  flex-direction: column;
  background: var(--c-paper);
  border: 1px solid var(--c-border);
  border-radius: var(--r-lg);
  padding: var(--sp-5);
  box-shadow: var(--sh-0);
  transition:
    transform var(--t-base),
    box-shadow var(--t-base),
    border-color var(--t-base);
  position: relative;
  isolation: isolate;
}
a.card { color: var(--c-text); }
a.card:hover {
  text-decoration: none;
  transform: translateY(-2px);
  border-color: var(--c-primary);
  box-shadow: var(--sh-2);
}
a.card:hover h3 { color: var(--c-primary-darker); }
a.card:focus-visible {
  outline: 3px solid var(--c-primary-darker);
  outline-offset: 2px;
}

.card__icon {
  width: 44px; height: 44px;
  border-radius: var(--r-md);
  background: var(--c-primary-soft);
  color: var(--c-primary-darker);
  display: inline-flex;
  align-items: center; justify-content: center;
  margin-bottom: var(--sp-4);
  flex: none;
  border: 1px solid color-mix(in srgb, var(--c-primary) 12%, transparent);
}
.card__icon svg { width: 24px; height: 24px; }

.card h3 {
  font-size: 1.18rem;
  color: var(--c-ink);
  transition: color var(--t-fast);
}
.card p {
  color: var(--c-muted);
  font-size: 0.98rem;
  margin-top: var(--sp-2);
  flex: 1;
  line-height: 1.55;
}
.card__cta {
  margin-top: var(--sp-4);
  font-weight: 600;
  color: var(--c-primary-darker);
  font-size: 0.94rem;
  display: inline-flex;
  align-items: center;
  gap: var(--sp-2);
  transition: gap var(--t-base);
}
a.card:hover .card__cta { gap: var(--sp-3); }

.card__tag {
  align-self: flex-start;
  font-family: var(--font-mono);
  font-size: 0.7rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--c-primary-darker);
  background: var(--c-primary-soft);
  padding: 0.22rem 0.6rem;
  border-radius: var(--r-full);
  margin-bottom: var(--sp-3);
  border: 1px solid color-mix(in srgb, var(--c-primary) 18%, transparent);
}

/* ============================================================
   Feature grid (why us)
   ============================================================ */
.feature-grid {
  display: grid;
  gap: var(--sp-5);
  grid-template-columns: 1fr;
  max-width: 760px;
  margin-inline: auto;
}
.feature {
  display: flex; gap: var(--sp-4);
  align-items: flex-start;
}
.feature__icon {
  width: 42px; height: 42px;
  border-radius: var(--r-md);
  flex: none;
  background: var(--c-primary-soft);
  color: var(--c-primary-darker);
  display: inline-flex;
  align-items: center; justify-content: center;
  border: 1px solid color-mix(in srgb, var(--c-primary) 12%, transparent);
}
.feature__icon svg { width: 22px; height: 22px; }
.feature h3 { font-size: 1.06rem; color: var(--c-ink); }
.feature p { font-size: 0.97rem; color: var(--c-muted); margin-top: var(--sp-2); line-height: 1.55; }

/* ============================================================
   Calculator widget (paper card)
   ============================================================ */
.calculator {
  background: var(--c-paper);
  border: 1px solid var(--c-border);
  border-radius: var(--r-lg);
  box-shadow: var(--sh-1);
  padding: var(--sp-5);
  margin-block: var(--sp-5);
}
.calculator__title {
  display: flex; align-items: center; gap: var(--sp-3);
  font-family: var(--font-heading);
  font-size: 1.32rem;
  font-weight: 700;
  color: var(--c-ink);
  letter-spacing: -0.014em;
  margin-bottom: var(--sp-2);
}
.calculator__title svg {
  width: 24px; height: 24px;
  color: var(--c-primary);
  flex: none;
}
.calculator__hint {
  color: var(--c-muted);
  font-size: 0.98rem;
  margin-bottom: var(--sp-5);
  line-height: 1.6;
  max-width: 64ch;
}

/* Field group (fieldset-like card) */
.field-group {
  border: 1px solid var(--c-border);
  border-radius: var(--r-md);
  padding: var(--sp-4);
  margin-bottom: var(--sp-4);
  background: var(--c-paper-alt);
}
.field-group > legend,
.field-group__title {
  font-family: var(--font-heading);
  font-weight: 600;
  color: var(--c-ink);
  font-size: 1rem;
  padding-inline: var(--sp-2);
  letter-spacing: -0.01em;
}
.field-row {
  display: grid;
  gap: var(--sp-4);
  grid-template-columns: 1fr;
  margin-top: var(--sp-4);
}
.field-row--single { grid-template-columns: 1fr; }

.field {
  display: flex; flex-direction: column;
  gap: var(--sp-2);
}
.field label {
  font-weight: 500;
  color: var(--c-ink);
  font-size: 0.94rem;
  letter-spacing: -0.005em;
}
.field .help {
  font-size: 0.86rem;
  color: var(--c-muted);
  font-style: italic;
  font-family: var(--font-heading);
  line-height: 1.5;
}
.help--block { display: block; margin: var(--sp-2) 0 var(--sp-3); }

/* Inputs */
.input,
select.input,
textarea.input {
  font-family: var(--font-mono);
  font-feature-settings: 'tnum', 'zero', 'ss01';
  font-size: 1rem;
  color: var(--c-ink);
  padding: 0.7rem 0.85rem;
  border: 1px solid var(--c-border);
  border-radius: var(--r-sm);
  background: var(--c-paper);
  width: 100%;
  min-height: 44px;
  transition: border-color var(--t-fast), box-shadow var(--t-fast), background var(--t-fast);
}
.input::placeholder { color: var(--c-muted); font-family: var(--font-body); font-style: italic; }
.input:hover { border-color: color-mix(in srgb, var(--c-primary) 35%, var(--c-border)); }
.input:focus {
  outline: none;
  border-color: var(--c-primary);
  box-shadow: var(--sh-focus);
  background: var(--c-paper);
}
.input.has-error {
  border-color: var(--c-danger);
  background: var(--c-danger-bg);
}
.input.has-error:focus { box-shadow: 0 0 0 3px rgba(185, 28, 28, 0.18); }

select.input {
  font-family: var(--font-body);
  appearance: none;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='8' viewBox='0 0 12 8'%3E%3Cpath fill='%235B6473' d='M6 8L0 0h12z'/%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: right 0.85rem center;
  padding-right: 2.2rem;
}

textarea.input {
  min-height: 130px;
  resize: vertical;
  line-height: 1.55;
  font-variant-numeric: tabular-nums;
}

/* Input with affix (unit) */
.input-affix { position: relative; }
.input-affix .input { padding-right: 2.6rem; }
.input-affix__unit {
  position: absolute; right: 0.85rem;
  top: 50%; transform: translateY(-50%);
  color: var(--c-muted);
  font-family: var(--font-mono);
  font-weight: 500;
  font-size: 0.92rem;
  pointer-events: none;
}

/* Segmented control (pill-animated) */
.segmented {
  display: inline-flex;
  flex-wrap: wrap;
  gap: var(--sp-1);
  background: var(--c-paper);
  border: 1px solid var(--c-border);
  border-radius: var(--r-full);
  padding: var(--sp-1);
  margin-top: var(--sp-2);
  position: relative;
}
.field-group > .segmented { margin-top: var(--sp-3); }
.segmented label {
  cursor: pointer;
  position: relative;
  z-index: 1;
}
.segmented input {
  position: absolute;
  opacity: 0;
  pointer-events: none;
}
.segmented span {
  display: inline-flex; align-items: center; justify-content: center;
  padding: 0.5rem 0.95rem;
  border-radius: var(--r-full);
  font-weight: 500;
  font-size: 0.92rem;
  color: var(--c-text);
  background: transparent;
  border: 1px solid transparent;
  transition:
    background var(--t-base),
    color var(--t-base),
    box-shadow var(--t-base),
    transform var(--t-fast);
  white-space: nowrap;
  min-height: 36px;
}
.segmented label:hover span {
  color: var(--c-primary-darker);
  background: var(--c-primary-soft);
}
.segmented input:checked + span {
  background: var(--c-primary);
  color: #fff;
  box-shadow: var(--sh-1);
  font-weight: 600;
}
.segmented input:focus-visible + span {
  outline: 3px solid var(--c-primary-darker);
  outline-offset: 2px;
}

/* Field error */
.field-error {
  display: none;
  color: var(--c-danger);
  font-size: 0.88rem;
  font-weight: 500;
  margin-top: var(--sp-2);
  font-family: var(--font-body);
}
.field-error.is-visible { display: block; }
.field-error::before { content: "! "; font-family: var(--font-mono); font-weight: 700; }

.calculator__actions {
  display: flex; flex-wrap: wrap; gap: var(--sp-3);
  margin-top: var(--sp-4);
}

/* ============================================================
   Result card (verdict + breakdown)
   ============================================================ */
.result {
  margin-top: var(--sp-5);
  border-radius: var(--r-lg);
  border: 1px solid var(--c-border);
  overflow: hidden;
  background: var(--c-paper);
  box-shadow: var(--sh-1);
}
.result[hidden] { display: none; }

/* Verdict banner */
.result__banner {
  padding: var(--sp-4) var(--sp-5);
  display: flex; gap: var(--sp-3);
  align-items: flex-start;
  border-bottom: 1px solid var(--c-border);
}
.result__banner svg {
  width: 26px; height: 26px;
  flex: none; margin-top: 0.18rem;
}
.result__headline {
  font-family: var(--font-heading);
  font-size: 1.22rem;
  font-weight: 700;
  letter-spacing: -0.012em;
  line-height: 1.25;
  color: var(--c-ink);
}
.result__sub {
  font-size: 0.96rem;
  margin-top: var(--sp-1);
  line-height: 1.55;
  color: var(--c-text);
}

/* Variants */
.result--significant {
  border-color: var(--c-success-border);
  box-shadow: var(--sh-result);
}
.result--significant .result__banner {
  background: var(--c-success-bg);
  border-bottom-color: var(--c-success-border);
}
.result--significant .result__headline,
.result--significant .result__banner svg { color: var(--c-success-strong); }

.result--ns { border-color: var(--c-warning-border); }
.result--ns .result__banner {
  background: var(--c-warning-bg);
  border-bottom-color: var(--c-warning-border);
}
.result--ns .result__headline,
.result--ns .result__banner svg { color: var(--c-warning); }

.result--neutral { border-color: color-mix(in srgb, var(--c-primary) 20%, var(--c-border)); }
.result--neutral .result__banner {
  background: var(--c-primary-soft);
  border-bottom-color: color-mix(in srgb, var(--c-primary) 18%, transparent);
}
.result--neutral .result__headline,
.result--neutral .result__banner svg { color: var(--c-primary-darker); }

.result__body {
  padding: var(--sp-5);
  background: var(--c-paper);
}

/* Wolfram-style hero answer (optional helper) */
.result__hero {
  display: flex; flex-wrap: wrap; align-items: baseline;
  gap: var(--sp-4);
  margin-bottom: var(--sp-5);
  padding-bottom: var(--sp-4);
  border-bottom: 1px dashed var(--c-border);
}
.result__hero-value {
  font-family: var(--font-heading);
  font-style: italic;
  font-weight: 600;
  font-size: clamp(2.5rem, 6vw, 3.5rem);
  line-height: 1;
  color: var(--c-ink);
  letter-spacing: -0.03em;
}
.result__hero-pvalue {
  font-family: var(--font-mono);
  font-size: 1.05rem;
  color: var(--c-muted);
  font-weight: 500;
  letter-spacing: -0.01em;
}

/* Metric grid (receipt-style breakdown) */
.metric-grid {
  display: grid;
  gap: var(--sp-3);
  grid-template-columns: repeat(2, 1fr);
}
.metric {
  background: var(--c-paper-alt);
  border: 1px solid var(--c-border);
  border-radius: var(--r-md);
  padding: var(--sp-3) var(--sp-4);
  display: flex; flex-direction: column;
  gap: 0.15rem;
}
.metric__label {
  font-size: 0.76rem;
  color: var(--c-muted);
  font-family: var(--font-mono);
  font-weight: 500;
  text-transform: uppercase;
  letter-spacing: 0.06em;
}
.metric__value {
  font-family: var(--font-mono);
  font-size: 1.6rem;
  font-weight: 500;
  color: var(--c-ink);
  font-variant-numeric: tabular-nums slashed-zero;
  font-feature-settings: 'tnum', 'zero', 'ss01';
  line-height: 1.15;
  letter-spacing: -0.01em;
}
.metric__value.is-pos { color: var(--c-success-strong); }
.metric__value.is-neg { color: var(--c-danger); }
.metric__note {
  font-size: 0.82rem;
  color: var(--c-muted);
  margin-top: var(--sp-1);
  font-style: italic;
  font-family: var(--font-heading);
}

.result__interpretation {
  margin-top: var(--sp-5);
  padding-top: var(--sp-4);
  border-top: 1px dashed var(--c-border);
  font-size: 1rem;
  line-height: 1.65;
  color: var(--c-text);
}
.result__interpretation strong { color: var(--c-ink); }

/* Sticky result on desktop */
@media (min-width: 960px) {
  .calculator--has-result {
    display: grid;
    grid-template-columns: minmax(0, 1fr) minmax(320px, 420px);
    gap: var(--sp-5);
    align-items: start;
  }
  .calculator--has-result .result {
    position: sticky;
    top: var(--sticky-offset);
    max-height: calc(100vh - 120px);
    overflow-y: auto;
    margin-top: 0;
  }
}

/* ============================================================
   Prose (long-form article)
   ============================================================ */
.prose {
  font-size: 1.0625rem;
  line-height: 1.7;
  color: var(--c-text);
}
.prose h2 {
  font-size: clamp(1.45rem, 3.2vw, 1.85rem);
  margin-top: var(--sp-7);
  scroll-margin-top: var(--sticky-offset);
  color: var(--c-ink);
}
.prose h3 {
  font-size: 1.22rem;
  margin-top: var(--sp-6);
  scroll-margin-top: var(--sticky-offset);
  color: var(--c-ink);
}
.prose h4 {
  font-size: 1.06rem;
  margin-top: var(--sp-5);
  scroll-margin-top: var(--sticky-offset);
}
.prose p { margin-top: var(--sp-4); }
.prose ul, .prose ol { margin-top: var(--sp-3); padding-left: 1.4rem; }
.prose li { margin-top: var(--sp-2); line-height: 1.6; }
.prose li::marker { color: var(--c-primary); }
.prose strong { color: var(--c-ink); }
.prose h2 + p, .prose h3 + p { margin-top: var(--sp-3); }
.prose a {
  color: var(--c-primary-darker);
  text-decoration: underline;
  text-decoration-color: color-mix(in srgb, var(--c-primary) 35%, transparent);
  text-underline-offset: 3px;
  transition: text-decoration-color var(--t-fast);
}
.prose a:hover { text-decoration-color: var(--c-primary); }
.prose em { font-style: italic; color: var(--c-ink); }

/* ============================================================
   Formula box (LaTeX-card style)
   ============================================================ */
.formula {
  background: var(--c-paper-alt);
  border: 1px solid var(--c-border);
  border-left: 3px solid var(--c-primary);
  border-radius: var(--r-md);
  padding: var(--sp-4) var(--sp-5);
  margin-block: var(--sp-4);
  overflow-x: auto;
  font-family: var(--font-heading);
  font-style: italic;
  font-size: 1.08rem;
  color: var(--c-ink);
  line-height: 1.55;
  font-feature-settings: 'tnum';
}
.formula .formula__where {
  display: block;
  margin-top: var(--sp-3);
  font-family: var(--font-body);
  font-style: normal;
  font-size: 0.9rem;
  color: var(--c-muted);
  border-top: 1px dashed var(--c-border);
  padding-top: var(--sp-3);
}

/* ============================================================
   Callouts
   ============================================================ */
.callout {
  border: 1px solid var(--c-border);
  border-left: 3px solid var(--c-muted);
  border-radius: var(--r-md);
  padding: var(--sp-4) var(--sp-5);
  margin-block: var(--sp-5);
  background: var(--c-paper-alt);
}
.callout__title {
  display: flex; align-items: center; gap: var(--sp-2);
  font-family: var(--font-heading);
  font-weight: 700;
  color: var(--c-ink);
  margin-bottom: var(--sp-2);
  font-size: 1.04rem;
  letter-spacing: -0.012em;
}
.callout__title svg { width: 20px; height: 20px; flex: none; }
.callout p { margin-top: var(--sp-2); }
.callout p:first-of-type { margin-top: 0; }
.callout--example {
  border-left-color: var(--c-primary);
  background: var(--c-primary-soft);
}
.callout--example .callout__title { color: var(--c-primary-darker); }
.callout--tip {
  border-left-color: var(--c-accent);
  background: var(--c-accent-soft);
}
.callout--tip .callout__title { color: var(--c-success-strong); }
.callout--warning {
  border-left-color: var(--c-warning);
  background: var(--c-warning-bg);
}
.callout--warning .callout__title { color: var(--c-warning); }

/* ============================================================
   TOC
   ============================================================ */
.toc {
  background: var(--c-paper-alt);
  border: 1px solid var(--c-border);
  border-radius: var(--r-md);
  padding: var(--sp-4) var(--sp-5);
  margin-block: var(--sp-5);
}
.toc > strong {
  display: block;
  font-family: var(--font-mono);
  font-size: 0.74rem;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--c-muted);
  margin-bottom: var(--sp-3);
  font-weight: 500;
}
.toc ol { margin: 0; padding-left: 1.3rem; }
.toc li { margin-top: var(--sp-2); }
.toc a {
  color: var(--c-primary-darker);
  font-weight: 500;
  font-size: 0.98rem;
}
.toc a:hover { text-decoration: underline; }

/* ============================================================
   Tables
   ============================================================ */
.table-wrap {
  overflow-x: auto;
  margin-block: var(--sp-5);
  border: 1px solid var(--c-border);
  border-radius: var(--r-md);
  background: var(--c-paper);
}
table.data {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.96rem;
  min-width: 360px;
}
table.data th,
table.data td {
  padding: 0.7rem 0.85rem;
  text-align: left;
  border-bottom: 1px solid var(--c-border);
}
table.data thead th {
  background: var(--c-paper-alt);
  color: var(--c-ink);
  font-family: var(--font-body);
  font-weight: 600;
  font-size: 0.86rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  position: sticky;
  top: 0;
  z-index: 1;
  box-shadow: 0 1px 0 var(--c-border);
}
table.data tbody tr:nth-child(even) {
  background: color-mix(in srgb, var(--c-paper-alt) 50%, transparent);
}
table.data tbody tr:hover { background: var(--c-primary-soft); }
table.data td.num,
table.data th.num {
  text-align: right;
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums slashed-zero;
  font-feature-settings: 'tnum', 'zero', 'ss01';
}
table.data tbody tr:last-child td { border-bottom: 0; }

/* Matrix grid for contingency tables */
.matrix-grid {
  border-collapse: separate;
  border-spacing: 6px;
  width: 100%;
}
.matrix-grid th { font-weight: 600; color: var(--c-ink); font-size: 0.92rem; }
.matrix-grid .input {
  min-width: 78px;
  text-align: center;
  padding: 0.55rem 0.4rem;
  font-family: var(--font-mono);
}
.matrix-grid thead .input,
.matrix-grid tbody th .input {
  background: var(--c-primary-soft);
  font-weight: 600;
  color: var(--c-primary-darker);
}
.matrix-corner { width: 1px; padding: 0; }
.matrix-controls {
  display: flex; flex-wrap: wrap; gap: var(--sp-2);
  margin-top: var(--sp-4);
}

/* ============================================================
   Numbered steps
   ============================================================ */
.steps {
  list-style: none;
  padding: 0;
  counter-reset: step;
  margin-top: var(--sp-4);
}
.steps li {
  position: relative;
  padding-left: 3rem;
  margin-top: var(--sp-4);
  min-height: 2rem;
}
.steps li::before {
  counter-increment: step;
  content: counter(step);
  position: absolute;
  left: 0; top: -0.2rem;
  width: 2rem; height: 2rem;
  border-radius: 50%;
  background: var(--c-primary);
  color: #fff;
  font-family: var(--font-mono);
  font-weight: 600;
  display: inline-flex;
  align-items: center; justify-content: center;
  font-size: 0.92rem;
  font-feature-settings: 'tnum';
  box-shadow: var(--sh-1);
}

/* ============================================================
   FAQ (details/summary with chevron)
   ============================================================ */
.faq { margin-top: var(--sp-4); }
.faq details {
  border: 1px solid var(--c-border);
  border-radius: var(--r-md);
  margin-top: var(--sp-3);
  background: var(--c-paper);
  transition: border-color var(--t-fast), background var(--t-fast);
  overflow: hidden;
}
.faq details:hover { background: var(--c-paper-alt); border-color: color-mix(in srgb, var(--c-primary) 25%, var(--c-border)); }
.faq details[open] { background: var(--c-paper); border-color: color-mix(in srgb, var(--c-primary) 30%, var(--c-border)); }

.faq summary {
  cursor: pointer;
  padding: var(--sp-4) var(--sp-5);
  font-family: var(--font-heading);
  font-weight: 600;
  font-size: 1.05rem;
  color: var(--c-ink);
  list-style: none;
  display: flex;
  justify-content: space-between;
  gap: var(--sp-4);
  align-items: center;
  letter-spacing: -0.012em;
  line-height: 1.4;
}
.faq summary::-webkit-details-marker { display: none; }
.faq summary::after {
  content: "";
  width: 12px; height: 12px;
  border-right: 2px solid var(--c-primary);
  border-bottom: 2px solid var(--c-primary);
  transform: rotate(-45deg);
  transition: transform var(--t-base);
  flex: none;
  margin-right: 0.25rem;
}
.faq details[open] summary::after { transform: rotate(45deg); }
.faq details[open] summary { border-bottom: 1px solid var(--c-border); }
.faq .faq__answer {
  padding: var(--sp-3) var(--sp-5) var(--sp-5);
  color: var(--c-text);
  line-height: 1.65;
}
.faq .faq__answer p { margin-top: var(--sp-3); }
.faq .faq__answer p:first-child { margin-top: var(--sp-2); }
.faq .faq__answer a {
  color: var(--c-primary-darker);
  text-decoration: underline;
  text-underline-offset: 3px;
}

/* ============================================================
   Citation chips
   ============================================================ */
.citation-chips,
.tag-list {
  display: flex; flex-wrap: wrap; gap: var(--sp-2);
  margin-top: var(--sp-4);
}
.tag-list a, .tag-list span,
.citation-chips a, .citation-chips span {
  font-family: var(--font-mono);
  font-size: 0.78rem;
  font-weight: 500;
  padding: 0.28rem 0.7rem;
  background: var(--c-paper-alt);
  border: 1px solid var(--c-border);
  border-radius: var(--r-full);
  color: var(--c-text);
  letter-spacing: 0.01em;
  transition: background var(--t-fast), border-color var(--t-fast), color var(--t-fast);
}
.tag-list a:hover,
.citation-chips a:hover {
  background: var(--c-primary-soft);
  border-color: var(--c-primary);
  color: var(--c-primary-darker);
  text-decoration: none;
}

/* ============================================================
   Ad slot (AdSense)
   ============================================================ */
.ad-slot {
  margin-block: var(--sp-5);
  text-align: center;
  min-height: 0;
}
.ad-slot:empty { display: none; }
.ad-slot:not(:empty)::before {
  content: "Publicidade";
  display: block;
  font-family: var(--font-mono);
  font-size: 0.7rem;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--c-muted);
  margin-bottom: var(--sp-2);
  font-weight: 500;
}

/* ============================================================
   Recommend / affiliate box
   ============================================================ */
.recommend {
  border: 1px solid color-mix(in srgb, var(--c-primary) 22%, var(--c-border));
  background: var(--c-primary-soft);
  border-radius: var(--r-lg);
  padding: var(--sp-5);
  margin-block: var(--sp-6);
  box-shadow: var(--sh-1);
}
.recommend__title {
  display: flex; align-items: center; gap: var(--sp-2);
  font-family: var(--font-heading);
  font-weight: 700;
  color: var(--c-primary-darker);
  font-size: 1.12rem;
  letter-spacing: -0.012em;
}
.recommend__title svg { width: 22px; height: 22px; flex: none; }
.recommend p { font-size: 0.98rem; margin-top: var(--sp-3); }
.recommend ul { margin-top: var(--sp-3); }
.recommend li { margin-top: var(--sp-2); }
.recommend .disclosure {
  font-size: 0.84rem;
  color: var(--c-muted);
  margin-top: var(--sp-4);
  border-top: 1px dashed color-mix(in srgb, var(--c-primary) 25%, transparent);
  padding-top: var(--sp-3);
  font-style: italic;
  font-family: var(--font-heading);
}

/* ============================================================
   Related (linked calculators)
   ============================================================ */
.related { margin-top: var(--sp-7); }
.related h2 {
  font-size: 1.32rem;
  margin-bottom: var(--sp-4);
  color: var(--c-ink);
}

/* ============================================================
   CTA band (THE only gradient in the system)
   ============================================================ */
.cta-band {
  background: linear-gradient(135deg, var(--c-primary) 0%, var(--c-primary-darker) 100%);
  color: #fff;
  border-radius: var(--r-xl);
  padding: var(--sp-6) var(--sp-5);
  text-align: center;
  margin-block: var(--sp-6);
  box-shadow: var(--sh-3);
  position: relative;
  overflow: hidden;
}
.cta-band::before {
  content: "";
  position: absolute;
  inset: 0;
  background:
    radial-gradient(circle at 20% 0%, rgba(16, 185, 129, 0.18), transparent 50%),
    radial-gradient(circle at 80% 100%, rgba(255, 255, 255, 0.08), transparent 50%);
  pointer-events: none;
}
.cta-band > * { position: relative; }
.cta-band h2 {
  color: #fff;
  font-size: clamp(1.4rem, 3vw, 1.7rem);
  letter-spacing: -0.018em;
}
.cta-band p {
  color: color-mix(in srgb, #fff 88%, var(--c-primary));
  margin-top: var(--sp-3);
  max-width: 60ch;
  margin-inline: auto;
}
.cta-band .btn { margin-top: var(--sp-5); }

/* ============================================================
   AI Search (Linear command-bar style)
   ============================================================ */
.ai-search {
  background: var(--c-paper);
  border: 1px solid var(--c-border);
  border-radius: var(--r-lg);
  padding: var(--sp-5);
  margin-block: var(--sp-5);
  box-shadow: var(--sh-1);
}
.ai-search__head {
  display: flex; align-items: center; gap: var(--sp-3);
  margin-bottom: var(--sp-3);
}
.ai-search__head svg {
  width: 24px; height: 24px;
  color: var(--c-primary);
  flex: none;
}
.ai-search__head h2 {
  font-size: 1.32rem;
  color: var(--c-ink);
  letter-spacing: -0.014em;
  margin: 0;
}
.ai-search__hint {
  color: var(--c-muted);
  font-size: 0.96rem;
  margin-bottom: var(--sp-4);
  font-style: italic;
  font-family: var(--font-heading);
  line-height: 1.55;
}
.ai-search__textarea {
  font-family: var(--font-mono);
  font-size: 1rem;
  line-height: 1.55;
  color: var(--c-ink);
  padding: var(--sp-4);
  border: 1px solid var(--c-border);
  border-radius: var(--r-md);
  background: var(--c-paper);
  width: 100%;
  min-height: 96px;
  resize: vertical;
  transition: border-color var(--t-fast), box-shadow var(--t-fast);
}
.ai-search__textarea::placeholder {
  color: var(--c-muted);
  font-family: var(--font-mono);
  font-style: normal;
}
.ai-search__textarea:focus {
  outline: none;
  border-color: var(--c-primary);
  box-shadow: var(--sh-focus);
}
.ai-search__actions {
  display: flex; flex-wrap: wrap; gap: var(--sp-3);
  align-items: center;
  margin-top: var(--sp-4);
}
.ai-search__status {
  font-family: var(--font-mono);
  font-size: 0.86rem;
  color: var(--c-muted);
}
.ai-search__status.is-error { color: var(--c-danger); }

.ai-progress {
  margin-top: var(--sp-3);
  height: 6px;
  background: var(--c-paper-alt);
  border-radius: var(--r-full);
  overflow: hidden;
  border: 1px solid var(--c-border);
}
.ai-progress__bar {
  height: 100%;
  width: 0;
  background: linear-gradient(90deg, var(--c-primary), var(--c-accent));
  transition: width var(--t-slow);
  border-radius: var(--r-full);
}

.ai-examples {
  display: flex; flex-wrap: wrap; gap: var(--sp-2);
  margin-top: var(--sp-5);
  padding-top: var(--sp-4);
  border-top: 1px dashed var(--c-border);
  align-items: center;
}
.ai-examples__label {
  font-family: var(--font-mono);
  font-size: 0.78rem;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--c-muted);
  width: 100%;
  margin-bottom: var(--sp-2);
  font-weight: 500;
}
.ai-example {
  font-family: var(--font-body);
  font-size: 0.9rem;
  padding: 0.42rem 0.85rem;
  border-radius: var(--r-full);
  border: 1px solid var(--c-border);
  background: var(--c-paper-alt);
  color: var(--c-text);
  cursor: pointer;
  transition:
    background var(--t-fast),
    border-color var(--t-fast),
    color var(--t-fast),
    transform var(--t-fast);
  line-height: 1.4;
}
.ai-example:hover {
  background: var(--c-primary-soft);
  border-color: var(--c-primary);
  color: var(--c-primary-darker);
}
.ai-example:active { transform: translateY(1px); }

/* AI result card */
.ai-result { margin-top: var(--sp-5); }
.ai-result:empty { display: none; }
.ai-result h3 {
  font-size: 1.18rem;
  color: var(--c-ink);
  margin-bottom: var(--sp-3);
}
.ai-result__primary {
  display: block;
  background: var(--c-paper);
  border: 1px solid var(--c-primary);
  border-radius: var(--r-lg);
  padding: var(--sp-5);
  box-shadow: var(--sh-2);
  transition: transform var(--t-base), box-shadow var(--t-base);
  color: var(--c-text);
  position: relative;
}
.ai-result__primary:hover {
  text-decoration: none;
  transform: translateY(-2px);
  box-shadow: var(--sh-3);
}
.ai-result__badge {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 0.72rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--c-primary-darker);
  background: var(--c-primary-soft);
  border: 1px solid color-mix(in srgb, var(--c-primary) 20%, transparent);
  padding: 0.2rem 0.6rem;
  border-radius: var(--r-full);
  margin-bottom: var(--sp-3);
}
.ai-result__score {
  display: inline-block;
  margin-left: var(--sp-2);
  font-family: var(--font-mono);
  font-size: 0.78rem;
  color: var(--c-accent);
  background: var(--c-accent-soft);
  border: 1px solid color-mix(in srgb, var(--c-accent) 25%, transparent);
  padding: 0.18rem 0.55rem;
  border-radius: var(--r-full);
  font-weight: 500;
}
.ai-result__title {
  font-family: var(--font-heading);
  font-size: 1.32rem;
  font-weight: 700;
  color: var(--c-ink);
  letter-spacing: -0.014em;
  line-height: 1.25;
  margin-top: var(--sp-2);
}
.ai-result__summary {
  color: var(--c-text);
  margin-top: var(--sp-2);
  font-size: 0.98rem;
  line-height: 1.6;
}
.ai-result__cta {
  margin-top: var(--sp-4);
  font-weight: 600;
  color: var(--c-primary-darker);
  font-size: 0.96rem;
  display: inline-flex; align-items: center; gap: var(--sp-2);
}

/* Alternative AI results */
.ai-alts {
  display: grid;
  gap: var(--sp-3);
  margin-top: var(--sp-3);
  grid-template-columns: 1fr;
}
.ai-alt {
  display: block;
  background: var(--c-paper);
  border: 1px solid var(--c-border);
  border-radius: var(--r-md);
  padding: var(--sp-4);
  color: var(--c-text);
  transition: border-color var(--t-base), transform var(--t-base), box-shadow var(--t-base);
}
.ai-alt:hover {
  text-decoration: none;
  border-color: var(--c-primary);
  transform: translateY(-1px);
  box-shadow: var(--sh-1);
}
.ai-alt__type {
  font-family: var(--font-mono);
  font-size: 0.7rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--c-muted);
  margin-bottom: var(--sp-2);
}
.ai-alt__title {
  font-family: var(--font-heading);
  font-weight: 700;
  font-size: 1.06rem;
  color: var(--c-ink);
  letter-spacing: -0.012em;
}
.ai-alt__summary {
  font-size: 0.93rem;
  color: var(--c-muted);
  margin-top: var(--sp-2);
  line-height: 1.55;
}

/* Source card (citation reference) */
.source-card {
  border: 1px solid var(--c-border);
  border-radius: var(--r-md);
  padding: var(--sp-4);
  background: var(--c-paper-alt);
  margin-block: var(--sp-3);
  font-size: 0.94rem;
}
.source-card strong {
  font-family: var(--font-heading);
  color: var(--c-ink);
}
.source-card .source-meta {
  font-family: var(--font-mono);
  font-size: 0.8rem;
  color: var(--c-muted);
  margin-top: var(--sp-2);
}

/* ============================================================
   Footer (dark institutional)
   ============================================================ */
.site-footer {
  background: var(--c-ink);
  color: #cbd5e1;
  padding-block: var(--sp-7) var(--sp-5);
  margin-top: var(--sp-7);
  font-size: 0.96rem;
  border-top: 1px solid color-mix(in srgb, var(--c-primary) 30%, var(--c-ink));
}
.site-footer h3 {
  color: #fff;
  font-family: var(--font-mono);
  font-size: 0.74rem;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  margin-bottom: var(--sp-3);
  font-weight: 600;
}
.footer-grid {
  display: grid;
  gap: var(--sp-6) var(--sp-5);
  grid-template-columns: 1fr;
}
.footer-grid ul {
  list-style: none;
  padding: 0;
  display: grid;
  gap: var(--sp-2);
}
.footer-grid li { margin: 0; }
.site-footer a {
  color: #cbd5e1;
  transition: color var(--t-fast);
}
.site-footer a:hover { color: #fff; text-decoration: none; }
.footer-brand .brand,
.footer-brand .brand__name {
  color: #fff;
  font-size: 1.18rem;
}
.footer-brand .brand__name span { color: var(--c-accent); font-style: italic; }
.footer-brand .brand__mark { width: 40px; height: 40px; }
.footer-brand p {
  margin-top: var(--sp-3);
  color: #94a3b8;
  font-size: 0.94rem;
  max-width: 36ch;
  line-height: 1.6;
}
.footer-bottom {
  margin-top: var(--sp-6);
  padding-top: var(--sp-4);
  border-top: 1px solid color-mix(in srgb, #fff 8%, transparent);
  color: #94a3b8;
  font-size: 0.84rem;
  font-family: var(--font-mono);
  letter-spacing: 0.01em;
}
.footer-bottom p + p { margin-top: var(--sp-2); }

/* ============================================================
   Donation page
   ============================================================ */
.donate-card {
  text-align: center;
  background: var(--c-paper);
}
.donate-card h3 {
  font-size: 1.22rem;
  color: var(--c-ink);
}
.donate-qr {
  width: 200px; height: 200px;
  margin: var(--sp-4) auto 0;
  display: block;
  border: 1px solid var(--c-border);
  border-radius: var(--r-md);
  padding: 8px;
  background: #fff;
  box-shadow: var(--sh-1);
}
.pix-key {
  display: inline-block;
  font-family: var(--font-mono);
  font-weight: 600;
  color: var(--c-ink);
  background: var(--c-primary-soft);
  padding: 0.35rem 0.7rem;
  border-radius: var(--r-sm);
  border: 1px solid color-mix(in srgb, var(--c-primary) 20%, transparent);
  font-size: 0.94rem;
}
.pix-code {
  display: block;
  width: 100%;
  margin-top: var(--sp-3);
  padding: var(--sp-3) var(--sp-4);
  background: var(--c-paper-alt);
  border: 1px solid var(--c-border);
  border-radius: var(--r-sm);
  font-family: var(--font-mono);
  font-size: 0.76rem;
  line-height: 1.55;
  word-break: break-all;
  color: var(--c-ink);
  text-align: left;
}

/* ============================================================
   Group list (k-samples, ANOVA inputs)
   ============================================================ */
.group-list {
  display: grid;
  gap: var(--sp-4);
}

/* ============================================================
   Utilities
   ============================================================ */
.text-center { text-align: center; }
.text-left { text-align: left; }
.text-right { text-align: right; }
.text-sm { font-size: 0.92rem; }
.text-lg { font-size: 1.12rem; }
.mt-0 { margin-top: 0; }
.mt-2 { margin-top: var(--sp-5); }
.mt-3 { margin-top: var(--sp-6); }
.u-mt-md { margin-top: var(--sp-5); }
.u-mb-md { margin-bottom: var(--sp-5); }
.muted { color: var(--c-muted); }
.ink { color: var(--c-ink); }
.mono { font-family: var(--font-mono); font-feature-settings: 'tnum', 'zero', 'ss01'; }
.serif { font-family: var(--font-heading); }
.italic { font-style: italic; }
.no-wrap { white-space: nowrap; }

.text-center .lead { margin-inline: auto; }
.text-center .hero__actions { justify-content: center; }

.visually-hidden,
.sr-only {
  position: absolute;
  width: 1px; height: 1px;
  padding: 0; margin: -1px;
  overflow: hidden;
  clip: rect(0 0 0 0);
  white-space: nowrap;
  border: 0;
}

/* ============================================================
   Container queries (calculator + result two-col)
   ============================================================ */
@container (min-width: 720px) {
  .field-row { grid-template-columns: 1fr 1fr; }
  .field-row--single { grid-template-columns: 1fr; }
}

/* ============================================================
   Responsive — mobile-first up
   ============================================================ */

/* sm: 640px */
@media (min-width: 640px) {
  .container { padding-inline: var(--sp-5); }
  .field-row { grid-template-columns: 1fr 1fr; }
  .field-row--single { grid-template-columns: 1fr; }
  .metric-grid { grid-template-columns: repeat(3, 1fr); }
  .ai-alts { grid-template-columns: repeat(2, 1fr); }
}

/* md: 860px */
@media (min-width: 860px) {
  .card-grid--2 { grid-template-columns: repeat(2, 1fr); }
  .card-grid--3 { grid-template-columns: repeat(2, 1fr); }
  .feature-grid { grid-template-columns: repeat(2, 1fr); }
  .footer-grid { grid-template-columns: 2fr 1fr 1fr 1fr; }
  .calculator { padding: var(--sp-6); }
  .section { padding-block: var(--sp-8); }
  .hero { padding-block: clamp(var(--sp-8), 10vw, var(--sp-9)) var(--sp-8); }
  .page-head { padding-block: var(--sp-6) var(--sp-7); }
}

/* lg: 1024px */
@media (min-width: 1024px) {
  .card-grid--3 { grid-template-columns: repeat(3, 1fr); }
  .feature-grid { grid-template-columns: repeat(2, 1fr); }
  .ai-alts { grid-template-columns: repeat(3, 1fr); }

  /* Desktop nav */
  .nav-toggle { display: none; }
  .main-nav {
    display: block;
    position: static;
    box-shadow: none;
    border: 0;
    background: transparent;
    padding: 0;
  }
  .main-nav ul {
    flex-direction: row;
    align-items: center;
    padding: 0;
    gap: var(--sp-1);
  }
  .main-nav a {
    padding: 0.5rem 0.85rem;
    font-size: 0.94rem;
  }
  .main-nav .nav-cta {
    margin-top: 0;
    margin-left: var(--sp-3);
    padding: 0.6rem 1.1rem;
  }
}

/* xl: 1280px */
@media (min-width: 1280px) {
  :root { --header-h: 76px; }
  .container { padding-inline: var(--sp-6); }
}

/* ============================================================
   Print
   ============================================================ */
@media print {
  .site-header,
  .site-footer,
  .ad-slot,
  .nav-toggle,
  .main-nav,
  .cta-band,
  .skip-link,
  .calculator__actions,
  .ai-search,
  .recommend { display: none !important; }

  body {
    background: #fff;
    color: #000;
    font-size: 11pt;
    line-height: 1.45;
  }
  .container, .narrow { max-width: 100%; padding: 0; }
  a { color: #000; text-decoration: underline; }
  .card,
  .calculator,
  .result,
  .formula,
  .callout { break-inside: avoid; box-shadow: none; border-color: #888; }
  .hero,
  .page-head { background: transparent; padding-block: 0; border: 0; }
  h1, h2, h3 { color: #000; }
  .result__banner { background: transparent !important; border-bottom: 1px solid #888; }
}

/* ============================================================
   Reduced motion
   ============================================================ */
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after {
    transition-duration: 0.01ms !important;
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    scroll-behavior: auto !important;
  }
  a.card:hover,
  .ai-result__primary:hover,
  .ai-alt:hover,
  .btn:active { transform: none; }
}