/* HQ Calculators — Shared Design System CSS v1.0 */
/* hqcalculators.com | Owner: Mav | March 2026 */

@import url('https://fonts.googleapis.com/css2?family=Inter:wght@400;500;600;700;800&family=DM+Mono:wght@400;500&display=swap');

/* ─────────────────────────────────────────────
   CSS VARIABLES (Master Token Set)
───────────────────────────────────────────── */
:root {
  /* Purple primary ramp */
  --color-purple-50:  #F5F3FF;
  --color-purple-100: #EDE9FE;
  --color-purple-200: #DDD6FE;
  --color-purple-300: #C4B5FD;
  --color-purple-400: #A78BFA;
  --color-purple-500: #8B5CF6;
  --color-purple-600: #7C3AED;
  --color-purple-700: #6D28D9; /* PRIMARY */
  --color-purple-800: #5B21B6;
  --color-purple-900: #4C1D95;
  --color-purple-950: #1E1B4B;

  /* Neutrals */
  --color-gray-50:  #F9FAFB;
  --color-gray-100: #F3F4F6;
  --color-gray-200: #E5E7EB;
  --color-gray-300: #D1D5DB;
  --color-gray-400: #9CA3AF;
  --color-gray-500: #6B7280;
  --color-gray-700: #374151;
  --color-gray-900: #111827;
  --color-white:    #FFFFFF;

  /* Semantic */
  --color-success-bg:   #D1FAE5;
  --color-success-text: #065F46;
  --color-warning-bg:   #FEF3C7;
  --color-warning-text: #92400E;
  --color-danger-bg:    #FEE2E2;
  --color-danger-text:  #991B1B;
  --color-info-bg:      #EFF6FF;
  --color-info-text:    #1E40AF;

  /* Typography */
  --font-ui:   'Inter', system-ui, -apple-system, sans-serif;
  --font-mono: 'DM Mono', 'Courier New', monospace;

  /* Spacing */
  --space-1:  4px;
  --space-2:  8px;
  --space-3:  12px;
  --space-4:  16px;
  --space-5:  20px;
  --space-6:  24px;
  --space-8:  32px;
  --space-10: 40px;
  --space-12: 48px;
  --space-16: 64px;

  /* Border radius */
  --radius-sm:   4px;
  --radius-md:   6px;
  --radius-lg:   8px;
  --radius-xl:   12px;
  --radius-pill: 9999px;

  /* Shadows */
  --shadow-none:  none;
  --shadow-focus: 0 0 0 3px rgba(109, 40, 217, 0.25);

  /* Transitions */
  --transition-fast: 100ms ease;
  --transition-base: 150ms ease;

  /* Layout */
  --content-width: 720px;
  --nav-height: 64px;
}

/* ─────────────────────────────────────────────
   RESET & BASE
───────────────────────────────────────────── */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  font-size: 16px;
  -webkit-text-size-adjust: 100%;
  scroll-behavior: smooth;
}

body {
  font-family: var(--font-ui);
  font-size: 16px;
  line-height: 1.7;
  color: var(--color-gray-500);
  background-color: var(--color-gray-50);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

img, svg { display: block; max-width: 100%; }
a { color: var(--color-purple-600); text-decoration: none; }
a:hover { color: var(--color-purple-700); }
ul, ol { list-style: none; }

/* ─────────────────────────────────────────────
   NAVIGATION
───────────────────────────────────────────── */
.site-nav {
  position: sticky;
  top: 0;
  z-index: 50;
  background: var(--color-white);
  border-bottom: 1px solid var(--color-gray-200);
  height: var(--nav-height);
}

.nav-inner {
  max-width: 1280px;
  margin: 0 auto;
  padding: 0 var(--space-4);
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-4);
}

.nav-logo {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-family: var(--font-ui);
  font-size: 17px;
  font-weight: 800;
  color: var(--color-purple-950);
  text-decoration: none;
  white-space: nowrap;
  flex-shrink: 0;
  letter-spacing: -0.02em;
}

.nav-logo .logo-icon {
  width: 30px;
  height: 30px;
  min-width: 30px;
  min-height: 30px;
  max-width: 30px;
  max-height: 30px;
  flex-shrink: 0;
  display: block;
}

.nav-logo .logo-hq { color: var(--color-purple-700); }
.nav-logo:hover .logo-hq { color: var(--color-purple-800); }

.nav-links {
  display: flex;
  align-items: center;
  gap: var(--space-1);
}

.nav-links a {
  font-size: 14px;
  font-weight: 500;
  color: var(--color-gray-700);
  padding: var(--space-2) var(--space-3);
  border-radius: var(--radius-md);
  transition: background var(--transition-base), color var(--transition-base);
  white-space: nowrap;
}

.nav-links a:hover {
  background: var(--color-purple-50);
  color: var(--color-purple-700);
}

.nav-links a.active {
  color: var(--color-purple-700);
  font-weight: 600;
  background: var(--color-purple-100);
}

.nav-hamburger {
  display: none;
  flex-direction: column;
  gap: 5px;
  cursor: pointer;
  padding: var(--space-2);
  min-width: 44px;
  min-height: 44px;
  align-items: center;
  justify-content: center;
  background: none;
  border: none;
  border-radius: var(--radius-md);
}

.nav-hamburger span {
  display: block;
  width: 22px;
  height: 2px;
  background: var(--color-gray-700);
  border-radius: 2px;
  transition: all var(--transition-base);
}

.nav-mobile-menu {
  display: none;
  position: fixed;
  top: var(--nav-height);
  left: 0;
  right: 0;
  background: var(--color-white);
  border-bottom: 1px solid var(--color-gray-200);
  padding: var(--space-4);
  z-index: 49;
  flex-direction: column;
  gap: var(--space-1);
}

.nav-mobile-menu.open { display: flex; }

.nav-mobile-menu a {
  font-size: 15px;
  font-weight: 500;
  color: var(--color-gray-700);
  padding: 12px var(--space-3);
  border-radius: var(--radius-md);
  min-height: 44px;
  display: flex;
  align-items: center;
}

.nav-mobile-menu a:hover {
  background: var(--color-purple-50);
  color: var(--color-purple-700);
}

@media (max-width: 767px) {
  .nav-links { display: none; }
  .nav-hamburger { display: flex; }
}

/* ─────────────────────────────────────────────
   PAGE WRAPPER & CONTENT
───────────────────────────────────────────── */
.page-wrapper {
  min-height: calc(100vh - var(--nav-height));
}

.content-container {
  max-width: var(--content-width);
  margin: 0 auto;
  padding: 0 var(--space-4);
}

/* ─────────────────────────────────────────────
   BREADCRUMB
───────────────────────────────────────────── */
.breadcrumb {
  padding: var(--space-4) 0 0;
}

.breadcrumb ol {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 4px;
  font-size: 13px;
  color: var(--color-gray-400);
}

.breadcrumb ol li { display: flex; align-items: center; gap: 4px; }
.breadcrumb ol li a { color: var(--color-gray-500); }
.breadcrumb ol li a:hover { color: var(--color-purple-700); }
.breadcrumb ol li.current { font-weight: 600; color: var(--color-gray-700); }

/* ─────────────────────────────────────────────
   PAGE HEADER (H1 + TAGLINE + TRUST PILLS)
───────────────────────────────────────────── */
.page-header {
  padding: var(--space-8) 0 var(--space-6);
  text-align: center;
}

.page-header h1 {
  font-size: clamp(28px, 5vw, 36px);
  font-weight: 800;
  color: var(--color-purple-950);
  line-height: 1.2;
  margin-bottom: var(--space-3);
}

.page-tagline {
  font-size: 17px;
  color: var(--color-gray-500);
  margin-bottom: var(--space-4);
  max-width: 520px;
  margin-left: auto;
  margin-right: auto;
}

.trust-pills {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: var(--space-2);
}

.trust-pill {
  font-size: 11px;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--color-purple-600);
  background: var(--color-purple-50);
  border: 1px solid var(--color-purple-200);
  border-radius: var(--radius-pill);
  padding: 4px 12px;
  min-height: 24px;
  display: inline-flex;
  align-items: center;
}

/* ─────────────────────────────────────────────
   CALCULATOR CARD
───────────────────────────────────────────── */
.calc-card {
  background: var(--color-white);
  border: 1px solid var(--color-gray-200);
  border-radius: var(--radius-lg);
  padding: var(--space-6);
  margin-bottom: var(--space-6);
}

@media (max-width: 767px) {
  .calc-card { padding: var(--space-4); }
}

/* ─────────────────────────────────────────────
   INPUT FIELDS
───────────────────────────────────────────── */
.input-group {
  margin-bottom: var(--space-4);
}

.input-label {
  display: block;
  font-size: 13px;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--color-purple-700);
  margin-bottom: var(--space-2);
}

.input-field {
  width: 100%;
  height: 56px;
  font-family: var(--font-ui);
  font-size: 36px;
  font-weight: 800;
  color: var(--color-gray-900);
  background: var(--color-gray-100);
  border: 1.5px solid var(--color-gray-200);
  border-radius: var(--radius-md);
  padding: 0 var(--space-4);
  transition: border-color var(--transition-base), background var(--transition-base), box-shadow var(--transition-base);
  appearance: none;
  -webkit-appearance: none;
}

.input-field::placeholder { color: var(--color-gray-400); font-weight: 400; font-size: 20px; }

.input-field:focus {
  outline: none;
  background: var(--color-white);
  border-color: var(--color-purple-700);
  box-shadow: var(--shadow-focus);
}

@media (max-width: 767px) {
  .input-field { height: 52px; font-size: 32px; }
}

/* Input grid */
.input-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--space-4);
}

@media (max-width: 767px) {
  .input-grid { grid-template-columns: 1fr; }
}

/* ─────────────────────────────────────────────
   UNIT SELECTOR TABS
───────────────────────────────────────────── */
.unit-tabs {
  display: flex;
  gap: var(--space-1);
  margin-bottom: var(--space-2);
}

.unit-tab {
  flex: 1;
  min-height: 44px;
  font-family: var(--font-ui);
  font-size: 13px;
  font-weight: 500;
  cursor: pointer;
  border: 1px solid var(--color-gray-200);
  border-radius: var(--radius-md);
  background: var(--color-gray-100);
  color: var(--color-gray-700);
  transition: background var(--transition-base), color var(--transition-base), border-color var(--transition-base);
  padding: 0 var(--space-3);
}

.unit-tab.active {
  background: var(--color-purple-700);
  color: var(--color-white);
  border-color: var(--color-purple-700);
  font-weight: 700;
}

.unit-tab:hover:not(.active) {
  background: var(--color-purple-50);
  border-color: var(--color-purple-300);
}

/* ─────────────────────────────────────────────
   BUTTONS
───────────────────────────────────────────── */
.btn-primary {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-2);
  height: 48px;
  padding: 0 var(--space-6);
  min-width: 120px;
  font-family: var(--font-ui);
  font-size: 15px;
  font-weight: 700;
  color: var(--color-white);
  background: var(--color-purple-700);
  border: none;
  border-radius: var(--radius-md);
  cursor: pointer;
  transition: background var(--transition-base), transform var(--transition-fast);
}

.btn-primary:hover { background: var(--color-purple-800); }
.btn-primary:active { background: var(--color-purple-900); transform: scale(0.98); }
.btn-primary:focus-visible { outline: none; box-shadow: 0 0 0 3px rgba(109,40,217,0.3); }

.btn-primary:disabled {
  background: var(--color-purple-400);
  color: var(--color-purple-100);
  cursor: not-allowed;
}

.btn-secondary {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-2);
  height: 48px;
  padding: 0 var(--space-6);
  min-width: 120px;
  font-family: var(--font-ui);
  font-size: 15px;
  font-weight: 700;
  color: var(--color-purple-800);
  background: var(--color-purple-100);
  border: 1px solid var(--color-purple-200);
  border-radius: var(--radius-md);
  cursor: pointer;
  transition: background var(--transition-base);
}

.btn-secondary:hover { background: var(--color-purple-200); }

.btn-row {
  display: flex;
  gap: var(--space-3);
  margin-top: var(--space-5);
}

@media (max-width: 479px) {
  .btn-primary, .btn-secondary { width: 100%; }
  .btn-row { flex-direction: column; }
  .btn-primary { height: 52px; }
}

/* ─────────────────────────────────────────────
   RESULT DISPLAY
───────────────────────────────────────────── */
.result-display {
  background: var(--color-white);
  border: 1px solid var(--color-purple-200);
  border-radius: var(--radius-lg);
  padding: var(--space-6);
  margin-bottom: var(--space-6);
  display: none;
}

.result-display.visible { display: block; }

.result-label {
  font-size: 14px;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--color-purple-600);
  margin-bottom: var(--space-2);
}

.result-number {
  font-family: var(--font-mono);
  font-size: 48px;
  font-weight: 800;
  color: var(--color-gray-900);
  line-height: 1;
  margin-bottom: var(--space-3);
}

@media (max-width: 767px) {
  .result-number { font-size: 36px; }
}

.result-badge {
  display: inline-flex;
  align-items: center;
  padding: 4px 14px;
  border-radius: var(--radius-pill);
  font-size: 11px;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  min-height: 24px;
}

.result-badge.success { background: var(--color-success-bg); color: var(--color-success-text); }
.result-badge.warning { background: var(--color-warning-bg); color: var(--color-warning-text); }
.result-badge.danger  { background: var(--color-danger-bg);  color: var(--color-danger-text); }
.result-badge.info    { background: var(--color-info-bg);    color: var(--color-info-text); }

.result-subtext {
  font-size: 14px;
  color: var(--color-gray-500);
  margin-top: var(--space-3);
  line-height: 1.5;
}

/* BMI Classification Bar */
.bmi-bar-container {
  margin-top: var(--space-5);
}

.bmi-bar-label {
  font-size: 13px;
  font-weight: 600;
  color: var(--color-gray-700);
  margin-bottom: var(--space-2);
  text-transform: uppercase;
  letter-spacing: 0.04em;
}

.bmi-bar {
  position: relative;
  height: 12px;
  border-radius: var(--radius-pill);
  background: linear-gradient(
    to right,
    #3B82F6 0%, #3B82F6 20%,       /* Underweight */
    #10B981 20%, #10B981 46%,       /* Normal */
    #F59E0B 46%, #F59E0B 66%,       /* Overweight */
    #EF4444 66%, #EF4444 80%,       /* Obese I */
    #DC2626 80%, #DC2626 91%,       /* Obese II */
    #991B1B 91%, #991B1B 100%       /* Obese III */
  );
  margin-bottom: var(--space-3);
}

.bmi-bar-marker {
  position: absolute;
  top: -4px;
  width: 20px;
  height: 20px;
  background: var(--color-white);
  border: 3px solid var(--color-purple-700);
  border-radius: 50%;
  transform: translateX(-50%);
  transition: left 0.4s ease;
  box-shadow: 0 2px 6px rgba(0,0,0,0.15);
}

.bmi-bar-labels {
  display: flex;
  justify-content: space-between;
  font-size: 11px;
  color: var(--color-gray-400);
}

/* ─────────────────────────────────────────────
   SLIDERS
───────────────────────────────────────────── */
.slider-group {
  margin-bottom: var(--space-4);
}

.slider-value-display {
  font-family: var(--font-mono);
  font-size: 36px;
  font-weight: 800;
  color: var(--color-gray-900);
  margin-bottom: var(--space-2);
  display: block;
}

@media (max-width: 767px) { .slider-value-display { font-size: 32px; } }

input[type="range"] {
  -webkit-appearance: none;
  appearance: none;
  width: 100%;
  height: 6px;
  border-radius: var(--radius-pill);
  background: var(--color-gray-200);
  cursor: pointer;
  outline: none;
}

input[type="range"]::-webkit-slider-thumb {
  -webkit-appearance: none;
  appearance: none;
  width: 24px;
  height: 24px;
  border-radius: 50%;
  background: var(--color-purple-700);
  cursor: pointer;
  border: 3px solid var(--color-white);
  box-shadow: 0 1px 4px rgba(0,0,0,0.2);
  transition: background var(--transition-base);
}

input[type="range"]::-moz-range-thumb {
  width: 24px;
  height: 24px;
  border-radius: 50%;
  background: var(--color-purple-700);
  cursor: pointer;
  border: 3px solid var(--color-white);
  box-shadow: 0 1px 4px rgba(0,0,0,0.2);
}

input[type="range"]:focus-visible::-webkit-slider-thumb {
  box-shadow: 0 0 0 3px rgba(109, 40, 217, 0.3);
}

@media (max-width: 767px) {
  input[type="range"]::-webkit-slider-thumb { width: 28px; height: 28px; }
}

/* ─────────────────────────────────────────────
   AI ASSISTANT SECTION
───────────────────────────────────────────── */
.ai-section {
  background: var(--color-white);
  border: 1px solid var(--color-gray-200);
  border-radius: var(--radius-lg);
  padding: var(--space-6);
  margin-bottom: var(--space-6);
}

.ai-section-heading {
  font-size: 20px;
  font-weight: 600;
  color: var(--color-gray-900);
  margin-bottom: var(--space-4);
  display: flex;
  align-items: center;
  gap: var(--space-2);
}

.ai-section-heading svg {
  flex-shrink: 0;
  color: var(--color-purple-700);
}

.ai-input-row {
  display: flex;
  gap: var(--space-3);
  margin-bottom: var(--space-4);
}

.ai-text-input {
  flex: 1;
  height: 48px;
  font-family: var(--font-ui);
  font-size: 15px;
  color: var(--color-gray-900);
  background: var(--color-gray-100);
  border: 1.5px solid var(--color-gray-200);
  border-radius: var(--radius-md);
  padding: 0 var(--space-4);
  transition: border-color var(--transition-base), background var(--transition-base), box-shadow var(--transition-base);
}

.ai-text-input::placeholder { color: var(--color-gray-400); }

.ai-text-input:focus {
  outline: none;
  background: var(--color-white);
  border-color: var(--color-purple-700);
  box-shadow: var(--shadow-focus);
}

.ai-response-area {
  background: var(--color-white);
  border: 1px solid var(--color-purple-200);
  border-left: 4px solid var(--color-purple-700);
  border-radius: 0 var(--radius-md) var(--radius-md) 0;
  padding: var(--space-5);
  font-size: 15px;
  line-height: 1.75;
  color: var(--color-gray-700);
  display: none;
  margin-top: var(--space-3);
}

.ai-response-area.visible { display: block; }

.ai-response-area.loading {
  color: var(--color-gray-400);
  font-style: italic;
  border-left-color: var(--color-gray-300);
}

/* Prose inside AI response */
.ai-response-area p {
  margin: 0 0 var(--space-3) 0;
  color: var(--color-gray-700);
  font-size: 15px;
  line-height: 1.75;
}

.ai-response-area p:last-child { margin-bottom: 0; }

.ai-response-area strong {
  font-weight: 700;
  color: var(--color-gray-900);
}

.ai-response-area em {
  font-style: italic;
  color: var(--color-gray-600);
}

/* AI disclaimer note styling */
.ai-response-area .ai-note {
  display: block;
  margin-top: var(--space-4);
  padding: var(--space-3) var(--space-4);
  background: var(--color-gray-50);
  border-radius: var(--radius-md);
  font-size: 13px;
  color: var(--color-gray-500);
  border: 1px solid var(--color-gray-200);
  font-style: normal;
}

@media (max-width: 479px) {
  .ai-input-row { flex-direction: column; }
  .ai-text-input { width: 100%; }
}

/* ─────────────────────────────────────────────
   ADSENSE SLOTS
───────────────────────────────────────────── */
.adsense-slot {
  min-height: 90px;
  background: var(--color-white);
  border: 1px dashed var(--color-gray-200);
  border-radius: var(--radius-md);
  margin: var(--space-6) 0;
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--color-gray-400);
  font-size: 13px;
  padding: var(--space-2);
}

/* ─────────────────────────────────────────────
   SEO CONTENT SECTION
───────────────────────────────────────────── */
.seo-content {
  padding: var(--space-8) 0;
}

.seo-content h2 {
  font-size: 24px;
  font-weight: 700;
  color: var(--color-purple-900);
  margin-bottom: var(--space-4);
  margin-top: var(--space-8);
  padding-top: var(--space-8);
  border-top: 1px solid var(--color-gray-200);
}

.seo-content h2:first-child {
  margin-top: 0;
  padding-top: 0;
  border-top: none;
}

.seo-content h3 {
  font-size: 20px;
  font-weight: 600;
  color: var(--color-gray-900);
  margin-bottom: var(--space-3);
  margin-top: var(--space-5);
}

.seo-content p {
  font-size: 16px;
  color: var(--color-gray-500);
  line-height: 1.7;
  margin-bottom: var(--space-4);
}

.seo-content ul, .seo-content ol {
  margin-bottom: var(--space-4);
  padding-left: var(--space-5);
}

.seo-content ul { list-style: disc; }
.seo-content ol { list-style: decimal; }

.seo-content li {
  font-size: 16px;
  color: var(--color-gray-500);
  line-height: 1.7;
  margin-bottom: var(--space-2);
}

.seo-content strong { color: var(--color-gray-900); font-weight: 600; }

.formula-block {
  background: var(--color-gray-100);
  border-left: 3px solid var(--color-purple-700);
  border-radius: 0 var(--radius-md) var(--radius-md) 0;
  padding: var(--space-4) var(--space-5);
  margin: var(--space-4) 0;
  font-family: var(--font-mono);
  font-size: 15px;
  color: var(--color-purple-900);
}

/* Classification Table */
.classification-table {
  width: 100%;
  border-collapse: collapse;
  margin: var(--space-4) 0;
  font-size: 15px;
}

.classification-table th {
  text-align: left;
  font-size: 13px;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--color-gray-700);
  padding: var(--space-2) var(--space-3);
  border-bottom: 2px solid var(--color-gray-200);
}

.classification-table td {
  padding: var(--space-3);
  border-bottom: 1px solid var(--color-gray-200);
  color: var(--color-gray-700);
}

.classification-table tr:last-child td { border-bottom: none; }

.class-badge {
  display: inline-block;
  padding: 2px 10px;
  border-radius: var(--radius-pill);
  font-size: 12px;
  font-weight: 700;
}

.class-badge.success { background: var(--color-success-bg); color: var(--color-success-text); }
.class-badge.warning { background: var(--color-warning-bg); color: var(--color-warning-text); }
.class-badge.danger  { background: var(--color-danger-bg);  color: var(--color-danger-text); }
.class-badge.info    { background: var(--color-info-bg);    color: var(--color-info-text); }

/* ─────────────────────────────────────────────
   FAQ — Pure HTML details/summary accordion
   Zero JavaScript required. Works everywhere.
───────────────────────────────────────────── */
.faq-list { margin: var(--space-4) 0; }

.faq-item {
  border-bottom: 1px solid var(--color-gray-200);
}

/* Remove default details marker */
.faq-item summary {
  list-style: none;
}
.faq-item summary::-webkit-details-marker { display: none; }
.faq-item summary::marker { display: none; }

.faq-question {
  width: 100%;
  padding: var(--space-4) 0;
  font-family: var(--font-ui);
  font-size: 16px;
  font-weight: 600;
  color: var(--color-gray-900);
  cursor: pointer;
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: var(--space-4);
  min-height: 44px;
  user-select: none;
  -webkit-user-select: none;
}

.faq-question:hover { color: var(--color-purple-700); }

.faq-icon {
  flex-shrink: 0;
  width: 20px;
  height: 20px;
  color: var(--color-purple-700);
  transition: transform var(--transition-base);
}

/* Rotate icon when open */
details.faq-item[open] .faq-icon { transform: rotate(45deg); }

.faq-answer {
  padding: 0 0 var(--space-4);
  font-size: 15px;
  color: var(--color-gray-500);
  line-height: 1.7;
}



/* ─────────────────────────────────────────────
   DISCLAIMER
───────────────────────────────────────────── */
.disclaimer {
  background: var(--color-warning-bg);
  border: 1px solid #FDE68A;
  border-radius: var(--radius-md);
  padding: var(--space-4);
  font-size: 13px;
  color: var(--color-warning-text);
  line-height: 1.6;
  margin: var(--space-6) 0;
}

.last-updated {
  font-size: 13px;
  color: var(--color-gray-400);
  margin-top: var(--space-4);
}

/* ─────────────────────────────────────────────
   RELATED CALCULATORS GRID
───────────────────────────────────────────── */
.related-section {
  padding: var(--space-8) 0;
  border-top: 1px solid var(--color-gray-200);
}

.related-section h2 {
  font-size: 22px;
  font-weight: 700;
  color: var(--color-purple-950);
  margin-bottom: var(--space-5);
}

.related-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--space-4);
}

@media (max-width: 767px) { .related-grid { grid-template-columns: repeat(2, 1fr); } }
@media (max-width: 479px) { .related-grid { grid-template-columns: 1fr; } }

.related-card {
  background: var(--color-white);
  border: 1px solid var(--color-gray-200);
  border-radius: var(--radius-lg);
  padding: var(--space-4);
  text-decoration: none;
  transition: background var(--transition-base), border-color var(--transition-base), transform var(--transition-base);
  display: flex;
  flex-direction: column;
  gap: var(--space-2);
}

.related-card:hover {
  background: var(--color-purple-50);
  border-color: var(--color-purple-200);
  transform: translateY(-2px);
  color: inherit;
}

.related-card-icon {
  width: 36px;
  height: 36px;
  color: var(--color-purple-700);
}

.related-card-name {
  font-size: 14px;
  font-weight: 600;
  color: var(--color-gray-900);
}

.related-card-desc {
  font-size: 12px;
  color: var(--color-gray-500);
  line-height: 1.5;
}

/* ─────────────────────────────────────────────
   FOOTER
───────────────────────────────────────────── */
.site-footer {
  background: var(--color-white);
  border-top: 1px solid var(--color-gray-200);
  padding: var(--space-10) 0;
  margin-top: var(--space-8);
}

.footer-inner {
  max-width: 1280px;
  margin: 0 auto;
  padding: 0 var(--space-4);
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: var(--space-8);
}

@media (max-width: 767px) {
  .footer-inner { grid-template-columns: 1fr 1fr; }
}

@media (max-width: 479px) {
  .footer-inner { grid-template-columns: 1fr; }
}

.footer-brand .footer-logo {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-size: 17px;
  font-weight: 800;
  color: var(--color-purple-950);
  letter-spacing: -0.02em;
  display: inline-block;
  margin-bottom: var(--space-3);
}

.footer-brand p {
  font-size: 13px;
  color: var(--color-gray-400);
  line-height: 1.6;
  max-width: 260px;
}

.footer-col h4 {
  font-size: 13px;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--color-gray-700);
  margin-bottom: var(--space-3);
}

.footer-col ul { display: flex; flex-direction: column; gap: var(--space-2); }

.footer-col ul li a {
  font-size: 13px;
  color: var(--color-gray-400);
}

.footer-col ul li a:hover { color: var(--color-purple-700); }

.footer-bottom {
  max-width: 1280px;
  margin: var(--space-8) auto 0;
  padding: var(--space-4) var(--space-4) 0;
  border-top: 1px solid var(--color-gray-200);
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: var(--space-3);
  font-size: 13px;
  color: var(--color-gray-400);
}

/* ─────────────────────────────────────────────
   HOMEPAGE — HERO
───────────────────────────────────────────── */
.hero-section {
  background: var(--color-white);
  border-bottom: 1px solid var(--color-gray-200);
  padding: var(--space-16) 0;
  text-align: center;
}

.hero-inner {
  max-width: var(--content-width);
  margin: 0 auto;
  padding: 0 var(--space-4);
}

.hero-section h1 {
  font-size: clamp(32px, 6vw, 52px);
  font-weight: 800;
  color: var(--color-purple-950);
  line-height: 1.15;
  margin-bottom: var(--space-5);
}

.hero-section h1 span { color: var(--color-purple-700); }

.hero-tagline {
  font-size: 18px;
  color: var(--color-gray-500);
  max-width: 500px;
  margin: 0 auto var(--space-6);
  line-height: 1.6;
}

.hero-illustration {
  margin: var(--space-8) auto;
  max-width: 480px;
}

/* ─────────────────────────────────────────────
   HOMEPAGE — CATEGORY GRID
───────────────────────────────────────────── */
.categories-section {
  padding: var(--space-16) 0;
}

.categories-inner {
  max-width: 1100px;
  margin: 0 auto;
  padding: 0 var(--space-4);
}

.section-heading {
  font-size: 28px;
  font-weight: 800;
  color: var(--color-purple-950);
  margin-bottom: var(--space-2);
}

.section-subheading {
  font-size: 16px;
  color: var(--color-gray-500);
  margin-bottom: var(--space-8);
}

.category-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: var(--space-4);
}

@media (max-width: 1023px) { .category-grid { grid-template-columns: repeat(3, 1fr); } }
@media (max-width: 767px)  { .category-grid { grid-template-columns: repeat(2, 1fr); } }
@media (max-width: 400px)  { .category-grid { grid-template-columns: 1fr; } }

.category-card {
  background: var(--color-white);
  border: 1px solid var(--color-gray-200);
  border-radius: var(--radius-lg);
  padding: var(--space-5);
  text-decoration: none;
  transition: background var(--transition-base), border-color var(--transition-base), transform var(--transition-base);
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  gap: var(--space-3);
}

.category-card:hover {
  background: var(--color-purple-50);
  border-color: var(--color-purple-200);
  transform: translateY(-2px);
  color: inherit;
}

.category-icon {
  width: 44px;
  height: 44px;
  color: var(--color-purple-700);
}

.category-card-name {
  font-size: 16px;
  font-weight: 700;
  color: var(--color-gray-900);
}

.category-card-desc {
  font-size: 13px;
  color: var(--color-gray-500);
  line-height: 1.5;
}

.category-card-count {
  font-size: 12px;
  font-weight: 600;
  color: var(--color-purple-600);
  margin-top: auto;
}

/* ─────────────────────────────────────────────
   HOMEPAGE — FEATURED CALCULATORS
───────────────────────────────────────────── */
.featured-section {
  padding: var(--space-12) 0 var(--space-16);
  background: var(--color-gray-50);
  border-top: 1px solid var(--color-gray-200);
}

.featured-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--space-4);
}

@media (max-width: 767px) { .featured-grid { grid-template-columns: repeat(2, 1fr); } }
@media (max-width: 479px) { .featured-grid { grid-template-columns: 1fr; } }

.featured-card {
  background: var(--color-white);
  border: 1px solid var(--color-gray-200);
  border-radius: var(--radius-lg);
  padding: var(--space-5);
  text-decoration: none;
  transition: all var(--transition-base);
  display: flex;
  flex-direction: column;
  gap: var(--space-3);
}

.featured-card:hover {
  border-color: var(--color-purple-300);
  transform: translateY(-2px);
  box-shadow: 0 4px 16px rgba(109, 40, 217, 0.08);
  color: inherit;
}

.featured-card-icon {
  width: 40px;
  height: 40px;
  color: var(--color-purple-700);
}

.featured-card-name {
  font-size: 15px;
  font-weight: 700;
  color: var(--color-gray-900);
}

.featured-card-desc {
  font-size: 13px;
  color: var(--color-gray-500);
  line-height: 1.5;
  flex: 1;
}

.featured-card-tag {
  font-size: 11px;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--color-purple-600);
}

/* ─────────────────────────────────────────────
   PAGE ILLUSTRATION
───────────────────────────────────────────── */
.page-illustration {
  margin: 0 auto var(--space-6);
  max-width: 300px;
  display: flex;
  justify-content: center;
}

/* Label + unit tabs on same row */
.label-unit-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: var(--space-2);
}

.label-unit-row .input-label {
  margin-bottom: 0;
}

/* Small compact unit tabs (cm/ft, kg/lbs) */
.unit-tabs-sm {
  gap: 3px;
}

.unit-tabs-sm .unit-tab {
  min-height: 28px;
  height: 28px;
  font-size: 12px;
  padding: 0 10px;
  flex: none;
}

/* BMI gauge needle animation */
#bmi-needle {
  transition: transform 0.55s cubic-bezier(0.34, 1.4, 0.64, 1);
}

/* Slider + number input side by side */
.slider-input-row {
  display: flex;
  align-items: center;
  gap: var(--space-2);
}

.slider-input-row .input-field {
  flex: 1;
  min-width: 0;
}

.input-unit-label {
  font-size: 14px;
  font-weight: 600;
  color: var(--color-purple-600);
  white-space: nowrap;
  flex-shrink: 0;
}

.imperial-height-row {
  display: flex;
  gap: var(--space-3);
}

.slider-range-hint {
  display: flex;
  justify-content: space-between;
  font-size: 11px;
  color: var(--color-gray-400);
  margin-top: 4px;
  padding: 0 2px;
}

.mt-2 { margin-top: 8px; }

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

.text-center { text-align: center; }
.mt-4 { margin-top: var(--space-4); }
.mt-6 { margin-top: var(--space-6); }
.mb-4 { margin-bottom: var(--space-4); }
.mb-6 { margin-bottom: var(--space-6); }