/* ============================================================
   Insulin Calculator — Global Design System
   insulin-calculator.org
   ============================================================ */

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

/* ── Design Tokens ── */
:root {
  --bg-primary:      #F8FAFB;
  --bg-surface:      #FFFFFF;
  --bg-elevated:     #F1F5F9;
  --bg-secondary:    #F1F5F9;
  --warning:         #B45309;
  --text-primary:    #1A2530;
  --text-secondary:  #5A6B7B;
  --accent-primary:  #0E7C86;
  --accent-hover:    #0A6570;
  --accent-result:   #0369A1;
  --warn:            #B45309;
  --warn-bg:         #FFFBEB;
  --warn-border:     #FCD34D;
  --danger:          #B91C1C;
  --danger-bg:       #FEF2F2;
  --success:         #15803D;
  --success-bg:      #F0FDF4;
  --border:          #D7E0E6;
  --border-focus:    rgba(14,124,134,0.45);
  --shadow-sm:       0 1px 3px rgba(0,0,0,0.08);
  --shadow-md:       0 4px 16px rgba(0,0,0,0.10);
  --radius-sm:       6px;
  --radius-md:       10px;
  --radius-lg:       14px;
  --transition:      150ms ease-out;
}

[data-theme="dark"] {
  --bg-primary:      #0D1117;
  --bg-surface:      #161B22;
  --bg-elevated:     #21262D;
  --bg-secondary:    #21262D;
  --warning:         #F59E0B;
  --text-primary:    #E6EDF3;
  --text-secondary:  #8B949E;
  --accent-primary:  #2DD4BF;
  --accent-hover:    #5EEAD4;
  --accent-result:   #38BDF8;
  --warn:            #F59E0B;
  --warn-bg:         #1c1506;
  --warn-border:     #78350F;
  --danger:          #F87171;
  --danger-bg:       #1c0505;
  --success:         #4ADE80;
  --success-bg:      #052011;
  --border:          #30363D;
  --border-focus:    rgba(45,212,191,0.45);
  --shadow-sm:       0 1px 3px rgba(0,0,0,0.30);
  --shadow-md:       0 4px 16px rgba(0,0,0,0.40);
}

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

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

body {
  font-family: 'Inter', system-ui, -apple-system, sans-serif;
  font-size: 1rem;
  line-height: 1.65;
  color: var(--text-primary);
  background: var(--bg-primary);
  transition: background var(--transition), color var(--transition);
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

img { max-width: 100%; height: auto; display: block; }
a { color: var(--accent-primary); text-decoration: none; }
a:hover { color: var(--accent-hover); text-decoration: underline; }
ul, ol { padding-left: 1.4em; }

/* ── Typography ── */
h1 { font-size: clamp(1.75rem, 4vw, 2.5rem); font-weight: 700; line-height: 1.2; letter-spacing: -0.02em; }
h2 { font-size: clamp(1.35rem, 3vw, 1.75rem); font-weight: 700; line-height: 1.25; letter-spacing: -0.01em; }
h3 { font-size: clamp(1.1rem, 2.5vw, 1.3rem); font-weight: 600; line-height: 1.3; }
h4 { font-size: 1.05rem; font-weight: 600; }
h5 { font-size: 0.95rem; font-weight: 600; }
p { margin-bottom: 1rem; }
p:last-child { margin-bottom: 0; }
strong { font-weight: 600; }

.mono { font-family: 'JetBrains Mono', 'Courier New', monospace; font-weight: 600; }

/* ── Layout Utilities ── */
.container { width: 100%; max-width: 960px; margin: 0 auto; padding: 0 1.25rem; }
.container--wide { max-width: 1200px; }
.container--narrow { max-width: 720px; }

.flex { display: flex; }
.flex-col { flex-direction: column; }
.items-center { align-items: center; }
.justify-between { justify-content: space-between; }
.gap-1 { gap: 0.5rem; }
.gap-2 { gap: 1rem; }
.gap-3 { gap: 1.5rem; }
.gap-4 { gap: 2rem; }

.grid-2 { display: grid; grid-template-columns: repeat(2, 1fr); gap: 1.25rem; }
.grid-3 { display: grid; grid-template-columns: repeat(3, 1fr); gap: 1.25rem; }
.grid-4 { display: grid; grid-template-columns: repeat(4, 1fr); gap: 1.25rem; }

.text-center { text-align: center; }
.text-sm { font-size: 0.875rem; }
.text-xs { font-size: 0.78rem; }
.text-secondary { color: var(--text-secondary); }
.text-accent { color: var(--accent-primary); }
.text-warn { color: var(--warn); }
.text-danger { color: var(--danger); }

.mt-1 { margin-top: 0.5rem; }
.mt-2 { margin-top: 1rem; }
.mt-3 { margin-top: 1.5rem; }
.mt-4 { margin-top: 2rem; }
.mb-1 { margin-bottom: 0.5rem; }
.mb-2 { margin-bottom: 1rem; }
.mb-3 { margin-bottom: 1.5rem; }
.mb-4 { margin-bottom: 2rem; }

.hidden { display: none !important; }

/* ── Header / Navigation ── */
.site-header {
  background: var(--bg-surface);
  border-bottom: 1px solid var(--border);
  position: sticky;
  top: 0;
  z-index: 100;
  box-shadow: var(--shadow-sm);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 64px;
  gap: 1.5rem;
}

.logo {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  text-decoration: none;
  flex-shrink: 0;
}

.logo-icon {
  width: 36px;
  height: 36px;
  background: var(--accent-primary);
  border-radius: var(--radius-sm);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.2rem;
  color: #fff;
  flex-shrink: 0;
}

.logo-text {
  font-size: 1.05rem;
  font-weight: 700;
  color: var(--text-primary);
  line-height: 1.1;
}

.logo-text span {
  display: block;
  font-size: 0.7rem;
  font-weight: 500;
  color: var(--text-secondary);
  letter-spacing: 0.04em;
}

.main-nav {
  display: flex;
  align-items: center;
  gap: 0.25rem;
  flex-wrap: nowrap;
}

.nav-link {
  font-size: 0.88rem;
  font-weight: 500;
  color: var(--text-secondary);
  padding: 0.4rem 0.7rem;
  border-radius: var(--radius-sm);
  text-decoration: none;
  white-space: nowrap;
  transition: color var(--transition), background var(--transition);
}

.nav-link:hover,
.nav-link.active {
  color: var(--accent-primary);
  background: var(--bg-elevated);
  text-decoration: none;
}

.header-actions {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  flex-shrink: 0;
}

/* Dark mode toggle */
.theme-toggle {
  background: var(--bg-elevated);
  border: 1px solid var(--border);
  border-radius: 20px;
  cursor: pointer;
  width: 40px;
  height: 24px;
  position: relative;
  transition: background var(--transition);
  flex-shrink: 0;
}

.theme-toggle::after {
  content: '';
  position: absolute;
  top: 3px;
  left: 3px;
  width: 16px;
  height: 16px;
  background: var(--text-secondary);
  border-radius: 50%;
  transition: transform var(--transition), background var(--transition);
}

[data-theme="dark"] .theme-toggle::after {
  transform: translateX(16px);
  background: var(--accent-primary);
}

.theme-toggle:focus-visible {
  outline: none;
  box-shadow: 0 0 0 3px var(--border-focus);
}

/* Mobile menu button */
.menu-toggle {
  display: none;
  background: none;
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  padding: 0.4rem;
  cursor: pointer;
  color: var(--text-primary);
  align-items: center;
  justify-content: center;
  width: 36px;
  height: 36px;
}

/* ── Footer ── */
.site-footer {
  background: var(--bg-surface);
  border-top: 1px solid var(--border);
  margin-top: auto;
}

.footer-top {
  padding: 2.5rem 0 2rem;
}

.footer-grid {
  display: grid;
  grid-template-columns: 1.8fr 1fr 1fr 1fr;
  gap: 2rem;
}

.footer-brand p {
  font-size: 0.875rem;
  color: var(--text-secondary);
  margin-top: 0.75rem;
  max-width: 280px;
}

.footer-col h4 {
  font-size: 0.8rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--text-secondary);
  margin-bottom: 0.75rem;
}

.footer-col ul {
  list-style: none;
  padding: 0;
}

.footer-col li {
  margin-bottom: 0.45rem;
}

.footer-col a {
  font-size: 0.875rem;
  color: var(--text-secondary);
  text-decoration: none;
  transition: color var(--transition);
}

.footer-col a:hover {
  color: var(--accent-primary);
}

.footer-disclaimer {
  background: var(--warn-bg);
  border-top: 1px solid var(--warn-border);
  padding: 0.9rem 0;
}

.footer-disclaimer p {
  font-size: 0.78rem;
  color: var(--warn);
  text-align: center;
  margin: 0;
  line-height: 1.5;
}

.footer-bottom {
  padding: 1rem 0;
  border-top: 1px solid var(--border);
}

.footer-bottom-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  flex-wrap: wrap;
}

.footer-bottom p {
  font-size: 0.8rem;
  color: var(--text-secondary);
  margin: 0;
}

/* ── Breadcrumbs ── */
.breadcrumbs {
  padding: 0.65rem 0;
  font-size: 0.8rem;
  color: var(--text-secondary);
}

.breadcrumbs ol {
  list-style: none;
  padding: 0;
  display: flex;
  flex-wrap: wrap;
  gap: 0.25rem;
  align-items: center;
}

.breadcrumbs li + li::before {
  content: '/';
  margin-right: 0.25rem;
  color: var(--border);
}

.breadcrumbs a {
  color: var(--text-secondary);
  text-decoration: none;
}

.breadcrumbs a:hover { color: var(--accent-primary); }
.breadcrumbs [aria-current="page"] { color: var(--text-primary); }

/* ── Disclaimer Banner ── */
.disclaimer-banner {
  background: var(--warn-bg);
  border: 1px solid var(--warn-border);
  border-radius: var(--radius-md);
  padding: 0.85rem 1.1rem;
  display: flex;
  gap: 0.75rem;
  align-items: flex-start;
}

.disclaimer-banner--bottom {
  margin-top: 2rem;
}

.disclaimer-banner .icon {
  font-size: 1.1rem;
  flex-shrink: 0;
  margin-top: 0.1rem;
}

.disclaimer-banner p {
  font-size: 0.82rem;
  color: var(--warn);
  margin: 0;
  line-height: 1.55;
}

.disclaimer-banner strong {
  color: var(--warn);
}

/* ── Hero / Page Header ── */
.page-hero {
  padding: 2.5rem 0 2rem;
  border-bottom: 1px solid var(--border);
}

.page-hero h1 {
  margin-bottom: 0.5rem;
}

.page-hero .subtitle {
  font-size: 1.05rem;
  color: var(--text-secondary);
  max-width: 620px;
  margin: 0;
}

/* Centered hero variant — used on the tools hub and category pages */
.page-hero--center { text-align: center; }
.page-hero--center .subtitle { max-width: 720px; margin-left: auto; margin-right: auto; }

/* ── Calculator Panel ── */
.calc-panel {
  background: var(--bg-surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 1.75rem;
  box-shadow: var(--shadow-md);
}

.calc-panel h2 {
  font-size: 1.15rem;
  margin-bottom: 1.25rem;
  padding-bottom: 0.75rem;
  border-bottom: 1px solid var(--border);
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

/* Input groups */
.input-group {
  margin-bottom: 1.1rem;
}

.input-group label {
  display: block;
  font-size: 0.85rem;
  font-weight: 500;
  color: var(--text-secondary);
  margin-bottom: 0.35rem;
}

.input-row {
  display: flex;
  gap: 0.5rem;
  align-items: stretch;
}

.input-row input,
.input-row select {
  flex: 1;
}

input[type="number"],
input[type="text"],
input[type="email"],
textarea,
select {
  width: 100%;
  padding: 0.6rem 0.85rem;
  border: 1.5px solid var(--border);
  border-radius: var(--radius-sm);
  background: var(--bg-primary);
  color: var(--text-primary);
  font-family: inherit;
  font-size: 0.95rem;
  transition: border-color var(--transition), box-shadow var(--transition);
  -moz-appearance: textfield;
  appearance: auto;
}

input[type="number"]::-webkit-inner-spin-button,
input[type="number"]::-webkit-outer-spin-button { opacity: 1; }

input:focus,
select:focus,
textarea:focus {
  outline: none;
  border-color: var(--accent-primary);
  box-shadow: 0 0 0 3px var(--border-focus);
}

input.input-error {
  border-color: var(--danger);
  box-shadow: 0 0 0 3px rgba(185,28,28,0.15);
}

input.input-valid {
  border-color: var(--success);
}

.input-error-msg {
  font-size: 0.78rem;
  color: var(--danger);
  margin-top: 0.3rem;
  display: none;
}

.input-error-msg.visible { display: block; }

/* Unit toggle pills */
.unit-toggle {
  display: inline-flex;
  border: 1.5px solid var(--border);
  border-radius: var(--radius-sm);
  overflow: hidden;
  flex-shrink: 0;
}

.unit-toggle button {
  background: var(--bg-primary);
  border: none;
  padding: 0.6rem 0.9rem;
  font-size: 0.82rem;
  font-weight: 500;
  color: var(--text-secondary);
  cursor: pointer;
  transition: background var(--transition), color var(--transition);
}

.unit-toggle button.active {
  background: var(--accent-primary);
  color: #fff;
}

.unit-toggle button:hover:not(.active) {
  background: var(--bg-elevated);
}

.unit-toggle button:focus-visible {
  outline: none;
  box-shadow: 0 0 0 3px var(--border-focus);
  z-index: 1;
  position: relative;
}

/* Calc grid */
.calc-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1rem;
}

/* Result box */
.result-box {
  background: var(--bg-elevated);
  border: 1.5px solid var(--border);
  border-radius: var(--radius-md);
  padding: 1.25rem 1.5rem;
  margin-top: 1.25rem;
  display: none;
}

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

.result-box h3 {
  font-size: 0.8rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--text-secondary);
  margin-bottom: 1rem;
}

.result-primary {
  display: flex;
  align-items: baseline;
  gap: 0.4rem;
  margin-bottom: 0.25rem;
}

.result-value {
  font-family: 'JetBrains Mono', monospace;
  font-size: 2.2rem;
  font-weight: 600;
  color: var(--accent-result);
  line-height: 1;
}

.result-unit {
  font-size: 1rem;
  font-weight: 500;
  color: var(--text-secondary);
}

.result-label {
  font-size: 0.82rem;
  color: var(--text-secondary);
  margin-bottom: 1.25rem;
}

.result-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 0.75rem;
  margin-top: 1rem;
  padding-top: 1rem;
  border-top: 1px solid var(--border);
}

.result-item {
  background: var(--bg-surface);
  border-radius: var(--radius-sm);
  padding: 0.75rem 1rem;
  text-align: center;
}

.result-item-value {
  font-family: 'JetBrains Mono', monospace;
  font-size: 1.35rem;
  font-weight: 600;
  color: var(--accent-result);
  display: block;
}

.result-item-label {
  font-size: 0.75rem;
  color: var(--text-secondary);
  display: block;
  margin-top: 0.2rem;
  line-height: 1.3;
}

.result-formula {
  background: var(--bg-primary);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  padding: 0.75rem 1rem;
  margin-top: 1rem;
  font-size: 0.8rem;
  color: var(--text-secondary);
}

.result-formula code {
  font-family: 'JetBrains Mono', monospace;
  font-size: 0.8rem;
  color: var(--accent-primary);
}

.result-warning {
  background: var(--warn-bg);
  border: 1px solid var(--warn-border);
  border-radius: var(--radius-sm);
  padding: 0.6rem 0.85rem;
  margin-top: 0.75rem;
  font-size: 0.78rem;
  color: var(--warn);
}

/* Calc actions */
.calc-actions {
  display: flex;
  gap: 0.75rem;
  margin-top: 1.25rem;
  flex-wrap: wrap;
}

/* ── Buttons ── */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  padding: 0.65rem 1.25rem;
  border-radius: var(--radius-sm);
  font-family: inherit;
  font-size: 0.9rem;
  font-weight: 600;
  cursor: pointer;
  border: 1.5px solid transparent;
  text-decoration: none;
  transition: background var(--transition), color var(--transition), border-color var(--transition), box-shadow var(--transition);
  white-space: nowrap;
}

.btn:focus-visible {
  outline: none;
  box-shadow: 0 0 0 3px var(--border-focus);
}

.btn-primary {
  background: var(--accent-primary);
  color: #fff;
  border-color: var(--accent-primary);
}

.btn-primary:hover {
  background: var(--accent-hover);
  border-color: var(--accent-hover);
  text-decoration: none;
  color: #fff;
}

.btn-secondary {
  background: transparent;
  color: var(--accent-primary);
  border-color: var(--accent-primary);
}

.btn-secondary:hover {
  background: var(--bg-elevated);
  text-decoration: none;
}

.btn-ghost {
  background: transparent;
  color: var(--text-secondary);
  border-color: var(--border);
}

.btn-ghost:hover {
  background: var(--bg-elevated);
  color: var(--text-primary);
  text-decoration: none;
}

.btn-sm {
  padding: 0.4rem 0.85rem;
  font-size: 0.82rem;
}

.btn-lg {
  padding: 0.85rem 1.75rem;
  font-size: 1rem;
}

.btn-block { width: 100%; justify-content: center; }

/* ── Main Content Layout ── */
.page-main {
  flex: 1;
  padding: 1.5rem 0 3rem;
}

.content-with-sidebar {
  display: grid;
  grid-template-columns: 1fr 300px;
  gap: 2rem;
  align-items: start;
}

.page-content { min-width: 0; }

/* ── Section Spacing ── */
.section {
  margin-top: 2.5rem;
  padding-top: 2rem;
  border-top: 1px solid var(--border);
}

.section-heading {
  margin-bottom: 1.25rem;
}

.section-heading h2 {
  margin-bottom: 0.35rem;
}

.section-heading p {
  color: var(--text-secondary);
  margin: 0;
}

/* ── How to Use Steps ── */
.steps-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1.25rem;
  margin-top: 1.25rem;
}

.step-card {
  background: var(--bg-surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  padding: 1.25rem;
  position: relative;
}

.step-number {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 32px;
  height: 32px;
  background: var(--accent-primary);
  color: #fff;
  border-radius: 50%;
  font-size: 0.85rem;
  font-weight: 700;
  margin-bottom: 0.75rem;
  flex-shrink: 0;
}

.step-card h3 {
  font-size: 0.95rem;
  margin-bottom: 0.4rem;
}

.step-card p {
  font-size: 0.85rem;
  color: var(--text-secondary);
  margin: 0;
}

/* ── Formula Block ── */
.formula-block {
  background: var(--bg-surface);
  border: 1px solid var(--border);
  border-left: 4px solid var(--accent-primary);
  border-radius: var(--radius-md);
  padding: 1.25rem 1.5rem;
  margin: 1.25rem 0;
}

.formula-block h3 {
  font-size: 0.9rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--text-secondary);
  margin-bottom: 0.75rem;
}

.formula-eq {
  font-family: 'JetBrains Mono', monospace;
  font-size: 1rem;
  font-weight: 600;
  color: var(--accent-primary);
  background: var(--bg-elevated);
  padding: 0.5rem 0.85rem;
  border-radius: var(--radius-sm);
  display: inline-block;
  margin-bottom: 0.5rem;
}

.formula-block p {
  font-size: 0.85rem;
  color: var(--text-secondary);
  margin: 0;
  margin-top: 0.5rem;
}

/* ── Feature Points ── */
.features-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 1rem;
  margin-top: 1.25rem;
}

.feature-item {
  display: flex;
  gap: 0.75rem;
  align-items: flex-start;
  background: var(--bg-surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  padding: 1rem 1.1rem;
}

.feature-icon {
  font-size: 1.35rem;
  flex-shrink: 0;
  margin-top: 0.05rem;
}

.feature-item h4 {
  font-size: 0.9rem;
  margin-bottom: 0.2rem;
}

.feature-item p {
  font-size: 0.82rem;
  color: var(--text-secondary);
  margin: 0;
}

/* ── FAQ Section ── */
.faq-list {
  margin-top: 1.25rem;
}

.faq-item {
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  overflow: hidden;
  margin-bottom: 0.5rem;
}

.faq-question {
  width: 100%;
  background: var(--bg-surface);
  border: none;
  padding: 1rem 1.25rem;
  text-align: left;
  font-family: inherit;
  font-size: 0.95rem;
  font-weight: 600;
  color: var(--text-primary);
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  transition: background var(--transition);
}

.faq-question:hover { background: var(--bg-elevated); }

.faq-question[aria-expanded="true"] { background: var(--bg-elevated); }

.faq-chevron {
  width: 18px;
  height: 18px;
  flex-shrink: 0;
  transition: transform var(--transition);
  color: var(--text-secondary);
}

.faq-question[aria-expanded="true"] .faq-chevron { transform: rotate(180deg); }

.faq-answer {
  display: none;
  padding: 0 1.25rem 1rem;
  font-size: 0.9rem;
  color: var(--text-secondary);
  line-height: 1.65;
  border-top: 1px solid var(--border);
  background: var(--bg-surface);
}

.faq-answer.open { display: block; }
.faq-answer p { margin-top: 0.75rem; margin-bottom: 0; }

/* ── Related Calculators ── */
.related-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
  gap: 0.85rem;
  margin-top: 1.25rem;
}

.related-card {
  background: var(--bg-surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  padding: 1rem 1.1rem;
  text-decoration: none;
  display: flex;
  align-items: center;
  gap: 0.7rem;
  transition: border-color var(--transition), box-shadow var(--transition), background var(--transition);
}

.related-card:hover {
  border-color: var(--accent-primary);
  box-shadow: var(--shadow-sm);
  background: var(--bg-elevated);
  text-decoration: none;
}

.related-card-icon {
  font-size: 1.4rem;
  flex-shrink: 0;
}

.related-card-text { min-width: 0; }

.related-card-text strong {
  display: block;
  font-size: 0.88rem;
  color: var(--text-primary);
  line-height: 1.3;
}

.related-card-text span {
  display: block;
  font-size: 0.77rem;
  color: var(--text-secondary);
  margin-top: 0.15rem;
}

/* ── Tool Card (Category Pages) ── */
.tool-cards-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
  gap: 1rem;
  margin-top: 1.5rem;
}

.tool-card {
  background: var(--bg-surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  padding: 1.25rem;
  text-decoration: none;
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
  transition: border-color var(--transition), box-shadow var(--transition), transform var(--transition);
}

.tool-card:hover {
  border-color: var(--accent-primary);
  box-shadow: var(--shadow-md);
  transform: translateY(-2px);
  text-decoration: none;
}

.tool-card-icon { font-size: 1.75rem; }

.tool-card h3 {
  font-size: 0.95rem;
  color: var(--text-primary);
  margin: 0;
  line-height: 1.3;
}

.tool-card p {
  font-size: 0.82rem;
  color: var(--text-secondary);
  margin: 0;
  line-height: 1.45;
}

.tool-card-arrow {
  margin-top: auto;
  padding-top: 0.5rem;
  font-size: 0.8rem;
  color: var(--accent-primary);
  font-weight: 500;
}

/* ── Citation Block ── */
.citations {
  background: var(--bg-elevated);
  border-radius: var(--radius-md);
  padding: 1.25rem;
  margin-top: 1.5rem;
}

.citations h4 {
  font-size: 0.8rem;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--text-secondary);
  margin-bottom: 0.75rem;
}

.citations ol {
  font-size: 0.82rem;
  color: var(--text-secondary);
  padding-left: 1.25rem;
}

.citations li {
  margin-bottom: 0.35rem;
}

.citations a {
  color: var(--accent-primary);
}

.last-updated {
  font-size: 0.78rem;
  color: var(--text-secondary);
  margin-top: 0.75rem;
  display: flex;
  align-items: center;
  gap: 0.3rem;
}

/* ── Alert / Info Box ── */
.alert {
  border-radius: var(--radius-md);
  padding: 0.9rem 1.1rem;
  font-size: 0.88rem;
  display: flex;
  gap: 0.75rem;
  align-items: flex-start;
  margin: 1rem 0;
}

.alert-info { background: #EFF6FF; border: 1px solid #BFDBFE; color: #1E40AF; }
.alert-warn { background: var(--warn-bg); border: 1px solid var(--warn-border); color: var(--warn); }
.alert-danger { background: var(--danger-bg); border: 1px solid #FECACA; color: var(--danger); }
.alert-success { background: var(--success-bg); border: 1px solid #BBF7D0; color: var(--success); }

[data-theme="dark"] .alert-info { background: #0c1a33; border-color: #1e3a6e; color: #93C5FD; }

.alert-icon { font-size: 1.05rem; flex-shrink: 0; }
.alert p { margin: 0; font-size: 0.88rem; }

/* ── Sidebar ── */
.sidebar { position: sticky; top: 80px; }

.sidebar-card {
  background: var(--bg-surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  padding: 1.25rem;
  margin-bottom: 1rem;
}

.sidebar-card h4 {
  font-size: 0.85rem;
  font-weight: 600;
  margin-bottom: 0.75rem;
  padding-bottom: 0.5rem;
  border-bottom: 1px solid var(--border);
}

.sidebar-links { list-style: none; padding: 0; }
.sidebar-links li { margin-bottom: 0.4rem; }
.sidebar-links a { font-size: 0.85rem; color: var(--text-secondary); }
.sidebar-links a:hover { color: var(--accent-primary); }

/* ── Tables ── */
table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.9rem;
  margin: 1.25rem 0;
}

th {
  background: var(--bg-elevated);
  font-size: 0.8rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.04em;
  color: var(--text-secondary);
  padding: 0.65rem 0.85rem;
  text-align: left;
  border-bottom: 2px solid var(--border);
}

td {
  padding: 0.65rem 0.85rem;
  border-bottom: 1px solid var(--border);
  color: var(--text-primary);
}

tr:last-child td { border-bottom: none; }
tr:hover td { background: var(--bg-elevated); }

/* ── Inline code ── */
code {
  font-family: 'JetBrains Mono', monospace;
  font-size: 0.85em;
  background: var(--bg-elevated);
  padding: 0.1em 0.4em;
  border-radius: 4px;
  color: var(--accent-primary);
}

/* ── Emergency Banner ── */
.emergency-banner {
  background: var(--danger-bg);
  border: 1px solid #FECACA;
  border-radius: var(--radius-md);
  padding: 0.9rem 1.1rem;
  margin: 1.5rem 0;
  display: flex;
  gap: 0.75rem;
  align-items: flex-start;
}

.emergency-banner p {
  font-size: 0.85rem;
  color: var(--danger);
  margin: 0;
  line-height: 1.55;
}

/* ── Homepage Hero ── */
.home-hero {
  padding: 3rem 0 2rem;
  background: linear-gradient(135deg, var(--bg-surface) 0%, var(--bg-elevated) 100%);
  border-bottom: 1px solid var(--border);
}

.home-hero-inner {
  display: grid;
  grid-template-columns: 1fr 1.1fr;
  gap: 3rem;
  align-items: start;
}

/* Left column groups the heading and the disclaimer/badges on desktop */
.home-hero-left { display: flex; flex-direction: column; }
.home-hero-aside { margin-top: 1.5rem; }
.home-hero-calc { min-width: 0; }

.home-hero-text h1 { margin-bottom: 0.75rem; }

.home-hero-text .lead {
  font-size: 1.05rem;
  color: var(--text-secondary);
  line-height: 1.7;
  margin-bottom: 1.5rem;
}

.hero-badges {
  display: flex;
  gap: 0.5rem;
  flex-wrap: wrap;
  margin-top: 1rem;
}

.badge {
  display: inline-flex;
  align-items: center;
  gap: 0.3rem;
  padding: 0.3rem 0.75rem;
  border-radius: 20px;
  font-size: 0.78rem;
  font-weight: 500;
  background: var(--bg-elevated);
  color: var(--text-secondary);
  border: 1px solid var(--border);
}

.badge-teal { background: rgba(14,124,134,0.1); color: var(--accent-primary); border-color: rgba(14,124,134,0.2); }
[data-theme="dark"] .badge-teal { background: rgba(45,212,191,0.1); color: var(--accent-primary); border-color: rgba(45,212,191,0.2); }

/* ── Reduced motion ── */
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    transition-duration: 0.01ms !important;
    animation-duration: 0.01ms !important;
  }
  html { scroll-behavior: auto; }
}

/* ── Print ── */
@media print {
  .site-header, .site-footer, .calc-actions, .theme-toggle, .menu-toggle { display: none !important; }
  body { font-size: 12pt; color: #000; background: #fff; }
  .result-box { border: 1px solid #ccc; }
  .disclaimer-banner { border: 1px solid #ccc; background: #fffbe6; }
}

/* ── Responsive ── */
@media (max-width: 900px) {
  /* Stack and reorder: heading, then calculator, then disclaimer + badges */
  .home-hero-inner { display: flex; flex-direction: column; gap: 1.5rem; }
  .home-hero-left { display: contents; }
  .home-hero-text { order: 1; }
  .home-hero-calc { order: 2; }
  .home-hero-aside { order: 3; margin-top: 0; }
  .home-hero { padding: 2rem 0 1.5rem; }
  .content-with-sidebar { grid-template-columns: 1fr; }
  .sidebar { position: static; }
  .footer-grid { grid-template-columns: 1fr 1fr; }
  .steps-grid { grid-template-columns: repeat(2, 1fr); }
  .calc-grid { grid-template-columns: 1fr; }
}

@media (max-width: 640px) {
  .main-nav { display: none; }
  .main-nav.open { display: flex; flex-direction: column; position: absolute; top: 64px; left: 0; right: 0; background: var(--bg-surface); border-bottom: 1px solid var(--border); padding: 0.75rem; z-index: 99; box-shadow: var(--shadow-md); }
  .menu-toggle { display: flex; }
  .footer-grid { grid-template-columns: 1fr; }
  .steps-grid { grid-template-columns: 1fr; }
  .features-grid { grid-template-columns: 1fr; }
  .result-grid { grid-template-columns: 1fr; }
  .grid-2, .grid-3, .grid-4 { grid-template-columns: 1fr; }
  .calc-panel { padding: 1.25rem; }
  .result-value { font-size: 1.85rem; }
  h1 { font-size: 1.65rem; }
  h2 { font-size: 1.3rem; }
  .home-hero { padding: 1.5rem 0; }
  .footer-bottom-inner { flex-direction: column; text-align: center; }
}

/* ============================================================
   Brand Polish v2 + Tool Component System
   ============================================================ */

/* ── Logo mark ── */
.logo-icon {
  width: 38px;
  height: 38px;
  background: linear-gradient(135deg, var(--accent-primary), var(--accent-hover));
  border-radius: 11px;
  box-shadow: 0 3px 8px rgba(14,124,134,0.30);
}
.logo-icon svg { width: 22px; height: 22px; display: block; }
[data-theme="dark"] .logo-icon { box-shadow: 0 3px 10px rgba(45,212,191,0.22); }
.logo-text { letter-spacing: -0.01em; }

/* ── Header refinement ── */
.site-header { backdrop-filter: saturate(1.1) blur(8px); }

/* ── Professional branded dark footer (applies in both themes) ── */
.site-footer {
  background: #16202B;
  border-top: 3px solid var(--accent-primary);
  color: #AEBDC9;
}

/* Disclaimer band — amber tint that reads on the dark footer */
.site-footer .footer-disclaimer {
  background: rgba(180,83,9,0.16);
  border-top: none;
  border-bottom: 1px solid rgba(255,255,255,0.07);
}
.site-footer .footer-disclaimer p { color: #F4C77B; }
.site-footer .footer-disclaimer strong { color: #F8D99B; }

/* Brand column */
.footer-top { padding: 2.75rem 0 2.25rem; }
.footer-brand .logo { margin-bottom: 0.6rem; }
.footer-brand p { color: #8FA0AE; }
.footer-brand .logo-text { color: #FFFFFF; }
.footer-brand .logo-text span { color: #8FA0AE; }

/* Link columns */
.site-footer .footer-col h4 { color: #708495; }
.site-footer .footer-col a { color: #AEBDC9 !important; transition: color var(--transition), padding-left var(--transition); }
.site-footer .footer-col a:hover { color: #FFFFFF !important; padding-left: 3px; }

/* Bottom bar */
.site-footer .footer-bottom { border-top: 1px solid rgba(255,255,255,0.07); }
.site-footer .footer-bottom p { color: #7C8C99; }
.site-footer .footer-bottom a { color: #AEBDC9; }
.site-footer .footer-bottom a:hover { color: #FFFFFF; }

/* ── Primary button shadow ── */
.btn-primary { box-shadow: 0 2px 8px rgba(14,124,134,0.25); }
.btn-primary:hover { box-shadow: 0 5px 16px rgba(14,124,134,0.35); transform: translateY(-1px); }

/* ── Tool page subtitle ── */
.tool-subtitle {
  font-size: 1.05rem;
  color: var(--text-secondary);
  max-width: 680px;
  margin: 0.4rem 0 1.25rem;
  line-height: 1.6;
}

/* ── Calculator card ── */
.calculator-card {
  background: var(--bg-surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-md);
  overflow: hidden;
  margin: 1.25rem 0;
}
.calc-body { padding: 1.5rem; }

/* ── Fields ── */
.field-group { margin-bottom: 1.15rem; }
.field-label {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 0.5rem;
  font-size: 0.9rem;
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: 0.4rem;
}
.field-unit { font-size: 0.78rem; font-weight: 500; color: var(--text-secondary); white-space: nowrap; }
.field-input,
.field-select {
  width: 100%;
  padding: 0.7rem 0.9rem;
  border: 1.5px solid var(--border);
  border-radius: var(--radius-sm);
  background: var(--bg-primary);
  color: var(--text-primary);
  font-family: inherit;
  font-size: 1rem;
  transition: border-color var(--transition), box-shadow var(--transition);
}
.field-input:focus,
.field-select:focus {
  outline: none;
  border-color: var(--accent-primary);
  box-shadow: 0 0 0 3px var(--border-focus);
}
.field-hint { font-size: 0.78rem; color: var(--text-secondary); margin: 0.4rem 0 0; line-height: 1.5; }

/* ── Calculate button ── */
.calc-btn {
  width: 100%;
  margin-top: 0.35rem;
  padding: 0.85rem 1.5rem;
  border: none;
  border-radius: var(--radius-sm);
  background: linear-gradient(135deg, var(--accent-primary), var(--accent-hover));
  color: #fff;
  font-family: inherit;
  font-size: 1rem;
  font-weight: 600;
  cursor: pointer;
  box-shadow: 0 2px 8px rgba(14,124,134,0.28);
  transition: transform var(--transition), box-shadow var(--transition), filter var(--transition);
}
.calc-btn:hover { transform: translateY(-1px); box-shadow: 0 6px 18px rgba(14,124,134,0.40); filter: brightness(1.04); }
.calc-btn:active { transform: translateY(0); }
.calc-btn:focus-visible { outline: none; box-shadow: 0 0 0 3px var(--border-focus); }

/* ── Unit toggle (pill buttons) ── */
.unit-toggle { display: inline-flex; margin-bottom: 1.15rem; border-radius: var(--radius-sm); box-shadow: var(--shadow-sm); }
.unit-btn {
  background: var(--bg-primary);
  border: 1.5px solid var(--border);
  padding: 0.5rem 1rem;
  font-family: inherit;
  font-size: 0.82rem;
  font-weight: 600;
  color: var(--text-secondary);
  cursor: pointer;
  transition: background var(--transition), color var(--transition);
}
.unit-btn + .unit-btn { border-left: none; }
.unit-btn:first-child { border-radius: var(--radius-sm) 0 0 var(--radius-sm); }
.unit-btn:last-child { border-radius: 0 var(--radius-sm) var(--radius-sm) 0; }
.unit-btn.active { background: var(--accent-primary); color: #fff; border-color: var(--accent-primary); }
.unit-btn:hover:not(.active) { background: var(--bg-elevated); color: var(--text-primary); }
.unit-btn:focus-visible { outline: none; box-shadow: 0 0 0 3px var(--border-focus); position: relative; z-index: 1; }

/* ── Result area ── */
.result-area {
  border-top: 1px solid var(--border);
  background: var(--bg-elevated);
  padding: 1.5rem;
}
.result-area .result-primary {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 1rem;
  flex-wrap: wrap;
  margin: 0;
}
.result-area .result-label {
  margin: 0;
  font-size: 0.8rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.05em;
}
.result-area .result-value { font-size: 1.9rem; }
.result-secondary {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 1rem;
  flex-wrap: wrap;
  margin-top: 0.85rem;
  padding-top: 0.85rem;
  border-top: 1px dashed var(--border);
}
.result-secondary .result-value { font-size: 1.3rem; color: var(--text-primary); }
.result-secondary .result-label { margin: 0; font-size: 0.8rem; }
.result-note { font-size: 0.85rem; color: var(--text-secondary); margin-top: 1rem; line-height: 1.6; }
.result-disclaimer { margin-top: 1.15rem; }

/* ── Inline calc error ── */
.calc-error {
  background: var(--danger-bg);
  border: 1px solid var(--danger);
  color: var(--danger);
  border-radius: var(--radius-sm);
  padding: 0.7rem 0.9rem;
  margin-top: 1rem;
  font-size: 0.85rem;
  font-weight: 500;
}
#error-area:empty { display: none; }

/* ── Card hover lift ── */
.related-card:hover,
.tool-card:hover { transform: translateY(-2px); }

/* ── Mobile tweaks for tool components ── */
@media (max-width: 640px) {
  .calc-body { padding: 1.15rem; }
  .result-area { padding: 1.15rem; }
  .result-area .result-value { font-size: 1.65rem; }
  /* Keep cards in a 2-up grid on phones (like desktop) instead of stacking full-width */
  .tool-cards-grid { grid-template-columns: repeat(2, 1fr); gap: 0.75rem; }
  .tool-card { padding: 0.85rem; min-width: 0; }
  .tool-card-icon { font-size: 1.4rem; }
  .tool-card h3 { font-size: 0.85rem; word-break: break-word; hyphens: auto; line-height: 1.25; margin-bottom: 0.25rem; }
  .tool-card p { font-size: 0.75rem; line-height: 1.35; }
  .tool-card-arrow { font-size: 0.75rem; margin-top: auto; }

  /* Keep related cards in a 2-up grid on phones */
  .related-grid { grid-template-columns: repeat(2, 1fr); gap: 0.75rem; }
  .related-card { 
    padding: 0.85rem; 
    flex-direction: column; 
    align-items: flex-start; 
    gap: 0.5rem; 
    min-width: 0; 
  }
  .related-card-icon { font-size: 1.4rem; margin-bottom: 0.2rem; }
  .related-card-text strong { 
    font-size: 0.85rem; 
    word-break: break-word; 
    hyphens: auto; 
    line-height: 1.25; 
  }
  .related-card-text span { 
    font-size: 0.75rem; 
    line-height: 1.35; 
    margin-top: 0.25rem;
  }
}

/* ?? Tools Showcase Banner ?? */
.tools-showcase-banner {
  position: relative;
  margin: 3rem 0;
  border-radius: var(--radius-xl);
  overflow: hidden;
  box-shadow: 0 15px 35px rgba(0,0,0,0.1);
  display: flex;
  align-items: center;
  justify-content: center;
  min-height: 280px;
  background: var(--bg-surface);
  z-index: 1;
}

[data-theme="dark"] .tools-showcase-banner {
  box-shadow: 0 15px 35px rgba(0,0,0,0.4);
}

/* Animated Glow Background */
.showcase-glow-bg {
  position: absolute;
  top: -50%;
  left: -50%;
  width: 200%;
  height: 200%;
  background: radial-gradient(circle at 50% 50%, rgba(14,124,134,0.15), transparent 60%),
              radial-gradient(circle at 80% 20%, rgba(20,184,166,0.15), transparent 50%),
              radial-gradient(circle at 20% 80%, rgba(59,130,246,0.1), transparent 50%);
  animation: slowGlowRotate 20s linear infinite;
  z-index: -1;
}

[data-theme="dark"] .showcase-glow-bg {
  background: radial-gradient(circle at 50% 50%, rgba(45,212,191,0.15), transparent 60%),
              radial-gradient(circle at 80% 20%, rgba(14,124,134,0.2), transparent 50%),
              radial-gradient(circle at 20% 80%, rgba(129,140,248,0.15), transparent 50%);
}

@keyframes slowGlowRotate {
  0% { transform: rotate(0deg) scale(1); }
  50% { transform: rotate(180deg) scale(1.1); }
  100% { transform: rotate(360deg) scale(1); }
}

/* Glassmorphism Panel */
.showcase-content.glass-panel {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  width: 100%;
  height: 100%;
  padding: 3rem 4rem;
  background: rgba(255, 255, 255, 0.4);
  backdrop-filter: blur(20px) saturate(1.2);
  -webkit-backdrop-filter: blur(20px) saturate(1.2);
  border: 1px solid rgba(255, 255, 255, 0.5);
  box-sizing: border-box;
}

[data-theme="dark"] .showcase-content.glass-panel {
  background: rgba(22, 32, 43, 0.4);
  border: 1px solid rgba(255, 255, 255, 0.05);
}

/* Text Content */
.showcase-text {
  flex: 1 1 500px;
  max-width: 600px;
  z-index: 2;
}

.showcase-text h2 {
  font-size: 2.2rem;
  font-weight: 800;
  line-height: 1.2;
  margin-bottom: 1rem;
  background: linear-gradient(135deg, var(--text-primary), var(--accent-primary));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  color: var(--text-primary);
}

.showcase-text p {
  font-size: 1.15rem;
  color: var(--text-secondary);
  margin-bottom: 2rem;
  line-height: 1.6;
}

/* Premium Glowing CTA */
.btn-premium-glow {
  display: inline-block;
  padding: 0.9rem 2.2rem;
  background: linear-gradient(135deg, var(--accent-primary), var(--accent-hover));
  color: #ffffff !important;
  font-weight: 700;
  font-size: 1.05rem;
  border-radius: 50px;
  text-decoration: none;
  box-shadow: 0 4px 15px rgba(14,124,134,0.4), inset 0 1px 1px rgba(255,255,255,0.2);
  transition: all 0.3s cubic-bezier(0.25, 0.8, 0.25, 1);
  position: relative;
  overflow: hidden;
}

.btn-premium-glow::before {
  content: "";
  position: absolute;
  top: 0; left: -100%; width: 50%; height: 100%;
  background: linear-gradient(90deg, transparent, rgba(255,255,255,0.3), transparent);
  transition: all 0.5s ease;
}

.btn-premium-glow:hover {
  transform: translateY(-3px) scale(1.02);
  box-shadow: 0 8px 25px rgba(14,124,134,0.5), inset 0 1px 1px rgba(255,255,255,0.3);
}

.btn-premium-glow:hover::before {
  left: 100%;
  transition: all 0.6s ease;
}

/* Floating Visuals */
.showcase-visuals {
  flex: 0 1 200px;
  position: relative;
  height: 150px;
  display: flex;
  align-items: center;
  justify-content: center;
}

.floating-icon {
  position: absolute;
  color: var(--accent-primary);
  opacity: 0.8;
  filter: drop-shadow(0 8px 16px rgba(14,124,134,0.3));
}

[data-theme="dark"] .floating-icon {
  filter: drop-shadow(0 8px 16px rgba(45,212,191,0.2));
}

.floating-icon.icon-1 {
  width: 64px; height: 64px;
  top: 0; right: 20px;
  animation: floatBob 6s ease-in-out infinite;
}

.floating-icon.icon-2 {
  width: 48px; height: 48px;
  bottom: 0; left: 10px;
  animation: floatBob 5s ease-in-out infinite 1s;
}

.floating-icon.icon-3 {
  width: 56px; height: 56px;
  top: 50px; right: 100px;
  animation: floatBob 7s ease-in-out infinite 2s;
}

@keyframes floatBob {
  0% { transform: translateY(0) rotate(0deg); }
  50% { transform: translateY(-15px) rotate(5deg); }
  100% { transform: translateY(0) rotate(0deg); }
}

@media (max-width: 900px) {
  .showcase-content.glass-panel { padding: 2.5rem 2rem; }
  .showcase-visuals { display: none; }
}

@media (max-width: 600px) {
  .showcase-text h2 { font-size: 1.8rem; }
  .showcase-text p { font-size: 1.05rem; }
  .btn-premium-glow { width: 100%; text-align: center; }
}