/* ==========================================================================
   I LOVE FINANCE — GLOBAL STYLESHEET
   Design system: tokens, layout primitives, header/footer, shared components.
   Do not duplicate these rules inside individual calculator pages.
   ========================================================================== */

/* --------------------------------------------------------------------------
   1. DESIGN TOKENS
   -------------------------------------------------------------------------- */
:root {
  /* Color — surfaces */
  --color-bg: #FAF9F5;
  --color-surface: #FFFFFF;
  --color-surface-alt: #F2F0E9;
  --color-surface-dark: #0E2A1E;

  /* Color — text */
  --color-text: #1B211D;
  --color-text-secondary: #5B655F;
  --color-text-muted: #8A9289;
  --color-text-on-dark: #F3F5F2;
  --color-text-on-dark-secondary: #AEBBB2;

  /* Color — brand */
  --color-primary: #0B5D3B;
  --color-primary-dark: #073D27;
  --color-primary-light: #E7F1EA;
  --color-accent: #A9812F;
  --color-accent-light: #F4EDDA;

  /* Color — borders & feedback */
  --color-border: #E2DFD3;
  --color-border-strong: #C9C4B4;
  --color-danger: #B3261E;
  --color-danger-light: #FBEAE9;
  --color-success: #0B5D3B;

  /* Typography */
  --font-display: "Source Serif 4", Georgia, "Times New Roman", serif;
  --font-body: "Inter", -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  --font-mono: "IBM Plex Mono", "SFMono-Regular", Menlo, Consolas, monospace;

  --fs-2xs: 0.75rem;
  --fs-xs: 0.8125rem;
  --fs-sm: 0.9375rem;
  --fs-base: 1rem;
  --fs-md: 1.125rem;
  --fs-lg: 1.375rem;
  --fs-xl: 1.75rem;
  --fs-2xl: 2.25rem;
  --fs-3xl: 2.875rem;
  --fs-4xl: 3.5rem;

  /* Spacing scale */
  --space-1: 0.25rem;
  --space-2: 0.5rem;
  --space-3: 0.75rem;
  --space-4: 1rem;
  --space-5: 1.5rem;
  --space-6: 2rem;
  --space-7: 2.5rem;
  --space-8: 3rem;
  --space-9: 4rem;
  --space-10: 5.5rem;
  --space-11: 7.5rem;

  /* Radius — restrained, not pill-shaped */
  --radius-sm: 4px;
  --radius-md: 8px;
  --radius-lg: 12px;

  /* Shadow — very light */
  --shadow-sm: 0 1px 2px rgba(14, 25, 19, 0.06);
  --shadow-md: 0 6px 20px rgba(14, 25, 19, 0.08);
  --shadow-focus: 0 0 0 3px rgba(11, 93, 59, 0.28);

  /* Layout */
  --content-max: 1180px;
  --content-narrow: 760px;
  --header-height: 72px;
  --transition-fast: 140ms ease;
  --transition-base: 220ms ease;
}

/* --------------------------------------------------------------------------
   2. RESET & BASE
   -------------------------------------------------------------------------- */
*, *::before, *::after { box-sizing: border-box; }

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

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
    scroll-behavior: auto !important;
  }
}

body {
  margin: 0;
  background: var(--color-bg);
  color: var(--color-text);
  font-family: var(--font-body);
  font-size: var(--fs-base);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

img { max-width: 100%; display: block; }

a { color: inherit; text-decoration: none; }

ul, ol { padding: 0; margin: 0; list-style: none; }

h1, h2, h3, h4 {
  font-family: var(--font-display);
  font-weight: 600;
  line-height: 1.18;
  margin: 0 0 var(--space-3);
  color: var(--color-text);
  letter-spacing: -0.01em;
}

h1 { font-size: var(--fs-3xl); }
h2 { font-size: var(--fs-2xl); }
h3 { font-size: var(--fs-lg); }
h4 { font-size: var(--fs-md); }

p { margin: 0 0 var(--space-4); color: var(--color-text-secondary); }

/* Tabular figures everywhere money/percentages appear — the site's quiet
   "ledger" signature: numbers always line up like a balance sheet. */
.figure, .money, .num, input[type="number"] {
  font-variant-numeric: tabular-nums;
  font-feature-settings: "tnum" 1;
}

button { font-family: inherit; }

:focus-visible {
  outline: none;
  box-shadow: var(--shadow-focus);
  border-radius: var(--radius-sm);
}

/* --------------------------------------------------------------------------
   3. LAYOUT PRIMITIVES
   -------------------------------------------------------------------------- */
.container {
  width: 100%;
  max-width: var(--content-max);
  margin: 0 auto;
  padding: 0 var(--space-5);
}

.container--narrow {
  max-width: var(--content-narrow);
}

.section {
  padding: var(--space-10) 0;
}

.section--tight { padding: var(--space-8) 0; }

.section--alt {
  background: var(--color-surface-alt);
}

.section--dark {
  background: var(--color-surface-dark);
  color: var(--color-text-on-dark);
}

.section--dark h1, .section--dark h2, .section--dark h3, .section--dark h4 {
  color: var(--color-text-on-dark);
}

.section--dark p { color: var(--color-text-on-dark-secondary); }

.grid {
  display: grid;
  gap: var(--space-5);
}

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

@media (max-width: 900px) {
  .grid--3, .grid--4 { grid-template-columns: repeat(2, 1fr); }
}

@media (max-width: 600px) {
  .grid--2, .grid--3, .grid--4 { grid-template-columns: 1fr; }
}

.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  font-family: var(--font-mono);
  font-size: var(--fs-2xs);
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--color-primary);
  font-weight: 600;
  margin-bottom: var(--space-3);
}

.eyebrow::before {
  content: "";
  width: 18px;
  height: 2px;
  background: var(--color-accent);
  display: inline-block;
}

/* Ledger rule — signature divider used between major sections */
.ledger-rule {
  border: none;
  height: 1px;
  background: var(--color-border);
  position: relative;
  margin: 0;
}

.ledger-rule::after {
  content: "";
  position: absolute;
  left: 0;
  top: -1px;
  width: 34px;
  height: 3px;
  background: var(--color-primary);
}

.section-head {
  display: flex;
  align-items: flex-end;
  justify-content: space-between;
  gap: var(--space-5);
  margin-bottom: var(--space-6);
}

.section-head p { margin: 0; max-width: 46ch; }

@media (max-width: 700px) {
  .section-head { flex-direction: column; align-items: flex-start; }
}

/* --------------------------------------------------------------------------
   4. HEADER / NAV
   -------------------------------------------------------------------------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(250, 249, 245, 0.92);
  backdrop-filter: saturate(140%) blur(8px);
  border-bottom: 1px solid var(--color-border);
}

.site-header__inner {
  height: var(--header-height);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-5);
}

.brand {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  font-family: var(--font-display);
  font-weight: 700;
  font-size: var(--fs-md);
  color: var(--color-text);
  white-space: nowrap;
}

.brand__mark {
  width: 30px;
  height: 30px;
  border-radius: var(--radius-sm);
  background: var(--color-primary);
  color: #fff;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  font-family: var(--font-mono);
  font-size: 0.8125rem;
  font-weight: 700;
  flex-shrink: 0;
}

.main-nav {
  display: flex;
  align-items: center;
  gap: var(--space-6);
}

.main-nav__links {
  display: flex;
  align-items: center;
  gap: var(--space-5);
}

.main-nav__links a {
  font-size: var(--fs-sm);
  font-weight: 500;
  color: var(--color-text-secondary);
  padding: var(--space-2) 0;
  border-bottom: 2px solid transparent;
  transition: color var(--transition-fast), border-color var(--transition-fast);
}

.main-nav__links a:hover,
.main-nav__links a[aria-current="page"] {
  color: var(--color-text);
  border-bottom-color: var(--color-accent);
}

.header-actions {
  display: flex;
  align-items: center;
  gap: var(--space-3);
}

.header-search {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: var(--space-2) var(--space-3);
  min-width: 200px;
}

.header-search input {
  border: none;
  outline: none;
  background: transparent;
  font-size: var(--fs-sm);
  color: var(--color-text);
  width: 100%;
}

.header-search svg { flex-shrink: 0; color: var(--color-text-muted); }

.nav-toggle {
  display: none;
  border: 1px solid var(--color-border);
  background: var(--color-surface);
  border-radius: var(--radius-sm);
  width: 40px;
  height: 40px;
  align-items: center;
  justify-content: center;
  cursor: pointer;
}

@media (max-width: 900px) {
  .header-search { display: none; }
  .main-nav {
    position: fixed;
    inset: var(--header-height) 0 0 0;
    background: var(--color-bg);
    flex-direction: column;
    align-items: stretch;
    padding: var(--space-6) var(--space-5);
    transform: translateY(-8px);
    opacity: 0;
    pointer-events: none;
    transition: opacity var(--transition-base), transform var(--transition-base);
    overflow-y: auto;
  }
  .main-nav.is-open {
    opacity: 1;
    transform: translateY(0);
    pointer-events: auto;
  }
  .main-nav__links {
    flex-direction: column;
    align-items: stretch;
    gap: 0;
  }
  .main-nav__links a {
    padding: var(--space-4) 0;
    border-bottom: 1px solid var(--color-border);
  }
  .header-actions { width: 100%; }
  .nav-toggle { display: inline-flex; }
}

/* --------------------------------------------------------------------------
   5. BUTTONS
   -------------------------------------------------------------------------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-2);
  font-size: var(--fs-sm);
  font-weight: 600;
  padding: var(--space-3) var(--space-6);
  border-radius: var(--radius-md);
  border: 1px solid transparent;
  cursor: pointer;
  transition: background var(--transition-fast), border-color var(--transition-fast), color var(--transition-fast), transform var(--transition-fast);
  min-height: 46px;
}

.btn:active { transform: translateY(1px); }

.btn--primary {
  background: var(--color-primary);
  color: #fff;
}
.btn--primary:hover { background: var(--color-primary-dark); }

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

.btn--on-dark {
  background: var(--color-text-on-dark);
  color: var(--color-primary-dark);
}
.btn--on-dark:hover { background: #fff; }

.btn--block { width: 100%; }
.btn--sm { min-height: 38px; padding: var(--space-2) var(--space-4); }

/* --------------------------------------------------------------------------
   6. CARDS
   -------------------------------------------------------------------------- */
.card {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: var(--space-5);
  transition: box-shadow var(--transition-base), border-color var(--transition-base), transform var(--transition-base);
}

a.card:hover, .card.is-interactive:hover {
  box-shadow: var(--shadow-md);
  border-color: var(--color-border-strong);
  transform: translateY(-2px);
}

.calc-card {
  display: flex;
  flex-direction: column;
  gap: var(--space-3);
}

.calc-card__icon {
  width: 42px;
  height: 42px;
  border-radius: var(--radius-sm);
  background: var(--color-primary-light);
  color: var(--color-primary-dark);
  display: inline-flex;
  align-items: center;
  justify-content: center;
}

.calc-card__tag {
  font-family: var(--font-mono);
  font-size: var(--fs-2xs);
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--color-text-muted);
}

.calc-card h3 { margin: 0; font-size: var(--fs-md); }
.calc-card p { margin: 0; font-size: var(--fs-sm); }

.calc-card__cta {
  margin-top: auto;
  font-size: var(--fs-xs);
  font-weight: 600;
  color: var(--color-primary);
  display: inline-flex;
  align-items: center;
  gap: var(--space-1);
}

/* Category pill */
.pill {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  font-size: var(--fs-xs);
  font-weight: 500;
  padding: var(--space-2) var(--space-4);
  border: 1px solid var(--color-border);
  border-radius: 999px;
  background: var(--color-surface);
  color: var(--color-text-secondary);
  cursor: pointer;
  transition: all var(--transition-fast);
  white-space: nowrap;
}

.pill:hover { border-color: var(--color-primary); color: var(--color-text); }

.pill.is-active {
  background: var(--color-primary);
  border-color: var(--color-primary);
  color: #fff;
}

/* --------------------------------------------------------------------------
   7. FORM ELEMENTS (shared with calculators)
   -------------------------------------------------------------------------- */
.field { margin-bottom: var(--space-5); }

.field label {
  display: block;
  font-size: var(--fs-xs);
  font-weight: 600;
  color: var(--color-text);
  margin-bottom: var(--space-2);
}

.field__hint {
  font-size: var(--fs-2xs);
  color: var(--color-text-muted);
  margin-top: var(--space-1);
}

.field__error {
  font-size: var(--fs-2xs);
  color: var(--color-danger);
  margin-top: var(--space-1);
  display: none;
}

.field.has-error .field__error { display: block; }
.field.has-error input { border-color: var(--color-danger); background: var(--color-danger-light); }

.input-group {
  display: flex;
  align-items: center;
  border: 1px solid var(--color-border-strong);
  border-radius: var(--radius-md);
  background: var(--color-surface);
  overflow: hidden;
  transition: border-color var(--transition-fast), box-shadow var(--transition-fast);
}

.input-group:focus-within {
  border-color: var(--color-primary);
  box-shadow: var(--shadow-focus);
}

.input-group__affix {
  padding: 0 var(--space-4);
  font-size: var(--fs-sm);
  color: var(--color-text-muted);
  font-weight: 600;
  background: var(--color-surface-alt);
  align-self: stretch;
  display: flex;
  align-items: center;
  border-right: 1px solid var(--color-border);
}

.input-group__affix--suffix {
  border-right: none;
  border-left: 1px solid var(--color-border);
}

.input-group input {
  border: none;
  outline: none;
  background: transparent;
  padding: var(--space-3) var(--space-4);
  font-size: var(--fs-md);
  font-family: var(--font-mono);
  color: var(--color-text);
  width: 100%;
  min-height: 48px;
}

input[type="range"] {
  width: 100%;
  accent-color: var(--color-primary);
  margin-top: var(--space-3);
}

/* --------------------------------------------------------------------------
   8. FOOTER
   -------------------------------------------------------------------------- */
.site-footer {
  background: var(--color-surface-dark);
  color: var(--color-text-on-dark-secondary);
  padding: var(--space-9) 0 var(--space-6);
  margin-top: var(--space-10);
}

.footer-grid {
  display: grid;
  grid-template-columns: 1.4fr 1fr 1fr 1fr;
  gap: var(--space-6);
  padding-bottom: var(--space-8);
  border-bottom: 1px solid rgba(255,255,255,0.12);
}

@media (max-width: 800px) {
  .footer-grid { grid-template-columns: 1fr 1fr; }
}
@media (max-width: 500px) {
  .footer-grid { grid-template-columns: 1fr; }
}

.footer-grid h4 {
  color: var(--color-text-on-dark);
  font-size: var(--fs-xs);
  text-transform: uppercase;
  letter-spacing: 0.06em;
  font-family: var(--font-mono);
  margin-bottom: var(--space-4);
}

.footer-grid ul li { margin-bottom: var(--space-3); }
.footer-grid ul a { font-size: var(--fs-sm); transition: color var(--transition-fast); }
.footer-grid ul a:hover { color: var(--color-text-on-dark); }

.footer-about p { font-size: var(--fs-sm); max-width: 34ch; }

.footer-bottom {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-4);
  padding-top: var(--space-6);
  font-size: var(--fs-xs);
  flex-wrap: wrap;
}

.footer-disclaimer {
  font-size: var(--fs-2xs);
  color: var(--color-text-on-dark-secondary);
  max-width: 760px;
  margin-top: var(--space-5);
  line-height: 1.7;
}

/* --------------------------------------------------------------------------
   9. BREADCRUMBS
   -------------------------------------------------------------------------- */
.breadcrumbs {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: var(--space-2);
  font-size: var(--fs-xs);
  color: var(--color-text-muted);
  padding: var(--space-5) 0 0;
}

.breadcrumbs a { color: var(--color-text-secondary); }
.breadcrumbs a:hover { color: var(--color-primary); }
.breadcrumbs .sep { color: var(--color-border-strong); }
.breadcrumbs [aria-current="page"] { color: var(--color-text); font-weight: 500; }

/* --------------------------------------------------------------------------
   10. AD SLOTS — reserved, clearly labeled, never disguised as content
   -------------------------------------------------------------------------- */
.ad-slot {
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--color-surface-alt);
  border: 1px dashed var(--color-border-strong);
  border-radius: var(--radius-md);
  color: var(--color-text-muted);
  font-size: var(--fs-2xs);
  text-transform: uppercase;
  letter-spacing: 0.06em;
  font-family: var(--font-mono);
  min-height: 90px;
  margin: var(--space-8) 0;
}

/* --------------------------------------------------------------------------
   11. UTILITIES
   -------------------------------------------------------------------------- */
.text-center { text-align: center; }
.mt-0 { margin-top: 0; }
.mb-0 { margin-bottom: 0; }
.visually-hidden {
  position: absolute;
  width: 1px; height: 1px;
  overflow: hidden;
  clip: rect(0 0 0 0);
  white-space: nowrap;
}

.skip-link {
  position: absolute;
  left: -999px;
  top: 0;
  background: var(--color-primary);
  color: #fff;
  padding: var(--space-3) var(--space-5);
  z-index: 200;
  border-radius: 0 0 var(--radius-sm) 0;
}
.skip-link:focus {
  left: 0;
}

@media (max-width: 700px) {
  h1 { font-size: var(--fs-2xl); }
  h2 { font-size: var(--fs-xl); }
  .section { padding: var(--space-8) 0; }
}