/**
 * global.css — PrincipalSafe design tokens + base styles
 * Based on DESIGN.md: Vercel/Geist design system
 *
 * Font substitutes (per DESIGN.md §Typography §Note on Font Substitutes):
 *   Geist Sans  → Inter
 *   Geist Mono  → JetBrains Mono
 */

/* ─── Design Tokens ──────────────────────────────────────────────────────── */
:root {
  /* Colors — Brand & Ink */
  --color-primary:       #171717;
  --color-on-primary:    #ffffff;
  --color-ink:           #171717;
  --color-body:          #4d4d4d;
  --color-mute:          #8f8f8f;
  --color-faint:         #a1a1a1;

  /* Colors — Surface */
  --color-canvas:        #fafafa;
  --color-canvas-elevated: #ffffff;
  --color-hairline:      #ebebeb;
  --color-hairline-soft: #f2f2f2;

  /* Colors — Accent */
  --color-link:          #0070f3;
  --color-link-deep:     #0761d1;
  --color-link-soft:     #d3e5ff;
  --color-error:         #ee0000;
  --color-error-deep:    #c50000;
  --color-warning:       #f5a623;
  --color-warning-soft:  #ffefcf;
  --color-warning-deep:  #ab570a;
  --color-violet:        #7928ca;
  --color-cyan:          #50e3c2;
  --color-pink:          #ff0080;

  /* Gradient stops */
  --gradient-develop-start:  #007cf0;
  --gradient-develop-end:    #00dfd8;
  --gradient-preview-start:  #7928ca;
  --gradient-preview-end:    #ff0080;
  --gradient-ship-start:     #ff4d4d;
  --gradient-ship-end:       #f9cb28;

  /* Typography */
  --font-sans:   'Inter', Arial, sans-serif;
  --font-mono:   'JetBrains Mono', ui-monospace, SFMono-Regular, Menlo, monospace;

  /* Spacing */
  --space-xxs:     4px;
  --space-xs:      8px;
  --space-sm:      12px;
  --space-md:      16px;
  --space-lg:      24px;
  --space-xl:      32px;
  --space-2xl:     40px;
  --space-3xl:     64px;
  --space-4xl:     96px;
  --space-section: 128px;

  /* Border Radius */
  --radius-none:         0px;
  --radius-sm:           6px;
  --radius-md:           12px;
  --radius-lg:           16px;
  --radius-pill-cat:     64px;
  --radius-pill:         100px;
  --radius-full:         9999px;

  /* Shadows */
  --shadow-whisper: 0px 1px 1px rgba(0, 0, 0, 0.04);
  --shadow-float:   0px 2px 2px rgba(0, 0, 0, 0.04), 0px 8px 16px -4px rgba(0, 0, 0, 0.06);
}

/* ─── 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: var(--font-sans);
  font-size: 14px;
  font-weight: 400;
  line-height: 20px;
  color: var(--color-body);
  background-color: var(--color-canvas);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

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

a {
  color: var(--color-link);
  text-decoration: none;
  transition: color 0.15s ease;
}
a:hover { color: var(--color-link-deep); }
a:focus-visible {
  outline: 2px solid var(--color-link);
  outline-offset: 2px;
  border-radius: var(--radius-sm);
}

/* ─── Typography ─────────────────────────────────────────────────────────── */
h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-sans);
  font-weight: 600;
  color: var(--color-ink);
}

.display-xl {
  font-size: 48px;
  font-weight: 600;
  line-height: 48px;
  letter-spacing: -2.4px;
}

h1, .heading-h1 {
  font-size: 40px;
  font-weight: 600;
  line-height: 48px;
  letter-spacing: -2px;
}

h2, .heading-h2 {
  font-size: 32px;
  font-weight: 600;
  line-height: 40px;
  letter-spacing: -1.28px;
}

h3, .heading-h3 {
  font-size: 20px;
  font-weight: 600;
  line-height: 28px;
  letter-spacing: -0.4px;
}

.mono-eyebrow {
  font-family: var(--font-mono);
  font-size: 12px;
  font-weight: 500;
  line-height: 16px;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--color-mute);
}

.body-lg {
  font-size: 16px;
  line-height: 24px;
  color: var(--color-body);
}

code, kbd, samp, pre {
  font-family: var(--font-mono);
  font-size: 14px;
  line-height: 20px;
}

/* ─── Container ──────────────────────────────────────────────────────────── */
.container {
  width: 100%;
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 var(--space-lg);
}

/* ─── Navigation ─────────────────────────────────────────────────────────── */
.nav-bar {
  position: sticky;
  top: 0;
  z-index: 100;
  background-color: var(--color-canvas);
  border-bottom: 1px solid var(--color-hairline);
  backdrop-filter: blur(8px);
}

.nav-inner {
  display: flex;
  align-items: center;
  gap: var(--space-md);
  max-width: 1200px;
  margin: 0 auto;
  padding: var(--space-sm) var(--space-lg);
  height: 56px;
}

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

.nav-logo-text {
  font-size: 15px;
  font-weight: 600;
  color: var(--color-ink);
  letter-spacing: -0.3px;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: var(--space-xxs);
  list-style: none;
  flex: 1;
}

.nav-link {
  display: inline-flex;
  align-items: center;
  padding: var(--space-xs) var(--space-sm);
  border-radius: var(--radius-full);
  font-size: 14px;
  font-weight: 400;
  line-height: 20px;
  color: var(--color-body);
  text-decoration: none;
  transition: background-color 0.15s ease, color 0.15s ease;
}
.nav-link:hover {
  background-color: var(--color-hairline-soft);
  color: var(--color-ink);
}
.nav-link:focus-visible {
  outline: 2px solid var(--color-link);
  outline-offset: 2px;
}

.nav-actions {
  display: flex;
  align-items: center;
  gap: var(--space-xs);
  flex-shrink: 0;
}

/* ─── Buttons ────────────────────────────────────────────────────────────── */
/* Primary pill — marketing CTA */
.btn-primary {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  height: 40px;
  padding: 0 14px;
  background-color: var(--color-primary);
  color: var(--color-on-primary);
  font-family: var(--font-sans);
  font-size: 16px;
  font-weight: 500;
  line-height: 20px;
  border-radius: var(--radius-pill);
  border: none;
  cursor: pointer;
  text-decoration: none;
  transition: opacity 0.15s ease;
  white-space: nowrap;
}
.btn-primary:hover { opacity: 0.85; }

/* Secondary pill */
.btn-secondary {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  height: 40px;
  padding: 0 14px;
  background-color: var(--color-canvas-elevated);
  color: var(--color-ink);
  font-family: var(--font-sans);
  font-size: 16px;
  font-weight: 500;
  line-height: 20px;
  border-radius: var(--radius-pill);
  border: 1px solid var(--color-hairline);
  cursor: pointer;
  text-decoration: none;
  transition: background-color 0.15s ease;
  white-space: nowrap;
}
.btn-secondary:hover { background-color: var(--color-hairline-soft); }

/* Small nav/app button — 6px radius */
.btn-primary-sm {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  height: 32px;
  padding: 0 10px;
  background-color: var(--color-primary);
  color: var(--color-on-primary);
  font-family: var(--font-sans);
  font-size: 14px;
  font-weight: 500;
  line-height: 20px;
  border-radius: var(--radius-sm);
  border: none;
  cursor: pointer;
  text-decoration: none;
  transition: opacity 0.15s ease;
  white-space: nowrap;
}
.btn-primary-sm:hover { opacity: 0.85; }

.btn-ghost-sm {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  height: 32px;
  padding: 0 10px;
  background-color: var(--color-canvas-elevated);
  color: var(--color-ink);
  font-family: var(--font-sans);
  font-size: 14px;
  font-weight: 500;
  line-height: 20px;
  border-radius: var(--radius-sm);
  border: 1px solid var(--color-hairline);
  cursor: pointer;
  text-decoration: none;
  transition: background-color 0.15s ease;
}
.btn-ghost-sm:hover { background-color: var(--color-hairline-soft); }

/* ─── Cards ──────────────────────────────────────────────────────────────── */
.card {
  background-color: var(--color-canvas-elevated);
  border: 1px solid var(--color-hairline);
  border-radius: var(--radius-md);
  padding: var(--space-lg);
}

.card-elevated {
  background-color: var(--color-canvas-elevated);
  border: 1px solid var(--color-hairline);
  border-radius: var(--radius-md);
  padding: var(--space-lg);
  box-shadow: var(--shadow-float);
}

/* ─── Form Inputs ────────────────────────────────────────────────────────── */
.input {
  display: block;
  width: 100%;
  height: 36px;
  padding: var(--space-xs) var(--space-sm);
  background-color: var(--color-canvas-elevated);
  color: var(--color-ink);
  border: 1px solid var(--color-hairline);
  border-radius: var(--radius-sm);
  font-family: var(--font-sans);
  font-size: 14px;
  line-height: 20px;
  transition: border-color 0.15s ease, box-shadow 0.15s ease;
}
.input::placeholder { color: var(--color-faint); }
.input:focus {
  outline: none;
  border-color: var(--color-ink);
  box-shadow: 0 0 0 3px rgba(23, 23, 23, 0.08);
}
.input:invalid:not(:placeholder-shown) { border-color: var(--color-error); }

label {
  display: block;
  font-size: 12px;
  font-weight: 500;
  color: var(--color-ink);
  margin-bottom: var(--space-xxs);
  letter-spacing: -0.1px;
}

/* ─── Footer ─────────────────────────────────────────────────────────────── */
.site-footer {
  border-top: 1px solid var(--color-hairline);
  background-color: var(--color-canvas);
  color: var(--color-body);
  padding: var(--space-3xl) 0 var(--space-xl);
}

.footer-inner {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--space-3xl);
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 var(--space-lg);
}

.footer-logo {
  font-size: 16px;
  font-weight: 600;
  color: var(--color-ink);
  letter-spacing: -0.3px;
  display: block;
  margin-bottom: var(--space-xs);
}

.footer-tagline {
  font-size: 12px;
  color: var(--color-mute);
  line-height: 16px;
}

.footer-nav {
  display: flex;
  gap: var(--space-3xl);
}

.footer-col-title {
  font-family: var(--font-mono);
  font-size: 11px;
  font-weight: 500;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--color-mute);
  margin-bottom: var(--space-sm);
}

.footer-col ul {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: var(--space-xs);
}

.footer-col a {
  font-size: 14px;
  color: var(--color-body);
  text-decoration: none;
  transition: color 0.15s ease;
}
.footer-col a:hover { color: var(--color-ink); }

.footer-bottom {
  max-width: 1200px;
  margin: var(--space-xl) auto 0;
  padding: var(--space-xl) var(--space-lg) 0;
  border-top: 1px solid var(--color-hairline);
  display: flex;
  flex-direction: column;
  gap: var(--space-xs);
}

.footer-disclaimer {
  font-size: 12px;
  color: var(--color-mute);
  line-height: 16px;
}

.footer-copyright {
  font-size: 12px;
  color: var(--color-faint);
}

/* ─── Warning Banner ─────────────────────────────────────────────────────── */
.warning-banner {
  display: flex;
  align-items: flex-start;
  gap: var(--space-sm);
  padding: var(--space-sm) var(--space-md);
  background-color: var(--color-warning-soft);
  border: 1px solid var(--color-warning);
  border-radius: var(--radius-sm);
  color: var(--color-warning-deep);
  font-size: 14px;
  line-height: 20px;
}

/* ─── Responsive ─────────────────────────────────────────────────────────── */
@media (max-width: 768px) {
  .nav-links { display: none; }

  .footer-inner {
    grid-template-columns: 1fr;
    gap: var(--space-xl);
  }
  .footer-nav { flex-direction: column; gap: var(--space-xl); }

  h1, .heading-h1 { font-size: 28px; line-height: 34px; letter-spacing: -1.2px; }
  h2, .heading-h2 { font-size: 24px; line-height: 30px; }
  h3, .heading-h3 { font-size: 18px; line-height: 24px; }
}

@media (max-width: 640px) {
  .container { padding: 0 var(--space-md); }
  .btn-primary { width: 100%; justify-content: center; }
}

/* ─── Utility ────────────────────────────────────────────────────────────── */
.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;
}

.text-mute { color: var(--color-mute); }
.text-ink  { color: var(--color-ink); }

/* ─── Calculator Widget ──────────────────────────────────────────────────── */
.calculator-widget {
  max-width: 860px;
  margin: 0 auto;
}

/* Currency row */
.calc-currency-row {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  margin-bottom: var(--space-lg);
}

.calc-currency-row label {
  margin-bottom: 0;
  font-size: 14px;
  color: var(--color-mute);
  white-space: nowrap;
}

.input-narrow {
  width: auto;
  min-width: 140px;
  height: 36px;
}

.input-wide { max-width: 240px; }

/* Debt list */
.debt-list {
  display: flex;
  flex-direction: column;
  gap: var(--space-md);
  margin-bottom: var(--space-lg);
}

.debt-row {
  padding: var(--space-lg);
}

.debt-row-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: var(--space-md);
}

.debt-fields {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: var(--space-md);
}

@media (max-width: 768px) {
  .debt-fields { grid-template-columns: 1fr 1fr; }
}
@media (max-width: 500px) {
  .debt-fields { grid-template-columns: 1fr; }
}

.field { display: flex; flex-direction: column; }

.field-hint {
  font-weight: 400;
  color: var(--color-mute);
  font-size: 11px;
}

/* Buttons */
.add-debt-btn {
  width: 100%;
  margin-bottom: var(--space-lg);
  border-style: dashed;
}

.calc-submit-btn {
  width: 100%;
  height: 48px;
  font-size: 16px;
  margin-top: var(--space-md);
}

/* Extra payment */
.extra-payment-row {
  margin-bottom: var(--space-md);
}

/* Results */
.results-section {
  margin-top: var(--space-3xl);
  display: flex;
  flex-direction: column;
  gap: var(--space-xl);
}

.winner-callout {
  padding: var(--space-lg);
  border-left: 3px solid var(--color-ink);
}

.winner-callout .mono-eyebrow { margin-bottom: var(--space-xs); display: block; }

.winner-headline {
  font-size: 16px;
  color: var(--color-ink);
  line-height: 24px;
  margin: 0;
}

.results-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--space-lg);
}

@media (max-width: 600px) {
  .results-grid { grid-template-columns: 1fr; }
}

.result-col { position: relative; }

.result-col--winner {
  border-color: var(--color-ink);
  border-width: 2px;
}

.result-col-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: var(--space-xs);
}

.winner-badge {
  font-size: 11px;
  font-weight: 500;
  background: var(--color-ink);
  color: var(--color-on-primary);
  padding: 2px 8px;
  border-radius: var(--radius-full);
  letter-spacing: 0.02em;
}

.result-description {
  font-size: 12px;
  color: var(--color-mute);
  margin-bottom: var(--space-lg);
}

.result-stats {
  display: flex;
  flex-direction: column;
  gap: var(--space-md);
}

.stat dt {
  font-size: 11px;
  font-weight: 500;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--color-mute);
  font-family: var(--font-mono);
  margin-bottom: 2px;
}

.stat-value {
  font-size: 22px;
  font-weight: 600;
  color: var(--color-ink);
  letter-spacing: -0.5px;
  line-height: 28px;
}

.stat-value--interest { color: var(--color-error); }

.result-unavailable {
  color: var(--color-faint);
  font-size: 20px;
  padding: var(--space-xl) 0;
}

/* Chart */
.chart-wrapper {
  background: var(--color-canvas-elevated);
  border: 1px solid var(--color-hairline);
  border-radius: var(--radius-md);
  padding: var(--space-lg);
}

.chart-title {
  font-size: 14px;
  font-weight: 600;
  color: var(--color-ink);
  margin-bottom: var(--space-xs);
}

.chart-legend {
  display: flex;
  gap: var(--space-lg);
  margin-bottom: var(--space-md);
}

.legend-item {
  font-size: 12px;
  display: flex;
  align-items: center;
  gap: var(--space-xs);
  color: var(--color-body);
}

.legend-item::before {
  content: '';
  display: inline-block;
  width: 16px;
  height: 2px;
  border-radius: 1px;
}

.legend-item--snowball::before { background: #7928ca; }
.legend-item--avalanche::before { background: #0070f3; }

.payoff-chart {
  width: 100%;
  height: auto;
  display: block;
}