/* ===== VisaCryptoGuide — Design Tokens =====
   Palette: cool off-white surface, deep indigo-violet primary,
   signal-teal accent for CTAs/data, warm amber reserved for alerts.
   Type: Fraunces (display, editorial trust) + Inter (body/UI) +
   JetBrains Mono (data, card numbers, stats).
*/

:root {
  /* Color */
  --color-bg: #FAFAFC;
  --color-surface: #FFFFFF;
  --color-surface-sunken: #F1F1F7;
  --color-ink: #12131A;
  --color-ink-soft: #565A6E;
  --color-ink-faint: #8A8DA3;
  --color-border: #E4E4EC;
  --color-border-strong: #CBCBDA;

  --color-primary: #3730E0;
  --color-primary-ink: #FFFFFF;
  --color-primary-soft: #EDECFD;
  --color-primary-dark: #241C9E;

  --color-accent: #00B894;
  --color-accent-ink: #052E27;
  --color-accent-soft: #DEFBF3;

  --color-amber: #B45309;
  --color-amber-soft: #FEF3E2;

  --color-danger: #C4331E;

  /* Gradient used only in the hero card signature element */
  --gradient-card: linear-gradient(135deg, #3730E0 0%, #6D5BFF 45%, #00B894 100%);

  /* Type */
  --font-display: "Fraunces", "Iowan Old Style", Georgia, serif;
  --font-body: "Inter", -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  --font-mono: "JetBrains Mono", "SFMono-Regular", Consolas, monospace;

  /* Scale */
  --step--1: clamp(0.83rem, 0.8rem + 0.15vw, 0.9rem);
  --step-0: clamp(1rem, 0.96rem + 0.2vw, 1.125rem);
  --step-1: clamp(1.2rem, 1.1rem + 0.4vw, 1.4rem);
  --step-2: clamp(1.5rem, 1.3rem + 0.8vw, 1.9rem);
  --step-3: clamp(1.9rem, 1.6rem + 1.4vw, 2.6rem);
  --step-4: clamp(2.4rem, 1.9rem + 2.2vw, 3.6rem);
  --step-5: clamp(3rem, 2.2rem + 3.4vw, 4.8rem);

  /* Layout */
  --container-w: 1180px;
  --radius-sm: 8px;
  --radius-md: 14px;
  --radius-lg: 22px;
  --shadow-sm: 0 1px 2px rgba(18, 19, 26, 0.06);
  --shadow-md: 0 8px 24px -8px rgba(18, 19, 26, 0.16);
  --shadow-lg: 0 24px 60px -16px rgba(24, 22, 90, 0.22);
}

@media (prefers-color-scheme: dark) {
  :root { color-scheme: light; }
}

* { box-sizing: border-box; }
html {
  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-ink);
  font-family: var(--font-body);
  font-size: var(--step-0);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

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

h1, h2, h3, h4 {
  font-family: var(--font-display);
  font-weight: 600;
  line-height: 1.12;
  letter-spacing: -0.01em;
  margin: 0 0 0.5em;
  color: var(--color-ink);
}
h1 { font-size: var(--step-5); font-weight: 560; }
h2 { font-size: var(--step-3); }
h3 { font-size: var(--step-2); }
h4 { font-size: var(--step-1); font-family: var(--font-body); font-weight: 700; }

p { margin: 0 0 1.1em; color: var(--color-ink-soft); }
p:last-child { margin-bottom: 0; }

a { color: var(--color-primary); text-decoration-thickness: 1.5px; text-underline-offset: 3px; }
a:focus-visible, button:focus-visible, input:focus-visible, textarea:focus-visible, select:focus-visible, summary:focus-visible {
  outline: 2.5px solid var(--color-primary);
  outline-offset: 2px;
  border-radius: 4px;
}

.container {
  width: 100%;
  max-width: var(--container-w);
  margin-inline: auto;
  padding-inline: 20px;
}

.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-size: var(--step--1);
  font-weight: 700;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--color-primary);
}

.section { padding-block: clamp(56px, 8vw, 108px); }
.section-sunken { background: var(--color-surface-sunken); }

.lede {
  font-size: var(--step-1);
  color: var(--color-ink-soft);
  max-width: 62ch;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  font-family: var(--font-body);
  font-weight: 700;
  font-size: var(--step--1);
  padding: 14px 26px;
  border-radius: 999px;
  border: 1.5px solid transparent;
  cursor: pointer;
  min-height: 48px;
  text-decoration: none;
  transition: transform 0.15s ease, box-shadow 0.15s ease, background 0.15s ease;
}
.btn:hover { transform: translateY(-1px); }
.btn-primary {
  background: var(--color-ink);
  color: #fff;
  box-shadow: var(--shadow-sm);
}
.btn-primary:hover { background: var(--color-primary-dark); box-shadow: var(--shadow-md); }
.btn-accent {
  background: var(--color-accent);
  color: var(--color-accent-ink);
}
.btn-accent:hover { box-shadow: var(--shadow-md); }
.btn-ghost {
  background: transparent;
  border-color: var(--color-border-strong);
  color: var(--color-ink);
}
.btn-ghost:hover { border-color: var(--color-ink); }
.btn-sm { padding: 10px 18px; min-height: 40px; font-size: 0.8rem; }
.btn-block { width: 100%; }

.card {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: 28px;
}

.badge {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-size: 0.72rem;
  font-weight: 700;
  letter-spacing: 0.03em;
  text-transform: uppercase;
  padding: 5px 10px;
  border-radius: 999px;
  background: var(--color-primary-soft);
  color: var(--color-primary-dark);
}

table { width: 100%; border-collapse: collapse; font-size: var(--step--1); }
th, td { text-align: left; padding: 14px 16px; border-bottom: 1px solid var(--color-border); vertical-align: top; }
th { font-family: var(--font-body); font-weight: 700; color: var(--color-ink); background: var(--color-surface-sunken); }
tbody tr:hover { background: var(--color-primary-soft); }

.disclosure-banner {
  background: var(--color-amber-soft);
  color: var(--color-amber);
  border-top: 1px solid #F3D9AE;
  font-size: var(--step--1);
}

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

.skip-link {
  position: absolute;
  left: 12px; top: -60px;
  background: var(--color-ink);
  color: #fff;
  padding: 10px 16px;
  border-radius: var(--radius-sm);
  z-index: 100;
  transition: top 0.15s ease;
}
.skip-link:focus { top: 12px; }

article.prose h2 { margin-top: 1.6em; }
article.prose h3 { margin-top: 1.3em; font-size: var(--step-1); }
article.prose ul, article.prose ol { color: var(--color-ink-soft); padding-left: 1.3em; }
article.prose li { margin-bottom: 0.5em; }
article.prose p { max-width: 72ch; }
article.prose blockquote {
  margin: 1.6em 0;
  padding: 4px 0 4px 20px;
  border-left: 3px solid var(--color-primary);
  color: var(--color-ink);
  font-style: italic;
}