/* My First Krypto — site.css
   Design system matched to the MyFirstKrypto.com logo: deep navy,
   bright sky blue, and orange accents. Clean editorial base with a
   playful, friendly layer: soft gradient hero bands, gradient buttons,
   rounded cards, and illustrated heroes. Mobile-first, system fonts,
   no external requests. */

/* ------------------------------------------------- design tokens */
:root {
  /* Brand (sampled from the logo) */
  --c-navy-950: #000B14;
  --c-navy-900: #00162C;
  --c-navy-800: #123A63;
  --c-blue-600: #0099F2;
  --c-blue-700: #0072CE;
  --c-blue-800: #005BB8;
  --c-blue-100: #CBE7FA;
  --c-blue-50:  #EAF4FE;
  --c-orange-600: #F7941D;
  --c-orange-700: #E07C00;
  --c-orange-800: #A85B00;
  --c-orange-100: #FFE3B8;
  --c-orange-50:  #FFF3E2;
  /* Neutrals */
  --c-ink-900:  #101C28;
  --c-ink-700:  #3D4C5C;
  --c-ink-500:  #5C6C7D;
  --c-paper:    #ffffff;
  --c-bg:       #F4F8FB;
  --c-line:     #D9E4EE;
  --c-amber-100:#FDEBC8;
  --c-amber-900:#8A5300;
  --c-red-900:  #8C1D1D;
  --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  --measure: 72ch;
  --space-1: 0.25rem;
  --space-2: 0.5rem;
  --space-3: 0.75rem;
  --space-4: 1rem;
  --space-5: 1.5rem;
  --space-6: 2rem;
  --space-7: 3rem;
  --space-8: 4rem;
  --radius: 12px;
  --shadow: 0 1px 3px rgba(0, 22, 44, 0.08), 0 4px 14px rgba(0, 22, 44, 0.06);
  --shadow-lift: 0 10px 24px rgba(0, 22, 44, 0.13);
}

/* ------------------------------------------------------- reset-ish */
*, *::before, *::after { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }
body {
  margin: 0;
  font-family: var(--font-sans);
  font-size: 1.0625rem;
  line-height: 1.65;
  color: var(--c-ink-900);
  background: var(--c-paper);
}
img, svg, video { max-width: 100%; height: auto; }
h1, h2, h3, h4 { line-height: 1.25; color: var(--c-navy-900); margin: 0 0 var(--space-4); }
h1 { font-size: clamp(1.75rem, 1.2rem + 2.4vw, 2.5rem); letter-spacing: -0.015em; }
h2 { font-size: clamp(1.35rem, 1.1rem + 1.2vw, 1.7rem); }
h3 { font-size: 1.15rem; }
p { margin: 0 0 var(--space-4); }
a { color: var(--c-blue-700); text-decoration-thickness: 1px; text-underline-offset: 2px; }
a:hover { color: var(--c-navy-900); }
:focus-visible { outline: 3px solid var(--c-blue-600); outline-offset: 2px; border-radius: 2px; }
ul, ol { padding-left: 1.25em; }

/* ------------------------------------------------------- utilities */
/* Roomier on mobile (was 1rem, too tight to the edge). */
.container { max-width: 72rem; margin-inline: auto; padding-inline: 1.25rem; }
@media (min-width: 48em) { .container { padding-inline: 1.5rem; } }
@media (min-width: 64em) { .container { padding-inline: 2rem; } }
.skip-link {
  position: absolute; left: -9999px; top: 0;
  background: var(--c-navy-900); color: #fff; padding: var(--space-3) var(--space-4);
  z-index: 100; border-radius: 0 0 var(--radius) 0;
}
.skip-link:focus { left: 0; color: #fff; }

/* --------------------------------------------------------- header */
.site-header {
  /* Soft sky-blue tint (not pure white) so the logo's white glow/highlights
     read against it; the bottom edge matches the hero's top for a seamless flow. */
  background: linear-gradient(180deg, #E3F0FC 0%, #F2F8FE 100%);
  border-bottom: 1px solid var(--c-line);
  position: relative; /* anchor for the mobile dropdown panel */
}
/* Blue→orange swoosh under the header, echoing the logo underline. */
.site-header::after {
  content: "";
  position: absolute; left: 0; right: 0; bottom: -4px; height: 3px;
  background: linear-gradient(90deg, var(--c-blue-600), var(--c-orange-600));
}
.site-header__inner {
  display: flex; align-items: center; justify-content: space-between;
  gap: var(--space-4); min-height: 3.75rem; flex-wrap: wrap; padding-block: var(--space-3);
}
.brand { text-decoration: none; display: inline-flex; align-items: center; flex-shrink: 0; }
.brand:hover .brand__fallback { color: var(--c-blue-700); }
/* Full lockup on every viewport (owner wants the complete logo, incl. mobile);
   responsive height, aspect-ratio reserves space so there's no layout shift. */
.brand img { display: block; width: auto; aspect-ratio: 640 / 205; height: 2.75rem; }
@media (min-width: 48em) {
  .brand img { height: 3.5rem; }
}

.nav-toggle {
  display: inline-flex; align-items: center; gap: var(--space-3);
  background: transparent; color: var(--c-navy-900); border: 1px solid var(--c-line);
  border-radius: var(--radius); padding: var(--space-2) var(--space-4);
  font: inherit; cursor: pointer; min-height: 44px;
  transition: border-color 0.15s ease, background-color 0.15s ease;
}
.nav-toggle:hover { border-color: var(--c-blue-600); background: var(--c-blue-50); }
/* Hamburger icon: three bars that morph into an X when open (pure CSS). */
.nav-toggle__icon {
  position: relative; width: 1.125rem; height: 2px;
  background: var(--c-navy-900); border-radius: 1px;
  transition: background-color 0.18s ease;
}
.nav-toggle__icon::before,
.nav-toggle__icon::after {
  content: ""; position: absolute; left: 0; width: 100%; height: 2px;
  background: var(--c-navy-900); border-radius: 1px;
  transition: top 0.18s ease, bottom 0.18s ease, transform 0.18s ease;
}
.nav-toggle__icon::before { top: -5px; }
.nav-toggle__icon::after { bottom: -5px; }
.nav-toggle[aria-expanded="true"] .nav-toggle__icon { background: transparent; }
.nav-toggle[aria-expanded="true"] .nav-toggle__icon::before { top: 0; transform: rotate(45deg); }
.nav-toggle[aria-expanded="true"] .nav-toggle__icon::after { bottom: auto; top: 0; transform: rotate(-45deg); }

/* Mobile: the menu drops down from the header as a panel; it overlays
   content instead of pushing the page down, and never shows when closed. */
.primary-nav {
  position: absolute; top: 100%; left: 0; right: 0;
  z-index: 50;
}
.primary-nav__list {
  list-style: none; margin: 0; padding: var(--space-2);
  display: flex; flex-direction: column; gap: var(--space-1);
  background: var(--c-paper);
  border: 1px solid var(--c-line);
  border-top: 0;
  border-radius: 0 0 var(--radius) var(--radius);
  box-shadow: 0 16px 28px rgba(0, 22, 44, 0.14);
  opacity: 0; visibility: hidden; transform: translateY(-0.5rem);
  transition: opacity 0.18s ease, transform 0.18s ease, visibility 0s 0.18s;
}
.primary-nav.is-open .primary-nav__list {
  opacity: 1; visibility: visible; transform: none;
  transition: opacity 0.18s ease, transform 0.18s ease;
}
.primary-nav a {
  display: block; width: 100%; color: var(--c-navy-900); text-decoration: none;
  padding: var(--space-3) var(--space-4); border-radius: 8px;
  min-height: 44px; line-height: 1.2; font-weight: 500;
}
.primary-nav a:hover { background: var(--c-blue-50); color: var(--c-blue-800); }
.primary-nav a[aria-current="page"] { background: var(--c-blue-50); color: var(--c-blue-700); font-weight: 600; }

@media (min-width: 48em) {
  .nav-toggle { display: none; }
  .primary-nav { position: static; flex-basis: auto; }
  .primary-nav__list {
    display: flex; flex-direction: row; flex-wrap: wrap; gap: var(--space-1);
    padding: 0; background: transparent; border: 0; border-radius: 0; box-shadow: none;
    opacity: 1; visibility: visible; transform: none; transition: none;
  }
  .primary-nav a {
    display: inline-block; width: auto;
    padding: var(--space-2) var(--space-3); border-radius: var(--radius);
  }
  .site-header__inner { flex-wrap: nowrap; }
}

/* ------------------------------------------------------------- hero */
.hero {
  padding-block: var(--space-6) var(--space-7);
  border-bottom: 1px solid var(--c-line);
  background:
    radial-gradient(52rem 26rem at 88% -30%, rgba(0, 153, 242, 0.16), transparent 65%),
    radial-gradient(44rem 24rem at -10% 130%, rgba(247, 148, 29, 0.14), transparent 60%),
    linear-gradient(180deg, #F2F8FE 0%, #FFFFFF 100%);
}
.hero__inner {
  display: grid; gap: var(--space-5); grid-template-columns: 1fr; align-items: center;
}
.hero h1 { margin-bottom: var(--space-4); }
.hero p { margin: 0; font-size: 1.15rem; line-height: 1.6; color: var(--c-ink-700); max-width: 54ch; }
.hero__img { width: 100%; max-width: 24rem; height: auto; margin-inline: auto; }
@media (min-width: 48em) {
  .hero { padding-block: var(--space-8); }
  .hero__inner { grid-template-columns: 1.15fr 1fr; gap: var(--space-7); }
  .hero__img { margin-inline: 0 auto; max-width: 30rem; }
}

/* ------------------------------------------------------------ main */
/* Horizontal padding lives here (not on .article) so guide text, figures,
   and tools keep a comfortable margin from the viewport edge on mobile. */
.main { padding: var(--space-6) 1.25rem var(--space-8); min-height: 50vh; }
@media (min-width: 48em) { .main { padding-inline: 1.5rem; } }
@media (min-width: 64em) { .main { padding-inline: 2rem; } }
.article { max-width: var(--measure); margin-inline: auto; }
.article--narrow { max-width: 60ch; }

/* ---------------------------------------------------- breadcrumbs */
.breadcrumbs { margin-bottom: var(--space-5); }
.breadcrumbs ol {
  list-style: none; display: flex; flex-wrap: wrap; gap: var(--space-2);
  margin: 0; padding: 0; font-size: 0.9rem; color: var(--c-ink-500);
}
.breadcrumbs li { display: flex; gap: var(--space-2); }
.breadcrumbs li + li::before { content: "›"; color: var(--c-line); }
.breadcrumbs a { color: var(--c-ink-500); text-decoration: none; }
.breadcrumbs a:hover { color: var(--c-blue-700); text-decoration: underline; }

/* ------------------------------------------------------------- prose */
.prose h2 { margin-top: var(--space-7); }
.prose h3 { margin-top: var(--space-6); }
.prose table { width: 100%; border-collapse: collapse; margin: 0 0 var(--space-5); font-size: 0.95rem; }
.prose th, .prose td { border: 1px solid var(--c-line); padding: var(--space-2) var(--space-3); text-align: left; vertical-align: top; }
.prose th { background: var(--c-bg); color: var(--c-navy-900); }
.table-wrap { overflow-x: auto; margin: 0 0 var(--space-5); -webkit-overflow-scrolling: touch; }
.table-wrap table { margin: 0; min-width: 40rem; }
.prose details {
  border: 1px solid var(--c-line); border-radius: var(--radius);
  padding: var(--space-3) var(--space-4); margin: 0 0 var(--space-3); background: var(--c-bg);
}
.prose details summary { cursor: pointer; font-weight: 600; color: var(--c-navy-900); padding-block: var(--space-1); }
.prose details[open] summary { margin-bottom: var(--space-3); }
.prose svg { width: 100%; height: auto; }

/* ---------------------------------------------------------- figures */
.fig { margin: var(--space-6) 0; }
.fig img { width: 100%; height: auto; }
.fig figcaption { margin-top: var(--space-3); font-size: 0.88rem; color: var(--c-ink-500); text-align: center; }

/* ---------------------------------------------------------- callouts */
.callout {
  border-radius: var(--radius); padding: var(--space-4) var(--space-5);
  margin: 0 0 var(--space-5); border-left: 4px solid;
}
.callout--info { background: var(--c-blue-50); border-color: var(--c-blue-600); }
.callout--risk { background: var(--c-amber-100); border-color: var(--c-amber-900); }
.callout--risk strong { color: var(--c-amber-900); }

/* -------------------------------------------------------- disclosure */
.disclosure {
  background: var(--c-bg); border: 1px solid var(--c-line); border-radius: var(--radius);
  padding: var(--space-3) var(--space-4); margin: 0 0 var(--space-5);
  font-size: 0.92rem; color: var(--c-ink-700);
}
.disclosure p { margin: 0; }

/* ------------------------------------------------------------- cards */
.card-grid { display: grid; gap: var(--space-4); margin: 0 0 var(--space-6); grid-template-columns: 1fr; }
@media (min-width: 30em) { .card-grid--3 { grid-template-columns: repeat(2, 1fr); } }
@media (min-width: 48em) { .card-grid--3 { grid-template-columns: repeat(3, 1fr); } }
.card {
  position: relative; overflow: hidden;
  border: 1px solid var(--c-line); border-radius: var(--radius);
  padding: var(--space-4) var(--space-5); background: var(--c-paper); box-shadow: var(--shadow);
  transition: transform 0.15s ease, box-shadow 0.15s ease;
}
/* Gradient top bar, echoing the logo swoosh. */
.card::before {
  content: ""; position: absolute; top: 0; left: 0; right: 0; height: 4px;
  background: linear-gradient(90deg, var(--c-blue-600), var(--c-orange-600));
}
.card:hover { transform: translateY(-3px); box-shadow: var(--shadow-lift); }
.card h2, .card h3 { margin-bottom: var(--space-2); font-size: 1.05rem; }
.card p { margin: 0; font-size: 0.95rem; color: var(--c-ink-700); }
.card a { text-decoration: none; }
.card a:hover { text-decoration: underline; }

/* ------------------------------------------------------ related / sources */
.related, .sources { margin-top: var(--space-7); padding-top: var(--space-5); border-top: 1px solid var(--c-line); }
.related h2, .sources h2 { font-size: 1.2rem; margin-bottom: var(--space-4); }
.sources ul { list-style: none; padding: 0; margin: 0; font-size: 0.92rem; }
.sources li { margin-bottom: var(--space-2); }

/* ------------------------------------------------------------- byline */
.byline { margin-top: var(--space-6); padding-top: var(--space-4); border-top: 1px solid var(--c-line); font-size: 0.92rem; color: var(--c-ink-500); }
.byline p { margin: 0 0 var(--space-1); }
.byline__name { color: var(--c-ink-900); font-weight: 600; }
.byline__bio { display: block; }

/* ----------------------------------------------------------- landing */
.landing { max-width: 60rem; margin-inline: auto; }
.landing-actions { display: flex; flex-wrap: wrap; gap: var(--space-3); margin-top: var(--space-5); }

.btn {
  display: inline-block; padding: var(--space-3) var(--space-5);
  border-radius: var(--radius); font-weight: 600; text-decoration: none;
  min-height: 44px; line-height: 1.2; border: 2px solid transparent;
  transition: transform 0.15s ease, box-shadow 0.15s ease, background-color 0.15s ease, color 0.15s ease, border-color 0.15s ease;
}
.btn--primary {
  background: linear-gradient(135deg, #2FA8F5, var(--c-blue-700));
  color: #fff;
  box-shadow: 0 6px 16px rgba(0, 114, 206, 0.3);
}
.btn--primary:hover { color: #fff; transform: translateY(-1px); box-shadow: 0 8px 20px rgba(0, 114, 206, 0.4); }
.btn--secondary { border-color: var(--c-blue-700); color: var(--c-blue-700); background: transparent; }
.btn--secondary:hover { background: var(--c-blue-50); color: var(--c-blue-800); transform: translateY(-1px); }

.landing-steps { counter-reset: step; list-style: none; margin: 0 0 var(--space-7); padding: 0; }
.landing-steps li {
  counter-increment: step; display: flex; gap: var(--space-4); align-items: flex-start;
  padding: var(--space-4) 0; border-bottom: 1px solid var(--c-line);
}
.landing-steps li::before {
  content: counter(step); flex: 0 0 auto; width: 2.25rem; height: 2.25rem;
  display: grid; place-items: center; border-radius: 50%;
  background: linear-gradient(135deg, #2FA8F5, var(--c-blue-700)); color: #fff; font-weight: 700;
}
.landing-steps li:nth-child(even)::before {
  background: linear-gradient(135deg, #FFB84D, var(--c-orange-600));
}
.landing-steps h2 { margin: 0 0 var(--space-1); font-size: 1.15rem; }
.landing-steps p { margin: 0; color: var(--c-ink-700); }
.landing-steps a { display: inline-block; margin-top: var(--space-2); }

/* ------------------------------------------------------------ footer */
.site-footer { background: var(--c-navy-950); color: #C3CFDB; margin-top: var(--space-8); }
.site-footer a { color: #C3CFDB; text-decoration: none; }
.site-footer a:hover { color: #fff; text-decoration: underline; }
.site-footer .brand { font-size: 1.1rem; }
.site-footer__grid {
  display: grid; gap: var(--space-6); grid-template-columns: 1fr;
  padding-block: var(--space-7);
}
@media (min-width: 30em) { .site-footer__grid { grid-template-columns: repeat(2, 1fr); } }
@media (min-width: 48em) { .site-footer__grid { grid-template-columns: 2fr repeat(4, 1fr); } }
.site-footer__brand p { font-size: 0.92rem; margin: var(--space-3) 0 0; max-width: 34ch; }
.site-footer__heading { color: #fff; font-size: 0.95rem; margin-bottom: var(--space-3); }
.site-footer__col ul { list-style: none; margin: 0; padding: 0; }
.site-footer__col li { margin-bottom: var(--space-2); font-size: 0.92rem; }
.site-footer__legal {
  display: flex; flex-wrap: wrap; gap: var(--space-2) var(--space-4);
  padding-block: var(--space-4); border-top: 1px solid rgba(255,255,255,0.15);
  font-size: 0.88rem;
}
.site-footer__note { padding-bottom: var(--space-6); font-size: 0.85rem; color: #8FA1B3; margin: 0; }

/* ------------------------------------------------------------- error */
.error-page .card-grid { margin-top: var(--space-6); }

/* ---------------------------------------------------------- tools */
.tool {
  background: var(--c-bg); border: 1px solid var(--c-line); border-radius: var(--radius);
  padding: var(--space-5); margin: var(--space-5) 0; box-shadow: var(--shadow);
}
.tool__grid { display: grid; gap: var(--space-4); grid-template-columns: 1fr; }
@media (min-width: 40em) { .tool__grid { grid-template-columns: 1fr 1fr; } }
.tool label { display: block; font-weight: 600; color: var(--c-navy-900); margin-bottom: var(--space-1); font-size: 0.95rem; }
.tool .hint { font-weight: 400; color: var(--c-ink-500); font-size: 0.85rem; }
.tool input, .tool select {
  width: 100%; padding: var(--space-2) var(--space-3); min-height: 44px;
  border: 1px solid var(--c-line); border-radius: 8px; font: inherit; color: var(--c-ink-900);
  background: var(--c-paper);
}
.tool input:focus, .tool select:focus { outline: 3px solid var(--c-blue-100); border-color: var(--c-blue-600); }
.tool__actions { display: flex; flex-wrap: wrap; gap: var(--space-3); margin-top: var(--space-4); }
.tool__result { margin: var(--space-5) 0 0; }
.tool__result[hidden] { display: none; }
.result-rows { margin: 0; }
.result-rows div { display: flex; justify-content: space-between; gap: var(--space-3); padding-block: var(--space-2); border-bottom: 1px solid var(--c-line); }
.result-rows div:last-child { border-bottom: 0; }
.result-rows dt { color: var(--c-ink-700); }
.result-rows dd { margin: 0; font-weight: 700; color: var(--c-navy-900); font-variant-numeric: tabular-nums; }
.result-rows .is-total dd { color: var(--c-blue-700); }
.tool__note { font-size: 0.85rem; color: var(--c-ink-500); margin: var(--space-3) 0 0; }

/* checklist */
.checklist { list-style: none; margin: var(--space-4) 0 0; padding: 0; }
.checklist li {
  display: flex; gap: var(--space-3); align-items: flex-start;
  padding: var(--space-3); border: 1px solid var(--c-line); border-radius: 8px; margin-bottom: var(--space-2); background: var(--c-paper);
}
.checklist li.is-done { background: var(--c-blue-50); border-color: var(--c-blue-600); }
.checklist input[type="checkbox"] { width: 1.25rem; height: 1.25rem; min-height: 0; flex: 0 0 auto; margin-top: 0.15rem; }
.checklist label { margin: 0; font-weight: 500; }
.checklist .cl-hint { display: block; font-weight: 400; color: var(--c-ink-500); font-size: 0.85rem; }
.checklist__progress { font-weight: 700; color: var(--c-navy-900); }

/* ---------------------------------------------------- reduced motion */
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.001ms !important;
    transition-duration: 0.001ms !important;
    scroll-behavior: auto !important;
  }
}