/* =====================================================================
   [BRAND NAME] — styles.css
   Palette: deep navy → glacier blue. One motif: concentric "onion" rings.
   ===================================================================== */

:root {
  --navy-900: #071528;
  --navy-800: #0b1e3a;
  --navy-700: #12315c;
  --blue-600: #1f4e8c;
  --blue-500: #2f6fc0;
  --blue-400: #4f93e6;
  --sky-300:  #8ec2f6;
  --ice-100:  #e6f0fb;
  --ice-50:   #f3f8fd;
  --white:    #ffffff;

  --ink:      var(--navy-900);
  --ink-soft: #3d5578;
  --line:     rgba(31, 78, 140, 0.16);

  --font-ui:    "Manrope", "Segoe UI", system-ui, sans-serif;
  --font-serif: "Newsreader", Georgia, "Times New Roman", serif;

  --radius-s: 6px;
  --radius-m: 14px;
  --radius-pill: 999px;

  --wrap: 1180px;
  --gutter: clamp(1.25rem, 4vw, 2.5rem);

  --ease: cubic-bezier(.22,.7,.22,1);
}

/* ---------- reset-ish ---------- */
*,*::before,*::after { box-sizing: border-box; }
html { scroll-behavior: smooth; -webkit-text-size-adjust: 100%; }
body {
  margin: 0;
  font-family: var(--font-ui);
  font-size: 1.0625rem;
  line-height: 1.6;
  color: var(--ink);
  background: var(--ice-50);
  overflow-x: hidden;
}
img { max-width: 100%; height: auto; display: block; }
a { color: var(--blue-600); text-decoration-thickness: 1px; text-underline-offset: 3px; }
a:hover { color: var(--navy-700); }
ul, ol { padding-left: 0; margin: 0; }
h1, h2, h3 { margin: 0; font-family: var(--font-serif); font-weight: 600; line-height: 1.12; letter-spacing: -0.01em; }
h1 { font-size: clamp(2.4rem, 5.2vw, 4.25rem); font-optical-sizing: auto; }
h2 { font-size: clamp(1.75rem, 3.2vw, 2.6rem); }
h3 { font-size: 1.3rem; }
p { margin: 0 0 1.1em; }
.wrap { width: min(var(--wrap), 100% - 2 * var(--gutter)); margin-inline: auto; }

.visually-hidden {
  position: absolute !important; width: 1px; height: 1px; overflow: hidden;
  clip: rect(0 0 0 0); white-space: nowrap;
}
.skip-link {
  position: absolute; left: 1rem; top: -3rem; background: var(--navy-800); color: #fff;
  padding: .6rem 1rem; border-radius: var(--radius-s); z-index: 100; transition: top .2s;
}
.skip-link:focus { top: 1rem; }
:focus-visible { outline: 3px solid var(--blue-400); outline-offset: 3px; border-radius: 4px; }

/* ---------- buttons ---------- */
.btn {
  display: inline-flex; align-items: center; gap: .5rem;
  font-weight: 600; font-size: .98rem; text-decoration: none;
  padding: .85rem 1.5rem; border-radius: var(--radius-pill);
  border: 1.5px solid transparent; cursor: pointer;
  transition: transform .25s var(--ease), box-shadow .25s var(--ease), background .25s;
}
.btn-primary { background: var(--blue-600); color: #fff; box-shadow: 0 8px 24px -10px rgba(31,78,140,.7); }
.btn-primary:hover { background: var(--navy-700); color: #fff; transform: translateY(-2px); box-shadow: 0 14px 30px -12px rgba(31,78,140,.8); }
.btn-ghost { background: transparent; color: var(--navy-800); border-color: var(--line); }
.btn-ghost:hover { border-color: var(--blue-400); background: #fff; }

/* ---------- header ---------- */
.site-header {
  position: sticky; top: 0; z-index: 50;
  background: rgba(243,248,253,.82);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid transparent;
  transition: border-color .3s, box-shadow .3s;
}
.site-header.is-scrolled { border-color: var(--line); box-shadow: 0 6px 24px -18px rgba(7,21,40,.35); }
.header-inner { display: flex; align-items: center; justify-content: space-between; min-height: 72px; gap: 1rem; }
.brand { display: inline-flex; align-items: center; gap: .65rem; color: var(--navy-800); text-decoration: none; }
.brand-mark { color: var(--blue-600); }
.brand-name { font-family: var(--font-serif); font-size: 1.35rem; font-weight: 600; letter-spacing: -.01em; }

.nav-list { list-style: none; display: flex; gap: .25rem; align-items: center; }
.nav-list a { display: inline-block; padding: .55rem .9rem; border-radius: var(--radius-pill); color: var(--ink-soft); text-decoration: none; font-weight: 500; font-size: .95rem; transition: background .2s, color .2s; }
.nav-list a:hover, .nav-list a.is-active { color: var(--navy-800); background: var(--ice-100); }
.nav-list .nav-cta { background: var(--navy-800); color: #fff; margin-left: .5rem; }
.nav-list .nav-cta:hover { background: var(--blue-600); color: #fff; }

.nav-toggle { display: none; background: none; border: 0; width: 44px; height: 44px; position: relative; cursor: pointer; }
.nav-toggle-bar, .nav-toggle-bar::before, .nav-toggle-bar::after {
  content: ""; position: absolute; left: 10px; width: 24px; height: 2px; background: var(--navy-800); border-radius: 2px;
  transition: transform .3s var(--ease), opacity .2s;
}
.nav-toggle-bar { top: 21px; }
.nav-toggle-bar::before { top: -7px; left: 0; }
.nav-toggle-bar::after  { top: 7px;  left: 0; }
.nav-toggle[aria-expanded="true"] .nav-toggle-bar { background: transparent; }
.nav-toggle[aria-expanded="true"] .nav-toggle-bar::before { transform: translateY(7px) rotate(45deg); }
.nav-toggle[aria-expanded="true"] .nav-toggle-bar::after  { transform: translateY(-7px) rotate(-45deg); }

/* ---------- hero ---------- */
.hero {
  position: relative; isolation: isolate;
  background: radial-gradient(120% 90% at 85% 10%, #dbe9fa 0%, var(--ice-50) 55%);
  padding: clamp(3rem, 8vw, 6.5rem) 0 clamp(3rem, 7vw, 5rem);
  overflow: hidden;
}
/* ring motif bleeding from the right edge */
.hero::before {
  content: ""; position: absolute; z-index: -1; right: -18vw; top: -22vw; width: 70vw; height: 70vw;
  border-radius: 50%;
  background:
    repeating-radial-gradient(circle at center, transparent 0 46px, rgba(31,78,140,.09) 46px 47px);
  mask-image: radial-gradient(circle at center, #000 30%, transparent 72%);
  animation: rings-drift 30s linear infinite alternate;
}
@keyframes rings-drift { to { transform: translate(-4%, 3%) scale(1.04); } }

.hero-grid { display: grid; grid-template-columns: minmax(0, 1.1fr) minmax(0, .9fr); gap: clamp(2rem, 5vw, 5rem); align-items: center; }
.hero-kicker { font-size: .9rem; font-weight: 600; color: var(--blue-600); margin-bottom: 1.25rem; }
.hero h1 { color: var(--navy-800); margin-bottom: 1.5rem; max-width: 16ch; }
.hero-lead { font-family: var(--font-serif); font-size: 1.3rem; line-height: 1.5; color: var(--ink-soft); max-width: 46ch; margin-bottom: 2rem; }
.hero-actions { display: flex; flex-wrap: wrap; gap: .75rem; margin-bottom: 2.5rem; }
.hero-facts { display: flex; flex-wrap: wrap; gap: 2rem; margin: 0; padding-top: 1.5rem; border-top: 1px solid var(--line); }
.hero-facts dt { font-size: .8rem; color: var(--ink-soft); }
.hero-facts dd { margin: .15rem 0 0; font-weight: 600; color: var(--navy-800); }
.hero-art { margin: 0; position: relative; }
.hero-art img { width: 100%; max-width: 560px; margin-inline: auto; filter: drop-shadow(0 30px 40px rgba(31,78,140,.25)); }

/* page-load sequence — the one orchestrated moment */
.hero-copy > * { opacity: 0; transform: translateY(18px); animation: rise .8s var(--ease) forwards; }
.hero-copy > :nth-child(1) { animation-delay: .05s; }
.hero-copy > :nth-child(2) { animation-delay: .15s; }
.hero-copy > :nth-child(3) { animation-delay: .28s; }
.hero-copy > :nth-child(4) { animation-delay: .4s; }
.hero-copy > :nth-child(5) { animation-delay: .52s; }
.hero-art { opacity: 0; transform: scale(.94); animation: bloom 1.1s var(--ease) .3s forwards; }
@keyframes rise  { to { opacity: 1; transform: none; } }
@keyframes bloom { to { opacity: 1; transform: none; } }

/* ---------- generic section ---------- */
.section { padding: clamp(3.5rem, 8vw, 6.5rem) 0; }
.section-head { max-width: 62ch; margin-bottom: clamp(2rem, 4vw, 3.5rem); }
.section-head h2 { color: var(--navy-800); margin-bottom: .75rem; }
.section-head p { color: var(--ink-soft); font-size: 1.1rem; }

/* scroll reveal (single, applied once per section by script.js) */
.reveal { opacity: 0; transform: translateY(24px); transition: opacity .8s var(--ease), transform .8s var(--ease); }
.reveal.is-visible { opacity: 1; transform: none; }

/* ---------- overview: sticky serif prose ---------- */
.overview { background: #fff; border-block: 1px solid var(--line); }
.prose-grid { display: grid; grid-template-columns: minmax(0, .8fr) minmax(0, 1.4fr); gap: clamp(2rem, 5vw, 5rem); }
.prose-aside { position: sticky; top: 96px; align-self: start; }
.prose-aside h2 { color: var(--navy-800); }
.prose-aside p { color: var(--ink-soft); margin-top: .75rem; }
.prose { font-family: var(--font-serif); font-size: 1.2rem; line-height: 1.65; max-width: 66ch; }
.prose p { margin-bottom: 1.4em; }
.prose blockquote {
  margin: 2rem 0; padding: 1.25rem 1.5rem 1.25rem 1.75rem; position: relative;
  color: var(--navy-700); font-size: 1.35rem; font-style: italic;
  border-left: 3px solid var(--blue-400); background: var(--ice-50); border-radius: 0 var(--radius-m) var(--radius-m) 0;
}
.prose blockquote p { margin-bottom: .5rem; }
.prose blockquote footer { font-family: var(--font-ui); font-style: normal; font-size: .9rem; color: var(--ink-soft); }

/* ---------- layers ---------- */
.layers { background: linear-gradient(180deg, var(--ice-50) 0%, var(--ice-100) 100%); }
.layers-grid { display: grid; grid-template-columns: minmax(0, 1.1fr) minmax(0, .9fr); gap: clamp(2rem, 5vw, 4rem); align-items: start; }
.layers-art { margin: 0; background: var(--navy-800); border-radius: var(--radius-m); padding: 1.25rem; position: sticky; top: 96px; box-shadow: 0 30px 60px -30px rgba(7,21,40,.6); }
.layers-art img { width: 100%; border-radius: var(--radius-s); }
.layers-art figcaption { color: var(--sky-300); font-size: .9rem; margin-top: .9rem; }

.layer-list { list-style: none; display: grid; gap: 1rem; counter-reset: layer; }
.layer {
  position: relative; padding: 1.5rem 1.5rem 1.5rem 4.5rem; background: #fff;
  border: 1px solid var(--line); border-radius: var(--radius-m);
  transition: transform .3s var(--ease), border-color .3s, box-shadow .3s;
}
.layer:hover { transform: translateX(6px); border-color: var(--blue-400); box-shadow: 0 16px 40px -24px rgba(31,78,140,.5); }
.layer-index {
  position: absolute; left: 1.25rem; top: 1.45rem; width: 2.25rem; height: 2.25rem;
  display: grid; place-items: center; border-radius: 50%;
  font-family: var(--font-serif); font-weight: 600; color: var(--blue-600);
  background: var(--ice-100);
  box-shadow: 0 0 0 4px #fff, 0 0 0 5px var(--line);
}
.layer:nth-child(2) .layer-index { box-shadow: 0 0 0 4px #fff, 0 0 0 5px var(--line), 0 0 0 9px #fff, 0 0 0 10px var(--line); }
.layer:nth-child(3) .layer-index { box-shadow: 0 0 0 4px #fff, 0 0 0 5px var(--line), 0 0 0 9px #fff, 0 0 0 10px var(--line), 0 0 0 14px #fff, 0 0 0 15px var(--line); }
.layer h3 { color: var(--navy-800); margin-bottom: .5rem; }
.layer p { margin: 0; color: var(--ink-soft); }

/* ---------- guide / steps ---------- */
.guide { background: #fff; }
.steps { list-style: none; display: grid; grid-template-columns: repeat(4, minmax(0, 1fr)); gap: 1.5rem; counter-reset: step; }
.step { position: relative; padding-top: 2.25rem; }
.step::before {
  counter-increment: step; content: counter(step, decimal-leading-zero);
  position: absolute; top: 0; left: 0; font-family: var(--font-serif); font-size: 1rem; color: var(--blue-500); font-weight: 600;
}
.step::after { content: ""; position: absolute; top: .65rem; left: 2.25rem; right: 0; height: 1px; background: var(--line); }
.step:last-child::after { display: none; }
.step h3 { color: var(--navy-800); margin-bottom: .6rem; font-size: 1.2rem; }
.step p { color: var(--ink-soft); margin: 0; font-size: 1rem; }

/* ---------- tools ---------- */
.tools { background: var(--navy-800); color: var(--ice-100); position: relative; overflow: hidden; }
.tools::after {
  content: ""; position: absolute; left: -10vw; bottom: -30vw; width: 60vw; height: 60vw; border-radius: 50%;
  background: repeating-radial-gradient(circle at center, transparent 0 40px, rgba(142,194,246,.12) 40px 41px);
  mask-image: radial-gradient(circle at center, #000 30%, transparent 70%);
  pointer-events: none;
}
.tools-grid { display: grid; grid-template-columns: minmax(0, 1.1fr) minmax(0, .9fr); gap: clamp(2rem, 5vw, 5rem); align-items: center; position: relative; z-index: 1; }
.tools h2 { color: #fff; margin-bottom: 1rem; }
.tools-copy > p { color: var(--sky-300); font-size: 1.1rem; }
.checklist { list-style: none; margin: 1.75rem 0 2.25rem; display: grid; gap: .9rem; }
.checklist li { position: relative; padding-left: 2rem; color: var(--ice-100); }
.checklist li::before {
  content: ""; position: absolute; left: 0; top: .45em; width: 1.1rem; height: 1.1rem; border-radius: 50%;
  border: 1.5px solid var(--sky-300);
  background: radial-gradient(circle, var(--sky-300) 0 25%, transparent 27%);
}
.checklist strong { color: #fff; }
.tools .btn-primary { background: var(--sky-300); color: var(--navy-900); box-shadow: none; }
.tools .btn-primary:hover { background: #fff; color: var(--navy-900); }
.tools-art { margin: 0; }
.tools-art img { width: 100%; max-width: 480px; margin-inline: auto; }

/* ---------- faq ---------- */
.faq { background: var(--ice-50); }
.faq-grid { display: grid; grid-template-columns: minmax(0, .8fr) minmax(0, 1.4fr); gap: clamp(2rem, 5vw, 5rem); }
.faq-list { display: grid; gap: .75rem; }
.faq-item { background: #fff; border: 1px solid var(--line); border-radius: var(--radius-m); overflow: hidden; transition: border-color .3s; }
.faq-item[open] { border-color: var(--blue-400); }
.faq-item summary { list-style: none; cursor: pointer; padding: 1.15rem 3.25rem 1.15rem 1.5rem; position: relative; }
.faq-item summary::-webkit-details-marker { display: none; }
.faq-item summary h3 { font-size: 1.15rem; color: var(--navy-800); }
.faq-item summary::after {
  content: ""; position: absolute; right: 1.4rem; top: 50%; width: 12px; height: 12px;
  border-right: 2px solid var(--blue-600); border-bottom: 2px solid var(--blue-600);
  transform: translateY(-70%) rotate(45deg); transition: transform .3s var(--ease);
}
.faq-item[open] summary::after { transform: translateY(-30%) rotate(-135deg); }
.faq-item p { margin: 0; padding: 0 1.5rem 1.25rem; color: var(--ink-soft); }
.faq-item[open] p { animation: fade-in .4s var(--ease); }
@keyframes fade-in { from { opacity: 0; transform: translateY(-6px); } to { opacity: 1; transform: none; } }

/* ---------- cta ---------- */
.cta { background: #fff; border-top: 1px solid var(--line); }
.cta-inner { text-align: center; max-width: 620px; }
.cta h2 { color: var(--navy-800); margin-bottom: .75rem; }
.cta p { color: var(--ink-soft); }
.cta-form { display: flex; gap: .6rem; margin-top: 1.75rem; }
.cta-form input {
  flex: 1; min-width: 0; padding: .85rem 1.25rem; font: inherit; border-radius: var(--radius-pill);
  border: 1.5px solid var(--line); background: var(--ice-50); color: var(--ink);
  transition: border-color .2s, background .2s;
}
.cta-form input:focus { border-color: var(--blue-400); background: #fff; outline: none; }

/* ---------- footer ---------- */
.site-footer { background: var(--navy-900); color: var(--sky-300); padding: 3.5rem 0 2.5rem; }
.footer-grid { display: grid; grid-template-columns: 1.4fr 1fr 1fr; gap: 2.5rem; }
.footer-brand .brand-name { color: #fff; }
.footer-brand p { margin-top: 1rem; font-size: .95rem; max-width: 42ch; }
.footer-nav ul { list-style: none; display: grid; gap: .6rem; }
.footer-nav a { color: var(--ice-100); text-decoration: none; }
.footer-nav a:hover { color: #fff; text-decoration: underline; }
.footer-meta { font-size: .9rem; }
.footer-meta p { margin-bottom: .4rem; }

/* ---------- back to top ---------- */
.to-top {
  position: fixed; right: 1.25rem; bottom: 1.25rem; width: 46px; height: 46px; z-index: 40;
  display: grid; place-items: center; border-radius: 50%; text-decoration: none;
  background: var(--navy-800); color: #fff; font-weight: 700;
  opacity: 0; transform: translateY(10px); pointer-events: none;
  transition: opacity .3s, transform .3s var(--ease), background .2s;
}
.to-top.is-visible { opacity: 1; transform: none; pointer-events: auto; }
.to-top:hover { background: var(--blue-600); color: #fff; }

/* ---------- responsive ---------- */
@media (max-width: 960px) {
  .hero-grid, .prose-grid, .layers-grid, .tools-grid, .faq-grid { grid-template-columns: 1fr; }
  .hero-art { order: -1; }
  .hero-art img { max-width: 380px; }
  .prose-aside, .layers-art { position: static; }
  .steps { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .footer-grid { grid-template-columns: 1fr 1fr; }
  .footer-brand { grid-column: 1 / -1; }
}
@media (max-width: 720px) {
  .nav-toggle { display: block; }
  .nav-list {
    position: absolute; left: 0; right: 0; top: 100%; flex-direction: column; align-items: stretch; gap: .25rem;
    background: #fff; padding: 1rem var(--gutter) 1.5rem; border-bottom: 1px solid var(--line);
    transform: translateY(-8px); opacity: 0; visibility: hidden; transition: transform .3s var(--ease), opacity .3s, visibility .3s;
  }
  .nav-list.is-open { transform: none; opacity: 1; visibility: visible; }
  .nav-list .nav-cta { margin: .5rem 0 0; text-align: center; }
  .steps { grid-template-columns: 1fr; }
  .step::after { display: none; }
  .cta-form { flex-direction: column; }
  .footer-grid { grid-template-columns: 1fr; }
}

/* ---------- reduced motion ---------- */
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after { animation: none !important; transition: none !important; }
  .hero-copy > *, .hero-art, .reveal { opacity: 1; transform: none; }
}