/* ==========================================================================
   BASE — reset, typography, layout primitives, header, mobile menu, footer
   ========================================================================== */

/* ---- Reset ------------------------------------------------------------- */
*, *::before, *::after { box-sizing: border-box; }
* { margin: 0; }
html {
  -webkit-text-size-adjust: 100%;
  text-size-adjust: 100%;
  scroll-behavior: smooth;
  scroll-padding-top: calc(var(--header-h) + 1.5rem);
}
/* Large monitors: everything is rem-based, so this scales type, spacing and
   the container together instead of leaving a small island in a sea of white. */
@media (min-width: 1800px) { html { font-size: 106.25%; } }  /* 17px */
@media (min-width: 2300px) { html { font-size: 118.75%; } }  /* 19px */
body {
  min-height: 100vh;
  background: var(--color-bg);
  color: var(--color-text);
  font-family: var(--font-sans);
  font-size: var(--text-base);
  line-height: var(--leading-relaxed);
  letter-spacing: var(--tracking-body);
  font-feature-settings: "ss01", "cv11";
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  text-rendering: optimizeLegibility;
  overflow-x: clip;
}
img, svg, video, canvas { display: block; max-width: 100%; }
img { height: auto; }
input, button, textarea, select { font: inherit; color: inherit; letter-spacing: inherit; }
button { cursor: pointer; background: none; border: 0; padding: 0; }
a { color: inherit; text-decoration: none; }
ul[class], ol[class] { list-style: none; padding: 0; }
h1, h2, h3, h4 { font-weight: var(--weight-semibold); line-height: var(--leading-snug); text-wrap: balance; }
p { text-wrap: pretty; }
[hidden] { display: none !important; }
::selection { background: var(--blue-100); color: var(--blue-800); }

:focus { outline: none; }
:focus-visible {
  outline: 2px solid var(--color-primary);
  outline-offset: 3px;
  border-radius: var(--radius-xs);
}

.skip-link {
  position: fixed;
  top: var(--space-3);
  left: var(--space-3);
  z-index: 1000;
  padding: var(--space-3) var(--space-4);
  background: var(--color-dark);
  color: #fff;
  border-radius: var(--radius-sm);
  font-size: var(--text-sm);
  transform: translateY(-200%);
  transition: transform var(--dur) var(--ease-out);
}
.skip-link:focus-visible { transform: none; }

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

/* ---- Icons ------------------------------------------------------------- */
.icon-sprite { position: absolute; width: 0; height: 0; overflow: hidden; }
.icon {
  width: 1.25rem;
  height: 1.25rem;
  flex: none;
  fill: none;
  stroke: currentColor;
  stroke-width: 1.6;
  stroke-linecap: round;
  stroke-linejoin: round;
}
.icon--sm { width: 1rem; height: 1rem; }
.icon--lg { width: 1.5rem; height: 1.5rem; }

/* ---- Layout ------------------------------------------------------------ */
.container {
  width: 100%;
  max-width: calc(var(--container) + var(--gutter) * 2);
  margin-inline: auto;
  padding-inline: var(--gutter);
}
.container--wide { max-width: calc(var(--container-wide) + var(--gutter) * 2); }
.container--narrow { max-width: calc(var(--container-narrow) + var(--gutter) * 2); }

.section { position: relative; padding-block: var(--section-y); }
.section--sm { padding-block: var(--section-y-sm); }
.section--muted { background: var(--color-surface-muted); }
.section--white { background: var(--color-surface); }
.section--flush-top { padding-top: 0; }
.section--divider { border-top: 1px solid var(--color-border); }

/* ---- Typography -------------------------------------------------------- */
.display {
  font-size: var(--text-display);
  line-height: var(--leading-tight);
  letter-spacing: var(--tracking-display);
  font-weight: var(--weight-semibold);
}
.h1 {
  font-size: var(--text-4xl);
  line-height: 1.06;
  letter-spacing: var(--tracking-display);
}
.h2 {
  font-size: var(--text-3xl);
  line-height: 1.08;
  letter-spacing: var(--tracking-heading);
}
.h3 {
  font-size: var(--text-2xl);
  line-height: 1.15;
  letter-spacing: var(--tracking-heading);
}
.h4 {
  font-size: var(--text-lg);
  line-height: 1.3;
  letter-spacing: var(--tracking-title);
}
.lead {
  font-size: var(--text-lg);
  line-height: 1.55;
  color: var(--color-text-secondary);
  max-width: var(--measure);
}
.text-muted { color: var(--color-text-muted); }
.text-secondary { color: var(--color-text-secondary); }
.accent-dot { color: var(--color-accent); }
.text-blue { color: var(--color-primary); }
.soft { color: var(--gray-400); }

.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  font-weight: var(--weight-medium);
  letter-spacing: var(--tracking-label);
  text-transform: uppercase;
  color: var(--color-text-muted);
}
.eyebrow::before {
  content: "";
  width: 6px;
  height: 6px;
  border-radius: 2px;
  background: var(--color-accent);
}
.eyebrow__num { color: var(--color-text); }
.eyebrow--plain::before { display: none; }

.section-head { max-width: 46rem; margin-bottom: clamp(2.5rem, 1.5rem + 3vw, 4.5rem); }
.section-head .eyebrow { margin-bottom: var(--space-5); }
.section-head .lead { margin-top: var(--space-5); }
.section-head--center { margin-inline: auto; text-align: center; }
.section-head--center .lead { margin-inline: auto; }
.section-head--split {
  max-width: none;
  display: grid;
  gap: var(--space-6);
  align-items: end;
}
@media (min-width: 1024px) {
  .section-head--split { grid-template-columns: 1.1fr 0.9fr; gap: var(--space-16); }
  .section-head--split .lead { margin-top: 0; }
}

.prose { max-width: var(--measure); color: var(--color-text-secondary); }
.prose > * + * { margin-top: var(--space-4); }
.prose h2 { color: var(--color-text); font-size: var(--text-xl); letter-spacing: var(--tracking-title); margin-top: var(--space-12); }
.prose h3 { color: var(--color-text); font-size: var(--text-lg); letter-spacing: var(--tracking-title); margin-top: var(--space-8); }
.prose ul { padding-left: 1.2rem; }
.prose li + li { margin-top: var(--space-2); }
.prose a { color: var(--color-primary); text-decoration: underline; text-underline-offset: 3px; }
.prose strong { color: var(--color-text); font-weight: var(--weight-medium); }

/* ==========================================================================
   HEADER
   ========================================================================== */
.site-header {
  position: fixed;
  inset: 0 0 auto 0;
  z-index: var(--z-header);
  height: var(--header-h);
  border-bottom: 1px solid transparent;
  transition: background-color var(--dur-slow) var(--ease-out),
              border-color var(--dur-slow) var(--ease-out),
              box-shadow var(--dur-slow) var(--ease-out);
}
.site-header.is-scrolled,
.site-header.is-solid {
  background: rgba(251, 251, 253, 0.8);
  -webkit-backdrop-filter: saturate(180%) blur(16px);
  backdrop-filter: saturate(180%) blur(16px);
  border-bottom-color: var(--color-border);
  box-shadow: 0 1px 12px -8px rgba(11, 17, 32, 0.12);
}
.header__inner {
  height: 100%;
  display: flex;
  align-items: center;
  gap: var(--space-8);
}

.logo {
  display: inline-flex;
  align-items: center;
  gap: 0.6rem;
  font-size: 1.0625rem;
  letter-spacing: -0.02em;
  white-space: nowrap;
  flex: none;
}
.logo__img { display: block; width: auto; height: 28px; }
.logo:focus-visible { outline-offset: 6px; }
@media (max-width: 479px) { .logo__img { height: 24px; } }

.nav { flex: 1; display: none; justify-content: center; }
.nav__list { display: flex; align-items: center; gap: var(--space-1); }
.nav__link {
  position: relative;
  display: inline-flex;
  align-items: center;
  height: 2.25rem;
  padding: 0 0.8rem;
  font-size: var(--text-sm);
  font-weight: var(--weight-medium);
  color: var(--color-text-secondary);
  border-radius: var(--radius-pill);
  transition: color var(--dur) var(--ease-out), background-color var(--dur) var(--ease-out);
}
.nav__link:hover { color: var(--color-text); background: rgba(11, 17, 32, 0.04); }
.nav__link[aria-current="page"] { color: var(--color-text); }
.nav__link[aria-current="page"]::after {
  content: "";
  position: absolute;
  left: 50%;
  bottom: 1px;
  width: 4px;
  height: 4px;
  margin-left: -2px;
  border-radius: 50%;
  background: var(--color-accent);
}

.header__actions { margin-left: auto; display: flex; align-items: center; gap: var(--space-3); }
.header__actions .header__cta { display: none; }

.lang-switch {
  display: inline-flex;
  align-items: center;
  gap: 1px;
  padding: 3px;
  border-radius: var(--radius-pill);
  background: rgba(11, 17, 32, 0.045);
  font-family: var(--font-mono);
  font-size: var(--text-2xs);
  font-weight: var(--weight-medium);
  letter-spacing: 0.06em;
}
.lang-switch button {
  min-width: 2.1rem;
  height: 1.7rem;
  padding: 0 0.5rem;
  border-radius: var(--radius-pill);
  color: var(--color-text-muted);
  transition: color var(--dur) var(--ease-out), background-color var(--dur) var(--ease-out), box-shadow var(--dur) var(--ease-out);
}
.lang-switch button:hover { color: var(--color-text); }
.lang-switch button[aria-pressed="true"] {
  background: var(--color-surface);
  color: var(--color-text);
  box-shadow: var(--shadow-sm);
}

.menu-toggle {
  position: relative;
  width: 2.75rem;
  height: 2.75rem;
  margin-right: -0.5rem;
  border-radius: var(--radius-pill);
  display: grid;
  place-items: center;
}
.menu-toggle__bar {
  position: absolute;
  left: 50%;
  width: 18px;
  height: 1.5px;
  margin-left: -9px;
  border-radius: 2px;
  background: var(--color-text);
  transition: transform var(--dur-slow) var(--ease-out);
}
.menu-toggle__bar--top { transform: translateY(-4px); }
.menu-toggle__bar--bottom { transform: translateY(4px); }
.menu-toggle[aria-expanded="true"] .menu-toggle__bar--top { transform: rotate(45deg); }
.menu-toggle[aria-expanded="true"] .menu-toggle__bar--bottom { transform: rotate(-45deg); }

@media (min-width: 640px) {
  .header__actions .header__cta { display: inline-flex; }
}
@media (min-width: 1024px) {
  .nav { display: flex; }
  .menu-toggle { display: none; }
}
.cta-label--short { display: none; }
@media (min-width: 1024px) and (max-width: 1199px) {
  /* Compact desktop: short label visually; the full label stays available to screen readers. */
  .header__cta .cta-label--full { position: absolute; width: 1px; height: 1px; overflow: hidden; clip: rect(0 0 0 0); white-space: nowrap; }
  .header__cta .cta-label--short { display: inline; }
}
@media (min-width: 1024px) and (max-width: 1279px) {
  .logo__img { height: 24px; }
  .header__inner { gap: var(--space-5); }
  .nav__list { gap: 0; }
  .nav__link { padding: 0 0.6rem; font-size: 0.8125rem; }
}

/* ---- Mobile menu ------------------------------------------------------- */
.mobile-menu {
  position: fixed;
  inset: 0;
  z-index: var(--z-menu);
  padding: calc(var(--header-h) + var(--space-6)) var(--gutter) var(--space-8);
  background: rgba(251, 251, 253, 0.97);
  -webkit-backdrop-filter: blur(20px);
  backdrop-filter: blur(20px);
  display: flex;
  flex-direction: column;
  overflow-y: auto;
  opacity: 0;
  visibility: hidden;
  transition: opacity var(--dur-slow) var(--ease-out), visibility 0s linear var(--dur-slow);
}
.menu-open .mobile-menu {
  opacity: 1;
  visibility: visible;
  transition: opacity var(--dur-slow) var(--ease-out), visibility 0s;
}
.menu-open .site-header { background: transparent; border-color: transparent; box-shadow: none; -webkit-backdrop-filter: none; backdrop-filter: none; z-index: calc(var(--z-menu) + 1); }
.menu-open { overflow: hidden; }

.mobile-menu__list { display: flex; flex-direction: column; }
.mobile-menu__list a {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0.9rem 0;
  font-size: 1.75rem;
  font-weight: var(--weight-semibold);
  letter-spacing: var(--tracking-heading);
  border-bottom: 1px solid var(--color-border);
  opacity: 0;
  transform: translateY(12px);
  transition: opacity var(--dur-slow) var(--ease-out), transform var(--dur-slow) var(--ease-out), color var(--dur) var(--ease-out);
}
.mobile-menu__list li:nth-child(2) a { transition-delay: 40ms; }
.mobile-menu__list li:nth-child(3) a { transition-delay: 80ms; }
.mobile-menu__list li:nth-child(4) a { transition-delay: 120ms; }
.mobile-menu__list li:nth-child(5) a { transition-delay: 160ms; }
.mobile-menu__list li:nth-child(6) a { transition-delay: 200ms; }
.mobile-menu__list li:nth-child(7) a { transition-delay: 240ms; }
.mobile-menu__list a .icon { color: var(--gray-400); transition: transform var(--dur) var(--ease-out); }
.mobile-menu__list a:active .icon { transform: translateX(4px); }
.mobile-menu__list a[aria-current="page"] { color: var(--color-primary); }
.menu-open .mobile-menu__list a { opacity: 1; transform: none; }

.mobile-menu__footer {
  margin-top: auto;
  padding-top: var(--space-8);
  display: grid;
  gap: var(--space-4);
}
.mobile-menu__footer .btn { width: 100%; }
.mobile-menu__meta { display: flex; align-items: center; justify-content: space-between; color: var(--color-text-muted); font-size: var(--text-sm); }

/* ==========================================================================
   FOOTER
   ========================================================================== */
.site-footer {
  background: var(--color-surface);
  border-top: 1px solid var(--color-border);
  padding-top: clamp(3.5rem, 2.5rem + 4vw, 6rem);
  font-size: var(--text-sm);
  color: var(--color-text-secondary);
}
.footer__top {
  display: grid;
  gap: var(--space-12);
  padding-bottom: var(--space-12);
}
.footer__brand p { margin-top: var(--space-4); max-width: 22rem; line-height: 1.6; }
.footer__brand .btn-row { margin-top: var(--space-6); }
.footer__button { padding: 0 0 1px; font-size: inherit; color: inherit; text-align: left; transition: color var(--dur) var(--ease-out), background-size var(--dur-slow) var(--ease-out); }
.footer__button:hover { color: var(--color-primary); }
.footer__cols { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: var(--space-10) var(--space-6); }
.footer__title {
  font-family: var(--font-mono);
  font-size: var(--text-2xs);
  font-weight: var(--weight-medium);
  letter-spacing: var(--tracking-label);
  text-transform: uppercase;
  color: var(--color-text-muted);
  margin-bottom: var(--space-4);
}
.footer__links { display: grid; gap: 0.6rem; }
.footer__links a { transition: color var(--dur) var(--ease-out); overflow-wrap: anywhere; }
.footer__links a:hover { color: var(--color-primary); }
.footer__bottom {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-4);
  padding-block: var(--space-6);
  padding-bottom: calc(var(--space-6) + 4.5rem); /* room for the floating AI button */
  border-top: 1px solid var(--color-border);
  color: var(--color-text-muted);
  font-size: var(--text-xs);
}
.footer__legal { display: flex; flex-wrap: wrap; gap: var(--space-2) var(--space-5); }
.footer__note { color: var(--gray-400); }

@media (min-width: 768px) {
  .footer__cols { grid-template-columns: repeat(4, minmax(0, 1fr)); }
}
@media (min-width: 1200px) {
  .footer__top { grid-template-columns: 0.9fr 2fr; gap: var(--space-16); }
}

/* ---- Page offset for fixed header ------------------------------------- */
main { display: block; }
.page-top { padding-top: var(--header-h); }