/* ============================================================
   Kneuralabs — Components
   Header, nav, buttons, FAQ, footer, forms, theme toggle.
   ============================================================ */

/* ── Header ── */
header.top {
  position: sticky;
  top: 0;
  z-index: 50;
  background: var(--paper);
  background: color-mix(in oklab, var(--paper) 92%, transparent);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--rule);
  transition: background-color 420ms var(--ease-out), border-color 420ms var(--ease-out);
}
html[data-theme="dark"] header.top {
  background: var(--paper);
  background: color-mix(in oklab, var(--paper) 78%, transparent);
  border-bottom-color: rgba(255,255,255,.08);
}
header.top.scrolled { box-shadow: 0 1px 0 var(--rule); }

.topbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  min-height: 72px;
  gap: 18px;
  padding-top: 22px;
  padding-bottom: 22px;
}

.brand {
  display: flex;
  align-items: center;
  gap: 12px;
  font-family: var(--serif);
  font-size: clamp(24px, 2.6vw, 34px);
  font-weight: 500;
  letter-spacing: -.02em;
  line-height: 1;
  flex: none;
  font-style: normal;
}
.brand-img {
  display: block;
  width: clamp(34px, 3.4vw, 44px);
  height: clamp(34px, 3.4vw, 44px);
  border-radius: 10px;
  object-fit: cover;
  flex: none;
  box-shadow: 0 0 0 1px var(--rule);
  transition: transform var(--dur-l) var(--ease-out);
}
html[data-theme="dark"] .brand-img { box-shadow: 0 0 0 1px rgba(255,255,255,.14); }
.brand:hover .brand-img { transform: rotate(-12deg) scale(1.06); }

nav.primary {
  display: flex;
  gap: 2px;
  font-size: 13px;
  letter-spacing: .01em;
  min-width: 0;
  flex-wrap: nowrap;
}
nav.primary a {
  display: inline-flex;
  align-items: center;
  color: var(--ink-2);
  padding: 7px 11px;
  border-radius: 999px;
  white-space: nowrap;
  font-style: normal;
  transition: color var(--dur-xs) var(--ease-out), background-color var(--dur-xs) var(--ease-out);
}
@media (max-width: 1240px) {
  nav.primary { font-size: 12.5px; }
  nav.primary a { padding: 7px 9px; }
  .cta-mini { padding: 8px 12px; }
}
nav.primary a:hover { color: var(--ink); background: var(--hover-fill-2); }
nav.primary a.active { color: var(--paper); background: var(--ink); }
html[data-theme="dark"] nav.primary a.active { background: var(--ink); color: var(--paper); }

/* Dropdown menus */
nav.primary .nav-group { position: relative; display: inline-flex; }
nav.primary .nav-group > a { gap: 4px; }
nav.primary .nav-group > a .chevron {
  display: inline-block; width: 10px; height: 10px; flex-shrink: 0;
  transition: transform var(--dur-xs) var(--ease-out);
}
nav.primary .nav-group:hover > a .chevron,
nav.primary .nav-group:focus-within > a .chevron { transform: rotate(180deg); }
nav.primary .dropdown {
  position: absolute; top: calc(100% + 6px); left: 50%;
  background: var(--paper); border: 1px solid var(--stroke);
  border-radius: 12px; padding: 6px; min-width: 150px;
  box-shadow: 0 8px 24px rgba(0,0,0,.10);
  opacity: 0; pointer-events: none; visibility: hidden;
  /* hide: delay 120ms so mouse can travel from trigger → dropdown */
  transition: opacity .15s var(--ease-out) .12s, transform .15s var(--ease-out) .12s, visibility 0s .27s;
  transform: translateX(-50%) translateY(-4px);
  z-index: 200;
}
/* Invisible bridge fills the 6px gap so hover isn't broken mid-travel */
nav.primary .dropdown::before {
  content: ''; position: absolute; top: -8px; left: 0; right: 0; height: 8px;
}
html[data-theme="dark"] nav.primary .dropdown { box-shadow: 0 8px 24px rgba(0,0,0,.35); }
nav.primary .nav-group:hover .dropdown,
nav.primary .nav-group:focus-within .dropdown {
  opacity: 1; pointer-events: auto; visibility: visible;
  transform: translateX(-50%) translateY(0);
  /* show: no delay */
  transition: opacity .15s var(--ease-out), transform .15s var(--ease-out), visibility 0s;
}
nav.primary .dropdown a {
  display: flex; width: 100%; border-radius: 8px;
  padding: 7px 12px; white-space: nowrap;
}

/* Mobile accordion — full rules live in the hamburger/menu block below */

.cta-mini {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 9px 14px;
  border: 1px solid var(--ink);
  border-radius: 999px;
  font-size: 13px;
  font-weight: 500;
  white-space: nowrap;
  transition: background-color var(--dur-xs) var(--ease-out), color var(--dur-xs) var(--ease-out), border-color var(--dur-xs) var(--ease-out);
}
.cta-mini:hover { background: var(--ink); color: var(--paper); }
html[data-theme="dark"] .cta-mini { border-color: rgba(255,255,255,.32); }
html[data-theme="dark"] .cta-mini:hover { background: var(--ink); color: var(--paper); border-color: var(--ink); }
.cta-mini .dot {
  width: 6px; height: 6px;
  border-radius: 50%;
  background: #2ea66a;
  box-shadow: 0 0 0 3px #2ea66a22;
}

/* ── Buttons ── */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  padding: 14px 20px;
  border-radius: 999px;
  font-size: 14px;
  font-weight: 500;
  cursor: pointer;
  border: 0;
  will-change: transform;
  transition: transform var(--dur-s) var(--ease-out), background-color var(--dur-s) var(--ease-out), color var(--dur-s) var(--ease-out), border-color var(--dur-s) var(--ease-out);
}
.btn:hover { transform: translateY(-1px) scale(1.01); }
.btn:active { transform: translateY(0) scale(.99); transition-duration: 120ms; }
.btn-primary { background: var(--ink); color: var(--paper); }
.btn-primary:hover { background: var(--accent); color: var(--on-accent); }
.btn-ghost { border: 1px solid var(--ink); color: var(--ink); }
.btn-ghost:hover { background: var(--ink); color: var(--paper); }
html[data-theme="dark"] .btn-primary { background: var(--ink); color: var(--paper); }
html[data-theme="dark"] .btn-primary:hover { background: var(--accent); color: var(--on-accent); }
html[data-theme="dark"] .btn-ghost { border-color: rgba(255,255,255,.30); color: var(--ink); }
html[data-theme="dark"] .btn-ghost:hover { background: var(--ink); color: var(--paper); }
.btn-block { width: 100%; justify-content: center; }
.arr { transition: transform .25s var(--ease-out); }
.btn:hover .arr, .cta-mini:hover .arr { transform: translateX(4px); }
.btn-spinner {
  width: 14px; height: 14px;
  border: 2px solid currentColor;
  border-right-color: transparent;
  border-radius: 50%;
  display: inline-block;
  animation: spin .6s linear infinite;
}
@keyframes spin { to { transform: rotate(360deg); } }

/* ── FAQ / details ── */
.faq {
  display: grid;
  grid-template-columns: 1fr;
  border-top: 1px solid var(--ink);
}
details { border-bottom: 1px solid var(--rule); }
details summary {
  list-style: none;
  cursor: pointer;
  display: grid;
  grid-template-columns: 40px 1fr 40px;
  gap: 20px;
  align-items: center;
  padding: 24px 8px;
  font-family: var(--serif);
  font-weight: 400;
  font-size: 22px;
  letter-spacing: -.01em;
}
details summary::-webkit-details-marker { display: none; }
details summary .qn {
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: .14em;
  color: var(--ink-2);
}
details summary .pm {
  width: 28px; height: 28px;
  border-radius: 50%;
  border: 1px solid var(--ink);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 14px;
  line-height: 0;
  transition: transform var(--dur-s) var(--ease-spring), background-color var(--dur-xs), color var(--dur-xs);
}
html[data-theme="dark"] details summary .pm { border-color: rgba(255,255,255,.30); }
details[open] summary .pm { background: var(--ink); color: var(--paper); transform: rotate(45deg); }
details .body {
  padding: 0 8px 28px 68px;
  color: var(--ink-2);
  max-width: 80ch;
  font-size: 15.5px;
  line-height: 1.65;
  animation: faqOpen var(--dur-m) var(--ease-out) both;
}
@keyframes faqOpen { from { opacity: 0; transform: translateY(-6px); } to { opacity: 1; transform: none; } }
@media (max-width: 720px) {
  details summary { grid-template-columns: 28px 1fr 28px; gap: 14px; font-size: 18px; }
  details .body { padding: 0 8px 24px 50px; }
}

/* ── Question index (homepage FAQ teaser) ── */
.q-index { border-top: 1px solid var(--ink); }
.q-index a {
  display: grid;
  grid-template-columns: 44px 1fr 28px;
  gap: 20px;
  align-items: center;
  padding: 22px 8px;
  border-bottom: 1px solid var(--rule);
  text-decoration: none;
  color: var(--ink);
  transition: padding-left var(--dur-s) var(--ease-spring), background-color var(--dur-xs) var(--ease-out);
}
.q-index a:hover, .q-index a:focus-visible { background: var(--paper-2); padding-left: 16px; outline: none; }
.q-index .qn { font-family: var(--mono); font-size: 11px; letter-spacing: .14em; color: var(--ink-2); }
.q-index .qt { font-family: var(--serif); font-weight: 400; font-size: 21px; letter-spacing: -.01em; }
.q-index .go {
  width: 28px; height: 28px;
  border-radius: 50%;
  border: 1px solid var(--ink);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 14px;
  line-height: 0;
  transition: background-color var(--dur-xs) var(--ease-out), color var(--dur-xs) var(--ease-out), transform var(--dur-s) var(--ease-spring);
}
.q-index a:hover .go, .q-index a:focus-visible .go { background: var(--ink); color: var(--paper); transform: translateX(2px); }
html[data-theme="dark"] .q-index .go { border-color: rgba(255,255,255,.30); }
@media (max-width: 720px) {
  .q-index a { grid-template-columns: 30px 1fr 24px; gap: 14px; padding: 18px 2px; }
  .q-index a:hover, .q-index a:focus-visible { padding-left: 8px; }
  .q-index .qt { font-size: 17px; }
}

/* ── Footer ── */
footer.footer {
  padding: 48px 0 32px;
  font-size: 13px;
  color: var(--ink-2);
  border-top: 1px solid var(--rule);
}
.foot-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: 32px;
  padding-bottom: 32px;
  border-bottom: 1px solid var(--rule);
}
.foot-brand .brand {
  display: inline-flex;
  flex-direction: row;
  flex-wrap: nowrap;
  align-items: center;
  font-size: 22px;
  gap: 12px;
  margin-bottom: 14px;
}
.foot-brand .brand .brand-img {
  width: 28px; height: 28px; border-radius: 8px;
}
.foot-tagline { max-width: 38ch; color: var(--ink-2); line-height: 1.55; }
.foot-col h4 {
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: .14em;
  text-transform: uppercase;
  color: var(--ink);
  margin: 0 0 12px;
  font-weight: 500;
}
.foot-col a { display: block; padding: 5px 0; color: var(--ink-2); }
.foot-col a:hover { color: var(--ink); }
.foot-meta {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding-top: 20px;
  flex-wrap: wrap;
  gap: 12px;
}
.foot-meta .mono { font-family: var(--mono); font-size: 11px; letter-spacing: .1em; }
.foot-meta a:hover { color: var(--ink); }
@media (max-width: 820px) {
  .foot-grid { grid-template-columns: 1fr 1fr; }
  .foot-brand { grid-column: 1 / -1; }
}
@media (max-width: 520px) { .foot-grid { grid-template-columns: 1fr; gap: 24px; } }
/* Footer meta — stack copyright + tagline on small phones to prevent overflow */
@media (max-width: 480px) {
  .foot-meta { flex-direction: column; align-items: flex-start; gap: 8px; }
  .foot-meta .mono { font-size: 10.5px; }
}

/* ── Form ── */
form.card {
  background: var(--paper-2);
  border: 1px solid var(--rule);
  padding: 32px;
  border-radius: 6px;
  display: flex;
  flex-direction: column;
  gap: 18px;
}
html[data-theme="dark"] form.card { border-color: rgba(255,255,255,.08); }
form.card h3 {
  font-family: var(--serif);
  font-weight: 400;
  font-size: 22px;
  letter-spacing: -.01em;
  margin: 0 0 4px;
}
.field { display: flex; flex-direction: column; gap: 6px; }
form.card label {
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: .14em;
  text-transform: uppercase;
  color: var(--ink-2);
}
.form-label-note { text-transform: none; letter-spacing: 0; opacity: .7; }
form.card input,
form.card select,
form.card textarea {
  background: var(--paper);
  border: 1px solid var(--rule);
  padding: 12px 14px;
  font: inherit;
  font-size: 14.5px;
  color: var(--ink);
  border-radius: 4px;
  transition: border-color var(--dur-xs) var(--ease-out), box-shadow var(--dur-xs) var(--ease-out);
}
html[data-theme="dark"] form.card input,
html[data-theme="dark"] form.card select,
html[data-theme="dark"] form.card textarea { border-color: rgba(255,255,255,.10); }
form.card input::placeholder,
form.card textarea::placeholder { color: var(--ink-2); opacity: .7; }
form.card input:focus,
form.card select:focus,
form.card textarea:focus {
  outline: none;
  border-color: var(--ink);
  box-shadow: 0 0 0 3px var(--focus-ring);
}
form.card textarea { resize: vertical; min-height: 96px; }
.row2 { display: grid; grid-template-columns: 1fr 1fr; gap: 14px; }
@media (max-width: 540px) { .row2 { grid-template-columns: 1fr; } }
form.card button[type="submit"] {
  margin-top: 6px;
  background: var(--ink);
  color: var(--paper);
  border: 0;
  padding: 14px 18px;
  border-radius: 999px;
  font: inherit;
  font-size: 14px;
  font-weight: 500;
  cursor: pointer;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  transition: background-color var(--dur-s) var(--ease-out), transform var(--dur-s) var(--ease-out);
}
form.card button[type="submit"]:hover { background: var(--accent); color: var(--on-accent); transform: translateY(-1px); }
form.card button[disabled] { opacity: .7; cursor: progress; }
.form-note { font-size: 12.5px; color: var(--ink-2); margin: 4px 0 0; line-height: 1.5; }
.form-success {
  display: flex;
  flex-direction: column;
  gap: 10px;
  padding: 28px 4px;
  text-align: left;
}
.form-success svg { stroke: var(--accent); }
.form-success h3 { font-family: var(--serif); font-size: 24px; font-weight: 400; margin: 4px 0 0; }
.form-success p { color: var(--ink-2); font-size: 15px; line-height: 1.6; }
.form-success a { color: var(--ink); font-weight: 500; text-decoration: underline; text-underline-offset: 3px; }

/* ── Header action cluster ── */
.topbar-actions {
  display: flex;
  align-items: center;
  gap: 10px;
  flex: none;
}

/* ── Theme toggle (header control) ── */
.theme-toggle {
  flex: none;
  width: 40px;
  height: 40px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  border: 1px solid var(--rule);
  background: transparent;
  color: var(--ink);
  transition: border-color var(--dur-s) var(--ease-out), background-color var(--dur-s) var(--ease-out), transform var(--dur-s) var(--ease-spring);
}
.theme-toggle:hover { transform: scale(1.06); border-color: var(--ink); background: var(--hover-fill); }
html[data-theme="dark"] .theme-toggle { border-color: rgba(255,255,255,.18); }
html[data-theme="dark"] .theme-toggle:hover { border-color: rgba(255,255,255,.40); }
.theme-toggle svg { width: 18px; height: 18px; }
.theme-toggle .icon-moon { display: none; }
html[data-theme="dark"] .theme-toggle .icon-sun { display: none; }
html[data-theme="dark"] .theme-toggle .icon-moon { display: block; }

/* Floating variant — fixed to the viewport, scrolls with nothing,
   stays clear of content and the iOS home indicator. */
.theme-toggle.theme-fab {
  position: fixed;
  right: max(18px, env(safe-area-inset-right, 0px));
  bottom: calc(18px + env(safe-area-inset-bottom, 0px));
  z-index: 55;
  width: 46px;
  height: 46px;
  background: color-mix(in oklab, var(--paper) 80%, transparent);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  border-color: var(--rule);
  box-shadow: var(--shadow-card);
}
.theme-toggle.theme-fab:hover {
  background: color-mix(in oklab, var(--paper) 92%, transparent);
  border-color: var(--ink);
}
html[data-theme="dark"] .theme-toggle.theme-fab { border-color: rgba(255,255,255,.16); }
html[data-theme="dark"] .theme-toggle.theme-fab:hover { border-color: rgba(255,255,255,.40); }
@media (max-width: 760px) {
  .theme-toggle.theme-fab {
    right: max(14px, env(safe-area-inset-right, 0px));
    bottom: calc(14px + env(safe-area-inset-bottom, 0px));
  }
}

/* ── Hamburger — morphs to × ── */
.hamburger {
  display: none;
  position: relative;
  width: 44px;
  height: 44px;
  margin-right: -8px;
  border: 1px solid transparent;
  border-radius: 50%;
  background: transparent;
  cursor: pointer;
  flex: none;
  padding: 0;
  transition:
    background-color var(--dur-xs) var(--ease-out),
    border-color var(--dur-xs) var(--ease-out),
    transform var(--dur-s) var(--ease-spring);
}
.hamburger:hover {
  background: var(--hover-fill-2);
  border-color: var(--rule);
}
html[data-theme="dark"] .hamburger:hover { border-color: rgba(255,255,255,.16); }
.hamburger:active { transform: scale(0.88); }
.hamburger span {
  position: absolute;
  left: 10px;
  width: 24px;
  height: 2px;
  border-radius: 3px;
  background: var(--ink);
  transform-origin: center;
  transition:
    transform 440ms var(--ease-spring),
    opacity 200ms var(--ease-out),
    width 340ms var(--ease-spring);
}
/* Bar centres: 15px, 22px, 29px inside the 44px button */
.hamburger span:nth-child(1) { top: 14px; }
.hamburger span:nth-child(2) { top: 21px; }
.hamburger span:nth-child(3) { top: 28px; width: 16px; }
/* Bottom bar elongates on hover — micro-detail */
.hamburger:hover span:nth-child(3) { width: 24px; }
/* Morph to × */
.hamburger.open span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.hamburger.open span:nth-child(2) { opacity: 0; transform: scaleX(0.1); }
.hamburger.open span:nth-child(3) { width: 24px; transform: translateY(-7px) rotate(-45deg); }

/* ── Backdrop ── */
.nav-backdrop {
  position: fixed;
  inset: 0;
  background: rgba(0,0,0,.45);
  backdrop-filter: blur(3px);
  -webkit-backdrop-filter: blur(3px);
  opacity: 0;
  pointer-events: none;
  transition: opacity 360ms var(--ease-out);
  z-index: 70;
}
.nav-backdrop.open { opacity: 1; pointer-events: auto; }

/* ── Mobile menu — premium frosted card ── */
.mobile-menu {
  position: fixed;
  top: 10px;
  left: 10px;
  right: 10px;
  bottom: 10px;
  border-radius: 24px;
  background: color-mix(in oklab, var(--paper) 92%, transparent);
  backdrop-filter: blur(40px) saturate(200%);
  -webkit-backdrop-filter: blur(40px) saturate(200%);
  border: 1px solid color-mix(in oklab, var(--rule) 60%, transparent);
  box-shadow:
    0 0 0 1px color-mix(in oklab, white 14%, transparent) inset,
    0 32px 80px rgba(0,0,0,.22),
    0 6px 20px rgba(0,0,0,.10);
  z-index: 71;
  display: flex;
  flex-direction: column;
  padding: 8px 28px calc(20px + env(safe-area-inset-bottom, 0px));
  overflow-y: auto;
  -webkit-overflow-scrolling: touch;
  opacity: 0;
  visibility: hidden;
  transform: scale(0.94) translateY(-18px);
  transform-origin: top center;
  transition:
    opacity 280ms var(--ease-out),
    transform 440ms var(--ease-spring),
    visibility 0s linear 440ms;
}
html[data-theme="dark"] .mobile-menu {
  background: color-mix(in oklab, var(--paper) 90%, transparent);
  border-color: rgba(255,255,255,.10);
  box-shadow:
    0 0 0 1px rgba(255,255,255,.06) inset,
    0 32px 80px rgba(0,0,0,.55),
    0 6px 20px rgba(0,0,0,.25);
}
.mobile-menu.open {
  opacity: 1;
  visibility: visible;
  transform: none;
  transition:
    opacity 280ms var(--ease-out),
    transform 440ms var(--ease-spring),
    visibility 0s;
}

/* Top bar */
.mobile-menu-top {
  display: flex;
  align-items: center;
  justify-content: space-between;
  min-height: 54px;
  padding-bottom: 4px;
  flex-shrink: 0;
}
.mobile-menu-top::before {
  content: "MENU";
  font-family: var(--mono);
  font-size: 11px;
  font-weight: 500;
  letter-spacing: .22em;
  color: var(--ink-2);
  opacity: .65;
}

/* Close button — circular, rotates 90° on hover */
.menu-close {
  position: relative;
  width: 36px;
  height: 36px;
  border-radius: 50%;
  border: 1px solid var(--rule);
  background: var(--hover-fill);
  cursor: pointer;
  flex: none;
  display: flex;
  align-items: center;
  justify-content: center;
  transition:
    background-color var(--dur-xs) var(--ease-out),
    border-color var(--dur-xs) var(--ease-out),
    transform 420ms var(--ease-spring);
}
.menu-close:hover {
  background: var(--ink);
  border-color: var(--ink);
  transform: rotate(90deg) scale(1.08);
}
html[data-theme="dark"] .menu-close { border-color: rgba(255,255,255,.15); background: rgba(255,255,255,.06); }
html[data-theme="dark"] .menu-close:hover { background: var(--ink); border-color: var(--ink); }
.menu-close span {
  position: absolute;
  left: 50%;
  top: 50%;
  width: 14px;
  height: 1.5px;
  background: var(--ink);
  border-radius: 2px;
  transition: background-color var(--dur-xs) var(--ease-out);
}
.menu-close:hover span { background: var(--paper); }
.menu-close span:nth-child(1) { transform: translate(-50%, -50%) rotate(45deg); }
.menu-close span:nth-child(2) { transform: translate(-50%, -50%) rotate(-45deg); }

/* ── Mobile nav links ── */
.mobile-nav {
  display: flex;
  flex-direction: column;
  flex: 1;
  margin: 6px 0 18px;
  counter-reset: mnav;
}
.mobile-nav > a,
.mobile-nav > .nav-group { counter-increment: mnav; }
.mobile-nav a {
  display: flex;
  align-items: center;
  gap: 16px;
  font-family: var(--serif);
  font-size: clamp(22px, 7vw, 32px);
  font-weight: 400;
  letter-spacing: -.03em;
  color: var(--ink-2);
  padding: 14px 0;
  border-bottom: 1px solid color-mix(in oklab, var(--rule) 50%, transparent);
  transition:
    color var(--dur-xs) var(--ease-out),
    padding-left 320ms var(--ease-spring);
}
/* Editorial index number (01–05) before each primary item */
.mobile-nav > a::before,
.mobile-nav .mobile-row > a::before {
  content: counter(mnav, decimal-leading-zero);
  flex: none;
  font-family: var(--mono);
  font-size: 12px;
  font-weight: 500;
  letter-spacing: .04em;
  color: var(--accent);
  opacity: .5;
  transform: translateY(-.5em);
  transition: opacity var(--dur-xs) var(--ease-out);
}
.mobile-nav a::after {
  content: "→";
  font-family: var(--sans);
  font-size: 17px;
  font-weight: 400;
  letter-spacing: 0;
  flex-shrink: 0;
  margin-left: auto;
  opacity: 0;
  transform: translateX(-8px);
  transition:
    opacity var(--dur-s) var(--ease-out),
    transform var(--dur-s) var(--ease-spring);
}
.mobile-nav a:hover,
.mobile-nav a:focus-visible { color: var(--ink); padding-left: 8px; }
.mobile-nav a:hover::after,
.mobile-nav a:focus-visible::after { opacity: 1; transform: none; }
.mobile-nav a.active { color: var(--ink); }
.mobile-nav a.active::before { opacity: 1; }
.mobile-nav a.active::after { opacity: .4; transform: none; }

/* ── Mobile accordion groups ─────────────────────────────
   The section label navigates (like Home); an injected .sub-toggle
   chevron reveals the sub-pages. */
.mobile-nav .nav-group {
  display: flex;
  flex-direction: column;
  border-bottom: 1px solid color-mix(in oklab, var(--rule) 50%, transparent);
}

/* Row holds the navigating label + the expand toggle side by side */
.mobile-row {
  display: flex;
  align-items: center;
  gap: 8px;
}
.mobile-row > a {
  flex: 1 1 auto;
  min-width: 0;
  border-bottom: none;
}
.mobile-row > a::after { display: none; }              /* the chevron speaks for it */
.mobile-nav .nav-group a .chevron { display: none; } /* drop the inline svg */

/* Circular expand toggle — fills with ink when open */
.sub-toggle {
  flex: none;
  width: 42px;
  height: 42px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0;
  border: 1px solid var(--rule);
  border-radius: 50%;
  background: var(--hover-fill);
  color: var(--ink-2);
  cursor: pointer;
  transition:
    background-color var(--dur-xs) var(--ease-out),
    border-color var(--dur-xs) var(--ease-out),
    color var(--dur-xs) var(--ease-out),
    transform var(--dur-s) var(--ease-spring);
}
.sub-toggle svg {
  width: 14px;
  height: 14px;
  transition: transform var(--dur-s) var(--ease-spring);
}
.sub-toggle:hover {
  color: var(--ink);
  border-color: color-mix(in oklab, var(--ink) 28%, transparent);
}
.sub-toggle:active { transform: scale(.9); }
.sub-toggle:focus-visible {
  outline: 2px solid var(--focus-ring);
  outline-offset: 2px;
}
.nav-group.open .sub-toggle {
  background: var(--ink);
  border-color: var(--ink);
  color: var(--paper);
}
.nav-group.open .sub-toggle svg { transform: rotate(180deg); }

/* Smooth height reveal with a sienna index rail */
.mobile-nav .mobile-sub {
  display: flex;
  flex-direction: column;
  margin: 2px 0 0 9px;
  padding-left: 19px;
  border-left: 2px solid color-mix(in oklab, var(--accent) 45%, transparent);
  max-height: 0;
  overflow: hidden;
  opacity: 0;
  transition:
    max-height var(--dur-m) var(--ease-soft),
    opacity var(--dur-s) var(--ease-out),
    padding-bottom var(--dur-s) var(--ease-out);
}
.mobile-nav .nav-group.open .mobile-sub {
  max-height: 320px;
  opacity: 1;
  padding-bottom: 12px;
}
.mobile-nav .mobile-sub a {
  font-size: clamp(15px, 4.4vw, 19px);
  letter-spacing: -.01em;
  padding: 10px 0;
  border-bottom: none;
  opacity: .72;
  color: var(--ink-2);
}
.mobile-nav .mobile-sub a:hover,
.mobile-nav .mobile-sub a:focus-visible { opacity: 1; color: var(--ink); padding-left: 6px; }
.mobile-nav .mobile-sub a.active { opacity: 1; color: var(--ink); }
.mobile-nav .mobile-sub a::after { margin-left: auto; }

/* ── Staggered entrance for menu rows ── */
@media (prefers-reduced-motion: no-preference) {
  .mobile-nav > a,
  .mobile-nav > .nav-group,
  .mobile-menu .mobile-cta,
  .mobile-menu .mobile-menu-brand {
    opacity: 0;
    transform: translateY(16px);
    transition:
      opacity var(--dur-s) var(--ease-out),
      transform var(--dur-m) var(--ease-out);
  }
  .mobile-menu.open .mobile-nav > a,
  .mobile-menu.open .mobile-nav > .nav-group,
  .mobile-menu.open .mobile-cta,
  .mobile-menu.open .mobile-menu-brand {
    opacity: 1;
    transform: none;
  }
  .mobile-menu.open .mobile-nav > *:nth-child(1) { transition-delay: 70ms; }
  .mobile-menu.open .mobile-nav > *:nth-child(2) { transition-delay: 110ms; }
  .mobile-menu.open .mobile-nav > *:nth-child(3) { transition-delay: 150ms; }
  .mobile-menu.open .mobile-nav > *:nth-child(4) { transition-delay: 190ms; }
  .mobile-menu.open .mobile-nav > *:nth-child(5) { transition-delay: 230ms; }
  .mobile-menu.open .mobile-cta { transition-delay: 270ms; }
  .mobile-menu.open .mobile-menu-brand { transition-delay: 310ms; }
}

/* CTA */
.mobile-menu .mobile-cta {
  margin-top: auto;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 14px 20px;
  background: var(--ink);
  color: var(--paper);
  border-radius: 999px;
  font-family: var(--sans);
  font-size: 14px;
  font-weight: 500;
  letter-spacing: .01em;
  flex-shrink: 0;
  transition:
    background-color var(--dur-s) var(--ease-out),
    color var(--dur-s) var(--ease-out),
    transform var(--dur-s) var(--ease-spring);
}
html[data-theme="dark"] .mobile-menu .mobile-cta { background: var(--ink); color: var(--paper); }
.mobile-menu .mobile-cta:hover { background: var(--accent); color: var(--on-accent); transform: translateY(-1px); }

/* Brand footer */
.mobile-menu-brand {
  display: flex;
  align-items: center;
  padding-top: 14px;
  border-top: 1px solid color-mix(in oklab, var(--rule) 50%, transparent);
  margin-top: 12px;
  flex-shrink: 0;
}
.mobile-menu-brand .brand { font-size: 13px; color: var(--ink-2); gap: 7px; }
.mobile-menu-brand .brand-img { width: 24px; height: 24px; }

/* ── Staggered entrance — targets direct .mobile-nav children ── */
.mobile-menu .mobile-nav > *,
.mobile-menu .mobile-cta,
.mobile-menu .mobile-menu-brand {
  opacity: 0;
  transform: translateY(16px);
}
.mobile-menu.open .mobile-nav > *,
.mobile-menu.open .mobile-cta,
.mobile-menu.open .mobile-menu-brand {
  opacity: 1;
  transform: none;
  transition: opacity 460ms var(--ease-out), transform 460ms var(--ease-out);
}
.mobile-menu.open .mobile-nav > *:nth-child(1) { transition-delay:  70ms; }
.mobile-menu.open .mobile-nav > *:nth-child(2) { transition-delay: 110ms; }
.mobile-menu.open .mobile-nav > *:nth-child(3) { transition-delay: 150ms; }
.mobile-menu.open .mobile-nav > *:nth-child(4) { transition-delay: 190ms; }
.mobile-menu.open .mobile-nav > *:nth-child(5) { transition-delay: 230ms; }
.mobile-menu.open .mobile-nav > *:nth-child(6) { transition-delay: 270ms; }
.mobile-menu.open .mobile-cta               { transition-delay: 315ms; }
.mobile-menu.open .mobile-menu-brand        { transition-delay: 360ms; }

@media (max-width: 1080px) {
  nav.primary, .cta-mini { display: none; }
  .hamburger { display: flex; }
  .topbar { min-height: 64px; gap: 12px; }
  header.top { --nav-height: 64px; }
  .brand { font-size: clamp(20px, 5.6vw, 26px); min-width: 0; }
  .brand-img { width: 34px; height: 34px; }
}