/* ==========================================================================
   Butter Nav — a Linear-style navbar with a morphing mega-menu
   Design source: Figma "Accord" › node 504:173
   Motion reference: linear.app top navigation
   ========================================================================== */

.bn,
.bn *,
.bn *::before,
.bn *::after {
  box-sizing: border-box;
}

.bn {
  /* --- design tokens (from Figma) --- */
  --bn-bar-w: 840px;
  --bn-bar-h: 80px;
  --bn-bar-r: 18px;
  --bn-bar-bg: #000000;

  --bn-text: #f2f2f2;
  --bn-text-dim: rgba(242, 242, 242, 0.62);
  --bn-strong: #f2f2f2;
  --bn-brand: #ffffff;
  --bn-divider: rgba(242, 242, 242, 0.25);

  --bn-cta-bg: #f2f2f2;
  --bn-cta-fg: #0f0f0f;

  --bn-panel-bg: #0b0b0b;
  --bn-panel-inner: rgba(255, 255, 255, 0.028);
  --bn-line: rgba(255, 255, 255, 0.09);
  --bn-hover: rgba(255, 255, 255, 0.08);

  /* Figma stroke: #AAAAAA at 20%, position Inside, weight 0.4 */
  --bn-stroke: inset 0 0 0 0.4px rgba(170, 170, 170, 0.2);

  --bn-bar-shadow: var(--bn-stroke),
    0 1px 0 rgba(255, 255, 255, 0.05) inset,
    0 12px 40px -12px rgba(0, 0, 0, 0.9);
  --bn-panel-shadow: 0 0 0 1px rgba(0, 0, 0, 0.4),
    0 24px 60px -20px rgba(0, 0, 0, 0.9);

  --bn-font: "Inter", -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto,
    Helvetica, Arial, sans-serif;

  /* --- motion tokens ---
     Curves from the animations.dev catalogue; every duration sits under the
     300ms ceiling for UI motion. */
  --bn-ease-out: cubic-bezier(0.23, 1, 0.32, 1); /* entering / exiting */
  --bn-ease-in-out: cubic-bezier(0.77, 0, 0.175, 1); /* moving on screen */
  --bn-ease-drawer: cubic-bezier(0.32, 0.72, 0, 1); /* the sheet */

  --bn-morph: 240ms; /* size + position morph between menus */
  --bn-open: 200ms; /* cold open — the deliberate half */
  --bn-close: 140ms; /* system response — snappier than the open */
  --bn-fade: 160ms; /* content cross-fade */
  --bn-press: 160ms; /* press feedback */
  --bn-tint: 120ms; /* hover tint */
  --bn-pill-base: 100px; /* reference width the pill scales from */

  position: sticky;
  top: 0;
  z-index: 100;
  width: 100%;
  padding: 24px 16px 0;
  font-family: var(--bn-font);
  -webkit-font-smoothing: antialiased;
}

.bn__inner {
  position: relative;
  width: 100%;
  max-width: var(--bn-bar-w);
  margin: 0 auto;
}

/* ---------------------------------------------------------------- the bar */

.bn__bar {
  position: relative;
  z-index: 2;
  display: flex;
  align-items: center;
  height: var(--bn-bar-h);
  padding: 0 24px;
  border-radius: var(--bn-bar-r);
  background: var(--bn-bar-bg);
  box-shadow: var(--bn-bar-shadow);
}

.bn__brand {
  font-size: 24px;
  line-height: 1;
  letter-spacing: -0.01em;
  color: var(--bn-brand);
  text-decoration: none;
  white-space: nowrap;
}

.bn__nav {
  position: relative;
  display: flex;
  align-items: center;
  gap: 24px;
  margin-left: auto;
}

/* The sliding hover/active pill. Width is fixed and scaled on the GPU —
   animating `width` would run layout on every frame of a hover effect. */
.bn__pill {
  position: absolute;
  top: 50%;
  left: 0;
  width: var(--bn-pill-base);
  height: 30px;
  border-radius: 10px;
  background: var(--bn-hover);
  opacity: 0;
  pointer-events: none;
  transform-origin: 0 50%;
  transform: translate3d(0, -50%, 0) scaleX(0);
  transition: transform 220ms var(--bn-ease-out),
    opacity var(--bn-tint) linear;
}

.bn__link {
  position: relative;
  z-index: 1;
  appearance: none;
  border: 0;
  margin: 0;
  padding: 0;
  background: none;
  font: inherit;
  font-size: 12px;
  line-height: 1;
  color: var(--bn-text);
  text-decoration: none;
  white-space: nowrap;
  cursor: pointer;
  opacity: 0.85;
  transition: opacity 160ms linear;
}

.bn__link[aria-expanded="true"] {
  opacity: 1;
}

/* Touch fires a phantom hover on tap, so hover motion is gated. */
@media (hover: hover) and (pointer: fine) {
  .bn__link:hover {
    opacity: 1;
  }
}

.bn__link:focus-visible {
  outline: 2px solid var(--bn-strong);
  outline-offset: 6px;
  border-radius: 4px;
}

.bn__right {
  display: flex;
  align-items: center;
  gap: 24px;
  margin-left: 24px;
}

.bn__divider {
  width: 1px;
  height: 20px;
  background: var(--bn-divider);
}

.bn__cta {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 6px 14px;
  border-radius: 40px;
  background: var(--bn-cta-bg);
  color: var(--bn-cta-fg);
  font-size: 12px;
  line-height: normal;
  text-decoration: none;
  white-space: nowrap;
  transform: scale(1);
  transition: transform var(--bn-press) var(--bn-ease-out),
    opacity var(--bn-tint) ease;
}

@media (hover: hover) and (pointer: fine) {
  .bn__cta:hover {
    opacity: 0.9;
  }
}

/* Press feedback on any pressable surface: subtle, and fast to release. */
.bn__cta:active {
  transform: scale(0.97);
  transition-duration: 100ms;
}

/* --------------------------------------------------------- the mega menu */

.bn__pop {
  position: absolute;
  top: 100%;
  left: 0;
  width: 100%;
  height: 0;
  pointer-events: none;
}

.bn__card {
  position: absolute;
  top: 10px;
  left: 0;
  width: 0;
  height: 0;
  border-radius: 16px;
  background: var(--bn-panel-bg);
  box-shadow: var(--bn-stroke), 0 0 0 1px var(--bn-line),
    var(--bn-panel-shadow);
  overflow: hidden;
  contain: paint;
  opacity: 0;
  /* Scales from the trigger that opened it, not from its own centre. */
  transform-origin: var(--bn-origin, 50%) 0;
  transform: translate3d(0, -4px, 0) scale(0.97);
  pointer-events: none;
  transition: width var(--bn-close) var(--bn-ease-out),
    height var(--bn-close) var(--bn-ease-out),
    transform var(--bn-close) var(--bn-ease-out),
    opacity var(--bn-close) var(--bn-ease-out);
}

/* invisible bridge so the pointer can cross the 10px gap without closing */
.bn__card::before {
  content: "";
  position: absolute;
  top: -14px;
  left: 0;
  right: 0;
  height: 14px;
}

/* The card's transform / width / height are driven from JS so the size and
   the horizontal slide can be interpolated together. Opening is the
   deliberate half, so it runs slower than the close above. */
.bn.is-open .bn__card {
  opacity: 1;
  pointer-events: auto;
  will-change: width, height, transform;
  transition-duration: var(--bn-morph), var(--bn-morph), var(--bn-morph),
    var(--bn-open);
  transition-timing-function: var(--bn-ease-in-out), var(--bn-ease-in-out),
    var(--bn-ease-in-out), var(--bn-ease-out);
}

.bn__panel {
  position: absolute;
  top: 0;
  left: 0;
  width: max-content;
  padding: 8px;
  opacity: 0;
  pointer-events: none;
  /* A touch of blur blends the two panels into one perceived transformation
     instead of two overlapping states. */
  filter: blur(3px);
  transform: translate3d(var(--bn-shift, 12px), 0, 0);
  transition: opacity var(--bn-fade) linear,
    transform var(--bn-fade) var(--bn-ease-out),
    filter var(--bn-fade) var(--bn-ease-out);
}

.bn__panel.is-active {
  opacity: 1;
  pointer-events: auto;
  filter: blur(0);
  transform: translate3d(0, 0, 0);
  transition-delay: 40ms;
}

/* ------------------------------------------------------- panel internals */

.bn__grid {
  display: flex;
  align-items: stretch;
  border-radius: 12px;
  background: var(--bn-panel-inner);
}

.bn__col {
  padding: 22px 26px;
  min-width: 240px;
}

.bn__col + .bn__col {
  border-left: 1px solid var(--bn-line);
}

.bn__col--links {
  display: flex;
  flex-direction: column;
  gap: 4px;
  justify-content: flex-start;
  min-width: 210px;
}

.bn__card-link {
  display: block;
  padding: 10px 12px;
  margin: -10px -12px;
  border-radius: 10px;
  text-decoration: none;
  transition: background var(--bn-tint) ease;
}

.bn__card-link + .bn__card-link {
  margin-top: 12px;
}

@media (hover: hover) and (pointer: fine) {
  .bn__card-link:hover,
  .bn__plain:hover {
    background: var(--bn-hover);
  }
}

.bn__card-title {
  display: block;
  font-size: 13px;
  font-weight: 600;
  line-height: 1.3;
  color: var(--bn-strong);
}

.bn__card-desc {
  display: block;
  margin-top: 4px;
  max-width: 21ch;
  font-size: 13px;
  line-height: 1.45;
  color: var(--bn-text-dim);
}

.bn__plain {
  display: block;
  padding: 9px 12px;
  border-radius: 8px;
  font-size: 13px;
  line-height: 1.3;
  color: var(--bn-strong);
  text-decoration: none;
  transition: background var(--bn-tint) ease;
}

.bn__foot {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 40px;
  padding: 14px 18px 10px;
  font-size: 13px;
}

.bn__badge {
  display: inline-block;
  margin-right: 8px;
  font-weight: 600;
  color: var(--bn-strong);
}

.bn__foot-text {
  color: var(--bn-text-dim);
}

.bn__foot-cta {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  color: var(--bn-strong);
  text-decoration: none;
  white-space: nowrap;
}

.bn__foot-cta span {
  transition: transform 150ms var(--bn-ease-out);
}

@media (hover: hover) and (pointer: fine) {
  .bn__foot-cta:hover span {
    transform: translateX(3px);
  }
}

/* --------------------------------------------------------------- mobile */

.bn__burger {
  display: none;
  margin-left: auto;
  width: 40px;
  height: 40px;
  padding: 0;
  border: 0;
  border-radius: 10px;
  background: none;
  cursor: pointer;
}

.bn__burger i {
  display: block;
  width: 18px;
  height: 1.5px;
  margin: 0 auto;
  background: var(--bn-text);
  border-radius: 2px;
  transition: transform var(--bn-morph) var(--bn-ease-in-out),
    opacity var(--bn-tint) linear;
}

.bn__burger i + i {
  margin-top: 5px;
}

.bn.is-sheet .bn__burger i:nth-child(1) {
  transform: translateY(3.25px) rotate(45deg);
}

.bn.is-sheet .bn__burger i:nth-child(2) {
  opacity: 0;
}

.bn.is-sheet .bn__burger i:nth-child(3) {
  transform: translateY(-3.25px) rotate(-45deg);
}

.bn__sheet {
  position: absolute;
  top: calc(100% + 10px);
  left: 0;
  right: 0;
  display: none;
  padding: 8px;
  border-radius: 16px;
  background: var(--bn-panel-bg);
  box-shadow: var(--bn-stroke), 0 0 0 1px var(--bn-line),
    var(--bn-panel-shadow);
  opacity: 0;
  transform: translate3d(0, -8px, 0) scale(0.98);
  transform-origin: top center;
  pointer-events: none;
  transition: opacity var(--bn-close) var(--bn-ease-out),
    transform var(--bn-close) var(--bn-ease-drawer);
}

.bn.is-sheet .bn__sheet {
  transition-duration: var(--bn-open);
  opacity: 1;
  transform: none;
  pointer-events: auto;
}

.bn__acc-btn {
  display: flex;
  align-items: center;
  justify-content: space-between;
  width: 100%;
  padding: 14px;
  border: 0;
  border-radius: 10px;
  background: none;
  font: inherit;
  font-size: 14px;
  color: var(--bn-strong);
  text-align: left;
  text-decoration: none;
  cursor: pointer;
  transition: transform var(--bn-press) var(--bn-ease-out),
    background var(--bn-tint) ease;
}

.bn__acc-btn:active {
  transform: scale(0.985);
  transition-duration: 100ms;
}

.bn__acc-btn svg {
  transition: transform var(--bn-morph) var(--bn-ease-in-out);
}

.bn__acc.is-open .bn__acc-btn svg {
  transform: rotate(180deg);
}

.bn__acc-body {
  height: 0;
  overflow: hidden;
  transition: height var(--bn-morph) var(--bn-ease-in-out);
}

.bn__acc-inner {
  padding: 2px 14px 14px;
}

.bn__acc-inner a {
  display: block;
  padding: 9px 0;
  font-size: 13px;
  color: var(--bn-text-dim);
  text-decoration: none;
}

.bn__acc-inner a:hover {
  color: var(--bn-text);
}

@media (max-width: 860px) {
  .bn {
    padding-top: 16px;
  }

  .bn__bar {
    height: 64px;
    padding: 0 16px;
  }

  .bn__brand {
    font-size: 20px;
  }

  .bn__nav,
  .bn__right,
  .bn__pop {
    display: none;
  }

  .bn__burger {
    display: block;
  }

  .bn__sheet {
    display: block;
  }
}

/* ------------------------------------------------------------ light theme */
/* Follows the host page: `data-theme` on <html> wins, otherwise the OS. */

@media (prefers-color-scheme: light) {
  html:not([data-theme="dark"]) .bn {
    --bn-bar-bg: #ffffff;
    --bn-text: #4d4d4d;
    --bn-text-dim: #8f8f8f;
    --bn-strong: #171717;
    --bn-brand: #171717;
    --bn-divider: rgba(0, 0, 0, 0.12);
    --bn-cta-bg: #171717;
    --bn-cta-fg: #ffffff;
    --bn-panel-bg: #ffffff;
    --bn-panel-inner: rgba(0, 0, 0, 0.02);
    --bn-line: rgba(0, 0, 0, 0.08);
    --bn-hover: rgba(0, 0, 0, 0.06);
    --bn-bar-shadow: var(--bn-stroke), 0 0 0 1px rgba(0, 0, 0, 0.08),
      0 8px 24px -12px rgba(0, 0, 0, 0.16);
    --bn-panel-shadow: 0 1px 1px rgba(0, 0, 0, 0.02),
      0 8px 16px -4px rgba(0, 0, 0, 0.04), 0 24px 32px -8px rgba(0, 0, 0, 0.06);
  }
}

html[data-theme="light"] .bn {
  --bn-bar-bg: #ffffff;
  --bn-text: #4d4d4d;
  --bn-text-dim: #8f8f8f;
  --bn-strong: #171717;
  --bn-brand: #171717;
  --bn-divider: rgba(0, 0, 0, 0.12);
  --bn-cta-bg: #171717;
  --bn-cta-fg: #ffffff;
  --bn-panel-bg: #ffffff;
  --bn-panel-inner: rgba(0, 0, 0, 0.02);
  --bn-line: rgba(0, 0, 0, 0.08);
  --bn-hover: rgba(0, 0, 0, 0.06);
  --bn-bar-shadow: var(--bn-stroke), 0 0 0 1px rgba(0, 0, 0, 0.08),
    0 8px 24px -12px rgba(0, 0, 0, 0.16);
  --bn-panel-shadow: 0 1px 1px rgba(0, 0, 0, 0.02),
    0 8px 16px -4px rgba(0, 0, 0, 0.04), 0 24px 32px -8px rgba(0, 0, 0, 0.06);
}

/* Reduced motion means gentler, not none: the fades that explain what
   changed stay, everything that moves or resizes lands instantly. */
@media (prefers-reduced-motion: reduce) {
  .bn__card,
  .bn__pill,
  .bn__panel,
  .bn__sheet,
  .bn__acc-body,
  .bn__acc-btn,
  .bn__burger i,
  .bn__cta,
  .bn__foot-cta span {
    transition-property: opacity !important;
    transition-duration: 150ms !important;
  }

  .bn__panel {
    transform: none !important;
    filter: none !important;
  }

  .bn__cta:active,
  .bn__acc-btn:active {
    transform: none !important;
  }
}