/* ==========================================================================
   IBPLD Prototype — Immersive first experience
   Independent from rejected /assets/css/ibpld.css layouts.
   Mobile-first art direction.
   ========================================================================== */

:root {
  --proto-bg: #F5F3EE;
  --proto-ink: #161719;
  --proto-graphite: #17191D;
  --proto-soft: #64696F;
  --proto-wine: #4C0911;
  --proto-champagne: #C8B69A;
  --proto-champagne-soft: rgba(200, 182, 154, 0.28);
  --proto-steel: #74808A;
  --proto-white: #FFFFFF;

  --proto-font: "Manrope", system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  --proto-ease: cubic-bezier(0.22, 1, 0.36, 1);
  --proto-gutter: 1.25rem;
  --proto-max: 80rem;
  --proto-mast-h: 4rem;
}

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

html {
  scroll-behavior: smooth;
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
}

body.proto-body {
  margin: 0;
  font-family: var(--proto-font);
  color: var(--proto-ink);
  background: var(--proto-bg);
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

/* Link color inheritance is handled in ibpld-polish.css.
   Do not force color:inherit on all anchors — it hides CTA text. */

.proto-body :focus-visible {
  outline: 2px solid var(--proto-wine);
  outline-offset: 3px;
}

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

/* --------------------------------------------------------------------------
   Masthead (new — not site-header)
   -------------------------------------------------------------------------- */

.proto-mast {
  /* sticky disabled during structural stabilization — see ibpld-stabilize.css */
  position: relative;
  top: auto;
  z-index: 40;
  height: var(--proto-mast-h);
  background: #F5F3EE;
  transition:
    background-color 280ms var(--proto-ease),
    backdrop-filter 280ms var(--proto-ease),
    -webkit-backdrop-filter 280ms var(--proto-ease);
}

.proto-mast.is-scrolled {
  background: rgba(245, 243, 238, 0.9);
  -webkit-backdrop-filter: blur(10px);
  backdrop-filter: blur(10px);
}

@supports not ((backdrop-filter: blur(10px)) or (-webkit-backdrop-filter: blur(10px))) {
  .proto-mast.is-scrolled {
    background: #F5F3EE;
  }
}

.proto-mast__bar {
  width: min(100%, var(--proto-max));
  margin-inline: auto;
  padding-inline: var(--proto-gutter);
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
}

.proto-mast__brand {
  display: inline-flex;
  align-items: center;
  min-height: 44px;
  text-decoration: none;
}

.proto-mast__brand img {
  width: 10rem;
  height: auto;
  display: block;
  filter: none;
  opacity: 1;
  object-fit: contain;
}

.proto-mast__nav {
  display: none;
}

.proto-mast__list {
  display: flex;
  align-items: center;
  gap: 0.15rem;
  margin: 0;
  padding: 0;
  list-style: none;
}

.proto-mast__link {
  display: inline-flex;
  align-items: center;
  min-height: 44px;
  padding: 0.4rem 0.65rem;
  font-size: 0.875rem;
  font-weight: 600;
  letter-spacing: -0.01em;
  text-decoration: none;
  color: var(--proto-ink);
  opacity: 0.82;
  transition: opacity 220ms var(--proto-ease), color 220ms var(--proto-ease);
}

.proto-mast__link:hover {
  opacity: 1;
  color: var(--proto-wine);
}

.proto-mast__link--feature {
  font-weight: 700;
  opacity: 1;
}

.proto-mast__student {
  display: none;
  align-items: center;
  min-height: 40px;
  padding: 0.45rem 0.8rem;
  font-size: 0.8125rem;
  font-weight: 600;
  text-decoration: none;
  color: var(--proto-ink);
  border-bottom: 1px solid transparent;
  transition: border-color 220ms var(--proto-ease), color 220ms var(--proto-ease);
}

.proto-mast__student:hover {
  color: var(--proto-wine);
  border-bottom-color: var(--proto-wine);
}

.proto-mast__toggle {
  width: 44px;
  height: 44px;
  border: 0;
  background: transparent;
  padding: 0;
  display: inline-grid;
  place-items: center;
  cursor: pointer;
  color: var(--proto-ink);
}

.proto-mast__toggle-lines {
  width: 18px;
  height: 12px;
  position: relative;
}

.proto-mast__toggle-lines span {
  position: absolute;
  left: 0;
  right: 0;
  height: 1.5px;
  background: currentColor;
  transition: transform 180ms var(--proto-ease), top 180ms var(--proto-ease), opacity 180ms var(--proto-ease);
}

.proto-mast__toggle-lines span:nth-child(1) { top: 0; }
.proto-mast__toggle-lines span:nth-child(2) { top: 5px; }
.proto-mast__toggle-lines span:nth-child(3) { top: 10px; }

.proto-mast__toggle[aria-expanded="true"] .proto-mast__toggle-lines span:nth-child(1) {
  top: 5px;
  transform: rotate(45deg);
}
.proto-mast__toggle[aria-expanded="true"] .proto-mast__toggle-lines span:nth-child(2) {
  opacity: 0;
}
.proto-mast__toggle[aria-expanded="true"] .proto-mast__toggle-lines span:nth-child(3) {
  top: 5px;
  transform: rotate(-45deg);
}

.proto-drawer {
  display: none;
  position: absolute;
  inset: var(--proto-mast-h) 0 auto 0;
  background: var(--proto-bg);
  padding: 0.5rem var(--proto-gutter) 1.5rem;
  border-bottom: 1px solid rgba(22, 23, 25, 0.06);
}

.proto-drawer.is-open {
  display: block;
}

.proto-drawer__list {
  list-style: none;
  margin: 0;
  padding: 0;
}

.proto-drawer__link {
  display: flex;
  align-items: center;
  min-height: 48px;
  text-decoration: none;
  font-size: 1.0625rem;
  font-weight: 600;
  border-bottom: 1px solid rgba(22, 23, 25, 0.06);
}

.proto-drawer__meta {
  margin-top: 1rem;
  display: grid;
  gap: 0.5rem;
}

.proto-drawer__meta a {
  display: inline-flex;
  align-items: center;
  min-height: 44px;
  font-weight: 600;
  text-decoration: none;
  color: var(--proto-wine);
}

@media (min-width: 1024px) {
  .proto-mast__nav {
    display: block;
    margin-left: auto;
  }

  .proto-mast__student {
    display: inline-flex;
    margin-left: 0.75rem;
  }

  .proto-mast__toggle,
  .proto-drawer {
    display: none !important;
  }
}

@media (min-width: 768px) {
  :root {
    --proto-gutter: 2rem;
    --proto-mast-h: 4.5rem;
  }
}

@media (min-width: 1440px) {
  :root {
    --proto-gutter: 2.75rem;
  }
}

/* --------------------------------------------------------------------------
   Immersive scene (single composition — NOT two columns)
   -------------------------------------------------------------------------- */

.immersion {
  position: relative;
  overflow: hidden;
  background: var(--proto-bg);
  min-height: auto;
  padding-bottom: 2.5rem;
}

.immersion__atmosphere {
  position: absolute;
  inset: 0;
  pointer-events: none;
  z-index: 0;
}

/* Soft organic champagne form */
.immersion__blob {
  position: absolute;
  width: min(88vw, 46rem);
  height: min(88vw, 46rem);
  right: -28%;
  top: 8%;
  border-radius: 58% 42% 46% 54% / 48% 56% 44% 52%;
  background: radial-gradient(
    closest-side,
    rgba(200, 182, 154, 0.34) 0%,
    rgba(200, 182, 154, 0.12) 55%,
    transparent 100%
  );
  filter: blur(8px);
  transform: rotate(-12deg);
}

.immersion__blob--secondary {
  width: min(70vw, 28rem);
  height: min(70vw, 28rem);
  left: -22%;
  bottom: 4%;
  right: auto;
  top: auto;
  opacity: 0.55;
  transform: rotate(18deg);
}

/* Extremely subtle grain */
.immersion__grain {
  position: absolute;
  inset: 0;
  opacity: 0.035;
  mix-blend-mode: multiply;
  background-image: url("data:image/svg+xml,%3Csvg viewBox='0 0 200 200' xmlns='http://www.w3.org/2000/svg'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.85' numOctaves='2' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23n)'/%3E%3C/svg%3E");
  background-size: 180px 180px;
}

.immersion__stage {
  position: relative;
  z-index: 1;
  width: min(100%, var(--proto-max));
  margin-inline: auto;
  padding: 1.75rem var(--proto-gutter) 0;
}

.immersion__eyebrow {
  margin: 0 0 1.5rem;
  font-size: 0.6875rem;
  font-weight: 600;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--proto-steel);
}

.immersion__title {
  margin: 0;
  font-weight: 700;
  letter-spacing: -0.045em;
  line-height: 0.95;
  font-size: clamp(3rem, 13vw, 3.625rem); /* ~48–58px on 360–390 */
}

.immersion__line {
  display: block;
  overflow: hidden;
}

.immersion__line span {
  display: inline-block;
}

.immersion__line--a {
  color: var(--proto-ink);
}

.immersion__line--b {
  margin-top: 0.12em;
  padding-left: 1.35rem;
  color: var(--proto-wine);
  font-weight: 700;
}

.immersion__sub {
  margin: 1.5rem 0 0;
  max-width: 34rem; /* ~544px */
  font-size: 1.015rem;
  line-height: 1.55;
  color: var(--proto-soft);
  font-weight: 500;
}

.immersion__actions {
  margin-top: 1.75rem;
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  gap: 0.85rem;
}

.immersion__cta {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 48px;
  padding: 0.85rem 1.35rem;
  background: var(--proto-ink);
  color: var(--proto-bg);
  text-decoration: none;
  font-size: 0.9375rem;
  font-weight: 700;
  letter-spacing: -0.01em;
  border: 0;
  transition: background-color 240ms var(--proto-ease), transform 240ms var(--proto-ease);
}

.immersion__cta:hover {
  background: var(--proto-wine);
  color: var(--proto-bg);
}

.immersion__textlink {
  display: inline-flex;
  align-items: center;
  min-height: 44px;
  font-size: 0.9375rem;
  font-weight: 600;
  text-decoration: none;
  color: var(--proto-ink);
  letter-spacing: -0.01em;
}

.immersion__textlink::after {
  content: "→";
  margin-left: 0.4rem;
  transition: transform 240ms var(--proto-ease);
}

.immersion__textlink:hover::after {
  transform: translateX(3px);
}

/* Brand media region — asymmetric, NOT a centered card */
.immersion__media-region {
  position: relative;
  margin-top: 2.25rem;
  min-height: 17.5rem;
}

.immersion__signal {
  margin-top: 1.75rem;
  padding-top: 0.25rem;
}

.immersion__signal-link {
  display: inline-flex;
  flex-wrap: wrap;
  gap: 0.35rem 0.55rem;
  align-items: center;
  max-width: 100%;
  font-size: 0.8125rem;
  font-weight: 600;
  letter-spacing: -0.01em;
  color: var(--proto-soft);
  text-decoration: none;
  min-height: 44px;
}

.immersion__signal-link:hover {
  color: var(--proto-wine);
}

.immersion__signal-sep {
  color: var(--proto-champagne);
}

.immersion__thread {
  margin-top: 2rem;
  height: 3.5rem;
  position: relative;
  display: flex;
  justify-content: center;
}

.immersion__thread-line {
  width: 1px;
  height: 100%;
  background: linear-gradient(
    180deg,
    rgba(200, 182, 154, 0.05) 0%,
    rgba(200, 182, 154, 0.7) 45%,
    rgba(23, 25, 29, 0.55) 100%
  );
  transform-origin: top center;
}

.immersion__thread-node {
  position: absolute;
  bottom: -0.2rem;
  width: 0.55rem;
  height: 0.55rem;
  border: 1px solid var(--proto-champagne);
  border-radius: 50%;
  display: grid;
  place-items: center;
}

.immersion__thread-node::after {
  content: "";
  width: 3px;
  height: 3px;
  border-radius: 50%;
  background: var(--proto-wine);
}

.immersion__coord {
  position: absolute;
  left: var(--proto-gutter);
  bottom: 0.25rem;
  z-index: 2;
  font-size: 0.625rem;
  font-weight: 700;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: rgba(116, 128, 138, 0.7);
}

/* --------------------------------------------------------------------------
   Brand media module (REAL BRAND MEDIA SLOT)
   -------------------------------------------------------------------------- */

.brand-media {
  position: relative;
  width: 100%;
  height: 100%;
  min-height: inherit;
}

/* Primary asymmetric vertical plane — enters from right on larger screens */
.brand-media__primary {
  position: relative;
  width: min(78%, 17.5rem);
  margin-left: auto;
  aspect-ratio: 3 / 4;
  overflow: hidden;
  /* Neutral temporary plane — not a colored placeholder box */
  background:
    linear-gradient(165deg, rgba(22, 23, 25, 0.06) 0%, rgba(22, 23, 25, 0.02) 100%);
  -webkit-clip-path: inset(0 0 0 0);
  clip-path: inset(0 0 0 0);
}

.brand-media__primary-inner {
  width: 100%;
  height: 100%;
  transform: scale(1);
  transition: transform 1200ms var(--proto-ease);
  will-change: transform;
}

.brand-media__tone {
  width: 100%;
  height: 100%;
  background:
    linear-gradient(180deg, rgba(245, 243, 238, 0.15) 0%, transparent 35%),
    repeating-linear-gradient(
      -18deg,
      transparent 0,
      transparent 14px,
      rgba(22, 23, 25, 0.025) 14px,
      rgba(22, 23, 25, 0.025) 15px
    );
}

.brand-media__caption {
  position: absolute;
  left: 0.85rem;
  bottom: 0.85rem;
  font-size: 0.625rem;
  font-weight: 700;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: rgba(22, 23, 25, 0.45);
}

/* Smaller editorial object — prepared for real book cover */
.brand-media__editorial {
  position: absolute;
  left: 0;
  bottom: 8%;
  width: min(42%, 8.5rem);
  aspect-ratio: 2 / 3;
  background:
    linear-gradient(145deg, rgba(22, 23, 25, 0.08) 0%, rgba(22, 23, 25, 0.03) 100%);
  box-shadow: none;
  overflow: hidden;
}

.brand-media__editorial-inner {
  width: 100%;
  height: 100%;
  display: grid;
  place-items: end start;
  padding: 0.65rem;
}

.brand-media__editorial-mark {
  font-size: 0.5625rem;
  font-weight: 700;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: rgba(76, 9, 17, 0.55);
}

/* Single graphic detail: short intelligence thread fragment */
.brand-media__thread-bit {
  position: absolute;
  left: 18%;
  top: 18%;
  width: 1px;
  height: 3.5rem;
  background: rgba(200, 182, 154, 0.55);
}

.brand-media__thread-bit::after {
  content: "";
  position: absolute;
  left: 50%;
  bottom: 0;
  width: 5px;
  height: 5px;
  border: 1px solid var(--proto-champagne);
  border-radius: 50%;
  transform: translate(-50%, 50%);
  background:
    radial-gradient(circle, var(--proto-wine) 0 1.5px, transparent 1.7px);
}

/* --------------------------------------------------------------------------
   Transition risk (dark start only)
   -------------------------------------------------------------------------- */

.risk-transit {
  background: var(--proto-graphite);
  color: #F5F3EE;
  min-height: 0;
  display: block;
  padding: 4.5rem 0 5rem;
}

.risk-transit__inner {
  width: min(100%, 40rem);
  margin-inline: auto;
  text-align: left;
}

.risk-transit__title {
  margin: 0;
  font-family: var(--proto-font);
  font-size: clamp(1.75rem, 6vw, 2.5rem);
  font-weight: 700;
  letter-spacing: -0.035em;
  line-height: 1.15;
}

.risk-transit__note {
  margin: 1.25rem 0 0;
  font-size: 1rem;
  font-weight: 500;
  color: rgba(245, 243, 238, 0.62);
}

/* --------------------------------------------------------------------------
   Entrance motion (progressive — hidden only when .js is present)
   -------------------------------------------------------------------------- */

.js .immersion [data-enter] {
  opacity: 0;
  transform: translateY(18px);
}

.js .immersion [data-enter].is-in {
  opacity: 1;
  transform: none;
  transition:
    opacity 700ms var(--proto-ease),
    transform 700ms var(--proto-ease);
  transition-delay: var(--enter-delay, 0ms);
}

.js .immersion__line span {
  transform: translateY(110%);
}

.js .immersion__line.is-in span {
  transform: translateY(0);
  transition: transform 800ms var(--proto-ease);
  transition-delay: var(--enter-delay, 0ms);
}

/* Hero video stays out of entrance stagger — absolute iframe + width:auto collapsed it. */

.js .immersion__thread-line {
  transform: scaleY(0);
}

.js .immersion__thread-line.is-in {
  transform: scaleY(1);
  transition: transform 900ms var(--proto-ease);
}

.js .risk-transit__title,
.js .risk-transit__note {
  opacity: 0;
  transform: translateY(16px);
}

.js .risk-transit__title.is-in,
.js .risk-transit__note.is-in {
  opacity: 1;
  transform: none;
  transition:
    opacity 700ms var(--proto-ease),
    transform 700ms var(--proto-ease);
  transition-delay: var(--enter-delay, 0ms);
}

@media (prefers-reduced-motion: reduce) {
  .js .immersion [data-enter],
  .js .immersion__line span,
  .js .brand-media__primary,
  .js .brand-media__editorial,
  .js .immersion__thread-line,
  .js .risk-transit__title,
  .js .risk-transit__note {
    opacity: 1 !important;
    transform: none !important;
    -webkit-clip-path: none !important;
    clip-path: none !important;
    transition: none !important;
  }
}

/* --------------------------------------------------------------------------
   Desktop / 1440 — one scene, displacement & overlap (NO two-column grid)
   -------------------------------------------------------------------------- */

/* Desktop hero absolute / vh composition REMOVED during structural
   stabilization. Layout is now a normal-flow grid in ibpld-stabilize.css. */

@media (min-width: 768px) {
  .immersion__actions {
    margin-top: 2.25rem;
  }

  .brand-media__primary {
    width: 100%;
    margin-left: 0;
  }
}

/* Proto end chrome — not definitive footer */
.proto-end {
  display: none;
}