/* Whitepaper cover widget. Flat, editorial mock of a PDF cover.
   Brand gradient spine, display title, subdued kicker + sub, small
   seal, and the TWG mark tucked in the bottom-right. */

.whitepaper-cover {
  width: 100%;
  max-width: 22rem;
  margin-inline: auto;
  padding: 0.5rem;
  transform: rotate(-0.75deg);
  transition: transform var(--dur-med) var(--ease);
}
.whitepaper-cover:hover { transform: rotate(-0.25deg) translateY(-2px); }

@media (prefers-reduced-motion: reduce) {
  .whitepaper-cover,
  .whitepaper-cover:hover { transform: none; }
}

.whitepaper-cover__paper {
  position: relative;
  display: flex;
  aspect-ratio: 3 / 4;
  border-radius: var(--radius-lg);
  background: #fff;
  overflow: hidden;
  box-shadow:
    0 1px 0 rgb(255 255 255 / 70%) inset,
    0 18px 40px -20px rgb(16 17 20 / 30%),
    0 2px 6px rgb(16 17 20 / 8%);
}

.whitepaper-cover__spine {
  flex: 0 0 1.25rem;
  background: var(--brand-gradient);
  box-shadow:
    inset -1px 0 0 rgb(0 0 0 / 10%),
    2px 0 0 rgb(255 255 255 / 60%);
}

.whitepaper-cover__body {
  position: relative;
  flex: 1 1 auto;
  display: flex;
  flex-direction: column;
  gap: 0.875rem;
  padding: 1.75rem 1.5rem 1.5rem;
  color: var(--on-light-foreground);
}

.whitepaper-cover__kicker {
  margin: 0;
  font-size: 0.625rem;
  font-weight: var(--font-weight-medium);
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--on-light-muted-foreground);
}

.whitepaper-cover__title {
  margin: 0;
  font-family: var(--font-display);
  font-size: clamp(1.25rem, 2.4vw, 1.625rem);
  font-weight: var(--font-weight-display);
  letter-spacing: -0.025em;
  line-height: 1.08;
  color: var(--on-light-foreground);
  text-wrap: balance;

  /* Optical limit so long titles don't touch the seal. */
  display: -webkit-box;
  -webkit-box-orient: vertical;
  -webkit-line-clamp: 4;
  overflow: hidden;
}

.whitepaper-cover__sub {
  margin: 0;
  font-size: var(--fs-sm);
  color: var(--on-light-muted-foreground);
  line-height: var(--lh-snug);
  max-width: 22ch;

  display: -webkit-box;
  -webkit-box-orient: vertical;
  -webkit-line-clamp: 3;
  overflow: hidden;
}

.whitepaper-cover__seal {
  position: absolute;
  bottom: 1rem;
  right: 1rem;
  display: inline-flex;
  align-items: center;
  padding: 0.25rem 0.5rem;
  border: 1px solid var(--on-light-border);
  border-radius: 9999px;
  font-size: 0.625rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--on-light-muted-foreground);
  background: color-mix(in oklch, var(--on-light-foreground) 3%, #fff);
}

.whitepaper-cover__mark {
  margin-top: auto;
  align-self: flex-start;
  width: 1.75rem;
  height: auto;
  opacity: 0.85;
}