:root {
  --world-red: #c60000;
  --world-ink: #242424;
  --world-paper: #f4f4f4;
}

* { box-sizing: border-box; }

body {
  margin: 0;
  background: var(--world-paper);
  color: var(--world-ink);
  font-family: sans-serif;
  line-height: 1.7;
}

.header-border { background: #e5355b; }

.world-history-hero {
  min-height: 320px;
  display: grid;
  place-items: center;
  position: relative;
  background-position: center;
  background-size: cover;
  color: #fff;
  text-align: center;
}

.world-history-hero::before {
  content: "";
  position: absolute;
  inset: 0;
  background: linear-gradient(125deg, rgba(112, 0, 0, .83), rgba(28, 28, 28, .42));
}

.world-history-hero > div {
  position: relative;
  z-index: 1;
  padding: 3rem 1.5rem;
  text-shadow: 0 2px 8px rgba(0, 0, 0, .45);
}

.world-history-hero h1 {
  margin: .2rem 0 .5rem;
  color: #fff;
  font-size: clamp(2.2rem, 6vw, 4.8rem);
  letter-spacing: .04em;
}

.world-history-kicker {
  margin: 0;
  font-size: .8rem;
  font-weight: 700;
  letter-spacing: .17em;
}

.world-history-intro {
  max-width: 920px;
  margin: 0 auto;
  padding: 4.5rem 1.5rem 2.3rem;
  text-align: center;
}

.world-history-intro h2 {
  margin: 0 0 1rem;
  font-size: clamp(1.65rem, 4vw, 2.45rem);
}

.world-history-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 2rem;
  width: min(1180px, calc(100% - 3rem));
  margin: 0 auto;
  padding: 1rem 0 5rem;
}

.world-history-card {
  overflow: hidden;
  background: #fff;
  border-radius: 18px;
  box-shadow: 0 12px 30px rgba(0, 0, 0, .13);
}

.world-history-card img {
  display: block;
  width: 100%;
  aspect-ratio: 4 / 3;
  object-fit: cover;
}

.world-history-content { padding: 1.35rem 1.55rem 1.65rem; }

.world-history-number {
  margin: 0;
  color: var(--world-red);
  font-size: .8rem;
  font-weight: 700;
  letter-spacing: .14em;
}

.world-history-content h2 {
  margin: .2rem 0 .7rem;
  font-size: 1.5rem;
}

.world-history-meta {
  display: grid;
  gap: .25rem;
  margin: 0 0 1rem;
  color: #555;
  font-size: .92rem;
}

.world-history-meta strong { color: #333; }

.world-history-placeholder {
  display: grid;
  min-height: 330px;
  place-items: center;
  border: 2px dashed #b9b9b9;
  background: linear-gradient(135deg, #fff, #ededed);
  color: #666;
  text-align: center;
}

.world-history-placeholder p { margin: .25rem 1rem; }

.world-history-back {
  display: block;
  width: fit-content;
  margin: -2rem auto 5rem;
  padding: .65rem 1.2rem;
  border-radius: 999px;
  background: var(--world-red);
  color: #fff;
  font-weight: 700;
  text-decoration: none;
}

.world-history-back:hover { filter: brightness(.86); }

footer {
  padding: 1rem;
  background: var(--world-red);
  color: #fffdef;
  text-align: center;
}

footer a { color: #fff; }

.fade-in-left, .fade-in-right {
  opacity: 0;
  transition: opacity .8s ease, transform .8s ease;
}
.fade-in-left { transform: translateX(-28px); }
.fade-in-right { transform: translateX(28px); }
.visible { opacity: 1; transform: translate(0, 0); }

@media (max-width: 760px) {
  .world-history-hero { min-height: 240px; }
  .world-history-grid {
    grid-template-columns: 1fr;
    width: min(100% - 2rem, 620px);
  }
}

@media (prefers-reduced-motion: reduce) {
  .fade-in-left, .fade-in-right {
    opacity: 1;
    transform: none;
    transition: none;
  }
}