/* Ruled-paper texture used behind hero/section backgrounds */
.ruled-paper {
  background-image: repeating-linear-gradient(
    to bottom,
    transparent,
    transparent 27px,
    rgba(34, 48, 74, 0.08) 28px
  );
}

/* Exercise-book style card: cream cover with a red margin line and a
   colored "spine" on the left, evoking a school notebook. */
.notebook-card {
  position: relative;
  background: #FFFDF7;
  border: 1px solid rgba(34, 48, 74, 0.12);
  border-radius: 6px;
  padding-left: 1.25rem;
  overflow: hidden;
}
.notebook-card::before {
  content: "";
  position: absolute;
  top: 0;
  bottom: 0;
  left: 0.85rem;
  width: 1px;
  background: rgba(192, 57, 43, 0.35); /* red margin line */
}
.notebook-card::after {
  content: "";
  position: absolute;
  top: 0;
  bottom: 0;
  left: 0;
  width: 0.35rem;
}

/* The signature element: a circular red teacher's stamp mark */
.stamp-badge {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 3.25rem;
  height: 3.25rem;
  border-radius: 9999px;
  border: 2px solid currentColor;
  transform: rotate(-8deg);
  font-family: "Space Mono", monospace;
  font-size: 0.55rem;
  font-weight: 700;
  letter-spacing: 0.03em;
  text-align: center;
  line-height: 1.1;
  color: #C0392B;
  opacity: 0.9;
}

@media (prefers-reduced-motion: reduce) {
  * { animation: none !important; transition: none !important; }
}