/* ==========================================================================
   step-card.css — Step card component
   ========================================================================== */

.step-card {
  background-color: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--space-sm);
  padding: var(--space-md);
  opacity: 0;
  transform: translateY(12px);
  transition: opacity var(--transition-step),
              transform var(--transition-step);
}

.step-card.is-visible {
  opacity: 1;
  transform: none;
}

.step-card__header {
  display: flex;
  align-items: baseline;
  gap: var(--space-sm);
  margin-bottom: var(--space-md);
}

.step-card__round-badge {
  display: inline-block;
  padding: var(--space-xs) var(--space-sm);
  background-color: var(--color-primary);
  color: #fff;
  border-radius: var(--space-xs);
  font-size: var(--font-size-sm);
  font-weight: 600;
  white-space: nowrap;
}

.step-card__title {
  font-size: var(--font-size-lg);
  font-weight: 600;
}

.step-card__description {
  color: var(--color-text-muted);
  font-size: var(--font-size-sm);
  margin-bottom: var(--space-md);
  line-height: 1.5;
}

.step-card__content {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-lg);
  align-items: flex-start;
}

/* --- RSA formula display --- */
.step-card__formula {
  font-family: var(--font-mono);
  font-size: var(--font-size-md);
  background-color: var(--color-bg);
  padding: var(--space-md);
  border-radius: var(--space-xs);
  border-left: 3px solid var(--color-primary);
  word-break: break-all;
}

.step-card__values {
  display: grid;
  grid-template-columns: auto 1fr;
  gap: var(--space-xs) var(--space-md);
  font-size: var(--font-size-sm);
}

.step-card__value-key {
  color: var(--color-text-muted);
  font-weight: 600;
}

.step-card__value-val {
  font-family: var(--font-mono);
  color: var(--color-highlight);
}

/* --- Operation detail --- */
.step-card__detail {
  font-size: var(--font-size-sm);
  color: var(--color-text-muted);
  margin-top: var(--space-md);
  padding-top: var(--space-md);
  border-top: 1px solid var(--color-border);
}

.step-card__detail-title {
  font-weight: 600;
  color: var(--color-text);
  margin-bottom: var(--space-sm);
}

.step-card__content--vertical {
  flex-direction: column;
}

/* --- Caesar cipher character visualization --- */
.caesar-chars {
  display: flex;
  flex-direction: column;
  gap: var(--space-sm);
  overflow-x: auto;
}

.caesar-chars__row {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
}

.caesar-chars__row-label {
  font-size: var(--font-size-sm);
  color: var(--color-text-muted);
  font-weight: 600;
  min-width: 60px;
  text-align: right;
  flex-shrink: 0;
}

.caesar-chars__cells {
  display: flex;
  gap: 2px;
  flex-wrap: wrap;
}

.caesar-chars__cell {
  display: flex;
  align-items: center;
  justify-content: center;
  width: calc(var(--space-lg) - var(--space-xs));
  height: calc(var(--space-lg) - var(--space-xs));
  background-color: var(--color-bg);
  border: 1px solid var(--color-border);
  border-radius: 2px;
  font-family: var(--font-mono);
  font-size: var(--font-size-sm);
  transition: background-color var(--transition-step),
              border-color var(--transition-step),
              transform var(--transition-step);
}

.caesar-chars__cell--active {
  background-color: var(--color-highlight);
  border-color: var(--color-highlight);
  color: var(--color-bg);
  font-weight: 700;
  transform: scale(1.15);
}

.caesar-chars__cell--done {
  background-color: rgba(16, 185, 129, 0.15);
  border-color: var(--color-success);
  color: var(--color-success);
}

.caesar-chars__arrow {
  display: flex;
  align-items: center;
  justify-content: center;
  width: calc(var(--space-lg) - var(--space-xs));
  height: var(--space-md);
  font-size: var(--font-size-sm);
  color: var(--color-text-muted);
}

.caesar-chars__arrow--active {
  color: var(--color-highlight);
  font-weight: 700;
}