/* ==========================================================================
   ذَرّة | ZARRA — Chemical Equation Balancer Styles
   المرحلة 4: ميزان وزن المعادلات الكيميائية التفاعلي
   ========================================================================== */

.balancer-card {
  background: var(--color-bg-surface);
  border: 1px solid var(--color-border-soft);
  border-radius: var(--radius-xl);
  padding: var(--spacing-xl);
  box-shadow: var(--shadow-sm);
  margin-bottom: var(--spacing-xl);
  transition: all var(--transition-normal);
}

.balancer-card.balanced-success {
  border-color: var(--color-mint-dark);
  box-shadow: 0 0 25px rgba(63, 126, 80, 0.25);
  background: linear-gradient(135deg, var(--color-bg-surface) 0%, var(--color-mint-soft) 100%);
}

/* سطر المعادلة القابلة للضبط */
.equation-row {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: var(--spacing-sm);
  flex-wrap: wrap;
  padding: var(--spacing-lg) var(--spacing-md);
  background: var(--color-bg-surface-soft);
  border-radius: var(--radius-lg);
  margin-bottom: var(--spacing-xl);
  direction: ltr;
}

.coeff-selector {
  display: inline-flex;
  align-items: center;
  gap: 4px;
  background: var(--color-bg-surface);
  border: 1.5px solid var(--color-border-medium);
  border-radius: var(--radius-md);
  padding: 3px 6px;
}

.coeff-btn {
  width: 26px;
  height: 26px;
  border-radius: 4px;
  border: 1px solid var(--color-border-soft);
  background: var(--color-bg-surface-soft);
  font-weight: bold;
  font-size: 1rem;
  color: var(--color-text-main);
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: all var(--transition-fast);
}

.coeff-btn:hover {
  background: var(--color-primary);
  color: #fff;
  border-color: var(--color-primary);
}

.coeff-val {
  min-width: 22px;
  text-align: center;
  font-weight: 800;
  font-family: var(--font-chem-code);
  font-size: 1.15rem;
  color: var(--color-primary);
}

.formula-part {
  font-family: var(--font-chem-code);
  font-size: 1.35rem;
  font-weight: 700;
  color: var(--color-text-main);
}

.equation-symbol {
  font-size: 1.4rem;
  font-weight: bold;
  color: var(--color-text-muted);
  margin: 0 4px;
}

/* شبكة موازين العناصر الذرية */
.atomic-scales-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: var(--spacing-md);
  margin-bottom: var(--spacing-lg);
}

.scale-box {
  background: var(--color-bg-surface-soft);
  border: 1.5px solid var(--color-border-soft);
  border-radius: var(--radius-lg);
  padding: var(--spacing-md);
  text-align: center;
  transition: all var(--transition-fast);
}

.scale-box.balanced {
  border-color: var(--color-mint-dark);
  background: var(--color-mint-soft);
}

.scale-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: var(--spacing-sm);
}

.scale-elem-badge {
  width: 32px;
  height: 32px;
  border-radius: 50%;
  background: var(--color-primary-light);
  color: var(--color-primary);
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: bold;
  font-family: var(--font-chem-code);
  font-size: 0.95rem;
}

.scale-beam {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 8px 12px;
  background: var(--color-bg-surface);
  border-radius: var(--radius-sm);
  border: 1px solid var(--color-border-soft);
  font-family: var(--font-chem-code);
  font-weight: 700;
}

.scale-status-icon {
  font-size: 1.1rem;
}