.cst-shell {
  border: 1px solid var(--border, #cbd5e1);
  border-radius: 18px;
  padding: 18px;
  background:
    radial-gradient(circle at top right, rgba(56, 189, 248, 0.12), transparent 22rem),
    linear-gradient(180deg, rgba(248, 250, 252, 0.98), rgba(255, 255, 255, 0.99));
}

.cst-mode-tabs,
.cst-button-row,
.cst-example-row,
.cst-mini-grid {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}

.cst-mode-tabs .button.active {
  color: #fff;
  background: linear-gradient(135deg, #0f766e, #0284c7);
  border-color: transparent;
}

.cst-grid {
  display: grid;
  gap: 18px;
  grid-template-columns: minmax(0, 1.25fr) minmax(280px, 0.9fr);
}

.cst-panel[hidden] {
  display: none;
}

.cst-card {
  border: 1px solid var(--border, #cbd5e1);
  border-radius: 16px;
  padding: 18px;
  background: rgba(255, 255, 255, 0.94);
  box-shadow: 0 12px 28px rgba(15, 23, 42, 0.05);
}

.cst-table,
.cst-result-table {
  width: 100%;
  border-collapse: collapse;
}

.cst-table th,
.cst-table td,
.cst-result-table th,
.cst-result-table td {
  padding: 10px 8px;
  border-bottom: 1px solid var(--border, #cbd5e1);
  vertical-align: top;
  text-align: left;
}

.cst-table input,
.cst-result-table input,
.cst-mini-field input,
.cst-matrix-input {
  width: 100%;
}

.cst-mini-grid {
  display: grid;
  gap: 12px;
  grid-template-columns: repeat(auto-fit, minmax(160px, 1fr));
}

.cst-mini-field {
  display: flex;
  flex-direction: column;
  gap: 6px;
  font-weight: 700;
}

.cst-summary-grid {
  display: grid;
  gap: 12px;
  grid-template-columns: repeat(auto-fit, minmax(140px, 1fr));
}

.cst-summary-item {
  border: 1px solid var(--border, #cbd5e1);
  border-radius: 14px;
  padding: 14px;
  background: rgba(248, 250, 252, 0.92);
}

.cst-summary-label {
  display: block;
  font-size: 0.85rem;
  color: var(--muted, #64748b);
}

.cst-summary-value {
  display: block;
  margin-top: 6px;
  font-size: 1.25rem;
  font-weight: 800;
}

.cst-message-list {
  margin: 0;
  padding-left: 18px;
}

.cst-message {
  border-radius: 14px;
  padding: 14px 16px;
  margin-bottom: 14px;
}

.cst-message--error {
  background: #fef2f2;
  border: 1px solid #fecaca;
  color: #991b1b;
}

.cst-message--warn {
  background: #fffbeb;
  border: 1px solid #fde68a;
  color: #92400e;
}

.cst-note {
  color: var(--muted, #64748b);
}

.cst-cell-stack {
  display: grid;
  gap: 4px;
}

.cst-cell-stack strong {
  font-size: 0.95rem;
}

.cst-canvas {
  width: 100%;
  height: auto;
  display: block;
  border: 1px solid var(--border, #cbd5e1);
  border-radius: 14px;
  background: #fff;
}

.cst-status {
  min-height: 1.3em;
  color: var(--muted, #64748b);
  font-size: 0.95rem;
}

@media (max-width: 940px) {
  .cst-grid {
    grid-template-columns: 1fr;
  }
}