:root {
  color-scheme: light dark;
  --ifs-page-bg: #f8fafc;
  --ifs-text: #0f172a;
  --ifs-subtext: #334155;
  --ifs-panel-bg: #ffffff;
  --ifs-panel-border: #cbd5e1;
  --ifs-canvas-bg: #f8fafc;
  --ifs-canvas-border: #94a3b8;
  --ifs-table-border: #cbd5e1;
  --ifs-input-bg: #ffffff;
  --ifs-input-border: #94a3b8;
  --ifs-button-bg: #e2e8f0;
  --ifs-button-text: #0f172a;
  --ifs-button-hover: #cbd5e1;
  --ifs-formula-bg: #f1f5f9;
}

@media (prefers-color-scheme: dark) {
  :root {
    --ifs-page-bg: #020617;
    --ifs-text: #e2e8f0;
    --ifs-subtext: #cbd5e1;
    --ifs-panel-bg: #111827;
    --ifs-panel-border: #1f2937;
    --ifs-canvas-bg: #020617;
    --ifs-canvas-border: #334155;
    --ifs-table-border: #334155;
    --ifs-input-bg: #0f172a;
    --ifs-input-border: #475569;
    --ifs-button-bg: #1e293b;
    --ifs-button-text: #f8fafc;
    --ifs-button-hover: #334155;
    --ifs-formula-bg: #020617;
  }
}

body {
  margin: 0;
  background: var(--ifs-page-bg);
  color: var(--ifs-text);
}

.ifs-fern-container {
  max-width: 1240px;
  margin: 0 auto;
  padding: 20px;
  color: var(--ifs-text);
  font-family:
    Inter,
    -apple-system,
    BlinkMacSystemFont,
    "Segoe UI",
    sans-serif;
}

.ifs-fern-header {
  margin-bottom: 16px;
}

.ifs-fern-subtitle {
  margin-top: 8px;
  color: var(--ifs-subtext);
}

.ifs-fern-main {
  display: grid;
  grid-template-columns: minmax(360px, 1fr) minmax(420px, 1fr);
  gap: 16px;
}

.ifs-fern-canvas-panel,
.ifs-fern-controls,
.ifs-fern-formula-card {
  background: var(--ifs-panel-bg);
  border: 1px solid var(--ifs-panel-border);
  border-radius: 12px;
  padding: 14px;
}

#ifsFernCanvas {
  width: 100%;
  max-height: 72vh;
  background: var(--ifs-canvas-bg);
  border: 1px solid var(--ifs-canvas-border);
  border-radius: 8px;
  display: block;
}

.ifs-fern-stats {
  margin-top: 10px;
  display: flex;
  flex-wrap: wrap;
  gap: 14px;
  font-size: 14px;
}

.ifs-fern-controls h2,
.ifs-fern-controls h3 {
  margin: 4px 0 10px;
}

.ifs-fern-control-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 8px;
  margin-bottom: 12px;
}

.ifs-fern-control-grid label {
  font-size: 14px;
}

.ifs-fern-control-grid input,
.ifs-fern-control-grid select {
  width: 100%;
}

.ifs-fern-hint {
  margin: 0 0 10px;
  font-size: 13px;
  opacity: 0.8;
}

.ifs-fern-table-wrap {
  overflow-x: auto;
}

.ifs-fern-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 12px;
}

.ifs-fern-table th,
.ifs-fern-table td {
  border: 1px solid var(--ifs-table-border);
  padding: 4px;
  text-align: center;
}

.ifs-fern-table input {
  width: 68px;
  padding: 3px;
  border-radius: 6px;
  border: 1px solid var(--ifs-input-border);
  background: var(--ifs-input-bg);
  color: var(--ifs-text);
}

.ifs-fern-actions {
  margin-top: 12px;
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.ifs-fern-actions button {
  border: 1px solid var(--ifs-input-border);
  background: var(--ifs-button-bg);
  color: var(--ifs-button-text);
  padding: 7px 12px;
  border-radius: 8px;
  cursor: pointer;
}

.ifs-fern-actions button:hover {
  background: var(--ifs-button-hover);
}

.ifs-fern-formula-card {
  margin-top: 16px;
}

.ifs-fern-formula {
  margin: 10px 0 0;
  padding: 10px;
  background: var(--ifs-formula-bg);
  border-radius: 8px;
  overflow-x: auto;
}

@media (max-width: 980px) {
  .ifs-fern-main {
    grid-template-columns: 1fr;
  }
}