:root {
  --bg: #f4f5f7;
  --panel: #ffffff;
  --border: #e2e4e9;
  --text: #1f2430;
  --text-muted: #6b7280;
  --accent: #2563eb;
  --accent-soft: #eff4ff;
  --radius: 10px;
  font-size: 16px;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: "Inter", "Segoe UI", "Helvetica Neue", Helvetica, Arial, sans-serif;
  line-height: 1.5;
}

.app {
  max-width: 1400px;
  margin: 0 auto;
  padding: 24px 20px 48px;
}

.app-header {
  text-align: center;
  margin-bottom: 28px;
}

.app-header h1 {
  margin: 0 0 6px;
  font-size: 2.4rem;
  font-weight: 700;
  letter-spacing: -0.02rem;
  color: var(--accent);
}

.subtitle {
  margin: 0;
  color: var(--text-muted);
  font-size: 0.95rem;
}

.tabs {
  display: flex;
  gap: 4px;
  justify-content: center;
  margin-bottom: 20px;
  border-bottom: 1px solid var(--border);
}

.tab-btn {
  appearance: none;
  background: none;
  border: none;
  border-bottom: 2px solid transparent;
  padding: 10px 18px;
  font-size: 0.92rem;
  font-family: inherit;
  color: var(--text-muted);
  cursor: pointer;
}

.tab-btn:hover {
  color: var(--text);
}

.tab-btn.active {
  color: var(--accent);
  border-bottom-color: var(--accent);
  font-weight: 600;
}

.layout {
  display: grid;
  grid-template-columns: 390px 1fr;
  gap: 20px;
  align-items: start;
}

.inputs-panel,
.chart-card {
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 18px 20px;
}

.inputs-panel h2 {
  margin: 0 0 14px;
  font-size: 1.1rem;
}

.inputs-panel h3 {
  margin: 18px 0 10px;
  font-size: 0.9rem;
  text-transform: uppercase;
  letter-spacing: 0.04rem;
  color: var(--text-muted);
}

.field {
  margin-bottom: 12px;
}

.field-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 10px 14px;
}

label {
  display: block;
  font-size: 0.82rem;
  color: var(--text-muted);
  margin-bottom: 4px;
}

.field-grid label {
  min-height: 3em;
}

.unit {
  color: #9aa1ad;
}

input[type="number"] {
  width: 100%;
  height: 36px;
  padding: 4px 10px;
  border: 1px solid var(--border);
  border-radius: 6px;
  font-size: 0.95rem;
  font-family: inherit;
  color: var(--text);
  background: #fff;
}

input[type="number"]:focus {
  outline: none;
  border-color: var(--accent);
  box-shadow: 0 0 0 3px var(--accent-soft);
}

input[type="number"]:disabled {
  background: var(--bg);
  color: var(--text-muted);
  border-style: dashed;
}

.checkbox-field {
  display: flex;
  align-items: flex-start;
  gap: 8px;
  margin: 10px 0 4px;
  font-size: 0.82rem;
  color: var(--text-muted);
  cursor: pointer;
}

.checkbox-field input[type="checkbox"] {
  margin-top: 2px;
  accent-color: var(--accent);
}

.field-note {
  margin: 0;
  font-size: 0.78rem;
  color: var(--text-muted);
  min-height: 1.1em;
}

.slider-field {
  margin-bottom: 16px;
}

.slider-label-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 10px;
}

.slider-label-row label {
  margin-bottom: 0;
  flex: 1;
}

.slider-readout {
  width: 70px !important;
  height: 30px !important;
  text-align: center;
  flex: 0 0 auto;
}

input[type="range"] {
  width: 100%;
  margin-top: 8px;
  accent-color: var(--accent);
}

.summary {
  margin: 0;
  font-size: 0.9rem;
}

.summary div.row {
  display: flex;
  justify-content: space-between;
  padding: 6px 0;
  border-bottom: 1px solid var(--border);
}

.summary div.row:last-child {
  border-bottom: none;
}

.summary .label {
  color: var(--text-muted);
}

.summary .value {
  font-weight: 600;
  font-variant-numeric: tabular-nums;
}

.summary .value.good {
  color: #16803c;
}

.summary .value.warn {
  color: #b45309;
}

.charts-panel {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 16px;
}

.chart-card h4 {
  margin: 0 0 6px;
  font-size: 0.9rem;
  color: var(--text-muted);
  font-weight: 600;
}

.chart {
  width: 100%;
  height: 300px;
}

@media (max-width: 980px) {
  .layout {
    grid-template-columns: 1fr;
  }
  .charts-panel {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 480px) {
  .field-grid {
    grid-template-columns: 1fr;
  }
}

.layout[hidden],
.docs-view[hidden] {
  display: none;
}

.docs-view {
  display: flex;
  justify-content: center;
}

.docs-card {
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 28px 32px;
  max-width: 820px;
  width: 100%;
}

.docs-card h2 {
  font-size: 1.15rem;
  margin: 28px 0 10px;
}

.docs-card h2:first-child {
  margin-top: 0;
}

.docs-card p {
  color: var(--text);
  font-size: 0.95rem;
  line-height: 1.65;
  margin: 0 0 12px;
}

.docs-card ul {
  margin: 0 0 12px;
  padding-left: 20px;
}

.docs-card li {
  margin-bottom: 10px;
  font-size: 0.95rem;
  line-height: 1.6;
}

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

.docs-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.88rem;
}

.docs-table th,
.docs-table td {
  text-align: left;
  padding: 8px 12px;
  border-bottom: 1px solid var(--border);
}

.docs-table th {
  color: var(--text-muted);
  font-weight: 600;
  font-size: 0.8rem;
  text-transform: uppercase;
  letter-spacing: 0.03rem;
}

.docs-table td:first-child {
  font-weight: 600;
  white-space: nowrap;
}