body {
  margin: 0;
  font-family: Arial, Helvetica, sans-serif;
  font-size: 14px;
  line-height: 1.4;
  color: #1f1f1f;
  background: #f3f3f3;
}

* {
  box-sizing: border-box;
}

button,
input,
select {
  font: inherit;
}

.app-shell {
  max-width: 1280px;
  margin: 0 auto;
  padding: 20px;
}

.app-header {
  display: grid;
  grid-template-columns: 1fr 360px;
  gap: 16px;
  margin-bottom: 16px;
}

.app-header h1 {
  margin: 0 0 6px;
  font-size: 28px;
  font-weight: 700;
}

.app-subtitle {
  margin: 0;
  color: #555;
}

.status-panel,
.panel,
.field-card,
.plot-card,
.table-card {
  background: #fff;
  border: 1px solid #cfcfcf;
}

.status-panel {
  padding: 12px;
}

.status-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
}

.status-label {
  font-weight: 700;
}

.runtime-tag {
  display: inline-block;
  min-width: 88px;
  padding: 4px 10px;
  border: 1px solid #9aa7b1;
  background: #eceff1;
  color: #203040;
  text-align: center;
  font-weight: 700;
}

.runtime-tag[data-ready="true"] {
  background: #e4f0e4;
  border-color: #7aa67a;
  color: #1d5a1d;
}

.status-text {
  margin: 10px 0 0;
  color: #555;
}

.error-banner {
  margin-bottom: 16px;
  padding: 10px 12px;
  border: 1px solid #d79f9f;
  background: #fff1f1;
  color: #7a1f1f;
}

.tabs {
  display: flex;
  gap: 8px;
  margin-bottom: 12px;
}

.tab-button {
  padding: 8px 14px;
  border: 1px solid #aeb7bf;
  background: #f7f7f7;
  cursor: pointer;
}

.tab-button[data-active="true"] {
  background: #dfe9f6;
  border-color: #6d8fb3;
  font-weight: 700;
}

.panel {
  margin-bottom: 16px;
  padding: 16px;
}

.panel-header {
  margin-bottom: 16px;
}

.panel-header-actions {
  display: flex;
  align-items: start;
  justify-content: space-between;
  gap: 12px;
}

.panel-header h2,
.field-card h3,
.plot-card h3,
.table-card h3 {
  margin: 0 0 6px;
  font-size: 20px;
}

.panel-header p,
.field-card p,
.table-card p {
  margin: 0;
  color: #555;
}

.analysis-layout {
  display: grid;
  grid-template-columns: 420px 1fr;
  gap: 16px;
}

.analysis-layout-wide {
  grid-template-columns: 440px 1fr;
}

.controls-stack,
.results-stack {
  display: grid;
  gap: 16px;
}

.field-card,
.plot-card,
.table-card {
  padding: 14px;
}

.field-grid {
  display: grid;
  gap: 12px;
}

.field-hint {
  color: #666;
  font-size: 12px;
}

.form-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 12px;
}

.option-stack {
  display: grid;
  gap: 8px;
  align-content: start;
}

.field label {
  display: block;
  margin-bottom: 6px;
  font-weight: 700;
}

.field input[type="text"],
.field input[type="file"],
.field input[type="number"],
.field select,
.table-input {
  width: 100%;
  padding: 8px 10px;
  border: 1px solid #bfc6cc;
  background: #fff;
}

.checkbox-row {
  display: flex;
  align-items: center;
  gap: 8px;
  padding-top: 26px;
  font-weight: 700;
}

.checkbox-row-compact {
  padding-top: 0;
}

.file-meta,
.empty-state,
.info-box {
  padding: 10px;
  border: 1px solid #d7d7d7;
  background: #fafafa;
  color: #555;
}

.parameter-grid {
  display: grid;
  gap: 12px;
}

.collapsible-section,
.collapsible-card {
  border: 1px solid #d7d7d7;
  background: #fafafa;
}

.collapsible-section > summary,
.collapsible-card > summary {
  list-style: none;
  cursor: pointer;
  font-weight: 700;
}

.collapsible-section > summary::-webkit-details-marker,
.collapsible-card > summary::-webkit-details-marker {
  display: none;
}

.collapsible-section > summary::after,
.collapsible-card > summary::after {
  content: "+";
  float: right;
  color: #666;
}

.collapsible-section[open] > summary::after,
.collapsible-card[open] > summary::after {
  content: "−";
}

.collapsible-section > summary {
  padding: 10px 12px;
}

.collapsible-section-body {
  padding: 0 12px 12px;
}

.collapsible-card {
  padding: 0;
}

.collapsible-card > summary {
  padding: 14px;
  background: #f7f7f7;
}

.collapsible-card-body {
  padding: 14px;
}

.collapsible-card-body > p {
  margin: 0 0 12px;
}

.plot-toolbar {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 16px;
  margin-bottom: 12px;
}

.slider-field {
  min-width: 220px;
  display: grid;
  gap: 6px;
}

.slider-field p {
  margin: 0;
}

.slider-field label {
  font-weight: 700;
}

.slider-field input[type="range"] {
  width: 100%;
}

.slider-field-meta {
  display: grid;
  gap: 8px;
}

.slider-value {
  color: #555;
  font-weight: 700;
}

.range-input-row {
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto minmax(0, 1fr);
  gap: 8px;
  align-items: center;
}

.range-input-row input[type="text"] {
  width: 100%;
  padding: 6px 8px;
  border: 1px solid #bfc6cc;
  background: #fff;
}

.range-input-row input[type="text"]:disabled {
  background: #f3f3f3;
  color: #777;
}

.range-separator {
  color: #555;
  font-weight: 700;
}

.result-text {
  margin-bottom: 12px;
}

.button-row {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.primary-button,
.secondary-button,
.ghost-button {
  padding: 8px 14px;
  border: 1px solid #8f9aa3;
  background: #f1f1f1;
  cursor: pointer;
}

.primary-button {
  background: #dfe9f6;
  border-color: #6d8fb3;
}

.secondary-button {
  background: #f3e8da;
  border-color: #b59b76;
}

.ghost-button {
  background: #f7f7f7;
}

.compact-button {
  padding: 5px 9px;
}

.primary-button:disabled,
.secondary-button:disabled,
.ghost-button:disabled {
  cursor: not-allowed;
  opacity: 0.6;
}

.metric-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(120px, 1fr));
  gap: 8px;
  margin-bottom: 12px;
}

.metric-card {
  padding: 8px 10px;
  border: 1px solid #d4d4d4;
  background: #fafafa;
}

.metric-card span {
  display: block;
  color: #555;
  font-size: 12px;
  margin-bottom: 4px;
}

.metric-card strong {
  font-size: 16px;
}

.plot-surface {
  min-height: 460px;
  border: 1px solid #d0d0d0;
  background: #fff;
}

.plot-surface-secondary {
  min-height: 340px;
  margin-top: 12px;
}

.table-scroll {
  overflow: auto;
}

table {
  width: 100%;
  border-collapse: collapse;
}

th,
td {
  padding: 8px 10px;
  border: 1px solid #d8d8d8;
  text-align: left;
  vertical-align: top;
}

th {
  background: #f3f3f3;
}

.table-file {
  font-weight: 700;
}

.table-subtle {
  color: #666;
  font-size: 12px;
  margin-top: 4px;
}

.help-dialog {
  width: min(880px, calc(100vw - 40px));
  border: 1px solid #c8c8c8;
  padding: 0;
}

.help-dialog::backdrop {
  background: rgba(0, 0, 0, 0.25);
}

.help-dialog-body {
  padding: 16px;
}

.help-dialog-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  margin-bottom: 16px;
}

.help-dialog-header h3,
.help-section h3,
.help-item h4 {
  margin: 0 0 8px;
}

.help-section + .help-section {
  margin-top: 20px;
}

.help-item {
  padding: 10px 12px;
  border: 1px solid #d6d6d6;
  background: #fafafa;
}

.help-item + .help-item {
  margin-top: 10px;
}

.help-item p {
  margin: 6px 0 0;
}

@media (max-width: 980px) {
  .app-header,
  .analysis-layout,
  .form-grid {
    grid-template-columns: 1fr;
  }

  .plot-toolbar {
    flex-direction: column;
  }

  .slider-field {
    min-width: 0;
    width: 100%;
  }

  .range-input-row {
    grid-template-columns: 1fr;
  }

  .range-separator {
    display: none;
  }

  .checkbox-row {
    padding-top: 0;
  }
}