style.css

/* =========================
   Modern UI theme (Dash + DBC)
   ========================= */

:root {
  --bg: #ffffff;
  --bg-muted: #f6f7fb;
  --surface: #ffffff;
  --surface-2: #fbfbfd;

  --text: #0f172a;
  --text-muted: #475569;
  --text-subtle: #64748b;

  --border: #e5e7eb;
  --border-strong: #d1d5db;

  /* Active */
  --primary: #2563EB;
  --primary-700: #1D4ED8;

  /* RGB triples (for rgba usage) */
  --ink-rgb: 15, 23, 42;
  --primary-rgb: 37, 99, 235;

  /* Surfaces */
  --primary-tint: #EFF6FF;
  --primary-tint-2: #DBEAFE;

  --shadow-sm: 0 1px 2px rgba(var(--ink-rgb), 0.06);
  --shadow-md: 0 10px 25px rgba(var(--ink-rgb), 0.08);

  /* Radius (reduced + standardized) */
  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-pill: 999px;

  /* Optional: use for tight focus rounding */
  --radius-focus: 10px;

  --focus: 0 0 0 3px rgba(var(--primary-rgb), 0.20);

  /* Common alpha accents */
  --primary-a35: rgba(var(--primary-rgb), 0.35);
  --primary-a55: rgba(var(--primary-rgb), 0.55);
  --primary-a85: rgba(var(--primary-rgb), 0.85);
}

* { box-sizing: border-box; }

body {
  margin: 0;
  padding: 16px 20px;
  background: var(--bg-muted);
  color: var(--text);
  font-family: ui-sans-serif, system-ui, -apple-system, Segoe UI, Roboto, Helvetica, Arial, "Apple Color Emoji", "Segoe UI Emoji";
  line-height: 1.35;
  overflow-x: hidden;
}

@media (max-width: 576px) {
  body { padding: 12px 12px; }
}

._dash-undo-redo { display: none; }

.container.scalable,
.container-fluid.scalable {
  width: 100%;
  max-width: none;
}

/* App shell spacing */
.app-shell {
  max-width: 1400px;
  margin: 0 auto;
}

/* =========================
   Top app header
   ========================= */

.app-shell .app-banner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;

  padding: 14px 16px;
  margin: 6px 0 14px;

  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-sm);
}

.app-shell .app-banner h6 {
  margin: 0;
  font-size: 16px;
  font-weight: 800;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--text);
}

/* GitHub link styled like pill button */
.app-shell .btn-link {
  display: inline-flex;
  align-items: center;
  justify-content: center;

  padding: 9px 12px;
  border-radius: var(--radius-pill);
  border: 1px solid var(--border);
  background: var(--surface-2);
  color: var(--text-muted);
  text-decoration: none;
  font-weight: 700;
  font-size: 13px;

  transition: background 120ms ease, border-color 120ms ease, color 120ms ease, transform 120ms ease;
}

.app-shell .btn-link:hover {
  color: var(--primary);
  border-color: var(--primary-a35);
  background: var(--primary-tint);
  transform: translateY(-1px);
}

.app-shell .btn-link:focus-visible {
  outline: none;
  box-shadow: var(--focus);
}

/* =========================
   Cards / containers
   ========================= */

.app-shell .pretty-container {
  margin: 14px 0;
  padding: 16px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-md);
}

.app-shell .card-header {
  display: flex;
  align-items: center;
  justify-content: space-between;

  margin: -2px 0 10px;
  padding: 8px 0;

  border-bottom: 1px solid var(--border);
}

.app-shell .card-header h6 {
  margin: 0;
  font-size: 15px;
  font-weight: 800;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--text);
}

/* Labels + small text */
.app-shell label {
  font-size: 14px;
  font-weight: 700;
  color: var(--text-muted);
  margin-top: 6px;
  display: inline-block;
}

.app-shell small {
  color: var(--text-subtle);
}

/* =========================
   Buttons (opt-in via .btn-neutral)
   ========================= */

.app-shell .btn-neutral {
  appearance: none;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  vertical-align: middle;

  height: 34px;
  padding: 0 12px;
  border-radius: var(--radius-sm);
  border: 1px solid var(--border);
  background: var(--surface-2);
  color: var(--text-muted);

  font-weight: 700;
  font-size: 14px;
  box-shadow: var(--shadow-sm);

  transition: border-color 120ms ease, color 120ms ease, background 120ms ease, transform 120ms ease;
}

.app-shell .btn-neutral:hover {
  color: var(--primary);
  border-color: var(--primary-a35);
  background: var(--primary-tint);
  transform: translateY(-1px);
}

.app-shell .btn-neutral:focus-visible {
  outline: none;
  box-shadow: var(--focus);
}

.app-shell .button-row {
  display: flex;
  gap: 8px;
  flex-wrap: wrap;
  margin-bottom: 10px;
}

.app-shell .field-label {
  display: block;
  margin-top: 10px;
}

/* =========================
   Inputs / Dropdowns
   ========================= */

.app-shell .input-control,
.app-shell input[type="text"],
.app-shell input[type="number"] {
  width: 100%;
  height: 38px;
  padding: 6px 10px;

  background: var(--surface-2);
  color: var(--text);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  box-shadow: none;
  font-size: 14px;
}

.app-shell .input-control:focus-visible,
.app-shell input[type="text"]:focus-visible,
.app-shell input[type="number"]:focus-visible {
  outline: none;
  border-color: var(--primary-a55);
  box-shadow: var(--focus);
}

/* Dash Dropdown legacy react-select v1 */
.app-shell .Select-control {
  min-height: 38px;
  background: var(--surface-2);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  box-shadow: none;
}

.app-shell .Select.is-focused .Select-control {
  border-color: var(--primary-a55);
  box-shadow: var(--focus);
}

.app-shell .Select-placeholder,
.app-shell .Select-value-label {
  color: var(--text-subtle);
  font-size: 14px;
}

/* Dash Dropdown newer react-select hooks (future/variant-safe) */
.app-shell .Select__control {
  min-height: 38px;
  background: var(--surface-2);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  box-shadow: none;
}

.app-shell .Select__control--is-focused {
  border-color: var(--primary-a55);
  box-shadow: var(--focus);
}

.app-shell .Select__placeholder,
.app-shell .Select__single-value,
.app-shell .Select__input-container {
  color: var(--text-subtle);
  font-size: 14px;
}

/* Menu */
.app-shell .Select-menu-outer,
.app-shell .Select__menu {
  background: var(--surface);
  color: var(--text);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-md);
  overflow: hidden;
}

.app-shell .Select-option,
.app-shell .Select__option {
  font-size: 14px;
}

.app-shell .Select-option:hover,
.app-shell .Select__option--is-focused {
  background: var(--primary-tint);
  color: var(--primary);
  cursor: pointer;
}

/* Hide clear X (legacy) */
.app-shell span.Select-clear-zone { display: none; }

/* =========================
   Details/Summary styling (lighter, less “box in a box”)
   ========================= */

.app-shell details {
  background: var(--surface-2);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  padding: 10px 12px;
  margin-top: 10px;
}

.app-shell details + details {
  margin-top: 12px;
}

.app-shell summary.section-title {
  list-style: none;
  cursor: pointer;
  user-select: none;

  font-size: 14px;
  font-weight: 800;
  color: var(--text);
  letter-spacing: 0.04em;

  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 10px;

  padding: 6px 2px;
}

.app-shell summary.section-title::-webkit-details-marker { display: none; }

.app-shell summary.section-title:focus-visible {
  outline: none;
  box-shadow: var(--focus);
  border-radius: var(--radius-focus);
}

/* =========================
   RangeSlider
   ========================= */

.app-shell .rc-slider { margin-top: 10px; }

.app-shell .rc-slider-rail { background: var(--primary-tint-2); }

.app-shell .rc-slider-track { background: var(--primary-a85); }

.app-shell .rc-slider-handle,
.app-shell .rc-slider-dot-active {
  border-color: var(--primary-a85);
  background: var(--primary-a85);
}

.app-shell .rc-slider-handle {
  border-width: 1px;
  box-shadow: 0 2px 10px rgba(var(--ink-rgb), 0.12);
}

/* =========================
   Checklist styling (opt-in via .checklist class or specific IDs)
   ========================= */

.app-shell .checklist label,
.app-shell #yf_checklist label,
.app-shell #exit_checklist label,
.app-shell #sim_checklist label,
.app-shell #prob_checklist label,
.app-shell #stats_checklist label {
  display: flex;
  align-items: center;
  gap: 8px;
  margin: 6px 0;
  color: var(--text-muted);
  font-size: 14px;
}

.app-shell .checklist input,
.app-shell #yf_checklist input,
.app-shell #exit_checklist input,
.app-shell #sim_checklist input,
.app-shell #prob_checklist input,
.app-shell #stats_checklist input {
  margin-right: 8px;
}

.app-shell input[type="checkbox"] {
  accent-color: var(--primary);
}

/* =========================
   DataTable (Dash)
   ========================= */

.app-shell .dash-table-container .dash-spreadsheet-container {
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  overflow: hidden;
  box-shadow: var(--shadow-sm);
}

.app-shell .dash-spreadsheet-inner {
  background: var(--surface);
}

.app-shell .dash-spreadsheet-inner th {
  background: #f8fafc;
  color: var(--text-muted);
  font-weight: 800;
  border-bottom: 1px solid var(--border);
}

.app-shell .dash-spreadsheet-inner td {
  border-bottom: 1px solid rgba(229, 231, 235, 0.7);
  color: var(--text);
}

.app-shell .dash-table-container .dash-cell.focused,
.app-shell .dash-table-container .dash-cell.cell--selected {
  outline: none;
  box-shadow: inset 0 0 0 2px var(--primary-a35);
}

.app-shell .dash-spreadsheet-inner .row { margin: 0; }