* {
  box-sizing: border-box;
}
html,
body,
#root {
  height: 100%;
  margin: 0;
}
body {
  font-family: var(--pl-font);
  color: var(--pl-text);
  background: #eef0f3;
  font-size: 13px;
}
.app {
  display: grid;
  grid-template-rows: auto 1fr;
  height: 100%;
}
.app-header {
  display: flex;
  align-items: center;
  gap: 14px;
  padding: 8px 14px;
  background: #fff;
  border-bottom: 1px solid var(--pl-border);
  flex-wrap: wrap;
}
.app-header h1 {
  font-size: 16px;
  margin: 0;
  font-weight: 650;
}
.app-header .sub {
  color: var(--pl-muted);
  font-size: 12px;
}
.method-picker {
  display: flex;
  align-items: center;
  gap: 8px;
  margin-left: auto;
}
.method-picker .picker-label {
  font-size: 11px;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--pl-muted);
}
.mode-tabs {
  display: flex;
  gap: 2px;
  background: var(--pl-panel);
  border: 1px solid var(--pl-border);
  border-radius: 6px;
  padding: 2px;
}
.mode-tabs button {
  font: inherit;
  padding: 4px 12px;
  border: 0;
  background: transparent;
  border-radius: 4px;
  cursor: pointer;
  color: var(--pl-muted);
}
.mode-tabs button.active {
  background: #fff;
  color: var(--pl-text);
  box-shadow: 0 1px 2px rgba(0, 0, 0, 0.08);
}
.app-body {
  display: grid;
  grid-template-columns: 320px minmax(420px, 1fr) minmax(460px, 560px);
  gap: 10px;
  padding: 10px;
  min-height: 0;
}
.col {
  min-height: 0;
  overflow: auto;
  display: flex;
  flex-direction: column;
  gap: 10px;
}
.action-bar {
  position: sticky;
  top: 0;
  z-index: 2;
  background: #eef0f3;
  padding-bottom: 6px;
  display: flex;
  flex-direction: column;
  gap: 6px;
}
.run-btn {
  width: 100%;
  padding: 9px 12px;
  font-size: 14px;
  font-weight: 600;
}
.action-meta {
  display: flex;
  gap: 8px;
  align-items: center;
  font-size: 12px;
  flex-wrap: wrap;
}
.col-right {
  display: grid;
  grid-template-rows: auto 1fr;
  gap: 6px;
  min-height: 0;
}
.col-right .pl-code {
  min-height: 320px;
}
.tabs {
  display: flex;
  gap: 2px;
  border-bottom: 1px solid var(--pl-border);
}
.tabs button {
  font: inherit;
  font-size: 12px;
  padding: 5px 10px;
  border: 1px solid transparent;
  border-bottom: 0;
  background: transparent;
  cursor: pointer;
  color: var(--pl-muted);
  border-radius: 5px 5px 0 0;
}
.tabs button.active {
  background: #fff;
  border-color: var(--pl-border);
  color: var(--pl-text);
}
.tab-body {
  background: #fff;
  border: 1px solid var(--pl-border);
  border-top: 0;
  border-radius: 0 0 6px 6px;
  padding: 10px;
  overflow: auto;
  min-height: 0;
}
.results {
  display: flex;
  flex-direction: column;
  gap: 12px;
}
.results-toolbar {
  display: flex;
  gap: 8px;
  align-items: center;
  flex-wrap: wrap;
  font-size: 12px;
}
.two-up {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 10px;
}
.modes-table {
  font-size: 11px;
  border-collapse: collapse;
}
.modes-table td,
.modes-table th {
  padding: 1px 8px;
  text-align: right;
  border-bottom: 1px solid var(--pl-border);
}
.modes-table th:first-child,
.modes-table td:first-child {
  text-align: left;
}
.banner {
  padding: 8px 10px;
  border-radius: 6px;
  background: var(--pl-warn-bg);
  border: 1px solid #f1d7a8;
  font-size: 12px;
  display: flex;
  gap: 8px;
  align-items: center;
}
.empty {
  color: var(--pl-muted);
  padding: 24px 26px;
  background: #fff;
  border: 1px dashed var(--pl-border);
  border-radius: 6px;
  max-width: 560px;
}
.empty h2 {
  font-size: 15px;
  margin: 0 0 8px;
  color: var(--pl-text);
  font-weight: 650;
}
.empty ol {
  margin: 0 0 10px;
  padding-left: 20px;
  line-height: 1.7;
}
.empty p {
  margin: 0;
  font-size: 12px;
}

/* Left column structure: the problem, then the numerics, then everything else */
.panel-head {
  font-size: 11px;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--pl-muted);
  font-weight: 650;
  margin: 12px 0 6px;
}
.panel-head:first-child {
  margin-top: 0;
}
.method-note {
  font-size: 12px;
  line-height: 1.45;
  padding: 8px 10px;
  background: #fff;
  border: 1px solid var(--pl-border);
  border-left: 3px solid var(--pl-accent);
  border-radius: 5px;
}
.plan-line {
  margin-top: 6px;
}
.pl-params + .pl-params,
.plan-line + .pl-params {
  margin-top: 10px;
}
details.advanced {
  margin-top: 12px;
  border-top: 1px solid var(--pl-border);
  padding-top: 8px;
}
details.advanced > summary {
  font-size: 12px;
  color: var(--pl-muted);
  cursor: pointer;
  margin-bottom: 8px;
}
details.advanced > summary:hover {
  color: var(--pl-accent);
}
/* The result on screen is from other settings: the button says so without moving. */
.run-btn-stale {
  box-shadow: 0 0 0 3px rgba(31, 95, 168, 0.25);
}
kbd {
  font-family: var(--pl-mono);
  font-size: 11px;
  border: 1px solid var(--pl-border);
  border-bottom-width: 2px;
  border-radius: 3px;
  padding: 0 4px;
  background: #fff;
}
@media (max-width: 1250px) {
  .app-body {
    grid-template-columns: 300px 1fr;
  }
  .col-right {
    grid-column: 1 / -1;
  }
}
@media (max-width: 800px) {
  .app-body {
    grid-template-columns: 1fr;
  }
  .col-right {
    grid-column: auto;
  }
}
.sound-bar {
  padding: 6px 8px;
  background: #fff;
  border: 1px solid var(--pl-border);
  border-radius: 6px;
}
.pair-picker .pl-select {
  width: auto;
  flex: 1;
}
.tab-intro {
  margin-bottom: 10px;
  padding-bottom: 8px;
  border-bottom: 1px solid var(--pl-border);
}

/* Equation groups */
.eq-group {
  margin-bottom: 14px;
}
.eq-group h3 {
  font-size: 12px;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--pl-muted);
  margin: 10px 0 6px;
}