:root {
  --bg: #0f1720;
  --panel: #1a2532;
  --panel-2: #202e3d;
  --text: #e6edf3;
  --muted: #93a4b8;
  --accent: #4fb3ff;
  --accent-2: #35d488;
  --danger: #ff6b6b;
  --border: #2c3b4c;
}

* { box-sizing: border-box; }

body {
  margin: 0;
  font-family: -apple-system, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  background: var(--bg);
  color: var(--text);
}

header {
  padding: 1.2rem 1.5rem;
  border-bottom: 1px solid var(--border);
}

header h1 { margin: 0; font-size: 1.4rem; }
.badge {
  font-size: 0.65rem;
  vertical-align: middle;
  background: var(--accent);
  color: #06202f;
  padding: 0.15rem 0.5rem;
  border-radius: 1rem;
  font-weight: 700;
  margin-left: 0.5rem;
}
.subtitle { margin: 0.3rem 0 0; color: var(--muted); font-size: 0.9rem; }

main { padding: 1.5rem; max-width: 1440px; margin: 0 auto; }

.panel { margin-bottom: 1.5rem; }
.hidden { display: none !important; }

#loading-panel {
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: 0.5rem;
  padding: 1rem 1.2rem;
}
#loading-bar { width: 100%; height: 0.6rem; }

.grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 1rem;
}

.workspace {
  display: grid;
  grid-template-columns: minmax(280px, 340px) 1fr;
  align-items: start;
  gap: 1rem;
}
@media (max-width: 900px) {
  .workspace { grid-template-columns: 1fr; }
}

.sidebar {
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: 0.6rem;
  padding: 0 1rem 1rem;
  margin-top: 1rem;
}

.tabs {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(120px, 1fr));
  gap: 0.3rem;
  border-bottom: 1px solid var(--border);
  margin-bottom: 1rem;
  padding-bottom: 0.7rem;
}
.tab-btn {
  background: transparent;
  border: 1px solid var(--border);
  color: var(--muted);
  padding: 0.45rem 0.5rem;
  border-radius: 0.4rem;
  font-size: 0.78rem;
  text-align: center;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
  cursor: pointer;
}
.tab-btn:hover:not(.active) { color: var(--text); border-color: var(--accent); }
.tab-btn.active { background: var(--panel-2); color: var(--accent); border-color: var(--accent); }

.tab-panel { display: none; }
.tab-panel.active { display: block; }
.tab-panel label:last-child { margin-bottom: 0; }

.chart-pane { min-width: 0; }
/* Matches .sidebar's border-width + padding-top, so whichever of these two
   is visible lines up with the sidebar's tab row regardless of state. */
.chart-pane > #results,
.chart-pane > #chart-placeholder {
  margin-top: calc(1rem + 1px);
}
#chart-placeholder {
  background: var(--panel);
  border: 1px dashed var(--border);
  border-radius: 0.6rem;
  padding: 2.5rem 1rem;
  text-align: center;
}

.card {
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: 0.6rem;
  padding: 1rem;
}
.card h2 { margin-top: 0; font-size: 1rem; color: var(--accent); }
.card + .card { margin-top: 1rem; }

label {
  display: block;
  margin-bottom: 0.7rem;
  font-size: 0.85rem;
  color: var(--muted);
}
label.checkbox { display: flex; align-items: center; gap: 0.4rem; }
label.checkbox input { width: auto; }

.radio-group { display: flex; gap: 1rem; margin-bottom: 0.9rem; }
.radio-group .radio { display: flex; align-items: center; gap: 0.35rem; margin-bottom: 0; width: auto; }
.radio-group .radio input { width: auto; margin-top: 0; }

input, select {
  width: 100%;
  margin-top: 0.25rem;
  padding: 0.4rem 0.5rem;
  background: var(--panel-2);
  color: var(--text);
  border: 1px solid var(--border);
  border-radius: 0.35rem;
  font-size: 0.9rem;
}

.unit { color: var(--muted); font-size: 0.75rem; margin-left: 0.3rem; }
.hint { color: var(--muted); font-size: 0.8rem; margin: 0.3rem 0 0.8rem; }

.param-list {
  display: grid;
  grid-template-columns: 1fr auto;
  row-gap: 0.3rem;
  column-gap: 0.75rem;
  font-size: 0.85rem;
}
.param-list .param-label { color: var(--muted); }
.param-list .param-value { color: var(--text); font-variant-numeric: tabular-nums; text-align: right; }

table {
  width: 100%;
  border-collapse: collapse;
  margin-top: 0.5rem;
  font-size: 0.85rem;
}
table th, table td {
  border: 1px solid var(--border);
  padding: 0.35rem 0.5rem;
  text-align: left;
}
table input { padding: 0.25rem 0.4rem; }

button {
  background: var(--panel-2);
  color: var(--text);
  border: 1px solid var(--border);
  border-radius: 0.4rem;
  padding: 0.5rem 1rem;
  cursor: pointer;
  font-size: 0.9rem;
}
button:hover:not(:disabled) { border-color: var(--accent); }
button:disabled { opacity: 0.5; cursor: not-allowed; }
button.primary {
  background: var(--accent);
  color: #06202f;
  font-weight: 700;
  border: none;
}
button.remove-row { color: var(--danger); border-color: var(--danger); padding: 0.1rem 0.5rem; }

.actions { display: flex; flex-wrap: wrap; gap: 0.8rem; margin: 1.2rem 0; }
.sidebar .actions { margin: 1.2rem 0 0.8rem; }
.sidebar .actions button { flex: 1 1 auto; }

.chart-wrap {
  position: relative;
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: 0.6rem;
  padding: 1rem;
  margin-bottom: 1rem;
  height: 340px;
}
.chart-tooltip {
  position: absolute;
  display: none;
  top: 0.6rem;
  background: #101a24;
  color: var(--text);
  border: 1px solid var(--border);
  border-radius: 0.3rem;
  padding: 0.35rem 0.55rem;
  font-size: 0.75rem;
  line-height: 1.35;
  white-space: nowrap;
  pointer-events: none;
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.4);
  z-index: 10;
}
.tooltip-swatch {
  display: inline-block;
  width: 0.6rem;
  height: 0.6rem;
  border-radius: 50%;
  margin-right: 0.35rem;
}
.table-scroll { max-height: 400px; overflow-y: auto; overflow-x: auto; -webkit-overflow-scrolling: touch; }

#error-panel {
  background: #3a1c1c;
  border: 1px solid var(--danger);
  color: #ffd9d9;
  padding: 0.8rem 1rem;
  border-radius: 0.5rem;
  margin-top: 1rem;
  white-space: pre-wrap;
  font-family: monospace;
  font-size: 0.85rem;
}

footer {
  padding: 1rem 1.5rem 2rem;
  color: var(--muted);
  font-size: 0.75rem;
  text-align: center;
}

/* Mobile / small-screen responsiveness */
@media (max-width: 640px) {
  main { padding: 0.8rem; }
  header { padding: 1rem; }
  header h1 { font-size: 1.15rem; }
  .sidebar, .card, .chart-wrap { padding: 0.7rem; }
  .chart-wrap { height: 260px; }
  .actions { flex-direction: column; }
  .actions button { width: 100%; }
  input, select { font-size: 16px; } /* avoids iOS Safari auto-zoom on focus */
  table { font-size: 0.75rem; }
  .tab-btn { font-size: 0.72rem; padding: 0.4rem 0.35rem; }
  .chart-tooltip { font-size: 0.7rem; max-width: 60vw; white-space: normal; }
}