:root {
  --bg: #0b1020;
  --bg-alt: #111733;
  --surface: #161d3d;
  --surface-2: #1d254a;
  --border: rgba(255, 255, 255, 0.08);
  --text: #e7ecff;
  --muted: #9aa4c7;
  --accent: #6ea8ff;
  --accent-2: #8b5cf6;
  --success: #4ade80;
  --danger: #f87171;
  --radius: 14px;
  --shadow: 0 10px 30px rgba(0, 0, 0, 0.35);
  --max-width: 1200px;
  font-family: "Inter", system-ui, -apple-system, "Segoe UI", Roboto,
    "Helvetica Neue", Arial, sans-serif;
}

* {
  box-sizing: border-box;
}

html,
body {
  margin: 0;
  padding: 0;
  background: radial-gradient(
      1200px 800px at 10% -10%,
      rgba(110, 168, 255, 0.18),
      transparent 60%
    ),
    radial-gradient(
      900px 600px at 100% 0%,
      rgba(139, 92, 246, 0.18),
      transparent 55%
    ),
    var(--bg);
  color: var(--text);
  scroll-behavior: smooth;
  line-height: 1.55;
}

a {
  color: inherit;
  text-decoration: none;
}

.container {
  width: 100%;
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 24px;
}

/* Header */
.site-header {
  position: sticky;
  top: 0;
  z-index: 10;
  backdrop-filter: blur(10px);
  background: rgba(11, 16, 32, 0.65);
  border-bottom: 1px solid var(--border);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 64px;
}

.brand {
  display: flex;
  align-items: center;
  gap: 10px;
  font-weight: 700;
  letter-spacing: 0.2px;
}

.brand-mark {
  width: 22px;
  height: 22px;
  border-radius: 6px;
  background: linear-gradient(135deg, var(--accent), var(--accent-2));
  box-shadow: 0 0 0 2px rgba(110, 168, 255, 0.2);
}

.site-nav {
  display: flex;
  gap: 22px;
}

.site-nav a {
  color: var(--muted);
  font-size: 14px;
  transition: color 0.2s;
}

.site-nav a:hover {
  color: var(--text);
}

/* Sections */
.section {
  padding: 70px 0;
}

.section-alt {
  background: linear-gradient(
    180deg,
    rgba(255, 255, 255, 0.02),
    rgba(255, 255, 255, 0)
  );
  border-top: 1px solid var(--border);
}

.section-header {
  margin-bottom: 32px;
}

.section-header.centered {
  text-align: center;
  max-width: 760px;
  margin-left: auto;
  margin-right: auto;
  margin-bottom: 48px;
}

.section-header h1,
.section-header h2 {
  margin: 0 0 10px;
}

.section-header h1 {
  font-size: clamp(32px, 4.5vw, 52px);
  line-height: 1.1;
  background: linear-gradient(90deg, #fff, #c3d0ff);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}

.section-header h2 {
  font-size: 28px;
}

.section-header p {
  color: var(--muted);
  margin: 0;
}

.section-header .lede {
  font-size: 18px;
  margin-top: 12px;
}

.eyebrow {
  text-transform: uppercase;
  letter-spacing: 2px;
  font-size: 12px;
  color: var(--accent);
  margin: 0 0 10px;
  font-weight: 600;
}

.hero-actions {
  display: flex;
  gap: 12px;
  flex-wrap: wrap;
  margin-top: 22px;
  justify-content: center;
}

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 12px 18px;
  border-radius: 10px;
  font-weight: 600;
  font-size: 14px;
  border: 1px solid transparent;
  cursor: pointer;
  transition: transform 0.1s ease, background 0.2s, border-color 0.2s, color 0.2s;
  font-family: inherit;
}

.btn:active {
  transform: translateY(1px);
}

.btn-primary {
  background: linear-gradient(135deg, var(--accent), var(--accent-2));
  color: white;
}

.btn-primary:hover {
  filter: brightness(1.08);
}

.btn-ghost {
  background: transparent;
  border-color: var(--border);
  color: var(--text);
}

.btn-ghost:hover {
  border-color: var(--accent);
  color: var(--accent);
}

.btn-sm {
  padding: 7px 12px;
  font-size: 13px;
  border-radius: 8px;
}

/* Examples grid (section 1) */
.examples-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 20px;
}

.example-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 18px;
  box-shadow: var(--shadow);
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.example-card h3 {
  margin: 0;
  font-size: 16px;
}

.example-card p {
  margin: 0;
  color: var(--muted);
  font-size: 14px;
}

/* Chart card shared */
.chart-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 18px;
  box-shadow: var(--shadow);
  display: flex;
  flex-direction: column;
  gap: 14px;
}

.chart-toolbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  flex-wrap: wrap;
}

.chart-toolbar h3 {
  margin: 0;
  font-size: 16px;
}

.chart-save-bar {
  display: flex;
  align-items: center;
  gap: 8px;
  padding-top: 10px;
  border-top: 1px solid var(--border);
  margin-top: 4px;
  flex-wrap: wrap;
}

.chart-name-input {
  font: inherit;
  font-size: 13px;
  color: var(--text);
  background: var(--surface-2);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 7px 10px;
  outline: none;
  min-width: 160px;
  flex: 1;
}

.chart-name-input:focus {
  border-color: var(--accent);
}

.saved-charts-select {
  font: inherit;
  font-size: 13px;
  color: var(--text);
  background: var(--surface-2);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 7px 10px;
  outline: none;
  cursor: pointer;
  min-width: 180px;
}

.saved-charts-select:focus {
  border-color: var(--accent);
}

.toolbar-controls {
  display: flex;
  gap: 10px;
  align-items: center;
  flex-wrap: wrap;
}

.toolbar-controls label {
  color: var(--muted);
  font-size: 13px;
  display: inline-flex;
  align-items: center;
  gap: 8px;
}

.chart-wrap {
  position: relative;
  width: 100%;
  height: 220px;
}

.chart-wrap.large {
  height: 360px;
}

/* Form controls */
select,
input[type="text"],
input[type="number"] {
  font: inherit;
  color: var(--text);
}

select {
  background: var(--surface-2);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 8px 10px;
  outline: none;
  cursor: pointer;
}

select:focus {
  border-color: var(--accent);
}

/* Explorer layout */
.explorer {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(0, 1fr);
  gap: 20px;
  align-items: start;
}

.control-row {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
  gap: 12px;
}

.field {
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.field label {
  font-size: 13px;
  color: var(--muted);
}

/* Y-axis multi-select pills */
.pills {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  padding: 6px;
  background: var(--surface-2);
  border: 1px solid var(--border);
  border-radius: 8px;
  min-height: 38px;
  max-height: 110px;
  overflow-y: auto;
}

.pill {
  padding: 5px 11px;
  border-radius: 999px;
  font-size: 12px;
  font-weight: 600;
  background: transparent;
  color: var(--muted);
  border: 1px solid var(--border);
  cursor: pointer;
  transition: color 0.15s, border-color 0.15s, background 0.15s,
    transform 0.1s ease;
  font-family: inherit;
}

.pill:hover {
  color: var(--text);
  border-color: rgba(110, 168, 255, 0.4);
}

.pill.active {
  color: var(--text);
  border-color: var(--accent);
  background: rgba(110, 168, 255, 0.18);
}

.pill.active::before {
  content: "✓ ";
  color: var(--accent);
}

.pill:active {
  transform: translateY(1px);
}

.field-wide {
  grid-column: 1 / -1;
}

/* Inline toggle (e.g. Stack checkbox) */
.inline-toggle {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-size: 13px;
  color: var(--muted);
  cursor: pointer;
  user-select: none;
}

.inline-toggle input[type="checkbox"] {
  accent-color: var(--accent);
  cursor: pointer;
}

/* Color picker */
.color-picker {
  display: flex;
  align-items: center;
  gap: 12px;
  flex-wrap: wrap;
  padding-top: 6px;
  border-top: 1px solid var(--border);
  padding-top: 14px;
}

.color-picker-label {
  font-size: 13px;
  color: var(--muted);
}

.color-swatches {
  display: flex;
  gap: 8px;
  flex-wrap: wrap;
  flex: 1;
}

.swatch {
  position: relative;
  width: 28px;
  height: 28px;
  border-radius: 8px;
  border: 2px solid rgba(255, 255, 255, 0.15);
  cursor: pointer;
  padding: 0;
  overflow: hidden;
  transition: transform 0.1s ease, border-color 0.2s;
}

.swatch:hover {
  transform: scale(1.08);
  border-color: rgba(255, 255, 255, 0.4);
}

.swatch input[type="color"] {
  position: absolute;
  inset: 0;
  opacity: 0;
  cursor: pointer;
  border: none;
  padding: 0;
}

/* Data editor */
.file-btn {
  position: relative;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 7px 12px;
  font-size: 13px;
  font-weight: 600;
  border-radius: 8px;
  background: transparent;
  border: 1px solid var(--border);
  color: var(--text);
  cursor: pointer;
  transition: border-color 0.2s, color 0.2s;
}

.file-btn:hover {
  border-color: var(--accent);
  color: var(--accent);
}

.file-btn input[type="file"] {
  position: absolute;
  inset: 0;
  opacity: 0;
  cursor: pointer;
}

.table-wrap {
  overflow: auto;
  max-height: 360px;
  border: 1px solid var(--border);
  border-radius: 10px;
}

table {
  width: 100%;
  border-collapse: collapse;
  font-size: 13px;
}

th,
td {
  padding: 0;
  border-bottom: 1px solid var(--border);
  border-right: 1px solid var(--border);
  text-align: left;
  vertical-align: middle;
}

th:last-child,
td:last-child {
  border-right: none;
}

thead th {
  background: var(--surface-2);
  position: sticky;
  top: 0;
  z-index: 1;
  color: var(--muted);
  font-weight: 600;
  text-transform: uppercase;
  font-size: 11px;
  letter-spacing: 1px;
}

thead th .col-head {
  display: flex;
  align-items: center;
  gap: 6px;
  padding: 6px 8px;
}

.cell-input,
.col-input {
  width: 100%;
  border: none;
  background: transparent;
  color: inherit;
  padding: 10px 12px;
  outline: none;
  font: inherit;
}

.cell-input.numeric {
  text-align: right;
  font-variant-numeric: tabular-nums;
}

.col-input {
  padding: 0;
  font: inherit;
  font-weight: 600;
  color: var(--text);
  text-transform: none;
  letter-spacing: 0;
  font-size: 13px;
}

.cell-input:focus,
.col-input:focus {
  background: rgba(110, 168, 255, 0.1);
}

.row-action,
.col-action {
  width: 24px;
  height: 24px;
  border-radius: 6px;
  border: none;
  background: transparent;
  color: var(--muted);
  cursor: pointer;
  font-size: 14px;
  line-height: 1;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  transition: background 0.15s, color 0.15s;
}

.row-action:hover,
.col-action:hover {
  background: rgba(248, 113, 113, 0.15);
  color: var(--danger);
}

.row-action-cell {
  width: 36px;
  text-align: center;
  padding: 4px;
}

.editor-actions {
  display: flex;
  align-items: center;
  gap: 10px;
  flex-wrap: wrap;
}

.editor-actions .chart-hint {
  margin: 0 0 0 auto;
}

.chart-hint {
  color: var(--muted);
  font-size: 13px;
  margin: 0;
}

/* Chart library */
.chart-library {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(210px, 1fr));
  gap: 16px;
}

.library-empty {
  text-align: center;
  color: var(--muted);
  padding: 32px 0;
  font-size: 15px;
  margin: 0;
}

.chart-tile {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  overflow: hidden;
  cursor: pointer;
  transition: border-color 0.2s, transform 0.15s, box-shadow 0.15s;
  display: flex;
  flex-direction: column;
}

.chart-tile:hover {
  border-color: var(--accent);
  transform: translateY(-2px);
  box-shadow: 0 8px 24px rgba(110, 168, 255, 0.12);
}

.chart-tile-preview {
  aspect-ratio: 16 / 9;
  background: var(--surface-2);
  overflow: hidden;
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
}

.chart-tile-preview img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
}

.chart-tile-placeholder {
  color: var(--muted);
  font-size: 11px;
  text-transform: uppercase;
  letter-spacing: 1px;
  font-weight: 600;
}

.chart-tile-footer {
  padding: 10px 12px;
  display: flex;
  align-items: center;
  gap: 8px;
  border-top: 1px solid var(--border);
  flex: 1;
}

.chart-tile-name {
  font-size: 13px;
  font-weight: 500;
  flex: 1;
  min-width: 0;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
  color: var(--text);
}

.chart-tile-actions {
  display: flex;
  gap: 4px;
  flex-shrink: 0;
  opacity: 0;
  transition: opacity 0.15s;
}

.chart-tile:hover .chart-tile-actions {
  opacity: 1;
}

.btn-ghost.danger:hover {
  border-color: var(--danger);
  color: var(--danger);
}

/* Footer */
.site-footer {
  border-top: 1px solid var(--border);
  padding: 30px 0;
  margin-top: 20px;
}

.footer-inner {
  display: flex;
  justify-content: space-between;
  gap: 12px;
  flex-wrap: wrap;
  font-size: 14px;
}

.muted {
  color: var(--muted);
  margin: 0;
}

/* Responsive */
@media (max-width: 980px) {
  .examples-grid {
    grid-template-columns: 1fr;
  }
  .explorer {
    grid-template-columns: 1fr;
  }
  .site-nav {
    display: none;
  }
}

@media (max-width: 520px) {
  .section {
    padding: 50px 0;
  }
  .control-row {
    grid-template-columns: 1fr;
  }
}