:root {
  --bg: #0f1014;
  --panel: #181c24;
  --panel-2: #1f2530;
  --border: #2a3140;
  --fg: #e6ecf2;
  --muted: #8b95a3;
  --accent: #7cc4ff;
  --accent-dim: #4a7aa8;
  --warn: #ffce67;
  --pink: #ff7c9d;
}

* { box-sizing: border-box; }

html, body {
  margin: 0;
  padding: 0;
  background: var(--bg);
  color: var(--fg);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", system-ui, sans-serif;
  font-size: 14px;
  line-height: 1.5;
  min-height: 100vh;
}

code, .mono {
  font-family: "JetBrains Mono", "SF Mono", Consolas, monospace;
}

code {
  background: var(--panel);
  padding: 1px 5px;
  border-radius: 3px;
  font-size: 0.88em;
}

a { color: var(--accent); }

header {
  max-width: 1080px;
  margin: 28px auto 16px;
  padding: 0 20px;
}

h1 {
  margin: 0 0 6px;
  font-size: 1.7rem;
  font-weight: 700;
  letter-spacing: -0.01em;
}

h1 .mono { color: var(--accent); }

.subtitle {
  margin: 0;
  color: var(--muted);
  font-size: 0.92rem;
  max-width: 76ch;
}

main {
  max-width: 1080px;
  margin: 0 auto;
  padding: 0 20px 40px;
  display: flex;
  flex-direction: column;
  gap: 14px;
}

.panel {
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 16px 18px;
}

.panel h2 {
  margin: 0 0 10px;
  font-size: 0.78rem;
  font-weight: 600;
  color: var(--muted);
  text-transform: uppercase;
  letter-spacing: 0.07em;
}

.panel-row {
  display: grid;
  grid-template-columns: 1fr 1.4fr;
  gap: 14px;
}

/* ── Config panel ── */

.config-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 10px;
}

.field {
  display: flex;
  flex-direction: column;
  gap: 3px;
}

.field .label {
  font-size: 0.7rem;
  font-weight: 600;
  color: var(--muted);
  text-transform: uppercase;
  letter-spacing: 0.07em;
}

.field input {
  background: #0c0e13;
  color: var(--fg);
  border: 1px solid var(--border);
  border-radius: 4px;
  padding: 6px 8px;
  font-family: "JetBrains Mono", "SF Mono", Consolas, monospace;
  font-size: 0.92rem;
  outline: none;
}

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

.error-list {
  margin-top: 10px;
  padding: 8px 12px;
  background: rgba(255, 206, 103, 0.08);
  border: 1px solid rgba(255, 206, 103, 0.3);
  border-radius: 4px;
  color: var(--warn);
  font-size: 0.85rem;
}

.error-list code {
  background: rgba(255, 206, 103, 0.18);
  color: var(--warn);
}

/* ── Preview panel ── */

.preview-stage {
  background:
    linear-gradient(45deg, #1a1d24 25%, transparent 25%),
    linear-gradient(-45deg, #1a1d24 25%, transparent 25%),
    linear-gradient(45deg, transparent 75%, #1a1d24 75%),
    linear-gradient(-45deg, transparent 75%, #1a1d24 75%);
  background-size: 14px 14px;
  background-position: 0 0, 0 7px, 7px -7px, -7px 0;
  background-color: #14171d;
  border-radius: 6px;
  padding: 20px;
  min-height: 140px;
  display: flex;
  align-items: center;
  justify-content: center;
}

.preview-text {
  color: var(--fg);
  font-weight: 600;
  text-align: center;
  line-height: 1.2;
  /* font-size injected by JS */
}

.vw-row {
  margin-top: 12px;
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.vw-label {
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 0.78rem;
  color: var(--muted);
  font-family: "JetBrains Mono", "SF Mono", Consolas, monospace;
}

.vw-label output {
  color: var(--pink);
  font-weight: 700;
}

#vwSlider {
  width: 100%;
  accent-color: var(--accent);
}

.vw-info {
  margin-top: 6px;
  font-size: 0.85rem;
  color: var(--muted);
}

.vw-info strong {
  color: var(--accent);
  font-family: "JetBrains Mono", "SF Mono", Consolas, monospace;
}

/* ── Output panel ── */

.css-out {
  background: #0c0e13;
  color: var(--accent);
  border: 1px solid var(--border);
  border-radius: 6px;
  padding: 12px 14px;
  font-family: "JetBrains Mono", "SF Mono", Consolas, monospace;
  font-size: 0.95rem;
  line-height: 1.55;
  white-space: pre-wrap;
  overflow-x: auto;
  margin: 0;
}

.copy {
  margin-top: 10px;
  background: transparent;
  color: var(--accent);
  border: 1px solid var(--accent-dim);
  border-radius: 4px;
  padding: 4px 12px;
  font-size: 0.82rem;
  cursor: pointer;
  font-family: inherit;
}

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

/* ── Chart panel ── */

#chartSvg {
  width: 100%;
  height: auto;
  background: #0c0e13;
  border-radius: 6px;
}

.chart-legend {
  margin-top: 8px;
  font-size: 0.78rem;
  color: var(--muted);
  display: flex;
  align-items: center;
  gap: 14px;
  flex-wrap: wrap;
}

.legend-dot {
  display: inline-block;
  width: 10px;
  height: 10px;
  border-radius: 2px;
  margin-right: 4px;
  vertical-align: middle;
}

.legend-dot.accent { background: var(--accent); }
.legend-dot.dim    { background: var(--accent-dim); }

/* ── Presets ── */

.presets {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
}

.preset {
  background: var(--panel-2);
  color: var(--fg);
  border: 1px solid var(--border);
  border-radius: 4px;
  padding: 4px 12px;
  font-size: 0.82rem;
  cursor: pointer;
  font-family: inherit;
}

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

/* ── Notes ── */

.notes-panel ul {
  margin: 0;
  padding-left: 18px;
}

.notes-panel li { margin-bottom: 6px; }

footer {
  margin-top: 4px;
  color: var(--muted);
  font-size: 0.82rem;
  text-align: center;
  line-height: 1.6;
}

footer code {
  background: var(--panel-2);
  padding: 1px 5px;
  border-radius: 3px;
  font-family: "JetBrains Mono", "SF Mono", Consolas, monospace;
  font-size: 0.8rem;
}

@media (max-width: 720px) {
  .panel-row { grid-template-columns: 1fr; }
}