:root {
  --bg: #0f1014;
  --panel: #181c24;
  --panel-2: #1f2530;
  --border: #2a3140;
  --fg: #e6ecf2;
  --muted: #8b95a3;
  --accent: #7cc4ff;
  --accent-dim: #4a7aa8;
  --warn-bg: rgba(255, 200, 70, 0.08);
  --warn-border: rgba(255, 200, 70, 0.4);
  --warn-fg: #ffce67;
}

* { box-sizing: border-box; }

html, body {
  margin: 0;
  padding: 0;
  background: var(--bg);
  color: var(--fg);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, system-ui, sans-serif;
  min-height: 100vh;
  font-size: 14px;
  line-height: 1.55;
}

header {
  max-width: 980px;
  margin: 32px auto 16px;
  padding: 0 20px;
}

h1 {
  margin: 0 0 8px;
  font-size: 1.8rem;
  font-weight: 700;
  letter-spacing: -0.01em;
}

h1 .arrow {
  color: var(--accent);
  font-weight: 400;
  margin: 0 6px;
}

.subtitle {
  margin: 0 0 8px;
  color: var(--muted);
  font-size: 0.92rem;
  max-width: 72ch;
  line-height: 1.6;
}

main {
  max-width: 980px;
  margin: 0 auto;
  padding: 0 20px 40px;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 16px;
}

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

.panel:first-of-type {
  grid-column: 1 / -1;
}

.panel h2 {
  margin: 0 0 10px;
  font-size: 0.82rem;
  font-weight: 600;
  color: var(--muted);
  text-transform: uppercase;
  letter-spacing: 0.07em;
}

textarea {
  width: 100%;
  min-height: 90px;
  background: #0c0e13;
  color: var(--fg);
  border: 1px solid var(--border);
  border-radius: 6px;
  padding: 12px 14px;
  font-family: "JetBrains Mono", "SF Mono", Consolas, monospace;
  font-size: 0.92rem;
  line-height: 1.55;
  resize: vertical;
  outline: none;
}

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

.presets {
  margin-top: 10px;
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  align-items: center;
  font-size: 0.82rem;
  color: var(--muted);
}

.preset {
  background: var(--panel-2);
  color: var(--fg);
  border: 1px solid var(--border);
  border-radius: 4px;
  padding: 4px 10px;
  font-size: 0.8rem;
  cursor: pointer;
  font-family: inherit;
}

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

.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;
  min-height: 160px;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 20px;
}

.preview-target {
  display: inline-block;
  /* the inline styles set from JS will override everything below */
}

.output {
  background: #0c0e13;
  color: #c6d4e6;
  border: 1px solid var(--border);
  border-radius: 6px;
  padding: 12px 14px;
  font-family: "JetBrains Mono", "SF Mono", Consolas, monospace;
  font-size: 0.85rem;
  line-height: 1.55;
  white-space: pre;
  overflow-x: auto;
  margin: 0;
  min-height: 160px;
}

.copy-btn {
  margin-top: 10px;
  background: transparent;
  color: var(--accent);
  border: 1px solid var(--accent-dim);
  border-radius: 4px;
  padding: 4px 12px;
  font-size: 0.8rem;
  cursor: pointer;
  font-family: inherit;
}

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

.warn {
  grid-column: 1 / -1;
  background: var(--warn-bg);
  border: 1px solid var(--warn-border);
  border-radius: 8px;
  padding: 14px 18px;
}

.warn h3 {
  margin: 0 0 6px;
  color: var(--warn-fg);
  font-size: 0.95rem;
}

.warn p {
  margin: 0 0 10px;
  color: var(--muted);
  font-size: 0.85rem;
}

.warn ul {
  margin: 0;
  padding: 0;
  list-style: none;
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
}

.warn li code {
  background: rgba(255, 200, 70, 0.12);
  color: var(--warn-fg);
  padding: 2px 8px;
  border-radius: 4px;
  font-family: "JetBrains Mono", "SF Mono", Consolas, monospace;
  font-size: 0.82rem;
}

footer {
  grid-column: 1 / -1;
  margin-top: 8px;
  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) {
  main { grid-template-columns: 1fr; }
}