:root {
  color-scheme: dark;
  --bg: #04080b;
  --panel: #0a151c;
  --line: #29404b;
  --ink: #eef7f7;
  --muted: #91a8b1;
  --green: #7feabb;
  --amber: #e8bc70;
  --mono: ui-monospace, Consolas, monospace;
  font-family: var(--mono);
}

* { box-sizing: border-box; }
body { margin: 0; background: radial-gradient(circle at 80% -10%, #12343c, transparent 42rem), var(--bg); color: var(--ink); }
a { color: inherit; text-decoration: none; }
.skip { position: fixed; top: 8px; left: 8px; transform: translateY(-150%); background: var(--green); color: var(--bg); padding: 8px; z-index: 5; }
.skip:focus { transform: none; }
main { width: min(1500px, calc(100% - 24px)); margin: auto; padding: 16px 0 40px; }
header { display: flex; justify-content: space-between; gap: 30px; align-items: end; border-bottom: 1px solid var(--line); padding-bottom: 18px; }
.eyebrow, .panel-head span, label > span { color: var(--green); font-size: .62rem; letter-spacing: .16em; text-transform: uppercase; }
h1 { margin: .18em 0; font: 800 2.5rem/.98 Arial Narrow, Segoe UI, sans-serif; letter-spacing: 0; text-transform: none; }
.deck { max-width: 760px; color: var(--muted); font-size: .72rem; line-height: 1.6; }
nav { display: flex; gap: 6px; flex-wrap: wrap; justify-content: end; }
nav a, button { border: 1px solid var(--line); background: #081219; color: var(--ink); padding: 9px 10px; font: 700 .62rem inherit; cursor: pointer; }
button:hover, button:focus-visible, nav a:hover { border-color: var(--green); color: var(--green); }

.plain-flow { margin-top: 12px; border: 1px solid var(--line); background: #071118; padding: 13px; }
.plain-flow ol { display: grid; grid-template-columns: repeat(5, 1fr); gap: 7px; margin: 0; padding: 0; list-style: none; counter-reset: flow; }
.plain-flow li { counter-increment: flow; border-left: 2px solid var(--green); background: #08141b; padding: 10px; color: var(--muted); font: .62rem/1.45 var(--mono); }
.plain-flow li::before { content: counter(flow, decimal-leading-zero); display: block; margin-bottom: 7px; color: var(--green); font-weight: 800; }
.plain-flow b { display: block; margin-bottom: 3px; color: var(--ink); font: 800 .7rem Arial Narrow, Segoe UI, sans-serif; }

.mode-rail { display: grid; grid-template-columns: repeat(3, 1fr); gap: 7px; margin-top: 12px; }
.mode-rail button { text-align: left; }
.mode-rail b, .mode-rail span { display: block; }
.mode-rail span { margin-top: 5px; color: var(--muted); font-size: .55rem; }
.mode-rail button[aria-pressed=true] { border-color: var(--green); box-shadow: inset 3px 0 var(--green); }
.layout { display: grid; grid-template-columns: 1fr 1fr; gap: 10px; margin-top: 10px; }
.panel { min-width: 0; border: 1px solid var(--line); background: linear-gradient(180deg, #0c1921, #071016); padding: 14px; }
.panel-head { display: grid; grid-template-columns: 110px 1fr auto; gap: 10px; align-items: start; margin-bottom: 13px; }
.panel-head h2 { margin: 0; font: 800 .95rem Arial Narrow, Segoe UI, sans-serif; letter-spacing: .07em; text-transform: uppercase; }
.panel-head strong { color: var(--green); font-size: .65rem; }
.presets { display: flex; gap: 5px; flex-wrap: wrap; margin-bottom: 10px; }
.presets button { font-size: .56rem; }
.presets button[aria-pressed=true] { border-color: var(--green); color: var(--green); box-shadow: inset 3px 0 var(--green); }
form { display: grid; grid-template-columns: 1fr 1fr; gap: 8px; }
label { display: block; }
.wide { grid-column: 1 / -1; }
textarea, input, select { width: 100%; margin-top: 5px; border: 1px solid var(--line); background: #03090d; color: var(--ink); padding: 9px; font: inherit; font-size: .65rem; }
textarea { min-height: 90px; resize: vertical; }
.check { display: flex; align-items: center; gap: 8px; border: 1px solid var(--line); padding: 9px; }
.check input { width: auto; margin: 0; accent-color: var(--green); }
.actions { display: flex; gap: 6px; flex-wrap: wrap; margin-top: 8px; }
.primary { background: var(--green); color: var(--bg); border-color: var(--green); }
button:disabled { opacity: .4; cursor: not-allowed; }
.output pre, .support pre { overflow: auto; min-height: 200px; border: 1px solid #1c3038; background: #03080b; color: #bad0d7; padding: 12px; font-size: .63rem; line-height: 1.45; white-space: pre-wrap; }
.flow { display: flex; gap: 0; overflow: auto; padding: 12px 0; }
.node { border: 1px solid var(--line); padding: 8px; font-size: .58rem; white-space: nowrap; }
.node.active { border-color: var(--green); color: var(--green); }
.edge { width: 24px; height: 1px; background: var(--line); align-self: center; }
.support { display: grid; grid-template-columns: repeat(3, 1fr); gap: 10px; margin-top: 10px; }
.record-mark { border: 1px solid var(--green); background: #061510; color: var(--green); padding: 24px; text-align: center; font: 800 2.2rem Arial Narrow, Segoe UI, sans-serif; letter-spacing: .08em; }
.boundary { color: var(--amber); font-size: .64rem; line-height: 1.5; }
footer { display: flex; justify-content: space-between; color: var(--muted); border-top: 1px solid var(--line); margin-top: 12px; padding: 16px; font-size: .62rem; }

@media (max-width: 900px) {
  header { display: block; }
  h1 { font-size: 2.125rem; }
  nav { justify-content: start; }
  .layout, .support, .mode-rail, .plain-flow ol { grid-template-columns: 1fr; }
}

@media (max-width: 560px) {
  h1 { font-size: 1.75rem; }
  form { grid-template-columns: 1fr; }
  .wide { grid-column: auto; }
  .panel-head { grid-template-columns: 1fr; }
  footer { display: block; }
}