:root {
  --bg: #f6f7f9;
  --panel: #ffffff;
  --ink: #14171c;
  --muted: #5d6673;
  --line-c: #e3e6eb;
  --accent: #1d4ed8;
  --accent-soft: #e8eefc;
  --ok: #0f7a3d;
  --ok-soft: #e5f5ec;
  --warn: #8a5a00;
  --warn-soft: #fdf3dc;
  --bad: #b42318;
  --bad-soft: #fdecea;
  --code-bg: #fbfbfc;
  --in: #0f7a3d;
  --out: #14171c;
  --line: 20px;
  --mono: ui-monospace, "SF Mono", "Cascadia Mono", Menlo, Consolas, monospace;
  --sans: system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
  color-scheme: light;
}
@media (prefers-color-scheme: dark) {
  :root {
    --bg: #0f1216;
    --panel: #161a20;
    --ink: #e7eaee;
    --muted: #98a2ae;
    --line-c: #262c34;
    --accent: #7aa2ff;
    --accent-soft: #1b2540;
    --ok: #4cc685;
    --ok-soft: #12291d;
    --warn: #e8b44a;
    --warn-soft: #2d2412;
    --bad: #ff7b6e;
    --bad-soft: #341815;
    --code-bg: #12161b;
    --in: #4cc685;
    --out: #e7eaee;
    color-scheme: dark;
  }
}

* { box-sizing: border-box; }
html, body { height: 100%; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  font: 15px/1.5 var(--sans);
  display: flex;
  flex-direction: column;
}
a { color: var(--accent); }
button { font: inherit; color: inherit; }
code { font-family: var(--mono); font-size: 0.88em; }
.sr-only { position: absolute; width: 1px; height: 1px; overflow: hidden; clip: rect(0 0 0 0); white-space: nowrap; }
.muted { color: var(--muted); }

/* header & footer */
.top {
  display: flex; align-items: center; gap: 8px 20px; flex-wrap: wrap;
  padding: 12px 20px; border-bottom: 1px solid var(--line-c); background: var(--panel);
}
.brand { display: flex; align-items: center; gap: 10px; }
.brand h1 { font-size: 17px; margin: 0; letter-spacing: -0.01em; }
.tagline { margin: 0; color: var(--muted); font-size: 14px; flex: 1; min-width: 220px; }
.top nav { display: flex; gap: 16px; font-size: 14px; }
.top nav a { text-decoration: none; }
.top nav a:hover { text-decoration: underline; }
.foot {
  display: flex; justify-content: space-between; gap: 6px 24px; flex-wrap: wrap;
  padding: 10px 20px; font-size: 12.5px; color: var(--muted); border-top: 1px solid var(--line-c);
}

/* layout */
.split { flex: 1; display: grid; grid-template-columns: minmax(0, 1fr) minmax(0, 1fr); min-height: 0; }
.pane { min-width: 0; min-height: 0; display: flex; flex-direction: column; }
.input-pane { border-right: 1px solid var(--line-c); }
@media (max-width: 900px) {
  body { height: auto; }
  .split { grid-template-columns: 1fr; }
  .input-pane { border-right: 0; border-bottom: 1px solid var(--line-c); height: 52vh; }
  .output-pane { min-height: 50vh; }
}

/* toolbar */
.toolbar { display: flex; gap: 8px; padding: 10px 12px; border-bottom: 1px solid var(--line-c); background: var(--panel); flex-wrap: wrap; }
.toolbar select, .toolbar .button, .toolbar button, button.small, .chip {
  height: 32px; padding: 0 12px; border: 1px solid var(--line-c); border-radius: 8px;
  background: var(--panel); color: var(--ink); font-size: 14px; cursor: pointer; display: inline-flex; align-items: center;
}
.toolbar select { max-width: 100%; }
.toolbar .button { background: var(--accent); border-color: var(--accent); color: #fff; font-weight: 550; }
@media (prefers-color-scheme: dark) { .toolbar .button { color: #0b1020; } }
.toolbar .ghost { background: transparent; }
.toolbar select:hover, .toolbar .ghost:hover, button.small:hover, .chip:hover { border-color: var(--accent); }
:focus-visible { outline: 2px solid var(--accent); outline-offset: 2px; }

/* editor */
.editor { flex: 1; display: flex; min-height: 0; background: var(--code-bg); position: relative; }
.gutter-wrap { position: relative; overflow: hidden; flex: none; border-right: 1px solid var(--line-c); }
.gutter { position: relative; min-width: 5ch; height: 100%; font: 12.5px/var(--line) var(--mono); color: var(--muted); }
.gutter .ln { position: absolute; right: 8px; left: 0; text-align: right; height: var(--line); user-select: none; }
.gutter .ln.error { color: var(--bad); font-weight: 700; }
.gutter .ln.error::before, .gutter .ln.warning::before { content: "●"; position: absolute; left: 4px; font-size: 9px; }
.gutter .ln.warning { color: var(--warn); font-weight: 700; }
.code { position: relative; flex: 1; min-width: 0; }
.marks-wrap { position: absolute; inset: 0; overflow: hidden; pointer-events: none; }
.marks { position: absolute; left: 0; right: 0; top: 0; }
.mark, .flash { position: absolute; left: 0; width: 100000px; height: var(--line); }
.mark.error { background: var(--bad-soft); }
.mark.warning { background: var(--warn-soft); }
.flash { background: var(--accent-soft); animation: flash 1.2s ease-out forwards; }
@keyframes flash { from { opacity: 1; } to { opacity: 0; } }
@media (prefers-reduced-motion: reduce) { .flash { animation-duration: 0.01s; } }
textarea {
  position: absolute; inset: 0; width: 100%; height: 100%; resize: none; border: 0; outline: 0;
  padding: 12px 14px; margin: 0; background: transparent; color: var(--ink);
  font: 13px/var(--line) var(--mono); white-space: pre; overflow: auto; tab-size: 2;
}
textarea:focus-visible { outline: none; }
.editor:focus-within { box-shadow: inset 0 0 0 1px var(--accent); }
.source { position: absolute; inset: 0; overflow: auto; font: 13px/var(--line) var(--mono); }
.source[hidden] { display: none; }
.source-spacer { pointer-events: none; }
.source-rows { position: absolute; left: 0; right: 0; }
.srow { height: var(--line); white-space: pre; display: flex; }
.srow .sn { flex: none; text-align: right; padding-right: 10px; margin-right: 14px; color: var(--muted); font-size: 12.5px; border-right: 1px solid var(--line-c); user-select: none; position: sticky; left: 0; background: var(--code-bg); }
.srow.error { background: var(--bad-soft); } .srow.error .sn { color: var(--bad); font-weight: 700; background: var(--bad-soft); }
.srow.warning { background: var(--warn-soft); } .srow.warning .sn { color: var(--warn); font-weight: 700; background: var(--warn-soft); }
.srow.flashing { background: var(--accent-soft); }
.big-note { align-self: center; color: var(--muted); font-size: 13px; }
textarea[hidden], .marks-wrap .marks[hidden], .gutter-wrap[hidden] { display: none; }
textarea::placeholder { color: var(--muted); }

/* status */
.status { padding: 0 16px; display: flex; align-items: baseline; gap: 10px; flex-wrap: wrap; font-size: 14px; }
.status:empty { display: none; }
.status { padding: 12px 16px; border-bottom: 1px solid var(--line-c); }
.status strong { font-size: 16px; }
.status span { color: var(--muted); }
.status.ok { background: var(--ok-soft); } .status.ok strong { color: var(--ok); }
.status.warn { background: var(--warn-soft); } .status.warn strong { color: var(--warn); }
.status.bad { background: var(--bad-soft); } .status.bad strong { color: var(--bad); }

#output { flex: 1; overflow: auto; min-height: 0; }
.empty { padding: 32px 24px; max-width: 640px; }
.empty h2 { margin: 0 0 8px; font-size: 22px; letter-spacing: -0.01em; }
.sample-list { display: flex; flex-wrap: wrap; gap: 8px; align-items: center; margin-top: 18px; }

/* tabs */
.tabs { display: flex; gap: 4px; padding: 8px 12px 0; border-bottom: 1px solid var(--line-c); position: sticky; top: 0; background: var(--bg); z-index: 1; }
.tabs button { border: 0; background: none; padding: 8px 12px; border-bottom: 2px solid transparent; cursor: pointer; color: var(--muted); font-weight: 550; }
.tabs button[aria-selected="true"] { color: var(--ink); border-bottom-color: var(--accent); }
.tabs button:disabled { opacity: 0.4; cursor: default; }
.panel { padding: 16px; }

/* summary */
.lead { font-size: 16.5px; line-height: 1.55; margin: 0 0 16px; max-width: 70ch; }
.note { padding: 10px 12px; border-radius: 8px; background: var(--accent-soft); margin: 0 0 14px; font-size: 14px; }
.note.bad { background: var(--bad-soft); color: var(--bad); }
.note.ok { background: var(--ok-soft); color: var(--ok); }
.card { background: var(--panel); border: 1px solid var(--line-c); border-radius: 12px; padding: 14px 16px; margin-bottom: 14px; }
.card h3 { margin: 0 0 6px; font-size: 15px; }
.card > p { margin: 0 0 10px; color: var(--muted); }
.facts { display: grid; grid-template-columns: minmax(120px, max-content) 1fr; gap: 6px 16px; margin: 0; }
.facts dt { color: var(--muted); font-size: 13.5px; }
.facts dd { margin: 0; min-width: 0; overflow-wrap: anywhere; }
@media (max-width: 520px) { .facts { grid-template-columns: 1fr; gap: 0; } .facts dd { margin-bottom: 8px; } }
.jump { border: 0; background: none; padding: 0; text-align: left; cursor: pointer; font: inherit; color: inherit; }
.jump:hover { color: var(--accent); text-decoration: underline; text-underline-offset: 3px; }
.jump.title { font-weight: 650; }
.help {
  display: inline-grid; place-items: center; width: 15px; height: 15px; margin-left: 6px; border-radius: 50%;
  font-size: 10px; font-weight: 700; color: var(--muted); border: 1px solid var(--line-c); cursor: help; vertical-align: 1px;
}
.table-wrap { overflow-x: auto; margin-top: 12px; }
table { border-collapse: collapse; width: 100%; font-size: 13.5px; }
th { text-align: left; color: var(--muted); font-weight: 550; padding: 6px 8px; border-bottom: 1px solid var(--line-c); white-space: nowrap; }
td { padding: 7px 8px; border-bottom: 1px solid var(--line-c); vertical-align: top; }
tbody tr { cursor: pointer; }
tbody tr:hover { background: var(--accent-soft); }
th.num { text-align: right; }
.nowrap { white-space: nowrap; }
td.num { text-align: right; font-variant-numeric: tabular-nums; white-space: nowrap; font-weight: 600; }
tr.in th.num { text-align: right; }
.nowrap { white-space: nowrap; }
td.num { color: var(--in); }
tr.out th.num { text-align: right; }
.nowrap { white-space: nowrap; }
td.num { color: var(--out); }
tr.muted td { color: var(--muted); font-style: italic; }
tr.more { cursor: default; } tr.more:hover { background: none; }
tfoot td { border-bottom: 0; color: var(--muted); font-size: 13px; }

/* issues */
.issue-list { list-style: none; padding: 0; margin: 0 0 16px; display: grid; gap: 8px; }
.issue {
  display: grid; grid-template-columns: auto auto 1fr; gap: 2px 10px; width: 100%; text-align: left; cursor: pointer;
  padding: 10px 12px; border-radius: 10px; border: 1px solid var(--line-c); background: var(--panel); border-left-width: 4px;
}
li.error .issue { border-left-color: var(--bad); }
li.warning .issue { border-left-color: var(--warn); }
.issue:hover { border-color: var(--accent); }
.issue .where { color: var(--muted); font-size: 13px; white-space: nowrap; font-variant-numeric: tabular-nums; }
.issue .code { justify-self: start; font: 600 12px/20px var(--mono); padding: 0 6px; border-radius: 5px; background: var(--bad-soft); color: var(--bad); white-space: nowrap; height: 20px; }
li.warning .issue .code { background: var(--warn-soft); color: var(--warn); }
.issue .msg { min-width: 0; }
.issue .path { grid-column: 3; color: var(--muted); overflow-wrap: anywhere; font-size: 12px; }
@media (max-width: 520px) { .issue { grid-template-columns: auto 1fr; } .issue .msg, .issue .path { grid-column: 1 / -1; } }
.row { display: flex; gap: 10px; align-items: flex-start; flex-wrap: wrap; }
.rules { flex: 1; min-width: 260px; }
.rules summary { cursor: pointer; color: var(--muted); font-size: 14px; }
.rules ul { list-style: none; padding: 0; margin: 8px 0 0; display: grid; gap: 6px; font-size: 13.5px; }
.rules label { display: flex; gap: 8px; align-items: baseline; }
.rules code { white-space: nowrap; }

/* field tree */
.tree-tools { margin-bottom: 10px; align-items: center; font-size: 13px; }
.tree { font-size: 14px; }
.tree details, .tree .leaf { margin-left: 14px; }
.tree > details { margin-left: 0; }
.tree summary, .leaf-row { display: flex; align-items: baseline; gap: 8px; padding: 3px 6px; border-radius: 6px; }
.tree summary { cursor: pointer; list-style: none; }
.tree summary::-webkit-details-marker { display: none; }
.tree summary::before { content: "▸"; color: var(--muted); width: 10px; flex: none; transition: transform .12s; }
.tree details[open] > summary::before { transform: rotate(90deg); }
.leaf-row::before { content: ""; width: 10px; flex: none; }
.tree summary:hover, .leaf-row:hover { background: var(--accent-soft); }
.kids { border-left: 1px solid var(--line-c); margin-left: 10px; }
.label { display: inline-flex; gap: 6px; align-items: baseline; min-width: 0; flex-wrap: wrap; }
.name { font-weight: 550; }
.tag { color: var(--muted); font-size: 11.5px; }
.value { margin-left: auto; text-align: right; font-variant-numeric: tabular-nums; overflow-wrap: anywhere; min-width: 0; }
.meaning { color: var(--muted); font-size: 12.5px; }
.count { margin-left: auto; color: var(--muted); font-size: 12px; }
.line-link { border: 0; background: none; color: var(--muted); font: 11.5px var(--mono); cursor: pointer; padding: 0 2px; flex: none; }
.line-link:hover { color: var(--accent); }
.has-issue > summary, .leaf.has-issue > .leaf-row { background: var(--bad-soft); }
.issue-inside > summary .name { color: var(--bad); }
.node-issues { margin: 2px 0 6px 30px; padding: 0; list-style: none; font-size: 13px; color: var(--bad); }
.node-issues li.warning { color: var(--warn); }

/* invisible characters made visible */
.hidden-char { font: 600 0.8em var(--mono); color: var(--bad); background: var(--bad-soft); border-radius: 3px; padding: 0 2px; margin: 0 1px; }
/* values from the message never change the direction of the text around them */
dd, td, .value, .msg, .lead, .label { unicode-bidi: isolate; }

/* drop overlay */
.drop { position: fixed; inset: 0; background: color-mix(in srgb, var(--accent) 18%, transparent); display: grid; place-items: center; z-index: 10; pointer-events: none; }
.drop[hidden] { display: none; }
.drop div { background: var(--panel); border: 2px dashed var(--accent); padding: 28px 40px; border-radius: 16px; font-size: 18px; font-weight: 600; }