/* CFG — styles. Same tokens and layout as FREX / FSA. */

:root {
    --paper: #F7F8FC;
    --ink:   #1B2238;
    --muted: #5E6784;
    --rule:  #D9DEEC;
    --wash:  #B3CBFF;
    --deep:  #2F47B8;
    --on-deep: #FFFFFF;
    --alert: #B42318;
    --ok:    #1E7A4C;
    --serif: "Literata", Georgia, "Times New Roman", serif;
    --sans:  "Public Sans", system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
    --mono:  ui-monospace, "SF Mono", Menlo, Consolas, monospace;
    color-scheme: light dark;
}
@media (prefers-color-scheme: dark) {
    :root {
        --paper: #11162A; --ink: #E4E8F6; --muted: #9BA4C4; --rule: #2B3354;
        --wash: #34467F; --deep: #A9BEFF; --on-deep: #11162A; --alert: #FF8A7A; --ok: #7FD6A8;
    }
}
* { box-sizing: border-box; }
body {
    margin: 0;
    background: var(--paper);
    color: var(--ink);
    font: 16px/1.5 var(--sans);
    -webkit-text-size-adjust: 100%;
}
a { color: var(--deep); }
.wrap { max-width: 66rem; margin: 0 auto; padding: clamp(1rem, 4vw, 2.5rem); }
.sr { position: absolute; width: 1px; height: 1px; overflow: hidden; clip-path: inset(50%); white-space: nowrap; }
[hidden] { display: none !important; }

/* header and navigation */
.top {
    display: flex; flex-wrap: wrap; align-items: baseline; justify-content: space-between;
    gap: .25rem 1.5rem; padding-bottom: 1rem; border-bottom: 1px solid var(--rule);
}
.top h1 { margin: 0; font: 600 1.75rem/1.2 var(--serif); letter-spacing: -.01em; }
.top h1 a { color: inherit; text-decoration: none; }
.top h1 span { font: 400 1rem var(--sans); color: var(--muted); margin-left: .5rem; letter-spacing: 0; }
.top p { margin: 0; color: var(--muted); font-size: .875rem; }
.tabs { display: flex; flex-wrap: wrap; gap: .25rem 1.5rem; margin-top: .75rem; font-size: .9375rem; }
.tabs a { color: var(--muted); text-decoration: none; padding: .2rem 0; border-bottom: 2px solid transparent; }
.tabs a:hover { color: var(--ink); }
.tabs a[aria-current] { color: var(--ink); font-weight: 600; border-bottom-color: var(--deep); }

/* form */
form.build { display: grid; grid-template-columns: minmax(0, 1fr); gap: 1.5rem; margin-top: 1.75rem; }
form.build > *, .grid2 > * { min-width: 0; }
.field label, .lbl { display: block; font-weight: 600; margin-bottom: .4rem; }
textarea, input[type=text] {
    display: block; width: 100%; padding: .7rem 1rem; border: 1px solid var(--rule); border-radius: 6px;
    background: transparent; color: inherit; font: 1.2rem/1.45 var(--serif);
}
textarea { min-height: 7.5rem; resize: vertical; font: .95rem/1.55 var(--mono); }
.hint { margin: .35rem 0 0; color: var(--muted); font-size: .8125rem; }
.hint code, p code, li code { font: .85em var(--mono); }
.grid2 { display: grid; grid-template-columns: 1fr 1fr; gap: 1.25rem; }
.controls { display: flex; flex-wrap: wrap; align-items: flex-end; gap: 1rem 1.75rem; }
fieldset { border: 0; margin: 0; padding: 0; min-width: 0; }
legend { padding: 0; margin-bottom: .4rem; color: var(--muted); font-size: .875rem; }
.seg { display: inline-flex; flex-wrap: wrap; border: 1px solid var(--rule); border-radius: 6px; overflow: hidden; }
.seg label { position: relative; }
.seg input { position: absolute; inset: 0; margin: 0; opacity: 0; cursor: pointer; }
.seg span { display: block; padding: .45rem .95rem; white-space: nowrap; }
.seg label + label span { border-left: 1px solid var(--rule); }
.seg input:checked + span { background: var(--wash); font-weight: 600; }
.seg input:focus-visible + span { outline: 3px solid var(--deep); outline-offset: -3px; }
.checks { display: flex; flex-wrap: wrap; gap: .35rem 1.25rem; font-size: .9375rem; }
.checks label { display: inline-flex; align-items: center; gap: .4rem; cursor: pointer; }
.checks input { width: 1.05rem; height: 1.05rem; accent-color: var(--deep); margin: 0; }
button {
    padding: .6rem 1.4rem; border: 0; border-radius: 6px;
    background: var(--deep); color: var(--on-deep); font: 600 1rem var(--sans); cursor: pointer;
}
.controls > button { margin-left: auto; }
button.ghost {
    padding: .45rem .9rem; background: transparent; color: var(--ink);
    border: 1px solid var(--rule); font-weight: 400; font-size: .9375rem;
}
button.ghost:hover:not(:disabled) { border-color: var(--muted); }
button:disabled { opacity: .45; cursor: default; }
textarea:focus-visible, input:focus-visible, button:focus-visible, .chip:focus-visible, summary:focus-visible {
    outline: 3px solid var(--wash); outline-offset: 2px;
}

/* panels */
.panel { border: 1px solid var(--rule); border-radius: 8px; padding: clamp(.85rem, 2.5vw, 1.25rem); }
.panel > h2, .section-h {
    margin: 0 0 .25rem; font: 600 1.2rem/1.3 var(--serif);
}
.section-h { margin-top: 2.25rem; }
.panel-head { display: flex; flex-wrap: wrap; align-items: baseline; justify-content: space-between; gap: .25rem 1rem; }
.panel-head h2 { margin: 0; font: 600 1.2rem/1.3 var(--serif); }
.panel-head a { font-size: .875rem; }

/* annotator */
.toolbar { display: flex; flex-wrap: wrap; align-items: center; gap: .5rem .75rem; margin-top: .9rem; }
.toolbar input[type=text] { width: 11rem; font-size: 1.05rem; padding: .45rem .8rem; }
.toolbar .end { margin-left: auto; display: flex; gap: .5rem; }
.toolbar button { padding: .45rem 1rem; font-size: .9375rem; }
.chips { display: flex; flex-wrap: wrap; gap: .4rem; min-height: 0; }
.chips:empty { display: none; }
.chip {
    display: inline-block; padding: .2rem .65rem; border: 1px solid var(--rule); border-radius: 999px;
    background: transparent; color: var(--ink); font: 600 .875rem var(--sans); cursor: pointer;
}
.chip:hover { border-color: var(--deep); }
.msg { margin: .6rem 0 0; font-size: .875rem; color: var(--muted); min-height: 1.3em; }
.msg.err { color: var(--alert); }
.msg.ok { color: var(--ok); }
.brk {
    margin: .75rem 0 0; padding: .55rem .8rem; border-left: 3px solid var(--rule);
    font: .875rem/1.5 var(--mono); overflow-wrap: anywhere; color: var(--muted);
}

/* trees */
.tree-wrap { overflow-x: auto; margin-top: .9rem; padding: .25rem 0; -webkit-overflow-scrolling: touch; }
.tree-wrap svg { display: block; margin: 0 auto; max-width: none; }
.tree-empty { padding: 1.5rem 0; text-align: center; color: var(--muted); font-size: .9375rem; }
svg.tree { font-family: var(--sans); }
svg.tree .e { stroke: var(--muted); stroke-width: 1.3; fill: none; }
svg.tree .e.dash { stroke-dasharray: 4 4; }
svg.tree .e.lex { stroke: var(--rule); }
svg.tree .lb { font: 600 14px var(--sans); fill: var(--ink); text-anchor: middle; dominant-baseline: central; }
svg.tree .wd { font: italic 16px var(--serif); fill: var(--ink); text-anchor: middle; dominant-baseline: central; }
svg.tree .wd.grey { fill: var(--muted); opacity: .55; }
svg.tree .box { fill: none; stroke: none; }
svg.tree .open .box { stroke: var(--muted); stroke-dasharray: 3 3; fill: var(--paper); }
svg.tree .open .lb { fill: var(--muted); font-weight: 400; }
svg.tree .hl .box { fill: var(--wash); stroke: var(--deep); stroke-dasharray: none; }
svg.tree .hl .lb { fill: var(--ink); font-weight: 600; }
svg.tree .hl .wd { font-weight: 600; }
svg.tree .bad .box { fill: none; stroke: var(--alert); stroke-width: 1.6; stroke-dasharray: none; }
svg.tree .bad .lb { fill: var(--alert); }
svg.tree .aux .lb { fill: var(--muted); font-weight: 400; font-style: italic; }
svg.tree .num { font: 600 10.5px var(--sans); fill: var(--on-deep); text-anchor: middle; dominant-baseline: central; }
svg.tree .numdot { fill: var(--deep); }
svg.tree .pick { cursor: pointer; outline: none; }
svg.tree .pick > g.n:first-of-type .box { stroke: var(--rule); }
svg.tree .pick:hover > g.n:first-of-type .box,
svg.tree .pick:focus-visible > g.n:first-of-type .box { stroke: var(--deep); stroke-dasharray: none; }
svg.tree .pick.sel > g.n:first-of-type .box { fill: var(--wash); stroke: var(--deep); stroke-width: 2; stroke-dasharray: none; }
svg.tree .pick.sel .e { stroke: var(--deep); }
svg.tree .hit { fill: transparent; }

/* notes */
.notes { margin: 1.5rem 0 0; padding: 0; list-style: none; display: grid; gap: .4rem; }
.notes li { padding: .55rem 1rem; border-left: 3px solid var(--muted); background: color-mix(in srgb, var(--rule) 30%, transparent); font-size: .9375rem; }
.notes li.err { border-left-color: var(--alert); }
.notes li.warn { border-left-color: #C98A0B; }

/* stepper */
.result { margin-top: 2rem; }
.summary { margin: .4rem 0 0; color: var(--muted); font-size: .9375rem; }
.summary strong { color: var(--ink); }
.stepper { display: flex; flex-wrap: wrap; align-items: center; gap: .5rem; margin-top: 1rem; }
.stepper button { padding: .35rem .75rem; font-size: 1rem; line-height: 1.2; min-width: 2.4rem; }
.stepper input[type=range] { flex: 1 1 10rem; accent-color: var(--deep); min-width: 8rem; }
.stepper .count { font-variant-numeric: tabular-nums; color: var(--muted); font-size: .875rem; min-width: 7.5rem; text-align: right; }
.action { display: flex; gap: .65rem; align-items: baseline; margin-top: 1rem; }
.tag {
    flex: none; display: inline-block; padding: .1rem .55rem; border-radius: 4px; font: 600 .75rem/1.5 var(--sans);
    text-transform: uppercase; letter-spacing: .04em; background: var(--rule); color: var(--ink);
}
.tag.predict, .tag.project { background: var(--wash); }
.tag.match, .tag.scan, .tag.shift, .tag.lex { background: color-mix(in srgb, var(--ok) 25%, transparent); }
.tag.reduce, .tag.complete, .tag.binary, .tag.unary, .tag.attach { background: color-mix(in srgb, var(--deep) 22%, transparent); }
.tag.fail, .tag.loop { background: var(--alert); color: var(--paper); }
.tag.success { background: var(--ok); color: var(--paper); }
.tag.pack { background: color-mix(in srgb, #C98A0B 35%, transparent); }
.action p { margin: 0; font-size: 1rem; }
.config { display: grid; grid-template-columns: max-content 1fr; gap: .45rem 1rem; margin-top: 1rem; align-items: baseline; font-size: .9375rem; }
.config dt { color: var(--muted); font-size: .8125rem; }
.config dd { margin: 0; display: flex; flex-wrap: wrap; gap: .3rem; align-items: baseline; min-width: 0; }
.sym {
    display: inline-block; padding: .05rem .5rem; border: 1px solid var(--rule); border-radius: 4px;
    font: 600 .875rem/1.5 var(--sans);
}
.sym.g { border-style: dashed; color: var(--muted); font-weight: 400; }
.sym.w { font: italic 1rem/1.4 var(--serif); }
.sym small { font-weight: 400; color: var(--muted); }
.sym.top { border-color: var(--deep); }
.none { color: var(--muted); font-style: italic; }
.input { font: 1.05rem/1.9 var(--serif); }
.input .i { font: .7rem var(--sans); color: var(--muted); vertical-align: sub; padding: 0 .2rem; }
.input .t { padding: 0 .1rem; border-radius: 3px; }
.input .t.in { background: color-mix(in srgb, var(--wash) 60%, transparent); }
.input .t.out { color: var(--muted); }
.input .i.at { color: var(--deep); font-weight: 600; }

/* Earley chart */
.chart { display: grid; grid-template-columns: repeat(auto-fill, minmax(13.5rem, 1fr)); gap: .75rem; margin-top: 1rem; }
.set { border: 1px solid var(--rule); border-radius: 6px; padding: .5rem .65rem; min-width: 0; }
.set h3 { margin: 0 0 .35rem; font: 600 .875rem var(--sans); display: flex; justify-content: space-between; gap: .5rem; }
.set h3 span { font: italic 400 .9375rem var(--serif); color: var(--muted); }
.set ol { margin: 0; padding: 0; list-style: none; font: .8125rem/1.5 var(--mono); }
.set li { padding: .05rem .3rem; border-radius: 3px; overflow-wrap: anywhere; }
.set li .o { color: var(--muted); }
.set li.cur { background: var(--wash); outline: 1px solid var(--deep); }
.set li.done { font-weight: 600; }
.set li .amb { color: #C98A0B; font-weight: 600; }

/* CKY table */
.table-wrap { overflow-x: auto; margin-top: 1rem; }
table.cky { border-collapse: collapse; font-size: .875rem; }
table.cky th { font-weight: 400; color: var(--muted); padding: .3rem .5rem; text-align: center; }
table.cky th.w { font: italic 1rem var(--serif); color: var(--ink); }
table.cky th small { display: block; font: .7rem var(--sans); color: var(--muted); }
table.cky td { border: 1px solid var(--rule); min-width: 5.5rem; height: 3.2rem; padding: .3rem .4rem; vertical-align: top; }
table.cky td.void { border: 0; }
table.cky td.src { background: color-mix(in srgb, var(--wash) 35%, transparent); }
table.cky td.cur { outline: 2px solid var(--deep); outline-offset: -2px; }
table.cky td.emptied { background: color-mix(in srgb, var(--rule) 45%, transparent); }
table.cky .ent { display: inline-block; margin: 0 .3rem .1rem 0; font-weight: 600; }
table.cky .ent.aux { font-weight: 400; font-style: italic; color: var(--muted); }
table.cky .ent.cur { background: var(--wash); padding: 0 .25rem; border-radius: 3px; }
table.cky .ent.top { color: var(--ok); }
.bin { margin-top: .75rem; font-size: .875rem; }
.bin summary { cursor: pointer; color: var(--muted); }
.bin code { display: inline-block; margin: .15rem .9rem 0 0; font: .8125rem var(--mono); }

/* step list and parses */
details.steps { margin-top: 1.25rem; }
details.steps > summary { cursor: pointer; color: var(--muted); font-size: .9375rem; }
ol.steplist { margin: .6rem 0 0; padding: 0 0 0 2.6rem; max-height: 22rem; overflow-y: auto; font-size: .875rem; border-top: 1px solid var(--rule); }
ol.steplist li { padding: .1rem 0; }
ol.steplist li::marker { color: var(--muted); font-variant-numeric: tabular-nums; }
ol.steplist button {
    all: unset; cursor: pointer; display: block; padding: .15rem .4rem; border-radius: 3px;
}
ol.steplist button:hover { background: color-mix(in srgb, var(--wash) 35%, transparent); }
ol.steplist li.cur button { background: var(--wash); }
ol.steplist li.bt button { color: var(--muted); }
ol.steplist .k { font: 600 .7rem var(--sans); text-transform: uppercase; letter-spacing: .04em; color: var(--muted); margin-right: .35rem; }
.parses { display: grid; grid-template-columns: minmax(0, 1fr); gap: 1rem; margin-top: 1rem; }
.parse { border-top: 1px solid var(--rule); padding-top: .75rem; }
.parse h3 { margin: 0; font: 600 .9375rem var(--sans); color: var(--muted); }
.stopnote { margin: 1rem 0 0; padding: .6rem 1rem; border-left: 3px solid var(--alert); font-size: .9375rem; }

/* algorithm pages */
.prose > p, .prose > ul, .prose > ol, .prose > dl, .prose > pre, .prose > h2, .prose > h3 { max-width: 46rem; }
.prose h2 { margin: 2.25rem 0 .5rem; font: 600 1.35rem/1.3 var(--serif); }
.prose h3 { margin: 1.5rem 0 .4rem; font: 600 1.05rem/1.3 var(--sans); }
.prose p, .prose li { font-size: 1rem; }
.prose .lead { font: 1.15rem/1.6 var(--serif); }
pre.code {
    margin: .75rem 0 0; padding: .9rem 1.1rem; border-left: 3px solid var(--deep);
    background: color-mix(in srgb, var(--wash) 18%, transparent);
    font: .85rem/1.55 var(--mono); overflow-x: auto; white-space: pre;
}
dl.ops { display: grid; grid-template-columns: max-content 1fr; gap: .4rem 1rem; margin: .75rem 0 0; }
dl.ops dt { font-weight: 600; }
dl.ops dd { margin: 0; }
.cards { display: grid; grid-template-columns: repeat(auto-fill, minmax(15rem, 1fr)); gap: 1rem; margin-top: 1.25rem; }
.card { border: 1px solid var(--rule); border-radius: 8px; padding: 1rem; text-decoration: none; color: inherit; display: block; }
.card:hover { border-color: var(--deep); }
.card h3 { margin: 0 0 .3rem; font: 600 1.1rem var(--serif); color: var(--deep); }
.card p { margin: 0; font-size: .9rem; color: var(--muted); }
table.cmp { border-collapse: collapse; width: 100%; font-size: .875rem; }
table.cmp th, table.cmp td { text-align: left; padding: .5rem .6rem; border-bottom: 1px solid var(--rule); vertical-align: top; }
table.cmp th { font-weight: 600; white-space: nowrap; }
table.cmp thead th { color: var(--muted); font-weight: 400; }
.figs { display: grid; grid-template-columns: repeat(auto-fit, minmax(18rem, 1fr)); gap: 1rem; margin-top: 1rem; }
.fig { margin: 0; border: 1px solid var(--rule); border-radius: 8px; padding: .75rem; min-width: 0; }
.fig figcaption { font-size: .875rem; color: var(--muted); }
.fig figcaption strong { color: var(--ink); }
ol.refs { padding-left: 0; list-style: none; }
ol.refs li { padding-left: 1.5rem; text-indent: -1.5rem; margin-bottom: .5rem; font-size: .9375rem; }
.try { display: inline-block; margin-top: 1rem; padding: .55rem 1.2rem; border-radius: 6px; background: var(--deep); color: var(--on-deep); text-decoration: none; font-weight: 600; }
.sub-nav { display: flex; flex-wrap: wrap; gap: .4rem; margin-top: 1.25rem; }
.sub-nav a { padding: .25rem .75rem; border: 1px solid var(--rule); border-radius: 999px; text-decoration: none; font-size: .875rem; color: var(--ink); }
.sub-nav a[aria-current] { background: var(--wash); border-color: var(--deep); font-weight: 600; }

.foot { margin-top: 3rem; padding-top: 1rem; border-top: 1px solid var(--rule); color: var(--muted); font-size: .8125rem; }
.foot p { margin: 0; }

@media (max-width: 44rem) {
    .grid2 { grid-template-columns: 1fr; }
}
@media (max-width: 34rem) {
    .controls > button { margin-left: 0; width: 100%; }
    .seg span { padding: .45rem .7rem; }
    .toolbar .end { margin-left: 0; }
    .toolbar input[type=text] { flex: 1 1 8rem; width: auto; }
    .stepper .count { min-width: 0; text-align: left; flex-basis: 100%; order: 9; }
    .config { grid-template-columns: 1fr; gap: .2rem; }
    .config dd { margin-bottom: .4rem; }
    dl.ops { grid-template-columns: 1fr; }
    dl.ops dd { margin-bottom: .5rem; }
}

/* start-symbol field in the controls row */
.field.start .lbl { color: var(--muted); font-weight: 400; font-size: .875rem; margin-bottom: .4rem; }
.field.start input { width: 7.5rem; font: 600 1rem var(--sans); padding: .45rem .7rem; }
.config dt small { font-size: .75rem; }