:root {
  --bg: #f6f7f9; --card: #fff; --fg: #15181d; --muted: #5b6470; --line: #dde1e6;
  --accent: #0b6bcb; --accent-fg: #fff; --ok: #1d7f3a; --warn: #a15c00; --err: #b3261e;
  --code: #eef1f5; --radius: 12px;
  --font: system-ui, -apple-system, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  --mono: ui-monospace, "SF Mono", Menlo, Consolas, "Liberation Mono", monospace;
  color-scheme: light dark;
}
@media (prefers-color-scheme: dark) {
  :root { --bg: #0f1216; --card: #171b21; --fg: #e8ebef; --muted: #9aa4b0; --line: #2a3038;
    --accent: #5aa8ff; --accent-fg: #06121f; --ok: #5fd27f; --warn: #f0b04a; --err: #ff7b72; --code: #20262e; }
}
* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }
body { margin: 0; background: var(--bg); color: var(--fg); font: 16px/1.5 var(--font); }
a { color: var(--accent); }
.wrap { max-width: 920px; margin: 0 auto; padding: 0 16px; }
header.site { border-bottom: 1px solid var(--line); background: var(--card); }
header.site .wrap { display: flex; flex-wrap: wrap; align-items: center; gap: 8px 20px; padding-top: 10px; padding-bottom: 10px; }
.brand { font-weight: 800; letter-spacing: -.02em; text-decoration: none; color: var(--fg); font-size: 1.15rem; }
.brand span { color: var(--accent); }
nav.main { display: flex; flex-wrap: wrap; gap: 4px 14px; font-size: .95rem; }
nav.main a { text-decoration: none; color: var(--muted); padding: 4px 0; }
nav.main a[aria-current="page"] { color: var(--fg); font-weight: 600; border-bottom: 2px solid var(--accent); }
main { padding: 20px 0 40px; }
h1 { font-size: 1.6rem; line-height: 1.2; margin: 4px 0 6px; letter-spacing: -.01em; }
h2 { font-size: 1.15rem; margin: 0 0 10px; }
.lead { color: var(--muted); margin: 0 0 18px; }
.card { background: var(--card); border: 1px solid var(--line); border-radius: var(--radius); padding: 16px; margin-bottom: 16px; }
.grid { display: grid; gap: 12px; }
@media (min-width: 640px) { .grid.two { grid-template-columns: 1fr 1fr; } .grid.three { grid-template-columns: repeat(3, 1fr); } h1 { font-size: 2rem; } }
label.f { display: block; font-size: .85rem; font-weight: 600; color: var(--muted); margin-bottom: 4px; }
.field { display: flex; align-items: stretch; border: 1px solid var(--line); border-radius: 8px; background: var(--bg); overflow: hidden; }
.field:focus-within { outline: 2px solid var(--accent); outline-offset: 1px; }
.field input, .field select { flex: 1; min-width: 0; border: 0; background: transparent; color: var(--fg); font: inherit; font-size: 1.1rem; padding: 10px 12px; }
.field input:focus, .field select:focus { outline: none; }
.field .unit { padding: 10px 12px; color: var(--muted); border-left: 1px solid var(--line); white-space: nowrap; display: flex; align-items: center; }
.field select.unit { flex: 0 0 auto; font-size: 1rem; padding: 10px 8px; }
select.plain { border: 1px solid var(--line); border-radius: 8px; background: var(--bg); color: var(--fg); font: inherit; padding: 8px 10px; }
.seg { display: inline-flex; border: 1px solid var(--line); border-radius: 8px; overflow: hidden; }
.seg button { border: 0; background: var(--bg); color: var(--fg); font: inherit; padding: 8px 14px; cursor: pointer; }
.seg button + button { border-left: 1px solid var(--line); }
.seg button[aria-pressed="true"] { background: var(--accent); color: var(--accent-fg); font-weight: 600; }
.btn { border: 1px solid var(--accent); background: transparent; color: var(--accent); font: inherit; border-radius: 8px; padding: 6px 12px; cursor: pointer; }
.btn:hover { background: var(--accent); color: var(--accent-fg); }
.result { font-size: 2rem; font-weight: 750; letter-spacing: -.02em; line-height: 1.15; font-variant-numeric: tabular-nums; }
.sub { color: var(--muted); font-size: .92rem; }
.kv { display: grid; grid-template-columns: auto 1fr; gap: 6px 14px; margin: 0; font-variant-numeric: tabular-nums; }
.kv dt { color: var(--muted); }
.kv dd { margin: 0; font-weight: 600; }
.msg { min-height: 1.5em; font-size: .95rem; }
.msg.err { color: var(--err); } .msg.warn { color: var(--warn); } .msg.ok { color: var(--ok); }
.badge { display: inline-block; font-size: .78rem; font-weight: 700; padding: 1px 7px; border-radius: 99px; border: 1px solid currentColor; margin-right: 4px; }
.badge.yes { color: var(--ok); } .badge.no { color: var(--muted); }
table.out { width: 100%; border-collapse: collapse; font-variant-numeric: tabular-nums; }
table.out th, table.out td { text-align: left; padding: 8px 6px; border-bottom: 1px solid var(--line); vertical-align: top; }
table.out th { font-size: .82rem; color: var(--muted); font-weight: 600; }
table.out td.big { font-size: 1.25rem; font-weight: 700; }
.formula { font-family: var(--mono); background: var(--code); border-radius: 8px; padding: 10px 12px; overflow-x: auto; font-size: .92rem; white-space: pre; }
details.explain summary { cursor: pointer; font-weight: 600; }
.explain p, .explain li { color: var(--fg); }
.share { display: flex; gap: 8px; align-items: center; flex-wrap: wrap; margin-top: 10px; }
.share .sub { flex: 1; }
/* Resistor colour picker */
.resistor svg { width: 100%; max-width: 560px; height: auto; display: block; margin: 0 auto; }
.bands { display: grid; gap: 10px; }
.band fieldset { border: 0; margin: 0; padding: 0; min-width: 0; }
.band legend { font-size: .85rem; font-weight: 600; color: var(--muted); padding: 0; margin-bottom: 4px; }
.sw { display: flex; flex-wrap: wrap; gap: 4px; }
.sw label { position: relative; cursor: pointer; }
.sw input { position: absolute; opacity: 0; width: 1px; height: 1px; }
.sw span { display: block; width: 29px; height: 34px; border-radius: 8px; border: 1px solid rgba(127,127,127,.5); }
.sw input:checked + span { outline: 3px solid var(--fg); outline-offset: 2px; }
.sw input:focus-visible + span { outline: 3px solid var(--accent); outline-offset: 2px; }
.sw span[data-c="none"] { background: repeating-linear-gradient(45deg, transparent 0 5px, rgba(127,127,127,.5) 5px 7px); }
@media (min-width: 640px) { .sw span { width: 30px; height: 30px; } }
.tiles { display: grid; gap: 12px; }
@media (min-width: 640px) { .tiles { grid-template-columns: repeat(3, 1fr); } }
.tile { display: block; text-decoration: none; color: var(--fg); background: var(--card); border: 1px solid var(--line); border-radius: var(--radius); padding: 16px; }
.tile:hover { border-color: var(--accent); }
.tile h2 { margin: 8px 0 4px; } .tile p { margin: 0; color: var(--muted); font-size: .95rem; }
.tile svg { width: 100%; height: 56px; }
footer.site { border-top: 1px solid var(--line); color: var(--muted); font-size: .88rem; padding: 18px 0 28px; }
footer.site p { margin: 4px 0; }
.sr { position: absolute; width: 1px; height: 1px; overflow: hidden; clip: rect(0 0 0 0); white-space: nowrap; }
@media print { header.site nav, .share, footer.site { display: none; } .card { break-inside: avoid; } }
.msg:empty { display: none; }
.pair { display: grid; grid-template-columns: 1fr 1fr; gap: 12px; }
table.out td + td { white-space: nowrap; }
@media (max-width: 639px) { table.out { font-size: .9rem; } table.out th, table.out td { padding: 7px 4px; } }
/* utility classes (no inline styles, so the CSP needs no 'unsafe-inline') */
.mt0 { margin-top: 0 !important; } .mt12 { margin-top: 12px !important; } .mt14 { margin-top: 14px !important; } .mt16 { margin-top: 16px !important; }
.mb0 { margin-bottom: 0 !important; } .mb6 { margin-bottom: 6px !important; } .m0 { margin: 0 !important; } .w100 { width: 100% !important; }
.swatch { display: inline-block; width: 12px; height: 12px; border-radius: 3px; vertical-align: -1px; margin-right: 6px; border: 1px solid rgba(127,127,127,.5); }
.disclaimer { font-weight: 600; }
.sources { margin: 0 0 4px; padding-left: 20px; } .sources a { word-break: break-all; }
/* SWR page: scrollable table on narrow screens, delivered/reflected power bar (width set via CSSOM) */
.scroll { overflow-x: auto; }
.bar { display: flex; height: 14px; border-radius: 7px; overflow: hidden; background: var(--line); margin-top: 8px; }
.bar .fwd { background: var(--ok); } .bar .ref { background: var(--err); }
.legend { display: flex; gap: 14px; flex-wrap: wrap; margin-top: 6px; }
.dot { display: inline-block; width: 10px; height: 10px; border-radius: 50%; margin-right: 5px; vertical-align: 0; }
.dot.fwd { background: var(--ok); } .dot.ref { background: var(--err); }
/* short numeric inputs side by side also on phones, so the result stays near the top */
.grid.pairs { grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 10px; }
.grid.pairs > div { min-width: 0; }
.grid.pairs .field input { width: 100%; }
.grid.pairs label.f { min-height: 2.5em; display: flex; align-items: flex-end; }
@media (max-width: 639px) { .grid.pairs .field input { font-size: 1rem; padding: 9px 8px; } .grid.pairs .field .unit { padding: 9px 7px; font-size: .9rem; } }
/* Printable chart pages (v1.2) */
.toolbar { display: flex; flex-wrap: wrap; gap: 8px 12px; align-items: center; margin: 0 0 16px; }
.toolbar .sub { flex: 1 1 220px; }
a.btn { text-decoration: none; display: inline-block; }
.btn.primary { background: var(--accent); color: var(--accent-fg); font-weight: 600; }
.chartlink { margin: 4px 0 14px; }
table.chart { width: 100%; border-collapse: collapse; font-variant-numeric: tabular-nums; font-size: .92rem; }
table.chart th, table.chart td { padding: 5px 7px; border-bottom: 1px solid var(--line); text-align: left; white-space: nowrap; }
table.chart th { font-size: .8rem; color: var(--muted); font-weight: 600; vertical-align: bottom; }
table.chart th.grp { text-align: center; border-bottom: 1px solid var(--line); }
table.chart td.num { text-align: right; }
table.chart tbody tr:nth-child(even) { background: var(--code); }
table.chart tr.major td { border-bottom: 1.5px solid var(--muted); }
.chip { display: inline-block; width: 14px; height: 14px; border-radius: 3px; vertical-align: -2px; margin-right: 6px; border: 1px solid #777; -webkit-print-color-adjust: exact; print-color-adjust: exact; }
.c-black { background: #1c1c1c; } .c-brown { background: #7a4a24; } .c-red { background: #d0281f; } .c-orange { background: #f07c12; }
.c-yellow { background: #f6d31b; } .c-green { background: #2f9a3c; } .c-blue { background: #2a62c9; } .c-violet { background: #8a3fc4; }
.c-grey { background: #8c8c8c; } .c-white { background: #f4f4f0; } .c-gold { background: #c99a2e; } .c-silver { background: #c0c4c8; }
.c-pink { background: #ff9fc6; } .c-none { background: repeating-linear-gradient(45deg, transparent 0 3px, #888 3px 4px); }
.examples { padding-left: 20px; margin: 8px 0 0; } .examples li { margin: 4px 0; }
.note { margin: 8px 0 0; }
.kfactor { border-left: 4px solid var(--accent); padding: 6px 10px; background: var(--code); border-radius: 4px; margin: 0 0 12px; }
.split { display: grid; gap: 0 18px; }
@media (min-width: 900px) { .split { grid-template-columns: 1fr 1fr; } }
.printonly { display: none; }
.pagebreak { display: none; }
@media print {
  @page { margin: 11mm 10mm; }
  :root { --bg: #fff; --card: #fff; --fg: #000; --muted: #222; --line: #888; --code: #eee; --accent: #000; --accent-fg: #fff; }
  html, body { background: #fff; color: #000; }
  .chartpage { font-size: 9.5pt; line-height: 1.3; }
  .chartpage header.site, .noprint, footer.site { display: none !important; }
  .chartpage main { padding: 0; }
  .chartpage .wrap { max-width: none; padding: 0; }
  .chartpage .card { border: 0; padding: 0; margin: 0 0 8pt; break-inside: auto; }
  .chartpage h1 { font-size: 15pt; margin: 0 0 2pt; }
  .chartpage h2 { font-size: 11pt; margin: 4pt 0 4pt; }
  .chartpage .lead { margin: 0 0 3pt; color: #000; }
  .chartpage .scroll { overflow: visible; }
  .chartpage table.chart { font-size: 8.5pt; }
  .chartpage table.chart th, .chartpage table.chart td { padding: .8pt 4pt; border-bottom: .5pt solid #999; }
  .chartpage table.chart th { color: #000; }
  .chartpage table.chart tbody tr:nth-child(even) { background: #eee; -webkit-print-color-adjust: exact; print-color-adjust: exact; }
  .chartpage table.chart tr.major td { border-bottom: 1pt solid #000; }
  .chartpage thead { display: table-header-group; }
  .chartpage tr { break-inside: avoid; }
  .chartpage .split { grid-template-columns: 1fr 1fr; gap: 0 10pt; }
  .chartpage .kfactor { border-left: 3pt solid #000; background: none; padding: 2pt 6pt; }
  .chartpage a { color: #000; text-decoration: none; }
  .chartpage .note, .chartpage .sub { color: #000; font-size: 8pt; }
  .chartpage .printonly { display: block; }
  .chartpage .pagebreak { display: block; break-before: page; }
  .chartpage .sourcesbox { margin-top: 6pt; }
}
table.chart.auto { width: auto; }
table.chart.auto th, table.chart.auto td { padding-left: 10px; padding-right: 14px; }
@media print { .chartpage table.chart.auto th, .chartpage table.chart.auto td { padding-left: 6pt; padding-right: 12pt; } }
@media print { .chartpage table.chart.dense th, .chartpage table.chart.dense td { padding-top: .2pt; padding-bottom: .2pt; } }
table.out td.wraptext { white-space: normal; }
/* v1.10: coax loss page (band buttons, selected cable row) */
.btnrow { display: flex; flex-wrap: wrap; gap: 6px; }
.btnrow .btn { padding: 4px 10px; font-size: .9rem; }
table.chart tbody tr.sel td { font-weight: 650; }
/* v1.13: LC resonance page (the solved field is read-only) */
.field.solved { background: var(--code); }
.field.solved input { font-weight: 700; }
.lcpage .grid > *, .lcpage .pair > * { min-width: 0; }
.lcpage .pair { grid-template-columns: minmax(0, 1fr) minmax(0, 1fr); }
.lcpage .field input { width: 100%; }
.lcpage .kv dd { overflow-wrap: anywhere; }
.out tr.hl td { background: rgba(184, 115, 51, .12); font-weight: 600; }
.lorapage .grid > *, .lorapage .pair > * { min-width: 0; }
.lorapage .pair { grid-template-columns: minmax(0, 1fr) minmax(0, 1fr); }
.lorapage .field input { width: 100%; }
.lorapage .kv dd { overflow-wrap: anywhere; }
/* v1.15: series-parallel */
.grid.four { grid-template-columns: repeat(2, minmax(0, 1fr)); }
@media (min-width: 640px) { .grid.four { grid-template-columns: repeat(4, minmax(0, 1fr)); } }
.sppage .grid > * { min-width: 0; }
.sppage .field input { width: 100%; min-width: 0; }