/* Antenna impedance matching calculator — rf.net.tw */
:root {
  --imc-ink: #1f2d3d;
  --imc-muted: #5b6b80;
  --imc-rule: #d8dfe8;
  --imc-paper: #f5f7fa;
  --imc-blue: #1a4a8a;
  --imc-blue-2: #2f72b8;
  --imc-accent: #ff8f1f;
}
* { box-sizing: border-box; }
[hidden] { display: none !important; }
body {
  margin: 0;
  background: var(--imc-paper);
  color: var(--imc-ink);
  font-family: Arial, "Microsoft JhengHei", "PingFang TC", "Noto Sans TC", sans-serif;
  line-height: 1.65;
}
a { color: var(--imc-blue-2); }
.imc-top {
  max-width: 1120px; margin: 0 auto; padding: 14px 16px;
  font-size: 14px; color: var(--imc-muted);
  display: flex; flex-wrap: wrap; gap: 6px; align-items: center;
}
.imc-top a { text-decoration: none; }
.imc-lang { margin-left: auto; border: 1px solid var(--imc-rule); border-radius: 6px; padding: 2px 10px; background: #fff; }
.imc-wrap { max-width: 1120px; margin: 0 auto; padding: 0 16px 32px; }
.imc-head { padding: 8px 0 18px; border-bottom: 1px solid var(--imc-rule); margin-bottom: 20px; }
.imc-eyebrow { margin: 0 0 4px; font-size: 12px; letter-spacing: .12em; color: var(--imc-muted); }
.imc-head h1 { margin: 0 0 8px; font-size: 28px; color: var(--imc-blue); line-height: 1.3; }
.imc-lead { margin: 0; max-width: 820px; color: #34455a; }
h2 { font-size: 19px; color: var(--imc-blue); margin: 0 0 12px; }
h3 { font-size: 16px; margin: 18px 0 6px; color: var(--imc-ink); }

.imc-tool { display: grid; grid-template-columns: minmax(280px, 380px) 1fr; gap: 20px; margin-bottom: 24px; }
.imc-panel { background: #fff; border: 1px solid var(--imc-rule); border-radius: 8px; padding: 18px; }
.imc-panel label { display: block; font-size: 14px; font-weight: bold; margin-bottom: 12px; }
.imc-unit { font-weight: normal; color: var(--imc-muted); font-size: 12px; margin-left: 4px; }
.imc-panel input[type=number] {
  display: block; width: 100%; margin-top: 4px; padding: 8px 10px; font-size: 16px;
  border: 1px solid #b9c4d2; border-radius: 6px; background: #fff; color: var(--imc-ink);
}
.imc-panel input[type=number]:focus { outline: 2px solid var(--imc-blue-2); outline-offset: 1px; border-color: var(--imc-blue-2); }
.imc-mode { border: 1px solid var(--imc-rule); border-radius: 6px; padding: 8px 12px 2px; margin: 0 0 12px; }
.imc-mode legend { font-size: 13px; color: var(--imc-muted); padding: 0 4px; }
.imc-panel .imc-radio { display: inline-flex; gap: 6px; align-items: center; font-weight: normal; margin-right: 16px; }
.imc-row2 { display: grid; grid-template-columns: 1fr 1fr; gap: 12px; }
.imc-actions { display: flex; flex-wrap: wrap; gap: 8px; margin-top: 4px; }
.imc-btn {
  border: 1px solid var(--imc-blue); background: var(--imc-blue); color: #fff; border-radius: 6px;
  padding: 9px 18px; font-size: 15px; font-weight: bold; cursor: pointer;
}
.imc-btn:hover { background: var(--imc-blue-2); border-color: var(--imc-blue-2); }
.imc-btn-ghost { background: #fff; color: var(--imc-blue); font-weight: normal; font-size: 13px; }
.imc-btn-ghost:hover { background: #eef3f9; color: var(--imc-blue); }
.imc-msg { color: #b3261e; min-height: 1em; margin: 10px 0 0; font-size: 14px; }

.imc-result { display: grid; grid-template-columns: 220px 1fr; gap: 16px; align-items: start; align-content: start; }
.imc-solutions > .imc-note { grid-column: 1 / -1; }
.imc-result h2 { grid-column: 1 / -1; margin-bottom: 0; }
.imc-stats { margin: 0; display: grid; gap: 8px; }
.imc-stats div { border-left: 3px solid var(--imc-rule); padding: 2px 0 2px 10px; }
.imc-stats dt { font-size: 12px; color: var(--imc-muted); }
.imc-stats dd { margin: 0; font-size: 18px; font-weight: bold; font-variant-numeric: tabular-nums; }
.imc-smith { width: 100%; max-width: 420px; height: auto; justify-self: center; }

.imc-solutions { display: grid; grid-template-columns: repeat(auto-fill, minmax(300px, 1fr)); gap: 12px; margin-bottom: 28px; }
.imc-card {
  display: flex; flex-direction: column; align-items: stretch; justify-content: flex-start; align-self: start;
  text-align: left; font: inherit; color: inherit; cursor: pointer;
  background: #fff; border: 1px solid var(--imc-rule); border-radius: 8px; padding: 14px;
}
.imc-card:hover { border-color: var(--imc-blue-2); }
.imc-card.is-on { border: 2px solid var(--imc-accent); padding: 13px; }
.imc-card .imc-tag { align-self: flex-start; }
.imc-card strong { display: block; font-size: 15px; margin: 6px 0 4px; }
.imc-schem {
  display: block; width: 100%; height: auto; margin: 6px 0 8px;
  background: #fafbfd; border: 1px solid var(--imc-rule); border-radius: 6px;
}
.imc-schem line, .imc-schem path { stroke: var(--imc-ink); stroke-width: 1.6; fill: none; stroke-linecap: round; }
.imc-schem line.mask { stroke: #fafbfd; stroke-width: 6; }
.imc-schem line.plate { stroke-width: 2.6; }
.imc-schem .node { fill: var(--imc-ink); }
.imc-schem .port { fill: #fff; stroke: var(--imc-blue); stroke-width: 1.6; }
.imc-schem .ant { fill: none; stroke: var(--imc-accent); stroke-width: 1.8; stroke-linejoin: round; }
.imc-schem text { font-family: Arial, "Microsoft JhengHei", sans-serif; font-size: 11px; fill: var(--imc-muted); }
.imc-schem text.val { fill: var(--imc-blue); font-weight: bold; font-size: 11.5px; }
.imc-chain { margin: 0 0 8px; font-size: 13px; color: #34455a; }
.imc-card table { width: 100%; border-collapse: collapse; font-size: 13px; font-variant-numeric: tabular-nums; }
.imc-card th, .imc-card td { border-top: 1px solid var(--imc-rule); padding: 4px 6px; text-align: left; }
.imc-card th { color: var(--imc-muted); font-weight: normal; }
.imc-sub { font-size: 13px; color: var(--imc-muted); margin: 6px 0 0; }
.imc-note { background: #fff; border: 1px solid var(--imc-rule); border-radius: 6px; padding: 10px 12px; margin: 0; }
.imc-tag { display: inline-block; font-size: 11px; border-radius: 4px; padding: 1px 6px; border: 1px solid; }
.imc-fold { border: 1px solid var(--imc-rule); border-radius: 6px; padding: 6px 12px; margin: 0 0 12px; }
.imc-fold > summary { cursor: pointer; font-size: 13px; color: var(--imc-muted); padding: 2px 0; }
.imc-fold[open] > summary { margin-bottom: 8px; }
.imc-smith-wrap { justify-self: center; width: 100%; max-width: 420px; }
.imc-smith-wrap .imc-smith { display: block; max-width: 100%; }
.imc-tiny { color: #8a1c1c; border-color: #e3a9a9; background: #fdf1f1; }
.imc-warn { color: #8a1c1c; }
.imc-tags { display: flex; flex-wrap: wrap; gap: 6px; }
.imc-best { color: #8a4a00; border-color: #ffc38a; background: #fff4e8; font-weight: bold; }
.imc-loss { margin: 2px 0 6px; font-size: 14px; font-weight: bold; color: var(--imc-ink); font-variant-numeric: tabular-nums; }
.imc-loss.is-best { color: #b85f00; }
.imc-lowpass { color: #1d6b3a; border-color: #9cc9ad; background: #f1f8f3; }
.imc-highpass { color: #1a4a8a; border-color: #a9bfdc; background: #f1f5fb; }
.imc-mixed { color: #6b5a1d; border-color: #d6c790; background: #fbf8ee; }

.imc-doc { background: #fff; border: 1px solid var(--imc-rule); border-radius: 8px; padding: 20px 22px; }
.imc-doc h2 { margin-top: 8px; }
.imc-doc h2 + * { margin-top: 0; }
.imc-doc ol { padding-left: 1.3em; }
.imc-related {
  max-width: 1120px; margin: 0 auto 28px; padding: 14px 18px; border: 1px solid var(--imc-rule);
  border-radius: 8px; background: #fff; font-size: 14px; line-height: 1.9;
}
.imc-related a { text-decoration: none; }

@media (max-width: 860px) {
  .imc-tool { grid-template-columns: 1fr; }
  .imc-result { grid-template-columns: 1fr; }
  .imc-stats { grid-template-columns: repeat(2, 1fr); }
  .imc-head h1 { font-size: 23px; }
}
@media (max-width: 420px) {
  .imc-row2 { grid-template-columns: 1fr; }
  .imc-solutions { grid-template-columns: 1fr; }
}