:root {
  --ink: #17202a;
  --muted: #617080;
  --line: #d8dee5;
  --canvas: #edf1f4;
  --red: #cc0000;
  --red-soft: #fce9e9;
  --blue: #0067a0;
  --blue-deep: #004c76;
  --blue-pale: #e8f3f9;
  --green: #24744f;
  --green-pale: #edf7f1;
  --paper: #dfe5e9;
  --shadow: 0 2px 8px rgb(18 32 43 / 10%);
}

* { box-sizing: border-box; }
html, body { max-width: 100%; overflow-x: hidden; }
body {
  min-width: 320px;
  margin: 0;
  color: var(--ink);
  font-family: Bahnschrift, "DIN Alternate", "Trebuchet MS", sans-serif;
  background: var(--paper);
}

button, input, select { font: inherit; }
button { cursor: pointer; }
.app-shell { width: 100%; min-width: 0; padding: 18px; max-width: 2000px; margin: auto; overflow-x: clip; background: var(--canvas); }
.app-header { margin: -18px -18px 12px; background: #fff; border-bottom: 3px solid var(--red); box-shadow: 0 1px 3px rgb(18 32 43 / 8%); }
.brand-strip { display: flex; align-items: center; gap: 18px; min-height: 64px; padding: 10px 26px; }
.ti-logo { display: block; width: 156px; height: 21px; object-fit: contain; object-position: left center; }
.banner-title { padding-left: 18px; border-left: 1px solid #c8d1d8; }
h1 { margin: 0; color: #202c36; font-size: 22px; line-height: 1.1; letter-spacing: 0; }
.top-actions { display: flex; gap: 10px; align-items: center; margin-left: auto; }
.command {
  min-height: 38px; padding: 0 15px; border: 1px solid #c8d1d8; border-radius: 4px;
  background: #fff; color: #3d5160; font-weight: 700; font-size: 13px;
}
.command:hover { border-color: var(--red); background: var(--red-soft); color: var(--red); }
.command.primary { color: #fff; border-color: var(--red); background: var(--red); }
.help { width: 38px; padding: 0; font-size: 20px; border-radius: 50%; }
.theme-toggle { width: 38px; padding: 0; font-size: 20px; border-radius: 50%; }

.flow-panel, .parameter-panel, .performance-panel, .results-panel {
  border: 1px solid var(--line); border-radius: 4px; background: #fff; box-shadow: var(--shadow);
}
.flow-panel { width: 100%; min-width: 0; max-width: 100%; padding: 8px; overflow: hidden; }
.diagram-caption { margin: 2px 8px 0; color: var(--muted); font-size: 14px; }
.diagram-scroll {
  width: 100%;
  min-width: 0;
  max-width: 100%;
  overflow-x: scroll;
  overflow-y: hidden;
  scrollbar-gutter: stable;
  scrollbar-color: #8a9aa7 #edf1f4;
  scrollbar-width: auto;
}
.diagram-scroll::-webkit-scrollbar { height: 12px; }
.diagram-scroll::-webkit-scrollbar-track { background: #edf1f4; }
.diagram-scroll::-webkit-scrollbar-thumb { background: #8a9aa7; border: 3px solid #edf1f4; border-radius: 8px; }
.diagram-scroll::-webkit-scrollbar-thumb:hover { background: var(--blue); }
.flow-diagram { display: block; min-width: 1500px; width: 100%; height: 228px; }
.signal-line { stroke: var(--blue); stroke-width: 3; fill: none; }
.block { fill: var(--blue); stroke: var(--blue-deep); stroke-width: 2; }
.block-label { fill: var(--ink); font-size: 20px; font-weight: 700; text-anchor: middle; dominant-baseline: middle; }
.flow-label { fill: #243441; font-size: 20px; font-weight: 700; }
.mixer-box { fill: #fafcfd; stroke: #8a9aa7; stroke-width: 2; stroke-dasharray: 9 7; }
.mixer-node { fill: var(--blue); stroke: var(--blue-deep); stroke-width: 2; }
.mixer-label { fill: var(--ink); font-size: 20px; font-weight: 700; dominant-baseline: middle; }
.symbol { fill: none; stroke: #fff; stroke-width: 3; stroke-linecap: round; stroke-linejoin: round; }
.wave { fill: none; stroke: #fff; stroke-width: 2; }

.section-heading { margin: 0; padding: 9px 13px 4px; color: #243441; font-size: 20px; letter-spacing: 0; }
.hint { color: var(--muted); font-size: 14px; font-weight: 400; }
.parameter-panel { margin-top: 10px; overflow: hidden; }
.component-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(210px, 1fr)); gap: 8px; padding: 0 8px 8px; }
.system-grid { display: grid; grid-template-columns: minmax(210px, 1fr); max-width: 320px; gap: 8px; padding: 0 8px 8px; }
.component-card { min-width: 0; border: 1px solid var(--line); border-radius: 3px; overflow: hidden; background: #fff; }
.component-card:focus-within { border-color: var(--blue); box-shadow: 0 0 0 2px rgb(0 103 160 / 12%); }
.component-title { margin: 0; padding: 7px 5px; color: #fff; text-align: center; font-size: 15px; background: var(--blue); }
.component-card.filter .component-title { color: #fff; background: var(--blue); }
.control-list { display: grid; gap: 7px; padding: 8px 10px 10px; }
.field { display: grid; grid-template-columns: 43px minmax(0, 1fr) 30px; align-items: center; gap: 4px; color: #4c5d6b; font-size: 14px; }
.field label { text-align: right; }
.file-field { display: grid; grid-template-columns: 43px minmax(0, 1fr); align-items: center; gap: 4px; color: #4c5d6b; font-size: 14px; }
.file-field label { text-align: right; }
.file-field input { width: 100%; height: auto; padding: 2px; font-size: 12px; }
.file-status { grid-column: 2; color: var(--muted); font-size: 12px; }
input, select { min-width: 0; height: 29px; padding: 3px 6px; color: #1d2a34; border: 1px solid #c8d1d8; border-radius: 3px; background: #fff; }
input:focus, select:focus { outline: 2px solid rgb(0 103 160 / 20%); border-color: var(--blue); }
.unit { color: #4c5d6b; white-space: nowrap; }

.bottom-grid { display: grid; grid-template-columns: minmax(0, 1.75fr) minmax(360px, 1fr); gap: 10px; margin-top: 10px; }
.chart-wrap { padding: 0 10px 10px; height: 295px; }
.plotly-chart { width: 100%; height: 100%; }
.results-panel { overflow: hidden; }
.result-cards { display: grid; grid-template-columns: repeat(auto-fit, minmax(120px, 1fr)); gap: 10px; padding: 4px 12px 10px; }
.result-card { min-height: 67px; padding: 10px 12px; border: 1px solid; border-left-width: 5px; border-radius: 3px; }
.result-card small { display: block; font-size: 13px; font-weight: 700; }
.result-card strong { display: block; margin-top: 3px; font-size: 23px; line-height: 1; }
.gain-card { color: #0067a0; border-color: #bad4e4; background: #edf6fa; }
.nf-card { color: var(--green); border-color: #b8d7c5; background: var(--green-pale); }
.iip3-card { color: var(--red); border-color: #e4b8b8; background: #fff8f8; }
.snr-card { color: #6b4d00; border-color: #e2cf98; background: #fffbed; }
.math-note { margin: 0 12px 12px; padding: 10px 12px; border: 1px solid #d8dee5; border-left: 3px solid var(--red); border-radius: 3px; background: #fafcfd; color: #4c5d6b; font-size: 13px; line-height: 1.45; }
.math-note strong { color: var(--red); }
.math-line { display: block; margin-left: 28px; font-family: Georgia, serif; color: #243441; }
dialog { max-width: 430px; border: 1px solid var(--line); border-radius: 4px; box-shadow: 0 12px 38px rgb(18 32 43 / 22%); color: var(--ink); }
dialog::backdrop { background: rgb(18 32 43 / 32%); }
dialog button { float: right; margin-top: 12px; }

:root[data-theme="dark"] {
  --ink: #e4eaee;
  --muted: #afbdc7;
  --line: #40505c;
  --canvas: #202a33;
  --red-soft: #45292c;
  --blue-pale: #253b4a;
  --green-pale: #253b30;
  --paper: #172027;
  --shadow: 0 2px 8px rgb(0 0 0 / 24%);
}

:root[data-theme="dark"] h1,
:root[data-theme="dark"] .section-heading,
:root[data-theme="dark"] .flow-label,
:root[data-theme="dark"] .component-card.filter .component-title,
:root[data-theme="dark"] .math-line { color: #e4eaee; }
:root[data-theme="dark"] .flow-panel,
:root[data-theme="dark"] .parameter-panel,
:root[data-theme="dark"] .performance-panel,
:root[data-theme="dark"] .results-panel,
:root[data-theme="dark"] .component-card,
:root[data-theme="dark"] input,
:root[data-theme="dark"] select { background: #29343d; }
:root[data-theme="dark"] .diagram-scroll { scrollbar-color: #71818e #202a33; }
:root[data-theme="dark"] .diagram-scroll::-webkit-scrollbar-track { background: #202a33; }
:root[data-theme="dark"] .diagram-scroll::-webkit-scrollbar-thumb { background: #71818e; border-color: #202a33; }
:root[data-theme="dark"] .mixer-box { fill: #29343d; stroke: #71818e; }
:root[data-theme="dark"] .component-card.filter .component-title { color: #fff; background: var(--blue); }
:root[data-theme="dark"] input,
:root[data-theme="dark"] select { color: #e4eaee; border-color: #52616d; }
:root[data-theme="dark"] .field,
:root[data-theme="dark"] .unit,
:root[data-theme="dark"] .file-field,
:root[data-theme="dark"] .math-note { color: #c4d0d8; }
:root[data-theme="dark"] .command { background: #29343d; color: #dce5ea; border-color: #52616d; }
:root[data-theme="dark"] .command.primary { color: #fff; border-color: var(--red); background: var(--red); }
:root[data-theme="dark"] .math-note { background: #29343d; border-color: #52616d; }
:root[data-theme="dark"] dialog { background: #29343d; color: #e4eaee; }
:root[data-theme="dark"] .app-header,
:root[data-theme="dark"] .brand-strip { background: #202a33; }
:root[data-theme="dark"] .banner-title { border-color: #52616d; }
:root[data-theme="dark"] .gain-card { color: #a8d7ee; border-color: #7dafc9; background: #263c4b; }
:root[data-theme="dark"] .nf-card { color: #a8d9bd; border-color: #83b89a; background: #243d30; }
:root[data-theme="dark"] .iip3-card { color: #ffb7b7; border-color: #df9292; background: #45292c; }
:root[data-theme="dark"] .snr-card { color: #f1d58a; border-color: #927b40; background: #42381f; }

@media (max-width: 850px) {
  .app-shell { padding: 10px; }
  .app-header { margin: -10px -10px 10px; }
  .brand-strip { padding-inline: 16px; flex-wrap: wrap; gap: 12px; }
  .banner-title { padding-left: 12px; }
  h1 { font-size: 25px; }
  .top-actions { margin-left: auto; }
  .bottom-grid { grid-template-columns: 1fr; }
  .chart-wrap { height: 260px; }
  .result-cards { gap: 6px; padding: 4px 8px 8px; }
  .result-card { padding: 8px; }
  .result-card strong { font-size: 18px; }
}

@media (max-width: 460px) {
  .ti-logo { width: 132px; height: 18px; }
  .banner-title { display: none; }
  .top-actions { width: 100%; margin-left: 0; }
  .diagram-caption { margin-inline: 4px; }
  .component-grid { grid-template-columns: 1fr; padding-inline: 6px; }
}