/* Layout: a live fan data sheet. Duty inputs on the left, the chosen fan always in view, working tabs below.
   Colour: galvanised steel neutrals with one petrol-blue accent. Status colours stay separate. */
:root {
  --bg: #e8eef0;
  --panel: #fbfcfc;
  --panel-2: #f0f4f5;
  --ink: #10262f;
  --ink-2: #3f5661;
  --muted: #5f7883;
  --line: #cdd8dc;
  --accent: #0a5f78;
  --accent-wash: rgba(10, 95, 120, 0.1);
  --on-accent: #ffffff;
  --good: #0ca30c;
  --good-ink: #006300;
  --warn: #fab219;
  --warn-ink: #7a5200;
  --bad: #d03b3b;
  --bad-ink: #a82525;
  --series-1: #2a78d6;
  --series-2: #eb6834;
  --series-3: #1baf7a;
  --grid: #e1e7e9;
  --axis: #b4c1c6;
  --font-display: "Barlow Semi Condensed", "Segoe UI", system-ui, sans-serif;
  --font-body: "Barlow", "Segoe UI", system-ui, sans-serif;
  --font-data: "IBM Plex Mono", ui-monospace, Consolas, monospace;
}
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --bg: #0e1619;
    --panel: #152125;
    --panel-2: #1b2a2f;
    --ink: #e7eff1;
    --ink-2: #b4c6cc;
    --muted: #8ba0a8;
    --line: #2b3b41;
    --accent: #5bbcd6;
    --accent-wash: rgba(91, 188, 214, 0.14);
    --on-accent: #06222b;
    --good-ink: #3ecb3e;
    --warn-ink: #fab219;
    --bad-ink: #f08080;
    --series-1: #3987e5;
    --series-2: #d95926;
    --series-3: #199e70;
    --grid: #223136;
    --axis: #3d5057;
    color-scheme: dark;
  }
}
:root[data-theme="dark"] {
  --bg: #0e1619;
  --panel: #152125;
  --panel-2: #1b2a2f;
  --ink: #e7eff1;
  --ink-2: #b4c6cc;
  --muted: #8ba0a8;
  --line: #2b3b41;
  --accent: #5bbcd6;
  --accent-wash: rgba(91, 188, 214, 0.14);
  --on-accent: #06222b;
  --good-ink: #3ecb3e;
  --warn-ink: #fab219;
  --bad-ink: #f08080;
  --series-1: #3987e5;
  --series-2: #d95926;
  --series-3: #199e70;
  --grid: #223136;
  --axis: #3d5057;
  color-scheme: dark;
}

* { box-sizing: border-box; }
[hidden] { display: none !important; }
html, body { margin: 0; }
body {
  background: var(--bg);
  color: var(--ink);
  font: 400 15px/1.45 var(--font-body);
}
h1, h2, h3 { font-family: var(--font-display); margin: 0; text-wrap: balance; }
h2 { font-size: 21px; font-weight: 600; }
h3 { font-size: 16px; font-weight: 600; }
p { margin: 0; }
a { color: var(--accent); }
button, input, select, textarea { font: inherit; color: inherit; }
:focus-visible { outline: 2px solid var(--accent); outline-offset: 2px; }

.app {
  max-width: 1320px;
  margin-inline: auto;
  padding-left: max(16px, env(safe-area-inset-left, 0px));
  padding-right: max(16px, env(safe-area-inset-right, 0px));
  padding-block: 14px 40px;
  display: grid;
  gap: 14px;
  grid-template-columns: 300px minmax(0, 1fr);
  grid-template-areas: "top top" "side main";
  align-items: start;
}

/* Top bar */
.topbar {
  grid-area: top;
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 10px 16px;
}
.brand { display: flex; align-items: center; gap: 10px; min-width: 0; }
.brand svg { width: 34px; height: 34px; flex: none; color: var(--accent); }
.brand h1 { font-size: 27px; font-weight: 700; line-height: 1; letter-spacing: 0.01em; }
.brand p { font-size: 13px; color: var(--muted); }
.toolbar { display: flex; flex-wrap: wrap; gap: 8px; }

.btn {
  border: 1px solid var(--line);
  background: var(--panel);
  border-radius: 6px;
  padding: 6px 12px;
  font-weight: 500;
  font-size: 14px;
  cursor: pointer;
}
.btn:hover { border-color: var(--accent); }
.btn-primary { background: var(--accent); border-color: var(--accent); color: var(--on-accent); }
.btn-danger { color: var(--bad-ink); }
.btn:disabled { opacity: 0.5; cursor: not-allowed; }

/* Inputs column */
.side {
  grid-area: side;
  display: grid;
  gap: 12px;
  position: sticky;
  top: calc(env(safe-area-inset-top, 0px) + 10px);
  max-height: calc(100vh - 20px);
  overflow-y: auto;
  scrollbar-width: thin;
}
.card {
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 14px;
  min-width: 0;
}
.card > summary { cursor: pointer; font: 600 16px var(--font-display); }
.card[open] > summary { margin-bottom: 10px; }
.fields { display: grid; gap: 10px; }
.field { display: grid; gap: 3px; min-width: 0; }
.field label, .field .label {
  font-size: 13px;
  font-weight: 500;
  color: var(--ink-2);
}
.field small { font-size: 12px; color: var(--muted); }
.field input, .field select, .field textarea {
  width: 100%;
  min-width: 0;
  background: var(--panel-2);
  border: 1px solid var(--line);
  border-radius: 5px;
  padding: 6px 8px;
}
.field input { font-family: var(--font-data); font-size: 14px; }
.field input.text { font-family: var(--font-body); }
.field textarea { font: 13px/1.4 var(--font-data); resize: vertical; }
.with-unit { display: grid; grid-template-columns: minmax(0, 1fr) 92px; gap: 6px; }
.two { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 10px; }
.density { font-size: 13px; color: var(--ink-2); border-top: 1px solid var(--line); padding-top: 8px; }
.density b { font-family: var(--font-data); font-weight: 500; }

/* Grid tracks may shrink, so wide tables and the tab row scroll inside themselves on a phone. */
.main, .side, .panel, .fields, .summary, .chart-stack { grid-template-columns: minmax(0, 1fr); }

/* Main column */
.main { grid-area: main; display: grid; gap: 14px; min-width: 0; }

.summary { display: grid; gap: 12px; }
.summary-head { display: grid; grid-template-columns: 76px minmax(0, 1fr) auto; gap: 14px; align-items: center; }
.impeller { width: 76px; height: 76px; color: var(--accent); }
.spin { transform-origin: 0 0; animation: spin linear infinite; } /* the viewBox is centred on 0,0 */
@keyframes spin { to { transform: rotate(360deg); } }
@media (prefers-reduced-motion: reduce) { .spin { animation: none; } }
.summary-title h2 { font-size: 25px; line-height: 1.1; }
.summary-title p { font-size: 14px; color: var(--ink-2); }
.stats { display: grid; grid-template-columns: repeat(auto-fit, minmax(112px, 1fr)); gap: 1px; background: var(--line); border: 1px solid var(--line); border-radius: 6px; overflow: hidden; }
.stat { background: var(--panel); padding: 8px 12px; min-width: 0; }
.stat .k { font-size: 12px; color: var(--muted); }
.stat .v { font: 600 24px/1.15 var(--font-display); }
.stat .v small { font: 500 13px var(--font-body); color: var(--ink-2); margin-left: 3px; }

.pill {
  display: inline-flex;
  align-items: center;
  gap: 5px;
  border-radius: 999px;
  padding: 2px 10px 2px 7px;
  font-size: 13px;
  font-weight: 600;
  white-space: nowrap;
  border: 1px solid;
}
.pill i { font-style: normal; font-size: 12px; }
.pill.ok { color: var(--good-ink); border-color: var(--good); }
.pill.warn { color: var(--warn-ink); border-color: var(--warn); }
.pill.reject { color: var(--bad-ink); border-color: var(--bad); }

.flags { display: grid; gap: 4px; list-style: none; margin: 0; padding: 0; font-size: 14px; }
.flags li { padding-left: 12px; border-left: 3px solid var(--warn); }
.flags li.reject { border-left-color: var(--bad); }
.notice {
  font-size: 13.5px;
  background: var(--panel-2);
  border: 1px solid var(--line);
  border-radius: 6px;
  padding: 7px 10px;
  color: var(--ink-2);
}
.notice b { color: var(--ink); }
.error-box { border-color: var(--bad); color: var(--ink); }

/* Tabs */
.tabs {
  display: flex;
  gap: 2px;
  overflow-x: auto;
  border-bottom: 2px solid var(--line);
  scrollbar-width: thin;
}
.tab {
  border: 0;
  background: none;
  padding: 8px 12px;
  font: 600 15px var(--font-display);
  color: var(--ink-2);
  border-bottom: 2px solid transparent;
  margin-bottom: -2px;
  white-space: nowrap;
  cursor: pointer;
}
.tab:hover { color: var(--ink); }
.tab[aria-selected="true"] { color: var(--accent); border-bottom-color: var(--accent); }
.panel { display: grid; gap: 14px; min-width: 0; }
.panel-lead { color: var(--ink-2); max-width: 70ch; }
.row { display: flex; flex-wrap: wrap; gap: 8px; align-items: center; }
.space-between { justify-content: space-between; }

/* Tables */
.table-wrap { overflow-x: auto; min-width: 0; }
table { border-collapse: collapse; width: 100%; font-size: 14px; }
th {
  text-align: left;
  font: 600 13px var(--font-display);
  color: var(--ink-2);
  padding: 6px 8px;
  border-bottom: 1px solid var(--axis);
  white-space: nowrap;
}
td { padding: 6px 8px; border-bottom: 1px solid var(--grid); }
td.n, th.n { text-align: right; font-variant-numeric: tabular-nums; }
td.n { font-family: var(--font-data); font-size: 13.5px; }
tr.pickable { cursor: pointer; }
tr.pickable:hover td { background: var(--panel-2); }
tr.picked td { background: var(--accent-wash); }
tr.muted-row td { color: var(--muted); }
.why { display: block; font-size: 12.5px; color: var(--muted); margin-top: 2px; max-width: 34ch; white-space: normal; }
.result-table td:last-child { width: 1%; white-space: nowrap; }
.total-row td { font-weight: 600; border-top: 1px solid var(--axis); }

/* Charts */
.chart-stack { position: relative; display: grid; gap: 4px; touch-action: pan-y; min-width: 0; }
.chart-title { font: 600 14px var(--font-display); color: var(--ink-2); }
.chart svg { display: block; width: 100%; overflow: visible; }
.chart text { font: 12px var(--font-body); fill: var(--muted); }
.chart .tick { font-variant-numeric: tabular-nums; }
.chart .direct { fill: var(--ink); font-weight: 500; }
.legend { display: flex; flex-wrap: wrap; gap: 4px 14px; font-size: 13px; color: var(--ink-2); }
.legend span { display: inline-flex; align-items: center; gap: 6px; }
.legend i { width: 18px; height: 3px; border-radius: 2px; display: inline-block; }
.tooltip {
  position: absolute;
  z-index: 3;
  pointer-events: none;
  background: var(--panel);
  border: 1px solid var(--axis);
  border-radius: 6px;
  padding: 6px 9px;
  font-size: 13px;
  box-shadow: 0 3px 10px rgba(16, 38, 47, 0.16);
  min-width: 132px;
}
.tooltip b { font-family: var(--font-data); font-weight: 500; }
.tooltip div { display: flex; justify-content: space-between; gap: 12px; }
.slider-row { display: grid; grid-template-columns: minmax(0, 1fr) auto; gap: 10px; align-items: center; }
.slider-row input { width: 100%; accent-color: var(--accent); }
details.data-view > summary { cursor: pointer; font-size: 14px; color: var(--ink-2); }
details.data-view[open] > summary { margin-bottom: 8px; }

.split { display: grid; grid-template-columns: repeat(auto-fit, minmax(280px, 1fr)); gap: 14px; align-items: start; }
.drawing { color: var(--ink); background: var(--panel); overflow-x: auto; }
.drawing svg { display: block; width: 100%; min-width: 520px; height: auto; }

/* Fan data editor */
.design-list { display: flex; flex-wrap: wrap; gap: 6px; }
.design-btn[aria-pressed="true"] { background: var(--accent); border-color: var(--accent); color: var(--on-accent); }
.points input { width: 100%; min-width: 74px; background: var(--panel-2); border: 1px solid var(--line); border-radius: 4px; padding: 4px 6px; font: 13.5px var(--font-data); text-align: right; }
.points td { padding: 3px 4px; }
.problems { color: var(--bad-ink); margin: 0; padding-left: 18px; font-size: 14px; }

/* Quotation */
.quote { background: #ffffff; color: #15262d; border: 1px solid var(--line); border-radius: 6px; padding: 22px; overflow-x: auto; }
.quote h3 { color: #15262d; }
.method { display: grid; gap: 14px; max-width: 78ch; }
.method .formula { font: 13.5px/1.6 var(--font-data); background: var(--panel-2); border-radius: 5px; padding: 8px 10px; overflow-x: auto; white-space: pre-wrap; }
.method ul { margin: 0; padding-left: 20px; }

.toast {
  position: fixed;
  left: 50%;
  bottom: calc(16px + env(safe-area-inset-bottom, 0px));
  transform: translateX(-50%);
  background: var(--ink);
  color: var(--panel);
  padding: 8px 14px;
  border-radius: 6px;
  font-size: 14px;
  z-index: 20;
  max-width: calc(100vw - 32px);
}

@media (max-width: 900px) {
  .app { grid-template-columns: minmax(0, 1fr); grid-template-areas: "top" "side" "main"; }
  .side { position: static; max-height: none; overflow: visible; }
}
@media (max-width: 520px) {
  .summary-head { grid-template-columns: 56px minmax(0, 1fr); }
  .summary-head .pill { grid-column: 1 / -1; justify-self: start; }
  .impeller { width: 56px; height: 56px; }
  .stat .v { font-size: 21px; }
}
@media print {
  .app, .toast { display: none !important; }
  #printArea { display: block !important; }
  body { background: #ffffff; }
}