:root {
  --bg: #f8fbfd;
  --panel: #fff;
  --soft: #f8fbfd;
  --text: #2f3a40;
  --muted: #66717a;
  --border: #d9e2e8;
  --grid: #d9e2e8;
  --axis: #7b8b95;
  --v: #168de2;
  --b1: #c97917;
  --b2: #168866;
  --danger: #b42318;
  --ok: #168866;
}

* { box-sizing: border-box; }

body {
  margin: 0;
  min-width: 320px;
  background: var(--bg);
  color: var(--text);
  font: 15px/1.45 -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
}

body.modal-open { overflow: hidden; }

[hidden] { display: none !important; }

button, input { font: inherit; }

.app { width: min(1180px, calc(100% - 24px)); margin: 10px auto 14px; }
h1 { margin: 0 0 4px; font-size: clamp(1.35rem, 3vw, 2rem); }
header p { margin: 0 0 10px; color: var(--muted); }
.layout { display: grid; grid-template-columns: minmax(230px, 300px) minmax(0, 1fr); gap: 14px; }
.panel { background: var(--panel); border: 1px solid var(--border); border-radius: 4px; box-shadow: 0 4px 14px rgba(28, 43, 54, .08); }
.controls, .visual { padding: 12px; }
fieldset { margin: 0 0 10px; padding: 8px; border: 1px solid var(--border); border-radius: 4px; background: var(--soft); }
legend { padding: 0 5px; font-weight: 700; }
.v { color: var(--v); } .b1 { color: var(--b1); } .b2 { color: var(--b2); }
.pair { display: grid; grid-template-columns: 1fr 1fr; gap: 8px; }
label { display: grid; gap: 4px; color: var(--muted); font-size: .86rem; }
input[type=number] { width: 100%; min-height: 34px; padding: 5px 7px; border: 1px solid #c8d6de; border-radius: 4px; background: var(--panel); color: var(--text); }
input:focus-visible, button:focus-visible { outline: 3px solid color-mix(in srgb, var(--v) 45%, transparent); outline-offset: 2px; }
.validity { display: none; min-height: 38px; margin: 2px 0 10px; padding: 7px 9px; border-left: 4px solid var(--ok); background: #eef8f4; color: var(--ok); font-size: .88rem; }
.validity.invalid { border-color: var(--danger); color: var(--danger); background: #fff1f0; }
.buttons { display: flex; flex-wrap: wrap; gap: 8px; }
button { min-height: 38px; padding: 7px 12px; border: 1px solid #c8d6de; border-radius: 4px; background: var(--panel); color: var(--text); cursor: pointer; }
button.primary { border-color: #168de2; background: #168de2; color: #fff; font-weight: 700; }
.slider-head, .slider-ends, .status-row { display: flex; justify-content: space-between; gap: 10px; align-items: baseline; }
.slider-head { margin-bottom: 5px; } .slider-head strong { font-variant-numeric: tabular-nums; }
input[type=range] { width: 100%; accent-color: var(--v); }
.slider-ends { color: var(--muted); font-size: .78rem; }
.status { display: grid; gap: 5px; margin: 8px 0 4px; padding: 8px; border: 1px solid var(--border); border-radius: 4px; background: var(--soft); font-variant-numeric: tabular-nums; }
.status-row span:first-child { color: var(--muted); } .status-row strong { text-align: right; font-size: .88rem; }
.plot-slot { cursor: zoom-in; }
#visual-content { min-width: 0; }
#plot { display: block; width: 100%; min-height: 0; }
.plot-modal { position: fixed; inset: 0; z-index: 1000; display: flex; align-items: center; justify-content: center; padding: 16px; background: rgba(21, 31, 38, .48); }
.plot-modal-panel { display: flex; flex-direction: column; width: min(96vw, 1400px); height: min(94vh, 900px); min-height: 0; border: 1px solid var(--border); border-radius: 4px; background: var(--panel); box-shadow: 0 14px 36px rgba(28, 43, 54, .28); }
.plot-modal-header { display: flex; align-items: center; justify-content: space-between; gap: 12px; padding: 10px 14px; border-bottom: 1px solid var(--border); color: var(--muted); }
.plot-modal-header button { min-height: 32px; padding: 5px 10px; }
.plot-modal-slot { display: flex; flex: 1; min-height: 0; padding: 12px; overflow: hidden; }
.plot-modal-slot #visual-content { display: flex; flex: 1; min-height: 0; flex-direction: column; }
.plot-modal-slot .plot-slot { flex: 1; min-height: 0; }
.plot-modal-slot #plot { width: 100%; height: 100%; cursor: default; }
.frame { fill: none; stroke: var(--border); } .reference-grid { stroke: var(--grid); opacity: .55; } .axis { stroke: var(--axis); stroke-width: 1.25; }
.moving-grid-1 { stroke: var(--b1); opacity: .3; } .moving-grid-2 { stroke: var(--b2); opacity: .3; }
.arrow-head-1 { fill: var(--b1); } .arrow-head-2 { fill: var(--b2); } .arrow-head-target { fill: var(--v); }
.basis-1 { stroke: var(--b1); fill: var(--b1); } .basis-2 { stroke: var(--b2); fill: var(--b2); } .target { stroke: var(--v); fill: var(--v); }
.vector { fill: none; stroke-width: 3; stroke-linecap: round; } .component { fill: none; stroke-width: 2; stroke-dasharray: 7 5; }
.tick, .axis-label, .vector-label { fill: var(--text); font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif; font-size: 12px; } .tick { fill: var(--muted); }
.legend { display: flex; flex-wrap: wrap; gap: 8px 16px; color: var(--muted); font-size: .82rem; } .legend span { display: inline-flex; align-items: center; gap: 6px; }
.swatch { width: 20px; height: 3px; border-radius: 3px; background: var(--v); } .swatch.b1 { background: var(--b1); } .swatch.b2 { background: var(--b2); }

@media (max-width: 760px) {
  .layout { grid-template-columns: 1fr; gap: 8px; }
  .controls { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 6px; padding: 8px; }
  fieldset { margin: 0; padding: 6px; }
  .validity, .buttons { grid-column: 1 / -1; margin: 0; }
  .buttons { gap: 6px; }
  .visual { padding: 8px; }
}

@media (max-width: 520px) {
  .plot-modal { padding: 6px; }
  .plot-modal-panel { width: 100%; height: 98vh; }
  .plot-modal-slot { padding: 6px; }
}