:root {
  --bg: #171514;
  --surface: #211f1d;
  --surface-2: #292623;
  --surface-3: #312d29;
  --text: #fbfaf8;
  --muted: #aaa39c;
  --muted-2: #7e7770;
  --border: rgba(255, 255, 255, .09);
  --border-strong: rgba(255, 255, 255, .16);
  --orange: #f97316;
  --orange-light: #fb923c;
  --blue: #2563eb;
  --focus: #fdba74;
  --radius: 14px;
  --shadow: 0 18px 42px rgba(0, 0, 0, .24);
  --font: "Segoe UI", "PingFang SC", "Microsoft YaHei", sans-serif;
  --mono: "Cascadia Code", "SFMono-Regular", Consolas, monospace;
}

* { box-sizing: border-box; }
html { color-scheme: dark; }
body {
  margin: 0;
  min-width: 320px;
  min-height: 100dvh;
  color: var(--text);
  background:
    radial-gradient(circle at 72% -10%, rgba(249, 115, 22, .09), transparent 36rem),
    var(--bg);
  font-family: var(--font);
  font-size: 16px;
  line-height: 1.5;
}
button, input, select { font: inherit; }
button, select, input[type="range"], label { touch-action: manipulation; }
button { color: inherit; }
button, select, input[type="checkbox"], input[type="range"] { cursor: pointer; }
svg { fill: none; stroke: currentColor; stroke-width: 1.8; stroke-linecap: round; stroke-linejoin: round; }

.skip-link {
  position: fixed;
  left: 16px;
  top: -80px;
  z-index: 1000;
  padding: 10px 14px;
  color: #16120f;
  background: var(--focus);
  border-radius: 8px;
  font-weight: 700;
}
.skip-link:focus { top: 12px; }

.app-shell { width: min(1760px, 100%); margin: 0 auto; padding: 0 24px 32px; }
.topbar {
  min-height: 76px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  border-bottom: 1px solid var(--border);
}
.brand-lockup { display: flex; align-items: center; gap: 12px; }
.brand-mark {
  width: 44px; height: 44px; display: grid; place-items: center;
  background: linear-gradient(145deg, #2d2926, #191715);
  border: 1px solid var(--border-strong);
  border-radius: 12px;
  box-shadow: inset 1px 1px rgba(255,255,255,.05), 5px 6px 16px rgba(0,0,0,.24);
  color: var(--orange);
}
.brand-mark svg { width: 32px; height: 32px; stroke-width: 2.2; }
.brand-mark .mark-array { stroke: #fff; stroke-dasharray: 2 3; }
h1, h2, p { margin: 0; }
h1 { font: 700 1.2rem/1 var(--mono); letter-spacing: -.04em; }
h1 span { color: var(--orange-light); }
.brand-lockup p { margin-top: 5px; color: var(--muted); font-size: .82rem; }
.topbar-actions { display: flex; align-items: center; gap: 14px; }
.topbar-status { display: flex; align-items: center; gap: 10px; color: var(--muted); font-size: .86rem; }
.status-dot { width: 7px; height: 7px; border-radius: 999px; background: #36c58b; box-shadow: 0 0 0 4px rgba(54,197,139,.12); }
.status-dot.paused { background: #f5b342; box-shadow: 0 0 0 4px rgba(245,179,66,.12); }
.divider { width: 1px; height: 18px; background: var(--border-strong); }
.mono { font-family: var(--mono); font-variant-numeric: tabular-nums; }
.language-button {
  min-width: 68px; min-height: 44px; padding: 0 12px;
  display: inline-flex; align-items: center; justify-content: center; gap: 7px;
  color: #f4eee9; background: #282522; border: 1px solid var(--border-strong); border-radius: 10px;
  font: 650 .76rem/1 var(--mono);
  transition: background-color .18s ease, border-color .18s ease, color .18s ease;
}
.language-button:hover { background: #34302c; border-color: rgba(255,255,255,.24); color: var(--orange-light); }
.language-button svg { width: 17px; height: 17px; }

.workspace {
  display: grid;
  grid-template-columns: 320px minmax(0, 1fr);
  gap: 16px;
  padding-top: 16px;
}
.control-panel, .simulation-panel, .timing-panel {
  background: linear-gradient(145deg, rgba(43,40,37,.98), rgba(29,27,25,.98));
  border: 1px solid var(--border);
  border-radius: var(--radius);
  box-shadow: var(--shadow), inset 1px 1px rgba(255,255,255,.025);
}
.control-panel { grid-row: span 2; padding: 18px; }
.panel-heading, .simulation-toolbar, .timing-header, .inspector-top {
  display: flex; align-items: center; justify-content: space-between; gap: 14px;
}
.eyebrow { color: var(--orange-light); font: 600 .71rem/1.2 var(--mono); letter-spacing: .12em; text-transform: uppercase; }
h2 { margin-top: 5px; font-size: 1.04rem; letter-spacing: -.01em; }
.icon-button, .tool-button, .text-button {
  min-width: 44px; min-height: 44px;
  display: inline-flex; align-items: center; justify-content: center; gap: 8px;
  border: 1px solid var(--border-strong);
  background: #282522;
  border-radius: 10px;
  transition: background-color .18s ease, border-color .18s ease, color .18s ease, box-shadow .18s ease;
}
.icon-button:hover, .tool-button:hover, .text-button:hover { background: #34302c; border-color: rgba(255,255,255,.24); }
.icon-button:active, .tool-button:active, .text-button:active { background: #1d1b19; }
.icon-button svg { width: 20px; height: 20px; }
button:focus-visible, select:focus-visible, input:focus-visible { outline: 3px solid rgba(253,186,116,.9); outline-offset: 2px; }

fieldset { border: 0; padding: 0; margin: 20px 0 0; }
legend { margin-bottom: 10px; color: var(--muted); font-size: .82rem; font-weight: 600; }
.preset-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 8px; }
.preset-card {
  min-height: 92px;
  display: grid;
  grid-template-columns: 30px 1fr;
  grid-template-rows: auto auto;
  align-items: center;
  column-gap: 8px;
  padding: 13px 11px;
  text-align: left;
  background: #24211f;
  border: 1px solid var(--border);
  border-radius: 11px;
  transition: background-color .18s ease, border-color .18s ease, box-shadow .18s ease;
}
.preset-card:hover { background: #2d2926; border-color: var(--border-strong); }
.preset-card.active { background: #33251d; border-color: rgba(249,115,22,.65); box-shadow: inset 0 0 0 1px rgba(249,115,22,.12); }
.preset-card svg { grid-row: 1 / 3; width: 30px; height: 30px; color: var(--orange-light); stroke-width: 1.5; }
.preset-card span { font-size: .88rem; font-weight: 650; align-self: end; }
.preset-card small { color: var(--muted); font-size: .7rem; align-self: start; }

.control-group { margin-top: 20px; padding-top: 18px; border-top: 1px solid var(--border); }
.control-row { margin-bottom: 17px; }
.control-row[hidden] { display: none; }
.label-row { display: flex; align-items: baseline; justify-content: space-between; gap: 12px; margin-bottom: 8px; }
.label-row label { color: #e9e5e1; font-size: .82rem; font-weight: 600; }
output { color: var(--orange-light); font: 500 .75rem var(--mono); }
input[type="range"] {
  width: 100%; height: 18px; margin: 0;
  appearance: none; -webkit-appearance: none;
  background: transparent;
}
input[type="range"]::-webkit-slider-runnable-track { height: 4px; border-radius: 99px; background: linear-gradient(90deg, var(--orange) var(--range-progress, 50%), #4a4540 var(--range-progress, 50%)); }
input[type="range"]::-webkit-slider-thumb { appearance: none; width: 16px; height: 16px; margin-top: -6px; border-radius: 50%; background: #fff7ed; border: 4px solid var(--orange); box-shadow: 0 2px 8px rgba(0,0,0,.35); }
input[type="range"]::-moz-range-track { height: 4px; border-radius: 99px; background: #4a4540; }
input[type="range"]::-moz-range-progress { height: 4px; background: var(--orange); }
input[type="range"]::-moz-range-thumb { width: 11px; height: 11px; border-radius: 50%; background: #fff7ed; border: 4px solid var(--orange); }

.visual-switches { padding-top: 2px; }
.switch-row { min-height: 58px; display: flex; align-items: center; justify-content: space-between; gap: 14px; border-top: 1px solid var(--border); }
.switch-row > span:first-child { display: flex; flex-direction: column; }
.switch-row b { font-size: .82rem; font-weight: 650; }
.switch-row small { margin-top: 2px; color: var(--muted); font-size: .7rem; }
.switch-row input { position: absolute; opacity: 0; pointer-events: none; }
.switch { position: relative; flex: 0 0 auto; width: 38px; height: 22px; border-radius: 999px; background: #4b4641; transition: background-color .18s ease; }
.switch::after { content: ""; position: absolute; left: 3px; top: 3px; width: 16px; height: 16px; border-radius: 50%; background: #d8d2cc; transition: transform .18s ease, background-color .18s ease; }
.switch-row input:checked + .switch { background: var(--orange); }
.switch-row input:checked + .switch.phase-switch { background: linear-gradient(90deg, #294bb9, #dc3545); }
.switch-row input:checked + .switch::after { transform: translateX(16px); background: white; }
.switch-row input:focus-visible + .switch { outline: 3px solid var(--focus); outline-offset: 3px; }

.simulation-panel { min-width: 0; overflow: hidden; }
.simulation-toolbar { min-height: 74px; padding: 14px 18px; border-bottom: 1px solid var(--border); }
.transport { display: flex; align-items: center; gap: 8px; }
.tool-button { padding: 0 14px; font-size: .82rem; font-weight: 650; }
.tool-button.primary { color: #21160d; background: var(--orange); border-color: var(--orange); }
.tool-button.primary:hover { background: var(--orange-light); border-color: var(--orange-light); }
.tool-button svg { width: 18px; height: 18px; }
.tool-button .play-icon { display: none; }
.tool-button.is-paused .pause-icon { display: none; }
.tool-button.is-paused .play-icon { display: block; }
.speed-control { display: flex; align-items: center; gap: 7px; color: var(--muted); font-size: .76rem; margin-left: 4px; }
select { min-height: 38px; padding: 0 28px 0 10px; color: #f5f2ef; background: #282522; border: 1px solid var(--border-strong); border-radius: 9px; }
.metrics { display: grid; grid-template-columns: repeat(4, 1fr); border-bottom: 1px solid var(--border); }
.metrics > div { padding: 12px 16px; border-right: 1px solid var(--border); }
.metrics > div:last-child { border-right: 0; }
.metrics span { display: block; color: var(--muted); font-size: .7rem; }
.metrics strong { display: block; margin-top: 4px; font-size: .86rem; font-weight: 600; }

.field-stage { position: relative; min-height: 520px; background: #dde6ec; overflow: hidden; }
#fieldCanvas { display: block; width: 100%; height: 520px; cursor: crosshair; }
.field-stage::after { content: ""; position: absolute; inset: 0; pointer-events: none; box-shadow: inset 0 0 70px rgba(16,36,52,.08); }
.field-hint, .coordinate-readout, .legend {
  position: absolute; z-index: 2;
  color: #20303d;
  background: rgba(247,250,252,.84);
  border: 1px solid rgba(25,49,69,.14);
  box-shadow: 0 6px 18px rgba(34,55,70,.09);
  backdrop-filter: blur(8px);
}
.field-hint { left: 14px; top: 14px; padding: 7px 10px; border-radius: 8px; font-size: .72rem; }
.coordinate-readout { right: 14px; top: 14px; padding: 7px 10px; border-radius: 8px; font-size: .68rem; }
.legend { left: 14px; bottom: 14px; display: flex; flex-wrap: wrap; gap: 12px; padding: 8px 10px; border-radius: 8px; font-size: .67rem; }
.legend > span { display: inline-flex; align-items: center; gap: 6px; }
.legend-line { width: 22px; height: 2px; background: #163f5c; }
.legend-line.past { background: #8faaba; }
.legend-swatch { width: 22px; height: 10px; border-radius: 3px; }
.legend-swatch.phase { background: linear-gradient(90deg,#254ac4 0%,#eef3f6 50%,#dc3545 100%); border: 1px solid rgba(25,49,69,.12); }
.legend-swatch.pressure { background: linear-gradient(90deg,rgba(249,115,22,.12),#f97316); }
.screen-reader-summary { position: absolute; width: 1px; height: 1px; overflow: hidden; clip: rect(0 0 0 0); }

.timing-panel { min-width: 0; padding: 16px 18px 18px; }
.timing-actions { display: flex; gap: 8px; }
.text-button { min-height: 38px; min-width: auto; padding: 0 12px; font-size: .76rem; }
.timing-body { display: grid; grid-template-columns: minmax(0, 1fr) 210px; gap: 18px; margin-top: 14px; }
.timing-chart-wrap { display: grid; grid-template-columns: 32px minmax(0,1fr); grid-template-rows: 178px 20px; min-width: 0; }
.time-axis { grid-row: 1; display: flex; flex-direction: column; justify-content: space-between; padding: 2px 6px 2px 0; color: var(--muted-2); text-align: right; font-size: .61rem; }
.timing-chart {
  position: relative; grid-column: 2; display: grid; grid-template-columns: repeat(50, minmax(4px, 1fr)); gap: 3px;
  height: 178px; padding: 7px 5px 6px;
  border: 1px solid var(--border);
  border-radius: 9px;
  background:
    linear-gradient(to bottom, transparent 32.7%, var(--border) 33%, transparent 33.3%, transparent 66%, var(--border) 66.3%, transparent 66.6%),
    #1c1a18;
}
.timing-column { position: relative; min-width: 4px; border: 0; padding: 0; background: transparent; border-radius: 4px; }
.timing-column::before { content: ""; position: absolute; top: 4px; left: 50%; width: 1px; height: var(--delay-y, 0%); background: rgba(249,115,22,.5); transform: translateX(-50%); }
.timing-column::after { content: ""; position: absolute; left: 50%; top: calc(4px + var(--delay-y, 0%)); width: max(5px, 80%); aspect-ratio: 1; transform: translate(-50%, -50%); border-radius: 50%; background: var(--orange-light); box-shadow: 0 0 0 2px rgba(249,115,22,.16); transition: box-shadow .15s ease, background-color .15s ease; }
.timing-column:hover::after, .timing-column:focus-visible::after { background: #fff7ed; box-shadow: 0 0 0 4px rgba(249,115,22,.3); }
.timing-column.selected { background: rgba(249,115,22,.10); }
.timing-column.disabled { opacity: .28; }
.timing-scale { grid-column: 2; display: flex; justify-content: space-between; padding-top: 5px; color: var(--muted-2); font: .61rem var(--mono); }
.element-inspector { padding: 12px 14px; background: #201e1c; border: 1px solid var(--border); border-radius: 10px; }
.inspector-top { margin-bottom: 14px; }
.inspector-top span { color: var(--muted); font-size: .72rem; }
.inspector-top strong { color: var(--orange-light); font-size: 1.05rem; }
.element-inspector > label:not(.switch-row) { display: block; margin-bottom: 8px; color: #e6e1dd; font-size: .75rem; }
.element-inspector > label span { float: right; color: var(--orange-light); }
.element-inspector > label span:first-child { float: none; color: inherit; }
.switch-row.compact { min-height: 56px; margin-top: 10px; }
.element-inspector p { margin-top: 10px; color: var(--muted-2); font-size: .67rem; line-height: 1.5; }

@media (max-width: 1100px) {
  .workspace { grid-template-columns: 280px minmax(0, 1fr); }
  .control-panel { padding: 15px; }
  .preset-card { grid-template-columns: 24px 1fr; padding: 11px 8px; }
  .preset-card svg { width: 24px; height: 24px; }
  .metrics { grid-template-columns: 1fr 1fr; }
  .metrics > div:nth-child(2) { border-right: 0; }
  .metrics > div:nth-child(-n+2) { border-bottom: 1px solid var(--border); }
}

@media (max-width: 820px) {
  .app-shell { padding: 0 12px 24px; }
  .workspace { grid-template-columns: 1fr; }
  .control-panel { grid-row: auto; }
  .preset-grid { grid-template-columns: repeat(4, 1fr); }
  .preset-card { min-height: 78px; grid-template-columns: 1fr; grid-template-rows: 27px auto; text-align: center; }
  .preset-card svg { grid-row: auto; margin: 0 auto; }
  .preset-card small { display: none; }
  .control-group { display: grid; grid-template-columns: 1fr 1fr; gap: 0 20px; }
  .visual-switches { display: grid; grid-template-columns: 1fr 1fr; gap: 18px; }
  .timing-body { grid-template-columns: 1fr; }
  .element-inspector { display: grid; grid-template-columns: 1fr 1fr; gap: 8px 20px; }
  .element-inspector p { grid-column: 1 / -1; }
  #fieldCanvas, .field-stage { height: 480px; min-height: 480px; }
}

@media (max-width: 560px) {
  .topbar { min-height: 68px; }
  .brand-lockup p, #fpsLabel, .topbar-status .divider { display: none; }
  .topbar-actions { gap: 10px; }
  .topbar-status { gap: 8px; }
  .language-button { min-width: 60px; padding: 0 10px; }
  .workspace { padding-top: 12px; gap: 12px; }
  .preset-grid { grid-template-columns: 1fr 1fr; }
  .control-group { grid-template-columns: 1fr; }
  .visual-switches { grid-template-columns: 1fr; gap: 0; }
  .simulation-toolbar { align-items: flex-start; flex-direction: column; }
  .transport { width: 100%; }
  .speed-control { margin-left: auto; }
  .metrics { font-size: .8rem; }
  .metrics > div { padding: 10px 12px; }
  #fieldCanvas, .field-stage { height: 420px; min-height: 420px; }
  .field-hint { max-width: 150px; }
  .legend { right: 14px; justify-content: center; }
  .timing-header { align-items: flex-start; flex-direction: column; }
  .timing-actions { width: 100%; }
  .timing-actions button { flex: 1; }
  .timing-chart { gap: 1px; }
  .timing-column::after { width: max(4px, 95%); }
  .element-inspector { grid-template-columns: 1fr; }
}

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { scroll-behavior: auto !important; transition-duration: .01ms !important; animation-duration: .01ms !important; animation-iteration-count: 1 !important; }
}