:root {
  --bg: #07111b;
  --surface: #0c1824;
  --surface-2: #101f2d;
  --surface-3: #132635;
  --line: #263b4a;
  --line-strong: #385469;
  --text: #edf4f7;
  --muted: #8da0ac;
  --faint: #607581;
  --cyan: #36d6e7;
  --blue: #3a8dde;
  --green: #63e7ab;
  --orange: #ffc15c;
  --red: #ff6374;
  --risk: #63e7ab;
  font-family: "IBM Plex Sans SC", "IBM Plex Sans", "PingFang SC", "Microsoft YaHei", sans-serif;
  color: var(--text);
  background: var(--bg);
}

* { box-sizing: border-box; }
html { min-width: 320px; background: var(--bg); }
body {
  margin: 0;
  min-height: 100vh;
  color: var(--text);
  background:
    linear-gradient(rgba(44, 75, 94, .055) 1px, transparent 1px),
    linear-gradient(90deg, rgba(44, 75, 94, .055) 1px, transparent 1px),
    var(--bg);
  background-size: 32px 32px;
}
button, select, input { font: inherit; }
button, select { outline: none; }
button:focus-visible, select:focus-visible, input:focus-visible, a:focus-visible {
  outline: 2px solid var(--cyan);
  outline-offset: 2px;
}

.app-header {
  height: 58px;
  padding: 0 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  border-bottom: 1px solid var(--line);
  background: rgba(7, 17, 27, .96);
  position: sticky;
  top: 0;
  z-index: 20;
  backdrop-filter: blur(12px);
}
.brand { display: flex; align-items: center; gap: 11px; color: inherit; text-decoration: none; }
.brand-mark {
  display: grid;
  place-items: center;
  width: 32px;
  height: 32px;
  border: 1px solid #4784a1;
  color: #d9f9ff;
  background: #123247;
  font-size: 12px;
  font-weight: 700;
  letter-spacing: .08em;
}
.brand-copy strong, .brand-copy small { display: block; }
.brand-copy strong { font-size: 12px; font-weight: 600; letter-spacing: .03em; }
.brand-copy small { margin-top: 2px; color: var(--faint); font-size: 8px; letter-spacing: .17em; }
.header-context { display: flex; align-items: center; gap: 18px; }
.standard-tag {
  padding: 5px 9px;
  border: 1px solid var(--line);
  color: #91a8b5;
  background: #0b1722;
  font-size: 9px;
  letter-spacing: .08em;
}
.back { color: #a9bac3; font-size: 11px; text-decoration: none; }
.back:hover { color: var(--cyan); }

.workspace { width: min(1540px, calc(100% - 32px)); margin: 0 auto; }
.workspace-title {
  min-height: 86px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  padding: 14px 2px;
}
.eyebrow { margin: 0 0 5px; color: var(--cyan); font-size: 9px; font-weight: 600; letter-spacing: .18em; }
.workspace-title h1 { margin: 0; font-size: 24px; line-height: 1.15; font-weight: 600; letter-spacing: -.025em; }
.model-identity { text-align: right; }
.model-identity span, .model-identity small { display: block; color: var(--muted); font-size: 9px; }
.model-identity strong { display: block; margin: 3px 0 1px; color: #dce8ed; font-size: 13px; font-weight: 600; }

.workbench {
  display: grid;
  grid-template-columns: 286px minmax(420px, 1fr) 330px;
  gap: 12px;
  align-items: stretch;
}
.panel {
  border: 1px solid var(--line);
  background: linear-gradient(155deg, rgba(16, 31, 45, .98), rgba(10, 22, 33, .98));
  box-shadow: 0 14px 32px rgba(0, 0, 0, .18);
}
.input-panel, .result-panel { padding: 16px; }
.panel-heading {
  min-height: 37px;
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 12px;
  padding-bottom: 12px;
  border-bottom: 1px solid var(--line);
}
.panel-heading > div { display: flex; align-items: center; gap: 9px; }
.panel-heading h2 { margin: 0; font-size: 14px; font-weight: 600; }
.panel-heading > small { color: var(--faint); font-size: 8px; letter-spacing: .14em; }
.step-no { color: var(--cyan); font-family: "IBM Plex Sans", sans-serif; font-size: 10px; font-weight: 700; }

.parameter-group { padding: 15px 0 16px; border-bottom: 1px solid var(--line); }
.parameter-group h3 {
  margin: 0 0 12px;
  color: #c7d5db;
  font-size: 10px;
  font-weight: 600;
  letter-spacing: .08em;
}
.field-label { display: block; margin-bottom: 7px; color: var(--muted); font-size: 10px; }
.choices { display: grid; grid-template-columns: 1fr 1fr; gap: 6px; }
.choice, .reset {
  min-height: 34px;
  border: 1px solid var(--line-strong);
  border-radius: 2px;
  color: #aebec6;
  background: #0b1925;
  font-size: 10px;
  cursor: pointer;
  transition: border-color .16s, color .16s, background .16s;
}
.choice:hover { border-color: #54809a; color: #e2f0f4; }
.choice.active {
  border-color: var(--cyan);
  color: #e9fdff;
  background: linear-gradient(180deg, #153848, #102c3b);
  box-shadow: inset 3px 0 0 var(--cyan);
}
.range-field { display: block; margin-top: 14px; }
.range-field > span:first-child { display: flex; justify-content: space-between; color: var(--muted); font-size: 10px; }
.range-field output { color: var(--cyan); font-weight: 600; }
input[type="range"] {
  width: 100%;
  height: 16px;
  margin: 8px 0 0;
  accent-color: var(--cyan);
  cursor: pointer;
}
.range-scale { display: flex; justify-content: space-between; color: var(--faint); font-size: 8px; }
.range-scale i { font-style: normal; }
.field-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 10px 8px; }
.field-grid label { color: var(--muted); font-size: 9px; }
.field-grid .full-field { grid-column: 1 / -1; }
.field-grid select {
  width: 100%;
  height: 34px;
  margin-top: 6px;
  padding: 0 26px 0 9px;
  border: 1px solid var(--line-strong);
  border-radius: 2px;
  color: #dbe7ec;
  background: #0a1823;
  font-size: 10px;
}
.reset { width: 100%; margin-top: 16px; color: #d6e6ec; background: #183245; }
.reset:hover { border-color: var(--cyan); color: white; }
.disclaimer { margin: 11px 1px 0; color: var(--faint); font-size: 8px; line-height: 1.55; }

.visual-panel { min-width: 0; display: flex; flex-direction: column; padding: 16px; }
.visual-heading { flex: 0 0 auto; }
.live-indicator { color: #91a8b4; font-size: 9px; }
.live-indicator i {
  display: inline-block;
  width: 6px;
  height: 6px;
  margin-right: 6px;
  border-radius: 50%;
  background: var(--green);
  box-shadow: 0 0 9px var(--green);
}
.visual-canvas {
  min-height: 520px;
  flex: 1 1 auto;
  position: relative;
  overflow: hidden;
  margin-top: 12px;
  border: 1px solid #203847;
  background: #071523;
}
#joint3d { display: block; width: 100%; height: 100%; min-height: 520px; }
.visual-legend {
  position: absolute;
  top: 12px;
  left: 12px;
  display: flex;
  flex-wrap: wrap;
  gap: 8px 13px;
  max-width: calc(100% - 24px);
  padding: 7px 9px;
  border: 1px solid rgba(64, 95, 113, .8);
  background: rgba(6, 18, 29, .87);
  backdrop-filter: blur(8px);
}
.visual-legend span { color: #a2b4be; font-size: 8px; }
.visual-legend i { display: inline-block; width: 13px; height: 2px; margin-right: 5px; vertical-align: middle; }
.legend-preload { background: var(--cyan); }
.legend-load { background: var(--orange); }
.legend-clamp { background: var(--green); }
.view-caption {
  position: absolute;
  left: 12px;
  bottom: 12px;
  padding: 7px 9px;
  color: #8299a6;
  background: rgba(6, 18, 29, .88);
  border-left: 2px solid var(--cyan);
  font-size: 8px;
}
.view-caption span { margin-right: 8px; color: #d5e8ee; font-weight: 600; }
.visual-note { display: flex; gap: 13px; padding: 12px 2px 0; }
.visual-note b { flex: 0 0 auto; color: #c8d7dd; font-size: 9px; }
.visual-note p { margin: 0; color: var(--faint); font-size: 9px; line-height: 1.55; }

.result-panel { min-width: 0; }
.status-card {
  margin-top: 14px;
  padding: 15px;
  border: 1px solid color-mix(in srgb, var(--risk) 62%, var(--line));
  border-left: 3px solid var(--risk);
  background: linear-gradient(100deg, color-mix(in srgb, var(--risk) 11%, #0d1b27), #0b1823);
}
.status-kicker { color: #94a8b3; font-size: 9px; }
.status-card strong { display: block; margin: 6px 0 5px; color: var(--risk); font-size: 20px; font-weight: 600; }
.status-card p { margin: 0; color: #8fa3ae; font-size: 9px; line-height: 1.45; }
.kpi-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 7px; margin-top: 8px; }
.kpi-card { min-width: 0; padding: 12px; border: 1px solid var(--line); background: #0a1722; }
.kpi-card.wide { grid-column: 1 / -1; }
.kpi-card > span { color: #8296a2; font-size: 8px; }
.kpi-card p { margin: 6px 0 3px; white-space: nowrap; }
.kpi-card strong { font-family: "IBM Plex Sans", sans-serif; font-size: 24px; font-weight: 600; letter-spacing: -.04em; }
.kpi-card small { margin-left: 4px; color: var(--faint); font-size: 9px; }
.kpi-card em { display: block; overflow: hidden; color: var(--faint); font-size: 8px; font-style: normal; text-overflow: ellipsis; white-space: nowrap; }
.verification { margin-top: 15px; padding-top: 14px; border-top: 1px solid var(--line); }
.verification-head > div { display: flex; align-items: center; justify-content: space-between; gap: 10px; }
.verification-head > div > span { color: #d4e0e5; font-size: 11px; font-weight: 600; }
.check-status {
  padding: 3px 7px;
  border: 1px solid var(--risk);
  border-radius: 99px;
  color: var(--risk);
  font-size: 8px;
  font-weight: 500;
}
.verification-head p { margin: 7px 0 0; color: var(--faint); font-size: 8px; line-height: 1.4; }
.check-list { display: grid; gap: 9px; margin: 13px 0; }
.check-row { display: grid; grid-template-columns: 62px 1fr 34px; align-items: center; gap: 7px; font-size: 9px; }
.check-row span { color: #9bafb9; }
.check-bar { height: 5px; overflow: hidden; border-radius: 20px; background: #182b38; }
.check-bar i { display: block; height: 100%; border-radius: inherit; background: var(--bar); }
.check-row b { color: var(--bar); font-size: 8px; font-weight: 600; text-align: right; }
.recommendation { padding: 10px; border-left: 2px solid var(--risk); background: #0a1722; }
.recommendation b { color: #c8d8de; font-size: 9px; }
.recommendation p { margin: 4px 0 0; color: #7f939e; font-size: 8px; line-height: 1.45; }

.scenario-lab {
  display: grid;
  grid-template-columns: 310px minmax(0, 1fr);
  gap: 20px;
  margin-top: 12px;
  padding: 20px;
  overflow: hidden;
}
.scenario-copy { padding: 5px 0; }
.scenario-copy h2 { margin: 0; font-size: 19px; font-weight: 600; }
.scenario-copy > p:last-of-type { margin: 10px 0 17px; color: var(--muted); font-size: 9px; line-height: 1.65; }
.scenario-selector { display: grid; gap: 7px; }
.scenario-selector input { position: absolute; opacity: 0; pointer-events: none; }
.scenario-selector label {
  display: grid;
  grid-template-columns: 26px 1fr auto;
  align-items: center;
  gap: 9px;
  min-height: 55px;
  padding: 9px 10px;
  border: 1px solid var(--line);
  color: #8499a4;
  background: #091620;
  cursor: pointer;
  transition: .18s ease;
}
.scenario-selector label:hover { border-color: #45677a; transform: translateX(2px); }
.scenario-selector label > i { color: var(--faint); font-size: 9px; font-style: normal; }
.scenario-selector label span, .scenario-selector label strong, .scenario-selector label small { display: block; }
.scenario-selector label strong { color: #c9d7dd; font-size: 10px; font-weight: 600; }
.scenario-selector label small { margin-top: 3px; color: var(--faint); font-size: 8px; }
.scenario-selector label > b { padding: 3px 6px; border: 1px solid currentColor; border-radius: 99px; font-size: 7px; font-weight: 500; }
#scenarioStandard:checked + label { border-color: var(--green); box-shadow: inset 3px 0 0 var(--green); }
#scenarioStandard:checked + label > b { color: var(--green); }
#scenarioOverload:checked + label { border-color: var(--red); box-shadow: inset 3px 0 0 var(--red); }
#scenarioOverload:checked + label > b { color: var(--red); }
#scenarioFatigue:checked + label { border-color: var(--orange); box-shadow: inset 3px 0 0 var(--orange); }
#scenarioFatigue:checked + label > b { color: var(--orange); }
.scenario-selector input:focus-visible + label { outline: 2px solid var(--cyan); outline-offset: 2px; }

.scenario-stage {
  min-width: 0;
  min-height: 390px;
  position: relative;
  overflow: hidden;
  border: 1px solid #284453;
  background: radial-gradient(circle at 50% 48%, #15364a 0, #091a27 48%, #06111a 100%);
}
.stage-grid {
  position: absolute;
  inset: 0;
  opacity: .55;
  background-image: linear-gradient(rgba(73, 117, 139, .12) 1px, transparent 1px), linear-gradient(90deg, rgba(73, 117, 139, .12) 1px, transparent 1px);
  background-size: 24px 24px;
  mask-image: linear-gradient(to bottom, black, transparent 90%);
}
.scenario-readout {
  position: absolute;
  z-index: 2;
  top: 12px;
  right: 12px;
  left: 12px;
  display: flex;
  align-items: center;
  gap: 18px;
  padding: 8px 10px;
  border: 1px solid rgba(69, 104, 121, .72);
  background: rgba(5, 16, 25, .82);
  backdrop-filter: blur(8px);
}
.scenario-readout span { color: #8299a5; font-size: 8px; }
.scenario-readout b { color: #d7e7ec; font-weight: 600; }
.readout-mode { margin-right: auto; }
.readout-mode i { display: inline-block; width: 6px; height: 6px; margin-right: 6px; border-radius: 50%; background: var(--green); box-shadow: 0 0 8px var(--green); }
.scenario-svg { display: block; width: 100%; height: 330px; margin-top: 29px; }
.machine-frame { fill: none; stroke: #456273; stroke-width: 1; stroke-dasharray: 4 5; opacity: .5; }
.plate { fill: url(#plateMetal); stroke: #7996a4; stroke-width: 1; }
.contact-line { stroke: var(--green); stroke-width: 7; opacity: .9; filter: url(#scenarioGlow); }
.bolt-body { fill: url(#boltMetal); stroke: #c3f2f7; stroke-width: 1.2; }
.threads { fill: none; stroke: #0a5172; stroke-width: 2; }
.load-arrows { fill: none; stroke: var(--orange); stroke-width: 4; stroke-linecap: round; stroke-linejoin: round; }
.clamp-arrows { fill: none; stroke: var(--green); stroke-width: 3; stroke-linecap: round; stroke-linejoin: round; }
.fatigue-pulse { fill: none; stroke: var(--orange); stroke-width: 2; opacity: 0; transform-box: fill-box; transform-origin: center; }
.force-wave { fill: none; stroke: var(--orange); stroke-width: 3; opacity: 0; }
.scenario-svg text { fill: #9fb4be; font-size: 10px; font-family: inherit; }
.scenario-svg .risk-label { fill: var(--orange); opacity: 0; }
.scenario-metrics {
  position: absolute;
  right: 12px;
  bottom: 12px;
  left: 12px;
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1px;
  background: #263e4c;
}
.scenario-metrics div { padding: 9px 11px; background: rgba(6, 18, 27, .93); }
.scenario-metrics span, .scenario-metrics strong { display: block; }
.scenario-metrics span { color: var(--faint); font-size: 7px; }
.scenario-metrics strong { margin-top: 3px; color: #c8d8de; font-size: 9px; font-weight: 500; }

.scenario-lab:has(#scenarioOverload:checked) .readout-mode b { font-size: 0; }
.scenario-lab:has(#scenarioOverload:checked) .readout-mode b::after { content: "突发过载"; font-size: 8px; }
.scenario-lab:has(#scenarioOverload:checked) .readout-mode i { background: var(--red); box-shadow: 0 0 10px var(--red); }
.scenario-lab:has(#scenarioOverload:checked) .readout-load b { font-size: 0; }
.scenario-lab:has(#scenarioOverload:checked) .readout-load b::after { content: "18.0 kN"; font-size: 8px; }
.scenario-lab:has(#scenarioOverload:checked) .readout-risk b { font-size: 0; }
.scenario-lab:has(#scenarioOverload:checked) .readout-risk b::after { content: "112%"; color: var(--red); font-size: 8px; }
.scenario-lab:has(#scenarioOverload:checked) .contact-line { stroke: var(--red); stroke-width: 3; stroke-dasharray: 18 10; }
.scenario-lab:has(#scenarioOverload:checked) .axial-arrows { stroke: var(--red); stroke-width: 8; animation: overload-pulse .85s ease-in-out infinite alternate; }
.scenario-lab:has(#scenarioOverload:checked) .clamp-arrows { stroke: var(--red); opacity: .35; }
.scenario-lab:has(#scenarioOverload:checked) .metric-contact { font-size: 0; }
.scenario-lab:has(#scenarioOverload:checked) .metric-contact::after { content: "局部分离"; color: var(--red); font-size: 9px; }
.scenario-lab:has(#scenarioOverload:checked) .metric-character { font-size: 0; }
.scenario-lab:has(#scenarioOverload:checked) .metric-character::after { content: "峰值冲击"; font-size: 9px; }
.scenario-lab:has(#scenarioOverload:checked) .metric-risk { font-size: 0; }
.scenario-lab:has(#scenarioOverload:checked) .metric-risk::after { content: "分离 / 屈服"; color: var(--red); font-size: 9px; }

.scenario-lab:has(#scenarioFatigue:checked) .readout-mode b { font-size: 0; }
.scenario-lab:has(#scenarioFatigue:checked) .readout-mode b::after { content: "循环疲劳"; font-size: 8px; }
.scenario-lab:has(#scenarioFatigue:checked) .readout-mode i { background: var(--orange); box-shadow: 0 0 10px var(--orange); }
.scenario-lab:has(#scenarioFatigue:checked) .readout-load b { font-size: 0; }
.scenario-lab:has(#scenarioFatigue:checked) .readout-load b::after { content: "5–15 kN"; font-size: 8px; }
.scenario-lab:has(#scenarioFatigue:checked) .readout-risk b { font-size: 0; }
.scenario-lab:has(#scenarioFatigue:checked) .readout-risk b::after { content: "86%"; color: var(--orange); font-size: 8px; }
.scenario-lab:has(#scenarioFatigue:checked) .joint-assembly { animation: micro-vibration .12s linear infinite alternate; }
.scenario-lab:has(#scenarioFatigue:checked) .axial-arrows { stroke: var(--orange); animation: cyclic-load 1.2s ease-in-out infinite; }
.scenario-lab:has(#scenarioFatigue:checked) .force-wave { opacity: 1; stroke-dasharray: 12 6; animation: wave-travel .7s linear infinite; }
.scenario-lab:has(#scenarioFatigue:checked) .fatigue-pulse { opacity: 1; animation: fatigue-ring 1.3s ease-out infinite; }
.scenario-lab:has(#scenarioFatigue:checked) .risk-label { opacity: 1; }
.scenario-lab:has(#scenarioFatigue:checked) .metric-contact { font-size: 0; }
.scenario-lab:has(#scenarioFatigue:checked) .metric-contact::after { content: "周期性波动"; color: var(--orange); font-size: 9px; }
.scenario-lab:has(#scenarioFatigue:checked) .metric-character { font-size: 0; }
.scenario-lab:has(#scenarioFatigue:checked) .metric-character::after { content: "交变循环"; font-size: 9px; }
.scenario-lab:has(#scenarioFatigue:checked) .metric-risk { font-size: 0; }
.scenario-lab:has(#scenarioFatigue:checked) .metric-risk::after { content: "螺纹根部疲劳"; color: var(--orange); font-size: 9px; }

@keyframes overload-pulse { to { transform: scaleY(1.1); transform-origin: center; } }
@keyframes cyclic-load { 0%, 100% { stroke-width: 3; opacity: .55; } 50% { stroke-width: 8; opacity: 1; } }
@keyframes micro-vibration { to { transform: translateX(1.5px); } }
@keyframes wave-travel { to { stroke-dashoffset: -18; } }
@keyframes fatigue-ring { 0% { transform: scale(.45); opacity: 1; } 100% { transform: scale(1.7); opacity: 0; } }

.bottom-deck { display: grid; grid-template-columns: minmax(0, 1.45fr) minmax(330px, .65fr); gap: 12px; margin-top: 12px; }
.diagram-card, .data-card { min-width: 0; padding: 18px; }
.section-heading { display: flex; align-items: flex-start; justify-content: space-between; gap: 18px; }
.section-heading h2 { margin: 0; font-size: 16px; font-weight: 600; }
.state-tabs { display: flex; padding: 2px; border: 1px solid var(--line-strong); background: #0a1721; }
.chart-tab { padding: 6px 9px; border: 0; color: #788f9c; background: transparent; font-size: 9px; cursor: pointer; }
.chart-tab.active { color: #e5f8fb; background: #19506a; }
.chart-help, .data-intro { margin: 10px 0 2px; color: var(--faint); font-size: 9px; line-height: 1.5; }
#jointChart { display: block; width: 100%; max-height: 330px; margin-top: 3px; }
.chart-callouts { display: flex; flex-wrap: wrap; gap: 10px 20px; color: #8297a2; font-size: 8px; }
.chart-callouts i { display: inline-block; width: 16px; height: 2px; margin-right: 5px; vertical-align: middle; }
.bolt-key { background: var(--cyan); }
.part-key { background: #ffbe62; }
.load-key { background: #ff6d91; }
.data-unit { color: var(--faint); font-size: 8px; }
.load-flow { margin: 24px 0; }
.flow-source, .flow-outputs > div { padding: 13px; border: 1px solid var(--line-strong); background: #0a1722; }
.flow-source { border-left: 3px solid var(--orange); }
.load-flow span { display: block; color: #8499a4; font-size: 9px; }
.load-flow strong { display: block; margin-top: 4px; font-family: "IBM Plex Sans", sans-serif; font-size: 20px; font-weight: 600; }
.flow-connector { height: 35px; position: relative; display: grid; place-items: center; }
.flow-connector i { width: 1px; height: 100%; background: var(--line-strong); }
.flow-connector span { position: absolute; padding: 2px 7px; background: #0d1b28; font-size: 8px; }
.flow-outputs { display: grid; grid-template-columns: 1fr 1fr; gap: 7px; }
.flow-outputs .bolt-flow { border-top: 2px solid var(--cyan); }
.flow-outputs .clamp-flow { border-top: 2px solid var(--green); }
.formula-notes { margin: 0; border-top: 1px solid var(--line); }
.formula-notes div { display: flex; justify-content: space-between; gap: 14px; padding: 10px 0; border-bottom: 1px solid var(--line); }
.formula-notes dt, .formula-notes dd { margin: 0; font-size: 8px; }
.formula-notes dt { color: var(--faint); }
.formula-notes dd { color: #a7bac3; text-align: right; }

footer {
  width: min(1540px, calc(100% - 32px));
  margin: 18px auto 0;
  padding: 17px 2px 24px;
  border-top: 1px solid var(--line);
  color: var(--faint);
  font-size: 8px;
  letter-spacing: .05em;
}

@media (max-width: 1180px) {
  .workbench { grid-template-columns: 270px minmax(390px, 1fr); }
  .result-panel { grid-column: 1 / -1; display: grid; grid-template-columns: 1fr 1fr 1.2fr; gap: 12px; }
  .result-panel > .panel-heading { grid-column: 1 / -1; }
  .status-card, .kpi-grid, .verification { margin-top: 0; }
  .verification { padding: 0 0 0 14px; border-top: 0; border-left: 1px solid var(--line); }
}

@media (max-width: 860px) {
  .workspace { width: min(100% - 20px, 680px); }
  .workspace-title { min-height: 94px; }
  .workbench { grid-template-columns: 1fr; }
  .input-panel { display: grid; grid-template-columns: 1fr 1fr; gap: 0 14px; }
  .input-panel > .panel-heading, .input-panel > .reset, .input-panel > .disclaimer { grid-column: 1 / -1; }
  .engineering-parameters { grid-column: 1 / -1; }
  .result-panel { grid-column: auto; grid-template-columns: 1fr 1fr; }
  .verification { grid-column: 1 / -1; padding: 14px 0 0; border-top: 1px solid var(--line); border-left: 0; }
  .bottom-deck { grid-template-columns: 1fr; }
  .scenario-lab { grid-template-columns: 1fr; }
  .scenario-selector { grid-template-columns: repeat(3, 1fr); }
  .scenario-selector label { grid-template-columns: 20px 1fr; }
  .scenario-selector label > b { display: none; }
  .visual-canvas, #joint3d { min-height: 460px; }
}

@media (max-width: 560px) {
  .app-header { height: 54px; padding: 0 12px; }
  .brand-copy strong { font-size: 11px; }
  .standard-tag { display: none; }
  .workspace { width: calc(100% - 16px); }
  .workspace-title { align-items: flex-start; flex-direction: column; gap: 9px; padding: 15px 2px; }
  .workspace-title h1 { font-size: 20px; }
  .model-identity { text-align: left; }
  .input-panel { display: block; }
  .result-panel { display: block; }
  .result-panel > * + * { margin-top: 10px; }
  .verification { padding-top: 14px; }
  .visual-canvas, #joint3d { min-height: 400px; }
  .visual-legend { right: 9px; left: 9px; }
  .section-heading { align-items: stretch; flex-direction: column; gap: 12px; }
  .state-tabs { align-self: flex-start; }
  .flow-outputs { grid-template-columns: 1fr; }
  .scenario-lab { padding: 13px; }
  .scenario-selector { grid-template-columns: 1fr; }
  .scenario-selector label { grid-template-columns: 26px 1fr auto; }
  .scenario-selector label > b { display: block; }
  .scenario-stage { min-height: 360px; }
  .scenario-svg { width: 142%; margin-left: -21%; }
  .scenario-readout { gap: 9px; }
  .readout-risk { display: none; }
  .scenario-metrics div { padding: 8px 6px; }
  .diagram-card, .data-card, .input-panel, .result-panel, .visual-panel { padding: 13px; }
}

@media (prefers-reduced-motion: reduce) {
  .scenario-lab *, .scenario-lab *::before, .scenario-lab *::after { animation: none !important; transition: none !important; }
}
.failure-open{margin:16px 0 3px;width:100%;border:1px solid #517b91;background:#123349;color:#dff8ff;padding:11px 12px;border-radius:7px;font-weight:700;cursor:pointer}.failure-modal{width:min(640px,calc(100% - 30px));border:1px solid #416d84;border-radius:16px;background:#0b1824;color:#e8f7fb;padding:28px;box-shadow:0 24px 80px #000b}.failure-modal::backdrop{background:#020810cc;backdrop-filter:blur(5px)}.failure-modal h2{margin:5px 0 18px}.modal-close{position:absolute;right:14px;top:12px;border:0;background:transparent;color:#b9d7e2;font-size:28px;cursor:pointer}.failure-scene{height:230px;position:relative;overflow:hidden;border:1px solid #31546a;background:radial-gradient(circle at 50% 50%,#173b50,#09141e);margin:14px 0}.failure-plate{position:absolute;left:15%;width:70%;height:45px;background:linear-gradient(90deg,#29495d,#7798a8,#29495d);border:1px solid #a5d3e1}.failure-plate.top{top:48px}.failure-plate.bottom{bottom:48px}.failure-bolt{position:absolute;left:calc(50% - 16px);top:28px;width:32px;height:174px;background:linear-gradient(90deg,#176e9c,#c7fbff,#176e9c)}.failure-bolt i{position:absolute;left:-28px;width:88px;height:20px;background:#56b9d2;clip-path:polygon(18% 0,82% 0,100% 50%,82% 100%,18% 100%,0 50%)}.failure-bolt i:first-child{top:0}.failure-bolt i:last-child{bottom:0}.fracture-line{position:absolute;left:calc(50% - 22px);top:112px;width:44px;border-top:5px dashed #ff6174;transform:rotate(-20deg);box-shadow:0 0 17px #ff6174;animation:fracture 1.2s infinite alternate}.failure-arrow{position:absolute;right:35px;top:108px;color:#ffbd62;font-weight:700}.failure-tabs{display:flex;gap:8px}.failure-tabs button{flex:1;padding:8px;border:1px solid #365d72;background:#102436;color:#9fc1cf}.failure-tabs .active{border-color:#ff6174;color:#ffd8de}@keyframes fracture{to{transform:rotate(-20deg) scaleX(1.25);filter:brightness(1.5)}}
/* The technical clamping chart is intentionally hidden in the visitor-facing demo; the load-distribution card is the plain-language alternative. */
.bottom-deck{grid-template-columns:1fr}.data-card{max-width:none}
.failure-scene{isolation:isolate}.failure-grid{position:absolute;inset:0;background:linear-gradient(#73d4ef15 1px,transparent 1px),linear-gradient(90deg,#73d4ef15 1px,transparent 1px);background-size:22px 22px;mask-image:radial-gradient(circle,#000,transparent 74%)}.failure-halo{position:absolute;inset:18%;border-radius:50%;background:#ff4f6970;filter:blur(28px);animation:halo 1.4s ease-in-out infinite alternate;z-index:-1}.failure-badge{position:absolute;left:12px;top:12px;border-left:2px solid #ff6a7c;padding-left:8px;font-size:8px;letter-spacing:.08em;color:#ffe2e7}.failure-badge span{display:block;color:#aabec8;margin-top:4px;letter-spacing:0}.fracture-shards i{position:absolute;width:9px;height:5px;background:#ff8a96;opacity:0;left:50%;top:52%;clip-path:polygon(0 0,100% 42%,26% 100%)}.failure-scene[data-mode=fracture] .fracture-shards i{animation:shard 1.1s infinite ease-out}.fracture-shards i:nth-child(2){animation-delay:.24s}.fracture-shards i:nth-child(3){animation-delay:.46s}.fracture-shards i:nth-child(4){animation-delay:.72s}.failure-copy{border-left:3px solid #ff6174;margin:14px 0 9px;padding:7px 10px;background:#121f2d}.failure-copy strong{display:block;font-size:13px}.failure-copy span{display:block;margin-top:4px;color:#9db4c1;font-size:11px;line-height:1.5}.failure-scene[data-mode=separation] .fracture-line,.failure-scene[data-mode=slip] .fracture-line{opacity:0}.failure-scene[data-mode=separation] .failure-plate.top{animation:separateTop 1.1s infinite alternate}.failure-scene[data-mode=separation] .failure-plate.bottom{animation:separateBottom 1.1s infinite alternate}.failure-scene[data-mode=separation] .failure-arrow{color:#ffc05f}.failure-scene[data-mode=separation] .failure-arrow{font-size:0}.failure-scene[data-mode=separation] .failure-arrow:after{content:'↕ 连接面分离';font-size:13px}.failure-scene[data-mode=slip] .failure-plate.top{animation:slipTop .8s infinite alternate}.failure-scene[data-mode=slip] .failure-plate.bottom{animation:slipBottom .8s infinite alternate}.failure-scene[data-mode=slip] .failure-arrow{font-size:0;color:#57dff2}.failure-scene[data-mode=slip] .failure-arrow:after{content:'↔ 接触面滑移';font-size:13px}.failure-scene[data-mode=slip] .failure-halo{background:#35c9e77a}.failure-scene[data-mode=separation] .failure-halo{background:#ffc05f68}@keyframes halo{to{transform:scale(1.18);opacity:.48}}@keyframes shard{to{transform:translate(var(--x,34px),var(--y,-45px)) rotate(170deg);opacity:0}.1%{opacity:1}}@keyframes separateTop{to{transform:translateY(-15px)}}@keyframes separateBottom{to{transform:translateY(15px)}}@keyframes slipTop{to{transform:translateX(20px)}}@keyframes slipBottom{to{transform:translateX(-20px)}}
.failure-video{position:absolute;inset:0;width:100%;height:100%;object-fit:cover;opacity:.62;mix-blend-mode:screen;filter:contrast(1.13) saturate(.85);z-index:-2}.failure-scene:after{content:"";position:absolute;inset:0;background:linear-gradient(90deg,#071320aa,transparent 50%,#07132080);pointer-events:none;z-index:-1}.failure-scene[data-mode=separation] .failure-video{filter:sepia(.35) saturate(1.3) contrast(1.16)}.failure-scene[data-mode=slip] .failure-video{filter:hue-rotate(35deg) contrast(1.16)}
/* Video mode: do not stack the older CSS failure animation over the footage. */
.failure-scene:has(.failure-video) .failure-grid,.failure-scene:has(.failure-video) .failure-halo,.failure-scene:has(.failure-video) .failure-plate,.failure-scene:has(.failure-video) .failure-bolt,.failure-scene:has(.failure-video) .fracture-line,.failure-scene:has(.failure-video) .fracture-shards,.failure-scene:has(.failure-video) .failure-arrow{display:none}.failure-scene:has(.failure-video){height:auto;aspect-ratio:16/9;background:#05090e}.failure-video{position:absolute;inset:0;opacity:1;mix-blend-mode:normal;filter:contrast(1.04) saturate(.95);z-index:0}.failure-scene:after{background:linear-gradient(180deg,transparent 55%,#07132099)}.failure-badge{z-index:2;background:#061522b8;border-radius:3px;padding:5px 7px}
/* Product-video pairing: the modal title and short film follow the model category. */
.failure-modal .failure-copy:before{content:'PRODUCT SCENARIO';display:block;color:#65dff2;font-size:9px;letter-spacing:.13em;margin-bottom:5px}
/* Visible scenario film: a user-controlled video, not a hidden modal-only asset. */
.scenario-film{margin-top:16px;border:1px solid #3b697d;border-radius:10px;overflow:hidden;background:#050c12;box-shadow:0 14px 32px #0006}.scenario-film video{display:block;width:100%;aspect-ratio:16/9;max-height:360px;object-fit:cover;background:#050c12}