:root {
  --ink: #eaf5f2;
  --muted: #91aaa8;
  --bg: #0b1619;
  --panel: #112327;
  --panel-deep: #0c1b1f;
  --line: #294247;
  --line-soft: #203c42;
  --cyan: #65e6d1;
  --orange: #ffad68;
  --red: #ff786d;
  --yellow: #f1d36a;
  --blue: #78aef7;
  --shadow: 0 22px 70px rgba(0, 0, 0, .26);
}

* { box-sizing: border-box; }

html { color-scheme: dark; }

body {
  margin: 0;
  min-height: 100vh;
  color: var(--ink);
  background: var(--bg);
  font-family: Manrope, "Microsoft YaHei", sans-serif;
}

body::before {
  content: "";
  position: fixed;
  inset: 0;
  pointer-events: none;
  opacity: .15;
  background-image:
    linear-gradient(rgba(101, 230, 209, .08) 1px, transparent 1px),
    linear-gradient(90deg, rgba(101, 230, 209, .08) 1px, transparent 1px);
  background-size: 42px 42px;
  mask-image: linear-gradient(to bottom, black, transparent 82%);
}

a { color: inherit; }
button, input { font: inherit; }

.shell {
  position: relative;
  width: min(1180px, calc(100% - 40px));
  margin: 0 auto;
  padding: 30px 0 54px;
}

.site-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 20px;
  min-height: 42px;
  margin-bottom: 44px;
}

.brand, .brand-link {
  display: flex;
  align-items: center;
  gap: 12px;
  min-width: 0;
  font-weight: 800;
  letter-spacing: 0;
  text-decoration: none;
}

.brand-link:hover .brand-name { color: var(--cyan); }
.brand-name { transition: color .2s; }

.mark {
  display: grid;
  flex: 0 0 34px;
  width: 34px;
  height: 34px;
  place-items: center;
  border: 1px solid var(--cyan);
  color: var(--cyan);
  font: 14px "DM Mono", monospace;
  box-shadow: 0 0 22px rgba(101, 230, 209, .18);
}

.header-side {
  display: flex;
  align-items: center;
  gap: 18px;
}

.status, .back-link {
  color: var(--muted);
  font: 12px "DM Mono", monospace;
  letter-spacing: .06em;
  text-transform: uppercase;
}

.back-link {
  padding: 8px 0;
  text-decoration: none;
  transition: color .2s;
}
.back-link:hover { color: var(--cyan); }

.hero {
  display: grid;
  grid-template-columns: 1.03fr .97fr;
  gap: 64px;
  align-items: end;
  margin-bottom: 34px;
}

.kicker {
  margin: 0 0 18px;
  color: var(--orange);
  font: 500 12px "DM Mono", monospace;
  letter-spacing: .12em;
  text-transform: uppercase;
}

h1 {
  max-width: 720px;
  margin: 0;
  font-size: clamp(42px, 6vw, 82px);
  line-height: .95;
  letter-spacing: 0;
}

h1 em { color: var(--ink); font-style: italic; }

.intro {
  max-width: 560px;
  margin: 24px 0 0;
  color: var(--muted);
  font-size: 15px;
  line-height: 1.8;
}

.hero-note {
  justify-self: end;
  max-width: 370px;
  padding: 10px 0 10px 20px;
  border-left: 2px solid var(--orange);
  color: #c9d8d5;
  font-size: 13px;
  line-height: 1.8;
}

.workspace {
  display: grid;
  grid-template-columns: 300px minmax(0, 1fr);
  border: 1px solid var(--line);
  background: rgba(17, 35, 39, .88);
  box-shadow: var(--shadow);
}

.controls {
  padding: 26px 24px 24px;
  border-right: 1px solid var(--line);
}

.section-label {
  margin: 0 0 24px;
  color: var(--muted);
  font: 500 11px "DM Mono", monospace;
  letter-spacing: .12em;
  text-transform: uppercase;
}

.control { margin-bottom: 27px; }
.control-head {
  display: flex;
  justify-content: space-between;
  gap: 15px;
  margin-bottom: 11px;
  font-size: 13px;
}
.control-head output {
  flex: 0 0 auto;
  color: var(--cyan);
  font: 500 13px "DM Mono", monospace;
}

input[type="range"] {
  width: 100%;
  height: 3px;
  appearance: none;
  border-radius: 0;
  outline: none;
  background: linear-gradient(90deg, var(--cyan) var(--fill), #365158 var(--fill));
}
input[type="range"]::-webkit-slider-thumb {
  width: 17px;
  height: 17px;
  appearance: none;
  border: 2px solid var(--cyan);
  border-radius: 50%;
  background: var(--bg);
  box-shadow: 0 0 0 5px rgba(101, 230, 209, .1);
  cursor: pointer;
}
input[type="range"]::-moz-range-thumb {
  width: 14px;
  height: 14px;
  border: 2px solid var(--cyan);
  border-radius: 50%;
  background: var(--bg);
  cursor: pointer;
}
input[type="range"]:focus-visible::-webkit-slider-thumb { outline: 2px solid var(--orange); outline-offset: 3px; }

.hint {
  margin-top: 9px;
  color: var(--muted);
  font-size: 11px;
  line-height: 1.65;
}

.formula {
  margin-top: 12px;
  padding-top: 20px;
  border-top: 1px solid var(--line);
}
.formula p { margin: 7px 0; color: #dcebe8; font: 14px "DM Mono", monospace; }
.formula span { color: var(--orange); }

.stage { min-width: 0; padding: 25px 25px 20px; }
.stage-top {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  gap: 18px;
  margin-bottom: 15px;
}
.stage-title { margin: 0; font-size: 16px; letter-spacing: 0; }
.stage-sub { margin: 5px 0 0; color: var(--muted); font-size: 12px; }
.stage-actions { display: flex; flex-wrap: wrap; justify-content: flex-end; gap: 8px; }

button {
  min-height: 40px;
  padding: 9px 13px;
  border: 1px solid var(--line);
  border-radius: 0;
  color: var(--ink);
  background: transparent;
  cursor: pointer;
  transition: background .2s, border-color .2s, transform .2s;
}
button:hover { border-color: var(--cyan); background: rgba(101, 230, 209, .08); transform: translateY(-1px); }
button:focus-visible, a:focus-visible { outline: 2px solid var(--orange); outline-offset: 2px; }
.transport { min-width: 82px; }
.transport.active { border-color: var(--cyan); color: #08211f; background: var(--cyan); }
.share { color: var(--cyan); }

.canvas-wrap {
  position: relative;
  overflow: hidden;
  border: 1px solid var(--line-soft);
  background: var(--panel-deep);
}
.scene { display: block; width: 100%; height: auto; min-height: 380px; }
.axis-label { fill: #71918f; font: 11px "DM Mono", monospace; }
.gridline { stroke: #234047; stroke-width: 1; stroke-dasharray: 2 7; }
.annotation {
  fill: #b0c6c3;
  font: 11px "DM Mono", monospace;
  paint-order: stroke;
  stroke: var(--panel-deep);
  stroke-width: 4px;
  stroke-linejoin: round;
}
.tick { fill: #587b79; font: 9px "DM Mono", monospace; }

.legend {
  display: flex;
  flex-wrap: wrap;
  gap: 10px 20px;
  min-height: 34px;
  padding-top: 13px;
  color: var(--muted);
  font-size: 11px;
}
.legend i { display: inline-block; width: 18px; height: 2px; margin-right: 6px; vertical-align: middle; }

.metrics {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  margin-top: 22px;
  border-top: 1px solid var(--line);
}
.metric { min-width: 0; padding: 17px 12px 2px 0; }
.metric + .metric { padding-left: 16px; border-left: 1px solid var(--line); }
.metric-label { margin-bottom: 7px; color: var(--muted); font-size: 11px; }
.metric-value { overflow-wrap: anywhere; color: var(--ink); font: 500 21px "DM Mono", monospace; }
.metric-unit { margin-left: 4px; color: var(--orange); font-size: 12px; white-space: nowrap; }

.bottom { display: grid; grid-template-columns: 1.1fr .9fr; gap: 18px; margin-top: 18px; }
.info { padding: 21px 23px; border: 1px solid var(--line); background: rgba(17, 35, 39, .6); }
.info h2 { margin: 0 0 11px; font-size: 15px; }
.info p { margin: 0; color: var(--muted); font-size: 13px; line-height: 1.8; }
.steps { display: flex; gap: 18px; margin-top: 18px; }
.step { flex: 1; padding-top: 10px; border-top: 1px solid var(--line); }
.step b { color: var(--orange); font: 12px "DM Mono", monospace; }
.step span { display: block; margin-top: 6px; color: #c9d8d5; font-size: 12px; line-height: 1.5; }

/* 典型题与三分钟讲解脚本（各实验页通用） */
.practice { margin-top: 18px; }
.practice .problem-text { color: #c9d8d5; }
.practice .problem-text b { color: var(--ink); font-weight: 600; }
.practice .num { font-family: "DM Mono", Consolas, monospace; color: var(--cyan); }
.practice details { margin-top: 14px; border-top: 1px solid var(--line); }
.practice summary { cursor: pointer; padding: 10px 0 2px; color: var(--cyan); font-size: 13px; user-select: none; }
.practice summary:hover { color: var(--ink); }
.solution-steps { margin: 10px 0 0; padding-left: 20px; color: var(--muted); font-size: 13px; line-height: 1.9; }
.solution-steps li + li { margin-top: 5px; }
.solution-answer { margin-top: 12px !important; color: var(--ink) !important; }
.practice .try-link { display: inline-block; margin-top: 12px; }
.script-line { display: flex; gap: 12px; margin-top: 10px; }
.script-line b { flex: none; min-width: 74px; color: var(--orange); font: 12px/1.9 "DM Mono", monospace; }
.script-line span { color: var(--muted); font-size: 13px; line-height: 1.8; }

.toast {
  position: fixed;
  right: 22px;
  bottom: 22px;
  z-index: 10;
  padding: 11px 15px;
  color: #102b2a;
  background: #d7fff5;
  font-size: 12px;
  opacity: 0;
  pointer-events: none;
  transform: translateY(16px);
  transition: .25s;
}
.toast.show { opacity: 1; transform: translateY(0); }

/* Home */
.home-shell { padding-bottom: 70px; }
.catalog-head {
  display: grid;
  grid-template-columns: minmax(0, 1.25fr) minmax(260px, .75fr);
  gap: 50px;
  align-items: end;
  margin: 72px 0 48px;
}
.catalog-head h1 { font-size: clamp(46px, 7vw, 88px); }
.catalog-meta { padding: 18px 0 4px 22px; border-left: 2px solid var(--orange); }
.catalog-meta strong { display: block; margin-bottom: 8px; font: 500 30px "DM Mono", monospace; color: var(--cyan); }
.catalog-meta span { color: var(--muted); font-size: 13px; line-height: 1.7; }

.catalog-group { margin-top: 34px; }
.catalog-group + .catalog-group { margin-top: 48px; }
.catalog-group-head { display: flex; align-items: baseline; justify-content: space-between; gap: 20px; margin-bottom: 13px; }
.catalog-group-head h2 { margin: 0; color: var(--ink); font-size: 15px; letter-spacing: 0; }
.catalog-group-head span { color: var(--muted); font: 11px "DM Mono", monospace; }
.experiment-list { border-top: 1px solid var(--line); }
.experiment-card {
  display: grid;
  grid-template-columns: 90px minmax(0, 1fr) 250px 32px;
  gap: 26px;
  align-items: center;
  min-height: 170px;
  padding: 28px 4px;
  border-bottom: 1px solid var(--line);
  text-decoration: none;
  transition: background .25s, padding .25s;
}
.experiment-card:hover { padding-right: 16px; padding-left: 16px; background: rgba(101, 230, 209, .045); }
.experiment-index { color: var(--orange); font: 500 15px "DM Mono", monospace; }
.experiment-card h2 { margin: 0 0 10px; font-size: clamp(24px, 3vw, 38px); letter-spacing: 0; }
.experiment-card p { max-width: 590px; margin: 0; color: var(--muted); font-size: 13px; line-height: 1.7; }
.experiment-visual { position: relative; height: 92px; overflow: hidden; }
.trajectory-mini { position: absolute; inset: 13px 12px; border-bottom: 1px solid #355258; }
.trajectory-mini::before { content: ""; position: absolute; left: 0; top: 5px; width: 190px; height: 62px; border-top: 3px solid var(--cyan); border-radius: 50% 70% 0 0; transform: rotate(13deg); }
.trajectory-mini::after { content: ""; position: absolute; left: 1px; top: 1px; width: 11px; height: 11px; border-radius: 50%; background: var(--orange); box-shadow: 0 0 12px rgba(255,173,104,.7); }
.oblique-mini::before { top: 28px; height: 46px; border-radius: 58% 58% 0 0; transform: rotate(-12deg); transform-origin: left top; }
.oblique-mini::after { top: 25px; }
.slope-mini { position: absolute; right: 12px; bottom: 10px; width: 210px; height: 68px; border-bottom: 1px solid #355258; border-left: 2px solid var(--cyan); transform: skewY(-17deg); transform-origin: bottom left; }
.slope-mini::after { content: ""; position: absolute; left: 82px; top: 21px; width: 28px; height: 28px; border: 2px solid var(--orange); background: var(--panel); transform: skewY(17deg) rotate(-17deg); }
.motion-mini { position: relative; height: 78px; margin: 7px 12px; border-bottom: 1px solid #355258; }
.motion-mini::before, .motion-mini::after { content: ""; position: absolute; width: 10px; height: 10px; border-radius: 50%; top: 45px; }
.motion-mini::before { left: 24px; background: var(--orange); box-shadow: 54px -24px 0 var(--cyan); }
.motion-mini::after { left: 24px; top: 50px; width: 130px; height: 1px; border-radius: 0; background: linear-gradient(90deg, var(--orange), transparent); transform: rotate(-18deg); transform-origin: left; }
.motion-mini i, .motion-mini b { position: absolute; display: block; width: 90px; height: 1px; left: 104px; top: 27px; background: var(--cyan); transform: rotate(13deg); }
.motion-mini b { left: 100px; top: 56px; background: var(--orange); transform: rotate(-16deg); }
.force-mini { position: absolute; inset: 35px 16px 18px; border-bottom: 2px solid #355258; }
.force-mini::before { content: ""; position: absolute; left: 96px; bottom: 2px; width: 42px; height: 28px; border: 2px solid var(--orange); background: var(--panel); }
.force-mini::after { content: "←        →"; position: absolute; left: 44px; bottom: 8px; width: 145px; color: var(--cyan); font: 20px "DM Mono", monospace; word-spacing: 65px; }
.spring-mini { position: absolute; inset: 22px 14px; border-left: 4px double #587471; }
.spring-mini::before { content: "／＼／＼／＼／＼"; position: absolute; left: 5px; top: 20px; color: var(--cyan); font: 18px "DM Mono", monospace; white-space: nowrap; }
.spring-mini::after { content: ""; position: absolute; right: 12px; top: 12px; width: 38px; height: 38px; border: 2px solid var(--orange); background: var(--panel); }
.circle-mini { position: absolute; left: 82px; top: 7px; width: 78px; height: 78px; border: 2px solid var(--cyan); border-radius: 50%; }
.circle-mini::before { content: ""; position: absolute; right: -7px; top: 31px; width: 12px; height: 12px; border-radius: 50%; background: var(--orange); box-shadow: 0 0 10px rgba(255,173,104,.65); }
.circle-mini::after { content: "←"; position: absolute; right: 12px; top: 23px; color: var(--yellow); font: 18px "DM Mono", monospace; }
.collision-mini { position: absolute; inset: 35px 14px 16px; border-bottom: 2px solid #355258; }
.collision-mini::before, .collision-mini::after { content: ""; position: absolute; bottom: 3px; width: 34px; height: 28px; border: 2px solid; background: var(--panel); }
.collision-mini::before { left: 62px; border-color: var(--orange); }
.collision-mini::after { right: 62px; border-color: var(--cyan); }
.energy-mini { position: absolute; inset: 13px 45px; border-left: 1px solid #355258; border-bottom: 1px solid #355258; }
.energy-mini::before { content: ""; position: absolute; left: 36px; bottom: 3px; width: 28px; height: 48px; background: var(--orange); box-shadow: 48px -22px 0 -8px var(--cyan); }
.circuit-mini { position: absolute; left: 35px; top: 18px; width: 180px; height: 56px; border: 2px solid var(--cyan); }
.circuit-mini::before { content: ""; position: absolute; left: 45px; top: -7px; width: 38px; height: 10px; border: 2px solid var(--orange); background: var(--panel); box-shadow: 63px 0 0 -2px var(--panel), 63px 0 0 0 var(--orange); }
.circuit-mini::after { content: "＋ −"; position: absolute; left: -30px; top: 15px; color: var(--yellow); font: 15px "DM Mono", monospace; }
.closed-circuit-mini { position: absolute; left: 48px; top: 20px; width: 166px; height: 52px; border: 2px solid var(--cyan); }
.closed-circuit-mini::before { content: "r"; position: absolute; left: -15px; top: 8px; width: 28px; height: 36px; border: 1px dashed #587471; background: var(--panel); color: var(--yellow); font: 12px/36px "DM Mono", monospace; text-align: center; }
.closed-circuit-mini::after { content: ""; position: absolute; right: 32px; top: -8px; width: 44px; height: 14px; border: 2px solid var(--orange); background: var(--panel); }
.field-mini { position: absolute; left: 88px; top: 10px; width: 72px; height: 72px; border: 2px dashed var(--cyan); border-radius: 50%; }
.field-mini::before { content: "×  ×  ×  ×  ×  ×  ×  ×  ×  ×  ×  ×\A×  ×  ×  ×  ×  ×  ×  ×  ×  ×  ×  ×\A×  ×  ×  ×  ×  ×  ×  ×  ×  ×  ×  ×"; white-space: pre; position: absolute; left: -88px; top: -13px; color: #2f5158; font: 11px/33px "DM Mono", monospace; }
.field-mini::after { content: ""; position: absolute; left: 26px; top: -8px; width: 13px; height: 13px; border-radius: 50%; background: var(--orange); box-shadow: 0 0 11px rgba(255,173,104,.7); }
.lens-mini { position: absolute; left: 122px; top: 7px; width: 2px; height: 78px; background: var(--cyan); }
.lens-mini::before { content: ""; position: absolute; left: -83px; top: 37px; width: 170px; height: 2px; background: #355258; transform: rotate(-10deg); transform-origin: center; }
.lens-mini::after { content: "↕"; position: absolute; left: -73px; top: 12px; color: var(--orange); font: 26px "DM Mono", monospace; }
.induction-mini { position: absolute; inset: 20px 24px 18px; border-top: 2px solid var(--cyan); border-bottom: 2px solid var(--cyan); }
.induction-mini::before { content: "×  ×  ×  ×  ×  ×  ×\A×  ×  ×  ×  ×  ×  ×"; white-space: pre; position: absolute; left: 14px; top: -3px; color: #2f5158; font: 12px/27px "DM Mono", monospace; }
.induction-mini::after { content: ""; position: absolute; left: 118px; top: -6px; width: 5px; height: calc(100% + 12px); background: var(--orange); box-shadow: 0 0 10px rgba(255,173,104,.6); }
.wave-mini { position: absolute; left: 52px; top: 10px; width: 74px; height: 74px; }
.wave-mini::before, .wave-mini::after { content: ""; position: absolute; top: 0; left: 0; width: 74px; height: 74px; border: 2px solid rgba(101,230,209,.8); border-radius: 50%; box-shadow: inset 0 0 0 12px var(--panel), inset 0 0 0 14px rgba(101,230,209,.55), inset 0 0 0 25px var(--panel), inset 0 0 0 27px rgba(101,230,209,.35); }
.wave-mini::after { left: 62px; border-color: rgba(122,168,255,.8); box-shadow: inset 0 0 0 12px var(--panel), inset 0 0 0 14px rgba(122,168,255,.55), inset 0 0 0 25px var(--panel), inset 0 0 0 27px rgba(122,168,255,.35); }
.wave-mini i { position: absolute; left: 62px; top: -4px; width: 12px; height: 12px; border-radius: 50%; background: var(--orange); box-shadow: 0 0 11px rgba(255,173,104,.7); z-index: 1; }
.gas-mini { position: absolute; left: 90px; top: 8px; width: 66px; height: 78px; border: 2px solid var(--cyan); border-top: 0; }
.gas-mini::before { content: ""; position: absolute; left: -2px; top: 16px; width: calc(100% + 4px); height: 7px; background: var(--orange); box-shadow: 0 0 8px rgba(255,173,104,.5); }
.gas-mini::after { content: "·  ˙  ·\A˙  ·  ˙\A·  ˙  ·"; white-space: pre; position: absolute; left: 10px; top: 24px; color: #6fdac6; font: 15px/17px "DM Mono", monospace; }
.experiment-arrow { color: var(--cyan); font: 24px "DM Mono", monospace; transition: transform .2s; }
.experiment-card:hover .experiment-arrow { transform: translateX(5px); }
.home-foot { display: flex; justify-content: space-between; gap: 24px; margin-top: 32px; color: var(--muted); font-size: 12px; line-height: 1.7; }

/* Projectile */
.trajectory { fill: none; stroke: var(--cyan); stroke-width: 3; filter: drop-shadow(0 0 5px rgba(101, 230, 209, .4)); }
.velocity { stroke: var(--orange); stroke-width: 2; opacity: .8; }
.ball { fill: var(--orange); stroke: #fff1d8; stroke-width: 2; filter: drop-shadow(0 0 8px rgba(255, 173, 104, .7)); }
.ground-line { stroke: #587471; stroke-width: 2; }
.key-point { fill: var(--panel-deep); stroke: var(--yellow); stroke-width: 2; }
.apex-point { fill: var(--yellow); }
.metrics-wide { grid-template-columns: repeat(4, minmax(0, 1fr)); }
.metrics-wide .metric:nth-child(n+5) { margin-top: 13px; padding-top: 17px; border-top: 1px solid var(--line); }
.metrics-wide .metric:nth-child(5) { padding-left: 0; border-left: 0; }
.metric-value-compact { font-size: 16px; line-height: 1.45; }
.comparison-list { display: grid; gap: 11px; }
.comparison-list p { display: grid; grid-template-columns: 82px minmax(0, 1fr); gap: 12px; }
.comparison-list strong { color: var(--orange); font: 500 12px "DM Mono", monospace; }

/* Inclined plane */
.state-strip {
  display: flex;
  align-items: center;
  gap: 9px;
  margin: 0 0 18px;
  padding: 11px 13px;
  border: 1px solid var(--line);
  color: #dcebe8;
  font-size: 12px;
  line-height: 1.5;
}
.state-dot { width: 8px; height: 8px; flex: 0 0 8px; border-radius: 50%; background: var(--cyan); box-shadow: 0 0 10px rgba(101,230,209,.7); }
.state-strip.sliding .state-dot { background: var(--orange); box-shadow: 0 0 10px rgba(255,173,104,.75); }
.state-strip.critical .state-dot { background: var(--yellow); box-shadow: 0 0 10px rgba(241,211,106,.75); }
.force-line { stroke-width: 2.4; }
.force-gravity { stroke: var(--orange); }
.force-normal { stroke: var(--cyan); }
.force-friction { stroke: var(--red); }
.force-component { stroke: var(--blue); stroke-width: 1.8; stroke-dasharray: 6 5; }
.force-label { font: 500 11px "DM Mono", monospace; paint-order: stroke; stroke: var(--panel-deep); stroke-width: 5px; stroke-linejoin: round; }
.slope-surface { stroke: #78908d; stroke-width: 3; }
.slope-fill { fill: rgba(101, 230, 209, .035); stroke: #254248; }
.block { fill: #173238; stroke: var(--orange); stroke-width: 2; filter: drop-shadow(0 5px 8px rgba(0,0,0,.35)); }
.angle-arc { fill: none; stroke: var(--yellow); stroke-width: 1.5; }
.angle-label { fill: var(--yellow); font: 11px "DM Mono", monospace; }
.critical-note { color: var(--muted); font: 11px "DM Mono", monospace; line-height: 1.65; }

/* Motion graphs */
.motion-workspace { grid-template-columns: 278px minmax(0, 1fr); }
.motion-stage { padding-bottom: 24px; }
.motion-status { display: flex; flex-wrap: wrap; gap: 8px 18px; margin: 0 0 16px; padding: 11px 13px; border: 1px solid var(--line); color: #c9d8d5; font-size: 12px; line-height: 1.5; }
.motion-status strong { color: var(--orange); font: 500 12px "DM Mono", monospace; }
.motion-status .status-meet { color: var(--cyan); }
.motion-views { display: grid; grid-template-columns: minmax(0, 1fr) minmax(0, 1fr); gap: 14px; }
.motion-view { min-width: 0; border: 1px solid var(--line-soft); background: var(--panel-deep); }
.motion-view:first-child { grid-column: 1 / -1; }
.motion-view-head { display: flex; justify-content: space-between; gap: 12px; padding: 11px 13px 8px; border-bottom: 1px solid rgba(41,66,71,.7); }
.motion-view-head h3 { margin: 0; font-size: 13px; }
.motion-view-head span { color: var(--muted); font: 10px "DM Mono", monospace; }
.motion-scene { display: block; width: 100%; height: auto; }
.motion-track { stroke: #587471; stroke-width: 2; }
.motion-tick { stroke: #416168; stroke-width: 1; }
.motion-car-a { fill: var(--orange); stroke: #fff1d8; stroke-width: 1.5; filter: drop-shadow(0 0 6px rgba(255,173,104,.55)); }
.motion-car-b { fill: var(--cyan); stroke: #d8fff6; stroke-width: 1.5; filter: drop-shadow(0 0 6px rgba(101,230,209,.5)); }
.motion-arrow-a { stroke: var(--orange); stroke-width: 2; }
.motion-arrow-b { stroke: var(--cyan); stroke-width: 2; }
.graph-axis { stroke: #66817e; stroke-width: 1.15; }
.graph-grid { stroke: #234047; stroke-width: 1; stroke-dasharray: 2 6; }
.graph-a { fill: none; stroke: var(--orange); stroke-width: 2.5; }
.graph-b { fill: none; stroke: var(--cyan); stroke-width: 2.5; }
.graph-cursor { stroke: #d9eae7; stroke-width: 1.2; stroke-dasharray: 4 4; opacity: .85; }
.graph-point-a { fill: var(--orange); stroke: #fff1d8; stroke-width: 1.2; }
.graph-point-b { fill: var(--cyan); stroke: #d8fff6; stroke-width: 1.2; }
.meeting-point { fill: var(--panel-deep); stroke: var(--yellow); stroke-width: 2; }
.meeting-label { fill: var(--yellow); font: 10px "DM Mono", monospace; paint-order: stroke; stroke: var(--panel-deep); stroke-width: 4px; }
.motion-metrics { grid-template-columns: repeat(3, minmax(0, 1fr)); }
.motion-metrics .metric:nth-child(n+4) { margin-top: 13px; padding-top: 17px; border-top: 1px solid var(--line); }
.motion-metrics .metric:nth-child(4) { padding-left: 0; border-left: 0; }
.motion-metrics .metric-value { font-size: 17px; line-height: 1.35; }
.motion-metrics .metric-value.compact { font-size: 14px; }
.observation-list { display: grid; gap: 9px; margin: 0; padding: 0; list-style: none; }
.observation-list li { padding-left: 14px; position: relative; color: var(--muted); font-size: 13px; line-height: 1.7; }
.observation-list li::before { content: ""; position: absolute; left: 0; top: .72em; width: 5px; height: 5px; background: var(--cyan); }

@media (max-width: 900px) {
  .workspace { grid-template-columns: 280px minmax(0, 1fr); }
  .motion-workspace { grid-template-columns: 260px minmax(0, 1fr); }
  .experiment-card { grid-template-columns: 70px minmax(0, 1fr) 190px 24px; }
}

@media (max-width: 820px) {
  .shell { width: min(calc(100% - 24px), 650px); padding-top: 18px; }
  .site-header { margin-bottom: 33px; }
  .hero { grid-template-columns: 1fr; gap: 22px; }
  .hero-note { justify-self: start; }
  .workspace { grid-template-columns: 1fr; }
  .controls { border-right: 0; border-bottom: 1px solid var(--line); }
  .bottom { grid-template-columns: 1fr; }
  .scene { min-height: 300px; }
  .catalog-head { grid-template-columns: 1fr; gap: 28px; margin-top: 48px; }
  .catalog-meta { max-width: 440px; }
  .experiment-card { grid-template-columns: 54px minmax(0, 1fr) 24px; min-height: 150px; gap: 18px; }
  .experiment-visual { display: none; }
  .metrics-wide { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .metrics-wide .metric:nth-child(n+3) { margin-top: 13px; padding-top: 17px; border-top: 1px solid var(--line); }
  .metrics-wide .metric:nth-child(odd) { padding-left: 0; border-left: 0; }
  .motion-views { grid-template-columns: 1fr; }
  .motion-view:first-child { grid-column: auto; }
  .motion-metrics { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .motion-metrics .metric:nth-child(n+3) { margin-top: 13px; padding-top: 17px; border-top: 1px solid var(--line); }
  .motion-metrics .metric:nth-child(odd) { padding-left: 0; border-left: 0; }
}

@media (max-width: 520px) {
  .site-header { align-items: flex-start; }
  .header-side { align-items: flex-end; flex-direction: column-reverse; gap: 5px; }
  .status { display: none; }
  .back-link { font-size: 10px; }
  .brand-name { font-size: 14px; }
  h1 { font-size: 44px; line-height: 1; }
  .hero { margin-bottom: 27px; }
  .hero-note { padding-left: 16px; }
  .controls { padding: 22px 18px; }
  .stage { padding: 18px 12px 16px; }
  .stage-top { display: block; }
  .stage-actions { justify-content: flex-start; margin-top: 14px; }
  .stage-actions button { flex: 1 1 88px; min-width: 0; padding-inline: 7px; }
  .metrics { grid-template-columns: 1fr; }
  .metric, .metric + .metric { padding: 13px 0; border-bottom: 1px solid var(--line); border-left: 0; }
  .metric:last-child { border-bottom: 0; }
  .steps { flex-direction: column; gap: 10px; }
  .legend { gap: 8px 13px; }
  .toast { right: 12px; bottom: 12px; max-width: calc(100% - 24px); }
  .catalog-head h1 { font-size: 45px; }
  .catalog-head { margin-top: 40px; }
  .catalog-group-head { align-items: flex-start; flex-direction: column; gap: 5px; }
  .experiment-card { grid-template-columns: 64px minmax(0, 1fr) 18px; min-height: 160px; gap: 8px; }
  .experiment-index { font-size: 11px; white-space: nowrap; }
  .experiment-card h2 { font-size: 24px; }
  .home-foot { flex-direction: column; }
  .force-label { font-size: 15px; stroke-width: 6px; }
  .scene .axis-label, .scene .annotation, .scene .angle-label { font-size: 13px; }
  .oblique-scene .annotation { font-size: 18px; }
  .oblique-scene .axis-label { font-size: 16px; }
  .oblique-scene .tick { font-size: 13px; }
  .oblique-scene .ball { r: 10px; }
  .oblique-scene .key-point { r: 5px; }
  .metrics-wide { grid-template-columns: 1fr; }
  .metrics-wide .metric, .metrics-wide .metric:nth-child(n) { margin-top: 0; padding: 13px 0; border-right: 0; border-bottom: 1px solid var(--line); border-left: 0; }
  .metrics-wide .metric:last-child { border-bottom: 0; }
  .comparison-list p { grid-template-columns: 1fr; gap: 3px; }
  .motion-status { display: block; }
  .motion-status span { display: block; margin-top: 5px; }
  .motion-metrics { grid-template-columns: 1fr; }
  .motion-metrics .metric, .motion-metrics .metric:nth-child(n) { margin-top: 0; padding: 13px 0; border-right: 0; border-bottom: 1px solid var(--line); border-left: 0; }
  .motion-metrics .metric:last-child { border-bottom: 0; }
}

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