:root {
  --entry-canvas: #f8f8f6;
  --entry-card: #ffffff;
  --entry-red: #a92122;
  --entry-bronze: #c98a3d;
  --entry-ink: #30343b;
  --entry-muted: #77787f;
  --entry-line: #e5dfdc;
}

html.entry-intro-skip .entry-intro { display: none !important; }

html.entry-intro-running,
html.entry-intro-running body { overflow: hidden !important; }

.entry-intro {
  position: fixed;
  inset: 0;
  z-index: 10000;
  display: grid;
  place-items: center;
  overflow: hidden;
  color: var(--entry-ink);
  background: var(--entry-canvas);
  font-family:-apple-system,BlinkMacSystemFont,"Segoe UI","PingFang SC","Hiragino Sans GB","Microsoft YaHei","Noto Sans SC","Helvetica Neue",Arial,sans-serif;
  isolation: isolate;
}

.entry-intro::before {
  content: "";
  position: absolute;
  inset: 0;
  z-index: 0;
  pointer-events: none;
  opacity: .7;
  background-image:
    radial-gradient(circle at 1px 1px, rgba(48,52,59,.09) 1px, transparent 1.1px),
    linear-gradient(115deg, transparent 48%, rgba(169,33,34,.025) 49%, transparent 50%);
  background-size: 32px 32px, 240px 240px;
  mask-image: linear-gradient(90deg, transparent, #000 18%, #000 82%, transparent);
}

.entry-intro__veil {
  position: absolute;
  inset: 0;
  z-index: 1;
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  pointer-events: none;
}

.entry-intro__veil span {
  min-width: 0;
  background: var(--entry-canvas);
  border-right: 1px solid rgba(169,33,34,.035);
  transition: transform .65s cubic-bezier(.76,0,.24,1);
}

.entry-intro--leaving {
  pointer-events: none;
  background: transparent;
  transition: background 0s .08s;
}

.entry-intro--leaving::before { opacity: 0; transition: opacity .15s ease; }
.entry-intro--leaving .entry-intro__veil span:nth-child(odd) { transform: translateY(-102%); }
.entry-intro--leaving .entry-intro__veil span:nth-child(even) { transform: translateY(102%); }

.entry-intro__skip {
  position: absolute;
  top: clamp(20px, 3.2vw, 46px);
  right: clamp(22px, 4.2vw, 68px);
  z-index: 5;
  padding: 8px 0;
  color: #79767a;
  border: 0;
  border-bottom: 1px solid #cfc7c4;
  border-radius: 0;
  background: transparent;
  font: 700 11px/1.2 "Consolas", monospace;
  letter-spacing: .12em;
  cursor: pointer;
  transition: color .2s ease, border-color .2s ease;
}

.entry-intro__skip:hover,
.entry-intro__skip:focus-visible {
  color: var(--entry-red);
  border-color: var(--entry-red);
  outline: none;
}

.entry-intro__stage {
  position: relative;
  z-index: 3;
  width: min(1180px, calc(100vw - 72px));
  min-height: min(740px, calc(100vh - 78px));
  display: grid;
  grid-template-columns: minmax(280px, .72fr) minmax(560px, 1.28fr);
  align-items: center;
  gap: clamp(30px, 5vw, 82px);
  transition: opacity .18s ease, transform .3s ease;
}

.entry-intro__meta {
  position: absolute;
  top: 0;
  left: 0;
  right: clamp(110px, 11vw, 156px);
  display: flex;
  justify-content: space-between;
  color: #a09ca0;
  font: 700 9px/1 "Consolas", monospace;
  letter-spacing: .2em;
}

.entry-intro__copy { align-self: center; }

.entry-intro__kicker {
  display: flex;
  align-items: center;
  gap: 10px;
  margin: 0 0 24px;
  color: var(--entry-red);
  font: 700 10px/1.3 "Consolas", monospace;
  letter-spacing: .18em;
  opacity: 0;
  animation: entry-white-copy .35s .12s ease forwards;
}

.entry-intro__kicker i {
  width: 28px;
  height: 2px;
  background: var(--entry-red);
}

.entry-intro__copy h1 {
  margin: 0;
  color: var(--entry-red);
  font-size: clamp(54px, 6.4vw, 98px);
  font-weight: 800;
  line-height: 1.08;
  letter-spacing: -.065em;
}

.entry-intro__copy h1 em {
  display: block;
  margin-top: 18px;
  color: var(--entry-ink);
  font-size: .34em;
  font-style: normal;
  font-weight: 650;
  line-height: 1.2;
  letter-spacing: .04em;
  opacity: 0;
  transform: translateY(14px);
  animation: entry-white-copy .4s .42s ease forwards;
}

.entry-intro__copy h1 {
  clip-path: inset(0 100% 0 0);
  animation: entry-white-title .55s .18s cubic-bezier(.16,1,.3,1) forwards;
}

.entry-intro__lead {
  margin: 26px 0 0;
  color: var(--entry-muted);
  font-size: 14px;
  line-height: 1.8;
  opacity: 0;
  transform: translateY(10px);
  animation: entry-white-copy .38s .55s ease forwards;
}

.entry-layer-stack {
  position: relative;
  width: 100%;
  aspect-ratio: 760 / 480;
  min-height: 380px;
  perspective: 1100px;
  transform-style: preserve-3d;
}

.entry-control-map {
  position: absolute;
  inset: 0;
  z-index: 4;
  width: 100%;
  height: 100%;
  overflow: visible;
  opacity: 0;
  animation: entry-map-in .4s .95s ease forwards;
}

.entry-control-map__grid path,
.entry-control-map__baseline,
.entry-control-map__axis,
.entry-control-map__setpoint {
  fill: none;
  stroke: #ded8d5;
  stroke-width: 1;
}

.entry-control-map__grid { opacity: .42; }
.entry-control-map__setpoint { stroke-dasharray: 4 6; }

.entry-control-map__feedback {
  fill: none;
  stroke: var(--entry-bronze);
  stroke-width: 1.5;
  stroke-dasharray: 760;
  stroke-dashoffset: 760;
  animation: entry-white-line .65s 1.3s ease forwards;
}

.entry-control-map__signal,
.entry-control-map__response {
  fill: none;
  stroke: var(--entry-red);
  stroke-width: 2.4;
  stroke-linecap: round;
  stroke-linejoin: round;
}

.entry-control-map__signal {
  stroke-dasharray: 690;
  stroke-dashoffset: 690;
  animation: entry-white-line .65s 1.08s ease forwards;
}

.entry-control-map__response {
  stroke-dasharray: 360;
  stroke-dashoffset: 360;
  animation: entry-white-line .65s 1.52s ease forwards;
}

.entry-control-map__sum,
.entry-control-map__block {
  fill: rgba(255,255,255,.92);
  stroke: #cfc6c3;
  stroke-width: 1.2;
  filter: drop-shadow(0 8px 12px rgba(91,64,60,.055));
}

.entry-control-map__sum-mark { stroke: var(--entry-red); stroke-width: 1.5; }
.entry-control-map__code { fill: var(--entry-ink); font: 700 20px "Consolas", monospace; }
.entry-control-map__label { fill: #6f6d72; font: 650 12px "PingFang SC", "Microsoft YaHei", sans-serif; }
.entry-control-map__utility { fill: #8f8a8c; font: 600 10px "PingFang SC", "Microsoft YaHei", sans-serif; letter-spacing: .06em; }

.entry-layer {
  position: absolute;
  z-index: 2;
  width: 210px;
  min-height: 96px;
  padding: 16px 18px;
  border: 1px solid rgba(169,33,34,.11);
  border-radius: 14px;
  background: rgba(255,255,255,.86);
  box-shadow: 0 20px 55px rgba(104,75,71,.11), 0 3px 10px rgba(104,75,71,.05);
  backdrop-filter: blur(8px);
  opacity: 0;
  transform-style: preserve-3d;
}

.entry-layer::before {
  content: "";
  position: absolute;
  top: 0;
  left: 18px;
  width: 42px;
  height: 2px;
  background: var(--entry-red);
}

.entry-layer--input {
  top: 10%;
  left: 2%;
  transform: translate3d(45px, 18px, 120px) rotateY(8deg) rotateX(5deg);
  animation: entry-layer-input .6s .32s cubic-bezier(.16,1,.3,1) forwards;
}

.entry-layer--model {
  top: 33%;
  left: 33%;
  transform: translate3d(30px, 24px, 190px) rotateY(5deg) rotateX(4deg);
  animation: entry-layer-model .6s .45s cubic-bezier(.16,1,.3,1) forwards;
}

.entry-layer--target {
  top: 57%;
  left: 62%;
  transform: translate3d(12px, 25px, 250px) rotateY(3deg) rotateX(3deg);
  animation: entry-layer-target .6s .55s cubic-bezier(.16,1,.3,1) forwards;
}

.entry-layer__index {
  position: absolute;
  top: 14px;
  right: 15px;
  color: rgba(169,33,34,.28);
  font: 700 20px/1 "Consolas", monospace;
}

.entry-layer small {
  display: block;
  margin-bottom: 8px;
  color: var(--entry-bronze);
  font: 700 8px/1 "Consolas", monospace;
  letter-spacing: .14em;
}

.entry-layer strong { display: block; font-size: 18px; color: var(--entry-ink); }
.entry-layer p { margin: 7px 0 0; color: #8a8588; font-size: 10px; }
.entry-layer__icon { width: 17px; height: 17px; margin-right: 7px; vertical-align: -3px; color: var(--entry-red); fill: none; stroke: currentColor; stroke-width: 1.6; stroke-linecap: square; stroke-linejoin: round; }

.entry-target-lock {
  position: absolute;
  top: 53.3%;
  right: -2%;
  z-index: 6;
  width: 122px;
  height: 122px;
  display: grid;
  place-content: center;
  text-align: center;
  opacity: 0;
  transform: translateY(-50%) scale(1.35);
  animation: entry-white-lock .5s 1.85s cubic-bezier(.16,1,.3,1) forwards;
}

.entry-target-lock span,
.entry-target-lock i {
  position: absolute;
  inset: 0;
  border: 1px solid rgba(169,33,34,.72);
  border-radius: 50%;
}

.entry-target-lock span:nth-child(2) { inset: 15px; border-color: rgba(169,33,34,.72); }
.entry-target-lock i {
  inset: 27px;
  border: 0;
  border-radius: 0;
  background:
    linear-gradient(var(--entry-red), var(--entry-red)) 50% 0 / 1px 100% no-repeat,
    linear-gradient(90deg, var(--entry-red), var(--entry-red)) 0 50% / 100% 1px no-repeat;
  opacity: .42;
  animation: entry-white-spin 8s linear infinite;
}

.entry-target-lock b { color: var(--entry-red); font-size: 13px; letter-spacing: .06em; }
.entry-target-lock small { margin-top: 4px; color: #777279; font: 700 8px/1 "Consolas", monospace; letter-spacing: .12em; }

.entry-signal-pulse {
  position: absolute;
  z-index: 7;
  top: 52.4%;
  left: 7.6%;
  width: 9px;
  height: 9px;
  border-radius: 50%;
  background: var(--entry-red);
  box-shadow: 0 0 0 6px rgba(169,33,34,.08), 0 0 20px rgba(169,33,34,.28);
  opacity: 0;
  animation: entry-white-pulse 1.3s 1.05s cubic-bezier(.42,.05,.24,1) forwards;
}

.entry-intro__progress {
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 20px;
  padding-top: 18px;
  border-top: 1px solid #ded8d5;
}

.entry-intro__progress span {
  display: flex;
  align-items: center;
  gap: 9px;
  color: #999397;
  font: 650 9px/1.2 "PingFang SC", "Microsoft YaHei", sans-serif;
  letter-spacing: .08em;
}

.entry-intro__progress i {
  width: 6px;
  height: 6px;
  border: 1px solid #c8c1bf;
  border-radius: 50%;
}

.entry-intro__progress span:nth-child(1) i { animation: entry-white-status .15s .45s forwards; }
.entry-intro__progress span:nth-child(2) i { animation: entry-white-status .15s .95s forwards; }
.entry-intro__progress span:nth-child(3) i { animation: entry-white-status .15s 1.45s forwards; }
.entry-intro__progress span:nth-child(4) i { animation: entry-white-status .15s 1.85s forwards; }

.entry-intro--leaving .entry-intro__stage,
.entry-intro--leaving .entry-intro__skip {
  opacity: 0;
  transform: scale(.985);
}

@keyframes entry-white-title { to { clip-path: inset(0 0 0 0); } }
@keyframes entry-white-copy { to { opacity: 1; transform: translateY(0); } }
@keyframes entry-map-in { to { opacity: 1; } }
@keyframes entry-white-line { to { stroke-dashoffset: 0; } }
@keyframes entry-layer-input { to { opacity: .34; transform: translate3d(-15px,-20px,-120px) rotateY(8deg) rotateX(5deg); } }
@keyframes entry-layer-model { to { opacity: .56; transform: translate3d(0,0,-45px) rotateY(5deg) rotateX(4deg); } }
@keyframes entry-layer-target { to { opacity: .8; transform: translate3d(16px,18px,35px) rotateY(3deg) rotateX(3deg); } }
@keyframes entry-white-lock { to { opacity: 1; transform: translateY(-50%) scale(1); } }
@keyframes entry-white-spin { to { transform: rotate(360deg); } }
@keyframes entry-white-pulse {
  0% { left: 7.6%; opacity: 0; }
  8% { opacity: 1; }
  82% { left: 89%; opacity: 1; }
  100% { left: 94%; opacity: 0; }
}
@keyframes entry-white-status { to { border-color: var(--entry-red); background: var(--entry-red); box-shadow: 0 0 0 4px rgba(169,33,34,.07); } }

@media (max-width: 820px) {
  .entry-intro__stage {
    width: min(100% - 36px, 620px);
    min-height: calc(100vh - 52px);
    grid-template-columns: 1fr;
    grid-template-rows: auto auto;
    align-content: center;
    gap: 24px;
  }
  .entry-intro__meta { right: 0; }
  .entry-intro__meta span:last-child { display: none; }
  .entry-intro__copy { padding-top: 24px; }
  .entry-intro__copy h1 { font-size: clamp(36px, 10.5vw, 56px); line-height: 1.1; }
  .entry-intro__copy h1 em { margin-top: 12px; }
  .entry-intro__lead { margin-top: 12px; font-size: 13px; }
  .entry-layer-stack { min-height: 0; height: auto; }
  .entry-layer { width: 142px; min-height: 68px; padding: 10px 12px; border-radius: 10px; }
  .entry-layer strong { font-size: 13px; }
  .entry-layer p { font-size: 8px; }
  .entry-layer__index { font-size: 13px; }
  .entry-target-lock { width: 68px; height: 68px; right: -1%; }
  .entry-target-lock span:nth-child(2) { inset: 9px; }
  .entry-target-lock i { inset: 18px; }
  .entry-target-lock b { font-size: 8px; }
  .entry-target-lock small { font-size: 6px; }
  .entry-intro__progress { gap: 4px; }
  .entry-intro__progress span { align-items: flex-start; font-size: 7px; letter-spacing: 0; }
}

/* 更窄视口（≤520px）：收敛三层卡片宽度与横向位置，避免第三层溢出视口。
   三层 base width 142px + left 2%/33%/62%，经 3D 动画 z 缩放后第三层
   视觉 right 可达 400px+，超出 390px 视口被截断。 */
@media (max-width: 520px) {
  .entry-intro__copy { padding-top: 12px; }
  .entry-intro__copy h1 { font-size: clamp(30px, 9vw, 42px); line-height: 1.15; }
  .entry-intro__copy h1 em { margin-top: 8px; }
  .entry-intro__lead { margin-top: 10px; font-size: 12px; }
  .entry-layer {
    width: 118px;
    min-height: 60px;
    padding: 8px 10px;
    border-radius: 9px;
  }
  .entry-layer--input { left: 0; }
  .entry-layer--model { left: 24%; }
  .entry-layer--target { left: 48%; }
  .entry-layer strong { font-size: 11.5px; }
  .entry-layer p { font-size: 7px; }
  .entry-layer small { margin-bottom: 5px; letter-spacing: .08em; }
  .entry-layer__index { font-size: 12px; }
  /* 目标锁定框：缩回视口内，不再贴边 */
  .entry-target-lock { width: 58px; height: 58px; right: 0; }
  .entry-target-lock span:nth-child(2) { inset: 8px; }
  .entry-target-lock i { inset: 16px; }
  .entry-target-lock b { font-size: 7px; }
  .entry-target-lock small { font-size: 5px; }
}

@media (prefers-reduced-motion: reduce) {
  .entry-intro *,
  .entry-intro *::before,
  .entry-intro *::after {
    animation-duration: .01ms !important;
    animation-delay: 0ms !important;
    transition-duration: .01ms !important;
  }
}