:root {
  --paper: #f4f1e9;
  --paper-deep: #e9e4d8;
  --ink: #171916;
  --muted: #696c65;
  --line: rgba(23, 25, 22, .16);
  --atlas: #2456c4;
  --atlas-soft: #dce5fb;
  --recorder: #b44b34;
  --recorder-soft: #f1ddd6;
  --shadow: 0 30px 80px rgba(41, 38, 31, .11);
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  min-height: 100vh;
  margin: 0;
  color: var(--ink);
  background: var(--paper);
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Microsoft YaHei", sans-serif;
  -webkit-font-smoothing: antialiased;
}

a { color: inherit; }

.page-grid {
  position: fixed;
  inset: 0;
  z-index: -1;
  pointer-events: none;
  opacity: .5;
  background-image:
    linear-gradient(to right, rgba(23, 25, 22, .04) 1px, transparent 1px),
    linear-gradient(to bottom, rgba(23, 25, 22, .04) 1px, transparent 1px);
  background-size: 56px 56px;
  mask-image: linear-gradient(to bottom, #000, transparent 88%);
}

.site-header,
main,
footer {
  width: min(1180px, calc(100% - 48px));
  margin-inline: auto;
}

.site-header {
  min-height: 84px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  border-bottom: 1px solid var(--line);
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  color: var(--ink);
  text-decoration: none;
  font-size: 12px;
  font-weight: 800;
  letter-spacing: .14em;
}

.brand-mark {
  width: 31px;
  height: 31px;
  display: grid;
  place-items: center;
  color: var(--paper);
  background: var(--ink);
  border-radius: 50%;
  font-family: Georgia, "Times New Roman", serif;
  font-size: 16px;
  letter-spacing: 0;
}

.site-label,
footer {
  color: var(--muted);
  font-size: 10px;
  font-weight: 750;
  letter-spacing: .18em;
}

main { padding: 82px 0 68px; }

.hero {
  display: grid;
  grid-template-columns: 1fr auto;
  align-items: end;
  gap: 20px;
  margin-bottom: 42px;
}

.eyebrow,
.tool-kicker {
  margin: 0;
  color: var(--muted);
  font-size: 10px;
  font-weight: 800;
  letter-spacing: .18em;
}

.hero h1 {
  grid-column: 1;
  margin: 8px 0 0;
  font-family: Georgia, "Times New Roman", "Songti SC", serif;
  font-size: clamp(58px, 10vw, 116px);
  font-weight: 500;
  line-height: .86;
  letter-spacing: -.07em;
}

.hero-note {
  grid-column: 2;
  grid-row: 1 / span 2;
  max-width: 210px;
  margin: 0 0 6px;
  color: var(--muted);
  font-size: 13px;
  line-height: 1.7;
  text-align: right;
}

.tools {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 18px;
}

.tool-card {
  min-width: 0;
  min-height: 590px;
  padding: 22px;
  display: flex;
  flex-direction: column;
  overflow: hidden;
  position: relative;
  border: 1px solid var(--line);
  border-radius: 24px;
  color: var(--ink);
  background: rgba(255, 255, 255, .42);
  box-shadow: 0 1px 0 rgba(255, 255, 255, .7) inset;
  text-decoration: none;
  transition: transform .32s ease, box-shadow .32s ease, border-color .32s ease;
}

.tool-card::after {
  content: "";
  position: absolute;
  inset: auto -80px -120px auto;
  width: 260px;
  aspect-ratio: 1;
  border-radius: 50%;
  opacity: .7;
  filter: blur(1px);
  transition: transform .4s ease;
}

.atlas-card::after { background: var(--atlas-soft); }
.recorder-card::after { background: var(--recorder-soft); }

.tool-card:hover {
  transform: translateY(-7px);
  border-color: rgba(23, 25, 22, .28);
  box-shadow: var(--shadow);
}

.tool-card:hover::after { transform: scale(1.18); }

.tool-card:focus-visible {
  outline: 3px solid var(--ink);
  outline-offset: 4px;
}

.card-topline {
  display: flex;
  justify-content: space-between;
  align-items: center;
  position: relative;
  z-index: 1;
}

.tool-index {
  font-family: Georgia, "Times New Roman", serif;
  font-size: 16px;
  font-style: italic;
}

.live-status {
  display: inline-flex;
  align-items: center;
  gap: 7px;
  color: var(--muted);
  font-size: 9px;
  font-weight: 800;
  letter-spacing: .16em;
}

.live-status i {
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: #3d8e61;
  box-shadow: 0 0 0 4px rgba(61, 142, 97, .13);
}

.tool-visual {
  height: 260px;
  margin: 38px 0 34px;
  position: relative;
  z-index: 1;
  border-radius: 17px;
  overflow: hidden;
}

.atlas-visual {
  display: grid;
  place-items: center;
  background: var(--atlas-soft);
}

.atlas-visual svg {
  width: 94%;
  height: auto;
}

.atlas-grid path {
  fill: none;
  stroke: rgba(36, 86, 196, .14);
  stroke-width: 1;
}

.atlas-brain .brain-outline {
  fill: rgba(255, 255, 255, .76);
  stroke: var(--atlas);
  stroke-width: 2.45;
}

.atlas-brain .brain-cortex {
  fill: rgba(255, 255, 255, .18);
  stroke: var(--atlas);
  stroke-width: 1.1;
}

.atlas-brain .brain-callosum {
  fill: rgba(255, 255, 255, .8);
  stroke: var(--atlas);
  stroke-width: 1.45;
}

.atlas-brain .brain-callosum-line {
  fill: none;
  stroke: rgba(36, 86, 196, .52);
  stroke-width: 1;
}

.atlas-brain .brain-striatum {
  fill: rgba(36, 86, 196, .14);
  stroke: var(--atlas);
  stroke-width: 1.15;
}

.atlas-brain .brain-ventricle {
  fill: #f4f7ff;
  stroke: var(--atlas);
  stroke-width: 1.5;
}

.atlas-brain .brain-third-ventricle {
  fill: var(--atlas);
  opacity: .75;
}

.atlas-brain .brain-midline {
  fill: none;
  stroke: var(--atlas);
  stroke-width: 1.15;
  stroke-dasharray: 3 3;
  opacity: .68;
}

.atlas-axis path,
.atlas-axis circle {
  fill: var(--atlas);
  stroke: var(--atlas);
  stroke-width: 1.5;
  opacity: .42;
}

.atlas-rotated path {
  fill: none;
  stroke: #c94a3f;
  stroke-width: 2.4;
}

.atlas-rotated circle {
  fill: #c94a3f;
}

.recorder-visual {
  padding: 24px;
  color: #fff;
  background: #1b211e;
}

.video-frame {
  height: 153px;
  display: grid;
  place-items: center;
  position: relative;
  border: 1px solid rgba(255, 255, 255, .15);
  border-radius: 11px;
  background:
    radial-gradient(circle at 68% 35%, rgba(255, 255, 255, .15), transparent 22%),
    linear-gradient(135deg, #303d36, #101511);
}

.play-symbol {
  width: 50px;
  height: 50px;
  display: grid;
  place-items: center;
  border: 1px solid rgba(255, 255, 255, .45);
  border-radius: 50%;
}

.play-symbol::before {
  content: "";
  margin-left: 4px;
  border-top: 7px solid transparent;
  border-bottom: 7px solid transparent;
  border-left: 11px solid #fff;
}

.video-timeline {
  height: 3px;
  position: absolute;
  right: 13px;
  bottom: 14px;
  left: 13px;
  background: rgba(255, 255, 255, .22);
}

.video-timeline span {
  width: 58%;
  height: 100%;
  display: block;
  background: var(--recorder);
}

.video-timeline i {
  width: 8px;
  height: 8px;
  position: absolute;
  top: 50%;
  left: 58%;
  border-radius: 50%;
  background: #fff;
  transform: translate(-50%, -50%);
}

.time-readout {
  margin: 17px 0 12px;
  font-family: "SFMono-Regular", Consolas, monospace;
  font-size: 23px;
  letter-spacing: -.04em;
}

.record-bars {
  display: flex;
  align-items: end;
  gap: 7px;
}

.record-bars span {
  width: var(--w);
  height: 8px;
  display: block;
  border-radius: 999px;
  background: var(--recorder);
}

.card-content {
  position: relative;
  z-index: 1;
}

.atlas-card .tool-kicker { color: var(--atlas); }
.recorder-card .tool-kicker { color: var(--recorder); }

.card-content h2 {
  max-width: 460px;
  margin: 11px 0 14px;
  font-family: Georgia, "Times New Roman", "Songti SC", serif;
  font-size: clamp(27px, 3vw, 38px);
  font-weight: 500;
  line-height: 1.18;
  letter-spacing: -.035em;
}

.card-content > p:last-child {
  max-width: 430px;
  margin: 0;
  color: var(--muted);
  font-size: 14px;
  line-height: 1.75;
}

.tool-link {
  margin-top: auto;
  padding-top: 28px;
  display: inline-flex;
  justify-content: space-between;
  align-items: center;
  position: relative;
  z-index: 1;
  border-top: 1px solid var(--line);
  font-size: 12px;
  font-weight: 780;
  letter-spacing: .06em;
}

.tool-link span {
  font-size: 18px;
  transition: transform .25s ease;
}

.tool-card:hover .tool-link span { transform: translate(3px, -3px); }

footer {
  min-height: 88px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  border-top: 1px solid var(--line);
}

@media (max-width: 800px) {
  .site-header,
  main,
  footer {
    width: min(100% - 30px, 620px);
  }

  .site-header { min-height: 72px; }
  .site-label { display: none; }
  main { padding: 62px 0 46px; }

  .hero {
    display: block;
    margin-bottom: 30px;
  }

  .hero h1 { margin-top: 10px; }

  .hero-note {
    max-width: none;
    margin-top: 20px;
    text-align: left;
  }

  .tools { grid-template-columns: 1fr; }
  .tool-card { min-height: 540px; }
  .tool-visual { height: 230px; margin: 30px 0; }
}

@media (max-width: 430px) {
  .brand { font-size: 10px; }
  .tool-card { padding: 17px; border-radius: 19px; }
  .tool-visual { height: 210px; }
  .recorder-visual { padding: 17px; }
  .video-frame { height: 130px; }
  footer { min-height: 74px; }
  footer span:last-child { display: none; }
}

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