/* Opt-in only: ?experience=spatial. The existing homepage stays the default. */
.spatial-preview .hero,
.spatial-preview .gallery-section {
  display: none;
}
.spatial-intro {
  --phone-width: clamp(174px, 23.7vh, 228px);
  margin-top: -96px;
  height: 240svh;
  position: relative;
  background: #fafafa;
}
.spatial-stage {
  height: 100svh;
  min-height: 680px;
  position: sticky;
  top: 0;
  overflow: clip;
  isolation: isolate;
  background: radial-gradient(
    ellipse at 50% 65%,
    #e9e9e9 0,
    #f5f5f5 29%,
    #fafafa 65%
  );
}
.spatial-opening,
.spatial-unfolded {
  position: absolute;
  top: max(122px, 13.2%);
  left: 24px;
  right: 24px;
  text-align: center;
  z-index: 2;
  pointer-events: none;
}
.spatial-kicker {
  font-size: 12px;
  font-weight: 600;
  letter-spacing: -0.2px;
  margin-bottom: 16px;
}
.spatial-kicker span {
  color: #7b7b7b;
  font-weight: 400;
  margin-left: 7px;
}
.spatial-opening h1 {
  font-size: clamp(54px, 5vw, 78px);
  font-weight: 550;
  letter-spacing: -4px;
  line-height: 1.04;
}
.spatial-opening h1 > span {
  display: block;
}
.spatial-opening h1 > span:last-child {
  color: #8a8a8a;
}
html[lang="zh-Hans"] .spatial-opening h1 {
  letter-spacing: -3px;
  font-weight: 580;
  line-height: 1.12;
}
.spatial-unfolded {
  opacity: 0;
  visibility: hidden;
  top: max(142px, 16%);
}
.spatial-unfolded h2 {
  font-size: clamp(32px, 3.5vw, 48px);
  font-weight: 550;
  letter-spacing: -1.8px;
}
.spatial-unfolded p {
  color: #757575;
  font-size: 15px;
  margin-top: 16px;
}
.spatial-world {
  position: absolute;
  top: 65%;
  left: 50%;
  width: 0;
  height: 0;
  perspective: 1400px;
  z-index: 1;
}
.spatial-parallax {
  width: 0;
  height: 0;
  transform-style: preserve-3d;
}
.spatial-orbit {
  position: absolute;
  width: 980px;
  height: 580px;
  margin: -250px 0 0 -490px;
  border: 1px solid #d8d8d8;
  border-radius: 50%;
  transform: translateZ(-420px) rotateX(67deg) rotateZ(-12deg);
  pointer-events: none;
}
.spatial-orbit::after {
  content: "";
  position: absolute;
  inset: 50px 70px;
  border: 1px solid #e0e0e0;
  border-radius: 50%;
}
.spatial-ground {
  position: absolute;
  width: 400px;
  height: 100px;
  left: -200px;
  top: 180px;
  border-radius: 50%;
  background: radial-gradient(ellipse, #3c3c3c24, #3c3c3c00 68%);
  pointer-events: none;
}
.spatial-phone-pose {
  position: absolute;
  width: var(--phone-width);
  left: calc(var(--phone-width) / -2);
  top: calc(var(--phone-width) * -1.0867);
  transform-style: preserve-3d;
  /* Keep idle UI text on a sharp 2D plane; drag rotation has its own wrapper. */
  transform: rotate(-9deg);
}
.spatial-phone-drag {
  transform-style: preserve-3d;
}
.spatial-device {
  display: block;
  position: relative;
  width: 100%;
  padding: 0;
  aspect-ratio: 1200 / 2608;
  border: 0;
  border-radius: 36px;
  background: transparent;
  box-shadow: none;
  cursor: grab;
  touch-action: pan-y;
  -webkit-user-select: none;
  user-select: none;
}
.spatial-device.is-dragging {
  cursor: grabbing;
}
.spatial-device-screen {
  display: block;
  position: relative;
  aspect-ratio: 1200 / 2608;
  overflow: hidden;
  border: 4px solid #181818;
  border-radius: 29px;
  background: #f6f6f6;
}
.spatial-device-screen img,
.spatial-device-screen video {
  position: absolute;
  inset: 0;
  height: 100%;
  width: 100%;
  object-fit: contain;
  pointer-events: none;
}
.spatial-device-screen video {
  opacity: 0;
  transition: opacity 0.18s;
}
.spatial-device-screen video.is-ready {
  opacity: 1;
}
.spatial-device-glint {
  display: none;
}
.spatial-phone-canvas {
  position: absolute;
  width: 200%;
  height: 130%;
  left: -50%;
  top: -15%;
  max-width: none;
  pointer-events: none;
  visibility: hidden;
}
.has-webgl-phone .spatial-phone-canvas {
  visibility: visible;
}
.has-webgl-phone .spatial-device-screen {
  opacity: 0;
}
.spatial-card {
  position: absolute;
  width: 214px;
  margin: -80px 0 0 -107px;
  padding: 0;
  border-radius: 17px;
  text-align: left;
  background: transparent;
  transform-style: preserve-3d;
  -webkit-user-select: none;
  user-select: none;
}
.spatial-card-face {
  display: flex;
  min-height: 160px;
  padding: 19px;
  flex-direction: column;
  border: 1px solid #fff;
  border-radius: inherit;
  background: #ffffffed;
  box-shadow:
    0 3px 4px #2a2a2a04,
    0 15px 30px -16px #35353530;
  transition:
    box-shadow 0.25s,
    background 0.25s,
    transform 0.25s;
}
.spatial-card:hover .spatial-card-face {
  transform: translateY(-5px);
  box-shadow: 0 18px 38px -14px #35353542;
}
.spatial-card.is-selected .spatial-card-face {
  background: #fff;
  box-shadow:
    0 0 0 1px #797979,
    0 15px 30px -16px #35353530;
}
.spatial-card-heading {
  display: flex;
  align-items: center;
  gap: 7px;
  font-size: 10px;
  font-weight: 500;
  color: #727272;
}
.spatial-card-heading > svg {
  width: 14px;
  height: 14px;
  margin-left: auto;
}
.spatial-card-index {
  font-variant-numeric: tabular-nums;
  color: #979797;
  font-size: 9px;
}
.spatial-course-name {
  font-size: 28px;
  font-weight: 550;
  line-height: 1.2;
  letter-spacing: -1px;
  margin-top: 18px;
}
.spatial-card-subtitle {
  color: #7a7a7a;
  font-size: 10px;
  line-height: 1.5;
}
.spatial-course-time {
  border-top: 1px solid #e6e6e6;
  display: flex;
  justify-content: space-between;
  margin-top: 14px;
  padding-top: 10px;
  font-size: 9px;
  color: #767676;
}
.spatial-wave {
  display: flex;
  height: 64px;
  align-items: center;
  justify-content: center;
  gap: 3px;
  margin-top: 9px;
}
.spatial-wave i {
  display: block;
  width: 2px;
  height: var(--bar-height);
  border-radius: 2px;
  background: #7a7a7a;
}
.spatial-question-text {
  font-size: 15px;
  font-weight: 500;
  line-height: 1.3;
  margin-top: 19px;
  margin-bottom: 17px;
  letter-spacing: -0.3px;
}
.spatial-source {
  display: flex;
  align-items: center;
  gap: 5px;
}
.spatial-source svg {
  width: 14px;
  height: 14px;
}
.spatial-recall-stack {
  display: block;
  position: relative;
  width: 103px;
  height: 56px;
  margin: 20px auto 16px;
}
.spatial-recall-stack > span {
  position: absolute;
  inset: 0;
  border-radius: 6px;
  border: 1px solid #dadada;
  background: #f4f4f4;
}
.spatial-recall-stack > span:nth-child(1) {
  transform: rotate(-13deg) translate(-6px, 1px);
}
.spatial-recall-stack > span:nth-child(2) {
  transform: rotate(9deg) translate(5px, -1px);
}
.spatial-recall-stack > span:last-child {
  display: flex;
  justify-content: center;
  align-items: center;
  gap: 14px;
  background: #f1f1f1;
  font-size: 16px;
  font-weight: 500;
}
.spatial-recall-stack svg {
  width: 18px;
  height: 18px;
  color: #858585;
}
.spatial-course {
  transform: translate(-260px, -110px) rotate(-8deg);
}
.spatial-recording {
  transform: translate(260px, -100px) rotate(9deg);
}
.spatial-question {
  transform: translate(-260px, 110px) rotate(4deg);
}
.spatial-recall {
  transform: translate(260px, 120px) rotate(-6deg);
}
.spatial-footer {
  position: absolute;
  bottom: 62px;
  left: max(32px, 5%);
  right: max(32px, 5%);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
  z-index: 3;
}
.spatial-drag-hint {
  display: flex;
  align-items: center;
  gap: 9px;
  color: #757575;
  font-size: 11px;
}
.spatial-drag-hint svg {
  width: 23px;
  height: 23px;
}
.spatial-explore {
  display: inline-flex;
  align-items: center;
  gap: 13px;
  font-size: 12px;
  font-weight: 500;
  text-decoration: none;
  min-height: 44px;
}
.spatial-explore svg {
  width: 20px;
  height: 20px;
}
.spatial-demo-note {
  position: absolute;
  bottom: 17px;
  left: 24px;
  right: 24px;
  color: #7d7d7d;
  font-size: 9px;
  display: flex;
  justify-content: center;
  align-items: center;
  gap: 15px;
  z-index: 3;
}
.spatial-demo-note a {
  text-underline-offset: 3px;
  min-height: 24px;
  display: flex;
  align-items: center;
}
.spatial-preview .intro-section {
  margin-top: 0;
}
.spatial-intro.is-static {
  height: auto;
}
.spatial-intro.is-static .spatial-stage {
  position: relative;
}
.spatial-intro.is-static .spatial-drag-hint {
  visibility: hidden;
}
@media (min-width: 621px) and (max-width: 850px) {
  .spatial-intro {
    margin-top: -80px;
  }
}
@media (min-width: 1700px) {
  .spatial-intro {
    --phone-width: 248px;
  }
}
@media (max-width: 960px) {
  .spatial-opening h1 {
    font-size: 64px;
  }
  .spatial-card {
    width: 174px;
    margin-left: -87px;
  }
  .spatial-card-face {
    padding: 15px;
    min-height: 145px;
  }
  .spatial-course {
    transform: translate(-224px, -105px) rotate(-8deg);
  }
  .spatial-recording {
    transform: translate(224px, -95px) rotate(9deg);
  }
  .spatial-question {
    transform: translate(-224px, 100px) rotate(4deg);
  }
  .spatial-recall {
    transform: translate(224px, 110px) rotate(-6deg);
  }
}
@media (max-width: 620px) {
  .spatial-intro {
    --phone-width: clamp(148px, 19.4vh, 164px);
    margin-top: -80px;
    height: 210svh;
  }
  .spatial-stage {
    min-height: 820px;
  }
  .spatial-opening {
    top: 120px;
    left: 12px;
    right: 12px;
  }
  .spatial-kicker {
    font-size: 10px;
    margin-bottom: 16px;
  }
  .spatial-opening h1 {
    font-size: clamp(39px, 11.2vw, 58px);
    letter-spacing: -2px;
    line-height: 1.07;
  }
  html[lang="zh-Hans"] .spatial-opening h1 {
    letter-spacing: -1px;
  }
  .spatial-world {
    top: 53%;
  }
  .spatial-phone-pose {
    transform: rotate(-7deg);
  }
  .spatial-device {
    border-radius: 28px;
    padding: 0;
  }
  .spatial-device-screen {
    border-width: 3px;
    border-radius: 23px;
  }
  .spatial-orbit {
    width: 550px;
    height: 400px;
    margin-left: -275px;
    margin-top: -180px;
  }
  .spatial-ground {
    width: 260px;
    left: -130px;
    top: 140px;
  }
  .spatial-card {
    width: 142px;
    margin: -27px 0 0 -71px;
  }
  .spatial-card-face {
    min-height: 54px;
    height: 54px;
    padding: 10px;
    border-radius: 12px;
  }
  .spatial-card-heading {
    font-size: 11px;
    gap: 5px;
  }
  .spatial-card-heading svg {
    width: 12px;
  }
  .spatial-card-face > :not(.spatial-card-heading) {
    display: none;
  }
  .spatial-card {
    border-radius: 12px;
  }
  .spatial-course {
    transform: translate(-78px, 215px) rotate(-3deg);
  }
  .spatial-recording {
    transform: translate(78px, 215px) rotate(3deg);
  }
  .spatial-question {
    transform: translate(-78px, 276px) rotate(2deg);
  }
  .spatial-recall {
    transform: translate(78px, 276px) rotate(-2deg);
  }
  .spatial-unfolded {
    top: 128px;
  }
  .spatial-unfolded h2 {
    font-size: clamp(25px, 7vw, 34px);
    letter-spacing: -0.8px;
  }
  .spatial-unfolded p {
    font-size: 12px;
    margin-top: 12px;
  }
  .spatial-footer {
    bottom: 42px;
    left: 20px;
    right: 20px;
  }
  .spatial-drag-hint {
    font-size: 10px;
    gap: 4px;
  }
  .spatial-drag-hint svg {
    width: 17px;
  }
  .spatial-explore {
    margin-left: auto;
    font-size: 10px;
    min-height: 30px;
  }
  .spatial-explore svg {
    width: 15px;
  }
  .spatial-demo-note {
    bottom: 8px;
    font-size: 10px;
    left: 12px;
    right: 12px;
    gap: 2px 8px;
    flex-wrap: wrap;
  }
}
@media (min-width: 621px) and (max-width: 760px) {
  .spatial-card {
    width: 148px;
    margin-left: -74px;
  }
  .spatial-course {
    transform: translate(-200px, -105px) rotate(-6deg);
  }
  .spatial-recording {
    transform: translate(200px, -95px) rotate(6deg);
  }
  .spatial-question {
    transform: translate(-200px, 100px) rotate(3deg);
  }
  .spatial-recall {
    transform: translate(200px, 110px) rotate(-3deg);
  }
}
@media (max-width: 360px) {
  html[lang="en"] .spatial-opening h1 {
    font-size: 34px;
    letter-spacing: -1.7px;
  }
}
@media (max-height: 780px) and (min-width: 621px) {
  .spatial-intro {
    --phone-width: 170px;
  }
  .spatial-opening {
    top: 120px;
  }
  .spatial-opening h1 {
    font-size: 56px;
  }
  .spatial-world {
    top: 65%;
  }
  .spatial-card {
    transform-origin: center;
  }
}
@media (max-height: 740px) and (max-width: 620px) {
  .spatial-intro {
    height: auto;
  }
  .spatial-stage {
    height: 790px;
    position: relative;
  }
  .spatial-world {
    top: 52%;
  }
}
@media (max-height: 740px) and (min-width: 621px) {
  .spatial-intro {
    height: auto;
  }
  .spatial-stage {
    height: 800px;
    position: relative;
  }
  .spatial-world {
    top: 60%;
  }
}
@media (prefers-reduced-motion: reduce) {
  .spatial-intro {
    height: auto;
  }
  .spatial-stage {
    position: relative;
  }
  .spatial-device-screen video,
  .spatial-card-face {
    transition: none;
  }
  .spatial-device {
    cursor: default;
  }
  .spatial-drag-hint {
    visibility: hidden;
  }
}