:root {
  color-scheme: dark;
  --bg: #0b0f14;
  --fg: #f2f5f7;
  --muted: #a8b3bd;
  --accent: #7ee6ff;
  --accent-2: #b68cff;
  --card: rgba(255, 255, 255, 0.06);
  --border: rgba(255, 255, 255, 0.12);
}
* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}
body {
  font-family:
    "Inter",
    "SF Pro Display",
    system-ui,
    -apple-system,
    sans-serif;
  background: radial-gradient(1200px 800px at 20% 90%, #1a2230 0%, transparent 55%),
    radial-gradient(900px 600px at 80% 85%, #241b38 0%, transparent 60%), var(--bg);
  color: var(--fg);
  height: 100vh;
  overflow: hidden;
}
.spacetime-grid {
  position: fixed;
  inset: 0;
  z-index: 0;
  pointer-events: none;
}
.spacetime-grid canvas {
  width: 100%;
  height: 100%;
  display: block;
  opacity: 0.55;
}
.top-links {
  position: fixed;
  top: 24px;
  right: 32px;
  z-index: 4;
  display: flex;
  gap: 16px;
  align-items: center;
  font-size: 0.95rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--fg);
}
.top-links a {
  color: inherit;
  text-decoration: none;
  opacity: 0.8;
}
.top-links a:hover {
  opacity: 1;
}
.lang-switch {
  display: flex;
  gap: 8px;
  align-items: center;
}
.lang-strong {
  font-weight: 700;
}
.top-home {
  position: fixed;
  top: 16px;
  left: 32px;
  z-index: 4;
  color: var(--fg);
  text-decoration: none;
  font-size: 1.4rem;
  letter-spacing: 0.2em;
  opacity: 0.8;
}
.top-home:hover {
  opacity: 1;
}
.deck {
  height: 100vh;
  width: 100vw;
  position: relative;
  z-index: 1;
}
.is-hidden {
  opacity: 0 !important;
  pointer-events: none !important;
}

@media (max-width: 768px) {
  .line.mobile-hide {
    display: none;
  }
  .progress {
    margin: 0 auto;
  }
}
.teaser {
  position: fixed;
  inset: 0;
  display: grid;
  place-items: center;
  z-index: 2;
  background: transparent;
}
.teaser-inner {
  display: grid;
  gap: 2vh;
  justify-items: center;
}
.slide {
  position: absolute;
  inset: 0;
  padding: 6vh 7vw 7vh;
  display: flex;
  flex-direction: column;
  justify-content: center;
  gap: 2vh;
  opacity: 0;
  transform: translateY(20px) scale(0.98);
  transition:
    opacity 420ms ease,
    transform 420ms ease;
  pointer-events: none;
  user-select: none;
}
.slide.active {
  opacity: 1;
  transform: translateY(0) scale(1);
  pointer-events: auto;
}
.kicker {
  text-transform: uppercase;
  letter-spacing: 0.2em;
  font-size: 0.8rem;
  color: var(--accent);
}
.title {
  font-size: clamp(2.6rem, 4.8vw, 5rem);
  font-weight: 600;
}
.subtitle {
  font-size: clamp(1.2rem, 2.2vw, 2rem);
  color: var(--muted);
  max-width: 900px;
}
.two-col {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 3vw;
}
.card {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 18px;
  padding: 3vh 2.5vw;
}
ul {
  list-style: none;
  display: grid;
  gap: 1.4vh;
}
li {
  padding-left: 1.2rem;
  position: relative;
}
li::before {
  content: "•";
  position: absolute;
  left: 0;
  color: var(--accent);
}
.line {
  display: grid;
  gap: 0.35rem;
}
.en {
  font-size: clamp(1.05rem, 1.6vw, 1.6rem);
}
.zh {
  font-size: clamp(0.95rem, 1.3vw, 1.2rem);
  color: var(--muted);
}
.metric {
  display: grid;
  gap: 0.4rem;
  font-size: clamp(1.2rem, 1.8vw, 1.8rem);
}
.hero-cta {
  display: grid;
  gap: 1.5vh;
  margin-top: 2vh;
  align-items: start;
  justify-items: start;
}
.ai-wordmark {
  max-height: 360px;
  max-width: 100%;
  width: auto;
  margin: 0 auto;
  pointer-events: none;
  user-select: none;
}
.ai-title-image {
  position: fixed;
  top: -36px;
  left: 50%;
  transform: translateX(-50%);
  max-height: 160px;
  pointer-events: none;
  user-select: none;
}
.open-button {
  font-size: clamp(1rem, 1.4vw, 1.4rem);
  padding: 0.9rem 2.2rem;
  border-radius: 999px;
  border: 1px solid rgba(255, 255, 255, 0.4);
  background: rgba(255, 255, 255, 0.08);
  color: #f7f6f3;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  cursor: pointer;
}
.monarch-foil {
  position: relative;
  display: inline-block;
  perspective: 1000px;
  transform-style: preserve-3d;
  --foil-x: 50%;
  --foil-y: 50%;
  --foil-rotate-x: 0deg;
  --foil-rotate-y: 0deg;
  --foil-opacity: 0;
  --foil-glare-opacity: 0;
  --monarch-foil-image: none;
}
.monarch-foil__inner {
  position: relative;
  width: 100%;
  height: 100%;
  transform-style: preserve-3d;
  transform: rotateX(var(--foil-rotate-x)) rotateY(var(--foil-rotate-y)) translateZ(0);
  transition: transform 0.3s ease;
  will-change: transform;
}
.monarch-foil.is-hovered .monarch-foil__inner {
  transform: rotateX(var(--foil-rotate-x)) rotateY(var(--foil-rotate-y)) translateZ(10px) scale(1.2);
}
.monarch-foil__foil,
.monarch-foil__glare {
  position: absolute;
  inset: 0;
  pointer-events: none;
  mask-image: var(--monarch-foil-image);
  -webkit-mask-image: var(--monarch-foil-image);
  mask-repeat: no-repeat;
  -webkit-mask-repeat: no-repeat;
  mask-position: center;
  -webkit-mask-position: center;
  mask-size: contain;
  -webkit-mask-size: contain;
  border-radius: 999px;
}
.monarch-foil__foil {
  background-image: linear-gradient(
      135deg,
      hsl(192, 97%, 60%) 0%,
      hsl(281, 62%, 58%) 25%,
      hsl(54, 87%, 63%) 50%,
      hsl(9, 81%, 59%) 75%,
      hsl(192, 97%, 60%) 100%
    ),
    radial-gradient(
      farthest-corner circle at var(--foil-x) var(--foil-y),
      hsla(180, 100%, 89%, 0.5) 5%,
      hsla(180, 14%, 57%, 0.3) 40%,
      hsl(0, 0%, 0%) 130%
    );
  background-size: 400% 400%;
  background-position: var(--foil-x) var(--foil-y);
  background-blend-mode: normal;
  filter: brightness(1) contrast(1) saturate(0.8);
  mix-blend-mode: color-dodge;
  opacity: var(--foil-opacity);
  transition: opacity 0.3s ease;
}
.monarch-foil__glare {
  background: radial-gradient(
    farthest-corner circle at var(--foil-x) var(--foil-y),
    hsla(204, 100%, 95%, 0.8) 5%,
    hsla(250, 15%, 20%, 1) 150%
  );
  filter: brightness(0.75) contrast(2) saturate(2);
  mix-blend-mode: overlay;
  opacity: var(--foil-glare-opacity);
  transition: opacity 0.3s ease;
}
@media (prefers-reduced-motion: reduce) {
  .monarch-foil__inner {
    transition: none;
  }
  .monarch-foil__foil,
  .monarch-foil__glare {
    transition: none;
  }
}
@media (pointer: coarse) {
  .monarch-foil__inner {
    transition: none;
  }
}
.quote {
  font-size: clamp(1.2rem, 2vw, 2.2rem);
  line-height: 1.4;
  color: var(--accent);
}
.footer {
  position: absolute;
  left: 5vw;
  right: 5vw;
  bottom: 3vh;
  display: flex;
  align-items: center;
  justify-content: space-between;
  color: var(--muted);
  font-size: 0.9rem;
  z-index: 1;
}
.progress {
  height: 4px;
  width: 45vw;
  background: rgba(255, 255, 255, 0.08);
  border-radius: 999px;
  overflow: hidden;
}
.progress span {
  display: block;
  height: 100%;
  width: 0%;
  background: linear-gradient(90deg, var(--accent), var(--accent-2));
  transition: width 420ms ease;
}
.notes {
  margin-top: 3vh;
  padding-top: 2vh;
  border-top: 1px solid var(--border);
  display: none;
  gap: 0.5rem;
}
body.show-notes .notes {
  display: grid;
}
.notes .en {
  font-size: 1rem;
}
.notes .zh {
  font-size: 0.95rem;
}
@media (max-width: 900px) {
  .two-col {
    grid-template-columns: 1fr;
  }
  .footer {
    flex-direction: column;
    gap: 1vh;
    align-items: flex-start;
  }
  .progress {
    width: 70vw;
  }
  .slide-compact {
    gap: 1.2vh;
  }
  .slide-compact .title {
    font-size: clamp(2rem, 7vw, 3rem);
  }
  .slide-compact .subtitle {
    font-size: clamp(1rem, 3.6vw, 1.4rem);
  }
}