:root {
  --bg: #07111f;
  --fg: #f4f7fb;
  --muted: rgba(244, 247, 251, 0.72);
  --line: rgba(255, 255, 255, 0.12);
  --card: rgba(10, 18, 32, 0.7);
  --card-strong: rgba(17, 29, 50, 0.88);
  --accent: #67d3ff;
  --accent-2: #7c5cff;
  --shadow: 0 30px 80px rgba(0, 0, 0, 0.38);
}

* {
  box-sizing: border-box;
}

html {
  scroll-snap-type: y mandatory;
  scroll-behavior: smooth;
}

body {
  margin: 0;
  min-height: 100vh;
  color: var(--fg);
  background:
    radial-gradient(circle at top left, rgba(103, 211, 255, 0.14), transparent 32%),
    radial-gradient(circle at bottom right, rgba(124, 92, 255, 0.16), transparent 30%),
    linear-gradient(180deg, #050a13 0%, #08111e 60%, #050913 100%);
  font-family: "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", system-ui, sans-serif;
  overflow-x: hidden;
}

body::before {
  content: "";
  position: fixed;
  inset: 0;
  background-image:
    linear-gradient(rgba(255, 255, 255, 0.03) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255, 255, 255, 0.03) 1px, transparent 1px);
  background-size: 48px 48px;
  pointer-events: none;
  mask-image: linear-gradient(180deg, rgba(0, 0, 0, 0.2), rgba(0, 0, 0, 0.8));
}

.backdrop {
  position: fixed;
  inset: auto;
  border-radius: 999px;
  filter: blur(60px);
  opacity: 0.5;
  pointer-events: none;
}

.backdrop-a {
  width: 28rem;
  height: 28rem;
  left: -6rem;
  top: 4rem;
  background: rgba(103, 211, 255, 0.16);
}

.backdrop-b {
  width: 24rem;
  height: 24rem;
  right: -6rem;
  bottom: 4rem;
  background: rgba(124, 92, 255, 0.16);
}

.shell {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 20;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 1rem 1.25rem;
  backdrop-filter: blur(14px);
  background: linear-gradient(180deg, rgba(4, 10, 18, 0.74), rgba(4, 10, 18, 0.18));
  border-bottom: 1px solid rgba(255, 255, 255, 0.08);
}

.brand,
.deck-meta,
.controls {
  display: flex;
  align-items: center;
  gap: 0.75rem;
}

.brand-mark {
  font-weight: 800;
  letter-spacing: 0.28em;
  font-size: 0.8rem;
  text-transform: uppercase;
}

.brand-copy,
.deck-meta {
  color: var(--muted);
  font-size: 0.92rem;
}

.divider {
  width: 1px;
  height: 1rem;
  background: var(--line);
}

.progress {
  position: fixed;
  top: 4.45rem;
  left: 0;
  right: 0;
  z-index: 19;
  height: 3px;
  background: rgba(255, 255, 255, 0.06);
}

.progress > div {
  height: 100%;
  width: 0;
  background: linear-gradient(90deg, var(--accent), var(--accent-2));
  box-shadow: 0 0 18px rgba(103, 211, 255, 0.55);
  transition: width 180ms ease;
}

.deck {
  position: relative;
  z-index: 1;
}

.slide {
  min-height: 100vh;
  padding: 7rem 1.25rem 4rem;
  scroll-snap-align: start;
  display: flex;
  align-items: center;
}

.slide-grid {
  width: min(1160px, 100%);
  margin: 0 auto;
  display: grid;
  grid-template-columns: 1.1fr 0.9fr;
  gap: 2rem;
  align-items: center;
}

.hero {
  grid-template-columns: 1.15fr 0.85fr;
}

.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  margin: 0 0 1rem;
  text-transform: uppercase;
  letter-spacing: 0.24em;
  color: rgba(255, 255, 255, 0.72);
  font-size: 0.8rem;
}

.eyebrow::before {
  content: "";
  width: 1.2rem;
  height: 1px;
  background: currentColor;
}

h1,
h2,
h3,
p {
  margin: 0;
}

h1 {
  font-size: clamp(3rem, 7vw, 6.4rem);
  line-height: 0.95;
  letter-spacing: -0.04em;
  max-width: 10ch;
}

h2 {
  font-size: clamp(2.2rem, 4.2vw, 4.6rem);
  line-height: 1;
  letter-spacing: -0.04em;
  max-width: 12ch;
}

h3 {
  font-size: 1.25rem;
  line-height: 1.15;
}

.lead,
.body,
.panel-card p,
.card p,
.hint {
  color: var(--muted);
}

.lead {
  margin-top: 1.35rem;
  font-size: 1.15rem;
  line-height: 1.8;
  max-width: 42rem;
}

.body {
  margin-top: 1.15rem;
  max-width: 38rem;
  font-size: 1.02rem;
  line-height: 1.9;
}

.hero-points {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
  margin-top: 1.5rem;
}

.hero-points span,
.tag {
  display: inline-flex;
  align-items: center;
  padding: 0.55rem 0.85rem;
  border-radius: 999px;
  border: 1px solid rgba(255, 255, 255, 0.14);
  background: rgba(255, 255, 255, 0.05);
  color: rgba(255, 255, 255, 0.88);
  font-size: 0.9rem;
}

.panel-card,
.card {
  border: 1px solid rgba(255, 255, 255, 0.12);
  background: linear-gradient(180deg, rgba(20, 29, 46, 0.82), rgba(11, 18, 31, 0.88));
  box-shadow: var(--shadow);
  border-radius: 28px;
}

.panel-card {
  padding: 1.6rem;
}

.panel-kicker {
  text-transform: uppercase;
  letter-spacing: 0.22em;
  font-size: 0.76rem;
  color: rgba(255, 255, 255, 0.6);
  margin-bottom: 0.8rem;
}

.panel-card h2,
.panel-card h3 {
  max-width: 10ch;
}

.panel-card ul {
  margin: 1.2rem 0 0;
  padding-left: 1.1rem;
  line-height: 2;
  color: rgba(255, 255, 255, 0.82);
}

.pulse {
  position: relative;
  overflow: hidden;
}

.pulse::after {
  content: "";
  position: absolute;
  inset: auto -20% -35% auto;
  width: 15rem;
  height: 15rem;
  border-radius: 50%;
  background: radial-gradient(circle, rgba(103, 211, 255, 0.3), transparent 62%);
}

.stack,
.bullets {
  display: grid;
  gap: 1rem;
}

.card {
  padding: 1.15rem 1.25rem;
}

.card strong {
  display: block;
  margin-bottom: 0.4rem;
  font-size: 1rem;
}

.card p,
.card span {
  color: var(--muted);
  line-height: 1.8;
}

.slide-grid > :first-child {
  align-self: start;
}

.hint {
  position: absolute;
  left: 50%;
  transform: translateX(-50%);
  bottom: 1.2rem;
  font-size: 0.88rem;
}

.hint kbd {
  display: inline-flex;
  align-items: center;
  padding: 0.15rem 0.38rem;
  border-radius: 0.4rem;
  border: 1px solid rgba(255, 255, 255, 0.18);
  background: rgba(255, 255, 255, 0.06);
  color: #fff;
}

.controls {
  position: fixed;
  right: 1rem;
  bottom: 1rem;
  z-index: 20;
  gap: 0.5rem;
}

.controls button {
  width: 3rem;
  height: 3rem;
  border: 1px solid rgba(255, 255, 255, 0.16);
  border-radius: 999px;
  color: var(--fg);
  background: rgba(8, 14, 24, 0.8);
  backdrop-filter: blur(14px);
  box-shadow: var(--shadow);
  cursor: pointer;
  font-size: 1.05rem;
}

.controls button:hover {
  transform: translateY(-1px);
  background: rgba(18, 28, 44, 0.92);
}

.theme-cobalt {
  --accent: #67d3ff;
  --accent-2: #7c5cff;
}

.theme-sand {
  --accent: #f6c36b;
  --accent-2: #ff8d6b;
}

.theme-forest {
  --accent: #67e2a2;
  --accent-2: #2bbbad;
}

.theme-amber {
  --accent: #ffd166;
  --accent-2: #ff7b54;
}

.theme-rose {
  --accent: #ff8bc5;
  --accent-2: #e45d9a;
}

.theme-crimson {
  --accent: #ff7866;
  --accent-2: #b83248;
}

.theme-slate {
  --accent: #9fb6d9;
  --accent-2: #72829b;
}

.theme-blue {
  --accent: #78b7ff;
  --accent-2: #456df0;
}

.theme-olive {
  --accent: #aecb77;
  --accent-2: #6d8f47;
}

.theme-midnight {
  --accent: #67d3ff;
  --accent-2: #6d8cff;
}

@media (max-width: 920px) {
  .shell {
    padding: 0.9rem 1rem;
  }

  .deck-meta {
    display: none;
  }

  .slide {
    padding-inline: 1rem;
    padding-top: 6.4rem;
  }

  .slide-grid,
  .hero {
    grid-template-columns: 1fr;
  }

  h1 {
    max-width: 100%;
    font-size: clamp(2.6rem, 12vw, 4.4rem);
  }

  h2 {
    max-width: 100%;
    font-size: clamp(2rem, 9vw, 3.3rem);
  }

  .hint {
    left: 1rem;
    transform: none;
    right: 1rem;
    text-align: center;
  }
}

@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }

  .progress > div,
  .controls button {
    transition: none;
  }
}

@media print {
  .shell,
  .progress,
  .controls,
  .hint,
  .backdrop {
    display: none !important;
  }

  html {
    scroll-snap-type: none;
  }

  body {
    background: #fff;
    color: #111;
  }

  .slide {
    min-height: auto;
    padding: 1.5rem 0;
    page-break-after: always;
  }
}