@font-face {
  font-family: "Yozai Annotation";
  src: url("vendor/fonts/yozai-annotations.woff2?v=3") format("woff2");
  font-style: normal;
  font-weight: 400;
  font-display: swap;
}

:root {
  --canvas: #f6f5f1;
  --surface: #fff;
  --surface-muted: #ecece6;
  --ink: #171914;
  --ink-secondary: #676b63;
  --ink-tertiary: #777d73;
  --green: #0a8f4b;
  --green-bright: #18b866;
  --mint: #dcefe3;
  --blue: #5b8def;
  --line: rgba(23, 25, 20, 0.11);
  --line-strong: rgba(23, 25, 20, 0.2);
  --shadow-soft: 0 24px 70px rgba(34, 43, 35, 0.08);
  --shadow-float: 0 28px 80px rgba(17, 30, 22, 0.15);
  --dark-canvas: #121510;
  --dark-surface: #1b201a;
  --dark-ink: #f1f3ed;
  --dark-ink-secondary: rgba(241, 243, 237, 0.84);
  --dark-ink-tertiary: rgba(241, 243, 237, 0.72);
  --dark-ring: 0 0 0 1px rgba(255, 255, 255, 0.08);
  --dark-ring-hover: 0 0 0 1px rgba(255, 255, 255, 0.14), 0 18px 44px rgba(0, 0, 0, 0.2);
  --ease-out-quint: cubic-bezier(0.22, 1, 0.36, 1);
  --radius-xl: 2.75rem;
  --radius-lg: 2rem;
  --radius-md: 1.25rem;
  --font: "Satoshi", -apple-system, BlinkMacSystemFont, "SF Pro Display", "PingFang SC", "Hiragino Sans GB", sans-serif;
  --annotation-font: "Yozai Annotation", "Yozai", "LXGW WenKai", "Kaiti SC", "STKaiti", "KaiTi", "楷体", cursive;
  color-scheme: light;
}

* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  scroll-behavior: smooth;
  scroll-padding-top: 5rem;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

body {
  min-width: 320px;
  overflow-x: hidden;
  background:
    radial-gradient(circle at 50% 4%, rgba(220, 239, 227, 0.72), transparent 27rem),
    var(--canvas);
  color: var(--ink);
  font-family: var(--font);
  font-size: 1rem;
  font-weight: 400;
  line-height: 1.7;
  text-rendering: optimizeLegibility;
}

h1,
h2,
h3 {
  text-wrap: balance;
}

p,
li,
small,
blockquote {
  text-wrap: pretty;
}

main {
  width: 100%;
  max-width: 100%;
  overflow-x: clip;
}

a {
  color: inherit;
  text-decoration: none;
}

button {
  color: inherit;
}

.ann {
  --ann-font: var(--annotation-font);
}

.ann::after {
  font-size: 12px;
}

.wrap {
  width: min(100% - 3rem, 72rem);
  margin-inline: auto;
}

.chapter {
  padding: clamp(6rem, 11vw, 10rem) 0;
}

.chapter-heading {
  max-width: 42rem;
  margin-bottom: clamp(2.5rem, 5vw, 4.5rem);
}

.chapter-heading-wide {
  max-width: 54rem;
}

.chapter-heading h2,
.difference-heading h2 {
  font-size: clamp(2.35rem, 5vw, 4.7rem);
  font-weight: 700;
  letter-spacing: -0.03em;
  line-height: 1.12;
}

.chapter-heading p,
.difference-heading p {
  max-width: 38rem;
  margin-top: 1.25rem;
  color: var(--ink-secondary);
  font-size: clamp(1rem, 1.6vw, 1.15rem);
  line-height: 1.7;
}

.nav {
  position: fixed;
  inset: 0 0 auto;
  z-index: 50;
  padding-top: env(safe-area-inset-top);
  transition: color 240ms ease, background-color 240ms ease, box-shadow 240ms ease, backdrop-filter 240ms ease;
}

.nav::after {
  position: absolute;
  inset: 100% 0 auto;
  height: 1rem;
  background: linear-gradient(to bottom, rgba(246, 245, 241, 0.55), transparent);
  content: "";
  opacity: 0;
  pointer-events: none;
  transition: opacity 240ms ease;
}

.nav.is-scrolled {
  background: rgba(246, 245, 241, 0.78);
  box-shadow: inset 0 -1px var(--line);
  backdrop-filter: blur(20px) saturate(160%);
  -webkit-backdrop-filter: blur(20px) saturate(160%);
}

.nav.is-scrolled::after {
  opacity: 1;
}

.nav.is-dark {
  background: rgba(18, 21, 16, 0.86);
  box-shadow: inset 0 -1px rgba(255, 255, 255, 0.08);
  color: var(--dark-ink);
}

.nav.is-dark::after {
  background: linear-gradient(to bottom, rgba(18, 21, 16, 0.58), transparent);
}

.nav.is-dark .nav-by {
  color: var(--dark-ink-tertiary);
}

.nav.is-dark .nav-cta {
  background: var(--dark-ink);
  color: var(--ink);
}

.nav.is-dark .nav-cta:hover {
  background: #fff;
}

.nav-inner {
  width: min(100% - 3rem, 72rem);
  min-height: 4.5rem;
  margin-inline: auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.nav-brand {
  display: inline-flex;
  align-items: center;
  gap: 0.6rem;
}

.mark {
  width: 1.55rem;
  height: 1.55rem;
  flex: none;
}

.mark svg {
  display: block;
  width: 100%;
  height: 100%;
}

.nav-name {
  font-size: 1rem;
  font-weight: 700;
  letter-spacing: -0.02em;
}

.nav-by {
  color: var(--ink-tertiary);
  font-size: 0.72rem;
  letter-spacing: 0.035em;
}

.nav-cta {
  min-height: 2.4rem;
  padding: 0 1.1rem;
  display: inline-flex;
  align-items: center;
  border-radius: 999px;
  background: var(--ink);
  color: #fff;
  font-size: 0.82rem;
  font-weight: 700;
  transition:
    opacity 180ms ease,
    transform 240ms var(--ease-out-quint),
    visibility 0s linear,
    background-color 180ms ease;
}

.nav.is-cta-managed .nav-cta {
  opacity: 0;
  visibility: hidden;
  pointer-events: none;
  transform: translateY(-0.35rem) scale(0.97);
  transition-delay: 0s, 0s, 240ms, 0s;
}

.nav.is-cta-managed.is-cta-visible .nav-cta {
  opacity: 1;
  visibility: visible;
  pointer-events: auto;
  transform: none;
  transition-delay: 0s;
}

.nav-cta:hover {
  background: #2d3029;
  transform: translateY(-1px);
}

.hero {
  position: relative;
  min-height: min(54rem, 100svh);
  padding: clamp(9rem, 18vh, 13rem) 0 clamp(6rem, 12vh, 9rem);
  display: grid;
  place-items: center;
  overflow: clip;
  isolation: isolate;
}

.hero::before {
  position: absolute;
  inset: 4.5rem 0 0;
  z-index: -1;
  background:
    radial-gradient(ellipse 36% 43% at 50% 42%, rgba(220, 239, 227, 0.62), transparent 74%),
    radial-gradient(circle at 14% 32%, rgba(91, 141, 239, 0.06), transparent 19rem),
    radial-gradient(circle at 86% 68%, rgba(24, 184, 102, 0.07), transparent 21rem);
  -webkit-mask-image: linear-gradient(
    to bottom,
    #000 0%,
    #000 66%,
    rgba(0, 0, 0, 0.88) 76%,
    rgba(0, 0, 0, 0.42) 89%,
    transparent 100%
  );
  mask-image: linear-gradient(
    to bottom,
    #000 0%,
    #000 66%,
    rgba(0, 0, 0, 0.88) 76%,
    rgba(0, 0, 0, 0.42) 89%,
    transparent 100%
  );
  content: "";
  pointer-events: none;
}

.hero-inner {
  position: relative;
  z-index: 2;
  text-align: center;
}

.hero-card-scatter {
  position: absolute;
  inset: 4.5rem 0 0;
  z-index: 0;
  overflow: hidden;
  pointer-events: none;
}

.hero-edge-card {
  --card-opacity: 0.62;
  --card-rotate: 0deg;
  --card-from-x: 0;
  --card-from-y: 0;
  --card-from-rotate: 0deg;
  position: absolute;
  width: clamp(9rem, 14vw, 13rem);
  aspect-ratio: 1.55;
  overflow: hidden;
  border: 1px solid currentColor;
  border-radius: clamp(0.65rem, 1vw, 0.95rem);
  background: rgba(255, 255, 255, 0.32);
  color: var(--card-light-color);
  opacity: 0;
  transform-origin: center;
}

.hero-card-scatter.is-ready .hero-edge-card {
  animation: hero-card-arrive 820ms var(--ease-out-quint) forwards;
  animation-delay: var(--card-delay, 0ms);
}

.hero-edge-card[data-hero-card-side="left"] {
  top: var(--card-top, 12%);
  left: var(--card-edge, -3rem);
}

.hero-edge-card[data-hero-card-side="right"] {
  top: var(--card-top, 12%);
  right: var(--card-edge, -3rem);
}

@keyframes hero-card-arrive {
  from {
    opacity: 0;
    transform:
      translate3d(var(--card-from-x), var(--card-from-y), 0)
      rotate(var(--card-from-rotate))
      scale(0.84);
  }

  to {
    opacity: var(--card-opacity);
    transform: translate3d(0, 0, 0) rotate(var(--card-rotate)) scale(1);
  }
}

.hero-mark {
  width: 3.5rem;
  height: 3.5rem;
  margin: 0 auto 1.75rem;
  display: block;
  filter: drop-shadow(0 0.75rem 1.5rem rgba(52, 180, 130, 0.24));
}

.hero-mark svg {
  width: 100%;
  height: 100%;
  display: block;
}

.hero-mark .face-star,
.hero-mark .face-wink {
  transform-origin: 24px 23px;
}

.hero-mark .face-star {
  animation: hero-star-cycle 4.8s ease-in-out infinite;
}

.hero-mark .face-wink {
  opacity: 0;
  animation: hero-wink-cycle 4.8s ease-in-out infinite;
}

.hero-mark .eye-closed {
  transform-box: fill-box;
  transform-origin: center;
  animation: hero-peek-shut 4.8s linear infinite;
}

.hero-mark .eye-peek {
  opacity: 0;
  transform-box: fill-box;
  transform-origin: center;
  animation: hero-peek-open 4.8s linear infinite;
}

@keyframes hero-star-cycle {
  0%, 58% {
    opacity: 1;
    transform: scale(1) rotate(0);
  }

  62%, 90% {
    opacity: 0;
    transform: scale(0.55) rotate(45deg);
  }

  95%, 100% {
    opacity: 1;
    transform: scale(1) rotate(0);
  }
}

@keyframes hero-wink-cycle {
  0%, 58% {
    opacity: 0;
    transform: scale(0.85);
  }

  62%, 90% {
    opacity: 1;
    transform: scale(1);
  }

  95%, 100% {
    opacity: 0;
    transform: scale(0.85);
  }
}

@keyframes hero-peek-shut {
  0%, 65.2%, 69.1%, 74.4%, 78.2%, 100% {
    opacity: 1;
    transform: scale(1) rotate(0);
    animation-timing-function: cubic-bezier(0.16, 1, 0.3, 1);
  }

  65.8%, 75% {
    opacity: 0.34;
    transform: scale(0.62, 0.3) rotate(-4deg);
    animation-timing-function: cubic-bezier(0.22, 1, 0.36, 1);
  }

  66.3%, 67.2%, 75.5%, 76.3% {
    opacity: 0;
    transform: scale(0.42, 0.12) rotate(-5deg);
    animation-timing-function: cubic-bezier(0.4, 0, 0.7, 0.2);
  }

  67.7%, 76.8% {
    opacity: 0.22;
    transform: scale(0.55, 0.22) rotate(-4deg);
    animation-timing-function: cubic-bezier(0.22, 1, 0.36, 1);
  }

  68.4%, 77.5% {
    opacity: 0.74;
    transform: scale(0.84, 0.62) rotate(-2deg);
    animation-timing-function: cubic-bezier(0.22, 1, 0.36, 1);
  }
}

@keyframes hero-peek-open {
  0%, 65.2%, 69.1%, 74.4%, 78.2%, 100% {
    opacity: 0;
    transform: scale(0.74, 0.12);
    animation-timing-function: cubic-bezier(0.16, 1, 0.3, 1);
  }

  65.8%, 75% {
    opacity: 0.72;
    transform: scale(0.92, 0.76);
    animation-timing-function: cubic-bezier(0.22, 1, 0.36, 1);
  }

  66.3%, 67.2%, 75.5%, 76.3% {
    opacity: 1;
    transform: scale(1);
    animation-timing-function: cubic-bezier(0.4, 0, 0.7, 0.2);
  }

  67.7%, 76.8% {
    opacity: 0.76;
    transform: scale(0.95, 0.82);
    animation-timing-function: cubic-bezier(0.22, 1, 0.36, 1);
  }

  68.4%, 77.5% {
    opacity: 0.22;
    transform: scale(0.84, 0.38);
    animation-timing-function: cubic-bezier(0.22, 1, 0.36, 1);
  }
}

.hero-title {
  max-width: 60rem;
  margin-inline: auto;
  font-size: clamp(3.2rem, 7vw, 6.4rem);
  font-weight: 700;
  letter-spacing: -0.04em;
  line-height: 1.08;
}

.hero-copy {
  max-width: 44rem;
  margin: 2rem auto 0;
  color: var(--ink-secondary);
  font-size: clamp(1.05rem, 1.8vw, 1.28rem);
  line-height: 1.75;
}

.hero-source-annotation {
  --ann-color: var(--green);
  --ann-mark: color-mix(in srgb, var(--green) 12%, transparent);
  --ann-target-gap: 8px;
  --ann-lower-label-gap: 8px;
  --ann-label-max-width: 20rem;
  --ann-rotate: -7deg;
  --ann-text-x: 3px;
  --ann-text-y: 1px;
}

.hero-source-annotation::after {
  font-size: 12px;
  letter-spacing: 0.02em;
  white-space: nowrap;
}

.hero-actions {
  margin-top: 6rem;
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 0.75rem;
}

.button {
  min-height: 3.1rem;
  padding: 0 1.5rem;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  border: 0;
  border-radius: 999px;
  font: 700 0.94rem/1 var(--font);
  cursor: pointer;
  touch-action: manipulation;
  transition: transform 180ms cubic-bezier(0.22, 1, 0.36, 1), background-color 180ms ease, color 180ms ease;
}

.button:hover {
  transform: translateY(-2px);
}

.button:active,
.nav-cta:active {
  transform: scale(0.96);
  transition-duration: 90ms;
}

.button-primary {
  background: var(--ink);
  color: #fff;
}

.button-primary:hover {
  background: #2d3029;
}

.button-secondary {
  background: rgba(255, 255, 255, 0.62);
  box-shadow: inset 0 0 0 1px var(--line);
  color: var(--ink);
  backdrop-filter: blur(12px);
}

.button-secondary:hover {
  background: #fff;
}

.button-mobile {
  display: none;
}

.nav-cta:focus-visible,
.button:focus-visible,
.voice-tab:focus-visible,
.faq-item summary:focus-visible,
.footer-meta a:focus-visible {
  outline: 3px solid rgba(91, 141, 239, 0.48);
  outline-offset: 4px;
}

.conversation-stage {
  min-height: 40rem;
  padding: clamp(2rem, 5vw, 4.5rem);
  display: grid;
  grid-template-columns: minmax(0, 0.9fr) minmax(20rem, 1.1fr);
  align-items: center;
  gap: clamp(3rem, 7vw, 7rem);
  overflow: hidden;
  border-radius: var(--radius-xl);
  background:
    radial-gradient(circle at 77% 12%, rgba(255, 255, 255, 0.74), transparent 16rem),
    linear-gradient(145deg, #d9eee1, #e8f1e9 54%, #f1e8dc);
}

.voice-tabs {
  display: grid;
}

.voice-tab {
  position: relative;
  padding: 1.4rem 2.5rem 1.4rem 0;
  display: grid;
  gap: 0.28rem;
  border: 0;
  border-bottom: 1px solid rgba(23, 25, 20, 0.13);
  background: transparent;
  text-align: left;
  cursor: pointer;
}

.voice-tab::after {
  position: absolute;
  top: 50%;
  right: 0;
  width: 0.55rem;
  height: 0.55rem;
  border-top: 1.5px solid currentColor;
  border-right: 1.5px solid currentColor;
  content: "";
  opacity: 0;
  transform: translate(-0.35rem, -50%) rotate(45deg);
  transition: opacity 180ms ease, transform 240ms cubic-bezier(0.22, 1, 0.36, 1);
}

.voice-tab span {
  font-size: clamp(1.15rem, 2vw, 1.45rem);
  font-weight: 700;
  letter-spacing: -0.025em;
  line-height: 1.35;
}

.voice-tab small {
  color: var(--ink-secondary);
  font: 400 0.88rem/1.6 var(--font);
}

.voice-tab:hover::after,
.voice-tab.is-active::after {
  opacity: 1;
  transform: translate(0, -50%) rotate(45deg);
}

.voice-tab:not(.is-active) {
  color: rgba(23, 25, 20, 0.53);
}

.phone-shell {
  width: min(100%, 27rem);
  height: 36rem;
  margin-inline: auto;
  display: grid;
  grid-template-rows: 3.4rem minmax(0, 1fr) 3.75rem;
  overflow: hidden;
  border: 0;
  border-radius: 2rem;
  background: #ededed;
  box-shadow:
    0 0 0 1px rgba(0, 0, 0, 0.1),
    0 1px 2px -1px rgba(0, 0, 0, 0.08),
    var(--shadow-float);
}

.phone-top {
  padding: 0 1rem;
  display: grid;
  grid-template-columns: 1.8rem 1fr 1.8rem;
  align-items: center;
  border-bottom: 1px solid rgba(0, 0, 0, 0.06);
  background: #f7f7f7;
}

.phone-back,
.phone-settings {
  width: 1.45rem;
  height: 1.45rem;
  fill: none;
  stroke: #171717;
  stroke-width: 1.7;
  stroke-linecap: round;
  stroke-linejoin: round;
}

.phone-settings {
  justify-self: end;
}

.phone-title {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 0.32rem;
}

.phone-title strong {
  color: #161616;
  font-size: 0.94rem;
  font-weight: 700;
}

.phone-title span {
  padding: 0.08rem 0.24rem;
  border-radius: 0.22rem;
  background: #c4c4c4;
  color: #fff;
  font-size: 0.58rem;
  font-weight: 700;
  line-height: 1.25;
}

.phone-scenes {
  min-height: 0;
  padding: 1.65rem 1.25rem 1rem;
  overflow: hidden;
  background: #ededed;
}

.chat-scene {
  min-height: 100%;
  display: flex;
  flex-direction: column;
  gap: 0.95rem;
}

.chat-scene[hidden] {
  display: none;
}

.message {
  position: relative;
  max-width: 86%;
  padding: 0.7rem 0.86rem;
  border-radius: 0.48rem;
  color: #171717;
  font-size: 0.91rem;
  line-height: 1.58;
}

.message-me {
  align-self: flex-end;
  background: #95ec69;
}

.message-me::after,
.message-echo::after {
  position: absolute;
  top: 1rem;
  width: 0.5rem;
  height: 0.62rem;
  background: inherit;
  content: "";
}

.message-me::after {
  right: -0.42rem;
  clip-path: polygon(0 0, 100% 50%, 0 100%);
}

.message-echo {
  align-self: flex-start;
  background: #fff;
}

.message-echo::after {
  left: -0.42rem;
  clip-path: polygon(100% 0, 0 50%, 100% 100%);
}

.chat-time {
  align-self: center;
  margin-top: 0.2rem;
  color: #b0b0b0;
  font-size: 0.72rem;
  line-height: 1;
}

.phone-composer {
  padding: 0.48rem 0.72rem 0.62rem;
  display: grid;
  grid-template-columns: 1.65rem minmax(0, 1fr) 1.65rem 1.65rem;
  align-items: center;
  gap: 0.62rem;
  border-top: 1px solid rgba(0, 0, 0, 0.07);
  background: #f7f7f7;
}

.phone-composer svg {
  width: 1.65rem;
  height: 1.65rem;
  fill: none;
  stroke: #171717;
  stroke-width: 1.65;
  stroke-linecap: round;
  stroke-linejoin: round;
}

.composer-input {
  align-self: stretch;
  border-radius: 0.3rem;
  background: #fff;
}

.conversation-annotation {
  --ann-color: var(--green);
  --ann-target-gap: 8px;
  --ann-label-gap: 9px;
  --ann-label-max-width: 13rem;
  --ann-mark: color-mix(in srgb, var(--green) 13%, transparent);
  --ann-text-y: 0px;
}

.conversation-annotation-a {
  --ann-rotate: -7deg;
}

.conversation-annotation-b {
  --ann-rotate: 6deg;
}

.conversation-annotation-c {
  --ann-rotate: -6deg;
}

.conversation-annotated-message {
  margin-top: 4.5rem;
}

.conversation-annotation::after,
.step-annotation::after {
  font-size: 12px;
  letter-spacing: 0.02em;
  white-space: nowrap;
}

.capabilities {
  overflow: clip;
  background: var(--dark-canvas);
  color: var(--dark-ink);
}

.capabilities .chapter-heading p {
  color: var(--dark-ink-secondary);
}

.capability-heading-mark {
  color: #66d596;
  white-space: nowrap;
}

.capability-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  grid-auto-flow: dense;
  gap: 1rem;
}

.capability {
  --capability-accent: 241, 243, 237;
  --capability-body-size: clamp(0.88rem, 1.15vw, 0.96rem);
  position: relative;
  min-width: 0;
  min-height: 32rem;
  padding: clamp(1.5rem, 3vw, 2.25rem);
  overflow: hidden;
  border: 0;
  border-radius: var(--radius-md);
  background: var(--dark-surface);
  box-shadow: var(--dark-ring);
  outline: none;
  transition-property: transform, background-color, box-shadow, opacity, filter;
  transition-duration: 280ms;
  transition-timing-function: var(--ease-out-quint);
}

.capability::before {
  position: absolute;
  inset: 0;
  background:
    radial-gradient(circle at 18% 5%, rgba(var(--capability-accent), 0.14), transparent 15rem);
  content: "";
  opacity: 0.62;
  pointer-events: none;
  transform: scale(1);
  transform-origin: top left;
  transition: opacity 280ms ease, transform 420ms var(--ease-out-quint);
}

.capability > * {
  position: relative;
  z-index: 1;
}

@media (hover: hover) {
  .hero-actions {
    margin-bottom: 4.75rem;
  }

  .capability:hover {
    background: #20261f;
    box-shadow: var(--dark-ring-hover);
    transform: translateY(-0.35rem);
  }

  .capability:hover::before {
    opacity: 1;
    transform: scale(1.04);
  }
}

.capability-memory {
  --capability-accent: 24, 184, 102;
}

.capability-reminder {
  --capability-accent: 91, 141, 239;
}

.capability-index,
.principle-card > span,
.step > span {
  color: var(--dark-ink-tertiary);
  font-size: 0.72rem;
  font-weight: 700;
  letter-spacing: 0.12em;
}

.capability h3 {
  margin-top: clamp(5rem, 8vw, 8rem);
  font-size: clamp(1.6rem, 3vw, 2.4rem);
  font-weight: 700;
  letter-spacing: -0.025em;
  line-height: 1.18;
}

.capability-lead {
  max-width: 25rem;
  margin-top: 1rem;
  color: var(--dark-ink-secondary);
  font-size: var(--capability-body-size);
  line-height: 1.8;
}

.memory-list,
.reminder-lines {
  margin-top: 2rem;
  display: grid;
  gap: 0.8rem;
}

.memory-list p,
.reminder-lines p {
  min-width: 0;
  color: rgba(243, 244, 239, 0.86);
  font-size: var(--capability-body-size);
  line-height: 1.7;
}

.memory-list span {
  width: 3.4rem;
  display: inline-block;
  color: var(--dark-ink-tertiary);
}

.capability blockquote {
  margin-top: 2.2rem;
  color: rgba(243, 244, 239, 0.9);
  font-size: var(--capability-body-size);
  line-height: 1.65;
}

.capability-foot {
  min-width: 0;
  margin-top: 2rem;
  color: var(--dark-ink-tertiary);
  font-size: var(--capability-body-size);
  line-height: 1.7;
  letter-spacing: 0.03em;
}

.difference {
  padding-bottom: clamp(8rem, 15vw, 14rem);
}

.difference-grid {
  display: grid;
  grid-template-columns: minmax(17rem, 0.8fr) minmax(0, 1.2fr);
  align-items: start;
  gap: clamp(4rem, 10vw, 10rem);
}

.difference-heading {
  position: sticky;
  top: 8rem;
}

.card-stack {
  padding-bottom: 12rem;
}

.principle-card {
  position: sticky;
  top: calc(7rem + var(--stack-index) * 1.15rem);
  min-height: 24rem;
  padding: clamp(2rem, 4vw, 3.5rem);
  display: flex;
  flex-direction: column;
  border: 1px solid var(--line);
  border-radius: var(--radius-lg);
  background: var(--surface);
  box-shadow: var(--shadow-soft);
  transform-origin: center top;
}

.principle-card + .principle-card {
  margin-top: 7rem;
}

.principle-card > span {
  color: var(--ink-tertiary);
}

.principle-card h3 {
  margin-top: auto;
  font-size: clamp(2rem, 4vw, 3.4rem);
  font-weight: 700;
  letter-spacing: -0.03em;
  line-height: 1.12;
}

.principle-card p {
  max-width: 34rem;
  margin-top: 1.2rem;
  color: var(--ink-secondary);
  font-size: 1rem;
  line-height: 1.75;
}

.manifesto {
  padding-block: clamp(9rem, 17vw, 17rem);
  background: var(--mint);
}

.manifesto-text {
  max-width: 66rem;
  font-size: clamp(2.7rem, 6.2vw, 6.3rem);
  font-weight: 700;
  letter-spacing: -0.035em;
  line-height: 1.12;
}

.manifesto-word {
  opacity: 0.14;
}

.manifesto-annotation {
  --ann-color: var(--green);
  --ann-target-gap: 10px;
  --ann-lower-label-gap: 10px;
  --ann-label-max-width: 7rem;
  --ann-rotate: -8deg;
  --ann-text-y: 0px;
  color: #087c43;
  white-space: nowrap;
}

.manifesto-annotation::after {
  font-size: 12px;
  letter-spacing: 0.02em;
  white-space: nowrap;
}

.steps-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  grid-auto-flow: dense;
  border-block: 1px solid var(--line-strong);
}

.step {
  min-height: 21rem;
  padding: 2rem clamp(1.25rem, 2.6vw, 2.5rem) 2.5rem;
  display: flex;
  flex-direction: column;
}

.step + .step {
  border-left: 1px solid var(--line);
}

.step > span {
  color: var(--green);
}

.step h3 {
  margin-top: clamp(6rem, 10vw, 9rem);
  font-size: clamp(1.5rem, 2.7vw, 2.2rem);
  font-weight: 700;
  letter-spacing: -0.025em;
  line-height: 1.18;
}

.step-annotation {
  --ann-color: var(--green);
  --ann-target-gap: 8px;
  --ann-label-gap: 9px;
  --ann-label-max-width: 10rem;
  --ann-rotate: -6deg;
  --ann-text-y: 0px;
}

.step p {
  margin-top: 1rem;
  color: var(--ink-secondary);
  font-size: 0.94rem;
  line-height: 1.75;
}

.step-invite {
  margin-top: auto;
  padding-top: 1.5rem;
  display: flex;
  align-items: center;
  gap: 1rem;
}

.invite-qr {
  width: clamp(7.5rem, 10vw, 9rem);
  height: auto;
  flex: none;
  border-radius: 8px;
}

.step-invite-copy {
  min-width: 0;
}

.step-invite-copy p {
  margin-top: 0;
  color: var(--ink-secondary);
  font-size: 0.78rem;
  line-height: 1.6;
}

.step-invite-copy .invite-note {
  margin-top: 0.5rem;
  color: var(--ink-tertiary);
  font-size: 0.74rem;
}

@media (max-width: 680px) {
  .step-invite {
    margin-top: 2rem;
    padding-top: 0;
    flex-direction: column;
    align-items: center;
    gap: 1rem;
    text-align: center;
  }

  .invite-qr {
    width: 11rem;
  }

  .step-invite-copy p {
    max-width: 18rem;
    margin-inline: auto;
  }
}

.faq {
  padding-top: 2rem;
}

.faq-grid {
  display: grid;
  grid-template-columns: minmax(14rem, 0.7fr) minmax(0, 1.3fr);
  align-items: start;
  gap: clamp(3rem, 9vw, 9rem);
}

.faq-heading {
  position: sticky;
  top: 8rem;
}

.faq-heading h2 {
  font-size: clamp(2.3rem, 4vw, 3.8rem);
  letter-spacing: -0.03em;
  line-height: 1.12;
}

.faq-item {
  border-bottom: 1px solid var(--line);
}

.faq-item:first-child {
  border-top: 1px solid var(--line);
}

.faq-item summary {
  position: relative;
  min-height: 4.75rem;
  padding: 1.45rem 3rem 1.45rem 0;
  list-style: none;
  font-size: 1.02rem;
  font-weight: 700;
  cursor: pointer;
}

.faq-item summary::-webkit-details-marker {
  display: none;
}

.faq-item summary::after {
  position: absolute;
  top: 50%;
  right: 0.25rem;
  color: var(--ink-tertiary);
  content: "+";
  font-size: 1.4rem;
  font-weight: 400;
  transform: translateY(-50%);
  transition: transform 240ms cubic-bezier(0.22, 1, 0.36, 1), color 180ms ease;
}

.faq-item[open] summary::after {
  color: var(--green);
  transform: translateY(-50%) rotate(45deg);
}

.faq-item p {
  max-width: 38rem;
  padding: 0 3rem 1.75rem 0;
  color: var(--ink-secondary);
  font-size: 0.94rem;
  line-height: 1.8;
}

.footer {
  padding: clamp(3.5rem, 7vw, 5rem) 0 max(2rem, env(safe-area-inset-bottom));
  border-top: 1px solid var(--line);
}

.footer-tagline {
  max-width: 36rem;
  font-size: clamp(1.65rem, 3vw, 2.6rem);
  font-weight: 700;
  letter-spacing: -0.03em;
  line-height: 1.18;
  text-wrap: balance;
}

.footer-meta {
  margin-top: clamp(3rem, 6vw, 5rem);
  padding-bottom: 0.5rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  color: var(--ink-tertiary);
  font-size: 0.78rem;
}

.footer-meta strong {
  color: var(--ink-secondary);
  font-size: 0.9rem;
}

.footer-meta a:hover {
  color: var(--ink);
}

.toast {
  position: fixed;
  left: 50%;
  bottom: max(2rem, env(safe-area-inset-bottom));
  z-index: 100;
  max-width: calc(100vw - 2rem);
  padding: 0.75rem 1.2rem;
  border: 1px solid rgba(255, 255, 255, 0.1);
  border-radius: 999px;
  background: rgba(23, 25, 20, 0.9);
  box-shadow: 0 14px 40px rgba(0, 0, 0, 0.2);
  color: #fff;
  font-size: 0.84rem;
  opacity: 0;
  pointer-events: none;
  transform: translate(-50%, 1rem) scale(0.96);
  backdrop-filter: blur(18px) saturate(150%);
  transition: opacity 220ms ease, transform 320ms cubic-bezier(0.22, 1, 0.36, 1);
}

.toast.is-visible {
  opacity: 1;
  transform: translate(-50%, 0) scale(1);
}

.reveal {
  opacity: 1;
  transform: none;
}

.motion-ready .reveal {
  opacity: 0;
  transform: translateY(1rem) scale(0.985);
  transition: opacity 600ms ease, transform 650ms cubic-bezier(0.22, 1, 0.36, 1);
}

.motion-ready .reveal.is-visible {
  opacity: 1;
  transform: none;
}

.motion-ready .capability[data-capability-card]:not(.is-entered) {
  opacity: 0;
  filter: blur(4px);
  transform: translateY(1.75rem) scale(0.985);
}

.motion-ready .capability[data-capability-card].is-entered {
  opacity: 1;
  filter: blur(0);
  transform: none;
  transition-duration: 620ms;
}

.motion-ready .capability[data-capability-card].has-entered {
  transition-duration: 280ms;
}

@media (hover: hover) {
  .motion-ready .capability[data-capability-card].has-entered:hover {
    transform: translateY(-0.35rem);
  }
}

@media (max-width: 1100px) {
  .capability-grid {
    grid-template-columns: 1fr;
  }

  .difference-grid {
    grid-template-columns: 1fr;
    gap: 3rem;
  }

  .difference-heading {
    position: static;
    max-width: 44rem;
  }

  .difference-heading .wide-break {
    display: none;
  }

  .card-stack {
    padding-bottom: 7rem;
  }

  .principle-card {
    min-height: 21rem;
  }

  .principle-card + .principle-card {
    margin-top: 4rem;
  }

  .principle-card h3 {
    margin-top: clamp(4rem, 8vw, 6rem);
  }

  .capability {
    min-height: 0;
    padding: clamp(1.5rem, 5vw, 2.5rem);
  }

  .capability h3 {
    margin-top: clamp(3rem, 8vw, 5rem);
  }

  .capability-lead {
    max-width: 38rem;
  }
}

@media (max-width: 900px) {
  .hero-actions {
    margin-top: 5rem;
    margin-bottom: 0;
  }

  .conversation-annotated-message {
    margin-top: 4rem;
  }

  .hero-source-annotation {
    --ann-label-max-width: min(18rem, 76vw);
    --ann-text-x: -36px;
  }

  .conversation-annotation {
    --ann-label-max-width: min(11rem, 52vw);
  }

  .manifesto-annotation {
    --ann-label-max-width: 6.5rem;
  }

  .step-annotation {
    --ann-label-max-width: 8.5rem;
  }

  .conversation-stage,
  .faq-grid {
    grid-template-columns: 1fr;
  }

  .faq-heading {
    position: static;
  }

  .capability-lead {
    max-width: none;
  }

  .memory-list,
  .reminder-lines {
    margin-top: 1.5rem;
  }

  .steps-grid {
    grid-template-columns: 1fr;
  }

  .step {
    min-height: 16rem;
  }

  .step h3 {
    margin-top: 4rem;
  }

  .step + .step {
    border-top: 1px solid var(--line);
    border-left: 0;
  }
}

@media (max-width: 680px) {
  .wrap,
  .nav-inner {
    width: min(100% - 2rem, 72rem);
  }

  .chapter {
    padding: 5.5rem 0;
  }

  .nav-inner {
    min-height: 4rem;
  }

  .nav-by {
    display: none;
  }

  .hero {
    min-height: 44rem;
    padding: 8rem 0 5rem;
  }

  .hero::before {
    inset: 0;
  }

  .hero-card-scatter {
    inset: 4rem 0 0;
  }

  .hero-edge-card {
    --card-opacity: 0.42;
    --mobile-edge: -6.3rem;
    width: 9.5rem;
  }

  .hero-edge-card[data-mobile-hide] {
    display: none;
  }

  .hero-edge-card[data-hero-card-side="left"] {
    left: var(--mobile-edge);
  }

  .hero-edge-card[data-hero-card-side="right"] {
    right: var(--mobile-edge);
  }

  .hero-edge-card[data-mobile-slot="1"] {
    top: var(--card-mobile-top, 10%);
  }

  .hero-edge-card[data-mobile-slot="2"] {
    top: var(--card-mobile-top, 25%);
  }

  .hero-edge-card[data-mobile-slot="3"] {
    top: var(--card-mobile-top, 40%);
  }

  .hero-edge-card[data-mobile-slot="4"] {
    top: var(--card-mobile-top, 55%);
  }

  .hero-edge-card[data-mobile-slot="5"] {
    top: var(--card-mobile-top, 70%);
  }

  .hero-title {
    font-size: clamp(2.2rem, 11vw, 4rem);
  }

  .hero-copy {
    margin-top: 1.5rem;
    font-size: 1rem;
  }

  .hero-actions {
    align-items: stretch;
    flex-direction: column;
  }

  .hero-actions .button {
    width: 100%;
  }

  .conversation-stage {
    min-height: auto;
    padding: 1.25rem;
    gap: 2rem;
    border-radius: 1.75rem;
  }

  .voice-tabs {
    grid-template-columns: repeat(3, 1fr);
    border-bottom: 1px solid rgba(23, 25, 20, 0.13);
  }

  .voice-tab {
    min-width: 0;
    padding: 0.85rem 0.35rem;
    border-bottom: 0;
    text-align: center;
  }

  .voice-tab::after,
  .voice-tab small {
    display: none;
  }

  .voice-tab span {
    font-size: 0.82rem;
  }

  .phone-shell {
    height: 32rem;
    grid-template-rows: 3.15rem minmax(0, 1fr) 3.45rem;
    border-radius: 1.25rem;
  }

  .phone-top {
    padding-inline: 0.75rem;
  }

  .phone-scenes {
    min-height: 0;
    padding: 1.5rem 1rem 1rem;
  }

  .message {
    font-size: 0.86rem;
  }

  .conversation-annotation-b::before {
    top: calc(100% + var(--ann-target-gap) - 2px + var(--ann-arrow-y));
    right: -0.3rem;
    bottom: auto;
    left: auto;
    transform: rotate(180deg);
  }

  .conversation-annotation-b::after {
    top: calc(
      100% + var(--ann-target-gap) + 31px + var(--ann-lower-label-gap) +
      var(--ann-text-y)
    );
    right: -1rem;
    bottom: auto;
    left: auto;
    transform: rotate(var(--ann-rotate));
  }

  .phone-composer {
    padding-inline: 0.55rem;
    gap: 0.48rem;
  }

  .capability {
    min-height: 0;
    padding: 1.35rem;
  }

  .capability h3 {
    margin-top: 2.25rem;
  }

  .principle-card {
    min-height: 18rem;
    top: calc(5.5rem + var(--stack-index) * 0.75rem);
  }

  .principle-card + .principle-card {
    margin-top: 2.5rem;
  }

  .principle-card h3 {
    margin-top: 3rem;
  }

  .card-stack {
    padding-bottom: 4.5rem;
  }

  .manifesto-text {
    font-size: clamp(2.55rem, 13vw, 4.2rem);
  }

  .footer-meta {
    flex-wrap: wrap;
    gap: 0.75rem 1.5rem;
  }
}

@media (hover: none) and (pointer: coarse) {
  .button-desktop {
    display: none;
  }

  .button-mobile {
    display: inline-flex;
  }
}

@media (prefers-color-scheme: dark) {
  :root {
    --canvas: #10130f;
    --surface: #191d18;
    --surface-muted: #20251f;
    --ink: #f1f3ed;
    --ink-secondary: rgba(241, 243, 237, 0.78);
    --ink-tertiary: rgba(241, 243, 237, 0.58);
    --green: #66d596;
    --green-bright: #7be4aa;
    --mint: #173126;
    --blue: #73a1f5;
    --line: rgba(241, 243, 237, 0.09);
    --line-strong: rgba(241, 243, 237, 0.17);
    --shadow-soft: 0 24px 70px rgba(0, 0, 0, 0.22);
    --shadow-float: 0 28px 80px rgba(0, 0, 0, 0.34);
    color-scheme: dark;
  }

  body {
    background:
      radial-gradient(circle at 50% 3%, rgba(35, 91, 61, 0.34), transparent 29rem),
      radial-gradient(circle at 9% 22%, rgba(50, 79, 122, 0.12), transparent 24rem),
      var(--canvas);
  }

  .nav::after {
    background: linear-gradient(to bottom, rgba(16, 19, 15, 0.62), transparent);
  }

  .nav.is-scrolled,
  .nav.is-dark {
    background: rgba(16, 19, 15, 0.8);
    box-shadow: inset 0 -1px var(--line);
    color: var(--ink);
  }

  .nav.is-scrolled::after,
  .nav.is-dark::after {
    background: linear-gradient(to bottom, rgba(16, 19, 15, 0.62), transparent);
  }

  .nav-cta,
  .nav.is-dark .nav-cta,
  .button-primary {
    background: #f1f3ed;
    color: #171914;
  }

  .nav-cta:hover,
  .nav.is-dark .nav-cta:hover,
  .button-primary:hover {
    background: #fff;
  }

  .button-secondary {
    background: rgba(241, 243, 237, 0.07);
    box-shadow: inset 0 0 0 1px var(--line-strong);
  }

  .button-secondary:hover {
    background: rgba(241, 243, 237, 0.12);
  }

  .hero::before {
    background:
      radial-gradient(ellipse 38% 44% at 50% 42%, rgba(35, 91, 61, 0.44), transparent 74%),
      radial-gradient(circle at 14% 32%, rgba(91, 141, 239, 0.11), transparent 19rem),
      radial-gradient(circle at 86% 68%, rgba(24, 184, 102, 0.1), transparent 21rem);
  }

  .hero-edge-card {
    background: rgba(241, 243, 237, 0.018);
    color: var(--card-dark-color);
  }

  .conversation-stage {
    background:
      radial-gradient(circle at 77% 12%, rgba(102, 213, 150, 0.08), transparent 16rem),
      linear-gradient(145deg, #16251d, #18231c 54%, #211f1a);
  }

  .phone-shell {
    background: #111411;
    box-shadow:
      0 0 0 1px rgba(255, 255, 255, 0.1),
      0 28px 80px rgba(0, 0, 0, 0.38);
  }

  .phone-top,
  .phone-composer {
    background: #191c19;
  }

  .phone-top {
    border-bottom-color: rgba(255, 255, 255, 0.07);
  }

  .phone-composer {
    border-top-color: rgba(255, 255, 255, 0.07);
  }

  .phone-back,
  .phone-settings,
  .phone-composer svg {
    stroke: #eef1eb;
  }

  .phone-title strong {
    color: #f1f3ed;
  }

  .phone-title span {
    background: #454944;
    color: #f1f3ed;
  }

  .phone-scenes {
    background: #111411;
  }

  .message {
    color: #f1f3ed;
  }

  .message-me {
    background: #3f7742;
  }

  .message-echo {
    background: #252925;
  }

  .chat-time {
    color: #747a73;
  }

  .composer-input {
    background: #252925;
  }

  .voice-tab {
    border-bottom-color: var(--line-strong);
  }

  .voice-tabs {
    border-bottom-color: var(--line-strong);
  }

  .voice-tab:not(.is-active) {
    color: rgba(241, 243, 237, 0.5);
  }

  .manifesto-annotation {
    color: #79dda5;
  }

  .toast {
    border-color: var(--line-strong);
    background: rgba(241, 243, 237, 0.94);
    color: #171914;
  }
}

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

  *,
  *::before,
  *::after {
    scroll-behavior: auto !important;
    transition-duration: 0.01ms !important;
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
  }

  .motion-ready .reveal,
  .motion-ready .capability[data-capability-card],
  .manifesto-word {
    opacity: 1 !important;
    filter: none !important;
    transform: none !important;
  }

  .hero-mark .face-star,
  .hero-mark .face-wink,
  .hero-mark .eye-closed,
  .hero-mark .eye-peek {
    animation: none;
  }

  .hero-mark .face-star {
    opacity: 1;
  }

  .hero-mark .face-wink {
    opacity: 0;
  }

  .hero-card-scatter.is-ready .hero-edge-card {
    opacity: var(--card-opacity);
    transform: translate3d(0, 0, 0) rotate(var(--card-rotate)) scale(1);
    animation: none;
  }
}

@media (prefers-reduced-transparency: reduce) {
  .nav.is-scrolled,
  .button-secondary,
  .toast {
    backdrop-filter: none;
    -webkit-backdrop-filter: none;
  }

  .nav.is-scrolled {
    background: var(--canvas);
  }

  .nav.is-dark {
    background: var(--dark-canvas);
  }

  .button-secondary {
    background: var(--surface);
  }
}

@media (prefers-contrast: more) {
  :root {
    --line: rgba(23, 25, 20, 0.32);
    --line-strong: rgba(23, 25, 20, 0.58);
  }

  .nav.is-scrolled,
  .button-secondary {
    background: var(--surface);
  }

  .nav.is-dark {
    background: var(--dark-canvas);
    color: var(--dark-ink);
  }

  .capability {
    box-shadow: 0 0 0 1px rgba(255, 255, 255, 0.24);
  }
}

@media (prefers-color-scheme: dark) and (prefers-contrast: more) {
  :root {
    --line: rgba(241, 243, 237, 0.28);
    --line-strong: rgba(241, 243, 237, 0.5);
  }
}