:root {
  color-scheme: light;
  --canvas: #f8f5ed;
  --surface: #fffdf8;
  --surface-soft: #eef2eb;
  --primary: #55705a;
  --primary-deep: #3f5745;
  --primary-container: #e3eae2;
  --accent: #e4ae69;
  --accent-soft: #f5e7d3;
  --ink: #30332f;
  --muted: #656c65;
  --outline: #d6ddd4;
  --shadow: rgb(75 91 77 / 0.14);
  --radius-card: 24px;
  --radius-control: 14px;
  --page: min(1120px, calc(100% - 40px));
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
  background: var(--canvas);
}

body {
  min-width: 320px;
  margin: 0;
  color: var(--ink);
  background:
    radial-gradient(circle at 88% 8%, rgb(228 174 105 / 0.13), transparent 24rem),
    radial-gradient(circle at 5% 34%, rgb(111 138 114 / 0.1), transparent 22rem),
    var(--canvas);
  font-family:
    "Noto Sans CJK SC",
    "Microsoft YaHei",
    "PingFang SC",
    system-ui,
    sans-serif;
  font-size: 16px;
  line-height: 1.75;
  text-rendering: optimizeLegibility;
}

img {
  display: block;
  max-width: 100%;
}

a {
  color: var(--primary-deep);
  text-decoration-thickness: 1px;
  text-underline-offset: 0.22em;
}

a:focus-visible,
button:focus-visible,
summary:focus-visible {
  outline: 3px solid rgb(85 112 90 / 0.32);
  outline-offset: 4px;
}

.skip-link {
  position: fixed;
  top: 10px;
  left: 10px;
  z-index: 100;
  padding: 10px 16px;
  color: #fff;
  background: var(--primary-deep);
  border-radius: 10px;
  transform: translateY(-160%);
}

.skip-link:focus {
  transform: translateY(0);
}

.site-header {
  position: relative;
  z-index: 10;
  border-bottom: 1px solid rgb(85 112 90 / 0.12);
  background: rgb(248 245 237 / 0.9);
}

.nav {
  width: var(--page);
  min-height: 76px;
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  color: var(--ink);
  font-size: 1.08rem;
  font-weight: 760;
  text-decoration: none;
  white-space: nowrap;
}

.brand img {
  width: 42px;
  height: 42px;
  border-radius: 13px;
  background: var(--primary-container);
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 26px;
  margin: 0;
  padding: 0;
  list-style: none;
}

.nav-links a {
  color: var(--muted);
  font-size: 0.94rem;
  font-weight: 650;
  text-decoration: none;
  white-space: nowrap;
}

.nav-links a[aria-current="page"],
.nav-links a:hover {
  color: var(--primary-deep);
}

.page {
  width: var(--page);
  margin: 0 auto;
}

.hero {
  min-height: 690px;
  padding: 76px 0 84px;
  display: grid;
  grid-template-columns: minmax(0, 1.05fr) minmax(340px, 0.78fr);
  align-items: center;
  gap: clamp(54px, 8vw, 108px);
}

.hero-copy {
  max-width: 660px;
}

.eyebrow {
  margin: 0 0 18px;
  color: var(--primary);
  font-size: 0.86rem;
  font-weight: 760;
  letter-spacing: 0.1em;
}

h1,
h2,
h3,
p {
  overflow-wrap: anywhere;
}

h1 {
  max-width: 11ch;
  margin: 0;
  font-size: clamp(3rem, 7vw, 5.7rem);
  line-height: 1.07;
  letter-spacing: -0.055em;
}

.hero-lead {
  max-width: 35rem;
  margin: 28px 0 0;
  color: var(--muted);
  font-size: clamp(1.05rem, 2vw, 1.22rem);
}

.actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 34px;
}

.button {
  min-height: 50px;
  padding: 12px 20px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  border: 1px solid var(--primary);
  border-radius: var(--radius-control);
  color: #fff;
  background: var(--primary);
  font-weight: 720;
  text-decoration: none;
  transition: transform 120ms ease, background-color 120ms ease;
}

.button:hover {
  background: var(--primary-deep);
}

.button:active {
  transform: translateY(1px);
}

.button.secondary {
  color: var(--primary-deep);
  background: transparent;
}

.button.secondary:hover {
  background: var(--primary-container);
}

.trust-line {
  margin: 28px 0 0;
  padding: 0;
  display: flex;
  flex-wrap: wrap;
  gap: 8px 22px;
  color: var(--muted);
  font-size: 0.9rem;
  list-style: none;
}

.trust-line li::before {
  content: "✓";
  margin-right: 7px;
  color: var(--primary);
  font-weight: 800;
}

.phone-stage {
  position: relative;
  display: grid;
  place-items: center;
}

.phone-stage::before {
  content: "";
  position: absolute;
  width: 92%;
  aspect-ratio: 1;
  border-radius: 46% 54% 60% 40%;
  background: var(--primary-container);
  transform: rotate(-5deg);
}

.phone {
  position: relative;
  width: min(330px, 82vw);
  margin: 0;
  padding: 10px;
  border: 1px solid rgb(63 87 69 / 0.18);
  border-radius: 36px;
  background: #fff;
  box-shadow: 0 26px 72px var(--shadow);
}

.phone img {
  width: 100%;
  border-radius: 27px;
}

.cat-friend {
  position: absolute;
  right: -30px;
  bottom: -24px;
  width: 128px;
  filter: drop-shadow(0 14px 20px rgb(75 91 77 / 0.15));
}

.fact-strip {
  padding: 26px 0;
  border-block: 1px solid var(--outline);
}

.facts {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
}

.fact {
  min-height: 92px;
  padding: 8px 32px;
  display: flex;
  flex-direction: column;
  justify-content: center;
  border-right: 1px solid var(--outline);
}

.fact:first-child {
  padding-left: 0;
}

.fact:last-child {
  padding-right: 0;
  border-right: 0;
}

.fact strong {
  font-size: 1.08rem;
}

.fact span {
  color: var(--muted);
  font-size: 0.92rem;
}

.section {
  padding: 96px 0;
}

.section-heading {
  max-width: 660px;
  margin-bottom: 44px;
}

.section-heading h2,
.policy-header h1 {
  margin: 0;
  font-size: clamp(2.1rem, 5vw, 3.8rem);
  line-height: 1.14;
  letter-spacing: -0.04em;
}

.section-heading p,
.policy-header p {
  margin: 16px 0 0;
  color: var(--muted);
}

.feature-grid {
  display: grid;
  grid-template-columns: repeat(12, 1fr);
  gap: 18px;
}

.feature {
  grid-column: span 4;
  min-height: 230px;
  padding: 30px;
  border: 1px solid var(--outline);
  border-radius: var(--radius-card);
  background: rgb(255 253 248 / 0.78);
}

.feature.wide {
  grid-column: span 7;
}

.feature.medium {
  grid-column: span 5;
  background: var(--primary-container);
}

.feature.accent {
  background: var(--accent-soft);
}

.feature-index {
  display: block;
  margin-bottom: 46px;
  color: var(--primary);
  font-size: 0.82rem;
  font-weight: 760;
}

.feature h3 {
  margin: 0;
  font-size: 1.28rem;
}

.feature p {
  margin: 10px 0 0;
  color: var(--muted);
}

.privacy-flow {
  display: grid;
  grid-template-columns: 0.82fr 1.18fr;
  gap: 70px;
  align-items: start;
}

.privacy-flow h2 {
  position: sticky;
  top: 32px;
  margin: 0;
  font-size: clamp(2.1rem, 5vw, 3.7rem);
  line-height: 1.14;
  letter-spacing: -0.04em;
}

.flow-list {
  margin: 0;
  padding: 0;
  list-style: none;
  counter-reset: local-flow;
}

.flow-list li {
  position: relative;
  min-height: 150px;
  padding: 10px 0 34px 82px;
  border-bottom: 1px solid var(--outline);
  counter-increment: local-flow;
}

.flow-list li + li {
  padding-top: 34px;
}

.flow-list li::before {
  content: counter(local-flow, decimal-leading-zero);
  position: absolute;
  left: 0;
  top: 9px;
  color: var(--primary);
  font-weight: 800;
}

.flow-list li + li::before {
  top: 33px;
}

.flow-list strong {
  display: block;
  margin-bottom: 8px;
  font-size: 1.16rem;
}

.flow-list p {
  margin: 0;
  color: var(--muted);
}

.public-notes {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 18px;
}

.note-link {
  min-height: 260px;
  padding: 34px;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  border: 1px solid var(--outline);
  border-radius: var(--radius-card);
  color: var(--ink);
  background: var(--surface);
  text-decoration: none;
}

.note-link:hover {
  border-color: var(--primary);
}

.note-link span {
  color: var(--primary);
  font-weight: 760;
}

.note-link h3 {
  max-width: 12ch;
  margin: 0;
  font-size: clamp(1.6rem, 3vw, 2.3rem);
  line-height: 1.22;
}

.contact-band {
  margin-bottom: 92px;
  padding: clamp(36px, 7vw, 72px);
  display: grid;
  grid-template-columns: 1.2fr 0.8fr;
  gap: 34px;
  align-items: end;
  border-radius: var(--radius-card);
  background: var(--primary);
  color: #fff;
}

.contact-band h2 {
  max-width: 12ch;
  margin: 0;
  font-size: clamp(2rem, 5vw, 3.8rem);
  line-height: 1.12;
  letter-spacing: -0.04em;
}

.contact-band p {
  margin: 12px 0 0;
  color: rgb(255 255 255 / 0.8);
}

.contact-band a {
  color: #fff;
}

.contact-meta {
  justify-self: end;
  text-align: right;
}

.site-footer {
  padding: 32px 0 46px;
  border-top: 1px solid var(--outline);
  color: var(--muted);
  font-size: 0.9rem;
}

.footer-inner {
  width: var(--page);
  margin: 0 auto;
  display: flex;
  justify-content: space-between;
  gap: 24px;
}

.footer-links {
  display: flex;
  flex-wrap: wrap;
  gap: 18px;
}

.policy-main {
  padding: 76px 0 100px;
}

.policy-header {
  max-width: 820px;
  padding-bottom: 52px;
  border-bottom: 1px solid var(--outline);
}

.policy-meta {
  margin-top: 24px;
  display: flex;
  flex-wrap: wrap;
  gap: 8px 24px;
  color: var(--muted);
  font-size: 0.9rem;
}

.policy-layout {
  margin-top: 54px;
  display: grid;
  grid-template-columns: 240px minmax(0, 720px);
  gap: 70px;
  justify-content: space-between;
  align-items: start;
}

.toc {
  position: sticky;
  top: 28px;
}

.toc strong {
  display: block;
  margin-bottom: 12px;
}

.toc ol {
  margin: 0;
  padding-left: 20px;
  color: var(--muted);
}

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

.toc a:hover {
  color: var(--primary-deep);
}

.policy-content section {
  padding: 0 0 42px;
}

.policy-content section + section {
  padding-top: 42px;
  border-top: 1px solid var(--outline);
}

.policy-content h2 {
  margin: 0 0 16px;
  font-size: 1.55rem;
  line-height: 1.35;
}

.policy-content h3 {
  margin: 26px 0 8px;
  font-size: 1.08rem;
}

.policy-content p,
.policy-content li {
  color: var(--muted);
}

.policy-content ul,
.policy-content ol {
  padding-left: 1.3rem;
}

.policy-content strong {
  color: var(--ink);
}

.notice {
  padding: 22px 24px;
  border-left: 4px solid var(--primary);
  border-radius: 0 var(--radius-control) var(--radius-control) 0;
  background: var(--primary-container);
}

.sdk-list {
  display: grid;
  gap: 12px;
}

.sdk-item {
  border: 1px solid var(--outline);
  border-radius: var(--radius-control);
  background: var(--surface);
}

.sdk-item summary {
  min-height: 66px;
  padding: 18px 22px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 18px;
  color: var(--ink);
  cursor: pointer;
  font-weight: 760;
  list-style: none;
}

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

.sdk-item summary::after {
  content: "+";
  flex: 0 0 auto;
  color: var(--primary);
  font-size: 1.35rem;
}

.sdk-item[open] summary::after {
  content: "−";
}

.sdk-body {
  padding: 0 22px 22px;
  color: var(--muted);
}

.sdk-body dl {
  margin: 0;
  display: grid;
  grid-template-columns: 8rem 1fr;
  gap: 8px 18px;
}

.sdk-body dt {
  color: var(--ink);
  font-weight: 680;
}

.sdk-body dd {
  margin: 0;
}

@media (max-width: 860px) {
  :root {
    --page: min(100% - 32px, 720px);
  }

  .hero {
    min-height: auto;
    padding-top: 58px;
    grid-template-columns: 1fr;
    gap: 64px;
  }

  .hero-copy {
    max-width: 620px;
  }

  .phone-stage {
    width: min(420px, 100%);
    margin: 0 auto;
  }

  .feature,
  .feature.wide,
  .feature.medium {
    grid-column: span 6;
  }

  .privacy-flow,
  .contact-band {
    grid-template-columns: 1fr;
  }

  .privacy-flow {
    gap: 36px;
  }

  .privacy-flow h2 {
    position: static;
  }

  .contact-meta {
    justify-self: start;
    text-align: left;
  }

  .policy-layout {
    grid-template-columns: 1fr;
    gap: 34px;
  }

  .toc {
    position: static;
    padding: 22px;
    border-radius: var(--radius-control);
    background: var(--primary-container);
  }
}

@media (max-width: 640px) {
  :root {
    --page: calc(100% - 28px);
    --radius-card: 20px;
  }

  .nav {
    min-height: 68px;
  }

  .brand span {
    display: none;
  }

  .nav-links {
    width: 100%;
    justify-content: flex-end;
    gap: 16px;
  }

  .nav-links a {
    font-size: 0.86rem;
  }

  .hero {
    padding: 50px 0 68px;
  }

  h1 {
    max-width: 9ch;
    font-size: clamp(2.65rem, 15vw, 4.3rem);
  }

  .actions {
    display: grid;
    grid-template-columns: 1fr;
  }

  .button {
    width: 100%;
  }

  .cat-friend {
    right: -8px;
    width: 102px;
  }

  .fact-strip {
    padding: 10px 0;
  }

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

  .fact,
  .fact:first-child,
  .fact:last-child {
    min-height: 78px;
    padding: 18px 0;
    border-right: 0;
    border-bottom: 1px solid var(--outline);
  }

  .fact:last-child {
    border-bottom: 0;
  }

  .section {
    padding: 70px 0;
  }

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

  .feature,
  .feature.wide,
  .feature.medium {
    grid-column: auto;
    min-height: 210px;
  }

  .public-notes {
    grid-template-columns: 1fr;
  }

  .note-link {
    min-height: 220px;
  }

  .flow-list li {
    padding-left: 54px;
  }

  .footer-inner {
    flex-direction: column;
  }

  .policy-main {
    padding-top: 54px;
  }

  .policy-meta {
    display: grid;
  }

  .sdk-body dl {
    grid-template-columns: 1fr;
  }

  .sdk-body dd + dt {
    margin-top: 8px;
  }
}

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

  .button {
    transition: none;
  }
}