/* 使用 App 图标色彩建立轻量、响应式且支持 RTL 的公开站点视觉系统。 */
:root {
  color-scheme: light;
  --background: #ffffff;
  --ink: #12231a;
  --muted: #5d6861;
  --line: #dfe7df;
  --sage: #58773d;
  --sage-strong: #35572d;
  --sage-soft: #eef4e9;
  --terracotta: #cf6838;
  --focus: #2458c6;
  --shell: min(1180px, calc(100vw - 48px));
  --shadow: 0 16px 40px rgb(18 35 26 / 9%);
  font-family: -apple-system, BlinkMacSystemFont, "SF Pro Text", "Segoe UI", sans-serif;
  font-synthesis: none;
}

* {
  box-sizing: border-box;
}

html {
  background: var(--background);
  color: var(--ink);
  scroll-behavior: smooth;
  text-rendering: optimizeLegibility;
}

body {
  margin: 0;
  min-width: 320px;
  background: var(--background);
  font-size: 17px;
  line-height: 1.65;
}

img,
svg {
  display: block;
}

a {
  color: inherit;
  text-decoration-thickness: 1px;
  text-underline-offset: 0.2em;
}

a:focus-visible,
button:focus-visible,
select:focus-visible,
summary:focus-visible {
  outline: 3px solid var(--focus);
  outline-offset: 4px;
}

.shell {
  width: var(--shell);
  margin-inline: auto;
}

.visually-hidden {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

.skip-link {
  position: fixed;
  inset-block-start: 12px;
  inset-inline-start: 12px;
  z-index: 20;
  padding: 10px 14px;
  background: var(--ink);
  color: white;
  transform: translateY(-180%);
}

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

.site-header {
  position: sticky;
  inset-block-start: 0;
  z-index: 10;
  background: rgb(255 255 255 / 84%);
  border-block-end: 1px solid rgb(223 231 223 / 78%);
  backdrop-filter: blur(22px) saturate(140%);
}

.site-header__inner {
  min-height: 84px;
  display: grid;
  grid-template-columns: auto 1fr auto;
  align-items: center;
  gap: 28px;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  color: var(--ink);
  font-size: 1.28rem;
  font-weight: 750;
  letter-spacing: -0.025em;
  text-decoration: none;
}

.brand img {
  border-radius: 11px;
}

.primary-nav {
  justify-self: end;
  display: flex;
  align-items: center;
  gap: 30px;
}

.primary-nav a {
  color: var(--ink);
  font-size: 0.96rem;
  font-weight: 620;
  text-decoration: none;
}

.primary-nav a:hover {
  color: var(--sage-strong);
}

.language-control {
  min-height: 46px;
  display: flex;
  align-items: center;
  gap: 8px;
  padding-inline: 14px 10px;
  border: 1px solid var(--line);
  border-radius: 16px;
  background: rgb(255 255 255 / 72%);
  box-shadow: 0 7px 20px rgb(18 35 26 / 5%);
}

.language-control svg {
  width: 20px;
  height: 20px;
  fill: none;
  stroke: currentColor;
  stroke-width: 1.7;
}

.language-control select {
  max-width: 170px;
  border: 0;
  background: transparent;
  color: var(--ink);
  font: 600 0.94rem/1.2 inherit;
  cursor: pointer;
}

.hero {
  min-height: 600px;
  display: grid;
  grid-template-columns: minmax(0, 1.05fr) minmax(360px, 0.95fr);
  align-items: center;
  gap: 72px;
  padding-block: 78px 86px;
}

.hero h1 {
  max-width: 760px;
  margin: 0;
  font-size: clamp(3.35rem, 6.1vw, 5.9rem);
  line-height: 0.98;
  letter-spacing: -0.065em;
  text-wrap: balance;
}

.hero__copy > p {
  max-width: 680px;
  margin: 30px 0 0;
  color: var(--muted);
  font-size: clamp(1.12rem, 1.7vw, 1.42rem);
  line-height: 1.55;
  text-wrap: pretty;
}

.hero__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 14px;
  margin-block-start: 34px;
}

.button {
  min-height: 52px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 13px 22px;
  border: 1px solid var(--sage-strong);
  border-radius: 16px;
  font-size: 1rem;
  font-weight: 700;
  line-height: 1.2;
  text-align: center;
  text-decoration: none;
  transition: transform 160ms ease, box-shadow 160ms ease, background-color 160ms ease;
}

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

.button--primary {
  background: var(--sage);
  color: white;
  box-shadow: 0 12px 24px rgb(53 87 45 / 18%);
}

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

.button--secondary {
  background: rgb(255 255 255 / 75%);
  color: var(--sage-strong);
}

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

.hero__art::before {
  content: "";
  position: absolute;
  width: 78%;
  aspect-ratio: 1;
  border: 1px solid var(--line);
  border-radius: 50%;
}

.hero__art img {
  position: relative;
  width: min(100%, 430px);
  height: auto;
  border-radius: 22%;
  box-shadow: var(--shadow);
}

.features {
  padding-block: 100px 110px;
  border-block-start: 1px solid var(--line);
}

.features > h2 {
  max-width: 780px;
  margin: 0 auto 68px;
  font-size: clamp(2.25rem, 4.5vw, 4.25rem);
  line-height: 1.08;
  letter-spacing: -0.045em;
  text-align: center;
  text-wrap: balance;
}

.feature-list {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 42px;
}

.feature-item {
  min-width: 0;
}

.feature-icon {
  width: 42px;
  height: 42px;
  margin-block-end: 22px;
  fill: none;
  stroke: var(--sage-strong);
  stroke-linecap: round;
  stroke-linejoin: round;
  stroke-width: 1.55;
}

.feature-item h3 {
  margin: 0;
  font-size: 1.2rem;
  line-height: 1.25;
  letter-spacing: -0.02em;
}

.feature-item p {
  margin: 12px 0 0;
  color: var(--muted);
  font-size: 0.98rem;
  line-height: 1.65;
}

.screenshots {
  display: grid;
  grid-auto-flow: column;
  grid-auto-columns: minmax(250px, 1fr);
  gap: 24px;
  overflow-x: auto;
  padding-block: 40px 100px;
  scroll-snap-type: inline mandatory;
}

.screenshots figure {
  margin: 0;
  scroll-snap-align: start;
}

.screenshots img {
  width: 100%;
  height: auto;
  border: 1px solid var(--line);
  border-radius: 28px;
  box-shadow: var(--shadow);
}

.privacy-promise {
  padding-block: 42px;
  background: var(--sage-soft);
  border-block: 1px solid var(--line);
}

.privacy-promise p {
  margin-block: 0;
  color: var(--sage-strong);
  font-size: clamp(1.2rem, 2.3vw, 1.65rem);
  font-weight: 720;
  text-align: center;
}

.prose-hero,
.legal {
  max-width: min(820px, calc(100vw - 48px));
}

.prose-hero {
  padding-block: 110px 76px;
}

.prose-hero h1,
.legal h1 {
  margin: 0;
  font-size: clamp(3rem, 7vw, 5.3rem);
  line-height: 1;
  letter-spacing: -0.06em;
}

.prose-hero p,
.legal__summary {
  margin: 28px 0 32px;
  color: var(--muted);
  font-size: clamp(1.1rem, 2vw, 1.35rem);
  line-height: 1.6;
}

.faq {
  max-width: min(820px, calc(100vw - 48px));
  padding-block-end: 120px;
}

.faq h2,
.legal h2 {
  margin: 0 0 28px;
  font-size: clamp(1.75rem, 3vw, 2.4rem);
  line-height: 1.18;
  letter-spacing: -0.035em;
}

.faq details {
  border-block-start: 1px solid var(--line);
  padding-block: 22px;
}

.faq details:last-child {
  border-block-end: 1px solid var(--line);
}

.faq summary {
  color: var(--ink);
  font-size: 1.08rem;
  font-weight: 720;
  cursor: pointer;
}

.faq details p {
  max-width: 720px;
  margin: 14px 0 0;
  color: var(--muted);
}

.legal {
  padding-block: 100px 120px;
}

.legal header {
  padding-block-end: 52px;
  border-block-end: 1px solid var(--line);
}

.legal__updated {
  margin: 18px 0 0;
  color: var(--muted);
  font-size: 0.92rem;
}

.legal section {
  padding-block-start: 48px;
}

.legal section p {
  margin: 0;
  color: var(--muted);
  font-size: 1.03rem;
}

.site-footer {
  border-block-start: 1px solid var(--line);
}

.site-footer__inner {
  min-height: 112px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
}

.site-footer p {
  margin: 0;
  color: var(--muted);
}

.site-footer nav {
  display: flex;
  gap: 24px;
}

.redirect-page {
  min-height: 100vh;
  display: grid;
  place-items: center;
  text-align: center;
}

.redirect-page main {
  padding: 32px;
}

.redirect-page img {
  margin-inline: auto;
  border-radius: 22px;
  box-shadow: var(--shadow);
}

.redirect-page h1 {
  margin: 24px 0 8px;
}

@media (max-width: 920px) {
  .site-header__inner {
    grid-template-columns: 1fr auto;
    gap: 14px;
    padding-block: 14px;
  }

  .primary-nav {
    grid-column: 1 / -1;
    grid-row: 2;
    justify-self: start;
    gap: 22px;
    overflow-x: auto;
    max-width: 100%;
  }

  .hero {
    min-height: auto;
    grid-template-columns: 1fr;
    gap: 54px;
    padding-block: 70px 82px;
  }

  .hero__art {
    grid-row: 1;
  }

  .hero__art img {
    width: min(62vw, 360px);
  }

  .feature-list {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 50px 34px;
  }
}

@media (max-width: 620px) {
  :root {
    --shell: min(100% - 32px, 1180px);
  }

  body {
    font-size: 16px;
  }

  .site-header__inner {
    min-height: 72px;
  }

  .brand span {
    max-width: 150px;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
  }

  .language-control {
    min-height: 44px;
    padding-inline: 10px 7px;
  }

  .language-control select {
    max-width: 108px;
  }

  .primary-nav {
    gap: 18px;
    padding-block-end: 4px;
    font-size: 0.92rem;
  }

  .hero {
    padding-block: 52px 72px;
  }

  .hero h1 {
    font-size: clamp(2.85rem, 14vw, 4.3rem);
  }

  .hero__copy > p {
    margin-block-start: 24px;
  }

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

  .button {
    width: 100%;
  }

  .features {
    padding-block: 72px 82px;
  }

  .features > h2 {
    margin-block-end: 52px;
    text-align: start;
  }

  .feature-list {
    grid-template-columns: 1fr;
    gap: 42px;
  }

  .prose-hero,
  .legal {
    padding-block-start: 68px;
  }

  .site-footer__inner {
    align-items: flex-start;
    flex-direction: column;
    justify-content: center;
    padding-block: 28px;
  }
}

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

  .button {
    transition: none;
  }
}