:root {
  --bg: #f5f4ef;
  --surface: rgba(255, 255, 255, 0.52);
  --text: #111111;
  --muted: #5f5f5a;
  --soft: #8a8a84;
  --line: #1a1a1a;
  --soft-line: #cecac0;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  background: linear-gradient(180deg, #f7f6f2 0%, var(--bg) 100%);
  color: var(--text);
  line-height: 1.6;
}

body.brand-home {
  --bg: #ffffff;
  --surface: #ffffff;
  --muted: #4a4a4a;
  --soft: #8a8a8a;
  --line: #111111;
  --soft-line: #d8d8d8;
  background: #ffffff;
}

body.app-page {
  --bg: #ffffff;
  --surface: #ffffff;
  --muted: #4a4a4a;
  --soft: #8a8a8a;
  --line: #111111;
  --soft-line: #d8d8d8;
  background: #ffffff;
}

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

main {
  max-width: 1080px;
  margin: 0 auto;
  padding: 24px 24px 96px;
}

.brand-home main {
  max-width: 1040px;
  padding-top: 26px;
}

.app-page main {
  max-width: 1040px;
  padding-top: 26px;
}

.site-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 20px;
  padding: 2px 0 18px;
  border-bottom: 1px solid var(--soft-line);
}

.brand-home .site-header {
  padding-bottom: 16px;
  border-bottom-color: var(--line);
}

.app-page .site-header {
  padding-bottom: 16px;
  border-bottom-color: var(--line);
}

.brand {
  font-size: 13px;
  letter-spacing: 0.18em;
  text-transform: uppercase;
}

.brand-lockup {
  display: inline-flex;
  align-items: center;
  max-width: 132px;
  letter-spacing: 0;
  text-transform: none;
}

.brand-home .brand-lockup {
  max-width: 118px;
}

.app-page .brand-lockup {
  max-width: 118px;
}

.brand-lockup img {
  display: block;
  width: 100%;
  height: auto;
}

.site-nav {
  display: flex;
  flex-wrap: wrap;
  justify-content: flex-end;
  gap: 18px;
}

.site-nav a {
  padding: 0 0 7px;
  border-bottom: 1px solid transparent;
  font-size: 14px;
  color: var(--muted);
  transition: color 120ms ease, border-color 120ms ease, opacity 120ms ease;
}

.brand-home .site-nav {
  gap: 18px;
}

.brand-home .site-nav a {
  font-size: 12px;
  letter-spacing: 0.12em;
  text-transform: uppercase;
}

.app-page .site-nav {
  gap: 18px;
}

.app-page .site-nav a {
  font-size: 12px;
  letter-spacing: 0.12em;
  text-transform: uppercase;
}

.site-nav a:hover,
.site-nav a[aria-current="page"] {
  color: var(--text);
  border-bottom-color: var(--text);
}

.site-nav-minimal {
  justify-content: flex-start;
}

.hero {
  padding: 38px 0 34px;
  border-bottom: 1px solid var(--line);
}

.home-hero {
  display: grid;
  grid-template-columns: 148px minmax(0, 1fr);
  gap: 34px;
  align-items: center;
  padding: 54px 0 48px;
  border-bottom: 1px solid var(--line);
}

.home-hero-mark {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 132px;
  height: 132px;
}

.home-hero-mark img {
  display: block;
  width: 116px;
  height: auto;
}

.home-hero-copy {
  min-width: 0;
}

.spark-hero {
  display: block;
  padding: 58px 0 38px;
  border-bottom: 1px solid var(--line);
}

.spark-hero-main {
  display: grid;
  grid-template-columns: 164px minmax(0, 1fr);
  gap: 36px;
  align-items: center;
  max-width: 820px;
}

.spark-hero-mark {
  width: 142px;
  height: auto;
  filter: grayscale(1) contrast(1.16);
}

.brand-home .spark-hero h1 {
  max-width: 600px;
  margin: 0;
  font-size: clamp(27px, 3.4vw, 40px);
  line-height: 1.1;
  letter-spacing: -0.01em;
  font-weight: 720;
}

.brand-home .spark-hero h1 span {
  display: block;
  color: #777777;
}

.hero-kicker,
.section-label {
  margin: 0 0 14px;
  color: var(--soft);
  font-size: 12px;
  letter-spacing: 0.16em;
  text-transform: uppercase;
}

.section-label {
  margin-top: 34px;
  margin-bottom: 4px;
}

.brand-home .section-label {
  margin-top: 0;
  margin-bottom: 0;
  color: var(--soft);
  font-size: 12px;
  letter-spacing: 0.18em;
}

.app-page .section-label {
  margin-top: 0;
  margin-bottom: 0;
  color: var(--soft);
  font-size: 12px;
  letter-spacing: 0.18em;
}

.hero-head {
  display: flex;
  align-items: flex-start;
  gap: 20px;
}

.hero-copy {
  flex: 1;
  min-width: 0;
}

h1 {
  margin: 0 0 14px;
  font-size: clamp(34px, 6vw, 64px);
  line-height: 1.08;
  letter-spacing: -0.03em;
  font-weight: 700;
}

.brand-home h1 {
  max-width: 740px;
  font-size: clamp(34px, 4.6vw, 52px);
  letter-spacing: 0;
  font-weight: 620;
}

.subtitle {
  margin: 0;
  max-width: 48rem;
  color: var(--muted);
  font-size: 15px;
  line-height: 1.8;
}

.home-intro {
  max-width: 50rem;
  margin-top: 16px;
}

.brand-note {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 180px;
  gap: 34px;
  align-items: center;
  padding: 28px 0 30px;
  border-bottom: 1px solid var(--soft-line);
}

.brand-note .section-label {
  margin-top: 0;
}

.brand-note p:last-child {
  margin-bottom: 0;
}

.brand-note img {
  display: block;
  width: 170px;
  height: auto;
  justify-self: end;
  opacity: 0.92;
}

.app-mark {
  width: 72px;
  height: 72px;
  border: 1px solid var(--soft-line);
  border-radius: 18px;
  background: rgba(255, 255, 255, 0.66);
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
  overflow: hidden;
}

.app-mark img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
}

.app-mark-mono {
  font-size: 18px;
  font-weight: 700;
  letter-spacing: 0.18em;
}

.page-tabs,
.fact-strip,
.actions {
  display: flex;
  flex-wrap: wrap;
}

.page-tabs {
  gap: 18px;
  margin-top: 26px;
}

.page-tabs a {
  padding: 0 0 7px;
  border-bottom: 1px solid transparent;
  font-size: 14px;
  color: var(--muted);
}

.page-tabs a:hover,
.page-tabs a[aria-current="page"] {
  color: var(--text);
  border-bottom-color: var(--text);
}

.fact-strip {
  gap: 10px 12px;
  margin-top: 24px;
}

.fact {
  border: 1px solid var(--soft-line);
  padding: 7px 10px 6px;
  font-size: 12px;
  color: var(--muted);
  letter-spacing: 0.04em;
  background: var(--surface);
}

.product-grid,
.doc-sections {
  margin-top: 16px;
  border-top: 1px solid var(--soft-line);
}

.product-row,
.doc-section {
  border-bottom: 1px solid var(--soft-line);
}

.product-row {
  display: grid;
  grid-template-columns: 88px minmax(0, 1fr) 220px;
  align-items: start;
  gap: 18px;
  padding: 28px 0 30px;
}

.doc-section {
  max-width: 760px;
  padding: 24px 0 26px;
}

.product-main {
  min-width: 0;
}

.row-title,
h2 {
  margin: 0 0 10px;
  font-size: 28px;
  line-height: 1.2;
  letter-spacing: -0.02em;
  font-weight: 650;
}

h2 {
  font-size: 22px;
}

.row-summary,
.row-note,
p,
li {
  margin: 0 0 14px;
  color: var(--muted);
  font-size: 15px;
  line-height: 1.78;
}

.row-note {
  font-size: 14px;
}

.actions {
  justify-content: flex-end;
  gap: 10px;
}

.button-link,
.text-link {
  border-bottom: 1px solid var(--text);
}

.button-link {
  display: inline-flex;
  align-items: center;
  padding: 10px 0 8px;
  font-size: 14px;
}

ul {
  margin: 0 0 14px;
  padding-left: 20px;
}

.meta {
  margin-top: 34px;
  padding-top: 18px;
  border-top: 1px solid var(--soft-line);
  color: var(--soft);
  font-size: 14px;
}

.site-footer {
  display: flex;
  align-items: center;
  gap: 10px;
  margin-top: 34px;
  padding-top: 18px;
  border-top: 1px solid var(--soft-line);
}

.site-footer img {
  width: 22px;
  height: auto;
  opacity: 0.72;
}

.site-footer p {
  margin: 0;
  color: var(--soft);
  font-size: 14px;
}

.apps-section {
  margin-top: 0;
}

.apps-toolbar {
  display: flex;
  justify-content: space-between;
  gap: 18px;
  align-items: center;
  padding: 16px 0;
  border-bottom: 1px solid var(--soft-line);
}

.quality-list {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.quality-chip {
  border: 1px solid var(--soft-line);
  border-radius: 2px;
  padding: 7px 11px;
  color: var(--muted);
  background: #ffffff;
  font-size: 12px;
}

.quality-chip.is-active {
  color: #ffffff;
  border-color: var(--text);
  background: var(--text);
}

.spark-products {
  display: grid;
  gap: 12px;
  padding-top: 20px;
}

.spark-row {
  display: grid;
  grid-template-columns: 44px 68px minmax(0, 1fr) auto;
  gap: 18px;
  align-items: center;
  min-height: 128px;
  padding: 18px;
  border: 1px solid var(--soft-line);
  border-radius: 7px;
  background: #fcfcfc;
}

.spark-row:not(:has(.actions)) {
  grid-template-columns: 44px 68px minmax(0, 1fr);
}

.spark-row-number {
  color: var(--soft);
  font-size: 12px;
  letter-spacing: 0.18em;
}

.spark-row .app-mark {
  width: 58px;
  height: 58px;
  border-color: var(--soft-line);
  border-radius: 7px;
  background: #ffffff;
  filter: grayscale(1) contrast(1.1);
}

.spark-row .app-mark-link {
  transition: border-color 120ms ease, opacity 120ms ease, filter 120ms ease;
}

.spark-row .app-mark-link:hover {
  border-color: var(--text);
  opacity: 0.88;
}

.spark-row h2 {
  margin: 0 0 7px;
  font-size: 22px;
  line-height: 1.15;
  letter-spacing: 0;
  font-weight: 700;
}

.app-title-link {
  border-bottom: 1px solid transparent;
  transition: border-color 120ms ease, color 120ms ease;
}

.app-title-link:hover {
  color: var(--muted);
  border-bottom-color: var(--text);
}

.spark-row p {
  max-width: 650px;
  margin: 0 0 10px;
  color: var(--muted);
  font-size: 14px;
  line-height: 1.65;
}

.brand-home .zh-copy {
  margin-top: -4px;
  color: #747474;
  font-size: 13px;
  line-height: 1.72;
  letter-spacing: 0.01em;
}

.spark-row .zh-copy {
  margin-bottom: 12px;
}

.tag-row {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.tag-row span {
  border: 1px solid var(--soft-line);
  border-radius: 2px;
  padding: 5px 8px;
  color: var(--muted);
  font-size: 11px;
}

.spark-row .actions {
  justify-content: flex-end;
}

.spark-row .text-link {
  font-size: 12px;
  letter-spacing: 0.12em;
  text-transform: uppercase;
}

.spark-footer {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 260px;
  gap: 40px;
  margin-top: 28px;
  padding-top: 18px;
  border-top: 1px solid var(--line);
  color: var(--muted);
  font-size: 13px;
}

.spark-footer p {
  margin: 0;
  color: var(--muted);
  font-size: 13px;
  line-height: 1.7;
}

.spark-footer .copyright {
  color: var(--soft);
  letter-spacing: 0.04em;
}

.app-hero {
  display: grid;
  grid-template-columns: 130px minmax(0, 1fr) 138px;
  gap: 36px;
  align-items: center;
  padding: 58px 0 38px;
  border-bottom: 1px solid var(--line);
}

.app-hero-icon {
  width: 112px;
  height: 112px;
  border: 1px solid var(--soft-line);
  border-radius: 8px;
  overflow: hidden;
  background: #ffffff;
  filter: grayscale(1) contrast(1.08);
}

.app-hero-icon img {
  display: block;
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.app-hero-mono {
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--text);
  font-size: 24px;
  font-weight: 750;
  letter-spacing: 0.12em;
}

.app-hero h1 {
  max-width: 620px;
  margin: 0;
  font-size: clamp(42px, 6vw, 76px);
  line-height: 0.98;
  letter-spacing: -0.025em;
  font-weight: 780;
}

.app-lede {
  max-width: 610px;
  margin: 22px 0 0;
  color: var(--muted);
  font-size: 16px;
  line-height: 1.8;
}

.app-qr-card {
  justify-self: end;
  width: 124px;
}

.app-qr-card img {
  display: block;
  width: 124px;
  height: 124px;
  border: 1px solid var(--soft-line);
  border-radius: 7px;
  background: #ffffff;
}

.app-summary {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 52px;
  padding: 24px 0;
  border-bottom: 1px solid var(--soft-line);
}

.app-summary p,
.app-info-grid p {
  color: var(--muted);
  font-size: 14px;
  line-height: 1.75;
}

.app-page .zh-copy {
  margin-top: -6px;
  color: #747474;
  font-size: 13px;
  line-height: 1.75;
  letter-spacing: 0.01em;
}

.app-actions-panel {
  display: flex;
  flex-wrap: wrap;
  gap: 14px;
  align-items: center;
  padding: 16px 0;
  border-bottom: 1px solid var(--soft-line);
}

.primary-link {
  display: inline-flex;
  align-items: center;
  border: 1px solid var(--text);
  border-radius: 2px;
  padding: 8px 12px;
  background: var(--text);
  color: #ffffff;
  font-size: 12px;
  letter-spacing: 0.1em;
  text-transform: uppercase;
}

.app-feature-list {
  display: grid;
  gap: 12px;
  padding-top: 20px;
}

.app-feature-row {
  display: grid;
  grid-template-columns: 54px minmax(0, 1fr);
  gap: 18px;
  padding: 18px;
  border: 1px solid var(--soft-line);
  border-radius: 7px;
  background: #fcfcfc;
}

.feature-number {
  color: var(--soft);
  font-size: 12px;
  letter-spacing: 0.18em;
}

.app-feature-row h2,
.app-info-grid h2 {
  margin: 0 0 7px;
  font-size: 22px;
  line-height: 1.15;
  letter-spacing: 0;
  font-weight: 700;
}

.app-feature-row p {
  max-width: 700px;
  margin: 0;
  color: var(--muted);
  font-size: 14px;
  line-height: 1.65;
}

.app-feature-row .zh-copy {
  margin-top: 6px;
}

.app-info-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 12px;
  padding-top: 12px;
}

.app-info-grid article {
  padding: 18px;
  border: 1px solid var(--soft-line);
  border-radius: 7px;
  background: #ffffff;
}

.app-doc-hero {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 250px;
  gap: 44px;
  align-items: end;
  padding: 58px 0 38px;
  border-bottom: 1px solid var(--line);
}

.app-doc-title h1 {
  max-width: 720px;
  margin: 0;
  font-size: clamp(38px, 5.7vw, 68px);
  line-height: 1;
  letter-spacing: -0.025em;
  font-weight: 780;
}

.app-doc-aside {
  justify-self: end;
  max-width: 230px;
}

.app-doc-aside p {
  margin: 14px 0 0;
  color: var(--muted);
  font-size: 13px;
  line-height: 1.65;
}

.app-doc-aside .zh-copy {
  margin-top: 6px;
}

.app-doc-icon {
  width: 74px;
  height: 74px;
  border: 1px solid var(--soft-line);
  border-radius: 7px;
  overflow: hidden;
  background: #ffffff;
  filter: grayscale(1) contrast(1.08);
}

.app-doc-icon img {
  display: block;
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.app-doc-summary {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 52px;
  padding: 24px 0;
  border-bottom: 1px solid var(--soft-line);
}

.app-doc-summary p {
  color: var(--muted);
  font-size: 14px;
  line-height: 1.75;
}

.app-doc-list {
  display: grid;
  gap: 12px;
  padding-top: 20px;
}

.app-doc-row {
  display: grid;
  grid-template-columns: 54px minmax(0, 1fr);
  gap: 18px;
  padding: 18px;
  border: 1px solid var(--soft-line);
  border-radius: 7px;
  background: #fcfcfc;
}

.app-doc-row h2 {
  margin: 0 0 7px;
  font-size: 22px;
  line-height: 1.15;
  letter-spacing: 0;
  font-weight: 700;
}

.app-doc-row p,
.app-doc-row li {
  max-width: 760px;
  color: var(--muted);
  font-size: 14px;
  line-height: 1.72;
  overflow-wrap: anywhere;
}

.app-doc-row p:last-child,
.app-doc-row ul:last-child {
  margin-bottom: 0;
}

.app-doc-row .zh-copy {
  margin-top: -8px;
}

@media (max-width: 900px) {
  .product-row {
    grid-template-columns: 72px minmax(0, 1fr);
  }

  .actions {
    grid-column: 2;
    justify-content: flex-start;
  }
}

@media (max-width: 720px) {
  main {
    padding: 20px 18px 84px;
  }

  .site-header,
  .hero-head {
    flex-direction: column;
    align-items: flex-start;
  }

  .home-header {
    gap: 16px;
  }

  .site-nav {
    justify-content: flex-start;
  }

  .spark-hero-main,
  .spark-row,
  .spark-footer,
  .app-hero,
  .app-summary,
  .app-info-grid,
  .app-doc-hero,
  .app-doc-summary {
    grid-template-columns: minmax(0, 1fr);
    gap: 18px;
  }

  .spark-hero {
    padding: 42px 0 32px;
  }

  .spark-hero-mark {
    width: 92px;
  }

  .brand-home .spark-hero h1 {
    font-size: 27px;
  }

  .apps-toolbar {
    align-items: flex-start;
    flex-direction: column;
  }

  .spark-row .actions {
    justify-content: flex-start;
  }

  .app-hero {
    padding: 42px 0 32px;
  }

  .app-hero-icon {
    width: 82px;
    height: 82px;
  }

  .app-hero h1 {
    font-size: 42px;
  }

  .app-qr-card {
    justify-self: start;
    width: 112px;
  }

  .app-qr-card img {
    width: 112px;
    height: 112px;
  }

  .app-doc-hero {
    align-items: start;
    padding: 42px 0 32px;
  }

  .app-doc-title h1 {
    font-size: 36px;
  }

  .app-doc-aside {
    justify-self: start;
  }

  .app-doc-title,
  .app-doc-summary > div,
  .app-doc-row > div {
    min-width: 0;
  }

  .app-doc-row {
    grid-template-columns: minmax(0, 1fr);
  }

  .app-doc-summary p,
  .app-doc-row p,
  .app-doc-row li {
    max-width: 32rem;
  }

  .app-actions-panel {
    align-items: flex-start;
    flex-direction: column;
  }

  .home-hero,
  .brand-note {
    grid-template-columns: minmax(0, 1fr);
  }

  .home-hero {
    gap: 24px;
    padding: 42px 0 38px;
  }

  .home-hero-mark {
    justify-content: flex-start;
    width: 88px;
    height: 88px;
  }

  .home-hero-mark img {
    width: 78px;
  }

  .brand-home h1 {
    font-size: 31px;
  }

  .brand-note img {
    justify-self: start;
    width: 146px;
  }

  .product-row {
    grid-template-columns: minmax(0, 1fr);
  }

  .actions {
    grid-column: auto;
  }

  .app-mark {
    width: 64px;
    height: 64px;
    border-radius: 16px;
  }

  .row-title {
    font-size: 24px;
  }
}