:root {
  --paper: #f1f1ee;
  --ink: #202120;
  --body: #333431;
  --muted: #6d6e68;
  --line: #cacbc5;
  --panel: #e8e8e3;
  --orange: #ff6b3d;
  --dark: #171815;
  --sans: "PingFang SC", "Hiragino Sans GB", "Noto Sans CJK SC", "Source Han Sans SC", "Microsoft YaHei", -apple-system, BlinkMacSystemFont, "Helvetica Neue", Arial, sans-serif;
  --wrap: 1280px;
  --gutter: clamp(20px, 4.5vw, 80px);
}

*,
*::before,
*::after {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
  scroll-padding-top: 92px;
}

body {
  margin: 0;
  background: var(--paper);
  color: var(--body);
  font-family: var(--sans);
  font-size: 16px;
  line-height: 1.75;
  -webkit-font-smoothing: antialiased;
  font-feature-settings: "palt" 1;
}

h1,
h2,
h3,
p,
dl,
dd,
figure {
  margin: 0;
}

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

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

button {
  font: inherit;
  color: inherit;
  cursor: pointer;
}

button,
a {
  -webkit-tap-highlight-color: transparent;
}

button:focus-visible,
a:focus-visible,
summary:focus-visible,
[tabindex]:focus-visible {
  outline: 2px solid var(--ink);
  outline-offset: 4px;
}

::selection {
  background: var(--orange);
  color: var(--ink);
}

.wrap {
  width: min(var(--wrap), calc(100% - var(--gutter) * 2));
  margin-inline: auto;
}

.skip {
  position: fixed;
  top: -100px;
  left: 20px;
  z-index: 50;
  padding: 12px 18px;
  background: var(--ink);
  color: var(--paper);
  font-size: 14px;
}

.skip:focus {
  top: 12px;
}

/* Header */

.site-head {
  position: sticky;
  top: 0;
  z-index: 30;
  background: var(--paper);
  border-bottom: 1px solid var(--line);
}

.head-inner {
  display: grid;
  grid-template-columns: 1fr auto 1fr;
  align-items: center;
  gap: 24px;
  width: min(var(--wrap), calc(100% - var(--gutter) * 2));
  height: 76px;
  margin-inline: auto;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 9px;
  width: fit-content;
}

.brand span {
  font-size: 19px;
  font-weight: 800;
  letter-spacing: -0.6px;
  color: var(--ink);
}

.brand-dot {
  color: var(--orange);
}

.site-nav {
  display: flex;
  gap: clamp(18px, 2.4vw, 34px);
  font-size: 13px;
  color: var(--muted);
}

.site-nav a {
  padding-block: 6px;
  border-bottom: 1px solid transparent;
}

.site-nav a:hover {
  color: var(--ink);
  border-bottom-color: var(--line);
}

.head-action {
  justify-self: end;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 38px;
  padding: 0 17px;
  border: 1px solid var(--ink);
  border-radius: 2px;
  background: var(--orange);
  color: var(--ink);
  font-size: 12.5px;
  font-weight: 650;
}

.head-action:hover {
  background: var(--ink);
  color: var(--paper);
}

/* Hero */

.hero {
  padding-block: clamp(52px, 6vw, 88px) clamp(62px, 8vw, 110px);
}

.hero-grid {
  display: grid;
  grid-template-columns: minmax(0, 5fr) minmax(0, 7fr);
  gap: clamp(36px, 5.5vw, 84px);
  align-items: start;
}

.hero-copy {
  padding-top: clamp(4px, 2vw, 28px);
}

h1 {
  color: var(--ink);
  font-size: clamp(46px, 5.15vw, 74px);
  font-weight: 600;
  line-height: 1.08;
  letter-spacing: -0.045em;
  margin-bottom: 30px;
}

.hero-lead {
  max-width: 31em;
  font-size: 16.5px;
  line-height: 1.95;
  color: var(--body);
  text-wrap: pretty;
}

.hero-permission {
  max-width: 30em;
  margin-top: 28px;
  padding-top: 15px;
  border-top: 1px solid var(--line);
  font-size: 12.5px;
  line-height: 1.8;
  color: var(--muted);
}

.hero-links {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 22px;
  margin-top: 30px;
}

.primary-link {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 48px;
  padding: 0 22px;
  border: 1px solid var(--ink);
  border-radius: 2px;
  background: var(--orange);
  color: var(--ink);
  font-size: 13.5px;
  font-weight: 650;
}

.primary-link:hover {
  background: var(--ink);
  color: var(--paper);
}

.quiet-link {
  padding-bottom: 3px;
  border-bottom: 1px solid var(--line);
  color: var(--body);
  font-size: 13px;
}

.quiet-link:hover {
  border-bottom-color: var(--ink);
}

/* Reference demo */

.hero-stage {
  min-width: 0;
}

.stage {
  position: relative;
  aspect-ratio: 1.18;
  overflow: hidden;
  border: 1px solid #34352e;
  border-radius: 3px;
  background: var(--dark);
  box-shadow: 0 30px 55px -42px rgba(23, 24, 21, 0.85);
  isolation: isolate;
}

.video-toggle {
  display: block;
  width: 100%;
  padding: 0;
  background: var(--dark);
}

.sample-frame .video-toggle {
  border: 0;
}

.video-toggle video {
  display: block;
  width: 100%;
  height: auto;
}

.stage video {
  height: 100%;
  object-fit: contain;
}

/* Sections */

.section {
  border-top: 1px solid var(--line);
  --section-space: clamp(64px, 7.5vw, 108px);
  padding-block: var(--section-space);
}

.section h2 {
  color: var(--ink);
  font-size: clamp(30px, 3.3vw, 45px);
  font-weight: 600;
  line-height: 1.22;
  letter-spacing: -0.035em;
  text-wrap: balance;
}

.section-lead {
  max-width: 42em;
  color: var(--body);
  font-size: 15.5px;
  line-height: 1.95;
  text-wrap: pretty;
}

.section h2 + .section-lead,
.section-head .section-lead {
  margin-top: 20px;
}

.section-head {
  display: grid;
  grid-template-columns: minmax(0, 6fr) minmax(0, 5fr);
  gap: clamp(30px, 6vw, 100px);
  align-items: end;
  margin-bottom: clamp(38px, 5vw, 62px);
}

.section-head .section-lead {
  margin-top: 0;
}

.note {
  max-width: 38em;
  margin-top: 20px;
  padding-left: 14px;
  border-left: 2px solid var(--orange);
  color: var(--muted);
  font-size: 13px;
  line-height: 1.9;
}

/* What */

.what-grid {
  display: grid;
  grid-template-columns: minmax(0, 6fr) minmax(0, 6fr);
  gap: clamp(38px, 7vw, 110px);
  align-items: start;
}

.facts {
  border-top: 1px solid var(--ink);
}

.facts > div {
  display: grid;
  grid-template-columns: 92px minmax(0, 1fr);
  gap: 22px;
  padding: 17px 0 18px;
  border-bottom: 1px solid var(--line);
}

.facts dt {
  color: var(--muted);
  font-size: 12.5px;
  line-height: 1.9;
}

.facts dd {
  color: var(--body);
  font-size: 14.5px;
  line-height: 1.85;
}

/* Three actions */

.actions {
  border-top: 1px solid var(--ink);
}

.action {
  display: grid;
  grid-template-columns: 72px minmax(0, 1.04fr) minmax(0, 0.96fr);
  gap: clamp(22px, 3.4vw, 52px);
  padding: 30px 0 32px;
  border-bottom: 1px solid var(--line);
  align-items: start;
}

.action-mark {
  color: var(--ink);
  font-size: 40px;
  font-weight: 500;
  line-height: 1;
  letter-spacing: 0.04em;
}

.action-copy h3 {
  color: var(--ink);
  font-size: 21px;
  font-weight: 600;
  line-height: 1.4;
  letter-spacing: -0.02em;
  margin-bottom: 12px;
}

.action-copy p {
  max-width: 33em;
  font-size: 14.5px;
  line-height: 1.9;
}

.action-detail {
  max-width: 34em;
  padding-top: 3px;
  color: var(--muted);
  font-size: 13px;
  line-height: 1.9;
}

/* Image effects feature */

.color-grid {
  display: grid;
  grid-template-columns: minmax(0, 5fr) minmax(0, 7fr);
  gap: clamp(40px, 7vw, 110px);
  align-items: start;
}

.color-copy {
  padding-top: 6px;
}

.color-copy .section-lead {
  margin-top: 20px;
}

.effects-example {
  min-width: 0;
}

.sample-frame {
  position: relative;
  overflow: hidden;
  border: 1px solid var(--line);
  border-radius: 2px;
}

/* Reference lists */

.lists-head {
  display: grid;
  grid-template-columns: minmax(0, 5fr) minmax(0, 7fr);
  gap: clamp(34px, 6vw, 100px);
  align-items: start;
  margin-bottom: clamp(34px, 4.5vw, 54px);
}

.lists-head .section-lead {
  max-width: 40em;
}

.lists-head .note {
  max-width: 36em;
}

.guide img {
  width: 100%;
  height: auto;
  border: 1px solid var(--line);
  border-radius: 2px;
  background: var(--panel);
  box-shadow: 0 20px 44px -38px rgba(32, 33, 32, 0.7);
}

/* Questions */

.questions-head {
  grid-template-columns: minmax(0, 4fr) minmax(0, 7fr);
}

.qa-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  column-gap: clamp(36px, 6vw, 96px);
  border-top: 1px solid var(--ink);
}

.qa-grid details {
  border-bottom: 1px solid var(--line);
}

.qa-grid summary {
  position: relative;
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 20px;
  padding: 19px 0;
  color: var(--ink);
  font-size: 15.5px;
  font-weight: 550;
  line-height: 1.6;
  list-style: none;
  cursor: pointer;
}

.qa-grid summary::-webkit-details-marker {
  display: none;
}

.qa-grid summary::after {
  content: "+";
  flex: 0 0 auto;
  color: var(--muted);
  font-size: 20px;
  font-weight: 400;
  line-height: 1;
  transition: transform 0.18s ease;
}

.qa-grid details[open] summary::after {
  transform: rotate(45deg);
}

.qa-grid details p {
  max-width: 36em;
  padding: 0 34px 22px 0;
  color: var(--muted);
  font-size: 13.5px;
  line-height: 1.95;
}

/* Closing and footer */

.closing-grid {
  max-width: 880px;
  margin-left: max(var(--gutter), calc((100% - var(--wrap)) / 2));
}

.closing h2 {
  max-width: 15em;
}

.closing .section-lead {
  margin-top: 22px;
  max-width: 40em;
}

.site-foot {
  border-top: 1px solid var(--line);
}

.foot-grid {
  display: grid;
  grid-template-columns: auto 1fr auto auto;
  gap: 28px;
  align-items: center;
  padding-block: 25px 30px;
}

.site-foot .brand span {
  font-size: 16px;
}

.foot-grid > p {
  color: var(--muted);
  font-size: 12px;
  line-height: 1.7;
}

.foot-tagline {
  color: var(--ink) !important;
}

.foot-copy {
  grid-column: -2;
  white-space: nowrap;
}

/* Responsive */

@media (max-width: 1080px) {
  .site-nav {
    gap: 18px;
  }

  .hero-grid {
    gap: 36px;
  }

  .action {
    grid-template-columns: 54px minmax(0, 1fr) minmax(0, 0.92fr);
  }

  .action-mark {
    font-size: 32px;
  }
}

@media (max-width: 880px) {
  html {
    scroll-padding-top: 84px;
  }

  .head-inner {
    grid-template-columns: 1fr auto;
    height: 70px;
  }

  .site-nav {
    display: none;
  }

  .hero-grid,
  .what-grid,
  .color-grid {
    grid-template-columns: minmax(0, 1fr);
  }

  .hero-grid {
    gap: 42px;
  }

  .hero-copy {
    padding-top: 0;
  }

  h1 {
    font-size: clamp(44px, 8.2vw, 66px);
  }

  .hero-lead {
    max-width: 34em;
  }

  .section-head,
  .lists-head,
  .questions-head {
    grid-template-columns: minmax(0, 1fr);
    gap: 20px;
  }

  .section-head {
    align-items: start;
  }

  .section-head .section-lead {
    margin-top: 0;
  }

  .what-grid,
  .color-grid {
    gap: 38px;
  }

  .action {
    grid-template-columns: 48px minmax(0, 1fr);
    gap: 18px 24px;
  }

  .action-detail {
    grid-column: 2;
    padding-top: 0;
  }

  .qa-grid {
    column-gap: 40px;
  }

  .foot-grid {
    grid-template-columns: 1fr auto;
    gap: 14px 24px;
  }

  .foot-grid > p:nth-child(2) {
    grid-column: 1 / -1;
    grid-row: 2;
  }

  .foot-copy {
    grid-column: 2;
    grid-row: 1;
    justify-self: end;
  }

  .foot-tagline {
    grid-column: 1;
    grid-row: 3;
  }
}

@media (max-width: 620px) {
  :root {
    --gutter: 20px;
  }

  html {
    scroll-padding-top: 78px;
  }

  .head-inner {
    height: 66px;
    gap: 12px;
  }

  .brand img {
    width: 28px;
    height: 28px;
  }

  .brand span {
    font-size: 17px;
  }

  .head-action {
    min-height: 36px;
    padding-inline: 13px;
    font-size: 12px;
  }

  .hero {
    padding-block: 40px 58px;
  }

  .hero-grid {
    gap: 34px;
  }

  h1 {
    font-size: clamp(40px, 11.7vw, 52px);
    margin-bottom: 24px;
  }

  .hero-lead {
    font-size: 15.5px;
    line-height: 1.9;
  }

  .hero-permission {
    margin-top: 23px;
    font-size: 12px;
  }

  .hero-links {
    gap: 18px;
    margin-top: 24px;
  }

  .primary-link {
    min-height: 46px;
    padding-inline: 19px;
  }

  .section {
    --section-space: 58px;
  }

  .section h2 {
    font-size: clamp(28px, 8vw, 35px);
  }

  .section-lead {
    font-size: 14.5px;
    line-height: 1.9;
  }

  .facts > div {
    grid-template-columns: 70px minmax(0, 1fr);
    gap: 16px;
    padding-block: 15px 16px;
  }

  .facts dd {
    font-size: 14px;
  }

  .action {
    grid-template-columns: 38px minmax(0, 1fr);
    gap: 14px 18px;
    padding-block: 25px 26px;
  }

  .action-mark {
    font-size: 28px;
  }

  .action-copy h3 {
    font-size: 19px;
    margin-bottom: 9px;
  }

  .action-copy p,
  .action-detail {
    font-size: 13.5px;
  }

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

  .qa-grid summary {
    font-size: 15px;
    padding-block: 17px;
  }

  .qa-grid details p {
    font-size: 13px;
  }

  .closing-grid {
    gap: 0;
  }

  .foot-grid {
    grid-template-columns: 1fr;
    gap: 10px;
    padding-block: 22px 26px;
  }

  .foot-grid > p:nth-child(2),
  .foot-copy,
  .foot-tagline {
    grid-column: 1;
    grid-row: auto;
    justify-self: start;
  }

  .foot-tagline {
    margin-top: 4px;
  }
}

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

  *,
  *::before,
  *::after {
    transition: none !important;
    animation: none !important;
  }
}


.header-actions {
  display: flex;
  align-items: center;
  justify-content: flex-end;
  gap: clamp(10px, 2vw, 20px);
}

html[lang="en"] .action-mark {
  font-size: 1.1rem;
  letter-spacing: 0;
}