:root {
  --deep: #071f55;
  --blue: #0b328f;
  --blue-2: #1747c7;
  --blue-3: #4c7fe6;
  --blue-4: #a9c7f2;
  --pale: #e9f1fa;
  --paper: #f7f9fc;
  --ink: #12203a;
  --muted: #5d6d88;
  --line: rgba(18, 32, 58, 0.12);
  --line-strong: rgba(18, 32, 58, 0.2);
  --white: #ffffff;
  --white-80: rgba(255, 255, 255, 0.8);
  --white-64: rgba(255, 255, 255, 0.64);
  --white-48: rgba(255, 255, 255, 0.48);
  --line-white: rgba(255, 255, 255, 0.18);
  --sun: #ff8a4c;
  --sun-2: #ffb38a;
  --green: #25d366;
  --accent: var(--sun);
  --surface: #ffffff;
  --shadow: 0 30px 70px -30px rgba(3, 12, 40, 0.5);
  --shadow-soft: 0 16px 40px -24px rgba(3, 12, 40, 0.35);
  --radius: 24px;
  --font: "HarmonyOS Sans SC", "MiSans", "PingFang SC", "Microsoft YaHei UI", sans-serif;
  --mono: ui-monospace, "SFMono-Regular", "Cascadia Code", Consolas, monospace;
  --ease: cubic-bezier(0.22, 1, 0.36, 1);
  interpolate-size: allow-keywords;
}

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

html {
  scroll-behavior: smooth;
  scrollbar-width: none;
  -ms-overflow-style: none;
}
html::-webkit-scrollbar { display: none; }
html,
body { margin: 0; padding: 0; overflow-x: clip; }

body {
  min-height: 100svh;
  color: var(--white);
  background:
    linear-gradient(
      180deg,
      #071f55 0%,
      #0b328f 12%,
      #1747c7 30%,
      #4c7fe6 46%,
      #a9c7f2 56%,
      #e9f1fa 64%,
      #f7f9fc 100%
    );
  font-family: var(--font);
  font-size: 16px;
  font-weight: 400;
  line-height: 1.7;
  font-variant-numeric: tabular-nums;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

body::before {
  content: "";
  position: fixed;
  inset: 0;
  z-index: 0;
  pointer-events: none;
  background-image:
    linear-gradient(rgba(255, 255, 255, 0.055) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255, 255, 255, 0.055) 1px, transparent 1px),
    repeating-linear-gradient(180deg, rgba(255, 255, 255, 0.028) 0 1px, transparent 1px 4px);
  background-size: 72px 72px, 72px 72px, 100% 4px;
  -webkit-mask-image: linear-gradient(180deg, #000 0%, #000 66%, transparent 92%);
  mask-image: linear-gradient(180deg, #000 0%, #000 66%, transparent 92%);
}

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

img { display: block; max-width: 100%; }
a { color: inherit; text-decoration: none; }
button,
select { font: inherit; }
time { font-variant-numeric: tabular-nums; }


:where(a, button, summary, select):focus-visible {
  outline: 2px solid var(--sun-2);
  outline-offset: 3px;
  border-radius: 8px;
}

.sr-only {
  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;
  top: 10px;
  left: 10px;
  z-index: 200;
  padding: 10px 14px;
  border-radius: 10px;
  background: var(--white);
  color: var(--ink);
  font-size: 14px;
  font-weight: 600;
  box-shadow: var(--shadow-soft);
  transform: translateY(-160%);
  transition: transform 0.25s var(--ease);
}
.skip-link:focus-visible { transform: translateY(0); }

section[id] { scroll-margin-top: 24px; }

.wrap {
  width: min(1160px, calc(100% - 64px));
  margin-inline: auto;
}

main,
footer { position: relative; z-index: 1; }
.nav,
main,
footer {
  transition: opacity 0.2s var(--ease), filter 0.2s var(--ease);
}
html.lang-switching .nav,
html.lang-switching main,
html.lang-switching footer {
  opacity: 0.2;
  filter: blur(5px);
}

/* Navigation */
.nav {
  position: absolute;
  inset-inline: 0;
  top: 0;
  z-index: 20;
  padding-top: 20px;
}
.nav-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
  min-height: 44px;
}
.brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  min-width: 0;
  color: var(--white);
  font-size: 15px;
  font-weight: 600;
  letter-spacing: 0.02em;
}
.brand-mark {
  width: 30px;
  height: 30px;
  flex: none;
}
.brand-name { white-space: nowrap; }
.nav-actions {
  display: flex;
  align-items: center;
  gap: 10px;
  flex: none;
}
.nav-icon {
  display: grid;
  place-items: center;
  width: 36px;
  height: 36px;
  border-radius: 999px;
  color: var(--white);
  transition: opacity 0.2s var(--ease);
}
.nav-icon:hover { opacity: 0.72; }
.nav-icon svg { width: 22px; height: 22px; }
.lang-menu { position: relative; }
.lang-toggle {
  display: grid;
  place-items: center;
  width: 36px;
  height: 36px;
  padding: 0;
  border: 0;
  border-radius: 999px;
  background: transparent;
  color: var(--white);
  cursor: pointer;
  transition: opacity 0.2s var(--ease), transform 0.2s var(--ease);
}
.lang-toggle:hover,
.lang-toggle[aria-expanded="true"] { opacity: 0.72; }
.lang-toggle svg { width: 22px; height: 22px; }
.lang-popover {
  position: absolute;
  top: calc(100% + 9px);
  right: 0;
  min-width: 132px;
  padding: 6px;
  border: 1px solid rgba(255, 255, 255, 0.16);
  border-radius: 14px;
  background: rgba(7, 26, 67, 0.95);
  box-shadow: 0 20px 44px rgba(2, 10, 36, 0.42);
  -webkit-backdrop-filter: blur(16px);
  backdrop-filter: blur(16px);
  opacity: 0;
  visibility: hidden;
  transform: translateY(-6px) scale(0.98);
  transform-origin: top right;
  pointer-events: none;
  transition: opacity 0.18s var(--ease), transform 0.18s var(--ease), visibility 0s 0.18s;
}
.lang-menu.is-open .lang-popover {
  opacity: 1;
  visibility: visible;
  transform: none;
  pointer-events: auto;
  transition: opacity 0.18s var(--ease), transform 0.18s var(--ease), visibility 0s;
}
.lang-option {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 14px;
  width: 100%;
  padding: 8px 10px;
  border: 0;
  border-radius: 9px;
  background: transparent;
  color: var(--white-80);
  font-size: 13px;
  font-weight: 500;
  text-align: left;
  white-space: nowrap;
  cursor: pointer;
  transition: background-color 0.18s var(--ease), color 0.18s var(--ease);
}
.lang-option:hover,
.lang-option:focus-visible {
  background: rgba(255, 255, 255, 0.1);
  color: var(--white);
}
.lang-option[aria-checked="true"] { color: var(--white); }
.lang-option[aria-checked="true"]::after {
  content: "✓";
  color: var(--green);
  font-size: 11px;
}
.nav-cta {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  height: 36px;
  padding: 0 17px;
  border-radius: 999px;
  background: var(--white);
  color: var(--ink);
  font-size: 13px;
  font-weight: 600;
  overflow: hidden;
  white-space: nowrap;
  transition: transform 0.25s var(--ease), background-color 0.25s var(--ease), width 0.25s var(--ease);
}
.nav-cta:hover { transform: translateY(-1px); background: #f4f8ff; }

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 9px;
  min-height: 52px;
  padding: 0 26px;
  border: 1px solid transparent;
  border-radius: 999px;
  font-size: 15px;
  font-weight: 600;
  line-height: 1;
  white-space: nowrap;
  cursor: pointer;
  transition: transform 0.25s var(--ease), background-color 0.25s var(--ease), border-color 0.25s var(--ease), color 0.25s var(--ease);
}
.btn svg { width: 17px; height: 17px; flex: none; }
.btn-light {
  background: var(--white);
  color: var(--ink);
  box-shadow: 0 18px 38px -22px rgba(3, 12, 40, 0.65);
}
.btn-light:hover { transform: translateY(-2px); background: #f4f8ff; }
.btn-blue {
  background: var(--blue-2);
  color: var(--white);
  box-shadow: 0 18px 34px -20px rgba(23, 71, 199, 0.6);
}
.btn-blue:hover { transform: translateY(-2px); background: #1c52dc; }
.btn-ghost {
  border-color: var(--line-strong);
  background: var(--white);
  color: var(--ink);
}
.btn-ghost:hover { transform: translateY(-2px); border-color: rgba(18, 32, 58, 0.32); }
.btn-primary {
  background: var(--blue-2);
  color: var(--white);
}
.btn-primary:hover { background: #1c52dc; }

/* Hero */
.hero {
  position: relative;
  isolation: isolate;
  display: flex;
  align-items: center;
  min-height: 100svh;
  padding: 138px 0 64px;
  overflow: hidden;
  text-align: center;
}
.hero-word {
  position: absolute;
  top: clamp(48px, 8vw, 96px);
  left: 50%;
  z-index: -1;
  width: 100%;
  transform: translateX(-50%);
  color: var(--white);
  font-size: clamp(96px, 25vw, 380px);
  font-weight: 600;
  line-height: 0.8;
  letter-spacing: -0.035em;
  white-space: nowrap;
  opacity: 0.1;
  pointer-events: none;
}
.hero-inner { position: relative; z-index: 1; }
.hero h1 {
  max-width: 980px;
  margin: 0 auto;
  color: var(--white);
  font-size: clamp(46px, 6.8vw, 88px);
  font-weight: 600;
  line-height: 1.04;
  letter-spacing: -0.025em;
  text-wrap: balance;
}
.hero-actions {
  display: flex;
  justify-content: center;
  margin-top: 30px;
}
.hero-meta {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: center;
  margin-top: 14px;
  color: var(--white-48);
  font-size: 12.5px;
  letter-spacing: 0.02em;
}
.hero-meta span + span::before {
  content: "·";
  margin-inline: 8px;
  color: rgba(255, 255, 255, 0.28);
}
.hero-shot {
  width: min(420px, 70%);
  margin: 38px auto 0;
}
.hero-shot img {
  width: 100%;
  height: auto;
  filter: drop-shadow(0 34px 44px rgba(2, 10, 36, 0.5));
}

/* Sections */
.section-title {
  color: var(--white);
  font-size: clamp(30px, 4vw, 46px);
  font-weight: 600;
  line-height: 1.2;
  letter-spacing: -0.015em;
  text-align: center;
  text-wrap: balance;
}

/* Three states: no card wrappers, only the screenshot and its label. */
.states { padding-block: clamp(80px, 10vw, 124px); }
.states .section-title { margin-bottom: 36px; }
.state-row {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 16px;
  align-items: start;
  width: calc(75% - 4px);
  margin-inline: auto;
}
.state { min-width: 0; text-align: center; }
.state-shot {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 100%;
  aspect-ratio: 2 / 1;
}
.state-shot img {
  width: 100%;
  height: 100%;
  object-fit: contain;
  filter: drop-shadow(0 24px 34px rgba(2, 10, 36, 0.4));
}
.state-compact .state-shot img { width: 77.33%; }
.state figcaption {
  margin-top: 18px;
  color: var(--white-64);
  font-size: 14px;
  font-weight: 500;
  letter-spacing: 0.04em;
}

/* Four backdrops: one line, one preview, four tabs. */
.themes { padding-block: clamp(80px, 10vw, 124px); }
.themes-line {
  max-width: 1020px;
  margin: 0 auto;
  color: var(--white);
  font-size: clamp(24px, 3.2vw, 40px);
  font-weight: 600;
  line-height: 1.35;
  letter-spacing: -0.01em;
  text-align: center;
  text-wrap: balance;
}
.theme-row {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 16px;
  align-items: start;
  margin-top: 38px;
}
.theme-card { min-width: 0; margin: 0; text-align: center; }
.theme-card figcaption {
  margin-top: 22px;
  color: var(--white-64);
  font-size: 14px;
  font-weight: 500;
  letter-spacing: 0.04em;
}
.theme-row img {
  width: 100%;
  height: auto;
  filter: drop-shadow(0 20px 30px rgba(2, 10, 36, 0.38));
}
@media (max-width: 760px) {
  .theme-row {
    display: flex;
    gap: 12px;
    overflow-x: auto;
    padding-bottom: 6px;
    scroll-snap-type: x mandatory;
    scrollbar-width: none;
  }
  .theme-row::-webkit-scrollbar { display: none; }
  .theme-card {
    flex: 0 0 72%;
    max-width: 280px;
    scroll-snap-align: center;
  }
  .theme-row img { width: 100%; }
}
.hero-shot img,
.state-shot img,
.theme-row img {
  transition: transform 0.3s var(--ease), filter 0.3s var(--ease);
}
@media (hover: hover) {
  .hero-shot:hover img,
  .state:hover .state-shot img,
  .theme-card:hover img {
    transform: translateY(-6px);
  }
  .hero-shot:hover img {
    filter: drop-shadow(0 42px 52px rgba(2, 10, 36, 0.55));
  }
  .state:hover .state-shot img {
    filter: drop-shadow(0 32px 42px rgba(2, 10, 36, 0.48));
  }
  .theme-card:hover img {
    filter: drop-shadow(0 28px 38px rgba(2, 10, 36, 0.46));
  }
}

/* Download */
.download {
  padding-block: clamp(76px, 9vw, 112px);
  color: var(--ink);
}
.download-panel {
  display: grid;
  grid-template-columns: minmax(0, 1.1fr) minmax(0, 0.9fr);
  gap: 40px;
  align-items: center;
  padding: clamp(24px, 3.8vw, 44px);
  border: 1px solid rgba(255, 255, 255, 0.55);
  border-radius: 28px;
  background: var(--white);
  box-shadow: 0 22px 54px -28px rgba(3, 12, 40, 0.26);
}
.download-copy { min-width: 0; }
.download-head { display: flex; align-items: center; gap: 18px; }
.download-icon {
  width: 72px;
  height: 72px;
  flex: none;
}
.download-head h2 {
  color: var(--ink);
  font-size: clamp(26px, 3.2vw, 38px);
  font-weight: 600;
  line-height: 1.2;
  letter-spacing: -0.015em;
}
.download-copy > p:not(.download-meta) {
  max-width: 440px;
  margin-top: 16px;
  color: var(--muted);
  font-size: 14.5px;
  line-height: 1.8;
  text-wrap: pretty;
}
.download-meta {
  display: flex;
  gap: 14px;
  margin-top: 14px;
  color: var(--muted);
  font-size: 12px;
}
.download-actions {
  display: flex;
  flex-direction: column;
  gap: 10px;
  min-width: 0;
}
.download-actions .btn { width: 100%; }
.download-note {
  margin-top: 2px;
  color: var(--muted);
  font-size: 11.5px;
  line-height: 1.6;
  text-align: center;
}
.download-trust {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 10px 22px;
  margin-top: 24px;
  padding: 0;
  list-style: none;
  color: var(--ink);
  font-size: 13px;
}
.download-trust li { display: inline-flex; align-items: center; gap: 7px; }
.download-trust li::before {
  content: "";
  width: 5px;
  height: 5px;
  border-radius: 50%;
  background: var(--green);
}
.download-trust a {
  color: var(--ink);
  text-decoration: underline;
  text-underline-offset: 3px;
  text-decoration-color: var(--line-strong);
}
.download-struck {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 8px 22px;
  margin-top: 12px;
  color: var(--muted);
  font-size: 13px;
}
.download-struck s {
  text-decoration-thickness: 1px;
  text-decoration-color: rgba(93, 109, 136, 0.65);
  opacity: 0.85;
}
.checksum {
  max-width: 720px;
  margin: 20px auto 0;
  padding: 14px 0;
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
  color: var(--muted);
  font-size: 12px;
}
.checksum summary { cursor: pointer; list-style: none; text-align: center; }
.checksum summary::-webkit-details-marker { display: none; }
details::details-content {
  block-size: 0;
  overflow: hidden;
  opacity: 0;
  content-visibility: hidden;
  transition: block-size 0.28s var(--ease), opacity 0.2s var(--ease),
    content-visibility 0.28s allow-discrete;
}
details[open]::details-content {
  block-size: auto;
  opacity: 1;
  content-visibility: visible;
}
.checksum code {
  display: block;
  margin-top: 10px;
  padding: 0;
  background: none;
  color: var(--ink);
  font-family: var(--mono);
  font-size: 11px;
  line-height: 1.7;
  text-align: center;
  word-break: break-all;
}

/* FAQ */
.faq { padding-block: clamp(72px, 8vw, 104px); color: var(--ink); }
.faq-grid {
  display: grid;
  grid-template-columns: minmax(0, 0.72fr) minmax(0, 1.28fr);
  gap: clamp(32px, 5vw, 72px);
  align-items: start;
}
.faq-head h2 {
  color: var(--ink);
  font-size: clamp(28px, 3.4vw, 40px);
  font-weight: 600;
  line-height: 1.2;
  letter-spacing: -0.015em;
}
.faq-head p {
  max-width: 320px;
  margin-top: 14px;
  color: var(--muted);
  font-size: 15px;
  line-height: 1.8;
}
.faq-list { border-top: 1px solid var(--line); }
.faq-list details { border-bottom: 1px solid var(--line); }
.faq-list summary {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
  padding: 20px 0;
  color: var(--ink);
  font-size: 15.5px;
  font-weight: 500;
  line-height: 1.5;
  cursor: pointer;
  list-style: none;
}
.faq-list summary::-webkit-details-marker { display: none; }
.plus {
  position: relative;
  flex: none;
  width: 14px;
  height: 14px;
}
.plus::before,
.plus::after {
  content: "";
  position: absolute;
  border-radius: 1px;
  background: var(--muted);
  transition: transform 0.25s var(--ease);
}
.plus::before { left: 6px; top: 0; width: 2px; height: 14px; }
.plus::after { left: 0; top: 6px; width: 14px; height: 2px; }
.faq-list details[open] .plus::before { transform: scaleY(0); }
.faq-list details p {
  max-width: 680px;
  padding-bottom: 20px;
  color: var(--muted);
  font-size: 14px;
  line-height: 1.8;
  text-wrap: pretty;
  overflow-wrap: anywhere;
}
.faq-list code {
  padding: 2px 6px;
  border-radius: 5px;
  background: rgba(18, 32, 58, 0.05);
  color: var(--ink);
  font-family: var(--mono);
  font-size: 0.9em;
}

/* Footer */
footer {
  padding: 34px 0 38px;
  border-top: 1px solid var(--line);
  color: var(--ink);
}
.footer-inner {
  display: flex;
  align-items: center;
  gap: 12px;
  color: var(--ink);
}
.footer-brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  color: var(--ink);
  font-size: 14px;
  font-weight: 600;
}
.footer-brand img { width: 24px; height: 24px; }
.footer-made,
.footer-copy { color: var(--muted); font-size: 12px; }
.footer-copy { margin-left: auto; }

/* Reveals: only the section entrance; 12px, under 400ms. */
.js .reveal {
  opacity: 0;
  transform: translateY(12px);
  transition: opacity 0.4s var(--ease), transform 0.4s var(--ease);
}
.js .reveal.is-in { opacity: 1; transform: none; }

@media (max-width: 1000px) {
  .download-panel { grid-template-columns: minmax(0, 1fr); gap: 26px; }
  .download-actions { max-width: 420px; }
  .faq-grid { grid-template-columns: minmax(0, 1fr); }
  .faq-head p { max-width: 560px; margin-bottom: 8px; }
}

@media (max-width: 760px) {
  .wrap { width: min(1160px, calc(100% - 40px)); }
  .nav { padding-top: 14px; }
  .nav-inner { min-height: 40px; }
  .brand { font-size: 14px; }
  .brand-mark { width: 26px; height: 26px; }
  .lang-toggle { width: 32px; height: 32px; }
  .lang-toggle svg { width: 20px; height: 20px; }
  .nav-icon { width: 32px; height: 32px; }
  .nav-icon svg { width: 20px; height: 20px; }
  .nav-cta { height: 32px; padding: 0 13px; font-size: 12.5px; }
  .hero { min-height: auto; padding: 108px 0 48px; }
  .hero h1 { font-size: clamp(40px, 10.5vw, 56px); }
  .hero-actions { margin-top: 24px; }
  .hero-shot { margin-top: 30px; }
  .states, .themes { padding-block: 72px; }
  .states .section-title { margin-bottom: 26px; }
  .state-row { gap: 20px; }
  .state figcaption { margin-top: 14px; font-size: 13px; }
  .theme-card figcaption { margin-top: 18px; font-size: 13px; }
  .download { padding-block: 64px; }
  .download-panel { padding: 22px; border-radius: 22px; }
  .download-icon { width: 56px; height: 56px; }
  .download-head { gap: 14px; }
  .download-head h2 { font-size: 27px; }
  .download-actions { max-width: none; }
  .download-trust { gap: 8px 18px; margin-top: 20px; font-size: 12.5px; }
  .download-struck { font-size: 12.5px; }
  .faq { padding-block: 64px; }
  .faq-list summary { padding: 18px 0; font-size: 15px; }
  .faq-list details p { font-size: 14px; }
}

@media (max-width: 760px) {
  .state-row {
    grid-template-columns: minmax(0, 1fr);
    gap: 34px;
    width: 100%;
  }
  .state-shot { max-width: 280px; margin-inline: auto; }
}

@media (max-width: 480px) {
  .wrap { width: calc(100% - 32px); }
  .brand-name { font-size: 13px; }
  .nav-actions { gap: 8px; }
  .hero h1 { font-size: 40px; }
  .hero-meta { font-size: 11px; }
  .hero-meta span + span::before { margin-inline: 5px; }
  .btn { min-height: 48px; padding: 0 20px; font-size: 14.5px; }
  .themes-line { font-size: 23px; }
  .download-head h2 { font-size: 24px; }
  .download-head { align-items: flex-start; }
  .download-icon { width: 50px; height: 50px; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  .js .reveal { opacity: 1; transform: none; transition: none; }
  .nav,
  main,
  footer,
  .hero-shot img,
  .state-shot img,
  .theme-row img,
  .lang-popover,
  .lang-toggle,
  .lang-option,
  .lang-menu.is-open .lang-popover,
  details::details-content { transition: none; }
  .hero-shot:hover img,
  .state:hover .state-shot img,
  .theme-card:hover img { transform: none; }
  .btn,
  .nav-cta,
  .plus::before,
  .plus::after { transition: none; }
}