:root {
  color-scheme: light dark;
  --background: #f3f6fb;
  --surface: #fbfcfe;
  --surface-strong: #fbfdff;
  --surface-muted: #e9eef6;
  --text: #132033;
  --text-soft: #5c6879;
  --line: rgba(28, 48, 78, 0.12);
  --accent: #245fc7;
  --accent-hover: #194fae;
  --accent-soft: #dce8fb;
  --accent-text: #f8fbff;
  --shadow: 0 24px 80px rgba(44, 72, 112, 0.16);
  --radius: 18px;
  --header-height: 72px;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
  scroll-padding-top: calc(var(--header-height) + 24px);
}

body {
  margin: 0;
  min-width: 320px;
  overflow-x: clip;
  background:
    radial-gradient(circle at 78% 12%, rgba(36, 95, 199, 0.1), transparent 28rem),
    var(--background);
  color: var(--text);
  font-family: "Microsoft YaHei UI", "PingFang SC", "Noto Sans CJK SC", system-ui, sans-serif;
  -webkit-font-smoothing: antialiased;
}

body::before {
  position: fixed;
  inset: 0;
  z-index: -1;
  background-image: linear-gradient(rgba(30, 62, 106, 0.025) 1px, transparent 1px),
    linear-gradient(90deg, rgba(30, 62, 106, 0.025) 1px, transparent 1px);
  background-size: 48px 48px;
  content: "";
  pointer-events: none;
}

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

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

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

:focus-visible {
  outline: 3px solid color-mix(in srgb, var(--accent) 70%, white);
  outline-offset: 4px;
}

.shell {
  width: min(1240px, calc(100% - 64px));
  margin-inline: auto;
}

.skip-link {
  position: fixed;
  top: 12px;
  left: 12px;
  z-index: 20;
  padding: 10px 14px;
  border-radius: 10px;
  background: var(--accent);
  color: var(--accent-text);
  transform: translateY(-160%);
  transition: transform 180ms ease;
}

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

.site-header {
  position: sticky;
  top: 0;
  z-index: 10;
  height: var(--header-height);
  border-bottom: 1px solid var(--line);
  background: color-mix(in srgb, var(--background) 86%, transparent);
  backdrop-filter: blur(18px) saturate(140%);
  -webkit-backdrop-filter: blur(18px) saturate(140%);
}

.nav-bar {
  display: grid;
  grid-template-columns: 1fr auto 1fr;
  align-items: center;
  height: 100%;
}

.brand {
  display: inline-flex;
  align-items: center;
  justify-self: start;
  gap: 11px;
  font-size: 16px;
  font-weight: 760;
  letter-spacing: -0.02em;
  white-space: nowrap;
}

.brand-mark {
  display: grid;
  width: 38px;
  height: 38px;
  place-items: center;
  border-radius: 11px;
  background: var(--accent);
  color: var(--accent-text);
  font-size: 18px;
  font-weight: 800;
  box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.3);
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 30px;
  color: var(--text-soft);
  font-size: 14px;
  white-space: nowrap;
}

.nav-links a,
.nav-admin {
  transition: color 220ms ease, background 220ms ease, transform 220ms ease;
}

.nav-links a:hover {
  color: var(--text);
}

.nav-admin {
  justify-self: end;
  padding: 10px 15px;
  border: 1px solid var(--line);
  border-radius: 12px;
  background: var(--surface-strong);
  color: var(--text);
  font-size: 13px;
  font-weight: 700;
  white-space: nowrap;
}

.nav-admin:hover {
  border-color: color-mix(in srgb, var(--accent) 35%, var(--line));
  color: var(--accent);
}

.nav-admin:active,
.button:active,
.download-card:active {
  transform: translateY(1px) scale(0.985);
}

.hero {
  display: grid;
  grid-template-columns: minmax(0, 0.92fr) minmax(420px, 1.08fr);
  align-items: center;
  gap: clamp(40px, 6vw, 92px);
  min-height: calc(100dvh - var(--header-height));
  padding-block: clamp(42px, 6vh, 72px);
}

.hero-copy {
  position: relative;
  z-index: 1;
}

.eyebrow {
  margin: 0 0 18px;
  color: var(--accent);
  font-size: 12px;
  font-weight: 800;
  letter-spacing: 0.18em;
  text-transform: uppercase;
}

h1,
h2,
p {
  margin-top: 0;
}

h1 {
  max-width: 720px;
  margin-bottom: 24px;
  font-size: clamp(46px, 5.4vw, 76px);
  line-height: 1.06;
  letter-spacing: -0.065em;
}

h1 span {
  color: var(--text-soft);
  font-weight: 520;
}

.hero-description {
  max-width: 30rem;
  margin-bottom: 32px;
  color: var(--text-soft);
  font-size: clamp(16px, 1.4vw, 18px);
  line-height: 1.8;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}

.button {
  display: inline-flex;
  min-height: 50px;
  align-items: center;
  justify-content: center;
  padding: 0 22px;
  border: 1px solid transparent;
  border-radius: 14px;
  font-size: 15px;
  font-weight: 760;
  white-space: nowrap;
  transition: background 220ms ease, border-color 220ms ease, color 220ms ease,
    transform 220ms cubic-bezier(0.16, 1, 0.3, 1), box-shadow 220ms ease;
}

.button-primary {
  background: var(--accent);
  color: var(--accent-text);
  box-shadow: 0 14px 30px rgba(36, 95, 199, 0.22);
}

.button-primary:hover {
  background: var(--accent-hover);
  box-shadow: 0 18px 34px rgba(36, 95, 199, 0.28);
  transform: translateY(-2px);
}

.button-secondary {
  border-color: var(--line);
  background: var(--surface-strong);
  color: var(--text);
}

.button-secondary:hover {
  border-color: color-mix(in srgb, var(--accent) 35%, var(--line));
  color: var(--accent);
  transform: translateY(-2px);
}

.hero-visual {
  position: relative;
  width: min(100%, 600px);
  margin: 0 0 0 auto;
}

.hero-visual::before {
  position: absolute;
  inset: 11% -8% -7% 18%;
  z-index: -1;
  border-radius: var(--radius);
  background: var(--accent);
  content: "";
  opacity: 0.12;
  transform: rotate(4deg);
}

.image-frame {
  overflow: hidden;
  border: 1px solid rgba(42, 70, 110, 0.12);
  border-radius: var(--radius);
  background: var(--surface-muted);
  box-shadow: var(--shadow);
}

.hero-image-frame {
  aspect-ratio: 4 / 5;
}

.hero-image-frame img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.download-section {
  padding-block: clamp(76px, 9vw, 120px);
}

.section-heading {
  max-width: 650px;
  margin-bottom: clamp(32px, 4vw, 46px);
}

.section-heading h2,
.experience-copy h2,
.admin-panel h2 {
  margin-bottom: 16px;
  font-size: clamp(34px, 4.1vw, 58px);
  line-height: 1.08;
  letter-spacing: -0.055em;
}

.section-heading p,
.experience-copy > p {
  max-width: 39rem;
  margin-bottom: 0;
  color: var(--text-soft);
  font-size: 17px;
  line-height: 1.8;
}

.download-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 16px;
}

.download-card {
  position: relative;
  display: grid;
  grid-template-columns: auto minmax(0, 1fr) auto;
  align-items: center;
  min-height: 142px;
  gap: 22px;
  padding: 26px;
  overflow: hidden;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--surface-strong);
  transition: border-color 240ms ease, transform 240ms cubic-bezier(0.16, 1, 0.3, 1),
    box-shadow 240ms ease;
  color: inherit;
  font: inherit;
  text-align: left;
  cursor: pointer;
}

.download-card:hover {
  border-color: color-mix(in srgb, var(--accent) 38%, var(--line));
  box-shadow: 0 18px 50px rgba(44, 72, 112, 0.12);
  transform: translateY(-4px);
}

.download-card-android,
.download-card-macos {
  background: color-mix(in srgb, var(--accent-soft) 24%, var(--surface-strong));
}

.platform-code {
  position: relative;
  z-index: 1;
  display: grid;
  min-width: 62px;
  height: 62px;
  place-items: center;
  padding-inline: 9px;
  border-radius: 15px;
  background: var(--accent-soft);
  color: var(--accent);
  font-size: 15px;
  font-weight: 840;
  letter-spacing: -0.03em;
}

.download-copy {
  position: relative;
  z-index: 1;
  display: grid;
  min-width: 0;
  gap: 6px;
}

.download-copy strong {
  font-size: clamp(18px, 2vw, 23px);
  letter-spacing: -0.035em;
}

.download-copy small {
  color: var(--text-soft);
  font-size: 13px;
  line-height: 1.5;
}

.download-label {
  position: relative;
  z-index: 1;
  display: inline-flex;
  min-height: 36px;
  align-items: center;
  justify-content: center;
  padding-inline: 13px;
  border: 1px solid color-mix(in srgb, var(--accent) 22%, transparent);
  border-radius: 11px;
  background: color-mix(in srgb, var(--accent-soft) 48%, transparent);
  color: var(--accent);
  font-size: 13px;
  font-weight: 760;
  white-space: nowrap;
}

.experience-section {
  display: grid;
  grid-template-columns: 1.25fr 0.75fr;
  align-items: center;
  gap: clamp(48px, 7vw, 100px);
  padding-block: clamp(68px, 9vw, 120px);
}

.experience-media {
  margin-left: max(-8vw, -110px);
}

.experience-image-frame {
  aspect-ratio: 16 / 10;
  border-top-left-radius: 0;
  border-bottom-left-radius: 0;
}

.experience-image-frame img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.experience-copy {
  max-width: 470px;
}

.experience-copy > p {
  margin-bottom: 34px;
}

.feature-list {
  display: grid;
}

.feature-list > div {
  display: grid;
  gap: 7px;
  padding-block: 19px;
  border-bottom: 1px solid var(--line);
}

.feature-list > div:last-child {
  border-bottom: 0;
}

.feature-list strong {
  font-size: 16px;
}

.feature-list span {
  color: var(--text-soft);
  font-size: 14px;
  line-height: 1.65;
}

.admin-section {
  padding-block: clamp(82px, 10vw, 136px);
}

.admin-panel {
  position: relative;
  display: grid;
  grid-template-columns: 1fr auto;
  align-items: end;
  gap: 40px;
  overflow: hidden;
  padding: clamp(34px, 6vw, 76px);
  border: 1px solid color-mix(in srgb, var(--accent) 24%, var(--line));
  border-radius: var(--radius);
  background:
    linear-gradient(120deg, transparent 54%, rgba(36, 95, 199, 0.09)),
    var(--surface-strong);
  box-shadow: 0 30px 90px rgba(44, 72, 112, 0.12);
}

.admin-panel::after {
  position: absolute;
  top: -100px;
  right: 10%;
  width: 240px;
  height: 240px;
  border-radius: 50%;
  background: var(--accent-soft);
  content: "";
  opacity: 0.7;
  pointer-events: none;
}

.admin-panel > * {
  position: relative;
  z-index: 1;
}

.admin-kicker {
  margin-bottom: 13px;
  color: var(--accent);
  font-size: 14px;
  font-weight: 760;
}

.admin-panel h2 {
  max-width: 740px;
  margin-bottom: 0;
}

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

.footer-inner {
  display: grid;
  grid-template-columns: 1fr auto auto;
  align-items: center;
  gap: 40px;
  min-height: 120px;
  color: var(--text-soft);
  font-size: 13px;
}

.footer-inner p {
  margin: 0;
}

.footer-brand {
  color: var(--text);
}

.footer-brand .brand-mark {
  width: 34px;
  height: 34px;
  font-size: 16px;
}

.toast {
  position: fixed;
  right: 22px;
  bottom: 22px;
  z-index: 30;
  max-width: min(380px, calc(100vw - 44px));
  padding: 14px 18px;
  border: 1px solid var(--line);
  border-radius: 13px;
  background: var(--text);
  color: var(--background);
  font-size: 14px;
  box-shadow: var(--shadow);
  opacity: 0;
  pointer-events: none;
  transform: translateY(12px);
  transition: opacity 220ms ease, transform 220ms ease;
}

.toast.is-active {
  opacity: 1;
  transform: translateY(0);
}

.download-dialog {
  width: min(calc(100% - 32px), 560px);
  padding: 0;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--surface-strong);
  color: var(--text);
  box-shadow: var(--shadow);
}

.download-dialog::backdrop { background: rgba(9, 19, 34, 0.48); backdrop-filter: blur(4px); }
.dialog-heading { display: flex; align-items: flex-start; justify-content: space-between; gap: 22px; padding: 30px 30px 0; }
.dialog-kicker { margin: 0 0 8px; color: var(--accent); font-size: 13px; font-weight: 760; }
.dialog-heading h2 { margin: 0; font-size: 28px; letter-spacing: -0.05em; }
.dialog-close { display: grid; width: 36px; height: 36px; place-items: center; padding: 0; border: 1px solid var(--line); border-radius: 10px; background: transparent; color: var(--text-soft); font-size: 24px; line-height: 1; cursor: pointer; }
.dialog-description { margin: 14px 30px 24px; color: var(--text-soft); font-size: 14px; line-height: 1.7; }
.windows-download-options { display: grid; gap: 10px; padding: 0 22px 22px; }
.windows-download-option { display: grid; grid-template-columns: auto 1fr auto; align-items: center; gap: 15px; padding: 16px; border: 1px solid var(--line); border-radius: 14px; color: var(--text); transition: border-color 180ms ease, transform 180ms ease, background 180ms ease; }
.windows-download-option:hover { border-color: color-mix(in srgb, var(--accent) 45%, var(--line)); background: color-mix(in srgb, var(--accent-soft) 35%, transparent); transform: translateY(-1px); }
.windows-download-option > span:nth-child(2) { display: grid; gap: 4px; }
.windows-download-option strong { font-size: 16px; }
.windows-download-option small { color: var(--text-soft); font-size: 13px; }
.option-icon { display: grid; width: 42px; height: 42px; place-items: center; border-radius: 11px; background: var(--accent-soft); color: var(--accent); font-size: 11px; font-weight: 800; }

.reveal {
  opacity: 0;
  transform: translateY(24px);
}

.reveal.is-visible {
  opacity: 1;
  transform: translateY(0);
  transition: opacity 700ms cubic-bezier(0.16, 1, 0.3, 1),
    transform 700ms cubic-bezier(0.16, 1, 0.3, 1);
}

.download-card:nth-child(2).is-visible,
.feature-list > div:nth-child(2) {
  transition-delay: 70ms;
}

.download-card:nth-child(3).is-visible {
  transition-delay: 120ms;
}

.download-card:nth-child(4).is-visible {
  transition-delay: 180ms;
}

@media (prefers-color-scheme: dark) {
  :root {
    --background: #0d131c;
    --surface: #111a25;
    --surface-strong: #151f2c;
    --surface-muted: #1d2938;
    --text: #edf3fc;
    --text-soft: #a9b6c8;
    --line: rgba(188, 207, 234, 0.14);
    --accent: #73a6ff;
    --accent-hover: #8cb6ff;
    --accent-soft: #203c66;
    --accent-text: #0a1424;
    --shadow: 0 24px 80px rgba(1, 6, 14, 0.38);
  }

  body {
    background:
      radial-gradient(circle at 78% 12%, rgba(62, 125, 232, 0.13), transparent 28rem),
      var(--background);
  }

  .hero-image-frame img,
  .experience-image-frame img {
    filter: brightness(0.84) contrast(1.05);
  }

  .button-primary {
    box-shadow: 0 14px 30px rgba(8, 25, 52, 0.38);
  }
}

@media (max-width: 960px) {
  .nav-bar {
    grid-template-columns: 1fr auto;
  }

  .nav-links {
    display: none;
  }

  .experience-section {
    grid-template-columns: 1fr;
  }

  .experience-media {
    margin-left: 0;
  }

  .experience-image-frame {
    border-radius: var(--radius);
  }

  .experience-copy {
    max-width: 680px;
  }

  .footer-inner {
    grid-template-columns: 1fr auto;
  }

  .footer-inner > p:first-of-type {
    display: none;
  }
}

@media (max-width: 1100px) {
  .download-grid {
    grid-template-columns: 1fr;
  }

  .download-card {
    min-height: 128px;
  }
}

@media (max-width: 920px) {
  .hero {
    grid-template-columns: 1fr;
    gap: 44px;
    min-height: auto;
    padding-block: 56px 80px;
  }

  .hero-copy {
    max-width: 650px;
  }

  .hero-visual {
    width: min(100%, 560px);
    margin-inline: auto;
  }

  .admin-panel {
    grid-template-columns: 1fr;
    align-items: start;
    gap: 28px;
  }

  .admin-panel .button {
    justify-self: start;
  }
}

@media (max-width: 767px) {
  :root {
    --header-height: 64px;
    --radius: 16px;
  }

  .shell {
    width: min(100% - 32px, 680px);
  }

  .brand {
    font-size: 14px;
  }

  .brand-mark {
    width: 34px;
    height: 34px;
    border-radius: 10px;
    font-size: 16px;
  }

  .nav-admin {
    padding: 9px 11px;
    font-size: 12px;
  }

  .hero {
    grid-template-columns: 1fr;
    min-height: auto;
    gap: 40px;
    padding-block: 52px 72px;
  }

  .eyebrow {
    margin-bottom: 14px;
  }

  h1 {
    margin-bottom: 20px;
    font-size: clamp(40px, 13vw, 60px);
  }

  .hero-description {
    margin-bottom: 26px;
    font-size: 16px;
  }

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

  .button {
    min-height: 48px;
    padding-inline: 14px;
    font-size: 14px;
  }

  .hero-visual {
    width: 100%;
    margin: 0;
  }

  .hero-visual::before {
    inset: 12% -3% -5% 20%;
  }

  .hero-image-frame {
    aspect-ratio: 1 / 1;
  }

  .download-section,
  .experience-section,
  .admin-section {
    padding-block: 76px;
  }

  .section-heading {
    margin-bottom: 32px;
  }

  .section-heading h2,
  .experience-copy h2,
  .admin-panel h2 {
    font-size: clamp(32px, 9vw, 44px);
  }

  .section-heading p,
  .experience-copy > p {
    font-size: 15px;
  }

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

  .download-card {
    min-height: 132px;
    gap: 16px;
    padding: 20px;
  }

  .platform-code {
    min-width: 54px;
    height: 54px;
    border-radius: 14px;
    font-size: 13px;
  }

  .download-copy strong {
    font-size: 18px;
  }

  .download-label {
    display: none;
  }

  .experience-section {
    gap: 38px;
  }

  .experience-image-frame {
    aspect-ratio: 5 / 4;
  }

  .experience-image-frame img {
    object-position: 62% center;
  }

  .admin-panel {
    grid-template-columns: 1fr;
    align-items: start;
    gap: 28px;
    padding: 28px;
  }

  .admin-panel .button {
    justify-self: stretch;
    width: 100%;
  }

  .footer-inner {
    grid-template-columns: 1fr;
    gap: 18px;
    padding-block: 32px;
  }
}

@media (max-width: 420px) {
  .brand > span:last-child {
    display: none;
  }

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

  .download-card {
    grid-template-columns: auto 1fr;
  }
}

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

  *,
  *::before,
  *::after {
    scroll-behavior: auto !important;
    transition-duration: 0.01ms !important;
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
  }

  .reveal {
    opacity: 1;
    transform: none;
  }
}

@media (prefers-reduced-transparency: reduce) {
  .site-header {
    background: var(--background);
    backdrop-filter: none;
    -webkit-backdrop-filter: none;
  }
}