:root {
  --brand-hot: #ff0064;
  --brand-shift: #a050a0;
  --brand: var(--brand-hot);
  --brand-two: var(--brand-shift);
  --white: #ffffff;
  --line: rgba(255, 255, 255, 0.08);
  --card-radius: 10px;
  --content-width: min(1380px, calc(100vw - clamp(1.5rem, 3vw, 3rem)));
  --header-top-gap: clamp(1rem, 1.9vw, 1.45rem);
  --header-side-gap: clamp(1.3rem, 2.35vw, 1.8rem);
  --header-width: calc(100vw - (var(--header-side-gap) * 2));
  --header-shell-radius: 999px;
  --header-shell-gap: 1rem;
  --header-shell-padding-y: 0.36rem;
  --header-shell-padding-x: 0.92rem;
  --header-shell-background: rgba(30, 36, 46, 0.18);
  --header-shell-backdrop: blur(24px) saturate(145%);
  --header-shell-shadow: 0 14px 30px rgba(0, 0, 0, 0.08);
  --header-brand-offset: 0.48rem;
  --header-brand-gap: 0.98rem;
  --header-brand-mark-offset: 0.18rem;
  --header-brand-mark-shift: 2%;
  --header-brand-mark-scale: 1.08;
  --header-nav-gap: 1.05rem;
  --header-font: "Segoe UI Variable", "Segoe UI", Arial, "Microsoft YaHei", "PingFang SC", "Hiragino Sans GB", "Hiragino Sans", "Yu Gothic UI", "Yu Gothic", "Meiryo", "Noto Sans JP", sans-serif;
  --header-link-font-size: 0.86rem;
  --header-link-letter-spacing: 0.06em;
  --header-link-weight: 700;
  --header-signup-padding-y: 0.66rem;
  --header-signup-padding-x: 0.98rem;
  --header-lang-shell-padding: 0.2rem;
  --header-lang-button-padding-y: 0.46rem;
  --header-lang-button-padding-x: 0.84rem;
  --font-latin: "Segoe UI Variable", "Segoe UI", "Helvetica Neue", Arial, sans-serif;
  --font-zh: "Microsoft YaHei", "PingFang SC", "Noto Sans SC", "Source Han Sans SC", "Hiragino Sans GB", "Segoe UI", sans-serif;
  --font-ja: "Noto Sans JP", "Meiryo", "Yu Gothic UI", "Yu Gothic", "Hiragino Sans", "Segoe UI", sans-serif;
  --font-latin-apple: Arial, "Helvetica Neue", sans-serif;
  --font-zh-apple: "PingFang SC", "Hiragino Sans GB", "Noto Sans SC", "Source Han Sans SC", sans-serif;
  --font-ja-apple: "Hiragino Kaku Gothic ProN", "Hiragino Sans", "Noto Sans JP", sans-serif;
  --ui-font: var(--font-ja);
  --heading-font: var(--font-ja);
  --body-font: var(--font-ja);
  --font-body-weight: 400;
  --font-heading-weight: 650;
  --font-strong-weight: 700;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
  text-size-adjust: 100%;
  font-size: 17px;
  text-rendering: optimizeLegibility;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

body {
  margin: 0;
  font-family: var(--body-font);
  font-weight: var(--font-body-weight);
}

html:lang(zh),
html[lang^="zh-"] {
  --ui-font: var(--font-zh);
  --heading-font: var(--font-zh);
  --body-font: var(--font-zh);
}

html:lang(en),
html[lang^="en-"] {
  --ui-font: var(--font-latin);
  --heading-font: var(--font-latin);
  --body-font: var(--font-latin);
}

html:lang(ja),
html[lang^="ja-"] {
  --ui-font: var(--font-ja);
  --heading-font: var(--font-ja);
  --body-font: var(--font-ja);
  --font-body-weight: 450;
  --font-heading-weight: 690;
  --font-strong-weight: 730;
  --header-link-weight: 720;
}

html[data-platform="apple"] {
  --font-body-weight: 430;
  --font-heading-weight: 680;
  --font-strong-weight: 720;
  --header-link-weight: 720;
}

html[data-platform="apple"]:lang(zh),
html[data-platform="apple"][lang^="zh-"] {
  --ui-font: var(--font-zh-apple);
  --heading-font: var(--font-zh-apple);
  --body-font: var(--font-zh-apple);
}

html[data-platform="apple"]:lang(en),
html[data-platform="apple"][lang^="en-"] {
  --ui-font: var(--font-latin-apple);
  --heading-font: var(--font-latin-apple);
  --body-font: var(--font-latin-apple);
}

html[data-platform="apple"]:lang(ja),
html[data-platform="apple"][lang^="ja-"] {
  --ui-font: var(--font-ja-apple);
  --heading-font: var(--font-ja-apple);
  --body-font: var(--font-ja-apple);
  --font-body-weight: 455;
  --font-heading-weight: 700;
  --font-strong-weight: 740;
  --header-link-weight: 730;
}

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

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

button,
input,
select,
textarea {
  font: inherit;
}

.shell {
  width: var(--content-width);
  margin: 0 auto;
}

.site-header {
  position: sticky;
  top: var(--header-top-gap);
  z-index: 100;
  padding: 0;
  background: transparent;
  border: 0;
  backdrop-filter: none;
}

.site-header .shell {
  width: var(--header-width);
  position: relative;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--header-shell-gap);
  padding: var(--header-shell-padding-y) var(--header-shell-padding-x);
  border-radius: var(--header-shell-radius);
  border: 0;
  background: var(--header-shell-background);
  backdrop-filter: var(--header-shell-backdrop);
  box-shadow: var(--header-shell-shadow);
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: var(--header-brand-gap);
  min-width: 0;
  margin-left: var(--header-brand-offset);
}

.brand-mark {
  width: 4.8rem;
  height: 3rem;
  display: grid;
  place-items: center;
  overflow: visible;
  flex: 0 0 auto;
  margin-left: var(--header-brand-mark-offset);
}

.brand-mark img {
  grid-area: 1 / 1;
  width: 126%;
  height: auto;
  display: block;
  max-width: none;
  transform: translateX(var(--header-brand-mark-shift)) scale(var(--header-brand-mark-scale));
  transform-origin: center center;
  transition: opacity 180ms ease, transform 180ms ease;
}

.brand-mark .brand-mark-hover {
  opacity: 0;
}

.brand-copy {
  display: grid;
  gap: 0.15rem;
  min-width: 0;
  color: var(--white);
}

.brand-copy strong {
  font-family: var(--header-font);
  font-size: 1.36rem;
  line-height: 1;
  letter-spacing: 0.05em;
  text-transform: none;
  font-weight: 700;
  color: var(--white);
  transition: color 180ms ease;
}

.brand-copy span {
  font-family: var(--header-font);
  font-size: 0.76rem;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: rgba(255, 255, 255, 0.66);
  white-space: nowrap;
  transition: color 180ms ease;
}

.brand:hover .brand-mark-default,
.brand:focus-visible .brand-mark-default {
  opacity: 0;
}

.brand:hover .brand-mark-hover,
.brand:focus-visible .brand-mark-hover {
  opacity: 1;
}

.brand:hover .brand-copy strong,
.brand:hover .brand-copy span,
.brand:focus-visible .brand-copy strong,
.brand:focus-visible .brand-copy span {
  color: var(--brand-hot);
}

.header-actions {
  display: flex;
  align-items: center;
  gap: var(--header-shell-gap);
  min-width: 0;
  margin-left: auto;
}

.nav-links {
  position: absolute;
  left: 50%;
  top: 50%;
  display: inline-flex;
  align-items: center;
  gap: var(--header-nav-gap);
  flex-wrap: nowrap;
  justify-content: center;
  min-width: 0;
  transform: translate(-50%, -50%);
}

.nav-links a,
.nav-link {
  font-family: var(--header-font);
  color: rgba(255, 255, 255, 0.78);
  font-size: var(--header-link-font-size);
  font-weight: 700;
  line-height: 1;
  letter-spacing: var(--header-link-letter-spacing);
  text-transform: none;
  transition: color 180ms ease;
}

.nav-links a:not(.nav-signup):hover,
.nav-links a:not(.nav-signup):focus-visible,
.nav-links a.is-current:not(.nav-signup),
.nav-link:not(.nav-signup):hover,
.nav-link:not(.nav-signup):focus-visible,
.nav-link.is-current:not(.nav-signup) {
  color: #ffffff;
}

.nav-signup {
  order: 99;
  position: relative;
  isolation: isolate;
  overflow: hidden;
  padding: var(--header-signup-padding-y) var(--header-signup-padding-x);
  border-radius: var(--header-shell-radius);
  border: 1px solid transparent;
  background: transparent;
  color: var(--white) !important;
  box-shadow: 0 12px 24px rgba(255, 0, 100, 0.18);
  transition:
    color 240ms cubic-bezier(0.22, 1, 0.36, 1),
    border-color 420ms cubic-bezier(0.22, 1, 0.36, 1),
    box-shadow 420ms cubic-bezier(0.22, 1, 0.36, 1);
}

.nav-signup::before,
.nav-signup::after {
  content: "";
  position: absolute;
  inset: 0;
  border-radius: inherit;
  pointer-events: none;
}

.nav-signup::before {
  z-index: -2;
  background: linear-gradient(135deg, var(--brand-hot), var(--brand-shift));
  opacity: 1;
  transition: opacity 420ms cubic-bezier(0.22, 1, 0.36, 1);
}

.nav-signup::after {
  z-index: -1;
  background: linear-gradient(135deg, rgba(255, 0, 100, 0.16), rgba(160, 80, 160, 0.12));
  opacity: 0;
  transition: opacity 420ms cubic-bezier(0.22, 1, 0.36, 1);
}

.nav-signup:hover,
.nav-signup:focus-visible {
  color: var(--white) !important;
  border-color: rgba(255, 0, 100, 0.72);
  box-shadow:
    0 12px 24px rgba(255, 0, 100, 0.12),
    0 0 0 1px rgba(255, 0, 100, 0.18) inset;
  transform: none;
}

.nav-signup:hover::before,
.nav-signup:focus-visible::before {
  opacity: 0;
}

.nav-signup:hover::after,
.nav-signup:focus-visible::after {
  opacity: 1;
}

.nav-social {
  order: 0;
}

.lang-toggle {
  position: absolute;
  right: calc(var(--header-shell-padding-x) + 0.78rem);
  top: 50%;
  transform: translateY(-50%);
  display: inline-flex;
  align-items: center;
  justify-content: flex-end;
  gap: 0.9rem;
  padding: 0;
  background: transparent;
  border: 0;
}

.lang-toggle button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  position: relative;
  font-family: var(--header-font);
  border: 0;
  border-radius: 0;
  padding: 0;
  cursor: pointer;
  color: rgba(255, 255, 255, 0.74);
  background: transparent;
  transition: color 180ms ease;
  font-size: var(--header-link-font-size);
  line-height: 1;
  font-weight: 700;
  letter-spacing: var(--header-link-letter-spacing);
}

.lang-toggle button + button::before {
  content: "";
  position: absolute;
  left: -0.48rem;
  top: 50%;
  width: 1px;
  height: 0.8em;
  background: rgba(255, 255, 255, 0.28);
  transform: translateY(-50%);
  pointer-events: none;
}

.lang-toggle button.is-active {
  color: var(--white);
}

.lang-toggle button:hover,
.lang-toggle button:focus-visible {
  color: var(--brand-hot);
}

@media (min-width: 1280px) {
  html {
    font-size: 17.5px;
  }
}

@media (min-width: 1600px) {
  :root {
    --content-width: min(1480px, calc(100vw - 2.25rem));
  }

  html {
    font-size: 18px;
  }
}

@media (max-width: 760px) {
  html {
    font-size: 16.25px;
  }

  :root {
    --header-top-gap: 0.95rem;
    --header-side-gap: 1.15rem;
  }

  .site-header .shell {
    flex-wrap: wrap;
    padding: 0.82rem 1rem;
  }

  .header-actions {
    width: 100%;
    gap: 0.8rem;
  }

  .site-header .shell,
  .header-actions,
  .nav-links {
    gap: 0.8rem;
  }

  .nav-links {
    position: static;
    order: 3;
    width: 100%;
    flex-wrap: wrap;
    justify-content: space-between;
    transform: none;
  }

  .lang-toggle {
    position: static;
    right: auto;
    top: auto;
    transform: none;
  }
}