:root {
  --bg: #000;
  --text: #fff;
  --muted: rgba(255, 255, 255, 0.72);
  --title-design-width: 3840px;
  --title-header-height: 200px;
  --title-scale: var(--page-scale, clamp(0.25, calc(100vw / var(--title-design-width)), 1));
  --font-sans: "Source Han Sans CN", "Noto Sans SC", Inter, "Microsoft YaHei", "PingFang SC", "Segoe UI", Arial, sans-serif;
}

html {
  background: var(--bg);
}

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: var(--font-sans);
  overflow-x: hidden;
}

body.is-header-preview .design-canvas {
  height: 200px;
}

.site-header {
  position: fixed;
  left: 0;
  right: 0;
  top: 0;
  z-index: 40;
  height: calc(var(--title-header-height) * var(--title-scale));
  min-height: 72px;
  overflow: hidden;
  background: var(--bg);
  color: var(--text);
}

.site-header a,
.site-header button {
  color: inherit;
  text-decoration: none;
  background: none;
  border: 0;
  padding: 0;
  font: inherit;
  cursor: pointer;
}

.site-header__brand {
  position: absolute;
  left: calc(160px * var(--title-scale));
  top: calc(44px * var(--title-scale));
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  justify-content: flex-start;
  line-height: 1.05;
  white-space: nowrap;
}

.site-header__brand-line--cn {
  font-family: Inter, var(--font-sans);
  font-size: calc(52px * var(--title-scale));
  font-weight: 900;
  letter-spacing: 0.02em;
}

.site-header__brand-line--en {
  font-family: Inter, var(--font-sans);
  font-size: calc(28px * var(--title-scale));
  font-weight: 700;
  letter-spacing: 0.14em;
  opacity: 0.92;
}

.site-header__nav {
  position: absolute;
  right: calc(520px * var(--title-scale));
  top: calc(72px * var(--title-scale));
  display: flex;
  align-items: center;
  gap: calc(88px * var(--title-scale));
  white-space: nowrap;
}

.site-header__nav-link {
  display: block;
  font-size: calc(48px * var(--title-scale));
  font-weight: 500;
  letter-spacing: 0.04em;
  line-height: 1;
  transition: color 180ms ease, opacity 180ms ease, transform 180ms ease;
}

.site-header__nav-link:hover,
.site-header__nav-link:focus-visible,
.site-header__nav-link.is-active {
  color: var(--muted);
  outline: none;
}

.site-header__nav-link:hover {
  transform: translateY(calc(-2px * var(--title-scale)));
}

.site-header__lang {
  position: absolute;
  right: calc(160px * var(--title-scale));
  top: calc(78px * var(--title-scale));
  display: inline-flex;
  align-items: center;
  gap: calc(12px * var(--title-scale));
  font-family: Inter, var(--font-sans);
  font-size: calc(36px * var(--title-scale));
  font-weight: 500;
  letter-spacing: 0.04em;
  line-height: 1;
  opacity: 0.9;
}

.site-header__lang [data-lang-option] {
  opacity: 0.45;
  transition: opacity 160ms ease;
}

.site-header__lang [data-lang-option].is-active {
  opacity: 1;
}

.site-header__lang:hover,
.site-header__lang:focus-visible {
  opacity: 1;
  outline: none;
}

.site-header__lang-sep {
  opacity: 0.35;
}

@media (max-width: 767px) {
  .site-header {
    height: 72px;
    min-height: 72px;
    border-bottom: 1px solid rgba(255, 255, 255, 0.12);
  }

  .site-header__brand {
    left: 16px;
    top: 14px;
  }

  .site-header__brand-line--cn {
    font-size: 20px;
  }

  .site-header__brand-line--en {
    font-size: 11px;
  }

  .site-header__nav {
    display: none;
  }

  .site-header__lang {
    right: 16px;
    top: 26px;
    font-size: 14px;
  }
}