.site-header {
  position: sticky;
  top: 0;
  inset-inline: 0;
  z-index: var(--z-header);
  height: var(--header-h);
  display: flex;
  align-items: center;
  background: #000;
  transition: background-color var(--dur-base) var(--ease-standard),
    box-shadow var(--dur-base) var(--ease-standard),
    backdrop-filter var(--dur-base) var(--ease-standard);
  --header-fg: #ffffff;
  --header-fg-soft: rgba(255, 255, 255, 0.78);
}

.site-header.is-scrolled {
  background: #000;
  box-shadow: var(--shadow-header);
}

.site-header__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-6);
  width: 100%;
  height: 100%;
}

.site-header__logo {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  color: var(--header-fg);
  transition: opacity var(--dur-fast) var(--ease-standard);
}

.site-header .site-header__logo {
  align-items: flex-end;
  align-self: flex-start;
  gap: 7px;
  margin-block-start: 4px;
}

.site-header__logo:hover {
  opacity: 0.85;
}

.site-header__logo-image {
  width: 49px;
  height: 49px;
  object-fit: contain;
  flex-shrink: 0;
}

.site-header .site-header__logo-text {
  font-size: 1.75rem;
  line-height: 1.2;
}

.site-header__logo-mark {
  width: 34px;
  height: 34px;
  border-radius: 10px;
  background: linear-gradient(135deg, var(--color-brand), var(--color-brand-2));
  flex-shrink: 0;
}

.site-header__logo-text {
  font-size: 1.15rem;
  font-weight: 800;
  font-variation-settings: "wght" 800;
  letter-spacing: -0.01em;
  white-space: nowrap;
}

.site-nav {
  display: none;
}

.site-nav__list {
  display: flex;
  align-items: center;
  gap: var(--space-7);
}

.site-nav__link {
  position: relative;
  font-size: var(--fs-small);
  font-weight: 600;
  color: var(--header-fg-soft);
  padding-block: var(--space-2);
  transition: color var(--dur-fast) var(--ease-standard);
}

.site-nav__link::after {
  content: "";
  position: absolute;
  inset-inline-start: 0;
  bottom: -2px;
  width: 100%;
  height: 2px;
  border-radius: var(--radius-full);
  background: var(--color-brand-bright);
  transform: scaleX(0);
  transform-origin: center;
  transition: transform var(--dur-base) var(--ease-standard);
}

.site-nav__link:hover,
.site-nav__link.is-current {
  color: var(--header-fg);
}

.site-nav__link:hover::after,
.site-nav__link.is-current::after {
  transform: scaleX(1);
}

.site-header__menu-btn {
  display: inline-flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  gap: 5px;
  width: 40px;
  height: 40px;
  border-radius: var(--radius-sm);
}

.menu-btn__bar {
  display: block;
  width: 20px;
  height: 2px;
  border-radius: var(--radius-full);
  background: var(--header-fg);
  transition: transform var(--dur-base) var(--ease-standard), opacity var(--dur-base) var(--ease-standard);
}

.nav-open .menu-btn__bar:nth-child(1) {
  transform: translateY(7px) rotate(45deg);
}

.nav-open .menu-btn__bar:nth-child(2) {
  opacity: 0;
}

.nav-open .menu-btn__bar:nth-child(3) {
  transform: translateY(-7px) rotate(-45deg);
}

.nav-open .site-header {
  background: #000;
}

.mobile-nav {
  position: fixed;
  inset: var(--header-h) 0 0 0;
  z-index: var(--z-mobile-nav);
  background: var(--color-bg);
  transform: translateY(-8px);
  opacity: 0;
  visibility: hidden;
  pointer-events: none;
  transition: opacity var(--dur-base) var(--ease-standard), transform var(--dur-base) var(--ease-standard),
    visibility var(--dur-base);
  padding: var(--space-7) var(--container-pad);
  overflow-y: auto;
}

.mobile-nav.is-open {
  opacity: 1;
  visibility: visible;
  pointer-events: auto;
  transform: translateY(0);
}

.mobile-nav__list {
  display: flex;
  flex-direction: column;
  gap: var(--space-2);
}

.mobile-nav__list a {
  display: block;
  padding-block: var(--space-4);
  font-size: var(--fs-h3);
  font-weight: 700;
  border-bottom: 1px solid var(--color-line);
  color: var(--color-ink);
  transition: color var(--dur-fast) var(--ease-standard);
}

.mobile-nav__list a.is-current {
  color: var(--color-brand);
}

@media (min-width: 900px) {
  .site-nav {
    display: block;
  }

  .site-header__menu-btn {
    display: none;
  }
}