:root {
  --header-width: var(--layout-width);
  --header-height:    55px;
  --header-top:       33px;
  --header-radius:    12px;
  --header-nav-gap:  117px;

  --header-bg:      rgba(255, 255, 255, 0.1);
  --header-border:  rgba(0, 0, 0, 0.08);
  --header-blur:    12px;
}

.page {
  padding-top: calc(var(--header-top) + var(--header-height) + var(--page-padding-y));
}

.site-header {
  position: fixed;
  top: var(--header-top);
  left: 50%;
  transform: translateX(-50%);
  z-index: 100;

  width: var(--header-width);
  max-width: calc(100% - 2rem);
  height: var(--header-height);

  display: flex;
  align-items: center;
  justify-content: space-between;

  color: var(--color-text);

  padding: 0.5rem var(--card-padding);
  border-radius: var(--header-radius);
  border: 1px solid
    color-mix(in srgb, var(--header-border) calc(var(--scroll-progress, 0) * 100%), transparent);
  background: color-mix(in srgb, var(--header-bg) calc(var(--scroll-progress, 0) * 100%), transparent);
  backdrop-filter: blur(calc(var(--scroll-progress, 0) * var(--header-blur)));
  -webkit-backdrop-filter: blur(calc(var(--scroll-progress, 0) * var(--header-blur)));

  transition: border-color 0.3s ease, background-color 0.3s ease;
}

.site-header__controls {
  display: flex;
  align-items: center;
  gap: 0.9375rem;
}

.theme-changer {
  position: relative;
  width: 1.125rem;
  height: 1.3125rem;
  padding: 0;
  border: 0;
  background: none;
  color: inherit;
  cursor: pointer;
  transition: transform 0.3s ease;
}

.theme-changer:hover {
  transform: scale(1.25);
}

.theme-changer__icon {
  position: absolute;
  inset: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  transition:
    opacity 300ms var(--ease),
    transform 460ms cubic-bezier(0.34, 1.5, 0.5, 1);
}

.theme-changer__icon--dark {
  opacity: 0;
  transform: rotate(-100deg) scale(0.4);
  pointer-events: none;
}

.theme-changer.is-dark .theme-changer__icon--light {
  opacity: 0;
  transform: rotate(100deg) scale(0.4);
  pointer-events: none;
}

.theme-changer__icon--light,
.theme-changer.is-dark .theme-changer__icon--dark {
  opacity: 1;
  transform: rotate(0deg) scale(1);
}

.theme-changer svg {
  display: block;
  fill: currentColor;
}

.theme-changer__icon--light svg {
  width: 1.125rem;
  height: 1.125rem;
}

.theme-changer__icon--dark svg {
  width: 1.125rem;
  height: 1.3125rem;
}

.lang-changer {
  position: relative;
  user-select: none;
}

.lang-changer__current {
  display: flex;
  align-items: center;
  gap: 0.25rem;
  padding: 0;
  border: 0;
  background: none;
  color: inherit;
  font: inherit;
  line-height: 1em;
  cursor: pointer;
}

.lang-changer__arrow {
  width: 0.75rem;
  height: 0.375rem;
  transform: translateY(0.125rem);
  transition: transform 0.3s ease;
}

.lang-changer__arrow path {
  stroke: currentColor;
}

.lang-changer.is-open .lang-changer__arrow {
  transform: translateY(0.125rem) rotate(180deg);
}

.lang-changer.is-translating {
  opacity: 0.5;
  pointer-events: none;
}

.lang-changer__dropdown {
  position: absolute;
  top: calc(100% + 0.25rem);
  left: -0.5rem;
  z-index: 60;

  display: flex;
  flex-direction: column;
  overflow: hidden;

  opacity: 0;
  max-height: 0;

  background: color-mix(in srgb, var(--header-bg) calc(var(--scroll-progress, 0) * 100%), transparent);
  backdrop-filter: blur(calc(var(--scroll-progress, 0) * var(--header-blur)));
  -webkit-backdrop-filter: blur(calc(var(--scroll-progress, 0) * var(--header-blur)));
  border-radius: calc(var(--scroll-progress, 0) * 0.5rem);
  border: calc(var(--scroll-progress, 0) * 1px) solid
    color-mix(in srgb, var(--header-border) calc(var(--scroll-progress, 0) * 100%), transparent);

  transition:
    opacity 0.3s cubic-bezier(0.4, 0, 0.2, 1),
    max-height 0.3s cubic-bezier(0.4, 0, 0.2, 1),
    padding 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

.lang-changer.is-open .lang-changer__dropdown {
  max-height: 5rem;
  opacity: 1;
  padding: 0.25rem 0.5rem;
}

.lang-changer__option {
  padding: 0;
  border: 0;
  background: none;
  color: inherit;
  font: inherit;
  cursor: pointer;
  transition: opacity 0.2s ease;
}

.lang-changer__option:hover {
  opacity: 0.6;
}

.site-header__nav {
  display: flex;
  gap: var(--header-nav-gap);
}

.nav-link {
  display: inline-block;
  text-align: center;
  color: var(--color-text);
  text-decoration: none;
  cursor: pointer;
  font-weight: var(--font-weight-regular);
  font-variation-settings: "wght" 400;
  transition: font-variation-settings 0.3s ease, font-weight 0.3s ease;
}

.nav-link::before {
  content: attr(data-label);
  display: block;
  height: 0;
  overflow: hidden;
  visibility: hidden;
  font-weight: var(--font-weight-medium);
  font-variation-settings: "wght" 500;
}

.nav-link--active,
.nav-link:hover {
  font-weight: var(--font-weight-medium);
  font-variation-settings: "wght" 500;
}

.site-header__telegram {
  display: flex;
  color: var(--color-text);
  transition: transform 0.3s ease;
}

.site-header__telegram:hover {
  transform: scale(1.25);
}

.site-header__telegram svg {
  display: block;
  width: 1.375rem;
  height: 1.125rem;
  fill: currentColor;
}

@media (max-width: 1024px) {
  :root {
    --header-nav-gap: 2.5rem;
  }
}

@media (max-width: 880px) {
  :root {
    --header-top: 12px;
    --header-height: 48px;
    --header-nav-gap: 1.25rem;
  }

  .site-header {
    max-width: calc(100% - 1.5rem);
    font-size: 14px;
  }
}

@media (max-width: 560px) {
  :root {
    --header-nav-gap: 0.875rem;
  }

  .site-header {
    font-size: 13px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .site-header,
  .site-header *,
  .theme-changer,
  .nav-link {
    transition-duration: 0.01ms !important;
  }
}

.burger,
.menu,
.menu__scrim {
  display: none;
}

@media (max-width: 560px) {
  .has-menu .site-header {
    justify-content: flex-start;
    gap: 14px;
    font-size: 14px;
  }

  .has-menu .site-header__nav {
    display: none;
  }

  .has-menu .site-header__telegram {
    margin-left: auto;
  }

  .has-menu .burger {
    display: block;
    position: relative;
    width: 22px;
    height: 22px;
    flex: none;
    padding: 0;
    border: 0;
    background: none;
    color: inherit;
    cursor: pointer;
  }

  .burger__line {
    position: absolute;
    top: 50%;
    right: 1px;
    width: 20px;
    height: 1.5px;
    margin-top: -0.75px;
    border-radius: 2px;
    background: currentColor;
    transition:
      translate 340ms cubic-bezier(0.4, 0, 0.2, 1),
      rotate 340ms cubic-bezier(0.4, 0, 0.2, 1);
  }

  .burger__line:nth-child(1) {
    translate: 0 -4px;
  }

  .burger__line:nth-child(2) {
    translate: 0 4px;
  }

  .burger.is-open .burger__line {
    translate: 0 0;
  }

  .burger.is-open .burger__line:nth-child(1) {
    rotate: 45deg;
  }

  .burger.is-open .burger__line:nth-child(2) {
    rotate: -45deg;
  }

  .has-menu .menu__scrim {
    display: block;
    position: fixed;
    inset: 0;
    z-index: 250;
    background: var(--menu-scrim);
    backdrop-filter: blur(2px);
    -webkit-backdrop-filter: blur(2px);
    opacity: 0;
    visibility: hidden;
    transition: opacity 260ms var(--ease), visibility 0s 260ms;
  }

  .menu-open .menu__scrim {
    opacity: 1;
    visibility: visible;
    transition: opacity 260ms var(--ease), visibility 0s;
  }

  .menu-open .site-header {
    z-index: 270;
  }

  .has-menu .menu {
    display: block;
    position: fixed;
    top: calc(var(--header-top) + var(--header-height) + 8px);
    left: 50%;
    z-index: 260;

    width: var(--header-width);
    max-width: calc(100% - 1.5rem);
    padding: 4px 6px;

    border-radius: 20px;
    background: var(--color-surface);
    box-shadow:
      0 0 0 1px var(--menu-edge),
      0 18px 40px rgba(0, 0, 0, 0.16),
      0 3px 10px rgba(0, 0, 0, 0.08);

    opacity: 0;
    translate: -50% -10px;
    visibility: hidden;
    transition:
      opacity 260ms var(--ease),
      translate 320ms var(--ease),
      visibility 0s 320ms;
  }

  .menu-open .menu {
    opacity: 1;
    translate: -50% 0;
    visibility: visible;
    transition:
      opacity 260ms var(--ease),
      translate 320ms var(--ease),
      visibility 0s;
  }

  .menu__sheet {
    display: flex;
    flex-direction: column;
  }

  .menu__link {
    display: block;
    position: relative;
    padding: 15px 16px;
    text-align: left;
    font-size: var(--font-size-section);
    line-height: var(--line-height-value);
    color: var(--color-text);
    text-decoration: none;
  }

  .menu__link + .menu__link {
    border-top: 1px solid var(--color-chip-bg);
  }

  .menu__link.nav-link--active::after {
    content: "";
    position: absolute;
    top: 50%;
    right: 16px;
    width: 6px;
    height: 6px;
    margin-top: -3px;
    border-radius: 50%;
    background: var(--color-bullet);
  }

  .menu-open .menu__link {
    animation: appear 320ms var(--ease) both;
  }

  .menu-open .menu__link:nth-child(1) { animation-delay: 70ms; }
  .menu-open .menu__link:nth-child(2) { animation-delay: 130ms; }
  .menu-open .menu__link:nth-child(3) { animation-delay: 190ms; }
  .menu-open .menu__link:nth-child(4) { animation-delay: 250ms; }
  .menu-open .menu__link:nth-child(5) { animation-delay: 310ms; }

  .menu-open,
  .menu-open body {
    overflow: hidden;
  }
}

@media (max-width: 560px) and (prefers-reduced-motion: reduce) {
  .burger__line,
  .has-menu .menu,
  .has-menu .menu__scrim {
    transition: none;
  }

  .menu-open .menu__link {
    animation: none;
  }
}