html.is-preloading,
body.is-preloading {
  overflow: hidden;
  height: 100%;
}

.preloader {
  position: fixed;
  inset: 0;
  z-index: 2000;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--color-dark-1000);
  transition: opacity 0.5s ease, filter 0.5s ease;
}

.preloader.is-hiding {
  opacity: 0;
  filter: blur(24px);
  pointer-events: none;
}

.preloader__logo {
  width: 200px;
  height: auto;
  display: block;
  opacity: 0;
  filter: blur(20px);
  transition: opacity 0.45s ease, filter 0.45s ease;
  will-change: opacity, filter, transform;
}

.preloader__logo.is-visible {
  opacity: 1;
  filter: none;
}

/* Кувырок вправо по граням, как брошенный кубик: каждые 90° — перекат
   через нижний правый угол (сдвиг на сторону = 200px), в середине каждой
   четверти центр квадрата приподнимается на (√2/2 − 1/2)·сторона ≈ 41px.
   Тайминг четвертей растянут к концу — кубик замедляется, докатываясь. */
@keyframes preloader-roll {
  0%    { transform: translate(0, 0) rotate(0deg); opacity: 1; }
  5%    { transform: translate(100px, -41px) rotate(45deg); }
  10%   { transform: translate(200px, 0) rotate(90deg); }
  16%   { transform: translate(300px, -41px) rotate(135deg); }
  22%   { transform: translate(400px, 0) rotate(180deg); }
  29%   { transform: translate(500px, -41px) rotate(225deg); }
  36%   { transform: translate(600px, 0) rotate(270deg); }
  44.5% { transform: translate(700px, -41px) rotate(315deg); }
  53%   { transform: translate(800px, 0) rotate(360deg); }
  63.5% { transform: translate(900px, -41px) rotate(405deg); }
  74%   { transform: translate(1000px, 0) rotate(450deg); opacity: 1; }
  87%   { transform: translate(1100px, -41px) rotate(495deg); opacity: 0.5; }
  100%  { transform: translate(1200px, 0) rotate(540deg); opacity: 0; }
}

.preloader__logo.is-rolling {
  animation: preloader-roll 1.7s cubic-bezier(0.45, 0, 0.55, 1) forwards;
}

/* Hero content stays hidden behind the preloader curtain and reveals from
   blur only once the curtain actually starts lifting — not the instant
   scroll-fx's IntersectionObserver fires on load. The real hero logo is
   deliberately left out of this: the preloader's own logo already sits
   docked in that exact spot, so the real one should just already be there
   underneath, not fade in a second time on top of it. */
body.is-preloading .hero__topbar {
  opacity: 0 !important;
  filter: blur(16px);
}

.hero__topbar {
  transition: opacity 0.8s ease, filter 0.8s ease;
}

@media (prefers-reduced-motion: reduce) {
  .preloader {
    transition: none;
  }

  .preloader__logo {
    transition: none;
  }

  body.is-preloading .hero__topbar {
    opacity: 1 !important;
    filter: none;
  }
}

/* ============ Mobile ≤767px — лого меньше, шаг кувырка = сторона 140px ============ */
@media (max-width: 767px) {
  .preloader__logo {
    width: 140px;
  }

  @keyframes preloader-roll-mobile {
    0%    { transform: translate(0, 0) rotate(0deg); opacity: 1; }
    5%    { transform: translate(70px, -29px) rotate(45deg); }
    10%   { transform: translate(140px, 0) rotate(90deg); }
    16%   { transform: translate(210px, -29px) rotate(135deg); }
    22%   { transform: translate(280px, 0) rotate(180deg); }
    29%   { transform: translate(350px, -29px) rotate(225deg); }
    36%   { transform: translate(420px, 0) rotate(270deg); }
    44.5% { transform: translate(490px, -29px) rotate(315deg); }
    53%   { transform: translate(560px, 0) rotate(360deg); }
    63.5% { transform: translate(630px, -29px) rotate(405deg); }
    74%   { transform: translate(700px, 0) rotate(450deg); opacity: 1; }
    87%   { transform: translate(770px, -29px) rotate(495deg); opacity: 0.5; }
    100%  { transform: translate(840px, 0) rotate(540deg); opacity: 0; }
  }

  .preloader__logo.is-rolling {
    animation-name: preloader-roll-mobile;
  }
}