/* ==========================================================================
   UMMU — Teaser page
   Iteration 1: Logo-only with black/white inversion animation
   ========================================================================== */

/* --- Custom Properties (theming-ready for iteration 2+) --- */
:root {
  --color-black: #000000;
  --color-white: #ffffff;
  --invert-duration: 16s;
  --breathe-duration: 6s;
  --animation-timing: ease-in-out;
  --logo-max-width: min(70vw, 480px);
}

/* --- Reset & Base --- */
*,
*::before,
*::after {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html {
  height: 100%;
}

body {
  height: 100%;
  overflow: hidden;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

/* --- Page container — fullscreen centered --- */
.page {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 100vw;
  height: 100vh;
  height: 100dvh;
  animation: bg-invert var(--invert-duration) var(--animation-timing) infinite;
  background-color: var(--color-white);
}

/* --- Logo --- */
.logo {
  display: block;
  width: var(--logo-max-width);
  animation:
    fg-invert var(--invert-duration) var(--animation-timing) infinite,
    breathe var(--breathe-duration) var(--animation-timing) infinite;
  color: var(--color-black);
}

.logo svg {
  display: block;
  width: 100%;
  height: auto;
}

/* --- Keyframes: background color cycle ---
   16s total: 5s white → 3s transition → 5s black → 3s transition
*/
@keyframes bg-invert {
  0%, 31% {
    background-color: var(--color-white);
  }
  50%, 81% {
    background-color: var(--color-black);
  }
  100% {
    background-color: var(--color-white);
  }
}

/* --- Keyframes: foreground (logo) color cycle --- */
@keyframes fg-invert {
  0%, 31% {
    color: var(--color-black);
  }
  50%, 81% {
    color: var(--color-white);
  }
  100% {
    color: var(--color-black);
  }
}

/* --- Keyframes: subtle breathing scale --- */
@keyframes breathe {
  0%, 100% {
    transform: scale(1);
  }
  50% {
    transform: scale(1.03);
  }
}

/* --- Reduced motion: respect user preference --- */
@media (prefers-reduced-motion: reduce) {
  .page {
    animation: none;
    background-color: var(--color-black);
  }

  .logo {
    animation: none;
    color: var(--color-white);
  }
}