*,
  *::before,
  *::after {
      box-sizing: border-box;
      margin: 0;
      padding: 0;
  }

  body {
      font-family: 'Vazirmatn', sans-serif;
      overflow: hidden;
      width: 100vw;
      height: 100vh;
      direction: rtl;
  }

  #app {
      width: 100%;
      height: 100vh;
      position: relative;
      overflow: hidden;
      transition: background-color 650ms cubic-bezier(0.4, 0, 0.2, 1);
  }

  #inner {
      position: relative;
      width: 100%;
      height: 100vh;
      overflow: hidden;
  }

  #grain {
      position: absolute;
      inset: 0;
      pointer-events: none;
      z-index: 50;
      opacity: 0.4;
      background-repeat: repeat;
      background-size: 200px 200px;
  }

  #ghost-text {
      position: absolute;
      inset: 0;
      display: flex;
      align-items: center;
      justify-content: center;
      transform: translateY(-14%);
      pointer-events: none;
      user-select: none;
      z-index: 2;
      font-family: 'Vazirmatn', sans-serif;
      font-size: clamp(60px, 22vw, 280px);
      font-weight: 900;
      color: white;
      opacity: 1;
      line-height: 1.2;
      letter-spacing: -0.02em;
      white-space: nowrap;
  }

  #brand {
      position: absolute;
      top: 1.5rem;
      inset-inline-start: 1rem;
      z-index: 60;
      font-size: 0.75rem;
      font-weight: 700;
      color: white;
      opacity: 0.9;
      letter-spacing: 0.05em;
  }

  .carousel-item {
      position: absolute;
      aspect-ratio: 0.6 / 1;
      transition:
          transform 650ms cubic-bezier(0.4, 0, 0.2, 1),
          filter 650ms cubic-bezier(0.4, 0, 0.2, 1),
          opacity 650ms cubic-bezier(0.4, 0, 0.2, 1),
          left 650ms cubic-bezier(0.4, 0, 0.2, 1),
          height 650ms cubic-bezier(0.4, 0, 0.2, 1),
          bottom 650ms cubic-bezier(0.4, 0, 0.2, 1);
      will-change: transform, filter, opacity;
  }

  .carousel-item img {
      width: 100%;
      height: 100%;
      object-fit: contain;
      object-position: bottom center;
      display: block;
      user-select: none;
      -webkit-user-drag: none;
  }

  #bottom-info {
      position: absolute;
      bottom: 1.5rem;
      inset-inline-start: 1rem;
      z-index: 60;
      max-width: 320px;
      text-align: right;
  }

  #product-title {
      font-weight: 800;
      letter-spacing: 0.02em;
      font-size: 1rem;
      color: white;
      opacity: 0.95;
      margin-bottom: 0.5rem;
  }

  #product-desc {
      font-size: 0.8rem;
      color: white;
      opacity: 0.85;
      line-height: 1.8;
      margin-bottom: 1rem;
      display: none;
  }

  #nav-buttons {
      display: flex;
      gap: 0.75rem;
      flex-direction: row-reverse;
  }

  .nav-btn {
      width: 3rem;
      height: 3rem;
      border-radius: 50%;
      background: transparent;
      border: 2px solid white;
      color: white;
      cursor: pointer;
      display: flex;
      align-items: center;
      justify-content: center;
      transition: transform 150ms, background-color 150ms;
  }

  .nav-btn:hover {
      transform: scale(1.08);
      background-color: rgba(255, 255, 255, 0.12);
  }

  .nav-btn svg {
      width: 26px;
      height: 26px;
      stroke: white;
      stroke-width: 2.25;
      fill: none;
      stroke-linecap: round;
      stroke-linejoin: round;
  }

  #discover {
      position: absolute;
      bottom: 1.5rem;
      inset-inline-end: 1rem;
      z-index: 60;
      display: flex;
      align-items: center;
      gap: 8px;
      flex-direction: row-reverse;
      font-family: 'Vazirmatn', sans-serif;
      font-size: clamp(20px, 4vw, 48px);
      font-weight: 800;
      color: white;
      opacity: 0.95;
      letter-spacing: -0.02em;
      line-height: 1;
      text-decoration: none;
      transition: opacity 200ms;
  }

  #discover:hover {
      opacity: 1;
  }

  #discover svg {
      width: 1.25rem;
      height: 1.25rem;
      stroke: white;
      stroke-width: 2.25;
      fill: none;
      stroke-linecap: round;
      stroke-linejoin: round;
      transform: scaleX(-1);
  }

  @media (min-width: 640px) {
      #brand {
          inset-inline-start: 2rem;
      }

      #bottom-info {
          bottom: 5rem;
          inset-inline-start: 6rem;
          max-width: 360px;
      }

      #product-title {
          font-size: 1.375rem;
          margin-bottom: 0.75rem;
      }

      #product-desc {
          display: block;
      }

      .nav-btn {
          width: 4rem;
          height: 4rem;
      }

      #discover {
          bottom: 5rem;
          inset-inline-end: 2.5rem;
      }

      #discover svg {
          width: 2rem;
          height: 2rem;
      }
  }

/* Real scroll behavior layer
   ظاهر اصلی تغییر نکرده؛ فقط خود صفحه ارتفاع واقعی می‌گیرد و #app ثابت می‌ماند
   تا با اسکرول دسکتاپ و موبایل، مرحله‌های طرح عوض شوند. */
html {
    width: 100%;
    min-height: 100%;
    overflow-x: hidden;
}

body {
    height: auto !important;
    min-height: 400vh;
    overflow-x: hidden !important;
    overflow-y: auto !important;
    -webkit-overflow-scrolling: touch;
}

#app {
    position: fixed !important;
    inset: 0;
    z-index: 1;
    touch-action: pan-y;
}

#inner {
    height: 100vh;
}