:root {
    --font-size: 1rem;
    --line-height: 1.5;
    --background-color: #fff;
    --text-color: #000;  
    --background-color-carousel: white;  
    --background-color-footer: #f4f4f4;  
    --text-color-footer: #888888;         
    --text-color-h1-slogan: #0d47a1; 
    --background-color-slogan: #e3f2fd;   
    --secondary-text-color: #888888; 
    --background-color-nav: #f4f4f4; 
    --background-color-lang-dropdown: #f0f0f0; 
    --background-lang-dropdown: #fff; 
    --color-lang-dropdown-a: #000; 
    --border-lang-dropdown: 1px solid #ccc;
    --info-block-background-color: #ffffff;  
    --info-block-border: #cccccc;  
}

body {
    background-color: var(--background-color);
    color: var(--text-color);
    font-size: var(--font-size);
    line-height: var(--line-height);   
    font-family: 'Inter', sans-serif; 
    font-weight: 400;
}

html, body {
    height: 100%;
    margin: 0;
    padding: 0;
}


.wrapper {
    display: flex;
    flex-direction: column;
    min-height: 100vh; /*  make the wrapper stretch to the full height of the window */
}

main {
    flex: 1; /*  the main content takes up all available space */
}

/* footer */
.footer {  
    background-color: var(--background-color-footer);
    color: var(--text-color-footer);
    text-align: center; 
    padding: 1rem 0;
    font-size: 0.9rem;
}


header nav {
    background-color: var(--background-color-nav);   
    padding: 10px;
    text-align: right; 
}

header nav a {
    color: #fff;
    text-decoration: none;
    padding: 5px 10px;
}

header nav a:hover {
    background-color: #555;
}


    .language-selector {
      position: relative;
      display: inline-block;
    }

    .lang-toggle {
      display: flex;
      align-items: center;
      gap: 8px;
      background: none;
      border: none;
      cursor: pointer;
      font-size: 16px;
      padding: 6px 10px;
      color: inherit;
    }

    .globe-icon svg,
    .arrow-icon {
      stroke: currentColor;
      transition: transform 0.3s ease, stroke 0.3s ease;
    }

    .arrow-down {
      display: flex;
      align-items: center;
      transition: transform 0.3s ease;
    }

    .lang-toggle[aria-expanded="true"] .arrow-down {
      transform: rotate(180deg);
    }

    .lang-dropdown {
      position: absolute;
      top: 100%;
      right: 0;
      margin-top: 4px;
      background: var(--background-lang-dropdown); 
      border: var(--border-lang-dropdown);
      list-style: none;
      padding: 0;
      display: none;
      width: max-content;          
      z-index: 100;
      box-shadow: 0 4px 8px rgba(0,0,0,0.1);
      color: #222 ; 
      text-align: right; 
    }

    .lang-dropdown.open {
      display: block;
    }

    .lang-dropdown li {
    padding: 0;     
      cursor: pointer;
      white-space: nowrap;
    }

    .lang-dropdown li:hover {
    background-color: var(--background-color-lang-dropdown);    
    }


.lang-dropdown a,
.lang-dropdown button {
    display: block;
    width: 100%;
    padding: 10px 20px;
    text-decoration: none; 
    color: var(--color-lang-dropdown-a);  
    background: none;
    border: none;
    cursor: pointer;
    font: inherit;
    text-align: right; 
    transition: background-color 0.2s ease;
}

.lang-dropdown a:hover,
.lang-dropdown button:hover {
    background-color: var(--background-color-lang-dropdown); 
}


.tech {
    text-align: center;
    padding: 2rem 1rem;
}

.tech-text {
    font-size: 1.2rem;
    margin-bottom: 1rem;
    color: var(--secondary-text-color);  
}

.tech-logos {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: 1rem;
}

.tech-logos img {
    height: 50px; 
    width: auto;  
    opacity: 0.4; 
    transition: opacity 0.3s ease;
    cursor: pointer;
}

.tech-logos img:hover {
    opacity: 1;
}

.base-vertical {
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
    padding: 2rem 1rem;
    max-width: 800px;           
    margin: 0 auto;           
}

.base-item {
    display: flex;
    align-items: center;
    gap: 1rem;
}

.base-icon {
    height: 48px;
    width: auto;
    fill: currentColor;
    transition: color 0.3s ease;
}
.base-desc {
    font-size: 1rem;
    line-height: 1.4;
}

.slogan {
    display: flex;
    justify-content: center;  
    align-items: center;     
    height: 60vh;             
    text-align: center;
    background-color: var(--background-color-slogan);  
}

.slogan h1 {
    font-size: 2rem;
    color: var(--text-color-h1-slogan);
    margin: 0;      
    font-weight: 600; 
}


/* - carousel -  */
.carousel {
  width: 300px;
  height: 200px;
  margin: 2rem auto;
  overflow: hidden;
  position: relative;
  background-color: var(--background-color-carousel); 
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 20px;  
  transition: background-color 0.3s;
  box-sizing: border-box;
}

.carousel img {
  display: none;
  width: 100%;
  height: 100%;
  object-fit: cover; 
  border-radius: 20px; 
  box-sizing: border-box;
  padding: 2px; 
  background-clip: padding-box;
  background-color: transparent;
  border: 2px solid #ccc; 
  cursor: default;
}

.carousel img.active {
  display: block;
}
/*  - carousel -  */

/*  - messenger - start */
.messenger-button {
  position: fixed;
  right: 20px;
  bottom: 20px;
  display: flex;
  align-items: center;
  justify-content: center;
  background-color: #007bff; 
  color: white;
  border: none;
  border-radius: 50%;
  width: 56px;
  height: 56px;
  font-size: 24px;
  cursor: pointer;
  z-index: 1000;
  animation: pulse 2s infinite;
  transition: 0.3s;
}

    /* pulse */
    @keyframes pulse {
      0% {
        box-shadow: 0 0 0 0 rgba(0, 122, 255, 0.5);
      }
      70% {
        box-shadow: 0 0 0 12px rgba(0, 122, 255, 0);
      }
      100% {
        box-shadow: 0 0 0 0 rgba(0, 122, 255, 0);
      }
    }

.messenger-menu {
  position: fixed;
  right: 20px;
  bottom: 90px;
  display: flex;
  gap: 10px;
  z-index: 999;
  flex-direction: column;
  transition: all 0.3s ease;
}

.messenger-link {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 48px;
  height: 48px;
  border-radius: 50%;
  color: #000;
  text-decoration: none;
  font-size: 20px;
  transition: 0.3s;
}

.messenger-link:hover {
  transform: scale(1.1);
}  
  
.telegram { background-color: #0088cc; }
.whatsapp { background-color: #25D366; }
.viber    { background-color: #7360F2; }  
  
.messenger-menu.hidden {
  display: none;
}


  
 /*  - messenger - end */

.site-block {
  padding: 2rem;
}


.info-block {
  background-color: var(--info-block-background-color);
  border: 1px solid var(--info-block-border);
  padding: 1.5rem;
  border-radius: 10px;
  margin-bottom: 2rem;
}


/*  Dark mode */
@media (prefers-color-scheme: dark) {
    :root {
    --background-color: #121212;
    --text-color: #fff;
    --background-color-carousel: #121212;  
    --background-color-footer:   #000000;     
    --text-color-footer: #888888;                 
    --text-color-h1-slogan: #f5f5f5;  
    --background-color-slogan:   #000000;
    --background-color-footer: #000000;
    --background-color-nav: #121212;     
    --background-color-lang-dropdown: #333;
    --background-lang-dropdown: #1e1e1e;   
    --color-lang-dropdown-a: #ffffff;   
    --border-lang-dropdown: 1px solid #444;
    --info-block-background-color: #1c1c1c;
    --info-block-border: #444444;  
    }            
  .carousel {
    background-color: #000;
  }
  .carousel img {
    border-color: #666;
  }  
}
/*  Dark mode */

/*  for mobile */

        /* - base-icon resize -  */
    @media (max-width: 768px) {
       .base-icon {
        height: 24px;
      }
    }
        /* - base-icon resize -  */

    @media (max-width: 350px) {
      .messenger-menu .messenger-link:not(:first-child) {
        display: none;
      }
    }

    @media (max-height: 300px) {
      .messenger-menu {
        flex-direction: row;
        right: 90px;
        bottom: 20px;
      }
    }

    @media (max-width: 280px), (max-height: 200px) {
      .messenger-button,
      .messenger-menu {
        display: none !important;
      }
    }

/*  for mobile */