:root {
  --header-height: 60px;
}
body { 
   padding-top: 60px /*var(--header-height)*/; 
   font-family: 'Segoe UI', Arial, sans-serif; 
   margin: 0; 
   background: #f3f3f3; 
   background-size: cover;
   background-position: center;
}
header { 
   background: linear-gradient(0deg,#00bbff, #ffffff);
   color: #fff;
   display: flex;
   align-items: center;
   justify-content: space-between; 
   position: fixed;
   top: 0;
   left: 0;
   width: 100%;
   height: var(--header-height);
   z-index: 1000;  
   opacity: 0.65;
   min-width: 0;
}
header h1 { 
   margin: 0;
   font-size: 1.5rem; 
}
header nav {
   flex-shrink: 1;
   min-width: 0;
   overflow-x: auto;
   white-space: nowrap;
}
nav a { 
   color: #000000; 
   margin-left: 2rem;
   text-decoration: none;
   font-weight: 500; 
}
.bartxt { 
   color: #000000; 
   text-decoration: none;
   font-weight: 500; 
}