body {
      background-image: url('/assets/background.jpg');
      background-size: cover;
      background-repeat: no-repeat;
      background-attachment: fixed;
      background-position: center;
      display: flex;
      justify-content: center;
      align-items: center;
      min-height: 100vh;
      padding: 1rem;
    }
    body::before {
      content: "";
      position: fixed;
      top: 0; left: 0;
      width: 100%; height: 100%;
      background-color: rgba(0, 0, 0, 0.5);
      z-index: -1;
    }
    .login-card {
      max-width: 420px;
      width: 100%;
      padding: 2rem;
      background: #fff;
      border-radius: 12px;
      box-shadow: 0 10px 25px rgba(0,0,0,0.12);
    }
    .login-card img {
      width: 120px; height: auto;
      display: block;
      margin: 0 auto 1rem;
    }
    .login-card h4 {
      text-align: center;
      margin-bottom: 1.5rem;
      font-weight: 600;
      color: #333;
    }
    .pw-toggle-btn {
      position: absolute;
      right: 10px;
      top: 50%;
      transform: translateY(-50%);
      border: none;
      background: transparent;
      font-size: 1.1rem;
      line-height: 1;
      cursor: pointer;
    }
    .pw-wrap { 
        position: relative;
        }


    
    /* Background slideshow */
    .bg-slideshow {
      position: fixed;
      inset: 0;
      z-index: -1;
      overflow: hidden;
      pointer-events: none;
    }
    
    .bg-slideshow .slide {
      position: absolute;
      inset: 0;
      background-position: center;
      background-size: cover;
      background-repeat: no-repeat;
      opacity: 0;
      will-change: opacity;
      animation: bg-fade 28s linear infinite;
    }
    
    /* staggered delays for 4 slides (each shows ~4s) */
    .bg-slideshow .slide.s1 { animation-delay: 0s; }
    .bg-slideshow .slide.s2 { animation-delay: 7s; }
    .bg-slideshow .slide.s3 { animation-delay: 14s; }
    .bg-slideshow .slide.s4 { animation-delay: 21s; }
    
    /* gentle dark overlay so form stays readable */
    .bg-slideshow::after {
      content: "";
      position: absolute;
      inset: 0;
      background: rgba(0,0,0,0.45);
      pointer-events: none;
    }
    
    /* keyframes: fade in, hold, fade out */
    @keyframes bg-fade {
      0%    { opacity: 0; }
      6%    { opacity: 1; }
      24%   { opacity: 1; }
      30%   { opacity: 0; }
      100%  { opacity: 0; }
    }
    
    /* make sure login card stays above background */
    .login-card {
      position: relative;
      z-index: 2;
    }
    
    /* optional: smooth background loading */
    .bg-slideshow .slide {
      transition: opacity 600ms ease-in-out;
      background-attachment: fixed;
    }