:root{
    --bg:#eef3f8; --card:#ffffff; --ink:#14243a; --muted:#5b6b7f;
    --blue:#0b5fa5; --blue-d:#084a82; --teal:#0f8a7a; --gold:#e8a020;
    --green:#1e8e4e; --red:#c93a3a; --line:#dde5ee;
    --shadow:0 2px 10px rgba(20,36,58,.08);
  }
  *{box-sizing:border-box; margin:0; padding:0;}
  html,body{height:100%;}
  body{
    font-family:"Segoe UI",system-ui,-apple-system,Roboto,Arial,sans-serif;
    background:var(--bg); color:var(--ink); line-height:1.5;
    -webkit-font-smoothing:antialiased;
  }
  .wrap{max-width:920px; margin:0 auto; padding:18px 16px 60px;}

  /* Header */
  header{
    display:flex; align-items:center; gap:12px; padding:14px 0 6px;
  }
  header .logo{
    width:44px; height:44px; border-radius:12px; flex:0 0 auto;
    background:linear-gradient(135deg,var(--blue),var(--teal));
    display:flex; align-items:center; justify-content:center;
    font-size:24px; color:#fff; box-shadow:var(--shadow);
  }
  header h1{font-size:1.25rem; font-weight:700; letter-spacing:.2px;}
  header p{font-size:.82rem; color:var(--muted);}

  /* Buttons */
  .btn{
    display:inline-flex; align-items:center; justify-content:center; gap:8px;
    border:none; cursor:pointer; font-weight:600; font-size:.95rem;
    padding:11px 18px; border-radius:11px; transition:.15s ease;
    background:var(--blue); color:#fff; box-shadow:var(--shadow);
  }
  .btn:hover{background:var(--blue-d); transform:translateY(-1px);}
  .btn.ghost{background:#fff; color:var(--ink); border:1px solid var(--line);}
  .btn.ghost:hover{background:#f4f7fb;}
  .btn:disabled{opacity:.5; cursor:not-allowed; transform:none;}

  /* Cards grid */
  .grid{display:grid; grid-template-columns:repeat(auto-fill,minmax(260px,1fr)); gap:14px; margin-top:18px;}
  .card{
    background:var(--card); border-radius:14px; padding:18px; cursor:pointer;
    box-shadow:var(--shadow); border:1px solid var(--line); transition:.15s ease;
    position:relative; overflow:hidden;
  }
  .card:hover{transform:translateY(-3px); box-shadow:0 8px 22px rgba(20,36,58,.14);}
  .card .ico{font-size:30px;}
  .card h3{margin:10px 0 4px; font-size:1.05rem;}
  .card p{font-size:.82rem; color:var(--muted);}
  .card .bar{height:5px; border-radius:5px; background:var(--line); margin-top:12px; overflow:hidden;}
  .card .bar i{display:block; height:100%; background:var(--teal); border-radius:5px; width:0; transition:.4s;}
  .card .tag{
    position:absolute; top:14px; right:14px; font-size:.68rem; font-weight:700;
    padding:3px 9px; border-radius:20px; color:#fff; letter-spacing:.3px;
  }
  .card .actions{display:flex; gap:8px; margin-top:14px;}
  .card .actions .btn{flex:1; padding:9px 8px; font-size:.85rem;}
  .card .actions .btn.ghost{background:#f4f7fb;}
  .card{cursor:default;}
  .card:hover{transform:none; box-shadow:var(--shadow);}

  /* Section titles */
  .sec-title{margin-top:26px; font-size:1.05rem; font-weight:700; color:var(--ink);}
  .hint{font-size:.8rem; color:var(--muted); margin-top:4px;}

  /* Quiz */
  .quiz-top{display:flex; align-items:center; gap:12px; margin:8px 0 14px;}
  .back{background:#fff; border:1px solid var(--line); border-radius:10px; padding:8px 12px; cursor:pointer; font-size:.9rem; font-weight:600; color:var(--ink);}
  .back:hover{background:#f4f7fb;}
  .progress{flex:1; height:8px; background:var(--line); border-radius:8px; overflow:hidden;}
  .progress i{display:block; height:100%; background:linear-gradient(90deg,var(--blue),var(--teal)); border-radius:8px; transition:.3s;}
  .score{font-size:.85rem; font-weight:700; color:var(--muted); white-space:nowrap;}

  .q-box{background:var(--card); border-radius:16px; padding:22px; box-shadow:var(--shadow); border:1px solid var(--line);}
  .q-num{font-size:.78rem; font-weight:700; color:var(--blue); text-transform:uppercase; letter-spacing:.5px;}
  .q-text{font-size:1.18rem; font-weight:600; margin:8px 0 18px; line-height:1.45;}

  .opts{display:flex; flex-direction:column; gap:10px;}
  .opt{
    display:flex; align-items:flex-start; gap:12px; text-align:left;
    background:#f7fafd; border:1.5px solid var(--line); border-radius:12px;
    padding:13px 15px; cursor:pointer; font-size:.98rem; transition:.12s ease; width:100%;
  }
  .opt:hover{border-color:var(--blue); background:#f0f6fc;}
  .opt .letter{
    flex:0 0 auto; width:26px; height:26px; border-radius:8px; font-weight:700; font-size:.82rem;
    display:flex; align-items:center; justify-content:center; background:#e3ecf5; color:var(--blue);
  }
  .opt.correct{border-color:var(--green); background:#eaf7ef;}
  .opt.correct .letter{background:var(--green); color:#fff;}
  .opt.wrong{border-color:var(--red); background:#fdecec;}
  .opt.wrong .letter{background:var(--red); color:#fff;}
  .opt.disabled{pointer-events:none;}

  .explain{
    margin-top:16px; border-radius:12px; padding:14px 16px; font-size:.92rem;
    display:none; border:1px solid var(--line);
  }
  .explain.show{display:block; animation:fade .25s;}
  .explain.ok{background:#eaf7ef; border-color:#bfe3cd;}
  .explain.no{background:#fdecec; border-color:#f2c6c6;}
  .explain b{display:block; margin-bottom:4px;}
  .explain .ref{margin-top:8px; font-size:.8rem; color:var(--muted); font-style:italic;}
  .ref a, .fl-ref a{color:var(--blue); text-decoration:underline; text-underline-offset:2px;}
  .ref a:hover, .fl-ref a:hover{color:var(--ink);}
  @keyframes fade{from{opacity:0; transform:translateY(4px);} to{opacity:1; transform:none;}}

  .next-row{display:flex; justify-content:flex-end; margin-top:16px;}

  /* Result */
  .result{background:var(--card); border-radius:16px; padding:30px; text-align:center; box-shadow:var(--shadow); border:1px solid var(--line);}
  .result .big{font-size:3rem; font-weight:800;}
  .result .ring{font-size:1rem; color:var(--muted); margin:8px 0 18px;}
  .result .stats{display:flex; gap:14px; justify-content:center; margin-bottom:22px; flex-wrap:wrap;}
  .result .stat{background:#f7fafd; border:1px solid var(--line); border-radius:12px; padding:12px 20px;}
  .result .stat b{display:block; font-size:1.3rem;}
  .result .stat span{font-size:.78rem; color:var(--muted);}

  /* Flashcards */
  .flash{
    background:var(--card); border-radius:18px; padding:34px 26px; min-height:260px;
    box-shadow:var(--shadow); border:1px solid var(--line); cursor:pointer;
    display:flex; flex-direction:column; align-items:center; justify-content:center; text-align:center;
    transition:.2s; position:relative;
  }
  .flash .fl-tag{position:absolute; top:16px; left:16px; font-size:.72rem; font-weight:700; color:var(--muted); text-transform:uppercase; letter-spacing:.5px;}
  .flash .fl-q{font-size:1.3rem; font-weight:700; line-height:1.45;}
  .flash .fl-a{font-size:1.05rem; color:var(--ink); line-height:1.55; display:none;}
  .flash .fl-hint{position:absolute; bottom:16px; font-size:.76rem; color:var(--muted);}
  .flash.flipped .fl-q{display:none;}
  .flash.flipped .fl-a{display:block; animation:fade .25s;}
  .flash .fl-ref{display:none; margin-top:12px; font-size:.78rem; color:var(--muted); font-style:italic;}
  .flash.flipped .fl-ref{display:block;}
  .flash.flipped{background:#f0f8f5; border-color:#bfe3cd;}

  /* Cheat sheet */
  table{width:100%; border-collapse:collapse; background:#fff; border-radius:12px; overflow:hidden; box-shadow:var(--shadow); margin-top:12px; font-size:.9rem;}
  th,td{padding:10px 12px; text-align:left; border-bottom:1px solid var(--line);}
  th{background:#0b5fa5; color:#fff; font-size:.82rem; letter-spacing:.3px;}
  tr:last-child td{border-bottom:none;}
  tr:nth-child(even) td{background:#f8fafc;}
  .pill{display:inline-block; padding:2px 9px; border-radius:20px; font-size:.72rem; font-weight:700;}

  .view{display:none;}
  .view.active{display:block; animation:fade .25s;}

  .footer{margin-top:40px; text-align:center; font-size:.76rem; color:var(--muted);}
  .build-tag{margin-top:6px; font-size:.72rem; color:var(--muted); opacity:.75; font-family:ui-monospace,SFMono-Regular,Menlo,Consolas,monospace;}
  @media(max-width:560px){
    .q-text{font-size:1.05rem;}
    .grid{grid-template-columns:1fr 1fr;}
    .card h3{font-size:.95rem;}
  }

  /* ===== Galerije (znakovi / oznake / svjetla) ===== */
  .tabs{display:flex; gap:8px; flex-wrap:wrap; margin:14px 0 4px;}
  .tab{
    border:1px solid var(--line); background:#fff; color:var(--ink);
    border-radius:20px; padding:7px 14px; cursor:pointer; font-size:.84rem; font-weight:600;
    transition:.12s ease;
  }
  .tab:hover{background:#f4f7fb;}
  .tab.active{background:var(--blue); color:#fff; border-color:var(--blue);}

  .gallery{display:grid; grid-template-columns:repeat(auto-fill,minmax(170px,1fr)); gap:12px; margin-top:14px;}
  .sign-card{
    background:var(--card); border:1px solid var(--line); border-radius:12px;
    padding:10px; text-align:center; cursor:pointer; transition:.14s ease;
    display:flex; flex-direction:column; box-shadow:var(--shadow);
  }
  .sign-card:hover{transform:translateY(-3px); box-shadow:0 8px 20px rgba(20,36,58,.14);}
  .sign-card .img{
    height:110px; display:flex; align-items:center; justify-content:center;
    background:#fff; border-radius:8px; padding:6px; margin-bottom:8px;
  }
  .sign-card .img img{max-width:100%; max-height:104px; object-fit:contain;}
  .sign-card .code{font-size:.72rem; font-weight:800; color:var(--blue); letter-spacing:.3px;}
  .sign-card .nm{font-size:.8rem; color:var(--ink); line-height:1.25; margin-top:2px;}

  /* Lightbox */
  .lightbox{
    position:fixed; inset:0; background:rgba(10,20,35,.82); z-index:1000;
    display:none; align-items:center; justify-content:center; padding:24px;
  }
  .lightbox.show{display:flex;}
  .lightbox .box{
    background:#fff; border-radius:16px; max-width:640px; width:100%;
    padding:22px; text-align:center; position:relative; max-height:92vh; overflow:auto;
  }
  .lightbox .box img{max-width:100%; max-height:56vh; object-fit:contain;}
  .lightbox .close{
    position:absolute; top:10px; right:14px; font-size:1.5rem; cursor:pointer;
    color:var(--muted); background:none; border:none; line-height:1;
  }
  .lightbox .lb-code{font-size:.8rem; font-weight:800; color:var(--blue); margin-top:12px;}
  .lightbox .lb-name{font-size:1.1rem; font-weight:700; margin-top:4px;}
  .lightbox .lb-desc{font-size:.88rem; color:var(--muted); margin-top:6px;}

  /* ===== Autentikacija ===== */
  .auth-overlay{
    position:fixed; inset:0; background:linear-gradient(135deg,#0b5fa5,#0f8a7a); z-index:2000;
    display:flex; align-items:center; justify-content:center; padding:20px; overflow:auto;
  }
  .auth-box{background:#fff; border-radius:18px; padding:30px 28px; width:100%; max-width:400px; box-shadow:0 20px 50px rgba(0,0,0,.3);}
  .auth-box .logo{width:52px; height:52px; border-radius:14px; background:linear-gradient(135deg,var(--blue),var(--teal)); display:flex; align-items:center; justify-content:center; font-size:26px; color:#fff; margin:0 auto 10px;}
  .auth-box h2{text-align:center; font-size:1.25rem; margin-bottom:4px;}
  .auth-box .sub{text-align:center; font-size:.84rem; color:var(--muted); margin-bottom:18px;}
  .auth-tabs{display:flex; gap:6px; background:#eef3f8; border-radius:12px; padding:4px; margin-bottom:18px;}
  .auth-tabs button{flex:1; border:none; background:none; padding:9px; border-radius:9px; font-weight:700; font-size:.9rem; cursor:pointer; color:var(--muted);}
  .auth-tabs button.active{background:#fff; color:var(--ink); box-shadow:var(--shadow);}
  .field{margin-bottom:14px;}
  .field label{display:block; font-size:.8rem; font-weight:700; color:var(--muted); margin-bottom:5px;}
  .field input{
    width:100%; padding:11px 13px; border:1.5px solid var(--line); border-radius:10px;
    font-size:.95rem; font-family:inherit; transition:.12s;
  }
  .field input:focus{outline:none; border-color:var(--blue); box-shadow:0 0 0 3px rgba(11,95,165,.12);}
  .auth-err{background:#fdecec; border:1px solid #f2c6c6; color:var(--red); border-radius:10px; padding:10px 12px; font-size:.84rem; margin-bottom:12px; display:none;}
  .auth-ok{background:#eaf7ef; border:1px solid #bfe3cd; color:var(--green); border-radius:10px; padding:10px 12px; font-size:.84rem; margin-bottom:12px; display:none;}
  .auth-box .btn{width:100%; margin-top:4px;}
  .auth-foot{text-align:center; font-size:.76rem; color:var(--muted); margin-top:16px;}

  /* Admin panel */
  .admin-panel{margin-top:20px;}
  .user-row{display:flex; align-items:center; gap:10px; background:#fff; border:1px solid var(--line); border-radius:12px; padding:12px 14px; margin-bottom:8px;}
  .user-row .u-info{flex:1; min-width:0;}
  .user-row .u-name{font-weight:700; font-size:.92rem;}
  .user-row .u-mail{font-size:.78rem; color:var(--muted);}
  .status-pill{font-size:.7rem; font-weight:800; padding:3px 10px; border-radius:20px; white-space:nowrap;}
  .status-pill.pending{background:#fff3e0; color:#b26a00;}
  .status-pill.approved{background:#eaf7ef; color:var(--green);}
  .status-pill.rejected{background:#fdecec; color:var(--red);}
  .user-row .mini{flex:0 0 auto;}
  .mini{display:inline-flex; align-items:center; justify-content:center; border:none; cursor:pointer; font-weight:700; font-size:.8rem; padding:7px 12px; border-radius:9px;}
  .mini.approve{background:var(--green); color:#fff;}
  .mini.reject{background:var(--red); color:#fff;}
  .mini:hover{opacity:.88;}

  .topbar{display:flex; align-items:center; justify-content:flex-end; gap:10px; padding:6px 0;}
  .topbar .who{font-size:.8rem; color:var(--muted);}
  .topbar .btn{padding:8px 14px; font-size:.84rem;}