:root {
  --bg: #3c2f2f;
  --bg-accent:#2f2626;
  --shelf: #5a3e2b;
  --shelf-edge:#402b1f;
  --text:#f6efe7;
  --muted:#cbb8a6;
  --card:#1e1a1a;
  --shadow: rgba(0,0,0,.35);
  --focus: #ffd280;
}

* { box-sizing: border-box; }
html,body { height:100%; }
body {
  margin:0;
  font-family: system-ui, sans-serif;
  color:var(--text);
  background: linear-gradient(180deg, var(--bg) 0%, var(--bg) 60%, var(--bg-accent) 100%);
}

/* Header */
.site-header {
  position:sticky; top:0; z-index:10;
  background:linear-gradient(180deg, rgba(0,0,0,.35) 0%, rgba(0,0,0,0) 100%), var(--bg);
  padding: 16px 20px 10px;
  box-shadow: 0 2px 8px var(--shadow);
}
.site-header h1 {
  margin:0 0 8px;
  font-weight:700;
}

/* Tabs */
.tabs {
  display:flex; gap:8px; flex-wrap:wrap;
}
.tabs button {
  border:1px solid #6b4e3b; background:#6b4e3b; color:#fff;
  padding:8px 12px; border-radius:999px; cursor:pointer; font-weight:600;
}
.tabs button[aria-selected="true"] {
  background:#8b5a3c;
  box-shadow: 0 6px 16px var(--shadow);
}

/* Shelves */
.shelves {
  max-width: 1100px; margin: 18px auto 60px; padding: 0 14px;
  display:grid; gap: 28px;
}
.shelf-row {
  position:relative;
  display:grid;
  grid-template-columns: repeat(auto-fill, minmax(140px, 1fr));
  gap: 18px 16px;
  padding: 22px 10px 46px;
}
.shelf-row::after {
  content:""; position:absolute; left:0; right:0; bottom:0; height: 22px;
  background: linear-gradient(180deg, var(--shelf) 0%, var(--shelf-edge) 100%);
  box-shadow: 0 10px 18px var(--shadow);
}

/* Book card */
.book {
  background: var(--card);
  border-radius: 10px;
  padding: 10px;
  box-shadow: 0 8px 16px var(--shadow);
  cursor:pointer;
}
.book-cover {
  border-radius: 6px;
  aspect-ratio: 2 / 3;
  display:flex; align-items:flex-end; padding:10px;
  background: linear-gradient(135deg, #c4af9a, #9c7b5c);
}
.book-cover[data-img] { background-size:cover; background-position:center; }
.book-title { font-weight:700; font-size: 14px; }
.book-author { margin:8px 2px 0; color: var(--muted); font-size: 12px }

/* Modal */
.modal[aria-hidden="true"] { display:none; }
.modal { position:fixed; inset:0; z-index:1000; }
.modal-backdrop { position:absolute; inset:0; background: rgba(0,0,0,.6); }
.modal-dialog {
  position:relative; max-width: 1080px; margin: 4vh auto; background: #211b1b;
  border-radius: 14px; overflow:hidden; box-shadow: 0 16px 40px var(--shadow);
  display:flex; flex-direction:column; min-height: 70vh;
}
.modal-close {
  position:absolute; top:10px; right:10px; border:none; background:#3a2e2e; color:#fff;
  border-radius: 999px; width:34px; height:34px; cursor:pointer;
}

/* Toolbar */
.modal-toolbar {
  display:flex; align-items:center; gap:10px; padding: 10px 12px; background:#2a2222;
}
.modal-tab {
  border:1px solid #5a4336; background:#4c3a2e; color:#fff;
  padding:6px 10px; border-radius:8px; cursor:pointer;
}
.modal-tab[aria-selected="true"] { background:#7b5640; }

/* Panels */
.modal-panels { flex:1; display:flex; flex-direction:column; }
.panel-details { flex:1; display:grid; grid-template-columns: 1fr 1.2fr; }
.modal-cover { min-height: 320px; background-size:cover; }
.modal-body { padding: 22px; }
.panel-reader { flex:1; display:flex; }
.pdf-frame { flex:1; border:none; }

/* Panel visibility - THIS IS THE FIX */
.panel[hidden] { 
  display: none !important; 
}