/* ═══════════════════════════════════════════════════════════
   pdf.css — Thumbnail image based design
═══════════════════════════════════════════════════════════ */
:root{
  --bg:#050A14;--bg2:#081428;--card:#0B1A33;
  --blue:#1A6EE8;--blue2:#3B8FF5;--cyan:#00D4FF;
  --text:#E6EEF8;--muted:#8AA0BC;--border:rgba(96,207,255,.15);
}
*{margin:0;padding:0;box-sizing:border-box}
html,body{background:var(--bg);color:var(--text);font-family:'Li Ador Noirit','Hind Siliguri','Poppins',sans-serif;min-height:100vh;-webkit-user-select:none;user-select:none;}

/* ─── NAV ─── */
.quiz-nav{display:flex;justify-content:space-between;align-items:center;padding:18px 5%;border-bottom:1px solid var(--border);background:rgba(5,10,20,.8);backdrop-filter:blur(10px);position:sticky;top:0;z-index:100;}
.logo-img{height:42px}
.back-home{color:var(--text);text-decoration:none;font-size:14px;padding:10px 18px;border:1px solid var(--border);border-radius:10px;transition:.3s;display:inline-flex;align-items:center;gap:8px;font-family:'Poppins','DM Sans',sans-serif;}
.back-home:hover{background:var(--blue);border-color:var(--blue)}

/* ─── HEADER ─── */
.pdf-header{padding:50px 5% 30px;text-align:center}
.eyebrow{display:inline-block;font-family:'Poppins','DM Sans',sans-serif;font-size:11px;letter-spacing:3px;text-transform:uppercase;color:var(--cyan);padding:6px 16px;border:1px solid var(--border);border-radius:50px;margin-bottom:20px;}
h1{font-family:'Playfair Display',serif;font-size:clamp(32px,5vw,52px);font-weight:900;margin-bottom:14px;line-height:1.15;}
h1 em{color:var(--cyan);font-style:italic;font-weight:400}
.subtitle{color:var(--muted);font-size:16px}

/* ─── GRID ─── */
.pdf-section{padding:30px 5% 80px}
.pdf-grid{max-width:1200px;margin:0 auto;display:grid;grid-template-columns:repeat(auto-fill,minmax(300px,1fr));gap:22px;}

/* ─── LOADER ─── */
.pdf-loader{width:40px;height:40px;border:3px solid var(--border);border-top-color:var(--cyan);border-radius:50%;animation:spin .8s linear infinite;margin:0 auto;}
@keyframes spin{to{transform:rotate(360deg)}}

/* ═══ PDF CARD — Thumbnail Image ═══ */
.pdf-card{
  background:var(--card);
  border:1px solid var(--border);
  border-radius:18px;
  overflow:hidden;
  cursor:pointer;
  transition:.4s cubic-bezier(.23,1,.32,1);
  position:relative;
  display:flex;flex-direction:column;
  text-decoration:none;
  color:inherit;
}

/* Top accent line */
.pdf-card::before{
  content:'';position:absolute;top:0;left:0;right:0;height:3px;
  background:linear-gradient(90deg,var(--blue),var(--cyan));
  transform:scaleX(0);transform-origin:left;
  transition:.4s;z-index:2;
}
.pdf-card:hover{
  transform:translateY(-6px);
  border-color:var(--cyan);
  box-shadow:0 20px 50px rgba(0,212,255,.15);
}
.pdf-card:hover::before{transform:scaleX(1)}

/* Cover — Thumbnail Image */
.pdf-cover-img{
  position:relative;
  width:100%;
  aspect-ratio:16/10;
  background:linear-gradient(135deg,var(--bg2),var(--card));
  overflow:hidden;
}
.pdf-cover-img img{
  width:100%;
  height:100%;
  object-fit:cover;
  transition:.6s cubic-bezier(.23,1,.32,1);
  display:block;
}
.pdf-card:hover .pdf-cover-img img{
  transform:scale(1.08);
}

/* Optional emoji badge (top-right corner) */
.pdf-emoji-badge{
  position:absolute;
  top:12px;
  right:12px;
  font-size:32px;
  filter:drop-shadow(0 4px 12px rgba(0,0,0,.6));
  z-index:1;
  transition:.4s;
}
.pdf-card:hover .pdf-emoji-badge{
  transform:scale(1.15) rotate(-8deg);
}

/* Body */
.pdf-body{padding:20px 22px 22px;display:flex;flex-direction:column;flex:1}
.pdf-title{
  font-family:'Poppins','DM Sans',sans-serif;
  font-size:18px;
  font-weight:700;
  color:var(--text);
  line-height:1.3;
  margin-bottom:8px;
  white-space:nowrap;
  overflow:hidden;
  text-overflow:ellipsis;
}
.pdf-desc{
  font-size:13.5px;
  color:var(--muted);
  line-height:1.6;
  margin-bottom:16px;
  display:-webkit-box;
  -webkit-line-clamp:2;
  -webkit-box-orient:vertical;
  overflow:hidden;
}

/* Footer */
.pdf-footer{
  display:flex;
  align-items:center;
  justify-content:space-between;
  padding-top:14px;
  border-top:1px solid var(--border);
  margin-top:auto;
  gap:8px;
  flex-wrap:wrap;
}
.pdf-meta{
  font-family:'Poppins','DM Sans',sans-serif;
  font-size:11px;
  color:var(--muted);
  letter-spacing:.5px;
  display:flex;
  align-items:center;
  gap:5px;
}
.pdf-read-btn{
  display:inline-flex;
  align-items:center;
  gap:7px;
  color:var(--cyan);
  font-size:13px;
  font-weight:600;
  font-family:'Poppins','DM Sans',sans-serif;
  margin-left:auto;
}
.pdf-read-btn i{transition:.3s}
.pdf-card:hover .pdf-read-btn i{transform:translateX(4px)}

/* ─── RESPONSIVE ─── */
@media(max-width:600px){
  .pdf-grid{grid-template-columns:1fr;gap:16px}
  .pdf-header{padding:30px 5% 20px}
  .pdf-cover-img{aspect-ratio:16/9}
}