:root{
  --bg: #0a0f1f;
  --card: rgba(255,255,255,0.06);
  --border: rgba(0,247,255,0.25);
  --accent: #0df2ff;
  --accent2: #8bc6ff;
  --text: #e9f2ff;
  --text-dim: #9bb3c980;
}

body {
  font-family: "Poppins", sans-serif;
  background: var(--bg);
  margin:0;
  padding:0;
  overflow-x:hidden;
  color: var(--text);
}

/* ---------------- HEADER ---------------- */
.header {
  display:flex;
  align-items:center;
  justify-content:center;
  gap:12px;
  padding:18px;
  background:rgba(255,255,255,0.04);
  backdrop-filter:blur(12px);
  border-bottom:1px solid var(--border);
  position:sticky;
  top:0;
  z-index:1000;
  box-shadow:0 0 20px rgba(0,255,255,0.15);
}

.header img {
  height:52px;
  border-radius:10px;
}

.header h1 {
  font-weight:700;
  font-size:1.8rem;
  color:var(--accent);
  text-shadow:0 0 15px rgba(0,255,255,0.5);
}

/* ---------------- 3D BOOK CARD ---------------- */
.cover-card {
  width:90%;
  max-width:650px;
  margin:40px auto;
  background:var(--card);
  border:1px solid var(--border);
  border-radius:22px;
  overflow:hidden;
  box-shadow:0 0 25px rgba(0,255,255,0.2);
  transition:0.4s;
  transform-style:preserve-3d;
  perspective:1200px;
}

.cover-card:hover {
  transform:rotateY(6deg) rotateX(3deg) scale(1.02);
  box-shadow:0 0 35px rgba(0,255,255,0.4);
}

.cover-card img {
  width:100%;
  display:block;
}

/* ---------------- SPECS BOX ---------------- */
.specs {
  max-width:900px;
  margin:40px auto;
  background:var(--card);
  padding:35px;
  border-radius:25px;
  border:1px solid var(--border);
  box-shadow:0 0 25px rgba(0,255,255,0.15);
}

.specs h2{
  color:var(--accent);
  font-weight:700;
  margin-bottom:14px;
}

.specs h3{
  margin-top:25px;
  margin-bottom:10px;
  color:var(--accent2);
}

.specs p, .specs li{
  color:var(--text);
}

/* ---------------- DOWNLOAD BUTTON ---------------- */
.download-btn {
  display:inline-block;
  background:var(--accent);
  color:#001219;
  padding:12px 22px;
  border-radius:10px;
  font-weight:700;
  text-decoration:none;
  margin-top:20px;
  transition:0.25s;
}

.download-btn:hover {
  transform:scale(1.04);
  box-shadow:0 0 20px rgba(0,255,255,0.6);
}

/* ---------------- FLOATING BUY BUTTON ---------------- */
.floating-btn {
  position:fixed;
  bottom:30px;
  right:25px;
  background:var(--accent);
  border:none;
  border-radius:50px;
  padding:15px 28px;
  font-weight:700;
  font-size:1.1rem;
  color:#001219;
  box-shadow:0 0 20px rgba(0,255,255,0.5);
  animation:pulse 2s infinite;
  transition:0.3s;
  z-index:1000;
}

.floating-btn:hover {
  transform:scale(1.12);
  box-shadow:0 0 30px rgba(0,255,255,0.7);
}

@keyframes pulse {
  0% { transform:scale(1);}
  50% { transform:scale(1.05);}
  100% { transform:scale(1);}
}

/* ---------------- POPUP FORM ---------------- */
.popup-form {
  position:fixed;
  right:25px;
  bottom:95px;
  width:330px;
  background:rgba(10,15,31,0.95);
  backdrop-filter:blur(12px);
  display:none;
  padding:25px;
  border-radius:22px;
  border:1px solid var(--accent);
  box-shadow:0 0 30px rgba(0,255,255,0.4);
  animation:fadeInUp 0.4s ease;
  color:var(--text);
}

.popup-close {
  position:absolute;
  right:15px;
  top:10px;
  font-size:1.4rem;
  color:var(--accent);
  cursor:pointer;
  font-weight:bold;
}

.popup-form input, .popup-form textarea {
  background:rgba(255,255,255,0.05);
  border:1px solid var(--border);
  color:var(--text);
}

.popup-form input::placeholder,
.popup-form textarea::placeholder{
  color:var(--text-dim);
}

/* ---------------- BUTTON ---------------- */
.btn-gold {
  background:var(--accent);
  color:#001219;
  border:none;
  font-weight:700;
  box-shadow:0 0 15px rgba(0,255,255,0.4);
}
.btn-gold:hover{
  transform:scale(1.03);
}

/* ---------------- FOOTER ---------------- */
.footer {
  text-align:center;
  padding:30px;
  background:rgba(255,255,255,0.04);
  border-top:1px solid var(--border);
  box-shadow:0 0 20px rgba(0,255,255,0.15);
  margin-top:60px;
  color:var(--accent2);
}

.footer a {
  color:var(--accent);
  text-decoration:none;
  font-weight:600;
}
.footer a:hover{
  text-decoration:underline;
}