*{
  margin:0;
  padding:0;
  box-sizing:border-box;
  font-family:Arial, Helvetica, sans-serif;
}

body{
  background:#f5f5f5;
}

/* HEADER */
.header{
  display:flex;
  justify-content:space-between;
  align-items:center;
  padding:15px 30px;
  background:#111;
  color:#fff;
}

.logo{
  font-size:22px;
  font-weight:bold;
}

.logo span{ color:#ffb703; }

.header nav a{
  color:#fff;
  text-decoration:none;
  margin-left:20px;
}

.header nav a:hover{ color:#ffb703; }

/* HERO */
.hero{
  text-align:center;
  padding:80px 20px;
  background:#ffb703;
}

.hero h1{ font-size:36px; }
.hero p{ margin-top:10px; font-size:18px; }

/* SLIDER */
.ebook-slider{
  position:relative;
  width:100%;
  overflow:hidden;
  background:#000;
}

.slides{
  position:relative;
  height:350px;
}

.slide{
  position:absolute;
  width:100%;
  height:100%;
  object-fit:cover;
  opacity:0;
  transition:.5s;
}

.slide.active{ opacity:1; }

.slide-btn{
  position:absolute;
  top:50%;
  transform:translateY(-50%);
  font-size:30px;
  background:rgba(0,0,0,.6);
  color:#fff;
  border:none;
  padding:10px 15px;
  cursor:pointer;
}

.prev{ left:10px; }
.next{ right:10px; }

/* CATEGORIES */
.categories{
  display:flex;
  gap:20px;
  justify-content:center;
  flex-wrap:wrap;
  margin:40px auto;
}

.card{
  background:#fff;
  width:250px;
  padding:25px;
  text-align:center;
  border-radius:8px;
  box-shadow:0 4px 15px rgba(0,0,0,.1);
}

.card i{
  font-size:40px;
  color:#ffb703;
}

.card h3{ margin:15px 0; }

.card a{
  background:#111;
  color:#fff;
  padding:8px 20px;
  text-decoration:none;
  border-radius:4px;
}

/* FOOTER */
footer{
  background:#111;
  color:#fff;
  padding:40px 20px;
}

.footer-container{
  display:flex;
  justify-content:space-between;
  flex-wrap:wrap;
}

.footer-box h4{ color:#ffb703; }

.footer-box p,
.footer-box a{
  color:#ccc;
  font-size:14px;
}

.copy{
  text-align:center;
  margin-top:20px;
  font-size:13px;
  color:#aaa;
}

/* MOBILE */
@media(max-width:768px){
  .header{ flex-direction:column; }
  .slides{ height:220px; }
  .footer-container{ flex-direction:column; }
}