/* Navbar */
.navbar {
  position: fixed;
  top: 0;
  width: 100%;
  background: rgba(255, 255, 255, 0.98);
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 12px 40px;
  box-shadow: 0 2px 8px rgba(0,0,0,0.1);
  z-index: 1000;
}

/* Left Logo Text */
.nav-left {
  font-size: 1.2rem;
  font-weight: bold;
  color: #007bff;
  letter-spacing: 0.5px;
}

/* Center Menu */
.nav-center {
  display: flex;
  gap: 32px;
  justify-content: center;
  flex-grow: 1;
}

.nav-center a {
  position: relative;
  text-decoration: none;
  color: #333;
  font-weight: 600;
  transition: color 0.2s ease;
}

/* Underline hover effect */
.nav-center a::after {
  content: "";
  position: absolute;
  width: 0;
  height: 2px;
  left: 0;
  bottom: -4px;
  background-color: #007bff;
  transition: width 0.3s ease;
}

.nav-center a:hover::after {
  width: 100%;
}

.nav-center a:hover {
  color: #007bff;
}

/* Right Buttons */
.nav-right {
  display: flex;
  gap: 10px;
}

.btn {
  text-decoration: none;
  padding: 8px 16px;
  border-radius: 4px;
  font-weight: bold;
  transition: background-color 0.2s ease;
}

.register-btn {
  background-color: #007bff;
  color: white;
}

.register-btn:hover {
  background-color: #0056b3;
}

.login-btn {
  background-color: #28a745;
  color: white;
}

.login-btn:hover {
  background-color: #1e7e34;
}

/* Ad Box */
.ad-box {
  width: 30cm;      /* slightly narrower to fit screen */
  height: 5cm;    /* proportionally reduced */
  background: linear-gradient(90deg, #e6f0ff, #fafdff);
  border: 2px dashed #99bbff;
  margin: 0 auto 0 auto;
  border-radius: 8px;
  display:flex;
  justify-content:center;
  align-items:center;
  color:#0043a9;
  font-size: 1rem;
  font-weight:600;
  letter-spacing: 1px;
  box-shadow: 0 3px 10px rgba(0,0,0,0.08);
}