h1, h2, h3, h4 {
  font-size: 24px;
  -webkit-text-stroke: 1px black;
}

#introduction {
  background-color: #F3FDE8;
  padding: 15px;
}

#contact {
  background-image: url('bg3.jpg');
  background-repeat: repeat;
  text-align: center;
  padding: 20px;
}

table, th, td {
  border: 1px solid black;
  border-collapse: collapse;
  padding: 5px;
}

nav, footer {
  background-color: #d4f2f4;
  color: #0b0848;
  padding: 10px;
  text-align: center;
}

nav a {
  margin: 0 15px;
  text-decoration: none;
  color: #0b0848;
  font-weight: bold;
}

input[type="submit"] {
  background-color: #D8B4F8;
  color: white;
  padding: 10px 20px;
  border: none;
  border-radius: 10px;
  cursor: pointer;
  font-size: 16px;
  font-weight: bold;
  transition: all 0.3s ease;
}

input[type="submit"]:hover {
  background-color: #CAEDFF;
  color: #333;
  transform: scale(1.05);
  box-shadow: 0 0 10px #CAEDFF;
}

input[type="submit"]:active {
  background-color: #B197FC;
  transform: scale(0.95);
}
.error-box {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 10px 14px;
  background-color: #ffe5e5;
  border-left: 5px solid #ff0000;
  border-radius: 8px;
  box-shadow: 0 2px 8px rgba(0,0,0,0.1);
  color: red;
  font-weight: 500;
  min-width: 280px;
}
.error b {
  color: #e60000;
  font-weight: 700;
}