* {
  box-sizing: border-box;
}

body {
  margin: 0;
  font-family: Arial, sans-serif;
  background: linear-gradient(135deg, #dfe9f3, #ffffff);
  min-height: 100vh;
}

/* container */
.container {
  width: 90%;
  max-width: 900px;
  margin: 40px auto;
}

/* header */
.header {
  background: #1f2937;
  color: white;
  border: 4px solid black;
  min-height: 150px;
  display: flex;
  justify-content: center;
  align-items: center;
}

.header h1 {
  margin: 0;
  font-size: 42px;
}

/* layout */
.main-layout {
  display: block;
}

/* content */
.content {
  background: white;
  border: 4px solid black;
  padding: 40px;
  margin-top: 20px;
}

.intro {
  text-align: center;
  font-size: 22px;
  margin-bottom: 30px;
}

/* succesmelding */
.success-message {
  display: none;
  background: #d1fae5;
  border: 2px solid #10b981;
  padding: 15px;
  margin-bottom: 20px;
  text-align: center;
  font-weight: bold;
}

/* card */
.card {
  background: #f3f4f6;
  border: 3px solid black;
  padding: 25px;
  text-align: center;
}

/* form */
.contact-form {
  display: flex;
  flex-direction: column;
  gap: 10px;
  max-width: 500px;
  margin: 20px auto;
}

.contact-form input,
.contact-form textarea {
  padding: 10px;
  font-size: 16px;
  border: 2px solid black;
}

.contact-form button {
  padding: 12px;
  background: #1f2937;
  color: white;
  border: none;
  cursor: pointer;
}

.contact-form button:hover {
  background: #333;
}

/* footer */
.footer {
  background: #1f2937;
  color: white;
  border: 4px solid black;
  min-height: 100px;
  margin-top: 20px;
  display: flex;
  justify-content: center;
  align-items: center;
}