/* Reset */
* {
  box-sizing: border-box;
}

html, body {
  margin: 0;
  padding: 0;
  font-family: Arial, Helvetica, sans-serif;
  background-color: #f0f0f0;
}

/* 1. Header */
.site-header {
  width: 100%;
  margin-top: 10%;
  display: flex;
  justify-content: center;
}

.header-img {
  width: 10%;
  max-width: 1200px;
  height: auto;
  display: block;
  border-radius: 10px;
}

/* 2. Navigation */
.tab-container {
  width: 75%;
  margin: 20px auto;
  display: flex;
}

.tablink {
  flex: 1;
  text-align: center;
  padding: 14px 16px;
  font-size: 17px;
  text-decoration: none;
  color: black;
  background-color: #007BFF;
  transition: opacity 0.3s ease;
}

.tablink:hover {
  opacity: 0.85;
}

.tablink.active {
  opacity: 0.65;
}

/* 3. Body */
.page-body {
  width: 75%;
  margin: 40px auto;
  padding: 40px;
  text-align: center;
  background-color: red;
  color: black;
  border-radius: 10px;
}