body {
  margin: 0;
  min-width: 300px;
  font-family: Arial, sans-serif;
}

.header-content {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  min-width: 300px;
  padding: 2px 0;
  background-color: grey;
  height: 120px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-bottom: 2px solid #0fdbf9;
  z-index: 999;
}

.header-logo {
  display: block;
  margin: 0 auto;
  border-radius: 10px;
  position: relative;
  z-index: 1;
}

.menu-btn {
  position: absolute;
  left: 10px;
  top: 50%;
  transform: translateY(-50%);
  background: none;
  border: none;
  font-size: 2rem;
  cursor: pointer;
  color: #fff;
  transition: background 0.2s;
  padding: 8px 16px;
  border-radius: 5px;
}

.menu-btn:hover {
  background: rgba(255, 255, 255, 0.1);
}

.side-menu {
  position: fixed;
  top: 0;
  left: -260px;
  width: 250px;
  height: 100%;
  background: #222;
  color: #fff;
  box-shadow: -2px 0 8px rgba(0, 0, 0, 0.2);
  transition: left 0.3s ease;
  z-index: 1000;
  padding-top: 60px;
}

.side-menu.open {
  left: 0;
}

.close-btn {
  position: absolute;
  top: 10px;
  right: 15px;
  background: none;
  border: none;
  font-size: 2rem;
  color: #fff;
  cursor: pointer;
  padding: 5px 15px;
}

.close-btn:hover {
  color: #0fdbf9;
  background: rgba(255, 255, 255, 0.08);
}

.menu-list {
  list-style: none;
  padding: 0;
  margin: 0;
}

.menu-list li {
  margin: 20px 0;
  text-align: left;
}

.menu-list a {
  display: block;
  width: 100%;
  color: #fff;
  text-decoration: none;
  font-size: 1.2rem;
  transition: color 0.2s, background 0.2s;
  padding: 12px 20px;
  border-radius: 6px;
  box-sizing: border-box;
}

.menu-list a:hover {
  color: #0fdbf9;
  background: rgba(255, 255, 255, 0.08);
}

.main {
  padding: 5px 20px 10px;
  background-color: lightgrey;
  margin: 129px 5px 5px;
  border-radius: 10px;
}

.main h2 {
  color: #333;
}