сам файл в public добавить

В head

<link rel="stylesheet" href="/style.css">


* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

body {
  font-family: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  background: #f9f9f9;
  color: #333;
  padding: 16px;
  line-height: 1.4;
}

header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 10px;
  background: #ffffff;
  border-radius: 8px;
  box-shadow: 0 1px 3px rgba(0,0,0,0.08);
  margin-bottom: 16px;
}

.nav-link {
  text-decoration: none;     
  color: #444;
  font-weight: 500;
  padding: 6px 10px;
  border-radius: 6px;
  margin-right: 12px;
  transition: background 0.2s, color 0.2s;
}

header nav a {
  text-decoration: none;
  color: #444;
  font-weight: 500;
  padding: 6px 10px;
  border-radius: 6px;
  margin-right: 12px;
  transition: background 0.2s, color 0.2s;
}

header nav a:hover {
  background: #f0f0f0;
  color: #000;
  text-decoration: none;
}
.user-info {
  text-align: right;
  font-weight: 600;
  font-size: 14px;
  color: #555;
}