* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
  font-family: "Microsoft YaHei", sans-serif;
}
body {
  background: #f5f7fa;
  color: #333;
}
.container {
  width: 1200px;
  margin: 0 auto;
}

/* 头部导航 */
.header {
  background: #1f4e79;
  padding: 15px 0;
}
.nav {
  display: flex;
  justify-content: space-between;
  align-items: center;
}
.logo {
  color: white;
  font-size: 24px;
  font-weight: bold;
}
.nav-menu a {
  color: white;
  text-decoration: none;
  margin-left: 30px;
  font-size: 16px;
}
.nav-menu a:hover {
  color: #ffcc00;
}

/*  banner */
.banner {
  height: 380px;
  background: #e6eff7;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 32px;
  color: #1f4e79;
  font-weight: bold;
}

/* 内容区域 */
.content {
  padding: 50px 0;
  background: white;
  margin-top: 20px;
  border-radius: 8px;
  box-shadow: 0 2px 10px rgba(0,0,0,0.05);
}
.title {
  font-size: 26px;
  color: #1f4e79;
  margin-bottom: 30px;
  text-align: center;
}

/* 后台登录 */
.login-box {
  width: 400px;
  margin: 80px auto;
  padding: 40px;
  background: white;
  border-radius: 10px;
  box-shadow: 0 3px 15px rgba(0,0,0,0.1);
}
.login-box h2 {
  text-align: center;
  margin-bottom: 30px;
  color: #1f4e79;
}
.form-item {
  margin-bottom: 20px;
}
.form-item label {
  display: block;
  margin-bottom: 8px;
}
.form-item input {
  width: 100%;
  padding: 10px;
  border: 1px solid #ddd;
  border-radius: 5px;
  font-size: 16px;
}
.btn {
  width: 100%;
  padding: 12px;
  background: #1f4e79;
  color: white;
  border: none;
  border-radius: 5px;
  font-size: 16px;
  cursor: pointer;
}
.btn:hover {
  background: #163b5e;
}

/* 底部 */
.footer {
  background: #222;
  color: #ccc;
  text-align: center;
  padding: 25px 0;
  margin-top: 30px;
}