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

body {
  font-family: Arial, sans-serif;
  width: 100%;
}

/* Tiêu đề đầu trang */
.header {
  width: 100%;
  background-color: #111;
  color: white;
  text-align: center;
  padding: 20px;
  font-size: 26px;
  font-weight: bold;
}

/* Box chứa slogan */
.slogan-box {
  width: 100%;
  height: 350px ;
  padding: 0 0;
  text-align: center;
}

.slogan {
  font-size: 28px;
  font-weight: bold;
  color: #e0c300;
  background-image: url("../images/images/phonebgrd.jpg");
  height: 350px ;
  align-content: center;
}

/* Phần tính năng */
.features {
  display: flex;
  justify-content: center;

  gap: 20px;
  padding: 30px 20px;
  width: 100%;
  background-color: #fff;
}

.feature-box {
  border: 1px solid #ccc;
  border-radius: 6px;
  padding: 15px;
  width: 300px;
  background-color: #f9f9f9;
}

.feature-box label {
  font-weight: bold;
  display: block;
  margin-bottom: 10px;
}

/* Ưu đãi */
.promo {
  width: 100%;
  background-color: #28a745;
  color: white;
  text-align: center;
  padding: 30px 10px;
  font-size: 18px;
  font-weight: bold;
}

/* Nút */
.promo button {
  margin-top: 15px;
  padding: 10px 20px;
  background-color: white;
  color: #28a745;
  border: none;
  border-radius: 4px;
  font-weight: bold;
  cursor: pointer;
}