* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: "Microsoft YaHei", sans-serif;
}

a {
    text-decoration: none;
    color: #333;
}

/* 导航栏 */
.navbar {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem 5%;
    background: #fff;
    box-shadow: 0 2px 5px #eee;
    position: sticky;
    top: 0;
    z-index: 99;
}
.logo {
    font-size: 22px;
    font-weight: bold;
    color: #2563eb;
}
.nav-menu a {
    margin-left: 25px;
    transition: color 0.3s;
}
.nav-menu a:hover {
    color: #2563eb;
}

/* 横幅区域 */
.banner {
    height: 80vh;
    background: linear-gradient(135deg, #2563eb, #60a5fa);
    display: flex;
    align-items: center;
    justify-content: center;
    text-align: center;
    color: white;
}
.banner-text h1 {
    font-size: 42px;
    margin-bottom: 15px;
}
.banner-text p {
    font-size: 18px;
    margin-bottom: 30px;
}
#clickBtn {
    padding: 12px 30px;
    border: none;
    border-radius: 6px;
    font-size: 16px;
    background: white;
    color: #2563eb;
    cursor: pointer;
    transition: 0.3s;
}
#clickBtn:hover {
    background: #f0f7ff;
}

/* 通用区块 */
.section {
    padding: 80px 5%;
    text-align: center;
}
.section h2 {
    font-size: 30px;
    margin-bottom: 20px;
    color: #222;
}
.section p {
    max-width: 700px;
    margin: 0 auto;
    font-size: 17px;
    color: #555;
    line-height: 1.8;
}
.bg-gray {
    background: #f8fafc;
}

/* 卡片布局 */
.card-box {
    display: flex;
    gap: 25px;
    justify-content: center;
    margin-top: 40px;
    flex-wrap: wrap;
}
.card {
    width: 220px;
    padding: 40px 20px;
    background: white;
    border-radius: 8px;
    box-shadow: 0 3px 10px #e2e8f0;
    font-size: 18px;
    color: #333;
}

/* 页脚 */
.footer {
    padding: 25px;
    text-align: center;
    background: #1e293b;
    color: #ccc;
}