/* 全局重置与基础样式 */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
}
body {
    background-color: #f5f7fa;
    color: #333;
    line-height: 1.6;
}
.container {
    width: 90%;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 15px;
}

/* 导航栏 - 蓝色主基调 */
header {
    background: linear-gradient(135deg, #0a5fbf, #094b99);
    box-shadow: 0 2px 10px rgba(0,0,0,0.1);
    position: sticky;
    top: 0;
    z-index: 999;
}
.nav {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 18px 0;
}
.logo {
    color: white;
    font-size: 24px;
    font-weight: 700;
    text-decoration: none;
}
.nav-menu a {
    color: white;
    text-decoration: none;
    margin-left: 28px;
    font-size: 15px;
    font-weight: 500;
    transition: 0.3s;
}
.nav-menu a:hover {
    color: #a0d2ff;
}

/* 按钮样式 */
.btn {
    display: inline-block;
    padding: 12px 28px;
    background: #0a74da;
    color: white;
    border-radius: 6px;
    text-decoration: none;
    font-weight: 600;
    transition: 0.3s;
    border: none;
    cursor: pointer;
    font-size: 15px;
}
.btn:hover {
    background: #085bb5;
    transform: translateY(-2px);
}
.btn-outline {
    background: transparent;
    border: 2px solid #0a74da;
    color: #0a74da;
}

/* 卡片与布局 */
.card {
    background: white;
    border-radius: 12px;
    box-shadow: 0 4px 15px rgba(0,0,0,0.05);
    padding: 30px;
    margin-bottom: 30px;
}
.section-title {
    font-size: 32px;
    color: #1e293b;
    margin-bottom: 15px;
    text-align: center;
}
.section-desc {
    text-align: center;
    color: #64748b;
    max-width: 700px;
    margin: 0 auto 50px;
}

/* 表单样式 */
.form-box {
    max-width: 500px;
    margin: 50px auto;
}
.form-group {
    margin-bottom: 20px;
}
.form-group label {
    display: block;
    margin-bottom: 8px;
    font-weight: 600;
    color: #334155;
}
.form-control {
    width: 100%;
    padding: 14px;
    border: 1px solid #cbd5e1;
    border-radius: 6px;
    font-size: 15px;
    transition: 0.3s;
}
.form-control:focus {
    outline: none;
    border-color: #0a74da;
    box-shadow: 0 0 0 3px rgba(10,116,218,0.15);
}

/* 产品网格 */
.product-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    gap: 30px;
    margin-top: 40px;
}
.product-card {
    background: white;
    border-radius: 12px;
    overflow: hidden;
    box-shadow: 0 4px 15px rgba(0,0,0,0.05);
    transition: 0.3s;
}
.product-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 8px 25px rgba(0,0,0,0.1);
}
.product-body {
    padding: 25px;
}
.product-title {
    font-size: 20px;
    margin-bottom: 10px;
    color: #1e293b;
}
.product-price {
    font-size: 24px;
    color: #0a74da;
    font-weight: 700;
    margin: 15px 0;
}
.product-features {
    list-style: none;
    margin: 15px 0;
}
.product-features li {
    padding: 6px 0;
    border-bottom: 1px solid #f1f5f9;
}

/* 首页banner */
.banner {
    background: linear-gradient(135deg, #0a5fbf, #0a74da);
    color: white;
    padding: 80px 0;
    text-align: center;
}
.banner h1 {
    font-size: 48px;
    margin-bottom: 20px;
}
.banner p {
    font-size: 18px;
    max-width: 700px;
    margin: 0 auto 30px;
    opacity: 0.95;
}

/* 底部 */
footer {
    background: #0f172a;
    color: white;
    padding: 40px 0;
    text-align: center;
    margin-top: 60px;
}