/* 全局变量 */
:root {
    --primary-color: #0056b3;
    --secondary-color: #25d366; /* WhatsApp 绿色 */
    --text-color: #333;
    --light-bg: #f4f7f6;
    --white: #fff;
    --border-color: #ddd;
}

/* 基础重置 */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    line-height: 1.6;
    color: var(--text-color);
    background: var(--white);
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

/* 导航栏 */
header {
    background: var(--white);
    border-bottom: 1px solid var(--border-color);
    padding: 15px 0;
    position: sticky;
    top: 0;
    z-index: 1000;
}

header .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo {
    font-size: 24px;
    font-weight: bold;
    color: var(--primary-color);
    text-decoration: none;
}

nav ul {
    display: flex;
    list-style: none;
}

nav ul li {
    margin-left: 25px;
}

nav ul li a {
    text-decoration: none;
    color: var(--text-color);
    font-weight: 500;
}

nav ul li a:hover {
    color: var(--primary-color);
}

.menu-toggle {
    display: none;
    cursor: pointer;
    font-size: 24px;
}

/* 按钮样式 */
.btn {
    display: inline-block;
    background: var(--primary-color);
    color: var(--white);
    padding: 12px 30px;
    text-decoration: none;
    border-radius: 5px;
    font-weight: bold;
    transition: 0.3s;
    border: none;
    cursor: pointer;
}

.btn:hover {
    opacity: 0.9;
}

/* WhatsApp 浮动按钮 */
.whatsapp-float {
    position: fixed;
    bottom: 30px;
    right: 30px;
    background-color: var(--secondary-color);
    color: #FFF;
    border-radius: 50px;
    text-align: center;
    font-size: 30px;
    box-shadow: 2px 2px 10px rgba(0,0,0,0.2);
    z-index: 1000;
    width: 60px;
    height: 60px;
    display: flex;
    align-items: center;
    justify-content: center;
    text-decoration: none;
}

/* 首页 Hero */
.hero {
    background: linear-gradient(rgba(0,0,0,0.5), rgba(0,0,0,0.5)), url('../assets/images/hero-bg.jpg') no-repeat center center/cover;
    height: 80vh;
    color: white;
    display: flex;
    align-items: center;
    text-align: center;
}

.hero h1 {
    font-size: 3.5rem;
    margin-bottom: 20px;
}

/* 优势区块 */
.features {
    padding: 60px 0;
    background: var(--light-bg);
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 30px;
    text-align: center;
}

.feature-item i {
    font-size: 40px;
    color: var(--primary-color);
    margin-bottom: 15px;
}

/* 产品卡片 */
.product-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 30px;
    padding: 40px 0;
}

.product-card {
    border: 1px solid var(--border-color);
    border-radius: 8px;
    overflow: hidden;
    background: var(--white);
}

.product-card img {
    width: 100%;
    height: 250px;
    object-fit: cover;
}

.product-info {
    padding: 20px;
}

.specs-list {
    margin: 15px 0;
    font-size: 14px;
    list-style: none;
}

.specs-list li {
    border-bottom: 1px solid #eee;
    padding: 5px 0;
}

/* 联系表单 */
.contact-container {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 50px;
    padding: 60px 0;
}

.form-group {
    margin-bottom: 20px;
}

.form-group input, .form-group textarea {
    width: 100%;
    padding: 10px;
    border: 1px solid var(--border-color);
    border-radius: 4px;
}

/* 响应式 */
@media (max-width: 768px) {
    .menu-toggle {
        display: block;
    }

    nav ul {
        display: none;
        flex-direction: column;
        position: absolute;
        top: 60px;
        left: 0;
        width: 100%;
        background: var(--white);
        border-bottom: 1px solid var(--border-color);
        padding: 20px 0;
    }

    nav ul.active {
        display: flex;
    }

    nav ul li {
        margin: 10px 0;
        text-align: center;
    }

    .contact-container {
        grid-template-columns: 1fr;
    }

    .hero h1 {
        font-size: 2.5rem;
    }
}