/* 基础重置与全局样式 */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'Inter', sans-serif;
    line-height: 1.7;
    color: #333;
    background-color: #f8fafc;
}

.container {
    width: 90%;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

/* 按钮通用样式 */
.btn {
    padding: 12px 28px;
    border: none;
    border-radius: 6px;
    cursor: pointer;
    font-size: 16px;
    font-weight: 500;
    transition: all 0.3s ease;
}

.btn-primary {
    background-color: #007bff;
    color: white;
}

.btn-primary:hover {
    background-color: #0056b3;
    transform: translateY(-2px);
}

.btn-secondary {
    background-color: transparent;
    color: #007bff;
    border: 2px solid #007bff;
}

.btn-secondary:hover {
    background-color: #007bff;
    color: white;
}

/* 头部导航栏 */
.header {
    background-color: white;
    box-shadow: 0 2px 10px rgba(0,0,0,0.05);
    position: sticky;
    top: 0;
    z-index: 100;
}

.navbar {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 18px 0;
}

.nav-links {
    list-style: none;
    display: flex;
    gap: 30px;
}

.nav-links a {
    text-decoration: none;
    color: #333;
    font-weight: 500;
    transition: color 0.3s ease;
}

.nav-links a:hover {
    color: #007bff;
}

/* 英雄区域 */
.hero {
    background-image: linear-gradient(rgba(0,123,255,0.8), rgba(0,123,255,0.8)), 
                      url('https://placehold.co/1920x800/007bff/ffffff?text=Business+Analytics+Hero');
    background-size: cover;
    background-position: center;
    height: 85vh;
    display: flex;
    align-items: center;
    justify-content: center;
    text-align: center;
    color: white;
    padding-top: 80px;
}

.hero-content h1 {
    font-size: 3.2rem;
    margin-bottom: 24px;
    font-weight: 700;
    line-height: 1.2;
}

.hero-content p {
    font-size: 1.3rem;
    margin-bottom: 36px;
    max-width: 650px;
    opacity: 0.95;
}

/* 功能模块 */
.features {
    padding: 100px 0;
    background-color: white;
}

.features h2 {
    text-align: center;
    font-size: 2.8rem;
    margin-bottom: 70px;
    color: #222;
    font-weight: 600;
}

.feature-cards {
    display: flex;
    gap: 32px;
    justify-content: center;
    flex-wrap: wrap;
}

.card {
    background-color: white;
    border-radius: 12px;
    box-shadow: 0 6px 20px rgba(0,0,0,0.06);
    padding: 42px 36px;
    flex: 1;
    min-width: 280px;
    max-width: 360px;
    text-align: center;
    transition: transform 0.3s ease;
}

.card:hover {
    transform: translateY(-8px);
}

.icon {
    font-size: 3.5rem;
    color: #007bff;
    margin-bottom: 26px;
}

.card h3 {
    font-size: 1.6rem;
    margin-bottom: 18px;
    color: #222;
    font-weight: 600;
}

.card p {
    color: #555;
    font-size: 1.05rem;
    line-height: 1.6;
}

/* 数据展示模块 */
.data-section {
    padding: 100px 0;
    background-color: #f1f5f9;
}

.data-section h2 {
    text-align: center;
    font-size: 2.8rem;
    margin-bottom: 50px;
    color: #222;
    font-weight: 600;
}

/* 联系表单 */
.contact {
    padding: 100px 0;
    background-color: white;
}

.contact h2 {
    text-align: center;
    font-size: 2.8rem;
    margin-bottom: 50px;
    color: #222;
    font-weight: 600;
}

.contact-form {
    max-width: 650px;
    margin: 0 auto;
}

.contact-form input,
.contact-form textarea {
    width: 100%;
    padding: 16px 20px;
    margin-bottom: 24px;
    border: 1px solid #e2e8f0;
    border-radius: 8px;
    font-size: 1rem;
    font-family: inherit;
    transition: border-color 0.3s ease;
}

.contact-form input:focus,
.contact-form textarea:focus {
    outline: none;
    border-color: #007bff;
}

.contact-form textarea {
    resize: vertical;
    min-height: 140px;
}

/* 页脚 */
.footer {
    background-color: #1e293b;
    color: #cbd5e1;
    padding: 50px 0;
}

.footer-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: 20px;
}

.footer-links {
    list-style: none;
    display: flex;
    gap: 24px;
}

.footer-links a {
    text-decoration: none;
    color: #cbd5e1;
    transition: color 0.3s ease;
}

.footer-links a:hover {
    color: white;
}

/* 响应式适配（移动端优化） */
@media (max-width: 768px) {
    .navbar {
        flex-direction: column;
        gap: 20px;
    }

    .nav-links {
        flex-direction: column;
        gap: 15px;
    }

    .hero-content h1 {
        font-size: 2.4rem;
    }

    .hero-content p {
        font-size: 1.1rem;
    }

    .feature-cards {
        flex-direction: column;
        align-items: center;
    }

    .card {
        max-width: 100%;
    }

    .footer-content {
        flex-direction: column;
        text-align: center;
    }
}