:root {
    --primary-color: #004d40; /* 深绿色 */
    --secondary-color: #00796b;
    --text-color: #333;
    --light-bg: #f4f7f6;
    --white: #ffffff;
    --font-family: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
}

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

body {
    font-family: var(--font-family);
    line-height: 1.6;
    color: var(--text-color);
    background-color: var(--white);
}

a {
    text-decoration: none;
    color: inherit;
}

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

/* Header & Navigation */
header {
    padding: 20px 0;
    background: var(--white);
    position: sticky;
    top: 0;
    z-index: 1000;
    box-shadow: 0 2px 10px rgba(0,0,0,0.05);
}

nav {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo img {
    height: 40px;
}

.nav-links {
    display: flex;
    gap: 30px;
    align-items: center;
}

.nav-links a {
    font-weight: 500;
    color: #555;
    transition: color 0.3s;
}

.nav-links a:hover {
    color: var(--primary-color);
}

.contact-btn {
    background-color: var(--primary-color);
    color: var(--white) !important;
    padding: 10px 25px;
    border-radius: 8px;
    font-weight: 600;
}

/* Hero Section */
.hero {
    padding: 80px 0;
    display: flex;
    align-items: center;
    gap: 50px;
}

.hero-content {
    flex: 1;
}

.hero-content h1 {
    font-size: 3.5rem;
    line-height: 1.2;
    margin-bottom: 20px;
    color: var(--primary-color);
}

.hero-content p {
    font-size: 1.2rem;
    color: #666;
    margin-bottom: 30px;
}

.hero-image {
    flex: 1;
}

.hero-image img {
    width: 100%;
    border-radius: 20px;
}

/* Features Section */
.features {
    padding: 80px 0;
    background-color: var(--light-bg);
}

.section-title {
    text-align: center;
    margin-bottom: 50px;
}

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

.feature-card {
    background: var(--white);
    padding: 30px;
    border-radius: 15px;
    box-shadow: 0 5px 15px rgba(0,0,0,0.05);
}

.feature-icon {
    width: 50px;
    height: 50px;
    margin-bottom: 20px;
}

/* Footer */
footer {
    background-color: var(--primary-color);
    color: var(--white);
    padding: 60px 0 30px;
}

.footer-content {
    display: flex;
    justify-content: space-between;
    margin-bottom: 40px;
}

.footer-logo img {
    height: 40px;
    filter: brightness(0) invert(1);
}

.footer-links {
    display: flex;
    gap: 40px;
}

.footer-column h4 {
    margin-bottom: 20px;
}

.footer-column a {
    display: block;
    margin-bottom: 10px;
    opacity: 0.8;
}

.footer-bottom {
    text-align: center;
    padding-top: 30px;
    border-top: 1px solid rgba(255,255,255,0.1);
    font-size: 0.9rem;
    opacity: 0.7;
}

/* Responsive */
@media (max-width: 768px) {
    .hero {
        flex-direction: column;
        text-align: center;
    }
    .nav-links {
        display: none;
    }
}