/* Reset and Base Styles */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    --primary-color: #2563eb;
    --secondary-color: #1e40af;
    --accent-color: #3b82f6;
    --text-dark: #1f2937;
    --text-light: #6b7280;
    --bg-light: #f9fafb;
    --white: #ffffff;
    --border-color: #e5e7eb;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, 'Noto Sans', sans-serif, 'Microsoft YaHei', 微软雅黑;
    line-height: 1.6;
    color: var(--text-dark);
    background-color: var(--white);
}

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

/* Language Toggle */
.language-toggle {
    position: fixed;
    top: 20px;
    right: 20px;
    z-index: 1000;
}

#langBtn {
    background-color: var(--white);
    color: var(--primary-color);
    border: 2px solid var(--primary-color);
    padding: 8px 16px;
    border-radius: 20px;
    cursor: pointer;
    font-weight: 600;
    transition: all 0.3s ease;
    font-size: 14px;
}

#langBtn:hover {
    background-color: var(--primary-color);
    color: var(--white);
}

/* Header */
header {
    background-color: var(--white);
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
    position: sticky;
    top: 0;
    z-index: 999;
}

header .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 20px;
}

.logo {
    font-size: 24px;
    font-weight: 700;
    color: var(--primary-color);
}

nav {
    display: flex;
    gap: 30px;
}

nav a {
    color: var(--text-dark);
    text-decoration: none;
    font-weight: 500;
    transition: color 0.3s ease;
}

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

/* Hero Section */
.hero {
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--secondary-color) 100%);
    color: var(--white);
    padding: 120px 20px;
    text-align: center;
}

.hero-title {
    font-size: 48px;
    font-weight: 700;
    margin-bottom: 20px;
    line-height: 1.2;
}

.hero-subtitle {
    font-size: 20px;
    margin-bottom: 40px;
    opacity: 0.95;
}

.cta-button {
    display: inline-block;
    background-color: var(--white);
    color: var(--primary-color);
    padding: 15px 40px;
    border-radius: 30px;
    text-decoration: none;
    font-weight: 600;
    font-size: 18px;
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.cta-button:hover {
    transform: translateY(-2px);
    box-shadow: 0 10px 20px rgba(0, 0, 0, 0.2);
}

/* Sections */
.section {
    padding: 80px 20px;
}

.bg-light {
    background-color: var(--bg-light);
}

.section-title {
    font-size: 36px;
    font-weight: 700;
    text-align: center;
    margin-bottom: 50px;
    color: var(--text-dark);
}

.content p {
    font-size: 18px;
    line-height: 1.8;
    margin-bottom: 20px;
    color: var(--text-light);
}

.content .mission {
    font-size: 22px;
    text-align: center;
    margin-top: 30px;
    color: var(--primary-color);
}

/* Why Us Card */
.why-card {
    background-color: var(--white);
    border-radius: 12px;
    padding: 40px;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
    text-align: center;
    max-width: 800px;
    margin: 0 auto;
}

.why-card .icon {
    font-size: 60px;
    margin-bottom: 20px;
}

.why-card p {
    font-size: 18px;
    line-height: 1.8;
    color: var(--text-light);
}

/* Impact Section */
.impact-stats {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 40px;
    margin-bottom: 60px;
}

.stat-card {
    background-color: var(--white);
    border-radius: 12px;
    padding: 40px;
    text-align: center;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
    transition: transform 0.3s ease;
}

.stat-card:hover {
    transform: translateY(-5px);
}

.stat-number {
    font-size: 48px;
    font-weight: 700;
    color: var(--primary-color);
    margin-bottom: 10px;
}

.stat-label {
    font-size: 18px;
    color: var(--text-light);
    font-weight: 500;
}

.clients {
    max-width: 800px;
    margin: 0 auto;
}

.clients h3 {
    font-size: 24px;
    margin-bottom: 30px;
    text-align: center;
    color: var(--text-dark);
}

.client-list {
    list-style: none;
}

.client-list li {
    background-color: var(--white);
    padding: 20px;
    margin-bottom: 15px;
    border-radius: 8px;
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
    font-size: 18px;
}

.client-list li strong {
    color: var(--primary-color);
}

.period {
    color: var(--text-light);
    font-size: 16px;
}

/* Contact Section */
.contact-content {
    max-width: 700px;
    margin: 0 auto;
    text-align: center;
}

.contact-content p {
    font-size: 18px;
    line-height: 1.8;
    color: var(--text-light);
}

.email-link {
    color: var(--primary-color);
    font-weight: 600;
    text-decoration: none;
    border-bottom: 2px solid var(--accent-color);
    transition: color 0.3s ease;
}

.email-link:hover {
    color: var(--secondary-color);
}

/* Footer */
footer {
    background-color: var(--text-dark);
    color: var(--white);
    text-align: center;
    padding: 30px 20px;
}

footer p {
    opacity: 0.8;
}

/* Responsive Design */
@media (max-width: 768px) {
    .hero-title {
        font-size: 32px;
    }

    .hero-subtitle {
        font-size: 16px;
    }

    header .container {
        flex-direction: column;
        gap: 20px;
    }

    nav {
        flex-wrap: wrap;
        justify-content: center;
        gap: 15px;
    }

    .section-title {
        font-size: 28px;
    }

    .content p,
    .why-card p,
    .contact-content p {
        font-size: 16px;
    }

    .stat-number {
        font-size: 36px;
    }

    .language-toggle {
        top: 10px;
        right: 10px;
    }
}

/* Smooth Scrolling */
html {
    scroll-behavior: smooth;
}