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

:root {
    --primary-color: #4A90E2;
    --primary-dark: #357ABD;
    --secondary-color: #F5A623;
    --text-dark: #2C3E50;
    --text-light: #7F8C8D;
    --bg-light: #F8F9FA;
    --bg-white: #FFFFFF;
    --border-color: #E1E8ED;
    --shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
    --shadow-hover: 0 4px 20px rgba(0, 0, 0, 0.15);
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', 'Helvetica Neue', Helvetica, Arial, sans-serif;
    line-height: 1.6;
    color: var(--text-dark);
    background-color: var(--bg-white);
}

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

/* Header and Navigation */
.header {
    background: var(--bg-white);
    box-shadow: var(--shadow);
    position: sticky;
    top: 0;
    z-index: 1000;
}

.navbar {
    padding: 1rem 0;
}

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

.nav-brand h1 {
    font-size: 1.5rem;
    color: var(--primary-color);
    font-weight: 700;
}

.nav-menu {
    display: flex;
    list-style: none;
    gap: 2rem;
    align-items: center;
}

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

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

.nav-actions {
    display: flex;
    align-items: center;
    gap: 1rem;
}

.lang-selector {
    padding: 0.5rem 1rem;
    border: 1px solid var(--border-color);
    border-radius: 6px;
    background: var(--bg-white);
    color: var(--text-dark);
    font-size: 0.9rem;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.3s ease;
    appearance: none;
    background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='12' viewBox='0 0 12 12'%3E%3Cpath fill='%232C3E50' d='M6 9L1 4h10z'/%3E%3C/svg%3E");
    background-repeat: no-repeat;
    background-position: right 0.75rem center;
    padding-right: 2.5rem;
}

.lang-selector:hover {
    border-color: var(--primary-color);
    color: var(--primary-color);
}

.lang-selector:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(74, 144, 226, 0.1);
}

.btn-primary {
    background: var(--primary-color);
    color: white;
    padding: 0.6rem 1.5rem;
    border-radius: 6px;
    text-decoration: none;
    font-weight: 600;
    transition: background 0.3s ease, transform 0.2s ease;
    display: inline-block;
}

.btn-primary:hover {
    background: var(--primary-dark);
    transform: translateY(-2px);
}

/* Hero Section */
.hero {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    padding: 6rem 0;
    text-align: center;
}

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

.hero-title {
    font-size: 3rem;
    font-weight: 700;
    margin-bottom: 1.5rem;
    line-height: 1.2;
}

.hero-description {
    font-size: 1.25rem;
    margin-bottom: 2.5rem;
    opacity: 0.95;
    line-height: 1.8;
}

.hero-cta {
    display: flex;
    gap: 1rem;
    justify-content: center;
    flex-wrap: wrap;
}

.btn-large {
    background: white;
    color: var(--primary-color);
    padding: 1rem 2.5rem;
    border-radius: 8px;
    text-decoration: none;
    font-weight: 700;
    font-size: 1.1rem;
    transition: transform 0.3s ease, box-shadow 0.3s ease;
    display: inline-block;
}

.btn-large:hover {
    transform: translateY(-3px);
    box-shadow: 0 8px 25px rgba(0, 0, 0, 0.2);
}

.btn-secondary {
    background: transparent;
    color: white;
    padding: 1rem 2.5rem;
    border: 2px solid white;
    border-radius: 8px;
    text-decoration: none;
    font-weight: 700;
    font-size: 1.1rem;
    transition: background 0.3s ease, transform 0.3s ease;
    display: inline-block;
}

.btn-secondary:hover {
    background: rgba(255, 255, 255, 0.1);
    transform: translateY(-3px);
}

/* Section Styles */
section {
    padding: 5rem 0;
}

.section-title {
    font-size: 2.5rem;
    text-align: center;
    margin-bottom: 3rem;
    color: var(--text-dark);
    font-weight: 700;
}

/* Features Section */
.features {
    background: var(--bg-light);
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
}

.feature-card {
    background: var(--bg-white);
    padding: 2.5rem;
    border-radius: 12px;
    box-shadow: var(--shadow);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
    text-align: center;
}

.feature-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-hover);
}

.feature-icon {
    font-size: 3rem;
    margin-bottom: 1rem;
}

.feature-card h3 {
    font-size: 1.5rem;
    margin-bottom: 1rem;
    color: var(--text-dark);
}

.feature-card p {
    color: var(--text-light);
    line-height: 1.8;
}

/* Guide Section */
.guide {
    background: var(--bg-white);
}

.guide-steps {
    max-width: 900px;
    margin: 0 auto 3rem;
}

.step {
    display: flex;
    gap: 2rem;
    margin-bottom: 3rem;
    align-items: flex-start;
}

.step-number {
    background: var(--primary-color);
    color: white;
    width: 60px;
    height: 60px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.5rem;
    font-weight: 700;
    flex-shrink: 0;
}

.step-content {
    flex: 1;
}

.step-content h3 {
    font-size: 1.5rem;
    margin-bottom: 0.5rem;
    color: var(--text-dark);
}

.step-content p {
    color: var(--text-light);
    line-height: 1.8;
}

.step-content a {
    color: var(--primary-color);
    text-decoration: none;
    font-weight: 600;
}

.step-content a:hover {
    text-decoration: underline;
}

.guide-cta {
    text-align: center;
}

/* Benefits Section */
.benefits {
    background: var(--bg-light);
}

.benefits-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
}

.benefit-item {
    background: var(--bg-white);
    padding: 2rem;
    border-radius: 12px;
    box-shadow: var(--shadow);
    transition: transform 0.3s ease;
}

.benefit-item:hover {
    transform: translateY(-3px);
}

.benefit-item h3 {
    font-size: 1.3rem;
    margin-bottom: 1rem;
    color: var(--text-dark);
}

.benefit-item p {
    color: var(--text-light);
    line-height: 1.8;
}

/* FAQ Section */
.faq {
    background: var(--bg-white);
}

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

.faq-item {
    background: var(--bg-light);
    padding: 2rem;
    margin-bottom: 1.5rem;
    border-radius: 12px;
    border-left: 4px solid var(--primary-color);
}

.faq-item h3 {
    font-size: 1.3rem;
    margin-bottom: 1rem;
    color: var(--text-dark);
}

.faq-item p {
    color: var(--text-light);
    line-height: 1.8;
}

/* CTA Section */
.cta-section {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    text-align: center;
    padding: 5rem 0;
}

.cta-content h2 {
    font-size: 2.5rem;
    margin-bottom: 1rem;
    font-weight: 700;
}

.cta-content p {
    font-size: 1.2rem;
    margin-bottom: 2rem;
    opacity: 0.95;
}

/* Footer */
.footer {
    background: var(--text-dark);
    color: white;
    padding: 3rem 0 1.5rem;
}

.footer-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
    margin-bottom: 2rem;
}

.footer-section h3 {
    margin-bottom: 1rem;
    font-size: 1.2rem;
}

.footer-section p {
    color: rgba(255, 255, 255, 0.8);
    line-height: 1.8;
}

.footer-section ul {
    list-style: none;
}

.footer-section ul li {
    margin-bottom: 0.5rem;
}

.footer-section a {
    color: rgba(255, 255, 255, 0.8);
    text-decoration: none;
    transition: color 0.3s ease;
}

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

.footer-bottom {
    text-align: center;
    padding-top: 2rem;
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    color: rgba(255, 255, 255, 0.6);
    font-size: 0.9rem;
}

.footer-bottom a {
    color: rgba(255, 255, 255, 0.8);
    text-decoration: none;
}

.footer-bottom a:hover {
    color: white;
    text-decoration: underline;
}

/* Responsive Design */
@media (max-width: 768px) {
    .nav-menu {
        display: none;
    }
    
    .nav-actions {
        gap: 0.5rem;
    }
    
    .lang-selector {
        padding: 0.4rem 0.8rem;
        font-size: 0.85rem;
        padding-right: 2rem;
    }
    
    .hero-title {
        font-size: 2rem;
    }
    
    .hero-description {
        font-size: 1.1rem;
    }
    
    .section-title {
        font-size: 2rem;
    }
    
    .features-grid,
    .benefits-content {
        grid-template-columns: 1fr;
    }
    
    .step {
        flex-direction: column;
        text-align: center;
    }
    
    .step-number {
        margin: 0 auto;
    }
    
    .hero-cta {
        flex-direction: column;
    }
    
    .btn-large,
    .btn-secondary {
        width: 100%;
        text-align: center;
    }
    
    .cta-content h2 {
        font-size: 2rem;
    }
}

@media (max-width: 480px) {
    .container {
        padding: 0 15px;
    }
    
    .hero {
        padding: 4rem 0;
    }
    
    .hero-title {
        font-size: 1.75rem;
    }
    
    section {
        padding: 3rem 0;
    }
    
    .feature-card,
    .benefit-item,
    .faq-item {
        padding: 1.5rem;
    }
}