:root {
    --primary-color: #3370FF;
    --secondary-color: #F0F4FF;
    --text-primary: #2A2A2A;
    --text-secondary: #6C6C6C;
    --background-light: #FFFFFF;
    --background-dark: #F6F9FF;
    --spacing-unit: 8px;
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: 'Inter', sans-serif;
}

body {
    color: var(--text-primary);
    background-color: var(--background-light);
}

/* 辅助功能 */
.skip-link {
    position: absolute;
    top: -40px;
    left: 0;
    background: var(--primary-color);
    color: white;
    padding: 8px;
    z-index: 1000;
    transition: top 0.3s;
}

.skip-link:focus {
    top: 0;
}

/* 社交媒体链接 */
.social-links {
    display: flex;
    list-style: none;
    gap: calc(var(--spacing-unit) * 2);
    margin-top: calc(var(--spacing-unit) * 2);
}

.social-links a {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 36px;
    height: 36px;
    background-color: rgba(255, 255, 255, 0.1);
    border-radius: 50%;
    color: white;
    transition: background-color 0.3s;
}

.social-links a:hover {
    background-color: rgba(255, 255, 255, 0.2);
}

/* 法律链接 */
.legal-links {
    margin-top: calc(var(--spacing-unit) * 2);
    display: flex;
    justify-content: center;
    gap: calc(var(--spacing-unit) * 3);
}

.legal-links a {
    color: rgba(255, 255, 255, 0.6);
    text-decoration: none;
    font-size: 14px;
    transition: color 0.3s;
}

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

/* 引用块样式 */
blockquote {
    position: relative;
    padding-left: calc(var(--spacing-unit) * 2);
}

blockquote::before {
    content: "";
    position: absolute;
    left: 0;
    top: 0;
    height: 100%;
    width: 4px;
    background-color: var(--primary-color);
    opacity: 0.5;
    border-radius: 2px;
}

.container {
    max-width: 1440px;
    margin: 0 auto;
    padding: 0 calc(var(--spacing-unit) * 3);
}

/* 12-column grid system */
.grid {
    display: grid;
    grid-template-columns: repeat(12, 1fr);
    gap: calc(var(--spacing-unit) * 3);
}

/* Typography */
h1 {
    font-size: 48px;
    font-weight: 700;
    line-height: 1.2;
    margin-bottom: calc(var(--spacing-unit) * 3);
}

h2 {
    font-size: 36px;
    font-weight: 600;
    line-height: 1.3;
    margin-bottom: calc(var(--spacing-unit) * 2);
}

h3 {
    font-size: 24px;
    font-weight: 600;
    line-height: 1.4;
    margin-bottom: var(--spacing-unit);
}

p {
    font-size: 16px;
    line-height: 1.6;
    margin-bottom: calc(var(--spacing-unit) * 2);
}

.small-text {
    font-size: 12px;
    color: var(--text-secondary);
}

/* Components */
.btn {
    display: inline-block;
    padding: calc(var(--spacing-unit) * 1.5) calc(var(--spacing-unit) * 3);
    border-radius: 4px;
    font-weight: 500;
    text-decoration: none;
    cursor: pointer;
    transition: all 0.3s ease;
    min-width: 48px;
    min-height: 48px;
    text-align: center;
}

.btn-primary {
    background-color: var(--primary-color);
    color: white;
}

.btn-primary:hover {
    background-color: #2250CC;
}

.btn-secondary {
    background-color: var(--secondary-color);
    color: var(--primary-color);
}

.btn-secondary:hover {
    background-color: #DDE6FF;
}

.card {
    background-color: white;
    border-radius: 8px;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.1);
    padding: calc(var(--spacing-unit) * 3);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.card:hover {
    transform: translateY(-4px);
    box-shadow: 0 8px 24px rgba(0, 0, 0, 0.12);
}

/* Layout sections */
header {
    padding: calc(var(--spacing-unit) * 2) 0;
    position: sticky;
    top: 0;
    background-color: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    z-index: 100;
    border-bottom: 1px solid rgba(0, 0, 0, 0.05);
}

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

.logo {
    font-weight: 700;
    font-size: 24px;
    color: var(--primary-color);
    text-decoration: none;
}

nav ul {
    display: flex;
    list-style: none;
    gap: calc(var(--spacing-unit) * 4);
    align-items: center;
}

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

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

.hero {
    padding: calc(var(--spacing-unit) * 12) 0;
    background-color: var(--secondary-color);
}

.hero-content {
    grid-column: 1 / 7;
}

.hero-image {
    grid-column: 8 / 13;
}

.hero-image img {
    width: 100%;
    border-radius: 8px;
    box-shadow: 0 8px 24px rgba(0, 0, 0, 0.12);
}

.features {
    padding: calc(var(--spacing-unit) * 10) 0;
}

.section-header {
    text-align: center;
    margin-bottom: calc(var(--spacing-unit) * 8);
}

.feature-card {
    grid-column: span 4;
    padding: calc(var(--spacing-unit) * 3);
}

.feature-icon {
    background-color: var(--secondary-color);
    color: var(--primary-color);
    width: 64px;
    height: 64px;
    border-radius: 8px;
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: calc(var(--spacing-unit) * 2);
}

.feature-icon i {
    font-size: 32px;
}

.workflow {
    padding: calc(var(--spacing-unit) * 10) 0;
    background-color: var(--background-dark);
}

.workflow-step {
    display: flex;
    margin-bottom: calc(var(--spacing-unit) * 6);
    gap: calc(var(--spacing-unit) * 4);
    align-items: center;
}

.workflow-step:nth-child(even) {
    flex-direction: row-reverse;
}

.workflow-content {
    flex: 1;
}

.workflow-image {
    flex: 1;
}

.workflow-image img {
    width: 100%;
    border-radius: 8px;
    box-shadow: 0 8px 24px rgba(0, 0, 0, 0.12);
}

.step-number {
    background-color: var(--primary-color);
    color: white;
    width: 40px;
    height: 40px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 600;
    margin-bottom: calc(var(--spacing-unit) * 2);
}

.testimonials {
    padding: calc(var(--spacing-unit) * 10) 0;
}

.testimonial-card {
    grid-column: span 4;
    padding: calc(var(--spacing-unit) * 4);
}

.testimonial-header {
    display: flex;
    align-items: center;
    margin-bottom: calc(var(--spacing-unit) * 2);
}

.testimonial-avatar {
    width: 48px;
    height: 48px;
    border-radius: 50%;
    margin-right: calc(var(--spacing-unit) * 2);
    object-fit: cover;
}

.cta {
    background-color: var(--primary-color);
    color: white;
    padding: calc(var(--spacing-unit) * 10) 0;
    text-align: center;
}

.cta h2 {
    margin-bottom: calc(var(--spacing-unit) * 4);
}

.cta-buttons {
    display: flex;
    gap: calc(var(--spacing-unit) * 2);
    justify-content: center;
}

footer {
    background-color: var(--text-primary);
    color: white;
    padding: calc(var(--spacing-unit) * 6) 0;
}

.footer-content {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: calc(var(--spacing-unit) * 4);
}

.footer-column h3 {
    margin-bottom: calc(var(--spacing-unit) * 3);
}

.footer-links {
    list-style: none;
}

.footer-links li {
    margin-bottom: calc(var(--spacing-unit) * 1.5);
}

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

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

.copyright {
    margin-top: calc(var(--spacing-unit) * 6);
    padding-top: calc(var(--spacing-unit) * 3);
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    text-align: center;
    color: rgba(255, 255, 255, 0.6);
}

/* Responsive adjustments */
@media (max-width: 1200px) {
    .container {
        width: 100%;
        padding: 0 calc(var(--spacing-unit) * 2);
    }
    
    .hero-content {
        grid-column: 1 / 8;
    }
    
    .hero-image {
        grid-column: 8 / 13;
    }
    
    .feature-card {
        grid-column: span 6;
    }
    
    .testimonial-card {
        grid-column: span 6;
    }
}

@media (max-width: 768px) {
    .grid {
        grid-template-columns: 1fr;
    }
    
    .hero-content, .hero-image {
        grid-column: 1 / -1;
    }
    
    .hero-content {
        margin-bottom: calc(var(--spacing-unit) * 4);
    }
    
    .feature-card, .testimonial-card {
        grid-column: 1 / -1;
    }
    
    .workflow-step, .workflow-step:nth-child(even) {
        flex-direction: column;
    }
    
    .footer-content {
        grid-template-columns: 1fr 1fr;
    }
    
    .social-links {
        justify-content: center;
    }
    
    .legal-links {
        flex-direction: column;
        align-items: center;
        gap: calc(var(--spacing-unit) * 1);
    }
}