/* ==================== 全局样式 ==================== */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    --primary: #2563eb;
    --primary-dark: #1e40af;
    --text-primary: #1e293b;
    --text-secondary: #64748b;
    --text-light: #94a3b8;
    --bg-primary: #ffffff;
    --bg-secondary: #f8fafc;
    --bg-tertiary: #f1f5f9;
    --border: #e2e8f0;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    color: var(--text-primary);
    background: var(--bg-primary);
    line-height: 1.6;
    overflow-x: hidden;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 24px;
}

/* ==================== 导航栏 ==================== */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    background: #ffffff;
    border-bottom: 1px solid var(--border);
    z-index: 1000;
    transition: all 0.3s;
}

.nav-content {
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 64px;
}

.logo {
    display: flex;
    align-items: center;
    gap: 10px;
    font-size: 18px;
    font-weight: 600;
    color: var(--text-primary);
}

.nav-menu {
    display: none;
}

.nav-actions {
    display: flex;
    gap: 12px;
    align-items: center;
}

/* ==================== 按钮 ==================== */
.btn-text {
    padding: 8px 16px;
    color: var(--text-primary);
    text-decoration: none;
    font-size: 14px;
    font-weight: 500;
    transition: all 0.2s;
}

.btn-text:hover {
    color: var(--primary);
}

.btn-primary {
    padding: 8px 20px;
    background: var(--primary);
    color: white;
    text-decoration: none;
    font-size: 14px;
    font-weight: 500;
    transition: all 0.2s;
}

.btn-primary:hover {
    background: var(--primary-dark);
    transform: translateY(-1px);
}

.btn-large {
    padding: 14px 32px;
    font-size: 15px;
    font-weight: 500;
    text-decoration: none;
    transition: all 0.2s;
}

.btn-outline {
    border: 2px solid var(--border);
    color: var(--text-primary);
}

.btn-outline:hover {
    border-color: var(--primary);
    color: var(--primary);
}

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

.btn-white:hover {
    transform: translateY(-2px);
    box-shadow: 0 10px 20px rgba(0, 0, 0, 0.1);
}

.btn-outline-white {
    border: 2px solid rgba(255, 255, 255, 0.3);
    color: white;
}

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

/* ==================== Hero区域 ==================== */
.hero {
    padding: 140px 0 80px;
    background: linear-gradient(180deg, var(--bg-secondary) 0%, var(--bg-primary) 100%);
}

.hero-content {
    text-align: center;
    max-width: 800px;
    margin: 0 auto 60px;
}

.hero-title {
    font-size: 56px;
    font-weight: 700;
    line-height: 1.2;
    margin-bottom: 20px;
    letter-spacing: -0.02em;
}

.hero-subtitle {
    font-size: 18px;
    color: var(--text-secondary);
    margin-bottom: 32px;
    line-height: 1.8;
}

.hero-actions {
    display: flex;
    gap: 16px;
    justify-content: center;
}

/* ==================== API可视化 ==================== */
.api-visual {
    position: relative;
    height: 500px;
    max-width: 900px;
    margin: 0 auto;
}

#canvas {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    pointer-events: none;
}

.central-node {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    background: white;
    border: 2px solid var(--primary);
    padding: 20px 24px;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 8px;
    box-shadow: 0 20px 25px -5px rgba(0, 0, 0, 0.1);
    z-index: 10;
}

.central-node svg {
    color: var(--primary);
}

.central-node span {
    font-size: 14px;
    font-weight: 600;
    color: var(--text-primary);
}

.provider-nodes {
    position: relative;
    width: 100%;
    height: 100%;
}

.provider-node {
    position: absolute;
    background: white;
    border: 1px solid var(--border);
    padding: 12px;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.07);
    opacity: 0;
    animation: fadeIn 0.6s ease forwards;
    transition: all 0.3s;
}

.provider-node:hover {
    transform: translateY(-4px) scale(1.05);
    box-shadow: 0 10px 15px rgba(0, 0, 0, 0.1);
    border-color: var(--primary);
}

.provider-node img {
    display: block;
    width: 40px;
    height: 40px;
}

/* 节点位置 */
.provider-node[data-index="0"] {
    top: 5%;
    left: 15%;
    animation-delay: 0.1s;
}

.provider-node[data-index="1"] {
    top: 5%;
    right: 15%;
    animation-delay: 0.2s;
}

.provider-node[data-index="2"] {
    top: 40%;
    left: 2%;
    animation-delay: 0.3s;
}

.provider-node[data-index="3"] {
    top: 40%;
    right: 2%;
    animation-delay: 0.4s;
}

.provider-node[data-index="4"] {
    bottom: 5%;
    left: 15%;
    animation-delay: 0.5s;
}

.provider-node[data-index="5"] {
    bottom: 5%;
    right: 15%;
    animation-delay: 0.6s;
}

@keyframes fadeIn {
    to {
        opacity: 1;
    }
}

/* ==================== 特性区域 ==================== */
.features {
    padding: 100px 0;
}

.section-title {
    font-size: 40px;
    font-weight: 700;
    text-align: center;
    margin-bottom: 12px;
    letter-spacing: -0.01em;
}

.section-subtitle {
    font-size: 16px;
    color: var(--text-secondary);
    text-align: center;
    margin-bottom: 60px;
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 32px;
}

.feature-item {
    padding: 32px 24px;
    background: var(--bg-secondary);
    border: 1px solid var(--border);
    transition: all 0.3s;
}

.feature-item:hover {
    transform: translateY(-4px);
    box-shadow: 0 10px 15px rgba(0, 0, 0, 0.1);
    border-color: var(--primary);
}

.feature-icon {
    width: 48px;
    height: 48px;
    background: white;
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: 16px;
    color: var(--primary);
    border: 1px solid var(--border);
}

.feature-item h3 {
    font-size: 18px;
    font-weight: 600;
    margin-bottom: 8px;
}

.feature-item p {
    font-size: 14px;
    color: var(--text-secondary);
    line-height: 1.6;
}

/* ==================== 供应商区域 ==================== */
.providers {
    padding: 100px 0;
    background: var(--bg-secondary);
}

.providers-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
    gap: 24px;
    max-width: 900px;
    margin: 0 auto;
}

.provider-card {
    background: white;
    border: 1px solid var(--border);
    padding: 32px 24px;
    text-align: center;
    transition: all 0.3s;
}

.provider-card:hover {
    transform: translateY(-4px);
    box-shadow: 0 10px 15px rgba(0, 0, 0, 0.1);
    border-color: var(--primary);
}

.provider-card img {
    width: 48px;
    height: 48px;
    margin: 0 auto 16px;
    display: block;
}

.provider-card h4 {
    font-size: 15px;
    font-weight: 600;
    color: var(--text-primary);
}

/* ==================== CTA区域 ==================== */
.cta {
    padding: 100px 0;
    background: linear-gradient(135deg, var(--primary) 0%, #1e40af 100%);
    text-align: center;
    position: relative;
    overflow: hidden;
}

.cta::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: repeating-linear-gradient(
        45deg,
        transparent,
        transparent 40px,
        rgba(255, 255, 255, 0.03) 40px,
        rgba(255, 255, 255, 0.03) 80px
    );
}

.cta-title {
    font-size: 40px;
    font-weight: 700;
    color: white;
    margin-bottom: 12px;
    position: relative;
    letter-spacing: -0.01em;
}

.cta-subtitle {
    font-size: 16px;
    color: rgba(255, 255, 255, 0.9);
    margin-bottom: 32px;
    position: relative;
}

.cta-actions {
    display: flex;
    gap: 16px;
    justify-content: center;
    position: relative;
}

/* ==================== 页脚 ==================== */
.footer {
    background: var(--bg-secondary);
    padding: 60px 0 24px;
    border-top: 1px solid var(--border);
}

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

.footer-brand {
    max-width: 300px;
}

.footer-logo {
    display: flex;
    align-items: center;
    gap: 10px;
    font-size: 16px;
    font-weight: 600;
    margin-bottom: 12px;
}

.footer-brand p {
    font-size: 14px;
    color: var(--text-secondary);
}

.footer-links {
    display: flex;
    gap: 60px;
}

.footer-group {
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.footer-group h4 {
    font-size: 13px;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    margin-bottom: 4px;
}

.footer-group a {
    font-size: 14px;
    color: var(--text-secondary);
    text-decoration: none;
    transition: color 0.2s;
}

.footer-group a:hover {
    color: var(--primary);
}

.footer-bottom {
    text-align: center;
    padding-top: 24px;
    border-top: 1px solid var(--border);
}

.footer-bottom p {
    font-size: 13px;
    color: var(--text-light);
}

/* ==================== 响应式 ==================== */
@media (max-width: 768px) {
    .nav-menu {
        display: none;
    }
    
    .hero-title {
        font-size: 36px;
    }
    
    .hero-actions {
        flex-direction: column;
    }
    
    .api-visual {
        height: 400px;
    }
    
    .features-grid {
        grid-template-columns: 1fr;
    }
    
    .providers-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .footer-content {
        flex-direction: column;
        gap: 32px;
    }
    
    .footer-links {
        gap: 32px;
    }
}