:root {
    /* 现代化渐变色系与霓虹科技色彩 */
    --primary-color: #6366f1; /* 靛蓝 */
    --primary-hover: #4f46e5;
    --secondary-color: #06b6d4; /* 青色 */
    --accent-color: #8b5cf6; /* 紫色 */
    
    /* 背景色 */
    --bg-main: #f4f7fb;
    --bg-surface: #ffffff;
    --bg-gradient: linear-gradient(135deg, #e0e7ff 0%, #f3e8ff 100%);
    --dark-bg: #111827;
    --dark-gradient: linear-gradient(135deg, #1e1b4b 0%, #111827 50%, #0f172a 100%);
    
    /* 字体颜色 */
    --text-main: #1e293b;
    --text-muted: #64748b;
    --text-light: #f8fafc;
    
    /* 其他辅助 */
    --border-color: rgba(99, 102, 241, 0.15);
    --shadow-sm: 0 4px 6px -1px rgba(0, 0, 0, 0.05), 0 2px 4px -1px rgba(0, 0, 0, 0.03);
    --shadow-md: 0 10px 15px -3px rgba(99, 102, 241, 0.1), 0 4px 6px -2px rgba(99, 102, 241, 0.05);
    --shadow-glow: 0 0 20px rgba(99, 102, 241, 0.4);
    --transition: all 0.4s cubic-bezier(0.4, 0, 0.2, 1);
    
    --radius-md: 12px;
    --radius-lg: 20px;
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
}

body {
    color: var(--text-main);
    line-height: 1.6;
    background-color: var(--bg-main);
    scroll-behavior: smooth;
    background-image: radial-gradient(circle at 100% 0%, rgba(99,102,241,0.08) 0%, transparent 25%),
                      radial-gradient(circle at 0% 100%, rgba(6,182,212,0.08) 0%, transparent 25%);
    background-attachment: fixed;
}

a {
    text-decoration: none;
    color: var(--primary-color);
    transition: var(--transition);
}

a:hover {
    color: var(--accent-color);
}

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

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

/* 炫酷按钮样式 */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 12px 28px;
    border-radius: 50px;
    font-weight: 600;
    font-size: 1rem;
    cursor: pointer;
    text-align: center;
    border: none;
    transition: var(--transition);
    letter-spacing: 0.5px;
    position: relative;
    overflow: hidden;
    z-index: 1;
}

.btn-primary {
    background: linear-gradient(135deg, var(--primary-color), var(--accent-color));
    color: var(--text-light) !important;
    box-shadow: 0 4px 15px rgba(99, 102, 241, 0.3);
}

.btn-primary:hover {
    transform: translateY(-3px);
    box-shadow: var(--shadow-glow);
}

.btn-secondary {
    background: rgba(99, 102, 241, 0.1);
    color: var(--primary-color) !important;
    border: 2px solid var(--primary-color);
}

.btn-secondary:hover {
    transform: translateY(-3px);
    box-shadow: 0 4px 15px rgba(99, 102, 241, 0.3);
    color: var(--text-light) !important;
    background: var(--primary-color);
}

.btn-large { padding: 16px 40px; font-size: 1.15rem; }
.btn-block { display: block; width: 100%; }

/* 毛玻璃导航栏 */
.navbar {
    background-color: rgba(255, 255, 255, 0.85);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    box-shadow: var(--shadow-sm);
    position: sticky;
    top: 0;
    z-index: 100;
    border-bottom: 1px solid rgba(255,255,255,0.3);
}

.navbar .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 76px;
}

.logo {
    font-size: 1.6rem;
    font-weight: 800;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    letter-spacing: -0.5px;
}

.nav-links { display: flex; gap: 32px; }
.nav-links a {
    color: var(--text-main);
    font-weight: 500;
    font-size: 0.95rem;
    position: relative;
}

.nav-links a::after {
    content: '';
    position: absolute;
    width: 0; height: 2px;
    bottom: -4px; left: 0;
    background: linear-gradient(90deg, var(--primary-color), var(--secondary-color));
    transition: var(--transition);
    border-radius: 2px;
}

.nav-links a:hover::after { width: 100%; }
.mobile-menu-btn { display: none; font-size: 1.8rem; cursor: pointer; color: var(--primary-color); }

/* Sections */
.section { padding: 100px 0; }
.bg-light { background: var(--bg-gradient); }

.section-title {
    text-align: center;
    font-size: 2.5rem;
    font-weight: 800;
    margin-bottom: 60px;
    color: var(--dark-bg);
    position: relative;
}

.section-title::after {
    content: '';
    display: block;
    width: 60px;
    height: 4px;
    background: linear-gradient(90deg, var(--primary-color), var(--secondary-color));
    margin: 20px auto 0;
    border-radius: 2px;
}

/* 渐变暗黑首屏 (Hero) */
.hero {
    background: var(--dark-gradient);
    color: var(--text-light);
    padding: 140px 0 120px;
    text-align: center;
    position: relative;
    overflow: hidden;
}

.hero::before {
    content: '';
    position: absolute;
    width: 600px; height: 600px;
    background: radial-gradient(circle, rgba(139,92,246,0.15) 0%, transparent 70%);
    top: -200px; left: -200px;
}

.hero::after {
    content: '';
    position: absolute;
    width: 500px; height: 500px;
    background: radial-gradient(circle, rgba(6,182,212,0.15) 0%, transparent 70%);
    bottom: -100px; right: -100px;
}

.hero-content { position: relative; z-index: 10; }
.hero-title {
    font-size: 3.5rem;
    font-weight: 800;
    margin-bottom: 24px;
    line-height: 1.2;
    background: linear-gradient(135deg, #ffffff 0%, #e0e7ff 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    letter-spacing: -1px;
}
.hero-subtitle {
    font-size: 1.2rem;
    color: #94a3b8;
    max-width: 700px;
    margin: 0 auto 48px;
    line-height: 1.8;
}
.hero-actions { display: flex; justify-content: center; gap: 20px; }

/* Grid Layouts */
.features-grid { display: grid; gap: 30px; grid-template-columns: repeat(auto-fit, minmax(260px, 1fr)); }
.audience-grid { display: grid; gap: 30px; grid-template-columns: repeat(auto-fit, minmax(320px, 1fr)); }
.pricing-grid { display: grid; gap: 30px; grid-template-columns: repeat(auto-fit, minmax(320px, 1fr)); align-items: center;}
.reviews-grid { display: grid; gap: 30px; grid-template-columns: repeat(auto-fit, minmax(400px, 1fr)); }
.article-grid { display: grid; gap: 30px; grid-template-columns: repeat(auto-fit, minmax(320px, 1fr)); }

/* 现代卡片设计 */
.feature-card, .audience-card, .pricing-card, .review-card, .article-card {
    background: rgba(255, 255, 255, 0.7);
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
    padding: 40px 30px;
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-sm);
    transition: var(--transition);
    border: 1px solid rgba(255, 255, 255, 0.5);
    position: relative;
    overflow: hidden;
}

.feature-card:hover, .audience-card:hover, .pricing-card:hover, .article-card:hover {
    transform: translateY(-8px);
    box-shadow: var(--shadow-md);
    background: rgba(255, 255, 255, 0.95);
    border-color: rgba(99, 102, 241, 0.2);
}

.feature-icon {
    font-size: 3rem;
    margin-bottom: 24px;
    display: inline-block;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

.feature-card h3, .audience-card h3, .article-card h3 {
    font-size: 1.3rem;
    margin-bottom: 15px;
    color: var(--dark-bg);
}

/* Pricing 特效 */
.pricing-card {
    text-align: center;
    background: #ffffff;
    border: 1px solid #e2e8f0;
}

.pricing-card.popular {
    border: 2px solid var(--primary-color);
    background: #ffffff;
    transform: scale(1.05);
    z-index: 2;
    box-shadow: 0 20px 25px -5px rgba(99, 102, 241, 0.1), 0 10px 10px -5px rgba(99, 102, 241, 0.04);
}

.pricing-card.popular:hover { 
    transform: scale(1.05) translateY(-8px); 
    box-shadow: 0 25px 30px -5px rgba(99, 102, 241, 0.2);
}

.badge {
    position: absolute;
    top: -14px; left: 50%;
    transform: translateX(-50%);
    background: linear-gradient(135deg, var(--primary-color), var(--accent-color));
    color: #ffffff;
    padding: 6px 18px;
    border-radius: 20px;
    font-size: 0.85rem;
    font-weight: 700;
    box-shadow: 0 4px 10px rgba(99, 102, 241, 0.3);
    letter-spacing: 1px;
    white-space: nowrap;
}

.price {
    font-size: 1.8rem;
    font-weight: 800;
    background: linear-gradient(135deg, var(--primary-color), var(--accent-color));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    margin: 25px 0;
}

.pricing-features {
    list-style: none;
    margin-bottom: 35px;
    text-align: left;
    color: var(--text-main);
}

.pricing-features li {
    padding: 12px 0;
    border-bottom: 1px dashed var(--border-color);
    display: flex;
    align-items: center;
    color: var(--text-muted);
}

.pricing-features li:before {
    content: "✓";
    color: var(--secondary-color);
    margin-right: 12px;
    font-weight: 900;
    font-size: 1.1rem;
}

/* Reviews */
.review-card {
    background: linear-gradient(135deg, var(--bg-surface) 0%, var(--bg-main) 100%);
}
.review-text { font-style: italic; margin-bottom: 24px; color: var(--text-main); font-size: 1.05rem; }
.review-author { font-weight: 700; color: var(--primary-color); }

/* FAQ 交互 */
.faq-list { max-width: 800px; margin: 0 auto; }
.faq-item {
    margin-bottom: 16px;
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    background: var(--bg-surface);
    overflow: hidden;
    transition: var(--transition);
}
.faq-item:hover { border-color: var(--primary-color); box-shadow: var(--shadow-sm); }
.faq-question {
    padding: 24px;
    font-weight: 600;
    font-size: 1.1rem;
    cursor: pointer;
    display: flex;
    justify-content: space-between;
    align-items: center;
    color: var(--dark-bg);
}
.faq-answer {
    padding: 0 24px;
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.4s ease, padding 0.4s ease;
    color: var(--text-muted);
}
.faq-item.active .faq-answer {
    padding: 0 24px 24px;
    max-height: 500px;
}
.faq-item.active .faq-question .icon {
    transform: rotate(45deg);
    color: var(--primary-color);
}
.faq-question .icon {
    transition: transform 0.3s ease;
    font-size: 1.5rem;
    color: var(--text-muted);
}

/* 文章目录特殊样式 */
.article-card p {
    color: var(--text-muted);
    font-size: 0.95rem;
    margin-bottom: 15px;
    display: -webkit-box;
    -webkit-line-clamp: 3;
    -webkit-box-orient: vertical;
    overflow: hidden;
}
.article-card .btn-secondary {
    border-radius: 8px;
    padding: 8px 20px;
    font-size: 0.9rem;
}

/* 底部极客风 */
.footer {
    background: var(--dark-bg);
    color: #94a3b8;
    padding: 80px 0 30px;
    border-top: 5px solid var(--primary-color);
}
.footer-grid { display: grid; grid-template-columns: 2fr 1fr 1fr; gap: 50px; margin-bottom: 50px; }
.footer h3, .footer h4 { color: var(--text-light); margin-bottom: 24px; font-weight: 700;}
.footer-links ul { list-style: none; }
.footer-links li { margin-bottom: 12px; }
.footer-links a { color: #94a3b8; transition: var(--transition); }
.footer-links a:hover { color: var(--secondary-color); padding-left: 8px; }
.footer-bottom { text-align: center; padding-top: 30px; border-top: 1px solid rgba(255,255,255,0.1); font-size: 0.9rem; }

/* Article Details Page Specific */
.article-header { background: var(--bg-gradient); padding: 80px 0; border-bottom: 1px solid var(--border-color); margin-bottom: 50px; }
.article-title { font-size: 2.8rem; font-weight: 800; margin-bottom: 15px; color: var(--dark-bg); letter-spacing: -0.5px;}
.article-meta { color: var(--text-muted); font-size: 1rem; font-weight: 500;}
.article-content { max-width: 800px; font-size: 1.1rem; color: var(--text-main); }
.article-content h2 { margin: 40px 0 20px; color: var(--dark-bg); font-size: 1.8rem; position: relative; padding-left: 15px;}
.article-content h2::before { content: ''; position: absolute; left: 0; top: 5px; bottom: 5px; width: 4px; background: var(--primary-color); border-radius: 2px;}
.article-content h3 { margin: 30px 0 15px; color: var(--dark-bg); font-size: 1.4rem;}
.article-content p { margin-bottom: 24px; }
.article-content ul, .article-content ol { margin: 0 0 24px 20px; padding-left: 20px;}
.article-content li { margin-bottom: 12px; }
.article-layout { display: grid; grid-template-columns: 1fr 320px; gap: 50px; }
.sidebar h3 { margin-bottom: 24px; padding-bottom: 12px; border-bottom: 2px solid var(--primary-color); font-size: 1.3rem;}
.related-articles { list-style: none; }
.related-articles li { margin-bottom: 16px; }
.related-articles a { color: var(--text-main); font-weight: 500; display: block; padding: 12px 16px; background: var(--bg-surface); border-radius: 8px; border: 1px solid var(--border-color); transition: var(--transition);}
.related-articles a:hover { color: var(--primary-color); border-color: var(--primary-color); transform: translateX(5px);}

/* 响应式适配 */
@media (max-width: 768px) {
    .nav-links, .nav-buttons { display: none; }
    .mobile-menu-btn { display: block; }
    .nav-links.active {
        display: flex; flex-direction: column; position: absolute; top: 75px; left: 0; right: 0;
        background: rgba(255, 255, 255, 0.98); backdrop-filter: blur(10px); padding: 30px;
        box-shadow: var(--shadow-md); text-align: center; border-bottom: 1px solid var(--border-color);
    }
    .hero-title { font-size: 2.2rem; }
    .hero { padding: 100px 0 80px; }
    .pricing-card.popular { transform: scale(1); }
    .pricing-card.popular:hover { transform: translateY(-5px); }
    .footer-grid { grid-template-columns: 1fr; gap: 30px;}
    .article-layout { grid-template-columns: 1fr; }
    .article-title { font-size: 2rem; }
    .btn { width: 100%; margin-bottom: 10px;}
}