/* AI创业内参 - 全站样式 */
:root {
    --primary: #6366f1;
    --primary-dark: #4f46e5;
    --secondary: #8b5cf6;
    --bg: #f8fafc;
    --bg-card: #ffffff;
    --text: #1e293b;
    --text-light: #64748b;
    --border: #e2e8f0;
}

* { margin: 0; padding: 0; box-sizing: border-box; }

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

.container {
    max-width: 1000px;
    margin: 0 auto;
    padding: 0 20px;
}

/* 头部 */
.site-header {
    background: var(--bg-card);
    border-bottom: 1px solid var(--border);
    padding: 15px 0;
    position: sticky;
    top: 0;
    z-index: 100;
}

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

.site-header .logo {
    font-size: 1.3em;
    font-weight: bold;
    color: var(--primary);
    text-decoration: none;
}

.site-header nav {
    display: flex;
    gap: 20px;
    align-items: center;
}

.site-header nav a {
    color: var(--text);
    text-decoration: none;
    font-size: 0.95em;
}

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

.subscribe-btn {
    background: var(--primary);
    color: white !important;
    padding: 8px 16px;
    border-radius: 20px;
}

/* Hero 头部 */
.hero-header {
    background: linear-gradient(135deg, var(--primary) 0%, var(--secondary) 100%);
    color: white;
    padding: 60px 20px;
    text-align: center;
}

.hero-header h1 {
    font-size: 2.5em;
    margin-bottom: 10px;
}

.hero-header .tagline {
    font-size: 1.3em;
    opacity: 0.9;
    margin-bottom: 15px;
}

.hero-header .description {
    max-width: 600px;
    margin: 0 auto 30px;
    opacity: 0.9;
}

.hero-stats {
    display: flex;
    justify-content: center;
    gap: 40px;
}

.stat {
    text-align: center;
}

.stat-num {
    font-size: 2em;
    font-weight: bold;
    display: block;
}

.stat-label {
    font-size: 0.9em;
    opacity: 0.8;
}

/* 主内容 */
.main-content {
    padding: 40px 20px;
}

.section-title {
    margin-bottom: 25px;
    font-size: 1.5em;
}

/* 文章卡片 */
.articles-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: 20px;
    margin-bottom: 50px;
}

.article-card {
    background: var(--bg-card);
    padding: 25px;
    border-radius: 12px;
    box-shadow: 0 2px 15px rgba(0,0,0,0.05);
    transition: transform 0.2s, box-shadow 0.2s;
}

.article-card:hover {
    transform: translateY(-3px);
    box-shadow: 0 5px 25px rgba(0,0,0,0.1);
}

.article-card h3 {
    margin: 10px 0;
    font-size: 1.1em;
}

.article-card h3 a {
    color: var(--text);
    text-decoration: none;
}

.article-card h3 a:hover {
    color: var(--primary);
}

.article-type {
    display: inline-block;
    padding: 4px 10px;
    border-radius: 12px;
    font-size: 0.75em;
    font-weight: 500;
    background: #e0e7ff;
    color: var(--primary);
}

.article-type.deep, .article-type.case {
    background: #dcfce7;
    color: #16a34a;
}

.article-type.hot, .article-type.hotspot {
    background: #fee2e2;
    color: #dc2626;
}

.article-meta {
    color: var(--text-light);
    font-size: 0.85em;
    margin-top: 10px;
}

/* 订阅区块 */
.subscribe-section {
    margin-top: 60px;
}

.subscribe-box {
    background: linear-gradient(135deg, var(--primary) 0%, var(--secondary) 100%);
    color: white;
    padding: 50px;
    border-radius: 16px;
    text-align: center;
}

.subscribe-box h2 {
    font-size: 1.8em;
    margin-bottom: 15px;
}

.subscribe-box p {
    margin-bottom: 20px;
    opacity: 0.9;
}

.subscribe-form {
    display: flex;
    gap: 10px;
    max-width: 450px;
    margin: 0 auto 15px;
}

.subscribe-form input {
    flex: 1;
    padding: 12px 20px;
    border: none;
    border-radius: 25px;
    font-size: 1em;
}

.subscribe-form button {
    background: white;
    color: var(--primary);
    border: none;
    padding: 12px 25px;
    border-radius: 25px;
    font-weight: bold;
    cursor: pointer;
}

.subscribe-note {
    font-size: 0.85em;
    opacity: 0.7;
}

.social-links {
    margin-top: 30px;
    padding-top: 20px;
    border-top: 1px solid rgba(255,255,255,0.2);
}

.social-links a {
    color: white;
    font-weight: bold;
}

/* 页脚 */
.site-footer {
    background: #1e293b;
    color: white;
    padding: 50px 20px 20px;
    margin-top: 60px;
}

.footer-content {
    display: grid;
    grid-template-columns: 2fr 1fr 1fr;
    gap: 40px;
    margin-bottom: 30px;
}

.footer-brand h3 {
    margin-bottom: 10px;
}

.footer-links h4 {
    margin-bottom: 15px;
    font-size: 1em;
}

.footer-links a, .footer-links p {
    display: block;
    color: #94a3b8;
    text-decoration: none;
    margin-bottom: 8px;
    font-size: 0.9em;
}

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

.footer-bottom {
    text-align: center;
    padding-top: 20px;
    border-top: 1px solid #334155;
    color: #64748b;
    font-size: 0.85em;
}

.footer-bottom a {
    color: #64748b;
}

/* 响应式 */
@media (max-width: 768px) {
    .hero-stats {
        flex-wrap: wrap;
        gap: 20px;
    }
    .footer-content {
        grid-template-columns: 1fr;
    }
    .subscribe-form {
        flex-direction: column;
    }
    .site-header nav {
        gap: 10px;
    }
    .site-header nav a:not(.subscribe-btn) {
        display: none;
    }
}