:root {
    --primary: #2563eb;
    --bg: #f8fafc;
    --card-bg: #ffffff;
    --text: #1e293b;
    --text-secondary: #64748b;
    --border: #e2e8f0;
    --shadow: 0 1px 3px rgba(0,0,0,0.1);
    --radius: 12px;
}

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

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'PingFang SC', sans-serif;
    background: var(--bg);
    color: var(--text);
    line-height: 1.6;
}

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

/* 导航 */
.header {
    background: var(--card-bg);
    border-bottom: 1px solid var(--border);
    position: sticky;
    top: 0;
    z-index: 100;
}
.header .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 60px;
}
.logo {
    font-size: 20px;
    font-weight: 700;
    color: var(--primary);
    text-decoration: none;
}
.nav a {
    margin-left: 24px;
    color: var(--text-secondary);
    text-decoration: none;
    font-size: 15px;
}
.nav a:hover { color: var(--primary); }

/* 搜索区 */
.search-section {
    background: linear-gradient(135deg, #1e40af, #3b82f6);
    color: white;
    padding: 60px 0;
    text-align: center;
}
.search-section h1 {
    font-size: 36px;
    margin-bottom: 12px;
}
.search-section p {
    font-size: 18px;
    opacity: 0.9;
    margin-bottom: 30px;
}
.search-box {
    display: flex;
    max-width: 600px;
    margin: 0 auto;
    gap: 8px;
}
.search-box input {
    flex: 1;
    padding: 14px 20px;
    border: none;
    border-radius: 50px;
    font-size: 16px;
    outline: none;
}
.search-box button {
    padding: 14px 28px;
    border: none;
    border-radius: 50px;
    background: #f59e0b;
    color: white;
    font-size: 16px;
    cursor: pointer;
    font-weight: 600;
}
.search-box button:hover { background: #d97706; }

/* 热门内容 */
.hot-content, .latest-content {
    padding: 40px 0;
}
.hot-content h2, .latest-content h2 {
    font-size: 24px;
    margin-bottom: 24px;
}
.card-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: 20px;
}
.card {
    background: var(--card-bg);
    border-radius: var(--radius);
    padding: 24px;
    box-shadow: var(--shadow);
    border: 1px solid var(--border);
    transition: transform 0.2s, box-shadow 0.2s;
    cursor: pointer;
}
.card:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(0,0,0,0.15);
}
.card .tag {
    display: inline-block;
    background: #eff6ff;
    color: var(--primary);
    padding: 2px 10px;
    border-radius: 20px;
    font-size: 12px;
    margin-bottom: 12px;
}
.card .title {
    font-size: 18px;
    font-weight: 600;
    margin-bottom: 8px;
}
.card .excerpt {
    color: var(--text-secondary);
    font-size: 14px;
    margin-bottom: 16px;
}
.card .meta {
    display: flex;
    justify-content: space-between;
    font-size: 12px;
    color: var(--text-secondary);
}

/* 列表 */
.feed-list .feed-item {
    background: var(--card-bg);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 20px 24px;
    margin-bottom: 12px;
    cursor: pointer;
    transition: box-shadow 0.2s;
}
.feed-item:hover { box-shadow: var(--shadow); }
.feed-item .source {
    color: var(--primary);
    font-size: 13px;
    font-weight: 500;
}
.feed-item .content { margin: 8px 0; font-size: 15px; }
.feed-item .time { color: var(--text-secondary); font-size: 12px; }

/* 页脚 */
.footer {
    background: var(--card-bg);
    border-top: 1px solid var(--border);
    padding: 24px 0;
    text-align: center;
    color: var(--text-secondary);
    font-size: 14px;
    margin-top: 40px;
}

/* 响应式 */
@media (max-width: 768px) {
    .search-section h1 { font-size: 24px; }
    .card-grid { grid-template-columns: 1fr; }
    .nav { display: none; }
}