* { margin: 0; padding: 0; box-sizing: border-box; }
body { font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif; background: #fff; color: #333; line-height: 1.8; }
a { text-decoration: none; color: #576b95; }
.container { max-width: 680px; margin: 0 auto; padding: 0 16px; }
header { background: #fff; border-bottom: 1px solid #e5e5e5; padding: 12px 0; position: sticky; top: 0; z-index: 100; }
header .header-inner { display: flex; align-items: center; justify-content: space-between; }
header h1 { font-size: 18px; font-weight: 500; }
header h1 a { color: #333; }
nav { display: flex; gap: 20px; }
nav a { font-size: 14px; color: #666; }
nav a:hover { color: #576b95; }
.search-section { background: linear-gradient(180deg, #e8f4fc 0%, #f8fbfe 100%); padding: 16px 0 20px; }
.search-section .container { max-width: 680px; margin: 0 auto; padding: 0 16px; }
.logo { text-align: center; margin-bottom: 12px; }
.slogan { width: 260px; height: 44px; display: block; margin: 0 auto; }
.slogan text { font-size: 12px; font-family: inherit; font-weight: 500; }
.search-wrapper { background: #fff; border-radius: 10px; border: 2px solid var(--theme-color, #4e6ef2); margin-bottom: 12px; display: flex; align-items: center; }
#searchInput { flex: 1; padding: 14px 16px; font-size: 15px; border: none; outline: none; background: transparent; color: #222; }
#searchInput::placeholder { color: #bbb; }
#clearBtn { display: none; width: 20px; height: 20px; line-height: 18px; text-align: center; font-size: 16px; color: #999; cursor: pointer; margin-right: 8px; border-radius: 50%; background: #eee; }
#clearBtn:hover { background: #ddd; color: #666; }
#searchBtn { padding: 0 24px; height: 48px; margin: -2px -2px -2px 0; border: none; background: var(--theme-color, #4e6ef2); border-radius: 0 10px 10px 0; cursor: pointer; font-size: 15px; color: #fff; font-weight: 500; }
#searchBtn:hover { background: var(--theme-hover, #4662d9); }
.engines { display: flex; justify-content: flex-start; gap: 16px; }
.engine-option { display: none; }
.engine-label { display: inline-block; padding: 6px 4px; font-size: 14px; cursor: pointer; color: #666; border-bottom: 2px solid transparent; }
.engine-label:hover { color: #222; }
.engine-option:checked + .engine-label { color: #4e6ef2; font-weight: 500; border-bottom: 2px solid #4e6ef2; }
.search-section.fixed { position: fixed; top: 49px; left: 0; right: 0; z-index: 99; background: #fff; padding: 10px 0; box-shadow: 0 2px 8px rgba(0,0,0,0.1); }
.search-section.fixed .logo, .search-section.fixed .engines { display: none; }
.search-section.fixed .search-wrapper { margin-bottom: 0; }
.search-section.expanded { position: fixed; top: 49px; left: 0; right: 0; z-index: 99; background: linear-gradient(180deg, #e8f4fc 0%, #f8fbfe 100%); padding: 16px 0 20px; box-shadow: 0 2px 8px rgba(0,0,0,0.1); }
.search-section.expanded .logo, .search-section.expanded .engines { display: block; }
.search-section.expanded .logo { display: flex; justify-content: center; }
.search-placeholder { display: none; }
.article { padding: 20px 0; }
.article-title { font-size: 22px; font-weight: 600; color: #333; line-height: 1.4; margin-bottom: 16px; }
.article-meta { font-size: 14px; color: #999; margin-bottom: 20px; padding-bottom: 16px; border-bottom: 1px solid #f0f0f0; }
.article-meta span { margin-right: 16px; }
.article-meta .author { color: #576b95; }
.article-content { font-size: 17px; color: #333; line-height: 1.9; }
.article-content p { margin-bottom: 20px; text-align: justify; }
.article-content img { max-width: 70%; height: auto; display: block; margin: 20px auto; border-radius: 4px; }
.article-content h2 { font-size: 20px; font-weight: 600; margin: 30px 0 15px; }
.article-content h3 { font-size: 18px; font-weight: 600; margin: 25px 0 12px; }
.article-content blockquote { background: #f7f7f7; border-left: 3px solid #576b95; padding: 12px 16px; margin: 20px 0; color: #666; }
.article-content ul, .article-content ol { padding-left: 24px; margin-bottom: 20px; }
.article-content li { margin-bottom: 8px; }
.article-tags { margin-top: 30px; padding-top: 16px; border-top: 1px solid #f0f0f0; font-size: 14px; color: #999; }
.article-tags span { display: inline-block; background: #f7f7f7; padding: 4px 12px; border-radius: 4px; margin-right: 8px; margin-bottom: 8px; }
.related { margin-top: 30px; padding: 20px; background: #f7f7f7; border-radius: 8px; }
.related h3 { font-size: 16px; font-weight: 500; margin-bottom: 16px; color: #333; }
.related-list { list-style: none; }
.related-item { background: #fff; margin-bottom: 8px; border-radius: 4px; }
.related-item a { display: flex; padding: 12px; align-items: center; }
.related-item .info { flex: 1; min-width: 0; padding-right: 12px; }
.related-item .title { font-size: 15px; font-weight: 500; color: #333; line-height: 1.4; display: -webkit-box; -webkit-line-clamp: 2; -webkit-box-orient: vertical; overflow: hidden; }
.related-item .meta { font-size: 12px; color: #999; margin-top: 6px; }
.related-item .meta span { margin-right: 10px; }
.related-item .thumb { width: 80px; height: 54px; flex-shrink: 0; border-radius: 4px; overflow: hidden; }
.related-item .thumb img { width: 100%; height: 100%; object-fit: cover; }
.related-item:hover .title { color: #576b95; }
footer { text-align: center; padding: 30px 16px; font-size: 12px; color: #999; background: #f7f7f7; margin-top: 40px; }
footer .divider { margin: 0 10px; color: #ddd; }
footer a { color: #666; text-decoration: none; }
footer a:hover { color: #576b95; }
.back-top { position: fixed; right: calc(50% - 380px); bottom: 20px; width: 40px; height: 40px; background: #576b95; color: #fff; border: none; border-radius: 50%; cursor: pointer; font-size: 18px; display: none; align-items: center; justify-content: center; box-shadow: 0 2px 8px rgba(0,0,0,0.15); }
.back-top:hover { background: #465a7c; }
@media (max-width: 800px) {
    .back-top { right: 20px; }
}
@media (max-width: 480px) {
    .article-title { font-size: 20px; }
    .article-content { font-size: 16px; }
}