/* AI 工具导航（v6.84）独立浅色主题：与博客前台同款浅灰底 + 白卡 + 直角，ai.snswhy.com 子域名与主站 /ai 共用，不影响博客前台样式 */
* { box-sizing: border-box; }
html, body { margin: 0; padding: 0; }
body { background: #f2f3f5; color: #23272f; font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Microsoft YaHei", sans-serif; font-size: 15px; line-height: 1.6; }
a { color: inherit; text-decoration: none; }
img { max-width: 100%; }

.ai-top { position: sticky; top: 0; z-index: 50; background: rgba(255, 255, 255, .95); backdrop-filter: blur(8px); border-bottom: 1px solid #e3e6ea; }
.ai-top-in { max-width: 1240px; margin: 0 auto; padding: 12px 16px; display: flex; align-items: center; gap: 16px; }
.ai-brand { display: inline-flex; align-items: center; gap: 10px; flex: none; }
.ai-brand-ic { font-size: 30px; }
.ai-brand-tx { display: flex; flex-direction: column; line-height: 1.15; }
.ai-brand-tx b { font-size: 19px; letter-spacing: .5px; }
.ai-brand-tx i { font-style: normal; font-size: 10px; color: #8a93a3; letter-spacing: 2px; }
.ai-search { flex: 1; display: flex; max-width: 560px; margin: 0 auto; }
.ai-search input { flex: 1; height: 40px; border: 1px solid #d8dde3; border-right: 0; border-radius: 0; background: #fff; color: #23272f; padding: 0 14px; font-size: 14px; outline: none; min-width: 0; }
.ai-search input:focus { border-color: #4f7cff; }
.ai-search button { height: 40px; padding: 0 20px; border: 0; border-radius: 0; background: #4f7cff; color: #fff; font-size: 14px; cursor: pointer; flex: none; }
.ai-back { flex: none; font-size: 13px; color: #5b6472; border: 1px solid #d8dde3; padding: 8px 12px; border-radius: 0; background: #fff; }
.ai-back:hover { color: #4f7cff; border-color: #4f7cff; }
.ai-cats { max-width: 1240px; margin: 0 auto; padding: 0 16px 12px; display: flex; gap: 8px; overflow-x: auto; scrollbar-width: none; }
.ai-cats::-webkit-scrollbar { display: none; }
.ai-cats a { flex: none; font-size: 13px; color: #3c4450; background: #fff; border: 1px solid #e3e6ea; padding: 6px 12px; border-radius: 0; }
.ai-cats a span { color: #9aa3af; font-size: 12px; }
.ai-cats a.on { background: #4f7cff; border-color: #4f7cff; color: #fff; }
.ai-cats a.on span { color: #dbe6ff; }

.ai-main { max-width: 1240px; margin: 0 auto; padding: 22px 16px 40px; }
.ai-hero { text-align: center; padding: 30px 10px 26px; }
.ai-hero h1 { font-size: 34px; margin: 0 0 8px; background: linear-gradient(90deg, #3b78ff, #7a5cff, #f59e0b); -webkit-background-clip: text; background-clip: text; color: transparent; }
.ai-hero p { color: #6b7280; margin: 0 0 18px; }
.ai-hero p b { color: #d97706; }
.ai-hero-search { display: flex; max-width: 640px; margin: 0 auto; }
.ai-hero-search input { flex: 1; height: 48px; border: 1px solid #d8dde3; border-right: 0; border-radius: 0; background: #fff; color: #23272f; padding: 0 16px; font-size: 15px; outline: none; min-width: 0; }
.ai-hero-search input:focus { border-color: #4f7cff; }
.ai-hero-search button { height: 48px; padding: 0 26px; border: 0; border-radius: 0; background: linear-gradient(90deg, #4f7cff, #7a5cff); color: #fff; font-size: 15px; cursor: pointer; flex: none; }

.ai-catgrid { display: grid; grid-template-columns: repeat(5, 1fr); gap: 12px; margin: 8px 0 10px; }
.ai-catcard { background: #fff; border: 1px solid #e3e6ea; border-radius: 0; padding: 20px 10px 16px; text-align: center; display: flex; flex-direction: column; align-items: center; gap: 5px; transition: border-color .15s, transform .15s; }
.ai-catcard:hover { border-color: #4f7cff; transform: translateY(-2px); }
.ai-catcard-ic { font-size: 26px; }
.ai-catcard b { font-size: 15px; }
.ai-catcard i { font-style: normal; font-size: 12px; color: #9aa3af; }

.ai-sec { margin-top: 30px; }
.ai-sec-head { display: flex; align-items: baseline; justify-content: space-between; margin-bottom: 12px; }
.ai-sec-head h2 { font-size: 20px; margin: 0; }
.ai-sec-head a { font-size: 13px; color: #4f7cff; }

.ai-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 12px; }
.ait-card { background: #fff; border: 1px solid #e3e6ea; border-radius: 0; padding: 14px; display: flex; flex-direction: column; gap: 9px; min-height: 128px; transition: border-color .15s, transform .15s; }
.ait-card:hover { border-color: #4f7cff; transform: translateY(-2px); }
.ait-card-top { display: flex; align-items: center; gap: 10px; }
.ait-card-top b { font-size: 15px; flex: 1; min-width: 0; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.ait-logo { width: 38px; height: 38px; flex: none; border-radius: 0; overflow: hidden; background: #eef1f4; display: inline-flex; }
.ait-logo img { width: 100%; height: 100%; object-fit: cover; }
.ait-logo.big { width: 64px; height: 64px; border-radius: 0; }
.ait-letter { width: 100%; height: 100%; display: inline-flex; align-items: center; justify-content: center; color: #fff; font-weight: 700; font-size: 18px; }
.ait-score { flex: none; color: #d97706; font-size: 13px; font-weight: 700; }
.ait-card-desc { font-size: 13px; color: #5b6472; display: -webkit-box; -webkit-line-clamp: 2; -webkit-box-orient: vertical; overflow: hidden; flex: 1; }
.ait-card-meta { display: flex; gap: 6px; flex-wrap: wrap; align-items: center; }
.ait-tag { font-size: 11px; color: #3b6fe0; background: rgba(79, 124, 255, .1); padding: 2px 8px; border-radius: 0; }
.ait-price { font-size: 11px; color: #b45309; background: rgba(245, 158, 11, .13); padding: 2px 8px; border-radius: 0; }
.ait-lang { font-size: 11px; color: #8a93a3; border: 1px solid #d8dde3; padding: 1px 7px; border-radius: 0; }

.ai-h1 { font-size: 26px; margin: 6px 0 14px; }
.ai-h1 span { font-size: 14px; color: #9aa3af; margin-left: 10px; font-weight: 400; }
.ai-chips { display: flex; gap: 8px; flex-wrap: wrap; margin-bottom: 14px; }
.ai-chips a { font-size: 13px; background: #fff; border: 1px solid #e3e6ea; color: #3c4450; padding: 6px 12px; border-radius: 0; }
.ai-chips a span { color: #9aa3af; font-size: 12px; }
.ai-chips a.on { background: #4f7cff; border-color: #4f7cff; color: #fff; }
.ai-chips a.on span { color: #dbe6ff; }
.ai-sortbar { display: flex; gap: 16px; margin-bottom: 14px; font-size: 13px; }
.ai-sortbar a { color: #6b7280; }
.ai-sortbar a.on { color: #23272f; font-weight: 700; border-bottom: 2px solid #4f7cff; padding-bottom: 3px; }
.ai-pager { display: flex; gap: 8px; justify-content: center; margin-top: 26px; flex-wrap: wrap; }
.ai-pager a, .ai-pager span { padding: 7px 13px; border-radius: 0; background: #fff; border: 1px solid #e3e6ea; font-size: 13px; color: #3c4450; }
.ai-pager span.on { background: #4f7cff; border-color: #4f7cff; color: #fff; }
.ai-empty { color: #6b7280; padding: 40px 0; text-align: center; }
.ai-empty a { color: #4f7cff; }

.ai-crumb { font-size: 13px; color: #9aa3af; margin: 4px 0 14px; }
.ai-crumb a { color: #5b6472; }
.ai-detail { background: #fff; border: 1px solid #e3e6ea; border-radius: 0; padding: 22px; }
.ai-detail-head { display: flex; gap: 16px; align-items: center; }
.ai-detail-title { flex: 1; min-width: 0; }
.ai-detail-title h1 { font-size: 26px; margin: 0 0 4px; }
.ai-detail-slogan { color: #d97706; margin: 0 0 8px; font-size: 15px; }
.ai-detail-meta { display: flex; gap: 14px; flex-wrap: wrap; font-size: 13px; color: #6b7280; }
.ai-goto { flex: none; background: linear-gradient(90deg, #4f7cff, #7a5cff); color: #fff; font-size: 15px; font-weight: 700; padding: 12px 22px; border-radius: 0; }
.ai-detail-body { margin-top: 18px; border-top: 1px solid #eef0f3; padding-top: 16px; color: #3c4450; }
.ai-detail-body p { margin: 0 0 12px; }
.ai-detail-tags { display: flex; gap: 8px; flex-wrap: wrap; margin-top: 6px; }
.ai-detail-tags a { font-size: 12px; color: #3b6fe0; background: rgba(79, 124, 255, .1); padding: 4px 10px; border-radius: 0; }

.ai-foot { border-top: 1px solid #e3e6ea; margin-top: 20px; background: #fff; }
.ai-foot-in { max-width: 1240px; margin: 0 auto; padding: 22px 16px 30px; color: #8a93a3; font-size: 13px; }
.ai-foot-in b { color: #3c4450; }
.ai-foot-links { display: flex; gap: 18px; }
.ai-foot-links a { color: #4f7cff; }
.ai-foot-copy { margin-bottom: 0; }

@media (max-width: 1080px) {
  .ai-grid { grid-template-columns: repeat(3, 1fr); }
  .ai-catgrid { grid-template-columns: repeat(4, 1fr); }
}
@media (max-width: 760px) {
  .ai-grid { grid-template-columns: repeat(2, 1fr); }
  .ai-catgrid { grid-template-columns: repeat(3, 1fr); }
  .ai-hero h1 { font-size: 26px; }
  .ai-back { display: none; }
  .ai-brand-tx i { display: none; }
  .ai-detail-head { flex-wrap: wrap; }
  .ai-goto { width: 100%; text-align: center; }
}
@media (max-width: 430px) {
  .ai-grid { grid-template-columns: 1fr 1fr; }
  .ait-card { min-height: 120px; padding: 11px; }
  .ait-card-top b { font-size: 14px; }
}