/* 仿知乎排版（Demo 站点皮肤，§18.1） */
* { box-sizing: border-box; margin: 0; padding: 0; }
:root {
  --zb-blue: #056de8;
  --zb-text: #121212;
  --zb-gray: #8590a6;
  --zb-border: #e7e7e7;
  --zb-bg: #f6f6f6;
}
html { font-size: 15px; }
body {
  font-family: -apple-system, BlinkMacSystemFont, "PingFang SC", "Microsoft YaHei", "Segoe UI", sans-serif;
  background: var(--zb-bg);
  color: var(--zb-text);
}
.Topbar {
  position: sticky; top: 0; z-index: 100;
  height: 52px; background: #fff; border-bottom: 1px solid var(--zb-border);
  display: flex; align-items: center; gap: 24px; padding: 0 24px;
}
.Topbar .logo { font-size: 20px; font-weight: 700; color: var(--zb-blue); letter-spacing: 1px; }
.Topbar nav { display: flex; gap: 20px; color: #444; }
.Topbar nav a { color: inherit; text-decoration: none; font-size: 15px; }
.Topbar nav a.active { color: var(--zb-blue); font-weight: 600; }
.Topbar .spacer { flex: 1; }
.Topbar .mock-badge { font-size: 12px; color: var(--zb-gray); border: 1px solid var(--zb-border); border-radius: 4px; padding: 2px 8px; }

.App { max-width: 1000px; margin: 0 auto; padding: 16px; }
.QuestionHeader { background: #fff; border-radius: 6px; padding: 20px 24px; margin-bottom: 12px; }
.QuestionHeader h1 { font-size: 22px; line-height: 1.5; }
.QuestionHeader .meta { color: var(--zb-gray); font-size: 13px; margin-top: 8px; }
.AnswerCard { background: #fff; border-radius: 6px; padding: 20px 24px; }
.AnswerAuthor { display: flex; align-items: center; gap: 10px; margin-bottom: 12px; }
.AnswerAuthor .avatar {
  width: 40px; height: 40px; border-radius: 50%;
  background: linear-gradient(135deg, #056de8, #06b7fd);
  color: #fff; display: flex; align-items: center; justify-content: center; font-weight: 700;
}
.AnswerAuthor .name { font-weight: 600; }
.AnswerAuthor .bio { color: var(--zb-gray); font-size: 13px; }
.AnswerVote { display: flex; align-items: center; gap: 8px; margin-top: 16px; padding-top: 12px; border-top: 1px solid var(--zb-border); color: var(--zb-gray); font-size: 14px; }

/* 正文排版 */
.zb-RichText { font-size: 16px; line-height: 1.9; }
.zb-RichText p { margin: 0 0 1em; }
.zb-RichText h2 { font-size: 19px; margin: 1.4em 0 0.6em; }
.zb-RichText strong { font-weight: 700; }
.zb-RichText a { color: var(--zb-blue); text-decoration: none; }

/* 高亮（§10.3：原生自定义高亮 + 伪元素样式） */
::highlight(zhiban-concept) { background-color: rgba(5, 109, 232, 0.14); text-decoration: underline wavy rgba(5, 109, 232, 0.55) 1px; text-underline-offset: 4px; }
::highlight(zhiban-concept-expanded) { background-color: rgba(214, 122, 39, 0.18); text-decoration: underline wavy rgba(214, 122, 39, 0.7) 1px; text-underline-offset: 4px; }
/* Learning Hub 回原文锚点闪烁（§新功能：跳转后短暂高亮） */
::highlight(zhiban-jump) { background-color: rgba(255, 213, 79, 0.55); }

/* 首页 */
.HomeHero { background: #fff; border-radius: 6px; padding: 32px; margin-bottom: 12px; }
.HomeHero h1 { font-size: 26px; margin-bottom: 8px; }
.HomeHero .sub { color: var(--zb-gray); margin-bottom: 20px; }
/* §4.1 / §1 主视觉：首屏先摆困境——「知乎知道的」与「知乎不知道的」左右对比，中间一道裂痕 */
.HomeInsight { margin: 4px 0 20px; }
.insight-compare { position: relative; display: grid; grid-template-columns: 1fr 1fr; gap: 40px; }
/* 裂痕线：贯通左右的视觉隐喻，喻知乎的数据断层 */
.insight-compare::before {
  content: ''; position: absolute; left: 50%; top: 6px; bottom: 6px; width: 2px; transform: translateX(-50%);
  background: linear-gradient(180deg, transparent, #d5dbe6 14%, #c3cbd9 50%, #d5dbe6 86%, transparent);
}
.insight-crack {
  position: absolute; left: 50%; top: 50%; transform: translate(-50%, -50%);
  writing-mode: vertical-rl; letter-spacing: 3px; white-space: nowrap;
  background: #fff; color: var(--zb-gray); font-size: 11px; padding: 8px 3px; border-radius: 10px;
}
.insight-col { border-radius: 8px; padding: 16px 18px; }
/* 左半：知乎灰、低饱和、静态——赞/评论说的是「结果」 */
.insight-know { background: #f2f3f5; }
.insight-know .insight-col-head { color: #7a8296; }
.insight-know .insight-metric { color: #7a8296; }
.insight-know .insight-metric b { color: #5b6377; }
/* 右半：品牌强调色、动态——卡点说的是「过程」 */
.insight-unknown { background: #f2f7ff; border: 1px solid #d8e6ff; }
.insight-unknown .insight-col-head { color: var(--zb-blue); }
.insight-col-head { font-size: 13px; font-weight: 700; margin-bottom: 12px; }
.insight-metric { font-size: 15px; line-height: 1.9; }
.insight-metric b { font-size: 19px; color: var(--zb-blue); }
.insight-col-foot { margin-top: 10px; padding-top: 10px; font-size: 12px; color: var(--zb-gray); border-top: 1px dashed #dfe3ea; }
.insight-cta { margin-top: 10px; font-size: 14px; font-weight: 700; color: var(--zb-blue); line-height: 1.6; }
.HomeInsight .insight-note { font-size: 12px; color: var(--zb-gray); margin-top: 12px; }
@media (max-width: 720px) {
  .insight-compare { grid-template-columns: 1fr; gap: 12px; }
  .insight-compare::before { display: none; }
  .insight-crack { position: static; transform: none; writing-mode: horizontal-tb; display: block; width: max-content; margin: 0 auto; padding: 4px 10px; }
}
/* 演示数据标注：赞数等写死的数字与卡点数据一样标出来，不冒充真实统计（剩余问题 2） */
.demo-tag {
  display: inline-block; margin-left: 6px; padding: 1px 6px;
  border: 1px solid var(--zb-border); border-radius: 4px;
  background: #f6f7f9; color: var(--zb-gray);
  font-size: 11px; font-weight: 400; line-height: 1.6; vertical-align: middle;
}
.insight-stuck { margin-top: 16px; border-top: 1px solid var(--zb-border); }
.insight-stuck-item { display: flex; align-items: center; gap: 10px; padding: 10px 0; border-bottom: 1px solid var(--zb-border); cursor: pointer; font-size: 14px; }
.insight-stuck-item:hover { background: #fafbfd; }
.insight-stuck-item .rank { color: var(--zb-gray); font-weight: 600; }
.insight-stuck-item .concept { font-weight: 700; }
.insight-stuck-item .count { color: var(--zb-blue); }
.insight-stuck-item .go { margin-left: auto; color: var(--zb-gray); font-size: 13px; }
.insight-actions { margin-top: 16px; }
.HomeGuide { background: #fff; border-radius: 6px; padding: 28px 32px; }
.HomeGuide .lead { color: var(--zb-gray); font-size: 14px; margin-bottom: 16px; border-left: 3px solid var(--zb-blue); padding-left: 12px; line-height: 1.8; }
.HomeGuide h2 { font-size: 20px; margin-bottom: 16px; }
.ArticleList { display: grid; grid-template-columns: repeat(auto-fill, minmax(280px, 1fr)); gap: 12px; margin-top: 16px; }
.ArticleCard { background: #fff; border: 1px solid var(--zb-border); border-radius: 6px; padding: 16px; cursor: pointer; }
.ArticleCard:hover { border-color: var(--zb-blue); }
.ArticleCard h3 { font-size: 16px; margin-bottom: 8px; }
.ArticleCard .meta { color: var(--zb-gray); font-size: 13px; }
/* P1 真实内容接入：真实来源用品牌色标注，与「示例数据」灰标签一眼区分（§七-6） */
.real-tag {
  display: inline-block; margin-left: 6px; padding: 1px 6px;
  border: 1px solid #b9d4f6; border-radius: 4px;
  background: #eef5ff; color: var(--zb-blue);
  font-size: 11px; font-weight: 400; line-height: 1.6; vertical-align: middle;
}
.HomeReal { background: #fff; border-radius: 6px; padding: 28px 32px; margin-top: 12px; }
.HomeReal h2 { font-size: 20px; margin-bottom: 12px; }
.HomeReal .lead { color: var(--zb-gray); font-size: 14px; margin-bottom: 16px; border-left: 3px solid var(--zb-blue); padding-left: 12px; line-height: 1.8; }
.RealSearch { display: flex; gap: 10px; }
.RealSearch .real-input {
  flex: 1; padding: 8px 12px; font-size: 14px;
  border: 1px solid var(--zb-border); border-radius: 6px; outline: none;
}
.RealSearch .real-input:focus { border-color: var(--zb-blue); }
.RealSearch .zb-btn:disabled { opacity: .5; cursor: default; }
.RealStatus { color: var(--zb-gray); font-size: 13px; margin-top: 12px; }
.AnswerSource { display: flex; align-items: center; gap: 4px; flex-wrap: wrap; margin-bottom: 10px; padding: 8px 12px; background: #f6f9ff; border-radius: 6px; font-size: 13px; color: var(--zb-gray); }
.zb-RichText .src-note { font-size: 13px; color: var(--zb-gray); }