/* ============================================================
   博客系统专属样式:列表页 + 文章页
   颜色 / 字体 / 阴影全部引用 base.css :root 设计令牌
   ============================================================ */

/* ---------- 列表页:标签筛选 ---------- */
.tag-filter {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-top: 32px;
}

.tag-btn {
  appearance: none;
  border: none;
  cursor: pointer;
  font-family: var(--font-body);
  font-size: 0.92rem;
  font-weight: 600;
  line-height: 1;
  color: var(--text-muted);
  background: var(--bg-panel-2);
  border-radius: 999px;
  padding: 12px 20px;
  transition: color 0.2s ease, background 0.2s ease, transform 0.2s ease, box-shadow 0.2s ease;
}

.tag-btn:hover {
  color: var(--text);
  background: var(--bg-panel-2-soft);
  transform: translateY(-1px);
}

.tag-btn.is-on {
  color: var(--ink);
  background: var(--accent);
  box-shadow: var(--glow-accent);
}

.tag-btn:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 2px;
}

.post-count {
  margin: 20px 0 0;
  font-family: var(--font-mono);
  font-size: 0.82rem;
  color: var(--text-muted);
}

/* ---------- 文章卡片(列表页 + 延伸阅读共用) ---------- */
.post-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 20px;
  margin-top: 24px;
}

.post-card {
  display: flex;
  flex-direction: column;
  gap: 12px;
  padding: 24px;
  background: var(--bg-panel-2);
  border-radius: 20px;
  text-decoration: none;
  color: var(--text);
  box-shadow: var(--shadow-card);
  transition: transform 0.22s ease, background 0.22s ease, box-shadow 0.22s ease;
}

.post-card:hover {
  transform: translateY(-4px);
  background: var(--bg-panel-2-soft);
  box-shadow: var(--shadow-deep);
}

.post-card:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 3px;
}

.post-tag {
  align-self: flex-start;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  font-weight: 700;
  letter-spacing: 0.04em;
  color: var(--ink);
  background: var(--accent);
  border-radius: 8px;
  padding: 6px 10px;
}

.post-title {
  margin: 0;
  font-family: var(--font-display);
  font-size: 1.12rem;
  font-weight: 700;
  line-height: 1.5;
  color: var(--text);
}

.post-summary {
  margin: 0;
  flex: 1;
  font-size: 0.92rem;
  line-height: 1.75;
  color: var(--text-muted);
}

.post-meta {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  font-family: var(--font-mono);
  font-size: 0.8rem;
  color: var(--text-muted);
}

.post-meta svg {
  width: 18px;
  height: 18px;
  color: var(--accent);
  transition: transform 0.2s ease;
}

.post-card:hover .post-meta svg {
  transform: translateX(4px);
}

.post-empty {
  grid-column: 1 / -1;
  margin: 0;
  padding: 40px 24px;
  text-align: center;
  color: var(--text-muted);
  background: var(--bg-panel-2);
  border-radius: 20px;
}

/* ---------- 文章页:面包屑(与页头留呼吸距) ---------- */
.crumb {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  padding-top: 28px;
  font-size: 0.86rem;
  color: var(--text-muted);
}

.crumb a {
  color: var(--text-muted);
  text-decoration: none;
  transition: color 0.2s ease;
}

.crumb a:hover {
  color: var(--accent);
}

.crumb a:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 2px;
  border-radius: 4px;
}

.crumb .crumb-sep {
  color: var(--text-muted);
  user-select: none;
}

.crumb [aria-current="page"] {
  color: var(--text);
}

/* ---------- 文章页:Hero ---------- */
.post-hero {
  padding-top: 24px;
}

.post-hero-meta {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 12px;
  font-family: var(--font-mono);
  font-size: 0.8rem;
  color: var(--text-muted);
}

.post-hero h1 {
  margin: 18px 0 0;
  max-width: 22em;
}

.post-lead {
  margin: 18px 0 0;
  max-width: 44em;
  font-size: 1.05rem;
  line-height: 1.85;
  color: var(--text-muted);
}

/* ---------- 文章页:正文 ---------- */
.post-body {
  margin-top: 40px;
  max-width: 760px;
}

/* ---------- 文末下载引导卡 ---------- */
.dl-cta {
  margin-top: 56px;
  padding: 40px 32px;
  background: var(--bg-panel);
  color: var(--ink);
  border-radius: 24px;
  box-shadow: var(--glow-board), var(--shadow-card);
  text-align: center;
}

.dl-cta h2 {
  margin: 0;
  font-family: var(--font-display);
  font-size: 1.5rem;
  font-weight: 800;
  color: var(--ink);
}

.dl-cta p {
  margin: 12px auto 0;
  max-width: 36em;
  line-height: 1.8;
  color: var(--ink-soft);
}

.dl-cta .btn-row {
  margin-top: 24px;
  justify-content: center;
}

/* ---------- 延伸阅读 ---------- */
#related-posts {
  margin-top: 56px;
}

.related-head h2 {
  margin: 0;
  display: flex;
  align-items: center;
  gap: 12px;
  font-family: var(--font-display);
  font-size: 1.35rem;
  font-weight: 800;
  color: var(--text);
}

.related-head h2::before {
  content: "";
  width: 10px;
  height: 22px;
  border-radius: 4px;
  background: var(--accent);
  box-shadow: var(--glow-accent);
}

/* ---------- 上一篇 / 下一篇 ---------- */
.post-nav {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 16px;
  margin-top: 48px;
}

.post-nav-link {
  display: flex;
  flex-direction: column;
  gap: 8px;
  padding: 20px 22px;
  background: var(--bg-panel-2);
  border-radius: 18px;
  text-decoration: none;
  box-shadow: var(--shadow-card);
  transition: transform 0.2s ease, background 0.2s ease;
}

.post-nav-link:hover {
  transform: translateY(-3px);
  background: var(--bg-panel-2-soft);
}

.post-nav-link:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 3px;
}

.post-nav-link .dir {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  font-weight: 700;
  letter-spacing: 0.06em;
  color: var(--accent);
}

.post-nav-link .t {
  font-size: 0.95rem;
  font-weight: 600;
  line-height: 1.6;
  color: var(--text);
}

.post-nav-link.prev {
  grid-column: 1;
  text-align: left;
}

.post-nav-link.next {
  grid-column: 2;
  text-align: right;
}

/* ---------- 响应式 ---------- */
@media (max-width: 1024px) {
  .post-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

@media (max-width: 640px) {
  .tag-filter {
    gap: 8px;
    margin-top: 24px;
  }

  .tag-btn {
    padding: 10px 16px;
    font-size: 0.88rem;
  }

  .post-grid {
    grid-template-columns: minmax(0, 1fr);
  }

  .dl-cta {
    padding: 32px 22px;
  }

  .post-nav {
    grid-template-columns: minmax(0, 1fr);
  }

  .post-nav-link.prev,
  .post-nav-link.next {
    grid-column: 1;
    text-align: left;
  }
}