/* =====================================================
   忠台AI — Blog 樣式
   沿用 style-config.css 的 CSS 變數，視覺與全站一致
   ===================================================== */

.blog-main {
  max-width: 820px;
  margin: 0 auto;
  padding: calc(var(--space-xl, 2rem) * 1.5) var(--space-lg, 1.5rem) var(--space-xl, 2rem);
  min-height: 60vh;
}

/* ── 列表頁 header ─────────────────────────────── */
.blog-list-head {
  text-align: center;
  margin-bottom: var(--space-xl, 2rem);
}
.blog-list-title {
  position: relative;
  display: inline-block;
  font-family: var(--font-serif, serif);
  font-size: var(--text-4xl, 2.25rem);
  color: var(--color-text-dark, #000);
  margin: 0 0 var(--space-md, 1rem);
  padding-bottom: 0.6rem;
}
.blog-list-title::after {
  content: '';
  position: absolute;
  left: 50%; bottom: 0;
  transform: translateX(-50%);
  width: 48px; height: 3px;
  border-radius: 999px;
  background: linear-gradient(90deg, #00e5ff, #00b4d8);
}
.blog-list-subtitle {
  font-size: var(--text-lg, 1.125rem);
  color: var(--color-muted-dark, #333);
  line-height: 1.7;
  max-width: 620px;
  margin: 0 auto;
}

/* ── 分類篩選 ──────────────────────────────────── */
.blog-filter {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-sm, 0.75rem);
  justify-content: center;
  margin-bottom: var(--space-xl, 2rem);
}
.blog-filter-btn {
  padding: 0.45rem 1.1rem;
  border: 1px solid var(--color-border, #e5e9f0);
  border-radius: var(--radius-full, 999px);
  background: var(--color-white, #fff);
  color: var(--color-muted-dark, #333);
  font-family: var(--font-sans, sans-serif);
  font-size: var(--text-sm, 0.875rem);
  cursor: pointer;
  transition: all 0.2s;
}
.blog-filter-btn:hover {
  border-color: var(--color-accent, #0088dd);
  color: var(--color-accent, #0088dd);
}
.blog-filter-btn.active {
  background: var(--color-accent, #0088dd);
  border-color: var(--color-accent, #0088dd);
  color: #fff;
  box-shadow: 0 2px 12px rgba(0,136,221,.35);
}

/* ── 文章卡片 grid ─────────────────────────────── */
.blog-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(340px, 1fr));
  gap: var(--space-lg, 1.5rem);
}
.blog-card {
  position: relative;
  display: block;
  padding: var(--space-lg, 1.5rem);
  background: var(--color-white, #fff);
  border: 1px solid var(--color-border, #e5e9f0);
  border-radius: var(--radius-md, 10px);
  text-decoration: none;
  overflow: hidden;
  transition: transform 0.25s cubic-bezier(0.2,0.8,0.2,1), box-shadow 0.25s, border-color 0.25s;
}
/* 科技頂線：預設隱藏，hover 時從左展開 */
.blog-card::before {
  content: '';
  position: absolute;
  top: 0; left: 0; right: 100%;
  height: 2px;
  background: linear-gradient(90deg, #00e5ff, #00b4d8);
  transition: right 0.3s cubic-bezier(0.2,0.8,0.2,1);
}
.blog-card:hover {
  transform: translateY(-3px);
  border-color: rgba(0,180,216,.55);
  box-shadow: 0 8px 28px rgba(0,136,221,.14), 0 0 0 1px rgba(0,229,255,.12);
}
.blog-card:hover::before { right: 0; }
.blog-card-cat {
  display: inline-block;
  font-size: var(--text-xs, 0.75rem);
  color: var(--color-accent, #0088dd);
  font-weight: 600;
  margin-bottom: var(--space-sm, 0.75rem);
  padding: 0.18rem 0.6rem;
  border: 1px solid rgba(0,136,221,.25);
  border-radius: var(--radius-full, 999px);
  background: rgba(0,136,221,.05);
  letter-spacing: 0.06em;
  text-transform: uppercase;
}
.blog-card-title {
  font-family: var(--font-serif, serif);
  font-size: var(--text-xl, 1.25rem);
  color: var(--color-text-dark, #000);
  margin: 0 0 var(--space-sm, 0.75rem);
  line-height: 1.45;
}
.blog-card-summary {
  font-size: var(--text-sm, 0.875rem);
  color: var(--color-muted-dark, #333);
  line-height: 1.65;
  margin: 0 0 var(--space-md, 1rem);
}
.blog-card-date {
  font-size: var(--text-xs, 0.75rem);
  color: var(--color-muted2, #506070);
}

/* ── 文章頁 ────────────────────────────────────── */
.blog-breadcrumb {
  font-size: var(--text-sm, 0.875rem);
  color: var(--color-muted2, #506070);
  margin-bottom: var(--space-lg, 1.5rem);
}
.blog-breadcrumb a {
  color: var(--color-accent, #0088dd);
  text-decoration: none;
}
.blog-breadcrumb a:hover { text-decoration: underline; }
.blog-breadcrumb .sep { margin: 0 0.4rem; opacity: 0.5; }

.blog-article-head {
  position: relative;
  margin-bottom: var(--space-xl, 2rem);
  padding-bottom: var(--space-lg, 1.5rem);
  padding-left: var(--space-lg, 1.5rem);
  border-bottom: 1px solid var(--color-border, #e5e9f0);
}
/* 左側科技漸層細線 — 標題區的記憶點 */
.blog-article-head::before {
  content: '';
  position: absolute;
  left: 0; top: 0.2rem; bottom: var(--space-lg, 1.5rem);
  width: 3px;
  border-radius: 999px;
  background: linear-gradient(180deg, #00e5ff, #00b4d8);
}
.blog-article-meta {
  display: flex;
  align-items: center;
  gap: var(--space-md, 1rem);
  margin-bottom: var(--space-md, 1rem);
}
.blog-article-cat {
  font-size: var(--text-xs, 0.75rem);
  color: var(--color-accent, #0088dd);
  font-weight: 600;
  padding: 0.18rem 0.6rem;
  border: 1px solid rgba(0,136,221,.25);
  border-radius: var(--radius-full, 999px);
  background: rgba(0,136,221,.05);
  letter-spacing: 0.06em;
  text-transform: uppercase;
}
.blog-article-date {
  font-size: var(--text-xs, 0.75rem);
  color: var(--color-muted2, #506070);
}
.blog-article-title {
  font-family: var(--font-serif, serif);
  font-size: var(--text-4xl, 2.25rem);
  color: var(--color-text-dark, #000);
  line-height: 1.3;
  margin: 0 0 var(--space-md, 1rem);
}
.blog-article-summary {
  font-size: var(--text-lg, 1.125rem);
  color: var(--color-muted-dark, #333);
  line-height: 1.7;
  margin: 0;
}

/* ── 文章正文排版 ──────────────────────────────── */
.blog-article-body {
  font-size: var(--text-lg, 1.125rem);
  color: var(--color-text-dark, #000);
  line-height: 1.85;
}
.blog-article-body h2 {
  position: relative;
  font-family: var(--font-serif, serif);
  font-size: var(--text-2xl, 1.5rem);
  margin: var(--space-xl, 2rem) 0 var(--space-md, 1rem);
  padding-left: 0.85rem;
  color: var(--color-text-dark, #000);
}
.blog-article-body h2::before {
  content: '';
  position: absolute;
  left: 0; top: 0.15em; bottom: 0.15em;
  width: 3px;
  border-radius: 999px;
  background: linear-gradient(180deg, #00e5ff, #00b4d8);
}
.blog-article-body h3 {
  font-size: var(--text-xl, 1.25rem);
  margin: var(--space-lg, 1.5rem) 0 var(--space-sm, 0.75rem);
  color: var(--color-text-dark, #000);
}
.blog-article-body p { margin: 0 0 var(--space-md, 1rem); }
.blog-article-body ul,
.blog-article-body ol { margin: 0 0 var(--space-md, 1rem); padding-left: 1.6rem; }
.blog-article-body li { margin-bottom: 0.4rem; }
.blog-article-body a {
  color: var(--color-accent, #0088dd);
  text-decoration: underline;
}
.blog-article-body strong { font-weight: 700; }
.blog-article-body code {
  background: var(--color-light-bg, #f0f4fa);
  padding: 0.15em 0.4em;
  border-radius: var(--radius-sm, 6px);
  font-size: 0.9em;
  font-family: 'SF Mono', Menlo, Consolas, monospace;
}
.blog-article-body pre {
  background: var(--color-dark, #0a1020);
  color: #e0eeff;
  padding: var(--space-md, 1rem);
  border-radius: var(--radius-md, 10px);
  overflow-x: auto;
  margin: 0 0 var(--space-md, 1rem);
}
.blog-article-body pre code {
  background: none;
  padding: 0;
  color: inherit;
}
.blog-article-body blockquote {
  border-left: 3px solid var(--color-accent, #0088dd);
  padding-left: var(--space-md, 1rem);
  margin: 0 0 var(--space-md, 1rem);
  color: var(--color-muted-dark, #333);
  font-style: italic;
}
.blog-article-body img {
  max-width: 100%;
  height: auto;
  border-radius: var(--radius-md, 10px);
  margin: var(--space-md, 1rem) 0;
}
.blog-article-body hr {
  border: none;
  border-top: 1px solid var(--color-border, #e5e9f0);
  margin: var(--space-xl, 2rem) 0;
}

.blog-article-foot {
  margin-top: var(--space-xl, 2rem);
  padding-top: var(--space-lg, 1.5rem);
  border-top: 1px solid var(--color-border, #e5e9f0);
}
.blog-back {
  color: var(--color-accent, #0088dd);
  text-decoration: none;
  font-size: var(--text-base, 1rem);
}
.blog-back:hover { text-decoration: underline; }

/* ── RWD ───────────────────────────────────────── */
@media (max-width: 640px) {
  .blog-grid { grid-template-columns: 1fr; }
  .blog-article-title { font-size: var(--text-3xl, 1.875rem); }
  .blog-list-title { font-size: var(--text-3xl, 1.875rem); }
}