/* ==========================================================================
   VPNQF 博客样式包
   列表页：面包屑 / 通栏色带首屏 / 标签筛选 / 文章卡
   文章页：通栏色带 hero / 单列阅读栏 / 富文本组件 / 文末推广 / 延伸阅读 / 上下篇
   所有颜色、圆角、阴影、字体一律取自 base.css 的设计令牌
   ========================================================================== */

:root {
  --blog-col: 56rem;
  --blog-gutter: max(var(--gutter), 1.5rem);
  --blog-col-box: calc(var(--blog-col) + var(--blog-gutter) * 2);
}

/* --------------------------------------------------------------------------
   1. 面包屑（与页头留呼吸空间，不贴 header 底边）
   -------------------------------------------------------------------------- */

.breadcrumb {
  max-width: var(--container);
  margin-inline: auto;
  padding-inline: var(--gutter);
  padding-top: 1.4rem;
}

.breadcrumb--article {
  max-width: var(--blog-col-box);
  padding-inline: var(--blog-gutter);
  padding-top: 1.4rem;
}

.breadcrumb-list {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.3rem 0.4rem;
  margin: 0;
  padding: 0;
  list-style: none;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  letter-spacing: 0.06em;
  color: var(--text-muted);
}

.breadcrumb-list li {
  display: inline-flex;
  align-items: center;
  gap: 0.45rem;
  min-width: 0;
}

.breadcrumb-list li + li::before {
  content: "/";
  color: var(--dot-sep);
}

.breadcrumb-list a {
  padding-block: 0.15rem;
  color: var(--text-muted);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: color 0.18s ease, border-color 0.18s ease;
}

.breadcrumb-list a:hover {
  color: var(--accent-dark);
  border-bottom-color: var(--accent);
}

.breadcrumb-list [aria-current="page"] {
  color: var(--text);
  overflow-wrap: anywhere;
}

/* --------------------------------------------------------------------------
   2. 列表页通栏色带首屏
   -------------------------------------------------------------------------- */

.blog-band {
  position: relative;
  overflow: hidden;
  margin-top: 1.35rem;
  border-block: 1px solid var(--border);
  background:
    radial-gradient(115% 130% at 88% -12%, var(--accent-10), transparent 62%),
    linear-gradient(180deg, var(--bg-top), var(--bg-deep));
}

.blog-band::before {
  content: "";
  position: absolute;
  inset: 0;
  background-image: radial-gradient(color-mix(in srgb, var(--accent) 26%, transparent) 1px, transparent 1px);
  background-size: 20px 20px;
  opacity: 0.35;
  pointer-events: none;
}

.blog-band-in {
  position: relative;
  z-index: 1;
  max-width: var(--container);
  margin-inline: auto;
  padding-inline: var(--blog-gutter);
  padding-block: clamp(2rem, 4.5vw, 3.25rem);
}

.band-title {
  margin: 0.55rem 0 0;
  font-family: var(--font-display);
  font-size: clamp(1.85rem, 3.9vw, 3rem);
  font-weight: 900;
  line-height: 1.14;
  letter-spacing: -0.018em;
  color: var(--text);
  text-wrap: pretty;
}

.band-accent {
  color: var(--accent-dark);
}

.band-lead {
  margin: 0.9rem 0 0;
  max-width: 44rem;
  font-size: 1.0625rem;
  line-height: 1.75;
  color: var(--text-muted);
}

.band-meta {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.3rem 0.5rem;
  margin: 1.1rem 0 0;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  letter-spacing: 0.07em;
  color: var(--text-muted);
}

/* --------------------------------------------------------------------------
   3. 列表区与标签筛选
   -------------------------------------------------------------------------- */

.blog-index {
  padding-block: clamp(1.75rem, 3.5vw, 2.75rem) clamp(3rem, 6vw, 4.5rem);
}

.index-head {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  justify-content: space-between;
  gap: 0.4rem 1rem;
  margin-bottom: 1.1rem;
  padding-bottom: 0.85rem;
  border-bottom: 1px solid var(--border);
}

.list-title {
  margin: 0;
  font-family: var(--font-display);
  font-size: clamp(1.2rem, 1.8vw, 1.5rem);
  font-weight: 800;
  letter-spacing: -0.01em;
  color: var(--text);
  text-wrap: pretty;
}

.list-count {
  margin: 0;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  letter-spacing: 0.08em;
  color: var(--text-muted);
}

.filter-bar {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  margin-bottom: 1.5rem;
}

.filter-btn {
  appearance: none;
  min-height: 36px;
  padding: 0.5rem 1rem;
  border: 1px solid var(--border);
  border-radius: var(--r-pill);
  background: var(--surface-1);
  color: var(--text-muted);
  font-family: var(--font-mono);
  font-size: 0.8125rem;
  letter-spacing: 0.08em;
  cursor: pointer;
  transition: color 0.18s ease, background-color 0.18s ease, border-color 0.18s ease, transform 0.18s ease;
}

.filter-btn:hover {
  color: var(--text);
  background: var(--surface-2);
  border-color: var(--border-strong);
}

.filter-btn.is-active {
  background: var(--accent);
  border-color: var(--accent);
  color: var(--text);
  font-weight: 700;
  box-shadow: var(--shadow-btn);
}

.filter-btn:active {
  transform: translateY(1px);
}

/* --------------------------------------------------------------------------
   4. 文章卡网格
   -------------------------------------------------------------------------- */

.post-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(min(100%, 20rem), 1fr));
  gap: 1.25rem;
}

.post-grid .post-card {
  position: relative;
  display: flex;
  flex-direction: column;
  gap: 0.7rem;
  padding: 1.35rem 1.35rem 1.15rem;
  background: var(--surface-1);
  border: 1px solid var(--border);
  border-radius: var(--r-lg);
  box-shadow: var(--shadow-card);
  transition: transform 0.2s ease, border-color 0.2s ease, box-shadow 0.2s ease;
}

.post-grid .post-card::before {
  content: "";
  position: absolute;
  inset: 0 0 auto 0;
  height: 3px;
  border-radius: var(--r-lg) var(--r-lg) 0 0;
  background: linear-gradient(90deg, var(--accent), var(--accent-light));
  opacity: 0;
  transition: opacity 0.2s ease;
}

.post-grid .post-card:hover {
  transform: translateY(-3px);
  border-color: var(--border-strong);
  box-shadow: var(--shadow-window);
}

.post-grid .post-card:hover::before {
  opacity: 1;
}

.post-grid .post-meta {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.5rem 0.65rem;
  font-family: var(--font-mono);
  font-size: 0.6875rem;
  letter-spacing: 0.06em;
  color: var(--text-muted);
}

.post-grid .post-tag {
  display: inline-block;
  max-width: 100%;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
  padding: 0.2rem 0.55rem;
  border-radius: var(--r-xs);
  background: var(--accent-10);
  color: var(--accent-dark);
  font-size: 0.6875rem;
  letter-spacing: 0.08em;
}

.post-grid .post-title {
  margin: 0;
  font-family: var(--font-display);
  font-size: clamp(1.0625rem, 1.5vw, 1.25rem);
  font-weight: 800;
  line-height: 1.45;
  letter-spacing: -0.01em;
  text-wrap: pretty;
}

.post-grid .post-title a {
  color: var(--text);
  text-decoration: none;
  transition: color 0.18s ease;
}

.post-grid .post-title a:hover {
  color: var(--accent-dark);
  text-decoration: underline;
  text-underline-offset: 0.18em;
  text-decoration-thickness: 1px;
}

.post-grid .post-summary {
  margin: 0;
  flex: 1 1 auto;
  font-size: 0.9375rem;
  line-height: 1.75;
  color: var(--text-muted);
}

.post-grid .post-more {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  align-self: flex-start;
  margin-top: auto;
  padding-top: 0.35rem;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  letter-spacing: 0.08em;
  color: var(--accent-dark);
  text-decoration: none;
  transition: gap 0.18s ease, color 0.18s ease;
}

.post-grid .post-more:hover {
  gap: 0.6rem;
  color: var(--accent);
}

.list-empty {
  margin: 1rem 0 0;
  padding: 1.1rem 1.2rem;
  border: 1px dashed var(--border-strong);
  border-radius: var(--r-md);
  background: var(--surface-2);
  color: var(--text-muted);
  font-size: 0.9375rem;
  line-height: 1.7;
}

/* --------------------------------------------------------------------------
   5. 文章页通栏色带 hero（full-bleed-band）
   -------------------------------------------------------------------------- */

.article-hero {
  position: relative;
  overflow: hidden;
  margin-top: 1.35rem;
  border-block: 1px solid var(--border);
  background:
    radial-gradient(120% 140% at 10% -20%, var(--accent-08), transparent 60%),
    linear-gradient(180deg, var(--bg-top), var(--bg-deep));
}

.article-hero::before {
  content: "";
  position: absolute;
  inset: 0;
  background-image: linear-gradient(to right, var(--contour-1) 1px, transparent 1px);
  background-size: 64px 100%;
  opacity: 0.55;
  pointer-events: none;
}

.article-hero-in {
  position: relative;
  z-index: 1;
  max-width: var(--blog-col-box);
  margin-inline: auto;
  padding-inline: var(--blog-gutter);
  padding-block: clamp(1.6rem, 3.4vw, 2.6rem);
}

.article-meta {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.3rem 0.55rem;
  margin: 0;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  letter-spacing: 0.06em;
  color: var(--text-muted);
}

.article-meta .meta-sep {
  color: var(--dot-sep);
}

.article-meta .meta-tag {
  color: var(--accent-dark);
  font-weight: 700;
}

.article-title {
  margin: 0.65rem 0 0;
  font-family: var(--font-display);
  font-size: clamp(1.55rem, 3.2vw, 2.6rem);
  font-weight: 900;
  line-height: 1.22;
  letter-spacing: -0.015em;
  color: var(--text);
  text-wrap: pretty;
}

.article-summary {
  margin: 0.85rem 0 0;
  font-size: 1.0625rem;
  line-height: 1.78;
  color: var(--text-muted);
}

/* --------------------------------------------------------------------------
   6. 单列阅读栏（与 hero 同一列、同一内衬）
   -------------------------------------------------------------------------- */

.reading-wrap {
  width: 100%;
  max-width: var(--blog-col-box);
  margin-inline: auto;
  padding-inline: var(--blog-gutter);
  padding-block: clamp(1.6rem, 3vw, 2.25rem) 0;
}

/* --------------------------------------------------------------------------
   7. 正文排版
   -------------------------------------------------------------------------- */

.article-body {
  counter-reset: section;
  font-size: 1rem;
  line-height: 1.8;
  color: var(--text);
}

.article-body p {
  margin: 0 0 1.05em;
}

.article-body p:last-child {
  margin-bottom: 0;
}

.article-body h2 {
  margin: 2.1em 0 0.75em;
  font-family: var(--font-display);
  font-size: clamp(1.25rem, 1.9vw, 1.6rem);
  font-weight: 800;
  line-height: 1.35;
  letter-spacing: -0.01em;
  color: var(--text);
  text-wrap: pretty;
  counter-increment: section;
}

.article-body h2::before {
  content: counter(section, decimal-leading-zero);
  display: inline-block;
  margin-right: 0.6em;
  padding-bottom: 0.06em;
  border-bottom: 2px solid var(--accent);
  font-family: var(--font-mono);
  font-size: 0.68em;
  font-weight: 700;
  letter-spacing: 0.1em;
  color: var(--accent-dark);
  vertical-align: 0.08em;
}

.article-body > h2:first-child {
  margin-top: 0;
}

.article-body h3 {
  margin: 1.7em 0 0.55em;
  font-family: var(--font-display);
  font-size: clamp(1.05rem, 1.4vw, 1.3rem);
  font-weight: 800;
  line-height: 1.45;
  color: var(--text);
  text-wrap: pretty;
}

.article-body ul,
.article-body ol {
  margin: 0 0 1.15em;
  padding-left: 1.4em;
}

.article-body li {
  margin-bottom: 0.4em;
}

.article-body li:last-child {
  margin-bottom: 0;
}

.article-body a {
  color: var(--accent-dark);
  text-decoration: underline;
  text-underline-offset: 0.18em;
  text-decoration-thickness: 1px;
  text-decoration-color: var(--accent-40);
  overflow-wrap: anywhere;
  transition: color 0.16s ease, text-decoration-color 0.16s ease;
}

.article-body a:hover {
  color: var(--accent);
  text-decoration-color: var(--accent);
}

.article-body strong {
  font-weight: 700;
  color: var(--text);
}

.article-body code {
  padding: 0.1em 0.35em;
  border: 1px solid var(--border);
  border-radius: var(--r-xs);
  background: var(--surface-3);
  font-family: var(--font-mono);
  font-size: 0.875em;
  overflow-wrap: anywhere;
}

.article-body blockquote {
  margin: 1.4em 0;
  padding: 0.9rem 1.1rem;
  border-left: 3px solid var(--accent);
  border-radius: 0 var(--r-sm) var(--r-sm) 0;
  background: var(--surface-2);
  color: var(--text-muted);
}

.article-body blockquote p:last-child {
  margin-bottom: 0;
}

.article-body img {
  max-width: 100%;
  height: auto;
  border-radius: var(--r-md);
}

.article-body hr {
  margin: 2em 0;
  border: 0;
  border-top: 1px dashed var(--border-strong);
}

/* 终端窗风格的代码块 */
.article-body pre {
  position: relative;
  margin: 1.4em 0;
  padding: 2.3rem 1.1rem 1.1rem;
  border-radius: var(--r-md);
  background: linear-gradient(180deg, var(--text), var(--ink-soft));
  color: var(--on-dark);
  font-family: var(--font-mono);
  font-size: 0.8125rem;
  line-height: 1.7;
  overflow-x: auto;
  box-shadow: var(--shadow-soft);
}

.article-body pre::before {
  content: "";
  position: absolute;
  top: 0.9rem;
  left: 1.1rem;
  width: 10px;
  height: 10px;
  border-radius: 50%;
  background: var(--error);
  box-shadow: 18px 0 0 var(--warn), 36px 0 0 var(--success);
}

.article-body pre code {
  padding: 0;
  border: 0;
  background: none;
  color: inherit;
  font-size: inherit;
  overflow-wrap: normal;
}

/* 表格：实色表头 + 斑马纹 + hover，窄屏可横滑 */
.article-body table {
  width: 100%;
  min-width: 34rem;
  margin: 1.4em 0;
  border-collapse: collapse;
  font-size: 0.9375rem;
  line-height: 1.6;
  background: var(--surface-1);
  border: 1px solid var(--border);
}

.article-body caption {
  caption-side: top;
  padding-bottom: 0.5rem;
  text-align: left;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  letter-spacing: 0.08em;
  color: var(--text-muted);
}

.article-body thead th {
  padding: 0.6rem 0.75rem;
  background: var(--text);
  color: var(--on-dark);
  font-size: 0.8125rem;
  font-weight: 700;
  letter-spacing: 0.04em;
  text-align: left;
  white-space: nowrap;
}

.article-body tbody th,
.article-body tbody td {
  padding: 0.6rem 0.75rem;
  border-top: 1px solid var(--border);
  text-align: left;
  vertical-align: top;
  overflow-wrap: anywhere;
}

.article-body tbody tr:nth-child(even) {
  background: var(--surface-2);
}

.article-body tbody tr:hover {
  background: var(--accent-05);
}

/* --------------------------------------------------------------------------
   8. 富文本组件：callout / stat-grid / check-list / verdict
   -------------------------------------------------------------------------- */

.callout {
  position: relative;
  margin: 1.4em 0;
  padding: 1rem 1.1rem 1rem 2.9rem;
  border: 1px solid var(--border);
  border-left: 3px solid var(--accent);
  border-radius: var(--r-md);
  background: var(--surface-2);
  color: var(--text);
  font-size: 0.9375rem;
  line-height: 1.75;
}

.callout::before {
  content: "";
  position: absolute;
  top: 1.05rem;
  left: 0.95rem;
  width: 1.15rem;
  height: 1.15rem;
  border: 2px solid var(--accent);
  border-radius: 50%;
  background: var(--accent-16);
}

.callout::after {
  content: "!";
  position: absolute;
  top: 1.02rem;
  left: 0.95rem;
  width: 1.15rem;
  text-align: center;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  font-weight: 700;
  color: var(--accent-dark);
}

.callout .callout-title {
  margin: 0 0 0.35rem;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  font-weight: 700;
  letter-spacing: 0.1em;
  color: var(--accent-dark);
}

.callout p:last-child {
  margin-bottom: 0;
}

.callout--warn {
  border-left-color: var(--warn);
  background: color-mix(in srgb, var(--warn) 9%, var(--surface-1));
}

.callout--warn::before {
  border-color: var(--warn);
  background: color-mix(in srgb, var(--warn) 18%, transparent);
}

.callout--warn::after {
  color: var(--warn);
}

.callout--warn .callout-title {
  color: var(--warn);
}

.callout--success {
  border-left-color: var(--success);
  background: var(--success-16);
}

.callout--success::before {
  border-color: var(--success);
  background: var(--success-40);
}

.callout--success::after {
  content: "\2713";
  color: var(--success);
}

.callout--success .callout-title {
  color: var(--success);
}

.stat-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(min(100%, 10rem), 1fr));
  gap: 0.85rem;
  margin: 1.4em 0;
}

.stat-card {
  position: relative;
  overflow: hidden;
  padding: 1rem 1rem 0.9rem;
  background: var(--surface-1);
  border: 1px solid var(--border);
  border-radius: var(--r-md);
}

.stat-card::before {
  content: "";
  position: absolute;
  inset: 0 0 auto 0;
  height: 3px;
  background: var(--accent);
}

.stat-card:nth-child(even) {
  background: var(--surface-2);
}

.stat-card:nth-child(even)::before {
  background: var(--text);
}

.stat-num {
  display: block;
  font-family: var(--font-display);
  font-size: 1.5rem;
  font-weight: 900;
  letter-spacing: -0.02em;
  line-height: 1.2;
  color: var(--text);
}

.stat-card:nth-child(even) .stat-num {
  color: var(--accent-dark);
}

.stat-label {
  display: block;
  margin-top: 0.25rem;
  font-size: 0.8125rem;
  line-height: 1.55;
  color: var(--text-muted);
}

/* 勾叉清单：只做容器与行卡装饰，语义符号由正文文本自带 */
.check-list {
  margin: 1.4em 0;
  padding: 0;
  list-style: none;
  display: grid;
  gap: 0.5rem;
}

.check-list li {
  margin: 0;
  padding: 0.7rem 0.9rem;
  background: var(--surface-1);
  border: 1px solid var(--border);
  border-radius: var(--r-sm);
  font-size: 0.9375rem;
  line-height: 1.7;
}

.verdict {
  margin: 1.5em 0;
  padding: 0.9rem 1.1rem;
  border-left: 3px solid var(--accent);
  border-radius: 0 var(--r-sm) var(--r-sm) 0;
  background: color-mix(in srgb, var(--accent) 7%, var(--surface-1));
  font-size: 0.96875rem;
  line-height: 1.75;
  color: var(--text);
}

.verdict strong {
  color: var(--accent-dark);
}

/* --------------------------------------------------------------------------
   9. 文末推广卡（全站唯一）
   -------------------------------------------------------------------------- */

.promo-block {
  position: relative;
  overflow: hidden;
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 1rem 1.5rem;
  width: 100%;
  max-width: var(--blog-col-box);
  margin: 2.25rem auto 0;
  padding: 1.5rem;
  border: 1px solid var(--border-strong);
  border-radius: var(--r-lg);
  background: linear-gradient(135deg, var(--text), var(--ink-soft));
  color: var(--on-dark);
  box-shadow: var(--shadow-dark);
}

.promo-block::before {
  content: "";
  position: absolute;
  inset: 0;
  background-image: radial-gradient(color-mix(in srgb, var(--accent) 42%, transparent) 1px, transparent 1px);
  background-size: 18px 18px;
  opacity: 0.25;
  pointer-events: none;
}

.promo-block > * {
  position: relative;
  z-index: 1;
}

.reading-wrap .promo-block {
  max-width: none;
  margin-inline: 0;
}

.promo-block .promo-brand {
  margin: 0;
  font-family: var(--font-mono);
  font-size: 0.8125rem;
  font-weight: 700;
  letter-spacing: 0.16em;
  color: var(--accent-light);
}

.promo-block .promo-line {
  margin: 0.4rem 0 0;
  max-width: 32rem;
  font-size: 0.9375rem;
  line-height: 1.7;
  color: var(--on-dark);
}

.promo-block .btn {
  flex-shrink: 0;
  background: var(--surface-1);
  border-color: var(--surface-1);
  color: var(--text);
  box-shadow: none;
}

.promo-block .btn:hover {
  background: var(--accent);
  border-color: var(--accent);
  color: var(--text);
}

/* --------------------------------------------------------------------------
   10. 延伸阅读
   -------------------------------------------------------------------------- */

#related-posts {
  width: 100%;
  max-width: var(--blog-col-box);
  margin-inline: auto;
  padding-inline: var(--blog-gutter);
  padding-top: 2.25rem;
}

.reading-wrap #related-posts {
  max-width: none;
  padding-inline: 0;
}

.related-heading {
  margin: 0 0 0.9rem;
  font-family: var(--font-display);
  font-size: clamp(1.1rem, 1.5vw, 1.35rem);
  font-weight: 800;
  letter-spacing: -0.01em;
  color: var(--text);
  text-wrap: pretty;
}

.related-heading::before {
  content: "// ";
  font-family: var(--font-mono);
  font-size: 0.8em;
  color: var(--accent);
}

.related-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(min(100%, 15rem), 1fr));
  gap: 0.85rem;
}

.related-card {
  display: flex;
  flex-direction: column;
  gap: 0.45rem;
  padding: 1rem 1.05rem;
  background: var(--surface-1);
  border: 1px solid var(--border);
  border-radius: var(--r-md);
  color: inherit;
  text-decoration: none;
  transition: border-color 0.18s ease, transform 0.18s ease, box-shadow 0.18s ease;
}

.related-card:hover {
  border-color: var(--accent);
  transform: translateY(-2px);
  box-shadow: var(--shadow-card);
}

.related-tag {
  font-family: var(--font-mono);
  font-size: 0.6875rem;
  letter-spacing: 0.1em;
  color: var(--accent-dark);
}

.related-title {
  font-size: 0.9375rem;
  font-weight: 700;
  line-height: 1.55;
  color: var(--text);
}

.related-date {
  margin-top: auto;
  font-family: var(--font-mono);
  font-size: 0.6875rem;
  letter-spacing: 0.06em;
  color: var(--text-muted);
}

/* --------------------------------------------------------------------------
   11. 上一篇 / 下一篇
   -------------------------------------------------------------------------- */

#post-nav {
  width: 100%;
  max-width: var(--blog-col-box);
  margin-inline: auto;
  padding-inline: var(--blog-gutter);
  padding-top: 1.5rem;
  padding-bottom: 2.25rem;
}

.reading-wrap #post-nav {
  max-width: none;
  padding-inline: 0;
}

.post-nav-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 0.85rem;
}

.post-nav-grid.is-single {
  grid-template-columns: 1fr;
}

.post-nav-card {
  display: flex;
  flex-direction: column;
  gap: 0.35rem;
  padding: 1rem 1.1rem;
  background: var(--surface-1);
  border: 1px solid var(--border);
  border-radius: var(--r-md);
  color: inherit;
  text-decoration: none;
  transition: border-color 0.18s ease, transform 0.18s ease, box-shadow 0.18s ease;
}

.post-nav-card:hover {
  border-color: var(--accent);
  transform: translateY(-2px);
  box-shadow: var(--shadow-card);
}

.post-nav-dir {
  font-family: var(--font-mono);
  font-size: 0.6875rem;
  letter-spacing: 0.12em;
  color: var(--accent-dark);
}

.post-nav-title {
  font-size: 0.9375rem;
  font-weight: 700;
  line-height: 1.55;
  color: var(--text);
}

/* --------------------------------------------------------------------------
   12. 悬浮 CTA（文章页使用，列表页不放）
   -------------------------------------------------------------------------- */

.float-cta {
  position: fixed;
  right: clamp(1rem, 3vw, 1.75rem);
  bottom: clamp(1rem, 3vw, 1.75rem);
  z-index: 60;
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  max-width: calc(100vw - 1.5rem);
  padding: 0.7rem 1.15rem;
  border-radius: var(--r-pill);
  background: var(--accent);
  color: var(--text);
  font-family: var(--font-mono);
  font-size: 0.8125rem;
  font-weight: 700;
  letter-spacing: 0.06em;
  text-decoration: none;
  box-shadow: var(--shadow-btn);
  transition: transform 0.18s ease, background-color 0.18s ease;
}

.float-cta:hover {
  background: var(--accent-dark);
  color: var(--on-dark);
  transform: translateY(-2px);
}

.float-cta svg {
  display: block;
  width: 1rem;
  height: 1rem;
}

/* --------------------------------------------------------------------------
   13. 响应式
   -------------------------------------------------------------------------- */

@media (max-width: 860px) {
  .article-body table {
    display: block;
    width: fit-content;
    max-width: 100%;
    min-width: 0;
    overflow-x: auto;
    white-space: normal;
  }
}

@media (max-width: 640px) {
  .breadcrumb {
    padding-top: 1.2rem;
  }

  .breadcrumb--article {
    padding-top: 1.2rem;
  }

  .band-title {
    font-size: clamp(1.7rem, 7vw, 2.1rem);
  }

  .article-title {
    font-size: clamp(1.45rem, 6.4vw, 1.9rem);
  }

  .post-nav-grid {
    grid-template-columns: 1fr;
  }

  .promo-block {
    padding: 1.25rem;
  }

  .promo-block .btn {
    width: 100%;
    justify-content: center;
  }

  .float-cta {
    right: 0.75rem;
    bottom: 0.75rem;
    padding: 0.6rem 0.95rem;
    font-size: 0.75rem;
  }
}

/* --------------------------------------------------------------------------
   14. 动效降级
   -------------------------------------------------------------------------- */

@media (prefers-reduced-motion: reduce) {
  .post-grid .post-card,
  .post-grid .post-card::before,
  .post-grid .post-more,
  .related-card,
  .post-nav-card,
  .filter-btn,
  .float-cta,
  .breadcrumb-list a {
    transition: none;
  }

  .post-grid .post-card:hover,
  .related-card:hover,
  .post-nav-card:hover,
  .float-cta:hover {
    transform: none;
  }

  .post-grid .post-more:hover {
    gap: 0.35rem;
  }
}