/* ============================================================
   VPNBN · 博客系统样式
   适用:zh-CN/blog/index.html、zh-CN/blog/articles/*.html
   全部色值 / 字体 / 圆角取自 base.css 的 :root 设计令牌
   ============================================================ */

:root {
  --blog-col: 54rem;
  --blog-pad: clamp(1.5rem, 4vw, 2rem);
  --blog-h1: clamp(1.7rem, 1.15rem + 2.1vw, 2.6rem);
  --blog-hero-h1: clamp(1.9rem, 1.25rem + 2.8vw, 3rem);
  --blog-h2: clamp(1.28rem, 1.16rem + 0.5vw, 1.6rem);
  --blog-h3: clamp(1.08rem, 1.02rem + 0.3vw, 1.3rem);
  --blog-gap: clamp(1.15rem, 2.4vw, 1.65rem);
}

/* 动态插入的卡片:兜底可见,防止滚动淡入观察器接管不到 */
.post-card.reveal,
.related-card.reveal,
.post-nav-card.reveal {
  opacity: 1;
  transform: none;
}

/* ------------------------------------------------------------
   1. 面包屑(与页头之间保留呼吸空间)
   ------------------------------------------------------------ */
.breadcrumb {
  width: min(100%, calc(var(--blog-col) + 2 * var(--blog-pad)));
  margin: clamp(1.35rem, 3vw, 1.9rem) auto 0;
  padding-inline: var(--blog-pad);
}

.breadcrumb-list {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: .45rem;
  margin: 0;
  padding: 0;
  list-style: none;
  font-size: .85rem;
  line-height: 1.6;
  color: var(--text-muted);
}

.breadcrumb-list li {
  display: inline-flex;
  align-items: center;
  gap: .45rem;
  min-width: 0;
}

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

.breadcrumb-list a {
  color: var(--text-muted);
  text-decoration: none;
}

.breadcrumb-list a:hover {
  color: var(--accent-dark);
  text-decoration: underline;
  text-underline-offset: .2em;
}

.breadcrumb-list [aria-current="page"] {
  color: var(--text);
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
  max-width: 22rem;
}

/* ------------------------------------------------------------
   2. 列表页 hero
   ------------------------------------------------------------ */
.blog-hero-sec {
  padding-top: clamp(1.75rem, 4vw, 2.75rem);
}

.blog-hero {
  position: relative;
  display: grid;
  grid-template-columns: minmax(0, 3fr) minmax(0, 1fr);
  gap: clamp(2rem, 4vw, 3rem);
  align-items: start;
  padding: clamp(1.75rem, 4vw, 2.5rem) var(--blog-pad);
  border: 1px solid var(--border);
  border-radius: var(--r-card-lg);
  background: var(--bg-panel);
  background-image: linear-gradient(180deg, var(--bg-panel), color-mix(in srgb, var(--sky-low) 52%, var(--bg-panel)));
  box-shadow: var(--sh-neutral-10);
  overflow: hidden;
}

.blog-hero::before,
.article-hero::before {
  content: "";
  position: absolute;
  inset: 0 0 auto 0;
  height: 4px;
  background: linear-gradient(90deg, var(--accent), var(--teal-line) 58%, var(--candy-honey));
}

.blog-hero::after,
.article-hero::after {
  content: "";
  position: absolute;
  top: 1rem;
  right: 1.25rem;
  width: 9rem;
  height: 9rem;
  border-radius: 50%;
  background: radial-gradient(circle at 50% 50%, color-mix(in srgb, var(--accent) 14%, transparent), transparent 68%);
  pointer-events: none;
}

.blog-hero > * {
  position: relative;
  z-index: 1;
}

.blog-kicker,
.article-hero-kicker {
  display: inline-flex;
  align-items: center;
  gap: .5rem;
  margin: 0 0 .75rem;
  font-family: var(--font-mono);
  font-size: .78rem;
  letter-spacing: .04em;
  color: var(--accent-dark);
}

.kicker-dot {
  flex: none;
  width: .5rem;
  height: .5rem;
  border-radius: 50%;
  background: var(--accent);
  box-shadow: 0 0 0 4px color-mix(in srgb, var(--accent) 16%, transparent);
}

.blog-hero-title {
  margin: 0;
  font-family: var(--font-display);
  font-size: var(--blog-hero-h1);
  font-weight: 800;
  line-height: 1.16;
  letter-spacing: -.015em;
  color: var(--text);
  text-wrap: pretty;
}

.blog-hero-lead {
  margin: 1rem 0 0;
  max-width: 42rem;
  font-size: 1rem;
  line-height: 1.85;
  color: var(--text-muted);
}

/* ------------------------------------------------------------
   3. meta 小卡(列表页 / 文章页共用)
   ------------------------------------------------------------ */
.blog-meta-card,
.article-meta-card {
  display: grid;
  gap: 1rem;
  padding: 1.25rem 1.35rem;
  border: 1px solid var(--border);
  border-radius: var(--r-card);
  background: var(--bg-panel);
  box-shadow: var(--sh-neutral-10);
}

.meta-item {
  display: grid;
  gap: .3rem;
  min-width: 0;
}

.meta-item + .meta-item {
  padding-top: 1rem;
  border-top: 1px dashed var(--border);
}

.meta-key {
  font-family: var(--font-mono);
  font-size: .72rem;
  letter-spacing: .06em;
  color: var(--text-muted);
}

.meta-val {
  font-size: .95rem;
  font-weight: 600;
  line-height: 1.6;
  color: var(--text);
  overflow-wrap: anywhere;
}

.meta-chip {
  display: inline-block;
  padding: .2rem .65rem;
  border: 1px solid var(--border);
  border-radius: var(--r-pill);
  background: var(--bg-panel);
  font-family: var(--font-mono);
  font-size: .8rem;
  font-weight: 500;
  color: var(--text-muted);
}

.article-meta-row {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: .6rem;
}

/* ------------------------------------------------------------
   4. 标签筛选
   ------------------------------------------------------------ */
.blog-sec-title {
  margin: 0 0 1.25rem;
  font-family: var(--font-display);
  font-size: clamp(1.25rem, 1.1rem + .7vw, 1.5rem);
  font-weight: 800;
  letter-spacing: -.01em;
  color: var(--text);
}

.blog-list-sec {
  padding-block: clamp(2.25rem, 5vw, 3.5rem) clamp(3rem, 6vw, 4.5rem);
}

.tag-filter {
  display: flex;
  flex-wrap: wrap;
  gap: .6rem;
  margin-bottom: clamp(1.5rem, 3vw, 2.25rem);
}

.tag-btn {
  font-family: inherit;
  font-size: .9rem;
  line-height: 1.4;
  padding: .5rem 1.05rem;
  border: 1px solid var(--border);
  border-radius: var(--r-pill);
  background: var(--bg-panel);
  color: var(--text-muted);
  cursor: pointer;
  transition: color .2s ease, border-color .2s ease, background-color .2s ease, transform .2s ease;
}

.tag-btn:hover {
  color: var(--accent-dark);
  border-color: var(--accent);
  transform: translateY(-1px);
}

.tag-btn.is-active {
  background: var(--accent);
  border-color: var(--accent);
  color: var(--text-invert);
  box-shadow: var(--sh-accent-14);
}

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

/* ------------------------------------------------------------
   5. 文章卡片列表
   ------------------------------------------------------------ */
.post-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(min(100%, 22rem), 1fr));
  gap: var(--blog-gap);
}

.post-card {
  position: relative;
  display: flex;
  flex-direction: column;
  gap: .8rem;
  padding: 1.5rem 1.6rem 1.35rem;
  border: 1px solid var(--border);
  border-radius: var(--r-card);
  background: var(--bg-panel);
  box-shadow: var(--sh-neutral-10);
  overflow: hidden;
  transition: transform .24s ease, box-shadow .24s ease, border-color .24s ease;
}

.post-card::before {
  content: "";
  position: absolute;
  inset: 0 0 auto 0;
  height: 3px;
  background: linear-gradient(90deg, var(--accent), var(--teal-line));
  opacity: 0;
  transition: opacity .24s ease;
}

.post-card:hover {
  transform: translateY(-4px);
  border-color: var(--border-strong);
  box-shadow: var(--sh-accent-14);
}

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

.post-meta {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: .75rem;
}

.post-tag {
  display: inline-block;
  padding: .22rem .62rem;
  border-radius: var(--r-pill);
  background: var(--bg-panel2);
  background: color-mix(in srgb, var(--accent) 14%, var(--bg-panel));
  font-family: var(--font-mono);
  font-size: .74rem;
  line-height: 1.5;
  color: var(--accent-dark);
}

.post-date {
  font-family: var(--font-mono);
  font-size: .78rem;
  color: var(--text-muted);
}

.post-title {
  margin: 0;
  font-family: var(--font-display);
  font-size: 1.15rem;
  font-weight: 700;
  line-height: 1.5;
  letter-spacing: -.005em;
  color: var(--text);
}

.post-title-link {
  color: inherit;
  text-decoration: none;
}

.post-title-link:hover {
  color: var(--accent-dark);
}

.post-summary {
  margin: 0;
  font-size: .92rem;
  line-height: 1.78;
  color: var(--text-muted);
}

.post-more {
  display: inline-flex;
  align-items: center;
  gap: .35rem;
  margin-top: auto;
  padding-top: .35rem;
  font-size: .88rem;
  font-weight: 600;
  color: var(--accent-dark);
  text-decoration: none;
}

.post-more-arrow {
  transition: transform .22s ease;
}

.post-card:hover .post-more-arrow {
  transform: translateX(4px);
}

.post-empty {
  display: block;
  margin: 0;
  padding: 2rem 1.5rem;
  border: 1px dashed var(--border-strong);
  border-radius: var(--r-card);
  background: var(--bg-panel);
  text-align: center;
  color: var(--text-muted);
}

.post-empty[hidden] {
  display: none;
}

/* ------------------------------------------------------------
   6. 文章页 hero(split-meta:左 3/4 标题摘要 + 右 1/4 竖排 meta 卡)
   ------------------------------------------------------------ */
.article-hero {
  position: relative;
  width: min(100%, calc(var(--blog-col) + 2 * var(--blog-pad)));
  margin: clamp(1.25rem, 3vw, 1.75rem) auto clamp(1.75rem, 3vw, 2.25rem);
  padding: clamp(1.9rem, 4vw, 2.6rem) var(--blog-pad) clamp(1.75rem, 3.5vw, 2.25rem);
  border: 1px solid var(--border);
  border-radius: var(--r-card-lg);
  background: var(--bg-panel);
  background-image: linear-gradient(180deg, var(--bg-panel), color-mix(in srgb, var(--sky-low) 52%, var(--bg-panel)));
  box-shadow: var(--sh-neutral-10);
  overflow: hidden;
}

.article-hero-inner {
  position: relative;
  z-index: 1;
  display: grid;
  grid-template-columns: minmax(0, 3fr) minmax(0, 1fr);
  gap: clamp(2rem, 4vw, 3rem);
  align-items: start;
}

.article-hero-main {
  min-width: 0;
}

.article-hero-title {
  margin: 0;
  font-family: var(--font-display);
  font-size: var(--blog-h1);
  font-weight: 800;
  line-height: 1.22;
  letter-spacing: -.015em;
  color: var(--text);
  text-wrap: pretty;
}

.article-hero-lead {
  margin: 1rem 0 0;
  font-size: 1rem;
  line-height: 1.85;
  color: var(--text-muted);
}

/* ------------------------------------------------------------
   7. 正文阅读列(与 hero 同一条列,全部水平居中)
   ------------------------------------------------------------ */
.reading-wrap {
  width: min(100%, calc(var(--blog-col) + 2 * var(--blog-pad)));
  max-width: none;
  margin-inline: auto;
  padding-inline: var(--blog-pad);
}

.reading-wrap .prose {
  width: 100%;
  max-width: none;
  margin-inline: auto;
}

.prose {
  font-size: 1rem;
  line-height: 1.85;
  color: var(--text);
  overflow-wrap: break-word;
}

.prose > * + * {
  margin-top: 1.15rem;
}

.prose > * + h2 {
  margin-top: clamp(2.2rem, 4vw, 2.8rem);
}

.prose > * + h3 {
  margin-top: clamp(1.7rem, 3vw, 2.1rem);
}

.prose > * + .stat-grid,
.prose > * + .check-list,
.prose > * + .callout,
.prose > * + .verdict,
.prose > * + pre,
.prose > * + blockquote,
.prose > * + table {
  margin-top: 1.7rem;
}

.prose p,
.prose ul,
.prose ol,
.prose blockquote,
.prose pre,
.prose table,
.prose figure {
  margin: 0;
}

.prose h2 {
  margin: 0;
  font-family: var(--font-display);
  font-size: var(--blog-h2);
  font-weight: 800;
  line-height: 1.35;
  letter-spacing: -.01em;
  color: var(--text);
  scroll-margin-top: calc(var(--header-h) + 1.25rem);
  text-wrap: pretty;
}

.prose h2::before {
  content: "";
  display: inline-block;
  width: 1.5rem;
  height: .34rem;
  margin-right: .65rem;
  border-radius: var(--r-pill);
  background: linear-gradient(90deg, var(--accent) 0 40%, var(--teal-line) 40% 100%);
  vertical-align: .1em;
}

.prose h3 {
  margin: 0;
  font-family: var(--font-display);
  font-size: var(--blog-h3);
  font-weight: 700;
  line-height: 1.45;
  color: var(--text);
  scroll-margin-top: calc(var(--header-h) + 1.25rem);
  text-wrap: pretty;
}

.prose h3::before {
  content: "";
  display: inline-block;
  width: .5rem;
  height: .5rem;
  margin-right: .55rem;
  border-radius: 2px;
  background: var(--teal-line);
  transform: rotate(45deg);
  vertical-align: .08em;
}

.prose a {
  color: var(--accent-dark);
  text-decoration-color: color-mix(in srgb, var(--accent) 45%, transparent);
  text-underline-offset: .22em;
}

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

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

.prose ul,
.prose ol {
  padding-left: 1.4rem;
}

.prose li + li {
  margin-top: .5rem;
}

.prose li::marker {
  color: var(--accent);
}

.prose blockquote {
  padding: 1rem 1.35rem;
  border-left: 3px solid var(--teal-line);
  border-radius: 0 var(--r-sm) var(--r-sm) 0;
  background: var(--bg-panel);
  background: color-mix(in srgb, var(--teal-line) 9%, var(--bg-panel));
  color: var(--text-muted);
}

.prose blockquote p {
  margin: 0;
}

.prose code {
  font-family: var(--font-mono);
  font-size: .88em;
  padding: .15em .42em;
  border-radius: var(--r-sm);
  background: var(--bg-panel2);
  color: var(--accent-dark);
  overflow-wrap: anywhere;
}

.prose pre {
  position: relative;
  padding: 2.4rem 1.35rem 1.25rem;
  border-radius: var(--r-node);
  background-color: var(--bg-deep, var(--accent-dark));
  background-image:
    radial-gradient(circle at 1.35rem 1.2rem, var(--error) 0 4px, transparent 4.6px),
    radial-gradient(circle at 2.6rem 1.2rem, var(--warn) 0 4px, transparent 4.6px),
    radial-gradient(circle at 3.85rem 1.2rem, var(--success) 0 4px, transparent 4.6px);
  background-repeat: no-repeat;
  color: var(--bg);
  overflow-x: auto;
  box-shadow: var(--sh-neutral-10);
}

.prose pre code {
  display: block;
  padding: 0;
  background: none;
  color: inherit;
  font-size: .85rem;
  line-height: 1.7;
  white-space: pre;
  overflow-wrap: normal;
}

/* 表格:实色表头 + 斑马纹 + hover,窄屏横滑 */
.prose table {
  display: block;
  width: fit-content;
  min-width: 100%;
  max-width: 100%;
  overflow-x: auto;
  border-collapse: collapse;
  font-size: .92rem;
  line-height: 1.7;
}

.prose thead th {
  padding: .7rem .9rem;
  background: var(--bg-deep, var(--accent-dark));
  color: var(--bg);
  font-weight: 600;
  text-align: left;
  white-space: nowrap;
}

.prose tbody td {
  padding: .65rem .9rem;
  border-bottom: 1px solid var(--border-soft);
  vertical-align: top;
}

.prose tbody tr:nth-child(even) {
  background: color-mix(in srgb, var(--bg-panel2) 55%, transparent);
}

.prose tbody tr:hover {
  background: color-mix(in srgb, var(--accent) 8%, transparent);
}

.prose .table-scroll {
  max-width: 100%;
  overflow-x: auto;
}

@media (max-width: 860px) {
  .prose table {
    display: block;
    width: fit-content;
    max-width: 100%;
    overflow-x: auto;
    -webkit-overflow-scrolling: touch;
  }
}

/* ------------------------------------------------------------
   8. 正文视觉组件:数据卡 / 清单 / 结论块 / 提示块
   ------------------------------------------------------------ */
.stat-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(min(100%, 9.5rem), 1fr));
  gap: 1rem;
}

.stat-card {
  padding: 1.1rem 1.2rem;
  border: 1px solid var(--border);
  border-top: 3px solid var(--accent);
  border-radius: var(--r-node);
  background: var(--bg-panel);
  box-shadow: var(--sh-neutral-10);
}

.stat-card:nth-child(2) {
  border-top-color: var(--success);
}

.stat-card:nth-child(3) {
  border-top-color: var(--candy-honey);
}

.stat-card:nth-child(4) {
  border-top-color: var(--candy-sky);
}

.stat-card.is-teal {
  border-top-color: var(--success);
}

.stat-card.is-honey {
  border-top-color: var(--candy-honey);
}

.stat-num {
  display: block;
  font-family: var(--font-mono);
  font-size: 1.5rem;
  font-weight: 700;
  line-height: 1.25;
  color: var(--accent-dark);
}

.stat-label {
  display: block;
  margin-top: .3rem;
  font-size: .82rem;
  line-height: 1.6;
  color: var(--text-muted);
}

/* 勾叉清单:只做容器与行卡装饰,勾叉符号由正文文本自带 */
.check-list {
  display: grid;
  gap: .6rem;
  margin: 0;
  padding: 0;
  list-style: none;
}

.check-list li {
  margin: 0;
  padding: .8rem 1rem;
  border: 1px solid var(--border-soft);
  border-radius: var(--r-node);
  background: var(--bg-panel);
  line-height: 1.8;
  list-style: none;
}

.verdict {
  padding: 1.1rem 1.3rem 1.1rem 1.5rem;
  border-left: 4px solid var(--accent);
  border-radius: 0 var(--r-node) var(--r-node) 0;
  background: var(--bg-panel);
  background: color-mix(in srgb, var(--success) 8%, var(--bg-panel));
  font-size: .98rem;
  line-height: 1.85;
}

.verdict > :first-child {
  margin-top: 0;
}

.verdict > :last-child {
  margin-bottom: 0;
}

.callout {
  position: relative;
  padding: 1.1rem 1.3rem 1.1rem 3.6rem;
  border: 1px solid var(--border);
  border-left: 4px solid var(--accent);
  border-radius: 0 var(--r-node) var(--r-node) 0;
  background: var(--bg-panel);
  background: color-mix(in srgb, var(--accent) 8%, var(--bg-panel));
}

.callout::before {
  content: "i";
  position: absolute;
  left: 1.15rem;
  top: 1.15rem;
  width: 1.5rem;
  height: 1.5rem;
  display: grid;
  place-items: center;
  border-radius: 50%;
  background: var(--accent);
  color: var(--text-invert);
  font-family: var(--font-mono);
  font-size: .85rem;
  font-weight: 700;
  font-style: italic;
  line-height: 1;
}

.callout-title {
  display: block;
  margin-bottom: .35rem;
  font-weight: 700;
  color: var(--text);
}

.callout p {
  margin: 0;
}

.callout-warn {
  border-left-color: var(--warn);
  background: color-mix(in srgb, var(--warn) 12%, var(--bg-panel));
}

.callout-warn::before {
  content: "!";
  background: var(--warn);
  font-style: normal;
}

.callout-success {
  border-left-color: var(--success);
  background: color-mix(in srgb, var(--success) 10%, var(--bg-panel));
}

.callout-success::before {
  content: "i";
  background: var(--success);
}

/* ------------------------------------------------------------
   9. 文末推广卡
   ------------------------------------------------------------ */
.promo-block {
  position: relative;
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto;
  align-items: center;
  gap: 1.25rem 2rem;
  margin: clamp(2rem, 4vw, 2.75rem) 0 clamp(1.5rem, 3vw, 2rem);
  padding: clamp(1.5rem, 3.2vw, 2rem) clamp(1.5rem, 3vw, 2rem);
  border-radius: var(--r-card-lg);
  background: var(--accent);
  background-image: linear-gradient(135deg, var(--accent) 0%, var(--accent-dark) 62%, var(--teal-line) 145%);
  color: var(--text-invert);
  box-shadow: var(--sh-accent-28);
  overflow: hidden;
}

.promo-block::before {
  content: "";
  position: absolute;
  top: 12%;
  right: 8%;
  width: 10rem;
  height: 6rem;
  border-radius: 50%;
  background: radial-gradient(ellipse at center, color-mix(in srgb, var(--bg) 22%, transparent), transparent 70%);
  pointer-events: none;
}

.promo-block > * {
  position: relative;
  z-index: 1;
  min-width: 0;
}

.promo-block h3 {
  margin: 0;
  font-family: var(--font-display);
  font-size: 1.2rem;
  font-weight: 800;
  line-height: 1.4;
  color: var(--text-invert);
}

.promo-block p {
  margin: .5rem 0 0;
  font-size: .95rem;
  line-height: 1.8;
  color: var(--text-invert);
  opacity: .9;
}

.promo-block .btn-main {
  background: var(--bg-panel);
  border-color: var(--bg-panel);
  color: var(--accent-dark);
  box-shadow: var(--sh-neutral-10);
}

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

.promo-block .btn-ghost {
  background: transparent;
  border-color: color-mix(in srgb, var(--text-invert) 55%, transparent);
  color: var(--text-invert);
}

.promo-block .btn-ghost:hover {
  background: color-mix(in srgb, var(--text-invert) 14%, transparent);
  border-color: var(--text-invert);
  color: var(--text-invert);
}

@media (max-width: 640px) {
  .promo-block {
    grid-template-columns: 1fr;
  }
}

/* ------------------------------------------------------------
   10. 上一篇 / 下一篇
   ------------------------------------------------------------ */
#post-nav {
  margin-top: clamp(2rem, 4vw, 2.5rem);
  padding-bottom: 0;
}

#post-nav:empty {
  margin-top: 0;
}

.post-nav-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(min(100%, 16rem), 1fr));
  gap: 1rem;
}

.post-nav-grid > :only-child {
  grid-column: 1 / -1;
}

.post-nav-card {
  position: relative;
  display: flex;
  flex-direction: column;
  gap: .4rem;
  padding: 1.1rem 1.25rem;
  border: 1px solid var(--border);
  border-radius: var(--r-card);
  background: var(--bg-panel);
  box-shadow: var(--sh-neutral-10);
  color: var(--text);
  text-decoration: none;
  overflow: hidden;
  transition: transform .22s ease, box-shadow .22s ease, border-color .22s ease;
}

.post-nav-card::before {
  content: "";
  position: absolute;
  inset: 0 0 auto 0;
  height: 3px;
  background: linear-gradient(90deg, var(--accent), var(--teal-line));
  transform: scaleX(0);
  transform-origin: left center;
  transition: transform .25s ease;
}

.post-nav-card:hover {
  transform: translateY(-3px);
  border-color: var(--border-strong);
  box-shadow: var(--sh-accent-14);
}

.post-nav-card:hover::before {
  transform: scaleX(1);
}

.post-nav-next {
  text-align: right;
}

.post-nav-next::before {
  transform-origin: right center;
}

.post-nav-label {
  font-family: var(--font-mono);
  font-size: .75rem;
  letter-spacing: .06em;
  color: var(--accent-dark);
}

.post-nav-title {
  font-size: 1rem;
  font-weight: 600;
  line-height: 1.55;
}

.post-nav-date {
  font-family: var(--font-mono);
  font-size: .75rem;
  color: var(--text-muted);
}

/* ------------------------------------------------------------
   11. 延伸阅读
   ------------------------------------------------------------ */
#related-posts {
  margin-top: clamp(1.75rem, 3.5vw, 2.5rem);
  padding-top: 0;
  padding-bottom: clamp(2.5rem, 5vw, 4rem);
}

.related-title {
  margin: 0 0 1.1rem;
  font-family: var(--font-display);
  font-size: 1.25rem;
  font-weight: 800;
  letter-spacing: -.01em;
  color: var(--text);
}

.related-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(min(100%, 14rem), 1fr));
  gap: 1rem;
}

.related-card {
  display: flex;
  flex-direction: column;
  gap: .5rem;
  padding: 1.05rem 1.15rem;
  border: 1px solid var(--border);
  border-radius: var(--r-node);
  background: var(--bg-panel);
  box-shadow: var(--sh-neutral-10);
  color: var(--text);
  text-decoration: none;
  transition: transform .22s ease, box-shadow .22s ease, border-color .22s ease;
}

.related-card:hover {
  transform: translateY(-3px);
  border-color: var(--accent);
  box-shadow: var(--sh-accent-14);
}

.related-tag {
  align-self: flex-start;
  padding: .18rem .6rem;
  border-radius: var(--r-pill);
  background: var(--bg-panel2);
  background: color-mix(in srgb, var(--success) 14%, var(--bg-panel));
  font-family: var(--font-mono);
  font-size: .72rem;
  line-height: 1.5;
  color: var(--success-dark, var(--success));
}

.related-card-title {
  font-size: .95rem;
  font-weight: 600;
  line-height: 1.6;
}

.related-date {
  margin-top: auto;
  font-family: var(--font-mono);
  font-size: .75rem;
  color: var(--text-muted);
}

/* ------------------------------------------------------------
   12. 文末注册引导弹窗(由 signup-modal.js 动态创建)
   ------------------------------------------------------------ */
html.modal-open {
  overflow: hidden;
}

.signup-modal {
  position: fixed;
  inset: 0;
  z-index: 90;
  display: grid;
  place-items: center;
  padding: 1.25rem;
}

.signup-modal[hidden] {
  display: none;
}

.signup-modal-veil {
  position: absolute;
  inset: 0;
  background: var(--veil);
  backdrop-filter: blur(3px);
  opacity: 0;
  transition: opacity .22s ease;
}

.signup-modal.is-open .signup-modal-veil {
  opacity: 1;
}

.signup-modal-panel {
  position: relative;
  width: min(100%, 26rem);
  padding: 2rem 1.75rem 1.6rem;
  border: 1px solid var(--border);
  border-radius: var(--r-card-lg);
  background: var(--bg-panel);
  box-shadow: var(--sh-accent-28);
  text-align: center;
  opacity: 0;
  transform: translateY(12px) scale(.98);
  transition: opacity .24s ease, transform .24s ease;
}

.signup-modal.is-open .signup-modal-panel {
  opacity: 1;
  transform: none;
}

.signup-modal-close {
  position: absolute;
  top: .85rem;
  right: .85rem;
  width: 2rem;
  height: 2rem;
  display: grid;
  place-items: center;
  border: 1px solid var(--border);
  border-radius: 50%;
  background: var(--bg-panel);
  color: var(--text-muted);
  cursor: pointer;
  transition: color .2s ease, border-color .2s ease, transform .2s ease;
}

.signup-modal-close:hover {
  color: var(--accent-dark);
  border-color: var(--accent);
  transform: rotate(90deg);
}

.signup-modal-close:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 2px;
}

.signup-modal-brand {
  margin: 0;
  font-family: var(--font-mono);
  font-size: .78rem;
  letter-spacing: .12em;
  color: var(--accent-dark);
}

.signup-modal-title {
  margin: .55rem 0 0;
  font-family: var(--font-display);
  font-size: clamp(1.25rem, 1.1rem + .8vw, 1.5rem);
  font-weight: 800;
  line-height: 1.32;
  letter-spacing: -.01em;
  color: var(--text);
}

.signup-modal-text {
  margin: .75rem 0 0;
  font-size: .92rem;
  line-height: 1.8;
  color: var(--text-muted);
}

.signup-modal-cta {
  width: 100%;
  justify-content: center;
  margin-top: 1.25rem;
}

.signup-modal-foot {
  margin: .85rem 0 0;
  font-family: var(--font-mono);
  font-size: .78rem;
  color: var(--text-muted);
}

/* ------------------------------------------------------------
   13. 悬浮 CTA(文章页使用;列表页不出现)
   ------------------------------------------------------------ */
.float-cta {
  position: fixed;
  right: clamp(1rem, 3vw, 1.75rem);
  bottom: clamp(1rem, 3vw, 1.75rem);
  z-index: 70;
  display: inline-flex;
  align-items: center;
  gap: .55rem;
  max-width: calc(100% - 2rem);
  padding: .8rem 1.35rem;
  border-radius: var(--r-pill);
  background: var(--accent);
  color: var(--text-invert);
  font-size: .95rem;
  font-weight: 600;
  line-height: 1.3;
  text-decoration: none;
  box-shadow: var(--sh-accent-28);
  transition: transform .2s ease, box-shadow .2s ease;
}

.float-cta:hover {
  transform: translateY(-2px);
  box-shadow: var(--sh-accent-28);
}

.float-cta svg {
  flex: none;
  width: 1.05rem;
  height: 1.05rem;
}

@media (max-width: 640px) {
  .float-cta {
    right: .85rem;
    bottom: .85rem;
    padding: .7rem 1.1rem;
    font-size: .88rem;
  }
}

/* ------------------------------------------------------------
   14. 窄屏折回单列
   ------------------------------------------------------------ */
@media (max-width: 768px) {
  .blog-hero,
  .article-hero-inner {
    grid-template-columns: 1fr;
    gap: 1.5rem;
  }

  .blog-meta-card,
  .article-meta-card {
    grid-auto-flow: column;
    grid-auto-columns: max-content;
    justify-content: start;
    gap: 1.5rem;
    padding: .9rem 1.1rem;
    overflow-x: auto;
  }

  .meta-item + .meta-item {
    padding-top: 0;
    border-top: 0;
  }

  .article-meta-card {
    order: -1;
  }

  .article-hero-lead {
    font-size: .96rem;
  }
}

@media (max-width: 480px) {
  .breadcrumb-list [aria-current="page"] {
    max-width: 12rem;
  }

  .post-card {
    padding: 1.25rem 1.2rem 1.15rem;
  }
}

/* ------------------------------------------------------------
   15. 动效降级
   ------------------------------------------------------------ */
@media (prefers-reduced-motion: reduce) {
  .post-card,
  .post-nav-card,
  .related-card,
  .tag-btn,
  .float-cta,
  .signup-modal-panel,
  .signup-modal-veil,
  .signup-modal-close,
  .post-more-arrow {
    transition: none;
  }

  .post-card:hover,
  .post-nav-card:hover,
  .related-card:hover,
  .tag-btn:hover,
  .float-cta:hover,
  .signup-modal-close:hover {
    transform: none;
  }

  .post-nav-card::before {
    transition: none;
  }
}