/* ========================================
   比特囤币 · blog.btchao.com
   设计规范遵循 bitcoin-brand-kit（lovexw/bitcoin-brand-kit）
   · 主色：比特币橙 #F7931A
   · 明亮米白底，无暗黑模式
   · 无渐变、无投影；悬停只加深描边
   · 橙底一律配近黑文字（禁止白字）
   · 圆角：按钮/瓦片 10px，卡片 16px
   ======================================== */

:root {
  /* ── 品牌色板（bitcoin-brand-kit tokens） ── */
  --bg: #faf9f6;
  --bg-card: #ffffff;
  --bg-hover: #f4f2ee;
  --text: #191714;
  --text-secondary: #4c4a44;
  --text-muted: #6d6a63;
  --accent: #F7931A;
  --accent-dark: #b26a08;
  --accent-ink: #b26a08; /* 浅底上的橙色文字用色（AA 对比） */
  --accent-ink-cm: color-mix(in oklch, var(--accent) 72%, black);
  --accent-light: rgba(247, 147, 26, 0.12);
  --accent-soft: rgba(247, 147, 26, 0.12);
  --border: #e7e4dc;
  --border-light: #f0eeea;
  --code-bg: #f4f2ee;
  --link: #b26a08;
  --link-hover: #F7931A;
  --radius-sm: 10px;
  --radius-md: 10px;
  --radius-lg: 16px;
  --max-width: 1080px;
  --content-width: 720px;
  --sidebar-width: 280px;
  --gap: 32px;
  --font-sans: -apple-system, BlinkMacSystemFont, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Segoe UI", sans-serif;
  --font-display: "Iowan Old Style", "Charter", Georgia, "Songti SC", "Noto Serif SC", serif;
  --font-mono: ui-monospace, "SF Mono", "JetBrains Mono", Menlo, Consolas, monospace;
  --transition: 0.15s ease;
}

/* 明亮主题，不提供暗黑模式（遵循 brand kit：明亮专业） */

* { margin: 0; padding: 0; box-sizing: border-box; }

html { scroll-behavior: smooth; -webkit-text-size-adjust: 100%; }

body {
  font-family: var(--font-sans);
  background: var(--bg);
  color: var(--text);
  line-height: 1.75;
  font-size: 16px;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  text-rendering: optimizeLegibility;
}

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

/* ===== Container ===== */
.container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 24px;
}

/* ===== Header ===== */
.site-header {
  border-bottom: 1px solid var(--border);
  padding: 12px 0;
  position: sticky;
  top: 0;
  background: color-mix(in oklch, var(--bg) 92%, transparent);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  z-index: 100;
}

.site-header__inner {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 16px;
  height: 44px;
}

.logo {
  display: flex;
  align-items: center;
  gap: 8px;
  text-decoration: none;
  white-space: nowrap;
}

.logo__icon {
  width: 32px;
  height: 32px;
  border-radius: 8px;
  object-fit: contain;
  flex-shrink: 0;
}

.logo__text {
  font-family: var(--font-display);
  font-size: 18px;
  font-weight: 600;
  color: var(--text);
  letter-spacing: -0.01em;
}

.nav {
  display: flex;
  gap: 2px;
  align-items: center;
  flex-wrap: nowrap;
}

.nav a {
  color: var(--text-muted);
  text-decoration: none;
  font-size: 14px;
  font-weight: 500;
  padding: 6px 12px;
  border-radius: var(--radius-sm);
  transition: color var(--transition);
  white-space: nowrap;
}

.nav a:hover { color: var(--text); }

.nav .random-btn { margin-left: 10px; }

/* ===== Buttons（brand kit：无投影无渐变；导航内为次要描边按钮，
   橙色主按钮只留给首屏搜索，一屏一个主要动作） ===== */
.random-btn {
  padding: 8px 14px;
  background: transparent;
  color: var(--text);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  cursor: pointer;
  font-size: 14px;
  font-weight: 500;
  font-family: inherit;
  transition: border-color var(--transition), color var(--transition), transform 0.05s ease;
  white-space: nowrap;
}

.random-btn:hover {
  border-color: var(--text);
}

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

.random-btn:disabled {
  opacity: 0.4;
  cursor: wait;
  transform: none;
}

/* ===== 移动端菜单开关（brand kit topnav 模式：折叠 + 下拉） ===== */
.nav-toggle {
  display: none;
  background: transparent;
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  padding: 6px 12px;
  color: var(--text);
  font-size: 16px;
  line-height: 1;
  cursor: pointer;
}

@media (max-width: 920px) {
  .nav { display: none; }
  .nav-toggle { display: inline-flex; }
  body.nav-open .nav {
    display: flex;
    flex-direction: column;
    align-items: stretch;
    position: absolute;
    left: 0;
    right: 0;
    top: 100%;
    background: var(--bg-card);
    border-bottom: 1px solid var(--border);
    padding: 14px 24px 18px;
    gap: 4px;
    box-shadow: none;
  }
  body.nav-open .nav a {
    display: block;
    padding: 10px 8px;
    font-size: 15px;
    text-align: left;
    border-radius: 0;
    background: transparent;
    border-bottom: 1px solid var(--border-light);
  }
  body.nav-open .nav a:last-of-type { border-bottom: none; }
  body.nav-open .nav .random-btn {
    margin-top: 8px;
    justify-content: center;
  }
}

/* ===== Eyebrow（brand kit：等宽小字标签，点明区块性质） ===== */
.eyebrow {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--accent-ink);
  margin: 0 0 16px;
}

/* ===== Hero ===== */
.hero {
  text-align: center;
  padding: 56px 0 40px;
}

.hero h1 {
  font-family: var(--font-display);
  font-size: 40px;
  font-weight: 600;
  color: var(--text);
  margin-bottom: 10px;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 12px;
  letter-spacing: -0.02em;
  line-height: 1.1;
}

.hero h1 .logo__icon {
  width: 44px;
  height: 44px;
  border-radius: 12px;
}

.hero__subtitle {
  font-size: 16px;
  color: var(--text-muted);
  margin-bottom: 6px;
  font-weight: 400;
}

.hero__desc {
  font-size: 14px;
  color: var(--text-muted);
  margin-bottom: 28px;
  font-style: italic;
}

.hero__search {
  display: flex;
  max-width: 420px;
  margin: 0 auto;
  gap: 8px;
}

.hero__search input {
  flex: 1;
  padding: 11px 16px;
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  font-size: 15px;
  background: var(--bg-card);
  color: var(--text);
  outline: none;
  font-family: inherit;
  transition: border-color var(--transition);
}

.hero__search input::placeholder { color: var(--text-muted); }

.hero__search input:focus {
  outline: 2px solid rgba(247, 147, 26, 0.25);
  border-color: var(--accent);
}

.hero__search button {
  padding: 0 20px;
  background: var(--accent);
  color: var(--text);
  border: 1px solid var(--accent);
  border-radius: var(--radius-sm);
  cursor: pointer;
  font-size: 15px;
  transition: background var(--transition), transform 0.05s ease;
}

.hero__search button:hover {
  background: color-mix(in oklch, var(--accent) 86%, black);
}

.hero__search button:active { transform: translateY(1px); }

/* ===== Layout: Two Column ===== */
.layout-with-sidebar {
  display: grid;
  grid-template-columns: 1fr var(--sidebar-width);
  gap: var(--gap);
  margin: 32px 0;
  align-items: start;
}

.layout-main {
  min-width: 0;
}

/* ===== Sidebar ===== */
.sidebar {
  display: flex;
  flex-direction: column;
  gap: 16px;
  position: sticky;
  top: 76px;
  align-self: start;
}

/* 卡片（brand kit：白底、1px 描边、16px 圆角，悬停只加深描边） */
.sidebar-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 20px;
  transition: border-color var(--transition);
}

.sidebar-card:hover {
  border-color: color-mix(in oklch, var(--text) 22%, var(--border));
}

.sidebar-card__icon {
  display: block;
  width: 48px;
  height: 48px;
  border-radius: 50%;
  margin: 0 auto 8px;
  object-fit: contain;
}

.sidebar-card__title {
  font-size: 14px;
  text-align: center;
  margin-bottom: 4px;
  color: var(--text);
  font-weight: 600;
}

.sidebar-card__desc {
  font-size: 12px;
  text-align: center;
  color: var(--text-muted);
  margin-bottom: 12px;
}

.sidebar-card__slogan {
  font-size: 12px;
  color: var(--text-secondary);
  font-style: italic;
  text-align: center;
  line-height: 1.7;
  padding: 10px 0;
  border-top: 1px solid var(--border-light);
  border-bottom: 1px solid var(--border-light);
  margin-bottom: 12px;
}

.sidebar-card__stats {
  display: flex;
  justify-content: center;
  gap: 28px;
  margin-bottom: 12px;
}

.sidebar-stat { text-align: center; }

.sidebar-stat__num {
  display: block;
  font-family: var(--font-display);
  font-size: 22px;
  font-weight: 600;
  color: var(--accent-ink);
  letter-spacing: -0.02em;
  font-variant-numeric: tabular-nums;
}

.sidebar-stat__label {
  font-size: 11px;
  color: var(--text-muted);
  letter-spacing: 0.5px;
}

.sidebar-card__link {
  display: block;
  padding: 7px 10px;
  color: var(--text-secondary);
  text-decoration: none;
  font-size: 13px;
  border-radius: var(--radius-sm);
  transition: color var(--transition), background var(--transition);
}

.sidebar-card__link:hover {
  color: var(--accent-ink);
  background: var(--accent-light);
}

/* QR code card */
.sidebar-card--qrcode {
  text-align: center;
}

.sidebar-qrcode {
  width: 100%;
  max-width: 200px;
  height: auto;
  border-radius: var(--radius-sm);
  margin: 8px 0;
  display: block;
  margin-left: auto;
  margin-right: auto;
}

/* Tag cloud */
.tag-cloud {
  display: flex;
  flex-wrap: wrap;
  gap: 5px;
}

/* ===== Pill / Tag（brand kit pill：accent-soft 底 + 深橙文字 + 全圆角） ===== */
.tag {
  display: inline-block;
  background: var(--accent-soft);
  color: var(--accent-ink-cm, #9a5b06);
  padding: 2px 10px;
  border-radius: 999px;
  font-family: var(--font-mono);
  font-size: 11px;
  text-decoration: none;
  font-weight: 500;
  transition: background var(--transition);
  line-height: 1.7;
  letter-spacing: 0.02em;
}

.tag:hover {
  background: rgba(247, 147, 26, 0.22);
}

.tag--small { font-size: 10px; opacity: 0.85; }

.tag--cloud {
  font-size: 12px;
  padding: 3px 10px;
}

/* ===== Post List ===== */
.post-list {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.post-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 20px 24px;
  transition: border-color var(--transition);
  position: relative;
}

.post-card:hover {
  border-color: color-mix(in oklch, var(--text) 22%, var(--border));
}

.post-card__title {
  font-size: 17px;
  margin-bottom: 6px;
  line-height: 1.4;
}

.post-card__title a {
  color: var(--text);
  text-decoration: none;
  transition: color var(--transition);
}

.post-card__title a:hover { color: var(--accent-ink); }

.post-card__meta {
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--text-muted);
  margin-bottom: 8px;
  display: flex;
  gap: 6px;
  align-items: center;
  flex-wrap: wrap;
}

.post-card__meta time { font-weight: 600; color: var(--text-secondary); }

.post-card__summary {
  color: var(--text-secondary);
  font-size: 14px;
  margin-bottom: 10px;
  line-height: 1.7;
}

.post-card__readmore {
  color: var(--accent-ink);
  text-decoration: none;
  font-size: 13px;
  font-weight: 600;
  display: inline-flex;
  align-items: center;
  gap: 4px;
  border-bottom: 1px solid transparent;
  transition: border-color var(--transition);
}

.post-card__readmore:hover { border-bottom-color: var(--accent); }

/* ===== Single Post ===== */
.post {
  max-width: var(--content-width);
  margin: 0 auto;
  padding: 40px 0;
}

.post__header {
  margin-bottom: 32px;
  text-align: center;
}

.post__title {
  font-family: var(--font-display);
  font-size: 32px;
  line-height: 1.3;
  margin-bottom: 14px;
  font-weight: 600;
  letter-spacing: -0.015em;
}

.post__meta {
  font-family: var(--font-mono);
  font-size: 13px;
  color: var(--text-muted);
  display: flex;
  gap: 8px;
  justify-content: center;
  align-items: center;
  flex-wrap: wrap;
}

.post__content {
  font-size: 16px;
  line-height: 1.9;
  color: var(--text);
}

.post__content h2 {
  font-family: var(--font-display);
  font-size: 23px;
  margin: 38px 0 14px;
  font-weight: 600;
  padding-bottom: 6px;
  letter-spacing: -0.01em;
  border-bottom: 1px solid var(--border);
}

.post__content h3 {
  font-family: var(--font-display);
  font-size: 19px;
  margin: 26px 0 10px;
  font-weight: 600;
}

.post__content h4 {
  font-size: 17px;
  margin: 20px 0 8px;
  font-weight: 600;
}

.post__content p { margin-bottom: 18px; }

.post__content img {
  max-width: 100%;
  height: auto;
  border-radius: var(--radius-lg);
  border: 1px solid var(--border-light);
  margin: 20px auto;
  display: block;
}

.post__content blockquote {
  border-left: 3px solid var(--accent);
  padding: 10px 18px;
  margin: 18px 0;
  color: var(--text-secondary);
  background: var(--accent-soft);
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
  font-size: 15px;
}

.post__content blockquote p { margin-bottom: 0; }

/* 正文链接（brand kit .ext：描边下划线，悬停变橙） */
.post__content a {
  color: var(--accent-ink-cm, #9a5b06);
  text-decoration: none;
  border-bottom: 1px solid var(--border);
  transition: border-color var(--transition), color var(--transition);
}

.post__content a:hover {
  border-bottom-color: var(--accent);
  color: var(--accent-ink);
}

.post__content code {
  background: var(--code-bg);
  border: 1px solid var(--border-light);
  padding: 2px 6px;
  border-radius: 6px;
  font-size: 13px;
  font-family: var(--font-mono);
}

.post__content pre {
  background: var(--code-bg);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  padding: 16px;
  overflow-x: auto;
}

.post__content pre code {
  background: transparent;
  border: none;
  padding: 0;
}

.post__content ul,
.post__content ol {
  padding-left: 22px;
  margin-bottom: 14px;
}

.post__content li { margin-bottom: 5px; }

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

.post__content hr {
  border: none;
  border-top: 1px solid var(--border);
  margin: 28px 0;
}

/* ===== Table（brand kit：无渐变，表头浅底深字） ===== */
.post__content table {
  width: 100%;
  border-collapse: collapse;
  margin: 20px 0;
  font-size: 14px;
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  overflow: hidden;
}

.post__content thead {
  background: var(--bg-hover);
}

.post__content th {
  padding: 10px 16px;
  text-align: center;
  color: var(--text);
  font-weight: 600;
  font-size: 13px;
  letter-spacing: 0.02em;
  border-bottom: 1px solid var(--border);
}

.post__content tbody tr {
  border-bottom: 1px solid var(--border-light);
  transition: background var(--transition);
}

.post__content tbody tr:last-child { border-bottom: none; }

.post__content tbody tr:nth-child(even) {
  background: color-mix(in oklch, var(--text) 3%, transparent);
}

.post__content tbody tr:hover {
  background: var(--accent-soft);
}

.post__content td {
  padding: 8px 16px;
  text-align: center;
  color: var(--text);
}

.post__content td:first-child {
  font-weight: 500;
}

@media (max-width: 768px) {
  .post__content table {
    display: block;
    overflow-x: auto;
    white-space: nowrap;
    -webkit-overflow-scrolling: touch;
  }
}

@media (max-width: 768px) {
  .post__content table { font-size: 13px; }
  .post__content th { padding: 8px 10px; font-size: 12px; }
  .post__content td { padding: 6px 10px; }
}

.post__footer {
  margin-top: 48px;
  padding-top: 24px;
  border-top: 1px solid var(--border);
}

.post__share p {
  text-align: center;
  color: var(--accent-ink);
  font-style: italic;
  font-size: 14px;
  font-weight: 500;
}

.post__qrcode {
  text-align: center;
  margin-top: 16px;
  padding-top: 16px;
  border-top: 1px solid var(--border);
}

.post__qrcode img {
  width: 180px;
  height: auto;
  border-radius: var(--radius-sm);
  display: block;
  margin: 0 auto 8px;
}

.post__qrcode p {
  font-size: 13px;
  color: var(--text-secondary);
  margin: 0;
}

.post__nav {
  display: flex;
  justify-content: space-between;
  margin-top: 20px;
  gap: 12px;
}

.post__nav a {
  color: var(--text-secondary);
  text-decoration: none;
  font-size: 13px;
  padding: 8px 14px;
  border-radius: var(--radius-sm);
  background: transparent;
  border: 1px solid var(--border);
  transition: border-color var(--transition), color var(--transition);
}

.post__nav a:hover {
  border-color: var(--text);
  color: var(--text);
}

.post__nav-prev,
.post__nav-next {
  max-width: 45%;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.post__nav-next { margin-left: auto; text-align: right; }

/* ===== Comments ===== */
.comments {
  max-width: var(--content-width);
  margin: 48px auto 0;
  padding-top: 32px;
  border-top: 1px solid var(--border);
}

.comments__title {
  font-size: 17px;
  margin-bottom: 18px;
  color: var(--text);
  font-weight: 600;
}

.comments__container { min-height: 80px; }

.comments__loading {
  text-align: center;
  color: var(--text-muted);
  font-size: 13px;
  padding: 20px 0;
}

/* ===== Pagination（brand kit：次级描边 + 主色实底，均无投影） ===== */
.pagination {
  display: flex;
  justify-content: center;
  align-items: center;
  gap: 6px;
  padding: 32px 0;
  flex-wrap: wrap;
}

.pagination__page,
.pagination__arrow {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-width: 36px;
  height: 36px;
  padding: 0 10px;
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  font-size: 14px;
  color: var(--text-secondary);
  text-decoration: none;
  background: transparent;
  transition: border-color var(--transition), color var(--transition);
  cursor: pointer;
  font-weight: 500;
  font-variant-numeric: tabular-nums;
}

.pagination__page:hover,
.pagination__arrow:hover {
  border-color: var(--text);
  color: var(--text);
}

.pagination__page--active {
  background: var(--accent);
  border-color: var(--accent);
  color: var(--text);
  font-weight: 700;
}

.pagination__page--active:hover {
  background: color-mix(in oklch, var(--accent) 86%, black);
  color: var(--text);
}

.pagination__arrow--disabled {
  opacity: 0.3;
  cursor: not-allowed;
  pointer-events: none;
}

.pagination__dots {
  color: var(--text-muted);
  padding: 0 3px;
}

/* ===== Search Page ===== */
.search-page {
  max-width: var(--content-width);
  margin: 0 auto;
  padding: 40px 0;
}

.search-title {
  font-family: var(--font-display);
  font-size: 24px;
  margin-bottom: 24px;
  color: var(--text);
  font-weight: 600;
  letter-spacing: -0.01em;
}

.search-box input#search-input {
  width: 100%;
  padding: 11px 16px;
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  font-size: 15px;
  background: var(--bg-card);
  color: var(--text);
  outline: none;
  font-family: inherit;
  transition: border-color var(--transition);
  margin-bottom: 20px;
}

.search-box input#search-input:focus {
  outline: 2px solid rgba(247, 147, 26, 0.25);
  border-color: var(--accent);
}

.search-loading,
.search-error,
.search-hint,
.search-empty,
.search-count,
.search-more {
  color: var(--text-muted);
  font-size: 13px;
  padding: 6px 0;
}

.search-empty {
  color: var(--text-secondary);
  font-size: 15px;
  padding: 28px 0;
  text-align: center;
}

.search-results-list {
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.search-result-item {
  display: block;
  padding: 16px 20px;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  text-decoration: none;
  transition: border-color var(--transition);
}

.search-result-item:hover {
  border-color: color-mix(in oklch, var(--text) 22%, var(--border));
}

.search-result-title {
  font-size: 15px;
  font-weight: 600;
  color: var(--text);
  margin-bottom: 3px;
}

.search-result-meta {
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--text-muted);
  margin-bottom: 5px;
}

.search-result-summary {
  font-size: 13px;
  color: var(--text-secondary);
  line-height: 1.6;
}

mark {
  background: var(--accent-soft);
  color: var(--accent-ink);
  padding: 1px 3px;
  border-radius: 3px;
  font-weight: 600;
}

/* ===== Footer ===== */
.site-footer {
  border-top: 1px solid var(--border);
  padding: 40px 0;
  margin-top: 64px;
  text-align: center;
  background: transparent;
}

.site-footer p {
  color: var(--text-muted);
  font-size: 13px;
  margin-bottom: 3px;
}

.site-footer a {
  color: var(--text-secondary);
  text-decoration: none;
  border-bottom: 1px solid var(--border);
  transition: border-color var(--transition), color var(--transition);
  font-size: 13px;
}

.site-footer a:hover {
  color: var(--accent-ink);
  border-bottom-color: var(--accent);
}

.site-footer p a { font-size: 13px; }

.disclaimer {
  font-size: 12px !important;
  max-width: 480px;
  margin: 10px auto 0 !important;
  line-height: 1.7;
  color: var(--text-muted) !important;
}

.view-all {
  display: block;
  text-align: center;
  color: var(--accent-ink);
  text-decoration: none;
  padding: 16px;
  font-size: 14px;
  font-weight: 600;
  border-bottom: 1px solid transparent;
  transition: border-color var(--transition);
}

.view-all:hover { border-bottom-color: var(--accent); }

/* ===== Password Lock ===== */
.password-lock {
  max-width: 400px;
  margin: 56px auto;
  padding: 40px 28px;
  text-align: center;
  background: var(--bg-card);
  border-radius: var(--radius-lg);
  border: 1px solid var(--border);
}

.password-lock__icon {
  font-size: 40px;
  margin-bottom: 16px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 72px;
  height: 72px;
  background: var(--accent-soft);
  border-radius: 50%;
}

.password-lock__hint {
  color: var(--text-secondary);
  font-size: 14px;
  margin-bottom: 24px;
  line-height: 1.6;
}

.password-lock__input-wrap {
  display: flex;
  gap: 8px;
  justify-content: center;
}

.password-lock__input {
  flex: 1;
  max-width: 240px;
  padding: 10px 14px;
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  font-size: 14px;
  outline: none;
  font-family: inherit;
  transition: border-color var(--transition);
  background: var(--bg-card);
  color: var(--text);
}

.password-lock__input:focus {
  outline: 2px solid rgba(247, 147, 26, 0.25);
  border-color: var(--accent);
}

.password-lock__btn {
  padding: 10px 22px;
  background: var(--accent);
  color: var(--text);
  border: 1px solid var(--accent);
  border-radius: var(--radius-sm);
  font-size: 14px;
  font-weight: 600;
  cursor: pointer;
  font-family: inherit;
  transition: background var(--transition), transform 0.05s ease;
}

.password-lock__btn:hover {
  background: color-mix(in oklch, var(--accent) 86%, black);
}

.password-lock__btn:active { transform: translateY(1px); }

.password-lock__error {
  color: #b42318;
  font-size: 13px;
  margin-top: 12px;
  min-height: 18px;
}

.post-card__summary--locked {
  color: var(--text-muted);
  font-style: italic;
  font-size: 13px;
}

/* ===== Selection & Scrollbar ===== */
::selection { background: var(--accent); color: #191714; }

::-webkit-scrollbar { width: 6px; height: 6px; }
::-webkit-scrollbar-track { background: var(--bg); }
::-webkit-scrollbar-thumb { background: var(--border); border-radius: 3px; }
::-webkit-scrollbar-thumb:hover { background: var(--text-muted); }

/* ===== Animation ===== */
@keyframes fadeInUp {
  from { opacity: 0; transform: translateY(8px); }
  to { opacity: 1; transform: translateY(0); }
}

.post-card {
  animation: fadeInUp 0.3s ease-out backwards;
}

.post-card:nth-child(1) { animation-delay: 0.04s; }
.post-card:nth-child(2) { animation-delay: 0.08s; }
.post-card:nth-child(3) { animation-delay: 0.12s; }
.post-card:nth-child(4) { animation-delay: 0.16s; }
.post-card:nth-child(5) { animation-delay: 0.2s; }
.post-card:nth-child(6) { animation-delay: 0.24s; }
.post-card:nth-child(7) { animation-delay: 0.28s; }
.post-card:nth-child(8) { animation-delay: 0.32s; }
.post-card:nth-child(9) { animation-delay: 0.36s; }
.post-card:nth-child(10) { animation-delay: 0.4s; }

@media (prefers-reduced-motion: reduce) {
  * { animation-duration: 0.01ms !important; transition-duration: 0.01ms !important; }
}

/* ===== Responsive ===== */
@media (max-width: 960px) {
  .layout-with-sidebar {
    grid-template-columns: 1fr;
    gap: 20px;
  }

  .sidebar {
    position: static;
    flex-direction: row;
    flex-wrap: wrap;
    gap: 12px;
  }

  .sidebar-card {
    flex: 1;
    min-width: 240px;
  }
}

@media (max-width: 768px) {
  .container { padding: 0 16px; }

  .hero { padding: 36px 0 24px; }
  .hero h1 { font-size: 30px; }
  .hero h1 .logo__icon { width: 40px; height: 40px; }
  .hero__subtitle { font-size: 14px; }
  .hero__desc { font-size: 13px; }
  .hero__search { max-width: 100%; }

  .post-card { padding: 18px 16px; }
  .post-card__title { font-size: 16px; }

  .post { padding: 32px 0; }
  .post__title { font-size: 25px; }
  .post__content { font-size: 15px; }
  .post__content h2 { font-size: 20px; }
  .post__content h3 { font-size: 17px; }

  .nav a { font-size: 13px; padding: 5px 8px; }
  .logo__text { font-size: 15px; }
  .logo__icon { width: 28px; height: 28px; }

  .pagination__page,
  .pagination__arrow { min-width: 32px; height: 32px; font-size: 13px; }

  .sidebar { flex-direction: column; }
  .random-btn { padding: 6px 12px; font-size: 13px; }

  .post__nav { flex-direction: column; gap: 8px; }
  .post__nav-prev,
  .post__nav-next { max-width: 100%; text-align: center; }
}

@media (max-width: 480px) {
  .container { padding: 0 12px; }

  .hero h1 { font-size: 26px; gap: 8px; }
  .hero h1 .logo__icon { width: 36px; height: 36px; }
  .hero__subtitle { font-size: 13px; }
  .hero__desc { font-size: 12px; }
  .hero__search input { padding: 10px 14px; font-size: 14px; }

  .post-card { padding: 16px 12px; }
  .post-card__title { font-size: 15px; }
  .post-card__summary { font-size: 13px; }

  .nav a { font-size: 12px; padding: 4px 6px; }
  .logo__text { font-size: 14px; }

  .site-header { padding: 8px 0; }
  .site-header__inner { height: 36px; }

  .post__title { font-size: 22px; }
  .post__content { font-size: 14px; line-height: 1.8; }

  .sidebar-card { padding: 16px 12px; }
  .site-footer { padding: 24px 0; margin-top: 40px; }
}

/* ========== Breadcrumb 面包屑（brand kit meta：等宽字体） ========== */
.breadcrumb {
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--text-muted);
  margin-bottom: 16px;
  padding: 8px 0;
  max-width: var(--content-width);
  margin-left: auto;
  margin-right: auto;
}
.breadcrumb a {
  color: var(--accent-ink);
  text-decoration: none;
  border-bottom: 1px solid var(--border);
  transition: border-color var(--transition);
}
.breadcrumb a:hover { border-bottom-color: var(--accent); }
.breadcrumb__sep { margin: 0 6px; color: var(--text-muted); }
.breadcrumb__current { color: var(--text-secondary); }

/* ========== 404 Page ========== */
.not-found {
  text-align: center;
  padding: 80px 20px;
  max-width: 600px;
  margin: 0 auto;
}
.not-found__icon {
  font-size: 64px;
  margin-bottom: 16px;
}
.not-found__title {
  font-family: var(--font-display);
  font-size: 72px;
  font-weight: 600;
  color: var(--accent);
  margin: 0 0 12px;
  letter-spacing: -0.03em;
}
.not-found__desc {
  font-size: 16px;
  color: var(--text-secondary);
  margin: 0 0 32px;
}
.not-found__actions {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 12px;
}
.not-found__link {
  display: inline-flex;
  align-items: center;
  padding: 9px 18px;
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  background: transparent;
  color: var(--text);
  text-decoration: none;
  font-size: 14px;
  font-weight: 500;
  transition: border-color var(--transition);
}
.not-found__link:hover { border-color: var(--text); }
.not-found__link--primary {
  background: var(--accent);
  border-color: var(--accent);
  color: var(--text);
  font-weight: 600;
}
.not-found__link--primary:hover {
  background: color-mix(in oklch, var(--accent) 86%, black);
  border-color: var(--accent);
}

/* ========== Related Posts ========== */
.related-posts {
  margin-top: 48px;
  padding-top: 32px;
  border-top: 1px solid var(--border);
}
.related-posts__title {
  font-size: 18px;
  font-weight: 600;
  margin: 0 0 16px;
  color: var(--text);
}
.related-posts__list {
  display: grid;
  grid-template-columns: 1fr;
  gap: 12px;
}
@media (min-width: 768px) {
  .related-posts__list {
    grid-template-columns: 1fr 1fr;
  }
}
.related-post {
  display: block;
  padding: 16px;
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  text-decoration: none;
  color: inherit;
  transition: border-color var(--transition);
}
.related-post:hover {
  border-color: color-mix(in oklch, var(--text) 22%, var(--border));
}
.related-post__title {
  font-size: 14px;
  font-weight: 500;
  margin: 0 0 4px;
  color: var(--text);
  line-height: 1.4;
}
.related-post__meta {
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--text-muted);
}

/* ========== Bitcoin Guide Page ========== */
.bitcoin-guide-page {
  max-width: 900px;
  margin: 0 auto;
  padding: 0 20px 60px;
}
.guide-sections {
  display: grid;
  grid-template-columns: 1fr;
  gap: 24px;
  margin-top: 32px;
}
@media (min-width: 768px) {
  .guide-sections {
    grid-template-columns: 1fr 1fr;
  }
}
.guide-section {
  padding: 24px;
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  background: var(--bg-card);
  transition: border-color var(--transition);
}
.guide-section:hover {
  border-color: color-mix(in oklch, var(--text) 22%, var(--border));
}
.guide-section__eyebrow {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--accent-ink);
  margin: 0 0 10px;
}
.guide-section__title {
  font-size: 18px;
  font-weight: 600;
  margin: 0 0 8px;
  color: var(--text);
}
.guide-section__desc {
  font-size: 13px;
  color: var(--text-muted);
  margin: 0 0 16px;
}
.guide-section__list {
  list-style: none;
  padding: 0;
  margin: 0;
}
.guide-section__list li {
  padding: 6px 0;
  font-size: 14px;
  border-bottom: 1px solid var(--border-light);
}
.guide-section__list li:last-child { border-bottom: none; }
.guide-section__list li a {
  color: var(--accent-ink);
  text-decoration: none;
  border-bottom: 1px solid var(--border);
  transition: border-color var(--transition);
}
.guide-section__list li a:hover { border-bottom-color: var(--accent); }
.guide-footer {
  text-align: center;
  margin-top: 48px;
  padding-top: 32px;
  border-top: 1px solid var(--border);
  font-size: 14px;
  color: var(--text-secondary);
}
.guide-footer a {
  color: var(--accent-ink);
  text-decoration: none;
  border-bottom: 1px solid var(--border);
  transition: border-color var(--transition);
}
.guide-footer a:hover { border-bottom-color: var(--accent); }