:root {
  --color-bg: #fbfbfa;
  --color-surface: #ffffff;
  --color-text: #20242a;
  --color-muted: #667085;
  --color-border: #e4e7ec;
  --color-accent: #2563eb;
  --color-code-bg: #f6f8fa;
  --shadow-soft: 0 18px 50px rgba(15, 23, 42, 0.06);
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  background: var(--color-bg);
  color: var(--color-text);
  font-family:
    system-ui,
    -apple-system,
    BlinkMacSystemFont,
    "Segoe UI",
    sans-serif;
  line-height: 1.65;
}

a {
  color: var(--color-accent);
  text-decoration: none;
}

a:hover {
  text-decoration: underline;
}

.site-header {
  background: rgba(251, 251, 250, 0.88);
  border-bottom: 1px solid var(--color-border);
  backdrop-filter: blur(14px);
  position: sticky;
  top: 0;
  z-index: 10;
}

.navbar {
  min-height: 64px;
}

.nav-link {
  color: var(--color-muted);
  padding-left: 0;
  padding-right: 0;
}

.nav-link.active,
.nav-link:hover {
  color: var(--color-text);
}

.language-switcher {
  align-items: center;
  border-left: 1px solid var(--color-border);
  display: inline-flex;
  gap: 4px;
  margin-left: 4px;
  padding-left: 12px;
}

.language-switcher a {
  border-radius: 999px;
  color: var(--color-muted);
  font-size: 0.84rem;
  font-weight: 700;
  line-height: 1.2;
  padding: 0.28rem 0.55rem;
}

.language-switcher a:hover,
.language-switcher a.is-active {
  background: var(--color-text);
  color: var(--color-surface);
  text-decoration: none;
}

.hero {
  padding: 56px 0 28px;
}

.hero__content {
  align-items: center;
  display: flex;
  gap: 24px;
  max-width: 760px;
}

.hero-avatar {
  border: 1px solid var(--color-border);
  border-radius: 50%;
  box-shadow: var(--shadow-soft);
  flex: 0 0 auto;
  height: 92px;
  width: 92px;
}

.hero h1 {
  font-size: clamp(2rem, 4vw, 2.75rem);
  letter-spacing: 0;
  line-height: 1.05;
  margin-bottom: 0.2rem;
}

.github-icon-link,
.profile-icon-link {
  align-items: center;
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: 50%;
  color: var(--color-text);
  display: inline-flex;
  height: 34px;
  justify-content: center;
  margin: 0 4px 0 0;
  transition:
    border-color 160ms ease,
    transform 160ms ease;
  width: 34px;
}

.github-icon-link:hover,
.profile-icon-link:hover {
  border-color: rgba(37, 99, 235, 0.42);
  text-decoration: none;
  transform: translateY(-1px);
}

.github-icon-link img,
.profile-icon-link img {
  display: block;
  height: 20px;
  width: 20px;
}

.lead {
  color: var(--color-muted);
  font-size: 1.06rem;
  margin-bottom: 0.5rem;
  max-width: 520px;
}

.section {
  padding: 48px 0;
}

.section-muted {
  background: #f4f4f2;
}

.section-heading,
.page-heading {
  max-width: 720px;
  margin-bottom: 18px;
}

.page-main {
  min-height: calc(100vh - 144px);
  padding: 64px 0;
}

.page-heading h1,
.section-heading h2 {
  font-size: clamp(1.8rem, 3vw, 2.35rem);
  margin: 0 0 0.65rem;
  font-weight: 720;
}

.page-heading p,
.section-heading p,
.focus-item p,
.article-description {
  color: var(--color-muted);
}

.eyebrow {
  color: var(--color-accent);
  font-size: 0.78rem;
  font-weight: 700;
  letter-spacing: 0.12em;
  margin-bottom: 0.45rem;
  text-transform: uppercase;
}

.post-list {
  display: grid;
  border-top: 1px solid var(--color-border);
  gap: 0;
}

.blog-filters {
  margin: 30px 0 12px;
}

.blog-filter-grid {
  align-items: end;
  display: grid;
  gap: 14px;
  grid-template-columns: minmax(220px, 2fr) minmax(220px, 1fr) auto;
}

.blog-filter-field {
  color: var(--color-muted);
  display: grid;
  font-size: 0.92rem;
  font-weight: 700;
  gap: 6px;
  margin: 0;
}

.blog-filter-field input,
.blog-tag-combobox {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: 8px;
  color: var(--color-text);
  min-height: 46px;
  width: 100%;
}

.blog-filter-field input {
  font-size: 1rem;
  padding: 0 14px;
}

.blog-filter-field input:focus,
.blog-tag-combobox:focus-within {
  border-color: rgba(37, 99, 235, 0.48);
  box-shadow: 0 0 0 4px rgba(37, 99, 235, 0.08);
  outline: 0;
}

.blog-filter-field input::placeholder {
  color: #8a8f98;
}

.blog-filter-field:has(.blog-tag-combobox) {
  position: relative;
}

.blog-tag-combobox {
  align-items: center;
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  padding: 5px 12px;
}

.blog-tag-combobox input {
  border: 0;
  box-shadow: none;
  flex: 1 1 140px;
  min-height: 30px;
  min-width: 120px;
  padding: 0;
}

.blog-tag-combobox input:focus {
  box-shadow: none;
}

.blog-selected-tags {
  display: contents;
}

.selected-tag {
  align-items: center;
  background: #eef4ff;
  border-radius: 999px;
  color: #1d4ed8;
  display: inline-flex;
  font-size: 0.86rem;
  font-weight: 700;
  line-height: 1.2;
  padding: 0.32rem 0.72rem;
  position: relative;
}

.selected-tag button {
  align-items: center;
  background: #dbeafe;
  border: 0;
  border-radius: 50%;
  color: #1e40af;
  display: inline-flex;
  height: 18px;
  justify-content: center;
  line-height: 1;
  opacity: 0;
  padding: 0;
  position: absolute;
  right: -6px;
  top: -6px;
  transition: opacity 120ms ease;
  width: 18px;
}

.selected-tag:hover button,
.selected-tag button:focus {
  opacity: 1;
}

.blog-tag-suggestions {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: 8px;
  box-shadow: var(--shadow-soft);
  display: grid;
  left: 0;
  max-height: 260px;
  overflow-y: auto;
  padding: 6px;
  position: absolute;
  right: 0;
  top: calc(100% + 6px);
  z-index: 15;
}

.blog-tag-suggestions button {
  background: transparent;
  border: 0;
  border-radius: 6px;
  color: var(--color-text);
  padding: 0.55rem 0.7rem;
  text-align: left;
}

.blog-tag-suggestions button:hover,
.blog-tag-suggestions button:focus {
  background: #f4f4f2;
  outline: 0;
}

.blog-tag-suggestions__empty {
  color: var(--color-muted);
  font-size: 0.92rem;
  padding: 0.55rem 0.7rem;
}

.blog-filter-actions {
  display: flex;
  gap: 12px;
}

.button {
  border: 1px solid var(--color-border);
  border-radius: 8px;
  font-weight: 700;
  min-height: 46px;
  padding: 0 18px;
  transition:
    background-color 160ms ease,
    border-color 160ms ease,
    color 160ms ease;
}

.button-primary {
  background: var(--color-text);
  border-color: var(--color-text);
  color: var(--color-surface);
}

.button-primary:hover {
  background: var(--color-accent);
  border-color: var(--color-accent);
}

.button-secondary {
  background: var(--color-surface);
  color: var(--color-text);
}

.button-secondary:hover {
  border-color: rgba(37, 99, 235, 0.42);
  color: var(--color-accent);
}

.blog-result-summary {
  color: var(--color-muted);
  margin-bottom: 0.75rem;
}

.empty-state {
  color: var(--color-muted);
  margin: 0;
  padding: 24px 0;
}

.blog-pagination {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  justify-content: center;
  margin-top: 24px;
}

.blog-pagination button,
.pagination-ellipsis {
  align-items: center;
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: 8px;
  color: var(--color-text);
  display: inline-flex;
  font-weight: 700;
  justify-content: center;
  min-height: 40px;
  min-width: 40px;
  padding: 0 12px;
}

.blog-pagination button:hover:not(:disabled),
.blog-pagination button.is-active {
  background: var(--color-text);
  border-color: var(--color-text);
  color: var(--color-surface);
}

.blog-pagination button:disabled {
  color: var(--color-muted);
  cursor: not-allowed;
  opacity: 0.58;
}

.pagination-ellipsis {
  background: transparent;
  border-color: transparent;
  color: var(--color-muted);
}

.focus-item,
.comments-setup {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: 8px;
}

.post-card {
  display: block;
  border-bottom: 1px solid var(--color-border);
  color: inherit;
  padding: 20px 0;
  transition: color 160ms ease;
}

.post-card:hover {
  color: var(--color-accent);
  text-decoration: none;
}

.post-card h3 {
  font-size: 1.22rem;
  margin-bottom: 0.35rem;
}

.post-card p {
  color: var(--color-muted);
  margin-bottom: 0.75rem;
}

.post-meta {
  color: var(--color-muted);
  font-size: 0.92rem;
}

.tag-row {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.tag {
  background: #eef4ff;
  border-radius: 999px;
  color: #1d4ed8;
  display: inline-flex;
  font-size: 0.8rem;
  padding: 0.18rem 0.6rem;
}

.focus-item {
  height: 100%;
  padding: 22px;
}

.focus-item h3 {
  font-size: 1.08rem;
}

.site-footer {
  border-top: 1px solid var(--color-border);
  color: var(--color-muted);
  font-size: 0.92rem;
  padding: 26px 0;
}

.article-layout {
  align-items: start;
  display: grid;
  gap: 44px;
  grid-template-columns: minmax(160px, 220px) minmax(0, 780px);
}

.article-shell {
  max-width: 780px;
  min-width: 0;
}

.article-toc {
  color: var(--color-muted);
  font-size: 0.92rem;
  position: sticky;
  top: 96px;
}

.article-toc__inner {
  border-left: 1px solid var(--color-border);
  padding-left: 16px;
}

.article-toc__title {
  color: var(--color-text);
  font-size: 0.78rem;
  font-weight: 700;
  letter-spacing: 0.12em;
  margin-bottom: 0.65rem;
  text-transform: uppercase;
}

.article-toc a {
  color: var(--color-muted);
  display: block;
  line-height: 1.4;
  padding: 0.28rem 0;
}

.article-toc a:hover {
  color: var(--color-accent);
  text-decoration: none;
}

.article-toc a[data-level="3"] {
  padding-left: 14px;
}

.back-link {
  color: var(--color-muted);
  display: inline-block;
  margin-bottom: 32px;
}

.article-header {
  border-bottom: 1px solid var(--color-border);
  margin-bottom: 32px;
  padding-bottom: 28px;
}

.article-header h1 {
  font-size: clamp(1.85rem, 3.5vw, 2.75rem);
  line-height: 1.12;
  margin-bottom: 1rem;
}

.markdown-body {
  font-size: 1.06rem;
}

.markdown-body h2,
.markdown-body h3,
.markdown-body h4 {
  line-height: 1.25;
  margin: 2.1em 0 0.75em;
}

.markdown-body p,
.markdown-body ul,
.markdown-body ol,
.markdown-body blockquote,
.markdown-body pre,
.markdown-body table,
.markdown-body .table-wrap {
  margin-bottom: 1.2rem;
}

.markdown-body .table-wrap {
  overflow-x: auto;
}

.markdown-body table {
  border-collapse: collapse;
  font-size: 0.96rem;
  min-width: 100%;
}

.markdown-body th,
.markdown-body td {
  border: 1px solid var(--color-border);
  padding: 0.55rem 0.7rem;
  vertical-align: top;
}

.markdown-body th {
  background: #f4f4f2;
  font-weight: 700;
}

.markdown-body code {
  background: var(--color-code-bg);
  border-radius: 5px;
  font-size: 0.92em;
  padding: 0.1rem 0.3rem;
}

.markdown-body pre {
  background: #111827;
  border-radius: 8px;
  color: #f9fafb;
  overflow-x: auto;
  padding: 1rem;
}

.markdown-body pre code {
  background: transparent;
  color: inherit;
  padding: 0;
}

.markdown-body .mermaid {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: 8px;
  color: var(--color-text);
  overflow-x: auto;
  padding: 1rem;
}

.markdown-body .katex-display {
  max-width: 100%;
  overflow: visible !important;
  padding: 0.45rem 0;
}

.markdown-body .katex-display > .katex {
  max-width: 100%;
  overflow: visible !important;
}

.markdown-body .katex-display.is-scaled {
  transform-origin: left center;
}

.markdown-body .katex {
  line-height: 1.35;
}

.markdown-body blockquote {
  border-left: 4px solid var(--color-border);
  color: var(--color-muted);
  padding-left: 1rem;
}

.markdown-body img {
  border-radius: 8px;
  height: auto;
  max-width: 100%;
}

.comments-section {
  border-top: 1px solid var(--color-border);
  margin-top: 48px;
  padding-top: 28px;
}

.comments-section h2 {
  font-size: 1.35rem;
  margin-bottom: 0.35rem;
}

.comments-section__note {
  color: var(--color-muted);
  margin-bottom: 1.25rem;
}

.comments-setup {
  color: var(--color-muted);
  display: grid;
  gap: 0.45rem;
  padding: 18px;
}

.comments-setup strong {
  color: var(--color-text);
}

.comments-setup code {
  background: var(--color-code-bg);
  border-radius: 5px;
  color: var(--color-text);
  padding: 0.1rem 0.3rem;
}

.post-nav {
  border-top: 1px solid var(--color-border);
  display: grid;
  gap: 16px;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  margin-top: 48px;
  padding-top: 24px;
}

.post-nav__item {
  border: 1px solid var(--color-border);
  border-radius: 8px;
  color: inherit;
  display: block;
  padding: 16px;
}

.post-nav__item:hover {
  border-color: rgba(37, 99, 235, 0.36);
  text-decoration: none;
}

.post-nav__item span {
  color: var(--color-muted);
  display: block;
  font-size: 0.82rem;
  margin-bottom: 0.35rem;
}

.post-nav__item strong {
  display: block;
  font-size: 0.98rem;
  line-height: 1.45;
}

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

.post-nav__item.is-disabled {
  color: var(--color-muted);
  pointer-events: none;
}

.back-to-top {
  align-items: center;
  background: var(--color-text);
  border: 0;
  border-radius: 50%;
  bottom: 24px;
  box-shadow: var(--shadow-soft);
  color: var(--color-surface);
  display: inline-flex;
  font-size: 1.1rem;
  height: 42px;
  justify-content: center;
  opacity: 0;
  pointer-events: none;
  position: fixed;
  right: 24px;
  transform: translateY(8px);
  transition:
    opacity 160ms ease,
    transform 160ms ease,
    background-color 160ms ease;
  width: 42px;
  z-index: 20;
}

.back-to-top:hover {
  background: var(--color-accent);
}

.back-to-top.is-visible {
  opacity: 1;
  pointer-events: auto;
  transform: translateY(0);
}

@media (max-width: 575.98px) {
  .hero {
    padding: 40px 0 24px;
  }

  .hero__content {
    align-items: flex-start;
    flex-direction: column;
    gap: 18px;
  }

  .hero-avatar {
    height: 84px;
    width: 84px;
  }

  .article-layout {
    display: block;
  }

  .blog-filter-grid {
    grid-template-columns: 1fr;
  }

  .blog-filter-actions {
    justify-content: stretch;
  }

  .blog-filter-actions .button {
    flex: 1;
  }

  .article-toc {
    margin-bottom: 28px;
    position: static;
  }

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

  .post-nav__item--next {
    text-align: left;
  }

  .navbar {
    min-height: auto;
    padding: 14px 0;
  }

  .navbar .container {
    align-items: flex-start;
    flex-direction: column;
    gap: 8px;
  }

  .language-switcher {
    border-left: 0;
    margin-left: 0;
    padding-left: 0;
  }

  .back-to-top {
    bottom: 18px;
    height: 38px;
    right: 18px;
    width: 38px;
  }
}