:root,
:root[data-theme='light'] {
  --bg: #f7f9fc;
  --bg-soft: #eef3fb;
  --bg-hero-start: rgba(96, 165, 250, 0.20);
  --bg-hero-end: rgba(167, 139, 250, 0.16);
  --panel: rgba(255, 255, 255, 0.88);
  --panel-strong: rgba(255, 255, 255, 0.96);
  --panel-border: rgba(148, 163, 184, 0.22);
  --text: #172033;
  --heading: #101828;
  --muted: #5f6f85;
  --primary: #4f8ef7;
  --primary-strong: #2563eb;
  --accent: #7c3aed;
  --success: #059669;
  --shadow: 0 24px 60px rgba(15, 23, 42, 0.10);
  --shadow-soft: 0 10px 30px rgba(15, 23, 42, 0.06);
  --radius: 22px;
  --line-soft: rgba(148, 163, 184, 0.18);
  --code-bg: #0f172a;
  --code-text: #e6eefc;
  --flash-bg: rgba(16, 185, 129, 0.12);
  --flash-text: #065f46;
  --glass-backdrop: blur(16px);
}

:root[data-theme='dark'] {
  --bg: #09111f;
  --bg-soft: #0f172a;
  --bg-hero-start: rgba(59, 130, 246, 0.18);
  --bg-hero-end: rgba(124, 58, 237, 0.16);
  --panel: rgba(15, 23, 42, 0.72);
  --panel-strong: rgba(15, 23, 42, 0.9);
  --panel-border: rgba(148, 163, 184, 0.18);
  --text: #e5eefc;
  --heading: #f8fbff;
  --muted: #a8b3c7;
  --primary: #61a8ff;
  --primary-strong: #3b82f6;
  --accent: #7c3aed;
  --success: #10b981;
  --shadow: 0 24px 60px rgba(0, 0, 0, 0.28);
  --shadow-soft: 0 10px 30px rgba(2, 6, 23, 0.28);
  --radius: 22px;
  --line-soft: rgba(148, 163, 184, 0.12);
  --code-bg: rgba(2, 6, 23, 0.92);
  --code-text: #e6eefc;
  --flash-bg: rgba(16, 185, 129, .14);
  --flash-text: #c8f7e3;
  --glass-backdrop: blur(18px);
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  color: var(--text);
  background:
    radial-gradient(circle at top left, var(--bg-hero-start), transparent 28%),
    radial-gradient(circle at top right, var(--bg-hero-end), transparent 22%),
    linear-gradient(180deg, var(--bg), var(--bg-soft) 42%, var(--bg) 100%);
  min-height: 100vh;
  transition: background .25s ease, color .25s ease;
}

body, input, button, textarea, select { font: inherit; }
a { color: inherit; text-decoration: none; }
p { line-height: 1.75; color: var(--muted); }
h1, h2, h3, h4 { margin: 0 0 12px; line-height: 1.15; color: var(--heading); }

.container { width: min(1120px, calc(100% - 32px)); margin: 0 auto; }
.section-space { padding: 56px 0; }
.page-shell { min-height: 100vh; }

.site-header {
  position: sticky; top: 0; z-index: 20;
  backdrop-filter: var(--glass-backdrop);
  background: color-mix(in srgb, var(--panel-strong) 82%, transparent);
  border-bottom: 1px solid var(--line-soft);
}
.nav-row {
  display: flex; align-items: center; justify-content: space-between; gap: 24px;
  padding: 16px 0;
}
.brand { display: flex; align-items: center; gap: 14px; }
.brand small { display: block; color: var(--muted); margin-top: 4px; }
.brand-mark {
  width: 44px; height: 44px; border-radius: 14px;
  display: grid; place-items: center; font-weight: 800; color: white;
  background: linear-gradient(135deg, var(--primary), var(--accent));
  box-shadow: var(--shadow-soft);
}
.brand-logo-image {
  width: 44px;
  height: 44px;
  border-radius: 14px;
  object-fit: cover;
  box-shadow: var(--shadow-soft);
}
.article-cover-image {
  width: 100%;
  aspect-ratio: 16 / 9;
  object-fit: cover;
  border-radius: 18px;
  margin-bottom: 16px;
}
.article-detail-cover {
  width: 100%;
  max-height: 360px;
  object-fit: cover;
  border-radius: 22px;
  margin: 18px 0 10px;
  border: 1px solid var(--panel-border);
}
.profile-grid-top { align-items: stretch; }
.profile-card { display: flex; align-items: center; }
.profile-head { display: flex; gap: 18px; align-items: center; }
.profile-avatar {
  width: 84px; height: 84px; border-radius: 50%; object-fit: cover;
  border: 1px solid var(--panel-border); box-shadow: var(--shadow-soft);
}
.profile-avatar.placeholder {
  display: grid; place-items: center; font-weight: 800; font-size: 1.6rem;
  background: linear-gradient(135deg, var(--primary), var(--accent)); color: white;
}
.profile-form input[type="file"] { padding: 10px 0; }
.single-column-hero { grid-template-columns: 1fr; }
.simple-card-list { display: grid; gap: 16px; }
.simple-card-item {
  padding: 18px;
  border-radius: 18px;
  border: 1px solid var(--panel-border);
  background: color-mix(in srgb, var(--panel) 88%, transparent);
}
.simple-card-item p { margin: 8px 0 0; }
.footer-grid-rich { grid-template-columns: 1.1fr .8fr .9fr; }
.pagination-bar {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 16px;
  margin-top: 30px;
  flex-wrap: wrap;
}
.pagination-info {
  color: var(--muted);
  font-size: .95rem;
}
.search-panel { display: grid; gap: 10px; }
.search-meta-inline { margin-top: 10px; }
.nav-links { display: flex; align-items: center; gap: 18px; flex-wrap: wrap; }
.nav-links a, .link-button, .theme-toggle { color: var(--muted); }
.nav-links a:hover, .link-button:hover, .theme-toggle:hover { color: var(--heading); }
.inline-form { display: inline; }
.link-button {
  background: transparent; border: none; cursor: pointer; font: inherit; padding: 0;
}
.theme-toggle {
  display: inline-flex; align-items: center; gap: 8px;
  border: 1px solid var(--panel-border);
  background: color-mix(in srgb, var(--panel) 92%, transparent);
  border-radius: 999px; padding: 10px 14px; cursor: pointer;
  transition: .2s ease;
}
.theme-toggle:hover { transform: translateY(-1px); box-shadow: var(--shadow-soft); }
.theme-toggle-icon { font-size: .95rem; }
.language-form { margin: 0; }
.language-select {
  min-height: 42px;
  border-radius: 999px;
  border: 1px solid var(--panel-border);
  background: color-mix(in srgb, var(--panel) 92%, transparent);
  color: var(--heading);
  padding: 0 14px;
}

.hero-section { padding: 64px 0 36px; }
.hero-grid {
  display: grid; grid-template-columns: 1.4fr 0.8fr; gap: 24px; align-items: stretch;
}
.hero-section h1 { font-size: clamp(2.4rem, 5vw, 4.2rem); max-width: 12ch; }
.hero-text { font-size: 1.08rem; max-width: 62ch; }
.hero-actions { display: flex; gap: 14px; margin-top: 24px; flex-wrap: wrap; }

.glass-card, .article-card, .auth-card, .feature-panel, .share-card, .article-content {
  background: var(--panel);
  border: 1px solid var(--panel-border);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
}
.glass-card, .article-card, .auth-card, .share-card { padding: 24px; }
.stat-card { padding: 28px; }
.stat-list {
  display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 18px; margin-top: 18px;
}
.stat-list div {
  padding: 18px; border-radius: 18px;
  background: color-mix(in srgb, var(--panel) 82%, transparent);
  border: 1px solid color-mix(in srgb, var(--panel-border) 80%, transparent);
}
.stat-list strong { display: block; font-size: 1.2rem; margin-bottom: 8px; color: var(--heading); }
.stat-list span { color: var(--muted); }

.button {
  display: inline-flex; align-items: center; justify-content: center;
  padding: 12px 18px; border-radius: 999px; font-weight: 600;
  border: 1px solid transparent; transition: .2s ease; cursor: pointer;
}
.button.primary {
  color: white;
  background: linear-gradient(135deg, var(--primary-strong), var(--accent));
}
.button.ghost {
  color: var(--heading);
  border-color: color-mix(in srgb, var(--panel-border) 100%, transparent);
  background: color-mix(in srgb, var(--panel) 88%, transparent);
}
.button:hover { transform: translateY(-1px); }
.full { width: 100%; }

.section-heading {
  display: flex; align-items: end; justify-content: space-between; gap: 24px; margin-bottom: 22px;
}
.eyebrow, .pill {
  display: inline-flex; align-items: center; gap: 6px; text-transform: uppercase; letter-spacing: .16em;
  font-size: .72rem; font-weight: 700;
}
.eyebrow { color: var(--primary-strong); margin-bottom: 10px; }
.pill {
  color: white; padding: 8px 12px; border-radius: 999px;
  background: linear-gradient(135deg, color-mix(in srgb, var(--primary) 88%, white), color-mix(in srgb, var(--accent) 88%, white));
}
.pill.soft {
  background: color-mix(in srgb, var(--primary) 12%, var(--panel));
  color: var(--primary-strong);
}
.subtle { color: var(--muted); }
.text-link { color: var(--primary-strong); }

.card-grid {
  display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 20px;
}
.card-grid.two-up { grid-template-columns: repeat(2, minmax(0, 1fr)); }
.article-card { transition: .2s ease; }
.article-card:hover { transform: translateY(-3px); border-color: color-mix(in srgb, var(--primary) 40%, var(--panel-border)); }
.article-card h3 { margin-top: 18px; font-size: 1.2rem; }
.meta-row {
  display: flex; gap: 16px; flex-wrap: wrap; color: var(--muted); font-size: .92rem; margin-top: 16px;
}
.empty-state {
  grid-column: 1 / -1; padding: 28px; border-radius: 20px;
  background: color-mix(in srgb, var(--panel) 78%, transparent); color: var(--muted);
}

.search-form {
  display: flex; gap: 10px; flex-wrap: wrap; align-items: center;
}
.search-form input, .auth-form input {
  min-height: 48px; border-radius: 14px; border: 1px solid var(--panel-border);
  background: color-mix(in srgb, var(--panel) 92%, white 8%);
  color: var(--heading); padding: 0 14px; width: 100%;
}
.search-form input::placeholder, .auth-form input::placeholder { color: var(--muted); }
.search-form input { min-width: min(360px, 100%); }
.feature-panel {
  display: grid; grid-template-columns: 1.25fr .75fr; gap: 20px; padding: 26px; margin-bottom: 24px;
}
.feature-art {
  min-height: 220px; border-radius: 22px; display: grid; place-items: center; text-align: center;
  background: linear-gradient(135deg, color-mix(in srgb, var(--primary) 18%, transparent), color-mix(in srgb, var(--accent) 18%, transparent));
  border: 1px dashed color-mix(in srgb, var(--primary) 24%, var(--panel-border));
  color: var(--primary-strong); font-size: 1.4rem; font-weight: 800;
}

.article-wrap { max-width: 1180px; }
.article-layout-with-toc {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 280px;
  gap: 24px;
  align-items: start;
}
.article-main-column { min-width: 0; }
.article-hero {
  display: grid; grid-template-columns: 1.35fr .65fr; gap: 20px; margin-bottom: 24px;
}
.toc-sidebar {
  position: sticky;
  top: 92px;
}
.toc-card { padding: 22px; }
.toc-body ul {
  list-style: none;
  padding-left: 0;
  margin: 0;
}
.toc-body li { margin: 8px 0; }
.toc-body a { color: var(--muted); }
.toc-body a:hover { color: var(--primary-strong); }
.share-card h3 { margin-bottom: 14px; }
.share-actions { display: flex; flex-wrap: wrap; gap: 10px; }
.article-content { padding: 30px; }
.prose h2, .prose h3, .prose h4 { margin-top: 1.5em; }
.prose ul, .prose ol { color: var(--muted); line-height: 1.8; }
.prose strong { color: var(--heading); }
.prose blockquote {
  margin: 20px 0; padding: 14px 18px; border-left: 4px solid var(--primary);
  background: color-mix(in srgb, var(--panel) 80%, transparent); border-radius: 14px;
}
.prose pre {
  overflow: auto; padding: 16px; border-radius: 16px; background: var(--code-bg);
  border: 1px solid color-mix(in srgb, var(--panel-border) 72%, transparent); color: var(--code-text);
}
.prose code {
  font-family: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, monospace;
  background: color-mix(in srgb, var(--panel-border) 22%, transparent); padding: 2px 6px; border-radius: 8px;
}
.related-block { margin-top: 36px; }

.auth-shell { display: grid; place-items: center; min-height: 60vh; }
.auth-card { width: min(100%, 520px); }
.auth-form p { margin: 0 0 14px; }
.auth-form label { display: block; margin-bottom: 8px; font-weight: 600; color: var(--heading); }
.auth-form ul.errorlist { color: #dc2626; }
.feature-list, .simple-list { margin: 0; padding-left: 18px; color: var(--muted); }
.simple-list li, .feature-list li { margin: 10px 0; }

.flash-stack { padding-top: 20px; }
.flash {
  padding: 14px 18px; border-radius: 16px; background: var(--flash-bg); color: var(--flash-text);
  border: 1px solid color-mix(in srgb, var(--success) 24%, transparent); margin-bottom: 10px;
}

.site-footer { padding: 36px 0 64px; }
.footer-grid {
  display: grid; grid-template-columns: 1.2fr .8fr; gap: 20px; padding-top: 28px; border-top: 1px solid var(--line-soft);
}
.footer-grid ul { list-style: none; padding: 0; margin: 0; }
.footer-grid li { margin: 10px 0; color: var(--muted); }

.topic-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 20px;
}
.topic-card {
  display: block;
  padding: 24px;
  border-radius: var(--radius);
  border: 1px solid var(--panel-border);
  background: var(--panel);
  box-shadow: var(--shadow-soft);
  transition: .2s ease;
}
.topic-card:hover { transform: translateY(-3px); }
.filter-shell {
  display: grid;
  gap: 18px;
  margin-bottom: 24px;
}
.filter-title {
  margin: 0 0 10px;
  font-size: .9rem;
  color: var(--muted);
}
.chip-row {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-top: 14px;
}
.chip-row.wide-gap { gap: 12px; }
.chip {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 8px 12px;
  border-radius: 999px;
  border: 1px solid var(--panel-border);
  background: color-mix(in srgb, var(--panel) 92%, transparent);
  color: var(--muted);
  font-size: .92rem;
}
.chip:hover, .chip.active {
  color: var(--heading);
  border-color: color-mix(in srgb, var(--primary) 40%, var(--panel-border));
}
.chip.strong {
  color: var(--primary-strong);
}
.comment-block {
  margin-top: 34px;
}
.comment-form,
.inline-action-form {
  margin: 0;
}
.comment-form {
  padding: 24px;
  border-radius: var(--radius);
  background: var(--panel);
  border: 1px solid var(--panel-border);
  box-shadow: var(--shadow-soft);
}
.comment-form p { margin-bottom: 14px; }
.comment-form textarea {
  width: 100%;
  min-height: 140px;
  border-radius: 16px;
  border: 1px solid var(--panel-border);
  background: color-mix(in srgb, var(--panel) 92%, white 8%);
  color: var(--heading);
  padding: 14px;
}
.comment-list {
  display: grid;
  gap: 16px;
  margin-top: 18px;
}
.comment-card {
  padding: 20px 22px;
  border-radius: 18px;
  background: var(--panel);
  border: 1px solid var(--panel-border);
  box-shadow: var(--shadow-soft);
}
.comment-head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  margin-bottom: 10px;
}
.comment-head span { color: var(--muted); font-size: .92rem; }
.stack-on-mobile { align-items: stretch; }
.three-up {
  grid-template-columns: repeat(3, minmax(0, 1fr));
}
.single-column {
  grid-template-columns: 1fr;
}
.compact-stats { gap: 12px; }
.nested-section { padding-bottom: 0; }

@media (max-width: 900px) {
  .hero-grid, .card-grid, .card-grid.two-up, .three-up, .topic-grid, .feature-panel, .article-hero, .article-layout-with-toc, .footer-grid {
    grid-template-columns: 1fr;
  }
  .section-heading, .split-mobile, .nav-row, .comment-head { align-items: flex-start; flex-direction: column; }
  .search-form input { min-width: 0; }
}