/* =========================================================
   华中科技大学电信本科 · 操作系统复习笔记 站点样式
   现代笔记风格：舒适行宽、稳定锚点、深浅色双主题、
   适度过渡动画（150-300ms）。
   ========================================================= */

/* hust-eic-os-review · Jason DS layer 2 override：默认态走 jx，[data-theme] 71 主题保留 */
:root:not([data-theme]) {
  --jx-paper: #f6f6f3;
  --jx-ink: #16181d;
  --jx-accent: #16607a;
  --jx-accent-hub: #2240d6;
}

/* [data-theme="..."] 状态视为用户主动选择，DS 规则降级 — 71 主题保持原 token 不被 jx 覆盖 */
:root[data-theme] {
  /* 不引用 --jx-* token，保留 themes.css 自有取值 */
  /* 但仍保留 jx 的 chrome 组件能用（footer/return-to-hub 用 jx-* class，独立 css） */
}


/* ---------- design tokens ---------- */
:root {
  --bg:           #f7f7f5;
  --bg-elev:      #ffffff;
  --bg-soft:      #ececec;
  --fg:           #1c1c1e;
  --fg-soft:      #4a4a4d;
  --fg-mute:      #74747a;
  --fg-faint:     #9c9ca1;
  --accent:       #0f6cbf;
  --accent-soft:  #d6e8f6;
  --accent-fg:    #ffffff;
  --danger:       #b43a30;
  --danger-soft:  #f6dedb;
  --border:       #e2e2df;
  --border-soft:  #ececea;
  --code-bg:      #f1f1ee;
  --code-fg:      #2b2b30;
  --quote-bg:     #f8f6ee;
  --quote-bd:     #d9c97f;
  --table-stripe: #f8f8f6;
  --shadow-sm:    0 1px 2px rgba(0,0,0,.04);
  --shadow-md:    0 4px 12px rgba(0,0,0,.06);
  --radius:       10px;
  --radius-sm:    6px;
  --maxw-prose:   72ch;
  --w-side:       260px;
  --w-toc:        220px;
  --t-fast:       150ms;
  --t-mid:        220ms;
  --t-slow:       320ms;
  --ease:         cubic-bezier(.4,.0,.2,1);
  --font-sans:    -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC",
                  "Hiragino Sans GB", "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;
  --font-mono:    ui-monospace, SFMono-Regular, "SF Mono", Menlo, Consolas,
                  "Liberation Mono", monospace;
}

:root[data-theme="dark"], :root[data-theme="dark"] body {
  --bg:           #14161a;
  --bg-elev:      #1c1f24;
  --bg-soft:      #23262c;
  --fg:           #e7e7ea;
  --fg-soft:      #c8c8cc;
  --fg-mute:      #9c9ca1;
  --fg-faint:     #6c6c72;
  --accent:       #5aa8ee;
  --accent-soft:  #1d3148;
  --accent-fg:    #0d1117;
  --danger:       #ff8a80;
  --danger-soft:  #3d2423;
  --border:       #2c2f35;
  --border-soft:  #232529;
  --code-bg:      #1a1c20;
  --code-fg:      #e0e0e3;
  --quote-bg:     #20221c;
  --quote-bd:     #8c7e3a;
  --table-stripe: #1a1c20;
  --shadow-sm:    0 1px 2px rgba(0,0,0,.4);
  --shadow-md:    0 4px 14px rgba(0,0,0,.45);
}

@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --bg:           #14161a;
    --bg-elev:      #1c1f24;
    --bg-soft:      #23262c;
    --fg:           #e7e7ea;
    --fg-soft:      #c8c8cc;
    --fg-mute:      #9c9ca1;
    --fg-faint:     #6c6c72;
    --accent:       #5aa8ee;
    --accent-soft:  #1d3148;
    --accent-fg:    #0d1117;
    --danger:       #ff8a80;
    --danger-soft:  #3d2423;
    --border:       #2c2f35;
    --border-soft:  #232529;
    --code-bg:      #1a1c20;
    --code-fg:      #e0e0e3;
    --quote-bg:     #20221c;
    --quote-bd:     #8c7e3a;
    --table-stripe: #1a1c20;
    --shadow-sm:    0 1px 2px rgba(0,0,0,.4);
    --shadow-md:    0 4px 14px rgba(0,0,0,.45);
  }
}

/* ---------- base ---------- */
* { box-sizing: border-box; }
.practice-track-menu[hidden],
.practice-workbench [hidden] { display: none !important; }
html { -webkit-text-size-adjust: 100%; scroll-behavior: smooth; scroll-padding-top: 96px; }
body {
  margin: 0;
  font-family: var(--font-sans);
  font-size: 16px;
  line-height: 1.7;
  color: var(--fg);
  background: var(--bg);
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

/* skip-to-content (accessibility) */
.sr-only {
  position: absolute; clip: rect(0 0 0 0); width: 1px; height: 1px;
  padding: 0; margin: -1px; overflow: hidden; border: 0;
}

a { color: var(--accent); text-decoration: none; transition: color var(--t-fast) var(--ease); }
a:hover { text-decoration: underline; text-underline-offset: 3px; }
a:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 2px;
  border-radius: 3px;
}

img { max-width: 100%; height: auto; border-radius: var(--radius-sm); display: block; }
hr { border: 0; border-top: 1px solid var(--border); margin: 2.4rem 0; }

/* ---------- topbar ---------- */
.topbar {
  position: sticky; top: 0; z-index: 50;
  background: color-mix(in srgb, var(--bg-elev) 92%, transparent);
  backdrop-filter: saturate(160%) blur(12px);
  -webkit-backdrop-filter: saturate(160%) blur(12px);
  border-bottom: 1px solid var(--border);
}
.topbar-inner {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr) auto;
  align-items: center;
  max-width: 1360px; margin: 0 auto; padding: .65rem 1.25rem;
  gap: 1rem;
}
.brand {
  display: inline-flex; align-items: center; gap: .55rem;
  color: var(--fg); font-weight: 600; font-size: .98rem;
  text-decoration: none;
}
.brand:hover { text-decoration: none; color: var(--accent); }
.brand-icon { width: 22px; height: 22px; color: var(--accent); }

.site-nav {
  display: flex;
  justify-content: center;
  align-items: center;
  gap: .28rem;
  min-width: 0;
}
.site-nav-link {
  display: inline-flex;
  align-items: center;
  min-height: 34px;
  padding: .32rem .68rem;
  border-radius: 999px;
  color: var(--fg-soft);
  font-size: .88rem;
  font-weight: 560;
  line-height: 1.3;
  text-decoration: none;
  white-space: nowrap;
  transition: all var(--t-fast) var(--ease);
}
.site-nav-link:hover {
  background: var(--bg-soft);
  color: var(--fg);
  text-decoration: none;
}
.site-nav-link.is-active {
  background: var(--accent-soft);
  color: var(--accent);
}
.site-nav-toggle {
  display: none;
  min-height: 36px;
  padding: .36rem .72rem;
  border: 1px solid var(--border);
  border-radius: 999px;
  background: var(--bg-elev);
  color: var(--fg-soft);
  font: inherit;
  font-size: .86rem;
  cursor: pointer;
  transition: all var(--t-fast) var(--ease);
}
.site-nav-toggle:hover,
.site-nav-toggle[aria-expanded="true"] {
  border-color: var(--accent);
  background: var(--accent-soft);
  color: var(--accent);
}

.theme-toggle {
  background: transparent; border: 1px solid var(--border);
  color: var(--fg-soft); border-radius: 999px; padding: .35rem .55rem;
  cursor: pointer; transition: all var(--t-fast) var(--ease);
  display: inline-flex; align-items: center;
}
.theme-toggle:hover { color: var(--accent); border-color: var(--accent); }
.theme-toggle .i { width: 18px; height: 18px; }

/* ---------- layout ---------- */
.layout {
  display: grid;
  grid-template-columns: var(--w-side) minmax(0, 1fr) var(--w-toc);
  gap: 2.5rem;
  max-width: 1280px;
  margin: 0 auto;
  padding: 1.6rem 1.25rem 2rem;
}
.layout-home { grid-template-columns: var(--w-side) minmax(0, 1fr); }
.layout-practice {
  grid-template-columns: var(--w-side) minmax(0, 1fr);
  max-width: 1440px;
}

/* ---------- sidebar ---------- */
.sidebar {
  position: sticky; top: 96px;
  align-self: start;
  max-height: calc(100vh - 116px);
  overflow-y: auto;
  padding-right: .5rem;
  scrollbar-width: thin;
  font-size: .92rem;
}
.home-link {
  display: inline-flex; align-items: center; gap: .4rem;
  padding: .35rem .55rem; margin-bottom: .8rem;
  border-radius: var(--radius-sm); color: var(--fg-soft);
  background: var(--bg-soft);
  font-size: .85rem;
  text-decoration: none;
  transition: all var(--t-fast) var(--ease);
}
.home-link:hover { background: var(--accent-soft); color: var(--accent); text-decoration: none; }
.home-link .i { width: 16px; height: 16px; }

.nav-group { margin-bottom: 1.4rem; }
.nav-group-title {
  display: flex; align-items: center; gap: .4rem;
  font-size: .78rem; font-weight: 700;
  text-transform: uppercase; letter-spacing: .04em;
  color: var(--fg-mute);
  margin: .2rem 0 .55rem;
}
.nav-group-icon { font-size: .9rem; }
.nav-list { list-style: none; padding: 0; margin: 0; }
.nav-list li { margin: .15rem 0; }
.nav-link {
  display: block;
  padding: .45rem .6rem; border-radius: var(--radius-sm);
  color: var(--fg-soft); text-decoration: none;
  border-left: 2px solid transparent;
  transition: all var(--t-fast) var(--ease);
}
.nav-link:hover {
  background: var(--bg-soft); color: var(--fg);
  text-decoration: none;
}
.nav-link-active {
  background: var(--accent-soft);
  color: var(--accent);
  border-left-color: var(--accent);
}
.nav-link-active:hover { background: var(--accent-soft); color: var(--accent); }
.nav-link-title { display: block; font-weight: 500; line-height: 1.3; }
.nav-link-desc {
  display: block;
  font-size: .78rem; color: var(--fg-faint);
  line-height: 1.45; margin-top: .15rem;
}
.nav-link-active .nav-link-desc { color: color-mix(in srgb, var(--accent) 75%, var(--fg-soft)); }

.sidebar-footer { margin-top: 1.5rem; padding-top: 1rem; border-top: 1px solid var(--border-soft); }
.sidebar-note { margin-top: .6rem; }
.ghost {
  display: inline-flex; align-items: center; gap: .35rem;
  font-size: .82rem; color: var(--fg-mute); text-decoration: none;
}
.ghost:hover { color: var(--accent); text-decoration: none; }
.ghost .i { width: 14px; height: 14px; }

/* ---------- main ---------- */
.main { min-width: 0; padding-bottom: 3rem; }
.main-home { grid-column: 2; }

.surface {
  background: var(--bg-elev);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  box-shadow: var(--shadow-sm);
}

.kicker,
.practice-kicker {
  margin: 0 0 .35rem;
  color: var(--accent);
  font-size: .82rem;
  font-weight: 700;
  letter-spacing: .04em;
  text-transform: uppercase;
}

.section-head {
  max-width: 68ch;
  margin: 0 0 .95rem;
}
.section-head h2 {
  margin: .08rem 0 .25rem;
  font-size: 1.22rem;
  line-height: 1.3;
}
.section-head p:last-child {
  margin: 0;
  color: var(--fg-mute);
}

.page-head { margin: .5rem 0 1.6rem; }
.page-head h1 {
  font-size: 2rem;
  line-height: 1.25;
  margin: 0 0 .35rem;
  letter-spacing: -.01em;
}
.page-lede { color: var(--fg-mute); font-size: 1.02rem; margin: 0; }

/* ---------- prose ---------- */
.prose { max-width: var(--maxw-prose); }
.prose-practice { max-width: none; }
.prose h2, .prose h3, .prose h4 {
  font-weight: 700; line-height: 1.35;
  scroll-margin-top: 96px;
}
.prose h2 {
  font-size: 1.5rem;
  margin: 2.2rem 0 .7rem;
  padding-top: 1.4rem;
  border-top: 1px solid var(--border-soft);
}
.prose h2:first-of-type { border-top: 0; padding-top: 0; margin-top: 1.4rem; }
.prose h3 { font-size: 1.18rem; margin: 1.6rem 0 .5rem; }
.prose h4 { font-size: 1.02rem; margin: 1.3rem 0 .4rem; color: var(--fg-soft); }

.prose p { margin: .8rem 0; }
.prose ul, .prose ol { margin: .8rem 0; padding-left: 1.5rem; }
.prose li { margin: .25rem 0; }
.prose strong { color: var(--fg); font-weight: 600; }
.prose em { color: var(--fg-soft); }

.prose blockquote {
  margin: 1.2rem 0;
  padding: .8rem 1rem;
  background: var(--quote-bg);
  border-left: 3px solid var(--quote-bd);
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
  color: var(--fg-soft);
}
.prose blockquote p:first-child { margin-top: 0; }
.prose blockquote p:last-child { margin-bottom: 0; }

.prose code {
  font-family: var(--font-mono);
  font-size: .9em;
  background: var(--code-bg);
  color: var(--code-fg);
  padding: .12rem .35rem;
  border-radius: 4px;
}
.prose pre {
  background: var(--code-bg);
  color: var(--code-fg);
  padding: 1rem 1.1rem;
  border-radius: var(--radius);
  overflow-x: auto;
  margin: 1.2rem 0;
  border: 1px solid var(--border-soft);
  font-size: .88rem;
  line-height: 1.55;
}
.prose pre code {
  background: transparent; padding: 0; border-radius: 0;
  font-size: inherit; color: inherit;
}

/* mermaid blocks */
.prose pre.mermaid {
  background: transparent;
  border: 1px solid var(--border-soft);
  text-align: center;
  padding: 1.2rem 1rem;
  overflow-x: auto;
}
:root[data-theme="dark"] .prose pre.mermaid svg,
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) .prose pre.mermaid { background: var(--bg-elev); }
}

/* tables */
.prose table {
  border-collapse: collapse;
  width: 100%;
  margin: 1.2rem 0;
  font-size: .92rem;
  display: block;
  overflow-x: auto;
}
.prose thead { background: var(--bg-soft); }
.prose th, .prose td {
  border: 1px solid var(--border);
  padding: .55rem .8rem;
  text-align: left;
  vertical-align: top;
}
.prose th { font-weight: 600; }
.prose tbody tr:nth-child(even) { background: var(--table-stripe); }

.prose img {
  margin: 1.2rem 0;
  box-shadow: var(--shadow-sm);
}

.knowledge-figure {
  margin: .75rem 0 1.25rem;
  overflow: hidden;
  border: 1px solid var(--border-soft);
  border-radius: var(--radius);
  background: var(--bg-elev);
  box-shadow: var(--shadow-sm);
}
.knowledge-figure img {
  width: 100%;
  aspect-ratio: 3 / 2;
  object-fit: cover;
  margin: 0;
  border-radius: 0;
  box-shadow: none;
}
.knowledge-figure figcaption {
  margin: 0;
  padding: .45rem .65rem .55rem;
  color: var(--fg-mute);
  border-top: 1px solid var(--border-soft);
  background: color-mix(in srgb, var(--bg-soft) 58%, transparent);
  font-size: .82rem;
  line-height: 1.45;
}

/* heading anchor permalinks (markdown.toc anchorlink=True) */
.prose .headerlink {
  opacity: 0;
  margin-left: .35rem;
  font-weight: normal;
  color: var(--fg-faint);
  font-size: .85em;
  text-decoration: none;
  transition: opacity var(--t-fast) var(--ease);
}
.prose h2:hover .headerlink,
.prose h3:hover .headerlink,
.prose h4:hover .headerlink { opacity: 1; }

/* ---------- right TOC ---------- */
.page-toc {
  position: sticky; top: 96px; align-self: start;
  max-height: calc(100vh - 116px);
  overflow-y: auto;
  padding-left: .5rem;
  border-left: 1px solid var(--border-soft);
  font-size: .86rem;
  scrollbar-width: thin;
}
.page-toc-title {
  font-size: .78rem; font-weight: 700;
  text-transform: uppercase; letter-spacing: .04em;
  color: var(--fg-mute);
  margin: .2rem 0 .55rem .6rem;
}
.page-toc .toc { padding: 0; }
.page-toc ul { list-style: none; padding: 0; margin: 0; }
.page-toc ul ul { padding-left: .85rem; }
.page-toc a {
  display: block;
  padding: .25rem .6rem;
  color: var(--fg-mute);
  border-left: 2px solid transparent;
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
  text-decoration: none;
  line-height: 1.4;
  transition: all var(--t-fast) var(--ease);
}
.page-toc a:hover {
  color: var(--fg);
  background: var(--bg-soft);
  text-decoration: none;
}
.page-toc a.toc-active {
  color: var(--accent);
  border-left-color: var(--accent);
  background: var(--accent-soft);
}

/* ---------- back to top ---------- */
.back-to-top {
  position: fixed;
  right: 1.25rem; bottom: 1.25rem;
  width: 42px; height: 42px;
  border-radius: 50%;
  background: var(--bg-elev);
  border: 1px solid var(--border);
  color: var(--fg-soft);
  display: flex; align-items: center; justify-content: center;
  box-shadow: var(--shadow-md);
  opacity: 0; pointer-events: none;
  transform: translateY(8px);
  transition: all var(--t-mid) var(--ease);
  z-index: 40;
}
.back-to-top.show {
  opacity: 1; pointer-events: auto;
  transform: translateY(0);
}
.back-to-top:hover { color: var(--accent); border-color: var(--accent); text-decoration: none; }
.back-to-top .i { width: 20px; height: 20px; }

/* ---------- footer ---------- */
.page-footer {
  border-top: 1px solid var(--border);
  padding: 2rem 1.25rem;
  text-align: center;
  font-size: .85rem;
  color: var(--fg-mute);
  background: var(--bg-elev);
}
.page-footer p { margin: .35rem 0; max-width: 56ch; margin-left: auto; margin-right: auto; }
.page-footer .meta { color: var(--fg-faint); font-size: .8rem; }

/* ---------- index / home ---------- */
.home { max-width: 980px; }
.home-dashboard,
.gallery-page {
  display: grid;
  gap: 1.8rem;
}
.hero {
  padding: 2rem 0 1.4rem;
  text-align: left;
}
.home-hero {
  padding: 1.25rem 1.35rem;
}
.hero-eyebrow {
  display: inline-block;
  font-size: .82rem; color: var(--accent);
  text-transform: uppercase; letter-spacing: .06em;
  margin: 0 0 .35rem;
  font-weight: 600;
}
.hero-title {
  font-size: clamp(1.9rem, 3.6vw, 2.6rem);
  line-height: 1.18;
  margin: 0 0 .6rem;
  letter-spacing: -.015em;
}
.hero-lede {
  color: var(--fg-soft);
  font-size: 1.04rem;
  max-width: 60ch;
  margin: 0 0 1.2rem;
}
.hero-actions { display: flex; gap: .6rem; flex-wrap: wrap; }

.btn {
  display: inline-flex; align-items: center;
  padding: .55rem 1rem;
  border-radius: 999px;
  background: var(--bg-elev);
  border: 1px solid var(--border);
  color: var(--fg);
  font-size: .94rem; font-weight: 500;
  text-decoration: none;
  transition: all var(--t-fast) var(--ease);
}
.btn:hover {
  border-color: var(--accent); color: var(--accent);
  text-decoration: none;
  transform: translateY(-1px);
  box-shadow: var(--shadow-sm);
}
.btn-primary {
  background: var(--accent);
  border-color: var(--accent);
  color: var(--accent-fg);
}
.btn-primary:hover { background: color-mix(in srgb, var(--accent) 92%, black); color: var(--accent-fg); }
.btn-secondary {
  background: var(--bg-soft);
  border-color: var(--border);
  color: var(--fg);
}
.btn-secondary:hover {
  border-color: var(--accent);
  color: var(--accent);
}
.btn-ghost {
  background: transparent;
  border-color: transparent;
  color: var(--fg-soft);
}
.btn-ghost:hover {
  background: var(--bg-soft);
  border-color: var(--border);
  color: var(--fg);
}

.map { margin: 0; }
.learning-section {
  display: grid;
  gap: .1rem;
}
.map-title {
  display: flex; align-items: center; gap: .55rem;
  font-size: 1.18rem; font-weight: 700;
  margin: 0 0 1rem;
}

.cards {
  list-style: none; padding: 0; margin: 0;
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(240px, 1fr));
  gap: .85rem;
}
.cards-2 {
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
}
.card {
  background: var(--bg-elev);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  transition: all var(--t-mid) var(--ease);
  overflow: hidden;
}
.card:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
  border-color: var(--accent);
}
.card-link {
  display: block;
  padding: 1rem 1.1rem;
  color: var(--fg);
  text-decoration: none;
  height: 100%;
}
.card-link:hover { text-decoration: none; }
.card-top {
  display: flex; justify-content: space-between; align-items: center;
  margin-bottom: .55rem;
  min-height: 24px;
}
.card-badge {
  font-size: .72rem; font-weight: 700;
  letter-spacing: .04em;
  background: var(--accent-soft);
  color: var(--accent);
  padding: .15rem .5rem;
  border-radius: 999px;
}
.card-arrow {
  width: 18px; height: 18px;
  color: var(--fg-faint);
  transition: transform var(--t-fast) var(--ease), color var(--t-fast) var(--ease);
}
.card:hover .card-arrow {
  color: var(--accent);
  transform: translateX(3px);
}
.card-title { font-size: 1.03rem; margin: 0 0 .35rem; line-height: 1.35; }
.card-desc { font-size: .88rem; color: var(--fg-mute); margin: 0; line-height: 1.55; }

.tips {
  margin: .2rem 0 1rem;
  padding: 1.2rem 1.4rem;
}
.bullets { padding-left: 1.3rem; margin: .5rem 0; }
.bullets li { margin: .35rem 0; color: var(--fg-soft); }

/* ---------- practice mode ---------- */
.practice-intro {
  margin: .4rem 0 1.4rem;
  padding: 1rem 1.1rem;
  background: var(--bg-elev);
  border: 1px solid var(--border);
  border-radius: var(--radius);
}
.practice-kicker {
  margin: 0 0 .35rem;
  color: var(--accent);
  font-size: .82rem;
  font-weight: 700;
  letter-spacing: .04em;
  text-transform: uppercase;
}
.practice-sources {
  margin: 2rem 0 1rem;
  padding-top: 1rem;
  border-top: 1px solid var(--border-soft);
}
.practice-workbench {
  margin: 1.4rem 0 2rem;
}
.practice-loading,
.practice-empty {
  padding: 1rem;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  background: var(--bg-elev);
  color: var(--fg-mute);
}
.practice-shell {
  display: grid;
  align-items: start;
}
.practice-side {
  position: sticky;
  top: 112px;
  display: grid;
  gap: .75rem;
}
.practice-side-card {
  background: var(--bg-elev);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: .85rem;
}
.practice-lab-tabs {
  display: grid;
  gap: .45rem;
}
.practice-lab-tab {
  width: 100%;
  display: flex;
  justify-content: space-between;
  gap: .55rem;
  text-align: left;
  padding: .65rem .7rem;
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  background: var(--bg-elev);
  color: var(--fg-soft);
  cursor: pointer;
  font: inherit;
  transition: all var(--t-fast) var(--ease);
}
.practice-lab-tab:hover,
.practice-lab-tab.is-active {
  border-color: var(--accent);
  color: var(--accent);
  background: var(--accent-soft);
}
.practice-lab-tab span {
  min-width: 0;
}
.practice-lab-tab small {
  white-space: nowrap;
  color: inherit;
}
.practice-stage {
  min-width: 0;
}
.practice-stage-head {
  background: var(--bg-elev);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1rem 1.05rem;
  margin-bottom: 1rem;
}
.practice-stage-head h2 {
  border: 0;
  padding: 0;
  margin: .2rem 0 .35rem;
}
.practice-stage-head p {
  margin: 0;
}
.practice-stage-meta {
  display: flex;
  flex-wrap: wrap;
  gap: .45rem;
  margin-top: .7rem;
}
.practice-stage-meta span {
  display: inline-flex;
  padding: .22rem .58rem;
  border-radius: 999px;
  background: var(--bg-soft);
  color: var(--fg-mute);
  font-size: .78rem;
}
.practice-task-type {
  display: inline-flex;
  border-radius: 999px;
  padding: .16rem .5rem;
  font-size: .72rem;
  font-weight: 700;
  letter-spacing: .04em;
}
.practice-task-type {
  background: var(--bg-soft);
  color: var(--fg-mute);
}
.practice-prompt {
  margin: .45rem 0;
}
.practice-prompt {
  font-weight: 600;
}
.practice-options,
.practice-fill-list {
  display: grid;
  gap: .45rem;
  margin: .8rem 0;
}
.practice-option,
.practice-fill {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  gap: .55rem;
  align-items: center;
  padding: .6rem .65rem;
  border: 1px solid var(--border-soft);
  border-radius: var(--radius-sm);
  background: var(--bg);
}
.practice-fill {
  grid-template-columns: minmax(110px, .7fr) minmax(0, 1fr);
}
.practice-fill input,
.practice-textarea,
.practice-code,
.practice-command {
  width: 100%;
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  background: var(--bg);
  color: var(--fg);
  font: inherit;
  padding: .58rem .65rem;
}
.practice-code,
.practice-command,
.practice-report-text {
  font-family: var(--font-mono);
  font-size: .86rem;
  line-height: 1.55;
}
.practice-terminal {
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  overflow: hidden;
  background: var(--code-bg);
  margin: .8rem 0;
}
.practice-terminal-head {
  padding: .42rem .65rem;
  border-bottom: 1px solid var(--border);
  color: var(--fg-mute);
  font-size: .78rem;
  font-weight: 700;
}
.practice-command {
  border: 0;
  border-radius: 0;
  background: transparent;
}
.practice-task-actions {
  display: flex;
  flex-wrap: wrap;
  gap: .5rem;
  margin-top: .75rem;
}
.practice-hint {
  margin: .75rem 0 0;
  padding: .65rem .75rem;
  border-radius: var(--radius-sm);
}
.practice-hint {
  background: var(--quote-bg);
  color: var(--fg-soft);
  border-left: 3px solid var(--quote-bd);
}
.practice-side-card h3 {
  margin: 0 0 .4rem;
  font-size: .98rem;
}
.practice-side-card p,
.practice-side-card li {
  color: var(--fg-mute);
  font-size: .84rem;
}
.practice-side-card .btn {
  width: 100%;
  justify-content: center;
  margin-top: .55rem;
}
.practice-report-panel {
  position: fixed;
  inset: 7vh 1.25rem auto auto;
  width: min(560px, calc(100vw - 2.5rem));
  max-height: 86vh;
  z-index: 85;
  background: var(--bg-elev);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  box-shadow: var(--shadow-md);
  display: grid;
  grid-template-rows: auto minmax(0, 1fr);
}
.practice-report-head {
  position: relative;
  padding: .9rem 1rem;
  border-bottom: 1px solid var(--border-soft);
}
.practice-report-head h3 {
  margin: 0;
}
.practice-report-text {
  resize: vertical;
  min-height: 360px;
  border: 0;
  border-radius: 0 0 var(--radius) var(--radius);
  background: var(--bg);
  color: var(--fg);
  padding: 1rem;
}
.practice-studio {
  display: grid;
  gap: 1rem;
}
.practice-beginner-guide {
  display: grid;
  grid-template-columns: minmax(0, 1.05fr) minmax(260px, .95fr);
  gap: .85rem;
  margin: 0 0 .9rem;
  padding: .95rem;
  border: 1px solid color-mix(in srgb, var(--accent) 30%, var(--border));
  border-radius: var(--radius);
  background: var(--bg-elev);
}
.practice-beginner-main h3 {
  margin: .1rem 0 .45rem;
  font-size: 1.08rem;
}
.practice-beginner-main p,
.practice-beginner-side p {
  margin: .4rem 0;
  color: var(--fg-soft);
}
.practice-beginner-why {
  padding-top: .35rem;
  border-top: 1px solid var(--border-soft);
}
.practice-beginner-side {
  display: grid;
  gap: .45rem;
  align-content: start;
}
.practice-beginner-side h4 {
  margin: 0;
  color: var(--fg);
  font-size: .86rem;
}
.practice-glossary {
  display: grid;
  gap: .45rem;
  margin: 0;
}
.practice-glossary div {
  display: grid;
  gap: .12rem;
  padding: .48rem .55rem;
  border: 1px solid var(--border-soft);
  border-radius: var(--radius-sm);
  background: var(--bg);
}
.practice-glossary dt {
  color: var(--accent);
  font-weight: 780;
}
.practice-glossary dd {
  margin: 0;
  color: var(--fg-mute);
  font-size: .82rem;
  line-height: 1.45;
}
.practice-glossary.compact div {
  padding: .42rem .5rem;
}
.practice-beginner-tip {
  margin: .55rem 0;
  padding: .58rem .68rem;
  border: 1px solid color-mix(in srgb, var(--quote-bd) 42%, var(--border-soft));
  border-radius: var(--radius-sm);
  background: var(--quote-bg);
  color: var(--fg-soft);
  font-size: .9rem;
}
.practice-goal {
  margin: .45rem 0;
  color: var(--accent);
  font-weight: 690;
}
.practice-hints {
  display: grid;
  gap: .45rem;
  margin-top: .75rem;
}
.practice-hint strong {
  display: inline-block;
  margin-right: .45rem;
  color: var(--quote-bd);
}
.practice-trace {
  display: grid;
  gap: .8rem;
  margin: .8rem 0;
}
.practice-trace-region {
  padding: .55rem .65rem;
  border: 1px solid var(--border-soft);
  border-radius: var(--radius-sm);
  background: var(--bg-soft);
}
.practice-trace-region .practice-kicker {
  margin: 0 0 .4rem;
}
.practice-trace-candidates {
  display: flex;
  flex-direction: column;
  gap: .35rem;
}
.practice-trace-candidate {
  display: inline-flex;
  align-items: center;
  gap: .35rem;
  width: 100%;
  padding: .4rem .55rem;
  border: 1px dashed var(--border);
  border-radius: var(--radius-sm);
  background: var(--bg);
  color: var(--fg);
  font-size: .85rem;
  text-align: left;
  cursor: pointer;
}
.practice-trace-candidate:hover,
.practice-trace-candidate:focus-visible {
  border-color: var(--accent);
  background: var(--accent-soft);
}
.practice-trace-pick-mark {
  display: inline-grid;
  place-items: center;
  width: 1.2rem;
  height: 1.2rem;
  border-radius: 50%;
  background: var(--accent);
  color: var(--bg);
  font-weight: 700;
  font-size: .75rem;
}
.practice-trace-answer {
  display: grid;
  gap: .4rem;
}
.practice-trace-item {
  display: grid;
  grid-template-columns: 2rem minmax(0, 1fr) auto;
  gap: .6rem;
  align-items: center;
  min-height: 46px;
  padding: .55rem .62rem;
  border: 1px solid var(--border-soft);
  border-radius: var(--radius-sm);
  background: var(--bg);
}
.practice-trace-index {
  display: inline-grid;
  place-items: center;
  width: 1.55rem;
  height: 1.55rem;
  border-radius: 50%;
  background: var(--accent-soft);
  color: var(--accent);
  font-weight: 800;
  font-size: .78rem;
}
.practice-trace-item strong {
  min-width: 0;
  overflow-wrap: anywhere;
}
.practice-trace-controls {
  display: inline-flex;
  gap: .32rem;
}
.practice-sim-flow {
  display: flex;
  flex-wrap: wrap;
  gap: .45rem;
  margin-top: .75rem;
}
.practice-sim-flow span {
  display: inline-flex;
  align-items: center;
  min-height: 28px;
  padding: .22rem .55rem;
  border: 1px solid var(--border-soft);
  border-radius: 999px;
  background: var(--bg);
  color: var(--fg-soft);
  font-size: .8rem;
}
.practice-sim-terminal {
  margin: .75rem 0 0;
  max-height: 210px;
  overflow: auto;
  padding: .75rem;
  border-radius: var(--radius-sm);
  background: var(--code-bg);
  color: var(--fg);
  font-family: var(--font-mono);
  font-size: .8rem;
  line-height: 1.55;
}
/* ---------- mechanism board: 折叠次要项 ---------- */
.practice-side-details {
  padding: 0;
}
.practice-side-details > summary {
  cursor: pointer;
  list-style: none;
  padding: .65rem .9rem;
  font-size: .85rem;
  font-weight: 600;
  color: var(--fg-soft);
}
.practice-side-details > summary::-webkit-details-marker {
  display: none;
}
.practice-side-details > summary::before {
  content: "▸ ";
  display: inline-block;
  margin-right: .25rem;
  color: var(--fg-soft);
  transition: transform .15s ease;
}
.practice-side-details[open] > summary::before {
  content: "▾ ";
}
.practice-side-detail-block {
  padding: 0 .9rem .8rem;
}
.practice-side-detail-block + .practice-side-detail-block {
  border-top: 1px dashed var(--border-soft);
  padding-top: .7rem;
}
.practice-side-detail-block h4 {
  margin: 0 0 .35rem;
  font-size: .85rem;
}
.practice-side-detail-block ul {
  margin: 0;
  padding-left: 1.1rem;
  font-size: .8rem;
  line-height: 1.55;
}
.practice-side-detail-block .btn {
  margin-top: .4rem;
  font-size: .8rem;
}
/* ---------- simulator: 7 kind 各自视觉 ---------- */
.practice-sim {
  margin: .75rem 0 0;
}
.practice-sim-concept-map {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(120px, 1fr));
  gap: .5rem;
}
.practice-sim-concept-node {
  padding: .55rem .65rem;
  border: 1px dashed var(--border);
  border-radius: var(--radius-sm);
  background: var(--bg);
  text-align: center;
  font-size: .85rem;
}
.practice-sim-state-flow {
  display: flex;
  flex-wrap: wrap;
  gap: .35rem .15rem;
  margin: .75rem 0 0;
  padding: 0;
  list-style: none;
}
.practice-sim-flow-node {
  display: inline-flex;
  align-items: center;
  gap: .25rem;
  padding: .25rem .55rem;
  border: 1px solid var(--border-soft);
  border-radius: 6px;
  background: var(--bg);
  color: var(--fg-soft);
  font-size: .8rem;
}
.practice-sim-flow-node.is-highlight {
  border-color: var(--accent);
  color: var(--fg);
  font-weight: 600;
}
.practice-sim-flow-arrow {
  color: var(--fg-soft);
  font-size: .7rem;
}
.practice-sim-flow-node:first-child .practice-sim-flow-arrow {
  display: none;
}
.practice-sim-state-note {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
  gap: .4rem;
  margin: .75rem 0 0;
}
.practice-sim-state-item {
  padding: .45rem .6rem;
  border-left: 3px solid var(--accent);
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
  background: var(--bg);
}
.practice-sim-state-item dt {
  font-weight: 600;
  font-size: .85rem;
  color: var(--fg);
}
.practice-sim-state-item dd {
  margin: .15rem 0 0;
  font-size: .75rem;
  color: var(--fg-soft);
}
.practice-sim-code-context {
  margin: .75rem 0 0;
  padding: .65rem .8rem;
  background: var(--code-bg);
  border-radius: var(--radius-sm);
  font-family: var(--font-mono);
  font-size: .8rem;
  line-height: 1.6;
  overflow: auto;
}
.practice-sim-code-token {
  display: inline-block;
  padding: 0 .25rem;
  color: var(--accent);
}
.practice-sim-failure-card {
  margin: .75rem 0 0;
  padding: .65rem .8rem;
  border: 1px solid var(--danger-soft);
  border-radius: var(--radius-sm);
  background: var(--danger-soft);
  color: var(--fg);
}
.practice-sim-failure-card h5 {
  margin: 0 0 .25rem;
  font-size: .85rem;
  color: var(--danger);
}
.practice-sim-failure-card ul {
  margin: 0;
  padding-left: 1.1rem;
  font-size: .8rem;
  line-height: 1.5;
}
/* ---------- practice workspace navigation ---------- */
.layout-practice-focused {
  grid-template-columns: minmax(0, 1fr);
  max-width: 1360px;
}
.practice-workspace-head {
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto;
  grid-template-areas:
    "copy controls"
    "progress progress";
  gap: .8rem 1rem;
  align-items: start;
  padding: 1rem;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  background: var(--bg-elev);
}
.practice-workspace-copy {
  grid-area: copy;
  min-width: 0;
}
.practice-workspace-copy h2 {
  margin: .1rem 0 .28rem;
  padding: 0;
  border: 0;
  font-size: 1.35rem;
}
.practice-workspace-copy p:last-child {
  margin: 0;
  color: var(--fg-soft);
}
.practice-workspace-controls {
  grid-area: controls;
  display: flex;
  align-items: stretch;
  justify-content: flex-end;
  gap: .55rem;
}
.practice-workspace-controls .btn {
  min-height: 66px;
  align-items: center;
  border-radius: var(--radius-sm);
  padding-inline: 1rem;
  white-space: nowrap;
}
.practice-track-menu-wrap {
  position: relative;
}
.practice-path-button {
  min-width: 178px;
  height: 100%;
  display: grid;
  gap: .1rem;
  padding: .55rem .72rem;
  text-align: left;
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  background: var(--bg);
  color: var(--fg);
  cursor: pointer;
  font: inherit;
}
.practice-path-button span {
  color: var(--fg-mute);
  font-size: .75rem;
  font-weight: 720;
}
.practice-path-button strong {
  font-size: .92rem;
}
.practice-path-button:hover,
.practice-path-button[aria-expanded="true"] {
  border-color: var(--accent);
  background: var(--accent-soft);
  color: var(--accent);
}
.practice-track-menu {
  position: absolute;
  top: calc(100% + .45rem);
  right: 0;
  z-index: 40;
  width: min(430px, calc(100vw - 2rem));
  display: grid;
  gap: .45rem;
  padding: .55rem;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  background: var(--bg-elev);
  box-shadow: var(--shadow-md);
}
.practice-track-option {
  display: grid;
  gap: .16rem;
  padding: .62rem .68rem;
  text-align: left;
  border: 1px solid var(--border-soft);
  border-radius: var(--radius-sm);
  background: var(--bg);
  color: var(--fg-soft);
  cursor: pointer;
  font: inherit;
}
.practice-track-option:hover,
.practice-track-option.is-active {
  border-color: var(--accent);
  background: var(--accent-soft);
  color: var(--fg);
}
.practice-track-option span {
  font-weight: 760;
}
.practice-track-option small {
  color: var(--fg-mute);
  line-height: 1.35;
}
.practice-track-option em {
  justify-self: start;
  padding: .1rem .42rem;
  border-radius: 999px;
  background: color-mix(in srgb, var(--accent) 12%, var(--bg-elev));
  color: var(--accent);
  font-size: .7rem;
  font-style: normal;
  font-weight: 760;
}
.practice-workspace-progress {
  grid-area: progress;
  display: grid;
  grid-template-columns: auto auto minmax(160px, 1fr);
  gap: .65rem;
  align-items: center;
  color: var(--fg-mute);
  font-size: .84rem;
}
.practice-workspace-progress strong {
  color: var(--fg);
  font-size: .9rem;
}
.practice-progress-bar {
  height: .55rem;
  overflow: hidden;
  border-radius: 999px;
  background: var(--bg-soft);
}
.practice-progress-bar span {
  display: block;
  height: 100%;
  border-radius: inherit;
  background: var(--accent);
}
.practice-lab-journey {
  display: grid;
  grid-template-columns: minmax(130px, .42fr) minmax(0, 1fr) minmax(130px, .42fr) auto;
  gap: .65rem;
  align-items: stretch;
}
.practice-journey-nav,
.practice-journey-current,
.practice-lab-drawer > summary {
  border: 1px solid var(--border);
  border-radius: var(--radius);
  background: var(--bg-elev);
}
.practice-journey-nav {
  display: grid;
  gap: .18rem;
  align-content: center;
  min-height: 94px;
  padding: .72rem .78rem;
  text-align: left;
  color: var(--fg-soft);
  cursor: pointer;
  font: inherit;
}
.practice-journey-nav span {
  color: var(--fg-mute);
  font-size: .74rem;
  font-weight: 720;
}
.practice-journey-nav strong {
  min-width: 0;
  font-size: .88rem;
  line-height: 1.35;
}
.practice-journey-nav:hover:not(:disabled) {
  border-color: var(--accent);
  background: var(--accent-soft);
  color: var(--accent);
}
.practice-journey-nav:disabled {
  cursor: default;
  opacity: .58;
}
.practice-journey-current {
  min-width: 0;
  padding: .85rem .95rem;
}
.practice-journey-current h3 {
  margin: .1rem 0 .25rem;
  font-size: 1.08rem;
}
.practice-journey-current p {
  margin: 0;
  color: var(--fg-soft);
}
.practice-journey-current span {
  display: inline-flex;
  margin-top: .55rem;
  padding: .2rem .52rem;
  border-radius: 999px;
  background: var(--bg-soft);
  color: var(--fg-mute);
  font-size: .78rem;
  font-weight: 680;
}
.practice-lab-drawer {
  position: relative;
  min-width: 118px;
}
.practice-lab-drawer > summary {
  height: 100%;
  display: grid;
  place-items: center;
  padding: .7rem .78rem;
  color: var(--fg-soft);
  cursor: pointer;
  font-weight: 720;
  list-style: none;
}
.practice-lab-drawer > summary::-webkit-details-marker {
  display: none;
}
.practice-lab-drawer > summary:hover,
.practice-lab-drawer[open] > summary {
  border-color: var(--accent);
  background: var(--accent-soft);
  color: var(--accent);
}
.practice-lab-drawer[open] .practice-lab-tabs {
  position: absolute;
  top: calc(100% + .45rem);
  right: 0;
  z-index: 35;
  width: min(520px, calc(100vw - 2rem));
  max-height: min(540px, calc(100vh - 150px));
  overflow-y: auto;
  padding: .55rem;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  background: var(--bg-elev);
  box-shadow: var(--shadow-md);
}
.practice-phase-progress {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: .55rem;
  margin: 0 0 .85rem;
}
.practice-phase-step {
  display: flex;
  align-items: center;
  gap: .55rem;
  min-height: 58px;
  padding: .58rem .66rem;
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  background: var(--bg-elev);
  color: var(--fg-soft);
  cursor: pointer;
  font: inherit;
  text-align: left;
}
.practice-phase-number {
  flex: 0 0 auto;
  display: inline-grid;
  place-items: center;
  width: 1.55rem;
  height: 1.55rem;
  border-radius: 999px;
  background: var(--bg-soft);
  color: var(--fg-mute);
  font-size: .78rem;
  font-weight: 800;
}
.practice-phase-copy {
  display: grid;
  min-width: 0;
}
.practice-phase-copy strong {
  font-size: .9rem;
  line-height: 1.2;
}
.practice-phase-copy small {
  color: var(--fg-mute);
  font-size: .76rem;
}
.practice-phase-step:hover,
.practice-phase-step.is-active {
  border-color: var(--accent);
  background: var(--accent-soft);
  color: var(--accent);
}
.practice-phase-step.is-active .practice-phase-number,
.practice-phase-step.is-complete .practice-phase-number {
  background: var(--accent);
  color: var(--accent-fg);
}
.practice-phase-step.is-complete:not(.is-active) {
  border-color: color-mix(in srgb, var(--accent) 42%, var(--border));
}
.practice-empty-inline {
  color: var(--fg-mute);
  font-size: .86rem;
}
.practice-studio .practice-shell {
  grid-template-columns: minmax(0, 1fr) minmax(260px, .34fr);
  gap: 1.05rem;
}
.practice-coach-layout {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(220px, .34fr);
  gap: .9rem;
  align-items: start;
}
.practice-coach-card {
  display: grid;
  gap: .9rem;
  min-width: 0;
  padding: 1.05rem;
  border: 1px solid color-mix(in srgb, var(--accent) 24%, var(--border));
  border-radius: var(--radius);
  background: var(--bg-elev);
  box-shadow: var(--shadow-sm);
}
.practice-coach-card.is-complete {
  border-color: color-mix(in srgb, var(--accent) 58%, var(--border));
  box-shadow: inset 3px 0 0 var(--accent);
}
.practice-coach-head {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 1rem;
  padding-bottom: .75rem;
  border-bottom: 1px solid var(--border-soft);
}
.practice-coach-head h3 {
  margin: .1rem 0 .3rem;
  font-size: 1.25rem;
  line-height: 1.3;
}
.practice-coach-head p:last-child {
  margin: 0;
  color: var(--fg-soft);
}
.practice-coach-why,
.practice-coach-observe,
.practice-coach-action {
  display: grid;
  gap: .38rem;
}
.practice-coach-why h4,
.practice-coach-observe h4,
.practice-coach-action h4,
.practice-coach-result h4 {
  margin: 0;
  color: var(--fg);
  font-size: .9rem;
}
.practice-coach-why p,
.practice-coach-observe p {
  margin: 0;
  color: var(--fg-soft);
}
.practice-coach-observe {
  padding: .78rem .85rem;
  border: 1px solid var(--border-soft);
  border-radius: var(--radius-sm);
  background: var(--bg);
}
.practice-coach-action {
  padding-top: .15rem;
}
.practice-coach-result {
  display: grid;
  gap: .35rem;
  margin-top: .15rem;
  padding: .78rem .85rem;
  border-radius: var(--radius-sm);
}
.practice-coach-result p {
  margin: 0;
}
.practice-coach-result.is-ok {
  border: 1px solid color-mix(in srgb, var(--accent) 42%, var(--border));
  background: var(--accent-soft);
  color: var(--accent);
}
.practice-coach-result.is-repair {
  border: 1px solid color-mix(in srgb, var(--danger) 36%, var(--border));
  background: var(--danger-soft);
}
.practice-repair-drill {
  display: grid;
  gap: .18rem;
  padding-top: .45rem;
  border-top: 1px solid color-mix(in srgb, currentColor 16%, transparent);
  color: var(--fg-soft);
}
.practice-repair-drill strong {
  color: var(--fg);
  font-size: .86rem;
}
.practice-learning-route {
  position: sticky;
  top: 74px;
  display: grid;
  gap: .55rem;
  padding: .75rem;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  background: var(--bg-elev);
}
.practice-route-head {
  display: grid;
  gap: .1rem;
}
.practice-route-head strong {
  font-size: .92rem;
}
.practice-route-list {
  display: grid;
  gap: .42rem;
}
.practice-route-step {
  display: grid;
  grid-template-columns: 1.45rem minmax(0, 1fr);
  gap: .18rem .48rem;
  align-items: start;
  width: 100%;
  padding: .55rem .58rem;
  border: 1px solid var(--border-soft);
  border-radius: var(--radius-sm);
  background: var(--bg);
  color: var(--fg-soft);
  cursor: pointer;
  text-align: left;
  font: inherit;
}
.practice-route-step span {
  grid-row: 1 / span 2;
  display: inline-grid;
  place-items: center;
  width: 1.35rem;
  height: 1.35rem;
  border-radius: 999px;
  background: var(--bg-soft);
  color: var(--fg-mute);
  font-size: .72rem;
  font-weight: 800;
}
.practice-route-step strong {
  min-width: 0;
  color: var(--fg);
  font-size: .84rem;
  line-height: 1.28;
}
.practice-route-step small {
  color: var(--fg-mute);
  font-size: .74rem;
  line-height: 1.25;
}
.practice-route-step:hover,
.practice-route-step.is-active {
  border-color: var(--accent);
  background: var(--accent-soft);
  color: var(--accent);
}
.practice-route-step.is-active span,
.practice-route-step.is-complete span {
  background: var(--accent);
  color: var(--accent-fg);
}
.practice-mechanism-board {
  align-content: start;
}
.practice-mechanism-card {
  border-color: color-mix(in srgb, var(--accent) 24%, var(--border));
}
.practice-model-flow {
  display: grid;
  gap: .38rem;
  margin-top: .65rem;
}
.practice-model-flow span {
  position: relative;
  padding: .42rem .55rem .42rem 1.55rem;
  border: 1px solid var(--border-soft);
  border-radius: var(--radius-sm);
  background: var(--bg);
  color: var(--fg-soft);
  font-size: .82rem;
  line-height: 1.35;
}
.practice-model-flow span::before {
  content: "";
  position: absolute;
  left: .65rem;
  top: .86rem;
  width: .38rem;
  height: .38rem;
  border-radius: 999px;
  background: var(--accent);
}
.practice-first-principles {
  display: grid;
  gap: .7rem;
}
.practice-principles-grid {
  display: grid;
  gap: .58rem;
}
.practice-principle {
  display: grid;
  gap: .32rem;
  padding: .62rem .68rem;
  border: 1px solid var(--border-soft);
  border-radius: var(--radius-sm);
  background: var(--bg);
}
.practice-principle strong {
  color: var(--fg);
  font-size: .82rem;
}
.practice-principle ul {
  margin: 0;
  padding-left: 1.05rem;
}
.practice-principle li + li {
  margin-top: .22rem;
}

/* ---------- responsive ---------- */
@media (max-width: 1100px) {
  :root { --w-toc: 200px; }
  .layout { gap: 1.6rem; }
  .practice-studio .practice-shell {
    grid-template-columns: minmax(0, 1fr);
  }
  .practice-coach-layout {
    grid-template-columns: minmax(0, 1fr);
  }
  .practice-learning-route {
    position: static;
  }
  .practice-lab-journey {
    grid-template-columns: minmax(0, 1fr);
  }
  .practice-lab-drawer[open] .practice-lab-tabs,
  .practice-track-menu {
    left: 0;
    right: auto;
    width: min(560px, calc(100vw - 2rem));
  }
}

@media (max-width: 960px) {
  .layout { grid-template-columns: minmax(0, 1fr); }
  .layout-home { grid-template-columns: minmax(0, 1fr); }
  .sidebar { display: none; }
  .page-toc { display: none; }
}

@media (max-width: 720px) {
  body { font-size: 15px; }
  .topbar-inner {
    grid-template-columns: minmax(0, 1fr) auto auto;
    gap: .45rem;
    padding: .55rem .9rem;
  }
  .brand span {
    min-width: 0;
    max-width: 52vw;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
  }
  .site-nav-toggle {
    display: inline-flex;
    justify-content: center;
    align-items: center;
  }
  .site-nav {
    grid-column: 1 / -1;
    display: none;
    justify-content: flex-start;
    flex-wrap: wrap;
    padding-top: .5rem;
    border-top: 1px solid var(--border-soft);
  }
  .site-nav.is-open {
    display: flex;
  }
  .site-nav-link {
    min-height: 36px;
  }
  .topbar-actions {
    justify-content: flex-end;
  }
  .layout { padding: 1rem .9rem 2rem; }
  .prose h1 { font-size: 1.55rem; }
  .prose h2 { font-size: 1.3rem; }
  .prose h3 { font-size: 1.08rem; }
  .hero-title { font-size: 1.7rem; }
  .practice-shell {
    grid-template-columns: minmax(0, 1fr);
  }
  .practice-studio .practice-shell {
    grid-template-columns: minmax(0, 1fr);
  }
  .practice-side {
    position: static;
  }
  .practice-lab-tabs {
    grid-template-columns: repeat(auto-fit, minmax(140px, 1fr));
  }
  .practice-workspace-head,
  .practice-workspace-progress {
    grid-template-columns: 1fr;
  }
  .practice-workspace-head {
    grid-template-areas:
      "copy"
      "controls"
      "progress";
  }
  .practice-workspace-controls {
    align-items: stretch;
    flex-direction: column;
  }
  .practice-path-button {
    width: 100%;
  }
  .practice-track-menu,
  .practice-lab-drawer[open] .practice-lab-tabs {
    width: calc(100vw - 1.8rem);
  }
  .practice-phase-progress {
    grid-template-columns: 1fr;
  }
  .practice-beginner-guide {
    grid-template-columns: 1fr;
  }
  .practice-coach-head {
    display: grid;
  }
  .practice-fill {
    grid-template-columns: 1fr;
  }
  .practice-trace-item {
    grid-template-columns: 1.8rem minmax(0, 1fr);
  }
  .practice-trace-item div {
    grid-column: 1 / -1;
    justify-content: flex-end;
  }
  .back-to-top { right: .9rem; bottom: .9rem; }
}

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
    scroll-behavior: auto !important;
  }
}

/* ---------- topbar actions cluster ---------- */
.topbar-actions { display: flex; gap: .35rem; }

/* ---------- theme picker drawer ---------- */
.theme-picker {
  position: fixed; top: 0; right: 0; bottom: 0;
  width: min(420px, 100vw);
  background: var(--bg-elev);
  border-left: 1px solid var(--border);
  box-shadow: -8px 0 32px rgba(0,0,0,.18);
  z-index: 90;
  display: flex; flex-direction: column;
  transform: translateX(100%);
  transition: transform var(--t-mid) var(--ease);
}
.theme-picker:not([hidden]) { transform: translateX(0); }
.theme-picker[hidden] { display: flex; visibility: hidden; pointer-events: none; }

.theme-picker-backdrop {
  position: fixed; inset: 0;
  background: rgba(0,0,0,.36);
  z-index: 80;
  opacity: 0; pointer-events: none;
  transition: opacity var(--t-mid) var(--ease);
}
.theme-picker-backdrop:not([hidden]) { opacity: 1; pointer-events: auto; }
.theme-picker-backdrop[hidden] { display: block; visibility: hidden; }

.theme-picker-head {
  position: relative;
  padding: 1.1rem 1.2rem .8rem;
  border-bottom: 1px solid var(--border-soft);
}
.theme-picker-title { font-size: 1.05rem; margin: 0 0 .2rem; }
.theme-picker-sub {
  font-size: .82rem; color: var(--fg-mute);
  margin: 0; line-height: 1.5;
}
.theme-picker-sub a { color: var(--accent); }
.theme-picker-close {
  position: absolute; top: .5rem; right: .6rem;
  width: 32px; height: 32px;
  font-size: 22px; line-height: 1;
  background: transparent; border: 0;
  color: var(--fg-mute); cursor: pointer;
  border-radius: 50%;
  transition: all var(--t-fast) var(--ease);
}
.theme-picker-close:hover { background: var(--bg-soft); color: var(--fg); }

.theme-picker-actions {
  display: flex; gap: .5rem; flex-wrap: wrap;
  padding: .7rem 1.2rem .4rem;
}

.btn-mini {
  padding: .35rem .7rem;
  font-size: .82rem;
  border-radius: 999px;
  background: var(--bg-soft);
  border: 1px solid var(--border);
  color: var(--fg-soft);
  cursor: pointer;
  font: inherit; font-size: .82rem;
  text-decoration: none;
  transition: all var(--t-fast) var(--ease);
}
.btn-mini:hover {
  border-color: var(--accent); color: var(--accent);
  text-decoration: none;
}
.btn-mini.btn-primary {
  background: var(--accent);
  border-color: var(--accent);
  color: var(--accent-fg);
}
.btn-mini.btn-secondary {
  background: var(--bg-soft);
  border-color: var(--border);
  color: var(--fg);
}

.theme-picker-grid {
  padding: .6rem 1.2rem 1.2rem;
  overflow-y: auto;
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(170px, 1fr));
  gap: .55rem;
}

.theme-card {
  text-align: left;
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  padding: .6rem .65rem .7rem;
  cursor: pointer;
  font: inherit;
  color: var(--fg);
  transition: all var(--t-fast) var(--ease);
  display: flex; flex-direction: column; gap: .35rem;
}
.theme-card:hover {
  border-color: var(--accent);
  transform: translateY(-1px);
  box-shadow: var(--shadow-sm);
}
.theme-card-active {
  border-color: var(--accent);
  background: var(--accent-soft);
}
.theme-card-active::after {
  content: "✓";
  position: absolute;
  margin-left: -1.4rem; margin-top: -.1rem;
  color: var(--accent);
  font-weight: 700;
}

.theme-card-swatch {
  display: flex; gap: 2px;
  height: 32px;
  border-radius: 4px;
  overflow: hidden;
  border: 1px solid var(--border-soft);
}
.theme-card-swatch span { flex: 1; }
.theme-card-name {
  font-size: .85rem; font-weight: 600;
  line-height: 1.3;
  display: flex; align-items: baseline; gap: .35rem;
}
.theme-card-mode {
  font-size: .68rem; font-weight: 500;
  color: var(--fg-faint);
  text-transform: uppercase;
  letter-spacing: .04em;
}
.theme-card-desc {
  font-size: .76rem; color: var(--fg-mute);
  line-height: 1.45;
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

/* ---------- gallery page ---------- */
.gallery-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
  gap: 1rem;
  margin: 1.6rem 0;
}
.gallery-card {
  background: var(--bg-elev);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  overflow: hidden;
  transition: all var(--t-mid) var(--ease);
}
.gallery-card:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
  border-color: var(--accent);
}
.gallery-card .swatch-row {
  display: flex; height: 64px;
}
.gallery-card .swatch-row span { flex: 1; }
.gallery-card-body { padding: .85rem 1rem 1rem; }
.gallery-card-head {
  display: flex; align-items: baseline; justify-content: space-between;
  margin-bottom: .25rem;
}
.gallery-card-name { font-size: 1rem; font-weight: 600; }
.gallery-card-mode {
  font-size: .7rem; font-weight: 600;
  letter-spacing: .04em; text-transform: uppercase;
  padding: .12rem .45rem;
  border-radius: 999px;
  background: var(--bg-soft); color: var(--fg-mute);
}
.gallery-card-desc {
  font-size: .82rem; color: var(--fg-mute);
  line-height: 1.5; margin: .2rem 0 .7rem;
  display: -webkit-box;
  -webkit-line-clamp: 3;
  -webkit-box-orient: vertical;
  overflow: hidden;
  min-height: 3.7em;
}
.gallery-card-actions { display: flex; gap: .4rem; flex-wrap: wrap; }
.site-toolbar {
  display: flex; gap: .6rem; align-items: center; flex-wrap: wrap;
  margin: 1rem 0;
  padding: .8rem 1rem;
  background: var(--bg-elev);
  border: 1px solid var(--border-soft);
  border-radius: var(--radius);
}
.gallery-search {
  flex: 1; min-width: 180px;
  padding: .5rem .8rem;
  border-radius: 999px;
  border: 1px solid var(--border);
  background: var(--bg);
  color: var(--fg);
  font: inherit;
}
.gallery-search:focus {
  outline: 2px solid var(--accent);
  outline-offset: 1px;
}
.site-segmented {
  display: flex; gap: .35rem;
}
.site-segment {
  padding: .35rem .8rem;
  font-size: .82rem;
  border-radius: 999px;
  border: 1px solid var(--border);
  background: var(--bg);
  color: var(--fg-soft);
  cursor: pointer;
  font: inherit; font-size: .82rem;
}
.site-segment.is-active {
  background: var(--accent);
  color: var(--accent-fg);
  border-color: var(--accent);
}
.gallery-meta {
  font-size: .78rem; color: var(--fg-mute);
}

/* small entrance animation */
.main, .home, .sidebar { animation: fadein var(--t-slow) var(--ease) both; }
.cards .card { animation: fadeup var(--t-mid) var(--ease) both; animation-delay: calc(var(--i, 0) * 40ms); }
@keyframes fadein {
  from { opacity: 0; }
  to   { opacity: 1; }
}
@keyframes fadeup {
  from { opacity: 0; transform: translateY(6px); }
  to   { opacity: 1; transform: translateY(0); }
}

/* —— Editorial Monocle 默认覆盖 (覆盖原工程蓝 token) —— */
:root:not([data-theme]) {
  --bg:           #faf6f0;
  --bg-elev:      #ffffff;
  --bg-soft:      #f1ece4;
  --fg:           #1a1a1a;
  --fg-soft:      #3a3a3a;
  --fg-mute:      #6b6862;
  --fg-faint:     #9c9892;
  --accent:       #c4452d;
  --accent-soft:  #f5dcd2;
  --accent-fg:    #ffffff;
  --border:       rgba(0, 0, 0, 0.12);
  --border-soft:  rgba(0, 0, 0, 0.06);
  --code-bg:      #f1ece4;
  --code-fg:      #2b2b30;
  --quote-bg:     #f5ede0;
  --quote-bd:     #c4452d;
  --table-stripe: #f5ede0;
  --font-serif:   "Source Serif Pro", "Source Serif 4", "Noto Serif SC", Georgia, "Songti SC", serif;
  --font-sans:    Inter, "PingFang SC", -apple-system, BlinkMacSystemFont, "Segoe UI", "Hiragino Sans GB", "Helvetica Neue", Arial, sans-serif;
  --font-mono:    "JetBrains Mono", ui-monospace, SFMono-Regular, "SF Mono", Menlo, Consolas, monospace;
}

/* Monocle dark：系统暗色时盖回深色 token，与 line 84 dark 调色板对齐 */
@media (prefers-color-scheme: dark) {
  :root:not([data-theme]) {
    --bg:           #14161a;
    --bg-elev:      #1c1f24;
    --bg-soft:      #23262c;
    --fg:           #e7e7ea;
    --fg-soft:      #c8c8cc;
    --fg-mute:      #9c9ca1;
    --fg-faint:     #6c6c72;
    --accent:       #ff6b4a;
    --accent-soft:  #3d2018;
    --accent-fg:    #0d1117;
    --border:       rgba(255, 255, 255, 0.12);
    --border-soft:  rgba(255, 255, 255, 0.06);
    --code-bg:      #1a1c20;
    --code-fg:      #e0e0e3;
    --quote-bg:     #20221c;
    --quote-bd:     #ff6b4a;
    --table-stripe: #1a1c20;
  }
}

/* light theme 显式时也走 Monocle */
:root[data-theme="light"] {
  --bg:           #faf6f0;
  --bg-elev:      #ffffff;
  --bg-soft:      #f1ece4;
  --fg:           #1a1a1a;
  --fg-soft:      #3a3a3a;
  --fg-mute:      #6b6862;
  --fg-faint:     #9c9892;
  --accent:       #c4452d;
  --accent-soft:  #f5dcd2;
  --accent-fg:    #ffffff;
  --border:       rgba(0, 0, 0, 0.12);
  --border-soft:  rgba(0, 0, 0, 0.06);
  --code-bg:      #f1ece4;
  --quote-bg:     #f5ede0;
  --quote-bd:     #c4452d;
  --table-stripe: #f5ede0;
}

body {
  font-family: var(--font-serif, "Noto Serif SC", Georgia, serif);
}
h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-serif, "Noto Serif SC", Georgia, serif);
  letter-spacing: -0.01em;
}
code, pre, kbd, samp {
  font-family: var(--font-mono, Menlo, monospace);
}

/* 旧 .return-to-hub 已删除：jx 标准用 .jx-return-to-hub（在 jx 层定义），唯一返回入口 */