/* ================================================================
   CaseForge SDK Documentation — Core Stylesheet
   Light + Dark mode via CSS custom properties
   Responsive: sidebar collapses on mobile
   ================================================================ */

/* ── Reset ── */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { font-size: 16px; scroll-behavior: smooth; }

/* ── Light mode tokens (default) ── */
:root {
  color-scheme: light;
  --bg:            #f6f7fc;
  --surface:       #ffffff;
  --surface-alt:   #eef0f8;
  --surface-hover: #e4e7f5;
  --border:        #d6daea;
  --border-mid:    #b8bdd4;
  --text:          #111827;
  --text-sec:      #4b5563;
  --text-muted:    #8890aa;
  --link:          #4f46e5;
  --link-hover:    #3730a3;
  --primary:       #4f46e5;
  --primary-bg:    #eef2ff;
  --primary-light: #818cf8;
  --success:       #059669;
  --success-bg:    #ecfdf5;
  --success-border:#6ee7b7;
  --warning:       #d97706;
  --warning-bg:    #fffbeb;
  --warning-border:#fde68a;
  --danger:        #dc2626;
  --danger-bg:     #fef2f2;
  --danger-border: #fca5a5;
  --tip:           #7c3aed;
  --tip-bg:        #f5f3ff;
  --tip-border:    #c4b5fd;
  --code-bg:       #1a1b2e;
  --code-surface:  #20223a;
  --code-text:     #cdd6f4;
  --code-comment:  #6272a4;
  --code-keyword:  #bd93f9;
  --code-string:   #50fa7b;
  --code-number:   #ffb86c;
  --code-type:     #8be9fd;
  --code-builtin:  #ff79c6;
  --code-attr:     #f1fa8c;
  --inline-code-bg:#eef0f8;
  --inline-code-fg:#be185d;
  --badge-new-bg:  #dcfce7;  --badge-new-fg:  #14532d;
  --badge-break-bg:#fee2e2;  --badge-break-fg:#7f1d1d;
  --badge-fix-bg:  #dbeafe;  --badge-fix-fg:  #1e3a8a;
  --badge-dep-bg:  #fef9c3;  --badge-dep-fg:  #713f12;
  --badge-note-bg: #f5f3ff;  --badge-note-fg: #4c1d95;
  --nav-w:         258px;
  --header-h:      56px;
  --shadow-sm:     0 1px 4px rgba(0,0,0,.07);
  --shadow-md:     0 4px 16px rgba(0,0,0,.09);
  --transition:    0.2s ease;
}

/* ── Dark mode tokens ── */
[data-theme="dark"] {
  color-scheme: dark;
  --bg:            #0b0c1a;
  --surface:       #111224;
  --surface-alt:   #181930;
  --surface-hover: #1f2138;
  --border:        #262844;
  --border-mid:    #363a5e;
  --text:          #e2e4f4;
  --text-sec:      #9aa2c2;
  --text-muted:    #555d80;
  --link:          #818cf8;
  --link-hover:    #a5b4fc;
  --primary:       #818cf8;
  --primary-bg:    #181a38;
  --primary-light: #a5b4fc;
  --success:       #34d399;
  --success-bg:    #052014;
  --success-border:#065f40;
  --warning:       #fbbf24;
  --warning-bg:    #160f00;
  --warning-border:#78450c;
  --danger:        #f87171;
  --danger-bg:     #180606;
  --danger-border: #7f2020;
  --tip:           #a78bfa;
  --tip-bg:        #120e2a;
  --tip-border:    #4c3570;
  --code-bg:       #111224;
  --code-surface:  #181930;
  --code-text:     #cdd6f4;
  --code-comment:  #6272a4;
  --code-keyword:  #bd93f9;
  --code-string:   #50fa7b;
  --code-number:   #ffb86c;
  --code-type:     #8be9fd;
  --code-builtin:  #ff79c6;
  --code-attr:     #f1fa8c;
  --inline-code-bg:#1f2138;
  --inline-code-fg:#f472b6;
  --badge-new-bg:  #052815;  --badge-new-fg:  #6ee7b7;
  --badge-break-bg:#2a0808;  --badge-break-fg:#fca5a5;
  --badge-fix-bg:  #071428;  --badge-fix-fg:  #93c5fd;
  --badge-dep-bg:  #1c1200;  --badge-dep-fg:  #fde68a;
  --badge-note-bg: #13082e;  --badge-note-fg: #c4b5fd;
  --shadow-sm:     0 1px 4px rgba(0,0,0,.3);
  --shadow-md:     0 4px 16px rgba(0,0,0,.4);
}

/* System preference dark (when no manual override) */
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    color-scheme: dark;
    --bg:            #0b0c1a;
    --surface:       #111224;
    --surface-alt:   #181930;
    --surface-hover: #1f2138;
    --border:        #262844;
    --border-mid:    #363a5e;
    --text:          #e2e4f4;
    --text-sec:      #9aa2c2;
    --text-muted:    #555d80;
    --link:          #818cf8;
    --link-hover:    #a5b4fc;
    --primary:       #818cf8;
    --primary-bg:    #181a38;
    --primary-light: #a5b4fc;
    --success:       #34d399;
    --success-bg:    #052014;
    --success-border:#065f40;
    --warning:       #fbbf24;
    --warning-bg:    #160f00;
    --warning-border:#78450c;
    --danger:        #f87171;
    --danger-bg:     #180606;
    --danger-border: #7f2020;
    --tip:           #a78bfa;
    --tip-bg:        #120e2a;
    --tip-border:    #4c3570;
    --code-bg:       #111224;
    --code-surface:  #181930;
    --code-text:     #cdd6f4;
    --inline-code-bg:#1f2138;
    --inline-code-fg:#f472b6;
    --badge-new-bg:  #052815;  --badge-new-fg:  #6ee7b7;
    --badge-break-bg:#2a0808;  --badge-break-fg:#fca5a5;
    --badge-fix-bg:  #071428;  --badge-fix-fg:  #93c5fd;
    --badge-dep-bg:  #1c1200;  --badge-dep-fg:  #fde68a;
    --badge-note-bg: #13082e;  --badge-note-fg: #c4b5fd;
    --shadow-sm:     0 1px 4px rgba(0,0,0,.3);
    --shadow-md:     0 4px 16px rgba(0,0,0,.4);
  }
}

/* ── Base ── */
body {
  font-family: 'Inter', 'Segoe UI', system-ui, -apple-system, sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.7;
  transition: background var(--transition), color var(--transition);
  min-height: 100vh;
}

/* ── Header ── */
.site-header {
  position: fixed; top: 0; left: 0; right: 0;
  height: var(--header-h);
  background: var(--surface);
  border-bottom: 1px solid var(--border);
  display: flex; align-items: center;
  padding: 0 1.25rem;
  gap: 1rem;
  z-index: 200;
  box-shadow: var(--shadow-sm);
  transition: background var(--transition), border-color var(--transition);
}
.hamburger {
  display: none;
  background: none; border: none; cursor: pointer;
  color: var(--text-sec); padding: 4px 8px; border-radius: 6px;
  font-size: 1.2rem; line-height: 1;
}
.hamburger:hover { background: var(--surface-alt); }

.site-logo {
  font-size: 0.95rem; font-weight: 700; color: var(--text);
  text-decoration: none; display: flex; align-items: center; gap: 8px;
  letter-spacing: -0.01em; white-space: nowrap;
}
.site-logo .logo-mark {
  width: 28px; height: 28px; border-radius: 7px;
  background: linear-gradient(135deg, var(--primary) 0%, #7c3aed 100%);
  display: flex; align-items: center; justify-content: center;
  color: #fff; font-size: 0.75rem; font-weight: 800; letter-spacing: 0;
  flex-shrink: 0;
}
.site-logo .logo-name { color: var(--text); }
.site-logo .logo-sdk  { color: var(--primary); }

.header-version {
  font-size: 0.7rem; font-weight: 600; letter-spacing: 0.06em;
  text-transform: uppercase; background: var(--primary-bg);
  color: var(--primary); padding: 0.15rem 0.55rem; border-radius: 4px;
  flex-shrink: 0;
}
.header-spacer { flex: 1; }

.header-links { display: flex; align-items: center; gap: 0.25rem; }
.header-links a {
  font-size: 0.82rem; color: var(--text-sec); text-decoration: none;
  padding: 0.3rem 0.65rem; border-radius: 6px;
  transition: background var(--transition), color var(--transition);
}
.header-links a:hover { background: var(--surface-alt); color: var(--text); }
.header-links a.active { color: var(--primary); }

.header-sep { width: 1px; height: 20px; background: var(--border); margin: 0 0.25rem; }

.github-btn {
  display: flex; align-items: center; gap: 6px;
  font-size: 0.82rem; font-weight: 500;
  color: var(--text-sec); text-decoration: none;
  padding: 0.3rem 0.65rem; border-radius: 6px;
  border: 1px solid var(--border);
  transition: all var(--transition);
}
.github-btn:hover { border-color: var(--border-mid); color: var(--text); background: var(--surface-alt); }
.github-btn svg { width: 16px; height: 16px; flex-shrink: 0; }

/* Theme toggle */
.theme-toggle {
  background: none; border: 1px solid var(--border); cursor: pointer;
  width: 36px; height: 36px; border-radius: 8px;
  display: flex; align-items: center; justify-content: center;
  color: var(--text-sec); flex-shrink: 0;
  transition: all var(--transition);
}
.theme-toggle:hover { background: var(--surface-alt); border-color: var(--border-mid); color: var(--text); }
.theme-toggle svg { width: 18px; height: 18px; }

/* ── Layout ── */
.layout {
  display: flex;
  margin-top: var(--header-h);
  min-height: calc(100vh - var(--header-h));
}

/* ── Sidebar ── */
.sidebar {
  width: var(--nav-w);
  min-width: var(--nav-w);
  background: var(--surface);
  border-right: 1px solid var(--border);
  position: fixed;
  top: var(--header-h);
  left: 0;
  bottom: 0;
  overflow-y: auto;
  padding: 1.5rem 0 2rem;
  z-index: 100;
  transition: background var(--transition), border-color var(--transition), transform 0.3s ease;
  scrollbar-width: thin;
  scrollbar-color: var(--border) transparent;
}
.sidebar::-webkit-scrollbar { width: 4px; }
.sidebar::-webkit-scrollbar-track { background: transparent; }
.sidebar::-webkit-scrollbar-thumb { background: var(--border); border-radius: 4px; }

.nav-group { margin-bottom: 0.5rem; }
.nav-group-label {
  padding: 0.2rem 1.1rem 0.45rem;
  font-size: 0.68rem; font-weight: 700; letter-spacing: 0.1em;
  text-transform: uppercase; color: var(--text-muted);
  margin-top: 1.25rem;
}
.nav-group:first-child .nav-group-label { margin-top: 0; }
.nav-item {
  display: block; padding: 0.38rem 1.1rem 0.38rem 1.35rem;
  font-size: 0.84rem; color: var(--text-sec); text-decoration: none;
  border-left: 2px solid transparent;
  transition: all 0.15s;
  line-height: 1.4;
}
.nav-item:hover { color: var(--text); background: var(--surface-hover); border-left-color: var(--border-mid); }
.nav-item.active { color: var(--primary); background: var(--primary-bg); border-left-color: var(--primary); font-weight: 600; }
.nav-item.sub { padding-left: 2rem; font-size: 0.8rem; }

/* ── Main ── */
.main {
  flex: 1;
  margin-left: var(--nav-w);
  padding: 2.5rem 3rem 5rem;
  max-width: calc(var(--nav-w) + 820px);
  min-width: 0;
}

/* ── Breadcrumb ── */
.breadcrumb {
  display: flex; align-items: center; gap: 0.4rem;
  font-size: 0.78rem; color: var(--text-muted);
  margin-bottom: 1.5rem;
}
.breadcrumb a { color: var(--text-muted); text-decoration: none; }
.breadcrumb a:hover { color: var(--link); }
.breadcrumb .sep { opacity: 0.5; }
.breadcrumb .current { color: var(--text-sec); }

/* ── Page header ── */
.page-header { margin-bottom: 2rem; padding-bottom: 1.5rem; border-bottom: 1px solid var(--border); }
.page-eyebrow {
  font-size: 0.72rem; font-weight: 700; letter-spacing: 0.1em;
  text-transform: uppercase; color: var(--primary); margin-bottom: 0.5rem;
}
h1.page-title {
  font-size: 2rem; font-weight: 800; line-height: 1.2;
  letter-spacing: -0.02em; color: var(--text); margin-bottom: 0.75rem;
}
.page-desc { font-size: 1.05rem; color: var(--text-sec); line-height: 1.6; max-width: 640px; }
.page-meta {
  display: flex; flex-wrap: wrap; gap: 1rem; margin-top: 1rem;
  font-size: 0.78rem; color: var(--text-muted);
}

/* ── Typography ── */
h2 {
  font-size: 1.35rem; font-weight: 700; color: var(--text);
  margin: 2.5rem 0 0.75rem; letter-spacing: -0.01em;
  padding-bottom: 0.4rem; border-bottom: 1px solid var(--border);
}
h3 {
  font-size: 1.08rem; font-weight: 600; color: var(--text);
  margin: 2rem 0 0.6rem;
}
h4 {
  font-size: 0.92rem; font-weight: 600; color: var(--text-sec);
  margin: 1.5rem 0 0.4rem; text-transform: uppercase;
  letter-spacing: 0.05em;
}
p { font-size: 0.92rem; margin-bottom: 1rem; color: var(--text-sec); }
ul, ol { margin-bottom: 1rem; padding-left: 1.5rem; }
li { font-size: 0.92rem; margin-bottom: 0.3rem; color: var(--text-sec); }
a { color: var(--link); text-decoration: none; }
a:hover { text-decoration: underline; color: var(--link-hover); }
strong { color: var(--text); font-weight: 600; }

/* ── Inline code ── */
code {
  font-family: 'Consolas', 'Fira Code', 'Courier New', monospace;
  font-size: 0.83em; background: var(--inline-code-bg);
  color: var(--inline-code-fg); padding: 0.15em 0.45em;
  border-radius: 4px; transition: background var(--transition);
}

/* ── Code blocks ── */
.code-block {
  background: var(--code-bg);
  border-radius: 10px; overflow: hidden;
  margin: 1.25rem 0;
  box-shadow: var(--shadow-sm);
  border: 1px solid var(--border);
  transition: border-color var(--transition);
}
.code-header {
  display: flex; align-items: center; justify-content: space-between;
  padding: 0.55rem 1rem;
  background: var(--code-surface);
  border-bottom: 1px solid rgba(255,255,255,0.06);
}
.code-lang {
  font-size: 0.72rem; font-weight: 600; letter-spacing: 0.07em;
  text-transform: uppercase; color: var(--code-comment);
}
.code-copy {
  background: none; border: 1px solid rgba(255,255,255,0.1);
  color: var(--code-comment); cursor: pointer; border-radius: 5px;
  padding: 0.2rem 0.6rem; font-size: 0.72rem; transition: all 0.15s;
  font-family: inherit;
}
.code-copy:hover { border-color: rgba(255,255,255,0.3); color: var(--code-text); }
.code-copy.copied { color: var(--code-string); border-color: var(--code-string); }
pre {
  margin: 0; padding: 1.1rem 1.25rem;
  font-family: 'Consolas', 'Fira Code', 'Courier New', monospace;
  font-size: 0.84rem; line-height: 1.65;
  color: var(--code-text); overflow-x: auto;
  tab-size: 2;
}
pre code { background: none; color: inherit; padding: 0; border-radius: 0; font-size: inherit; }

/* Syntax token classes */
.kw  { color: var(--code-keyword); }
.str { color: var(--code-string);  }
.num { color: var(--code-number);  }
.cm  { color: var(--code-comment); font-style: italic; }
.tp  { color: var(--code-type);    }
.fn  { color: var(--code-builtin); }
.at  { color: var(--code-attr);    }

/* ── Code tabs ── */
.code-tabs { margin: 1.25rem 0; }
.tab-bar {
  display: flex; gap: 0; border-bottom: 1px solid var(--border);
  margin-bottom: 0;
}
.tab-btn {
  background: none; border: none; cursor: pointer;
  padding: 0.55rem 1rem; font-size: 0.82rem; font-weight: 500;
  color: var(--text-muted); border-bottom: 2px solid transparent;
  margin-bottom: -1px; transition: all 0.15s; font-family: inherit;
}
.tab-btn:hover { color: var(--text-sec); }
.tab-btn.active { color: var(--primary); border-bottom-color: var(--primary); }
.tab-panel { display: none; }
.tab-panel.active { display: block; }
.tab-panel .code-block { border-radius: 0 0 10px 10px; margin-top: 0; border-top: none; }

/* ── Admonitions ── */
.admonition {
  padding: 0.9rem 1rem 0.9rem 1.1rem;
  border-radius: 8px; margin: 1.5rem 0;
  border-left: 3px solid; font-size: 0.88rem; line-height: 1.6;
  transition: background var(--transition);
}
.admonition-title {
  font-size: 0.72rem; font-weight: 700; letter-spacing: 0.08em;
  text-transform: uppercase; margin-bottom: 0.35rem;
  display: flex; align-items: center; gap: 0.4rem;
}
.admonition p { font-size: 0.88rem; margin-bottom: 0; }
.admonition code { font-size: 0.82em; }

.admonition.note     { background: var(--primary-bg); border-color: var(--primary); }
.admonition.note .admonition-title { color: var(--primary); }
.admonition.warning  { background: var(--warning-bg); border-color: var(--warning); }
.admonition.warning .admonition-title { color: var(--warning); }
.admonition.danger   { background: var(--danger-bg); border-color: var(--danger); }
.admonition.danger .admonition-title  { color: var(--danger); }
.admonition.tip      { background: var(--tip-bg); border-color: var(--tip); }
.admonition.tip .admonition-title     { color: var(--tip); }
.admonition.success  { background: var(--success-bg); border-color: var(--success); }
.admonition.success .admonition-title { color: var(--success); }

/* ── Tables ── */
.table-wrap {
  overflow-x: auto; margin: 1.25rem 0;
  border-radius: 8px; border: 1px solid var(--border);
}
table { width: 100%; border-collapse: collapse; font-size: 0.87rem; }
thead tr { background: var(--surface-alt); }
thead th {
  padding: 0.65rem 1rem; text-align: left;
  font-size: 0.75rem; font-weight: 700; letter-spacing: 0.05em;
  text-transform: uppercase; color: var(--text-muted);
  border-bottom: 1px solid var(--border);
}
tbody tr { border-bottom: 1px solid var(--border); transition: background 0.1s; }
tbody tr:last-child { border-bottom: none; }
tbody tr:hover { background: var(--surface-hover); }
tbody td { padding: 0.65rem 1rem; vertical-align: top; color: var(--text-sec); }
tbody td:first-child { font-weight: 500; color: var(--text); }

/* ── Step list ── */
.steps { list-style: none; padding: 0; counter-reset: steps; }
.steps li {
  counter-increment: steps; position: relative;
  padding: 1rem 1rem 1rem 3.5rem;
  margin-bottom: 0.75rem;
  background: var(--surface);
  border: 1px solid var(--border); border-radius: 8px;
  font-size: 0.9rem; color: var(--text-sec);
  transition: background var(--transition), border-color var(--transition);
}
.steps li::before {
  content: counter(steps);
  position: absolute; left: 1rem; top: 1rem;
  width: 1.75rem; height: 1.75rem;
  background: var(--primary); color: #fff;
  border-radius: 50%; font-size: 0.78rem; font-weight: 700;
  display: flex; align-items: center; justify-content: center;
}
.steps li p { margin: 0; }
.steps li code { font-size: 0.82em; }

/* ── Badges ── */
.badge {
  display: inline-block; padding: 0.2rem 0.55rem;
  border-radius: 4px; font-size: 0.7rem; font-weight: 700;
  letter-spacing: 0.05em; text-transform: uppercase; vertical-align: middle;
}
.badge-new    { background: var(--badge-new-bg);   color: var(--badge-new-fg); }
.badge-break  { background: var(--badge-break-bg); color: var(--badge-break-fg); }
.badge-fix    { background: var(--badge-fix-bg);   color: var(--badge-fix-fg); }
.badge-dep    { background: var(--badge-dep-bg);   color: var(--badge-dep-fg); }
.badge-note   { background: var(--badge-note-bg);  color: var(--badge-note-fg); }
.badge-blue   { background: var(--primary-bg);     color: var(--primary); }
.badge-green  { background: var(--success-bg);     color: var(--success); }
.badge-red    { background: var(--danger-bg);      color: var(--danger); }

/* ── Hero cards (index page) ── */
.hero {
  background: linear-gradient(135deg, var(--primary-bg) 0%, var(--surface) 60%);
  border: 1px solid var(--border); border-radius: 12px;
  padding: 2.5rem 2rem; margin-bottom: 2.5rem;
}
.hero h1 {
  font-size: 2.2rem; font-weight: 800; letter-spacing: -0.025em;
  color: var(--text); margin-bottom: 0.75rem; line-height: 1.15;
}
.hero p { font-size: 1.05rem; color: var(--text-sec); max-width: 600px; margin-bottom: 1.5rem; }
.hero-actions { display: flex; gap: 0.75rem; flex-wrap: wrap; }
.btn {
  display: inline-flex; align-items: center; gap: 0.4rem;
  padding: 0.6rem 1.25rem; border-radius: 7px; font-size: 0.88rem;
  font-weight: 600; text-decoration: none; border: none; cursor: pointer;
  transition: all 0.15s; font-family: inherit;
}
.btn-primary { background: var(--primary); color: #fff; }
.btn-primary:hover { opacity: 0.88; text-decoration: none; }
.btn-outline {
  background: transparent; color: var(--text-sec);
  border: 1px solid var(--border);
}
.btn-outline:hover { background: var(--surface-alt); border-color: var(--border-mid); color: var(--text); text-decoration: none; }

/* ── Quick links grid ── */
.card-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(220px, 1fr));
  gap: 1rem; margin: 1.5rem 0;
}
.card {
  background: var(--surface); border: 1px solid var(--border);
  border-radius: 10px; padding: 1.25rem;
  text-decoration: none; display: block;
  transition: all 0.15s;
}
.card:hover {
  border-color: var(--primary); box-shadow: 0 0 0 3px var(--primary-bg);
  text-decoration: none; transform: translateY(-1px);
}
.card-icon { font-size: 1.5rem; margin-bottom: 0.6rem; }
.card-title { font-size: 0.92rem; font-weight: 600; color: var(--text); margin-bottom: 0.3rem; }
.card-desc  { font-size: 0.8rem; color: var(--text-muted); line-height: 1.5; }

/* ── Install tabs ── */
.install-block {
  background: var(--code-bg); border-radius: 10px;
  border: 1px solid var(--border); overflow: hidden; margin: 1rem 0;
}
.install-tab-bar {
  display: flex; background: var(--code-surface);
  border-bottom: 1px solid rgba(255,255,255,0.06);
}
.install-tab {
  padding: 0.5rem 1rem; font-size: 0.78rem; font-weight: 600;
  color: var(--code-comment); cursor: pointer; border: none;
  background: none; border-bottom: 2px solid transparent;
  font-family: inherit; transition: all 0.15s;
}
.install-tab.active { color: var(--code-text); border-bottom-color: var(--primary); }
.install-tab:hover  { color: var(--code-text); }
.install-panel { display: none; }
.install-panel.active { display: block; }
.install-panel pre { padding: 0.85rem 1.25rem; }

/* ── Error code blocks ── */
.error-entry {
  border: 1px solid var(--border); border-radius: 8px;
  margin-bottom: 0.75rem; overflow: hidden;
  transition: border-color var(--transition);
}
.error-header {
  display: flex; align-items: center; gap: 0.75rem;
  padding: 0.75rem 1rem; background: var(--surface-alt);
  border-bottom: 1px solid var(--border);
}
.error-code {
  font-family: 'Consolas', monospace; font-size: 0.82rem;
  font-weight: 700; color: var(--danger); background: var(--danger-bg);
  padding: 0.15rem 0.5rem; border-radius: 4px; flex-shrink: 0;
}
.error-name { font-size: 0.88rem; font-weight: 600; color: var(--text); }
.error-body { padding: 0.75rem 1rem; font-size: 0.87rem; color: var(--text-sec); }
.error-body p { margin-bottom: 0.5rem; }
.error-body p:last-child { margin-bottom: 0; }

/* ── Changelog entries ── */
.release { margin-bottom: 2.5rem; }
.release-header {
  display: flex; align-items: center; gap: 0.75rem;
  margin-bottom: 1rem; padding-bottom: 0.75rem;
  border-bottom: 1px solid var(--border);
}
.release-version {
  font-size: 1.2rem; font-weight: 700; color: var(--text);
  font-family: 'Consolas', monospace;
}
.release-date { font-size: 0.82rem; color: var(--text-muted); }
.release-body { padding: 0; }
.change-list { list-style: none; padding: 0; }
.change-list li {
  display: flex; align-items: flex-start; gap: 0.6rem;
  padding: 0.4rem 0; font-size: 0.88rem; color: var(--text-sec);
  border-bottom: 1px solid var(--border);
}
.change-list li:last-child { border-bottom: none; }

/* ── Migration diff ── */
.diff-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 0.75rem; margin: 1rem 0; }
.diff-panel { font-size: 0.78rem; }
.diff-label {
  font-size: 0.7rem; font-weight: 700; letter-spacing: 0.07em;
  text-transform: uppercase; padding: 0.4rem 0.75rem;
  border-radius: 5px 5px 0 0;
}
.diff-label.before { background: var(--danger-bg); color: var(--danger); }
.diff-label.after  { background: var(--success-bg); color: var(--success); }
.diff-panel .code-block { margin-top: 0; border-radius: 0 0 8px 8px; }

/* ── Doc nav ── */
.doc-nav {
  display: flex; justify-content: space-between;
  margin-top: 3rem; padding-top: 1.5rem; border-top: 1px solid var(--border);
}
.doc-nav-item {
  display: flex; flex-direction: column; gap: 0.2rem;
  text-decoration: none; padding: 0.75rem 1rem;
  border: 1px solid var(--border); border-radius: 8px;
  transition: all 0.15s; max-width: 240px;
}
.doc-nav-item:hover { border-color: var(--primary); background: var(--primary-bg); text-decoration: none; }
.doc-nav-dir { font-size: 0.7rem; color: var(--text-muted); text-transform: uppercase; letter-spacing: 0.06em; }
.doc-nav-label { font-size: 0.88rem; font-weight: 600; color: var(--text); }
.doc-nav-item.next { text-align: right; }

/* ── Footer ── */
footer {
  margin-top: 4rem; padding-top: 2rem;
  border-top: 1px solid var(--border);
  font-size: 0.8rem; color: var(--text-muted);
  display: flex; flex-wrap: wrap; justify-content: space-between; gap: 0.5rem;
}
footer .copyright {
  width: 100%;
  padding-top: 0.25rem;
  font-style: italic;
  color: var(--text-muted);
}

/* ── Responsive ── */
@media (max-width: 900px) {
  .main { padding: 1.75rem 1.5rem 4rem; }
  .diff-grid { grid-template-columns: 1fr; }
}
@media (max-width: 768px) {
  .hamburger { display: flex; }
  .header-links { display: none; }
  .sidebar {
    transform: translateX(-100%);
    box-shadow: var(--shadow-md);
  }
  .sidebar.open { transform: translateX(0); }
  .main { margin-left: 0; padding: 1.5rem 1.25rem 4rem; }
  h1.page-title { font-size: 1.6rem; }
  .hero h1 { font-size: 1.7rem; }
  .card-grid { grid-template-columns: 1fr; }
}
@media (max-width: 480px) {
  .doc-nav { flex-direction: column; }
  .doc-nav-item.next { text-align: left; }
}

/* ── Scrollbar (webkit) ── */
::-webkit-scrollbar { width: 6px; height: 6px; }
::-webkit-scrollbar-track { background: transparent; }
::-webkit-scrollbar-thumb { background: var(--border); border-radius: 4px; }
::-webkit-scrollbar-thumb:hover { background: var(--border-mid); }

/* ── Selection ── */
::selection { background: var(--primary-bg); color: var(--primary); }