/* ==========================================================================
   Fortnite Replay Suite — User Guide · Redesign
   Themes: void (default) | terminal | copper
   Modes:  dark (default) | light
   ========================================================================== */

/* ---------- Google Fonts ---------- */
@import url('https://fonts.googleapis.com/css2?family=Inter:wght@300;400;500;600;700;800&family=JetBrains+Mono:ital,wght@0,400;0,500;0,700;1,400&family=Space+Grotesk:wght@400;500;600;700;800&display=swap');

/* ==========================================================================
   THEME TOKENS
   ========================================================================== */

/* ── Void (dark) ── */
:root,
[data-theme="void"][data-mode="dark"] {
  --bg:          #05090f;
  --bg-subtle:   #090e18;
  --surface:     #0d1420;
  --surface-2:   #131d2e;
  --surface-3:   #192540;
  --border:      #1a2638;
  --border-2:    #243650;
  --fg:          #dce8f4;
  --fg-2:        #a0b8d0;
  --muted:       #5a7a9a;
  --accent:      #3bbdf2;
  --accent-2:    #1a7ed4;
  --accent-weak: rgba(59,189,242,.12);
  --accent-glow: rgba(59,189,242,.30);
  --ok:          #3ecf8e;
  --warn:        #f0b429;
  --err:         #f87171;
  --font-ui:     'Inter', 'Noto Sans JP', ui-sans-serif, sans-serif;
  --font-display:'Space Grotesk', 'Inter', sans-serif;
  --font-mono:   'JetBrains Mono', ui-monospace, Consolas, monospace;
  --pre-bg:      #03040a;
  --pre-border:  #181e38;
  --header-bg:   rgba(6,8,15,.88);
  --radius:      10px;
  --radius-sm:   6px;
  --radius-lg:   16px;
  color-scheme: dark;
}

/* ── Void (light) ── */
[data-theme="void"][data-mode="light"] {
  --bg:          #f3f8fd;
  --bg-subtle:   #e8f2fb;
  --surface:     #ffffff;
  --surface-2:   #edf5fc;
  --surface-3:   #ddeef8;
  --border:      #c8dff0;
  --border-2:    #a8cce6;
  --fg:          #0d1e2e;
  --fg-2:        #2a4a6a;
  --muted:       #5a7a9a;
  --accent:      #1a8ed4;
  --accent-2:    #0e6aaa;
  --accent-weak: rgba(26,142,212,.1);
  --accent-glow: rgba(26,142,212,.22);
  --pre-bg:      #f0f7fd;
  --pre-border:  #c0d8ee;
  --header-bg:   rgba(243,248,253,.92);
  color-scheme: light;
}

/* ── Terminal (dark) ── */
[data-theme="terminal"][data-mode="dark"] {
  --bg:          #070b07;
  --bg-subtle:   #0b100b;
  --surface:     #0d120d;
  --surface-2:   #121812;
  --surface-3:   #182018;
  --border:      #1c281c;
  --border-2:    #243424;
  --fg:          #b8e0b4;
  --fg-2:        #89b884;
  --muted:       #4a6e46;
  --accent:      #4ade80;
  --accent-2:    #86efac;
  --accent-weak: rgba(74,222,128,.08);
  --accent-glow: rgba(74,222,128,.22);
  --ok:          #4ade80;
  --warn:        #fbbf24;
  --err:         #f87171;
  --font-ui:     'JetBrains Mono', ui-monospace, Consolas, monospace;
  --font-display:'JetBrains Mono', ui-monospace, Consolas, monospace;
  --font-mono:   'JetBrains Mono', ui-monospace, Consolas, monospace;
  --pre-bg:      #030503;
  --pre-border:  #162016;
  --header-bg:   rgba(7,11,7,.92);
  --radius:      4px;
  --radius-sm:   2px;
  --radius-lg:   6px;
  color-scheme: dark;
}

/* ── Terminal (light) ── */
[data-theme="terminal"][data-mode="light"] {
  --bg:          #f3faf3;
  --bg-subtle:   #e8f5e8;
  --surface:     #ffffff;
  --surface-2:   #edf7ed;
  --surface-3:   #dff0df;
  --border:      #c3dfc3;
  --border-2:    #a8cba8;
  --fg:          #0d1f0d;
  --fg-2:        #1a3d1a;
  --muted:       #4a7a4a;
  --accent:      #16a34a;
  --accent-2:    #15803d;
  --accent-weak: rgba(22,163,74,.1);
  --accent-glow: rgba(22,163,74,.2);
  --pre-bg:      #f0faf0;
  --pre-border:  #c8e6c8;
  --header-bg:   rgba(243,250,243,.92);
  color-scheme: light;
}

/* ── Copper (dark) ── */
[data-theme="copper"][data-mode="dark"] {
  --bg:          #0f0d0b;
  --bg-subtle:   #151210;
  --surface:     #1a1613;
  --surface-2:   #211c18;
  --surface-3:   #2b2420;
  --border:      #2e2720;
  --border-2:    #3d342b;
  --fg:          #f0e8df;
  --fg-2:        #c8b8a8;
  --muted:       #7a6858;
  --accent:      #e8895a;
  --accent-2:    #f0c060;
  --accent-weak: rgba(232,137,90,.1);
  --accent-glow: rgba(232,137,90,.25);
  --ok:          #5eead4;
  --warn:        #fbbf24;
  --err:         #f87171;
  --font-ui:     'Inter', 'Noto Sans JP', ui-sans-serif, sans-serif;
  --font-display:'Space Grotesk', 'Inter', sans-serif;
  --font-mono:   'JetBrains Mono', ui-monospace, Consolas, monospace;
  --pre-bg:      #090806;
  --pre-border:  #2a2018;
  --header-bg:   rgba(15,13,11,.9);
  --radius:      8px;
  --radius-sm:   4px;
  --radius-lg:   14px;
  color-scheme: dark;
}

/* ── Copper (light) ── */
[data-theme="copper"][data-mode="light"] {
  --bg:          #fdf9f6;
  --bg-subtle:   #f5ede4;
  --surface:     #ffffff;
  --surface-2:   #faf3ec;
  --surface-3:   #f2e6d8;
  --border:      #e4d0bc;
  --border-2:    #d4baa0;
  --fg:          #1c1410;
  --fg-2:        #3d2e22;
  --muted:       #7a6040;
  --accent:      #c2652a;
  --accent-2:    #b85a10;
  --accent-weak: rgba(194,101,42,.1);
  --accent-glow: rgba(194,101,42,.2);
  --pre-bg:      #fdf6ef;
  --pre-border:  #e4d0bc;
  --header-bg:   rgba(253,249,246,.9);
  color-scheme: light;
}

/* ==========================================================================
   RESET + BASE
   ========================================================================== */

*, *::before, *::after { box-sizing: border-box; }
html, body { margin: 0; padding: 0; }

body {
  font-family: var(--font-ui);
  background: var(--bg);
  color: var(--fg);
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
  transition: background .2s, color .2s;
}

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

code, pre, kbd { font-family: var(--font-mono); }

kbd {
  display: inline-block;
  padding: 1px 6px;
  border: 1px solid var(--border);
  border-bottom-width: 2px;
  border-radius: var(--radius-sm);
  background: var(--surface-2);
  font-size: .82em;
}

/* ==========================================================================
   PROGRESS BAR
   ========================================================================== */

#read-progress {
  position: fixed;
  top: 0; left: 0;
  height: 2px;
  width: 0%;
  background: linear-gradient(90deg, var(--accent), var(--accent-2));
  z-index: 200;
  transition: width .08s linear;
  box-shadow: 0 0 8px var(--accent-glow);
}

/* ==========================================================================
   HEADER
   ========================================================================== */

.page-header {
  position: sticky;
  top: 0;
  z-index: 100;
  height: 56px;
  background: var(--header-bg);
  backdrop-filter: blur(20px) saturate(1.6);
  -webkit-backdrop-filter: blur(20px) saturate(1.6);
  border-bottom: 1px solid var(--border);
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 28px;
  gap: 16px;
}

.brand {
  display: flex;
  align-items: center;
  gap: 12px;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 15px;
  color: var(--fg);
}
.brand a { display: flex; align-items: center; gap: 12px; color: inherit; }
.brand a:hover { text-decoration: none; }

.logo {
  width: 30px; height: 30px;
  border-radius: var(--radius-sm);
  background: linear-gradient(145deg, #5ecff5 0%, #1a7ed4 100%);
  display: grid; place-items: center;
  font-weight: 900; font-size: 13px;
  color: #fff;
  font-family: var(--font-display);
  flex-shrink: 0;
}
[data-theme="terminal"] .logo {
  background: transparent;
  border: 1px solid var(--accent);
  color: var(--accent);
  font-size: 12px;
}
[data-theme="copper"] .logo {
  border-radius: 3px;
}

.badge {
  display: inline-block;
  padding: 2px 8px;
  border-radius: 999px;
  font-size: 11px; font-weight: 600;
  border: 1px solid var(--border);
  background: var(--surface-2);
  color: var(--muted);
  font-family: var(--font-mono);
  vertical-align: middle;
}
[data-theme="terminal"] .badge { border-radius: var(--radius-sm); }

.badge-ok  { background: rgba(62,207,142,.1);  border-color: rgba(62,207,142,.35);  color: var(--ok);   }
.badge-warn{ background: rgba(240,180,41,.1);  border-color: rgba(240,180,41,.35);  color: var(--warn); }
.badge-err { background: rgba(248,113,113,.1); border-color: rgba(248,113,113,.35); color: var(--err);  }

.header-nav {
  display: flex; align-items: center; gap: 4px;
  font-size: 13px;
}
.header-nav a {
  color: var(--muted);
  padding: 5px 10px;
  border-radius: var(--radius-sm);
  transition: color .15s, background .15s;
}
.header-nav a:hover { color: var(--fg); background: var(--surface-2); text-decoration: none; }
.header-nav a.active { color: var(--fg); }

.theme-btn, .mode-btn {
  display: flex; align-items: center; gap: 6px;
  padding: 5px 10px;
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  background: var(--surface-2);
  color: var(--fg-2);
  font-size: 12px;
  cursor: pointer;
  font-family: var(--font-mono);
  transition: border-color .15s, color .15s;
}
.theme-btn:hover, .mode-btn:hover { border-color: var(--accent); color: var(--accent); }

/* ==========================================================================
   LAYOUT
   ========================================================================== */

.page {
  display: grid;
  grid-template-columns: 248px 1fr;
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 28px;
}

/* ==========================================================================
   SIDEBAR
   ========================================================================== */

.sidebar {
  position: sticky;
  top: 56px;
  align-self: start;
  height: calc(100vh - 56px);
  overflow-y: auto;
  padding: 28px 20px 28px 0;
  border-right: 1px solid var(--border);
  scrollbar-width: thin;
  scrollbar-color: var(--border) transparent;
}
.sidebar::-webkit-scrollbar { width: 3px; }
.sidebar::-webkit-scrollbar-thumb { background: var(--border); border-radius: 2px; }

.sidebar-section { margin-bottom: 24px; }

.sidebar-heading {
  font-size: 10px;
  text-transform: uppercase;
  letter-spacing: .1em;
  color: var(--muted);
  font-weight: 700;
  margin: 0 0 6px 12px;
  font-family: var(--font-mono);
}
[data-theme="void"] .sidebar-heading { font-family: var(--font-ui); }

.sidebar-list {
  list-style: none;
  padding: 0; margin: 0;
}
.sidebar-list li { margin: 1px 0; }

.sidebar-list a {
  display: flex;
  align-items: center;
  gap: 9px;
  padding: 6px 12px;
  border-radius: var(--radius-sm);
  color: var(--fg-2);
  font-size: 13px;
  transition: background .15s, color .15s, border-color .15s;
  border-left: 2px solid transparent;
  position: relative;
}
.sidebar-list a .sn {
  font-family: var(--font-mono);
  font-size: 10px;
  color: var(--muted);
  min-width: 20px;
  flex-shrink: 0;
  transition: color .15s;
}
.sidebar-list a:hover {
  background: var(--surface-2);
  color: var(--fg);
  text-decoration: none;
}
.sidebar-list a:hover .sn { color: var(--accent); }

[data-theme="terminal"] .sidebar-list a::before { content: ''; }

/* chapter links */
.sidebar-chapters a {
  display: flex; align-items: center; gap: 10px;
  padding: 7px 12px;
  border-radius: var(--radius-sm);
  color: var(--muted);
  font-size: 13px;
  border-left: 2px solid transparent;
  transition: background .15s, color .15s;
}
.sidebar-chapters a:hover {
  background: var(--surface-2);
  color: var(--fg);
  text-decoration: none;
}
.sidebar-chapters a .cn {
  font-family: var(--font-mono);
  font-size: 10px;
  background: var(--surface-2);
  border: 1px solid var(--border);
  padding: 1px 5px;
  border-radius: var(--radius-sm);
  color: var(--muted);
  min-width: 28px;
  text-align: center;
  flex-shrink: 0;
}

/* ==========================================================================
   CONTENT — SHARED
   ========================================================================== */

.content {
  padding: 44px 0 96px 44px;
  min-width: 0;
}

.content > section { margin-bottom: 52px; }

.content p { color: var(--fg); margin: 0 0 12px; }
.content ul, .content ol { padding-left: 1.5em; }
.content li { margin: 4px 0; color: var(--fg); }
.content strong { color: var(--fg); }

.lead {
  color: var(--fg-2);
  font-size: 16px;
  line-height: 1.65;
  max-width: 640px;
  margin: 0 0 28px;
}
[data-theme="terminal"] .lead { font-size: 13px; }

/* inline code */
.content :not(pre) > code {
  background: var(--surface-2);
  border: 1px solid var(--border);
  padding: 1px 6px;
  border-radius: var(--radius-sm);
  font-size: .86em;
  color: var(--accent);
}

/* ==========================================================================
   CODE BLOCKS
   ========================================================================== */

.code-wrap { margin: 14px 0; }

.code-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  background: var(--surface);
  border: 1px solid var(--border);
  border-bottom: none;
  border-radius: var(--radius) var(--radius) 0 0;
  padding: 6px 12px;
}
[data-theme="terminal"] .code-header {
  border-radius: var(--radius-sm) var(--radius-sm) 0 0;
  gap: 10px;
}
[data-theme="terminal"] .code-header::before {
  content: '● ● ●';
  font-size: 8px;
  color: var(--muted);
  letter-spacing: 3px;
}

.code-lang {
  font-family: var(--font-mono);
  font-size: 10px;
  color: var(--muted);
  text-transform: uppercase;
  letter-spacing: .08em;
}

.copy-btn {
  display: flex; align-items: center; gap: 5px;
  background: transparent;
  border: 1px solid var(--border);
  color: var(--muted);
  border-radius: var(--radius-sm);
  padding: 3px 8px;
  font-size: 11px;
  font-family: var(--font-mono);
  cursor: pointer;
  transition: border-color .15s, color .15s;
}
.copy-btn:hover { border-color: var(--accent); color: var(--accent); }
.copy-btn.copied { border-color: var(--ok); color: var(--ok); }

.content pre {
  background: var(--pre-bg);
  border: 1px solid var(--pre-border);
  border-top: none;
  border-radius: 0 0 var(--radius) var(--radius);
  padding: 16px 20px;
  overflow-x: auto;
  margin: 0;
}
[data-theme="terminal"] pre {
  border-radius: 0 0 var(--radius-sm) var(--radius-sm);
}
.content pre code {
  background: transparent;
  border: none; padding: 0;
  color: var(--fg);
  font-size: 13px;
  line-height: 1.65;
}
[data-theme="terminal"] pre code { color: var(--accent); font-size: 12.5px; }

/* ==========================================================================
   CALLOUTS
   ========================================================================== */

.callout {
  display: grid;
  grid-template-columns: 22px 1fr;
  gap: 0 12px;
  align-items: start;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 14px 16px;
  margin: 20px 0;
  background: var(--surface);
}
[data-theme="terminal"] .callout {
  border-radius: var(--radius-sm);
  display: block;
  padding: 10px 14px;
}
.callout-icon { font-size: 15px; line-height: 1.7; }
[data-theme="terminal"] .callout-icon { display: none; }
.callout-title {
  display: block;
  font-weight: 600;
  font-size: 13px;
  margin-bottom: 4px;
}
[data-theme="terminal"] .callout-title::before { content: '// '; color: var(--muted); }
.callout p { margin: 0; font-size: 14px; color: var(--fg-2); }

.callout-note  { border-left: 3px solid var(--accent); }
.callout-note  .callout-title { color: var(--accent); }
.callout-warn  { border-left: 3px solid var(--warn);  }
.callout-warn  .callout-title { color: var(--warn); }
.callout-ok    { border-left: 3px solid var(--ok);   }
.callout-ok    .callout-title { color: var(--ok); }

/* ==========================================================================
   TABLES
   ========================================================================== */

.content table {
  border-collapse: collapse;
  width: 100%;
  margin: 16px 0;
  font-size: 13.5px;
}
.content th, .content td {
  border: 1px solid var(--border);
  padding: 9px 14px;
  text-align: left;
  vertical-align: top;
}
.content th {
  background: var(--surface-2);
  font-weight: 600;
  font-size: 11px;
  text-transform: uppercase;
  letter-spacing: .05em;
  color: var(--muted);
}
[data-theme="terminal"] th { text-transform: none; letter-spacing: 0; font-size: 12px; }
.content tbody tr:hover td { background: var(--bg-subtle); }

/* ==========================================================================
   STEP LIST
   ========================================================================== */

.steps { list-style: none; padding: 0; margin: 16px 0; display: flex; flex-direction: column; gap: 10px; }

.steps > li {
  display: grid;
  grid-template-columns: 40px 1fr;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  overflow: hidden;
  transition: border-color .15s;
}
[data-theme="terminal"] .steps > li { border-radius: var(--radius-sm); }
.steps > li:hover { border-color: var(--accent); }

.step-num {
  display: grid; place-items: center;
  background: var(--surface-2);
  border-right: 1px solid var(--border);
  font-family: var(--font-mono);
  font-size: 13px; font-weight: 700;
  color: var(--accent);
  min-height: 48px;
}
[data-theme="terminal"] .step-num { font-size: 12px; }
[data-theme="terminal"] .step-num::after { content: '_'; animation: blink 1s step-end infinite; }
@keyframes blink { 0%,100% { opacity: 1; } 50% { opacity: 0; } }

.step-body { padding: 14px 16px 14px 0; }
.step-body > strong:first-child { display: block; font-size: 14px; font-weight: 600; margin-bottom: 8px; }
.step-body > p { margin: 6px 0 0; font-size: 13px; color: var(--fg-2); }

/* ==========================================================================
   FIGURES
   ========================================================================== */

.figure {
  margin: 20px 0;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  overflow: hidden;
  background: var(--surface);
}
[data-theme="terminal"] .figure { border-radius: var(--radius-sm); }
.figure img { display: block; width: 100%; height: auto; }
.figure figcaption {
  padding: 8px 16px;
  font-size: 12px;
  color: var(--muted);
  border-top: 1px solid var(--border);
  font-family: var(--font-mono);
}
[data-theme="terminal"] .figure figcaption::before { content: '# '; color: var(--accent); }
.figure-placeholder {
  aspect-ratio: 16/9;
  display: grid; place-items: center;
  background: repeating-linear-gradient(
    -45deg,
    var(--surface), var(--surface) 12px,
    var(--surface-2) 12px, var(--surface-2) 24px
  );
  color: var(--muted);
  font-size: 12px;
  font-family: var(--font-mono);
}

/* ==========================================================================
   PAGER
   ========================================================================== */

.pager {
  display: flex; gap: 12px;
  margin-top: 56px; padding-top: 24px;
  border-top: 1px solid var(--border);
}
.pager a {
  flex: 1;
  padding: 14px 18px;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  background: var(--surface);
  transition: border-color .15s, background .15s;
}
[data-theme="terminal"] .pager a { border-radius: var(--radius-sm); }
.pager a:hover { border-color: var(--accent); background: var(--accent-weak); text-decoration: none; }
.pager-label { display: block; font-size: 11px; color: var(--muted); text-transform: uppercase; letter-spacing: .08em; font-family: var(--font-mono); margin-bottom: 4px; }
.pager-title { display: block; font-weight: 600; font-size: 14px; }
.pager .next { text-align: right; }

/* ==========================================================================
   HEADINGS — chapter pages
   ========================================================================== */

.chapter-eyebrow {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .12em;
  text-transform: uppercase;
  color: var(--accent);
  margin-bottom: 10px;
}
[data-theme="terminal"] .chapter-eyebrow::before { content: '# '; }

.content h1 {
  font-family: var(--font-display);
  font-size: 40px; font-weight: 800;
  letter-spacing: -.02em; line-height: 1.1;
  margin: 0 0 16px;
  position: relative;
}
[data-theme="terminal"] h1 { font-size: 26px; font-weight: 700; letter-spacing: 0; }
[data-theme="terminal"] h1::before { content: '$ '; color: var(--accent); }
[data-theme="copper"] h1 { letter-spacing: -.03em; }

/* big decorative chapter number behind heading (void/copper only) */
.chapter-bg-num {
  position: absolute;
  right: 0; top: -12px;
  font-size: 96px; font-weight: 900; line-height: 1;
  font-family: var(--font-display);
  color: var(--accent-weak);
  user-select: none; pointer-events: none;
  z-index: -1;
}
[data-theme="terminal"] .chapter-bg-num { display: none; }

.content h2 {
  font-family: var(--font-display);
  font-size: 20px; font-weight: 700;
  margin: 0 0 14px;
  padding: 20px 0 14px;
  border-top: 1px solid var(--border);
  line-height: 1.3;
  display: flex; align-items: center; gap: 10px;
}
[data-theme="terminal"] h2 { font-size: 15px; font-weight: 500; }
[data-theme="terminal"] h2::before { content: '## '; color: var(--accent); font-size: 13px; }

.h2-num {
  font-family: var(--font-mono);
  font-size: 11px; font-weight: 400;
  color: var(--muted);
  background: var(--surface-2);
  border: 1px solid var(--border);
  padding: 2px 7px;
  border-radius: var(--radius-sm);
  flex-shrink: 0;
}

/* ==========================================================================
   INDEX PAGE — hero
   ========================================================================== */

.hero {
  padding: 52px 0 48px;
  position: relative;
  overflow: hidden;
}
.hero-eyebrow {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .12em;
  text-transform: uppercase;
  color: var(--accent);
  margin-bottom: 14px;
}
[data-theme="terminal"] .hero-eyebrow::before { content: '> '; }

.hero h1 {
  font-family: var(--font-display);
  font-size: 46px; font-weight: 800;
  letter-spacing: -.025em; line-height: 1.08;
  margin: 0 0 20px;
}
[data-theme="terminal"] .hero h1 { font-size: 28px; font-weight: 700; letter-spacing: 0; }
[data-theme="terminal"] .hero h1::before { content: '> '; color: var(--accent); }
[data-theme="copper"] .hero h1 { letter-spacing: -.035em; }

/* decorative gradient orb (void only) */
[data-theme="void"] .hero::before {
  content: '';
  position: absolute;
  right: -80px; top: -40px;
  width: 420px; height: 300px;
  background: radial-gradient(ellipse at center, rgba(59,189,242,.07) 0%, transparent 70%);
  pointer-events: none;
}
[data-theme="copper"] .hero::before {
  content: '';
  position: absolute;
  right: -60px; top: -30px;
  width: 380px; height: 260px;
  background: radial-gradient(ellipse at center, rgba(232,137,90,.07) 0%, transparent 70%);
  pointer-events: none;
}

/* ==========================================================================
   CHAPTER CARDS (index page)
   ========================================================================== */

.chapter-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
  gap: 14px;
  margin: 24px 0;
}

.chapter-card {
  display: block;
  padding: 20px 22px;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  background: var(--surface);
  color: var(--fg);
  transition: transform .15s, border-color .15s, box-shadow .15s;
  position: relative;
  overflow: hidden;
}
[data-theme="terminal"] .chapter-card { border-radius: var(--radius-sm); }
[data-theme="void"] .chapter-card::after {
  content: '';
  position: absolute; inset: 0;
  background: linear-gradient(135deg, var(--accent-weak) 0%, transparent 60%);
  opacity: 0;
  transition: opacity .2s;
}
[data-theme="void"] .chapter-card:hover::after { opacity: 1; }

.chapter-card:hover {
  border-color: var(--accent);
  transform: translateY(-2px);
  box-shadow: 0 8px 24px var(--accent-glow);
  text-decoration: none;
}
.chapter-card .cn {
  font-family: var(--font-mono);
  font-size: 10px;
  color: var(--muted);
  letter-spacing: .06em;
  text-transform: uppercase;
  margin-bottom: 6px;
  display: block;
}
[data-theme="terminal"] .chapter-card .cn::before { content: '> '; color: var(--accent); }
.chapter-card h3 {
  font-family: var(--font-display);
  font-size: 16px; font-weight: 700;
  margin: 0 0 8px; line-height: 1.3;
}
[data-theme="terminal"] .chapter-card h3 { font-size: 14px; font-weight: 500; }
.chapter-card p {
  margin: 0;
  color: var(--fg-2);
  font-size: 13px; line-height: 1.55;
}
.chapter-card .card-arrow {
  position: absolute; right: 18px; top: 20px;
  color: var(--border-2);
  font-size: 16px;
  transition: color .15s, transform .15s;
}
.chapter-card:hover .card-arrow { color: var(--accent); transform: translateX(3px); }
[data-theme="terminal"] .chapter-card .card-arrow { display: none; }

/* ==========================================================================
   TWEAKS PANEL
   ========================================================================== */

#tweaks-panel {
  display: none;
  position: fixed;
  bottom: 24px; right: 24px;
  width: 268px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  box-shadow: 0 20px 60px rgba(0,0,0,.6);
  z-index: 300;
  overflow: hidden;
}
#tweaks-panel.visible { display: block; }

.tweaks-hd {
  padding: 11px 16px;
  border-bottom: 1px solid var(--border);
  font-size: 11px; font-weight: 700;
  color: var(--muted);
  text-transform: uppercase;
  letter-spacing: .1em;
  font-family: var(--font-mono);
  display: flex; align-items: center; gap: 8px;
}
.tweaks-dot { width: 6px; height: 6px; border-radius: 50%; background: var(--accent); }

.tweaks-bd { padding: 14px 16px; }
.tweaks-lbl { font-size: 10px; text-transform: uppercase; letter-spacing: .1em; color: var(--muted); font-family: var(--font-mono); margin-bottom: 8px; }

.tw-themes { display: flex; flex-direction: column; gap: 7px; margin-bottom: 14px; }

.tw-opt {
  display: flex; align-items: center; gap: 10px;
  padding: 9px 12px;
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  cursor: pointer;
  transition: border-color .15s, background .15s;
}
.tw-opt:hover { border-color: var(--accent); }
.tw-opt.active { border-color: var(--accent); background: var(--accent-weak); }
.tw-swatch { width: 22px; height: 22px; border-radius: 5px; flex-shrink: 0; }
.tw-name { font-size: 13px; font-weight: 600; }
.tw-sub { font-size: 11px; color: var(--muted); display: block; }

.tw-mode {
  display: flex;
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  overflow: hidden;
}
.tw-mode-btn {
  flex: 1;
  padding: 7px 0;
  text-align: center;
  font-size: 12px;
  font-family: var(--font-mono);
  cursor: pointer;
  transition: background .15s, color .15s;
  color: var(--muted);
  background: transparent;
  border: none;
}
.tw-mode-btn.active { background: var(--accent-weak); color: var(--accent); font-weight: 600; }

/* ==========================================================================
   RESPONSIVE
   ========================================================================== */

.content > section,
.hero {
  scroll-margin-top: 72px;
}

@media (max-width: 880px) {
  .page { grid-template-columns: 1fr; padding: 0 16px; }
  .sidebar {
    position: static; height: auto;
    border-right: none;
    border-bottom: 1px solid var(--border);
    padding: 16px 0;
    display: flex; flex-wrap: wrap; gap: 0 24px;
  }
  .sidebar-section { min-width: 160px; }
  .content { padding: 24px 0 64px; }
  .content h1 { font-size: 30px; }
  .hero h1 { font-size: 32px; }
  .chapter-bg-num { display: none; }
}