/* =========================================================================
   Java Architect · AI Interview Lab  —  Dark Future-Tech Theme
   Shared stylesheet for index.html + part1..part10.html
   ========================================================================= */

:root {
  --bg: #070B14;
  --bg2: #0D1324;
  --card: rgba(18, 27, 48, 0.72);
  --card-solid: #0E1626;
  --glass: rgba(20, 30, 54, 0.55);
  --ink: #E6EDF6;
  --muted: #93A1BC;
  --faint: #5E6B85;

  --accent: #00D9FF;      /* Electric Blue */
  --purple: #7C3AED;
  --cyan: #22D3EE;
  --ok: #10F5A0;
  --warn: #FFB020;
  --err: #FF4D6D;

  --line: rgba(120, 150, 200, 0.16);
  --line-strong: rgba(0, 217, 255, 0.35);

  --grad-accent: linear-gradient(135deg, #00D9FF 0%, #7C3AED 100%);
  --grad-soft: linear-gradient(135deg, rgba(0,217,255,.18), rgba(124,58,237,.18));

  --shadow: 0 10px 40px rgba(0, 0, 0, .45);
  --shadow-glow: 0 8px 30px rgba(0, 217, 255, .18);

  --r-lg: 22px;
  --r-md: 16px;
  --r-sm: 10px;

  --font-ui: "Inter", "Noto Sans SC", -apple-system, BlinkMacSystemFont, "Segoe UI", "Microsoft YaHei", "PingFang SC", sans-serif;
  --font-disp: "Space Grotesk", "Inter", "Noto Sans SC", sans-serif;
  --font-mono: "JetBrains Mono", "SF Mono", Consolas, monospace;
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  font-family: var(--font-ui);
  background: var(--bg);
  color: var(--ink);
  line-height: 1.8;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
  overflow-x: hidden;
}

a { color: var(--accent); text-decoration: none; transition: color .2s; }
a:hover { color: var(--cyan); }

/* ---------- Animated tech background ---------- */
.bg-fx {
  position: fixed;
  inset: 0;
  z-index: -2;
  background:
    radial-gradient(1200px 800px at 12% -10%, rgba(0, 217, 255, .14), transparent 60%),
    radial-gradient(1000px 700px at 100% 0%, rgba(124, 58, 237, .16), transparent 55%),
    radial-gradient(900px 900px at 50% 120%, rgba(34, 211, 238, .10), transparent 60%),
    linear-gradient(160deg, #070B14 0%, #0A0F1E 45%, #0D0A1E 100%);
}
.bg-fx::before {
  /* faint grid */
  content: "";
  position: absolute;
  inset: -2px;
  background-image:
    linear-gradient(rgba(120, 160, 220, .05) 1px, transparent 1px),
    linear-gradient(90deg, rgba(120, 160, 220, .05) 1px, transparent 1px);
  background-size: 46px 46px;
  mask-image: radial-gradient(circle at 50% 30%, #000 0%, transparent 80%);
}
.bg-orb {
  position: absolute;
  border-radius: 50%;
  filter: blur(70px);
  opacity: .5;
  will-change: transform;
}
.bg-orb.o1 { width: 420px; height: 420px; left: -80px; top: 8%;  background: radial-gradient(circle, rgba(0,217,255,.55), transparent 70%); animation: float1 18s ease-in-out infinite; }
.bg-orb.o2 { width: 480px; height: 480px; right: -120px; top: 30%; background: radial-gradient(circle, rgba(124,58,237,.5), transparent 70%); animation: float2 22s ease-in-out infinite; }
.bg-orb.o3 { width: 360px; height: 360px; left: 30%; bottom: -60px; background: radial-gradient(circle, rgba(34,211,238,.4), transparent 70%); animation: float3 26s ease-in-out infinite; }

@keyframes float1 { 0%,100% { transform: translateY(0) translateX(0); } 50% { transform: translateY(40px) translateX(30px); } }
@keyframes float2 { 0%,100% { transform: translateY(0) translateX(0); } 50% { transform: translateY(-50px) translateX(-20px); } }
@keyframes float3 { 0%,100% { transform: translateY(0) translateX(0); } 50% { transform: translateY(-30px) translateX(25px); } }

/* ---------- Glass Nav ---------- */
.nav {
  position: sticky;
  top: 14px;
  z-index: 50;
  margin: 14px auto 0;
  max-width: 1180px;
  display: flex;
  align-items: center;
  gap: 18px;
  padding: 12px 20px;
  background: var(--glass);
  backdrop-filter: blur(18px) saturate(140%);
  -webkit-backdrop-filter: blur(18px) saturate(140%);
  border: 1px solid var(--line);
  border-radius: 18px;
  box-shadow: var(--shadow), inset 0 1px 0 rgba(255,255,255,.04);
}
.nav .logo { display: flex; align-items: center; gap: 12px; }
.nav .logo svg { width: 34px; height: 34px; filter: drop-shadow(0 0 8px rgba(0,217,255,.6)); }
.nav .logo .txt { display: flex; flex-direction: column; line-height: 1.05; }
.nav .logo .t1 {
  font-family: var(--font-disp);
  font-weight: 700;
  font-size: 15px;
  letter-spacing: 3px;
  background: var(--grad-accent);
  -webkit-background-clip: text; background-clip: text;
  -webkit-text-fill-color: transparent;
}
.nav .logo .t2 { font-size: 9.5px; letter-spacing: 3.5px; color: var(--muted); }
.nav .links { display: flex; gap: 6px; margin-left: 10px; }
.nav .links a {
  color: var(--muted);
  font-size: 13.5px;
  padding: 7px 12px;
  border-radius: 10px;
  transition: all .2s;
}
.nav .links a:hover, .nav .links a.active { color: var(--ink); background: rgba(0,217,255,.10); }
.nav .spacer { flex: 1; }
.nav .nav-tools { display: flex; align-items: center; gap: 10px; }
.nav .icon-btn {
  width: 38px; height: 38px; display: grid; place-items: center;
  border-radius: 11px; border: 1px solid var(--line);
  background: rgba(255,255,255,.03); color: var(--muted);
  cursor: pointer; font-size: 16px; transition: all .2s;
}
.nav .icon-btn:hover { color: var(--accent); border-color: var(--line-strong); box-shadow: var(--shadow-glow); }

/* progress chip in nav */
.nav .progress-chip { display: flex; align-items: center; gap: 10px; min-width: 190px; }
.nav .progress-chip .bar { flex: 1; height: 7px; border-radius: 99px; background: rgba(255,255,255,.07); overflow: hidden; }
.nav .progress-chip .bar > i { display: block; height: 100%; width: 0; background: var(--grad-accent); border-radius: 99px; transition: width .6s cubic-bezier(.2,.8,.2,1); box-shadow: 0 0 12px rgba(0,217,255,.6); }
.nav .progress-chip .num { font-family: var(--font-mono); font-size: 12px; color: var(--ink); white-space: nowrap; }

.nav .menu-btn { display: none; }

/* ---------- Layout ---------- */
.layout {
  max-width: 1180px;
  margin: 30px auto 80px;
  padding: 0 20px;
  display: grid;
  grid-template-columns: minmax(0, 1fr) 268px;
  gap: 30px;
  align-items: start;
}
.doc { min-width: 0; }
main.doc { /* index uses plain main */ }

/* ---------- Buttons ---------- */
.btn {
  display: inline-flex; align-items: center; gap: 8px;
  font-family: var(--font-disp); font-weight: 600; letter-spacing: .5px;
  padding: 12px 22px; border-radius: 12px; border: 0; cursor: pointer;
  color: #04121b; background: var(--grad-accent);
  box-shadow: 0 6px 22px rgba(0,217,255,.35);
  transition: transform .2s, box-shadow .2s, filter .2s;
}
.btn:hover { transform: translateY(-2px); box-shadow: 0 10px 30px rgba(124,58,237,.45); filter: brightness(1.05); }
.btn.ghost { background: transparent; color: var(--accent); border: 1px solid var(--line-strong); box-shadow: none; }
.btn.ghost:hover { background: rgba(0,217,255,.08); }

/* =========================================================================
   INDEX PAGE
   ========================================================================= */
.index-hero {
  position: relative;
  margin: 26px auto 0;
  max-width: 1180px;
  padding: 54px 48px;
  display: grid;
  grid-template-columns: 1.1fr .9fr;
  gap: 40px;
  align-items: center;
  background: var(--card);
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
  border: 1px solid var(--line);
  border-radius: var(--r-lg);
  box-shadow: var(--shadow);
  overflow: hidden;
}
.index-hero::after {
  content: ""; position: absolute; inset: 0;
  background: radial-gradient(600px 300px at 90% 10%, rgba(0,217,255,.10), transparent 60%);
  pointer-events: none;
}
.index-hero .eyebrow {
  display: inline-flex; align-items: center; gap: 8px;
  font-size: 12px; letter-spacing: 2px; color: var(--accent);
  border: 1px solid var(--line-strong); border-radius: 99px; padding: 5px 12px;
  background: rgba(0,217,255,.07);
}
.index-hero h1 {
  font-family: var(--font-disp);
  font-size: clamp(34px, 5vw, 60px);
  line-height: 1.05; margin: 18px 0 10px; letter-spacing: -1px;
}
.index-hero h1 .grad {
  background: var(--grad-accent);
  -webkit-background-clip: text; background-clip: text; -webkit-text-fill-color: transparent;
}
.index-hero .lead { color: var(--muted); font-size: 16px; max-width: 480px; }
.index-hero .hero-cta { margin-top: 26px; display: flex; gap: 14px; flex-wrap: wrap; }

.stats-row { display: flex; gap: 14px; margin-top: 30px; flex-wrap: wrap; }
.stat-card {
  flex: 1; min-width: 130px;
  background: rgba(10,16,30,.6);
  border: 1px solid var(--line);
  border-radius: var(--r-md);
  padding: 18px 18px;
  position: relative; overflow: hidden;
}
.stat-card .v { font-family: var(--font-disp); font-size: 34px; font-weight: 700; color: var(--accent); line-height: 1; }
.stat-card .v small { font-size: 18px; }
.stat-card .l { color: var(--muted); font-size: 12.5px; margin-top: 8px; letter-spacing: .5px; }
.stat-card::before { content:""; position:absolute; left:0; top:0; bottom:0; width:3px; background: var(--grad-accent); }

/* AI core visual */
.ai-core { position: relative; height: 360px; display: grid; place-items: center; }
.ai-core svg { width: 100%; height: 100%; overflow: visible; }
.ai-core .ring { transform-origin: 50% 50%; }
.ai-core .spin-slow { animation: spin 26s linear infinite; }
.ai-core .spin-rev  { animation: spin 18s linear infinite reverse; }
@keyframes spin { to { transform: rotate(360deg); } }
.ai-core .pulse { animation: pulse 3.4s ease-in-out infinite; transform-origin: 50% 50%; }
@keyframes pulse { 0%,100% { opacity: .55; } 50% { opacity: 1; } }
.ai-core .node { fill: rgba(0,217,255,.12); stroke: var(--accent); stroke-width: 1.4; }
.ai-core .core-glow { filter: drop-shadow(0 0 14px rgba(0,217,255,.8)); }

/* Category cards */
.section-head { display: flex; align-items: end; justify-content: space-between; margin: 56px auto 22px; max-width: 1180px; padding: 0 4px; }
.section-head h2 { font-family: var(--font-disp); font-size: 26px; margin: 0; letter-spacing: -.5px; }
.section-head .sub { color: var(--muted); font-size: 13.5px; }

.cards-grid {
  max-width: 1180px; margin: 0 auto;
  display: grid; grid-template-columns: repeat(auto-fill, minmax(255px, 1fr)); gap: 18px;
  padding: 0 4px;
}
.cat-card {
  position: relative;
  display: flex; flex-direction: column; gap: 12px;
  padding: 22px;
  background: var(--card);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border: 1px solid var(--line);
  border-radius: var(--r-md);
  overflow: hidden;
  transition: transform .25s cubic-bezier(.2,.8,.2,1), border-color .25s, box-shadow .25s;
}
.cat-card::before {
  content: ""; position: absolute; inset: 0;
  background: var(--grad-soft); opacity: 0; transition: opacity .3s; pointer-events: none;
}
.cat-card:hover { transform: translateY(-8px); border-color: var(--line-strong); box-shadow: 0 18px 50px rgba(0,217,255,.20); }
.cat-card:hover::before { opacity: 1; }
.cat-card .ic {
  width: 46px; height: 46px; border-radius: 13px; display: grid; place-items: center;
  font-size: 22px; background: rgba(0,217,255,.10); border: 1px solid var(--line-strong);
  color: var(--accent);
}
.cat-card .ct { font-family: var(--font-disp); font-size: 18px; font-weight: 600; }
.cat-card .cd { color: var(--muted); font-size: 13px; line-height: 1.6; }
.cat-card .meta { display: flex; align-items: center; justify-content: space-between; margin-top: auto; }
.cat-card .qcount { font-family: var(--font-mono); font-size: 12px; color: var(--cyan); letter-spacing: 1px; }
.cat-card .go { color: var(--accent); font-size: 18px; transition: transform .2s; }
.cat-card:hover .go { transform: translateX(5px); }
.cat-card .stripe { position: absolute; left: 0; top: 0; bottom: 0; width: 4px; }
.cat-card.d-junior .stripe, .cat-card.d-junior .ic { background: rgba(16,245,160,.12); color: var(--ok); }
.cat-card.d-senior .stripe, .cat-card.d-senior .ic { background: rgba(0,217,255,.12); color: var(--accent); }
.cat-card.d-architect .stripe, .cat-card.d-architect .ic { background: rgba(124,58,237,.16); color: #b08bff; }
.cat-card.d-expert .stripe, .cat-card.d-expert .ic { background: rgba(255,77,109,.12); color: var(--err); }

/* full TOC */
.toc-full { max-width: 1180px; margin: 50px auto 0; padding: 0 4px; }
.toc-full .toc-part { margin-bottom: 22px; }
.toc-full h3 { font-family: var(--font-disp); font-size: 17px; color: var(--ink); margin: 0 0 12px; display: flex; align-items: center; gap: 10px; }
.toc-full h3 .pill { font-family: var(--font-mono); font-size: 11px; color: var(--accent); border: 1px solid var(--line-strong); padding: 2px 9px; border-radius: 99px; }
.toc-full .toc-list { display: grid; grid-template-columns: repeat(auto-fill, minmax(260px, 1fr)); gap: 8px; }
.toc-full .toc-list a {
  display: flex; align-items: center; gap: 10px; padding: 9px 12px;
  border: 1px solid var(--line); border-radius: 10px; color: var(--muted);
  font-size: 13px; background: rgba(10,16,30,.4); transition: all .2s;
}
.toc-full .toc-list a:hover { color: var(--ink); border-color: var(--line-strong); background: rgba(0,217,255,.06); transform: translateX(3px); }
.toc-full .toc-list a .n { font-family: var(--font-mono); color: var(--accent); font-size: 12px; min-width: 26px; }

/* =========================================================================
   PART PAGES — question doc
   ========================================================================= */
.part-hero {
  position: relative;
  background: var(--card);
  backdrop-filter: blur(12px);
  border: 1px solid var(--line);
  border-radius: var(--r-lg);
  padding: 30px 32px;
  margin-bottom: 26px;
  overflow: hidden;
}
.part-hero::after { content:""; position:absolute; inset:0; background: radial-gradient(500px 200px at 100% 0, rgba(124,58,237,.14), transparent 60%); pointer-events:none; }
.part-hero .back { display: inline-flex; align-items: center; gap: 6px; color: var(--muted); font-size: 13px; }
.part-hero .back:hover { color: var(--accent); }
.part-hero h1 { font-family: var(--font-disp); font-size: clamp(24px, 3.4vw, 34px); margin: 14px 0 8px; letter-spacing: -.5px; }
.part-hero .sub { color: var(--muted); font-size: 14px; max-width: 760px; }

.toc-mini {
  display: flex; flex-wrap: wrap; gap: 8px; align-items: center;
  background: rgba(10,16,30,.5); border: 1px solid var(--line);
  border-radius: 12px; padding: 12px 14px; margin-bottom: 26px;
}
.toc-mini b { color: var(--muted); font-size: 12.5px; margin-right: 4px; font-weight: 600; }
.toc-mini a { font-family: var(--font-mono); font-size: 12px; color: var(--muted); border: 1px solid var(--line); padding: 3px 9px; border-radius: 8px; transition: all .2s; }
.toc-mini a:hover { color: var(--accent); border-color: var(--line-strong); background: rgba(0,217,255,.06); }

/* question card */
.q {
  position: relative;
  background: var(--card);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border: 1px solid var(--line);
  border-radius: var(--r-lg);
  padding: 26px 28px;
  margin: 22px 0;
  box-shadow: var(--shadow);
  scroll-margin-top: 96px;
  opacity: 0; transform: translateY(22px);
  transition: opacity .6s ease, transform .6s cubic-bezier(.2,.8,.2,1), border-color .3s;
}
.q.in { opacity: 1; transform: none; }
.q:hover { border-color: rgba(0,217,255,.22); }
.q > h2 {
  font-family: var(--font-disp); font-size: 22px; color: var(--ink);
  margin: 0 0 16px; padding-bottom: 14px; border-bottom: 1px solid var(--line);
  display: flex; align-items: center; gap: 10px; flex-wrap: wrap;
}
.q > h2 .idx { font-family: var(--font-mono); font-size: 13px; color: var(--accent); background: rgba(0,217,255,.10); border: 1px solid var(--line-strong); padding: 2px 9px; border-radius: 8px; }
.q > h2 .tag { font-family: var(--font-mono); font-size: 11px; color: #04121b; background: var(--cyan); padding: 3px 10px; border-radius: 99px; letter-spacing: .5px; }

/* per-question top bar: difficulty + done */
.q-top { display: flex; align-items: center; gap: 10px; margin-bottom: 14px; flex-wrap: wrap; }
.badge-diff {
  display: inline-flex; align-items: center; gap: 7px;
  font-family: var(--font-mono); font-size: 11px; letter-spacing: 1.5px;
  padding: 4px 11px; border-radius: 99px; border: 1px solid;
}
.badge-diff .dot { width: 8px; height: 8px; border-radius: 50%; box-shadow: 0 0 8px currentColor; }
.badge-diff.d-junior { color: var(--ok); border-color: rgba(16,245,160,.4); background: rgba(16,245,160,.08); }
.badge-diff.d-senior { color: var(--accent); border-color: rgba(0,217,255,.4); background: rgba(0,217,255,.08); }
.badge-diff.d-architect { color: #b08bff; border-color: rgba(124,58,237,.45); background: rgba(124,58,237,.10); }
.badge-diff.d-expert { color: var(--err); border-color: rgba(255,77,109,.4); background: rgba(255,77,109,.08); }

.done-btn {
  margin-left: auto;
  display: inline-flex; align-items: center; gap: 7px;
  font-family: var(--font-ui); font-size: 12.5px; color: var(--muted);
  background: rgba(255,255,255,.03); border: 1px solid var(--line);
  padding: 6px 13px; border-radius: 99px; cursor: pointer; transition: all .2s;
}
.done-btn:hover { color: var(--ink); border-color: var(--line-strong); }
.done-btn.done { color: #04121b; background: var(--ok); border-color: var(--ok); box-shadow: 0 0 16px rgba(16,245,160,.4); }

/* segments */
.sec { margin: 18px 0; position: relative; }
.sec > .lab {
  display: inline-flex; align-items: center; gap: 8px;
  font-weight: 700; font-size: 14px; margin-bottom: 8px;
  color: var(--accent); font-family: var(--font-disp); letter-spacing: .3px;
}
.sec > .lab::before {
  content: attr(data-n);
  font-family: var(--font-mono); font-size: 11px; color: #04121b;
  background: var(--grad-accent); padding: 1px 7px; border-radius: 6px; font-weight: 700;
}

/* modular knowledge cards */
.scene {
  background: linear-gradient(135deg, rgba(0,217,255,.06), rgba(124,58,237,.06));
  border: 1px solid var(--line); border-left: 3px solid var(--accent);
  padding: 14px 18px; border-radius: var(--r-sm); font-size: 14.5px; color: #d7e2f2;
  position: relative; overflow-wrap: anywhere; word-break: break-word;
}
.scene::before {
  content: "🏢 BUSINESS SCENARIO"; display: block;
  font-family: var(--font-mono); font-size: 10.5px; letter-spacing: 2px;
  color: var(--accent); margin-bottom: 6px; opacity: .9;
}

ol, ul { margin: 6px 0; padding-left: 22px; }
li { margin: 4px 0; color: #cfdaeb; }
code.inline {
  background: rgba(0,217,255,.10); color: #7fe9ff;
  padding: 1px 7px; border-radius: 6px; font-family: var(--font-mono); font-size: 12.5px;
  border: 1px solid rgba(0,217,255,.18);
}

/* tables */
.tbl { width: 100%; border-collapse: collapse; margin: 10px 0; font-size: 13.5px; border-radius: 12px; overflow: hidden; }
.tbl th, .tbl td { border: 1px solid var(--line); padding: 9px 11px; text-align: left; vertical-align: top; }
.tbl th { background: rgba(0,217,255,.08); color: #bfe9ff; font-family: var(--font-disp); font-weight: 600; }
.tbl tr:nth-child(even) td { background: rgba(255,255,255,.02); }

/* architecture console */
.arch {
  background: #060A12;
  color: #9fe9ff;
  padding: 18px 20px; border-radius: var(--r-md);
  border: 1px solid rgba(0,217,255,.28);
  overflow: auto; font-size: 13px; white-space: pre; line-height: 1.55;
  font-family: var(--font-mono);
  position: relative;
  box-shadow: inset 0 0 40px rgba(0,217,255,.06), 0 0 22px rgba(0,217,255,.10);
}
.arch::before {
  content: "◈ ARCHITECTURE FLOW";
  display: block; color: var(--accent); font-size: 10.5px; letter-spacing: 2px; margin-bottom: 10px; opacity: .8;
}
.arch::after {
  content: ""; position: absolute; left: 0; right: 0; top: 0; height: 2px;
  background: linear-gradient(90deg, transparent, var(--accent), transparent);
  opacity: .5; animation: scan 4s linear infinite;
}
@keyframes scan { 0% { transform: translateY(0); } 100% { transform: translateY(220px); } }

/* code block (VS Code style) */
.code-block {
  margin: 12px 0; border-radius: var(--r-md); overflow: hidden;
  border: 1px solid var(--line); background: #0A0E18; box-shadow: var(--shadow);
}
.code-block .cb-head {
  display: flex; align-items: center; gap: 10px;
  padding: 9px 14px; background: #111726;
  border-bottom: 1px solid var(--line);
}
.code-block .cb-dots { display: flex; gap: 6px; }
.code-block .cb-dots i { width: 11px; height: 11px; border-radius: 50%; display: block; }
.code-block .cb-dots i:nth-child(1) { background: #FF5F57; }
.code-block .cb-dots i:nth-child(2) { background: #FEBC2E; }
.code-block .cb-dots i:nth-child(3) { background: #28C840; }
.code-block .cb-lang { font-family: var(--font-mono); font-size: 11.5px; color: var(--muted); letter-spacing: 1px; }
.code-block .cb-copy {
  margin-left: auto; font-family: var(--font-ui); font-size: 12px; color: var(--muted);
  background: rgba(255,255,255,.04); border: 1px solid var(--line);
  padding: 4px 11px; border-radius: 7px; cursor: pointer; transition: all .2s;
}
.code-block .cb-copy:hover { color: var(--accent); border-color: var(--line-strong); }
.code-block pre {
  margin: 0; background: #0A0E18; color: #d8e2f0;
  padding: 16px 18px; overflow: auto; font-size: 13px; line-height: 1.65;
  font-family: var(--font-mono); white-space: pre;
}
/* syntax tokens (keep existing .c/.k/.s) */
.code-block pre .c, pre .c { color: #5E7A99; font-style: italic; }
.code-block pre .k, pre .k { color: #FF7BD5; }
.code-block pre .s, pre .s { color: #9FF0A8; }
.code-block pre .t, pre .t { color: #7FD8FF; }
.code-block pre .n, pre .n { color: #FFB86C; }

/* follow / err / score */
.follow { background: rgba(0,217,255,.05); border: 1px dashed rgba(0,217,255,.3); border-radius: var(--r-md); padding: 16px 18px; clear: both; position: relative; }
.follow::after { content: ""; display: block; clear: both; }
.follow p { display: block; background: transparent; box-shadow: none; border: 0; margin: 10px 0; padding: 0; line-height: 1.75; overflow-wrap: break-word; color: #d3deef; }
.follow p:first-child { margin-top: 0; }
.follow p:last-child { margin-bottom: 0; }
.follow b, .follow b.q { display: inline; background: transparent; box-shadow: none; border: 0; padding: 0; margin: 0; color: #7FE9FF; font-weight: 700; line-height: 1.75; }
.follow p b.q::before { content: "▸ "; color: var(--accent); }

.err { background: rgba(255,77,109,.06); border: 1px solid rgba(255,77,109,.3); border-radius: var(--r-md); padding: 14px 18px; clear: both; position: relative; overflow-wrap: anywhere; word-break: break-word; }
.err li { color: #FFB3C1; }
.err::before { content: "✕ COMMON MISTAKES"; display: block; font-family: var(--font-mono); font-size: 10.5px; letter-spacing: 2px; color: var(--err); margin-bottom: 8px; }

.score { display: grid; grid-template-columns: repeat(auto-fit, minmax(200px, 1fr)); gap: 10px; }
.score .sc { border: 1px solid var(--line); border-radius: var(--r-sm); padding: 12px 14px; font-size: 13px; position: relative; overflow-wrap: anywhere; word-break: break-word; color: #cfdaeb; background: rgba(10,16,30,.5); }
.score .sc .h { font-family: var(--font-disp); font-weight: 700; margin-bottom: 6px; }
.score .sc.l1 { border-color: rgba(255,77,109,.3); } .score .sc.l1 .h { color: var(--err); }
.score .sc.l2 { border-color: rgba(255,176,32,.3); } .score .sc.l2 .h { color: var(--warn); }
.score .sc.l3 { border-color: rgba(0,217,255,.3); } .score .sc.l3 .h { color: var(--accent); }
.score .sc.l4 { border-color: rgba(124,58,237,.4); } .score .sc.l4 .h { color: #b08bff; }

.kw { display: flex; flex-wrap: wrap; gap: 8px; }
.kw span { background: rgba(0,217,255,.08); color: var(--accent); padding: 4px 11px; border-radius: 99px; font-size: 12px; border: 1px solid rgba(0,217,255,.18); }

/* sticky TOC */
.toc-side { position: sticky; top: 96px; align-self: start; }
.toc-side .box {
  background: var(--card); backdrop-filter: blur(12px);
  border: 1px solid var(--line); border-radius: var(--r-md); padding: 16px 14px;
}
.toc-side .box .th { font-family: var(--font-mono); font-size: 10.5px; letter-spacing: 2px; color: var(--muted); margin-bottom: 12px; }
.toc-side .box a {
  display: flex; align-items: center; gap: 9px; padding: 7px 9px; border-radius: 8px;
  color: var(--muted); font-size: 12.5px; transition: all .2s; border-left: 2px solid transparent;
}
.toc-side .box a .n { font-family: var(--font-mono); font-size: 11px; color: var(--accent); }
.toc-side .box a:hover { color: var(--ink); background: rgba(0,217,255,.06); }
.toc-side .box a.active { color: var(--ink); background: rgba(0,217,255,.10); border-left-color: var(--accent); }

footer.foot {
  max-width: 1180px; margin: 40px auto 0; padding: 26px 20px 50px;
  text-align: center; color: var(--faint); font-size: 13px; border-top: 1px solid var(--line);
}
footer.foot a { color: var(--accent); }

/* reveal helper for generic blocks */
.reveal { opacity: 0; transform: translateY(18px); transition: opacity .6s ease, transform .6s cubic-bezier(.2,.8,.2,1); }
.reveal.in { opacity: 1; transform: none; }

/* ---------- Responsive ---------- */
@media (max-width: 1024px) {
  .layout { grid-template-columns: 1fr; }
  .toc-side { position: static; order: -1; margin-bottom: 20px; }
  .toc-side .box a { font-size: 13px; }
  .index-hero { grid-template-columns: 1fr; }
  .ai-core { height: 280px; }
}
@media (max-width: 760px) {
  .nav .links { display: none; }
  .nav .menu-btn { display: grid; }
  .nav .nav-menu {
    display: none; position: absolute; top: 64px; left: 12px; right: 12px;
    flex-direction: column; gap: 4px; padding: 10px;
    background: var(--glass); backdrop-filter: blur(18px);
    border: 1px solid var(--line); border-radius: 14px; z-index: 60;
  }
  .nav .nav-menu.open { display: flex; }
  .nav .nav-menu a { padding: 10px 12px; }
  .nav .progress-chip { min-width: 120px; }
  .index-hero { padding: 34px 22px; }
  .q { padding: 20px 16px; }
  .cards-grid { grid-template-columns: 1fr; }
}

@media (prefers-reduced-motion: reduce) {
  * { animation: none !important; transition: none !important; scroll-behavior: auto !important; }
  .q, .reveal { opacity: 1 !important; transform: none !important; }
}
body.no-anim * { animation: none !important; }