/* ========================================================================
   VLink Official Site  —  stylesheet
   Brand palette locked to official SVG logo: #345af6 #467cf9 #4faafd
   ======================================================================== */

:root {
  --brand-700: #1b3bd1;
  --brand-600: #345af6;
  --brand-500: #467cf9;
  --brand-400: #4faafd;
  --brand-300: #7fc4ff;
  --accent:    #00e5b0;
  --accent-2:  #ffd166;

  --bg-0: #070B18;
  --bg-1: #0B1228;
  --bg-2: #111A38;
  --bg-3: #18244A;
  --line: rgba(127, 196, 255, 0.14);
  --line-strong: rgba(127, 196, 255, 0.28);

  --ink-0: #F2F5FF;
  --ink-1: #C8D1EE;
  --ink-2: #8C98B9;
  --ink-3: #5A6687;

  --r-sm: 8px;
  --r-md: 14px;
  --r-lg: 22px;
  --r-xl: 32px;

  --shadow-1: 0 10px 30px rgba(0, 0, 0, 0.35);
  --shadow-2: 0 20px 60px rgba(52, 90, 246, 0.25);
  --glow:     0 0 0 1px rgba(79, 170, 253, 0.35), 0 12px 40px rgba(52, 90, 246, 0.35);

  --font-sans: "Inter", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Noto Sans SC", system-ui, sans-serif;
  --font-mono: "Noto Sans Mono", "DejaVu Sans Mono", "JetBrains Mono", "Fira Code", "SFMono-Regular", Menlo, Consolas, monospace;
  --font-terminal: "Noto Sans Mono", "JetBrains Mono", "DejaVu Sans Mono", "Fira Code", "SFMono-Regular", Menlo, Consolas, monospace;
}

* { box-sizing: border-box; }
html, body { margin: 0; padding: 0; }
html { scroll-behavior: smooth; scroll-padding-top: 20px; }
@media (max-width: 720px) {
  html { scroll-padding-top: 10px; }
}
body {
  font-family: var(--font-sans);
  color: var(--ink-1);
  background: var(--bg-0);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}
img { max-width: 100%; display: block; }
a { color: var(--brand-400); text-decoration: none; transition: color .2s; }
a:hover { color: var(--brand-300); }

.container { width: min(1200px, 92vw); margin-inline: auto; }

/* =============== Global atmospheric background =============== */
.bg-aurora {
  position: fixed; inset: 0; z-index: -2; pointer-events: none;
  background:
    radial-gradient(1200px 700px at 15% -10%, rgba(52,90,246,0.18), transparent 60%),
    radial-gradient(900px  600px at 85% 10%, rgba(79,170,253,0.12), transparent 60%),
    radial-gradient(900px  700px at 50% 110%, rgba(0,229,176,0.08), transparent 60%),
    linear-gradient(180deg, #070B18 0%, #060913 100%);
}
.bg-grid {
  position: fixed; inset: 0; z-index: -1; pointer-events: none;
  background-image:
    linear-gradient(rgba(127,196,255,0.05) 1px, transparent 1px),
    linear-gradient(90deg, rgba(127,196,255,0.05) 1px, transparent 1px);
  background-size: 56px 56px;
  mask-image: radial-gradient(ellipse at center, #000 40%, transparent 75%);
  animation: grid-drift 60s linear infinite;
}
@keyframes grid-drift {
  0%   { background-position: 0 0,         0 0; }
  100% { background-position: 560px 560px, 560px 560px; }
}

/* =============== Navbar =============== */
.nav {
  position: sticky; top: 0; z-index: 50;
  backdrop-filter: blur(14px) saturate(180%);
  background: rgba(7, 11, 24, 0.7);
  border-bottom: 1px solid var(--line);
}
.nav-inner {
  display: flex;
  flex-direction: column;
  align-items: stretch;
  min-width: 0;
  padding-block: 4px;                /* was 8 — shrink overall header */
  gap: 0;
}
.nav-row-top {
  display: flex;
  flex-direction: row;
  align-items: center;
  justify-content: space-between;
  flex-wrap: nowrap;
  min-height: 46px;                  /* was 64 */
  gap: 20px;
}
.nav-row-top > .nav-logo  { flex-shrink: 0; }
.nav-row-top > .nav-right { flex-shrink: 0; margin-left: auto; }

.nav-logo { display: flex; align-items: center; gap: 10px; }
.nav-logo img { height: 32px; }
.nav-logo .badge {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 11.5px;
  font-weight: 700;
  line-height: 1;
  letter-spacing: 0.05em;
  color: var(--brand-300);
  padding: 0;
  border: 0;
  border-radius: 0;
  background: none;
  box-shadow: none;
  white-space: nowrap;
  opacity: 0.96;
}
.nav-links {
  display: flex;
  gap: 24px;
  flex-wrap: wrap;
  justify-content: center;
  align-items: center;
  row-gap: 2px;
  padding: 4px 16px 3px;
  margin-top: 0;
  border-top: 1px solid var(--line);
}
.nav-links a {
  color: var(--ink-1); font-size: 14px; font-weight: 500;
  letter-spacing: 0.01em;
  position: relative; padding: 4px 2px;
  white-space: nowrap;
}
.nav-links a::after {
  content: ""; position: absolute; left: 0; bottom: 0; height: 2px; width: 0;
  background: linear-gradient(90deg, var(--brand-600), var(--brand-400));
  transition: width .3s;
}
.nav-links a:hover::after { width: 100%; }
.nav-right {
  display: flex;
  flex-direction: row;
  align-items: center;
  gap: 12px;
  justify-content: flex-end;            /* hard-pin children to the right */
  flex-wrap: nowrap;                    /* buttons stay on the same row as logo */
  flex-shrink: 0;
  margin-left: auto;
  white-space: nowrap;
}
.nav-right > * { flex-shrink: 0; }

/* ─── Language switcher (dropdown) ─── */
.lang-switch {
  position: relative;
}
.lang-switch > summary {
  list-style: none;
  display: inline-flex; align-items: center; gap: 5px;
  padding: 6px 10px; border-radius: 6px;
  border: 1px solid var(--line-strong);
  background: rgba(17, 26, 56, 0.55);
  backdrop-filter: blur(4px);
  color: var(--ink-1);
  font-family: inherit; font-size: 12.5px; font-weight: 600;
  cursor: pointer;
  transition: all .18s;
  user-select: none;
  outline: none;
}
.lang-switch > summary .lang-globe { width: 12px; height: 12px; }
.lang-switch > summary .lang-caret { width: 10px; height: 10px; }
.lang-switch > summary::-webkit-details-marker { display: none; }
.lang-switch > summary::marker { content: ""; }
.lang-switch > summary:hover { color: var(--ink-0); border-color: var(--brand-400); background: rgba(52, 90, 246, 0.14); }
.lang-switch[open] > summary {
  color: var(--ink-0);
  border-color: var(--brand-400);
  background: rgba(52, 90, 246, 0.18);
}
.lang-switch .lang-globe { color: var(--brand-400); }
.lang-switch .lang-caret { opacity: 0.7; transition: transform .2s; }
.lang-switch[open] .lang-caret { transform: rotate(180deg); }

.lang-switch .lang-menu {
  position: absolute; top: calc(100% + 8px); right: 0;
  min-width: 184px;
  margin: 0; padding: 6px;
  list-style: none;
  border: 1px solid var(--line-strong);
  border-radius: 6px;
  background: rgba(8, 12, 28, 0.92);
  backdrop-filter: blur(14px) saturate(180%);
  box-shadow: 0 18px 40px rgba(0, 0, 0, 0.5), 0 0 0 1px rgba(79, 170, 253, 0.12);
  z-index: 60;
  animation: lang-fade .14s ease-out;   /* fade-only, no position shift */
}
@keyframes lang-fade {
  from { opacity: 0; }
  to   { opacity: 1; }
}
/* Keep the summary pinned — no subpixel jiggle when clicked or focused */
.lang-switch > summary { outline: none; scroll-margin: 200px; }
.lang-switch > summary:focus,
.lang-switch > summary:focus-visible { outline: none; }
.lang-switch > summary .lang-label { display: inline-block; }
.lang-switch .lang-menu li { margin: 0; }
.lang-switch .lang-menu button {
  width: 100%; display: flex; align-items: center; justify-content: space-between;
  padding: 9px 12px; border-radius: 4px;
  border: 1px solid transparent; background: transparent;
  color: var(--ink-1);
  font-family: inherit; font-size: 13px; font-weight: 500;
  text-align: left; cursor: pointer;
  transition: all .15s;
}
.lang-switch .lang-menu button:hover {
  background: linear-gradient(90deg, rgba(52, 90, 246, 0.22), rgba(79, 170, 253, 0.08));
  border-color: rgba(79, 170, 253, 0.22);
  color: var(--ink-0);
}
.lang-switch .lang-menu button.active {
  color: var(--ink-0);
  background: rgba(52, 90, 246, 0.25);
  border-color: rgba(79, 170, 253, 0.3);
}
.lang-switch .lang-menu button.active::after {
  content: "✓";
  color: var(--accent);
  font-weight: 700;
  margin-left: 12px;
}
@media (max-width: 480px) {
  .lang-switch .lang-menu { right: auto; left: 0; }
}

/* Nav action pills — one unified look for Docs · Release · GitHub. */
.nav-btn {
  display: inline-flex; align-items: center; gap: 6px;
  padding: 6px 12px;
  border-radius: 999px;
  font-weight: 600; font-size: 12.5px;
  color: #ffffff;
  background: linear-gradient(180deg, #1e2a55, #141b38);
  border: 1px solid rgba(127, 196, 255, 0.22);
  box-shadow: 0 3px 8px rgba(0, 0, 0, 0.3),
              inset 0 1px 0 rgba(255, 255, 255, 0.05);
  transition: transform .18s, border-color .18s, background .18s, box-shadow .18s;
  white-space: nowrap;
  cursor: pointer;
}
.nav-btn svg { width: 13px; height: 13px; }
.nav-btn:hover {
  color: #ffffff;
  transform: translateY(-1px);
  border-color: var(--brand-400);
  background: linear-gradient(180deg, #25335f, #18224a);
  box-shadow: 0 6px 18px rgba(52, 90, 246, 0.35),
              inset 0 1px 0 rgba(255, 255, 255, 0.08);
}
.nav-btn svg { color: var(--brand-300); flex-shrink: 0; }
/* GitHub shares the same pill style — no louder gradient */
.nav-btn.nav-btn-github { /* intentionally identical to .nav-btn */ }

.nav-cta { /* legacy alias; kept so older references don't break */ }

@media (max-width: 1180px) {
  .nav-btn { padding: 8px 12px; font-size: 13.5px; gap: 6px; }
  .nav-btn span { display: none; }     /* icon-only at medium width */
}
@media (max-width: 720px) {
  /* Hide Docs/Release nav pills on phones; keep GitHub reachable via
     the larger icon-only pill below (see ≤ 520px rule). */
  .nav-btn:not(.nav-btn-github) { display: none; }
}

/* Mobile: the nav-links row turns into a horizontally-scrollable strip
   instead of disappearing, so phone users can still jump between sections. */
@media (max-width: 820px) {
  .nav-links {
    flex-wrap: nowrap;
    overflow-x: auto;
    justify-content: flex-start;
    padding: 4px 12px;
    margin: 0 -12px;                 /* bleed to the container edges */
    gap: 18px;
    scrollbar-width: none;
    -webkit-overflow-scrolling: touch;
    mask-image: linear-gradient(
      90deg, transparent 0, #000 12px, #000 calc(100% - 12px), transparent 100%);
  }
  .nav-links::-webkit-scrollbar { display: none; }
  .nav-links a {
    flex: 0 0 auto; font-size: 13px; padding: 4px 0;
  }
  .nav-links a::after { display: none; }
}

/* =============== Hero =============== */
.hero {
  position: relative; padding: 100px 0 80px;
  min-height: 88vh; display: flex; align-items: center;
  overflow: hidden;
}
.hero-inner {
  display: grid; grid-template-columns: 1.1fr 1fr; gap: 60px;
  align-items: center;
}
.hero-kicker {
  display: inline-flex; align-items: center; gap: 10px;
  padding: 6px 14px; border-radius: 999px;
  border: 1px solid var(--line-strong);
  background: rgba(52,90,246,0.08);
  font-family: var(--font-mono); font-size: 12px;
  color: var(--brand-300);
  margin-bottom: 24px;
}
.hero-kicker .hk-cpp  { color: var(--accent); font-weight: 700; }
.hero-kicker .hk-perf { color: #b993ff; font-weight: 700; }
.hero-kicker .hk-light{ color: var(--brand-300); font-weight: 700; }
.hero-kicker .hk-easy { color: #d8deec; font-weight: 700; }
.hero-kicker .hk-safe { color: #ffb15c; font-weight: 700; }
.hero-kicker .dot {
  width: 6px; height: 6px; border-radius: 50%;
  background: var(--accent); box-shadow: 0 0 10px var(--accent);
  animation: pulse 1.6s ease-in-out infinite;
}
@keyframes pulse {
  0%, 100% { opacity: 1; transform: scale(1); }
  50%      { opacity: 0.4; transform: scale(0.8); }
}
.hero h1 {
  font-size: clamp(38px, 5.4vw, 72px);
  line-height: 1.08; font-weight: 800; letter-spacing: -0.02em;
  color: var(--ink-0); margin: 0 0 20px;
}
.hero h1 .grad {
  background: linear-gradient(90deg, var(--brand-400) 0%, var(--brand-300) 45%, var(--accent) 100%);
  -webkit-background-clip: text; background-clip: text; color: transparent;
}
.hero h1 .num {
  display: inline-block; color: var(--brand-400); font-variant-numeric: tabular-nums;
}
.hero-sub {
  font-size: clamp(15px, 1.4vw, 18px);
  color: var(--ink-2); max-width: 560px; margin: 0 0 36px;
}
.hero-sub strong { color: var(--ink-0); font-weight: 600; }
.hero-cta { display: flex; gap: 14px; flex-wrap: wrap; }
.btn {
  display: inline-flex; align-items: center; gap: 10px;
  padding: 14px 24px; border-radius: 12px;
  font-weight: 600; font-size: 14px;
  transition: transform .2s, box-shadow .2s, border-color .2s;
  cursor: pointer; border: none; font-family: inherit;
}
.btn-primary {
  background: linear-gradient(90deg, var(--brand-600), var(--brand-400));
  color: white; box-shadow: var(--shadow-2);
}
.btn-primary:hover { transform: translateY(-2px); color: white;
  box-shadow: 0 24px 60px rgba(52,90,246,0.4); }
.btn-ghost {
  background: rgba(255,255,255,0.03); color: var(--ink-0);
  border: 1px solid var(--line-strong);
}
.btn-ghost:hover { border-color: var(--brand-400); transform: translateY(-2px); color: var(--ink-0); }
.btn svg { width: 16px; height: 16px; }

.hero-meta {
  display: flex; gap: 28px; margin-top: 48px;
  color: var(--ink-2); font-size: 13px;
  flex-wrap: wrap;
}
.hero-meta > div { display: flex; align-items: center; gap: 8px; }
.hero-meta strong { color: var(--ink-0); font-weight: 700; font-family: var(--font-mono); }

/* ─── Platform strip ─── */
.hero-os {
  margin-top: 20px;
  display: flex; flex-direction: column;
  align-items: flex-start; gap: 10px;
}
.hero-os .os-label {
  font-family: var(--font-mono);
  font-size: 10.5px;
  letter-spacing: 0.22em;
  color: var(--brand-300);
  text-transform: uppercase;
  opacity: .9;
}
.hero-os .os-chips {
  display: flex; flex-wrap: wrap; align-items: center;
  gap: 6px;
}
.hero-os .os-chip {
  display: inline-flex; align-items: center; gap: 6px;
  padding: 4px 10px;
  border-radius: 999px;
  border: 1px solid var(--line-strong);
  background: rgba(17, 26, 56, 0.55);
  color: var(--ink-0);
  font-size: 11.5px; font-weight: 600;
  letter-spacing: 0.01em;
  white-space: nowrap;
  transition: border-color .18s, background .18s, transform .18s, color .18s;
}
.hero-os .os-chip:hover {
  border-color: var(--brand-400);
  background: rgba(52, 90, 246, 0.18);
  transform: translateY(-1px);
}
.hero-os .os-ico {
  color: var(--brand-300);
  flex-shrink: 0;
  shape-rendering: geometricPrecision;
}

/* Special accent: QNX (safety-certified automotive OS) */
.hero-os .os-chip-safety {
  border-color: rgba(255, 209, 102, 0.48);
  background: rgba(255, 209, 102, 0.1);
  color: #ffd166;
}
.hero-os .os-chip-safety .os-ico { color: #ffd166; }
.hero-os .os-chip-safety:hover {
  background: rgba(255, 209, 102, 0.22);
  border-color: #ffd166;
}

/* Architecture chip — sits after a subtle divider */
.hero-os .os-sep {
  display: inline-block; width: 1px; height: 16px;
  background: var(--line-strong);
  margin: 0 2px;
}
.hero-os .os-chip-arch {
  font-family: var(--font-mono);
  color: var(--accent);
  border-color: rgba(0, 229, 176, 0.4);
  background: rgba(0, 229, 176, 0.06);
  letter-spacing: 0.04em;
}
.hero-os .os-chip-arch .os-ico { color: var(--accent); }
.hero-os .os-chip-arch:hover {
  background: rgba(0, 229, 176, 0.15);
  border-color: var(--accent);
}

@media (max-width: 720px) {
  .hero-os .os-chips { gap: 5px; }
  .hero-os .os-chip { padding: 3px 9px; font-size: 11px; }
  .hero-os .os-sep { display: none; }
}

/* Hero right: animated terminal */
.hero-term {
  background: rgba(7, 11, 24, 0.85);
  border: 1px solid var(--line-strong);
  border-radius: var(--r-lg);
  box-shadow: var(--shadow-2);
  backdrop-filter: blur(10px);
  overflow: hidden;
  position: relative;
}
/* rotating conic halo removed per design feedback -- keep terminal static */

.term-bar {
  display: flex; align-items: center; gap: 10px;
  padding: 10px 14px; border-bottom: 1px solid var(--line);
  background: rgba(7,11,24,0.6);
}
.term-bar .dots { display: flex; gap: 6px; }
.term-bar .dots span { width: 10px; height: 10px; border-radius: 50%; background: #2a355a; }
.term-bar .dots span:nth-child(1) { background: #ff5f56; }
.term-bar .dots span:nth-child(2) { background: #ffbd2e; }
.term-bar .dots span:nth-child(3) { background: #27c93f; }
.term-bar .title {
  font-family: var(--font-terminal); font-size: 11px; color: var(--ink-2);
  margin-left: 8px;
}
.term-body {
  padding: 22px 24px; font-family: var(--font-terminal);
  font-size: 13.5px; line-height: 1.75; color: var(--ink-1);
  min-height: 320px;
  white-space: pre;             /* critical: preserve code indentation & line breaks */
  overflow-x: auto;
  tab-size: 2;
  font-variant-numeric: tabular-nums slashed-zero;
  font-kerning: none;
}
.term-body > * { white-space: pre; }
.term-body .comment { color: var(--ink-3); }
.term-body .kw   { color: #c792ea; }
.term-body .tpl  { color: #82aaff; }
.term-body .str  { color: var(--accent); }
.term-body .fn   { color: #ffd166; }
.term-body .punc { color: var(--ink-2); }
.caret {
  display: inline-block;
  width: 2px;
  height: 1.08em;
  vertical-align: -0.14em;
  background: rgba(236, 242, 255, 0.96);
  animation: blink 1.06s steps(1, end) infinite;
  margin-left: 0;
  border-radius: 0;
}
@keyframes blink {
  0%, 47% { opacity: 1; }
  48%, 100% { opacity: 0; }
}

.hero-radial {
  margin: 0;
  position: relative;
  display: flex; justify-content: center; align-items: center;
  filter: drop-shadow(0 30px 60px rgba(52, 90, 246, 0.25));
}
.hero-radial img {
  width: 100%;
  max-width: 560px;
  height: auto;
  display: block;
}

@media (max-width: 980px) {
  .hero-inner { grid-template-columns: 1fr; }
  .hero { padding: 56px 0; min-height: auto; }
  .hero-radial img { max-width: 420px; margin-inline: auto; }
}

/* =============== Section common =============== */
.section { padding: 110px 0; position: relative; }
.section-eyebrow {
  font-family: var(--font-mono); font-size: 12px; letter-spacing: 0.2em;
  color: var(--brand-400); text-transform: uppercase;
}
.section-title {
  font-size: clamp(28px, 3.2vw, 44px);
  font-weight: 800; letter-spacing: -0.01em;
  color: var(--ink-0); margin: 10px 0 14px; line-height: 1.15;
}
.section-title .grad {
  background: linear-gradient(90deg, var(--brand-400), var(--accent));
  -webkit-background-clip: text; background-clip: text; color: transparent;
}
.section-sub { font-size: 16px; color: var(--ink-2); max-width: 700px; }
.section-head { margin-bottom: 54px; }
.section-head.center { text-align: center; }
.section-head.center .section-sub { margin-inline: auto; }

/* =============== Why VLink =============== */
.why-grid {
  display: grid;
  /* auto-fit keeps 2×2 on desktop when there's a 4th card, instead of 3+1 */
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 24px;
}
.why-card {
  position: relative;
  padding: 32px 28px; border-radius: var(--r-lg);
  border: 1px solid var(--line);
  background: linear-gradient(180deg, rgba(17,26,56,0.7), rgba(11,18,40,0.5));
  overflow: hidden; transition: transform .3s, border-color .3s;
}
.why-card::before {
  content: ""; position: absolute; top: 0; left: 0; right: 0; height: 2px;
  background: linear-gradient(90deg, transparent, var(--brand-400), transparent);
  opacity: 0; transition: opacity .3s;
}
.why-card:hover { transform: translateY(-4px); border-color: var(--line-strong); }
.why-card:hover::before { opacity: 1; }
.why-card .ico {
  width: 44px; height: 44px; border-radius: 12px; margin-bottom: 20px;
  display: grid; place-items: center;
  background: rgba(52,90,246,0.12); color: var(--brand-400);
  border: 1px solid var(--line-strong);
}
.why-card h3 { color: var(--ink-0); font-size: 20px; margin: 0 0 10px; }
.why-card p { color: var(--ink-2); font-size: 14.5px; margin: 0; }
.why-card .vs {
  margin-top: 18px; padding-top: 16px; border-top: 1px dashed var(--line);
  display: flex; justify-content: space-between; font-size: 12px;
  font-family: var(--font-mono); color: var(--ink-3);
}
.why-card .vs strong { color: var(--accent); font-weight: 600; }
.why-card .vs .strike { text-decoration: line-through; opacity: 0.7; }

@media (max-width: 860px) { .why-grid { grid-template-columns: 1fr; } }

/* =============== Number strip =============== */
.numbers {
  display: grid; grid-template-columns: repeat(4, 1fr); gap: 0;
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
  margin-top: 60px;
}
.num-item {
  padding: 30px 20px; text-align: center;
  border-right: 1px solid var(--line);
}
.num-item:last-child { border-right: none; }
.num-item .big {
  font-family: var(--font-mono); font-weight: 700;
  font-size: 48px; line-height: 1; color: var(--ink-0);
  background: linear-gradient(180deg, var(--brand-300), var(--brand-500));
  -webkit-background-clip: text; background-clip: text; -webkit-text-fill-color: transparent;
}
/* "+" suffix for animated counters marked as .count-plus (e.g. 12+ transports). */
.num-item .big.count-plus::after {
  content: "+"; font-size: 0.6em; vertical-align: 0.45em;
  margin-left: 2px;
  -webkit-background-clip: text; background-clip: text;
}
.num-item .label {
  margin-top: 10px; font-size: 13px; color: var(--ink-2);
  font-family: var(--font-mono); letter-spacing: 0.12em; text-transform: uppercase;
}
@media (max-width: 700px) {
  .numbers { grid-template-columns: repeat(2, 1fr); }
  .num-item:nth-child(2) { border-right: none; }
  .num-item { border-bottom: 1px solid var(--line); }
}

/* =============== Unified API + Transport Matrix (merged section) ========
   Row 1: four HEADLINE "benefit" feature-tiles with big numbered badges,
          a glowing gradient border, and large bold titles. These read as
          hero cards — the "why you want this".
   ——————— dashed divider with sub-heading ———————
   Row 2: 12 plain-bordered transport cards — the catalogue of backends.
   The stylistic gap between the two rows is intentional. */
.unified-benefits {
  list-style: none; padding: 0; margin: 0 0 40px;
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 16px;
  counter-reset: benefit;
}
@media (max-width: 1100px) {
  .unified-benefits { grid-template-columns: repeat(2, minmax(0, 1fr)); }
}
@media (max-width: 620px) {
  .unified-benefits { grid-template-columns: 1fr; }
}
.unified-benefits li {
  position: relative;
  padding: 22px 22px 20px;
  border: 1px solid rgba(79, 170, 253, 0.22);
  border-radius: var(--r-md);
  background:
    radial-gradient(600px 200px at 0% 0%, rgba(0, 229, 176, 0.08), transparent 60%),
    linear-gradient(180deg, rgba(22, 32, 72, 0.75), rgba(13, 20, 46, 0.55));
  color: var(--ink-2); font-size: 13.5px; line-height: 1.65;
  transition: transform .25s, border-color .25s, box-shadow .25s;
  overflow: hidden;
  counter-increment: benefit;
}
.unified-benefits li::after {
  /* Accent bar that glows on hover — gives the tile a "feature card" feel. */
  content: "";
  position: absolute; left: 0; top: 0; bottom: 0;
  width: 3px;
  background: linear-gradient(180deg, var(--accent), var(--brand-400));
  opacity: 0.85;
}
.unified-benefits li:hover {
  border-color: rgba(79, 170, 253, 0.55);
  transform: translateY(-4px);
  box-shadow: 0 16px 40px rgba(52, 90, 246, 0.28);
}
.unified-benefits li::before {
  /* Check-mark chip in the top-right — replaces the earlier "01/02" numerals. */
  content: "✓";
  position: absolute; top: 14px; right: 14px;
  width: 26px; height: 26px; border-radius: 8px;
  display: grid; place-items: center;
  background: linear-gradient(135deg, rgba(0, 229, 176, 0.22), rgba(52, 90, 246, 0.18));
  color: var(--accent);
  font-weight: 800; font-size: 14px; line-height: 1;
  box-shadow: 0 0 0 1px rgba(0, 229, 176, 0.35), 0 0 14px rgba(0, 229, 176, 0.16);
}
.unified-benefits li strong {
  color: var(--ink-0); font-weight: 700;
  display: block; margin-bottom: 6px;
  font-size: 16px; letter-spacing: -0.005em;
  max-width: calc(100% - 36px);   /* keep title clear of the ✓ chip */
}
.unified-benefits li code {
  font-family: var(--font-mono);
  font-size: 12.5px;
  padding: 2px 7px;
  background: rgba(52, 90, 246, 0.18);
  border: 1px solid rgba(79, 170, 253, 0.18);
  border-radius: 5px;
  color: var(--brand-300);
}

/* Transport matrix sub-heading — separates the catalogue from the benefits
   row above so the visual "what you get" ≠ "what's available" reads clean. */
.unified-matrix-head {
  display: flex; flex-direction: column; align-items: flex-start;
  gap: 6px;
  margin-bottom: 22px;
  padding-top: 10px;
  border-top: 1px dashed var(--line);
}
.unified-matrix-label {
  font-family: var(--font-mono); font-size: 11.5px; font-weight: 600;
  letter-spacing: 0.22em; text-transform: uppercase;
  color: var(--brand-400);
  margin-top: 16px;
}
.unified-matrix-title {
  margin: 0;
  color: var(--ink-0);
  font-size: 22px; font-weight: 700; letter-spacing: -0.005em;
}

/* =============== Three Models =============== */
/* Single column, full-width within the container. Cards stack top-down
   (Event → Method → Field) so the eye reads as one continuous flow; never
   lay them out side-by-side. */
.models {
  display: flex; flex-direction: column; gap: 28px;
  width: 100%;
}
.model-card {
  position: relative;
  background: linear-gradient(180deg, rgba(17,26,56,0.65), rgba(11,18,40,0.4));
  border: 1px solid var(--line); border-radius: var(--r-lg);
  padding: 28px; overflow: hidden;
  transition: transform .3s, border-color .3s, box-shadow .3s;
}
.model-card:hover { transform: translateY(-6px); border-color: var(--brand-400);
  box-shadow: var(--glow); }
.model-card .tag {
  font-family: var(--font-mono); font-size: 11px;
  color: var(--brand-400); letter-spacing: 0.15em; text-transform: uppercase;
}
.model-card h3 { font-size: 22px; color: var(--ink-0); margin: 8px 0 6px; }
.model-card .desc { color: var(--ink-2); font-size: 13.5px; margin: 0 0 18px; }
.model-card pre {
  margin: 0; padding: 16px; border-radius: var(--r-md);
  background: rgba(0,0,0,0.45); border: 1px solid var(--line);
  font-family: var(--font-mono); font-size: 12.5px; line-height: 1.7;
  color: var(--ink-1); overflow-x: auto;
}
.model-card pre .kw   { color: #c792ea; }
.model-card pre .tpl  { color: #82aaff; }
.model-card pre .str  { color: var(--accent); }
.model-card pre .fn   { color: #ffd166; }
.model-card pre .com  { color: var(--ink-3); font-style: italic; }

/* highlighter tokens (shared across .term-body highlighter) */
.term-body .kw      { color: #c792ea; }        /* keywords        */
.term-body .ns      { color: #89ddff; }        /* namespaces      */
.term-body .tpl     { color: #82aaff; }        /* template types  */
.term-body .fn      { color: #ffd166; }        /* method calls    */
.term-body .macro   { color: #ff8a65; }        /* VLOG_ macros    */
.term-body .str     { color: var(--accent); }
.term-body .comment { color: var(--ink-3); font-style: italic; }
.term-body .num-lit { color: #f78c6c; }

/* =============== Domestic / 国产化 strip =============== */
.domestic {
  margin-top: 40px; padding: 28px 32px;
  display: flex; align-items: center; gap: 24px;
  border-radius: var(--r-lg);
  background: linear-gradient(135deg, rgba(255,107,107,0.06), rgba(0,229,176,0.08));
  border: 1px solid rgba(0,229,176,0.25);
  position: relative; overflow: hidden;
}
.domestic::before {
  content: ""; position: absolute; right: -60px; top: -60px;
  width: 220px; height: 220px; border-radius: 50%;
  background: radial-gradient(circle, rgba(255,209,102,0.18), transparent 70%);
}
.domestic-ico {
  flex-shrink: 0; width: 62px; height: 62px; border-radius: 16px;
  display: grid; place-items: center;
  color: #ffd166;
  background: radial-gradient(circle, rgba(255,209,102,0.15), rgba(255,209,102,0.04));
  border: 1px solid rgba(255,209,102,0.35);
}
.domestic h3 {
  color: var(--ink-0); margin: 0 0 6px; font-size: 18px;
  letter-spacing: 0.02em;
}
.domestic p {
  color: var(--ink-2); margin: 0; font-size: 14px; line-height: 1.7;
}
.domestic p strong { color: #ffd166; font-weight: 700; }
@media (max-width: 700px) { .domestic { flex-direction: column; align-items: flex-start; } }
.model-card .arrow {
  position: absolute; bottom: 18px; right: 18px;
  color: var(--brand-400); font-size: 18px; opacity: 0;
  transition: opacity .3s, transform .3s;
}
.model-card:hover .arrow { opacity: 1; transform: translateX(4px); }

/* =============== Transport Matrix =============== */
.matrix-wrap {
  display: grid; grid-template-columns: repeat(4, 1fr); gap: 16px;
}
.mx {
  position: relative;
  padding: 22px 20px; border-radius: var(--r-md);
  border: 1px solid var(--line);
  background: linear-gradient(180deg, rgba(17,26,56,0.6), rgba(11,18,40,0.35));
  transition: transform .25s, border-color .25s, box-shadow .25s;
  cursor: default;
}
.mx:hover {
  transform: translateY(-4px); border-color: var(--brand-400);
  box-shadow: var(--glow);
}
.mx .transport-prefix {
  font-family: var(--font-mono); font-size: 15px; font-weight: 700;
  color: var(--brand-300);
}
.mx .transport-prefix::after { content: "://"; color: var(--ink-3); }
.mx .name { margin-top: 6px; color: var(--ink-0); font-weight: 600; font-size: 14px; }
.mx .meta { margin-top: 4px; font-size: 12px; color: var(--ink-2); }
.mx .status {
  position: absolute; top: 14px; right: 14px;
  font-family: var(--font-mono); font-size: 10px; padding: 2px 8px;
  border-radius: 999px; letter-spacing: 0.08em;
}
.status.stable { color: var(--accent); background: rgba(0,229,176,0.12); border: 1px solid rgba(0,229,176,0.3); }
.status.beta   { color: var(--accent-2); background: rgba(255,209,102,0.12); border: 1px solid rgba(255,209,102,0.3); }
.status.wip    { color: var(--ink-3); background: rgba(140,152,185,0.1); border: 1px solid var(--line-strong); }
.mx .tags { margin-top: 12px; display: flex; flex-wrap: wrap; gap: 6px; }
.mx .tag {
  font-family: var(--font-mono); font-size: 10px;
  padding: 2px 8px; border-radius: 999px;
  background: rgba(79,170,253,0.08); color: var(--brand-300);
  border: 1px solid rgba(79,170,253,0.18);
}
.mx .tag.zc { color: var(--accent); background: rgba(0,229,176,0.08);
              border-color: rgba(0,229,176,0.22); }

@media (max-width: 980px) { .matrix-wrap { grid-template-columns: repeat(2,1fr); } }
@media (max-width: 560px) { .matrix-wrap { grid-template-columns: 1fr; } }

/* =============== Quickstart: tag + title + caption + terminal ===============
   Row layout (outer grid):
     Row 1  head     (tag + title)
     Row 2  desc     (caption paragraph)
     Row 3  terminal (code / log)
     Row 4  live run (spans both columns)
   Pub/Sub blocks use `grid-row: subgrid` over rows 1–3 so their heads,
   descriptions, and terminal windows line up exactly regardless of how
   long each caption is. */
.qs-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(0, 1fr);
  grid-template-rows: auto auto 1fr auto;
  gap: 12px 28px;
  align-items: stretch;
}
.qs-grid > * { min-width: 0; }

.qs-block {
  display: grid;
  grid-template-rows: subgrid;
  grid-row: 1 / 4;
  row-gap: inherit;
}
.qs-block-live {
  display: flex; flex-direction: column; gap: 10px;
  grid-column: 1 / -1;
  grid-row: 4;
  margin-top: 24px;
  padding-top: 24px;
  border-top: 1px solid var(--line);
  position: relative;
}
.qs-block-live::before {
  content: "";
  position: absolute; top: -1px; left: 0;
  width: 80px; height: 2px;
  background: linear-gradient(90deg, var(--accent), transparent);
  border-radius: 1px;
}

.qs-block-head {
  display: flex; align-items: center; flex-wrap: wrap;
  gap: 10px; margin: 0;
}
.qs-block-title {
  margin: 0;
  color: var(--ink-0);
  font-size: 17px; font-weight: 700; letter-spacing: -0.005em;
}
.qs-desc {
  margin: 0; color: var(--ink-2);
  font-size: 13.5px; line-height: 1.65;
}
.qs-desc code {
  font-family: var(--font-mono); font-size: 12px;
  padding: 1px 6px; border-radius: 4px;
  background: rgba(52, 90, 246, 0.14); color: var(--brand-300);
}

.qs-tag {
  font-family: var(--font-mono); font-size: 10.5px; font-weight: 600;
  letter-spacing: 0.08em; text-transform: uppercase;
  color: var(--brand-300);
  padding: 3px 9px; border-radius: 999px;
  border: 1px solid rgba(79, 170, 253, 0.32);
  background: rgba(52, 90, 246, 0.12);
  flex-shrink: 0;
}
.qs-tag-live {
  color: var(--accent);
  border-color: rgba(0, 229, 176, 0.4);
  background: rgba(0, 229, 176, 0.08);
}
.qs-tag-notes {
  color: var(--accent-2);
  border-color: rgba(255, 209, 102, 0.4);
  background: rgba(255, 209, 102, 0.08);
}

.qs-file { display: flex; flex-direction: column; flex: 1; }
.qs-file .term-body { flex: 1; }
.qs-file .term-bar .title {
  display: inline-flex; align-items: center; gap: 10px;
  font-family: var(--font-mono); font-size: 11px; color: var(--ink-2);
}
.qs-file .qs-fname { color: var(--ink-3); }

/* "How it works" description panel in the bottom-right cell. */
.qs-notes .qs-notes-body {
  flex: 1;
  padding: 22px 24px;
  border: 1px solid var(--line);
  border-radius: var(--r-lg);
  background: linear-gradient(180deg, rgba(17,26,56,0.65), rgba(11,18,40,0.4));
}
.qs-notes p {
  margin: 0 0 14px; color: var(--ink-1);
  font-size: 14px; line-height: 1.7;
}
.qs-notes p strong { color: var(--ink-0); font-weight: 600; }
.qs-notes ul {
  list-style: none; padding: 0; margin: 0 0 14px;
  display: flex; flex-direction: column; gap: 8px;
}
.qs-notes li {
  position: relative; padding-left: 22px;
  color: var(--ink-2);
  font-size: 13.5px; line-height: 1.6;
}
.qs-notes li::before {
  content: "→"; position: absolute; left: 0; top: 0;
  color: var(--brand-400); font-family: var(--font-mono);
}
.qs-notes li strong { color: var(--ink-0); font-weight: 600; }
.qs-notes code {
  font-family: var(--font-mono); font-size: 12px;
  padding: 1px 6px; border-radius: 4px;
  background: rgba(52, 90, 246, 0.14); color: var(--brand-300);
}

.qs-demo-frame {
  border-radius: var(--r-md);
  border: 1px solid var(--line-strong);
  background: rgba(7,11,24,0.85);
  overflow: hidden;
  box-shadow: var(--shadow-1);
}
.qs-demo-head {
  display: flex; align-items: center; gap: 6px;
  padding: 10px 14px; border-bottom: 1px solid var(--line);
  background: rgba(7,11,24,0.6);
}
.qs-demo-head .ql-dot {
  width: 9px; height: 9px; border-radius: 50%; background: #2a355a;
}
.qs-demo-head .ql-dot:nth-child(1) { background: #ff5f56; }
.qs-demo-head .ql-dot:nth-child(2) { background: #ffbd2e; }
.qs-demo-head .ql-dot:nth-child(3) { background: #27c93f; }
.qs-demo-head .qs-demo-title {
  font-family: var(--font-terminal); font-size: 11px; color: var(--ink-2);
  margin-left: 6px;
}
.qs-demo-frame img { width: 100%; display: block; }
.qs-demo-log {
  margin: 0;
  padding: 16px 18px;
  background: #0c0c0c;
  color: #4af626;
  font-family: var(--font-terminal);
  font-size: 12.5px;
  line-height: 1.7;
  white-space: pre;
  font-variant-numeric: tabular-nums slashed-zero;
  font-kerning: none;
  /* hide scrollbars — content flows internally but the frame is seamless */
  overflow-x: hidden;
  overflow-y: auto;
  scrollbar-width: none;
  -ms-overflow-style: none;
  height: 300px;
  /* lock the outer width so long <pre> lines can't push the grid track wider */
  width: 100%;
  max-width: 100%;
  min-width: 0;
  box-sizing: border-box;
  contain: size layout;
}
.qs-demo-log::-webkit-scrollbar { display: none; width: 0; height: 0; }
/* Log output is intentionally monochrome — colors removed so it reads as a
   plain terminal transcript, consistent with what the real programs print. */
.qs-demo-log .qs-i,
.qs-demo-log .qs-hl,
.qs-demo-log .qs-url,
.qs-demo-log .qs-n,
.qs-demo-log .qs-p,
.qs-demo-log .qs-s { color: inherit; font-weight: inherit; text-decoration: none; }

/* =============== CLI Gallery — toolbar on top, full-width stage =============== */
.cli-grid {
  display: flex;
  flex-direction: column;
  gap: 28px;
}
.cli-card {
  display: flex;
  flex-direction: column;
  gap: 14px;
  width: 100%;
}
.cli-card-monitor {
  width: 100%;
}
.cli-card-copy {
  padding: 20px 22px 0;
}
.cli-card-copy h3 {
  margin: 8px 0 10px;
  color: var(--ink-0);
  font-size: 22px;
  line-height: 1.2;
}
.cli-card-copy p {
  margin: 0;
  color: var(--ink-2);
  font-size: 14px;
  line-height: 1.75;
  max-width: 72ch;
}
.cli-overview {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 18px;
  margin-bottom: 18px;
}
.cli-overview-card {
  padding: 20px 20px 18px;
  border-radius: var(--r-lg);
  border: 1px solid var(--line);
  background:
    linear-gradient(180deg, rgba(17, 26, 56, 0.82), rgba(11, 18, 40, 0.92)),
    radial-gradient(420px 220px at 0% 0%, rgba(79, 170, 253, 0.08), transparent 70%);
  box-shadow: 0 16px 36px rgba(0, 0, 0, 0.18);
}
.cli-overview-kicker {
  display: inline-flex;
  align-items: center;
  padding: 4px 10px;
  border-radius: 999px;
  border: 1px solid rgba(79, 170, 253, 0.22);
  background: rgba(52, 90, 246, 0.14);
  color: var(--brand-300);
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.02em;
  margin-bottom: 12px;
}
.cli-overview-card h3 {
  margin: 0 0 10px;
  color: var(--ink-0);
  font-size: 18px;
  line-height: 1.35;
}
.cli-overview-card p {
  margin: 0;
  color: var(--ink-2);
  font-size: 14px;
  line-height: 1.7;
}
.cli-chip-row {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin: 14px 0 20px;
}
.cli-chip {
  display: inline-flex;
  align-items: center;
  padding: 6px 10px;
  border-radius: 999px;
  border: 1px solid rgba(127, 196, 255, 0.18);
  background: rgba(12, 18, 36, 0.7);
  color: var(--ink-0);
  font-family: var(--font-mono);
  font-size: 11.5px;
}
.cli-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-bottom: 16px;
}
.cli-note {
  margin: 0 0 18px;
  padding: 14px 16px;
  border-left: 3px solid var(--brand-400);
  border-radius: 0 var(--r-md) var(--r-md) 0;
  background: rgba(17, 26, 56, 0.46);
  color: var(--ink-2);
  font-size: 14px;
  line-height: 1.75;
}
.cli-gallery {
  display: flex; flex-direction: column; gap: 18px;
  align-items: stretch;
}
.cli-tabs {
  display: flex; flex-direction: row; flex-wrap: wrap; gap: 8px;
}
.cli-tab {
  flex: 1 1 0;
  min-width: 0;
  text-align: center; padding: 12px 14px; border-radius: var(--r-md);
  background: rgba(17,26,56,0.4); border: 1px solid var(--line);
  color: var(--ink-1); cursor: pointer; transition: all .2s;
  display: flex; flex-direction: column; align-items: center; gap: 6px;
  font-family: inherit;
}
.cli-tab .icon {
  width: 32px; height: 32px; border-radius: 8px;
  display: grid; place-items: center; flex-shrink: 0;
  background: rgba(52,90,246,0.12); color: var(--brand-400);
  border: 1px solid var(--line-strong);
}
.cli-tab .txt {
  display: flex; flex-direction: column; align-items: center; gap: 3px;
  width: 100%;                              /* constrain to tab cell width */
  min-width: 0;
}
.cli-tab .name {
  font-family: var(--font-mono); font-size: 12.5px; font-weight: 700;
  color: var(--ink-0); white-space: nowrap;
  overflow: hidden; text-overflow: ellipsis; max-width: 100%;
}
.cli-tab .desc {
  font-size: 10.5px; color: var(--ink-2); line-height: 1.35;
  text-align: center;
  /* allow wrapping instead of spilling out of the tab cell */
  white-space: normal;
  word-break: break-word;
  overflow-wrap: anywhere;
  /* cap at 2 lines so tall labels can't blow up row height */
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
  max-height: 2.7em;
}
/* EN / JA labels are wider — lighten the desc further so 2 lines fit */
html[lang="en"]    .cli-tab .desc,
html[lang="ja-JP"] .cli-tab .desc { font-size: 9.5px; line-height: 1.3; }
.cli-tab:hover { border-color: var(--line-strong); background: rgba(17,26,56,0.7); }
.cli-tab.active {
  border-color: var(--brand-400);
  background: linear-gradient(180deg, rgba(52,90,246,0.22), rgba(17,26,56,0.4));
  box-shadow: var(--glow);
}
.cli-tab.active .icon { background: linear-gradient(135deg, var(--brand-600), var(--brand-400)); color: white; border-color: var(--brand-400); }
@media (max-width: 860px) {
  .cli-card-copy { padding: 18px 18px 0; }
  .cli-overview { grid-template-columns: 1fr; }
  .cli-tabs { flex-wrap: wrap; }
  .cli-tab { flex: 1 1 calc(25% - 8px); }
  .cli-tab .desc { display: none; }
}
.cli-stage {
  background: #0c0c0c;                             /* simulate a real terminal */
  border: 1px solid #2a2a2a;
  border-radius: var(--r-lg);
  overflow: hidden;
  box-shadow: 0 20px 50px rgba(0,0,0,0.55), inset 0 0 0 1px rgba(255,255,255,0.02);
}
.cli-stage .term-bar {
  background: linear-gradient(#262626, #1a1a1a);
  border-bottom: 1px solid #2a2a2a;
}
.cli-stage .term-bar .title { color: #d4d4d4; }
.cli-stage .term-bar .title strong { color: #98c379; }
.cli-stage .term-body {
  /* Fixed height keeps the stage from jumping between tabs.
     Internal overflow is scrollable for long demos but the scrollbar is hidden. */
  height: 700px;
  white-space: pre;
  overflow-x: hidden;
  overflow-y: auto;
  scrollbar-width: none;
  -ms-overflow-style: none;
  font-size: 12.5px; line-height: 1.65;
  background: #0c0c0c;
  color: #e6e6e6;
  font-family: var(--font-terminal);
  font-variant-ligatures: none;
  font-feature-settings: "liga" 0, "calt" 0;
  font-variant-numeric: tabular-nums slashed-zero;
  font-kerning: none;
  padding: 18px 22px;
  box-sizing: border-box;
}
.cli-card-monitor .term-body {
  height: 700px;
}
.cli-card:not(.cli-card-monitor) .term-body { height: 700px; }
.cli-stage .term-body::-webkit-scrollbar { display: none; width: 0; height: 0; }
.cli-stage .term-body .on   { text-decoration: underline;
                              text-decoration-color: #5ec8ff;
                              text-underline-offset: 2px;
                              color: #ffffff; font-weight: 700; }
.cli-stage .term-body .tpub { color: #4af626; font-weight: 700; }
.cli-stage .term-body .tsub { color: #5ec8ff; font-weight: 700; }
/* ANSI-accurate palette, scoped to CLI stage only */
.cli-stage .term-body .ok   { color: #4af626; }    /* ANSI bright green  */
.cli-stage .term-body .warn { color: #ffcc00; }    /* ANSI bright yellow */
.cli-stage .term-body .err  { color: #ff5555; }    /* ANSI bright red    */
.cli-stage .term-body .url  { color: #5ec8ff;      /* ANSI bright cyan   */
                               text-decoration: underline;
                               text-decoration-color: rgba(94,200,255,0.35); }
.cli-stage .term-body .dim  { color: #7d7d7d; }    /* ANSI dim / gray    */
.cli-stage .term-body .head { color: #ffffff; font-weight: 700; }
.cli-stage .term-body .term-cursor {
  display: inline-block;
  width: 1ch;
  color: #ffffff;
  animation: blink 1.06s steps(1, end) infinite;
}
.cli-stage .term-body .num  { color: #e5c07b; }    /* numeric / values   */
.cli-stage .term-body .hi   { background: #2d4f7c; color: #ffffff;
                               padding: 0 6px; border-radius: 3px; }
.cli-stage .term-body .monitor-head {
  display: inline-block;
  vertical-align: top;
  background: #235ea7;
  color: #ffffff;
  font-weight: 700;
  padding: 0;
  border-radius: 0;
}
.cli-stage .term-body .monitor-sel {
  display: inline-block;
  vertical-align: top;
  background: #f1f3f5;
  color: #111111;
  font-weight: 700;
  padding: 0;
  border-radius: 0;
}
.cli-stage .term-body .monitor-row {
  display: flex;
  align-items: flex-start;
  width: 100%;
  white-space: pre;
}
.cli-stage .term-body .monitor-row .monitor-left {
  display: block;
  flex: 1 1 auto;
  min-width: 0;
  white-space: pre;
  overflow: hidden;
}
.cli-stage .term-body .monitor-row .monitor-right {
  display: block;
  flex: 0 0 auto;
  white-space: pre;
}
.cli-stage .term-body .monitor-bar {
  display: inline-block;
  flex: 0 0 1ch;
  vertical-align: top;
  width: 1ch;
  background: #235ea7;
  color: transparent;
  overflow: hidden;
}
.cli-stage .term-body .monitor-ok { color: #4af626; }
.cli-stage .term-body .monitor-warn { color: #ffcc00; }
.cli-stage .term-body .monitor-err { color: #ff5555; }
.cli-stage .term-body .monitor-plain { color: #f1f3f5; }

.cli-line-note {
  padding: 10px 20px; border-top: 1px solid #1e1e1e;
  font-size: 12px; color: #7d7d7d;
  font-family: var(--font-terminal);
  background: #141414;
  display: flex; justify-content: space-between;
}

/* tab layout is now row-based by default; mobile tweaks are inline above */

/* Terminal color classes shared */
.term-body .ok     { color: var(--accent); }
.term-body .warn   { color: var(--accent-2); }
.term-body .err    { color: #ff6b6b; }
.term-body .url    { color: var(--brand-400); text-decoration: underline;
                     text-decoration-color: rgba(79,170,253,0.4); }
.term-body .dim    { color: var(--ink-3); }
.term-body .head   { color: var(--ink-0); font-weight: 600; }
.term-body .num    { color: #ffd166; }
.term-body .hi     { background: rgba(52,90,246,0.25);
                     color: var(--ink-0); padding: 0 6px; border-radius: 3px; }

/* ========================================================================
   Visualization gallery  —  same pattern as .cli-card.
   · .viz-card has NO outer border / background (just a flex column with gap).
   · .viz-meta is a plain text block (tag + h3 + description), no decoration.
   · .viz-mock is a standalone panel carrying its own border / radius / shadow.
   ======================================================================== */

/* ─── Grid (one column, airy gap between cards) ─── */
.viz-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 56px;
}

/* ─── Card = flex column, no chrome ─── */
.viz-card {
  display: flex;
  flex-direction: column;
  gap: 14px;
  width: 100%;
  border: 0;
  background: transparent;
  box-shadow: none;
  border-radius: 0;
  overflow: visible;
}
.viz-card:hover { transform: none; }    /* no more card-level hover glow */

/* ─── Meta: plain text block above the mock ─── */
.viz-meta {
  padding: 20px 22px 0;
  background: transparent;
  border: 0;
}
.viz-meta .tag {
  display: inline-block;
  padding: 3px 10px;
  border-radius: 999px;
  background: rgba(79, 170, 253, 0.10);
  font-family: var(--font-mono);
  font-size: 10.5px;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--brand-400);
}
.viz-meta h3 {
  margin: 8px 0 10px;
  color: var(--ink-0);
  font-size: 22px;
  font-weight: 700;
  line-height: 1.2;
  letter-spacing: -0.005em;
}
.viz-meta p {
  margin: 0;
  color: var(--ink-2);
  font-size: 14px;
  line-height: 1.75;
  max-width: 72ch;
}

/* ─── Rich bullet description for #viz cards ─── */
.viz-desc { color: var(--ink-2); font-size: 14px; line-height: 1.7; }
.viz-desc .viz-intro {
  margin: 0 0 10px;
  color: var(--ink-1);
  font-size: 14px;
  font-weight: 600;
}
.viz-desc ul {
  margin: 0; padding: 0; list-style: none;
  display: flex; flex-direction: column; gap: 6px;
  max-width: 72ch;
}
.viz-desc li {
  position: relative;
  padding-left: 18px;
  font-size: 13px;
  line-height: 1.65;
  color: var(--ink-2);
}
.viz-desc li::before {
  content: "▸";
  position: absolute; left: 2px; top: 0;
  color: var(--brand-400);
  font-size: 11px;
}
.viz-desc li code {
  background: rgba(79, 170, 253, 0.12);
  color: var(--brand-300);
  padding: 1px 6px; border-radius: 3px;
  font-family: var(--font-mono); font-size: 12px;
}

/* ─── Mock: standalone panel, same visual weight as .cli-stage ─── */
.viz-mock {
  width: 100%;
  background: #070b18;
  border: 1px solid var(--line);
  border-radius: var(--r-lg);
  overflow: hidden;
  position: relative;
  box-shadow: 0 20px 50px rgba(0,0,0,0.55), inset 0 0 0 1px rgba(255,255,255,0.02);
  transition: border-color .3s ease, transform .3s ease;
}
.viz-card:hover .viz-mock {
  border-color: var(--brand-400);
  transform: translateY(-2px);
}
#scenes .viz-card .viz-mock { aspect-ratio: 16 / 9; }        /* scenes: 800×450 */
#viz    .viz-card .viz-mock { aspect-ratio: 720 / 420; }     /* viz: 720×420 */
.viz-mock svg,
.viz-mock canvas,
.viz-mock video,
.viz-mock img {
  width: 100%; height: 100%;
  display: block;
  object-fit: contain !important;
}
/* (old duplicate .viz-mock / .viz-meta block removed —
    single source of truth is the block above.) */

@media (max-width: 860px) { .viz-grid { grid-template-columns: 1fr; } }

/* =============== Features (QoS / Security / Zerocopy / Bag) =============== */
.feat-grid {
  display: grid; grid-template-columns: repeat(4, 1fr); gap: 18px;
}
.feat {
  padding: 26px 22px; border-radius: var(--r-md);
  border: 1px solid var(--line);
  background: rgba(17,26,56,0.5);
  transition: all .3s;
  position: relative; overflow: hidden;
}
.feat:hover { border-color: var(--brand-400); transform: translateY(-3px); }
.feat::before {
  content: ""; position: absolute; width: 120px; height: 120px;
  right: -40px; top: -40px;
  background: radial-gradient(circle, rgba(79,170,253,0.15), transparent 70%);
  border-radius: 50%; opacity: 0; transition: opacity .3s;
}
.feat:hover::before { opacity: 1; }
.feat .ico {
  width: 40px; height: 40px; border-radius: 10px; margin-bottom: 16px;
  display: grid; place-items: center;
  background: linear-gradient(135deg, rgba(52,90,246,0.3), rgba(79,170,253,0.15));
  color: var(--brand-300); border: 1px solid var(--line-strong);
}
.feat h4 { color: var(--ink-0); margin: 0 0 8px; font-size: 17px; }
.feat p  { color: var(--ink-2); font-size: 13.5px; margin: 0 0 12px; }
.feat .link {
  font-family: var(--font-mono); font-size: 12px; color: var(--brand-400);
  display: inline-flex; align-items: center; gap: 4px;
}
.feat .link:hover { color: var(--brand-300); }

@media (max-width: 980px) { .feat-grid { grid-template-columns: repeat(2,1fr); } }
@media (max-width: 560px) { .feat-grid { grid-template-columns: 1fr; } }

/* =============== Docs / Links =============== */
.hub-grid {
  display: grid; grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 22px;
}
.hub-card {
  padding: 34px 28px; border-radius: var(--r-lg);
  border: 1px solid var(--line);
  background: linear-gradient(180deg, rgba(17,26,56,0.7), rgba(11,18,40,0.4));
  transition: all .3s; position: relative; overflow: hidden;
}
.hub-card:hover { border-color: var(--brand-400); transform: translateY(-4px); color: inherit; }
.hub-card .icon {
  width: 48px; height: 48px; border-radius: 12px;
  display: grid; place-items: center; margin-bottom: 20px;
  background: linear-gradient(135deg, var(--brand-600), var(--brand-400));
  color: white; box-shadow: var(--shadow-2);
}
.hub-card h3 { margin: 0 0 8px; color: var(--ink-0); font-size: 20px; }
.hub-card p  { margin: 0 0 14px; color: var(--ink-2); font-size: 14px; }
.hub-card .go {
  font-family: var(--font-mono); font-size: 12.5px; color: var(--brand-400);
  display: inline-flex; align-items: center; gap: 4px;
  transition: gap .2s;
}
.hub-card:hover .go { gap: 8px; }

@media (max-width: 860px) { .hub-grid { grid-template-columns: 1fr; } }

/* =============== Community channel cards =============== */
.community-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 20px;
}
.comm-card {
  display: block;
  text-align: left;
  padding: 28px 26px;
  border-radius: var(--r-lg);
  border: 1px solid var(--line);
  background: linear-gradient(180deg, rgba(17,26,56,0.7), rgba(11,18,40,0.45));
  color: inherit;
  text-decoration: none;
  font-family: inherit;
  transition: transform .25s, border-color .25s, box-shadow .25s;
  cursor: pointer;
  position: relative; overflow: hidden;
}
.comm-card:hover {
  transform: translateY(-4px);
  border-color: var(--brand-400);
  box-shadow: var(--shadow-2);
  color: inherit;
}
.comm-card .comm-ico {
  width: 46px; height: 46px;
  border-radius: 12px;
  display: grid; place-items: center;
  background: linear-gradient(135deg, var(--brand-600), var(--brand-400));
  color: #ffffff;
  box-shadow: 0 10px 22px rgba(52,90,246,0.32);
  margin-bottom: 18px;
}
.comm-card-qq .comm-ico { background: linear-gradient(135deg, #1a6dff, #00c2ff); }
.comm-card h3 { margin: 0 0 6px; color: var(--ink-0); font-size: 19px; }
.comm-card p  { margin: 0 0 14px; color: var(--ink-2); font-size: 14px; }
.comm-card .comm-link {
  font-family: var(--font-mono); font-size: 12.5px;
  color: var(--brand-400);
  display: inline-flex; align-items: center; gap: 4px;
  transition: gap .2s;
}
.comm-card:hover .comm-link { gap: 8px; color: var(--brand-300); }
.comm-card-qq { width: 100%; border: 1px solid var(--line); }  /* button reset */
.comm-card-qq:focus { outline: none; }

@media (max-width: 860px) { .community-grid { grid-template-columns: 1fr; } }

/* QQ group modal */
.qq-modal {
  position: fixed; inset: 0;
  background: rgba(6, 10, 22, 0.78);
  backdrop-filter: blur(6px);
  display: none;
  z-index: 120;
  align-items: center; justify-content: center;
  animation: qq-fade .18s ease-out;
}
.qq-modal[data-open] { display: flex; }
@keyframes qq-fade { from { opacity: 0; } to { opacity: 1; } }
.qq-modal-box {
  width: min(92vw, 420px);
  padding: 30px 32px 26px;
  border-radius: 18px;
  background: linear-gradient(180deg, #111a38, #0b1228);
  border: 1px solid var(--line-strong);
  box-shadow: 0 30px 80px rgba(0,0,0,0.55);
  position: relative;
}
.qq-modal-close {
  position: absolute; right: 14px; top: 10px;
  width: 32px; height: 32px; border-radius: 999px;
  border: 0; background: transparent;
  color: var(--ink-2); font-size: 22px; line-height: 1; cursor: pointer;
  transition: color .15s, background .15s;
}
.qq-modal-close:hover { color: var(--ink-0); background: rgba(255,255,255,0.06); }
.qq-modal-head {
  color: var(--ink-0); font-size: 18px; font-weight: 700;
  letter-spacing: 0.02em; margin-bottom: 20px;
}
.qq-modal-row {
  display: flex; align-items: center; gap: 12px;
  padding: 10px 14px; margin-bottom: 10px;
  border-radius: 10px;
  background: rgba(7,11,24,0.6);
  border: 1px solid var(--line);
}
.qq-modal-row > span {
  color: var(--ink-2); font-size: 12.5px;
  min-width: 58px;
}
.qq-modal-row > code {
  flex: 1; font-family: var(--font-mono); font-size: 16px;
  color: #5ec8ff; letter-spacing: 0.04em;
}
.qq-copy {
  border: 1px solid var(--line-strong);
  background: rgba(52,90,246,0.18);
  color: var(--ink-0);
  font-family: inherit; font-size: 12px; font-weight: 600;
  padding: 5px 12px; border-radius: 6px;
  cursor: pointer;
  transition: background .15s, color .15s;
}
.qq-copy:hover { background: rgba(52,90,246,0.36); }
.qq-copy.done { background: rgba(0,229,176,0.3); color: #00e5b0; }
.qq-modal-tip {
  color: var(--ink-3); font-size: 12.5px; line-height: 1.7;
  margin-top: 14px;
}

/* =============== Contact / CTA banner =============== */
.cta-banner {
  margin-top: 60px; padding: 60px 50px;
  border-radius: var(--r-xl);
  background:
    radial-gradient(600px 300px at 90% 50%, rgba(79,170,253,0.2), transparent 60%),
    linear-gradient(135deg, rgba(52,90,246,0.25), rgba(17,26,56,0.8));
  border: 1px solid var(--brand-500);
  display: flex; justify-content: space-between; align-items: center;
  gap: 40px; flex-wrap: wrap;
  position: relative; overflow: hidden;
}
.cta-banner::after {
  content: ""; position: absolute; inset: 0;
  background: url("data:image/svg+xml;utf8,<svg xmlns='http://www.w3.org/2000/svg' width='30' height='30'><path d='M0 0h1v30H0zM0 0v1h30V0z' fill='%234faafd' opacity='0.08'/></svg>");
  pointer-events: none;
}
.cta-banner h3 { color: var(--ink-0); font-size: 28px; margin: 0 0 8px; }
.cta-banner p  { color: var(--ink-1); margin: 0; font-size: 15px; }
.cta-banner .btns { display: flex; gap: 14px; flex-wrap: wrap; }

/* =============== Footer =============== */
.footer {
  padding: 60px 0 40px; border-top: 1px solid var(--line);
  background: rgba(7,11,24,0.6);
}
.footer-inner { display: grid; grid-template-columns: 1.5fr 1fr 1fr 1fr; gap: 40px; }
.footer-brand img { height: 32px; margin-bottom: 14px; }
.footer-brand p { color: var(--ink-2); font-size: 13px; max-width: 320px; }
.footer h5 {
  color: var(--ink-0); font-size: 13px; font-weight: 700;
  text-transform: uppercase; letter-spacing: 0.1em; margin: 0 0 14px;
}
.footer ul { list-style: none; padding: 0; margin: 0; display: flex; flex-direction: column; gap: 10px; }
.footer ul a { color: var(--ink-2); font-size: 13.5px; }
.footer ul a:hover { color: var(--brand-300); }
.footer-bar {
  margin-top: 40px; padding-top: 20px; border-top: 1px solid var(--line);
  display: flex; justify-content: space-between; align-items: center;
  color: var(--ink-3); font-size: 12px; font-family: var(--font-mono);
  flex-wrap: wrap; gap: 14px;
}

@media (max-width: 860px) { .footer-inner { grid-template-columns: 1fr 1fr; } }

/* =============== Reveal on scroll =============== */
.reveal {
  opacity: 0; transform: translateY(24px);
  transition: opacity .7s cubic-bezier(.2,.7,.3,1), transform .7s cubic-bezier(.2,.7,.3,1);
}
.reveal.in { opacity: 1; transform: translateY(0); }
.reveal.d1  { transition-delay: 0.05s; }
.reveal.d2  { transition-delay: 0.12s; }
.reveal.d3  { transition-delay: 0.2s; }
.reveal.d4  { transition-delay: 0.28s; }
.reveal.d5  { transition-delay: 0.36s; }
.reveal.d6  { transition-delay: 0.44s; }

/* =============== VS ROS2 table =============== */
.vs-table {
  border: 1px solid var(--line);
  border-radius: var(--r-lg);
  overflow: hidden;
  background: linear-gradient(180deg, rgba(17,26,56,0.45), rgba(11,18,40,0.3));
}
.vs-row {
  display: grid; grid-template-columns: 180px 1fr 1fr;
  border-top: 1px solid var(--line);
  transition: background .2s;
}
.vs-row:first-child { border-top: none; }
.vs-row:hover { background: rgba(52,90,246,0.06); }
.vs-row > div { padding: 16px 22px; font-size: 14px; }
.vs-row > div:first-child {
  color: var(--ink-0); font-weight: 600;
  border-right: 1px solid var(--line);
}
.vs-head > div { padding-top: 22px; padding-bottom: 22px;
  font-family: var(--font-mono); font-size: 12px; letter-spacing: 0.1em;
  text-transform: uppercase; color: var(--ink-2); background: rgba(7,11,24,0.5); }
.vs-head > div:first-child { color: var(--brand-300); }
.vs-col-ros2 {
  color: var(--ink-2); border-right: 1px solid var(--line);
  opacity: 0.85;
}
.vs-col-vlink {
  color: var(--ink-0);
  background: linear-gradient(90deg, rgba(52,90,246,0.08), transparent);
}
.vs-col-vlink strong {
  color: var(--accent); font-weight: 700;
}
.vs-head .vs-col-ros2 { color: var(--ink-3); }
.vs-head .vs-col-vlink { color: var(--brand-300); background: rgba(52,90,246,0.12); }

@media (max-width: 860px) {
  .vs-row { grid-template-columns: 1fr; }
  .vs-row > div { border-right: none !important; }
  .vs-row > div:first-child {
    background: rgba(52,90,246,0.12);
    font-family: var(--font-mono); font-size: 12px; font-weight: 700;
    letter-spacing: 0.1em; text-transform: uppercase;
    padding: 10px 22px;
    color: var(--brand-300);
  }
  /* Label the two comparison cells so you can tell which column you're
     reading once the row has collapsed to a stack. */
  .vs-row:not(.vs-head) .vs-col-ros2::before,
  .vs-row:not(.vs-head) .vs-col-vlink::before {
    display: block;
    font-family: var(--font-mono); font-size: 10.5px; font-weight: 700;
    letter-spacing: 0.14em; text-transform: uppercase;
    margin-bottom: 6px;
  }
  .vs-row:not(.vs-head) .vs-col-ros2::before  { content: "ROS2";  color: var(--ink-3); }
  .vs-row:not(.vs-head) .vs-col-vlink::before { content: "VLink"; color: var(--brand-300); }
  /* The header row's ROS2 / VLink labels are now redundant — hide it. */
  .vs-row.vs-head { display: none; }
}

/* =============== Full platform grid =============== */
.platform-grid {
  display: grid; grid-template-columns: repeat(4, 1fr); gap: 18px;
}
.plat, .plat-link {
  padding: 24px 20px; border-radius: var(--r-md);
  border: 1px solid var(--line);
  background: linear-gradient(180deg, rgba(17,26,56,0.5), rgba(11,18,40,0.3));
  transition: all .3s; position: relative; overflow: hidden;
  color: inherit; display: block;
}
.plat:hover, .plat-link:hover {
  transform: translateY(-4px); border-color: var(--brand-400);
  box-shadow: var(--glow);
}
.plat::after, .plat-link::after {
  content: ""; position: absolute; bottom: -30px; right: -30px;
  width: 100px; height: 100px; border-radius: 50%;
  background: radial-gradient(circle, rgba(79,170,253,0.12), transparent 70%);
  opacity: 0; transition: opacity .3s;
}
.plat:hover::after, .plat-link:hover::after { opacity: 1; }
.plat-link { text-decoration: none; }
.plat-ico {
  width: 44px; height: 44px; border-radius: 12px;
  display: grid; place-items: center; margin-bottom: 18px;
  box-shadow: 0 10px 22px rgba(52,90,246,0.25);
}
.plat h4 { color: var(--ink-0); margin: 0 0 6px; font-size: 16px; }
.plat p  { color: var(--ink-2); font-size: 13px; margin: 0; }
.plat-link h4 { color: var(--ink-0); }
.plat-link p  { color: var(--ink-2); }

@media (max-width: 980px) { .platform-grid { grid-template-columns: repeat(2,1fr); } }
@media (max-width: 560px) { .platform-grid { grid-template-columns: 1fr; } }

/* =============== Downloads =============== */
.dl-grid {
  display: grid; grid-template-columns: repeat(3, 1fr); gap: 22px;
}
.dl-card {
  display: block; padding: 32px 26px; border-radius: var(--r-lg);
  border: 1px solid var(--line);
  background: linear-gradient(180deg, rgba(17,26,56,0.7), rgba(11,18,40,0.4));
  transition: all .3s; position: relative; overflow: hidden;
  color: inherit; text-decoration: none;
}
.dl-card:hover {
  transform: translateY(-6px); border-color: var(--brand-400);
  box-shadow: var(--shadow-2); color: inherit;
}
.dl-card .dl-tag {
  display: inline-block; font-family: var(--font-mono); font-size: 11px;
  padding: 3px 10px; border-radius: 999px; margin-bottom: 16px;
  color: var(--brand-300); background: rgba(52,90,246,0.12);
  border: 1px solid var(--line-strong); letter-spacing: 0.08em;
}
.dl-card h3 {
  color: var(--ink-0); margin: 0 0 8px; font-size: 22px;
  font-family: var(--font-mono); font-weight: 700;
}
.dl-card .dl-ver {
  color: var(--accent); font-size: 14px; margin-left: 8px;
  font-weight: 500;
}
.dl-card p { color: var(--ink-2); font-size: 14px; margin: 0 0 16px; }
.dl-row { display: flex; flex-wrap: wrap; gap: 6px; margin-bottom: 18px; }
.dl-row code {
  font-family: var(--font-mono); font-size: 11px;
  padding: 3px 9px; border-radius: 4px;
  background: rgba(0,0,0,0.35); color: var(--ink-2);
  border: 1px solid var(--line);
}
.dl-card .go {
  font-family: var(--font-mono); font-size: 12.5px; color: var(--brand-400);
  display: inline-flex; align-items: center; gap: 4px;
  transition: gap .2s;
}
.dl-card:hover .go { gap: 10px; color: var(--brand-300); }

@media (max-width: 860px) { .dl-grid { grid-template-columns: 1fr; } }

/* =============== Architecture figure =============== */
.arch-figure {
  position: relative;
  border-radius: var(--r-lg);
  border: 1px solid var(--line);
  background: linear-gradient(180deg, rgba(17,26,56,0.5), rgba(11,18,40,0.3));
  overflow: hidden;
  padding: 16px;
}
.arch-figure img {
  width: 100%; display: block;
  border-radius: var(--r-md);
  background: rgba(7,11,24,0.5);
}
.arch-caption {
  margin-top: 16px;
  display: flex; gap: 24px; justify-content: center; flex-wrap: wrap;
  color: var(--ink-2); font-size: 13px;
}
.arch-caption strong { color: var(--brand-300); font-family: var(--font-mono); font-size: 12px; letter-spacing: 0.08em; }

/* =============== Serialization matrix =============== */
.ser-grid {
  display: grid; grid-template-columns: repeat(auto-fit, minmax(180px, 1fr)); gap: 14px;
}
.ser-pill {
  padding: 16px 18px; border-radius: var(--r-md);
  border: 1px solid var(--line);
  background: rgba(17,26,56,0.5);
  transition: all .25s;
}
.ser-pill:hover { border-color: var(--brand-400); transform: translateY(-3px); }
.ser-pill .name {
  font-family: var(--font-mono); font-weight: 700; font-size: 14px;
  color: var(--brand-300); margin-bottom: 4px;
}
.ser-pill .desc { font-size: 12.5px; color: var(--ink-2); line-height: 1.55; }

/* =============== Base components =============== */
.base-grid {
  display: grid; grid-template-columns: repeat(auto-fit, minmax(200px, 1fr)); gap: 16px;
}
.base-card {
  padding: 22px 20px; border-radius: var(--r-md);
  border: 1px solid var(--line);
  background: linear-gradient(180deg, rgba(17,26,56,0.5), rgba(11,18,40,0.3));
  transition: all .25s;
}
.base-card:hover { border-color: var(--brand-400); transform: translateY(-3px); }
.base-card .ico {
  width: 36px; height: 36px; border-radius: 10px;
  display: grid; place-items: center; margin-bottom: 14px;
  background: rgba(52,90,246,0.14);
  color: var(--brand-400);
  border: 1px solid var(--line-strong);
}
.base-card h4 { color: var(--ink-0); margin: 0 0 6px; font-size: 15px; }
.base-card p  { color: var(--ink-2); font-size: 13px; margin: 0; line-height: 1.6; }

/* =============== Perf metrics =============== */
.perf-grid {
  display: grid; grid-template-columns: repeat(4, 1fr); gap: 16px;
}
.perf {
  padding: 28px 22px; border-radius: var(--r-md);
  border: 1px solid var(--line);
  background: radial-gradient(circle at top right, rgba(79,170,253,0.08), transparent 70%),
              rgba(11,18,40,0.5);
  text-align: center;
}
.perf .val {
  font-family: var(--font-mono); font-weight: 800;
  font-size: 36px; line-height: 1; color: var(--brand-300);
  background: linear-gradient(180deg, var(--brand-300), var(--accent));
  -webkit-background-clip: text; background-clip: text; -webkit-text-fill-color: transparent;
}
.perf .label { margin-top: 10px; font-size: 13px; color: var(--ink-0); font-weight: 600; }
.perf .sub   { margin-top: 4px; font-size: 11.5px; color: var(--ink-3); font-family: var(--font-mono); letter-spacing: 0.06em; }
@media (max-width: 860px) { .perf-grid { grid-template-columns: repeat(2,1fr); } }

/* =============== FAQ =============== */
.faq-list { display: flex; flex-direction: column; gap: 12px; }
.faq-item {
  border: 1px solid var(--line);
  border-radius: var(--r-md);
  background: rgba(17,26,56,0.4);
  overflow: hidden;
  transition: border-color .2s;
}
.faq-item[open] { border-color: var(--brand-400); }
.faq-item summary {
  cursor: pointer; list-style: none;
  padding: 16px 22px;
  display: flex; justify-content: space-between; align-items: center;
  font-size: 15px; color: var(--ink-0); font-weight: 600;
}
.faq-item summary::-webkit-details-marker { display: none; }
.faq-item summary::after {
  content: "+"; color: var(--brand-400); font-size: 22px;
  font-weight: 400; transition: transform .2s;
}
.faq-item[open] summary::after { content: "−"; }
.faq-item summary:hover { color: var(--brand-300); }
.faq-item .body {
  padding: 0 22px 18px; color: var(--ink-2); font-size: 14px; line-height: 1.75;
}
.faq-item .body code {
  font-family: var(--font-mono); font-size: 12.5px;
  background: rgba(0,0,0,0.35); padding: 1px 6px; border-radius: 3px;
}

/* =============== Roadmap =============== */
.roadmap {
  display: grid; grid-template-columns: repeat(3, 1fr); gap: 22px;
  position: relative;
}
.rm-item {
  padding: 24px 22px; border-radius: var(--r-md);
  border: 1px solid var(--line);
  background: rgba(17,26,56,0.45);
  position: relative;
}
.rm-item .tag {
  font-family: var(--font-mono); font-size: 11px; letter-spacing: 0.1em;
  padding: 3px 10px; border-radius: 999px;
  display: inline-block; margin-bottom: 14px;
}
.rm-item.done .tag   { background: rgba(0,229,176,0.12); color: var(--accent); border: 1px solid rgba(0,229,176,0.3); }
.rm-item.now  .tag   { background: rgba(79,170,253,0.14); color: var(--brand-400); border: 1px solid rgba(79,170,253,0.3); }
.rm-item.next .tag   { background: rgba(255,209,102,0.12); color: var(--accent-2); border: 1px solid rgba(255,209,102,0.3); }
.rm-item h4 { color: var(--ink-0); margin: 0 0 12px; font-size: 17px; }
.rm-item ul { padding-left: 18px; margin: 0; color: var(--ink-2); font-size: 13.5px; line-height: 1.9; }
.rm-item ul li::marker { color: var(--brand-400); }
@media (max-width: 860px) { .roadmap { grid-template-columns: 1fr; } }

/* =============== Scrollbar =============== */
::-webkit-scrollbar { width: 10px; height: 10px; }
::-webkit-scrollbar-track { background: var(--bg-0); }
::-webkit-scrollbar-thumb { background: #1a2650; border-radius: 10px; }
::-webkit-scrollbar-thumb:hover { background: var(--brand-700); }


/* Prefer reduced motion */
@media (prefers-reduced-motion: reduce) {
  * { animation-duration: 0.01ms !important; transition-duration: 0.01ms !important; }
  .bg-grid, .hero-term::before { animation: none !important; }
}

/* =========================================================================
   RESPONSIVE — tablet & phone
   Breakpoints:  1180 : large tablet / small desktop
                  980 : portrait tablet
                  720 : landscape phone / small tablet
                  520 : phone portrait
                  380 : very small phone
   ========================================================================= */

/* ---- Tablet (≤ 1180px) ---- */
@media (max-width: 1180px) {
  .container            { width: min(1200px, 94vw); }
  .section              { padding: 92px 0; }
  .section-title        { font-size: clamp(26px, 3.6vw, 38px); }
  .hero                 { min-height: auto; padding: 80px 0 64px; }
  .hero-inner           { gap: 42px; }
  .hero h1              { font-size: clamp(38px, 6vw, 60px); }
  .hero-radial img      { max-width: 480px; margin-inline: auto; }
  .numbers              { grid-template-columns: repeat(4, 1fr); }
}

/* ---- Portrait tablet (≤ 980px) ---- */
@media (max-width: 980px) {
  .section              { padding: 78px 0; }
  .section-head         { margin-bottom: 40px; }
  .hero                 { padding: 64px 0 52px; }
  .hero-inner           { grid-template-columns: 1fr; gap: 36px; text-align: left; }
  .hero h1              { font-size: clamp(36px, 7vw, 56px); line-height: 1.1; }
  .hero-meta            { gap: 22px; }
  .hero-radial img      { max-width: 440px; margin: 0 auto; display: block; }

  .matrix-wrap          { grid-template-columns: repeat(2, 1fr); }
  .models               { grid-template-columns: 1fr; }
  .why-grid             { grid-template-columns: 1fr; }
  .hub-grid             { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .platform-grid        { grid-template-columns: repeat(2, 1fr); }
  .base-grid            { grid-template-columns: repeat(2, 1fr); }
  .perf-grid            { grid-template-columns: repeat(2, 1fr); }
  .ser-grid             { grid-template-columns: repeat(2, 1fr); }

  /* Scenes + Viz already stack via their own rule, just tighten spacing */
  #scenes .viz-card .viz-meta,
  #viz    .viz-card .viz-meta { padding: 22px 24px; }
  #scenes .viz-card .viz-meta h3,
  #viz    .viz-card .viz-meta h3 { font-size: 19px; }

  /* Quickstart: collapse to single column on narrow screens */
  .qs-grid { grid-template-columns: 1fr; gap: 28px; }

  /* Footer — collapse to 2 cols */
  .footer-inner         { grid-template-columns: 1fr 1fr; gap: 28px; }
}

/* ---- Phone / small tablet (≤ 720px) ---- */
@media (max-width: 720px) {
  .section              { padding: 60px 0; }
  .section-head         { margin-bottom: 32px; }
  .section-title        { font-size: clamp(22px, 6vw, 30px); }
  .section-sub          { font-size: 14.5px; }

  .hero                 { padding: 48px 0 40px; }
  .hero-kicker          { font-size: 11px; padding: 5px 11px; line-height: 1.4;
                          white-space: normal; }
  .hero h1              { font-size: clamp(30px, 8.4vw, 44px); line-height: 1.12;
                          word-break: break-word; }
  .hero-sub             { font-size: 15px; line-height: 1.7; }
  .hero-cta             { gap: 10px; }
  .hero-cta .btn        { padding: 12px 18px; font-size: 13.5px; flex: 1 1 auto;
                          justify-content: center; }
  .hero-meta            { gap: 14px 22px; flex-wrap: wrap; margin-top: 32px; }
  .hero-meta > div      { font-size: 12px; }
  .hero-radial          { margin-top: 24px; }
  .hero-radial img      { max-width: 100%; }
  .hero-os .os-label    { font-size: 10px; letter-spacing: 0.18em; }
  .hero-os .os-chips    { gap: 5px; }
  .hero-os .os-chip     { padding: 3px 9px; font-size: 11px; }
  .hero-os .os-sep      { display: none; }

  .numbers              { grid-template-columns: repeat(2, 1fr); }
  .num-item             { padding: 22px 14px; border-right: 0;
                          border-bottom: 1px solid var(--line); }
  .num-item:nth-last-child(-n+2) { border-bottom: 0; }
  .num-item .big        { font-size: 36px; }

  /* Grid-heavy sections → single column (or 2 cols for dense lists) */
  .matrix-wrap          { grid-template-columns: 1fr; gap: 12px; }
  .mx                   { padding: 16px 16px; }
  .platform-grid        { grid-template-columns: 1fr; }
  .base-grid            { grid-template-columns: 1fr 1fr; }
  .perf-grid            { grid-template-columns: 1fr 1fr; }
  .feat-grid            { grid-template-columns: 1fr 1fr; }
  .dl-grid              { grid-template-columns: 1fr; }
  .ser-grid             { grid-template-columns: 1fr 1fr; }
  .hub-grid             { grid-template-columns: 1fr; }

  /* Unified benefits — ensure tight readable tiles on phone */
  .unified-benefits     { gap: 12px; margin-bottom: 32px; }
  .unified-benefits li  { padding: 18px 18px 18px; font-size: 13px; line-height: 1.6; }
  .unified-benefits li strong { font-size: 15px; margin-bottom: 4px;
                                max-width: calc(100% - 32px); }
  .unified-benefits li::before { width: 24px; height: 24px; font-size: 13px;
                                 top: 12px; right: 12px; }
  .unified-matrix-head  { padding-top: 6px; margin-bottom: 16px; }
  .unified-matrix-title { font-size: 18px; }
  .unified-matrix-label { font-size: 10.5px; margin-top: 10px; }

  /* Three Models — code blocks must not force horizontal page scroll */
  .models               { gap: 20px; }
  .model-card           { padding: 22px 20px; }
  .model-card h3        { font-size: 19px; }
  .model-card pre       { font-size: 11.5px; line-height: 1.65; padding: 14px; }

  /* Quickstart 2×2 → single column on phone */
  .qs-grid              { grid-template-columns: 1fr; grid-template-rows: auto;
                          gap: 20px; }
  .qs-block             { display: flex; flex-direction: column;
                          grid-row: auto !important; grid-column: auto !important; }
  .qs-block-live        { margin-top: 4px; padding-top: 20px; }
  .qs-block-title       { font-size: 15px; }
  .qs-desc              { font-size: 13px; }
  .qs-file .term-body   { font-size: 11.5px; padding: 14px 14px; line-height: 1.7; }
  .qs-demo-log          { height: 240px; font-size: 11.5px; padding: 12px 14px; }

  /* CLI tabs → horizontally scrollable strip */
  .cli-overview-card     { padding: 18px 18px 16px; }
  .cli-note              { font-size: 13px; }
  .cli-actions .btn      { flex: 1 1 auto; justify-content: center; }
  .cli-tabs             { flex-wrap: nowrap; overflow-x: auto; padding-bottom: 4px;
                          scrollbar-width: none; }
  .cli-tabs::-webkit-scrollbar { display: none; }
  .cli-tab              { flex: 0 0 148px; }
  .cli-tab .desc        { display: none; }
  .cli-stage            { border-radius: 12px; }
  .cli-stage .term-body { font-size: 11px; padding: 14px 14px; height: 700px;
                          line-height: 1.65; }

  /* vs ROS2 table — already stacks at ≤ 860px; tighten fonts */
  .vs-row > div         { padding: 12px 14px; font-size: 13.5px; }
  .vs-head > div        { font-size: 11px; }
  .vs-foot              { font-size: 11.5px; line-height: 1.6; }

  /* Scenes / Viz — tighten */
  .viz-grid             { grid-template-columns: 1fr; gap: 18px; }
  #scenes .viz-card .viz-meta,
  #viz .viz-card .viz-meta { padding: 18px 20px; }
  #scenes .viz-card .viz-meta h3,
  #viz .viz-card .viz-meta h3 { font-size: 17px; }

  /* Domestic / supply-chain strip */
  .domestic             { padding: 22px 20px; gap: 16px; }
  .domestic h3          { font-size: 16px; }
  .domestic p           { font-size: 13.5px; line-height: 1.65; }

  /* Community */
  .community-grid       { grid-template-columns: 1fr; gap: 14px; }
  .comm-card            { padding: 22px 20px; }

  /* CTA banner */
  .cta-banner           { padding: 36px 22px; gap: 22px; }
  .cta-banner h3        { font-size: 22px; }
  .cta-banner .btns     { width: 100%; }
  .cta-banner .btns .btn{ flex: 1 1 auto; justify-content: center; }

  /* Footer */
  .footer-inner         { grid-template-columns: 1fr; gap: 26px; }
  .footer-bar           { flex-direction: column; align-items: flex-start;
                          gap: 6px; font-size: 11px; text-align: left; }

  /* Nav row top — tighter; keep lang-switch tappable */
  .nav-row-top          { min-height: 48px; gap: 10px; padding: 0 2px; }
  .nav-logo img         { height: 28px; }
  .nav-logo .badge      { display: none; }
  .lang-switch > summary{ padding: 7px 10px; font-size: 12.5px; }
  .lang-switch .lang-label { display: none; }     /* trigger becomes icon-only */

  /* QQ modal — stay inside viewport */
  .qq-modal-box         { width: calc(100vw - 32px); padding: 22px 20px; }

  /* Belt-and-braces: stop any long, non-wrapping URL / code fragment from
     pushing horizontal scroll on the whole page. */
  body                  { overflow-x: hidden; }
  p code, li code, .qs-desc code, .mx .meta, .mx .transport-prefix {
    overflow-wrap: anywhere; word-break: break-word;
  }
}

/* ---- Phone portrait (≤ 520px) ---- */
@media (max-width: 520px) {
  .container            { width: 94vw; }
  .section              { padding: 48px 0; }
  .section-head         { margin-bottom: 26px; }
  .section-title        { font-size: clamp(20px, 6.8vw, 26px); }

  .hero-cta             { flex-direction: column; }
  .hero-cta .btn        { width: 100%; }

  .base-grid            { grid-template-columns: 1fr; }
  .feat-grid            { grid-template-columns: 1fr; }
  .perf-grid            { grid-template-columns: 1fr; }
  .ser-grid             { grid-template-columns: 1fr; }

  /* Unified benefits — single column too on really small screens */
  .unified-benefits     { grid-template-columns: 1fr; }
  .unified-benefits li  { padding: 16px 16px; }

  .cli-stage .term-body { height: 700px; font-size: 10.5px; }
  .qs-demo-log          { height: 220px; font-size: 11px; }

  .viz-meta h3          { font-size: 16px; }
  .viz-meta p           { font-size: 13px; }

  /* Keep GitHub icon visible but compact the others */
  .nav-btn              { padding: 6px 10px; }
  .nav-btn span         { display: none; }
}

/* ---- Very small phones (≤ 380px) ---- */
@media (max-width: 380px) {
  .hero h1              { font-size: 26px; }
  .hero-sub             { font-size: 13.5px; }
  .section-title        { font-size: 20px; }
  .cli-stage .term-body { font-size: 9.5px; height: 700px; padding: 12px 10px; }
  .unified-benefits li strong { font-size: 14px; }
  .unified-benefits li  { font-size: 12.5px; }
  .qs-file .term-body   { font-size: 10.5px; }
  .mx                   { padding: 14px 14px; }
  .mx .name             { font-size: 13px; }
  .mx .meta             { font-size: 11.5px; }
}