/* ============================================================
   AIDC — Design System
   "Institutional Precision" — 黑白体系 + 单一信号色
   Brand: `//` slash family (wider gap + clipped ends)
   Type:  Archivo (display/body) + IBM Plex Mono (labels/code)
   ============================================================ */

:root {
  /* palette — dark (Geist dark neutrals + signal orange) */
  --bg: #0a0a0a;
  --bg-2: #111111;
  --bg-3: #1a1a1a;
  --ink: #ededed;
  --ink-strong: #ffffff;
  --mut: #a1a1a1;
  --mut-2: #7d7d7d;
  --line: rgba(255, 255, 255, 0.11);
  --line-soft: rgba(255, 255, 255, 0.06);
  --signal: #ff4d00;
  --signal-soft: rgba(255, 77, 0, 0.12);
  --signal-hover: #ff6b2e;

  /* type */
  --font-display: "Archivo", "PingFang SC", "Hiragino Sans", "Noto Sans JP", "Microsoft YaHei", "Yu Gothic", sans-serif;
  --font-body: "Archivo", "PingFang SC", "Hiragino Sans", "Noto Sans JP", "Microsoft YaHei", "Yu Gothic", sans-serif;
  --font-mono: "IBM Plex Mono", "SFMono-Regular", Consolas, monospace;

  /* scale */
  --w-max: 1280px;
  --pad-x: clamp(20px, 4vw, 56px);
  --nav-h: 64px;

  /* shapes & elevation — Geist (docs/geist-design.md): 6px controls, 12px cards/menus */
  --radius: 6px;
  --radius-md: 12px;
  --radius-full: 9999px;
  --shadow-card: 0 2px 2px rgba(0, 0, 0, 0.04);
  --shadow-menu: 0 1px 1px rgba(0, 0, 0, 0.02), 0 4px 8px -4px rgba(0, 0, 0, 0.04), 0 16px 24px -8px rgba(0, 0, 0, 0.06);
  --focus: #006bff;
  --ease: cubic-bezier(0.175, 0.885, 0.32, 1.1);
}

/* light theme (site default) — Geist light neutrals */
[data-theme="light"] {
  --bg: #ffffff;
  --bg-2: #fafafa;
  --bg-3: #f2f2f2;
  --ink: #333333;
  --ink-strong: #171717;
  --mut: #666666;
  --mut-2: #8f8f8f;
  --line: rgba(0, 0, 0, 0.09);
  --line-soft: rgba(0, 0, 0, 0.05);
  --signal: #e34400;
  --signal-soft: rgba(227, 68, 0, 0.09);
  --signal-hover: #ff4d00;
}

/* Geist two-layer focus ring on every interactive element */
a:focus-visible, button:focus-visible, input:focus-visible, [tabindex]:focus-visible {
  outline: none;
  box-shadow: 0 0 0 2px var(--bg), 0 0 0 4px var(--focus);
  border-radius: var(--radius);
}

/* ---------- base ---------- */
*, *::before, *::after { box-sizing: border-box; }
html { scroll-behavior: smooth; -webkit-text-size-adjust: 100%; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  font-family: var(--font-body);
  font-size: 16px;
  line-height: 1.7;
  font-weight: 400;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}
::selection { background: rgba(255, 77, 0, 0.25); }

img, svg { max-width: 100%; display: block; }
a { color: inherit; text-decoration: none; }
p a, li a, td a {
  color: var(--ink-strong);
  border-bottom: 1px solid var(--signal);
  transition: color .15s, background .15s;
}
p a:hover, li a:hover, td a:hover { color: var(--signal); }

h1, h2, h3, h4 {
  font-family: var(--font-display);
  color: var(--ink-strong);
  font-weight: 700;
  line-height: 1.12;
  letter-spacing: -0.015em;
  margin: 0 0 0.5em;
}
h1 { font-size: clamp(2.4rem, 5.4vw, 4.4rem); font-weight: 800; letter-spacing: -0.03em; }
h2 { font-size: clamp(1.7rem, 3.2vw, 2.6rem); letter-spacing: -0.02em; }
h3 { font-size: 1.25rem; }
h4 { font-size: 1.02rem; }
p { margin: 0 0 1em; }
strong { color: var(--ink-strong); font-weight: 600; }
hr { border: 0; border-top: 1px solid var(--line); margin: 2.5rem 0; }

code {
  font-family: var(--font-mono);
  font-size: 0.86em;
  background: var(--bg-3);
  border: 1px solid var(--line-soft);
  padding: 0.1em 0.4em;
  border-radius: var(--radius);
  color: var(--ink-strong);
}
pre {
  background: var(--bg-2);
  border: 1px solid var(--line);
  border-left: 2px solid var(--signal);
  border-radius: var(--radius);
  padding: 1.1rem 1.3rem;
  overflow-x: auto;
  font-family: var(--font-mono);
  font-size: 0.84rem;
  line-height: 1.65;
  margin: 1.4rem 0;
}
pre code { background: none; border: 0; padding: 0; font-size: inherit; }

/* ---------- the // mark ---------- */
.mark {
  display: inline-flex;
  align-items: center;
  gap: 0.30em;          /* wider gap — brand rule */
  height: 1em;
  flex: none;
}
.mark i {
  display: block;
  width: 0.26em;
  height: 1em;
  background: currentColor;
  transform: skewX(-20deg);   /* clipped ends — parallelogram */
}
.mark--signal i { background: var(--signal); }

/* ---------- kicker label ---------- */
.kicker {
  display: flex;
  align-items: center;
  gap: 0.8em;
  font-family: var(--font-mono);
  font-size: 0.72rem;
  font-weight: 500;
  letter-spacing: 0.22em;
  text-transform: uppercase;
  color: var(--mut);
  margin-bottom: 1.6rem;
}
.kicker::before {
  content: "";
  display: inline-block;
  width: 7px; height: 13px;
  background:
    linear-gradient(currentColor, currentColor) left/2px 100% no-repeat,
    linear-gradient(currentColor, currentColor) right/2px 100% no-repeat;
  transform: skewX(-20deg);
  color: var(--signal);
}
.kicker .num { color: var(--signal); }

/* ---------- layout ---------- */
.wrap {
  max-width: var(--w-max);
  margin: 0 auto;
  padding: 0 var(--pad-x);
}
.sec { padding: clamp(72px, 10vw, 140px) 0; position: relative; }
.sec + .sec { border-top: 1px solid var(--line-soft); }
.sec-head { max-width: 720px; margin-bottom: clamp(40px, 5vw, 64px); }
.sec-head .lede { font-size: 1.12rem; color: var(--mut); margin-top: 1.2rem; }
.lede { font-size: 1.15rem; line-height: 1.75; color: var(--mut); }
.en-sub {
  font-family: var(--font-mono);
  font-size: 0.8rem;
  letter-spacing: 0.04em;
  color: var(--mut-2);
  margin-top: 0.9rem;
  line-height: 1.7;
}

/* ---------- top navigation ---------- */
.nav {
  position: fixed;
  top: 0; left: 0; right: 0;
  z-index: 100;
  height: var(--nav-h);
  display: flex;
  align-items: center;
  border-bottom: 1px solid var(--line-soft);
  background: color-mix(in srgb, var(--bg) 82%, transparent);
  backdrop-filter: blur(14px) saturate(1.1);
  -webkit-backdrop-filter: blur(14px) saturate(1.1);
}
.nav-inner {
  width: 100%;
  max-width: var(--w-max);
  margin: 0 auto;
  padding: 0 var(--pad-x);
  display: flex;
  align-items: center;
  gap: 2.5rem;
}
.nav-logo {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: 1.05rem;
  letter-spacing: 0.06em;
  color: var(--ink-strong);
}
.nav-logo .mark { font-size: 0.95rem; color: var(--signal); }
.nav-links {
  display: flex;
  gap: 1.5rem;
  margin-left: auto;
  align-items: center;
}
.nav-links a {
  font-size: 0.85rem;
  font-weight: 500;
  letter-spacing: 0.02em;
  color: var(--mut);
  transition: color .15s;
  padding: 0.4rem 0;
}
.nav-links a:hover { color: var(--ink-strong); }
.nav-links a.active { color: var(--ink-strong); font-weight: 600; }
.nav-cta {
  font-size: 0.82rem !important;
  font-weight: 500;
  white-space: nowrap;
  color: var(--bg) !important;
  background: var(--ink-strong);
  border: 1px solid var(--ink-strong);
  border-radius: var(--radius);
  padding: 0.42rem 0.95rem !important;
  transition: background .15s var(--ease) !important;
}
.nav-cta:hover { background: color-mix(in srgb, var(--ink-strong) 86%, var(--bg)); color: var(--bg) !important; }
.nav-burger {
  display: none;
  margin-left: auto;
  background: none;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  color: var(--ink);
  font-family: var(--font-mono);
  font-size: 0.7rem;
  letter-spacing: 0.1em;
  padding: 0.5rem 0.9rem;
  cursor: pointer;
}
body { padding-top: var(--nav-h); }

/* ---------- buttons ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.55em;
  font-family: var(--font-display);
  font-size: 0.95rem;
  font-weight: 500;
  letter-spacing: 0;
  height: 46px;
  padding: 0 1.35rem;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  color: var(--ink-strong);
  background: var(--bg);
  cursor: pointer;
  transition: border-color .15s var(--ease), background .15s var(--ease), color .15s var(--ease), box-shadow .15s var(--ease);
}
.btn:hover { background: var(--bg-2); border-color: color-mix(in srgb, var(--ink-strong) 24%, transparent); }
.btn--primary {
  background: var(--ink-strong);
  border-color: var(--ink-strong);
  color: var(--bg);
}
.btn--primary:hover { background: color-mix(in srgb, var(--ink-strong) 86%, var(--bg)); border-color: transparent; color: var(--bg); }
.btn .arr { font-family: var(--font-mono); transition: transform .18s; }
.btn:hover .arr { transform: translateX(4px); }
.btn-row { display: flex; gap: 1rem; flex-wrap: wrap; }

/* ---------- hero ---------- */
.hero {
  position: relative;
  min-height: calc(92vh - var(--nav-h));
  display: flex;
  align-items: center;
  overflow: hidden;
}
.hero-inner { position: relative; z-index: 2; padding-top: clamp(60px, 8vw, 110px); padding-bottom: clamp(60px, 8vw, 110px); max-width: 880px; }
.hero h1 .accent { color: var(--signal); }
.hero .lede { max-width: 620px; margin-top: 1.6rem; font-size: 1.18rem; }
.hero .btn-row { margin-top: 2.6rem; }

/* giant background slashes */
.hero-slashes {
  position: absolute;
  inset: 0;
  z-index: 0;
  pointer-events: none;
  overflow: hidden;
}
.hero-slashes::before,
.hero-slashes::after {
  content: "";
  position: absolute;
  top: -12%;
  height: 124%;
  width: clamp(90px, 11vw, 170px);
  background: linear-gradient(180deg, var(--signal-soft), rgba(255,77,0,0.02));
  transform: skewX(-20deg);
}
.hero-slashes::before { right: clamp(180px, 24vw, 420px); }
.hero-slashes::after { right: clamp(40px, 10vw, 190px); }

/* engineering grid backdrop */
.grid-bg {
  position: absolute;
  inset: 0;
  z-index: 0;
  pointer-events: none;
  background-image:
    linear-gradient(var(--line-soft) 1px, transparent 1px),
    linear-gradient(90deg, var(--line-soft) 1px, transparent 1px);
  background-size: 72px 72px;
  -webkit-mask-image: radial-gradient(ellipse 90% 80% at 50% 0%, #000 30%, transparent 75%);
  mask-image: radial-gradient(ellipse 90% 80% at 50% 0%, #000 30%, transparent 75%);
}

/* ---------- stat strip ---------- */
.stats {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  border: 1px solid var(--line);
  border-width: 1px 0;
}
.stat {
  padding: 2rem var(--pad-x) 2rem 0;
  border-right: 1px solid var(--line-soft);
  padding-left: 1.6rem;
}
.stat:last-child { border-right: 0; }
.stat .n {
  font-family: var(--font-display);
  font-size: clamp(2rem, 3.4vw, 2.9rem);
  font-weight: 800;
  letter-spacing: -0.02em;
  color: var(--ink-strong);
}
.stat .n em { font-style: normal; color: var(--signal); }
.stat .l {
  font-family: var(--font-mono);
  font-size: 0.7rem;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--mut);
  margin-top: 0.4rem;
}

/* ---------- cards ---------- */
.cards {
  display: grid;
  gap: 12px;
}
.cards--2 { grid-template-columns: repeat(2, 1fr); }
.cards--3 { grid-template-columns: repeat(3, 1fr); }
.cards--4 { grid-template-columns: repeat(4, 1fr); }
.card {
  background: var(--bg);
  border: 1px solid var(--line);
  border-radius: var(--radius-md);
  padding: 2rem 1.8rem 2.2rem;
  position: relative;
  overflow: hidden;
  transition: background .2s var(--ease), border-color .2s var(--ease), box-shadow .2s var(--ease);
}
.card:hover { background: var(--bg-2); border-color: color-mix(in srgb, var(--ink-strong) 18%, transparent); box-shadow: var(--shadow-card); }
.card .idx {
  font-family: var(--font-mono);
  font-size: 0.7rem;
  letter-spacing: 0.16em;
  color: var(--signal);
  display: block;
  margin-bottom: 1.6rem;
}
.card h3 { margin-bottom: 0.7rem; }
.card p { color: var(--mut); font-size: 0.93rem; margin: 0; }
.card .card-link {
  display: inline-flex;
  align-items: center;
  gap: 0.5em;
  margin-top: 1.4rem;
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--ink-strong);
}
.card .card-link::after { content: "→"; transition: transform .18s; color: var(--signal); }
.card:hover .card-link::after { transform: translateX(4px); }
.card--flag::before {
  content: "";
  position: absolute;
  top: 0; left: 0;
  width: 100%; height: 2px;
  background: var(--signal);
  transform: scaleX(0);
  transform-origin: left;
  transition: transform .3s;
}
.card:hover.card--flag::before { transform: scaleX(1); }

/* ---------- split layout ---------- */
.split {
  display: grid;
  grid-template-columns: minmax(0, 5fr) minmax(0, 7fr);
  gap: clamp(40px, 6vw, 96px);
  align-items: start;
}
.split--rev { grid-template-columns: minmax(0, 7fr) minmax(0, 5fr); }
.split .sticky { position: sticky; top: calc(var(--nav-h) + 32px); }

/* ---------- numbered list (institutional) ---------- */
.numlist { list-style: none; margin: 0; padding: 0; counter-reset: nl; }
.numlist > li {
  counter-increment: nl;
  display: grid;
  grid-template-columns: 64px 1fr;
  gap: 1.4rem;
  padding: 1.6rem 0;
  border-top: 1px solid var(--line-soft);
}
.numlist > li::before {
  content: counter(nl, decimal-leading-zero);
  font-family: var(--font-mono);
  font-size: 0.85rem;
  color: var(--signal);
  padding-top: 0.2rem;
}
.numlist h4 { margin-bottom: 0.4rem; }
.numlist p { color: var(--mut); font-size: 0.93rem; margin: 0; }

/* ---------- tables ---------- */
table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.9rem;
  margin: 1.5rem 0;
}
th {
  font-family: var(--font-mono);
  font-size: 0.7rem;
  font-weight: 600;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--mut);
  text-align: left;
  padding: 0.8rem 1rem;
  border-bottom: 1px solid var(--line);
}
td {
  padding: 0.85rem 1rem;
  border-bottom: 1px solid var(--line-soft);
  vertical-align: top;
  color: var(--ink);
}
td:first-child { color: var(--ink-strong); font-weight: 500; }
tr:hover td { background: var(--bg-2); }

/* ---------- figure / diagram shell ---------- */
.figure {
  border: 1px solid var(--line);
  border-radius: var(--radius-md);
  background: var(--bg-2);
  padding: clamp(20px, 3vw, 40px);
  margin: 2rem 0;
  position: relative;
  overflow: hidden;
}
.figure .fig-label {
  position: absolute;
  top: 0; left: 0;
  font-family: var(--font-mono);
  font-size: 0.65rem;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--mut);
  background: var(--bg);
  border-right: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
  padding: 0.45rem 0.9rem;
}
.figure figcaption {
  font-family: var(--font-mono);
  font-size: 0.74rem;
  color: var(--mut);
  margin-top: 1.4rem;
  letter-spacing: 0.03em;
  line-height: 1.7;
}

/* stacked architecture layers */
.layers { display: flex; flex-direction: column; gap: 6px; margin-top: 1.5rem; }
.layer {
  display: grid;
  grid-template-columns: 56px 1fr auto;
  align-items: center;
  gap: 1.2rem;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--bg);
  padding: 1rem 1.3rem;
  transition: border-color .2s var(--ease), transform .2s var(--ease), background .2s var(--ease);
}
.layer:hover { border-color: var(--signal); background: var(--bg-2); transform: translateX(6px); }
.layer .ln {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  color: var(--signal);
  letter-spacing: 0.1em;
}
.layer .lt { font-weight: 600; color: var(--ink-strong); font-size: 0.95rem; }
.layer .ld {
  font-size: 0.8rem;
  color: var(--mut);
  font-family: var(--font-mono);
  letter-spacing: 0.02em;
  text-align: right;
}

/* ---------- big quote / thesis ---------- */
.thesis {
  font-family: var(--font-display);
  font-size: clamp(1.5rem, 3.2vw, 2.4rem);
  font-weight: 600;
  line-height: 1.35;
  letter-spacing: -0.015em;
  color: var(--ink-strong);
  max-width: 900px;
}
.thesis .accent { color: var(--signal); }
.thesis-src {
  font-family: var(--font-mono);
  font-size: 0.74rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--mut);
  margin-top: 2rem;
}

/* ---------- footer ---------- */
.footer {
  border-top: 1px solid var(--line);
  padding: clamp(48px, 6vw, 80px) 0 40px;
  background: var(--bg);
}
.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: 2.5rem;
  margin-bottom: 3.5rem;
}
.footer-brand .nav-logo { margin-bottom: 1.2rem; }
.footer-brand p { color: var(--mut); font-size: 0.88rem; max-width: 320px; }
.footer h5 {
  font-family: var(--font-mono);
  font-size: 0.68rem;
  font-weight: 600;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--mut);
  margin: 0 0 1.1rem;
}
.footer ul { list-style: none; margin: 0; padding: 0; }
.footer ul li { margin-bottom: 0.65rem; }
.footer ul a { font-size: 0.88rem; color: var(--mut); border-bottom: 0; transition: color .15s; }
.footer ul a:hover { color: var(--ink-strong); }
.footer-base {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 1.5rem;
  flex-wrap: wrap;
  border-top: 1px solid var(--line-soft);
  padding-top: 1.8rem;
  font-family: var(--font-mono);
  font-size: 0.7rem;
  letter-spacing: 0.08em;
  color: var(--mut-2);
}

/* ---------- CTA band ---------- */
.cta-band {
  border-top: 1px solid var(--line);
  background:
    linear-gradient(180deg, var(--bg), var(--bg-2));
  position: relative;
  overflow: hidden;
}
.cta-band .hero-slashes::before { right: 12%; }
.cta-band .hero-slashes::after { right: 4%; }
.cta-band .inner { position: relative; z-index: 1; padding-top: clamp(70px, 9vw, 120px); padding-bottom: clamp(70px, 9vw, 120px); max-width: 760px; }

/* ---------- reveal animations ---------- */
@media (prefers-reduced-motion: no-preference) {
  /* blur-fade reveal (magicui BlurFade / react-bits BlurText pattern) */
  .reveal {
    opacity: 0;
    transform: translateY(26px);
    filter: blur(7px);
    transition: opacity .8s cubic-bezier(.16,1,.3,1), transform .8s cubic-bezier(.16,1,.3,1), filter .8s cubic-bezier(.16,1,.3,1);
  }
  .reveal.is-in { opacity: 1; transform: none; filter: none; }
  .reveal[data-d="1"] { transition-delay: .08s; }
  .reveal[data-d="2"] { transition-delay: .16s; }
  .reveal[data-d="3"] { transition-delay: .24s; }
  .reveal[data-d="4"] { transition-delay: .32s; }
  .hero .reveal { transition-duration: 1s; }
}

/* (grain overlay removed — Geist surfaces stay clean) */

/* ---------- brand shapes (industry adaptability) ---------- */
.brand-shapes {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
  gap: 1px;
  background: var(--line-soft);
  border: 1px solid var(--line);
  border-radius: var(--radius-md);
  overflow: hidden;
  margin: 2.5rem 0 0;
}
.brand-shape {
  background: var(--bg);
  padding: 2.2rem 1rem 1.6rem;
  text-align: center;
  transition: background .25s;
}
.brand-shape:hover { background: var(--bg-2); }
.brand-shape svg { width: 84px; height: 84px; margin: 0 auto 1.1rem; display: block; }
.brand-shape svg .outline { fill: none; stroke: var(--mut); stroke-width: 2; transition: stroke .25s; }
.brand-shape:hover svg .outline { stroke: var(--ink-strong); }
.brand-shape svg .slash { fill: var(--signal); }
.brand-shape .bs-label {
  font-family: var(--font-mono);
  font-size: 0.66rem;
  font-weight: 500;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--mut);
}

/* ---------- language switcher / theme toggle ---------- */
.lang-switch { position: relative; }
.lang-btn, .theme-btn {
  background: none;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  color: var(--mut);
  font-family: var(--font-mono);
  font-size: 0.68rem;
  font-weight: 500;
  letter-spacing: 0.1em;
  padding: 0.5rem 0.75rem;
  cursor: pointer;
  transition: border-color .15s, color .15s;
  white-space: nowrap;
}
.lang-btn:hover, .theme-btn:hover { border-color: var(--signal); color: var(--signal); }
.lang-btn .tw { font-size: 0.6rem; }
.lang-menu {
  display: none;
  position: absolute;
  top: calc(100% + 8px);
  right: 0;
  list-style: none;
  margin: 0;
  padding: 4px;
  min-width: 140px;
  background: var(--bg);
  border: 1px solid var(--line-soft);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-menu);
  z-index: 120;
}
.lang-switch.open .lang-menu { display: block; }
.lang-menu button {
  display: block;
  width: 100%;
  text-align: left;
  background: none;
  border: 0;
  border-radius: var(--radius);
  color: var(--ink);
  font-family: var(--font-body);
  font-size: 0.85rem;
  padding: 0.5rem 0.7rem;
  cursor: pointer;
  transition: background .15s var(--ease);
}
.lang-menu button:hover { background: var(--bg-3); color: var(--ink-strong); }
.lang-menu button.cur { color: var(--signal); }
.lang-menu button.cur::after { content: " //"; font-family: var(--font-mono); font-size: 0.7em; }

/* ---------- nav mega menu (Vercel-style full-width panel) ---------- */
.nav-menu-btn {
  background: none;
  border: 0;
  color: var(--mut);
  font-family: var(--font-body);
  font-size: 0.85rem;
  font-weight: 500;
  letter-spacing: 0.02em;
  padding: 0.4rem 0;
  cursor: pointer;
  transition: color .15s;
  white-space: nowrap;
}
.nav-menu-btn .tw { font-size: 0.6rem; color: var(--mut); display: inline-block; transition: transform .18s var(--ease); }
.nav-menu-btn:hover, .nav-menu-btn.open { color: var(--ink-strong); }
.nav-menu-btn.open .tw { transform: rotate(180deg); }
.nav-menu-btn.active { color: var(--ink-strong); font-weight: 600; }

/* the panel spans the full viewport width, flush under the nav bar */
.nav-panel {
  position: absolute;
  top: 100%;
  left: 0; right: 0;
  background: var(--bg);
  border-bottom: 1px solid var(--line-soft);
  opacity: 0;
  transform: translateY(-6px);
  pointer-events: none;
  transition: opacity .18s var(--ease), transform .18s var(--ease);
}
.nav.panel-open .nav-panel {
  opacity: 1;
  transform: none;
  pointer-events: auto;
}
.nav-panel-in {
  max-width: var(--w-max);
  margin: 0 auto;
  padding: 1.9rem var(--pad-x) 2.6rem;
  display: grid;
  grid-template-columns: repeat(auto-fit, 260px);
  gap: 1.5rem 3.5rem;
}
.nav-panel-in[hidden] { display: none; }
.np-t {
  display: block;
  font-family: var(--font-mono);
  font-size: 0.64rem;
  font-weight: 500;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--mut-2);
  margin-bottom: 0.8rem;
}
.np-col a {
  display: block;
  font-family: var(--font-display);
  font-size: 1.18rem;
  font-weight: 500;
  letter-spacing: -0.01em;
  color: var(--ink-strong);
  padding: 0.36rem 0;
  transition: color .13s;
}
.np-col a:hover { color: var(--mut); }
.np-col a.cur { color: var(--signal); }
.np-col a .ext {
  font-family: var(--font-mono);
  font-size: 0.8em;
  color: var(--mut);
  margin-left: 0.3em;
}

/* page behind the open panel blurs (Vercel detail) */
.nav-veil {
  position: fixed;
  inset: var(--nav-h) 0 0 0;
  z-index: 90;
  background: color-mix(in srgb, var(--bg) 26%, transparent);
  -webkit-backdrop-filter: blur(9px) saturate(1.05);
  backdrop-filter: blur(9px) saturate(1.05);
  opacity: 0;
  pointer-events: none;
  transition: opacity .22s var(--ease);
}
body.nav-veiled .nav-veil { opacity: 1; }

/* inline (drawer) copies of the menus — hidden on desktop */
.nav-mob-menus { display: none; }

/* sign-in entry (console) — inherits color/padding/hover from .nav-links a */
.nav-links a.nav-signin {
  display: inline-flex;
  align-items: center;
  gap: 0.45rem;
  font-size: 0.85rem;
  white-space: nowrap;
}
.nav-links a.nav-signin svg { width: 15px; height: 15px; flex: none; }

/* theme toggle as a square icon button */
.theme-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0.46rem;
  line-height: 0;
}
.theme-btn svg { width: 16px; height: 16px; display: block; }

/* ---------- responsive ---------- */
@media (max-width: 980px) {
  .cards--3, .cards--4 { grid-template-columns: repeat(2, 1fr); }
  .split, .split--rev { grid-template-columns: 1fr; }
  .split .sticky { position: static; }
  .footer-grid { grid-template-columns: 1fr 1fr; }
  /* the busier nav (links + sign-in + CTA + lang + theme) collapses to the
     drawer here so it never overflows in the awkward tablet/small-laptop band */
  .nav-links {
    display: none;
    position: absolute;
    top: var(--nav-h);
    left: 0; right: 0;
    flex-direction: column;
    align-items: stretch;
    gap: 0;
    background: var(--bg);
    border-bottom: 1px solid var(--line);
    padding: 0.5rem var(--pad-x) 1.2rem;
    max-height: calc(100vh - var(--nav-h));
    overflow-y: auto;
  }
  .nav-links.open { display: flex; }
  .nav-links a { padding: 0.8rem 0; border-bottom: 1px solid var(--line-soft); }
  .nav-links a.nav-signin { justify-content: flex-start; }
  /* sign-in / get-started lead the drawer instead of trailing it */
  .nav-links .nav-signin { order: -2; }
  .nav-links .nav-cta {
    order: -1;
    padding: 0.72rem 1rem !important;
    margin: 0.3rem 0 0.5rem;
    font-size: 0.9rem !important;
    text-align: center;
    border: 1px solid var(--ink-strong);
  }
  .nav-burger { display: block; }
  /* mega menu: hide desktop buttons/panel, show inline drawer copies */
  .nav-menu-btn { display: none; }
  .nav-panel, .nav-veil { display: none; }
  .nav-mob-menus { display: block; }
  .nav-mob-menus .np-t { padding: 0.9rem 0 0.2rem; margin: 0; }
  /* hub-page link that leads each drawer menu (products/resources/pricing) */
  .nav-mob-menus a.np-hub { margin-top: 1.1rem; font-weight: 600; color: var(--ink-strong); }
  .nav-mob-menus a.np-hub .arr { font-family: var(--font-mono); color: var(--mut); }
  .nav-mob-menus a {
    display: block;
    font-size: 0.95rem;
    font-weight: 500;
    color: var(--ink);
    padding: 0.7rem 0;
    border-bottom: 1px solid var(--line-soft);
  }
  .nav-mob-menus a.cur { color: var(--signal); }
  .lang-switch { margin-top: 0.9rem; }
  .lang-menu { position: static; display: block; border: 0; padding: 0.2rem 0 0; min-width: 0; }
  .lang-switch .lang-btn { display: none; }
  .lang-menu button { padding: 0.5rem 0; border-bottom: 1px solid var(--line-soft); }
  .theme-btn { margin-top: 0.9rem; align-self: flex-start; }
}
@media (max-width: 720px) {
  body { font-size: 15px; }
  .cards--2, .cards--3, .cards--4 { grid-template-columns: 1fr; }
  .card { padding: 1.6rem 1.3rem 1.8rem; }
  .layer { grid-template-columns: 42px 1fr; padding: 0.85rem 1rem; }
  .layer .ld { display: none; }
  .layer:hover { transform: none; }
  .footer-grid { grid-template-columns: 1fr; gap: 1.8rem; }
  .numlist > li { grid-template-columns: 38px 1fr; gap: 0.9rem; padding: 1.2rem 0; }
  .stats { grid-template-columns: repeat(2, 1fr); }
  .stat { padding: 1.3rem 1rem; border-bottom: 1px solid var(--line-soft); }
  .stat .n { font-size: 1.8rem; }
  .hero { min-height: auto; }
  .hero-inner { padding-top: clamp(48px, 12vw, 80px); padding-bottom: clamp(48px, 12vw, 80px); }
  .hero .lede { font-size: 1.02rem; }
  .en-sub { font-size: 0.68rem; }
  .thesis { font-size: 1.3rem; }
  .figure { padding: 16px 14px; }
  .figure .fig-label { font-size: 0.58rem; padding: 0.35rem 0.6rem; }
  .sec { padding: 56px 0; }
  .btn { width: 100%; justify-content: center; text-align: center; }
  .btn-row { flex-direction: column; }
  /* tables scroll horizontally instead of breaking layout */
  table { display: block; overflow-x: auto; -webkit-overflow-scrolling: touch; }
  th, td { padding: 0.7rem 0.7rem; font-size: 0.84rem; }
  th { white-space: nowrap; }
  pre { font-size: 0.76rem; padding: 0.9rem 1rem; }
  .footer-base { flex-direction: column; align-items: flex-start; gap: 0.6rem; }
}
@media (max-width: 420px) {
  h1 { font-size: 2rem; }
  h2 { font-size: 1.4rem; }
  .kicker { font-size: 0.64rem; letter-spacing: 0.16em; }
}

/* ============================================================
   2026-07 — Vercel-grade marketing layer
   mega nav (Products), hero glyph, industry strip, bento viz,
   pricing cards + comparison table + FAQ
   ============================================================ */

/* ---------- hero glyph (giant // mark, Vercel-triangle role) ---------- */
.hero-glyph {
  position: absolute;
  z-index: 1;
  top: 50%;
  right: clamp(120px, 16vw, 320px);
  transform: translateY(-54%);
  display: flex;
  gap: clamp(26px, 3vw, 46px);
  pointer-events: none;
  filter: drop-shadow(0 18px 28px rgba(0, 0, 0, 0.10));
}
.hero-glyph i {
  display: block;
  width: clamp(54px, 6.4vw, 104px);
  height: clamp(220px, 30vw, 430px);
  transform: skewX(-20deg);
  background: linear-gradient(
    180deg,
    color-mix(in srgb, var(--ink-strong) 42%, var(--bg)),
    color-mix(in srgb, var(--ink-strong) 14%, var(--bg))
  );
}
.hero-glyph::after {
  /* light pooling under the mark */
  content: "";
  position: absolute;
  left: 50%;
  bottom: -14%;
  width: 150%;
  height: 26%;
  transform: translateX(-50%);
  background: radial-gradient(ellipse at center, color-mix(in srgb, var(--ink-strong) 10%, transparent), transparent 70%);
}
.hero-side {
  position: absolute;
  z-index: 1;
  top: 50%;
  right: var(--pad-x);
  transform: translateY(-50%);
  display: grid;
  gap: 1.1rem;
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.14em;
  color: var(--mut);
  text-transform: uppercase;
  pointer-events: none;
}

/* ---------- industry strip: infinite marquee (magicui Marquee pattern) ---------- */
.ind-strip {
  overflow: hidden;
  padding: clamp(28px, 4vw, 44px) 0;
  font-family: var(--font-mono);
  font-size: 0.76rem;
  font-weight: 500;
  letter-spacing: 0.16em;
  color: var(--mut-2);
  -webkit-mask-image: linear-gradient(90deg, transparent, #000 12%, #000 88%, transparent);
  mask-image: linear-gradient(90deg, transparent, #000 12%, #000 88%, transparent);
}
.ind-strip .marq {
  display: flex;
  width: max-content;
  animation: marq 36s linear infinite;
}
.ind-strip:hover .marq { animation-play-state: paused; }
.ind-strip .marq-row {
  display: flex;
  gap: 3.2rem;
  padding-right: 3.2rem;
  white-space: nowrap;
}
@keyframes marq { to { transform: translateX(-50%); } }
@media (prefers-reduced-motion: reduce) {
  .ind-strip .marq { animation: none; flex-wrap: wrap; width: auto; }
  .ind-strip .marq-row + .marq-row { display: none; }
}

/* ---------- spotlight hover (react-bits SpotlightCard pattern) ---------- */
.card::after, .price-card::after {
  content: "";
  position: absolute;
  inset: 0;
  border-radius: inherit;
  background: radial-gradient(240px circle at var(--mx, 50%) var(--my, 50%),
    color-mix(in srgb, var(--ink-strong) 6%, transparent), transparent 70%);
  opacity: 0;
  transition: opacity .25s var(--ease);
  pointer-events: none;
}
.card:hover::after, .price-card:hover::after { opacity: 1; }
.price-card { position: relative; overflow: hidden; }

/* ---------- border beam on the popular plan (magicui BorderBeam pattern) ---------- */
@property --beam { syntax: "<angle>"; inherits: false; initial-value: 0deg; }
.price-card--pop { overflow: visible; }
.price-card--pop .beam {
  position: absolute;
  inset: -1px;
  border-radius: var(--radius-md);
  padding: 1px;
  background: conic-gradient(from var(--beam),
    transparent 0deg 300deg,
    color-mix(in srgb, var(--signal) 65%, transparent) 330deg,
    transparent 360deg);
  -webkit-mask: linear-gradient(#000 0 0) content-box, linear-gradient(#000 0 0);
  -webkit-mask-composite: xor;
  mask: linear-gradient(#000 0 0) content-box, linear-gradient(#000 0 0);
  mask-composite: exclude;
  animation: beam 5.5s linear infinite;
  pointer-events: none;
}
@keyframes beam { to { --beam: 360deg; } }
@media (prefers-reduced-motion: reduce) {
  .price-card--pop .beam { animation: none; display: none; }
}

/* ---------- bento visualization panels (inside .card) ---------- */
.viz {
  height: 200px;
  margin-bottom: 1.5rem;
  border: 1px solid var(--line-soft);
  border-radius: var(--radius);
  background: var(--bg-2);
  position: relative;
  overflow: hidden;
}
.viz svg { width: 100%; height: 100%; display: block; }
.viz .vz-label {
  position: absolute;
  top: 0; left: 0;
  font-family: var(--font-mono);
  font-size: 0.58rem;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--mut-2);
  background: var(--bg);
  border-right: 1px solid var(--line-soft);
  border-bottom: 1px solid var(--line-soft);
  padding: 0.3rem 0.6rem;
  border-top-left-radius: var(--radius);
}
.viz-agents {
  display: grid;
  grid-template-columns: repeat(5, 1fr);
  gap: 7px;
  padding: 2.1rem 1.1rem 1.1rem;
  height: 100%;
  box-sizing: border-box;
}
.viz-agents b {
  display: flex;
  align-items: center;
  justify-content: center;
  font-family: var(--font-mono);
  font-size: 0.6rem;
  font-weight: 500;
  letter-spacing: 0.08em;
  color: var(--mut);
  background: var(--bg);
  border: 1px solid var(--line);
  border-radius: var(--radius);
}
.viz-agents b.hot { color: var(--signal); border-color: var(--signal); background: var(--signal-soft); }
.viz-log {
  display: flex;
  flex-direction: column;
  justify-content: center;
  gap: 0.6rem;
  height: 100%;
  padding: 2.1rem 1.2rem 1.1rem;
  box-sizing: border-box;
  font-family: var(--font-mono);
  font-size: 0.66rem;
  letter-spacing: 0.02em;
  color: var(--mut);
  white-space: nowrap;
}
.viz-log .ok { color: var(--signal); }
.viz-log .dim { color: var(--mut-2); }

/* ---------- pricing ---------- */
.price-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 12px;
  align-items: stretch;
}
.price-card {
  display: flex;
  flex-direction: column;
  background: var(--bg);
  border: 1px solid var(--line);
  border-radius: var(--radius-md);
  padding: 1.9rem 1.7rem;
  transition: border-color .2s var(--ease), box-shadow .2s var(--ease);
}
.price-card:hover { border-color: color-mix(in srgb, var(--ink-strong) 22%, transparent); box-shadow: var(--shadow-card); }
.price-card--pop {
  border-color: color-mix(in srgb, var(--ink-strong) 34%, transparent);
  box-shadow: var(--shadow-menu);
}
.price-plan {
  display: flex;
  align-items: center;
  gap: 0.7rem;
  font-family: var(--font-mono);
  font-size: 0.72rem;
  font-weight: 600;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--ink-strong);
  margin-bottom: 1.5rem;
}
.price-badge {
  font-size: 0.56rem;
  font-weight: 500;
  letter-spacing: 0.14em;
  color: var(--ink-strong);
  border: 1px solid var(--line);
  border-radius: 4px;
  padding: 0.14rem 0.5rem;
}
.price-amount {
  font-family: var(--font-display);
  font-size: clamp(2.5rem, 3.6vw, 3.4rem);
  font-weight: 800;
  letter-spacing: -0.03em;
  line-height: 1;
  color: var(--ink-strong);
}
.price-amount--custom { font-weight: 700; letter-spacing: -0.02em; }
.price-per {
  font-family: var(--font-mono);
  font-size: 0.8rem;
  font-weight: 400;
  letter-spacing: 0.02em;
  color: var(--mut);
  margin-left: 0.4rem;
}
.price-head-note {
  font-family: var(--font-mono);
  font-size: 0.66rem;
  letter-spacing: 0.06em;
  color: var(--mut-2);
  margin-top: 0.7rem;
}
.price-desc {
  color: var(--mut);
  font-size: 0.93rem;
  margin: 1.1rem 0 0;
  padding-bottom: 1.4rem;
  border-bottom: 1px solid var(--line-soft);
}
.price-list {
  list-style: none;
  margin: 1.4rem 0 1.9rem;
  padding: 0;
  display: flex;
  flex-direction: column;
  gap: 0.62rem;
  font-size: 0.9rem;
  color: var(--ink);
}
.price-list li { position: relative; padding-left: 1.5rem; }
.price-list li::before {
  content: "";
  position: absolute;
  left: 1px; top: 0.44em;
  width: 9px; height: 5px;
  border-left: 2px solid var(--signal);
  border-bottom: 2px solid var(--signal);
  transform: rotate(-45deg);
}
.price-card .btn { margin-top: auto; width: 100%; }
.price-note {
  font-family: var(--font-mono);
  font-size: 0.7rem;
  letter-spacing: 0.05em;
  color: var(--mut-2);
  margin-top: 1.6rem;
}

/* comparison table */
.cmp-wrap { overflow-x: auto; -webkit-overflow-scrolling: touch; margin-top: 2rem; }
table.cmp { min-width: 780px; margin: 0; }
.cmp thead th { border-bottom: 1px solid var(--line); }
.cmp thead th:not(:first-child) {
  text-align: center;
  font-size: 0.78rem;
  letter-spacing: 0.1em;
  color: var(--ink-strong);
}
.cmp th:first-child { width: 38%; }
.cmp td:not(:first-child) { text-align: center; color: var(--mut); font-size: 0.87rem; }
.cmp tr.cmp-group th {
  padding: 2.4rem 1rem 0.7rem;
  font-family: var(--font-display);
  font-size: 1rem;
  font-weight: 600;
  letter-spacing: -0.01em;
  text-transform: none;
  color: var(--ink-strong);
  border-bottom: 1px solid var(--line);
}
.cmp tr:hover td { background: var(--bg-2); }
.chk { display: inline-block; width: 12px; height: 8px; position: relative; }
.chk::before {
  content: "";
  position: absolute;
  left: 0; top: 0;
  width: 10px; height: 5px;
  border-left: 2px solid var(--ink-strong);
  border-bottom: 2px solid var(--ink-strong);
  transform: rotate(-45deg);
}
.dash { color: var(--mut-2); }

/* FAQ */
.faq-list { max-width: 780px; margin-top: 1.6rem; border-top: 1px solid var(--line-soft); }
details.faq { border-bottom: 1px solid var(--line-soft); }
details.faq summary {
  cursor: pointer;
  list-style: none;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  padding: 1.15rem 0.2rem;
  font-weight: 600;
  color: var(--ink-strong);
}
details.faq summary::-webkit-details-marker { display: none; }
details.faq summary::after {
  content: "+";
  font-family: var(--font-mono);
  font-size: 1rem;
  color: var(--mut);
  transition: transform .2s var(--ease);
  flex: none;
}
details.faq[open] summary::after { transform: rotate(45deg); }
details.faq p { color: var(--mut); font-size: 0.92rem; margin: 0 0 1.25rem; max-width: 660px; padding: 0 0.2rem; }

/* responsive for the new layer */
@media (max-width: 1100px) {
  .hero-side { display: none; }
}
@media (max-width: 980px) {
  .price-grid { grid-template-columns: 1fr; }
  .hero-glyph { right: 6vw; opacity: 0.5; }
}
@media (max-width: 720px) {
  .hero-glyph { display: none; }
  .ind-strip { justify-content: flex-start; gap: 0.9rem 1.8rem; font-size: 0.66rem; }
  .viz { height: 170px; }
}