/* ============================================================
   EV Lens — shared stylesheet
   Identity: "technical instrument / spec-sheet"
   Brand: deep navy (#0A1230) + electric aqua (#2FEACB), from the app icon.
   Type:  Bricolage Grotesque (display) · IBM Plex Sans (body) · IBM Plex Mono (data)
   ============================================================ */

/* ---------- Tokens: light (default / un-stamped) ---------- */
:root {
  --paper:      #F2F5F5;
  --surface:    #FFFFFF;
  --surface-2:  #E9EFEF;
  --ink:        #0B1424;
  --ink-2:      #33424E;
  --muted:      #5E6E77;
  --line:       #DBE3E4;
  --line-strong:#C4D0D1;

  --navy:       #0A1230;   /* hero ground, constant across themes */
  --navy-2:     #111A3E;
  --aqua:       #12B49E;   /* accent for fills on light */
  --aqua-bright:#2FEACB;   /* accent on navy/dark */
  --aqua-ink:   #0A6E60;   /* aqua-as-text / links on light (AA on paper) */
  --aqua-soft:  #DEF6F1;   /* tinted fill on light */

  /* content-driven powertrain coding */
  --pt-bev:  #12A67F;
  --pt-phev: #0E8FA6;
  --pt-hev:  #3D7CC4;
  --pt-ice:  #8A7F70;

  --focus:   #12B49E;
  --shadow:  0 1px 2px rgba(11,20,36,.05), 0 10px 30px -12px rgba(11,20,36,.18);
  --shadow-sm: 0 1px 2px rgba(11,20,36,.06);

  --font-display: "Bricolage Grotesque", "Segoe UI", system-ui, sans-serif;
  --font-body: "IBM Plex Sans", system-ui, -apple-system, "Segoe UI", sans-serif;
  --font-mono: "IBM Plex Mono", ui-monospace, "SFMono-Regular", Menlo, monospace;

  --maxw: 1120px;
  --measure: 68ch;
  --radius: 14px;
  --radius-sm: 9px;
}

/* ---------- Tokens: dark (system default when OS is dark) ---------- */
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --paper:      #070C1A;
    --surface:    #0C1428;
    --surface-2:  #121C36;
    --ink:        #EAF1F2;
    --ink-2:      #AFBCC5;
    --muted:      #7F8D98;
    --line:       #1D2A46;
    --line-strong:#2A3960;

    --aqua:       #2FEACB;
    --aqua-ink:   #35E3C6;
    --aqua-soft:  #0F2A33;

    --pt-bev:  #22C79B;
    --pt-phev: #29B6D4;
    --pt-hev:  #5E9CE0;
    --pt-ice:  #A99C88;

    --focus:   #2FEACB;
    --shadow:  0 1px 2px rgba(0,0,0,.3), 0 18px 40px -16px rgba(0,0,0,.6);
    --shadow-sm: 0 1px 2px rgba(0,0,0,.35);
  }
}

/* ---------- Tokens: dark (explicit toggle wins either OS) ---------- */
:root[data-theme="dark"] {
  --paper:      #070C1A;
  --surface:    #0C1428;
  --surface-2:  #121C36;
  --ink:        #EAF1F2;
  --ink-2:      #AFBCC5;
  --muted:      #7F8D98;
  --line:       #1D2A46;
  --line-strong:#2A3960;

  --aqua:       #2FEACB;
  --aqua-ink:   #35E3C6;
  --aqua-soft:  #0F2A33;

  --pt-bev:  #22C79B;
  --pt-phev: #29B6D4;
  --pt-hev:  #5E9CE0;
  --pt-ice:  #A99C88;

  --focus:   #2FEACB;
  --shadow:  0 1px 2px rgba(0,0,0,.3), 0 18px 40px -16px rgba(0,0,0,.6);
  --shadow-sm: 0 1px 2px rgba(0,0,0,.35);
}

/* ---------- Base ---------- */
*, *::before, *::after { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; scroll-behavior: smooth; }
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after { animation-duration: .001ms !important; transition-duration: .001ms !important; }
}

body {
  margin: 0;
  font-family: var(--font-body);
  font-size: 1.02rem;
  line-height: 1.65;
  color: var(--ink);
  background: var(--paper);
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

h1, h2, h3, h4 {
  font-family: var(--font-display);
  font-weight: 700;
  line-height: 1.08;
  letter-spacing: -0.012em;
  color: var(--ink);
  text-wrap: balance;
  margin: 0 0 .5em;
}

p { margin: 0 0 1rem; }
a { color: var(--aqua-ink); text-decoration-color: color-mix(in srgb, var(--aqua-ink) 40%, transparent); text-underline-offset: 3px; }
a:hover { text-decoration-color: currentColor; }
img { max-width: 100%; display: block; }
strong { font-weight: 650; }

:focus-visible {
  outline: 2.5px solid var(--focus);
  outline-offset: 2px;
  border-radius: 3px;
}

.container { width: 100%; max-width: var(--maxw); margin-inline: auto; padding-inline: clamp(1.1rem, 4vw, 2rem); }

.eyebrow {
  font-family: var(--font-mono);
  font-size: .74rem;
  font-weight: 500;
  letter-spacing: .18em;
  text-transform: uppercase;
  color: var(--aqua-ink);
  margin: 0 0 1rem;
  display: inline-flex;
  align-items: center;
  gap: .55rem;
}
.eyebrow::before { content: ""; width: 1.4rem; height: 1px; background: currentColor; opacity: .7; }

.section { padding-block: clamp(3.5rem, 8vw, 6.5rem); }
.section-sm { padding-block: clamp(2.5rem, 5vw, 3.5rem); }
.section-head { max-width: 42rem; margin-bottom: clamp(2rem, 4vw, 3rem); }
.section-head h2 { font-size: clamp(1.9rem, 3.6vw, 2.75rem); }
.section-head p { color: var(--ink-2); font-size: 1.1rem; }
.lede { font-size: 1.18rem; color: var(--ink-2); }

/* ---------- Header ---------- */
.site-header {
  position: sticky; top: 0; z-index: 50;
  background: color-mix(in srgb, var(--paper) 82%, transparent);
  backdrop-filter: saturate(160%) blur(12px);
  border-bottom: 1px solid var(--line);
}
.site-header .container { display: flex; align-items: center; gap: 1.5rem; height: 66px; }
.brand { display: inline-flex; align-items: center; gap: .6rem; font-family: var(--font-display); font-weight: 700; font-size: 1.14rem; color: var(--ink); text-decoration: none; letter-spacing: -.01em; }
.brand img { width: 30px; height: 30px; border-radius: 7px; }
.brand span b { color: var(--aqua-ink); font-weight: 700; }

.nav { display: flex; align-items: center; gap: .35rem; margin-left: auto; }
.nav a { color: var(--ink-2); text-decoration: none; font-size: .95rem; padding: .5rem .7rem; border-radius: 8px; font-weight: 500; }
.nav a:hover { color: var(--ink); background: var(--surface-2); }
.nav .btn { margin-left: .4rem; }

.header-tools { display: flex; align-items: center; gap: .3rem; margin-left: auto; }
.icon-btn {
  display: inline-grid; place-items: center; width: 38px; height: 38px;
  border: 1px solid var(--line); border-radius: 9px; background: var(--surface);
  color: var(--ink-2); cursor: pointer;
}
.icon-btn:hover { color: var(--ink); border-color: var(--line-strong); }
.theme-toggle .moon { display: none; }
:root[data-theme="dark"] .theme-toggle .sun { display: none; }
:root[data-theme="dark"] .theme-toggle .moon { display: block; }
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) .theme-toggle .sun { display: none; }
  :root:not([data-theme="light"]) .theme-toggle .moon { display: block; }
}
.menu-btn { display: none; }

/* ---------- Buttons ---------- */
.btn {
  display: inline-flex; align-items: center; justify-content: center; gap: .5rem;
  font-family: var(--font-body); font-weight: 600; font-size: .96rem;
  padding: .7rem 1.25rem; border-radius: 10px; border: 1px solid transparent;
  cursor: pointer; text-decoration: none; transition: transform .15s ease, background .2s ease, border-color .2s ease;
  white-space: nowrap;
}
.btn:active { transform: translateY(1px); }
.btn-primary { background: var(--aqua); color: #04211C; border-color: color-mix(in srgb, var(--aqua) 70%, #000 8%); }
.btn-primary:hover { background: color-mix(in srgb, var(--aqua) 88%, #fff 12%); }
:root[data-theme="dark"] .btn-primary, .btn-primary { color: #052018; }
.btn-ghost { background: transparent; color: var(--ink); border-color: var(--line-strong); }
.btn-ghost:hover { border-color: var(--ink-2); background: var(--surface-2); }
.btn-lg { padding: .85rem 1.6rem; font-size: 1.02rem; }
.btn-block { width: 100%; }

/* App-store style pill */
.store-badge {
  display: inline-flex; align-items: center; gap: .6rem;
  background: var(--navy); color: #fff; border: 1px solid #ffffff1a;
  padding: .6rem 1.15rem; border-radius: 12px; text-decoration: none; font-weight: 500;
}
.store-badge small { display: block; font-size: .66rem; opacity: .72; letter-spacing: .04em; text-transform: uppercase; font-family: var(--font-mono); }
.store-badge strong { font-size: 1.02rem; font-weight: 650; letter-spacing: -.01em; }
.store-badge:hover { background: var(--navy-2); }

/* ---------- Hero (navy, echoes the icon) ---------- */
.hero { position: relative; overflow: hidden; background: var(--navy); color: #EAF3F4; isolation: isolate; }
.hero::before {
  content: ""; position: absolute; inset: 0; z-index: -1;
  background:
    radial-gradient(120% 90% at 82% -10%, rgba(47,234,203,.16), transparent 55%),
    radial-gradient(90% 80% at 0% 110%, rgba(47,234,203,.08), transparent 50%),
    linear-gradient(180deg, #0A1230 0%, #0B1638 100%);
}
.hero::after { /* faint measurement grid */
  content: ""; position: absolute; inset: 0; z-index: -1; opacity: .5;
  background-image: linear-gradient(#ffffff08 1px, transparent 1px), linear-gradient(90deg, #ffffff08 1px, transparent 1px);
  background-size: 48px 48px; -webkit-mask-image: radial-gradient(120% 80% at 60% 0%, #000 25%, transparent 75%);
  mask-image: radial-gradient(120% 80% at 60% 0%, #000 25%, transparent 75%);
}
.hero .container { position: relative; display: grid; grid-template-columns: 1.15fr .85fr; gap: clamp(2rem, 5vw, 4rem); align-items: center; padding-block: clamp(3.5rem, 8vw, 6rem); }
.hero .eyebrow { color: var(--aqua-bright); }
.hero h1 { color: #F4FBFB; font-size: clamp(2.5rem, 6vw, 4.1rem); letter-spacing: -.02em; }
.hero h1 em { font-style: normal; color: var(--aqua-bright); }
.hero p.lede { color: #AFC2C6; max-width: 34rem; }
.hero-cta { display: flex; flex-wrap: wrap; gap: .8rem; margin-top: 1.8rem; align-items: center; }
/* ghost buttons sit on the constant navy hero — keep them light in every theme */
.hero .btn-ghost, .cta-band .btn-ghost { color: #EAF3F4; border-color: #ffffff38; }
.hero .btn-ghost:hover, .cta-band .btn-ghost:hover { border-color: #ffffff70; background: #ffffff14; }
.hero-meta { display: flex; flex-wrap: wrap; gap: 1.4rem; margin-top: 2rem; font-family: var(--font-mono); font-size: .8rem; color: #8DA1A6; letter-spacing: .02em; }
.hero-meta b { color: var(--aqua-bright); font-weight: 500; }

/* phone / device mock in hero */
.device {
  justify-self: center; width: min(280px, 78vw); aspect-ratio: 9 / 19;
  background: linear-gradient(160deg, #0E1740, #0A1030); border-radius: 34px;
  border: 1px solid #2b3a67; padding: 12px; box-shadow: 0 30px 70px -20px rgba(0,0,0,.6), inset 0 0 0 6px #05091d;
  position: relative;
}
.device .screen { height: 100%; border-radius: 24px; background: radial-gradient(90% 60% at 50% 0%, #14224e, #0a1230); overflow: hidden; position: relative; display: flex; flex-direction: column; }
.device .scanline { position: absolute; left: 8%; right: 8%; top: 30%; height: 2px; background: linear-gradient(90deg, transparent, var(--aqua-bright), transparent); box-shadow: 0 0 16px var(--aqua-bright); animation: scan 3.4s ease-in-out infinite; }
@keyframes scan { 0%,100% { top: 22%; opacity: .5;} 50% { top: 64%; opacity: 1; } }
.device .frame { margin: auto; width: 62%; aspect-ratio: 1; border: 2px dashed #2fead16b; border-radius: 16px; position: relative; }
.device .frame::after { content: "BEV"; position: absolute; bottom: -12px; left: 50%; transform: translateX(-50%); font-family: var(--font-mono); font-size: .62rem; letter-spacing: .12em; background: var(--pt-bev); color: #041b15; padding: .18rem .5rem; border-radius: 5px; font-weight: 600; }
.device .readout { position: absolute; bottom: 14px; left: 14px; right: 14px; font-family: var(--font-mono); font-size: .6rem; color: #9fb4b8; display: grid; gap: 5px; }
.device .readout span { display: flex; justify-content: space-between; border-bottom: 1px solid #ffffff12; padding-bottom: 4px; }
.device .readout b { color: var(--aqua-bright); font-weight: 500; }

/* trust bar under hero */
.trustbar { border-top: 1px solid #ffffff12; }
.trustbar .container { display: flex; flex-wrap: wrap; gap: 1rem 2.4rem; justify-content: center; padding-block: 1.1rem; font-family: var(--font-mono); font-size: .76rem; letter-spacing: .06em; text-transform: uppercase; color: #7f9398; }

/* ---------- Cards / feature grid ---------- */
.grid { display: grid; gap: 1.1rem; }
.grid-2 { grid-template-columns: repeat(2, 1fr); }
.grid-3 { grid-template-columns: repeat(3, 1fr); }
.grid-4 { grid-template-columns: repeat(4, 1fr); }

.card {
  background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius);
  padding: 1.5rem; box-shadow: var(--shadow-sm); transition: border-color .2s ease, transform .2s ease, box-shadow .2s ease;
}
.card:hover { border-color: var(--line-strong); transform: translateY(-2px); box-shadow: var(--shadow); }
.card h3 { font-size: 1.16rem; }
.card p { color: var(--ink-2); font-size: .98rem; margin: 0; }
.card .ic {
  width: 42px; height: 42px; border-radius: 11px; display: grid; place-items: center;
  background: var(--aqua-soft); color: var(--aqua-ink); margin-bottom: 1rem;
}
.card .ic svg { width: 22px; height: 22px; }
.card .kbd { font-family: var(--font-mono); font-size: .72rem; color: var(--muted); letter-spacing: .08em; text-transform: uppercase; }

/* ---------- Powertrain badges (content-driven color) ---------- */
.badges { display: flex; flex-wrap: wrap; gap: .6rem; }
.pt {
  display: inline-flex; align-items: center; gap: .5rem; font-family: var(--font-mono);
  font-size: .8rem; font-weight: 500; letter-spacing: .04em; padding: .4rem .75rem;
  border-radius: 8px; border: 1px solid var(--line); background: var(--surface);
}
.pt .dot { width: 9px; height: 9px; border-radius: 50%; }
.pt.bev  .dot { background: var(--pt-bev); }
.pt.phev .dot { background: var(--pt-phev); }
.pt.hev  .dot { background: var(--pt-hev); }
.pt.ice  .dot { background: var(--pt-ice); }

/* ---------- Spec row (instrument motif) ---------- */
.specs { border: 1px solid var(--line); border-radius: var(--radius); overflow: hidden; background: var(--surface); }
.specs .row { display: grid; grid-template-columns: 1fr auto; gap: 1rem; padding: .95rem 1.25rem; border-bottom: 1px solid var(--line); font-size: .96rem; }
.specs .row:last-child { border-bottom: 0; }
.specs .row .k { color: var(--ink-2); }
.specs .row .v { font-family: var(--font-mono); color: var(--ink); font-variant-numeric: tabular-nums; }

/* stat tiles */
.stats { display: grid; grid-template-columns: repeat(auto-fit, minmax(160px,1fr)); gap: 1rem; }
.stat { background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius); padding: 1.4rem 1.4rem; }
.stat .n { font-family: var(--font-display); font-size: 2.1rem; font-weight: 700; color: var(--ink); letter-spacing: -.02em; font-variant-numeric: tabular-nums; }
.stat .l { font-family: var(--font-mono); font-size: .74rem; letter-spacing: .08em; text-transform: uppercase; color: var(--muted); }

/* ---------- Pricing ---------- */
.tiers { display: grid; grid-template-columns: repeat(3, 1fr); gap: 1.1rem; align-items: start; }
.tier { background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius); padding: 1.7rem; display: flex; flex-direction: column; gap: 1rem; }
.tier.featured { border-color: var(--aqua); box-shadow: 0 0 0 1px var(--aqua), var(--shadow); position: relative; }
.tier.featured::before { content: "Most popular"; position: absolute; top: -.8rem; left: 1.5rem; background: var(--aqua); color: #05221c; font-family: var(--font-mono); font-size: .66rem; letter-spacing: .1em; text-transform: uppercase; padding: .25rem .6rem; border-radius: 6px; font-weight: 600; }
.tier h3 { font-size: 1.3rem; margin: 0; }
.tier .price { font-family: var(--font-display); font-size: 2.2rem; font-weight: 700; letter-spacing: -.02em; }
.tier .price small { font-size: .95rem; font-weight: 400; color: var(--muted); font-family: var(--font-body); }
.tier ul { list-style: none; margin: 0; padding: 0; display: grid; gap: .6rem; }
.tier li { display: flex; gap: .6rem; align-items: flex-start; color: var(--ink-2); font-size: .95rem; }
.tier li svg { flex: none; width: 18px; height: 18px; color: var(--aqua-ink); margin-top: .15rem; }
.tier .note { font-family: var(--font-mono); font-size: .72rem; color: var(--muted); }

/* ---------- CTA band ---------- */
.cta-band { background: var(--navy); color: #eaf3f4; border-radius: 20px; padding: clamp(2.2rem, 5vw, 3.5rem); position: relative; overflow: hidden; }
.cta-band::before { content:""; position:absolute; inset:0; background: radial-gradient(90% 120% at 90% 0%, rgba(47,234,203,.16), transparent 55%); }
.cta-band > * { position: relative; }
.cta-band h2 { color: #fff; font-size: clamp(1.7rem,3.4vw,2.4rem); }
.cta-band p { color: #aec2c6; max-width: 40rem; }

/* ---------- Document layout (legal / support) ---------- */
.page-hero { background: var(--surface); border-bottom: 1px solid var(--line); }
.page-hero .container { padding-block: clamp(2.4rem, 5vw, 3.6rem); }
.page-hero h1 { font-size: clamp(2rem, 4.5vw, 3rem); }
.page-hero p { color: var(--ink-2); max-width: 46rem; margin: 0; }
.updated { font-family: var(--font-mono); font-size: .76rem; letter-spacing: .05em; text-transform: uppercase; color: var(--muted); margin-bottom: .8rem; }

.doc { display: grid; grid-template-columns: 220px minmax(0,1fr); gap: clamp(1.5rem,4vw,3.5rem); align-items: start; }
.toc { position: sticky; top: 84px; font-size: .9rem; }
.toc .toc-title { font-family: var(--font-mono); font-size: .72rem; letter-spacing: .1em; text-transform: uppercase; color: var(--muted); margin-bottom: .7rem; }
.toc ol { list-style: none; margin: 0; padding: 0; display: grid; gap: .1rem; counter-reset: toc; }
.toc a { display: block; color: var(--ink-2); text-decoration: none; padding: .4rem .6rem; border-radius: 7px; border-left: 2px solid transparent; }
.toc a:hover { background: var(--surface-2); color: var(--ink); }

.prose { max-width: var(--measure); }
.prose h2 { font-size: 1.5rem; margin-top: 2.6rem; scroll-margin-top: 84px; padding-top: .3rem; }
.prose h2:first-child { margin-top: 0; }
.prose h3 { font-size: 1.14rem; margin-top: 1.8rem; }
.prose p, .prose li { color: var(--ink-2); }
.prose ul, .prose ol { padding-left: 1.2rem; display: grid; gap: .45rem; margin: 0 0 1.1rem; }
.prose li::marker { color: var(--aqua-ink); }
.prose a { font-weight: 500; }
.prose hr { border: 0; border-top: 1px solid var(--line); margin: 2.2rem 0; }

.note {
  border: 1px solid var(--line); border-left: 3px solid var(--aqua); background: var(--surface);
  border-radius: 10px; padding: 1rem 1.2rem; margin: 1.4rem 0; font-size: .95rem; color: var(--ink-2);
}
.note strong { color: var(--ink); }
.note.warn { border-left-color: #E0A73C; }
.placeholder { background: color-mix(in srgb, #E0A73C 16%, transparent); border-radius: 4px; padding: 0 .3em; font-family: var(--font-mono); font-size: .9em; color: var(--ink); }

/* FAQ */
.faq { display: grid; gap: .7rem; max-width: var(--measure); }
.faq details { border: 1px solid var(--line); border-radius: 11px; background: var(--surface); overflow: hidden; }
.faq summary { cursor: pointer; padding: 1.05rem 1.25rem; font-weight: 600; color: var(--ink); list-style: none; display: flex; justify-content: space-between; gap: 1rem; align-items: center; font-size: 1rem; }
.faq summary::-webkit-details-marker { display: none; }
.faq summary::after { content: "+"; font-family: var(--font-mono); color: var(--aqua-ink); font-size: 1.3rem; line-height: 1; transition: transform .2s ease; }
.faq details[open] summary::after { transform: rotate(45deg); }
.faq .body { padding: 0 1.25rem 1.2rem; color: var(--ink-2); font-size: .96rem; }
.faq .body p:last-child { margin-bottom: 0; }

/* contact cards */
.contact-row { display: grid; grid-template-columns: repeat(auto-fit,minmax(220px,1fr)); gap: 1rem; }
.contact-row .card a { font-weight: 600; }

/* ---------- Footer ---------- */
.site-footer { background: var(--surface); border-top: 1px solid var(--line); margin-top: 3rem; }
.site-footer .container { padding-block: clamp(2.5rem, 5vw, 3.5rem); }
.foot-grid { display: grid; grid-template-columns: 1.4fr repeat(3, 1fr); gap: 2rem; }
.foot-brand .brand { margin-bottom: .8rem; }
.foot-brand p { color: var(--muted); font-size: .9rem; max-width: 24rem; }
.foot-col h4 { font-family: var(--font-mono); font-size: .74rem; letter-spacing: .1em; text-transform: uppercase; color: var(--muted); font-weight: 500; margin-bottom: .9rem; }
.foot-col ul { list-style: none; margin: 0; padding: 0; display: grid; gap: .5rem; }
.foot-col a { color: var(--ink-2); text-decoration: none; font-size: .93rem; }
.foot-col a:hover { color: var(--aqua-ink); }
.foot-bottom { border-top: 1px solid var(--line); margin-top: 2.2rem; padding-top: 1.4rem; display: flex; flex-wrap: wrap; gap: .8rem 1.5rem; justify-content: space-between; align-items: center; color: var(--muted); font-size: .84rem; }
.foot-bottom .mono { font-family: var(--font-mono); letter-spacing: .03em; }

/* ---------- Helpers ---------- */
.center { text-align: center; }
.mx-auto { margin-inline: auto; }
.mt-2 { margin-top: 2rem; } .mt-3 { margin-top: 3rem; }
.stack { display: grid; gap: 1rem; }
.split { display: grid; grid-template-columns: 1fr 1fr; gap: clamp(1.5rem,4vw,3rem); align-items: center; }
.skip-link { position: absolute; left: -999px; top: 0; background: var(--aqua); color: #04211c; padding: .6rem 1rem; border-radius: 0 0 8px 0; z-index: 100; font-weight: 600; }
.skip-link:focus { left: 0; }

/* ---------- Responsive ---------- */
@media (max-width: 900px) {
  .hero .container { grid-template-columns: 1fr; }
  .device { grid-row: 1; margin-bottom: .5rem; }
  .grid-3, .grid-4 { grid-template-columns: repeat(2, 1fr); }
  .tiers { grid-template-columns: 1fr; }
  .doc { grid-template-columns: 1fr; }
  .toc { position: static; border: 1px solid var(--line); border-radius: 11px; padding: 1rem 1.2rem; background: var(--surface); }
  .foot-grid { grid-template-columns: 1fr 1fr; }
}
@media (max-width: 720px) {
  .nav { display: none; }
  .header-tools { margin-left: auto; }
  .menu-btn { display: inline-grid; }
  .nav.open {
    display: flex; flex-direction: column; align-items: stretch; position: absolute;
    top: 66px; left: 0; right: 0; background: var(--paper); border-bottom: 1px solid var(--line);
    padding: .8rem clamp(1.1rem,4vw,2rem) 1.2rem; gap: .2rem; margin: 0;
  }
  .nav.open a { padding: .7rem .5rem; }
  .nav.open .btn { margin: .5rem 0 0; }
  .split, .grid-2 { grid-template-columns: 1fr; }
}
@media (max-width: 480px) {
  .grid-3, .grid-4 { grid-template-columns: 1fr; }
  .foot-grid { grid-template-columns: 1fr; }
}