/* ═══════════════════════════════════════════════════════════════
   Featherfield — feather-light tools for the field.
   Zero dependencies. System fonts only. Dark by default, light on request.
   ═══════════════════════════════════════════════════════════════ */

:root{
  --ink:        #070b09;
  --ink-rgb:    7,11,9;
  --ink-2:      #0b110e;
  --panel:      #0f1713;
  --panel-2:    #131d18;
  --line:       rgba(255,255,255,.09);
  --line-2:     rgba(255,255,255,.17);

  --txt:        #bccbc2;
  --txt-hi:     #eef6f0;
  --txt-dim:    #7d9187;
  --txt-faint:  #4d5f55;

  --leaf:       #7fdc9a;
  --leaf-dim:   #2f7a4d;
  --sun:        #ffd27a;
  --sun-hot:    #fff0c4;
  --sky:        #8ed4ff;
  --warn:       #ff9d8a;

  --leaf-rgb:   127,220,154;
  --sun-rgb:    255,210,122;

  --btn-ink:    #1a1203;
  --frame:      #000;

  --sans: system-ui, -apple-system, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  --mono: ui-monospace, "Cascadia Mono", "JetBrains Mono", "SF Mono", Consolas, "Liberation Mono", monospace;

  --gut: clamp(18px, 5vw, 64px);
  --maxw: 1240px;
  --ease: cubic-bezier(.22,.68,.36,1);
  color-scheme: dark;
}

:root[data-theme="light"]{
  --ink:        #f5f7f1;
  --ink-rgb:    245,247,241;
  --ink-2:      #eef2ea;
  --panel:      #ffffff;
  --panel-2:    #f2f6ee;
  --line:       rgba(10,35,22,.12);
  --line-2:     rgba(10,35,22,.24);

  --txt:        #2e4237;
  --txt-hi:     #0c1a12;
  --txt-dim:    #587064;
  --txt-faint:  #8da094;

  --leaf:       #1b7a42;
  --leaf-dim:   #7fbf97;
  --sun:        #b86a00;
  --sun-hot:    #8a4f00;
  --sky:        #1769a0;
  --warn:       #b33a24;

  --leaf-rgb:   27,122,66;
  --sun-rgb:    184,106,0;

  --btn-ink:    #fffaf0;
  color-scheme: light;
}

@media (prefers-color-scheme: light){
  :root:not([data-theme="dark"]){
    --ink:#f5f7f1; --ink-rgb:245,247,241; --ink-2:#eef2ea; --panel:#ffffff; --panel-2:#f2f6ee;
    --line:rgba(10,35,22,.12); --line-2:rgba(10,35,22,.24);
    --txt:#2e4237; --txt-hi:#0c1a12; --txt-dim:#587064; --txt-faint:#8da094;
    --leaf:#1b7a42; --leaf-dim:#7fbf97; --sun:#b86a00; --sun-hot:#8a4f00; --sky:#1769a0; --warn:#b33a24;
    --leaf-rgb:27,122,66; --sun-rgb:184,106,0; --btn-ink:#fffaf0;
    color-scheme: light;
  }
}

*,*::before,*::after{ box-sizing:border-box; }

html{
  background:var(--ink);
  scroll-behavior:smooth;
  -webkit-text-size-adjust:100%;
  scroll-padding-top:76px;
}

body{
  margin:0;
  background:var(--ink);
  color:var(--txt);
  font-family:var(--sans);
  font-size:16px;
  line-height:1.62;
  overflow-x:hidden;
  -webkit-font-smoothing:antialiased;
  text-rendering:optimizeLegibility;
}

img,svg,canvas{ max-width:100%; display:block; }
a{ color:var(--leaf); text-decoration:none; }
a:hover{ color:var(--sun); }
:focus-visible{ outline:2px solid var(--sun); outline-offset:3px; border-radius:4px; }
::selection{ background:rgba(var(--sun-rgb),.3); color:var(--txt-hi); }

h1,h2,h3,h4,p,ul,ol,dl,dd,figure{ margin:0; }
ul,ol{ padding:0; list-style:none; }
.muted{ color:var(--txt-dim); }

code,.mono{
  font-family:var(--mono);
}
code{
  font-size:.9em;
  color:var(--sun-hot);
  background:rgba(var(--sun-rgb),.1);
  padding:.08em .36em;
  border-radius:4px;
}
:root[data-theme="light"] code{ color:var(--sun-hot); }

.wrap{
  width:100%;
  max-width:var(--maxw);
  margin-inline:auto;
  padding-inline:var(--gut);
  position:relative; z-index:1;
}

.sr-only{
  position:absolute; width:1px; height:1px; margin:-1px; padding:0;
  overflow:hidden; clip:rect(0 0 0 0); white-space:nowrap; border:0;
}

.skip-link{
  position:absolute; left:-9999px; top:0; z-index:300;
  background:var(--sun); color:var(--btn-ink);
  padding:12px 20px; font-weight:700; border-radius:0 0 8px 0;
}
.skip-link:focus{ left:0; }

/* ══════════════════ top bar ══════════════════ */

.bar{
  position:fixed; inset:0 0 auto 0; z-index:100;
  display:flex; align-items:center; gap:18px;
  padding:12px var(--gut);
  border-bottom:1px solid transparent;
  transition:background .35s var(--ease), border-color .35s var(--ease);
}
.bar.is-stuck{
  background:rgba(var(--ink-rgb),.84);
  backdrop-filter:blur(14px) saturate(1.3);
  -webkit-backdrop-filter:blur(14px) saturate(1.3);
  border-bottom-color:var(--line);
}

.brand{
  display:flex; align-items:center; gap:10px;
  color:var(--txt-hi);
  font-weight:700; letter-spacing:-.01em; font-size:17px;
}
.brand:hover{ color:var(--txt-hi); }
.brand-mark{ width:30px; height:30px; flex:none; }
.brand-mark .bm-bg{ fill:var(--panel-2); stroke:var(--line-2); stroke-width:1; }
.brand-mark .bm-ring{ fill:none; stroke:var(--sun); stroke-opacity:.35; stroke-width:2; }
.brand-mark .bm-leaf{ fill:var(--leaf); }
.brand-mark .bm-vein{ stroke:var(--ink); stroke-width:2.4; stroke-linecap:round; fill:none; }
.brand-mark .bm-sun{ fill:var(--sun); }

.bar-nav{
  display:flex; gap:24px; margin-left:auto;
  font-family:var(--mono); font-size:12.5px; letter-spacing:.1em; text-transform:uppercase;
}
.bar-nav a{ color:var(--txt-dim); position:relative; padding-block:4px; transition:color .2s; }
.bar-nav a::after{
  content:""; position:absolute; left:0; right:100%; bottom:0; height:1px; background:var(--sun);
  transition:right .3s var(--ease);
}
.bar-nav a:hover, .bar-nav a.is-current{ color:var(--txt-hi); }
.bar-nav a:hover::after, .bar-nav a.is-current::after{ right:0; }

.bar-actions{ display:flex; align-items:center; gap:8px; }

.pill{
  display:inline-flex; align-items:center; gap:8px;
  background:transparent; border:1px solid var(--line-2); color:var(--txt-dim);
  font-family:var(--mono); font-size:11.5px; letter-spacing:.12em; text-transform:uppercase;
  padding:7px 13px; border-radius:999px; cursor:pointer;
  transition:all .25s var(--ease);
}
.pill:hover{ border-color:var(--sun); color:var(--txt-hi); }
.pill[aria-pressed="true"]{ border-color:var(--sun); color:var(--txt-hi); background:rgba(var(--sun-rgb),.1); }

.nav-toggle{
  display:none; align-items:center; justify-content:center;
  width:34px; height:34px; padding:0;
  background:transparent; border:1px solid var(--line-2); border-radius:999px;
  color:var(--txt-dim); cursor:pointer;
}
.nav-toggle-icon{ position:relative; width:15px; height:1.5px; background:currentColor; }
.nav-toggle-icon::before,.nav-toggle-icon::after{
  content:""; position:absolute; left:0; width:100%; height:1.5px; background:currentColor;
  transition:transform .25s var(--ease), top .25s var(--ease);
}
.nav-toggle-icon::before{ top:-5px; } .nav-toggle-icon::after{ top:5px; }
.nav-toggle[aria-expanded="true"]{ border-color:var(--sun); color:var(--txt-hi); }
.nav-toggle[aria-expanded="true"] .nav-toggle-icon{ background:transparent; }
.nav-toggle[aria-expanded="true"] .nav-toggle-icon::before{ top:0; transform:rotate(45deg); }
.nav-toggle[aria-expanded="true"] .nav-toggle-icon::after{ top:0; transform:rotate(-45deg); }

/* ══════════════════ buttons ══════════════════ */

.btn{
  display:inline-flex; align-items:center; justify-content:center; gap:8px;
  font:600 14.5px/1 var(--sans);
  padding:13px 20px; border-radius:999px;
  border:1px solid var(--line-2); background:transparent; color:var(--txt-hi);
  cursor:pointer; transition:all .25s var(--ease);
}
.btn:hover{ border-color:var(--sun); color:var(--txt-hi); transform:translateY(-1px); }
.btn-primary{ background:var(--sun); border-color:var(--sun); color:var(--btn-ink); }
.btn-primary:hover{ background:var(--sun-hot); border-color:var(--sun-hot); color:var(--btn-ink); }
:root[data-theme="light"] .btn-primary:hover{ background:#9a5800; border-color:#9a5800; color:#fff; }
.btn-sm{ padding:9px 14px; font-size:13px; }
.btn[disabled]{ opacity:.5; cursor:not-allowed; transform:none; }

/* ══════════════════ hero ══════════════════ */

.hero{
  position:relative; isolation:isolate;
  padding:clamp(96px, 13vh, 150px) 0 clamp(48px, 7vw, 84px);
  overflow:hidden;
}
.hero::before{
  content:""; position:absolute; inset:-10% -10% auto auto; width:70vw; height:70vw; max-width:900px; max-height:900px;
  background:radial-gradient(closest-side, rgba(var(--sun-rgb),.16), rgba(var(--sun-rgb),0) 70%);
  z-index:-1; pointer-events:none;
}
.hero::after{
  content:""; position:absolute; inset:auto auto -25% -15%; width:70vw; height:70vw; max-width:900px; max-height:900px;
  background:radial-gradient(closest-side, rgba(var(--leaf-rgb),.12), rgba(var(--leaf-rgb),0) 70%);
  z-index:-1; pointer-events:none;
}
.hero-grid{
  display:grid;
  grid-template-columns:minmax(0,1.02fr) minmax(0,.98fr);
  gap:clamp(28px, 5vw, 72px);
  align-items:center;
}

.kicker{
  font-family:var(--mono); font-size:12px; letter-spacing:.16em; text-transform:uppercase;
  color:var(--leaf);
}
.kicker .dot{ color:var(--txt-faint); padding:0 .55em; }

.display{
  margin-top:18px;
  font-size:clamp(2.5rem, 5.6vw, 4.5rem);
  line-height:1.03; letter-spacing:-.035em; font-weight:800;
  color:var(--txt-hi);
  text-wrap:balance;
}
.display .glow{
  background:linear-gradient(100deg, var(--leaf) 0%, var(--sun) 100%);
  -webkit-background-clip:text; background-clip:text; color:transparent;
  white-space:nowrap;
}
.lede{ margin-top:22px; max-width:34em; font-size:clamp(1.02rem, 1.6vw, 1.18rem); color:var(--txt); }
.lede strong{ color:var(--txt-hi); font-weight:600; }
.lede-sub{ margin-top:14px; max-width:36em; color:var(--txt-dim); font-size:.97rem; }
.lede-sub a{ text-decoration:underline; text-underline-offset:3px; text-decoration-color:var(--line-2); }

.hero-cta{ display:flex; flex-wrap:wrap; gap:12px; margin-top:28px; }

.chips{ display:flex; flex-wrap:wrap; gap:8px; margin-top:26px; }
.chip{
  font-family:var(--mono); font-size:11.5px; letter-spacing:.06em;
  color:var(--txt-dim); border:1px solid var(--line); border-radius:999px; padding:6px 12px;
  background:rgba(var(--ink-rgb),.35);
}
.chip b{ color:var(--txt-hi); font-weight:600; }

/* ── the lens card ── */

.lens-card{
  position:relative;
  background:linear-gradient(180deg, var(--panel), var(--panel-2));
  border:1px solid var(--line-2);
  border-radius:24px;
  padding:14px;
  display:grid; gap:12px;
  box-shadow:0 30px 80px -30px rgba(0,0,0,.55), 0 0 0 1px rgba(var(--leaf-rgb),.05);
  max-width:600px; margin-inline:auto; width:100%;
}
.lens-frame{
  position:relative; aspect-ratio:1; width:100%;
  background:var(--frame);
  border-radius:16px; overflow:hidden;
  box-shadow:inset 0 0 0 1px rgba(255,255,255,.06);
}
.lens-canvas{ width:100%; height:100%; touch-action:manipulation; }
.lens-tag{
  position:absolute; left:10px; bottom:10px; right:10px;
  font-family:var(--mono); font-size:11px; letter-spacing:.04em; color:rgba(255,255,255,.78);
  background:rgba(0,0,0,.55); backdrop-filter:blur(4px);
  padding:5px 10px; border-radius:8px; width:fit-content; max-width:calc(100% - 20px);
  pointer-events:none;
}
.lens-drop{
  position:absolute; inset:0; display:grid; place-items:center;
  background:rgba(0,0,0,.66); color:#fff; font-weight:600; letter-spacing:.02em;
  border:2px dashed rgba(var(--sun-rgb),.7); border-radius:16px;
}
.lens-drop[hidden]{ display:none; }

.readout{
  display:grid; grid-template-columns:repeat(4, minmax(0,1fr)); gap:8px;
}
.ro{
  background:rgba(var(--ink-rgb),.5);
  border:1px solid var(--line); border-radius:12px; padding:9px 11px 8px;
  min-width:0;
}
.ro dt{
  font-family:var(--mono); font-size:11px; letter-spacing:.08em; color:var(--txt-hi); font-weight:700;
  display:flex; flex-direction:column; gap:1px;
}
.ro dt span{ font-weight:400; color:var(--txt-dim); letter-spacing:0; text-transform:none; font-size:10.5px; line-height:1.25; }
.ro dd{
  font-family:var(--mono); font-size:clamp(20px, 3.2vw, 26px); font-weight:700; letter-spacing:-.02em;
  color:var(--sun); line-height:1.25; margin-top:2px; font-variant-numeric:tabular-nums;
}
.ro dd small{ font-size:.55em; color:var(--txt-dim); font-weight:500; margin-left:2px; }
.ro.is-mute dd{ color:var(--txt-faint); }

.rings{
  display:grid; grid-template-columns:repeat(7, 1fr); gap:4px; align-items:end;
  height:52px; padding:0 2px; position:relative;
}
.rings .rb{ position:relative; height:52px; display:flex; align-items:flex-end; }
.rings .rb i{
  display:block; width:100%; min-height:2px; border-radius:3px 3px 1px 1px;
  background:linear-gradient(180deg, var(--sky), rgba(142,212,255,.35));
  transition:height .25s var(--ease);
}
:root[data-theme="light"] .rings .rb i{ background:linear-gradient(180deg, var(--sky), rgba(23,105,160,.35)); }
.rings .rb u{
  position:absolute; left:-1px; right:-1px; height:2px; background:var(--sun); border-radius:2px;
  text-decoration:none; transition:bottom .25s var(--ease);
}
.rings-cap{
  display:flex; justify-content:space-between; gap:10px; margin-top:6px;
  font-family:var(--mono); font-size:10.5px; letter-spacing:.03em; color:var(--txt-dim);
}
.rings-cap .lg-bar::before, .rings-cap .lg-tick::before{
  content:""; display:inline-block; vertical-align:middle; margin-right:5px;
}
.rings-cap .lg-bar::before{ width:9px; height:9px; border-radius:2px; background:var(--sky); }
.rings-cap .lg-tick::before{ width:12px; height:2px; background:var(--sun); }

.controls{ display:grid; grid-template-columns:1fr 1fr; gap:10px 18px; }
.ctl{
  display:grid; grid-template-columns:1fr auto; gap:4px 10px; align-items:center;
  font-size:12.5px; color:var(--txt-dim);
}
.ctl-k{ font-family:var(--mono); font-size:11.5px; letter-spacing:.06em; text-transform:uppercase; color:var(--txt); }
.ctl-k em{ font-style:normal; color:var(--txt-dim); text-transform:none; letter-spacing:0; }
.ctl output{ font-family:var(--mono); font-size:13px; color:var(--txt-hi); font-variant-numeric:tabular-nums; }
.ctl input[type=range]{ grid-column:1 / -1; width:100%; accent-color:var(--sun); height:22px; margin:0; }

.actions{ display:flex; flex-wrap:wrap; gap:8px; align-items:center; }
.seg{ display:inline-flex; border:1px solid var(--line-2); border-radius:999px; padding:2px; }
.seg button{
  font:600 12.5px/1 var(--sans); color:var(--txt-dim); background:transparent; border:0; border-radius:999px;
  padding:8px 13px; cursor:pointer; transition:all .2s var(--ease);
}
.seg button[aria-pressed="true"]{ background:rgba(var(--sun-rgb),.16); color:var(--txt-hi); }
.seg button:hover{ color:var(--txt-hi); }
.btn-file input{ position:absolute; width:1px; height:1px; opacity:0; pointer-events:none; }
.btn-file{ position:relative; }
.btn-file:focus-within{ outline:2px solid var(--sun); outline-offset:3px; }

.lens-check{
  font-family:var(--mono); font-size:11.5px; line-height:1.5; letter-spacing:.01em; color:var(--txt-dim);
  min-height:2.9em;
}
.lens-check b{ color:var(--txt-hi); font-weight:600; }
.lens-check .ok{ color:var(--leaf); font-weight:700; }
.lens-check .bad{ color:var(--warn); font-weight:700; }

.adv{ border-top:1px solid var(--line); padding-top:8px; font-size:13px; color:var(--txt-dim); }
.adv summary{ cursor:pointer; font-family:var(--mono); font-size:11.5px; letter-spacing:.1em; text-transform:uppercase; color:var(--txt-dim); }
.adv summary:hover{ color:var(--txt-hi); }
.adv-grid{ display:grid; grid-template-columns:1fr 1fr; gap:10px 18px; margin-top:10px; align-items:center; }
.adv label{ display:flex; align-items:center; gap:8px; }
.adv select{
  background:var(--panel); color:var(--txt-hi); border:1px solid var(--line-2); border-radius:8px; padding:6px 8px; font:inherit;
}
.adv input[type=checkbox]{ accent-color:var(--sun); width:16px; height:16px; }
.adv .note{ grid-column:1 / -1; font-size:12px; color:var(--txt-dim); }

/* ══════════════════ glance ══════════════════ */

.glance{ border-block:1px solid var(--line); background:rgba(var(--ink-rgb),.4); }
.glance-grid{ display:grid; grid-template-columns:repeat(4, minmax(0,1fr)); }
.gl{ padding:26px 22px; border-left:1px solid var(--line); }
.gl:first-child{ border-left:0; padding-left:0; }
.gl-v{ font-family:var(--mono); font-size:clamp(24px, 3.4vw, 34px); font-weight:700; letter-spacing:-.03em; color:var(--txt-hi); line-height:1.1; }
.gl-v small{ font-size:.5em; color:var(--txt-dim); font-weight:500; letter-spacing:0; margin-left:4px; }
.gl-v.is-live{ color:var(--leaf); }
.gl-k{ margin-top:8px; font-size:13.5px; color:var(--txt-dim); max-width:22em; }

/* ══════════════════ sections ══════════════════ */

.section{ padding:clamp(54px, 7vw, 92px) 0; position:relative; }
.sec-head{ max-width:44em; margin-bottom:clamp(28px, 4vw, 48px); }
.sec-title{
  margin-top:12px; font-size:clamp(1.8rem, 3.8vw, 2.9rem); line-height:1.08; letter-spacing:-.03em; font-weight:800; color:var(--txt-hi);
}
.sec-lede{ margin-top:16px; color:var(--txt); font-size:1.06rem; max-width:40em; }

/* tools */

.tools{ display:grid; grid-template-columns:minmax(0,1.55fr) minmax(0,1fr); gap:20px; align-items:stretch; }

.card{
  background:linear-gradient(180deg, var(--panel), var(--panel-2));
  border:1px solid var(--line); border-radius:22px; padding:clamp(22px, 3vw, 34px);
  position:relative; overflow:hidden;
  transition:border-color .3s var(--ease), transform .3s var(--ease);
}
.card:hover{ border-color:var(--line-2); }
.card-top{ display:flex; flex-wrap:wrap; align-items:center; gap:10px; }
.tag{
  font-family:var(--mono); font-size:11px; letter-spacing:.12em; text-transform:uppercase;
  padding:5px 10px; border-radius:999px; border:1px solid var(--line-2); color:var(--txt-dim);
}
.tag.is-live{ color:var(--leaf); border-color:rgba(var(--leaf-rgb),.5); background:rgba(var(--leaf-rgb),.08); }
.tag.is-next{ color:var(--sun); border-color:rgba(var(--sun-rgb),.5); background:rgba(var(--sun-rgb),.08); }
.card-title{ margin-top:16px; font-size:clamp(1.7rem, 3vw, 2.3rem); letter-spacing:-.03em; font-weight:800; color:var(--txt-hi); font-family:var(--mono); }
.card-tagline{ margin-top:6px; font-size:1.12rem; color:var(--sun); font-weight:600; }
.card-body{ margin-top:14px; max-width:40em; }
.facts{ display:grid; grid-template-columns:auto 1fr; gap:8px 18px; margin-top:20px; font-size:14.5px; }
.facts dt{ font-family:var(--mono); font-size:11.5px; letter-spacing:.1em; text-transform:uppercase; color:var(--txt-dim); padding-top:2px; }
.facts dd{ color:var(--txt); }
.card-links{ display:flex; flex-wrap:wrap; gap:10px; margin-top:24px; }
.linkrow{
  display:inline-flex; align-items:center; gap:8px; font-size:14px; font-weight:600;
  border:1px solid var(--line-2); border-radius:999px; padding:9px 15px; color:var(--txt-hi);
}
.linkrow:hover{ border-color:var(--sun); color:var(--txt-hi); }
.linkrow.is-primary{ background:rgba(var(--sun-rgb),.12); border-color:rgba(var(--sun-rgb),.55); }

.code{
  margin-top:22px; position:relative;
  background:var(--ink); border:1px solid var(--line); border-radius:14px;
  padding:14px 16px; font-family:var(--mono); font-size:13px; line-height:1.7; color:var(--txt);
  overflow-x:auto; white-space:pre;
}
.code .c{ color:var(--txt-faint); }
.code button{
  position:absolute; top:8px; right:8px; font:600 11px/1 var(--mono); letter-spacing:.08em; text-transform:uppercase;
  color:var(--txt-dim); background:var(--panel-2); border:1px solid var(--line-2); border-radius:8px; padding:6px 9px; cursor:pointer;
}
.code button:hover{ color:var(--txt-hi); border-color:var(--sun); }

.card-next{ display:flex; flex-direction:column; }
.card-next .card-links{ margin-top:auto; padding-top:24px; }
.criteria{ margin-top:16px; display:grid; gap:10px; font-size:14.8px; color:var(--txt); }
.criteria li{ position:relative; padding-left:24px; }
.criteria li::before{ content:"→"; position:absolute; left:0; color:var(--sun); font-family:var(--mono); }
.criteria b{ color:var(--txt-hi); font-weight:600; }
.card-next::before{
  content:""; position:absolute; inset:auto -20% -40% auto; width:360px; height:360px;
  background:radial-gradient(closest-side, rgba(var(--leaf-rgb),.14), rgba(var(--leaf-rgb),0) 70%); pointer-events:none;
}

/* principles */

.principles{ display:grid; grid-template-columns:repeat(4, minmax(0,1fr)); gap:16px; }
.pr{
  border:1px solid var(--line); border-radius:20px; padding:24px 22px; background:rgba(var(--ink-rgb),.4);
}
.pr-n{ font-family:var(--mono); font-size:12px; letter-spacing:.14em; color:var(--sun); }
.pr h3{ margin-top:12px; font-size:1.18rem; letter-spacing:-.01em; color:var(--txt-hi); }
.pr p{ margin-top:10px; font-size:14.5px; color:var(--txt); }

/* method */

.steps{ display:grid; grid-template-columns:repeat(4, minmax(0,1fr)); gap:16px; counter-reset:step; }
.step{
  border:1px solid var(--line); border-radius:20px; padding:22px; background:linear-gradient(180deg, var(--panel), var(--panel-2));
  counter-increment:step;
}
.step::before{
  content:counter(step, decimal-leading-zero); font-family:var(--mono); color:var(--leaf); font-size:12px; letter-spacing:.14em;
}
.step h3{ margin-top:10px; font-size:1.12rem; color:var(--txt-hi); font-family:var(--mono); letter-spacing:-.01em; }
.step p{ margin-top:8px; font-size:14.2px; }
.formulas{
  margin-top:20px; background:var(--ink); border:1px solid var(--line); border-radius:18px; padding:8px 22px 6px;
}
.fl-def{ padding:12px 0; font-family:var(--mono); font-size:13px; color:var(--txt-dim); }
.fr{
  display:grid; grid-template-columns:minmax(0,1.35fr) minmax(0,1fr); gap:6px 28px; align-items:baseline;
  padding:13px 0; border-top:1px solid var(--line);
}
.fr code{
  background:none; padding:0; color:var(--txt-hi); font-size:clamp(12.5px, 1.35vw, 14.5px); line-height:1.6;
}
.fr code b{ color:var(--sun); }
.fr span{ color:var(--txt-dim); font-size:13.5px; line-height:1.5; }

.proof{ display:grid; grid-template-columns:repeat(3, minmax(0,1fr)); gap:16px; margin-top:28px; }
.proof .card{ padding:22px; }
.proof h3{ font-size:1.05rem; color:var(--txt-hi); }
.proof p{ margin-top:8px; font-size:14.2px; }
.proof .num{ font-family:var(--mono); color:var(--leaf); font-weight:700; }
.limits{
  margin-top:20px; border-left:3px solid var(--sun); padding:6px 0 6px 18px; max-width:52em; color:var(--txt); font-size:15px;
}
.limits b{ color:var(--txt-hi); }

/* about */

.about{ display:grid; grid-template-columns:minmax(0,1.2fr) minmax(0,.8fr); gap:clamp(24px, 5vw, 64px); align-items:start; }
.about p + p{ margin-top:14px; }
.about strong{ color:var(--txt-hi); }
.about-card{ position:sticky; top:96px; }
.about-card h3{ font-size:.95rem; font-family:var(--mono); letter-spacing:.12em; text-transform:uppercase; color:var(--txt-dim); font-weight:600; }
.about-card ul{ margin-top:14px; display:grid; gap:10px; }
.about-card li a{
  display:flex; justify-content:space-between; gap:10px; padding:11px 14px; border:1px solid var(--line); border-radius:12px;
  color:var(--txt-hi); font-size:14.5px; font-weight:600;
}
.about-card li a span{ color:var(--txt-dim); font-weight:400; font-size:13px; }
.about-card li a:hover{ border-color:var(--sun); }
.disclaimer{ margin-top:18px; font-size:13px; color:var(--txt-dim); border-top:1px solid var(--line); padding-top:14px; }

/* cta */

.section-cta{ text-align:center; }
.cta-box{
  border:1px solid var(--line-2); border-radius:28px; padding:clamp(34px, 6vw, 72px) clamp(20px, 5vw, 56px);
  background:
    radial-gradient(60% 90% at 50% 0%, rgba(var(--leaf-rgb),.14), rgba(var(--leaf-rgb),0) 70%),
    linear-gradient(180deg, var(--panel), var(--panel-2));
}
.cta-title{ font-size:clamp(2rem, 5vw, 3.6rem); line-height:1.04; letter-spacing:-.035em; font-weight:800; color:var(--txt-hi); }
.cta-lede{ margin:18px auto 0; max-width:36em; color:var(--txt); font-size:1.08rem; }
.cta-actions{ display:flex; flex-wrap:wrap; justify-content:center; gap:12px; margin-top:28px; }

/* footer */

.foot{ border-top:1px solid var(--line); padding:44px 0 56px; color:var(--txt-dim); font-size:14px; }
.foot-grid{ display:grid; grid-template-columns:minmax(0,1.3fr) repeat(3, minmax(0,1fr)); gap:28px; }
.foot h4{ font-family:var(--mono); font-size:11.5px; letter-spacing:.14em; text-transform:uppercase; color:var(--txt-dim); font-weight:600; margin-bottom:12px; }
.foot li + li{ margin-top:8px; }
.foot a{ color:var(--txt); } .foot a:hover{ color:var(--sun); }
.foot-brand p{ margin-top:12px; max-width:26em; }
.foot-legal{ margin-top:36px; padding-top:20px; border-top:1px solid var(--line); display:flex; flex-wrap:wrap; justify-content:space-between; gap:10px 24px; font-size:13px; }

/* reveal */
.reveal{ opacity:0; transform:translateY(14px); transition:opacity .7s var(--ease), transform .7s var(--ease); }
.reveal.is-in{ opacity:1; transform:none; }
.no-js .reveal{ opacity:1; transform:none; }

/* ══════════════════ responsive ══════════════════ */

@media (max-width: 1020px){
  .hero-grid{ grid-template-columns:1fr; }
  .lens-card{ max-width:560px; }
  .tools{ grid-template-columns:1fr; }
  .principles{ grid-template-columns:repeat(2, minmax(0,1fr)); }
  .steps{ grid-template-columns:repeat(2, minmax(0,1fr)); }
  .proof{ grid-template-columns:1fr; }
  .about{ grid-template-columns:1fr; }
  .about-card{ position:static; }
  .foot-grid{ grid-template-columns:repeat(2, minmax(0,1fr)); }
  .foot-brand{ grid-column:1 / -1; }
}

@media (max-width: 760px){
  .nav-toggle{ display:inline-flex; }
  .bar-nav{
    position:absolute; top:100%; left:0; right:0; margin:0; flex-direction:column; gap:0;
    background:rgba(var(--ink-rgb),.97); border-bottom:1px solid var(--line);
    padding:6px var(--gut) 14px; display:none;
  }
  .bar-nav.is-open{ display:flex; }
  .bar-nav a{ padding:12px 0; border-bottom:1px solid var(--line); }
  .bar-nav a::after{ display:none; }
  .bar-actions{ margin-left:auto; }
  .pill .pill-label{ display:none; }
  .glance-grid{ grid-template-columns:repeat(2, minmax(0,1fr)); }
  .gl{ border-left:0; border-top:1px solid var(--line); padding-left:0; }
  .gl:nth-child(-n+2){ border-top:0; }
  .gl:nth-child(even){ padding-left:22px; border-left:1px solid var(--line); }
  .readout{ grid-template-columns:repeat(2, minmax(0,1fr)); }
  .principles, .steps{ grid-template-columns:1fr; }
  .fr{ grid-template-columns:1fr; }
  .controls{ grid-template-columns:1fr; }
  .adv-grid{ grid-template-columns:1fr; }
  .foot-grid{ grid-template-columns:1fr; }
  .facts{ grid-template-columns:1fr; gap:2px; }
  .facts dd{ margin-bottom:10px; }
}

@media (prefers-reduced-motion: reduce){
  html{ scroll-behavior:auto; }
  *,*::before,*::after{ transition-duration:.01ms !important; animation-duration:.01ms !important; }
  .reveal{ opacity:1; transform:none; }
}