/* ---------- tokens ---------- */
:root{
  --bg:#eef5fa;
  --surface:#ffffff;
  --surface-2:#dde9f1;
  --ink:#0b1b28;
  --muted:#4f6577;
  --border:#c7dae6;
  --accent:#1c7aa8;
  --accent-bright:#0ea5c9;
  --ice:#3fb9de;
  --shadow-1:0 1px 2px rgba(9,23,34,.07),0 1px 1px rgba(9,23,34,.05);
  --shadow-2:0 20px 40px -18px rgba(9,23,34,.28);
  --hero-bg:#0a1620;
  --hero-surface:#102232;
  --hero-surface-2:#153048;
  --hero-ink:#eaf5fb;
  --hero-muted:#8fa9ba;
  --hero-border:#1e3c50;
  --font-display:'Unbounded', system-ui, sans-serif;
  --font-body:'IBM Plex Sans', system-ui, sans-serif;
  --font-mono:'IBM Plex Mono', ui-monospace, monospace;
}
@media (prefers-color-scheme: dark){
  :root:not([data-theme="light"]){
    --bg:#081019;
    --surface:#0f2331;
    --surface-2:#14364a;
    --ink:#eaf4fa;
    --muted:#93aebd;
    --border:#1f3d4f;
    --accent:#4db8e0;
    --accent-bright:#79d6f2;
    --ice:#8fe6ff;
    --shadow-1:0 1px 2px rgba(0,0,0,.5),0 1px 1px rgba(0,0,0,.35);
    --shadow-2:0 20px 44px -18px rgba(0,0,0,.6);
  }
}
:root[data-theme="dark"]{
  --bg:#081019;
  --surface:#0f2331;
  --surface-2:#14364a;
  --ink:#eaf4fa;
  --muted:#93aebd;
  --border:#1f3d4f;
  --accent:#4db8e0;
  --accent-bright:#79d6f2;
  --ice:#8fe6ff;
  --shadow-1:0 1px 2px rgba(0,0,0,.5),0 1px 1px rgba(0,0,0,.35);
  --shadow-2:0 20px 44px -18px rgba(0,0,0,.6);
}

*,*::before,*::after{ box-sizing:border-box; }
html{ scroll-behavior:smooth; }
body{
  margin:0;
  background:var(--bg);
  color:var(--ink);
  font-family:var(--font-body);
  font-size:16px;
  line-height:1.55;
  -webkit-font-smoothing:antialiased;
  overflow-x:hidden;
}
img,svg{ display:block; max-width:100%; }
a{ color:inherit; }
h1,h2,h3{ font-family:var(--font-display); text-wrap:balance; margin:0; }
p{ margin:0; }
.container{ width:100%; max-width:1180px; margin-inline:auto; padding-inline:clamp(1.25rem,4vw,2.5rem); }
.eyebrow{
  font-family:var(--font-mono); font-size:.72rem; font-weight:600;
  letter-spacing:.14em; text-transform:uppercase; color:var(--accent);
}
.btn{
  display:inline-flex; align-items:center; gap:.5rem;
  font-family:var(--font-body); font-weight:600; font-size:.95rem;
  padding:.85rem 1.4rem; border-radius:999px; border:1px solid transparent;
  cursor:pointer; text-decoration:none; transition:transform .15s ease, box-shadow .15s ease, background .15s ease;
}
.btn:hover{ transform:translateY(-1px); box-shadow:var(--shadow-1); }
.btn:active{ transform:translateY(1px); box-shadow:none; }
.btn:focus-visible{ outline:2px solid var(--accent-bright); outline-offset:3px; }
.btn:focus-visible{ outline:2px solid var(--accent-bright); outline-offset:3px; }
.btn--primary{ background:var(--accent); color:#fff; box-shadow:var(--shadow-1); }
.btn--primary:hover{ background:var(--accent-bright); box-shadow:var(--shadow-2); }
.btn--ghost{ background:transparent; border-color:var(--hero-border); color:var(--hero-ink); }
.btn--ghost:hover{ border-color:var(--ice); color:var(--ice); }
.btn--outline{ background:transparent; border-color:var(--border); color:var(--ink); }
.btn--outline:hover{ border-color:var(--accent); color:var(--accent); }

/* ---------- header ---------- */
.site-header{
  position:sticky; top:0; z-index:40;
  background:color-mix(in srgb, var(--bg) 88%, transparent);
  backdrop-filter:blur(10px);
  border-bottom:1px solid var(--border);
}
.site-header__row{ display:flex; align-items:center; justify-content:space-between; gap:1.5rem; padding-block:.9rem; }
.brand{ display:flex; align-items:center; gap:.6rem; text-decoration:none; }
.brand__mark{
  width:34px; height:34px; border-radius:9px;
  background:linear-gradient(155deg, var(--ice), var(--accent));
  display:flex; align-items:center; justify-content:center;
  font-family:var(--font-display); font-weight:900; color:#04141d; font-size:1rem;
}
.brand__word{ font-family:var(--font-display); font-weight:800; font-size:1.05rem; letter-spacing:.01em; color:var(--ink); }
.nav__links{ display:flex; align-items:center; gap:1.9rem; list-style:none; margin:0; padding:0; }
.nav__links a{
  font-size:.9rem; font-weight:500; text-decoration:none; color:var(--muted);
  padding-block:.3rem; border-bottom:2px solid transparent; transition:color .15s ease, border-color .15s ease;
}
.nav__links a:hover, .nav__links a.is-active{ color:var(--ink); border-color:var(--accent); }
.header__actions{ display:flex; align-items:center; gap:.7rem; }
.theme-toggle{
  width:38px; height:38px; border-radius:999px; border:1px solid var(--border);
  background:var(--surface); color:var(--ink); cursor:pointer; display:flex; align-items:center; justify-content:center;
  font-size:1rem;
}
.theme-toggle:focus-visible{ outline:2px solid var(--accent-bright); outline-offset:2px; }
.nav-toggle{
  display:none; width:38px; height:38px; border-radius:999px; border:1px solid var(--border);
  background:var(--surface); color:var(--ink); cursor:pointer; align-items:center; justify-content:center;
  flex-direction:column; gap:4px;
}
.nav-toggle span{ display:block; width:16px; height:2px; background:currentColor; border-radius:2px; transition:transform .2s ease, opacity .2s ease; }
.nav-toggle[aria-expanded="true"] span:nth-child(1){ transform:translateY(6px) rotate(45deg); }
.nav-toggle[aria-expanded="true"] span:nth-child(2){ opacity:0; }
.nav-toggle[aria-expanded="true"] span:nth-child(3){ transform:translateY(-6px) rotate(-45deg); }
.nav-toggle:focus-visible{ outline:2px solid var(--accent-bright); outline-offset:2px; }
@media (max-width:820px){
  .nav-toggle{ display:flex; }
  .header__actions .btn{ display:none; }
  .nav__links{
    position:absolute; left:0; right:0; top:100%; flex-direction:column; align-items:stretch; gap:0;
    background:var(--bg); border-bottom:1px solid var(--border); box-shadow:var(--shadow-2);
    padding:.4rem 0 .6rem; display:none;
  }
  .nav__links.is-open{ display:flex; }
  .nav__links li{ padding:0 clamp(1.25rem,4vw,2.5rem); }
  .nav__links a{ display:block; padding:.85rem 0; border-bottom:1px solid var(--border); font-size:1rem; }
  .nav__links li:last-child a{ border-bottom:0; }
  .nav__links a.is-active{ border-color:var(--border); color:var(--accent); }
}


/* ---------- section shell ---------- */
section{ padding-block:clamp(3.5rem,7vw,5.5rem); }
.section__head{ max-width:56ch; margin-bottom:2.6rem; }
.section__head .eyebrow::before{ content:''; display:inline-block; width:1.4rem; height:2px; background:currentColor; vertical-align:middle; margin-right:.6rem; opacity:.7; }
.section__head h2{ font-size:clamp(1.7rem,3vw,2.3rem); margin-top:.6rem; }
.section__head p{ margin-top:.8rem; color:var(--muted); font-size:1.02rem; }


/* ---------- footer ---------- */
footer{ border-top:1px solid var(--border); padding-block:2.4rem; }
.footer__row{ display:flex; flex-wrap:wrap; justify-content:space-between; gap:1rem; align-items:center; }
.footer__note{ font-size:.78rem; color:var(--muted); max-width:52ch; margin-top:.8rem; font-family:var(--font-mono); }

@media (prefers-reduced-motion: reduce){
  *, *::before, *::after{ animation-duration:.001ms !important; animation-iteration-count:1 !important; transition-duration:.001ms !important; }
  html{ scroll-behavior:auto; }
}