/* ============================================================
   KAI-SOL — KAI Solutions
   base.css — dizajn-sistem (tokeni, tipografija, layout,
   header, footer, gumbi, kartice, animacije)
   Tamna "tech" tema. Dijeli ga svaka stranica.
   ============================================================ */

/* ---------- Reset ---------- */
*, *::before, *::after { box-sizing: border-box; }
* { margin: 0; padding: 0; }
html { -webkit-text-size-adjust: 100%; scroll-behavior: smooth; }
img, svg, video { display: block; max-width: 100%; height: auto; }
a { color: inherit; text-decoration: none; }
button, input, textarea, select { font: inherit; color: inherit; }
ul { list-style: none; }
:focus-visible { outline: 2px solid var(--accent); outline-offset: 3px; border-radius: 4px; }

/* ---------- Design tokens ---------- */
:root {
  /* boje */
  --bg:        #080b14;
  --bg-2:      #0b1020;
  --surface:   #10182b;
  --surface-2: #161f36;
  --border:    #22304f;
  --border-2:  #2c3a5c;

  --text:      #e8edf9;
  --text-soft: #b7c1d8;
  --muted:     #7e8aa6;

  --accent:    #5b8cff;   /* electric blue */
  --accent-2:  #22d3ee;   /* cyan */
  --accent-3:  #a78bfa;   /* violet */
  --success:   #34d399;

  --grad: linear-gradient(120deg, var(--accent) 0%, var(--accent-2) 60%, var(--accent-3) 120%);
  --grad-soft: linear-gradient(120deg, rgba(91,140,255,.14), rgba(34,211,238,.10));

  /* tipografija */
  --font-head: "Space Grotesk", "Segoe UI", system-ui, sans-serif;
  --font-body: "Inter", "Segoe UI", system-ui, -apple-system, sans-serif;

  /* razmaci / geometrija */
  --container: 1200px;
  --radius:   16px;
  --radius-sm: 10px;
  --radius-lg: 26px;

  --shadow:   0 20px 50px -20px rgba(0,0,0,.6);
  --shadow-glow: 0 0 0 1px rgba(91,140,255,.25), 0 20px 60px -18px rgba(91,140,255,.35);

  --ease: cubic-bezier(.22,.61,.36,1);
}

/* ---------- Base ---------- */
html, body { background: var(--bg); }
body {
  font-family: var(--font-body);
  color: var(--text);
  line-height: 1.65;
  font-size: 17px;
  letter-spacing: .1px;
  overflow-x: hidden;
  /* suptilni ambijentalni sjaj u pozadini */
  background:
    radial-gradient(1100px 700px at 78% -8%, rgba(91,140,255,.16), transparent 60%),
    radial-gradient(900px 600px at -6% 12%, rgba(34,211,238,.10), transparent 55%),
    var(--bg);
  background-attachment: fixed;
}

h1, h2, h3, h4 { font-family: var(--font-head); line-height: 1.12; font-weight: 600; letter-spacing: -.5px; color: #fff; }
h1 { font-size: clamp(2.4rem, 5.4vw, 4.1rem); }
h2 { font-size: clamp(1.9rem, 3.6vw, 2.9rem); }
h3 { font-size: clamp(1.2rem, 2vw, 1.45rem); }
p  { color: var(--text-soft); }

::selection { background: rgba(91,140,255,.35); color: #fff; }

.gradient-text {
  background: var(--grad);
  -webkit-background-clip: text; background-clip: text;
  -webkit-text-fill-color: transparent; color: transparent;
}

/* ---------- Layout ---------- */
.container { width: 100%; max-width: var(--container); margin-inline: auto; padding-inline: 24px; }
section { position: relative; }
.section { padding: clamp(64px, 9vw, 120px) 0; }
.section-tight { padding: clamp(48px, 6vw, 80px) 0; }

.eyebrow {
  display: inline-flex; align-items: center; gap: 8px;
  font-family: var(--font-head); font-size: .8rem; font-weight: 600;
  letter-spacing: 2px; text-transform: uppercase;
  color: var(--accent-2);
  padding: 7px 14px; border-radius: 999px;
  background: var(--grad-soft);
  border: 1px solid var(--border);
}
.eyebrow::before { content: ""; width: 6px; height: 6px; border-radius: 50%; background: var(--accent-2); box-shadow: 0 0 12px var(--accent-2); }

.section-head { max-width: 720px; margin-bottom: 54px; }
.section-head.center { margin-inline: auto; text-align: center; }
.section-head h2 { margin: 18px 0 14px; }
.section-head p { font-size: 1.08rem; color: var(--muted); }

.lead { font-size: 1.18rem; color: var(--text-soft); }

/* ---------- Buttons ---------- */
.btn {
  display: inline-flex; align-items: center; justify-content: center; gap: 10px;
  font-family: var(--font-head); font-weight: 600; font-size: .98rem;
  padding: 14px 26px; border-radius: 999px; cursor: pointer;
  border: 1px solid transparent; transition: transform .25s var(--ease), box-shadow .25s var(--ease), background .25s, border-color .25s;
  white-space: nowrap;
}
.btn svg { width: 18px; height: 18px; }
.btn-primary { background: var(--grad); color: #06101f; box-shadow: var(--shadow-glow); }
.btn-primary:hover { transform: translateY(-3px); box-shadow: 0 0 0 1px rgba(91,140,255,.4), 0 26px 60px -18px rgba(34,211,238,.6); }
.btn-ghost { background: rgba(255,255,255,.03); color: var(--text); border-color: var(--border-2); }
.btn-ghost:hover { background: rgba(255,255,255,.07); border-color: var(--accent); transform: translateY(-3px); }
.btn-lg { padding: 17px 34px; font-size: 1.05rem; }

/* ---------- Header ---------- */
.site-header {
  position: sticky; top: 0; z-index: 100;
  transition: background .3s, border-color .3s, backdrop-filter .3s;
  border-bottom: 1px solid transparent;
}
.site-header.scrolled {
  background: rgba(8,11,20,.72);
  backdrop-filter: blur(16px) saturate(140%);
  -webkit-backdrop-filter: blur(16px) saturate(140%);
  border-bottom-color: var(--border);
}
.nav { display: flex; align-items: center; justify-content: space-between; height: 74px; }
.brand { display: flex; align-items: center; gap: 12px; font-family: var(--font-head); font-weight: 700; font-size: 1.28rem; letter-spacing: -.5px; color: #fff; }
.brand .logo {
  width: 38px; height: 38px; border-radius: 11px; display: grid; place-items: center;
  background: var(--grad); color: #06101f; font-weight: 700; font-size: 1.05rem;
  box-shadow: var(--shadow-glow);
}
.brand small { display: block; font-family: var(--font-body); font-weight: 500; font-size: .62rem; letter-spacing: 2.5px; color: var(--muted); text-transform: uppercase; margin-top: -2px; }
.nav-links { display: flex; align-items: center; gap: 4px; }
.nav-links a {
  font-size: .95rem; color: var(--text-soft); padding: 9px 15px; border-radius: 999px;
  transition: color .2s, background .2s;
}
.nav-links a:hover { color: #fff; background: rgba(255,255,255,.05); }
.nav-links a.active { color: #fff; }
.nav-cta { margin-left: 10px; }
.nav-toggle { display: none; background: none; border: 1px solid var(--border-2); border-radius: 10px; width: 44px; height: 44px; cursor: pointer; }
.nav-toggle span { display: block; width: 20px; height: 2px; background: var(--text); margin: 4px auto; border-radius: 2px; transition: .3s; }

/* ---------- Cards ---------- */
.card {
  position: relative; background: linear-gradient(180deg, var(--surface), var(--bg-2));
  border: 1px solid var(--border); border-radius: var(--radius);
  padding: 30px; transition: transform .35s var(--ease), border-color .35s, box-shadow .35s;
  overflow: hidden;
}
.card::after {
  content: ""; position: absolute; inset: 0; border-radius: inherit; padding: 1px;
  background: var(--grad); opacity: 0; transition: opacity .35s;
  -webkit-mask: linear-gradient(#000 0 0) content-box, linear-gradient(#000 0 0);
  -webkit-mask-composite: xor; mask-composite: exclude; pointer-events: none;
}
.card:hover { transform: translateY(-6px); box-shadow: var(--shadow); }
.card:hover::after { opacity: .8; }
.card .ico {
  width: 54px; height: 54px; border-radius: 14px; display: grid; place-items: center;
  background: var(--grad-soft); border: 1px solid var(--border); color: var(--accent-2);
  margin-bottom: 20px;
}
.card .ico svg { width: 26px; height: 26px; }
.card h3 { margin-bottom: 10px; }
.card p { font-size: .98rem; color: var(--muted); }

.grid { display: grid; gap: 24px; }
.grid-2 { grid-template-columns: repeat(2, 1fr); }
.grid-3 { grid-template-columns: repeat(3, 1fr); }
.grid-4 { grid-template-columns: repeat(4, 1fr); }

/* ---------- Tag / chip ---------- */
.tag {
  display: inline-block; font-family: var(--font-head); font-size: .74rem; font-weight: 600;
  letter-spacing: .5px; padding: 5px 11px; border-radius: 999px;
  background: rgba(91,140,255,.10); border: 1px solid var(--border); color: var(--accent-2);
}

/* ---------- Footer ---------- */
.site-footer { border-top: 1px solid var(--border); background: var(--bg-2); padding: 66px 0 30px; margin-top: 40px; }
.footer-grid { display: grid; grid-template-columns: 1.6fr 1fr 1fr 1.2fr; gap: 40px; }
.footer-grid h4 { font-family: var(--font-head); font-size: .82rem; letter-spacing: 1.5px; text-transform: uppercase; color: var(--muted); margin-bottom: 18px; }
.footer-grid a { display: block; color: var(--text-soft); font-size: .95rem; padding: 6px 0; transition: color .2s, transform .2s; }
.footer-grid a:hover { color: var(--accent-2); transform: translateX(3px); }
.footer-about p { font-size: .95rem; color: var(--muted); margin: 16px 0; max-width: 34ch; }
.footer-bottom { display: flex; justify-content: space-between; align-items: center; flex-wrap: wrap; gap: 14px; margin-top: 48px; padding-top: 26px; border-top: 1px solid var(--border); color: var(--muted); font-size: .88rem; }
.footer-bottom .socials { display: flex; gap: 12px; }
.footer-bottom .socials a { width: 38px; height: 38px; border: 1px solid var(--border-2); border-radius: 10px; display: grid; place-items: center; transition: .25s; }
.footer-bottom .socials a:hover { border-color: var(--accent); color: var(--accent-2); transform: translateY(-2px); }

/* ---------- Reveal animation ---------- */
[data-reveal] { opacity: 0; transform: translateY(28px); transition: opacity .7s var(--ease), transform .7s var(--ease); }
[data-reveal].in { opacity: 1; transform: none; }
[data-reveal][data-delay="1"] { transition-delay: .08s; }
[data-reveal][data-delay="2"] { transition-delay: .16s; }
[data-reveal][data-delay="3"] { transition-delay: .24s; }
[data-reveal][data-delay="4"] { transition-delay: .32s; }

/* ---------- Responsive ---------- */
@media (max-width: 940px) {
  .grid-3, .grid-4 { grid-template-columns: repeat(2, 1fr); }
  .footer-grid { grid-template-columns: 1fr 1fr; gap: 32px; }
  .nav-links {
    position: fixed; inset: 74px 0 auto 0; flex-direction: column; align-items: stretch; gap: 6px;
    background: rgba(8,11,20,.97); backdrop-filter: blur(16px); border-bottom: 1px solid var(--border);
    padding: 18px 24px 26px; transform: translateY(-140%); transition: transform .4s var(--ease); z-index: 90;
  }
  .nav-links.open { transform: translateY(0); }
  .nav-links a { padding: 13px 15px; }
  .nav-cta { margin: 8px 0 0; }
  .nav-toggle { display: block; }
}
@media (max-width: 620px) {
  body { font-size: 16px; }
  .grid-2, .grid-3, .grid-4 { grid-template-columns: 1fr; }
  .footer-grid { grid-template-columns: 1fr; }
  .container { padding-inline: 18px; }
}

@media (prefers-reduced-motion: reduce) {
  * { animation: none !important; scroll-behavior: auto; }
  [data-reveal] { opacity: 1; transform: none; transition: none; }
}