/* ===== KiselevLabs landing — design tokens ===== */
:root {
  --bg: #14171f;
  --bg-2: #181c25;
  --surface: #1b1f2a;
  --surface-2: #20242f;
  --border: #2c3140;
  --border-soft: #232734;
  --text: #eef1f7;
  --text-soft: #c2c8d6;
  --text-mut: #8a90a2;
  --indigo: #818cf8;
  --indigo-2: #6b76e8;
  --indigo-deep: #4f46e5;
  --teal: #2dd4bf;
  --amber: #fbbf24;
  --radius: 16px;
  --radius-sm: 10px;
  --maxw: 1120px;
  --shadow: 0 10px 40px -12px rgba(0,0,0,.55);
  --font-display: "Space Grotesk", system-ui, sans-serif;
  --font-body: "Inter", system-ui, sans-serif;
  --font-mono: "JetBrains Mono", ui-monospace, monospace;
}
[data-theme="light"] {
  --bg: #f6f7fb;
  --bg-2: #eef0f7;
  --surface: #ffffff;
  --surface-2: #f3f4fa;
  --border: #dde1ea;
  --border-soft: #e7eaf2;
  --text: #14171f;
  --text-soft: #3a4150;
  --text-mut: #5a6071;
  --indigo: #5a63d8;
  --indigo-2: #4f46e5;
  --indigo-deep: #4338ca;
  --teal: #0d9488;
  --amber: #b45309;
  --shadow: 0 10px 40px -16px rgba(40,50,90,.28);
}

* { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; }
body {
  font-family: var(--font-body);
  background: var(--bg);
  color: var(--text);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  transition: background .3s ease, color .3s ease;
}
a { color: inherit; text-decoration: none; }
h1, h2, h3 { font-family: var(--font-display); line-height: 1.12; letter-spacing: -0.02em; }
section { scroll-margin-top: 84px; }

/* ===== Header ===== */
.site-header {
  position: sticky; top: 0; z-index: 50;
  display: flex; align-items: center; justify-content: space-between;
  padding: 16px clamp(20px, 5vw, 56px);
  background: color-mix(in srgb, var(--bg) 82%, transparent);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border-soft);
}
.brand { display: flex; align-items: center; gap: 10px; font-family: var(--font-display); font-weight: 700; font-size: 19px; }
.brand-mark { color: var(--indigo-2); flex: none; }
.brand-accent { color: var(--indigo); }
.site-nav { display: flex; align-items: center; gap: clamp(14px, 3vw, 30px); }
.site-nav a { color: var(--text-mut); font-weight: 500; font-size: 15px; transition: color .2s; }
.site-nav a:hover { color: var(--text); }
.theme-toggle {
  display: grid; place-items: center; width: 38px; height: 38px;
  border: 1px solid var(--border); border-radius: 10px;
  background: var(--surface); color: var(--text-soft); cursor: pointer; transition: all .2s;
}
.theme-toggle:hover { border-color: var(--indigo-2); color: var(--indigo); }
.icon-moon { display: none; }
[data-theme="light"] .icon-sun { display: none; }
[data-theme="light"] .icon-moon { display: block; }

/* ===== Hero ===== */
.hero { position: relative; overflow: hidden; padding: clamp(64px, 11vw, 132px) clamp(20px, 5vw, 56px) clamp(56px, 8vw, 96px); }
.hero-inner { position: relative; z-index: 2; max-width: var(--maxw); margin: 0 auto; }
.eyebrow {
  display: inline-block; font-family: var(--font-mono); font-size: 13px; letter-spacing: .08em;
  text-transform: uppercase; color: var(--teal); margin-bottom: 22px;
  padding: 5px 12px; border: 1px solid var(--border); border-radius: 999px; background: var(--surface);
}
.hero-title { font-size: clamp(34px, 6.2vw, 62px); font-weight: 700; max-width: 17ch; }
.grad { background: linear-gradient(100deg, var(--indigo), var(--teal)); -webkit-background-clip: text; background-clip: text; -webkit-text-fill-color: transparent; }
.hero-sub { margin-top: 24px; font-size: clamp(16px, 2vw, 19px); color: var(--text-soft); max-width: 56ch; }
.hero-cta { margin-top: 36px; display: flex; flex-wrap: wrap; gap: 14px; }
.hero-tags { margin-top: 40px; display: flex; flex-wrap: wrap; gap: 10px; list-style: none; }
.hero-tags li { font-family: var(--font-mono); font-size: 13px; color: var(--text-mut); padding: 6px 12px; border: 1px solid var(--border-soft); border-radius: 8px; background: var(--surface); }
.hero-glow {
  position: absolute; top: -25%; right: -8%; width: 60vw; height: 60vw; max-width: 760px; max-height: 760px;
  background: radial-gradient(circle, color-mix(in srgb, var(--indigo-2) 38%, transparent), transparent 62%);
  filter: blur(20px); z-index: 1; pointer-events: none;
}

/* ===== Buttons ===== */
.btn { display: inline-flex; align-items: center; gap: 8px; font-weight: 600; font-size: 15px; padding: 13px 22px; border-radius: 12px; border: 1px solid transparent; cursor: pointer; transition: transform .15s ease, box-shadow .2s, background .2s, border-color .2s; }
.btn-lg { padding: 16px 30px; font-size: 17px; }
.btn-primary { background: linear-gradient(100deg, var(--indigo-2), var(--indigo-deep)); color: #fff; box-shadow: 0 8px 24px -10px var(--indigo-2); }
.btn-primary:hover { transform: translateY(-2px); box-shadow: 0 14px 30px -10px var(--indigo-2); }
.btn-ghost { background: var(--surface); color: var(--text); border-color: var(--border); }
.btn-ghost:hover { border-color: var(--indigo-2); color: var(--indigo); transform: translateY(-2px); }

/* ===== Sections ===== */
.section { max-width: var(--maxw); margin: 0 auto; padding: clamp(56px, 8vw, 96px) clamp(20px, 5vw, 56px); }
.section-head { margin-bottom: 44px; }
.section-head h2, .section-about h2, .section-contact h2 { font-size: clamp(28px, 4vw, 40px); font-weight: 700; }
.section-head p { margin-top: 12px; color: var(--text-mut); font-size: 17px; }

/* ===== Cards ===== */
.cards { display: grid; grid-template-columns: repeat(2, 1fr); gap: 22px; }
.card { position: relative; display: flex; flex-direction: column; padding: 28px; background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius); transition: transform .18s ease, border-color .2s, box-shadow .2s; }
.card:hover { transform: translateY(-4px); border-color: var(--indigo-2); box-shadow: var(--shadow); }
.card-feature { grid-column: 1 / -1; background: linear-gradient(150deg, var(--surface), var(--surface-2)); border-color: color-mix(in srgb, var(--indigo-2) 45%, var(--border)); }
.card-top { display: flex; align-items: center; gap: 12px; margin-bottom: 16px; }
.card h3 { font-size: clamp(20px, 2.4vw, 25px); font-weight: 600; margin-bottom: 12px; }
.card p { color: var(--text-soft); font-size: 15.5px; }
.card-kicker { font-family: var(--font-mono); font-size: 12px; letter-spacing: .05em; text-transform: uppercase; color: var(--text-mut); }
.pill { font-family: var(--font-mono); font-size: 12px; font-weight: 500; padding: 4px 11px; border-radius: 999px; background: var(--surface-2); color: var(--text-mut); border: 1px solid var(--border); }
.pill-live { background: color-mix(in srgb, var(--teal) 18%, transparent); color: var(--teal); border-color: color-mix(in srgb, var(--teal) 40%, transparent); }
.card-meta { list-style: none; display: flex; flex-wrap: wrap; gap: 8px; margin-top: 18px; }
.card-meta li { font-size: 12.5px; color: var(--text-mut); padding: 4px 10px; border: 1px solid var(--border-soft); border-radius: 7px; }
.card-link { margin-top: 20px; font-family: var(--font-mono); font-size: 14px; font-weight: 500; color: var(--indigo); }

/* ===== About ===== */
.section-about { border-top: 1px solid var(--border-soft); }
.about-grid { display: grid; grid-template-columns: 1.4fr 1fr; gap: clamp(28px, 5vw, 56px); align-items: start; }
.about-text p { color: var(--text-soft); font-size: 16.5px; margin-top: 18px; max-width: 56ch; }
.about-text strong { color: var(--text); }
.stack { display: flex; flex-wrap: wrap; gap: 9px; margin-top: 26px; }
.stack span { font-family: var(--font-mono); font-size: 13px; color: var(--indigo); padding: 6px 12px; background: color-mix(in srgb, var(--indigo-2) 12%, transparent); border: 1px solid color-mix(in srgb, var(--indigo-2) 30%, transparent); border-radius: 8px; }
.about-side { display: flex; flex-direction: column; gap: 16px; }
.side-card { padding: 22px; background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius-sm); }
.side-label { font-family: var(--font-mono); font-size: 12px; letter-spacing: .06em; text-transform: uppercase; color: var(--teal); margin-bottom: 8px; }
.side-value { color: var(--text-soft); font-size: 15px; }
.side-value a { color: var(--indigo); font-weight: 500; }
.side-value a:hover { text-decoration: underline; }

/* ===== Contact ===== */
.section-contact { border-top: 1px solid var(--border-soft); }
.contact-inner { max-width: var(--maxw); margin: 0 auto; text-align: center; }
.contact-inner p { margin: 14px 0 30px; color: var(--text-mut); font-size: 17px; }
.contact-inner .btn { font-family: var(--font-mono); }

/* ===== Footer ===== */
.site-footer { border-top: 1px solid var(--border-soft); padding: 32px clamp(20px, 5vw, 56px); }
.footer-inner { max-width: var(--maxw); margin: 0 auto; display: flex; align-items: center; justify-content: space-between; flex-wrap: wrap; gap: 14px; }
.footer-brand { font-family: var(--font-display); font-weight: 700; font-size: 17px; }
.footer-copy { color: var(--text-mut); font-size: 14px; }
.footer-link { font-family: var(--font-mono); font-size: 14px; color: var(--indigo); }
.footer-link:hover { text-decoration: underline; }

/* ===== Responsive ===== */
@media (max-width: 760px) {
  .cards { grid-template-columns: 1fr; }
  .about-grid { grid-template-columns: 1fr; }
}
@media (max-width: 480px) {
  .site-nav a[href="#about"] { display: none; }
}
@media (max-width: 560px) {
  .hero-cta { flex-direction: column; align-items: stretch; }
  .btn { justify-content: center; }
  .footer-inner { flex-direction: column; text-align: center; }
}
@media (prefers-reduced-motion: reduce) {
  * { transition: none !important; scroll-behavior: auto !important; }
}