/* =========================================================================
   chatCOS — Fundament / Design-System
   Alle Farben ausschliesslich ueber CSS Custom Properties (Shared Contract).
   ========================================================================= */

/* ---- Farbwelten (Shared Design-Contract, exakt) ---- */
[data-mode="business"] {
  --bg:#f6f9fe; --surface:#ffffff; --surface-2:#eaf1fb;
  --text:#0e1c30; --text-muted:#5a6b83;
  --accent:#2563eb; --accent-2:#4f8bff; --accent-soft:rgba(37,99,235,.12);
  --on-accent:#ffffff;
  --border:rgba(14,28,48,.10);
}
[data-mode="technical"] {
  --bg:#080d0b; --surface:#0f1714; --surface-2:#15201b;
  --text:#e7f3ed; --text-muted:#89a498;
  --accent:#25d29a; --accent-2:#3ff0b0; --accent-soft:rgba(37,210,154,.12);
  --on-accent:#06120d;
  --border:rgba(231,243,237,.09);
}

/* ---- Tokens ---- */
:root {
  --font-sans: "Inter", system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
  --font-display: "Space Grotesk", var(--font-sans);

  --maxw: 1120px;
  --gutter: clamp(20px, 5vw, 48px);
  --radius: 18px;
  --radius-sm: 12px;
  --radius-lg: 26px;

  --nav-h: 68px;

  --shadow-sm: 0 1px 2px rgba(8,14,24,.05);
  --shadow: 0 18px 50px -24px rgba(10,22,44,.35);

  --ease: cubic-bezier(.22,.61,.36,1);
  --dur: .4s;
}

/* ---- Reset ---- */
*, *::before, *::after { box-sizing: border-box; }
* { margin: 0; }
html {
  -webkit-text-size-adjust: 100%;
  scroll-behavior: smooth;
  scroll-padding-top: calc(var(--nav-h) + 24px);
}
body {
  font-family: var(--font-sans);
  background: var(--bg);
  color: var(--text);
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
  transition: background-color var(--dur) var(--ease), color var(--dur) var(--ease);
  overflow-x: hidden;
}
img, svg { display: block; max-width: 100%; }
a { color: inherit; text-decoration: none; }
button { font: inherit; color: inherit; cursor: pointer; border: 0; background: none; }
:focus-visible { outline: 2px solid var(--accent); outline-offset: 3px; border-radius: 4px; }
::selection { background: var(--accent-soft); }

/* =========================================================================
   Typografie
   ========================================================================= */
h1, h2, h3 { font-family: var(--font-display); font-weight: 600; line-height: 1.1; letter-spacing: -.02em; }
.display {
  font-family: var(--font-display); font-weight: 600;
  font-size: clamp(2.4rem, 5.6vw, 4.1rem); line-height: 1.03; letter-spacing: -.035em;
}
h2.section-title { font-size: clamp(1.7rem, 3.4vw, 2.6rem); letter-spacing: -.03em; }
h3 { font-size: 1.16rem; letter-spacing: -.015em; }
p { color: var(--text-muted); }
.lead { font-size: clamp(1.05rem, 1.9vw, 1.32rem); color: var(--text-muted); line-height: 1.55; }

.eyebrow {
  display: inline-flex; align-items: center; gap: 9px;
  font-family: var(--font-sans); font-size: .78rem; font-weight: 600;
  letter-spacing: .14em; text-transform: uppercase; color: var(--accent);
}
.eyebrow::before {
  content: ""; width: 22px; height: 1.5px; background: var(--accent); opacity: .6;
}
/* Abstand Eyebrow -> Ueberschrift (inline-flex traegt keinen wirksamen margin-bottom,
   daher am folgenden Heading gesetzt) */
.eyebrow + h1, .eyebrow + h2 { margin-top: 13px; }

/* =========================================================================
   Layout
   ========================================================================= */
.container { width: 100%; max-width: var(--maxw); margin-inline: auto; padding-inline: var(--gutter); }
main { transition: opacity .22s var(--ease); }
section { padding-block: clamp(76px, 9vw, 128px); }
.section-head { max-width: 720px; margin-bottom: clamp(36px, 5vw, 60px); }
.section-head .lead { margin-top: 18px; }
.section-head.center { margin-inline: auto; text-align: center; }

/* Block-Rhythmus INNERHALB einer Sektion: zweite Bloecke bekommen sonst 0 Abstand */
#architecture-t .section-head.mode-business { margin-top: clamp(56px, 8vw, 96px); }
.containment + .grid { margin-top: clamp(40px, 6vw, 72px); }

.grid { display: grid; gap: clamp(20px, 2vw, 24px); }
.grid-2 { grid-template-columns: repeat(2, 1fr); }
.grid-3 { grid-template-columns: repeat(3, 1fr); }

/* Divider between sections */
.divider { border-top: 1px solid var(--border); transition: border-color var(--dur) var(--ease); }

/* =========================================================================
   Cards & shared primitives
   ========================================================================= */
.card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: clamp(24px, 2.6vw, 32px);
  transition: background-color var(--dur) var(--ease), border-color var(--dur) var(--ease),
              transform .35s var(--ease), box-shadow .35s var(--ease);
}
.card:hover { transform: translateY(-3px); box-shadow: var(--shadow); border-color: color-mix(in srgb, var(--accent) 34%, var(--border)); }
.card h3 { margin-bottom: 10px; }
.card p { font-size: .96rem; }

.icon-badge {
  width: 44px; height: 44px; border-radius: 12px;
  display: grid; place-items: center; margin-bottom: 18px;
  background: var(--accent-soft); color: var(--accent);
  transition: background-color var(--dur) var(--ease), color var(--dur) var(--ease);
}
.icon-badge svg { width: 22px; height: 22px; }

.pill {
  display: inline-flex; align-items: center; gap: 7px;
  padding: 5px 12px; border-radius: 999px;
  font-size: .74rem; font-weight: 600; letter-spacing: .02em;
  background: var(--accent-soft); color: var(--accent);
  border: 1px solid color-mix(in srgb, var(--accent) 26%, transparent);
}

/* =========================================================================
   Navigation
   ========================================================================= */
.nav {
  position: sticky; top: 0; z-index: 100;
  height: var(--nav-h);
  display: flex; align-items: center;
  background: color-mix(in srgb, var(--bg) 78%, transparent);
  backdrop-filter: saturate(160%) blur(14px);
  -webkit-backdrop-filter: saturate(160%) blur(14px);
  border-bottom: 1px solid transparent;
  transition: background-color var(--dur) var(--ease), border-color .3s var(--ease);
}
.nav.scrolled { border-bottom-color: var(--border); }
.nav .container { display: flex; align-items: center; justify-content: space-between; gap: 18px; }

.brand { display: inline-flex; align-items: center; gap: 10px; font-family: var(--font-display); font-weight: 600; font-size: 1.12rem; letter-spacing: -.02em; }
.brand .dot { width: 10px; height: 10px; border-radius: 50%; background: var(--accent); box-shadow: 0 0 0 4px var(--accent-soft); transition: background-color var(--dur) var(--ease), box-shadow var(--dur) var(--ease); }
.brand b { font-weight: 600; }
.brand span { color: var(--accent); transition: color var(--dur) var(--ease); }

.nav-links { display: flex; align-items: center; gap: 4px; }
.nav-links a {
  font-size: .88rem; font-weight: 500; color: var(--text-muted);
  padding: 8px 12px; border-radius: 9px;
  transition: color .2s var(--ease), background-color .2s var(--ease);
}
.nav-links a:hover { color: var(--text); background: var(--surface-2); }

.nav-right { display: flex; align-items: center; gap: 14px; }

/* Mode toggle */
.toggle {
  position: relative; display: inline-flex; align-items: center;
  padding: 4px; border-radius: 999px;
  background: var(--surface-2); border: 1px solid var(--border);
  transition: background-color var(--dur) var(--ease), border-color var(--dur) var(--ease);
}
.toggle__thumb {
  position: absolute; top: 4px; left: 4px; bottom: 4px; width: calc(50% - 4px);
  border-radius: 999px; background: var(--accent);
  box-shadow: 0 4px 14px -4px color-mix(in srgb, var(--accent) 70%, transparent);
  transition: transform .38s var(--ease), background-color var(--dur) var(--ease);
}
[data-mode="technical"] .toggle__thumb { transform: translateX(100%); }
.toggle__opt {
  position: relative; z-index: 1; display: inline-flex; align-items: center; gap: 6px;
  padding: 7px 16px; border-radius: 999px;
  font-size: .82rem; font-weight: 600; letter-spacing: .01em;
  color: var(--text-muted); transition: color .3s var(--ease);
  white-space: nowrap;
}
.toggle__opt svg { width: 15px; height: 15px; }
[data-mode="business"] .toggle__opt--business,
[data-mode="technical"] .toggle__opt--technical { color: var(--on-accent); }

/* Mobile nav */
.nav-toggle { display: none; width: 42px; height: 42px; border-radius: 11px; border: 1px solid var(--border); align-items: center; justify-content: center; }
.nav-toggle svg { width: 20px; height: 20px; }

/* =========================================================================
   Mode visibility + crossfade
   ========================================================================= */
[data-mode="business"] .mode-technical,
[data-mode="technical"] .mode-business { display: none !important; }

html.is-switching main { opacity: 0; }

/* =========================================================================
   Reveal on scroll
   ========================================================================= */
.reveal { opacity: 0; transform: translateY(26px); transition: opacity .7s var(--ease), transform .7s var(--ease); }
.reveal.is-visible { opacity: 1; transform: none; }
.reveal[data-delay="1"] { transition-delay: .07s; }
.reveal[data-delay="2"] { transition-delay: .14s; }
.reveal[data-delay="3"] { transition-delay: .21s; }
.reveal[data-delay="4"] { transition-delay: .28s; }

/* =========================================================================
   Hero
   ========================================================================= */
.hero { padding-top: clamp(56px, 8vw, 96px); position: relative; overflow: hidden; }
.hero::before {
  content: ""; position: absolute; inset: -30% 30% auto -10%; height: 620px; pointer-events: none;
  background: radial-gradient(50% 50% at 50% 50%, var(--accent-soft), transparent 70%);
  filter: blur(10px); z-index: -1; transition: background var(--dur) var(--ease);
}
.hero__inner { max-width: 820px; }
.hero .display { margin: 22px 0 24px; }
.hero .lead { max-width: 640px; }
.hero__cta { display: flex; flex-wrap: wrap; gap: 14px; margin-top: 36px; }

.btn {
  display: inline-flex; align-items: center; gap: 9px;
  padding: 13px 24px; border-radius: 12px; font-weight: 600; font-size: .95rem;
  transition: transform .25s var(--ease), background-color .25s var(--ease), border-color .25s var(--ease), color .25s var(--ease), box-shadow .25s var(--ease);
}
.btn svg { width: 17px; height: 17px; }
.btn--primary { background: var(--accent); color: var(--on-accent); box-shadow: 0 12px 30px -12px color-mix(in srgb, var(--accent) 75%, transparent); }
.btn--primary:hover { transform: translateY(-2px); background: var(--accent-2); }
.btn--ghost { border: 1px solid var(--border); color: var(--text); background: var(--surface); }
.btn--ghost:hover { transform: translateY(-2px); border-color: color-mix(in srgb, var(--accent) 45%, var(--border)); color: var(--accent); }

.hero__meta { display: flex; flex-wrap: wrap; gap: 26px 40px; margin-top: 52px; padding-top: 32px; border-top: 1px solid var(--border); transition: border-color var(--dur) var(--ease); }
.hero__meta .stat { min-width: 120px; }
.hero__meta .stat b { display: block; font-family: var(--font-display); font-size: 1.7rem; letter-spacing: -.02em; color: var(--text); }
.hero__meta .stat span { font-size: .84rem; color: var(--text-muted); }

/* =========================================================================
   Steps (5-Schritte Ablauf)
   ========================================================================= */
.steps { display: grid; gap: 2px; border-radius: var(--radius-lg); overflow: hidden; border: 1px solid var(--border); background: var(--border); }
.step {
  display: grid; grid-template-columns: auto 1fr; gap: 22px; align-items: start;
  background: var(--surface); padding: clamp(22px, 2.6vw, 30px) clamp(22px, 3vw, 38px);
  transition: background-color .3s var(--ease);
}
.step:hover { background: var(--surface-2); }
.step__num {
  font-family: var(--font-display); font-weight: 600; font-size: 1rem;
  width: 42px; height: 42px; border-radius: 12px; display: grid; place-items: center;
  background: var(--accent-soft); color: var(--accent);
}
.step__body h3 { margin-bottom: 6px; }
.step__body p { font-size: .96rem; max-width: 640px; }

/* =========================================================================
   Feature / principle grids
   ========================================================================= */
.feature h3 { display: flex; align-items: center; gap: 10px; }
.principle { padding: clamp(20px,2.2vw,26px); }
.principle .k { font-family: var(--font-display); font-size: .82rem; font-weight: 600; color: var(--accent); letter-spacing: .04em; text-transform: uppercase; }
.principle h3 { font-size: 1.05rem; margin: 12px 0 8px; }
.principle p { font-size: .92rem; }

/* =========================================================================
   Roles (technical)
   ========================================================================= */
.role { display: flex; flex-direction: column; gap: 12px; }
.role__top { display: flex; align-items: center; justify-content: space-between; gap: 12px; }
.role__model { font-family: var(--font-display); font-size: .72rem; font-weight: 600; letter-spacing: .04em; padding: 4px 10px; border-radius: 999px; background: var(--surface-2); color: var(--text-muted); border: 1px solid var(--border); white-space: nowrap; }
.role h3 { font-size: 1.08rem; }
.role p { font-size: .93rem; }

/* =========================================================================
   Architecture diagram (technical, self-built)
   ========================================================================= */
.arch { display: flex; flex-direction: column; gap: 14px; }
.arch__row { display: grid; gap: 14px; }
.arch__node {
  background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius);
  padding: 20px 22px; transition: background-color var(--dur) var(--ease), border-color var(--dur) var(--ease), transform .3s var(--ease);
}
.arch__node:hover { transform: translateY(-2px); border-color: color-mix(in srgb, var(--accent) 40%, var(--border)); }
.arch__node .k { font-size: .74rem; font-weight: 600; letter-spacing: .1em; text-transform: uppercase; color: var(--accent); }
.arch__node h3 { font-size: 1.02rem; margin: 8px 0 5px; }
.arch__node p { font-size: .88rem; }
.arch__node--hero { background: linear-gradient(180deg, var(--accent-soft), var(--surface)); border-color: color-mix(in srgb, var(--accent) 30%, var(--border)); }
.arch__flow { display: grid; place-items: center; color: var(--text-muted); }
.arch__flow svg { width: 22px; height: 22px; opacity: .6; }

/* =========================================================================
   Channels (business)
   ========================================================================= */
.channels { display: flex; flex-wrap: wrap; gap: 12px; }
.channels .chip {
  display: inline-flex; align-items: center; gap: 9px;
  padding: 11px 18px; border-radius: 12px; font-weight: 500; font-size: .95rem;
  background: var(--surface); border: 1px solid var(--border); color: var(--text);
  transition: background-color .3s var(--ease), border-color .3s var(--ease), transform .3s var(--ease);
}
.channels .chip:hover { transform: translateY(-2px); border-color: color-mix(in srgb, var(--accent) 40%, var(--border)); }
.channels .chip svg { width: 18px; height: 18px; color: var(--accent); }

/* =========================================================================
   Animations-Sektionen (Mount-Container)
   ========================================================================= */
.anim-mount {
  margin-top: clamp(30px, 4vw, 48px);
  min-height: 320px;
  border: 1px solid var(--border); border-radius: var(--radius-lg);
  background:
    radial-gradient(120% 120% at 50% 0%, var(--surface-2), var(--surface) 70%);
  display: grid; place-items: center;
  overflow: hidden;
  transition: background-color var(--dur) var(--ease), border-color var(--dur) var(--ease);
}
.anim-mount:empty::after {
  content: "Visualisierung wird geladen";
  font-size: .82rem; color: var(--text-muted); letter-spacing: .02em;
}

/* =========================================================================
   Closing / CTA band
   ========================================================================= */
.closing { text-align: center; }
.closing__card {
  border-radius: var(--radius-lg); padding: clamp(44px, 6vw, 76px) clamp(24px, 5vw, 64px);
  background: radial-gradient(120% 140% at 50% 0%, var(--accent-soft), var(--surface) 62%);
  border: 1px solid var(--border);
  transition: background-color var(--dur) var(--ease), border-color var(--dur) var(--ease);
}
.closing h2 { font-size: clamp(1.8rem, 4vw, 2.9rem); max-width: 760px; margin: 18px auto 20px; }
.closing .lead { max-width: 600px; margin-inline: auto; }
.closing__cta { margin-top: 34px; display: flex; justify-content: center; flex-wrap: wrap; gap: 14px; }

/* =========================================================================
   Footer
   ========================================================================= */
.footer { border-top: 1px solid var(--border); padding-block: 44px; transition: border-color var(--dur) var(--ease); }
/* Zwei Spalten statt eines Flex-Umbruchs: Wortmarke und Pflichtlinks bilden
   links eine Einheit, der Beschreibungssatz steht rechts daneben. Als
   space-between-Flexzeile lagen Marke, Satz und Links zusammen rund zehn Pixel
   ueber der Containerbreite und die Links kippten scheinbar zufaellig in eine
   zweite Reihe; im Grid ist ihr Platz definiert und bei jeder Breite gleich. */
.footer .container {
  display: grid; grid-template-columns: auto minmax(0, 1fr);
  column-gap: clamp(28px, 5vw, 72px); row-gap: 12px; align-items: start;
}
.footer .brand { grid-column: 1; grid-row: 1; font-size: 1rem; }
.footer__legal { grid-column: 1; grid-row: 2; display: flex; align-items: center; gap: 20px; }
.footer p { grid-column: 2; grid-row: 1 / span 2; align-self: center; font-size: .86rem; }
.footer__legal a {
  font-size: .86rem; color: var(--text-muted);
  transition: color .25s var(--ease);
}
.footer__legal a:hover, .footer__legal a[aria-current="page"] { color: var(--accent); }
@media (max-width: 720px) {
  .footer .container { grid-template-columns: 1fr; row-gap: 16px; }
  .footer .brand, .footer__legal, .footer p { grid-column: 1; grid-row: auto; }
}

/* =========================================================================
   Responsive
   ========================================================================= */
@media (max-width: 900px) {
  .grid-3 { grid-template-columns: repeat(2, 1fr); }
}
@media (max-width: 1100px) {
  .nav-links { display: none; }
  .nav-toggle { display: inline-flex; }
  .toggle__opt { padding: 7px 13px; }
}
@media (max-width: 640px) {
  .grid-2, .grid-3 { grid-template-columns: 1fr; }
  .step { grid-template-columns: 1fr; gap: 12px; }
  .step__num { width: 38px; height: 38px; }
  .hero__meta { gap: 20px 30px; }
  .toggle__opt span { display: none; }
  .toggle__opt { padding: 8px 14px; }
}

/* Mobile drawer for nav links */
.nav-drawer {
  position: fixed; inset: var(--nav-h) 0 auto 0; z-index: 99;
  background: color-mix(in srgb, var(--bg) 96%, transparent);
  backdrop-filter: blur(16px); -webkit-backdrop-filter: blur(16px);
  border-bottom: 1px solid var(--border);
  padding: 12px var(--gutter) 20px;
  display: none; flex-direction: column; gap: 2px;
  transform: translateY(-8px); opacity: 0;
  transition: transform .3s var(--ease), opacity .3s var(--ease);
}
.nav-drawer.open { display: flex; transform: none; opacity: 1; }
.nav-drawer a { padding: 13px 8px; font-weight: 500; color: var(--text-muted); border-bottom: 1px solid var(--border); }
.nav-drawer a:last-child { border-bottom: 0; }
.nav-drawer a:hover { color: var(--accent); }
@media (min-width: 1101px) { .nav-drawer { display: none !important; } }

/* =========================================================================
   Reduced motion
   ========================================================================= */
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  .reveal { opacity: 1; transform: none; transition: none; }
  * { animation-duration: .001ms !important; transition-duration: .001ms !important; }
}