/* Air Control — statische Seite, orientiert an longcipher-design-DESIGN.md (Vercel/Geist-System) */

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

:root {
  --vercel-black: #171717;
  --vercel-white: #ffffff;
  --surface: #fafafa;
  --muted: #666666;
  --develop-blue: #0a72ef;
  --focus-ring: hsla(212, 100%, 48%, 1);
  --shadow-ring: rgba(0, 0, 0, 0.08);
  --shadow-ambient: rgba(0, 0, 0, 0.04);
  --radius-lg: 12px;
  --radius-md: 8px;
  --radius-sm: 6px;
}

html {
  color-scheme: light;
}

body {
  margin: 0;
  font-family: "Geist Sans", ui-sans-serif, system-ui, -apple-system, "Segoe UI", sans-serif;
  font-feature-settings: "liga" 1;
  background: var(--vercel-white);
  color: var(--vercel-black);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

a {
  color: inherit;
  text-decoration: none;
}

a:hover {
  text-decoration: underline;
  text-underline-offset: 3px;
}

.container {
  width: min(1120px, 92%);
  margin: 0 auto;
}

/* Shadow-as-border (Design-Dokument) */
.shadow-surface {
  box-shadow:
    0 0 0 1px var(--shadow-ring),
    0 2px 4px var(--shadow-ambient);
}

.shadow-surface-strong {
  box-shadow:
    0 0 0 1px var(--shadow-ring),
    0 4px 12px rgba(0, 0, 0, 0.06);
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(255, 255, 255, 0.92);
  backdrop-filter: blur(10px);
  box-shadow:
    0 0 0 1px var(--shadow-ring),
    0 1px 0 rgba(0, 0, 0, 0.02);
}

.brand-wrap {
  padding: 20px 0 16px;
}

.brand {
  margin: 0;
  font-size: clamp(1.75rem, 3.2vw, 2.5rem);
  font-weight: 600;
  letter-spacing: -0.03em;
  line-height: 1.1;
  color: var(--vercel-black);
  text-wrap: balance;
}

.brand small {
  font-size: clamp(0.8rem, 1.2vw, 0.95rem);
  font-weight: 600;
  letter-spacing: -0.02em;
  color: var(--muted);
  text-transform: none;
}

.meta {
  margin-top: 8px;
  font-size: 0.9375rem;
  color: var(--muted);
  font-variant-numeric: tabular-nums;
}

.site-nav {
  background: var(--surface);
  border-top: 1px solid rgba(0, 0, 0, 0.06);
}

.site-nav ul {
  list-style: none;
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  margin: 0;
  padding: 10px 0 12px;
}

.site-nav a {
  display: inline-block;
  padding: 8px 14px;
  border-radius: 999px;
  font-weight: 500;
  font-size: 0.9375rem;
  color: var(--vercel-black);
  box-shadow: 0 0 0 1px transparent;
  transition: box-shadow 0.15s ease, background-color 0.15s ease;
}

.site-nav a:hover {
  text-decoration: none;
  background: rgba(0, 0, 0, 0.04);
  box-shadow: 0 0 0 1px rgba(0, 0, 0, 0.06);
}

.site-nav a.active {
  text-decoration: none;
  background: var(--vercel-black);
  color: var(--vercel-white);
  box-shadow: 0 0 0 1px var(--vercel-black);
}

.site-nav a:focus-visible {
  outline: none;
  box-shadow: 0 0 0 2px var(--vercel-white), 0 0 0 4px var(--focus-ring);
}

.tab-context {
  background: var(--vercel-white);
  border-top: 1px solid rgba(0, 0, 0, 0.06);
}

.tab-context .container {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 10px 18px;
  padding: 12px 0 14px;
}

.tab-context-label {
  flex-shrink: 0;
  font-size: 0.6875rem;
  font-weight: 600;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--muted);
}

.tab-context-text {
  margin: 0;
  flex: 1 1 220px;
  font-size: 0.875rem;
  line-height: 1.5;
  color: var(--vercel-black);
}

.tab-context-text strong {
  font-weight: 600;
}

main {
  padding: 40px 0 72px;
}

.card {
  background: var(--vercel-white);
  border-radius: var(--radius-lg);
  padding: 28px;
  margin-bottom: 20px;
  box-shadow:
    0 0 0 1px var(--shadow-ring),
    0 2px 4px var(--shadow-ambient),
    inset 0 0 0 1px rgba(255, 255, 255, 0.8);
}

.hero-title {
  margin: 0 0 10px;
  font-size: clamp(1.75rem, 4vw, 2.75rem);
  font-weight: 600;
  letter-spacing: -0.035em;
  line-height: 1.15;
  color: var(--vercel-black);
  text-wrap: balance;
}

.hero-subtitle {
  margin: 0;
  font-size: 1.0625rem;
  color: var(--muted);
  text-wrap: pretty;
}

.slider {
  margin-top: 22px;
}

.slider img {
  width: 100%;
  max-height: 520px;
  object-fit: cover;
  border-radius: var(--radius-md);
  display: block;
  box-shadow:
    0 0 0 1px var(--shadow-ring),
    0 8px 24px rgba(0, 0, 0, 0.06);
}

.slider .caption {
  margin-top: 10px;
  font-size: 0.8125rem;
  font-weight: 500;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--muted);
}

.actions {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 16px;
}

.action-box {
  border-radius: var(--radius-md);
  padding: 20px;
  background: var(--vercel-white);
  box-shadow:
    0 0 0 1px var(--shadow-ring),
    0 2px 4px var(--shadow-ambient);
  transition: box-shadow 0.2s ease, transform 0.2s ease;
}

.action-box:hover {
  box-shadow:
    0 0 0 1px rgba(0, 0, 0, 0.1),
    0 8px 20px rgba(0, 0, 0, 0.07);
  transform: translateY(-2px);
}

.action-box h3 {
  margin: 0 0 8px;
  font-size: 1.0625rem;
  font-weight: 600;
  letter-spacing: -0.02em;
  color: var(--vercel-black);
  text-wrap: balance;
}

.btn {
  display: inline-block;
  margin-top: 12px;
  padding: 10px 16px;
  border-radius: var(--radius-sm);
  font-weight: 600;
  font-size: 0.9375rem;
  color: var(--vercel-white);
  background: var(--develop-blue);
  box-shadow: 0 0 0 1px rgba(10, 114, 239, 0.35);
  transition: filter 0.15s ease, box-shadow 0.15s ease;
}

.btn:hover {
  text-decoration: none;
  filter: brightness(1.05);
}

.btn:focus-visible {
  outline: none;
  box-shadow:
    0 0 0 2px var(--vercel-white),
    0 0 0 4px var(--focus-ring),
    0 0 0 1px rgba(10, 114, 239, 0.35);
}

.content h1,
.content h2,
.content h3 {
  color: var(--vercel-black);
  letter-spacing: -0.02em;
  text-wrap: balance;
}

.content h1 {
  font-size: clamp(1.5rem, 3vw, 2rem);
  font-weight: 600;
}

.content h2 {
  font-size: 1.25rem;
  font-weight: 600;
  margin-top: 1.4em;
}

.content h3 {
  font-size: 1.0625rem;
  font-weight: 600;
}

.content p,
.content li {
  color: #3f3f3f;
}

.contact-form {
  display: grid;
  gap: 12px;
}

.contact-form label {
  font-size: 0.875rem;
  font-weight: 500;
  color: var(--vercel-black);
}

.contact-form input,
.contact-form textarea {
  width: 100%;
  min-height: 44px;
  padding: 12px 14px;
  font: inherit;
  font-size: 16px;
  color: var(--vercel-black);
  background: var(--vercel-white);
  border: none;
  border-radius: var(--radius-sm);
  box-shadow:
    0 0 0 1px rgba(0, 0, 0, 0.12),
    0 1px 2px rgba(0, 0, 0, 0.04);
  transition: box-shadow 0.15s ease;
}

.contact-form textarea {
  min-height: 140px;
  resize: vertical;
}

.contact-form input:focus-visible,
.contact-form textarea:focus-visible {
  outline: none;
  box-shadow:
    0 0 0 2px var(--vercel-white),
    0 0 0 4px var(--focus-ring),
    0 0 0 1px rgba(0, 0, 0, 0.12);
}

.contact-form button {
  min-height: 44px;
  padding: 0 20px;
  width: fit-content;
  font: inherit;
  font-size: 16px;
  font-weight: 600;
  color: var(--vercel-white);
  background: var(--develop-blue);
  border: none;
  border-radius: var(--radius-sm);
  cursor: pointer;
  box-shadow: 0 0 0 1px rgba(10, 114, 239, 0.35);
  transition: filter 0.15s ease;
}

.contact-form button:hover {
  filter: brightness(1.05);
}

.contact-form button:focus-visible {
  outline: none;
  box-shadow:
    0 0 0 2px var(--vercel-white),
    0 0 0 4px var(--focus-ring),
    0 0 0 1px rgba(10, 114, 239, 0.35);
}

.two-col {
  display: grid;
  gap: 28px;
  grid-template-columns: 1fr;
}

.project-images {
  display: grid;
  gap: 16px;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
}

.project-images img {
  width: 100%;
  border-radius: var(--radius-md);
  box-shadow:
    0 0 0 1px var(--shadow-ring),
    0 4px 12px rgba(0, 0, 0, 0.06);
}

.site-footer {
  margin-top: 0;
  padding: 28px 0 36px;
  background: var(--surface);
  box-shadow: inset 0 1px 0 rgba(0, 0, 0, 0.06);
}

.footer-bottom {
  color: var(--muted);
  font-size: 0.8125rem;
  text-align: center;
}

@media (min-width: 900px) {
  .two-col {
    grid-template-columns: 1fr 1fr;
  }
}

@media (prefers-reduced-motion: reduce) {
  .action-box,
  .site-nav a,
  .btn,
  .contact-form button,
  .contact-form input,
  .contact-form textarea {
    transition: none;
  }

  .action-box:hover {
    transform: none;
  }
}