/* =============================================================
   cfoai.de — Shared Stylesheet
   Clean, light, modern, professional
   ============================================================= */

/* Bunny Fonts — EU-hosted, GDPR-compliant (no IP logging, no cookies, no tracking) */
@import url('https://fonts.bunny.net/css?family=inter:300,400,500,600,700,800&display=swap');

/* ---- Design Tokens ---- */
:root {
  --bg:            #FFFFFF;
  --bg-subtle:     #F8FAFC;
  --bg-accent:     #EFF6FF;
  --bg-dark:       #0B1929;

  --text:          #0F172A;
  --text-muted:    #64748B;
  --text-inverse:  #FFFFFF;

  --accent:        #2563EB;
  --accent-dark:   #1D4ED8;
  --accent-subtle: #DBEAFE;

  --border:        #E2E8F0;
  --border-subtle: #F1F5F9;

  --font: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;

  --radius-sm: 6px;
  --radius-md: 12px;
  --radius-lg: 20px;

  --shadow-sm: 0 1px 3px rgba(0,0,0,0.06), 0 1px 2px rgba(0,0,0,0.04);
  --shadow-md: 0 4px 16px rgba(0,0,0,0.08), 0 2px 6px rgba(0,0,0,0.04);
  --shadow-lg: 0 20px 48px rgba(0,0,0,0.10), 0 8px 16px rgba(0,0,0,0.06);

  --max-w:    1200px;
  --header-h: 72px;
}

/* ---- Reset ---- */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { font-size: 16px; scroll-behavior: smooth; -webkit-text-size-adjust: 100%; }
body {
  font-family: var(--font);
  color: var(--text);
  background: var(--bg);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}
img, svg { display: block; max-width: 100%; }
ul, ol { list-style: none; }
a { color: var(--accent); text-decoration: none; }
a:hover { color: var(--accent-dark); }
button { font-family: var(--font); }

/* ---- Typography ---- */
h1, h2, h3, h4 { font-weight: 700; line-height: 1.15; letter-spacing: -0.025em; }
h1 { font-size: clamp(2.25rem, 5vw, 3.75rem); }
h2 { font-size: clamp(1.75rem, 3.5vw, 2.5rem); }
h3 { font-size: clamp(1.125rem, 2vw, 1.375rem); }
p  { line-height: 1.75; }

/* ---- Layout ---- */
.container { max-width: var(--max-w); margin: 0 auto; padding: 0 2rem; }

section { padding: 6rem 0; }
section.bg-subtle { background: var(--bg-subtle); }

.grid-2 { display: grid; grid-template-columns: repeat(2, 1fr); gap: 1.5rem; }
.grid-3 { display: grid; grid-template-columns: repeat(3, 1fr); gap: 1.5rem; }
.grid-4 { display: grid; grid-template-columns: repeat(4, 1fr); gap: 1.5rem; }

/* ---- Section headers ---- */
.section-label {
  display: inline-block;
  font-size: 0.75rem;
  font-weight: 600;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--accent);
  margin-bottom: 0.875rem;
}
.section-header { margin-bottom: 3.5rem; }
.section-header h2 { margin-bottom: 0.875rem; }
.section-header p { font-size: 1.125rem; color: var(--text-muted); max-width: 580px; }
.section-header.centered { text-align: center; }
.section-header.centered p { margin: 0 auto; }

/* ---- Navigation ---- */
header {
  position: sticky; top: 0; z-index: 100;
  background: rgba(255,255,255,0.96);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--border);
  height: var(--header-h);
}
.nav-inner {
  max-width: var(--max-w); margin: 0 auto; padding: 0 2rem;
  height: var(--header-h);
  display: flex; align-items: center; justify-content: space-between;
}
.logo {
  font-size: 1.1875rem; font-weight: 800; letter-spacing: -0.04em;
  color: var(--text); display: flex; align-items: center; gap: 1px;
}
.logo .dot { color: var(--accent); }

nav ul { display: flex; align-items: center; gap: 2rem; }
nav a { color: var(--text-muted); font-size: 0.9375rem; font-weight: 500; transition: color 0.15s; }
nav a:hover, nav a.active { color: var(--text); }
.nav-cta {
  background: var(--accent) !important;
  color: var(--text-inverse) !important;
  padding: 0.5rem 1.25rem;
  border-radius: var(--radius-sm);
  font-weight: 600 !important;
  transition: background 0.15s !important;
}
.nav-cta:hover { background: var(--accent-dark) !important; }

.nav-toggle {
  display: none; background: none; border: none;
  cursor: pointer; padding: 0.5rem; color: var(--text);
}

/* ---- Buttons ---- */
.btn {
  display: inline-flex; align-items: center; gap: 0.5rem;
  font-family: var(--font); font-size: 0.9375rem; font-weight: 600;
  padding: 0.8125rem 1.75rem; border-radius: var(--radius-sm);
  cursor: pointer; transition: all 0.15s ease;
  border: 2px solid transparent; text-decoration: none; white-space: nowrap;
}
.btn-primary {
  background: var(--accent); color: var(--text-inverse); border-color: var(--accent);
}
.btn-primary:hover {
  background: var(--accent-dark); border-color: var(--accent-dark);
  color: var(--text-inverse); transform: translateY(-1px);
  box-shadow: 0 4px 16px rgba(37,99,235,0.35);
}
.btn-outline {
  background: transparent; color: var(--text); border-color: var(--border);
}
.btn-outline:hover { border-color: var(--text); color: var(--text); }
.btn-white {
  background: var(--bg); color: var(--text); border-color: var(--bg);
}
.btn-white:hover {
  background: var(--bg-subtle); color: var(--text);
  transform: translateY(-1px); box-shadow: var(--shadow-md);
}

/* ---- Tags ---- */
.tag {
  display: inline-block; font-size: 0.75rem; font-weight: 600;
  padding: 0.3125rem 0.875rem; border-radius: 999px;
  background: var(--bg-accent); color: var(--accent); letter-spacing: 0.02em;
}
.tag-outline {
  background: transparent; border: 1px solid var(--border);
  color: var(--text-muted);
}
.tag-dark {
  background: rgba(255,255,255,0.12); color: rgba(255,255,255,0.75);
  border: 1px solid rgba(255,255,255,0.2);
}

/* ---- Cards ---- */
.card {
  background: var(--bg); border: 1px solid var(--border);
  border-radius: var(--radius-md); padding: 2rem;
  transition: box-shadow 0.2s, transform 0.2s;
}
.card:hover { box-shadow: var(--shadow-md); transform: translateY(-2px); }

.service-icon {
  width: 48px; height: 48px; border-radius: 12px;
  background: var(--bg-accent); display: flex; align-items: center;
  justify-content: center; margin-bottom: 1.25rem; color: var(--accent);
  flex-shrink: 0;
}
.card h3 { margin-bottom: 0.625rem; }
.card p { color: var(--text-muted); font-size: 0.9375rem; }

/* ---- Hero ---- */
.hero {
  padding: 8rem 0 6rem;
  position: relative; overflow: hidden;
  background: var(--bg);
}
.hero::before {
  content: '';
  position: absolute; inset: 0;
  background-image: radial-gradient(circle at 1px 1px, rgba(37,99,235,0.055) 1px, transparent 0);
  background-size: 32px 32px;
  pointer-events: none;
}
.hero-badge { margin-bottom: 1.5rem; }
.hero h1 { max-width: 820px; margin-bottom: 1.5rem; }
.hero-sub {
  font-size: 1.1875rem; color: var(--text-muted);
  max-width: 640px; margin-bottom: 2.5rem; line-height: 1.8;
}
.hero-ctas { display: flex; gap: 1rem; flex-wrap: wrap; }

/* ---- Page hero (inner pages) ---- */
.page-hero {
  padding: 5rem 0 4rem;
  background: var(--bg-subtle);
  border-bottom: 1px solid var(--border);
}
.page-hero .section-label { margin-bottom: 1rem; }
.page-hero h1 { font-size: clamp(1.875rem, 4vw, 3rem); margin-bottom: 1rem; }
.page-hero p { font-size: 1.125rem; color: var(--text-muted); max-width: 580px; }

/* ---- Pillars / value props ---- */
.pillar { display: flex; gap: 1rem; align-items: flex-start; }
.pillar-icon {
  width: 44px; height: 44px; border-radius: 10px;
  background: var(--bg-accent); display: flex; align-items: center;
  justify-content: center; color: var(--accent); flex-shrink: 0; margin-top: 2px;
}
.pillar-text h3 { margin-bottom: 0.375rem; font-size: 1.0625rem; }
.pillar-text p { font-size: 0.9375rem; color: var(--text-muted); }

/* ---- Cooperation models ---- */
.coop-card {
  background: var(--bg); border: 1px solid var(--border);
  border-radius: var(--radius-md); padding: 2.5rem;
}
.coop-card.featured {
  background: var(--bg-dark);
  border-color: transparent;
  color: var(--text-inverse);
}
.coop-card.featured p,
.coop-card.featured li { color: rgba(255,255,255,0.65); }
.coop-card .coop-label {
  font-size: 0.75rem; font-weight: 700; letter-spacing: 0.08em;
  text-transform: uppercase; color: var(--accent); margin-bottom: 0.75rem;
}
.coop-card.featured .coop-label { color: rgba(255,255,255,0.5); }
.coop-card h3 { font-size: 1.5rem; margin-bottom: 1rem; }
.coop-card p { font-size: 0.9375rem; margin-bottom: 1.5rem; line-height: 1.7; }
.coop-card ul { display: flex; flex-direction: column; gap: 0.625rem; margin-bottom: 2rem; }
.coop-card li {
  display: flex; align-items: flex-start; gap: 0.625rem;
  font-size: 0.9375rem; color: var(--text-muted);
}
.coop-card li::before {
  content: '';
  width: 16px; height: 16px; flex-shrink: 0; margin-top: 3px;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='16' height='16' viewBox='0 0 24 24' fill='none' stroke='%232563EB' stroke-width='2.5' stroke-linecap='round' stroke-linejoin='round'%3E%3Cpolyline points='20 6 9 17 4 12'/%3E%3C/svg%3E");
  background-repeat: no-repeat; background-size: contain;
}
.coop-card.featured li::before {
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='16' height='16' viewBox='0 0 24 24' fill='none' stroke='rgba(255,255,255,0.6)' stroke-width='2.5' stroke-linecap='round' stroke-linejoin='round'%3E%3Cpolyline points='20 6 9 17 4 12'/%3E%3C/svg%3E");
}

/* ---- Case cards ---- */
.case-card {
  background: var(--bg); border: 1px solid var(--border);
  border-radius: var(--radius-md); overflow: hidden;
  transition: box-shadow 0.2s, transform 0.2s;
}
.case-card:hover { box-shadow: var(--shadow-md); transform: translateY(-2px); }
.case-card-header {
  padding: 2rem 2rem 1.5rem;
  border-bottom: 1px solid var(--border-subtle);
}
.case-card-header .tag { margin-bottom: 1rem; }
.case-card-header h3 { font-size: 1.1875rem; margin-bottom: 0.5rem; }
.case-card-header p { font-size: 0.9375rem; color: var(--text-muted); }
.case-card-metrics {
  padding: 1.5rem 2rem;
  display: flex; gap: 1.5rem; flex-wrap: wrap;
}
.metric { }
.metric .metric-val {
  font-size: 1.375rem; font-weight: 700;
  letter-spacing: -0.02em; color: var(--text);
}
.metric .metric-label { font-size: 0.8125rem; color: var(--text-muted); margin-top: 0.125rem; }

/* ---- CTA Banner ---- */
.cta-banner {
  background: var(--bg-dark); color: var(--text-inverse);
  padding: 6rem 0;
  text-align: center;
}
.cta-banner h2 { color: var(--text-inverse); margin-bottom: 1rem; }
.cta-banner p { color: rgba(255,255,255,0.6); font-size: 1.125rem; max-width: 520px; margin: 0 auto 2.5rem; }
.cta-banner .btn-row { display: flex; gap: 1rem; justify-content: center; flex-wrap: wrap; }

/* ---- Footer ---- */
footer {
  background: var(--bg-dark);
  color: var(--text-inverse);
  padding: 5rem 0 2.5rem;
}
.footer-grid {
  display: grid; grid-template-columns: 2fr 1fr 1fr; gap: 3rem;
  padding-bottom: 3rem;
  border-bottom: 1px solid rgba(255,255,255,0.08);
  margin-bottom: 2rem;
}
.footer-brand .logo { color: var(--text-inverse); margin-bottom: 1rem; }
.footer-brand p {
  color: rgba(255,255,255,0.45); font-size: 0.9rem;
  line-height: 1.75; max-width: 280px;
}
.footer-col h4 {
  font-size: 0.75rem; font-weight: 600; letter-spacing: 0.08em;
  text-transform: uppercase; color: rgba(255,255,255,0.35); margin-bottom: 1.25rem;
}
.footer-col li + li { margin-top: 0.75rem; }
.footer-col a { color: rgba(255,255,255,0.6); font-size: 0.9375rem; transition: color 0.15s; }
.footer-col a:hover { color: var(--text-inverse); }
.footer-bottom {
  display: flex; align-items: center; justify-content: space-between;
  font-size: 0.8125rem; color: rgba(255,255,255,0.3);
}
.footer-bottom a { color: rgba(255,255,255,0.4); transition: color 0.15s; }
.footer-bottom a:hover { color: rgba(255,255,255,0.8); }

/* ---- Contact form ---- */
.contact-layout { display: grid; grid-template-columns: 1fr 2fr; gap: 4rem; align-items: start; }
.contact-info h3 { margin-bottom: 0.75rem; }
.contact-info p { color: var(--text-muted); font-size: 0.9375rem; margin-bottom: 2rem; }
.contact-detail { display: flex; align-items: flex-start; gap: 0.875rem; margin-bottom: 1.25rem; }
.contact-detail-icon {
  width: 36px; height: 36px; border-radius: 8px;
  background: var(--bg-accent); display: flex; align-items: center;
  justify-content: center; color: var(--accent); flex-shrink: 0;
}
.contact-detail-text p:first-child { font-weight: 600; font-size: 0.875rem; }
.contact-detail-text p:last-child { font-size: 0.875rem; color: var(--text-muted); }

.form-group { margin-bottom: 1.5rem; }
.form-group label { display: block; font-size: 0.875rem; font-weight: 500; margin-bottom: 0.5rem; }
.form-group input,
.form-group select,
.form-group textarea {
  width: 100%; padding: 0.8125rem 1rem;
  border: 1px solid var(--border); border-radius: var(--radius-sm);
  font-family: var(--font); font-size: 1rem; color: var(--text);
  background: var(--bg); transition: border-color 0.15s, box-shadow 0.15s; outline: none;
  appearance: none; -webkit-appearance: none;
}
.form-group input:focus,
.form-group select:focus,
.form-group textarea:focus {
  border-color: var(--accent);
  box-shadow: 0 0 0 3px rgba(37,99,235,0.12);
}
.form-group textarea { resize: vertical; min-height: 140px; }
.form-group select { background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='16' height='16' viewBox='0 0 24 24' fill='none' stroke='%2364748B' stroke-width='2'%3E%3Cpolyline points='6 9 12 15 18 9'/%3E%3C/svg%3E"); background-repeat: no-repeat; background-position: right 1rem center; padding-right: 2.5rem; }
.form-row { display: grid; grid-template-columns: 1fr 1fr; gap: 1rem; }
.form-success {
  display: none; padding: 1.5rem; background: #F0FDF4; border: 1px solid #BBF7D0;
  border-radius: var(--radius-md); text-align: center; color: #15803D;
  margin-bottom: 1.5rem;
}
.form-success strong { display: block; font-size: 1.125rem; margin-bottom: 0.375rem; }

/* Formspree Ajax inline field errors */
.form-field-error {
  display: block; font-size: 0.8125rem; color: #DC2626;
  margin-top: 0.375rem; min-height: 0;
}
.form-field-error:empty { display: none; }
/* Highlight invalid fields flagged by Formspree Ajax */
input[aria-invalid="true"],
select[aria-invalid="true"],
textarea[aria-invalid="true"] {
  border-color: #DC2626;
  box-shadow: 0 0 0 3px rgba(220,38,38,0.1);
}
/* Disable styling for submit button while submitting */
button[data-fs-submit-btn]:disabled {
  opacity: 0.65; cursor: not-allowed; transform: none; box-shadow: none;
}

/* ---- Services detail page ---- */
.service-row {
  display: grid; grid-template-columns: 1fr 2fr; gap: 3rem;
  padding: 3rem 0;
  border-bottom: 1px solid var(--border);
  align-items: start;
}
.service-row:last-child { border-bottom: none; }
.service-row-icon { display: flex; align-items: center; gap: 1rem; }
.service-row-icon .service-icon { margin-bottom: 0; }
.service-row-icon h3 { font-size: 1.25rem; }
.service-detail-list { display: flex; flex-direction: column; gap: 0.5rem; margin-top: 1rem; }
.service-detail-list li {
  display: flex; align-items: flex-start; gap: 0.625rem;
  font-size: 0.9375rem; color: var(--text-muted);
}
.service-detail-list li::before {
  content: '→';
  color: var(--accent); font-weight: 600; flex-shrink: 0;
}

/* ---- Case study full ---- */
.case-full {
  padding: 4rem 0;
  border-bottom: 1px solid var(--border);
}
.case-full:last-child { border-bottom: none; }
.case-full-header { margin-bottom: 2rem; }
.case-full-header .tag { margin-bottom: 1rem; }
.case-full-header h2 { font-size: clamp(1.5rem, 3vw, 2rem); margin-bottom: 0.75rem; }
.case-full-header .case-sub { font-size: 1rem; color: var(--text-muted); }
.case-full-body {
  display: grid; grid-template-columns: 2fr 1fr; gap: 3rem; align-items: start;
}
.case-narrative h4 { font-size: 0.875rem; font-weight: 600; text-transform: uppercase;
  letter-spacing: 0.06em; color: var(--text-muted); margin-top: 1.5rem; margin-bottom: 0.5rem; }
.case-narrative h4:first-child { margin-top: 0; }
.case-narrative p { font-size: 0.9375rem; color: var(--text-muted); }
.case-outcomes {
  background: var(--bg-subtle); border: 1px solid var(--border);
  border-radius: var(--radius-md); padding: 1.75rem;
}
.case-outcomes h4 { font-size: 0.8125rem; font-weight: 600; text-transform: uppercase;
  letter-spacing: 0.06em; color: var(--text-muted); margin-bottom: 1.25rem; }
.outcome-item { padding: 0.75rem 0; border-bottom: 1px solid var(--border); }
.outcome-item:last-child { border-bottom: none; padding-bottom: 0; }
.outcome-item .outcome-val { font-size: 1.625rem; font-weight: 700; letter-spacing: -0.02em; color: var(--text); }
.outcome-item .outcome-label { font-size: 0.8125rem; color: var(--text-muted); }

/* ---- Impressum ---- */
.impressum-content { max-width: 720px; }
.impressum-content h2 { font-size: 1.25rem; margin-top: 2.5rem; margin-bottom: 0.75rem; }
.impressum-content h2:first-child { margin-top: 0; }
.impressum-content p { font-size: 0.9375rem; color: var(--text-muted); margin-bottom: 0.5rem; }
.impressum-content a { color: var(--accent); }
.placeholder-box {
  background: #FFFBEB; border: 1px solid #FCD34D;
  border-radius: var(--radius-sm); padding: 1rem 1.25rem;
  font-size: 0.875rem; color: #92400E; margin: 0.5rem 0;
}

/* ---- Responsive ---- */
@media (max-width: 1024px) {
  .grid-4 { grid-template-columns: repeat(2, 1fr); }
  .contact-layout { grid-template-columns: 1fr; gap: 2.5rem; }
  .case-full-body { grid-template-columns: 1fr; }
  .service-row { grid-template-columns: 1fr; gap: 1.5rem; }
}

@media (max-width: 768px) {
  section { padding: 4rem 0; }
  .container { padding: 0 1.25rem; }
  .grid-2, .grid-3, .grid-4 { grid-template-columns: 1fr; }
  .footer-grid { grid-template-columns: 1fr; gap: 2rem; }
  .footer-bottom { flex-direction: column; gap: 0.75rem; text-align: center; }
  .cta-banner { padding: 4rem 0; }

  nav ul { display: none; flex-direction: column; gap: 0; }
  nav ul.open {
    display: flex; position: absolute; top: var(--header-h);
    left: 0; right: 0; background: var(--bg);
    padding: 1rem 1.25rem 1.5rem;
    border-bottom: 1px solid var(--border);
    box-shadow: var(--shadow-md);
  }
  nav ul.open li { border-bottom: 1px solid var(--border-subtle); }
  nav ul.open li:last-child { border-bottom: none; }
  nav ul.open a { display: block; padding: 0.875rem 0; }
  nav ul.open .nav-cta {
    display: inline-block; margin-top: 0.5rem; padding: 0.625rem 1.25rem;
  }
  .nav-toggle { display: block; }
  header { position: relative; }

  .hero { padding: 4rem 0 3.5rem; }
  .hero-ctas { flex-direction: column; align-items: flex-start; }
  .page-hero { padding: 3.5rem 0 2.5rem; }
  .form-row { grid-template-columns: 1fr; }
}