/*
 * ai‑edu Dark Theme inspired by Netlify aesthetic
 *
 * This stylesheet replaces the previous pastel‑based design with a unified dark
 * interface. A rich radial gradient in the hero sets the tone. Cards and
 * panels float over a deep charcoal background, separated by hairline
 * borders. Accent gradients provide colour without overwhelming the clean
 * layout.
 */

/* ---------- Design System ---------- */
:root {
  /* Base colours
   *
   * The original dark palette relied on very deep blacks (#0B0D11) and
   * high‑saturation purples and teals for accents. While this looked
   * “techy”, the combination felt harsh and inexpensive. To evoke the
   * refined feel of sites like Netlify, the palette has been
   * recalibrated to deeper blues and softened neutrals. The accent
   * gradient transitions from a calm periwinkle to a crisp aqua for a
   * contemporary look.
   */
  --bg: #0D1117;         /* deep navy backdrop for main pages */
  --panel: #111927;      /* slightly lighter panels for cards */
  --text: #E0E6EF;       /* off‑white text for high contrast */
  --muted: #8BA1C0;      /* muted slate blue for secondary text */
  --line: #1F2A3A;       /* dark blue/grey hairline separators */
  /* Accent colours */
  --accent-solid: #5C77FF; /* periwinkle primary accent */
  --accent-gradient: linear-gradient(135deg, #5C77FF 0%, #22D3EE 100%);
  /* Layout */
  --max-width: 1200px;
}

/* Reset & base styles */
* { box-sizing: border-box; }
html, body {
  margin: 0;
  padding: 0;
  font-family: 'Inter', system-ui, -apple-system, Segoe UI, Roboto, Ubuntu, 'Helvetica Neue', Arial;
  background: var(--bg);
  color: var(--text);
}
a { color: var(--text); text-decoration: none; transition: opacity 0.2s ease; }
a:hover { opacity: 0.85; }

/* Containers */
.container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 20px;
}

/* ---------- Header ---------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  backdrop-filter: saturate(150%) blur(10px);
  background: rgba(11, 13, 17, 0.6);
  border-bottom: 1px solid var(--line);
}
.header-container {
  height: 68px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}
.logo {
  font-weight: 700;
  letter-spacing: 0.02em;
  font-size: 1.3rem;
}
.logo .logo-sep {
  color: var(--accent-solid);
  margin: 0 2px;
}
.nav {
  display: flex;
  flex-wrap: wrap;
  gap: 18px;
}
.nav a {
  white-space: nowrap;
  font-weight: 500;
  font-size: 0.95rem;
  opacity: 0.95;
}

/* ---------- Buttons ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  padding: 12px 18px;
  border-radius: 10px;
  border: 1px solid transparent;
  font-weight: 600;
  transition: 0.18s ease;
  font-size: 0.95rem;
  cursor: pointer;
}
.btn-primary {
  background: var(--accent-gradient);
  color: #ffffff;
  box-shadow: 0 10px 30px rgba(6, 182, 212, 0.25);
}
.btn-primary:hover {
  transform: translateY(-1px) scale(1.01);
}
.btn-secondary {
  background: transparent;
  border-color: var(--line);
  color: var(--text);
}
.btn-secondary:hover {
  /* Subtle dark overlay on hover instead of harsh black */
  background: rgba(255, 255, 255, 0.05);
}

/* ---------- Hero ---------- */
.hero {
  position: relative;
  padding: 120px 0 80px;
  overflow: hidden;
  /* Radial gradients create subtle colour splashes reminiscent of Netlify */
  /* Use softer, less saturated radial gradients for a premium feel.  The
     radii and positions remain similar, but colours tie into the new
     accent palette. */
  background:
    radial-gradient(1200px 600px at 80% -100px, rgba(92, 119, 255, 0.30), transparent 60%),
    radial-gradient(1000px 500px at -10% -50px, rgba(34, 211, 238, 0.20), transparent 60%);
}
.hero .hero-columns {
  display: grid;
  grid-template-columns: 1.1fr 0.9fr;
  gap: 48px;
  align-items: center;
}
.hero h1 {
  font-size: 42px;
  line-height: 1.1;
  margin: 0 0 16px;
}
.hero p {
  margin: 0 0 24px;
  color: var(--muted);
  font-size: 18px;
}
.hero-image {
  aspect-ratio: 4/3;
  border-radius: 16px;
  border: 1px solid var(--line);
  background: linear-gradient(135deg, rgba(92, 119, 255, 0.12), rgba(34, 211, 238, 0.10));
  box-shadow: 0 20px 60px rgba(0, 0, 0, 0.35);
  display: flex;
  align-items: center;
  justify-content: center;
  overflow: hidden;
}
.hero-image img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

/* ---------- LLM Logos ---------- */
/*
 * The hero section displays a row of abstract icons representing various
 * language models (ChatGPT, Claude, Gemini, Copilot). Without explicit
 * styling these icons can appear oversized. This flex container keeps
 * them aligned and limits their size for a polished look.
 */
.llm-logos {
  display: flex;
  gap: 12px;
  align-items: center;
  margin: 16px 0;
}
.llm-logos img {
  width: 40px;
  height: 40px;
  object-fit: contain;
  /* Slightly brighten icons to stand out on dark background */
  filter: brightness(1.1);
}

/* ---------- Offers / Packages ---------- */
.offers-section {
  padding: 80px 0;
}
.offers-section h2 {
  text-align: center;
  margin: 0 0 32px;
  font-size: 32px;
}
.offers {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 24px;
}
.offer-card {
  background: rgba(15, 18, 25, 0.9);
  border: 1px solid var(--line);
  border-radius: 16px;
  padding: 22px;
  box-shadow: 0 1px 0 #111 inset, 0 12px 30px rgba(0, 0, 0, 0.25);
  transition: transform 0.18s ease, box-shadow 0.18s ease;
  display: flex;
  flex-direction: column;
  height: 100%;
}
.offer-card:hover {
  transform: translateY(-2px) scale(1.01);
  box-shadow: 0 1px 0 #111 inset, 0 22px 50px rgba(0, 0, 0, 0.35);
}
.offer-card .price {
  /* Price colour echoes the primary accent but muted slightly for subtlety */
  color: #8EA9FF;
  font-weight: 600;
  margin: 8px 0;
}
.offer-card h3 {
  margin: 8px 0 4px;
}

/* Text within an offer card should be muted except where emphasised. */
.offer-card p {
  color: var(--muted);
}
.offer-card p strong {
  color: var(--text);
}
.offer-card ul {
  list-style: none;
  padding: 0;
  margin: 10px 0 0;
  flex-grow: 1;
}
.offer-card li {
  position: relative;
  padding-left: 18px;
  margin: 6px 0;
  color: var(--muted);
}
.offer-card li::before {
  content: '';
  position: absolute;
  left: 0;
  top: 0.6em;
  width: 6px;
  height: 6px;
  border-radius: 99px;
  background: var(--accent-gradient);
}
.package-icon {
  width: 44px;
  height: 44px;
  opacity: 0.95;
  margin-bottom: 10px;
}
/* Featured / Meist gebucht */
.offer-card.featured {
  border-color: #4F8DFE;
  box-shadow: 0 1px 0 #111 inset, 0 22px 60px rgba(79, 141, 254, 0.22);
}
.offer-card .badge {
  display: inline-block;
  padding: 4px 8px;
  border-radius: 999px;
  background: rgba(92, 119, 255, 0.18);
  color: #D4DCFF;
  border: 1px solid rgba(92, 119, 255, 0.3);
  font-size: 0.75rem;
  font-weight: 600;
  margin: 4px 0 10px;
  align-self: flex-start;
}

/* ---------- Features ---------- */
.features-section {
  padding: 80px 0;
}
.features-section h2 {
  text-align: center;
  margin: 0 0 32px;
  font-size: 32px;
}
.features {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 20px;
}
.feature-card {
  display: flex;
  gap: 14px;
  align-items: flex-start;
  background: rgba(17, 25, 39, 0.85);
  border: 1px solid var(--line);
  border-radius: 14px;
  padding: 18px;
  box-shadow: 0 1px 0 #111 inset, 0 10px 26px rgba(0, 0, 0, 0.25);
}
.feature-icon {
  width: 40px;
  height: 40px;
  opacity: 0.9;
}
.feature-text h3 {
  margin: 0 0 4px;
}
.feature-text p {
  margin: 0;
  color: var(--muted);
}

/* ---------- Facts ---------- */
/*
 * The facts section displays key statistics to underline the relevance of
 * generative KI. Counters animate from zero and are styled to stand out
 * against the dark backdrop. The section spans the full width with
 * generous padding and subtle separators top and bottom.
 */
.facts-section {
  padding: 80px 0;
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
}
.facts {
  display: flex;
  justify-content: space-around;
  gap: 40px;
  flex-wrap: wrap;
  margin: 0 auto;
  max-width: 1000px;
}
.fact {
  text-align: center;
  min-width: 200px;
  flex: 1 1 200px;
  margin: 16px 0;
}
.fact h3 {
  font-size: 48px;
  margin: 0;
  color: var(--accent-solid);
}
.fact p {
  margin: 8px 0 0;
  color: var(--muted);
}

/* ---------- Why Section ---------- */
/*
 * The why-section explains the benefits of generative KI. Content is
 * presented in a single column for readability, with generous spacing
 * between paragraphs and clear hierarchy for headings. The muted text
 * colour provides sufficient contrast on the dark background.
 */
.why-section {
  padding: 80px 0;
}
.why-section h2 {
  font-size: 32px;
  margin: 0 0 16px;
}
.why-section p {
  color: var(--muted);
  line-height: 1.6;
  margin-bottom: 16px;
}
.why-section strong {
  color: var(--text);
}

/* ---------- Visual Section ---------- */
/*
 * The original design included a floating animated background between
 * sections. It distracted from the content in a dark theme, so we
 * hide it. If future animations are desired, they can be re-enabled
 * here with appropriate styling.
 */
.visual-section {
  display: none;
}
.animated-background {
  display: none;
}

/* ---------- Hero Buttons ---------- */
.hero-buttons {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}

/* ---------- Course Details ---------- */
/*
 * Sections that describe the contents of a course reuse this pattern. A
 * subtle list style enhances readability on dark backgrounds.
 */
.course-details {
  padding: 80px 0;
}
.course-details h2 {
  font-size: 28px;
  margin: 0 0 16px;
}
.course-details p {
  color: var(--muted);
  line-height: 1.6;
  margin-bottom: 16px;
}
.course-details ul {
  list-style: none;
  padding-left: 0;
  margin-bottom: 16px;
}
.course-details li {
  position: relative;
  padding-left: 20px;
  margin-bottom: 10px;
  color: var(--muted);
}
.course-details li::before {
  content: '';
  position: absolute;
  left: 0;
  top: 0.6em;
  width: 6px;
  height: 6px;
  border-radius: 99px;
  background: var(--accent-gradient);
}

/* ---------- PDF Links ---------- */
.pdf-link {
  display: inline-block;
  margin-top: 8px;
  font-weight: 500;
  color: var(--accent-solid);
}
.pdf-link:hover {
  text-decoration: underline;
}

/* ---------- Testimonials ---------- */
.testimonial-author {
  margin-top: 8px;
  color: var(--muted);
  font-style: italic;
}

/* ---------- Legal Pages ---------- */
/*
 * The legal pages (Impressum & Datenschutz) are styled to match the dark
 * theme. They reuse the panel colour and lines, with muted text for
 * readability. Links adopt the accent colour.
 */
.legal-wrapper {
  max-width: 900px;
  margin: 80px auto;
  padding: 0 16px;
}
.legal-card {
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: 12px;
  box-shadow: 0 2px 4px rgba(0, 0, 0, 0.4);
  padding: 32px;
}
.legal-card h1,
.legal-card h2 {
  margin-top: 24px;
  margin-bottom: 12px;
}
.legal-card h1:first-child {
  margin-top: 0;
}
.legal-card p,
.legal-card li {
  color: var(--muted);
  line-height: 1.6;
  margin-bottom: 8px;
}
.legal-card ul {
  margin-bottom: 8px;
  padding-left: 20px;
}
.legal-card a {
  color: var(--accent-solid);
}

/* ---------- Generic Section ---------- */
/*
 * Utility classes used on pages like Referenzen to avoid inline styles.
 * These classes add consistent vertical padding and container widths.
 */
.generic-section {
  padding: 80px 0;
}
.generic-container {
  max-width: 900px;
  margin: 0 auto;
  padding: 0 20px;
}

/* Clients logos on the references page */
.clients-logos {
  display: flex;
  flex-wrap: wrap;
  gap: 32px;
  justify-content: center;
  margin-top: 40px;
}
.clients-logos img {
  width: 120px;
  height: auto;
  opacity: 0.9;
}

/* ---------- FAQ ---------- */
.faq-section {
  padding: 80px 0;
}
.faq-section h2 {
  text-align: center;
  margin: 0 0 32px;
  font-size: 32px;
}
.faq-item {
  max-width: 860px;
  margin: 0 auto 14px;
  background: rgba(15, 18, 25, 0.85);
  border: 1px solid var(--line);
  border-radius: 14px;
  padding: 18px;
}
.faq-item h3 {
  margin: 0 0 6px;
}
.faq-item p {
  margin: 0;
  color: var(--muted);
}

/* ---------- Contact & Newsletter ---------- */
.contact-section {
  padding: 80px 0;
  border-top: 1px solid var(--line);
}
.contact-section h2 {
  text-align: center;
  margin: 0 0 16px;
  font-size: 32px;
}
.contact-section p {
  text-align: center;
  margin: 0 0 32px;
  color: var(--muted);
}
.form-row {
  display: flex;
  gap: 16px;
  margin-bottom: 32px;
}
.form-col {
  flex: 1;
}
.contact-section input,
.contact-section select,
.contact-section textarea {
  width: 100%;
  padding: 12px;
  margin-bottom: 16px;
  border-radius: 6px;
  border: 1px solid var(--line);
  background: rgba(0, 0, 0, 0.35);
  color: var(--text);
  resize: vertical;
}
.contact-section button {
  padding: 12px 24px;
  border: none;
  border-radius: 6px;
  background: var(--accent-gradient);
  color: #fff;
  font-weight: 500;
  cursor: pointer;
  transition: 0.2s ease;
}
.contact-section button:hover {
  transform: translateY(-1px) scale(1.01);
}
.newsletter-form {
  display: flex;
  gap: 12px;
  justify-content: center;
  flex-wrap: wrap;
}
.newsletter-form input[type="email"] {
  flex: 1 1 auto;
  height: 44px;
  background: rgba(0, 0, 0, 0.35);
  border: 1px solid var(--line);
  border-radius: 10px;
  color: var(--text);
  padding: 0 12px;
}
.newsletter-form button {
  height: 44px;
}

/* ---------- Footer ---------- */
.site-footer {
  border-top: 1px solid var(--line);
  padding: 24px 0;
  color: var(--muted);
  font-size: 0.9rem;
  text-align: center;
}

/* ---------- Interactive Booking Calendar ---------- */
.booking-calendar {
  display: flex;
  flex-wrap: nowrap;
  overflow-x: auto;
  gap: 16px;
  margin: 24px 0 32px;
  padding-bottom: 8px;
}
.booking-calendar .date-col {
  flex: 0 0 120px;
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 12px;
  box-shadow: 0 2px 4px rgba(0, 0, 0, 0.05);
  text-align: center;
}
.booking-calendar .date-label {
  font-weight: 600;
  margin-bottom: 8px;
  color: var(--text);
}
.booking-calendar .time-list {
  display: flex;
  flex-direction: column;
  gap: 6px;
}
.booking-calendar .time-list button {
  background: #1B283A;
  border: 1px solid var(--accent-solid);
  color: var(--text);
  padding: 6px 0;
  border-radius: 4px;
  cursor: pointer;
  font-size: 0.85rem;
  transition: background-color 0.2s ease, color 0.2s ease;
}
.booking-calendar .time-list button:hover,
.booking-calendar .time-list button.selected {
  background: var(--accent-solid);
  color: #ffffff;
}

/* ---------- Responsive Adjustments ---------- */
@media (max-width: 960px) {
  .hero .hero-columns {
    grid-template-columns: 1fr;
  }
  .hero {
    padding: 96px 0 64px;
  }
}