:root {
  --brand: #0d47a1;
  --brand-light: #1565c0;
  --brand-contrast: #ffffff;
  --text: #222;
  --muted: #555;
  --bg: #ffffff;
  --bg-alt: #f9f9f9;
  --border: #e5e5e5;
}

body {
  margin: 0;
  font-family: 'Noto Sans', Arial, sans-serif;
  line-height: 1.6;
  color: var(--text);
  background: var(--bg);
}

/* Skip link */
.skip-link {
  position: absolute;
  left: -999px;
  top: auto;
  width: 1px;
  height: 1px;
  overflow: hidden;
}
.skip-link:focus {
  left: 10px;
  top: 10px;
  width: auto;
  height: auto;
  padding: 8px 12px;
  background: var(--brand);
  color: var(--brand-contrast);
  z-index: 2000;
}

/* Sticky clickable Banner */
.program-banner {
  position: sticky;
  top: 0;
  z-index: 3000; /* πάνω από όλα */
  background: #fff;
  border-bottom: 2px solid var(--border);
}
.program-banner img {
  width: 100%;
  max-height: 100px;
  object-fit: contain;
  display: block;
}

/* Header */
.site-header {
  text-align: center;
  padding: 1rem;
  border-bottom: 1px solid var(--border);
  background: var(--bg-alt);
}
.logo {
  margin: 0;
  font-size: 1.8rem;
  color: var(--brand);
}
.tagline {
  margin: 0;
  font-size: 1rem;
  color: var(--muted);
}
.primary-nav ul {
  list-style: none;
  padding: 0;
  margin: 1rem 0 0 0;
  display: flex;
  justify-content: center;
  gap: 2rem;
  flex-wrap: wrap;
}
.primary-nav a {
  text-decoration: none;
  font-weight: 600;
  color: var(--text);
  padding-bottom: 0.25rem;
}
.primary-nav a[aria-current="page"] {
  color: var(--brand);
  border-bottom: 3px solid var(--brand);
}

/* Hero */
.hero {
  background: linear-gradient(rgba(13, 71, 161, 0.8), rgba(13, 71, 161, 0.8)),
              url('../assets/company-photo.svg') center/cover no-repeat;
  color: #fff;
  padding: 5rem 1rem;
  text-align: center;
}
.hero h2 {
  font-size: 2rem;
  margin-bottom: 1rem;
}
.hero p {
  max-width: 700px;
  margin: 0 auto 1.5rem auto;
}
.hero-buttons {
  display: flex;
  justify-content: center;
  gap: 1rem;
  flex-wrap: wrap;
}

/* Buttons */
.button {
  display: inline-block;
  background: var(--brand);
  color: var(--brand-contrast);
  padding: 0.6rem 1.2rem;
  text-decoration: none;
  border-radius: 6px;
  font-weight: 600;
  transition: background 0.2s ease;
}
.button:hover {
  background: var(--brand-light);
}
.button-secondary {
  background: var(--brand-contrast);
  color: var(--brand);
  border: 2px solid var(--brand);
}
.button-ghost {
  background: transparent;
  border: 2px solid var(--brand);
  color: var(--brand);
}

/* Sections */
.section {
  padding: 3rem 1rem;
  text-align: center;
}
.section h2 {
  font-size: 1.8rem;
  margin-bottom: 1.5rem;
}

/* Cards */
.cards {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 1.5rem;
}
.card {
  background: #fff;
  padding: 1.5rem;
  border-radius: 8px;
  border: 1px solid var(--border);
  box-shadow: 0 2px 6px rgba(0,0,0,0.05);
  text-align: left;
}
.card h3 {
  margin-top: 0;
  color: var(--brand);
}

/* Footer */
.site-footer {
  background: var(--bg-alt);
  text-align: center;
  padding: 1rem;
  font-size: 0.9rem;
  border-top: 1px solid var(--border);
}

.lang-switch {
  font-weight: 600;
}
.lang-switch a {
  color: var(--brand);
  text-decoration: none;
}
.lang-switch a[aria-current="page"] {
  border-bottom: 2px solid var(--brand);
}