/* ── Reset & base ── */
*,
*::before,
*::after {
  box-sizing: border-box;
}

:root {
  --blue: #0044cc;
  --blue-dark: #002a80;
  --blue-mid: #0055ff;
  --classid: #1c92ff;
  --accent: #ffd166;
  --bg: #f0f6ff;
  --card-bg: #ffffff;
  --text: #1a1a2e;
  --muted: #5a6a8a;
  --radius: 16px;
}

body {
  margin: 0;
  padding: 0;
  font-family: 'DM Sans', sans-serif;
  background: var(--bg);
  color: var(--text);
  overflow-x: hidden;
}

/* ── Header ── */
header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  background-color: var(--blue);
  height: 6rem;
  z-index: 100;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 2rem;
  box-shadow: 0 4px 20px rgba(0, 0, 0, 0.18);
}

.logo-link {
  display: flex;
  align-items: center;
}

header .imageContainer {
  height: 3.5rem;
  border-radius: 8px;
  background-color: white;
  padding: 0.2rem;
  box-shadow: 0 0 5px rgba(0, 0, 0, 0.15);
  margin-right: 1rem;
}

header .naam {
  font-size: 1.8rem;
  font-weight: 600;
  color: white;
  flex-grow: 1;
  font-family: 'DM Serif Display', serif;
  letter-spacing: 0.02em;
}

.menu-button {
  font-weight: 600;
  border: none;
  background-color: #ffffff;
  color: var(--blue);
  padding: 0.5rem 1.2rem;
  border-radius: 8px;
  transition: background-color 0.3s, box-shadow 0.3s;
  box-shadow: 0 0 5px rgba(0, 68, 204, 0.3);
  cursor: pointer;
}

.menu-button:hover {
  background-color: #e6e6e6;
  color: var(--blue-dark);
  box-shadow: 0 0 12px rgba(0, 68, 204, 0.5);
}

/* ── Page wrapper ── */
.page {
  margin-top: 6rem;
  min-height: calc(100vh - 6rem);
}

/* ── Hero ── */
.hero {
  background: linear-gradient(135deg, var(--blue-dark) 0%, var(--blue-mid) 100%);
  color: white;
  padding: 4rem 2rem 5rem;
  position: relative;
  overflow: hidden;
}

.hero::before {
  content: '';
  position: absolute;
  top: -60px;
  right: -80px;
  width: 340px;
  height: 340px;
  border-radius: 50%;
  background: rgba(250, 23, 23, 0.06);
}

.hero::after {
  content: '';
  position: absolute;
  bottom: -100px;
  left: -60px;
  width: 260px;
  height: 260px;
  border-radius: 50%;
  background: rgba(255, 255, 255, 0.04);
}

.hero-inner {
  max-width: 820px;
  margin: 0 auto;
  position: relative;
  z-index: 1;
}

.hero-label {
  display: inline-block;
  background: var(--classid);
  color: var(--blue-dark);
  font-size: 0.72rem;
  font-weight: 700;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  padding: 0.3rem 0.8rem;
  border-radius: 100px;
  margin-bottom: 1.2rem;
}

.hero h1 {
  font-family: 'DM Serif Display', serif;
  font-size: clamp(2.4rem, 5vw, 3.6rem);
  line-height: 1.12;
  margin: 0 0 0.5rem;
}

.hero-subtitle {
  font-size: 1.05rem;
  font-weight: 300;
  opacity: 0.82;
  margin: 0;
}

/* ── Content area ── */
.content-area {
  max-width: 900px;
  margin: 0 auto;
  padding: 3rem 1.5rem 5rem;
  display: flex;
  flex-direction: column;
  gap: 2.5rem;
}

/* ── Cards ── */
.card-section {
  background: var(--card-bg);
  border-radius: var(--radius);
  box-shadow: 0 2px 16px rgba(0, 68, 204, 0.08);
  padding: 2rem 2.2rem;
  position: relative;
  overflow: hidden;
  animation: fadeUp 0.5s ease both;
}

.card-section::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 4px;
  height: 100%;
  background: var(--blue);
  border-radius: 4px 0 0 4px;
}

.card-section:nth-child(2) {
  animation-delay: 0.08s;
}

.card-section:nth-child(3) {
  animation-delay: 0.16s;
}

.card-section:nth-child(4) {
  animation-delay: 0.24s;
}

@keyframes fadeUp {
  from {
    opacity: 0;
    transform: translateY(18px);
  }

  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.section-tag {
  font-size: 0.68rem;
  font-weight: 700;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--blue);
  margin-bottom: 0.6rem;
}

.card-section h2 {
  font-family: 'DM Serif Display', serif;
  font-size: 1.55rem;
  color: var(--blue-dark);
  margin: 0 0 0.9rem;
}

.card-section p {
  color: var(--muted);
  line-height: 1.75;
  margin: 0;
  font-size: 0.97rem;
}

/* ── Chapter buttons ── */
.chapters-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1.2rem;
  margin-top: 1.5rem;
}

@media (max-width: 640px) {
  .chapters-grid {
    grid-template-columns: 1fr;
  }
}

.chapter-btn {
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  gap: 0.5rem;
  text-decoration: none;
  background: linear-gradient(145deg, #f0f6ff 0%, #e4eeff 100%);
  border: 1.5px solid rgba(0, 68, 204, 0.14);
  border-radius: var(--radius);
  padding: 1.4rem 1.3rem 1.2rem;
  color: var(--text);
  transition: transform 0.22s ease, box-shadow 0.22s ease, border-color 0.22s ease;
  position: relative;
  overflow: hidden;
}

.chapter-btn::after {
  content: '→';
  position: absolute;
  bottom: 1rem;
  right: 1.1rem;
  font-size: 1.1rem;
  color: var(--blue);
  opacity: 0;
  transform: translateX(-6px);
  transition: opacity 0.22s, transform 0.22s;
}

.chapter-btn:hover {
  transform: translateY(-4px);
  box-shadow: 0 8px 28px rgba(0, 68, 204, 0.15);
  border-color: rgba(0, 68, 204, 0.35);
  color: var(--text);
  text-decoration: none;
}

.chapter-btn:hover::after {
  opacity: 1;
  transform: translateX(0);
}

.chapter-number {
  font-size: 0.68rem;
  font-weight: 700;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--blue);
  background: rgba(0, 68, 204, 0.09);
  padding: 0.2rem 0.55rem;
  border-radius: 100px;
}

.chapter-title {
  font-family: 'DM Serif Display', serif;
  font-size: 1.05rem;
  line-height: 1.25;
  color: var(--blue-dark);
}

.chapter-desc {
  font-size: 0.8rem;
  color: var(--muted);
  line-height: 1.5;
}