/* ============================================================
   WLD ON6WL — dB & dBm Cursus · Design System
   Waaslandse Radio Amateurs · ON6WL · on6wl.be
   ============================================================ */

@import url('https://fonts.googleapis.com/css2?family=Inter:wght@300;400;500;600;700;900&family=JetBrains+Mono:wght@400;500;700&display=swap');

/* ── Kleurenpalet WLD ON6WL ─────────────────────────────── */
:root {
  --navy:        #050D1A;
  --teal:        #00B4CC;
  --teal-dark:   #0A2342;
  --teal-dim:    rgba(0,180,204,0.12);
  --teal-mid:    rgba(0,180,204,0.25);
  --white:       #FFFFFF;
  --bg-light:    #F0F4F8;
  --text-dark:   #1A2332;
  --slate:       #6B7A99;
  --slate-light: #A8B5C9;
  --line:        #DEE2E6;
  --navy-mid:    #0A1628;
  --orange:      #FF6B35;
  --sky:         #7AB7DD;
  --green:       #22C55E;
  --green-dim:   rgba(34,197,94,0.12);
  --red-dim:     rgba(255,107,53,0.12);

  /* Lettertypen */
  --font:  'Inter', 'Trebuchet MS', Arial, sans-serif;
  --mono:  'JetBrains Mono', 'Consolas', monospace;

  /* Layout */
  --sidebar-w: 290px;
  --header-h:  60px;
  --content-max: 820px;

  /* Curves */
  --r-sm: 4px;
  --r-md: 8px;
  --r-lg: 12px;

  /* Transitions */
  --t: 0.2s ease;
}

/* ── Reset ───────────────────────────────────────────────── */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { font-size: 16px; scroll-behavior: smooth; }
body {
  font-family: var(--font);
  background: var(--bg-light);
  color: var(--text-dark);
  line-height: 1.65;
  min-height: 100vh;
}
a { color: var(--teal); text-decoration: none; transition: color var(--t); }
a:hover { color: var(--teal-dark); }
img, svg { max-width: 100%; display: block; }
::selection { background: var(--teal); color: var(--white); }

/* ── Taallagen ───────────────────────────────────────────── */
.lang { display: none; }
.lang.active { display: contents; }
.lang-block { display: none; }
.lang-block.active { display: block; }

/* ── Login pagina ────────────────────────────────────────── */
.login-page {
  min-height: 100vh;
  background: var(--navy);
  display: flex;
  align-items: center;
  justify-content: center;
  position: relative;
  overflow: hidden;
}

.login-waves {
  position: absolute;
  bottom: 0;
  left: 0;
  width: 100%;
  pointer-events: none;
}

.login-card {
  background: var(--teal-dark);
  border: 1px solid rgba(0,180,204,0.2);
  border-radius: var(--r-lg);
  padding: 48px 52px;
  width: 100%;
  max-width: 520px;
  position: relative;
  z-index: 10;
  box-shadow: 0 24px 64px rgba(0,0,0,0.5);
}

.login-logo {
  display: flex;
  align-items: center;
  gap: 16px;
  margin-bottom: 32px;
  padding-bottom: 24px;
  border-bottom: 1px solid rgba(0,180,204,0.2);
}
.login-logo-wld {
  font-family: 'Arial Black', Impact, sans-serif;
  font-size: 2.8rem;
  font-weight: 900;
  color: var(--white);
  letter-spacing: -2px;
  line-height: 1;
}
.login-logo-bar {
  width: 3px;
  height: 48px;
  background: var(--teal);
  border-radius: 2px;
  flex-shrink: 0;
}
.login-logo-info { display: flex; flex-direction: column; gap: 2px; }
.login-logo-sub {
  font-size: 0.7rem;
  font-weight: 700;
  letter-spacing: 0.12em;
  color: var(--teal);
  text-transform: uppercase;
}
.login-logo-name {
  font-size: 0.9rem;
  font-weight: 600;
  color: var(--slate-light);
}

.login-title {
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--white);
  margin-bottom: 8px;
}
.login-subtitle {
  font-size: 0.9rem;
  color: var(--slate);
  margin-bottom: 32px;
  line-height: 1.5;
}

.login-label {
  display: block;
  font-size: 0.78rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--slate-light);
  margin-bottom: 8px;
}

.login-input {
  width: 100%;
  background: var(--navy);
  border: 1.5px solid rgba(0,180,204,0.3);
  border-radius: var(--r-sm);
  padding: 12px 16px;
  color: var(--white);
  font-family: var(--mono);
  font-size: 1.1rem;
  font-weight: 700;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  outline: none;
  transition: border-color var(--t);
  margin-bottom: 24px;
}
.login-input:focus { border-color: var(--teal); }
.login-input::placeholder { color: var(--slate); font-weight: 400; text-transform: none; letter-spacing: 0; }

.login-lang-label {
  font-size: 0.78rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--slate-light);
  margin-bottom: 12px;
}

.login-lang-grid {
  display: grid;
  grid-template-columns: 1fr 1fr 1fr;
  gap: 10px;
  margin-bottom: 32px;
}

.lang-btn {
  padding: 14px 8px;
  border: 1.5px solid rgba(0,180,204,0.2);
  border-radius: var(--r-sm);
  background: var(--navy);
  cursor: pointer;
  text-align: center;
  transition: all var(--t);
  color: var(--slate-light);
}
.lang-btn:hover { border-color: var(--teal); color: var(--white); }
.lang-btn.selected {
  border-color: var(--teal);
  background: var(--teal-dim);
  color: var(--teal);
}
.lang-btn-flag { font-size: 1.6rem; display: block; margin-bottom: 4px; }
.lang-btn-name { font-size: 0.75rem; font-weight: 700; letter-spacing: 0.05em; text-transform: uppercase; }

.btn-start {
  width: 100%;
  padding: 14px;
  background: var(--teal);
  color: var(--white);
  font-family: var(--font);
  font-size: 0.95rem;
  font-weight: 700;
  letter-spacing: 0.04em;
  border: none;
  border-radius: var(--r-sm);
  cursor: pointer;
  transition: background var(--t), transform var(--t);
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
}
.btn-start:hover { background: var(--teal-dark); transform: translateY(-2px); }

/* ── App Shell ───────────────────────────────────────────── */
.app-header {
  position: fixed;
  top: 0; left: 0; right: 0;
  height: var(--header-h);
  background: var(--navy);
  border-bottom: 1px solid rgba(0,180,204,0.15);
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 24px;
  z-index: 200;
  gap: 16px;
}

.header-logo {
  display: flex;
  align-items: center;
  gap: 10px;
  flex-shrink: 0;
}
.header-logo-wld {
  font-family: 'Arial Black', Impact, sans-serif;
  font-size: 1.4rem;
  font-weight: 900;
  color: var(--white);
  letter-spacing: -1px;
  line-height: 1;
}
.header-logo-sep { width: 2px; height: 28px; background: var(--teal); border-radius: 1px; }
.header-logo-title {
  font-size: 0.82rem;
  font-weight: 600;
  color: var(--slate-light);
  max-width: 200px;
  line-height: 1.3;
}

.header-center {
  flex: 1;
  display: flex;
  align-items: center;
  justify-content: center;
}

.header-progress-wrap {
  width: 100%;
  max-width: 360px;
  display: flex;
  flex-direction: column;
  gap: 4px;
}
.header-progress-label {
  font-size: 0.72rem;
  color: var(--slate);
  display: flex;
  justify-content: space-between;
  font-weight: 500;
}
.header-progress-track {
  background: var(--teal-dark);
  height: 5px;
  border-radius: 100px;
  overflow: hidden;
}
.header-progress-fill {
  background: linear-gradient(90deg, var(--teal), var(--sky));
  height: 100%;
  border-radius: 100px;
  transition: width 0.6s cubic-bezier(.4,0,.2,1);
}

.header-right {
  display: flex;
  align-items: center;
  gap: 12px;
  flex-shrink: 0;
}

.header-callsign {
  font-family: var(--mono);
  font-size: 0.82rem;
  font-weight: 700;
  color: var(--teal);
  background: var(--teal-dim);
  border: 1px solid rgba(0,180,204,0.3);
  border-radius: var(--r-sm);
  padding: 4px 10px;
  letter-spacing: 0.06em;
}

.lang-switcher {
  display: flex;
  gap: 4px;
}
.lang-switch-btn {
  padding: 4px 9px;
  border: 1px solid rgba(0,180,204,0.2);
  border-radius: var(--r-sm);
  background: transparent;
  color: var(--slate);
  font-size: 0.75rem;
  font-weight: 700;
  cursor: pointer;
  transition: all var(--t);
  letter-spacing: 0.04em;
}
.lang-switch-btn:hover { border-color: var(--teal); color: var(--teal); }
.lang-switch-btn.active { background: var(--teal); border-color: var(--teal); color: var(--white); }

.menu-toggle {
  display: none;
  background: transparent;
  border: 1px solid rgba(0,180,204,0.3);
  border-radius: var(--r-sm);
  color: var(--teal);
  padding: 6px 10px;
  font-size: 1rem;
  cursor: pointer;
}

/* ── Sidebar ─────────────────────────────────────────────── */
.app-sidebar {
  position: fixed;
  top: var(--header-h);
  left: 0;
  bottom: 0;
  width: var(--sidebar-w);
  background: var(--white);
  border-right: 1px solid var(--line);
  overflow-y: auto;
  z-index: 100;
  display: flex;
  flex-direction: column;
}

.sidebar-section {
  padding: 20px 16px 8px;
}

.sidebar-section-label {
  font-size: 0.68rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--slate-light);
  padding: 0 8px 6px;
  border-bottom: 1px solid var(--line);
  margin-bottom: 4px;
  display: flex;
  align-items: center;
  gap: 8px;
}
.sidebar-section-num {
  font-family: var(--mono);
  font-size: 0.65rem;
  font-weight: 700;
  color: var(--teal);
  background: var(--teal-dim);
  border-radius: 3px;
  padding: 1px 5px;
}

.sidebar-nav { list-style: none; }
.sidebar-nav li a {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 7px 8px;
  border-radius: var(--r-sm);
  color: var(--slate);
  font-size: 0.845rem;
  font-weight: 500;
  transition: all var(--t);
  line-height: 1.35;
  text-decoration: none;
  border-left: 2px solid transparent;
}
.sidebar-nav li a:hover {
  background: var(--teal-dim);
  color: var(--text-dark);
  border-left-color: var(--teal);
}
.sidebar-nav li a.active {
  background: var(--teal-dim);
  color: var(--text-dark);
  border-left-color: var(--teal);
  font-weight: 600;
}
.nav-ch-num {
  font-family: var(--mono);
  font-size: 0.68rem;
  color: var(--slate-light);
  min-width: 24px;
  flex-shrink: 0;
}
.nav-status { margin-left: auto; flex-shrink: 0; }
.nav-status.done { color: var(--green); font-size: 0.8rem; }
.nav-status.active { color: var(--teal); font-size: 0.7rem; font-weight: 700; }

/* ── Hoofdinhoud ─────────────────────────────────────────── */
.app-main {
  margin-left: var(--sidebar-w);
  margin-top: var(--header-h);
  min-height: calc(100vh - var(--header-h));
  background: var(--bg-light);
}

.main-inner {
  max-width: var(--content-max);
  margin: 0 auto;
  padding: 44px 48px 80px;
}

/* ── Dashboard homepagina ────────────────────────────────── */
.dash-hero {
  background: var(--navy);
  border-radius: var(--r-lg);
  padding: 48px 52px 0;
  margin-bottom: 36px;
  overflow: hidden;
  position: relative;
}
.dash-hero-label {
  font-size: 0.72rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.12em;
  color: var(--teal);
  margin-bottom: 12px;
}
.dash-hero h1 {
  font-size: clamp(1.8rem, 3.5vw, 2.6rem);
  font-weight: 900;
  color: var(--white);
  line-height: 1.15;
  margin-bottom: 16px;
}
.dash-hero h1 span { color: var(--teal); }
.dash-hero-sub {
  font-size: 1rem;
  color: var(--slate-light);
  max-width: 500px;
  line-height: 1.65;
  margin-bottom: 28px;
}
.dash-hero-actions { display: flex; gap: 12px; flex-wrap: wrap; margin-bottom: 40px; }
.dash-hero-waves { display: block; width: 100%; height: 60px; }

/* ── Voortgangsbalk dashboard ────────────────────────────── */
.progress-card {
  background: var(--white);
  border: 1px solid var(--line);
  border-radius: var(--r-lg);
  padding: 24px 28px;
  margin-bottom: 32px;
  display: flex;
  align-items: center;
  gap: 24px;
  box-shadow: 0 2px 8px rgba(0,0,0,0.05);
}
.progress-circle-wrap { flex-shrink: 0; }
.progress-circle {
  width: 72px;
  height: 72px;
  border-radius: 50%;
  background: conic-gradient(var(--teal) 0deg, var(--bg-light) 0deg);
  display: flex;
  align-items: center;
  justify-content: center;
  position: relative;
}
.progress-circle::before {
  content: '';
  position: absolute;
  width: 52px; height: 52px;
  background: var(--white);
  border-radius: 50%;
}
.progress-pct {
  position: relative;
  z-index: 1;
  font-family: var(--mono);
  font-size: 0.95rem;
  font-weight: 700;
  color: var(--teal);
}
.progress-info { flex: 1; }
.progress-info h3 { font-size: 1rem; font-weight: 700; color: var(--text-dark); margin-bottom: 4px; }
.progress-info p { font-size: 0.85rem; color: var(--slate); }
.progress-bar-track {
  margin-top: 10px;
  background: var(--bg-light);
  border-radius: 100px;
  height: 7px;
  overflow: hidden;
}
.progress-bar-fill {
  background: linear-gradient(90deg, var(--teal), var(--sky));
  height: 100%;
  border-radius: 100px;
  transition: width 0.7s cubic-bezier(.4,0,.2,1);
}

/* ── Leerpad stages ──────────────────────────────────────── */
.leerpad-wrap {
  background: var(--white);
  border: 1px solid var(--line);
  border-radius: var(--r-lg);
  padding: 24px 28px;
  margin-bottom: 32px;
  box-shadow: 0 2px 8px rgba(0,0,0,0.05);
}
.leerpad-title {
  font-size: 0.72rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--slate);
  margin-bottom: 16px;
}
.leerpad-stages {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  align-items: center;
}
.stage {
  display: flex;
  align-items: center;
  gap: 6px;
  padding: 6px 14px;
  border: 1px solid var(--line);
  border-radius: 100px;
  font-size: 0.8rem;
  font-weight: 600;
  color: var(--slate);
  background: var(--bg-light);
  transition: all var(--t);
}
.stage.active { background: var(--teal-dim); border-color: var(--teal); color: var(--teal); }
.stage.done { background: var(--green-dim); border-color: var(--green); color: #15803d; }
.stage-arrow { color: var(--slate-light); font-size: 0.75rem; }

/* ── Hoofdstuk-kaarten grid ──────────────────────────────── */
.section-title {
  font-size: 0.72rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--slate);
  margin-bottom: 16px;
  margin-top: 32px;
  padding-bottom: 8px;
  border-bottom: 1px solid var(--line);
  display: flex;
  align-items: center;
  gap: 10px;
}
.section-title-num {
  font-family: var(--mono);
  font-size: 0.65rem;
  font-weight: 700;
  color: var(--teal);
  background: var(--teal-dim);
  border-radius: 3px;
  padding: 2px 6px;
}

.chapter-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
  gap: 14px;
  margin-bottom: 8px;
}

.chapter-card {
  background: var(--white);
  border: 1px solid var(--line);
  border-left: 4px solid var(--teal);
  border-radius: var(--r-md);
  padding: 18px 20px;
  display: block;
  text-decoration: none;
  transition: all var(--t);
  box-shadow: 0 2px 8px rgba(0,0,0,0.05);
  position: relative;
}
.chapter-card:hover {
  border-left-color: var(--teal);
  box-shadow: 0 6px 20px rgba(0,0,0,0.1);
  transform: translateY(-2px);
  text-decoration: none;
}
.chapter-card.done { border-left-color: var(--green); }
.chapter-card.stub { opacity: 0.6; cursor: default; pointer-events: none; }

.card-top { display: flex; align-items: center; gap: 8px; margin-bottom: 8px; }
.card-num {
  font-family: var(--mono);
  font-size: 0.7rem;
  font-weight: 700;
  color: var(--slate-light);
}
.card-badge {
  font-size: 0.65rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.07em;
  padding: 2px 8px;
  border-radius: 100px;
  background: var(--teal-dim);
  color: var(--teal);
  border: 1px solid rgba(0,180,204,0.3);
}
.card-badge.beginner { background: var(--teal-dim); color: var(--teal); border-color: rgba(0,180,204,0.3); }
.card-badge.basis { background: rgba(122,183,221,0.15); color: #2563eb; border-color: rgba(37,99,235,0.2); }
.card-badge.praktijk { background: rgba(255,107,53,0.12); color: var(--orange); border-color: rgba(255,107,53,0.25); }
.card-status-done { margin-left: auto; color: var(--green); font-size: 0.9rem; }

.chapter-card h3 { font-size: 0.93rem; font-weight: 700; color: var(--text-dark); margin-bottom: 6px; line-height: 1.35; }
.chapter-card p { font-size: 0.8rem; color: var(--slate); line-height: 1.5; }

/* ── Hoofdstukpagina ─────────────────────────────────────── */
.chapter-header {
  background: var(--navy);
  margin: -44px -48px 0;
  padding: 36px 52px 0;
  position: relative;
  overflow: hidden;
}
.ch-header-meta { display: flex; align-items: center; gap: 10px; margin-bottom: 14px; flex-wrap: wrap; }
.ch-breadcrumb {
  font-size: 0.75rem;
  color: var(--slate);
  display: flex;
  align-items: center;
  gap: 6px;
}
.ch-breadcrumb a { color: var(--teal); font-size: 0.75rem; }
.ch-breadcrumb span { color: var(--slate); }

.ch-badge {
  font-size: 0.68rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  padding: 3px 10px;
  border-radius: 100px;
  border: 1px solid;
}
.ch-badge-num { color: var(--teal); border-color: rgba(0,180,204,0.4); background: var(--teal-dim); }
.ch-badge-deel { color: var(--slate-light); border-color: rgba(168,181,201,0.3); background: rgba(168,181,201,0.08); }
.ch-badge-level { color: var(--teal); border-color: rgba(0,180,204,0.3); background: var(--teal-dim); }

.chapter-header h1 {
  font-size: clamp(1.5rem, 3vw, 2.1rem);
  font-weight: 900;
  color: var(--white);
  line-height: 1.15;
  margin-bottom: 12px;
}
.chapter-header .intro {
  font-size: 1rem;
  color: var(--slate-light);
  max-width: 620px;
  line-height: 1.65;
  margin-bottom: 32px;
}
.ch-header-waves { display: block; width: 100%; height: 44px; }

.chapter-body { padding-top: 36px; }

/* ── Leerdoelen ──────────────────────────────────────────── */
.leerdoelen {
  background: var(--white);
  border: 1px solid var(--line);
  border-top: 3px solid var(--teal);
  border-radius: var(--r-md);
  padding: 22px 26px;
  margin-bottom: 36px;
  box-shadow: 0 2px 8px rgba(0,0,0,0.05);
}
.leerdoelen-header {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 0.78rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--teal);
  margin-bottom: 14px;
}
.leerdoelen ul { list-style: none; display: flex; flex-direction: column; gap: 6px; }
.leerdoelen li {
  display: flex;
  align-items: flex-start;
  gap: 10px;
  font-size: 0.92rem;
  color: var(--text-dark);
  line-height: 1.5;
}
.leerdoelen li::before {
  content: '✓';
  color: var(--teal);
  font-weight: 700;
  flex-shrink: 0;
  margin-top: 1px;
}

/* ── Typografie in inhoud ────────────────────────────────── */
.chapter-body h2 {
  font-size: 1.35rem;
  font-weight: 700;
  color: var(--text-dark);
  margin: 40px 0 16px;
  padding-bottom: 10px;
  border-bottom: 1px solid var(--line);
  display: flex;
  align-items: center;
  gap: 10px;
}
.chapter-body h2 .section-num {
  font-family: var(--mono);
  font-size: 0.8rem;
  font-weight: 700;
  color: var(--teal);
  background: var(--teal-dim);
  padding: 2px 8px;
  border-radius: 4px;
  flex-shrink: 0;
}
.chapter-body h3 { font-size: 1.05rem; font-weight: 700; color: var(--text-dark); margin: 28px 0 10px; }
.chapter-body h4 { font-size: 0.95rem; font-weight: 700; color: var(--text-dark); margin: 20px 0 8px; }
.chapter-body p { margin-bottom: 14px; font-size: 0.96rem; color: var(--text-dark); }
.chapter-body ul, .chapter-body ol { padding-left: 22px; margin-bottom: 14px; }
.chapter-body li { font-size: 0.96rem; color: var(--text-dark); margin-bottom: 4px; line-height: 1.6; }

/* ── Formule-blokken ─────────────────────────────────────── */
.formula-block {
  background: var(--navy);
  border: 1px solid rgba(0,180,204,0.25);
  border-left: 5px solid var(--teal);
  border-radius: var(--r-md);
  padding: 22px 28px;
  margin: 24px 0;
}
.formula-label {
  font-size: 0.7rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--teal);
  margin-bottom: 12px;
  display: flex;
  align-items: center;
  gap: 8px;
}
.formula-main {
  font-family: var(--mono);
  font-size: 1.25rem;
  font-weight: 500;
  color: var(--white);
  line-height: 2;
  margin-bottom: 12px;
}
.formula-main .f-key { color: var(--teal); font-weight: 700; }
.formula-main .f-op  { color: var(--sky); }
.formula-vars {
  border-top: 1px solid rgba(0,180,204,0.15);
  padding-top: 10px;
  display: flex;
  flex-direction: column;
  gap: 4px;
}
.formula-var {
  font-size: 0.82rem;
  color: var(--slate-light);
  display: flex;
  gap: 8px;
}
.formula-var code {
  font-family: var(--mono);
  color: var(--teal);
  font-size: 0.82rem;
  background: rgba(0,180,204,0.1);
  padding: 0 4px;
  border-radius: 3px;
  white-space: nowrap;
  flex-shrink: 0;
}

/* ── Callout blokken ─────────────────────────────────────── */
.callout {
  border-radius: var(--r-md);
  padding: 18px 22px;
  margin: 24px 0;
  border: 1px solid;
}
.callout-header {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 0.75rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  margin-bottom: 8px;
}
.callout p { font-size: 0.92rem; margin: 0; line-height: 1.6; }
.callout p + p { margin-top: 8px; }
.callout strong { font-weight: 700; }

.callout-key { background: var(--teal-dim); border-color: rgba(0,180,204,0.35); }
.callout-key .callout-header { color: var(--teal); }
.callout-key p { color: var(--teal-dark); }

.callout-warning { background: var(--red-dim); border-color: rgba(255,107,53,0.35); }
.callout-warning .callout-header { color: var(--orange); }
.callout-warning p { color: #7a2d00; }

.callout-tip { background: var(--green-dim); border-color: rgba(34,197,94,0.35); }
.callout-tip .callout-header { color: #15803d; }
.callout-tip p { color: #14532d; }

.callout-shack { background: rgba(122,183,221,0.12); border-color: rgba(122,183,221,0.35); }
.callout-shack .callout-header { color: #1d4ed8; }
.callout-shack p { color: #1e3a5f; }

/* ── Tabellen ────────────────────────────────────────────── */
.table-wrap { overflow-x: auto; margin: 20px 0; border-radius: var(--r-md); box-shadow: 0 2px 8px rgba(0,0,0,0.06); }
table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.88rem;
  background: var(--white);
}
thead tr { background: var(--navy); }
th {
  padding: 11px 16px;
  text-align: left;
  font-size: 0.72rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--teal);
  border-bottom: 2px solid rgba(0,180,204,0.3);
  white-space: nowrap;
}
td {
  padding: 10px 16px;
  border-bottom: 1px solid var(--line);
  color: var(--text-dark);
  line-height: 1.5;
  vertical-align: middle;
}
tbody tr:last-child td { border-bottom: none; }
tbody tr:nth-child(even) td { background: var(--bg-light); }
tbody tr:hover td { background: var(--teal-dim); }
td.mono, td.val {
  font-family: var(--mono);
  font-size: 0.88rem;
  color: var(--teal);
  font-weight: 600;
  white-space: nowrap;
}
td.green { color: #15803d; font-weight: 600; }
td.orange { color: var(--orange); font-weight: 600; }
td.red-text { color: #c0392b; font-weight: 600; }
td.check { color: var(--green); font-size: 1rem; }
td.cross { color: var(--orange); font-size: 1rem; }

/* ── Voorbeeldblokken ────────────────────────────────────── */
.example-block {
  background: var(--white);
  border: 1px solid var(--line);
  border-top: 3px solid var(--sky);
  border-radius: var(--r-md);
  padding: 20px 24px;
  margin: 24px 0;
  box-shadow: 0 2px 8px rgba(0,0,0,0.05);
}
.example-title {
  font-size: 0.72rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--sky);
  margin-bottom: 14px;
  display: flex;
  align-items: center;
  gap: 8px;
}
.example-steps { list-style: none; counter-reset: step; }
.example-steps li {
  counter-increment: step;
  display: grid;
  grid-template-columns: 28px 1fr;
  gap: 10px;
  padding: 8px 0;
  border-bottom: 1px solid var(--line);
  font-size: 0.9rem;
  line-height: 1.55;
  color: var(--text-dark);
  align-items: start;
}
.example-steps li:last-child { border-bottom: none; }
.example-steps li::before {
  content: counter(step);
  font-family: var(--mono);
  font-size: 0.7rem;
  font-weight: 700;
  color: var(--white);
  background: var(--teal);
  border-radius: 50%;
  width: 22px;
  height: 22px;
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
  margin-top: 1px;
}
.example-steps li code {
  font-family: var(--mono);
  font-size: 0.88rem;
  color: var(--teal);
  background: var(--teal-dim);
  padding: 1px 5px;
  border-radius: 3px;
}

/* ── Oefeningen ──────────────────────────────────────────── */
.exercise-section {
  background: var(--white);
  border: 1px solid var(--line);
  border-radius: var(--r-lg);
  padding: 28px 32px;
  margin: 40px 0;
  box-shadow: 0 2px 8px rgba(0,0,0,0.05);
}
.exercise-section-title {
  font-size: 1.15rem;
  font-weight: 700;
  color: var(--text-dark);
  margin-bottom: 20px;
  display: flex;
  align-items: center;
  gap: 10px;
  padding-bottom: 12px;
  border-bottom: 1px solid var(--line);
}

.exercise {
  background: var(--bg-light);
  border: 1px solid var(--line);
  border-radius: var(--r-md);
  padding: 18px 22px;
  margin-bottom: 14px;
}
.ex-top { display: flex; align-items: center; gap: 10px; margin-bottom: 10px; flex-wrap: wrap; }
.ex-num {
  font-family: var(--mono);
  font-size: 0.7rem;
  font-weight: 700;
  color: var(--teal);
  background: var(--teal-dim);
  padding: 2px 8px;
  border-radius: 3px;
}
.ex-diff { display: flex; gap: 2px; }
.ex-diff span { font-size: 0.7rem; color: var(--line); }
.ex-diff span.lit { color: var(--teal); }

.ex-question { font-size: 0.93rem; color: var(--text-dark); line-height: 1.6; margin-bottom: 12px; }

.solution-btn {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 7px 16px;
  background: var(--teal-dim);
  border: 1px solid rgba(0,180,204,0.35);
  border-radius: var(--r-sm);
  color: var(--teal);
  font-size: 0.82rem;
  font-weight: 700;
  cursor: pointer;
  transition: all var(--t);
  font-family: var(--font);
}
.solution-btn:hover { background: var(--teal); color: var(--white); }
.solution-content {
  display: none;
  margin-top: 14px;
  background: var(--white);
  border: 1px solid var(--line);
  border-radius: var(--r-sm);
  padding: 16px 20px;
  font-size: 0.9rem;
  color: var(--text-dark);
  line-height: 1.65;
}
.solution-content.visible { display: block; }
.solution-content code { font-family: var(--mono); font-size: 0.88rem; color: var(--teal); background: var(--teal-dim); padding: 1px 5px; border-radius: 3px; }

/* ── dB-schaalvisual ─────────────────────────────────────── */
.db-scale {
  background: var(--white);
  border: 1px solid var(--line);
  border-radius: var(--r-md);
  overflow: hidden;
  margin: 20px 0;
  box-shadow: 0 2px 8px rgba(0,0,0,0.05);
}
.db-scale-head {
  background: var(--navy);
  display: grid;
  grid-template-columns: 90px 1fr 160px;
  gap: 12px;
  padding: 9px 16px;
  font-size: 0.68rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--teal);
  border-bottom: 1px solid rgba(0,180,204,0.2);
}
.db-scale-row {
  display: grid;
  grid-template-columns: 90px 1fr 160px;
  gap: 12px;
  padding: 9px 16px;
  border-bottom: 1px solid var(--line);
  align-items: center;
  font-size: 0.88rem;
  transition: background var(--t);
}
.db-scale-row:last-child { border-bottom: none; }
.db-scale-row:hover { background: var(--teal-dim); }
.db-val { font-family: var(--mono); font-size: 0.95rem; font-weight: 700; }
.db-val.pos { color: var(--green); }
.db-val.neg { color: var(--orange); }
.db-val.zero { color: var(--slate); }
.db-bar { height: 8px; background: var(--line); border-radius: 100px; overflow: hidden; }
.db-bar-fill { height: 100%; border-radius: 100px; }
.db-bar-fill.pos { background: linear-gradient(90deg, var(--teal), var(--green)); }
.db-bar-fill.neg { background: linear-gradient(90deg, var(--orange), #ff9a6c); }
.db-ratio { font-family: var(--mono); color: var(--slate); font-size: 0.82rem; text-align: right; }
.db-meaning { color: var(--text-dark); font-size: 0.85rem; }

/* ── Samenvatting ────────────────────────────────────────── */
.summary-box {
  background: var(--navy);
  border-radius: var(--r-lg);
  padding: 28px 32px;
  margin: 40px 0;
  position: relative;
  overflow: hidden;
}
.summary-box::before {
  content: '';
  position: absolute;
  left: 0; top: 0; bottom: 0;
  width: 5px;
  background: var(--teal);
}
.summary-box h3 {
  font-size: 0.95rem;
  font-weight: 700;
  color: var(--teal);
  margin-bottom: 16px;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  font-size: 0.78rem;
}
.summary-box ul { list-style: none; display: flex; flex-direction: column; gap: 8px; }
.summary-box li {
  display: flex;
  align-items: flex-start;
  gap: 10px;
  font-size: 0.9rem;
  color: var(--slate-light);
  line-height: 1.5;
  padding-bottom: 8px;
  border-bottom: 1px solid rgba(0,180,204,0.1);
}
.summary-box li:last-child { border-bottom: none; padding-bottom: 0; }
.summary-box li::before { content: '✓'; color: var(--teal); font-weight: 700; flex-shrink: 0; margin-top: 1px; }
.summary-box strong { color: var(--white); }

/* ── Geheugensteun ───────────────────────────────────────── */
.memory-box {
  background: linear-gradient(135deg, var(--teal-dark), #0a1e35);
  border: 1px solid rgba(0,180,204,0.3);
  border-radius: var(--r-md);
  padding: 22px 26px;
  margin: 24px 0;
}
.memory-header {
  font-size: 0.72rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--teal);
  margin-bottom: 12px;
  display: flex;
  align-items: center;
  gap: 8px;
}
.memory-content {
  font-family: var(--mono);
  font-size: 1rem;
  color: var(--white);
  line-height: 1.9;
}
.memory-content span { color: var(--teal); font-weight: 700; }

/* ── Voltooiing-knop ─────────────────────────────────────── */
.complete-area {
  text-align: center;
  padding: 40px 0 20px;
  border-top: 1px solid var(--line);
  margin-top: 40px;
}
.complete-area p { font-size: 0.88rem; color: var(--slate); margin-bottom: 14px; }
.btn-complete {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 12px 28px;
  background: var(--green);
  color: var(--white);
  font-family: var(--font);
  font-size: 0.9rem;
  font-weight: 700;
  border: none;
  border-radius: var(--r-sm);
  cursor: pointer;
  transition: all var(--t);
  letter-spacing: 0.03em;
}
.btn-complete:hover { background: #16a34a; transform: translateY(-2px); }
.btn-complete.done { background: var(--teal); cursor: default; }

/* ── Hoofstuk navigatie onderaan ────────────────────────── */
.chapter-nav-footer {
  display: flex;
  justify-content: space-between;
  gap: 16px;
  padding-top: 32px;
  border-top: 1px solid var(--line);
  margin-top: 40px;
  flex-wrap: wrap;
}
.ch-nav-btn {
  display: flex;
  flex-direction: column;
  padding: 14px 18px;
  background: var(--white);
  border: 1px solid var(--line);
  border-radius: var(--r-md);
  text-decoration: none;
  transition: all var(--t);
  max-width: 240px;
  box-shadow: 0 2px 8px rgba(0,0,0,0.05);
}
.ch-nav-btn:hover { border-color: var(--teal); box-shadow: 0 4px 16px rgba(0,0,0,0.1); transform: translateY(-2px); text-decoration: none; }
.ch-nav-btn .dir { font-size: 0.7rem; font-weight: 700; text-transform: uppercase; letter-spacing: 0.07em; color: var(--slate); margin-bottom: 4px; }
.ch-nav-btn .name { font-size: 0.88rem; font-weight: 600; color: var(--text-dark); line-height: 1.35; }
.ch-nav-btn.right { text-align: right; }

/* ── Buttons algemeen ────────────────────────────────────── */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 10px 22px;
  border-radius: var(--r-sm);
  font-family: var(--font);
  font-size: 0.88rem;
  font-weight: 700;
  cursor: pointer;
  transition: all var(--t);
  border: none;
  letter-spacing: 0.04em;
  text-decoration: none;
}
.btn-primary { background: var(--teal); color: var(--white); }
.btn-primary:hover { background: var(--teal-dark); transform: translateY(-2px); color: var(--white); text-decoration: none; }
.btn-outline { background: transparent; color: var(--teal); border: 1.5px solid var(--teal); }
.btn-outline:hover { background: var(--teal); color: var(--white); text-decoration: none; }
.btn-ghost { background: rgba(255,255,255,0.1); color: var(--slate-light); border: 1px solid rgba(255,255,255,0.15); }
.btn-ghost:hover { background: rgba(255,255,255,0.18); color: var(--white); text-decoration: none; }

/* ── Code inline ─────────────────────────────────────────── */
code {
  font-family: var(--mono);
  font-size: 0.87em;
  background: var(--teal-dim);
  color: var(--teal);
  padding: 1px 5px;
  border-radius: 3px;
}

/* ── Divider ─────────────────────────────────────────────── */
.section-divider { border: none; border-top: 1px solid var(--line); margin: 36px 0; }

/* ── Footer ──────────────────────────────────────────────── */
.app-footer {
  margin-left: var(--sidebar-w);
  background: var(--navy);
  padding: 20px 48px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 12px;
}
.footer-logo-row { display: flex; align-items: center; gap: 10px; }
.footer-wld { font-family: 'Arial Black', Impact, sans-serif; font-size: 1.1rem; font-weight: 900; color: var(--white); letter-spacing: -1px; }
.footer-sep { width: 2px; height: 18px; background: var(--teal); border-radius: 1px; }
.footer-info { font-size: 0.78rem; color: var(--slate); }
.footer-right { font-size: 0.75rem; color: var(--slate); text-align: right; }
.footer-right a { color: var(--teal); font-size: 0.75rem; }

/* ── RF-golven hero SVG ──────────────────────────────────── */
@keyframes wPulse1 { 0%,100%{opacity:.5} 50%{opacity:.78} }
@keyframes wPulse2 { 0%,100%{opacity:.22} 50%{opacity:.45} }
@keyframes wPulse3 { 0%,100%{opacity:.14} 50%{opacity:.28} }
@keyframes tbGlow  { 0%,100%{opacity:.75} 50%{opacity:1} }
.rf-w1 { animation: wPulse1 3.5s ease-in-out infinite; }
.rf-w2 { animation: wPulse2 5s ease-in-out infinite 0.6s; }
.rf-w3 { animation: wPulse3 6.5s ease-in-out infinite 1.3s; }

/* ── Utilities ───────────────────────────────────────────── */
.mt-sm { margin-top: 8px; }
.mt-md { margin-top: 16px; }
.mt-lg { margin-top: 28px; }
.mb-lg { margin-bottom: 28px; }
.text-muted { color: var(--slate); }
.text-teal { color: var(--teal); }
.text-sm { font-size: 0.85rem; }
.mono { font-family: var(--mono); }

/* ── Responsive ──────────────────────────────────────────── */
@media (max-width: 960px) {
  .app-sidebar {
    transform: translateX(-100%);
    transition: transform var(--t);
    z-index: 300;
  }
  .app-sidebar.open { transform: translateX(0); }
  .app-main, .app-footer { margin-left: 0; }
  .main-inner { padding: 28px 24px 60px; }
  .chapter-header { margin: -28px -24px 0; padding: 28px 24px 0; }
  .menu-toggle { display: flex !important; }
  .dash-hero { padding: 32px 28px 0; }
}

/* ── Print ───────────────────────────────────────────────── */
@media print {
  .app-header, .app-sidebar, .chapter-nav-footer, .complete-area, .solution-btn, .lang-switcher { display: none !important; }
  .app-main, .app-footer { margin-left: 0; }
  body, .chapter-body p, .chapter-body li { color: #000; }
  .chapter-header { background: #fff; }
  .chapter-header h1 { color: #000; }
  .formula-block { background: #f0f0f0; border-left: 4px solid #000; }
  .formula-main { color: #000; }
  .summary-box { background: #f0f0f0; }
  .summary-box li { color: #000; }
}

/* ── Zwevende sneltoetsenbalk (spiekfiche + PDF) ───────── */
  transform: translateY(-3px);
  box-shadow: 0 8px 28px rgba(0,0,0,0.28);
  text-decoration: none;
}
  background: var(--teal);
  color: var(--white);
}
  background: var(--navy);
  color: var(--teal);
  border: 1.5px solid rgba(0,180,204,0.35);
}

/* Modal overlay voor trigger warning */
.modal-overlay {
  position: fixed;
  inset: 0;
  background: rgba(5,13,26,0.82);
  z-index: 1000;
  display: none;
  align-items: center;
  justify-content: center;
  backdrop-filter: blur(3px);
}
.modal-overlay.visible { display: flex; }
.modal-card {
  background: var(--white);
  border-radius: var(--r-lg);
  padding: 36px 40px;
  max-width: 520px;
  width: 100%;
  margin: 20px;
  box-shadow: 0 24px 64px rgba(0,0,0,0.5);
  border-top: 4px solid var(--teal);
}
.modal-icon { font-size: 2.4rem; margin-bottom: 14px; }
.modal-title {
  font-size: 1.25rem;
  font-weight: 800;
  color: var(--text-dark);
  margin-bottom: 12px;
}
.modal-body {
  font-size: 0.92rem;
  color: var(--text-dark);
  line-height: 1.7;
  margin-bottom: 22px;
}
.modal-body strong { color: var(--text-dark); font-weight: 700; }
.modal-body ul { margin: 10px 0 0 18px; }
.modal-body li { margin-bottom: 4px; }
.modal-actions { display: flex; gap: 10px; justify-content: flex-end; flex-wrap: wrap; }
.modal-btn-cancel {
  padding: 9px 20px; background: var(--bg-light); border: 1px solid var(--line);
  border-radius: var(--r-sm); cursor: pointer; font-family: var(--font);
  font-size: 0.88rem; font-weight: 600; color: var(--slate); transition: all 0.15s;
}
.modal-btn-cancel:hover { background: var(--line); }
.modal-btn-confirm {
  padding: 9px 22px; background: var(--teal); border: none;
  border-radius: var(--r-sm); cursor: pointer; font-family: var(--font);
  font-size: 0.88rem; font-weight: 700; color: var(--white); transition: all 0.15s;
  display: flex; align-items: center; gap: 7px;
}
.modal-btn-confirm:hover { background: var(--teal-dark); }

@media (max-width: 640px) {
}
@media print {
}

 }

/* ── Header actieknoppen (spiekfiche + PDF) ─────────────────── */
.header-action-btn {
  display: inline-flex;
  align-items: center;
  gap: 5px;
  padding: 5px 11px;
  border-radius: var(--r-sm);
  font-family: var(--font);
  font-size: 0.75rem;
  font-weight: 700;
  cursor: pointer;
  transition: all var(--t);
  text-decoration: none;
  border: 1px solid;
  letter-spacing: 0.03em;
  white-space: nowrap;
}
.header-action-btn:hover { text-decoration: none; transform: translateY(-1px); }
.hab-teal {
  background: var(--teal-dim);
  border-color: rgba(0,180,204,.4);
  color: var(--teal);
}
.hab-teal:hover { background: var(--teal); color: var(--white); }
.hab-orange {
  background: rgba(255,107,53,.12);
  border-color: rgba(255,107,53,.4);
  color: var(--orange);
}
.hab-orange:hover { background: var(--orange); color: var(--white); }

/* ── PDF modal ───────────────────────────────────────────────── */
.pdf-modal-overlay {
  display: none;
  position: fixed; inset: 0;
  background: rgba(5,13,26,.85);
  z-index: 500;
  align-items: center;
  justify-content: center;
}
.pdf-modal-overlay.open { display: flex; }
.pdf-modal {
  background: var(--white);
  border-radius: var(--r-lg);
  padding: 32px 36px;
  max-width: 460px;
  width: 90%;
  box-shadow: 0 24px 64px rgba(0,0,0,.6);
}
.pdf-modal h2 {
  font-size: 1.15rem;
  font-weight: 700;
  color: var(--text-dark);
  margin-bottom: 12px;
  border: none;
  padding: 0;
}
.pdf-modal-warn {
  background: var(--red-dim);
  border: 1.5px solid rgba(255,107,53,.4);
  border-radius: var(--r-sm);
  padding: 12px 16px;
  font-size: .85rem;
  color: #7a2d00;
  line-height: 1.6;
  margin-bottom: 16px;
}
.pdf-modal-warn strong { color: var(--orange); }
.pdf-modal-body { font-size: .88rem; color: var(--text-dark); line-height: 1.6; margin-bottom: 20px; }
.pdf-modal-btns { display: flex; gap: 8px; flex-wrap: wrap; }
.pdf-dl-btn {
  flex: 1;
  padding: 9px 16px;
  background: var(--teal);
  color: var(--white);
  border: none;
  border-radius: var(--r-sm);
  font-family: var(--font);
  font-size: .85rem;
  font-weight: 700;
  cursor: pointer;
  text-decoration: none;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 6px;
  transition: background var(--t);
}
.pdf-dl-btn:hover { background: var(--teal-dark); color: var(--white); text-decoration: none; }
.pdf-dl-btn.docx { background: var(--teal-dark); font-size: .78rem; }
.pdf-dl-btn.docx:hover { background: #051828; }
.pdf-cancel-btn {
  padding: 9px 16px;
  background: var(--bg-light);
  color: var(--slate);
  border: 1px solid var(--line);
  border-radius: var(--r-sm);
  font-family: var(--font);
  font-size: .85rem;
  font-weight: 600;
  cursor: pointer;
  transition: all var(--t);
}
.pdf-cancel-btn:hover { background: var(--line); }

@media (max-width: 960px) {
  .header-action-btn span.hab-label { display: none; }
}
@media print { .pdf-modal-overlay { display: none !important; } }