:root {
  --bg: #0f172a;
  --surface: #1b2733;
  --surface-2: #24313f;
  --text: #f1f5f9;
  --muted: #94a3b8;
  --accent: #38bdf8;
  --accent-strong: #0ea5e9;
  --danger: #f87171;
  --ok: #4ade80;
  font-size: 18px;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: system-ui, -apple-system, "Segoe UI", sans-serif;
  min-height: 100vh;
}

.app-header {
  position: sticky;
  top: 0;
  z-index: 10;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0.75rem 1rem;
  background: var(--surface);
  border-bottom: 1px solid var(--surface-2);
}

.app-header h1 {
  font-size: 1.25rem;
  margin: 0;
}

.icon-button {
  background: none;
  border: none;
  color: var(--text);
  font-size: 1.75rem;
  line-height: 1;
  padding: 0.5rem;
  cursor: pointer;
}

main#app {
  padding: 1rem;
  padding-bottom: 4rem;
  max-width: 640px;
  margin: 0 auto;
}

button {
  font: inherit;
}

.btn {
  display: inline-block;
  background: var(--accent);
  color: #05202e;
  border: none;
  border-radius: 0.6rem;
  padding: 0.9rem 1.2rem;
  font-size: 1.1rem;
  font-weight: 600;
  min-height: 3rem;
  cursor: pointer;
  width: 100%;
  margin-bottom: 0.75rem;
}

.btn:active {
  background: var(--accent-strong);
}

.btn-secondary {
  background: var(--surface-2);
  color: var(--text);
}

.btn-danger {
  background: var(--danger);
  color: #2b0a0a;
}

.card {
  background: var(--surface);
  border-radius: 0.8rem;
  padding: 1rem;
  margin-bottom: 1rem;
}

.list-item {
  display: block;
  width: 100%;
  text-align: left;
  background: var(--surface);
  color: var(--text);
  border: none;
  border-radius: 0.6rem;
  padding: 0.9rem 1rem;
  margin-bottom: 0.6rem;
  font-size: 1rem;
  cursor: pointer;
}

.sessie-rij {
  display: flex;
  gap: 0.5rem;
  align-items: stretch;
  margin-bottom: 0.6rem;
}

.sessie-rij .list-item {
  flex: 1;
  margin-bottom: 0;
}

.sessie-rij .btn-danger {
  flex: 0 0 auto;
  width: auto;
  margin-bottom: 0;
}

.muted {
  color: var(--muted);
  font-size: 0.9rem;
}

label {
  display: block;
  margin: 0.75rem 0 0.3rem;
  font-size: 0.95rem;
  color: var(--muted);
}

input[type="text"],
input[type="number"],
input[type="date"],
input[type="password"],
textarea,
select {
  width: 100%;
  padding: 0.75rem;
  font-size: 1.2rem;
  border-radius: 0.5rem;
  border: 1px solid var(--surface-2);
  background: var(--surface-2);
  color: var(--text);
  min-height: 3rem;
}

textarea {
  min-height: 4.5rem;
  font-size: 1rem;
}

.checkbox-row {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  margin: 0.75rem 0;
}

.checkbox-row input[type="checkbox"] {
  width: 1.5rem;
  height: 1.5rem;
}

.groep-nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 0.5rem;
  margin-bottom: 0.75rem;
}

.groep-nav button {
  flex: 0 0 auto;
  width: auto;
  white-space: nowrap;
  padding: 0.9rem 0.9rem;
}

.groep-nav .letter {
  flex: 1;
  text-align: center;
  font-size: 1.5rem;
  font-weight: 700;
  white-space: nowrap;
}

.oefening-card {
  border: 1px solid var(--surface-2);
}

.set-row {
  display: grid;
  grid-template-columns: 2rem 1fr 1fr;
  gap: 0.5rem;
  align-items: center;
  margin-bottom: 0.5rem;
}

.set-row-2 {
  grid-template-columns: 2rem 1fr;
}

.set-row-4 {
  grid-template-columns: 2rem 1fr 1fr 1fr;
}

.set-row .set-nr {
  color: var(--muted);
  text-align: center;
}

.kop-rij {
  margin-bottom: 0.3rem;
}

.kop-rij span {
  font-size: 0.85rem;
  text-align: center;
}

.set-rij-wrapper {
  display: flex;
  align-items: center;
  gap: 0.4rem;
  margin-bottom: 0.5rem;
}

.set-rij-wrapper .set-row {
  flex: 1;
  margin-bottom: 0;
}

.set-verwijder,
.set-verwijder-spacer {
  flex: 0 0 auto;
  width: 2.2rem;
  height: 2.2rem;
  padding: 0;
  border-radius: 0.5rem;
  text-align: center;
  font-size: 1.2rem;
  line-height: 1;
}

.set-verwijder:disabled {
  opacity: 0.25;
  cursor: not-allowed;
}

.media-rij {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  margin: 0.5rem 0;
}

.media-rij .btn {
  width: auto;
  flex: 0 0 auto;
  margin-bottom: 0;
  text-decoration: none;
}

.afbeelding-overlay {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.75rem;
}

.afbeelding-popup {
  max-width: 100%;
  max-height: 70vh;
  object-fit: contain;
  border-radius: 0.5rem;
}

.groepen-overzicht {
  display: flex;
  flex-wrap: wrap;
  gap: 0.4rem;
  margin-bottom: 0.75rem;
}

.groep-pill {
  width: auto;
  flex: 0 0 auto;
  padding: 0.5rem 0.8rem;
  margin-bottom: 0;
}

.groep-pill.actief {
  background: var(--accent);
  color: #05202e;
}

.vorige-waarde {
  font-size: 0.85rem;
  color: var(--muted);
  margin-top: -0.2rem;
  margin-bottom: 0.4rem;
}

.timer {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  margin: 0.75rem 0;
}

.timer .countdown {
  font-size: 1.75rem;
  font-variant-numeric: tabular-nums;
  min-width: 4ch;
}

.progressie-prompt {
  background: var(--surface-2);
  border-radius: 0.6rem;
  padding: 0.75rem;
  margin-top: 0.5rem;
}

.progressie-prompt .keuzes {
  display: flex;
  gap: 0.5rem;
  margin-top: 0.5rem;
}

.progressie-prompt .keuzes .btn {
  margin-bottom: 0;
}

.error-message {
  color: var(--danger);
  margin: 0.5rem 0;
}

.overlay {
  position: fixed;
  inset: 0;
  background: rgba(0, 0, 0, 0.6);
  display: flex;
  align-items: flex-end;
  justify-content: center;
  z-index: 20;
}

.overlay-content {
  background: var(--surface);
  border-radius: 1rem 1rem 0 0;
  padding: 1rem;
  width: 100%;
  max-width: 640px;
  max-height: 80vh;
  overflow-y: auto;
}

@media (min-width: 480px) {
  :root {
    font-size: 17px;
  }
}

@media (min-width: 900px) {
  main#app {
    max-width: 1200px;
  }

  .beheer-layout {
    display: flex;
    gap: 1.5rem;
    align-items: flex-start;
  }

  .beheer-sidebar {
    flex: 0 0 240px;
    position: sticky;
    top: 4.5rem;
  }

  .beheer-content {
    flex: 1;
    min-width: 0;
  }

  .oefening-form-layout {
    display: flex;
    gap: 1.5rem;
    align-items: flex-start;
  }

  .oefening-form-links,
  .oefening-form-rechts {
    flex: 1;
    min-width: 0;
  }

  .bibliotheek-layout {
    display: flex;
    gap: 1.5rem;
    align-items: flex-start;
  }

  .bibliotheek-lijst {
    flex: 1;
    min-width: 0;
  }

  .bibliotheek-detail {
    flex: 0 0 400px;
    position: sticky;
    top: 4.5rem;
  }
}

.klikbare-naam {
  color: var(--accent);
  text-decoration: underline;
  cursor: pointer;
}

.handmatig-toevoegen summary {
  cursor: pointer;
  color: var(--accent);
  margin: 0.75rem 0;
}

.groep-kaart > summary {
  cursor: pointer;
  list-style-position: outside;
}

.groep-kaart > summary h3 {
  margin: 0;
}

.groep-kaart > summary .btn {
  width: auto;
  margin-bottom: 0;
}

.groep-kaart-summary-rij {
  display: inline-flex;
  align-items: center;
  justify-content: space-between;
  gap: 0.75rem;
  width: calc(100% - 1.5rem);
  vertical-align: middle;
}

.beheer-nav-item {
  width: 100%;
  text-align: left;
  margin-bottom: 0.4rem;
}

.beheer-nav-item.actief {
  background: var(--accent);
  color: #05202e;
}

.beheer-sidebar-scheiding {
  border-top: 1px solid var(--surface-2);
  margin: 0.75rem 0;
}

.bibliotheek-sleep-item {
  cursor: grab;
  margin-bottom: 0.4rem;
}

.groep-kaart-drop-actief {
  border: 1px dashed var(--accent);
}

.lijn-grafiek-lijn {
  fill: none;
  stroke: var(--accent);
  stroke-width: 2;
}

.lijn-grafiek-punt {
  fill: var(--accent);
}

.lijn-grafiek-leeg {
  fill: var(--muted);
  font-size: 0.8rem;
}

.dashboard-scroll {
  overflow-x: auto;
  margin-bottom: 1rem;
}

.dashboard-tabel {
  border-collapse: collapse;
  font-size: 0.85rem;
  white-space: nowrap;
}

.dashboard-tabel th,
.dashboard-tabel td {
  border: 1px solid var(--surface-2);
  padding: 0.3rem 0.5rem;
  text-align: center;
}

.dashboard-tabel th.dashboard-oefening-kolom,
.dashboard-tabel td.dashboard-oefening-kolom {
  position: sticky;
  left: 0;
  background: var(--surface);
  text-align: left;
  white-space: normal;
  min-width: 8rem;
}

.dashboard-tabel .dashboard-set-regel {
  display: block;
}

.dashboard-tabel .dashboard-set-regel + .dashboard-set-regel {
  margin-top: 0.15rem;
}

.dashboard-kaart {
  background: var(--surface);
  border-radius: 0.75rem;
  padding: 0.75rem;
  margin-bottom: 0.75rem;
}