/* ============================================================
   Kheders Taalhub — style
   Design-system hergebruikt van Kell's Study Hub
   ============================================================ */

/* ── Light mode (default) ── */
:root {
  --bg: #f5f6f8;
  --surface: #ffffff;
  --surface2: #f0f1f4;
  --surface3: #e8e9ee;
  --border: #dde0e6;
  --text: #1e2330;
  --text-muted: #6b7280;
  --accent: #4361d0;
  --accent-dim: #3550b5;
  --accent-glow: rgba(67, 97, 208, 0.08);
  --green: #16874a;
  --green-dim: rgba(22, 135, 74, 0.10);
  --orange: #c2630a;
  --orange-dim: rgba(194, 99, 10, 0.10);
  --red: #c53434;
  --red-dim: rgba(197, 52, 52, 0.10);
  --purple: #7044c9;
  --purple-dim: rgba(112, 68, 201, 0.10);
  --shadow: 0 1px 3px rgba(0, 0, 0, 0.06);
  --shadow-lg: 0 6px 24px rgba(0, 0, 0, 0.10);
  --radius: 12px;
  --radius-sm: 8px;
  --maxw: 900px;
}

/* ── Dark mode ── */
[data-theme="dark"] {
  --bg: #101218;
  --surface: #1a1d28;
  --surface2: #222632;
  --surface3: #2a2e3c;
  --border: #333847;
  --text: #e0e2e9;
  --text-muted: #828899;
  --accent: #7b9aff;
  --accent-dim: #5a7de8;
  --accent-glow: rgba(123, 154, 255, 0.12);
  --green: #4ade80;
  --green-dim: rgba(74, 222, 128, 0.12);
  --orange: #fb923c;
  --orange-dim: rgba(251, 146, 60, 0.12);
  --red: #f87171;
  --red-dim: rgba(248, 113, 113, 0.12);
  --purple: #a78bfa;
  --purple-dim: rgba(167, 139, 250, 0.12);
  --shadow: 0 1px 3px rgba(0, 0, 0, 0.3);
  --shadow-lg: 0 6px 24px rgba(0, 0, 0, 0.4);
}

* { margin: 0; padding: 0; box-sizing: border-box; }

body {
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', system-ui, sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.65;
  min-height: 100vh;
  transition: background .3s, color .3s;
}

/* ── Header ── */
header {
  background: var(--surface);
  border-bottom: 1px solid var(--border);
  box-shadow: var(--shadow);
  position: sticky;
  top: 0;
  z-index: 50;
  transition: background .3s, border-color .3s;
}
.header-inner {
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 14px 20px;
  display: flex;
  align-items: center;
  gap: 14px;
}
.brand { display: flex; align-items: center; gap: 10px; font-weight: 700; font-size: 1.15rem; }
.brand .logo { font-size: 1.5rem; }
.brand small { display: block; font-weight: 400; font-size: .72rem; color: var(--text-muted); }
.header-spacer { flex: 1; }

.theme-toggle {
  background: var(--surface2);
  border: 1px solid var(--border);
  color: var(--text);
  border-radius: var(--radius-sm);
  padding: 8px 12px;
  cursor: pointer;
  font-size: .95rem;
  transition: background .2s, border-color .2s;
}
.theme-toggle:hover { background: var(--surface3); }
.theme-toggle .icon-sun { display: none; }
.theme-toggle .icon-moon { display: inline; }
[data-theme="dark"] .theme-toggle .icon-sun { display: inline; }
[data-theme="dark"] .theme-toggle .icon-moon { display: none; }

/* ── Tabs ── */
.tabs {
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 0 20px;
  display: flex;
  gap: 4px;
  overflow-x: auto;
  scrollbar-width: none;
}
.tabs::-webkit-scrollbar { display: none; }
.tab {
  flex: 0 0 auto;
  background: none;
  border: none;
  border-bottom: 3px solid transparent;
  color: var(--text-muted);
  padding: 12px 14px;
  cursor: pointer;
  font-size: .9rem;
  font-weight: 500;
  white-space: nowrap;
  display: flex;
  align-items: center;
  gap: 7px;
  transition: color .2s, border-color .2s;
}
.tab:hover { color: var(--text); }
.tab.active { color: var(--accent); border-bottom-color: var(--accent); }
.tab .tab-icon { font-size: 1.05rem; }

/* ── Main ── */
main { max-width: var(--maxw); margin: 0 auto; padding: 24px 20px 80px; }
.panel { display: none; animation: fade .25s ease; }
.panel.active { display: block; }
@keyframes fade { from { opacity: 0; transform: translateY(6px); } to { opacity: 1; transform: none; } }

.panel-head h2 { font-size: 1.5rem; margin-bottom: 4px; }
.panel-head p.lead { color: var(--text-muted); margin-bottom: 20px; }

/* ── Section switch (theorie / oefenen) ── */
.subnav { display: inline-flex; background: var(--surface2); border: 1px solid var(--border); border-radius: var(--radius-sm); padding: 3px; margin-bottom: 20px; }
.subnav button {
  background: none; border: none; color: var(--text-muted);
  padding: 7px 16px; border-radius: 6px; cursor: pointer; font-size: .88rem; font-weight: 500;
  transition: background .2s, color .2s;
}
.subnav button.active { background: var(--surface); color: var(--text); box-shadow: var(--shadow); }

.section { display: none; }
.section.active { display: block; }

/* ── Theory ── */
.card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 20px 22px;
  margin-bottom: 16px;
  box-shadow: var(--shadow);
}
.card h3 { font-size: 1.1rem; margin-bottom: 10px; display: flex; align-items: center; gap: 8px; }
.card p { margin-bottom: 10px; }
.card ul { margin: 8px 0 12px 20px; }
.card li { margin-bottom: 5px; }

.rule-table { width: 100%; border-collapse: collapse; margin: 10px 0 14px; font-size: .92rem; }
.rule-table th, .rule-table td { text-align: left; padding: 8px 10px; border-bottom: 1px solid var(--border); vertical-align: top; }
.rule-table th { color: var(--text-muted); font-weight: 600; font-size: .8rem; text-transform: uppercase; letter-spacing: .03em; }
.rule-table tr:last-child td { border-bottom: none; }

.ex-wrong { color: var(--red); }
.ex-right { color: var(--green); }
.ex-wrong::before { content: "✗ "; }
.ex-right::before { content: "✓ "; }
mark { background: var(--accent-glow); color: var(--accent); padding: 0 3px; border-radius: 4px; font-weight: 600; }

.callout { border-left: 3px solid var(--accent); background: var(--accent-glow); padding: 12px 16px; border-radius: 0 var(--radius-sm) var(--radius-sm) 0; margin: 12px 0; }
.callout.tip { border-color: var(--green); background: var(--green-dim); }
.callout [data-tab] { color: var(--accent); font-weight: 600; cursor: pointer; text-decoration: underline; text-underline-offset: 2px; }

/* signaalwoord-chips */
.chip-group { margin: 12px 0; }
.chip-group-label { font-size: .78rem; font-weight: 600; color: var(--text-muted); text-transform: uppercase; letter-spacing: .03em; margin-bottom: 7px; }
.chip-row { display: flex; flex-wrap: wrap; gap: 7px; }
.word-chip { background: var(--surface2); border: 1px solid var(--border); color: var(--text); padding: 4px 11px; border-radius: 20px; font-size: .84rem; }

/* ── Exercises ── */
.ex-toolbar { display: flex; flex-wrap: wrap; align-items: center; gap: 10px; margin-bottom: 16px; }
.ex-toolbar .spacer { flex: 1; }
.filter-chip {
  background: var(--surface2); border: 1px solid var(--border); color: var(--text-muted);
  padding: 6px 12px; border-radius: 20px; cursor: pointer; font-size: .82rem; transition: all .2s;
}
.filter-chip.active { background: var(--accent); border-color: var(--accent); color: #fff; }

.btn {
  background: var(--accent); color: #fff; border: none; border-radius: var(--radius-sm);
  padding: 9px 18px; cursor: pointer; font-size: .9rem; font-weight: 600; transition: background .2s, transform .05s;
}
.btn:hover { background: var(--accent-dim); }
.btn:active { transform: translateY(1px); }
.btn.secondary { background: var(--surface2); color: var(--text); border: 1px solid var(--border); }
.btn.secondary:hover { background: var(--surface3); }
.btn:disabled { opacity: .5; cursor: not-allowed; }

.exercise {
  background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius);
  padding: 18px 20px; margin-bottom: 14px; box-shadow: var(--shadow);
}
.ex-meta { display: flex; align-items: center; gap: 8px; margin-bottom: 10px; }
.ex-num { font-size: .78rem; color: var(--text-muted); font-weight: 600; }
.badge { font-size: .68rem; font-weight: 700; text-transform: uppercase; letter-spacing: .04em; padding: 2px 8px; border-radius: 20px; }
.badge.avg { background: var(--green-dim); color: var(--green); }
.badge.hard { background: var(--orange-dim); color: var(--orange); }
.badge.brain { background: var(--purple-dim); color: var(--purple); }
.badge.expert { background: var(--red-dim); color: var(--red); }
.badge.master { background: var(--accent-glow); color: var(--accent); border: 1px solid var(--accent); }
.badge.type { background: var(--surface3); color: var(--text-muted); letter-spacing: 0; text-transform: none; }

/* moeilijkheidskop per blok in het oefengedeelte */
.level-group-head { font-weight: 700; font-size: 1.02rem; margin: 22px 0 10px; padding-bottom: 6px; border-bottom: 1px solid var(--border); display: flex; align-items: center; gap: 10px; }
.level-group-head:first-child { margin-top: 4px; }
.level-group-head .stars { color: var(--orange); font-size: .95rem; letter-spacing: 1px; }

.ex-prompt { font-weight: 500; margin-bottom: 14px; }
.ex-prompt .target { color: var(--accent); font-style: italic; }

/* MC options */
.mc-options { display: flex; flex-direction: column; gap: 8px; }
.mc-option {
  text-align: left; background: var(--surface2); border: 1.5px solid var(--border); color: var(--text);
  padding: 11px 14px; border-radius: var(--radius-sm); cursor: pointer; font-size: .92rem; transition: all .15s;
}
.mc-option:hover:not(:disabled) { border-color: var(--accent); }
.mc-option.selected { border-color: var(--accent); background: var(--accent-glow); }
.mc-option.correct { border-color: var(--green); background: var(--green-dim); }
.mc-option.wrong { border-color: var(--red); background: var(--red-dim); }
.mc-option:disabled { cursor: default; }

/* Order (drag) */
.order-zone {
  display: flex; flex-wrap: wrap; gap: 8px; min-height: 52px; padding: 12px;
  background: var(--surface2); border: 1.5px dashed var(--border); border-radius: var(--radius-sm); margin-bottom: 10px;
}
.order-bank { display: flex; flex-wrap: wrap; gap: 8px; padding: 8px 0; }
.chip {
  background: var(--surface); border: 1.5px solid var(--border); color: var(--text);
  padding: 7px 13px; border-radius: 20px; cursor: grab; font-size: .9rem; user-select: none;
  transition: border-color .15s, background .15s, transform .05s;
}
.chip:hover { border-color: var(--accent); }
.chip.dragging { opacity: .4; }
.chip:active { cursor: grabbing; transform: scale(.97); }
.order-zone.answered .chip { cursor: default; }
.order-zone.correct { border-color: var(--green); border-style: solid; background: var(--green-dim); }
.order-zone.wrong { border-color: var(--red); border-style: solid; background: var(--red-dim); }
.order-hint { font-size: .78rem; color: var(--text-muted); margin-bottom: 6px; }

/* Fix (correct the error) */
.fix-sentence { background: var(--surface2); border: 1px solid var(--border); border-radius: var(--radius-sm); padding: 12px 14px; margin-bottom: 10px; font-style: italic; }
.fix-input {
  width: 100%; background: var(--surface2); border: 1.5px solid var(--border); color: var(--text);
  border-radius: var(--radius-sm); padding: 11px 14px; font-size: .95rem; font-family: inherit; resize: vertical;
}
.fix-input:focus { outline: none; border-color: var(--accent); }
.fix-input.correct { border-color: var(--green); }
.fix-input.wrong { border-color: var(--red); }

/* Feedback */
.feedback { margin-top: 12px; padding: 11px 14px; border-radius: var(--radius-sm); font-size: .9rem; display: none; }
.feedback.show { display: block; }
.feedback.good { background: var(--green-dim); border-left: 3px solid var(--green); }
.feedback.bad { background: var(--red-dim); border-left: 3px solid var(--red); }
.feedback .answer-line { margin-top: 6px; }
.ex-actions { margin-top: 14px; display: flex; gap: 10px; }

/* Exam placeholder */
.placeholder {
  text-align: center; padding: 50px 20px; color: var(--text-muted);
  border: 2px dashed var(--border); border-radius: var(--radius); background: var(--surface);
}
.placeholder .big { font-size: 2.5rem; margin-bottom: 12px; }

.empty { color: var(--text-muted); font-style: italic; padding: 20px 0; }

/* ── Exam ── */
.exam-actions { display: flex; flex-wrap: wrap; gap: 10px; margin: 16px 0; }
.grade-line { display: flex; align-items: baseline; gap: 12px; margin: 8px 0; }
.grade-big { font-size: 3rem; font-weight: 800; color: var(--accent); line-height: 1; }
.grade-sub { color: var(--text-muted); font-size: .9rem; }

.result-q { border-left: 3px solid var(--border); padding: 10px 14px; margin: 10px 0; border-radius: 0 var(--radius-sm) var(--radius-sm) 0; background: var(--surface2); }
.result-q.ok { border-color: var(--green); background: var(--green-dim); }
.result-q.bad { border-color: var(--red); background: var(--red-dim); }
.result-q-head { font-weight: 700; margin-bottom: 4px; }
.result-q-head .muted { color: var(--text-muted); font-weight: 400; font-size: .82rem; }
.result-prompt { margin-bottom: 4px; }
.result-given, .result-correct { font-size: .9rem; margin-top: 3px; }
.result-explain { font-size: .85rem; color: var(--text-muted); margin-top: 4px; }

p.mini { font-size: .82rem; color: var(--text-muted); border-top: 1px solid var(--border); padding-top: 8px; margin-top: 4px; }

/* voortgangsgrafiek */
.spark-wrap { margin: 6px 0 14px; }
.spark { width: 100%; height: auto; max-height: 130px; }
.spark-line { fill: none; stroke: var(--accent); stroke-width: 2.5; stroke-linejoin: round; stroke-linecap: round; }
.spark-dot { fill: var(--accent); }
.spark-grid { stroke: var(--border); stroke-width: 1; stroke-dasharray: 4 4; }
.spark-goal { stroke: var(--green); stroke-width: 1.2; stroke-dasharray: 5 3; }
.spark-lbl { fill: var(--text-muted); font-size: 10px; }

/* ── Print (PDF) ── */
#print-root { display: none; }
@media print {
  header, main { display: none !important; }
  #print-root { display: block !important; }
  body { background: #fff; color: #000; }
}
.print-doc { max-width: 720px; margin: 0 auto; color: #000; font-size: 12pt; line-height: 1.5; }
.print-doc h1 { font-size: 18pt; margin-bottom: 4px; }
.print-doc h2 { font-size: 14pt; margin: 18px 0 8px; border-bottom: 1px solid #999; padding-bottom: 3px; }
.print-doc h3 { font-size: 12pt; margin: 12px 0 6px; }
.print-doc .p-meta { color: #555; margin-bottom: 10px; }
.print-doc .p-grade { font-size: 14pt; margin: 10px 0; padding: 8px 12px; border: 2px solid #000; border-radius: 6px; display: inline-block; }
.print-doc table { width: 100%; border-collapse: collapse; margin: 8px 0; }
.print-doc th, .print-doc td { border: 1px solid #999; padding: 5px 8px; text-align: left; font-size: 11pt; vertical-align: top; }
.print-doc .p-q { margin: 10px 0; padding: 6px 0; border-bottom: 1px dotted #bbb; page-break-inside: avoid; }
.print-doc .p-prompt { font-weight: 600; }
.print-doc .p-correct { color: #146c37; }
.print-doc .p-explain { color: #444; font-style: italic; }
.print-doc .p-words { font-weight: 600; letter-spacing: .02em; }
.print-doc .p-blank { color: #999; }
.print-doc .p-key li { margin-bottom: 3px; }
.print-doc .p-foot { margin-top: 20px; padding-top: 8px; border-top: 1px solid #999; color: #777; font-size: 9pt; text-align: center; }
.print-doc mark { background: none; color: #000; font-weight: 700; }
.print-doc [data-tab] { color: #000; text-decoration: none; }
.print-doc .ex-wrong { color: #b00; }
.print-doc .ex-right { color: #146c37; }

/* Responsive */
@media (max-width: 600px) {
  .header-inner { padding: 12px 14px; }
  main { padding: 18px 14px 60px; }
  .card { padding: 16px; }
  .ex-toolbar .btn.secondary { flex: 1 1 auto; }
  .exam-actions .btn { flex: 1 1 auto; }
  .brand small { display: none; }
  .grade-big { font-size: 2.4rem; }
}