/* Huisstijl lefief-powered.com */
:root {
  --lf-brand: #2F6BFF; --lf-brand-2: #14B8D6; --lf-ink: #0B1220; --lf-cloud: #F6F8FC; --lf-line: #E5EAF3;
  --lf-surface: #FFFFFF; --lf-surface-2: #F2F5FB;
  --lf-text: rgba(11, 18, 32, .92); --lf-muted: rgba(11, 18, 32, .66); --lf-faint: rgba(11, 18, 32, .4);
  --lf-success: #16A34A; --lf-danger: #EF4444; --lf-warning: #F59E0B; --lf-info: #0EA5E9;
  --lf-font-sans: "Inter", ui-sans-serif, system-ui, -apple-system, "Segoe UI", Roboto, Arial, sans-serif;
  --lf-font-mono: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, "Liberation Mono", monospace;
  --lf-radius-lg: 14px; --lf-radius-md: 10px; --lf-radius-sm: 8px;
  --lf-shadow-sm: 0 6px 18px rgba(11, 18, 32, .08); --lf-shadow-md: 0 16px 44px rgba(11, 18, 32, .12);
  --lf-focus: 0 0 0 4px rgba(47, 107, 255, .22);
  --lf-ease: cubic-bezier(.2, .9, .2, 1); --lf-fast: .14s var(--lf-ease);
  --lf-grad: linear-gradient(135deg, var(--lf-brand), var(--lf-brand-2));
  --ok-bg: #F0FDF4; --nok-bg: #FEF2F2; --brand-soft: rgba(47, 107, 255, .08);
}
* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }
body {
  margin: 0; font-family: var(--lf-font-sans); color: var(--lf-text); line-height: 1.55; background: #fff;
  background-image:
    radial-gradient(600px 400px at 0% 0%, rgba(47, 107, 255, .10), transparent 70%),
    radial-gradient(700px 500px at 100% 30%, rgba(20, 184, 214, .08), transparent 70%);
  background-attachment: fixed;
  -webkit-font-smoothing: antialiased;
}
a { color: var(--lf-brand); }
:focus-visible { outline: none; box-shadow: var(--lf-focus); border-radius: var(--lf-radius-sm); }
code { font-family: var(--lf-font-mono); background: var(--lf-surface-2); border: 1px solid var(--lf-line); padding: 0 5px; border-radius: 6px; font-size: .88em; }

/* ---- header ---- */
.top {
  position: sticky; top: 0; z-index: 20; height: 65px; display: flex; align-items: center; justify-content: space-between; gap: 16px;
  padding: 0 max(16px, calc((100vw - 1120px) / 2));
  background: rgba(255, 255, 255, .72); backdrop-filter: saturate(1.4) blur(14px); -webkit-backdrop-filter: saturate(1.4) blur(14px);
  border-bottom: 1px solid rgba(0, 0, 0, .06);
}
.brand { display: flex; align-items: center; gap: 10px; text-decoration: none; color: var(--lf-ink); font-weight: 600; font-size: 18px; white-space: nowrap; }
.brand img { display: block; }
.brand .sub { color: var(--lf-muted); font-weight: 500; padding-left: 10px; border-left: 1px solid var(--lf-line); font-size: 15px; }
nav { display: flex; gap: 4px; }
nav a { color: var(--lf-ink); text-decoration: none; font-size: 14px; font-weight: 500; padding: 8px 12px; border-radius: var(--lf-radius-md); white-space: nowrap; transition: background var(--lf-fast), color var(--lf-fast); }
nav a:hover { background: var(--lf-surface-2); }
nav a.on { background: var(--brand-soft); color: var(--lf-brand); font-weight: 600; }
@media (max-width: 700px) {
  .top { height: auto; flex-direction: column; align-items: stretch; gap: 6px; padding: 10px 10px 8px; }
  nav { justify-content: space-between; }
  nav a { flex: 1; display: flex; flex-direction: column; align-items: center; padding: 6px 2px; font-size: 18px; }
  nav a span { font-size: 11.5px; font-weight: 600; }
}

/* ---- layout ---- */
main { max-width: 1120px; margin: 0 auto; padding: 40px 16px 56px; }
@media (min-width: 900px) { main { padding: 56px 32px 72px; } }
footer { display: flex; justify-content: center; align-items: center; gap: 6px; flex-wrap: wrap; text-align: center; color: var(--lf-muted); font-size: 13px; padding: 28px 16px; border-top: 1px solid var(--lf-line); }
footer a { color: var(--lf-ink); font-weight: 600; text-decoration: none; }

.eyebrow { margin: 0 0 10px; font-size: 13px; font-weight: 600; letter-spacing: 2.34px; text-transform: uppercase; color: var(--lf-brand); }
h1 { margin: 0 0 14px; color: var(--lf-ink); font-weight: 800; letter-spacing: -1.6px; line-height: 1.05; font-size: clamp(34px, 6vw, 56px); }
h2 { margin: 0 0 12px; color: var(--lf-ink); font-weight: 700; font-size: 20px; letter-spacing: -.3px; }
.grad { background: var(--lf-grad); -webkit-background-clip: text; background-clip: text; color: transparent; }
main > p.muted { font-size: 17px; max-width: 760px; }
.muted { color: var(--lf-muted); }
.small { font-size: 13px; }

.card { background: var(--lf-surface); border: 1px solid var(--lf-line); border-radius: var(--lf-radius-lg); padding: 22px 24px; margin: 18px 0; box-shadow: var(--lf-shadow-sm); }
@media (max-width: 600px) { .card { padding: 16px; } }
.card.nok { background: var(--nok-bg); border-color: var(--lf-danger); }
.tag { display: inline-block; font-size: 12px; font-weight: 600; letter-spacing: 1.2px; text-transform: uppercase; color: var(--lf-brand); margin-bottom: 6px; }
.row { display: flex; gap: 10px; flex-wrap: wrap; align-items: center; margin: 14px 0; }
.row.between { justify-content: space-between; }

/* ---- overzicht ---- */
.search { width: 100%; padding: 14px 16px; border: 1px solid var(--lf-line); border-radius: var(--lf-radius-md); font: inherit; font-size: 16px; background: #fff; color: var(--lf-ink); box-shadow: var(--lf-shadow-sm); transition: box-shadow var(--lf-fast), border-color var(--lf-fast); }
.search:focus { outline: none; border-color: var(--lf-brand); box-shadow: var(--lf-focus); }
.chips { display: flex; flex-wrap: wrap; gap: 8px; margin: 16px 0 6px; }
.chip { text-decoration: none; color: var(--lf-ink); background: #fff; border: 1px solid var(--lf-line); padding: 6px 12px; border-radius: 99px; font-size: 13px; font-weight: 500; transition: border-color var(--lf-fast), color var(--lf-fast); }
.chip:hover { border-color: var(--lf-brand); color: var(--lf-brand); }
.sec { scroll-margin-top: 90px; }
.num { display: inline-grid; place-items: center; min-width: 38px; height: 26px; padding: 0 8px; margin-right: 6px; border-radius: var(--lf-radius-sm); background: var(--lf-grad); color: #fff; font-size: 13px; font-weight: 700; vertical-align: 2px; }

.tablewrap { overflow-x: auto; }
table.grid { border-collapse: collapse; width: 100%; font-size: 15px; }
table.grid th, table.grid td { border-bottom: 1px solid var(--lf-line); padding: 10px 12px; text-align: left; vertical-align: top; }
table.grid th { background: var(--lf-surface-2); color: var(--lf-ink); font-weight: 600; font-size: 13px; }
table.grid tbody tr:hover { background: rgba(47, 107, 255, .03); }
table.defs td.term { width: 32%; font-weight: 600; color: var(--lf-ink); }
table.data { width: auto; min-width: 300px; border: 1px solid var(--lf-line); border-radius: var(--lf-radius-md); border-collapse: separate; border-spacing: 0; overflow: hidden; }
table.data th { background: var(--lf-grad); color: #fff; font-size: 13px; }
table.data td { text-align: center; }
table.data td:first-child { text-align: left; }
table.data tr:last-child td { border-bottom: 0; }
table.calc td, table.calc th { white-space: nowrap; font-variant-numeric: tabular-nums; }
tr.tot td { font-weight: 700; color: var(--lf-ink); background: var(--lf-surface-2); }
.lvl { display: inline-block; margin-top: 5px; font-size: 11px; font-weight: 600; padding: 1px 8px; border-radius: 99px; background: var(--lf-surface-2); color: var(--lf-muted); }
.lvl-metrisch { background: rgba(20, 184, 214, .12); color: #0E7490; }
.lvl-ordinaal, .lvl-categorisch { background: rgba(245, 158, 11, .14); color: #B45309; }
.lvl-nominaal { background: rgba(47, 107, 255, .1); color: var(--lf-brand); }
table.defs td.term .lvl { display: table; }

.formula { font-family: "Cambria Math", "STIX Two Math", Georgia, serif; font-size: 17px; color: var(--lf-ink); margin: 2px 0 6px; display: flex; align-items: center; flex-wrap: wrap; gap: 4px; }
.frac { display: inline-flex; flex-direction: column; text-align: center; vertical-align: middle; margin: 0 3px; }
.frac > span:first-child { border-bottom: 1.5px solid currentColor; padding: 0 3px; }
.frac > span:last-child { padding: 0 3px; }
.sum { font-size: 1.25em; }
.ov { text-decoration: overline; }
.sqrt > span { border-top: 1.5px solid currentColor; padding: 0 2px; }

/* ---- voorbeelden ---- */
.steps { padding-left: 1.3rem; margin: 14px 0 10px; }
.steps li { margin: 8px 0; }
.steps li::marker { color: var(--lf-brand); font-weight: 700; }
details summary { cursor: pointer; font-weight: 600; color: var(--lf-ink); transition: color var(--lf-fast); }
details summary:hover { color: var(--lf-brand); }
details .ans { margin: 8px 0 4px; padding: 10px 14px; background: var(--lf-surface-2); border-left: 3px solid var(--lf-brand); border-radius: var(--lf-radius-sm); }

/* ---- knoppen ---- */
.btn { display: inline-flex; align-items: center; gap: 8px; background: var(--lf-brand); color: #fff; border: 0; border-radius: var(--lf-radius-md); padding: 12px 18px; font: inherit; font-size: 14px; font-weight: 600; cursor: pointer; box-shadow: 0 8px 22px rgba(47, 107, 255, .28); transition: transform var(--lf-fast), box-shadow var(--lf-fast); }
.btn:hover { transform: translateY(-1px); box-shadow: 0 12px 28px rgba(47, 107, 255, .34); }
.btn.ghost { background: #fff; color: var(--lf-ink); border: 1px solid var(--lf-line); box-shadow: none; }
.btn.ghost:hover { border-color: var(--lf-brand); color: var(--lf-brand); }
.btn.small { padding: 7px 12px; font-size: 13px; }
.link { background: none; border: 0; color: var(--lf-muted); text-decoration: underline; cursor: pointer; font: inherit; font-size: 13px; }
.seg { display: inline-flex; flex-wrap: wrap; gap: 4px; background: var(--lf-surface-2); border: 1px solid var(--lf-line); padding: 4px; border-radius: var(--lf-radius-md); }
.seg button { border: 0; background: transparent; color: var(--lf-muted); padding: 7px 12px; border-radius: var(--lf-radius-sm); cursor: pointer; font: inherit; font-size: 14px; font-weight: 500; }
.seg button:hover { color: var(--lf-ink); }
.seg button.on { background: #fff; color: var(--lf-brand); font-weight: 600; box-shadow: 0 2px 8px rgba(11, 18, 32, .08); }
.scorebox { font-size: 14px; color: var(--lf-muted); background: #fff; border: 1px solid var(--lf-line); border-radius: 99px; padding: 6px 14px; }
.scorebox b { color: var(--lf-ink); }

/* ---- oefenen ---- */
.ex p { margin: 6px 0 14px; }
.numbers { font-family: var(--lf-font-mono); font-size: 20px; font-weight: 600; color: var(--lf-ink); background: var(--lf-surface-2); border: 1px solid var(--lf-line); padding: 12px 16px; border-radius: var(--lf-radius-md); }
.q { border-top: 1px solid var(--lf-line); padding: 18px 0 8px; margin-top: 14px; }
.qhead { margin-bottom: 10px; color: var(--lf-ink); }
.pts { color: var(--lf-faint); font-size: 12px; margin-right: 8px; }
.opts { display: grid; gap: 8px; }
.opt { display: flex; gap: 12px; align-items: center; text-align: left; width: 100%; padding: 12px 14px; border: 1px solid var(--lf-line); background: #fff; color: var(--lf-text); border-radius: var(--lf-radius-md); cursor: pointer; font: inherit; font-size: 15px; transition: border-color var(--lf-fast), box-shadow var(--lf-fast); }
.opt:hover:not(:disabled) { border-color: var(--lf-brand); box-shadow: var(--lf-focus); }
.opt .dot { flex: none; width: 18px; height: 18px; border-radius: 50%; border: 2px solid var(--lf-faint); }
.opt.right { border-color: var(--lf-success); background: var(--ok-bg); }
.opt.right .dot { background: var(--lf-success); border-color: var(--lf-success); }
.opt.wrong { border-color: var(--lf-danger); background: var(--nok-bg); }
.opt.wrong .dot { background: var(--lf-danger); border-color: var(--lf-danger); }
.opt:disabled { cursor: default; }
.fb { margin-top: 10px; padding: 12px 14px; border-radius: var(--lf-radius-md); font-size: 15px; }
.fb.ok { background: var(--ok-bg); border-left: 3px solid var(--lf-success); }
.fb.nok { background: var(--nok-bg); border-left: 3px solid var(--lf-danger); }

/* ---- rekenen ---- */
textarea { width: 100%; font-family: var(--lf-font-mono); font-size: 15px; padding: 12px 14px; border: 1px solid var(--lf-line); border-radius: var(--lf-radius-md); background: #fff; color: var(--lf-ink); resize: vertical; margin-top: 4px; }
textarea:focus, select:focus { outline: none; border-color: var(--lf-brand); box-shadow: var(--lf-focus); }
.hint { color: var(--lf-muted); font-size: 14px; }
select { padding: 7px 10px; border-radius: var(--lf-radius-sm); border: 1px solid var(--lf-line); background: #fff; color: var(--lf-ink); font: inherit; font-size: 14px; }
.results { display: grid; grid-template-columns: repeat(auto-fill, minmax(min(220px, 44%), 1fr)); gap: 12px; }
.res { background: #fff; border: 1px solid var(--lf-line); border-radius: var(--lf-radius-md); padding: 12px 14px; position: relative; overflow: hidden; }
.res::before { content: ""; position: absolute; inset: 0 auto 0 0; width: 3px; background: var(--lf-grad); }
.res .k { font-size: 12px; color: var(--lf-muted); font-weight: 600; text-transform: uppercase; letter-spacing: .6px; }
.res .v { font-size: 24px; font-weight: 800; color: var(--lf-ink); letter-spacing: -.5px; font-variant-numeric: tabular-nums; }
.res .why { font-size: 12.5px; color: var(--lf-muted); }

figure { margin: 12px 0; }
figcaption { font-size: 13px; color: var(--lf-muted); margin-bottom: 4px; }
.chart { width: 100%; height: auto; max-width: 700px; }
.chart .axis { stroke: var(--lf-faint); }
.chart .lbl { font-size: 12px; fill: var(--lf-ink); font-family: var(--lf-font-sans); }
.chart .box { fill: rgba(47, 107, 255, .14); stroke: var(--lf-brand); stroke-width: 2; }
.chart .med { stroke: var(--lf-brand-2); stroke-width: 3.5; }
.chart .whisk { stroke: var(--lf-ink); stroke-width: 2; }
.chart .fence { stroke: var(--lf-faint); stroke-dasharray: 4 4; }
.chart .out { fill: var(--lf-danger); }
.pie { display: flex; flex-wrap: wrap; align-items: center; gap: 18px; }
.pie-svg { max-width: 220px; }
.legend { list-style: none; padding: 0; margin: 0; font-size: 14px; }
.legend li { display: flex; align-items: center; gap: 8px; margin: 4px 0; }
.legend span { width: 12px; height: 12px; border-radius: 4px; display: inline-block; }

/* ---- install toast ---- */
.install-toast {
  position: fixed; z-index: 50; left: 50%; bottom: max(16px, env(safe-area-inset-bottom));
  transform: translate(-50%, 140%); opacity: 0; transition: transform .3s var(--lf-ease), opacity .3s var(--lf-ease);
  display: flex; align-items: center; gap: 12px; width: min(520px, calc(100vw - 24px));
  padding: 12px 12px 12px 14px; background: rgba(255, 255, 255, .92); backdrop-filter: saturate(1.4) blur(14px); -webkit-backdrop-filter: saturate(1.4) blur(14px);
  border: 1px solid var(--lf-line); border-radius: var(--lf-radius-lg); box-shadow: var(--lf-shadow-md);
}
.install-toast.show { transform: translate(-50%, 0); opacity: 1; }
.install-toast img { flex: none; border-radius: 10px; }
.it-text { flex: 1; display: flex; flex-direction: column; font-size: 14px; line-height: 1.35; color: var(--lf-muted); }
.it-text b { color: var(--lf-ink); }
.it-share { display: inline-block; color: var(--lf-brand); font-weight: 700; }
.it-close { flex: none; width: 32px; height: 32px; border: 0; border-radius: 50%; background: var(--lf-surface-2); color: var(--lf-muted); cursor: pointer; font-size: 14px; }
.it-close:hover { color: var(--lf-ink); }