/* ── Stukje · De Stijl system ─────────────────────────────── */
:root {
  --paper: #FAFAF7;
  --ink: #16130F;
  --muted: #6E6A62;
  --line: 2px solid var(--ink);
  --red: #DD3B2B;
  --blue: #2451B8;
  --yellow: #F6C21C;
  --card: #FFFFFF;
  --sans: "Archivo", system-ui, sans-serif;
  --display: "Archivo Black", "Archivo", sans-serif;
  --mono: "IBM Plex Mono", ui-monospace, monospace;
  --sat: env(safe-area-inset-top, 0px);
  --sab: env(safe-area-inset-bottom, 0px);
}
* { box-sizing: border-box; margin: 0; padding: 0; }
html { -webkit-text-size-adjust: 100%; overscroll-behavior: none; }
body {
  background: var(--paper);
  color: var(--ink);
  font-family: var(--sans);
  font-size: 16px;
  line-height: 1.55;
  min-height: 100dvh;
  overscroll-behavior: none;
  -webkit-tap-highlight-color: transparent;
}
button { font: inherit; color: inherit; background: none; border: none; cursor: pointer; -webkit-tap-highlight-color: transparent; }
:focus-visible { outline: 3px solid var(--blue); outline-offset: 2px; }

.eyebrow {
  font-size: 11px;
  font-weight: 600;
  letter-spacing: .18em;
  text-transform: uppercase;
}

/* ── Home ─────────────────────────────────────────────────── */
.home { max-width: 560px; margin: 0 auto; padding: calc(20px + var(--sat)) 20px 40px; }

.masthead {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  padding-bottom: 12px;
  border-bottom: var(--line);
}
.wordmark {
  font-family: var(--display);
  font-size: 28px;
  letter-spacing: -.02em;
  text-transform: uppercase;
}
.wordmark i { font-style: normal; color: var(--red); }

.hero { padding: 26px 0 22px; }
.hero h1 {
  font-family: var(--display);
  font-size: clamp(34px, 9vw, 46px);
  line-height: 1.02;
  letter-spacing: -.02em;
  text-transform: uppercase;
}
.hero h1 span { color: var(--blue); }
.hero p { margin-top: 10px; color: var(--muted); max-width: 34ch; }

/* mosaic — the signature */
.mosaic-wrap {
  display: flex;
  align-items: flex-end;
  justify-content: space-between;
  gap: 16px;
  margin-top: 24px;
  padding: 14px;
  background: var(--card);
  border: var(--line);
  box-shadow: 4px 4px 0 var(--ink);
}
.mosaic {
  display: grid;
  grid-template-columns: repeat(24, 1fr);
  gap: 3px;
  flex: 1;
}
.mosaic b {
  aspect-ratio: 1;
  background: #EBE8E0;
}
.mosaic b.f-red    { background: var(--red); }
.mosaic b.f-blue   { background: var(--blue); }
.mosaic b.f-yellow { background: var(--yellow); }
.mosaic b.f-ink    { background: var(--ink); }
.mosaic-stat { text-align: right; flex-shrink: 0; }
.mosaic-stat strong {
  display: block;
  font-family: var(--display);
  font-size: 30px;
  line-height: 1;
}

/* continue card */
.continue {
  display: block;
  width: 100%;
  text-align: left;
  margin-top: 18px;
  padding: 18px;
  background: var(--ink);
  color: var(--paper);
  box-shadow: 4px 4px 0 rgba(22,19,15,.25);
  transition: transform .12s ease, box-shadow .12s ease;
}
.continue:active { transform: translate(2px, 2px); box-shadow: 1px 1px 0 rgba(22,19,15,.25); }
.continue .eyebrow { color: var(--yellow); }
.continue h2 {
  font-family: var(--display);
  font-size: 20px;
  line-height: 1.15;
  margin: 6px 0 10px;
}
.continue .meta { font-size: 13px; color: #B9B4AA; }
.continue .go {
  float: right;
  font-family: var(--display);
  color: var(--yellow);
  font-size: 18px;
}

/* contents */
.toc { margin-top: 36px; }
.toc > .eyebrow { display: block; padding-bottom: 10px; border-bottom: var(--line); }
.part { margin-top: 22px; }
.part-title {
  display: flex;
  align-items: center;
  gap: 10px;
  font-family: var(--display);
  font-size: 15px;
  text-transform: uppercase;
  letter-spacing: .04em;
}
.part-title::before {
  content: "";
  width: 14px; height: 14px;
  flex-shrink: 0;
}
.part:nth-of-type(3n+1) .part-title::before { background: var(--red); }
.part:nth-of-type(3n+2) .part-title::before { background: var(--blue); }
.part:nth-of-type(3n)   .part-title::before { background: var(--yellow); }

.chapter {
  display: flex;
  align-items: center;
  gap: 14px;
  width: 100%;
  text-align: left;
  padding: 14px 2px;
  border-bottom: 1px solid #DDD9D0;
  transition: background .12s ease;
}
.chapter:hover { background: #F1EEE6; }
.ch-num {
  width: 38px; height: 38px;
  flex-shrink: 0;
  display: grid;
  place-items: center;
  border: var(--line);
  font-family: var(--display);
  font-size: 14px;
  background: var(--card);
}
.chapter.done .ch-num { background: var(--ink); color: var(--paper); }
.ch-body { flex: 1; min-width: 0; }
.ch-body h3 {
  font-weight: 600;
  font-size: 15.5px;
  line-height: 1.25;
}
.ch-body .meta { font-size: 12px; color: var(--muted); margin-top: 2px; }
.ch-bar {
  width: 44px; height: 8px;
  flex-shrink: 0;
  border: 1.5px solid var(--ink);
  position: relative;
  background: var(--card);
}
.ch-bar i {
  position: absolute; inset: 0;
  transform-origin: left;
  background: var(--red);
}

.footer-note {
  margin-top: 40px;
  padding-top: 12px;
  border-top: var(--line);
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 12px;
  color: var(--muted);
}
.linklike { text-decoration: underline; color: inherit; }

/* ── Lesson view ──────────────────────────────────────────── */
.lesson {
  max-width: 560px;
  margin: 0 auto;
  min-height: 100dvh;
  display: flex;
  flex-direction: column;
}
.lesson-top {
  position: sticky;
  top: 0;
  z-index: 10;
  background: var(--paper);
  border-bottom: var(--line);
  padding: calc(10px + var(--sat)) 16px 10px;
  user-select: none; -webkit-user-select: none;
}
.top-row {
  display: flex;
  align-items: center;
  gap: 12px;
}
.back {
  width: 34px; height: 34px;
  flex-shrink: 0;
  border: var(--line);
  background: var(--card);
  display: grid;
  place-items: center;
  font-size: 17px;
  line-height: 1;
}
.top-label { flex: 1; min-width: 0; }
.top-label .crumb {
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
  font-weight: 600;
  font-size: 13.5px;
}
.top-label .pos { font-size: 11.5px; color: var(--muted); }
.squares { display: flex; gap: 4px; flex-shrink: 0; }
.squares b {
  width: 10px; height: 10px;
  background: #E4E1D8;
}
.squares b.on   { background: var(--ink); }
.squares b.here { outline: 2px solid var(--red); outline-offset: 1px; }
.top-compact { flex-shrink: 0; display: flex; align-items: center; gap: 8px; min-width: 96px; }
.top-compact-label { font-family: var(--display); font-size: 11.5px; letter-spacing: .04em; white-space: nowrap; }
.top-compact-track {
  position: relative;
  width: 72px; height: 8px;
  border: 1.5px solid var(--ink);
  background: var(--card);
  overflow: hidden;
  flex-shrink: 0;
}
.top-compact-track i { position: absolute; inset: 0 auto 0 0; background: var(--blue); }
.top-compact-track .here-marker {
  position: absolute; top: -2px; bottom: -2px; width: 2px;
  background: var(--red);
  transform: translateX(-50%);
}

.lesson-title {
  padding: 22px 20px 4px;
}
.lesson-title .kicker { color: var(--blue); }
.lesson-title h1 {
  font-family: var(--display);
  font-size: clamp(24px, 6.4vw, 32px);
  line-height: 1.06;
  letter-spacing: -.01em;
  text-transform: uppercase;
  margin-top: 6px;
}

.blocks { padding: 10px 20px calc(120px + var(--sab)); }
.block { margin-top: 20px; }
.block > :first-child { margin-top: 0; }

.b-paragraph { color: #2A2721; }

.b-rule {
  display: flex;
  gap: 12px;
  align-items: flex-start;
  background: var(--card);
  border: var(--line);
  padding: 14px;
  box-shadow: 3px 3px 0 var(--ink);
}
.b-rule .tick {
  flex-shrink: 0;
  width: 22px; height: 22px;
  background: var(--blue);
  color: #fff;
  display: grid;
  place-items: center;
  font-size: 13px;
  font-weight: 600;
}

.b-list { padding-left: 0; list-style: none; }
.b-list li {
  display: flex;
  gap: 10px;
  padding: 6px 0;
  border-bottom: 1px solid #E7E4DB;
}
.b-list li::before {
  content: "";
  width: 8px; height: 8px;
  flex-shrink: 0;
  margin-top: 8px;
  background: var(--ink);
}

.b-callout {
  border-left: 6px solid var(--ink);
  background: var(--card);
  padding: 12px 14px;
  font-size: 14.5px;
}
.callout-tag {
  display: inline-block;
  margin-bottom: 6px;
  padding: 2px 8px;
  font-size: 10.5px;
  font-weight: 600;
  letter-spacing: .12em;
  text-transform: uppercase;
  color: #fff;
}
.co-tip        { border-color: var(--yellow); } .co-tip .callout-tag        { background: var(--yellow); color: var(--ink); }
.co-grammar    { border-color: var(--blue);   } .co-grammar .callout-tag    { background: var(--blue); }
.co-culture    { border-color: var(--red);    } .co-culture .callout-tag    { background: var(--red); }
.co-audio      { border-color: var(--ink);    } .co-audio .callout-tag      { background: var(--ink); }

.b-heading4 {
  font-family: var(--display);
  font-size: 15px;
  text-transform: uppercase;
  letter-spacing: .03em;
  padding-bottom: 6px;
  border-bottom: 3px solid var(--yellow);
  display: inline-block;
}

/* vocabulary */
.b-phrase .dutch {
  font-family: var(--display);
  font-size: 21px;
  letter-spacing: -.01em;
}
.pron {
  font-family: var(--mono);
  font-style: italic;
  font-size: 13.5px;
  color: var(--blue);
}
.trans { color: var(--muted); font-size: 14.5px; }
.b-phrase .pron, .b-phrase .trans { margin-top: 2px; }

.pg-label {
  display: inline-block;
  background: var(--ink);
  color: var(--paper);
  padding: 3px 10px;
  font-size: 12px;
  font-weight: 600;
  letter-spacing: .08em;
  text-transform: uppercase;
  margin-bottom: 10px;
}
.vocab { border: var(--line); background: var(--card); }
.vocab-row {
  display: block;
  padding: 11px 14px;
}
.vocab-row + .vocab-row { border-top: 1px solid #E7E4DB; }
.vocab-row .dutch { font-weight: 600; font-size: 15.5px; line-height: 1.3; }
.vocab-row .pron { margin-top: 4px; line-height: 1.4; word-break: break-word; }
.vocab-row .trans { margin-top: 3px; line-height: 1.35; }
.article-de { color: var(--red); }
.article-het { color: var(--blue); }

/* dialogue */
.dialogue { border: var(--line); background: var(--card); box-shadow: 4px 4px 0 var(--ink); }
.dlg-title {
  background: var(--ink);
  color: var(--paper);
  padding: 9px 14px;
  font-family: var(--display);
  font-size: 13px;
  letter-spacing: .05em;
  text-transform: uppercase;
}
.dlg-line {
  display: flex;
  gap: 10px;
  padding: 11px 14px;
}
.dlg-line + .dlg-line { border-top: 1px dashed #D8D4CA; }
.avatar {
  width: 30px; height: 30px;
  flex-shrink: 0;
  display: grid;
  place-items: center;
  font-family: var(--display);
  font-size: 13px;
  color: #fff;
  margin-top: 2px;
}
.dlg-line:nth-child(odd)  .avatar { background: var(--blue); }
.dlg-line:nth-child(even) .avatar { background: var(--red); }
.dlg-body .speaker {
  font-size: 11px;
  font-weight: 600;
  letter-spacing: .1em;
  text-transform: uppercase;
  color: var(--muted);
}
.dlg-body .dutch { font-weight: 600; font-size: 15px; }
.dlg-body .pron { margin: 1px 0; }
.dlg-body .trans { font-size: 13.5px; }

/* table */
.tablewrap { overflow-x: auto; border: var(--line); background: var(--card); }
table { border-collapse: collapse; width: 100%; font-size: 13.5px; }
th {
  background: var(--yellow);
  text-align: left;
  padding: 8px 10px;
  font-size: 11px;
  letter-spacing: .08em;
  text-transform: uppercase;
  border-bottom: var(--line);
  white-space: nowrap;
}
td { padding: 8px 10px; vertical-align: top; border-bottom: 1px solid #E7E4DB; }
tr:last-child td { border-bottom: none; }
.table-cap {
  margin-top: 6px;
  font-size: 11.5px;
  color: var(--muted);
}

/* bottom bar */
.bottombar {
  position: fixed;
  left: 0; right: 0; bottom: 0;
  z-index: 20;
  background: var(--ink);
  padding: 12px 16px calc(12px + var(--sab));
  transform: translateY(0);
  transition: transform .25s ease;
}
.bottombar-inner {
  max-width: 560px;
  margin: 0 auto;
  display: flex;
  gap: 10px;
}
.btn-next {
  flex: 1;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  background: var(--paper);
  color: var(--ink);
  padding: 14px 16px;
  font-family: var(--display);
  font-size: 15px;
  text-transform: uppercase;
  letter-spacing: .02em;
  transition: transform .1s ease;
}
.btn-next:active { transform: scale(.98); }
.btn-next .arrow { color: var(--red); font-size: 18px; }
.btn-done .arrow { color: var(--blue); }

.toast {
  position: fixed;
  left: 50%;
  bottom: calc(96px + var(--sab));
  transform: translateX(-50%) translateY(8px);
  z-index: 30;
  background: var(--blue);
  color: #fff;
  padding: 9px 16px;
  font-size: 13px;
  font-weight: 500;
  opacity: 0;
  pointer-events: none;
  transition: opacity .25s ease, transform .25s ease;
}
.toast.show { opacity: 1; transform: translateX(-50%) translateY(0); }

@media (min-width: 720px) {
  .home, .lesson, .bottombar-inner { max-width: 620px; }
}
@media (prefers-reduced-motion: reduce) {
  * { transition: none !important; animation: none !important; }
}