/* style.css — kolme vyöhykettä: yläpalkki, tehtävä, alapalkki.
 * Litteät värit, ei liukuvärejä, ei varjoja paitsi paneelin reunassa.
 * Pääväri lila. Vihreä = oikein. Meripihka = huomio.
 */

:root {
  --bg: #14121a;
  --surface: #1c1926;
  --surface-2: #262232;
  --line: #332d42;
  --text: #ece9f2;
  --dim: #9b93ad;

  --lila: #8b5cf6;
  --lila-ink: #100a1c;   /* teksti lilan päällä */
  --ok: #3dbfa0;
  --note: #e0a33e;

  --radius: 12px;
  --tap: 52px;
  --bar: 60px;
  --safe-t: env(safe-area-inset-top);
  --safe-b: env(safe-area-inset-bottom);
}

@media (prefers-color-scheme: light) {
  :root {
    --bg: #f7f5fb;
    --surface: #ffffff;
    --surface-2: #efebf7;
    --line: #ded6ec;
    --text: #1b1725;
    --dim: #6a6280;

    --lila: #6d3fe0;
    --lila-ink: #ffffff;
    --ok: #0f7d67;
    --note: #8a5b00;
  }
}

* { box-sizing: border-box; }

html, body {
  margin: 0;
  padding: 0;
  height: 100%;
  background: var(--bg);
  color: var(--text);
  font: 400 17px/1.5 -apple-system, BlinkMacSystemFont, "Segoe UI", system-ui, sans-serif;
  -webkit-text-size-adjust: 100%;
  overscroll-behavior: none;
}

.hidden { display: none !important; }

/* ---------- kolme vyöhykettä ---------- */

.view {
  position: fixed;
  inset: 0;
  display: grid;
  grid-template-rows: auto 1fr auto;
  max-width: 640px;
  margin: 0 auto;
}

.middle {
  overflow-y: auto;
  -webkit-overflow-scrolling: touch;
  padding: 20px 18px 24px;
  display: flex;
  flex-direction: column;
}
.middle-center { justify-content: center; }

/* ---------- yläpalkki ---------- */

.topbar {
  display: flex;
  align-items: center;
  gap: 12px;
  height: calc(var(--bar) + var(--safe-t));
  padding: var(--safe-t) 10px 0 10px;
  border-bottom: 1px solid var(--line);
  background: var(--bg);
}

.topbar-title { padding: 0 8px; font-size: 17px; font-weight: 500; }

.iconbtn {
  flex: 0 0 auto;
  width: 40px; height: 40px;
  display: grid; place-items: center;
  background: none;
  border: 0;
  border-radius: 10px;
  color: var(--text);
  font-size: 15px;
  cursor: pointer;
}
.iconbtn:active { background: var(--surface-2); }

/* Hampurilainen: kolme viivaa, ei ikonikirjastoa. */
.burger, .burger::before, .burger::after {
  display: block;
  width: 18px; height: 2px;
  background: var(--text);
  border-radius: 2px;
}
.burger { position: relative; }
.burger::before, .burger::after { content: ''; position: absolute; left: 0; }
.burger::before { top: -6px; }
.burger::after  { top: 6px; }

.topbtn {
  flex: 0 0 auto;
  min-height: 36px;
  padding: 0 14px;
  background: none;
  border: 1px solid var(--lila);
  border-radius: 999px;
  color: var(--lila);
  font-size: 15px;
  font-weight: 500;
  cursor: pointer;
}

.dots {
  flex: 1;
  display: flex;
  justify-content: center;
  gap: 8px;
}

.dot {
  width: 8px; height: 8px;
  border-radius: 50%;
  background: var(--line);
}
.dot.done { background: var(--lila); }
.dot.now  { background: var(--lila); width: 22px; border-radius: 999px; }

/* ---------- alapalkki ---------- */

.bottombar {
  display: flex;
  gap: 10px;
  padding: 10px 12px calc(var(--safe-b) + 10px);
  border-top: 1px solid var(--line);
  background: var(--bg);
}

.btn {
  min-height: var(--tap);
  padding: 0 18px;
  font-size: 17px;
  font-weight: 500;
  border-radius: var(--radius);
  cursor: pointer;
}

.btn-primary {
  flex: 1 1 auto;
  background: var(--lila);
  color: var(--lila-ink);
  border: 0;
}

.btn-quiet {
  flex: 0 0 auto;
  background: transparent;
  color: var(--dim);
  border: 1px solid var(--line);
}

.btn-small { min-height: 42px; font-size: 15px; padding: 0 14px; }

/* ---------- tehtävä ---------- */

.problem { margin-bottom: 20px; }

.ptext {
  margin: 0;
  font-size: 21px;
  line-height: 1.45;
  white-space: pre-line;   /* T13 käyttää rivinvaihtoja */
}

/* ---------- tukirakenne ---------- */

.scaffold {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 2px 14px;
  margin-bottom: 20px;
}
.scaffold:empty { display: none; }

.row {
  display: flex;
  align-items: center;
  gap: 10px;
  min-height: 46px;
  border-bottom: 1px solid var(--line);
}
.row:last-child { border-bottom: 0; }

.row-label { flex: 1; color: var(--dim); font-size: 15px; }
.row-unit  { color: var(--dim); font-size: 14px; min-width: 42px; }

.row input {
  width: 92px;
  padding: 7px 9px;
  font-size: 17px;
  text-align: right;
  color: var(--text);
  background: var(--surface-2);
  border: 1px solid var(--line);
  border-radius: 9px;
}
.row input:focus { outline: 2px solid var(--lila); outline-offset: 1px; }
.row input.ok { border-color: var(--ok); }

.row-derived .row-value {
  font-size: 17px;
  font-variant-numeric: tabular-nums;
}

/* Yksikkötarkistus on oma, ohitettavissa oleva rivi — siihen kaatuvat laskut. */
.row-check { gap: 12px; }
.row-check .check-btn {
  padding: 8px 14px;
  font-size: 15px;
  border-radius: 9px;
  border: 1px solid var(--line);
  background: var(--surface-2);
  color: var(--dim);
  cursor: pointer;
}
.row-check .check-btn.on { border-color: var(--ok); color: var(--ok); }

/* ---------- vastaus ---------- */

.answer { margin-top: auto; padding-top: 12px; }

.answer-label {
  display: block;
  color: var(--dim);
  font-size: 13px;
  letter-spacing: .06em;
  text-transform: uppercase;
  margin-bottom: 8px;
}

.answer-row { display: flex; align-items: center; gap: 10px; }

.answer-input {
  flex: 1;
  min-width: 0;            /* ilman tätä inputin oletusleveys venyttää rivin yli ruudun */
  min-height: var(--tap);
  padding: 10px 14px;
  font-size: 26px;
  font-variant-numeric: tabular-nums;
  color: var(--text);
  background: var(--surface);
  border: 2px solid var(--line);
  border-radius: var(--radius);
}
.answer-input:focus { outline: none; border-color: var(--lila); }
.answer-input.correct { border-color: var(--ok); }

.answer-unit { color: var(--dim); font-size: 16px; min-width: 74px; }

/* ---------- palaute ---------- */

/* Ei punaista, ei rastia. Väärä vastaus on tieto, ei rangaistus. */
.feedback {
  min-height: 44px;
  margin: 12px 0 0;
  font-size: 16px;
  line-height: 1.4;
  color: var(--note);
}
.feedback.correct { color: var(--ok); }

/* ---------- sarjan loppu ---------- */

.done-score { color: var(--dim); margin: 0 0 18px; font-size: 17px; }

.done-list { list-style: none; padding: 0; margin: 0; }
.done-list li {
  display: flex; justify-content: space-between;
  padding: 12px 0; border-bottom: 1px solid var(--line);
  font-size: 16px;
}
.done-list .label { color: var(--dim); }

/* ---------- lukitus ---------- */

.lock { align-items: center; gap: 0; }

.lock-label {
  margin: 0 0 22px;
  color: var(--dim);
  font-size: 13px;
  letter-spacing: .06em;
  text-transform: uppercase;
}

.pin-dots { display: flex; gap: 14px; }

.pin-dots span {
  width: 13px; height: 13px;
  border-radius: 50%;
  border: 1.5px solid var(--line);
}
.pin-dots span.on { background: var(--lila); border-color: var(--lila); }

/* Väärä koodi tärähtää kerran. Ei punaista — sama sääntö kuin vastauspalautteessa. */
.pin-dots.wrong { animation: nyk .3s; }
@keyframes nyk {
  25% { transform: translateX(-7px); }
  75% { transform: translateX(7px); }
}
@media (prefers-reduced-motion: reduce) {
  .pin-dots.wrong { animation: none; }
}

.pin-msg {
  min-height: 22px;
  margin: 16px 0 26px;
  font-size: 15px;
  color: var(--note);
}

.pin-grid {
  display: grid;
  grid-template-columns: repeat(3, 74px);
  gap: 14px;
}
.pin-grid button {
  height: 74px;
  font-size: 26px;
  font-weight: 400;
  color: var(--text);
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: 50%;
  cursor: pointer;
}
.pin-grid button:active { background: var(--surface-2); border-color: var(--lila); }
.pin-grid .pin-del {
  background: none;
  border-color: transparent;
  font-size: 20px;
  color: var(--dim);
}

/* ---------- valikko ---------- */

.backdrop {
  position: fixed; inset: 0; z-index: 15;
  background: rgba(0, 0, 0, .55);
}

.drawer {
  position: fixed;
  top: 0; bottom: 0; left: 0;
  z-index: 16;
  width: min(86vw, 380px);
  display: flex;
  flex-direction: column;
  background: var(--bg);
  border-right: 1px solid var(--line);
}

.drawer-head {
  display: flex; align-items: center; gap: 8px;
  height: calc(var(--bar) + var(--safe-t));
  padding: var(--safe-t) 10px 0 18px;
  border-bottom: 1px solid var(--line);
}
.drawer-title { flex: 1; margin: 0; font-size: 19px; }

.drawer-body {
  overflow-y: auto;
  -webkit-overflow-scrolling: touch;
  padding: 14px 18px calc(var(--safe-b) + 26px);
}

.drawer-h, .t-h {
  font-size: 13px;
  letter-spacing: .06em;
  text-transform: uppercase;
  color: var(--dim);
  margin: 26px 0 10px;
}

.phase-label {
  margin: 0 0 14px;
  color: var(--lila);
  font-size: 14px;
}

.topics-list { list-style: none; padding: 0; margin: 0; }
.topics-list li {
  display: flex; justify-content: space-between; align-items: baseline; gap: 10px;
  padding: 13px 0; border-bottom: 1px solid var(--line);
  cursor: pointer;
}
.topics-list .label { color: var(--dim); font-size: 14px; white-space: nowrap; }
.topics-list .chev { color: var(--lila); font-size: 13px; margin-left: 10px; }

.select {
  display: block; width: 100%;
  min-height: 46px; padding: 0 10px;
  background: var(--surface); color: var(--text);
  border: 1px solid var(--line); border-radius: 10px; font-size: 15px;
}

.backup { display: flex; gap: 10px; }
.backup .btn { flex: 1; }

/* ---------- lehdet (teoria, laskin) ---------- */

.sheet {
  position: fixed;
  left: 0; right: 0; bottom: 0;
  z-index: 16;
  max-width: 640px; margin: 0 auto;
  max-height: 88dvh;
  display: flex; flex-direction: column;
  background: var(--bg);
  border-top: 1px solid var(--line);
  border-radius: 16px 16px 0 0;
}

.sheet-head {
  display: flex; align-items: center; gap: 12px;
  padding: 14px 12px 12px 18px;
  border-bottom: 1px solid var(--line);
}
.sheet-title { flex: 1; margin: 0; font-size: 19px; }

.sheet-body {
  overflow-y: auto;
  -webkit-overflow-scrolling: touch;
  padding: 4px 18px calc(var(--safe-b) + 26px);
}

/* Sääntö on ainoa asia joka pitää lukea jos lukee vain yhden asian. */
.t-rule {
  background: var(--surface);
  border-left: 3px solid var(--lila);
  border-radius: 0 10px 10px 0;
  padding: 13px 15px;
  margin: 16px 0 22px;
  font-size: 17px;
  line-height: 1.45;
}

.t-steps { margin: 0; padding-left: 22px; }
.t-steps li { margin: 7px 0; }

.t-table { width: 100%; border-collapse: collapse; font-size: 15px; }
.t-table th {
  text-align: left; color: var(--dim); font-weight: 500;
  padding: 7px 8px 7px 0; border-bottom: 1px solid var(--line);
  font-size: 13px;
}
.t-table td {
  padding: 9px 8px 9px 0;
  border-bottom: 1px solid var(--line);
  vertical-align: top;
}
.t-table tr td:first-child { white-space: nowrap; }
.t-table-wrap { overflow-x: auto; }

.t-ex {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: 12px;
  padding: 14px 15px;
  margin-bottom: 14px;
}
.t-ex-q { margin: 0 0 12px; font-size: 15px; }
.t-ex-lines {
  margin: 0; padding: 0; list-style: none;
  font-family: ui-monospace, SFMono-Regular, Menlo, monospace;
  font-size: 14.5px; line-height: 1.75;
  color: var(--dim);
  white-space: pre-wrap;
}
.t-ex-a {
  margin: 12px 0 0; padding-top: 11px;
  border-top: 1px solid var(--line);
  font-size: 16px; font-weight: 600; color: var(--ok);
}

.t-warn { margin: 0; padding: 0; list-style: none; }
.t-warn li {
  position: relative;
  padding: 0 0 0 22px;
  margin: 11px 0;
  font-size: 15.5px; line-height: 1.45;
}
.t-warn li::before {
  content: '!';
  position: absolute; left: 0; top: 0;
  color: var(--note); font-weight: 700;
}

/* ---------- laskin ---------- */

.sheet-calc { padding-bottom: calc(var(--safe-b) + 14px); }

.calc-display {
  flex: 1;
  text-align: right;
  font-size: 30px;
  font-variant-numeric: tabular-nums;
  overflow-x: auto;
}

.calc-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 8px;
  padding: 12px 14px 0;
}
.calc-grid button {
  min-height: 52px;
  font-size: 19px;
  background: var(--surface);
  color: var(--text);
  border: 1px solid var(--line);
  border-radius: 11px;
  cursor: pointer;
}
.calc-grid button.op { background: var(--surface-2); color: var(--lila); }
.calc-grid button.wide { grid-column: span 3; font-size: 16px; }