/* ПДР B — one stylesheet for the app (app.js), the privacy page and the static
   question / section pages (build_seo.py). Sections:
   1 tokens · 2 base · 3 buttons and fields · 4 layout pieces · 5 question card
   6 home · 7 study / exam · 8 lists, search, topics · 9 settings · 10 static pages
   11 feedback (toast, dialog, confetti) · 12 motion */

/* ---------- 1. tokens ---------- */
:root {
  --bg: #f4f5f7;
  --surface: #ffffff;
  --surface-2: #eef0f4;
  --text: #16181d;
  --muted: #5f6673;
  --border: #dde1e7;
  --accent: #1d4ed8;
  --accent-text: #ffffff;
  --accent-soft: #e3eafc;
  --ok: #157a3c;
  --ok-soft: #dcf3e4;
  --bad: #c0262d;
  --bad-soft: #fbe2e3;
  --warn: #a15c00;
  --warn-soft: #fdf0dc;
  --new: #1d4ed8;
  --learn: #c0262d;
  --review: #157a3c;
  --on-color: #ffffff;
  --shadow: 0 1px 2px rgba(16, 24, 40, .06), 0 1px 3px rgba(16, 24, 40, .08);
  --shadow-lg: 0 10px 40px rgba(16, 24, 40, .22);

  --radius: 14px;
  --radius-sm: 10px;
  --radius-pill: 999px;
  --s1: 4px; --s2: 8px; --s3: 12px; --s4: 16px; --s5: 24px; --s6: 32px;
  --fs-xs: 12px; --fs-sm: 13px; --fs-base: 16px; --fs-md: 18px; --fs-lg: 22px;
  --tap: 48px;
  --page: 720px;
  --ease-out: cubic-bezier(.2, .8, .2, 1);
  color-scheme: light;
}
@media (prefers-color-scheme: dark) {
  :root {
    --bg: #0f1115;
    --surface: #181b21;
    --surface-2: #22262e;
    --text: #e8eaee;
    --muted: #9aa1ad;
    --border: #2c313a;
    --accent: #5b8cff;
    --accent-text: #0b1020;
    --accent-soft: #1c2a4d;
    --ok: #4cc47d;
    --ok-soft: #173525;
    --bad: #ff6b70;
    --bad-soft: #3d1c1e;
    --warn: #f0a53a;
    --warn-soft: #3a2a12;
    --new: #6f9bff;
    --learn: #ff7a7f;
    --review: #4cc47d;
    --on-color: #0b1020;
    --shadow: none;
    --shadow-lg: 0 10px 40px rgba(0, 0, 0, .6);
    color-scheme: dark;
  }
}

/* ---------- 2. base ---------- */
* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font: var(--fs-base)/1.5 -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
}
#app {
  max-width: var(--page);
  margin: 0 auto;
  padding: var(--s4) var(--s4) calc(120px + env(safe-area-inset-bottom));
}
h1, h2, h3 { line-height: 1.25; margin: 0; }
h1 { font-size: 24px; letter-spacing: -.01em; }
h2 { font-size: var(--fs-md); }
h3 { font-size: 15px; }
[tabindex="-1"]:focus { outline: none; }
p { margin: 0; }
a { color: var(--accent); }
.loading { text-align: center; color: var(--muted); padding: 48px 0; }
.muted { color: var(--muted); }
.small { font-size: var(--fs-sm); }
.note { font-size: var(--fs-sm); color: var(--muted); }
.t-ok { color: var(--ok) !important; } .t-warn { color: var(--warn) !important; } .t-bad { color: var(--bad) !important; }
.sr-only {
  position: absolute; width: 1px; height: 1px; padding: 0; margin: -1px;
  overflow: hidden; clip: rect(0 0 0 0); white-space: nowrap; border: 0;
}

/* ---------- 3. buttons and fields ---------- */
button, .btn {
  font: inherit;
  border: 1px solid var(--border);
  background: var(--surface);
  color: var(--text);
  border-radius: 12px;
  padding: var(--s3) var(--s4);
  min-height: var(--tap);
  cursor: pointer;
  text-decoration: none;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--s2);
  -webkit-tap-highlight-color: transparent;
  transition: background-color .15s, border-color .15s, transform .1s;
}
button:focus-visible, .btn:focus-visible, summary:focus-visible, a:focus-visible {
  outline: 3px solid var(--accent); outline-offset: 2px;
}
button:disabled { opacity: .5; cursor: default; }
@media (hover: hover) { button:not(:disabled):hover { border-color: color-mix(in srgb, var(--accent) 40%, var(--border)); } }
.primary { background: var(--accent); border-color: var(--accent); color: var(--accent-text); font-weight: 600; }
.danger { background: var(--bad); border-color: var(--bad); color: var(--on-color); font-weight: 600; }
.text-bad { color: var(--bad); }
.block { width: 100%; }
.big { font-size: var(--fs-md); min-height: 56px; }
.ghost { background: transparent; border-color: transparent; color: var(--accent); padding: var(--s2) 10px; min-height: 40px; }
.icon-btn {
  min-height: 44px; width: 44px; padding: 0; border-radius: 50%;
  background: transparent; border-color: transparent; color: var(--muted);
}
@media (hover: hover) { .icon-btn:hover { background: var(--surface-2); } }
.chip {
  min-height: 34px; padding: var(--s1) var(--s3); border-radius: var(--radius-pill); font-size: 14px;
  background: var(--accent-soft); border-color: transparent; color: var(--accent); font-weight: 600;
}
.actions { display: grid; gap: var(--s2); }
.actions.two { grid-template-columns: 1fr 1fr; }

input[type="number"], input[type="date"], input[type="time"], select {
  font: inherit; font-size: var(--fs-base); color: var(--text); background: var(--surface);
  border: 1px solid var(--border); border-radius: var(--radius-sm); padding: 10px var(--s3); min-height: 44px; width: 100%;
}
label.field { display: grid; gap: var(--s1); }
label.field > span { font-weight: 500; }

/* segmented control (pace presets) */
.seg { display: grid; grid-auto-flow: column; grid-auto-columns: 1fr; gap: var(--s2); }
.seg button { padding-left: var(--s1); padding-right: var(--s1); }
.seg button { flex-direction: column; gap: 0; line-height: 1.25; }
.seg button small { font-size: var(--fs-xs); color: var(--muted); font-weight: 400; }
.seg button.on { border-color: var(--accent); background: var(--accent-soft); font-weight: 600; box-shadow: inset 0 0 0 1px var(--accent); }

/* on/off switch */
.switch {
  flex: 0 0 52px; width: 52px; min-height: 32px; height: 32px; padding: 3px; border-radius: var(--radius-pill);
  background: var(--surface-2); justify-content: flex-start;
}
.switch span { width: 24px; height: 24px; border-radius: 50%; background: #fff; box-shadow: 0 1px 3px rgba(0, 0, 0, .3); transition: transform .2s ease; }
.switch.on { background: var(--accent); border-color: var(--accent); }
.switch.on span { transform: translateX(20px); }

/* ---------- 4. layout pieces ---------- */
.stack > * + * { margin-top: var(--s3); }
.row { display: flex; gap: var(--s2); align-items: center; flex-wrap: wrap; }
.spread { justify-content: space-between; }
.grow { flex: 1 1 auto; }
.card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: var(--s4);
  box-shadow: var(--shadow);
}
.badge {
  display: inline-block; font-size: var(--fs-xs); font-weight: 600; padding: 2px var(--s2);
  border-radius: var(--radius-pill); background: var(--accent-soft); color: var(--accent);
}

/* screen header: back · title · right slot (privacy.html uses .top with a plain h1) */
.top { display: flex; align-items: center; gap: var(--s2); min-height: 48px; margin-bottom: var(--s3); }
.top > h1 { flex: 1; }
.nav-btn {
  flex: 0 0 auto; min-height: 44px; padding: var(--s1) var(--s2) var(--s1) var(--s1); gap: 2px;
  background: transparent; border-color: transparent; color: var(--accent); font-weight: 500;
}
@media (hover: hover) { .nav-btn:hover { background: var(--surface-2); } }
.top-title { flex: 1 1 auto; min-width: 0; }
.top-title h1 { font-size: 17px; font-weight: 700; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.top-title p { font-size: var(--fs-sm); color: var(--muted); font-variant-numeric: tabular-nums; }
.top-right { flex: 0 0 auto; display: flex; align-items: center; gap: var(--s2); }

/* bottom action bar */
.dock {
  position: fixed; left: 0; right: 0; bottom: 0; z-index: 10;
  background: color-mix(in srgb, var(--bg) 88%, transparent);
  backdrop-filter: blur(10px); -webkit-backdrop-filter: blur(10px);
  border-top: 1px solid var(--border);
  padding: 10px var(--s4) calc(10px + env(safe-area-inset-bottom));
}
.dock-inner { max-width: var(--page); margin: 0 auto; display: grid; gap: var(--s2); }

/* progress bars */
.bar { display: flex; height: 8px; border-radius: var(--radius-pill); overflow: hidden; background: var(--surface-2); }
.bar > span { display: block; height: 100%; transition: width .6s var(--ease-out); }
.bar.thin { height: 4px; margin: calc(-1 * var(--s1)) 0 var(--s3); }
.bar .b-known { background: var(--review); }
.bar .b-learn { background: var(--warn); }

.empty-state { text-align: center; padding: var(--s6) var(--s4); }
.empty-state .emoji { font-size: 44px; line-height: 1; }
.empty-state .actions { margin-top: var(--s5); }
.stat-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: var(--s2); text-align: center; }
.stat-grid b { display: block; font-size: var(--fs-lg); font-variant-numeric: tabular-nums; }
.stat-grid span { font-size: var(--fs-xs); color: var(--muted); }
.pills { display: flex; gap: 6px; flex-wrap: wrap; }
.pill { font-size: var(--fs-sm); font-weight: 600; padding: var(--s1) 10px; border-radius: var(--radius-pill); font-variant-numeric: tabular-nums; }
.pill.ok { background: var(--ok-soft); color: var(--ok); }
.pill.bad { background: var(--bad-soft); color: var(--bad); }
.pill.warn { background: var(--warn-soft); color: var(--warn); }
.pill.empty { background: var(--surface-2); color: var(--muted); }
.section-h { font-size: var(--fs-md); margin: var(--s5) var(--s1) var(--s3); }
footer { margin-top: 28px; font-size: var(--fs-sm); color: var(--muted); text-align: center; line-height: 1.6; }
footer a { color: var(--muted); }
footer p + p { margin-top: var(--s1); }

/* ---------- 5. question card ---------- */
.qsec { font-size: var(--fs-xs); color: var(--muted); margin-bottom: var(--s2); }
.qtext { font-size: var(--fs-md); font-weight: 600; margin-bottom: var(--s3); }
@media (min-width: 600px) { .qtext { font-size: 20px; } }
.qimg {
  display: block; width: 100%; height: auto; max-height: min(42vh, 340px); object-fit: contain;
  border-radius: var(--radius-sm); margin: 0 0 var(--s3);
}
.leech { color: var(--warn); font-weight: 600; white-space: nowrap; }
.opts { display: grid; gap: var(--s2); list-style: none; padding: 0; margin: 0; }
.opt {
  position: relative; width: 100%; text-align: left; justify-content: flex-start; align-items: flex-start;
  padding: var(--s3) 14px; line-height: 1.4; min-height: 52px;
}
.opt .n {
  flex: 0 0 26px; height: 26px; border-radius: 50%; background: var(--surface-2);
  display: inline-flex; align-items: center; justify-content: center; font-size: var(--fs-sm); font-weight: 700;
  margin-top: -1px; font-variant-numeric: tabular-nums;
}
.opt:disabled { opacity: 1; cursor: default; }
.opt:not(:disabled):active { transform: scale(.985); }
.opt.sel { border-color: var(--accent); background: var(--accent-soft); }
.opt.right { border-color: var(--ok); background: var(--ok-soft); }
.opt.right .n { background: var(--ok); color: var(--on-color); }
.opt.wrong { border-color: var(--bad); background: var(--bad-soft); }
.opt.wrong .n { background: var(--bad); color: var(--on-color); }
.opt.dim { opacity: .55; }
/* right / wrong are not told by colour alone */
.opt.right::after, .opt.wrong::after {
  margin-left: auto; padding-left: var(--s2); font-weight: 800; font-size: var(--fs-md); line-height: 1.2;
}
.opt.right::after { content: "✓"; color: var(--ok); }
.opt.wrong::after { content: "✗"; color: var(--bad); }
.verdict { font-weight: 700; margin-top: var(--s3); }
.verdict.ok { color: var(--ok); }
.verdict.bad { color: var(--bad); }
.verdict .hint { display: block; margin-top: 2px; font-weight: 400; font-size: 14px; color: var(--muted); }
.combo { display: inline-block; color: var(--warn); white-space: nowrap; }

/* look-alike questions after a mistake */
.twins { margin-top: var(--s4); padding-top: 14px; border-top: 1px dashed var(--border); display: grid; gap: var(--s2); }
.twins-h { font-size: 14px; font-weight: 700; color: var(--warn); }
.twin { border: 1px solid var(--border); border-radius: 12px; background: var(--surface); }
.twin summary {
  display: flex; align-items: center; gap: 10px; min-height: 52px; padding: var(--s2) var(--s3);
  cursor: pointer; list-style: none; font-size: 14px; line-height: 1.35;
}
.twin .thumb { flex: 0 0 44px; width: 44px; height: 44px; object-fit: cover; border-radius: var(--s2); }
.twin-body { padding: 0 var(--s3) var(--s3); }
.twin-body .qimg { max-height: 220px; }
.twin-body .opt { min-height: 44px; padding: var(--s2) var(--s3); font-size: 14px; }

/* disclosure arrows: one look for every <details> */
summary { cursor: pointer; list-style: none; }
summary::-webkit-details-marker { display: none; }
.twin summary::after, details.group summary::after, details.tiers summary::after,
details.more summary::after, #about summary::after {
  content: "›"; display: inline-block; margin-left: auto; padding-left: var(--s2);
  font-size: 20px; line-height: 1; color: var(--muted); transition: transform .2s;
}
details[open] > summary::after { transform: rotate(90deg); }

/* ---------- 6. home ---------- */
.brand { font-size: var(--fs-lg); flex: 1; }
.brand span { color: var(--muted); font-weight: 600; }
.streak {
  font-weight: 700; font-variant-numeric: tabular-nums; padding: var(--s1) 10px; border-radius: var(--radius-pill);
  background: var(--warn-soft); color: var(--warn); white-space: nowrap;
}
.streak.risk { animation: pulse 1.6s ease-in-out infinite; }
@keyframes pulse { 50% { opacity: .45; } }
.risk-note { color: var(--warn); }

.search-bar {
  width: 100%; justify-content: flex-start; gap: 10px; margin-bottom: var(--s3);
  border-radius: var(--radius-pill); color: var(--muted); background: var(--surface); box-shadow: var(--shadow); font-size: 15px;
}

.hero { display: grid; gap: var(--s4); }
.hero-row { display: flex; align-items: center; gap: var(--s4); }
.hero-text h2 { font-size: var(--fs-lg); }
.hero-text p { margin-top: 2px; }
.ring { position: relative; flex: 0 0 80px; height: 80px; }
.ring svg { transform: rotate(-90deg); display: block; }
.ring circle { fill: none; stroke-width: 8; }
.ring-bg { stroke: var(--surface-2); }
.ring-fg { stroke: var(--ok); stroke-linecap: round; transition: stroke-dashoffset .8s var(--ease-out); }
.ring span {
  position: absolute; inset: 0; display: flex; align-items: center; justify-content: center;
  font-size: 20px; font-weight: 800; font-variant-numeric: tabular-nums;
}
.ring small { font-size: var(--fs-xs); font-weight: 600; color: var(--muted); }
.meta { display: flex; flex-wrap: wrap; gap: 6px var(--s4); font-size: 14px; color: var(--muted); align-items: center; }
.meta b { color: var(--text); font-variant-numeric: tabular-nums; }
.gain { color: var(--ok); font-weight: 600; font-size: var(--fs-xs); }
.date-chip { position: relative; display: inline-flex; align-items: center; cursor: pointer; overflow: hidden; }
.date-chip input {
  position: absolute; inset: 0; width: 100%; height: 100%; min-height: 0; margin: 0; padding: 0;
  border: 0; opacity: 0; cursor: pointer; font-size: var(--fs-base);
}
.date-chip:focus-within { outline: 3px solid var(--accent); outline-offset: 2px; }

.week { display: grid; grid-template-columns: repeat(7, 1fr); gap: var(--s1); text-align: center; }
.week span { display: grid; justify-items: center; gap: var(--s1); }
.week i {
  width: 30px; height: 30px; border-radius: 50%; background: var(--surface-2);
  display: flex; align-items: center; justify-content: center; font-style: normal; font-size: 14px; font-weight: 700;
}
.week .on i { background: var(--ok); color: var(--on-color); }
.week .today i { box-shadow: 0 0 0 2px var(--surface), 0 0 0 4px var(--accent); }
.week small { font-size: 11px; color: var(--muted); }

.tiles { display: grid; grid-template-columns: 1fr 1fr; gap: var(--s3); }
.tile {
  display: grid; grid-template-rows: auto auto 1fr; align-content: start; justify-content: stretch; justify-items: start;
  gap: 2px; width: 100%; min-height: 112px; padding: var(--s4); text-align: left;
  border-radius: var(--radius); background: var(--surface); box-shadow: var(--shadow);
}
.tile:not(:disabled):active { transform: scale(.98); }
.tile:disabled { opacity: .6; }
.tile-title { font-weight: 700; font-size: var(--fs-base); }
.tile-sub { font-size: var(--fs-sm); color: var(--muted); }
.tile-num { align-self: end; margin-top: 10px; font-size: 28px; font-weight: 800; font-variant-numeric: tabular-nums; line-height: 1; }
.exam-dots { align-self: end; display: flex; gap: 5px; margin-top: var(--s3); }
.exam-dots i { width: 14px; height: 14px; border-radius: 50%; background: var(--surface-2); }
.exam-dots .ok { background: var(--ok); } .exam-dots .warn { background: var(--warn); } .exam-dots .bad { background: var(--bad); }

.legend { display: flex; flex-wrap: wrap; gap: var(--s1) var(--s4); font-size: var(--fs-sm); color: var(--muted); font-variant-numeric: tabular-nums; }
.legend i { display: inline-block; width: 8px; height: 8px; border-radius: 50%; background: var(--surface-2); margin-right: 6px; }
.legend i.k { background: var(--review); } .legend i.l { background: var(--warn); }
details.tiers summary { display: flex; font-size: 14px; font-weight: 600; color: var(--accent); padding: var(--s1) 0; }
details.tiers summary::after { margin-left: var(--s1); padding: 0; color: inherit; font-size: inherit; line-height: inherit; }
.tier { padding: 10px 0 0; }
.tier .row { flex-wrap: nowrap; align-items: flex-start; }
.tier .name { flex: 1; min-width: 0; font-size: 14px; }
.tier .num { font-size: var(--fs-sm); color: var(--muted); font-variant-numeric: tabular-nums; white-space: nowrap; }
.tier .bar { margin-top: 6px; height: 6px; }
.ready { display: grid; gap: 6px; text-align: left; }
.ready b { font-variant-numeric: tabular-nums; }

/* static text under the app: quiet, collapsible, still plain HTML for search engines */
#app.with-about { padding-bottom: var(--s2); }
.seo { max-width: var(--page); margin: 0 auto; padding: 0 var(--s4) calc(48px + env(safe-area-inset-bottom)); }
#about { color: var(--muted); font-size: 14px; border-top: 1px solid var(--border); padding-top: var(--s5); margin-top: var(--s2); }
#about h1 { color: var(--text); }
#about h2 { font-size: var(--fs-base); color: var(--text); margin-bottom: var(--s2); }
#about p { color: var(--muted); }
#about p + p { margin-top: var(--s2); }
#about .about-block + .about-block { margin-top: var(--s5); }
#about details { border-bottom: 1px solid var(--border); padding: var(--s2) 0; }
#about details:first-of-type { border-top: 1px solid var(--border); }
#about summary { display: flex; align-items: center; min-height: 40px; color: var(--text); font-weight: 500; }
#about details > :not(summary) { margin-top: 6px; }
#about footer { margin-top: var(--s6); }

/* ---------- 7. study / exam ---------- */
/* Anki-style counters with a caption under each number */
.counts { display: flex; gap: var(--s3); font-variant-numeric: tabular-nums; text-align: center; }
.counts span { display: grid; line-height: 1.1; font-weight: 700; font-size: var(--fs-md); padding-bottom: 2px; border-bottom: 2px solid transparent; }
.counts small { font-size: 10px; font-weight: 600; color: var(--muted); text-transform: lowercase; }
.c-new { color: var(--new); }
.c-learn { color: var(--learn); }
.c-review { color: var(--review); }
.counts .on { border-bottom-color: currentColor; }

.grades { display: grid; grid-template-columns: repeat(3, 1fr); gap: var(--s2); }
.grades button { flex-direction: column; gap: 0; padding: var(--s2) var(--s1); min-height: 56px; line-height: 1.2; }
.grades small { font-size: var(--fs-xs); color: var(--muted); font-weight: 400; }
.grades .primary small { color: inherit; opacity: .85; }
.undo { justify-self: start; }

.timer {
  font-variant-numeric: tabular-nums; font-weight: 700; font-size: var(--fs-md);
  padding: 2px 10px; border-radius: var(--radius-pill); background: var(--surface-2);
}
.timer.low { color: var(--bad); background: var(--bad-soft); }
.dots { display: grid; grid-template-columns: repeat(10, 1fr); gap: var(--s1); margin-bottom: var(--s3); }
.dot {
  min-height: 36px; padding: 0; border-radius: var(--s2); font-size: var(--fs-xs); font-weight: 700;
  background: var(--surface-2); color: var(--muted); border: 2px solid transparent;
  font-variant-numeric: tabular-nums;
}
.dot.ok { background: var(--ok); color: var(--on-color); }
.dot.bad { background: var(--bad); color: var(--on-color); }
.dot.cur { border-color: var(--accent); }
.result { text-align: center; }
.result .emoji { font-size: 44px; line-height: 1; }
.result-big { font-size: 40px; font-weight: 800; font-variant-numeric: tabular-nums; line-height: 1.1; }

/* ---------- 8. lists, search, topics ---------- */
.seclist { list-style: none; margin: var(--s2) 0 0; padding: 0; display: grid; }
@media (min-width: 700px) { #about .seclist, .static .seclist { grid-template-columns: 1fr 1fr; column-gap: var(--s5); } }
.seclist li { border-bottom: 1px solid var(--border); }
.seclist .sec {
  display: flex; align-items: center; gap: var(--s3); min-height: 56px; padding: var(--s2) var(--s1);
  color: var(--text); text-decoration: none; -webkit-tap-highlight-color: transparent;
}
.seclist button.sec {
  width: 100%; border: 0; border-radius: 0; background: none; text-align: left; justify-content: flex-start;
  font: inherit; color: var(--text);
}
.seclist .sec::after { content: "›"; margin-left: auto; padding-left: var(--s2); font-size: 20px; color: var(--muted); }
.seclist .sec:hover .sec-name, .seclist .sec:focus-visible .sec-name { color: var(--accent); }
.seclist .sec:active { background: var(--surface-2); }
.sec-no {
  flex: 0 0 40px; height: 34px; border-radius: var(--radius-sm);
  display: inline-flex; align-items: center; justify-content: center;
  background: var(--accent-soft); color: var(--accent); font-size: var(--fs-sm); font-weight: 700; font-variant-numeric: tabular-nums;
}
.sec-name { display: grid; font-size: 15px; line-height: 1.3; }
.sec-name small { font-size: var(--fs-xs); color: var(--muted); margin-top: 2px; }
.seclist .st { flex: 0 0 8px; width: 8px; height: 8px; border-radius: 50%; margin-left: auto; }
.st.ok { background: var(--ok); } .st.warn { background: var(--warn); } .st.bad { background: var(--bad); }
/* the status dot / ring takes the free space; the arrow then sits right after it */
.sec:has(.st)::after, .sec:has(.mini-ring)::after { margin-left: 10px; }
.mini-ring {
  flex: 0 0 22px; width: 22px; height: 22px; border-radius: 50%; margin-left: auto;
  background: conic-gradient(var(--ok) calc(var(--p) * 1%), var(--surface-2) 0);
  -webkit-mask: radial-gradient(circle, transparent 6px, #000 7px); mask: radial-gradient(circle, transparent 6px, #000 7px);
}
.list-card { background: var(--surface); border-radius: var(--radius); box-shadow: var(--shadow); padding: 0 var(--s3); }
.list-card li:last-child { border-bottom: 0; }
#results .seclist, .topic-list { background: var(--surface); border-radius: var(--radius); box-shadow: var(--shadow); padding: 0 var(--s3); }
#results .seclist li:last-child, .topic-list li:last-child { border-bottom: 0; }
.topic-list { margin-top: var(--s3); }

.search-box { position: sticky; top: 0; z-index: 5; background: var(--bg); padding: var(--s1) 0 var(--s3); }
.search-box input {
  width: 100%; font: inherit; font-size: 17px; color: var(--text); background: var(--surface);
  border: 1px solid var(--border); border-radius: var(--radius-pill); padding: var(--s3) 18px; min-height: 50px;
}
.search-box input:focus { outline: 3px solid var(--accent); outline-offset: 1px; }
.search-hint { margin: var(--s2) var(--s1); }
.res-h { font-size: 15px; margin: var(--s4) var(--s1) 0; }

details.group { background: var(--surface); border-radius: var(--radius); box-shadow: var(--shadow); margin-top: 10px; }
details.group summary { padding: 14px var(--s4); font-weight: 600; display: flex; gap: var(--s2); align-items: center; }
#results details.group .seclist { margin: 0; padding: 0 var(--s3) var(--s1); border-top: 1px solid var(--border); background: none; box-shadow: none; border-radius: 0; }
details.group .seclist li:last-child { border-bottom: 0; }
.topic-h { font-size: var(--fs-lg); }

/* ---------- 9. settings ---------- */
.pref { display: flex; gap: var(--s3); align-items: flex-start; justify-content: space-between; padding-top: var(--s3); border-top: 1px solid var(--border); }
.pref:first-of-type { border-top: 0; padding-top: 0; }
.pref b { font-weight: 600; }
details.more { border-top: 1px solid var(--border); padding-top: var(--s3); }
details.more summary { display: flex; align-items: center; min-height: 40px; font-weight: 600; color: var(--accent); }
details.more[open] summary { margin-bottom: var(--s3); }
details.more > :not(summary) + * { margin-top: var(--s3); }
.saved { color: var(--ok); font-size: var(--fs-sm); font-weight: 600; }

/* ---------- 10. static pages (build_seo.py) ---------- */
#app.static { padding-bottom: calc(48px + env(safe-area-inset-bottom)); }
#app.static > * + * { margin-top: var(--s4); }
.seo h3 { margin-top: var(--s4); }
.seo p { color: var(--text); }
.crumbs a { color: var(--muted); }
.static-opts .opt { display: flex; gap: var(--s2); border: 1px solid var(--border); border-radius: 12px; min-height: 0; }
.static-opts button.opt { width: 100%; }
.qnav .btn { flex: 1 1 0; }
/* question page quiz: with JS the answer stays hidden until an option is picked */
.js .quiz:not(.done) .reveal, .js .quiz:not(.done) .mark { display: none; }
.js .quiz:not(.done) .opt.right { border-color: var(--border); background: var(--surface); }
.js .quiz:not(.done) .opt.right .n { background: var(--surface-2); color: inherit; }
/* static pages mark the right option with their own .mark */
.static-opts .opt::after { content: none !important; }
.quiz.done .show, html:not(.js) .show { display: none; }
.quiz.done .opt:not(.right):not(.wrong) { opacity: .55; }
.expl h2 { margin-top: var(--s2); }
.why, .rules { margin: 0; padding-left: 20px; }
.why li + li, .rules li + li { margin-top: var(--s2); }
.rules p { margin-top: var(--s1); font-size: 14px; color: var(--muted); }
.steps { margin: 0; padding-left: 22px; }
.steps li + li { margin-top: var(--s1); }
.tip { background: var(--accent-soft); border-radius: var(--radius-sm); padding: 10px var(--s3); }
.clause { padding-top: var(--s3); border-top: 1px solid var(--border); scroll-margin-top: var(--s3); }
.clause h2 { font-size: var(--fs-base); }
.clause p + p { margin-top: var(--s2); }
.clause:target { background: var(--accent-soft); border-radius: var(--radius-sm); padding: var(--s3); }

/* ---------- 11. feedback: toast, dialog, confetti ---------- */
/* Toasts sit at the bottom, above the action bar, so they never cover the header or question. */
.toast {
  position: fixed; left: 50%; bottom: calc(96px + env(safe-area-inset-bottom)); z-index: 30;
  transform: translateX(-50%); width: max-content; max-width: min(calc(100% - 32px), 480px);
  background: var(--text); color: var(--bg); font-weight: 600; font-size: 15px; text-align: center;
  padding: 10px 18px; border-radius: 18px; box-shadow: var(--shadow-lg);
  animation: toast-in .35s cubic-bezier(.2, .9, .3, 1.3);
}
.toast.out { opacity: 0; transform: translate(-50%, 12px); transition: .4s ease; }
@keyframes toast-in { from { opacity: 0; transform: translate(-50%, 16px) scale(.95); } }
.confetti { position: fixed; inset: 0; width: 100vw; height: 100vh; pointer-events: none; z-index: 40; }

dialog.sheet {
  padding: 0; border: 0; border-radius: 20px; background: var(--surface); color: var(--text);
  width: min(calc(100% - 32px), 420px); box-shadow: var(--shadow-lg);
}
dialog.sheet::backdrop { background: rgba(0, 0, 0, .45); }
.sheet-body { padding: 20px; }
.sheet-body > p:first-child { font-size: 17px; font-weight: 600; line-height: 1.4; }
.transfer h2 { font-size: var(--fs-md); }
.sheet-body .actions { margin-top: 20px; }
.sheet-body .sheet-note { margin-top: var(--s2); font-size: 15px; font-weight: 400; color: var(--muted); }
dialog.sheet[open] { animation: sheet-in .22s var(--ease-out); }
@keyframes sheet-in { from { opacity: 0; transform: translateY(16px) scale(.98); } }

/* ---------- 12. motion ---------- */
.qcard { view-transition-name: qcard; }
::view-transition-old(root), ::view-transition-new(root) { animation-duration: .18s; }
html[data-vt="next"]::view-transition-old(root), html[data-vt="next"]::view-transition-new(root) { animation: none; }
html[data-vt="next"]::view-transition-old(qcard) { animation: vt-out .2s ease-in both; }
html[data-vt="next"]::view-transition-new(qcard) { animation: vt-in .26s var(--ease-out) both; }
@keyframes vt-out { to { transform: translateX(-30%); opacity: 0; } }
@keyframes vt-in { from { transform: translateX(30%); opacity: 0; } }

.opts.just .opt.right { animation: pop .38s cubic-bezier(.2, .9, .3, 1.4); }
.opts.just .opt.wrong { animation: shake .42s ease; }
@keyframes pop { 40% { transform: scale(1.035); } }
@keyframes shake { 20%, 60% { transform: translateX(-6px); } 40%, 80% { transform: translateX(6px); } }
.combo { animation: bump .4s ease; }
@keyframes bump { 40% { transform: scale(1.25) rotate(-4deg); } }

/* auto-advance: the "Добре" / "Далі" button fills up before it presses itself */
.auto { position: relative; overflow: hidden; }
.auto::after {
  content: ""; position: absolute; left: 0; bottom: 0; height: 4px; width: 100%;
  background: currentColor; opacity: .55; transform-origin: left; animation: fill var(--auto, 1.4s) linear both;
}
@keyframes fill { from { transform: scaleX(0); } to { transform: scaleX(1); } }

/* the in-app "Анімації" switch adds .no-motion to <html> */
@media (prefers-reduced-motion: reduce) {
  *, ::view-transition-group(*), ::view-transition-old(*), ::view-transition-new(*) { animation: none !important; transition: none !important; }
}
.no-motion *, .no-motion ::view-transition-group(*), .no-motion ::view-transition-old(*), .no-motion ::view-transition-new(*) {
  animation: none !important; transition: none !important;
}

/* ---------- 13. first-launch tour (app.js showTour) ---------- */
dialog.tour { width: min(calc(100% - 24px), 460px); max-height: calc(100dvh - 24px); }
.tour .sheet-body { display: grid; gap: var(--s3); padding: var(--s5) 20px 20px; }
.tour h2 { font-size: var(--fs-lg); text-align: center; }
.tour-emoji { font-size: 52px; line-height: 1; text-align: center; }
.tour-dots { display: flex; justify-content: center; gap: 6px; }
.tour-dots i { width: 8px; height: 8px; border-radius: 50%; background: var(--surface-2); transition: width .2s, background-color .2s; }
.tour-dots i.on { width: 22px; border-radius: var(--radius-pill); background: var(--accent); }
.tour-body { color: var(--text); font-size: 15px; line-height: 1.5; }
.tour-body p { font-size: inherit; font-weight: 400; }
.tour-grades { display: grid; grid-template-columns: repeat(3, 1fr); gap: 6px; }
.tour-grade {
  display: grid; justify-items: center; padding: var(--s2) var(--s1); border: 1px solid var(--border);
  border-radius: 12px; text-align: center; line-height: 1.25;
}
.tour-grade small { font-size: 11px; color: var(--muted); }
.tour-grade.on { background: var(--accent); border-color: var(--accent); color: var(--accent-text); }
.tour-grade.on small { color: inherit; opacity: .85; }
.tour-nav { display: flex; gap: var(--s2); margin-top: var(--s2); }
.tour-nav.col { flex-direction: column; gap: var(--s1); }
.pace-list { display: grid; gap: var(--s2); }
.pace-list > button, .pace-date {
  display: grid; justify-content: stretch; justify-items: start; gap: 0; width: 100%; text-align: left; line-height: 1.3; font-weight: 600;
}
.pace-list small { display: block; font-size: var(--fs-sm); font-weight: 400; color: var(--muted); }
.pace-list [aria-checked="true"] { border-color: var(--accent); background: var(--accent-soft); box-shadow: inset 0 0 0 1px var(--accent); }
.pace-date { position: relative; cursor: pointer; overflow: hidden; }
.pace-date input {
  position: absolute; inset: 0; width: 100%; height: 100%; min-height: 0; margin: 0; padding: 0;
  border: 0; opacity: 0; cursor: pointer; font-size: var(--fs-base);
}
.pace-date:focus-within { outline: 3px solid var(--accent); outline-offset: 2px; }

/* ---------- 14. picture viewer (ui.js openImage) ---------- */
.qcard .qimg, .twin-body .qimg, .result-list .qimg { cursor: zoom-in; }
.zoomable { position: relative; }
.zoomable::after {
  content: ""; position: absolute; right: 8px; bottom: 20px; width: 30px; height: 30px; border-radius: 50%;
  background: rgba(0, 0, 0, .55) url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='none' stroke='white' stroke-width='2.4' stroke-linecap='round'%3E%3Ccircle cx='11' cy='11' r='6'/%3E%3Cpath d='m20 20-4.5-4.5M11 8v6M8 11h6'/%3E%3C/svg%3E") center / 18px no-repeat;
  pointer-events: none;
}
dialog.viewer {
  width: 100vw; height: 100dvh; max-width: none; max-height: none; margin: 0; padding: 0; border: 0;
  background: #000; overflow: hidden; touch-action: none; display: grid; place-items: center;
}
dialog.viewer::backdrop { background: #000; }
dialog.viewer img {
  max-width: 100vw; max-height: 100dvh; object-fit: contain; user-select: none; -webkit-user-select: none;
  transform-origin: center; will-change: transform;
}
.viewer-close {
  position: fixed; top: calc(12px + env(safe-area-inset-top)); right: 12px; width: 48px; height: 48px; padding: 0;
  border-radius: 50%; background: rgba(255, 255, 255, .16); border: 0; color: #fff;
}
.viewer-hint {
  position: fixed; left: 0; right: 0; bottom: calc(20px + env(safe-area-inset-bottom)); text-align: center;
  color: rgba(255, 255, 255, .75); font-size: 14px; pointer-events: none; transition: opacity .3s;
}
dialog.viewer.zoomed .viewer-hint { opacity: 0; }

/* ---------- 15. explanations, weak topics, exam history ---------- */
.why-box { margin-top: var(--s4); padding: var(--s3) 14px; border-radius: 12px; background: var(--surface-2); }
.why-box summary { display: flex; align-items: center; min-height: 32px; font-weight: 700; }
.why-box summary::after {
  content: "›"; margin-left: auto; font-size: 20px; line-height: 1; color: var(--muted); transition: transform .2s;
}
.why-box[open] summary { margin-bottom: var(--s2); }
.why-box .tip { background: var(--surface); }

.weak { list-style: none; margin: 0; padding: 0; }
.weak li { display: flex; align-items: center; gap: var(--s3); min-height: 56px; padding: var(--s2) 0; border-top: 1px solid var(--border); }
.weak li:first-child { border-top: 0; padding-top: 0; }
.weak .sec-name { flex: 1; min-width: 0; }
.weak .chip, .topic-link .chip { flex: 0 0 auto; min-height: 40px; }
.topic-link { display: flex; align-items: center; gap: var(--s3); justify-content: space-between; margin-top: var(--s3); padding-top: var(--s3); border-top: 1px solid var(--border); }

.exh svg { display: block; width: 100%; height: auto; overflow: visible; }
.exh-axis { stroke: var(--border); stroke-width: 1; }
.exh-limit { stroke: var(--muted); stroke-width: 1; }
.exh-t { font-size: 11px; fill: var(--muted); font-variant-numeric: tabular-nums; }
.exh-t.strong { fill: var(--text); font-weight: 700; font-size: 12px; }
.exh-bar { cursor: pointer; outline: none; }
.exh-bar.ok path { fill: var(--ok); }
.exh-bar.bad path { fill: url(#hatch); }
.hatch-bg { fill: color-mix(in srgb, var(--bad) 35%, var(--surface)); }
.hatch-fg { fill: var(--bad); }
.exh-bar.on path, .exh-bar:focus-visible path { stroke: var(--text); stroke-width: 2; }
.legend i.bad-hatch {
  background: repeating-linear-gradient(45deg, var(--bad) 0 2px, color-mix(in srgb, var(--bad) 35%, var(--surface)) 2px 4px);
}
.exh .legend { font-size: var(--fs-xs); gap: var(--s1) var(--s3); }

/* ---------- 16. transfer to another device ---------- */
.qr-box { display: grid; place-items: center; }
.qr-box .qr { width: min(240px, 70vw); height: auto; border-radius: 12px; background: #fff; }