/* ============================================================
   A-Level Flashcards
   Its own look: cool indigo on a soft periwinkle ground, generous
   radii, soft elevation. Deliberately unlike the main site's
   warm-paper, hard-shadow, dashed-border index-card theme.
   ============================================================ */
@import url('https://fonts.googleapis.com/css2?family=Bricolage+Grotesque:opsz,wght@12..96,500;12..96,700;12..96,800&family=DM+Mono:wght@400;500&family=Karla:wght@400;500;700&display=swap');

:root {
  --bg: #F0F1F7;
  --surface: #FFFFFF;
  --surface-2: #F7F7FC;
  --ink: #191933;
  --ink-soft: #5C5C7B;
  --ink-faint: #8A8AA6;
  --line: #E2E3EE;
  --accent: #4B3FE4;
  --accent-soft: #E9E7FD;
  --yes: #0E8C7E;
  --yes-soft: #DCF2EF;
  --no: #D8383E;
  --no-soft: #FBE3E4;
  --shadow-1: 0 1px 2px rgba(25, 25, 51, 0.05);
  --shadow-2: 0 2px 6px rgba(25, 25, 51, 0.06), 0 18px 38px -20px rgba(25, 25, 51, 0.4);
  --display: "Bricolage Grotesque", "Trebuchet MS", system-ui, sans-serif;
  --body: "Karla", system-ui, -apple-system, "Segoe UI", sans-serif;
  --mono: "DM Mono", ui-monospace, Consolas, monospace;
}
@media (prefers-color-scheme: dark) {
  :root {
    --bg: #101020;
    --surface: #1B1B31;
    --surface-2: #23233D;
    --ink: #EDEDF7;
    --ink-soft: #A6A6C0;
    --ink-faint: #7B7B99;
    --line: #2E2E4C;
    --accent: #8C82FF;
    --accent-soft: #272348;
    --yes: #35D3B9;
    --yes-soft: #12332F;
    --no: #FF7377;
    --no-soft: #3B2024;
    --shadow-1: 0 1px 2px rgba(0, 0, 0, 0.4);
    --shadow-2: 0 2px 6px rgba(0, 0, 0, 0.35), 0 18px 38px -20px rgba(0, 0, 0, 0.8);
  }
}
html[data-theme="dark"] {
  --bg: #101020;
  --surface: #1B1B31;
  --surface-2: #23233D;
  --ink: #EDEDF7;
  --ink-soft: #A6A6C0;
  --ink-faint: #7B7B99;
  --line: #2E2E4C;
  --accent: #8C82FF;
  --accent-soft: #272348;
  --yes: #35D3B9;
  --yes-soft: #12332F;
  --no: #FF7377;
  --no-soft: #3B2024;
  --shadow-1: 0 1px 2px rgba(0, 0, 0, 0.4);
  --shadow-2: 0 2px 6px rgba(0, 0, 0, 0.35), 0 18px 38px -20px rgba(0, 0, 0, 0.8);
}
html[data-theme="light"] {
  --bg: #F0F1F7;
  --surface: #FFFFFF;
  --surface-2: #F7F7FC;
  --ink: #191933;
  --ink-soft: #5C5C7B;
  --ink-faint: #8A8AA6;
  --line: #E2E3EE;
  --accent: #4B3FE4;
  --accent-soft: #E9E7FD;
  --yes: #0E8C7E;
  --yes-soft: #DCF2EF;
  --no: #D8383E;
  --no-soft: #FBE3E4;
  --shadow-1: 0 1px 2px rgba(25, 25, 51, 0.05);
  --shadow-2: 0 2px 6px rgba(25, 25, 51, 0.06), 0 18px 38px -20px rgba(25, 25, 51, 0.4);
}

* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  font-family: var(--body);
  font-size: 17px;
  line-height: 1.6;
}
button { font: inherit; color: inherit; overflow: visible; }
a { color: var(--accent); text-underline-offset: 3px; }
:focus-visible { outline: 3px solid var(--accent); outline-offset: 3px; border-radius: 4px; }

.wrap { max-width: 880px; margin: 0 auto; padding: 0 22px; }

/* ---------- header ---------- */
header.site {
  display: flex;
  align-items: center;
  gap: 14px;
  padding: 20px 0 14px;
}
.mark {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-family: var(--display);
  font-weight: 800;
  font-size: 1.15rem;
  letter-spacing: -0.02em;
  color: var(--ink);
  text-decoration: none;
}
.mark svg { display: block; }
.mark-sub {
  font-family: var(--mono);
  font-size: 0.68rem;
  font-weight: 400;
  letter-spacing: 0.02em;
  color: var(--ink-faint);
  padding-left: 10px;
  border-left: 1px solid var(--line);
}
@media (max-width: 620px) { .mark-sub { display: none; } }
.header-tools { margin-left: auto; display: flex; gap: 8px; }
.icon-btn {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-family: var(--mono);
  font-size: 0.72rem;
  line-height: 1;
  padding: 9px 13px;
  border: 1px solid var(--line);
  border-radius: 12px;
  background: var(--surface);
  color: var(--ink-soft);
  cursor: pointer;
}
.icon-btn:hover { border-color: var(--accent); color: var(--accent); }
@media (max-width: 520px) { .icon-btn .icon-label { display: none; } }

/* ---------- headings ---------- */
h1 {
  font-family: var(--display);
  font-weight: 800;
  font-size: clamp(2rem, 6vw, 2.9rem);
  line-height: 1.05;
  letter-spacing: -0.035em;
  margin: 18px 0 12px;
}
.lede { color: var(--ink-soft); max-width: 54ch; margin: 0 0 26px; font-size: 1.02rem; }
.lede b { color: var(--ink); font-weight: 700; }

h2.cat-head {
  display: flex;
  align-items: center;
  gap: 11px;
  font-family: var(--display);
  font-weight: 700;
  font-size: 1.3rem;
  letter-spacing: -0.02em;
  margin: 34px 0 4px;
}
.cat-mark { width: 13px; height: 13px; border-radius: 4px; background: var(--tab, var(--accent)); flex: none; }
.cat-count { font-family: var(--mono); font-size: 0.7rem; font-weight: 400; color: var(--ink-faint); }
h3.sub-head {
  font-family: var(--mono);
  font-size: 0.72rem;
  font-weight: 500;
  letter-spacing: 0.05em;
  text-transform: uppercase;
  color: var(--ink-faint);
  margin: 20px 0 2px;
}

/* ---------- controls ---------- */
.chips { display: flex; gap: 7px; flex-wrap: wrap; margin: 16px 0 0; }
.chip {
  font-family: var(--body);
  font-weight: 500;
  font-size: 0.82rem;
  padding: 7px 15px;
  border: 1px solid var(--line);
  border-radius: 11px;
  background: var(--surface);
  color: var(--ink-soft);
  cursor: pointer;
  transition: border-color 0.12s ease, color 0.12s ease;
}
.chip:hover { border-color: var(--accent); color: var(--accent); }
.chip.on { background: var(--accent); border-color: var(--accent); color: #fff; }
html[data-theme="dark"] .chip.on { color: #14142A; }
@media (prefers-color-scheme: dark) { .chip.on { color: #14142A; } }
.chip[disabled] { opacity: 0.4; cursor: not-allowed; }
.chip[disabled]:hover { border-color: var(--line); color: var(--ink-soft); }

.search {
  width: 100%;
  max-width: 440px;
  font-family: var(--body);
  font-size: 1rem;
  padding: 13px 17px;
  margin: 16px 0 4px;
  border: 1px solid var(--line);
  border-radius: 14px;
  background: var(--surface);
  color: var(--ink);
  box-shadow: var(--shadow-1);
}
.search::placeholder { color: var(--ink-faint); }
.search:focus { border-color: var(--accent); outline: none; box-shadow: 0 0 0 4px var(--accent-soft); }

.status {
  font-family: var(--mono);
  font-size: 0.72rem;
  color: var(--ink-faint);
  margin: 12px 0 0;
  min-height: 1.2em;
}

/* ---------- deck tiles ---------- */
.tiles {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(238px, 1fr));
  gap: 13px;
  margin: 14px 0 4px;
}
.tile {
  position: relative;
  display: flex;
  flex-direction: column;
  gap: 9px;
  width: 100%;
  text-align: left;
  padding: 17px 18px 15px;
  border: 1px solid var(--line);
  border-radius: 18px;
  background: var(--surface);
  box-shadow: var(--shadow-1);
  cursor: pointer;
  overflow: hidden;
  transition: transform 0.14s ease, box-shadow 0.14s ease, border-color 0.14s ease;
}
.tile::before {
  content: "";
  position: absolute;
  left: 0; right: 0; top: 0;
  height: 5px;
  background: var(--tab, var(--accent));
}
.tile:hover { transform: translateY(-2px); box-shadow: var(--shadow-2); border-color: transparent; }
.tile-name { font-family: var(--display); font-weight: 700; font-size: 1rem; line-height: 1.25; letter-spacing: -0.01em; }
.tile-meta { font-family: var(--mono); font-size: 0.68rem; color: var(--ink-faint); margin-top: auto; }
.tile-bar { height: 5px; border-radius: 99px; background: var(--line); overflow: hidden; }
.tile-bar > span { display: block; height: 100%; border-radius: 99px; background: var(--tab, var(--accent)); }

/* ---------- the pile ---------- */
.stack { position: relative; perspective: 1800px; max-width: 620px; margin: 22px 0 16px; }
.ghost {
  position: absolute;
  inset: 0;
  border: 1px solid var(--line);
  border-radius: 22px;
  background: var(--surface);
  box-shadow: var(--shadow-1);
}
.g1 { transform: translateY(9px) scale(0.985); }
.g2 { transform: translateY(17px) scale(0.97); }
.g3 { transform: translateY(24px) scale(0.955); }
.ghost[hidden] { display: none; }

.flip {
  position: relative;
  display: grid;
  transform-style: preserve-3d;
  transition: transform 0.55s cubic-bezier(0.2, 0.75, 0.3, 1);
  cursor: pointer;
}
.flip.on { transform: rotateY(180deg); }
.flip:focus-visible { outline: 3px solid var(--accent); outline-offset: 5px; border-radius: 22px; }

.face {
  grid-area: 1 / 1;
  backface-visibility: hidden;
  -webkit-backface-visibility: hidden;
  position: relative;
  display: flex;
  flex-direction: column;
  justify-content: center;
  min-height: min(46vh, 300px);
  padding: 40px 30px 30px;
  border: 1px solid var(--line);
  border-radius: 22px;
  background: var(--surface);
  box-shadow: var(--shadow-2);
  overflow: hidden;
}
.face::before {
  content: "";
  position: absolute;
  left: 0; right: 0; top: 0;
  height: 6px;
  background: var(--tab, var(--accent));
}
.face.back { transform: rotateY(180deg); background: var(--surface-2); }
.tag {
  position: absolute;
  top: 19px;
  left: 30px;
  font-family: var(--mono);
  font-size: 0.65rem;
  letter-spacing: 0.09em;
  text-transform: uppercase;
  color: var(--ink-faint);
}
.q {
  font-family: var(--display);
  font-weight: 700;
  font-size: clamp(1.25rem, 3.4vw, 1.65rem);
  line-height: 1.25;
  letter-spacing: -0.02em;
  margin: 0;
}
.a { font-size: 1rem; line-height: 1.62; margin: 0; }
.a-q {
  font-family: var(--mono);
  font-size: 0.7rem;
  line-height: 1.5;
  color: var(--ink-faint);
  margin: 0 0 14px;
  padding-bottom: 12px;
  border-bottom: 1px solid var(--line);
}
.hint { margin: 16px 0 0; font-size: 0.88rem; color: var(--ink-soft); }
.hint b { font-family: var(--mono); font-size: 0.68rem; font-weight: 500; text-transform: uppercase; letter-spacing: 0.07em; color: var(--ink-faint); }

.prompt {
  font-family: var(--mono);
  font-size: 0.7rem;
  color: var(--ink-faint);
  text-align: center;
  max-width: 620px;
  margin: 0 0 16px;
}
.prompt[hidden] { display: none; }

/* ---------- got it / not yet ---------- */
.judge { display: flex; gap: 10px; max-width: 620px; margin: 0 0 18px; }
.judge[hidden] { display: none; }
.judge button {
  flex: 1;
  font-family: var(--display);
  font-weight: 700;
  font-size: 1rem;
  letter-spacing: -0.01em;
  padding: 15px 14px;
  border-radius: 16px;
  border: 1px solid transparent;
  cursor: pointer;
  transition: transform 0.1s ease, filter 0.12s ease;
}
.judge button:active { transform: scale(0.985); }
.judge kbd { font-family: var(--mono); font-size: 0.66rem; font-weight: 400; opacity: 0.7; margin-left: 6px; }
.btn-no { background: var(--no-soft); color: var(--no); border-color: var(--no-soft); }
.btn-no:hover { border-color: var(--no); }
.btn-yes { background: var(--yes); color: #fff; }
html[data-theme="dark"] .btn-yes { color: #0B241F; }
@media (prefers-color-scheme: dark) { .btn-yes { color: #0B241F; } }
.btn-yes:hover { filter: brightness(1.06); }

/* ---------- progress ---------- */
.meter {
  display: flex;
  align-items: center;
  gap: 12px;
  max-width: 620px;
  font-family: var(--mono);
  font-size: 0.7rem;
  color: var(--ink-faint);
}
.bar { flex: 1; height: 7px; border-radius: 99px; background: var(--line); overflow: hidden; }
.bar > span { display: block; height: 100%; border-radius: 99px; background: var(--accent); transition: width 0.3s ease; }

/* ---------- end of pile ---------- */
.panel {
  max-width: 620px;
  padding: 24px 26px;
  border: 1px solid var(--line);
  border-radius: 22px;
  background: var(--surface);
  box-shadow: var(--shadow-1);
}
.score-row { display: flex; align-items: center; gap: 16px; }
.score {
  font-family: var(--display);
  font-weight: 800;
  font-size: 2.1rem;
  letter-spacing: -0.04em;
  line-height: 1;
  padding: 12px 18px;
  border-radius: 16px;
  background: var(--accent-soft);
  color: var(--accent);
}
.score.clean { background: var(--yes-soft); color: var(--yes); }
.score-sub { font-size: 0.95rem; color: var(--ink-soft); }
.missed-head {
  font-family: var(--mono);
  font-size: 0.7rem;
  letter-spacing: 0.07em;
  text-transform: uppercase;
  color: var(--ink-faint);
  margin: 24px 0 8px;
}
.missed { list-style: none; padding: 0; margin: 0; }
.missed li { padding: 11px 0; border-top: 1px solid var(--line); font-size: 0.94rem; }
.actions { display: flex; gap: 9px; flex-wrap: wrap; margin-top: 22px; }
.btn {
  font-family: var(--display);
  font-weight: 700;
  font-size: 0.9rem;
  padding: 11px 19px;
  border-radius: 13px;
  border: 1px solid var(--line);
  background: var(--surface);
  color: var(--ink);
  cursor: pointer;
}
.btn:hover { border-color: var(--accent); color: var(--accent); }
.btn.primary { background: var(--accent); border-color: var(--accent); color: #fff; }
html[data-theme="dark"] .btn.primary { color: #14142A; }
@media (prefers-color-scheme: dark) { .btn.primary { color: #14142A; } }
.btn.primary:hover { filter: brightness(1.07); color: #fff; }
html[data-theme="dark"] .btn.primary:hover { color: #14142A; }

.empty { color: var(--ink-soft); padding: 26px 0; }
.note { font-size: 0.86rem; color: var(--ink-faint); margin: 30px 0 0; }
.linkish {
  font: inherit;
  background: none;
  border: 0;
  padding: 0;
  color: var(--accent);
  text-decoration: underline;
  text-underline-offset: 3px;
  cursor: pointer;
}

/* ---------- footer ---------- */
footer.site {
  margin-top: 46px;
  padding: 22px 0 40px;
  border-top: 1px solid var(--line);
  font-size: 0.88rem;
  color: var(--ink-faint);
  display: flex;
  gap: 14px;
  align-items: center;
  flex-wrap: wrap;
}
.back-link {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-family: var(--display);
  font-weight: 700;
  font-size: 0.92rem;
  padding: 9px 16px;
  border: 1px solid var(--line);
  border-radius: 12px;
  background: var(--surface);
  color: var(--ink);
  text-decoration: none;
}
.back-link:hover { border-color: var(--accent); color: var(--accent); }
footer.site a:not(.back-link) { color: var(--ink-soft); }

@media (max-width: 560px) {
  body { font-size: 16px; }
  .wrap { padding: 0 17px; }
  .search { max-width: none; font-size: 16px; }
  .face { padding: 38px 22px 26px; min-height: min(44vh, 270px); }
  .tag { left: 22px; }
  .panel { padding: 20px 18px; }
}
@media (prefers-reduced-motion: reduce) {
  .flip, .tile, .bar > span, .judge button { transition: none; }
}