:root {
  --bg: #fbfbfd;
  --surface: #ffffff;
  --text: #1d1d1f;
  --muted: #6e6e73;
  --line: rgba(0, 0, 0, 0.1);
  --fill: #f2f2f5;
  --accent: #0a6e5c;
  --accent-text: #ffffff;
  --wrong: #b3261e;
  --radius: 12px;
  font-family: -apple-system, "SF Pro Text", system-ui, "Segoe UI", Roboto, sans-serif;
  -webkit-font-smoothing: antialiased;
}
@media (prefers-color-scheme: dark) {
  :root {
    --bg: #000000;
    --surface: #1c1c1e;
    --text: #f5f5f7;
    --muted: #a1a1a6;
    --line: rgba(255, 255, 255, 0.14);
    --fill: #2c2c2e;
    --accent: #4cc2a6;
    --accent-text: #00140f;
    --wrong: #ff8a80;
  }
}

* { box-sizing: border-box; }
body { margin: 0; background: var(--bg); color: var(--text); font-size: 17px; line-height: 1.47; }
button, select, input { font: inherit; color: inherit; }
[hidden] { display: none !important; }

.bar {
  position: sticky; top: 0; z-index: 2;
  background: color-mix(in srgb, var(--bg) 88%, transparent);
  backdrop-filter: saturate(180%) blur(20px);
  -webkit-backdrop-filter: saturate(180%) blur(20px);
  border-bottom: 1px solid var(--line);
  padding-top: env(safe-area-inset-top);
}
.bar-inner, main {
  max-width: 720px; margin: 0 auto;
  padding-left: max(20px, env(safe-area-inset-left));
  padding-right: max(20px, env(safe-area-inset-right));
}
.bar-inner { display: flex; align-items: center; justify-content: space-between; gap: 16px; height: 56px; }
h1 { font-size: 20px; font-weight: 600; letter-spacing: -0.01em; margin: 0; }

.seg { display: inline-flex; background: var(--fill); border-radius: 9px; padding: 2px; }
.seg button {
  border: 0; background: transparent; border-radius: 7px;
  padding: 0 14px; min-height: 36px; font-size: 14px; font-weight: 500; color: var(--muted); cursor: pointer;
}
.seg button[aria-selected="true"] { background: var(--surface); color: var(--text); box-shadow: 0 1px 2px rgba(0,0,0,0.12); }

main { padding-top: 24px; padding-bottom: calc(48px + env(safe-area-inset-bottom)); }

.controls { display: flex; flex-wrap: wrap; align-items: flex-end; gap: 12px 16px; margin-bottom: 20px; }
.controls label { display: flex; flex-direction: column; gap: 4px; font-size: 13px; color: var(--muted); }
.controls label.check { flex-direction: row; align-items: center; gap: 8px; min-height: 44px; font-size: 15px; color: var(--text); }
.check input { width: 20px; height: 20px; accent-color: var(--accent); }
select, input[type="search"] {
  min-height: 44px; padding: 0 12px; border: 1px solid var(--line); border-radius: 10px;
  background: var(--surface); font-size: 15px;
}
input[type="search"] { flex: 1; min-width: 200px; font-size: 17px; }
input:focus-visible, select:focus-visible, button:focus-visible { outline: 2px solid var(--accent); outline-offset: 2px; }

.progress { margin-bottom: 16px; }
.meter { height: 4px; background: var(--fill); border-radius: 2px; overflow: hidden; }
#meter-fill { height: 100%; width: 0; background: var(--accent); transition: width 0.3s ease; }
#progress-text { margin: 8px 0 0; font-size: 13px; color: var(--muted); }

.card {
  position: relative; width: 100%; min-height: 360px; text-align: left; cursor: pointer;
  background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius);
  padding: 32px; display: flex; flex-direction: column;
}
.card .meta { display: flex; justify-content: space-between; gap: 12px; font-size: 13px; color: var(--muted); }
.card .term { font-size: 40px; font-weight: 700; letter-spacing: -0.02em; line-height: 1.1; margin: auto 0 8px; padding-top: 48px; }
.card .pos { font-size: 15px; color: var(--muted); font-style: italic; margin-bottom: auto; padding-bottom: 48px; }
.card .tap { font-size: 13px; color: var(--muted); }
.back .term { font-size: 28px; margin: 16px 0 4px; padding: 0; }
.back .pos { padding: 0; margin: 0 0 16px; }
.meaning { font-size: 22px; font-weight: 500; line-height: 1.3; margin: 0 0 20px; }
dl.rel { display: grid; grid-template-columns: max-content 1fr; gap: 6px 16px; margin: 0 0 24px; font-size: 15px; }
dl.rel dt { color: var(--muted); }
dl.rel dd { margin: 0; }
.cuet { border-top: 1px solid var(--line); padding-top: 16px; font-size: 15px; }
.cuet h3 { font-size: 13px; font-weight: 600; color: var(--muted); text-transform: uppercase; letter-spacing: 0.04em; margin: 0 0 8px; }
.cuet p { margin: 0 0 8px; white-space: pre-line; }
.cuet ol { margin: 0; padding-left: 0; list-style: none; display: grid; gap: 4px; }
.cuet li { padding: 6px 10px; border-radius: 8px; background: var(--fill); }
.cuet li.right { background: var(--accent); color: var(--accent-text); font-weight: 500; }
mark { background: transparent; color: inherit; font-weight: 700; text-decoration: underline; text-decoration-color: var(--accent); text-decoration-thickness: 2px; text-underline-offset: 3px; }

.actions { display: grid; grid-template-columns: 1fr 1fr; gap: 12px; margin-top: 16px; }
.btn {
  min-height: 50px; border-radius: 12px; border: 1px solid var(--line);
  background: var(--surface); font-size: 17px; font-weight: 600; cursor: pointer;
}
.btn.primary { background: var(--accent); border-color: var(--accent); color: var(--accent-text); }
kbd { font: 12px ui-monospace, monospace; opacity: 0.6; margin-left: 6px; }
@media (hover: none) { kbd { display: none; } }
.hint { font-size: 13px; color: var(--muted); margin: 16px 0 0; }

.done { text-align: center; padding: 64px 24px; border: 1px solid var(--line); border-radius: var(--radius); background: var(--surface); }
.done h2 { font-size: 28px; margin: 0 0 8px; }
.done p { color: var(--muted); margin: 0 0 24px; }
.done .btn { padding: 0 24px; }

.muted { color: var(--muted); font-size: 15px; align-self: center; }
.list { list-style: none; margin: 0; padding: 0; border-top: 1px solid var(--line); }
.list li { display: grid; grid-template-columns: 1fr auto; gap: 2px 16px; padding: 14px 0; border-bottom: 1px solid var(--line); }
.list .w { font-weight: 600; }
.list .w small { font-weight: 400; color: var(--muted); font-style: italic; margin-left: 6px; }
.list .n { font-size: 13px; color: var(--muted); text-align: right; }
.list .m { grid-column: 1 / -1; color: var(--muted); font-size: 15px; }
.list .known { font-size: 13px; color: var(--accent); }

@media (max-width: 520px) {
  .card { padding: 24px 20px; min-height: 320px; }
  .card .term { font-size: 34px; }
  .meaning { font-size: 20px; }
}

@media (max-width: 520px) {
  #cards-view .controls { display: grid; grid-template-columns: 1fr 1fr; gap: 8px 12px; }
  #cards-view .controls select { width: 100%; }
  #cards-view .controls label.check { grid-column: 1 / -1; min-height: 32px; }
}