:root {
  --bg: #f3efe6;
  --panel: #fffdf7;
  --ink: #1d2a33;
  --muted: #5a6872;
  --line: #d8d2c3;
  --brand: #0f766e;
  --brand-soft: #d7f3ef;
  --ok: #0f8f4f;
  --ok-soft: #d7f7e4;
  --bad: #bf2f45;
  --bad-soft: #ffe2e7;
  --btn: #1f2937;
}
* { box-sizing: border-box; }
body {
  margin: 0;
  font-family: "IBM Plex Sans", "Segoe UI", Tahoma, sans-serif;
  color: var(--ink);
  background:
    radial-gradient(circle at 12% 18%, #ffecc7 0%, transparent 42%),
    radial-gradient(circle at 82% 10%, #c8f2e8 0%, transparent 36%),
    linear-gradient(180deg, #faf7ef 0%, #efe8da 100%);
  min-height: 100vh;
}
.layout { width: min(1120px, 96vw); margin: 20px auto; display: grid; gap: 16px; }
.card { background: var(--panel); border: 1px solid var(--line); border-radius: 16px; box-shadow: 0 8px 24px rgba(32, 23, 7, 0.08); }
.header { padding: 16px 18px; display: flex; flex-wrap: wrap; align-items: center; justify-content: space-between; gap: 12px; }
.title { margin: 0; font-size: clamp(1.1rem, 2vw, 1.4rem); }
.stats { display: flex; gap: 10px; flex-wrap: wrap; }
.pill { border: 1px solid var(--line); border-radius: 999px; padding: 6px 10px; font-size: 13px; background: #fff; color: var(--muted); }
.main { padding: 16px; display: grid; gap: 14px; }
.question-block { border: 1px solid var(--line); border-radius: 14px; padding: 16px; background: #fff; }
.question-meta { color: var(--muted); font-size: 14px; margin-bottom: 8px; }
.question-text { margin: 0; font-size: clamp(1rem, 1.5vw, 1.1rem); line-height: 1.6; white-space: pre-line; }
.options { display: grid; gap: 10px; }
.option { width: 100%; text-align: left; border: 1px solid var(--line); border-radius: 12px; background: #fff; color: var(--ink); padding: 12px 14px; cursor: pointer; font: inherit; line-height: 1.5; }
.option:hover { border-color: #8aa39d; }
.option.selected { border-color: var(--brand); background: var(--brand-soft); }
.option.correct { border-color: var(--ok); background: var(--ok-soft); }
.option.wrong { border-color: var(--bad); background: var(--bad-soft); }
.option:disabled { cursor: default; }
.option-hint { margin-top: 6px; font-size: 13px; color: var(--muted); line-height: 1.4; }
.controls { display: flex; flex-wrap: wrap; gap: 10px; align-items: center; justify-content: space-between; }
.left-controls, .right-controls { display: flex; gap: 10px; }
.btn { border: 1px solid #0f172a; background: var(--btn); color: #fff; border-radius: 10px; padding: 10px 14px; font: inherit; cursor: pointer; }
.btn.alt { background: #fff; color: #1f2937; border: 1px solid var(--line); }
.btn:disabled { opacity: .45; cursor: default; }
.jump { border: 1px solid var(--line); background: #fff; border-radius: 10px; padding: 9px 10px; font: inherit; }
.grid-wrap { padding: 14px 16px 16px; border-top: 1px solid var(--line); }
.grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(40px, 1fr)); gap: 8px; }
.grid-category-group + .grid-category-group { margin-top: 18px; }
.grid-category-label { font-weight: 600; font-size: 13px; color: var(--muted); text-transform: uppercase; letter-spacing: .04em; margin-bottom: 8px; }
.qcell { border: 1px solid var(--line); border-radius: 8px; padding: 8px 0; background: #fff; color: #25333f; cursor: pointer; font-size: 12px; font-weight: 600; }
.qcell.current { outline: 2px solid var(--brand); }
.qcell.done { background: var(--brand-soft); border-color: #8ac0b8; }
.qcell.good { background: var(--ok-soft); border-color: #66b98c; }
.qcell.bad { background: var(--bad-soft); border-color: #dd8696; }
.footer { color: var(--muted); text-align: center; font-size: 13px; padding: 10px 0 16px; }
@media (max-width: 760px) {
  .controls { flex-direction: column; align-items: stretch; }
  .left-controls, .right-controls { width: 100%; }
  .btn, .jump { width: 100%; }
}

/* Set-choosing screen (reuses .card/.option look) */
.screen { display: none; }
.screen.active { display: block; }
.set-hint { color: var(--muted); font-size: 14px; margin: 0 0 14px; }
.set-list { display: grid; gap: 10px; }
.set-count { color: var(--muted); font-weight: 400; }

/* Login screen (reuses .layout/.card/.header/.btn look) */
.login-layout { min-height: 100vh; margin: 0; display: flex; align-items: center; justify-content: center; }
.login-card { width: min(360px, 92vw); }
.login-form label { display: block; font-size: 13px; color: var(--muted); margin-bottom: 6px; }
.login-form input {
  width: 100%;
  border: 1px solid var(--line);
  border-radius: 10px;
  padding: 10px 12px;
  font: inherit;
  margin-bottom: 14px;
}
.login-submit { width: 100%; }
.login-error {
  background: var(--bad-soft);
  color: var(--bad);
  border-radius: 8px;
  padding: 8px 10px;
  font-size: 13px;
  margin: 0 0 14px;
}