:root {
  --bg: #f6f7f9;
  --card: #ffffff;
  --ink: #16181d;
  --muted: #667085;
  --line: #e4e7ec;
  --brand: #1f5fd6;
  --ok: #157f4a;
  --ok-bg: #e9f7ef;
  --no: #b3261e;
  --no-bg: #fdeceb;
  --radius: 12px;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #0f1115; --card: #171a21; --ink: #e8eaed; --muted: #9aa3b2;
    --line: #272c36; --brand: #5b8def; --ok: #4ade80; --ok-bg: #12261c;
    --no: #f87171; --no-bg: #2a1516;
  }
}

* { box-sizing: border-box; }

body {
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  font: 16px/1.55 -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
}

.topbar {
  display: flex; align-items: center; justify-content: space-between; gap: 16px;
  padding: 14px 16px; background: var(--card); border-bottom: 1px solid var(--line);
}
.brand { font-weight: 650; color: var(--ink); text-decoration: none; }
.topbar nav { display: flex; align-items: center; gap: 12px; }
.who { color: var(--muted); font-size: 14px; }

.wrap { max-width: 760px; margin: 0 auto; padding: 24px 16px 64px; }

.card {
  background: var(--card); border: 1px solid var(--line); border-radius: var(--radius);
  padding: 20px; margin-bottom: 16px;
}
.card-narrow { max-width: 420px; margin-inline: auto; }

h1 { font-size: 22px; margin: 0 0 12px; line-height: 1.35; }
h2 { font-size: 17px; margin: 0 0 12px; }
.muted { color: var(--muted); }
.q { font-size: 19px; font-weight: 600; margin: 0 0 16px; line-height: 1.4; }
.qnum { color: var(--muted); font-size: 13px; margin: 0 0 6px; text-transform: uppercase; letter-spacing: .04em; }

/* ---------------------------------------------------------------- forms */
label { display: block; margin-bottom: 14px; font-size: 14px; color: var(--muted); }
input[type=text], input:not([type]), input[name=name], input[name=pin] {
  display: block; width: 100%; margin-top: 6px; padding: 10px 12px;
  font-size: 16px; color: var(--ink); background: var(--bg);
  border: 1px solid var(--line); border-radius: 8px;
}
input:focus-visible, .btn:focus-visible, .option:focus-visible {
  outline: 2px solid var(--brand); outline-offset: 2px;
}

.btn {
  display: inline-block; padding: 10px 16px; border: 1px solid var(--line);
  border-radius: 8px; background: var(--card); color: var(--ink);
  font: inherit; font-weight: 550; text-decoration: none; cursor: pointer;
}
.btn-primary { background: var(--brand); border-color: var(--brand); color: #fff; }
.btn-quiet { color: var(--muted); font-weight: 500; font-size: 14px; padding: 7px 12px; }

.modes { display: grid; gap: 12px; grid-template-columns: 1fr 1fr; }
@media (max-width: 560px) { .modes { grid-template-columns: 1fr; } }
.btn-mode { display: block; width: 100%; text-align: left; padding: 16px; }
.btn-mode strong { display: block; margin-bottom: 4px; }
.btn-mode span { display: block; color: var(--muted); font-weight: 400; font-size: 14px; }

/* ---------------------------------------------------------------- options */
.options { display: grid; gap: 10px; }
.option {
  display: flex; align-items: flex-start; gap: 12px; width: 100%; text-align: left;
  padding: 14px; font: inherit; color: var(--ink); cursor: pointer;
  background: var(--card); border: 1px solid var(--line); border-radius: 10px;
}
.option:hover { border-color: var(--brand); background: color-mix(in srgb, var(--brand) 5%, var(--card)); }
.label {
  flex: 0 0 26px; height: 26px; display: grid; place-items: center;
  background: var(--bg); border: 1px solid var(--line); border-radius: 6px;
  font-size: 13px; font-weight: 650;
}
.body { flex: 1; }

/* ---------------------------------------------------------------- progress */
.progress-head { display: flex; align-items: center; gap: 12px; flex-wrap: wrap; margin-bottom: 10px; }
.progress-head .muted { flex: 1; font-size: 14px; }
.tag {
  font-size: 12px; font-weight: 650; text-transform: uppercase; letter-spacing: .05em;
  padding: 3px 8px; border-radius: 999px; background: var(--bg); border: 1px solid var(--line);
}
.bar { height: 7px; background: var(--bg); border-radius: 999px; overflow: hidden; }
.bar span { display: block; height: 100%; background: var(--brand); transition: width .25s ease; }

/* ---------------------------------------------------------------- attempts list */
.attempts { list-style: none; margin: 0; padding: 0; display: grid; gap: 10px; }
.attempts li {
  display: flex; align-items: center; gap: 12px; flex-wrap: wrap;
  padding: 12px; border: 1px solid var(--line); border-radius: 10px;
}
.attempt-meta { flex: 1; min-width: 200px; display: grid; gap: 4px; }
.attempt-meta .muted { font-size: 14px; }
.pill { font-size: 13px; font-weight: 600; padding: 4px 10px; border-radius: 999px; }
.pill-pass { background: var(--ok-bg); color: var(--ok); }
.pill-fail { background: var(--no-bg); color: var(--no); }

/* ---------------------------------------------------------------- feedback + review */
.feedback.ok, .score.ok, .review li.ok { border-left: 4px solid var(--ok); }
.feedback.no, .score.no, .review li.no { border-left: 4px solid var(--no); }
.feedback.ok h2, .score.ok .verdict { color: var(--ok); }
.feedback.no h2, .score.no .verdict { color: var(--no); }
.answer { margin: 12px 0 8px; }
.explanation {
  margin: 10px 0 16px; padding: 12px; background: var(--bg);
  border-radius: 8px; color: var(--muted); font-size: 15px;
}

.score h1 { font-size: 34px; margin-bottom: 4px; }
.verdict { font-size: 17px; font-weight: 600; margin: 0 0 16px; }

.review { margin: 0; padding-left: 0; list-style: none; display: grid; gap: 20px; }
.review > li { padding: 14px; border: 1px solid var(--line); border-radius: 10px; }
.review-options { list-style: none; margin: 0 0 12px; padding: 0; display: grid; gap: 6px; }
.review-options li {
  display: flex; align-items: flex-start; gap: 10px; padding: 9px 12px;
  border: 1px solid var(--line); border-radius: 8px; font-size: 15px;
}
.review-options .is-answer { background: var(--ok-bg); border-color: var(--ok); }
.review-options .is-wrong  { background: var(--no-bg); border-color: var(--no); }
.mark { font-size: 12px; font-weight: 650; text-transform: uppercase; letter-spacing: .04em; color: var(--muted); }

.alert {
  padding: 12px 14px; margin-bottom: 16px; border-radius: 8px;
  background: var(--no-bg); color: var(--no); border: 1px solid var(--no);
}
.foot { max-width: 760px; margin: 0 auto; padding: 0 16px 40px; color: var(--muted); font-size: 13px; text-align: center; }