:root {
  --bg: #f5f8ff;
  --surface: #ffffff;
  --accent: #1d4ed8;
  --accent-soft: #dce8ff;
  --text: #12213f;
  --muted: #4f6491;
  --ok: #15803d;
  --warn: #b45309;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  min-height: 100vh;
  color: var(--text);
  font-family: "Plus Jakarta Sans", sans-serif;
  background:
    radial-gradient(circle at 92% 8%, #dfe9ff 0%, transparent 35%),
    radial-gradient(circle at 10% 90%, #d1ffe5 0%, transparent 30%),
    var(--bg);
}

.app {
  max-width: 920px;
  margin: 0 auto;
  padding: 24px 18px 40px;
}

.eyebrow {
  margin: 0;
  color: var(--accent);
  font-weight: 700;
}

h1 {
  margin: 6px 0 8px;
  font-family: "DM Serif Display", serif;
  font-size: clamp(2rem, 5vw, 3rem);
  font-weight: 400;
}

.subtitle {
  margin: 0;
  color: var(--muted);
}

.config,
.stats {
  margin-top: 14px;
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(140px, 1fr));
  gap: 8px;
}

.config {
  background: var(--surface);
  border: 1px solid #d4deef;
  border-radius: 10px;
  padding: 10px;
}

.config label {
  display: grid;
  gap: 6px;
  font-weight: 700;
}

.config p {
  margin: 0;
  padding: 10px;
  background: #f4f8ff;
  border-radius: 10px;
}

select {
  min-height: 42px;
  border-radius: 8px;
  border: 2px solid #b7c6e4;
  background: #fff;
  color: var(--text);
  padding: 6px;
  font-weight: 700;
}

.stats p {
  margin: 0;
  padding: 10px;
  background: var(--surface);
  border: 1px solid #d4deef;
  border-radius: 10px;
}

.card {
  margin-top: 14px;
  background: var(--surface);
  border: 1px solid #d4deef;
  border-radius: 14px;
  padding: 16px;
}

.sentence {
  margin: 0 0 12px;
  font-size: 1.2rem;
  line-height: 1.45;
}

.choices {
  display: grid;
  gap: 8px;
}

.choice {
  min-height: 48px;
  border-radius: 10px;
  border: 1px solid #b7c6e4;
  background: #f8fbff;
  color: var(--text);
  font-size: 1rem;
  font-weight: 700;
  text-align: left;
  padding: 10px;
  cursor: pointer;
}

.choice:hover,
.choice:focus-visible {
  outline: 2px solid #4f7ed9;
  outline-offset: 1px;
}

.choice.correct {
  background: #e6ffef;
  border-color: #7ec69b;
}

.choice.wrong,
.choice.disabled-choice {
  background: #fff3e6;
  border-color: #d6a36f;
}

.actions {
  margin-top: 12px;
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(140px, 1fr));
  gap: 8px;
}

.btn {
  min-height: 46px;
  border-radius: 10px;
  border: 1px solid transparent;
  background: var(--accent);
  color: #fff;
  font-weight: 700;
  cursor: pointer;
}

.btn:disabled {
  opacity: 0.6;
  cursor: default;
}

.btn-muted {
  background: #eff4ff;
  color: var(--text);
  border-color: #b7c6e4;
}

.explanation {
  min-height: 28px;
  margin: 10px 0 0;
  color: var(--muted);
}

.lookup {
  display: inline-block;
  margin-top: 8px;
  color: var(--accent);
  font-weight: 700;
  text-decoration: none;
}

.lookup:hover {
  text-decoration: underline;
}

h2 {
  margin: 0 0 8px;
  font-size: 1.1rem;
}

@media (max-width: 640px) {
  .sentence {
    font-size: 1.08rem;
  }
}