* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

body {
  min-height: 100vh;
  color: #333;
  background: linear-gradient(135deg, #fff8f0 0%, #ffe8d6 100%);
  font-family: Arial, "Microsoft YaHei", sans-serif;
  line-height: 1.6;
}

a {
  color: inherit;
  text-decoration: none;
}

.practice-shell {
  min-height: 100vh;
  display: grid;
  place-items: center;
  padding: 32px 18px;
}

.practice-card {
  width: min(980px, 100%);
  border-radius: 10px;
  background: #fff;
  box-shadow: 0 12px 36px rgba(0, 0, 0, 0.12);
  overflow: hidden;
}

.practice-header {
  display: grid;
  gap: 18px;
  padding: 26px;
  background: #ff6b35;
  color: #fff;
}

.back-link {
  width: fit-content;
  border-radius: 8px;
  background: rgba(255, 255, 255, 0.18);
  padding: 8px 14px;
  font-weight: 800;
}

.eyebrow {
  color: #ffd166;
  font-weight: 800;
  text-transform: uppercase;
}

h1 {
  font-size: clamp(34px, 6vw, 54px);
  line-height: 1.1;
}

.lesson-title {
  margin-top: 10px;
  font-size: 18px;
  font-weight: 700;
}

.intro-panel,
.quiz-panel,
.result-panel {
  padding: 28px;
}

.intro-panel p {
  max-width: 720px;
  color: #555;
  font-size: 18px;
}

.primary-btn,
.secondary-btn {
  min-height: 46px;
  border: 0;
  border-radius: 8px;
  padding: 0 18px;
  font: inherit;
  font-weight: 800;
  cursor: pointer;
  transition: transform 0.2s, background 0.2s;
}

.primary-btn {
  margin-top: 18px;
  background: #ff6b35;
  color: #fff;
}

.secondary-btn {
  background: #fff3e9;
  color: #ff6b35;
}

.primary-btn:hover,
.secondary-btn:hover,
.option-btn:hover {
  transform: translateY(-2px);
}

.quiz-topline {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 18px;
  margin-bottom: 20px;
}

.quiz-topline strong {
  display: block;
  color: #ff6b35;
  font-size: 22px;
}

.quiz-topline span {
  color: #777;
  font-weight: 800;
}

.timer-badge {
  min-width: 72px;
  border-radius: 30px;
  background: #333;
  color: #fff;
  padding: 8px 14px;
  text-align: center;
  font-weight: 800;
}

.question-text {
  border-radius: 10px;
  background: #fff8f0;
  padding: 20px;
  color: #333;
  font-size: 22px;
  font-weight: 800;
}

.options-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 14px;
  margin-top: 18px;
}

.option-btn {
  min-height: 64px;
  border: 2px solid #f2dccb;
  border-radius: 10px;
  background: #fff;
  color: #333;
  padding: 14px;
  font: inherit;
  font-weight: 800;
  text-align: left;
  cursor: pointer;
  transition: transform 0.2s, border-color 0.2s, background 0.2s;
}

.option-btn.is-correct {
  border-color: #2ecc71;
  background: #eafaf1;
}

.option-btn.is-wrong {
  border-color: #e74c3c;
  background: #fdecea;
}

.option-btn:disabled {
  cursor: default;
}

.feedback {
  min-height: 32px;
  margin-top: 18px;
  font-weight: 800;
}

.result-panel h2 {
  color: #ff6b35;
  font-size: 32px;
}

.result-panel p {
  margin-top: 8px;
  color: #555;
  font-size: 18px;
  font-weight: 800;
}

.result-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 18px;
}

.mistake-list {
  display: grid;
  gap: 14px;
  margin-top: 22px;
}

.mistake-card {
  border: 1px solid #f2dccb;
  border-radius: 10px;
  background: #fffaf5;
  padding: 16px;
}

.mistake-card strong {
  display: block;
  color: #333;
  margin-bottom: 8px;
}

.mistake-card span {
  display: block;
  color: #777;
  font-weight: 800;
}

@media (max-width: 700px) {
  .practice-shell {
    padding: 0;
    place-items: stretch;
  }

  .practice-card {
    min-height: 100vh;
    border-radius: 0;
  }

  .options-grid {
    grid-template-columns: 1fr;
  }

  .quiz-topline {
    align-items: flex-start;
    flex-direction: column;
  }
}