/* Teach workspace — shared stylesheet */
:root {
  --font-body: "Noto Serif SC", "Georgia", serif;
  --font-heading: "Noto Sans SC", "Helvetica Neue", sans-serif;
  --font-mono: "JetBrains Mono", "Menlo", monospace;
  --color-bg: #fefcf9;
  --color-text: #2c2c2c;
  --color-muted: #6b6b6b;
  --color-accent: #c0392b;
  --color-link: #2471a3;
  --color-border: #e0dcd4;
  --color-highlight: #fff9e6;
  --color-card-bg: #ffffff;
  --color-success: #27ae60;
  --color-warning: #e67e22;
  --color-danger: #c0392b;
  --max-width: 680px;
  --spacing: 1.6rem;
}

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

html { font-size: 17px; }

body {
  font-family: var(--font-body);
  color: var(--color-text);
  background: var(--color-bg);
  line-height: 1.8;
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 2.5rem var(--spacing);
}

h1, h2, h3, h4 {
  font-family: var(--font-heading);
  line-height: 1.3;
  margin-top: 2.4rem;
  margin-bottom: 0.8rem;
}
h1 { font-size: 1.8rem; border-bottom: 2px solid var(--color-accent); padding-bottom: 0.4rem; }
h2 { font-size: 1.35rem; color: var(--color-accent); }
h3 { font-size: 1.1rem; }

p { margin-bottom: 1rem; }

a { color: var(--color-link); text-decoration: none; border-bottom: 1px solid transparent; }
a:hover { border-bottom-color: var(--color-link); }

blockquote {
  border-left: 3px solid var(--color-accent);
  padding: 0.6rem 1.2rem;
  margin: 1.2rem 0;
  color: var(--color-muted);
  background: var(--color-highlight);
  font-style: italic;
}

code {
  font-family: var(--font-mono);
  font-size: 0.88rem;
  background: #f0ede6;
  padding: 0.15rem 0.4rem;
  border-radius: 3px;
}

/* Lesson meta */
.lesson-meta {
  font-family: var(--font-heading);
  font-size: 0.82rem;
  color: var(--color-muted);
  margin-bottom: 2rem;
  padding-bottom: 0.8rem;
  border-bottom: 1px solid var(--color-border);
}

/* Cards for key concepts */
.card {
  background: var(--color-card-bg);
  border: 1px solid var(--color-border);
  border-radius: 6px;
  padding: 1.2rem 1.4rem;
  margin: 1.2rem 0;
}
.card h3 { margin-top: 0; color: var(--color-accent); }

/* Good vs Bad comparison */
.compare {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1rem;
  margin: 1.2rem 0;
}
.compare-bad, .compare-good {
  padding: 1rem;
  border-radius: 6px;
  font-size: 0.92rem;
}
.compare-bad {
  background: #fdf0ed;
  border-left: 3px solid var(--color-danger);
}
.compare-good {
  background: #edf7ed;
  border-left: 3px solid var(--color-success);
}
.compare-bad h4 { color: var(--color-danger); margin-top: 0; }
.compare-good h4 { color: var(--color-success); margin-top: 0; }

/* Quiz widget */
.quiz {
  background: var(--color-card-bg);
  border: 1px solid var(--color-border);
  border-radius: 6px;
  padding: 1.4rem;
  margin: 1.6rem 0;
}
.quiz-question {
  font-family: var(--font-heading);
  font-weight: 600;
  margin-bottom: 1rem;
}
.quiz-options { list-style: none; }
.quiz-options li {
  padding: 0.7rem 1rem;
  margin: 0.4rem 0;
  border: 1px solid var(--color-border);
  border-radius: 4px;
  cursor: pointer;
  transition: background 0.15s;
  font-size: 0.94rem;
}
.quiz-options li:hover { background: #f5f3ee; }
.quiz-options li.selected { border-color: var(--color-accent); background: #fdf0ed; }
.quiz-options li.correct { border-color: var(--color-success); background: #edf7ed; }
.quiz-options li.wrong { border-color: var(--color-danger); background: #fdf0ed; }
.quiz-feedback {
  margin-top: 0.8rem;
  padding: 0.8rem;
  border-radius: 4px;
  font-size: 0.92rem;
  display: none;
}
.quiz-feedback.show { display: block; }

/* Highlight box */
.highlight-box {
  background: var(--color-highlight);
  border: 1px solid #e6d9a0;
  border-radius: 6px;
  padding: 1rem 1.2rem;
  margin: 1.2rem 0;
  font-size: 0.94rem;
}

/* Footer / nav */
.lesson-footer {
  margin-top: 3rem;
  padding-top: 1.2rem;
  border-top: 1px solid var(--color-border);
  font-family: var(--font-heading);
  font-size: 0.85rem;
  color: var(--color-muted);
}
.lesson-footer a { margin-right: 1rem; }

/* Print */
@media print {
  body { max-width: 100%; padding: 1rem; font-size: 11pt; }
  .quiz-options li { border: 1px solid #ccc; }
  a { color: var(--color-text); }
}

@media (max-width: 720px) {
  html { font-size: 15px; }
  body { padding: 1.5rem 1rem; }
  .compare { grid-template-columns: 1fr; }
}