/* Paper Reading Course - Shared Stylesheet */

:root {
  --font-serif: 'Georgia', 'Times New Roman', serif;
  --font-sans: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  --color-text: #1a1a1a;
  --color-text-light: #666;
  --color-accent: #2563eb;
  --color-accent-light: #dbeafe;
  --color-border: #e5e7eb;
  --color-bg: #ffffff;
  --color-bg-alt: #f9fafb;
  --max-width: 720px;
}

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

body {
  font-family: var(--font-serif);
  font-size: 18px;
  line-height: 1.7;
  color: var(--color-text);
  background: var(--color-bg);
  padding: 2rem 1rem;
}

.container {
  max-width: var(--max-width);
  margin: 0 auto;
}

/* Typography */
h1, h2, h3, h4 {
  font-family: var(--font-sans);
  font-weight: 600;
  line-height: 1.3;
  margin-top: 2rem;
  margin-bottom: 1rem;
}

h1 { font-size: 2rem; }
h2 { font-size: 1.5rem; color: var(--color-accent); }
h3 { font-size: 1.25rem; }

p {
  margin-bottom: 1.2rem;
}

/* Links */
a {
  color: var(--color-accent);
  text-decoration: none;
}

a:hover {
  text-decoration: underline;
}

/* Paper metadata box */
.paper-meta {
  background: var(--color-bg-alt);
  border-left: 4px solid var(--color-accent);
  padding: 1.5rem;
  margin: 2rem 0;
  border-radius: 0 8px 8px 0;
}

.paper-meta h3 {
  margin-top: 0;
  font-size: 1.1rem;
}

.paper-meta p {
  margin-bottom: 0.5rem;
  font-size: 0.95rem;
}

/* Key concept boxes */
.concept-box {
  background: var(--color-accent-light);
  border: 1px solid var(--color-accent);
  padding: 1.5rem;
  margin: 1.5rem 0;
  border-radius: 8px;
}

.concept-box h4 {
  margin-top: 0;
  color: var(--color-accent);
}

/* Quiz styles */
.quiz-container {
  background: var(--color-bg-alt);
  border: 2px solid var(--color-border);
  padding: 2rem;
  margin: 2rem 0;
  border-radius: 12px;
}

.quiz-question {
  font-weight: 600;
  font-size: 1.1rem;
  margin-bottom: 1rem;
}

.quiz-options {
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
}

.quiz-option {
  padding: 1rem;
  background: var(--color-bg);
  border: 2px solid var(--color-border);
  border-radius: 8px;
  cursor: pointer;
  transition: all 0.2s;
}

.quiz-option:hover {
  border-color: var(--color-accent);
}

.quiz-option.correct {
  background: #dcfce7;
  border-color: #16a34a;
}

.quiz-option.incorrect {
  background: #fee2e2;
  border-color: #dc2626;
}

/* Quote block */
blockquote {
  border-left: 4px solid var(--color-accent);
  padding-left: 1.5rem;
  margin: 1.5rem 0;
  font-style: italic;
  color: var(--color-text-light);
}

/* Figure */
figure {
  margin: 2rem 0;
  text-align: center;
}

figcaption {
  font-size: 0.9rem;
  color: var(--color-text-light);
  margin-top: 0.5rem;
}

/* Navigation */
.nav-links {
  display: flex;
  justify-content: space-between;
  margin-top: 3rem;
  padding-top: 2rem;
  border-top: 1px solid var(--color-border);
}

/* Print styles */
@media print {
  body {
    font-size: 12pt;
    padding: 0;
  }
  
  .quiz-container {
    break-inside: avoid;
  }
}