/* ============================================
   ATENA CRYPTO — LESSON PAGE
   ============================================ */

.lesson-container { max-width: 820px; margin: 0 auto; padding: 2.5rem 2rem 4rem; }

/* Breadcrumb */
.lesson-breadcrumb {
  font-family: var(--font-mono); font-size: 0.68rem;
  color: var(--text-tertiary); margin-bottom: 1.5rem;
  display: flex; align-items: center; gap: 0.5rem;
}
.lesson-breadcrumb a { color: var(--text-secondary); text-decoration: none; }
.lesson-breadcrumb a:hover { color: var(--text); }

/* Header */
.lesson-header { margin-bottom: 2rem; }
.lesson-section-badge {
  display: inline-block; font-family: var(--font-mono); font-size: 0.62rem;
  text-transform: uppercase; letter-spacing: 0.1em;
  padding: 0.22rem 0.7rem; border-radius: var(--radius-sm);
  background: var(--bg-elevated); border: 1px solid var(--glass-border);
  color: var(--text-secondary); margin-bottom: 0.75rem;
}
.lesson-header h1 { font-size: 2rem; font-weight: 800; letter-spacing: -0.02em; margin-bottom: 0.6rem; color: var(--text); }
.lesson-meta-row { display: flex; align-items: center; gap: 1rem; font-family: var(--font-mono); font-size: 0.68rem; color: var(--text-tertiary); }
.lesson-num-badge { background: var(--bg-elevated); border: 1px solid var(--glass-border); border-radius: var(--radius-sm); padding: 0.15rem 0.55rem; color: var(--text-secondary); }

/* Nav buttons */
.lesson-nav { display: flex; gap: 0.6rem; margin-bottom: 2rem; flex-wrap: wrap; }
.lesson-nav-bottom { margin-top: 2.5rem; margin-bottom: 0; }
.ln-btn {
  display: inline-flex; align-items: center; gap: 0.4rem;
  padding: 0.45rem 1rem; border-radius: var(--radius);
  font-size: 0.78rem; font-weight: 500; text-decoration: none;
  transition: border-color 0.15s, color 0.15s, background 0.15s;
  border: 1px solid var(--glass-border); color: var(--text-secondary); background: transparent;
}
.ln-btn:hover { border-color: rgba(46,184,92,0.3); color: var(--text); background: var(--bg-hover); }
.ln-btn.ln-back { background: var(--bg-elevated); border-color: var(--glass-border); color: var(--text-secondary); }
.ln-btn.ln-back:hover { border-color: var(--glass-border-hover); color: var(--text); }

/* Theory section */
.theory-section { margin-bottom: 1rem; }

/* Kernidee box — brand green left border */
.kernidee-box {
  background: var(--bg-elevated);
  border: 1px solid var(--glass-border);
  border-left: 3px solid var(--green);
  border-radius: 0 var(--radius) var(--radius) 0;
  padding: 1.25rem 1.5rem; margin-bottom: 2.25rem;
}
.ki-label { font-family: var(--font-mono); font-size: 0.62rem; text-transform: uppercase; letter-spacing: 0.12em; color: var(--green); margin-bottom: 0.5rem; }
.kernidee-box p { color: var(--text); font-size: 1rem; line-height: 1.65; margin: 0; }

/* Erklärung */
.erklaerung-body { margin-bottom: 2rem; }
.erklaerung-body h2 { font-size: 1.2rem; font-weight: 800; color: var(--text); margin-bottom: 1.25rem; padding-bottom: 0.5rem; border-bottom: 1px solid var(--glass-border); }
.erklaerung-body h3 { font-size: 0.95rem; font-weight: 700; color: var(--text); margin: 1.5rem 0 0.5rem; }
.erklaerung-body p { color: var(--text-secondary); font-size: 0.9rem; line-height: 1.7; margin-bottom: 0.75rem; }

/* Verbindung & Vorschau */
.verbindung-box, .vorschau-box {
  display: flex; gap: 0.85rem;
  background: var(--bg-elevated); border: 1px solid var(--glass-border);
  border-radius: var(--radius); padding: 0.9rem 1.1rem; margin-bottom: 1rem; align-items: flex-start;
}
.vb-icon { font-size: 1.1rem; flex-shrink: 0; margin-top: 0.1rem; }
.vb-text { font-size: 0.82rem; color: var(--text-secondary); line-height: 1.55; }
.vb-text strong { color: var(--text-tertiary); display: block; margin-bottom: 0.2rem; font-size: 0.78rem; font-family: var(--font-mono); text-transform: uppercase; letter-spacing: 0.08em; }

/* Key Learnings */
.key-learnings { margin: 1.75rem 0; }
.kl-title { font-size: 0.78rem; font-weight: 600; color: var(--text-secondary); text-transform: uppercase; letter-spacing: 0.1em; font-family: var(--font-mono); margin-bottom: 0.75rem; }
.kl-grid { display: flex; flex-wrap: wrap; gap: 0.5rem; }
.kl-chip { background: var(--bg-elevated); border: 1px solid var(--glass-border); border-radius: var(--radius-sm); padding: 0.3rem 0.9rem; font-size: 0.78rem; color: var(--text); line-height: 1.3; }

/* Practice divider */
.practice-divider { display: flex; align-items: center; gap: 1rem; margin: 2rem 0; color: var(--text-tertiary); font-family: var(--font-mono); font-size: 0.7rem; text-transform: uppercase; letter-spacing: 0.12em; }
.practice-divider::before, .practice-divider::after { content: ''; flex: 1; height: 1px; background: var(--glass-border); }

/* Praxisbeispiel */
.praxisbeispiel-box { background: var(--bg-elevated); border: 1px solid var(--glass-border); border-radius: var(--radius); padding: 1.25rem 1.4rem; margin-bottom: 2rem; }
.pb-label { font-family: var(--font-mono); font-size: 0.62rem; text-transform: uppercase; letter-spacing: 0.12em; color: var(--green); margin-bottom: 0.6rem; }
.praxisbeispiel-box p { font-size: 0.875rem; color: var(--text-secondary); line-height: 1.65; margin: 0; }

/* Quiz */
.quiz-section { margin-bottom: 2rem; }
.quiz-section-title { font-family: var(--font-mono); font-size: 0.68rem; text-transform: uppercase; letter-spacing: 0.12em; color: var(--text-tertiary); margin-bottom: 1rem; }
.quiz-card {
  background: var(--bg-glass); backdrop-filter: blur(12px);
  border: 1px solid var(--glass-border); border-radius: var(--radius);
  padding: 1.1rem 1.25rem; margin-bottom: 1rem;
}
.quiz-q { font-size: 0.875rem; font-weight: 600; color: var(--text); margin-bottom: 0.75rem; line-height: 1.5; }
.quiz-options { display: flex; flex-direction: column; gap: 0.45rem; }
.quiz-option {
  padding: 0.5rem 0.9rem; border-radius: var(--radius);
  border: 1px solid var(--glass-border); background: transparent;
  font-size: 0.82rem; color: var(--text-secondary); cursor: pointer;
  transition: all 0.15s; text-align: left;
}
.quiz-option:hover:not(.answered-opt) { border-color: rgba(46,184,92,0.3); color: var(--text); background: var(--green-dim); }
.quiz-option.correct   { border-color: var(--positive); background: rgba(46,184,92,0.07); color: var(--positive); }
.quiz-option.incorrect { border-color: var(--negative); background: rgba(230,90,79,0.07); color: var(--negative); }
.quiz-explanation { display: none; margin-top: 0.6rem; padding: 0.55rem 0.85rem; background: var(--bg-elevated); border-radius: var(--radius); font-size: 0.78rem; color: var(--text-secondary); line-height: 1.5; border-left: 2px solid var(--glass-border); }

/* Zusammenfassung */
.zusammenfassung-section { margin-top: 1.5rem; }
.zf-toggle-btn { display: flex; align-items: center; gap: 0.5rem; background: var(--bg-elevated); border: 1px solid var(--glass-border); border-radius: var(--radius); padding: 0.7rem 1.1rem; font-size: 0.82rem; font-weight: 600; color: var(--text-secondary); cursor: pointer; width: 100%; text-align: left; transition: all 0.15s; }
.zf-toggle-btn:hover { border-color: rgba(46,184,92,0.3); color: var(--text); background: var(--bg-hover); }
.zf-content { max-height: 0; overflow: hidden; transition: max-height 0.4s ease; }
.zf-content.open { max-height: 600px; }
.zf-inner { padding: 1rem 1.1rem; font-size: 0.85rem; color: var(--text-secondary); line-height: 1.65; border: 1px solid var(--glass-border); border-top: none; border-radius: 0 0 var(--radius) var(--radius); background: var(--bg-elevated); }
.zf-inner ul { padding-left: 1.2rem; margin: 0; }
.zf-inner li { margin-bottom: 0.35rem; }

@media (max-width: 900px) {
  .lesson-container { padding: 1.75rem 1.25rem 3rem; }
  .lesson-header h1 { font-size: 1.7rem; }
}
@media (max-width: 700px) {
  .lesson-container { padding: 1.25rem 1rem 3rem; }
  .lesson-header h1 { font-size: 1.45rem; }
  .kl-grid { gap: 0.4rem; }
  .lesson-breadcrumb { flex-wrap: wrap; }
  .ln-btn { min-height: 44px; padding: 0.5rem 1rem; font-size: 0.82rem; }
  .kernidee-box { padding: 1rem 1.1rem; }
  .erklaerung-body h2 { font-size: 1.05rem; }
  .quiz-option { min-height: 44px; }
}