/* Esasy Üýtgeýänler & Rejimler */
:root {
  --bg-color: #f4f6f8;
  --card-bg: #ffffff;
  --text-color: #1c1e21;
  --accent-color: #0088cc;
  --accent-hover: #006699;
  --border-color: #e0e0e0;
  --lock-color: #888888;
  --success-color: #2e7d32;
  --error-color: #c62828;
}

body.dark-theme {
  --bg-color: #151e27;
  --card-bg: #1d2733;
  --text-color: #f5f5f5;
  --accent-color: #64b5f6;
  --accent-hover: #42a5f5;
  --border-color: #2b394a;
  --lock-color: #6c7883;
}

* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
}

body {
  background-color: var(--bg-color);
  color: var(--text-color);
  transition: background-color 0.3s, color 0.3s;
  padding-bottom: 20px;
}

/* Header */
.app-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 12px 16px;
  background-color: var(--card-bg);
  border-bottom: 1px solid var(--border-color);
}

.theme-btn {
  background: none;
  border: none;
  font-size: 1.4rem;
  cursor: pointer;
}

/* Kategoriýa Navigasiýasy */
.category-nav {
  display: flex;
  overflow-x: auto;
  gap: 8px;
  padding: 10px 16px;
  background-color: var(--card-bg);
  border-bottom: 1px solid var(--border-color);
}

.cat-btn {
  padding: 8px 16px;
  border: 1px solid var(--border-color);
  border-radius: 20px;
  background: var(--bg-color);
  color: var(--text-color);
  font-weight: bold;
  cursor: pointer;
  white-space: nowrap;
}

.cat-btn.active {
  background-color: var(--accent-color);
  color: #fff;
  border-color: var(--accent-color);
}

/* Views & Layout */
.main-content {
  padding: 16px;
  max-width: 800px;
  margin: 0 auto;
}

.view {
  display: none;
}

.view.active {
  display: block;
}

/* Topics Grid */
.topics-grid {
  display: flex;
  flex-direction: column;
  gap: 10px;
  margin-top: 12px;
}

.topic-card {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 14px 16px;
  background-color: var(--card-bg);
  border-radius: 10px;
  border: 1px solid var(--border-color);
  cursor: pointer;
}

.topic-card.locked {
  opacity: 0.6;
  cursor: not-allowed;
}

.topic-title {
  font-size: 0.95rem;
  font-weight: 500;
}

.status-badge {
  font-size: 0.85rem;
  font-weight: bold;
}

.status-badge.passed { color: var(--success-color); }
.status-badge.locked { color: var(--lock-color); }

/* Lesson Detail */
.back-btn {
  background: none;
  border: none;
  color: var(--accent-color);
  font-weight: bold;
  font-size: 0.95rem;
  margin-bottom: 12px;
  cursor: pointer;
}

.markdown-body {
  background-color: var(--card-bg);
  padding: 16px;
  border-radius: 10px;
  line-height: 1.6;
  border: 1px solid var(--border-color);
}

.markdown-body h1, .markdown-body h2 {
  margin-bottom: 12px;
  color: var(--accent-color);
}

.markdown-body p, .markdown-body table {
  margin-bottom: 12px;
}

.markdown-body table {
  width: 100%;
  border-collapse: collapse;
}

.markdown-body th, .markdown-body td {
  border: 1px solid var(--border-color);
  padding: 8px;
  text-align: left;
}

.lesson-actions {
  margin-top: 16px;
}

.action-btn {
  width: 100%;
  padding: 12px;
  background-color: var(--accent-color);
  color: #fff;
  border: none;
  border-radius: 8px;
  font-size: 1rem;
  font-weight: bold;
  cursor: pointer;
}

.action-btn.secondary {
  background-color: var(--border-color);
  color: var(--text-color);
  margin-top: 8px;
}

/* Quiz */
.quiz-container {
  background-color: var(--card-bg);
  padding: 16px;
  border-radius: 10px;
  border: 1px solid var(--border-color);
}

.quiz-header {
  display: flex;
  justify-content: space-between;
  margin-bottom: 16px;
}

.question-text {
  font-size: 1.1rem;
  font-weight: bold;
  margin-bottom: 16px;
}

.options-grid {
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.option-btn {
  padding: 12px;
  border: 1px solid var(--border-color);
  background: var(--bg-color);
  color: var(--text-color);
  border-radius: 8px;
  text-align: left;
  font-size: 0.95rem;
  cursor: pointer;
}

.option-btn.selected {
  border-color: var(--accent-color);
  background-color: rgba(100, 181, 246, 0.1);
}

.result-box {
  margin-top: 20px;
  text-align: center;
}

.hidden { display: none; }