/* ==========================================================================
   Corporate Valuation — Reusable Component Styles
   ========================================================================== */

/* --- Stability Badges --- */
.stability-badge {
  font-size: 0.8rem;
  padding: 0.4rem 0.85rem;
  border-radius: 20px;
  display: inline-block;
  margin-bottom: 1rem;
  font-weight: 500;
}

.stable-badge {
  background: var(--info-bg);
  color: var(--info);
  border: 1px solid var(--info);
}

.volatile-badge {
  background: var(--warning-bg);
  color: var(--warning);
  border: 1px solid var(--warning);
}

.volatile-badge-expired {
  background: var(--danger-bg);
  color: var(--danger);
  border: 1px solid var(--danger);
}

/* --- Callout Boxes --- */
.callout {
  display: flex;
  gap: 1rem;
  padding: 1.25rem 1.5rem;
  border-radius: var(--radius);
  margin: 1.5rem 0;
  border-left: 4px solid;
  align-items: flex-start;
}

.callout-icon {
  font-size: 1.3rem;
  flex-shrink: 0;
  line-height: 1.4;
}

.callout-content { flex: 1; }
.callout-content p:last-child { margin-bottom: 0; }

.callout-warning {
  background: var(--warning-bg);
  border-color: var(--warning);
  color: var(--text);
}

.callout-tip {
  background: var(--success-bg);
  border-color: var(--success);
  color: var(--text);
}

.callout-note {
  background: var(--info-bg);
  border-color: var(--info);
  color: var(--text);
}

.callout-realworld {
  background: var(--surface);
  border-color: var(--primary);
  color: var(--text);
}

/* --- Hands-On Project --- */
.hands-on-project {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 2rem;
  margin: 3rem 0;
}

.hands-on-project h2 {
  margin-top: 0;
  color: var(--primary-light);
}

.project-brief { margin-bottom: 1.5rem; }
.project-steps { margin-bottom: 1.5rem; }

.project-steps ol { margin-left: 1.25rem; }
.project-steps li { margin-bottom: 0.6rem; }

.solution-toggle {
  margin-top: 1.5rem;
}

.solution-toggle > summary {
  cursor: pointer;
  padding: 0.75rem 1.25rem;
  background: var(--surface-hover);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  font-weight: 600;
  color: var(--primary-light);
  transition: all var(--transition);
  list-style: none;
}

.solution-toggle > summary::-webkit-details-marker { display: none; }

.solution-toggle > summary::before {
  content: "▶ ";
  font-size: 0.75rem;
  transition: transform var(--transition);
  display: inline-block;
}

.solution-toggle[open] > summary::before { transform: rotate(90deg); }

.solution-toggle > summary:hover {
  border-color: var(--primary);
  background: var(--surface);
}

.solution-content {
  margin-top: 1.25rem;
  padding: 1.25rem;
  background: var(--code-bg);
  border-radius: var(--radius);
  border: 1px solid var(--border-light);
}

/* --- End-of-Chapter Quiz --- */
.chapter-quiz {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 2rem;
  margin: 3rem 0;
}

.chapter-quiz h2 {
  margin-top: 0;
  color: var(--primary-light);
}

.quiz-container {
  display: flex;
  flex-direction: column;
  gap: 1.75rem;
  margin: 1.5rem 0;
}

.quiz-question {
  padding-bottom: 1.25rem;
  border-bottom: 1px solid var(--border-light);
}

.question-text {
  font-weight: 600;
  margin-bottom: 0.75rem;
  color: var(--text);
}

.quiz-options {
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}

.quiz-option {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  padding: 0.6rem 0.85rem;
  border-radius: var(--radius);
  cursor: pointer;
  transition: background var(--transition);
  font-size: 0.925rem;
  color: var(--text);
}

.quiz-option:hover { background: var(--surface-hover); }

.quiz-option input[type="radio"] { accent-color: var(--primary); }

.quiz-option.correct {
  background: var(--success-bg);
  border: 1px solid var(--success);
}

.quiz-option.incorrect {
  background: var(--danger-bg);
  border: 1px solid var(--danger);
}

.quiz-feedback {
  margin-top: 0.65rem;
  font-size: 0.85rem;
  padding: 0.5rem 0.85rem;
  border-radius: var(--radius);
}

.quiz-feedback.correct {
  background: var(--success-bg);
  color: var(--success);
}

.quiz-feedback.incorrect {
  background: var(--danger-bg);
  color: var(--danger);
}

.quiz-submit-btn {
  display: inline-block;
  background: linear-gradient(135deg, var(--primary-dark), var(--primary));
  color: #fff;
  border: none;
  padding: 0.75rem 2rem;
  border-radius: var(--radius);
  font-size: 1rem;
  font-weight: 600;
  cursor: pointer;
  transition: opacity var(--transition), transform var(--transition);
  margin-top: 1rem;
}

.quiz-submit-btn:hover { opacity: 0.9; transform: translateY(-1px); }
.quiz-submit-btn:disabled { opacity: 0.5; cursor: not-allowed; transform: none; }

.quiz-score {
  margin-top: 1rem;
  font-size: 1.2rem;
  font-weight: 700;
  padding: 1rem 1.5rem;
  border-radius: var(--radius);
  text-align: center;
}

.quiz-score.excellent { background: var(--success-bg); color: var(--success); }
.quiz-score.good { background: var(--info-bg); color: var(--info); }
.quiz-score.poor { background: var(--warning-bg); color: var(--warning); }
.quiz-score.fail { background: var(--danger-bg); color: var(--danger); }

/* --- Data Tables --- */
.data-table-container {
  margin: 1.5rem 0;
  overflow-x: auto;
}

.data-table-container table {
  font-size: 0.875rem;
}

.data-table-container .data-source-note {
  font-size: 0.75rem;
  color: var(--text-muted);
  margin-top: 0.5rem;
  text-align: right;
  font-style: italic;
}

/* --- Table of Contents (in-chapter) --- */
.chapter-toc {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.25rem 1.75rem;
  margin-bottom: 2rem;
}

.chapter-toc h3 {
  margin-top: 0;
  font-size: 1rem;
  color: var(--text-light);
  margin-bottom: 0.75rem;
}

.chapter-toc ol {
  margin: 0;
  font-size: 0.925rem;
}

.chapter-toc a { color: var(--text-light); }
.chapter-toc a:hover { color: var(--primary-light); }

/* --- Progress Bar --- */
.chapter-progress {
  width: 100%;
  height: 3px;
  background: var(--border);
  position: fixed;
  top: 0;
  left: 0;
  z-index: 200;
}

.chapter-progress-fill {
  height: 100%;
  background: linear-gradient(90deg, var(--primary), var(--accent));
  width: 0%;
  transition: width 100ms ease;
}

/* --- Concept Cards (for definitions) --- */
.concept-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.25rem 1.5rem;
  margin: 1.25rem 0;
}

.concept-card .concept-term {
  font-weight: 700;
  color: var(--primary-light);
  font-size: 1.05rem;
  margin-bottom: 0.35rem;
}

.concept-card .concept-definition {
  color: var(--text-light);
  font-size: 0.925rem;
  margin: 0;
}

/* --- Step-by-step walkthrough --- */
.steps-walkthrough { counter-reset: step; list-style: none; margin: 1.5rem 0 1.5rem 0; }

.steps-walkthrough li {
  counter-increment: step;
  padding: 1rem 1rem 1rem 3.5rem;
  position: relative;
  margin-bottom: 1rem;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
}

.steps-walkthrough li::before {
  content: counter(step);
  position: absolute;
  left: 0.75rem;
  top: 0.9rem;
  width: 2rem;
  height: 2rem;
  background: var(--primary);
  color: #fff;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  font-size: 0.875rem;
}

/* --- Comparison Grid --- */
.comparison-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1rem;
  margin: 1.5rem 0;
}

.comparison-col {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.25rem;
}

.comparison-col h4 {
  margin-top: 0;
  color: var(--primary-light);
  font-size: 1rem;
}

@media (max-width: 768px) {
  .comparison-grid { grid-template-columns: 1fr; }
}

/* --- Flash / Highlight animation --- */
@keyframes highlight-pulse {
  0% { background: var(--surface); }
  50% { background: var(--info-bg); }
  100% { background: var(--surface); }
}

.highlight-target {
  animation: highlight-pulse 1.5s ease;
}

/* --- Tool Tag --- */
.tool-tag {
  display: inline-flex;
  align-items: center;
  gap: 0.25rem;
  padding: 0.2rem 0.6rem;
  border-radius: 4px;
  font-size: 0.8rem;
  font-weight: 600;
  background: var(--surface-hover);
  color: var(--text-light);
  border: 1px solid var(--border);
}

.tool-tag.python { color: #4da6d9; border-color: #4da6d9; background: rgba(77,166,217,0.1); }
.tool-tag.excel { color: #4caf7d; border-color: #4caf7d; background: rgba(76,175,125,0.1); }
.tool-tag.powerbi { color: #f0c040; border-color: #f0c040; background: rgba(240,192,64,0.1); }
.tool-tag.knime { color: #f0a040; border-color: #f0a040; background: rgba(240,160,64,0.1); }
.tool-tag.chatgpt { color: #8fa8ff; border-color: #8fa8ff; background: rgba(143,168,255,0.1); }
.tool-tag.session-tag { color: var(--accent); border-color: var(--accent); background: rgba(0,201,167,0.1); margin-left: 0.4rem; vertical-align: middle; }

/* ==========================================================================
   Dual-Track: Excel Path (for students who prefer Excel over Python)
   ========================================================================== */

.excel-path {
  background: var(--surface);
  border: 1px solid #217346;
  border-left: 4px solid #217346;
  border-radius: var(--radius-lg);
  padding: 1.5rem 1.75rem;
  margin: 2rem 0;
}

.excel-path-header {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  margin-bottom: 0.9rem;
  flex-wrap: wrap;
}

.excel-path-icon {
  width: 2rem;
  height: 2rem;
  border-radius: 6px;
  background: rgba(33,115,70,0.18);
  color: #33c481;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.05rem;
  font-weight: 700;
  flex-shrink: 0;
}

.excel-path-title {
  font-weight: 700;
  font-size: 1rem;
  color: #33c481;
}

.excel-path-tag {
  font-size: 0.7rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--text-muted);
  background: var(--surface-hover);
  padding: 0.15rem 0.55rem;
  border-radius: 10px;
  margin-left: auto;
}

.excel-path-body {
  font-size: 0.93rem;
  color: var(--text);
}

.excel-path-body p:last-child { margin-bottom: 0; }
.excel-path-body ol, .excel-path-body ul { margin: 0.5rem 0 0.75rem 1.4rem; }
.excel-path-body li { margin-bottom: 0.35rem; }

/* Excel formula chip — inline */
.excel-formula {
  font-family: var(--font-mono);
  font-size: 0.82rem;
  background: rgba(33,115,70,0.12);
  border: 1px solid rgba(51,196,129,0.35);
  color: #33c481;
  padding: 0.15rem 0.5rem;
  border-radius: 5px;
  white-space: nowrap;
}

.excel-formula-block {
  font-family: var(--font-mono);
  font-size: 0.85rem;
  background: var(--code-bg);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1rem 1.25rem;
  margin: 0.75rem 0;
  overflow-x: auto;
  color: #33c481;
  line-height: 1.8;
}

.excel-formula-block .fx-comment {
  color: var(--text-muted);
  font-style: italic;
}

.excel-path-body table { font-size: 0.85rem; }

/* Dual-track notice banner (chapter intro) */
.dual-track-note {
  display: flex;
  gap: 0.9rem;
  align-items: flex-start;
  background: linear-gradient(135deg, rgba(33,115,70,0.10) 0%, rgba(77,166,217,0.08) 100%);
  border: 1px solid var(--border-light);
  border-radius: var(--radius-lg);
  padding: 1.25rem 1.5rem;
  margin: 0 0 2rem 0;
}

.dual-track-note .dtn-icon {
  font-size: 1.5rem;
  flex-shrink: 0;
  line-height: 1.2;
}

.dual-track-note .dtn-title {
  font-weight: 700;
  font-size: 0.95rem;
  margin-bottom: 0.3rem;
  color: var(--text);
}

.dual-track-note p {
  margin: 0;
  font-size: 0.88rem;
  color: var(--text-light);
}

.dual-track-note .dtn-paths {
  display: flex;
  gap: 0.5rem;
  margin-top: 0.55rem;
  flex-wrap: wrap;
}

@media (max-width: 768px) {
  .excel-path { padding: 1.1rem; }
  .excel-path-tag { display: none; }
}

/* ==========================================================================
   Student Engagement Components — Activities, Checkpoints, Polls
   ========================================================================== */

/* --- Generic Student Activity Box --- */
.student-activity {
  background: var(--surface);
  border: 1px solid var(--border-light);
  border-radius: var(--radius-lg);
  padding: 1.5rem 1.75rem;
  margin: 1.75rem 0;
  position: relative;
}

.student-activity::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 4px;
  height: 100%;
  border-radius: var(--radius-lg) 0 0 var(--radius-lg);
}

/* Activity type variants with colored left border */
.activity-your-turn::before    { background: var(--success); }
.activity-pair::before         { background: var(--primary); }
.activity-think::before        { background: var(--warning); }
.activity-group::before        { background: var(--accent); }
.activity-vote::before         { background: var(--danger); }
.activity-checkpoint::before   { background: var(--info); }
.activity-hook::before         { background: linear-gradient(180deg, var(--primary), var(--accent)); }
.activity-reflection::before   { background: #a0a0b8; }
.activity-peer-teach::before   { background: var(--accent-light); }
.activity-data::before         { background: var(--primary-light); }

/* Activity header row: icon + label + optional timer */
.activity-header {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  margin-bottom: 0.75rem;
  flex-wrap: wrap;
}

.activity-icon {
  width: 2rem;
  height: 2rem;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1rem;
  flex-shrink: 0;
}

.activity-icon-green    { background: var(--success-bg); color: var(--success); }
.activity-icon-blue     { background: var(--info-bg); color: var(--info); }
.activity-icon-yellow   { background: var(--warning-bg); color: var(--warning); }
.activity-icon-red      { background: var(--danger-bg); color: var(--danger); }
.activity-icon-purple   { background: rgba(143,168,255,0.15); color: var(--primary-light); }
.activity-icon-teal     { background: rgba(0,201,167,0.15); color: var(--accent); }
.activity-icon-gray     { background: var(--surface-hover); color: var(--text-muted); }

.activity-label {
  font-weight: 700;
  font-size: 0.85rem;
  text-transform: uppercase;
  letter-spacing: 0.04em;
}

.activity-label-green   { color: var(--success); }
.activity-label-blue    { color: var(--primary-light); }
.activity-label-yellow  { color: var(--warning); }
.activity-label-red     { color: var(--danger); }
.activity-label-teal    { color: var(--accent); }
.activity-label-purple  { color: var(--primary-light); }
.activity-label-gray    { color: var(--text-muted); }

.activity-timer {
  font-size: 0.75rem;
  background: var(--surface-hover);
  padding: 0.2rem 0.6rem;
  border-radius: 12px;
  color: var(--text-light);
  margin-left: auto;
  display: flex;
  align-items: center;
  gap: 0.25rem;
}

/* Activity body */
.activity-body {
  color: var(--text);
  font-size: 0.95rem;
}

.activity-body p:last-child { margin-bottom: 0; }

.activity-body ol, .activity-body ul {
  margin: 0.5rem 0 0 1.25rem;
}
.activity-body li { margin-bottom: 0.3rem; }

.activity-body .steps-walkthrough { margin: 0.5rem 0; }

/* --- Opening Hook --- */
.opening-hook {
  background: linear-gradient(135deg, #1a1a3e 0%, #161625 100%);
  border: 2px solid var(--primary);
  border-radius: var(--radius-xl);
  padding: 1.75rem 2rem;
  margin: 1.5rem 0 2.5rem;
  text-align: center;
}

.opening-hook h3 {
  margin-top: 0;
  font-size: 1.3rem;
  color: var(--primary-light);
}

.opening-hook .hook-question {
  font-size: 1.1rem;
  color: var(--accent);
  font-weight: 600;
  margin: 0.75rem 0;
}

.opening-hook .hook-instruction {
  font-size: 0.9rem;
  color: var(--text-light);
  font-style: italic;
  margin-bottom: 0;
}

/* --- Checkpoint ("Before You Move On") --- */
.checkpoint-box {
  background: var(--info-bg);
  border: 1px solid var(--info);
  border-radius: var(--radius-lg);
  padding: 1.5rem 1.75rem;
  margin: 2rem 0;
}

.checkpoint-box h3 {
  margin-top: 0;
  font-size: 1.05rem;
  color: var(--info);
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.checkpoint-question {
  padding: 0.5rem 0;
  border-bottom: 1px solid rgba(77,166,217,0.15);
}

.checkpoint-question:last-child { border-bottom: none; }

.checkpoint-question p {
  margin-bottom: 0.35rem;
  font-weight: 600;
  font-size: 0.95rem;
}

.checkpoint-question .answer-toggle {
  font-size: 0.85rem;
  color: var(--text-muted);
  cursor: pointer;
  display: inline-flex;
  align-items: center;
  gap: 0.3rem;
}

.checkpoint-question .answer-toggle:hover { color: var(--info); }

.checkpoint-question .answer-hidden {
  display: none;
  padding: 0.35rem 0.75rem;
  margin-top: 0.35rem;
  background: var(--surface);
  border-radius: var(--radius);
  font-size: 0.85rem;
  color: var(--accent);
}

/* --- Poll/Vote Box --- */
.vote-box {
  text-align: center;
}

.vote-options {
  display: flex;
  gap: 0.75rem;
  justify-content: center;
  flex-wrap: wrap;
  margin: 1rem 0;
}

.vote-option-btn {
  background: var(--surface);
  border: 2px solid var(--border);
  border-radius: var(--radius);
  padding: 0.75rem 1.25rem;
  font-size: 0.9rem;
  font-weight: 600;
  color: var(--text-light);
  cursor: pointer;
  transition: all var(--transition);
}

.vote-option-btn:hover {
  border-color: var(--primary);
  color: var(--primary-light);
  background: var(--surface-hover);
}

.vote-option-btn.selected {
  border-color: var(--primary);
  background: var(--info-bg);
  color: var(--primary-light);
}

.vote-option-btn.true-statement {
  border-color: var(--success);
  background: var(--success-bg);
  color: var(--success);
}

.vote-option-btn.false-statement {
  border-color: var(--danger);
  background: var(--danger-bg);
  color: var(--danger);
}

/* --- Matching Exercise --- */
.matching-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 0.75rem;
  margin: 1rem 0;
}

.matching-item {
  background: var(--surface-hover);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 0.75rem 1rem;
  font-size: 0.9rem;
  cursor: pointer;
  transition: all var(--transition);
}

.matching-item:hover {
  border-color: var(--primary);
  background: var(--surface);
}

.matching-item.matched {
  border-color: var(--success);
  background: var(--success-bg);
  color: var(--success);
}

@media (max-width: 768px) {
  .matching-grid { grid-template-columns: 1fr; }
  .student-activity { padding: 1.15rem; }
}

/* --- Thinking Prompt (Inline Quick Think) --- */
.think-prompt {
  background: none;
  border-left: 3px solid var(--warning);
  padding: 0.5rem 0 0.5rem 1.25rem;
  margin: 1.25rem 0;
  font-style: italic;
  color: var(--text-light);
}

.think-prompt strong {
  color: var(--warning);
  font-style: normal;
}

/* --- Reflection Box --- */
.reflection-box {
  background: var(--surface);
  border: 1px dashed var(--border);
  border-radius: var(--radius);
  padding: 1.25rem 1.5rem;
  margin: 1.5rem 0;
  text-align: center;
}

.reflection-box p {
  margin-bottom: 0.5rem;
  color: var(--text-light);
  font-size: 0.9rem;
}

/* ==========================================================================
   Session-Wise Navigation
   ========================================================================== */

.session-nav {
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 0.5rem;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 0.55rem 1rem;
  margin-bottom: 1rem;
  font-size: 0.85rem;
}

.session-nav-info {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  color: var(--text-light);
  flex-wrap: wrap;
}

.session-nav-info .session-current {
  font-weight: 700;
  color: var(--primary-light);
  background: var(--info-bg);
  border: 1px solid var(--info);
  padding: 0.15rem 0.6rem;
  border-radius: 12px;
  white-space: nowrap;
}

.session-nav-info .session-part {
  color: var(--text-muted);
  font-style: italic;
}

.session-nav-links {
  display: flex;
  gap: 0.4rem;
  align-items: center;
  flex-wrap: wrap;
}

.session-nav-links .nav-link {
  padding: 0.3rem 0.6rem;
  font-size: 0.78rem;
}

.session-nav-links .nav-link .session-num {
  font-weight: 700;
  color: var(--accent);
}

/* Anchor target for multi-session chapters */
.session-anchor {
  scroll-margin-top: 70px;
  border-top: 1px dashed var(--border-light);
  margin-top: 3rem;
  padding-top: 2rem;
}

.session-anchor:first-of-type {
  border-top: none;
  margin-top: 0;
  padding-top: 0;
}

.session-anchor .session-anchor-tag {
  display: inline-block;
  font-size: 0.75rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--accent);
  background: rgba(0,201,167,0.12);
  border: 1px solid var(--accent);
  padding: 0.2rem 0.7rem;
  border-radius: 12px;
  margin-bottom: 0.75rem;
}

.session-anchor .session-anchor-tag.second-session {
  color: var(--primary-light);
  background: rgba(108,140,255,0.12);
  border-color: var(--primary);
}

@media (max-width: 768px) {
  .session-nav {
    flex-direction: column;
    align-items: flex-start;
  }
}