/* ============================================================
   HSCScience — Shared Stylesheet
   Extracted from lesson template
   ============================================================ */

/* ============================================================
   DESIGN TOKENS
   ============================================================ */
:root {
  --bg: #f0f4f8;
  --surface: #ffffff;
  --surface-2: #f8fafc;
  --border: #e2e8f0;
  --primary: #2563eb;
  --primary-light: rgba(37,99,235,0.08);
  --secondary: #059669;
  --secondary-light: rgba(5,150,105,0.08);
  --accent: #d97706;
  --accent-light: rgba(217,119,6,0.08);
  --critical: #7c3aed;
  --purple:   #7c3aed;
  --purple-light: rgba(124,58,237,0.07);
  --danger: #dc2626;
  --text: #0f172a;
  --text-muted: #475569;
  --text-light: #94a3b8;
  --shadow-sm: 0 1px 3px rgba(0,0,0,0.08);
  --shadow: 0 2px 8px rgba(0,0,0,0.08);
  --shadow-md: 0 4px 16px rgba(0,0,0,0.10);
  --radius: 12px;
  --radius-sm: 8px;
}

/* ============================================================
   RESET & BASE
   ============================================================ */
*, *::before, *::after { margin: 0; padding: 0; box-sizing: border-box; }

html {
  scroll-behavior: smooth;
}

body {
  font-family: 'DM Sans', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.7;
  font-size: 24px;
}

/* ============================================================
   PROGRESS BAR (top of page)
   ============================================================ */
.progress-bar-wrap {
  position: fixed;
  top: 0; left: 0; right: 0;
  height: 3px;
  background: var(--border);
  z-index: 1000;
}
.progress-bar-fill {
  height: 100%;
  background: linear-gradient(90deg, var(--primary), var(--secondary));
  width: 0%;
  transition: width 0.2s ease;
}

/* ============================================================
   SECTION NAV (sticky side indicator — desktop)
   ============================================================ */
.section-nav {
  position: fixed;
  right: 24px;
  top: 50%;
  transform: translateY(-50%);
  display: flex;
  flex-direction: column;
  gap: 10px;
  z-index: 100;
}
.section-dot {
  width: 8px; height: 8px;
  border-radius: 50%;
  background: var(--border);
  border: 2px solid var(--text-light);
  cursor: pointer;
  transition: all 0.2s;
  position: relative;
}
.section-dot.active {
  background: var(--primary);
  border-color: var(--primary);
  transform: scale(1.4);
}
.section-dot:hover::after {
  content: attr(data-label);
  position: absolute;
  right: 16px;
  top: 50%;
  transform: translateY(-50%);
  background: var(--text);
  color: white;
  padding: 4px 10px;
  border-radius: 6px;
  font-size: 12px;
  white-space: nowrap;
  font-family: 'DM Sans', sans-serif;
}

/* ============================================================
   LAYOUT WRAPPER
   ============================================================ */
.page {
  max-width: 1500px;
  width: calc(100% - 60px);
  margin: 0 auto;
  padding: 40px 0 80px;
}

/* ============================================================
   HERO
   ============================================================ */
.hero {
  background: var(--surface);
  border-radius: var(--radius);
  padding: 48px 40px;
  margin-bottom: 32px;
  box-shadow: var(--shadow);
  position: relative;
  overflow: hidden;
}
.hero::after {
  content: '';
  position: absolute;
  top: 0; left: 0; right: 0;
  height: 4px;
  background: linear-gradient(90deg, var(--primary) 0%, var(--critical) 100%);
}
.hero-top {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  gap: 24px;
}
.hero-badges {
  display: flex;
  gap: 8px;
  flex-wrap: wrap;
  margin-bottom: 16px;
}
.badge {
  padding: 4px 12px;
  border-radius: 100px;
  font-size: 11px;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.6px;
}
.badge-blue { background: var(--primary); color: white; }
.badge-green { background: var(--secondary); color: white; }
.badge-purple { background: var(--critical); color: white; }
.badge-free  { background: var(--surface-2); color: var(--text-muted); border: 1px solid var(--border); }
.hero h1 {
  font-size: 48px;
  font-weight: 700;
  line-height: 1.15;
  margin-bottom: 12px;
  color: var(--text);
  letter-spacing: -0.5px;
}
.hero-desc {
  color: var(--text-muted);
  font-size: 22px;
  max-width: 780px;
  line-height: 1.6;
}
.hero-emoji {
  font-size: 80px;
  line-height: 1;
  flex-shrink: 0;
  opacity: 0.85;
}

/* ============================================================
   INTENTIONS GRID
   ============================================================ */
.intentions-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 16px;
  margin-bottom: 32px;
}
.intention-card {
  background: var(--surface);
  border-radius: var(--radius);
  padding: 24px;
  box-shadow: var(--shadow-sm);
  border-top: 3px solid var(--primary);
}
.intention-card.purple { border-top-color: var(--critical); }
.intention-card.green { border-top-color: var(--secondary); }
.intention-card h3 {
  font-size: 11px;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.8px;
  margin-bottom: 14px;
  color: var(--text);
  display: flex;
  align-items: center;
  gap: 6px;
}
.intention-card ul { list-style: none; }
.intention-card li {
  color: var(--text-muted);
  font-size: 19px;
  padding: 7px 0 7px 20px;
  position: relative;
  line-height: 1.45;
  border-bottom: 1px solid var(--border);
}
.intention-card li:last-child { border-bottom: none; }
.intention-card li::before {
  content: '›';
  position: absolute;
  left: 0;
  font-weight: 700;
  color: var(--primary);
}
.intention-card.purple li::before { color: var(--critical); }
.intention-card.green li::before { color: var(--secondary); }

/* ============================================================
   SECTION LABEL
   ============================================================ */
.section-label {
  font-size: 11px;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 1px;
  color: var(--text-light);
  margin: 40px 0 16px;
  display: flex;
  align-items: center;
  gap: 10px;
}
.section-label::after {
  content: '';
  flex: 1;
  height: 1px;
  background: var(--border);
}

/* ============================================================
   CARDS
   ============================================================ */
.card {
  background: var(--surface);
  border-radius: var(--radius);
  padding: 32px;
  margin-bottom: 20px;
  box-shadow: var(--shadow-sm);
  border: 1px solid var(--border);
}
.card-header {
  display: flex;
  align-items: center;
  gap: 12px;
  margin-bottom: 20px;
  padding-bottom: 16px;
  border-bottom: 1px solid var(--border);
}
.card-icon {
  width: 38px; height: 38px;
  background: var(--primary-light);
  border-radius: var(--radius-sm);
  display: grid;
  place-items: center;
  font-size: 18px;
  flex-shrink: 0;
}
/* Numbered pill — replaces emoji icon in newer lessons */
.card-num {
  width: 36px; height: 36px; border-radius: var(--radius-sm);
  display: grid; place-items: center;
  font-size: 13px; font-weight: 700;
  color: white; flex-shrink: 0; margin-top: 1px;
}
.card-num.blue   { background: var(--primary); }
.card-num.green  { background: var(--secondary); }
.card-num.amber  { background: var(--accent); }
.card-num.purple { background: var(--purple); }
.card-num.slate  { background: #64748b; }
.card h2 {
  font-size: 20px;
  font-weight: 700;
  color: var(--text);
  letter-spacing: -0.3px;
}
.card-subtitle { color: var(--text-light); font-size: 12.5px; margin-top: 3px; }
.card h3 {
  font-size: 16px;
  font-weight: 600;
  color: var(--text);
  margin: 24px 0 10px;
}
.card p {
  color: var(--text-muted);
  margin-bottom: 14px;
  line-height: 1.7;
}

/* ============================================================
   IMAGE PLACEHOLDER
   ============================================================ */
.img-placeholder {
  background: var(--surface-2);
  border: 2px dashed var(--border);
  border-radius: var(--radius-sm);
  padding: 40px 24px;
  text-align: center;
  margin: 20px 0;
  color: var(--text-light);
}
.img-placeholder .img-icon { font-size: 32px; margin-bottom: 8px; }
.img-placeholder p { font-size: 13px; margin: 0; color: var(--text-light); }
.img-placeholder strong { color: var(--text-muted); font-size: 14px; display: block; margin-bottom: 4px; }
.img-label {
  display: inline-block;
  background: var(--border); color: var(--text-muted);
  font-size: 10px; font-weight: 700;
  text-transform: uppercase; letter-spacing: 1px;
  padding: 4px 10px; border-radius: 4px; margin-bottom: 8px;
}

/* ============================================================
   TABLES
   ============================================================ */
.table-wrap {
  overflow-x: auto;
  border-radius: var(--radius-sm);
  border: 1px solid var(--border);
  margin: 16px 0;
}
table { width: 100%; border-collapse: collapse; font-size: 20px; }
th {
  background: var(--surface-2);
  padding: 12px 16px;
  text-align: left;
  font-weight: 600;
  font-size: 11px;
  text-transform: uppercase;
  letter-spacing: 0.5px;
  color: var(--text-muted);
  border-bottom: 1px solid var(--border);
}
td {
  padding: 12px 16px;
  border-bottom: 1px solid var(--border);
  color: var(--text-muted);
  line-height: 1.5;
}
tr:last-child td { border-bottom: none; }
tr:hover td { background: var(--surface-2); }

/* ============================================================
   CALLOUT BOXES
   ============================================================ */
.callout {
  padding: 14px 18px;
  border-radius: var(--radius-sm);
  margin: 16px 0;
  font-size: 14px;
  line-height: 1.65;
  display: flex;
  gap: 12px;
  align-items: flex-start;
}
.callout-amber {
  background: var(--accent-light);
  border-left: 3px solid var(--accent);
  color: var(--text-muted);
}
.callout-green {
  background: var(--secondary-light);
  border-left: 3px solid var(--secondary);
  color: var(--text-muted);
}
.callout-blue {
  background: var(--primary-light);
  border-left: 3px solid var(--primary);
  color: var(--text-muted);
}
.callout-purple {
  background: var(--purple-light);
  border-left: 3px solid var(--purple);
  color: var(--text-muted);
}
/* Coloured label tag inside callouts */
.callout-tag {
  font-size: 9.5px; font-weight: 800;
  text-transform: uppercase; letter-spacing: 1px;
  padding: 3px 7px; border-radius: 4px;
  white-space: nowrap; flex-shrink: 0; margin-top: 2px;
}
.callout-amber  .callout-tag { background: var(--accent);    color: white; }
.callout-green  .callout-tag { background: var(--secondary); color: white; }
.callout-blue   .callout-tag { background: var(--primary);   color: white; }
.callout-purple .callout-tag { background: var(--purple);    color: white; }
.callout strong { color: var(--text); }

/* ============================================================
   FLOWCHART
   ============================================================ */
.flowchart {
  background: var(--surface-2);
  border-radius: var(--radius-sm);
  padding: 20px 24px;
  margin: 16px 0;
  border: 1px solid var(--border);
  font-family: 'DM Mono', monospace;
  font-size: 13px;
  line-height: 1.9;
  color: var(--text-muted);
  overflow-x: auto;
}

/* ============================================================
   SCENARIO BOX
   ============================================================ */
.scenario-box {
  background: linear-gradient(135deg, #fef3c7 0%, #fff8e1 100%);
  border: 1px solid #fcd34d;
  border-radius: var(--radius-sm);
  padding: 20px 22px; margin: 18px 0;
}
.scenario-box .scenario-label {
  font-size: 10px; font-weight: 800;
  text-transform: uppercase; letter-spacing: 1px;
  color: var(--accent); margin-bottom: 8px;
}
.scenario-box p { color: #78350f; font-size: 14px; margin: 0; line-height: 1.7; }
.scenario-box strong { color: #92400e; }

/* ============================================================
   HIERARCHY LADDER
   ============================================================ */
.hierarchy { display: flex; flex-direction: column; gap: 0; margin: 18px 0; }
.hierarchy-step {
  display: flex; align-items: center; gap: 14px;
  padding: 10px 16px;
  border: 1px solid var(--border);
  border-bottom: none;
  background: var(--surface);
  transition: background 0.15s;
}
.hierarchy-step:first-child { border-radius: var(--radius-sm) var(--radius-sm) 0 0; }
.hierarchy-step:last-child  { border-bottom: 1px solid var(--border); border-radius: 0 0 var(--radius-sm) var(--radius-sm); }
.hierarchy-step:hover { background: var(--primary-light); }
.hierarchy-level {
  width: 28px; height: 28px; border-radius: 6px;
  background: var(--primary-light); color: var(--primary);
  font-size: 11px; font-weight: 700;
  display: grid; place-items: center; flex-shrink: 0;
}
.hierarchy-name { font-weight: 600; font-size: 16px; color: var(--text); min-width: 120px; }
.hierarchy-eg   { font-size: 15px; color: var(--text-muted); }
.hierarchy-arrow { font-size: 18px; color: var(--primary); flex-shrink: 0; margin-left: auto; opacity: 0.4; }

/* ============================================================
   COLLAPSIBLE COPY SECTION
   ============================================================ */
.collapsible-wrap {
  margin: 32px 0;
}
.collapsible-trigger {
  display: flex;
  align-items: center;
  justify-content: space-between;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 18px 24px;
  cursor: pointer;
  user-select: none;
  transition: background 0.15s;
}
.collapsible-trigger:hover { background: var(--surface-2); }
.collapsible-trigger h3 {
  font-size: 15px;
  font-weight: 600;
  color: var(--text);
  display: flex;
  align-items: center;
  gap: 10px;
  margin: 0;
}
.collapsible-arrow {
  font-size: 18px;
  color: var(--text-muted);
  transition: transform 0.2s;
}
.collapsible-trigger.open .collapsible-arrow { transform: rotate(180deg); }
.collapsible-body {
  display: none;
  background: var(--surface);
  border: 1px solid var(--border);
  border-top: none;
  border-radius: 0 0 var(--radius) var(--radius);
  padding: 24px;
}
.collapsible-body.open { display: block; }
.copy-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 16px;
}
.copy-item {
  background: var(--surface-2);
  border-radius: var(--radius-sm);
  padding: 18px;
  border: 1px solid var(--border);
}
.copy-item h4 {
  font-size: 12px;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.6px;
  color: var(--text);
  margin-bottom: 10px;
}
.copy-item ul { list-style: none; }
.copy-item li {
  color: var(--text-muted);
  font-size: 13px;
  padding: 4px 0 4px 14px;
  position: relative;
  line-height: 1.5;
}
.copy-item li::before {
  content: '•';
  position: absolute;
  left: 0;
  color: var(--primary);
  font-weight: 700;
}

/* ============================================================
   ACTIVITIES
   ============================================================ */
.activity {
  background: var(--surface);
  border-radius: var(--radius);
  padding: 28px 32px;
  margin-bottom: 20px;
  border: 1px solid var(--border);
  box-shadow: var(--shadow-sm);
  position: relative;
}
.activity-badge {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  background: linear-gradient(135deg, var(--secondary), var(--primary));
  color: white;
  padding: 6px 16px;
  border-radius: 100px;
  font-size: 11px;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.6px;
  margin-bottom: 14px;
}
.activity h3 {
  font-size: 19px;
  font-weight: 700;
  color: var(--text);
  margin-bottom: 6px;
  letter-spacing: -0.3px;
}
.activity-meta {
  color: var(--text-light);
  font-size: 13px;
  margin-bottom: 18px;
  font-style: italic;
}
.answer-area {
  background: var(--surface-2);
  border: 2px dashed var(--border);
  border-radius: var(--radius-sm);
  padding: 16px;
  min-height: 80px;
  font-family: 'DM Mono', monospace;
  color: var(--text-light);
  font-size: 13px;
  margin: 12px 0;
  transition: border-color 0.2s;
}
.answer-area:hover { border-color: var(--primary); }

/* ============================================================
   MULTIPLE CHOICE
   ============================================================ */
.mc-question { margin: 24px 0; }
.mc-question > p {
  font-weight: 600;
  color: var(--text);
  font-size: 15px;
  margin-bottom: 12px;
}
.mc-option {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 12px 16px;
  margin: 8px 0;
  background: var(--surface-2);
  border-radius: var(--radius-sm);
  border: 2px solid transparent;
  cursor: pointer;
  transition: all 0.15s;
  user-select: none;
}
.mc-option:hover {
  background: var(--primary-light);
  border-color: var(--primary);
  transform: translateX(3px);
}
.mc-option.correct {
  background: rgba(5,150,105,0.08);
  border-color: var(--secondary);
}
.mc-option.incorrect {
  background: rgba(220,38,38,0.06);
  border-color: var(--danger);
}
.mc-option.disabled { cursor: default; pointer-events: none; }
.mc-letter {
  width: 30px; height: 30px;
  background: var(--surface);
  border: 2px solid var(--border);
  border-radius: 6px;
  display: grid;
  place-items: center;
  font-weight: 700;
  font-size: 13px;
  color: var(--text);
  flex-shrink: 0;
  transition: all 0.15s;
}
.mc-option:hover .mc-letter {
  background: var(--primary);
  color: white;
  border-color: var(--primary);
}
.mc-option.correct .mc-letter {
  background: var(--secondary);
  color: white;
  border-color: var(--secondary);
}
.mc-option.incorrect .mc-letter {
  background: var(--danger);
  color: white;
  border-color: var(--danger);
}
.mc-text { color: var(--text-muted); font-size: 20px; }
.mc-feedback {
  margin-top: 8px;
  padding: 10px 14px;
  border-radius: var(--radius-sm);
  font-size: 15px;
  display: none;
}
.mc-feedback.correct-msg {
  background: var(--secondary-light);
  color: var(--secondary);
  display: block;
}
.mc-feedback.incorrect-msg {
  background: rgba(220,38,38,0.06);
  color: var(--danger);
  display: block;
}

/* ============================================================
   MARKS BADGE
   ============================================================ */
.marks {
  display: inline-flex;
  align-items: center;
  background: var(--secondary);
  color: white;
  padding: 3px 10px;
  border-radius: 100px;
  font-size: 11px;
  font-weight: 700;
  float: right;
  margin-top: 2px;
}

/* ============================================================
   SHORT ANSWER QUESTIONS
   ============================================================ */
.question-item {
  padding: 18px 20px;
  background: var(--surface-2);
  border-radius: var(--radius-sm);
  border-left: 3px solid var(--primary);
  margin: 20px 0;
}
.question-item p {
  font-weight: 500;
  color: var(--text);
  font-size: 15px;
  margin-bottom: 12px;
}

/* ============================================================
   COLLAPSIBLE ANSWERS SECTION
   ============================================================ */
.answers-section {
  margin-top: 48px;
}
.answers-trigger {
  display: flex;
  align-items: center;
  justify-content: space-between;
  background: var(--surface);
  border: 2px solid var(--secondary);
  border-radius: var(--radius);
  padding: 20px 28px;
  cursor: pointer;
  user-select: none;
  transition: background 0.15s;
}
.answers-trigger:hover { background: var(--secondary-light); }
.answers-trigger h2 {
  font-size: 18px;
  font-weight: 700;
  color: var(--text);
  display: flex;
  align-items: center;
  gap: 10px;
}
.answers-trigger .arrow {
  font-size: 20px;
  color: var(--secondary);
  transition: transform 0.2s;
}
.answers-trigger.open .arrow { transform: rotate(180deg); }
.answers-body {
  display: none;
  background: var(--surface);
  border: 2px solid var(--secondary);
  border-top: none;
  border-radius: 0 0 var(--radius) var(--radius);
  padding: 28px;
}
.answers-body.open { display: block; }
.answer-item {
  background: var(--surface-2);
  border-radius: var(--radius-sm);
  padding: 18px 22px;
  margin-bottom: 14px;
  border-left: 3px solid var(--secondary);
}
.answer-item h4 {
  font-size: 11px;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.6px;
  color: var(--secondary);
  margin-bottom: 10px;
  display: flex;
  align-items: center;
  gap: 6px;
}
.answer-item p, .answer-item li {
  color: var(--text-muted);
  font-size: 19px;
  line-height: 1.75;
  margin-bottom: 6px;
}
.answer-item ol, .answer-item ul { margin-left: 18px; margin-top: 6px; }
.answer-item strong { color: var(--text); }

/* ============================================================
   ANSWER TEXTAREAS
   ============================================================ */
.answer-wrap { margin: 12px 0; }
.answer-note { font-size: 12px; color: var(--text-light); margin-bottom: 6px; font-style: italic; }
.answer-instruction {
  font-size: 12px;
  color: var(--text-light);
  margin-bottom: 6px;
  font-style: italic;
  display: none;
}
.answer-textarea {
  width: 100%;
  background: var(--surface-2);
  border: 2px dashed var(--border);
  border-radius: var(--radius-sm);
  padding: 14px 16px;
  min-height: 80px;
  font-family: 'DM Sans', sans-serif;
  font-size: 19px;
  color: var(--text);
  line-height: 1.6;
  resize: vertical;
  transition: border-color 0.2s, background 0.2s;
  display: block;
}
.answer-textarea:focus {
  outline: none;
  border-color: var(--primary);
  background: white;
}
.answer-textarea::placeholder { color: var(--text-light); }
.autosave-indicator {
  font-size: 11px;
  color: var(--secondary);
  text-align: right;
  margin-top: 4px;
  height: 16px;
  display: block;
}

/* ============================================================
   COMPLETION CHECKBOX
   ============================================================ */
.completion-wrap {
  margin-top: 48px;
  background: var(--surface);
  border-radius: var(--radius);
  padding: 24px 28px;
  border: 1px solid var(--border);
  display: flex;
  align-items: center;
  gap: 18px;
  box-shadow: var(--shadow-sm);
}
.completion-checkbox {
  width: 28px; height: 28px;
  border: 2px solid var(--border);
  border-radius: 6px;
  cursor: pointer;
  display: grid;
  place-items: center;
  flex-shrink: 0;
  transition: all 0.2s;
  font-size: 16px;
  background: var(--surface-2);
}
.completion-checkbox.checked {
  background: var(--secondary);
  border-color: var(--secondary);
  color: white;
}
.completion-text h4 {
  font-size: 15px;
  font-weight: 600;
  color: var(--text);
  margin-bottom: 2px;
}
.completion-text p {
  font-size: 13px;
  color: var(--text-muted);
  margin: 0;
}
.completion-wrap.done { border-color: var(--secondary); background: var(--secondary-light); }

/* ============================================================
   LESSON NAV (prev / next)
   ============================================================ */
.lesson-nav {
  display: flex;
  justify-content: space-between;
  gap: 16px;
  margin-top: 24px;
}
.lesson-nav a {
  flex: 1;
  padding: 14px 20px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  text-decoration: none;
  color: var(--text-muted);
  font-size: 13.5px;
  transition: all 0.15s;
  display: flex;
  align-items: center;
  gap: 8px;
}
.lesson-nav a:hover {
  border-color: var(--primary);
  color: var(--primary);
  background: var(--primary-light);
}
.lesson-nav .next { justify-content: flex-end; text-align: right; }

/* ============================================================
   HOMEPAGE SPECIFIC STYLES
   ============================================================ */
.site-header {
  background: var(--surface);
  border-bottom: 1px solid var(--border);
  padding: 16px 24px;
  position: sticky;
  top: 0;
  z-index: 100;
}
.header-content {
  max-width: 1200px;
  margin: 0 auto;
  display: flex;
  justify-content: space-between;
  align-items: center;
}
.logo {
  font-size: 24px;
  font-weight: 700;
  color: var(--primary);
  text-decoration: none;
  letter-spacing: -0.5px;
}
.nav-links {
  display: flex;
  gap: 24px;
}
.nav-links a {
  color: var(--text-muted);
  text-decoration: none;
  font-size: 14px;
  font-weight: 500;
  transition: color 0.2s;
}
.nav-links a:hover {
  color: var(--primary);
}

.hero-home {
  background: linear-gradient(135deg, var(--primary) 0%, var(--critical) 100%);
  color: white;
  padding: 80px 24px;
  text-align: center;
}
.hero-home h1 {
  font-size: 48px;
  font-weight: 700;
  margin-bottom: 16px;
  letter-spacing: -1px;
}
.hero-home p {
  font-size: 20px;
  opacity: 0.9;
  max-width: 600px;
  margin: 0 auto 32px;
}
.trust-badge {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  background: rgba(255,255,255,0.15);
  padding: 10px 20px;
  border-radius: 100px;
  font-size: 14px;
}

.subjects-section {
  max-width: 1200px;
  margin: 0 auto;
  padding: 60px 24px;
}
.section-title {
  font-size: 28px;
  font-weight: 700;
  margin-bottom: 32px;
  text-align: center;
}
.subject-cards {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 24px;
}
.subject-card {
  background: var(--surface);
  border-radius: var(--radius);
  padding: 32px;
  box-shadow: var(--shadow);
  border: 1px solid var(--border);
  text-decoration: none;
  color: inherit;
  transition: transform 0.2s, box-shadow 0.2s;
}
.subject-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-md);
}
.subject-icon {
  width: 56px;
  height: 56px;
  border-radius: var(--radius);
  display: grid;
  place-items: center;
  font-size: 28px;
  margin-bottom: 16px;
}
.subject-card.biology .subject-icon {
  background: var(--secondary-light);
}
.subject-card.chemistry .subject-icon {
  background: var(--primary-light);
}
.subject-card h3 {
  font-size: 22px;
  font-weight: 700;
  margin-bottom: 8px;
}
.subject-card p {
  color: var(--text-muted);
  font-size: 14px;
  margin-bottom: 16px;
}
.subject-meta {
  display: flex;
  gap: 16px;
  font-size: 13px;
  color: var(--text-light);
}

/* ============================================================
   MODULE & LESSON INDEX PAGES
   ============================================================ */
.page-header {
  background: var(--surface);
  padding: 40px 24px;
  border-bottom: 1px solid var(--border);
}
.page-header-content {
  max-width: 1200px;
  margin: 0 auto;
}
.breadcrumb {
  display: flex;
  gap: 8px;
  align-items: center;
  margin-bottom: 16px;
  font-size: 13px;
  color: var(--text-light);
}
.breadcrumb a {
  color: var(--primary);
  text-decoration: none;
}
.breadcrumb a:hover {
  text-decoration: underline;
}
.page-header h1 {
  font-size: 32px;
  font-weight: 700;
}

.module-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 20px;
  margin-top: 32px;
}
.module-card {
  background: var(--surface);
  border-radius: var(--radius);
  padding: 24px;
  box-shadow: var(--shadow-sm);
  border: 1px solid var(--border);
  text-decoration: none;
  color: inherit;
  transition: all 0.2s;
}
.module-card:hover {
  border-color: var(--primary);
  box-shadow: var(--shadow);
}
.module-card h3 {
  font-size: 16px;
  font-weight: 700;
  margin-bottom: 8px;
  color: var(--primary);
}
.module-card h4 {
  font-size: 18px;
  font-weight: 600;
  margin-bottom: 8px;
}
.module-card p {
  color: var(--text-muted);
  font-size: 14px;
}
.module-card .lesson-count {
  margin-top: 12px;
  font-size: 13px;
  color: var(--text-light);
}

.lesson-list {
  margin-top: 32px;
}
.lesson-item {
  display: flex;
  align-items: center;
  gap: 16px;
  background: var(--surface);
  border-radius: var(--radius-sm);
  padding: 16px 20px;
  margin-bottom: 12px;
  border: 1px solid var(--border);
  text-decoration: none;
  color: inherit;
  transition: all 0.2s;
}
.lesson-item:hover {
  border-color: var(--primary);
  background: var(--primary-light);
}
.lesson-number {
  width: 36px;
  height: 36px;
  background: var(--primary-light);
  border-radius: 50%;
  display: grid;
  place-items: center;
  font-weight: 700;
  font-size: 14px;
  color: var(--primary);
  flex-shrink: 0;
}
.lesson-item:hover .lesson-number {
  background: var(--primary);
  color: white;
}
.lesson-info {
  flex: 1;
}
.lesson-info h4 {
  font-size: 15px;
  font-weight: 600;
  margin-bottom: 2px;
}
.lesson-info p {
  font-size: 13px;
  color: var(--text-light);
}
.lesson-badge {
  padding: 4px 10px;
  border-radius: 100px;
  font-size: 11px;
  font-weight: 600;
}
.lesson-badge.free {
  background: var(--secondary-light);
  color: var(--secondary);
}
.lesson-badge.premium {
  background: var(--accent-light);
  color: var(--accent);
}

/* ============================================================
   QUIZ SPECIFIC STYLES
   ============================================================ */
.quiz-header {
  text-align: center;
  margin-bottom: 40px;
}
.quiz-header h2 {
  font-size: 24px;
  margin-bottom: 8px;
}
.quiz-header p {
  color: var(--text-muted);
}
.quiz-progress {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 32px;
  padding: 16px 20px;
  background: var(--surface);
  border-radius: var(--radius);
  border: 1px solid var(--border);
}
.quiz-progress-bar {
  flex: 1;
  height: 8px;
  background: var(--border);
  border-radius: 4px;
  margin: 0 16px;
  overflow: hidden;
}
.quiz-progress-fill {
  height: 100%;
  background: linear-gradient(90deg, var(--primary), var(--secondary));
  border-radius: 4px;
  transition: width 0.3s ease;
}
.quiz-nav {
  display: flex;
  justify-content: center;
  gap: 16px;
  margin-top: 40px;
}
.quiz-btn {
  padding: 14px 32px;
  border-radius: var(--radius-sm);
  font-size: 15px;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.2s;
  border: none;
}
.quiz-btn.primary {
  background: var(--primary);
  color: white;
}
.quiz-btn.primary:hover {
  background: #1d4ed8;
}
.quiz-btn.secondary {
  background: var(--surface);
  color: var(--text);
  border: 1px solid var(--border);
}
.quiz-btn.secondary:hover {
  background: var(--surface-2);
}

/* ============================================================
   PRICING PAGE
   ============================================================ */
.pricing-hero {
  text-align: center;
  padding: 60px 24px;
}
.pricing-hero h1 {
  font-size: 40px;
  font-weight: 700;
  margin-bottom: 16px;
}
.pricing-hero p {
  font-size: 18px;
  color: var(--text-muted);
  max-width: 500px;
  margin: 0 auto;
}
.pricing-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 24px;
  max-width: 900px;
  margin: 0 auto;
  padding: 0 24px 60px;
}
.pricing-card {
  background: var(--surface);
  border-radius: var(--radius);
  padding: 32px;
  border: 1px solid var(--border);
  box-shadow: var(--shadow-sm);
}
.pricing-card.featured {
  border-color: var(--primary);
  box-shadow: var(--shadow-md);
  position: relative;
}
.pricing-card.featured::before {
  content: 'Most Popular';
  position: absolute;
  top: -12px;
  left: 50%;
  transform: translateX(-50%);
  background: var(--primary);
  color: white;
  padding: 4px 16px;
  border-radius: 100px;
  font-size: 12px;
  font-weight: 600;
}
.pricing-card h3 {
  font-size: 20px;
  font-weight: 700;
  margin-bottom: 8px;
}
.pricing-card .price {
  font-size: 42px;
  font-weight: 700;
  color: var(--text);
  margin-bottom: 8px;
}
.pricing-card .price span {
  font-size: 16px;
  font-weight: 400;
  color: var(--text-muted);
}
.pricing-card .description {
  color: var(--text-muted);
  font-size: 14px;
  margin-bottom: 24px;
}
.pricing-card ul {
  list-style: none;
  margin-bottom: 24px;
}
.pricing-card li {
  padding: 8px 0;
  font-size: 14px;
  color: var(--text-muted);
  display: flex;
  align-items: center;
  gap: 10px;
}
.pricing-card li::before {
  content: '✓';
  color: var(--secondary);
  font-weight: 700;
}
.pricing-card .cta-btn {
  display: block;
  width: 100%;
  padding: 14px;
  background: var(--primary);
  color: white;
  text-align: center;
  border-radius: var(--radius-sm);
  text-decoration: none;
  font-weight: 600;
  transition: background 0.2s;
}
.pricing-card .cta-btn:hover {
  background: #1d4ed8;
}
.pricing-card.featured .cta-btn {
  background: linear-gradient(135deg, var(--primary), var(--critical));
}

/* ============================================================
   FOOTER
   ============================================================ */
.site-footer {
  background: var(--surface);
  border-top: 1px solid var(--border);
  padding: 40px 24px;
  margin-top: 60px;
}
.footer-content {
  max-width: 1200px;
  margin: 0 auto;
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 24px;
}
.footer-logo {
  font-size: 20px;
  font-weight: 700;
  color: var(--primary);
}
.footer-links {
  display: flex;
  gap: 24px;
}
.footer-links a {
  color: var(--text-muted);
  text-decoration: none;
  font-size: 14px;
}
.footer-links a:hover {
  color: var(--primary);
}
.footer-copy {
  color: var(--text-light);
  font-size: 13px;
}

/* ============================================================
   HSC EXAM RELEVANCE BLOCK
   ============================================================ */
.hsc-relevance {
  background: var(--surface);
  border: 1px solid var(--border);
  border-top: 3px solid var(--accent);
  border-radius: var(--radius);
  padding: 28px;
  margin-bottom: 28px;
  box-shadow: var(--shadow-sm);
}
.hsc-relevance-header {
  margin-bottom: 20px;
}
.hsc-relevance-header p {
  color: var(--text-muted);
  font-size: 15.5px;
  margin-top: 6px;
}
.hsc-relevance-label {
  display: inline-flex;
  align-items: center;
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--accent);
  background: var(--accent-light);
  padding: 4px 10px;
  border-radius: 20px;
  margin-bottom: 8px;
}
.hsc-relevance-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 14px;
}
.hsc-item {
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  overflow: hidden;
}
.hsc-item-priority {
  font-size: 10.5px;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  padding: 5px 12px;
}
.hsc-high .hsc-item-priority {
  background: rgba(220,38,38,0.08);
  color: var(--danger);
}
.hsc-medium .hsc-item-priority {
  background: var(--accent-light);
  color: var(--accent);
}
.hsc-item-content {
  padding: 14px;
}
.hsc-item-content strong {
  display: block;
  margin-bottom: 6px;
  font-size: 19px;
  color: var(--text);
}
.hsc-item-content p {
  font-size: 18px;
  color: var(--text-muted);
  line-height: 1.55;
  margin: 0;
}

/* ============================================================
   RESPONSIVE
   ============================================================ */
@media (max-width: 768px) {
  .hero { padding: 32px 24px; }
  .hero-top { flex-direction: column; }
  .hero-emoji { font-size: 60px; }
  .hero h1 { font-size: 26px; }
  .intentions-grid { grid-template-columns: 1fr; }
  .copy-grid { grid-template-columns: 1fr; }
  .card { padding: 22px; }
  .activity { padding: 22px; }
  .section-nav { display: none; }
  .page { padding: 24px 14px 60px; }
  
  .hero-home { padding: 60px 24px; }
  .hero-home h1 { font-size: 32px; }
  .hero-home p { font-size: 16px; }
  
  .subject-cards { grid-template-columns: 1fr; }
  .module-grid { grid-template-columns: 1fr; }
  
  .site-header { padding: 12px 16px; }
  .nav-links { display: none; }
  
  .pricing-grid { grid-template-columns: 1fr; }
  .footer-content { flex-direction: column; text-align: center; }
  .hsc-relevance-grid { grid-template-columns: 1fr; }
}