/* Styles for Lesson 14: Phone Radiation Rules */

:root {
  --ink: #152239;
  --muted: #586579;
  --blue: #235ad3;
  --lime: #a8f074;
  --line: #dce2e9;
  --paper: #f5f7f9;
  --accent-red: #ef4444;
  --accent-amber: #f59e0b;
  --accent-green: #10b981;
  --radius: 12px;
}

/* Tabs */
.lesson-tabs {
  display: flex;
  gap: 10px;
  margin: 24px 0 16px;
  overflow-x: auto;
  padding-bottom: 6px;
}

.tab-btn {
  background: var(--paper);
  border: 1px solid var(--line);
  color: var(--ink);
  font-weight: 600;
  font-size: 14px;
  padding: 10px 18px;
  border-radius: 8px;
  cursor: pointer;
  white-space: nowrap;
  transition: all 0.2s ease;
}

.tab-btn:hover {
  border-color: var(--blue);
  color: var(--blue);
}

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

.lesson-panel {
  margin-top: 10px;
  padding: 32px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: #fff;
}

.panel-subtitle {
  color: var(--muted);
  font-size: 15px;
  margin-top: -6px;
  margin-bottom: 24px;
  line-height: 1.6;
}

/* Chapter 0: Phone Physics */
.phone-physics-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 16px;
  margin-bottom: 24px;
}

.ph-card {
  background: var(--paper);
  border: 1px solid var(--line);
  border-radius: 10px;
  padding: 20px;
}

.ph-icon {
  font-size: 26px;
  margin-bottom: 8px;
  display: block;
}

.ph-card h3 {
  margin: 0 0 6px;
  font-size: 16px;
  color: var(--ink);
}

.ph-card p {
  margin: 0;
  font-size: 13.5px;
  color: var(--muted);
  line-height: 1.5;
}

/* Chapter 1: Headsets Compared */
.headset-nav-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 12px;
  margin-bottom: 20px;
}

.headset-btn {
  background: var(--paper);
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 14px 10px;
  text-align: left;
  cursor: pointer;
  display: flex;
  flex-direction: column;
  gap: 4px;
  transition: all 0.2s ease;
}

.headset-btn:hover {
  border-color: var(--blue);
}

.headset-btn.active {
  background: #edf2fc;
  border-color: var(--blue);
  outline: 2px solid var(--blue);
}

.headset-btn strong {
  font-size: 13px;
  color: var(--ink);
}

.headset-btn span {
  font-size: 11px;
  color: var(--muted);
}

.headset-sim-stage {
  background: #0f172a;
  border-radius: 12px;
  padding: 24px;
  color: #fff;
  display: grid;
  grid-template-columns: 220px 1fr;
  gap: 24px;
  align-items: center;
}

.head-visualizer-box {
  background: #1e293b;
  border-radius: 10px;
  padding: 18px;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 14px;
}

.head-diagram {
  position: relative;
  width: 80px;
  height: 80px;
  display: flex;
  align-items: center;
  justify-content: center;
}

.head-icon {
  font-size: 46px;
  z-index: 2;
}

.rf-exposure-field {
  position: absolute;
  width: 90px;
  height: 90px;
  border-radius: 50%;
  background: radial-gradient(circle, rgba(239, 68, 68, 0.6) 0%, transparent 70%);
  transition: all 0.3s ease;
  pointer-events: none;
}

.head-meter-box {
  width: 100%;
}

.meter-title {
  font-size: 9px;
  font-weight: 700;
  color: #94a3b8;
  letter-spacing: 0.05em;
  display: block;
}

.head-meter-stat {
  font-size: 15px;
  font-weight: 800;
  margin: 4px 0 6px;
}

.head-meter-stat.high { color: #f87171; }
.head-meter-stat.med { color: #fbbf24; }
.head-meter-stat.low { color: #34d399; }

.meter-bar-bg {
  height: 8px;
  background: #334155;
  border-radius: 4px;
  overflow: hidden;
}

.meter-bar-lvl {
  height: 100%;
  background: #ef4444;
  transition: width 0.3s ease, background-color 0.2s;
}

.headset-analysis-box {
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.headset-analysis-box h3 {
  margin: 0;
  font-size: 19px;
  color: #fff;
}

.headset-analysis-box p {
  margin: 0;
  color: #cbd5e1;
  font-size: 14px;
  line-height: 1.6;
}

.headset-tip {
  background: #1e293b;
  border-left: 3px solid var(--blue);
  padding: 10px 14px;
  border-radius: 0 6px 6px 0;
  font-size: 13px;
  color: #93c5fd;
}

/* Chapter 2: Product Truth */
.product-truth-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 18px;
}

.truth-card {
  background: var(--paper);
  border: 1px solid var(--line);
  border-radius: 10px;
  padding: 22px;
  display: flex;
  flex-direction: column;
}

.red-top { border-top: 4px solid var(--accent-red); }
.amber-top { border-top: 4px solid var(--accent-amber); }
.green-top { border-top: 4px solid var(--accent-green); }

.t-badge {
  font-size: 10px;
  font-weight: 700;
  letter-spacing: 0.05em;
  margin-bottom: 6px;
}

.red-badge { color: #991b1b; }
.amber-badge { color: #92400e; }
.green-badge { color: #166534; }

.truth-card h3 {
  margin: 0 0 10px;
  font-size: 17px;
  color: var(--ink);
}

.truth-card p {
  color: var(--muted);
  font-size: 13.5px;
  line-height: 1.5;
  flex-grow: 1;
  margin: 0 0 14px;
}

.truth-verdict {
  background: #fff;
  border: 1px solid var(--line);
  font-size: 12px;
  font-weight: 700;
  padding: 8px 12px;
  border-radius: 6px;
  color: var(--ink);
}

/* Chapter 3: Habits */
.habits-list-layout {
  display: flex;
  flex-direction: column;
  gap: 14px;
}

.habit-item {
  display: flex;
  align-items: flex-start;
  gap: 18px;
  background: var(--paper);
  border: 1px solid var(--line);
  border-radius: 10px;
  padding: 18px 22px;
}

.h-num {
  font-size: 18px;
  font-weight: 800;
  color: #fff;
  background: var(--blue);
  width: 38px;
  height: 38px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
}

.h-body h3 {
  margin: 0 0 4px;
  font-size: 16px;
  color: var(--ink);
}

.h-body p {
  margin: 0;
  font-size: 13.5px;
  color: var(--muted);
  line-height: 1.5;
}

/* Chapter 4: Quiz */
.quiz-form {
  display: flex;
  flex-direction: column;
  gap: 20px;
}

.quiz-fieldset {
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 18px 20px;
  background: var(--paper);
}

.quiz-question {
  font-weight: 700;
  font-size: 15px;
  color: var(--ink);
  margin-bottom: 12px;
  padding: 0 6px;
}

.check {
  display: flex;
  align-items: flex-start;
  gap: 10px;
  margin-bottom: 10px;
  font-size: 14px;
  cursor: pointer;
  color: var(--ink);
}

.check input {
  margin-top: 4px;
}

.quiz-feedback {
  margin-top: 20px;
  padding: 16px 20px;
  border-radius: 8px;
  font-size: 14px;
  line-height: 1.6;
}

.quiz-feedback.success {
  background: #e6f7df;
  border: 1px solid #a3e635;
  color: #1b6321;
}

.quiz-feedback.retry {
  background: #fffbeb;
  border: 1px solid #fde68a;
  color: #92400e;
}

.complete-card {
  background: #f0f7ff;
  border: 1px solid #bfdbfe;
  border-radius: 10px;
  padding: 24px;
  margin-top: 20px;
}

.complete-card h3 {
  margin: 0 0 8px;
  color: var(--blue);
}

.next-actions {
  display: flex;
  gap: 12px;
  flex-wrap: wrap;
  margin-top: 16px;
}

.lesson-nav-controls {
  display: flex;
  justify-content: space-between;
  margin-top: 28px;
  padding-top: 20px;
  border-top: 1px solid var(--line);
}

.transcript-details {
  margin-top: 30px;
}

.transcript-content {
  font-size: 14px;
  color: var(--muted);
  line-height: 1.7;
}

@media (max-width: 800px) {
  .lesson-panel {
    padding: 20px 16px;
  }
  .phone-physics-grid, .headset-nav-grid, .headset-sim-stage, .product-truth-grid {
    grid-template-columns: 1fr;
  }
}