/* ========================================
   CSS Variables
   ======================================== */
:root {
  --color-aws-dark: #232F3E;
  --color-aws-orange: #dc7600;
  --color-aws-orange-original: #FF9900;
  --color-aws-orange-hover: #EC7211;
  --color-text-primary: #374151;
  --color-text-secondary: #6B7280;
  --color-text-white: #FFFFFF;
  --color-bg-light: #F9FAFB;
  --color-bg-white: #FFFFFF;
  --color-border: #909296;
  --color-border-light: #E5E7EB;
  --color-success: #10B981;
  --color-warning: #F59E0B;
  --color-error: #EF4444;
  --color-info: #3B82F6;
  --header-height: 60px;
  --container-max-width: 1200px;
  --radius-sm: 6px;
  --radius-md: 8px;
  --radius-base: 10px;
  --radius-lg: 15px;
  --radius-xl: 20px;
  --shadow-sm: 0 2px 4px rgba(0,0,0,0.1);
  --shadow-md: 0 4px 12px rgba(0,0,0,0.1);
  --transition-base: 0.3s ease;
  --z-header: 1002;
  --z-progress-bar: 1001;
  --z-scroll-top: 1000;
}

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

/* ========================================
   Main Container
   ======================================== */
.container {
  max-width: var(--container-max-width);
  margin: 0 auto; padding: 30px 25px;
}

/* ========================================
   Hero Section
   ======================================== */
.hero {
  background: linear-gradient(135deg, #232F3E 0%, #37475A 50%, #485769 100%);
  border-radius: var(--radius-xl);
  padding: 50px 40px;
  color: #fff; margin-bottom: 40px;
  position: relative; overflow: hidden;
}
.hero::before {
  content: ''; position: absolute; top: -50%; right: -10%;
  width: 400px; height: 400px;
  background: radial-gradient(circle, rgba(255,153,0,0.15) 0%, transparent 70%);
  border-radius: 50%;
}
.hero-badge {
  display: inline-block; background: rgba(255,153,0,0.2);
  color: var(--color-aws-orange-original);
  padding: 6px 18px; border-radius: 20px;
  font-size: 0.8em; font-weight: 600; margin-bottom: 20px;
  border: 1px solid rgba(255,153,0,0.3);
}
.hero h1 {
  font-size: 2.2em; font-weight: 800; margin-bottom: 15px;
  line-height: 1.3; position: relative; color: #fff;
}
.hero p { font-size: 1.05em; opacity: 0.9; max-width: 700px; position: relative; }

/* ========================================
   Conclusion First - Key Takeaways
   ======================================== */
.key-takeaways {
  background: var(--color-bg-white);
  border-radius: var(--radius-xl);
  padding: 35px; margin-bottom: 40px;
  border-left: 6px solid var(--color-aws-orange-original);
  box-shadow: var(--shadow-md);
}
.key-takeaways h2 {
  font-size: 1.4em; color: var(--color-aws-orange);
  margin-bottom: 20px; display: flex; align-items: center; gap: 10px;
  border-bottom: none; padding-bottom: 0;
}
.takeaway-grid {
  display: grid; grid-template-columns: 1fr 1fr;
  gap: 20px;
}
.takeaway-item {
  display: flex; gap: 15px; align-items: flex-start;
  padding: 18px; background: var(--color-bg-light);
  border-radius: var(--radius-base);
}
.takeaway-num {
  min-width: 38px; height: 38px;
  background: var(--color-aws-orange-original);
  color: #fff; border-radius: 50%;
  display: flex; align-items: center; justify-content: center;
  font-weight: 700; font-size: 0.9em;
}
.takeaway-text { font-size: 0.95em; line-height: 1.6; }

/* ========================================
   Section Styles
   ======================================== */
.section {
  background: var(--color-bg-white);
  border-radius: var(--radius-xl);
  padding: 35px; margin-bottom: 35px;
  box-shadow: var(--shadow-sm);
}
.section h2 {
  font-size: 1.5em; color: var(--color-text-primary);
  margin-bottom: 25px; padding-bottom: 12px;
  border-bottom: 3px solid var(--color-aws-orange-original);
  display: flex; align-items: center; gap: 12px;
}
.section h3 {
  font-size: 1.2em; color: var(--color-text-primary);
  margin-bottom: 15px; margin-top: 25px;
}

/* ========================================
   Analogy Section
   ======================================== */
.analogy-box {
  background: linear-gradient(135deg, #FFF7ED 0%, #FFFBF5 100%);
  border: 2px solid #FDBA74;
  border-radius: var(--radius-lg); padding: 30px;
  margin-bottom: 30px;
}
.analogy-title {
  font-size: 1.2em; font-weight: 700;
  color: #9A3412; margin-bottom: 15px;
  display: flex; align-items: center; gap: 10px;
}
.analogy-mapping {
  width: 100%; border-collapse: collapse;
  margin-top: 15px; font-size: 0.95em;
}
.analogy-mapping th {
  background: #FED7AA; color: #9A3412;
  padding: 12px 16px; text-align: left;
  font-weight: 700; border-bottom: 2px solid #FDBA74;
}
.analogy-mapping td {
  padding: 12px 16px; border-bottom: 1px solid #FDE8CD;
}
.analogy-mapping tr:nth-child(even) td { background: #FFF9F0; }

/* ========================================
   Mode Cards (2-col equal)
   ======================================== */
.mode-grid {
  display: grid; grid-template-columns: 1fr 1fr;
  gap: 25px; margin-bottom: 30px;
}
.mode-card {
  border-radius: var(--radius-lg); padding: 30px;
  border: 2px solid; position: relative;
}
.mode-card.single-arm {
  background: linear-gradient(135deg, #EEF2FF 0%, #F5F7FF 100%);
  border-color: #818CF8;
}
.mode-card.dual-arm {
  background: linear-gradient(135deg, #ECFDF5 0%, #F3FDF8 100%);
  border-color: #34D399;
}
.mode-card-header {
  display: flex; align-items: center; gap: 12px;
  margin-bottom: 18px;
}
.mode-icon {
  width: 50px; height: 50px; border-radius: 50%;
  display: flex; align-items: center; justify-content: center;
  font-size: 1.5em; color: #fff;
}
.single-arm .mode-icon { background: #6366F1; }
.dual-arm .mode-icon { background: #059669; }
.mode-card h3 {
  font-size: 1.15em; margin: 0;
  color: var(--color-text-primary);
}
.mode-card-subtitle {
  font-size: 0.8em; color: var(--color-text-secondary); font-weight: 400;
}
.mode-card ul {
  list-style: none; padding: 0;
}
.mode-card li {
  padding: 8px 0; font-size: 0.9em;
  display: flex; align-items: flex-start; gap: 10px;
}
.mode-card li::before {
  content: '\2713'; color: var(--color-success);
  font-weight: 700; min-width: 20px;
}

/* ========================================
   SVG Diagram Container
   ======================================== */
.svg-container {
  background: var(--color-bg-light);
  border-radius: var(--radius-lg);
  padding: 20px; margin: 25px 0;
  overflow-x: auto;
}
.svg-container svg {
  display: block; margin: 0 auto;
  max-width: 100%; height: auto;
}

/* ========================================
   Comparison Table
   ======================================== */
.comparison-table {
  width: 100%; border-collapse: collapse;
  margin: 25px 0; font-size: 0.92em;
  border-radius: var(--radius-base); overflow: hidden;
  box-shadow: var(--shadow-sm);
}
.comparison-table thead th {
  background: var(--color-aws-dark);
  color: #fff; padding: 14px 18px;
  text-align: left; font-weight: 600;
}
.comparison-table tbody td {
  padding: 14px 18px;
  border-bottom: 1px solid var(--color-border-light);
}
.comparison-table tbody tr:nth-child(even) td { background: var(--color-bg-light); }
.comparison-table tbody tr:hover td { background: #FFF7ED; }
.check-green { color: var(--color-success); font-weight: 700; }
.check-orange { color: var(--color-aws-orange); font-weight: 700; }

/* ========================================
   Cost Section
   ======================================== */
.cost-grid {
  display: grid; grid-template-columns: 1fr 1fr;
  gap: 25px; margin: 25px 0;
}
.cost-card {
  border-radius: var(--radius-lg); padding: 25px;
  text-align: center;
}
.cost-card.expensive {
  background: #FEF2F2; border: 2px solid #FECACA;
}
.cost-card.saving {
  background: #ECFDF5; border: 2px solid #A7F3D0;
}
.cost-label {
  font-size: 0.85em; color: var(--color-text-secondary);
  margin-bottom: 8px; font-weight: 600;
}
.cost-value {
  font-size: 1.6em; font-weight: 800;
}
.cost-card.expensive .cost-value { color: var(--color-error); }
.cost-card.saving .cost-value { color: var(--color-success); }
.cost-detail {
  font-size: 0.82em; color: var(--color-text-secondary);
  margin-top: 8px;
}

/* ========================================
   Tab Component
   ======================================== */
.tab-container { margin: 25px 0; }
.tab-buttons {
  display: flex; gap: 0;
  border-bottom: 2px solid var(--color-border-light);
}
.tab-btn {
  padding: 12px 24px; border: none;
  background: transparent; cursor: pointer;
  font-size: 0.9em; font-weight: 600;
  color: var(--color-text-secondary);
  border-bottom: 3px solid transparent;
  transition: all var(--transition-base);
  font-family: inherit;
}
.tab-btn.active {
  color: var(--color-aws-orange);
  border-bottom-color: var(--color-aws-orange-original);
}
.tab-btn:hover { color: var(--color-aws-orange); }
.tab-content { display: none; padding: 20px 0; }
.tab-content.active { display: block; }
pre {
  background: #1E293B; color: #E2E8F0;
  padding: 20px; border-radius: var(--radius-base);
  overflow-x: auto; font-size: 0.78em;
  line-height: 1.6; font-family: 'Fira Code', 'Consolas', monospace;
}
.code-comment { color: #64748B; }
.code-key { color: #7DD3FC; }
.code-value { color: #86EFAC; }
.code-string { color: #FDE68A; }

/* ========================================
   Best Practices / Anti-patterns
   ======================================== */
.practices-grid {
  display: grid; grid-template-columns: 1fr 1fr;
  gap: 25px;
}
.practice-card {
  padding: 25px; border-radius: var(--radius-lg);
}
.practice-card.do {
  background: #F0FDF4; border: 2px solid #86EFAC;
}
.practice-card.dont {
  background: #FEF2F2; border: 2px solid #FECACA;
}
.practice-title {
  font-size: 1.05em; font-weight: 700; margin-bottom: 15px;
  display: flex; align-items: center; gap: 8px;
}
.practice-card.do .practice-title { color: #166534; }
.practice-card.dont .practice-title { color: #991B1B; }
.practice-list {
  list-style: none; padding: 0;
}
.practice-list li {
  padding: 8px 0; font-size: 0.9em;
  display: flex; align-items: flex-start; gap: 8px;
}

/* ========================================
   Decision Flowchart Cards
   ======================================== */
.decision-flow {
  display: flex; flex-direction: column;
  gap: 0; align-items: center; margin: 25px 0;
}
.decision-step {
  background: var(--color-bg-white);
  border: 2px solid var(--color-border-light);
  border-radius: var(--radius-lg);
  padding: 20px 30px; width: 80%;
  text-align: center; position: relative;
}
.decision-step.question {
  background: #EFF6FF; border-color: #93C5FD;
}
.decision-step.answer-a {
  background: #EEF2FF; border-color: #818CF8;
}
.decision-step.answer-b {
  background: #ECFDF5; border-color: #34D399;
}
.decision-arrow {
  font-size: 1.5em; color: var(--color-text-secondary);
  padding: 5px 0;
}
.decision-label {
  font-size: 0.82em; font-weight: 600;
  color: var(--color-text-secondary);
}

/* ========================================
   Troubleshooting
   ======================================== */
.trouble-item {
  background: var(--color-bg-light);
  border-radius: var(--radius-base);
  padding: 20px; margin-bottom: 15px;
  border-left: 4px solid var(--color-warning);
}
.trouble-q {
  font-weight: 700; color: var(--color-text-primary);
  margin-bottom: 8px; font-size: 0.95em;
}
.trouble-a {
  font-size: 0.9em; color: var(--color-text-secondary);
}

/* ========================================
   Exam Tips
   ======================================== */
.exam-box {
  background: linear-gradient(135deg, #EFF6FF 0%, #F0F9FF 100%);
  border: 2px solid #93C5FD;
  border-radius: var(--radius-lg); padding: 30px;
  margin: 25px 0;
}
.exam-title {
  font-size: 1.15em; font-weight: 700;
  color: #1E40AF; margin-bottom: 15px;
  display: flex; align-items: center; gap: 10px;
}
.exam-point {
  padding: 12px 0; font-size: 0.92em;
  border-bottom: 1px solid #BFDBFE;
  display: flex; align-items: flex-start; gap: 10px;
}
.exam-point:last-child { border-bottom: none; }
.exam-badge {
  display: inline-block; background: #1E40AF;
  color: #fff; padding: 2px 10px; border-radius: 12px;
  font-size: 0.75em; font-weight: 700; white-space: nowrap;
}

/* ========================================
   FAQ Accordion
   ======================================== */
.faq-item {
  background: var(--color-bg-white);
  border: 1px solid var(--color-border-light);
  border-radius: var(--radius-base);
  margin-bottom: 10px; overflow: hidden;
}
.faq-question {
  width: 100%; padding: 18px 20px;
  background: none; border: none;
  font-size: 0.95em; font-weight: 600;
  color: var(--color-text-primary);
  cursor: pointer; text-align: left;
  display: flex; justify-content: space-between;
  align-items: center; font-family: inherit;
  transition: background var(--transition-base);
}
.faq-question:hover { background: var(--color-bg-light); }
.faq-question .arrow { transition: transform var(--transition-base); }
.faq-question.active .arrow { transform: rotate(180deg); }
.faq-answer {
  max-height: 0; overflow: hidden;
  transition: max-height 0.4s ease, padding 0.4s ease;
  padding: 0 20px; font-size: 0.9em;
  color: var(--color-text-secondary);
}
.faq-answer.show {
  max-height: 500px; padding: 0 20px 18px;
}

/* ========================================
   Glossary
   ======================================== */
.glossary-grid {
  display: grid; grid-template-columns: 1fr 1fr;
  gap: 15px;
}
.glossary-item {
  background: var(--color-bg-light);
  border-radius: var(--radius-base);
  padding: 15px;
}
.glossary-term {
  font-weight: 700; color: var(--color-aws-orange);
  font-size: 0.92em; margin-bottom: 5px;
}
.glossary-def {
  font-size: 0.85em; color: var(--color-text-secondary);
}

/* ========================================
   Cheat Sheet
   ======================================== */
.cheatsheet {
  background: linear-gradient(135deg, #232F3E 0%, #374151 100%);
  border-radius: var(--radius-xl); padding: 35px;
  color: #fff;
}
.cheatsheet h2 {
  color: var(--color-aws-orange-original);
  border-bottom-color: var(--color-aws-orange-original);
}
.cheat-grid {
  display: grid; grid-template-columns: 1fr 1fr;
  gap: 20px; margin-top: 20px;
}
.cheat-item {
  background: rgba(255,255,255,0.08);
  border-radius: var(--radius-base);
  padding: 18px; border-left: 4px solid var(--color-aws-orange-original);
}
.cheat-label {
  font-size: 0.82em; color: #9CA3AF;
  margin-bottom: 6px; font-weight: 600;
}
.cheat-value {
  font-size: 0.95em; color: #F3F4F6;
}

/* ========================================
   TOC
   ======================================== */
.toc {
  background: var(--color-bg-white);
  border-radius: var(--radius-xl);
  padding: 30px; margin-bottom: 35px;
  box-shadow: var(--shadow-sm);
  border: 1px solid var(--color-border-light);
}
.toc h2 {
  font-size: 1.2em; margin-bottom: 15px;
  border-bottom: none; padding-bottom: 0;
  color: var(--color-text-primary);
}
.toc-list {
  list-style: none; padding: 0;
  display: grid; grid-template-columns: 1fr 1fr; gap: 8px;
}
.toc-list a {
  color: var(--color-info); text-decoration: none;
  font-size: 0.88em; padding: 6px 0;
  display: flex; align-items: center; gap: 8px;
  transition: color var(--transition-base);
}
.toc-list a:hover { color: var(--color-aws-orange); }
.toc-num {
  background: var(--color-bg-light);
  border-radius: 4px; padding: 2px 8px;
  font-size: 0.82em; font-weight: 600;
  color: var(--color-text-secondary);
}

/* ========================================
   Responsive
   ======================================== */
@media (max-width: 768px) {
  .takeaway-grid, .mode-grid, .cost-grid, .practices-grid, .glossary-grid, .cheat-grid, .toc-list {
    grid-template-columns: 1fr;
  }
  .hero { padding: 30px 20px; }
  .hero h1 { font-size: 1.6em; }
  .section, .key-takeaways { padding: 25px; }
  .decision-step { width: 95%; }
}

/* ========================================
   Focus & Accessibility
   ======================================== */
a:focus, button:focus { outline: 3px solid var(--color-aws-orange-original); outline-offset: 2px; }