/* ========================================
       CSS Variables (Design System)
       ======================================== */
    :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-bg-gradient-start: #232F3E;
      --color-bg-gradient-end: #374151;
      --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);
      --shadow-lg: 0 10px 40px rgba(0,0,0,0.15);
      --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;
    }

    body {
      font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "Hiragino Sans", "Noto Sans JP", sans-serif;
      font-size: 20px;
      line-height: 1.75;
      color: var(--color-text-primary);
      background: var(--color-bg-light);
      padding-top: var(--header-height);
    }

    /* ========================================
       Fixed Navigation Header
       ======================================== */
    .fixed-nav-header {
      position: fixed;
      top: 0;
      left: 0;
      right: 0;
      height: var(--header-height);
      background: linear-gradient(135deg, var(--color-bg-gradient-start) 0%, var(--color-bg-gradient-end) 100%);
      box-shadow: 0 2px 10px rgba(0,0,0,0.3);
      z-index: var(--z-header);
      display: flex;
      align-items: center;
    }

    .fixed-nav-container {
      width: 100%;
      max-width: var(--container-max-width);
      margin: 0 auto;
      padding: 0 30px;
      display: flex;
      align-items: center;
      justify-content: space-between;
    }

    .fixed-nav-logo {
      font-size: 1.3em;
      font-weight: 700;
      color: var(--color-aws-orange-original);
      text-decoration: none;
    }

    .fixed-nav-links {
      display: flex;
      gap: 25px;
      align-items: center;
    }

    .fixed-nav-links a {
      color: var(--color-text-white);
      text-decoration: none;
      font-weight: 500;
      font-size: 0.85em;
      padding: 8px 16px;
      border-radius: var(--radius-sm);
      transition: all var(--transition-base);
      white-space: nowrap;
    }

    .fixed-nav-links a:hover {
      background: rgba(255,153,0,0.2);
      color: var(--color-aws-orange-original);
    }

    /* ========================================
       Reading Progress Bar
       ======================================== */
    .progress-bar {
      position: fixed;
      top: var(--header-height);
      left: 0;
      width: 0%;
      height: 4px;
      background: linear-gradient(90deg, var(--color-aws-orange-original), var(--color-aws-orange-hover));
      z-index: var(--z-progress-bar);
      transition: width 0.1s linear;
    }

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

    /* ========================================
       Hero Section
       ======================================== */
    .hero {
      background: linear-gradient(135deg, var(--color-bg-gradient-start) 0%, #1a2332 50%, var(--color-bg-gradient-end) 100%);
      color: var(--color-text-white);
      padding: 60px 0;
      margin-bottom: 40px;
    }

    .hero-badge {
      display: inline-block;
      background: rgba(255,153,0,0.2);
      color: var(--color-aws-orange-original);
      padding: 6px 18px;
      border-radius: 50px;
      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;
      line-height: 1.3;
      margin-bottom: 16px;
    }

    .hero-subtitle {
      font-size: 1.1em;
      color: rgba(255,255,255,0.8);
      margin-bottom: 30px;
    }

    .hero-analogy {
      background: rgba(255,255,255,0.08);
      border: 1px solid rgba(255,255,255,0.15);
      border-radius: var(--radius-lg);
      padding: 20px 24px;
      font-size: 0.95em;
      line-height: 1.7;
      color: rgba(255,255,255,0.9);
    }

    .hero-analogy-icon {
      font-size: 1.4em;
      margin-right: 10px;
    }

    /* ========================================
       Key Takeaways
       ======================================== */
    .key-takeaways {
      background: var(--color-bg-white);
      border-radius: var(--radius-lg);
      padding: 32px;
      margin-bottom: 40px;
      box-shadow: var(--shadow-md);
      border-left: 5px solid var(--color-aws-orange-original);
    }

    .key-takeaways h2 {
      font-size: 1.3em;
      margin-bottom: 20px;
      color: var(--color-aws-dark);
    }

    .takeaway-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 16px;
    }

    .takeaway-item {
      display: flex;
      align-items: flex-start;
      gap: 12px;
      padding: 14px 16px;
      background: var(--color-bg-light);
      border-radius: var(--radius-md);
    }

    .takeaway-num {
      flex-shrink: 0;
      width: 32px;
      height: 32px;
      background: var(--color-aws-orange-original);
      color: white;
      border-radius: 50%;
      display: flex;
      align-items: center;
      justify-content: center;
      font-weight: 700;
      font-size: 0.85em;
    }

    .takeaway-text {
      font-size: 0.9em;
      line-height: 1.6;
    }

    /* ========================================
       Section Styles
       ======================================== */
    .section {
      background: var(--color-bg-white);
      border-radius: var(--radius-lg);
      padding: 40px 36px;
      margin-bottom: 32px;
      box-shadow: var(--shadow-sm);
    }

    .section h2 {
      font-size: 1.5em;
      font-weight: 700;
      color: var(--color-aws-dark);
      margin-bottom: 12px;
      padding-bottom: 12px;
      border-bottom: 3px solid var(--color-aws-orange-original);
      display: inline-block;
    }

    .section h3 {
      font-size: 1.15em;
      font-weight: 700;
      color: var(--color-aws-dark);
      margin: 28px 0 14px;
    }

    .section p {
      margin-bottom: 16px;
      font-size: 0.95em;
    }

    .section-lead {
      font-size: 1em;
      color: var(--color-text-secondary);
      margin-bottom: 24px;
      margin-top: 16px;
    }

    /* ========================================
       Analogy Mapping Table
       ======================================== */
    .analogy-table-wrapper {
      overflow-x: auto;
      margin: 24px 0;
    }

    .analogy-table {
      width: 100%;
      border-collapse: collapse;
      font-size: 0.9em;
    }

    .analogy-table th {
      background: var(--color-aws-dark);
      color: var(--color-text-white);
      padding: 14px 18px;
      text-align: left;
      font-weight: 600;
    }

    .analogy-table td {
      padding: 14px 18px;
      border-bottom: 1px solid var(--color-border-light);
      vertical-align: top;
    }

    .analogy-table tr:nth-child(even) {
      background: var(--color-bg-light);
    }

    .analogy-table tr:hover {
      background: #FFF7ED;
    }

    .analogy-emoji {
      font-size: 1.3em;
      margin-right: 8px;
    }

    /* ========================================
       SVG Diagram Container
       ======================================== */
    .svg-container {
      margin: 28px 0;
      text-align: center;
    }

    .svg-container svg {
      max-width: 100%;
      height: auto;
    }

    .svg-caption {
      font-size: 0.82em;
      color: var(--color-text-secondary);
      margin-top: 10px;
      text-align: center;
    }

    /* ========================================
       Feature Cards (Equal Width Grid)
       ======================================== */
    .card-grid-2 {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 20px;
      margin: 24px 0;
    }

    .card-grid-3 {
      display: grid;
      grid-template-columns: 1fr 1fr 1fr;
      gap: 20px;
      margin: 24px 0;
    }

    .card-grid-4 {
      display: grid;
      grid-template-columns: 1fr 1fr 1fr 1fr;
      gap: 16px;
      margin: 24px 0;
    }

    .feature-card {
      background: var(--color-bg-light);
      border-radius: var(--radius-base);
      padding: 24px;
      border: 1px solid var(--color-border-light);
      transition: transform var(--transition-base), box-shadow var(--transition-base);
    }

    .feature-card:hover {
      transform: translateY(-2px);
      box-shadow: var(--shadow-md);
    }

    .feature-card-icon {
      font-size: 2em;
      margin-bottom: 12px;
    }

    .feature-card h3 {
      font-size: 1em;
      font-weight: 700;
      color: var(--color-aws-dark);
      margin-bottom: 10px;
    }

    .feature-card p {
      font-size: 0.85em;
      color: var(--color-text-secondary);
      line-height: 1.65;
    }

    /* Color accents for cards */
    .card-orange { border-top: 4px solid var(--color-aws-orange-original); }
    .card-blue { border-top: 4px solid var(--color-info); }
    .card-green { border-top: 4px solid var(--color-success); }
    .card-purple { border-top: 4px solid #8B5CF6; }

    /* ========================================
       Highlight Box
       ======================================== */
    .highlight-box {
      padding: 20px 24px;
      border-radius: var(--radius-base);
      margin: 20px 0;
      font-size: 0.9em;
    }

    .highlight-box-info {
      background: #EFF6FF;
      border-left: 4px solid var(--color-info);
    }

    .highlight-box-warning {
      background: #FFFBEB;
      border-left: 4px solid var(--color-warning);
    }

    .highlight-box-success {
      background: #ECFDF5;
      border-left: 4px solid var(--color-success);
    }

    .highlight-box-exam {
      background: #FFF7ED;
      border-left: 4px solid var(--color-aws-orange-original);
    }

    .highlight-box strong {
      display: block;
      margin-bottom: 6px;
      font-size: 1em;
    }

    /* ========================================
       Bandwidth Table
       ======================================== */
    .bw-table-wrapper {
      overflow-x: auto;
      margin: 24px 0;
    }

    .bw-table {
      width: 100%;
      border-collapse: collapse;
      font-size: 0.85em;
    }

    .bw-table th {
      background: var(--color-aws-dark);
      color: white;
      padding: 12px 16px;
      text-align: center;
      font-weight: 600;
    }

    .bw-table td {
      padding: 10px 16px;
      border-bottom: 1px solid var(--color-border-light);
      text-align: center;
    }

    .bw-table tr:nth-child(even) {
      background: var(--color-bg-light);
    }

    .bw-table .bw-highlight {
      background: #FFF7ED;
      font-weight: 600;
    }

    .bw-badge {
      display: inline-block;
      padding: 3px 10px;
      border-radius: 50px;
      font-size: 0.85em;
      font-weight: 600;
    }

    .bw-badge-burst { background: #DBEAFE; color: #1E40AF; }
    .bw-badge-baseline { background: #D1FAE5; color: #065F46; }
    .bw-badge-dedicated { background: #FEF3C7; color: #92400E; }

    /* ========================================
       Tabbed Code Examples
       ======================================== */
    .code-tabs {
      margin: 24px 0;
      border-radius: var(--radius-base);
      overflow: hidden;
      border: 1px solid var(--color-border-light);
    }

    .code-tab-buttons {
      display: flex;
      background: var(--color-aws-dark);
    }

    .code-tab-btn {
      padding: 12px 24px;
      background: transparent;
      color: rgba(255,255,255,0.7);
      border: none;
      cursor: pointer;
      font-size: 0.82em;
      font-weight: 600;
      transition: all var(--transition-base);
      font-family: inherit;
    }

    .code-tab-btn:hover {
      color: white;
      background: rgba(255,255,255,0.1);
    }

    .code-tab-btn.active {
      color: var(--color-aws-orange-original);
      background: rgba(255,153,0,0.15);
      border-bottom: 2px solid var(--color-aws-orange-original);
    }

    .code-tab-content {
      display: none;
      background: #1a1a2e;
      padding: 20px 24px;
      overflow-x: auto;
    }

    .code-tab-content.active {
      display: block;
    }

    .code-tab-content pre {
      margin: 0;
      font-family: "Fira Code", "Source Code Pro", "Consolas", monospace;
      font-size: 0.78em;
      line-height: 1.7;
      color: #E2E8F0;
      white-space: pre;
    }

    .code-comment { color: #6B7280; }
    .code-key { color: #93C5FD; }
    .code-value { color: #86EFAC; }
    .code-string { color: #FCD34D; }

    /* ========================================
       Comparison Table (Best Practices)
       ======================================== */
    .compare-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 20px;
      margin: 24px 0;
    }

    .compare-good {
      background: #ECFDF5;
      border: 1px solid #A7F3D0;
      border-radius: var(--radius-base);
      padding: 24px;
    }

    .compare-bad {
      background: #FEF2F2;
      border: 1px solid #FECACA;
      border-radius: var(--radius-base);
      padding: 24px;
    }

    .compare-good h3 { color: #065F46; font-size: 1em; margin-bottom: 14px; }
    .compare-bad h3 { color: #991B1B; font-size: 1em; margin-bottom: 14px; }

    .compare-item {
      display: flex;
      align-items: flex-start;
      gap: 10px;
      margin-bottom: 12px;
      font-size: 0.85em;
      line-height: 1.6;
    }

    .compare-icon {
      flex-shrink: 0;
      font-size: 1.1em;
    }

    /* ========================================
       FAQ Accordion
       ======================================== */
    .faq-item {
      border: 1px solid var(--color-border-light);
      border-radius: var(--radius-md);
      margin-bottom: 12px;
      overflow: hidden;
    }

    .faq-question {
      width: 100%;
      padding: 18px 24px;
      background: var(--color-bg-light);
      border: none;
      cursor: pointer;
      font-size: 0.92em;
      font-weight: 600;
      color: var(--color-aws-dark);
      text-align: left;
      display: flex;
      justify-content: space-between;
      align-items: center;
      transition: background var(--transition-base);
      font-family: inherit;
    }

    .faq-question:hover {
      background: #FFF7ED;
    }

    .faq-arrow {
      font-size: 0.8em;
      transition: transform var(--transition-base);
      color: var(--color-text-secondary);
    }

    .faq-item.open .faq-arrow {
      transform: rotate(180deg);
    }

    .faq-answer {
      display: none;
      padding: 18px 24px;
      font-size: 0.88em;
      line-height: 1.7;
      color: var(--color-text-secondary);
      border-top: 1px solid var(--color-border-light);
    }

    .faq-item.open .faq-answer {
      display: block;
    }

    /* ========================================
       Cheat Sheet
       ======================================== */
    .cheatsheet {
      background: linear-gradient(135deg, var(--color-aws-dark), #1a2332);
      color: white;
      border-radius: var(--radius-lg);
      padding: 36px;
      margin-bottom: 32px;
    }

    .cheatsheet h2 {
      color: var(--color-aws-orange-original);
      border-bottom-color: var(--color-aws-orange-original);
      margin-bottom: 24px;
    }

    .cheatsheet-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 16px;
    }

    .cheatsheet-item {
      background: rgba(255,255,255,0.08);
      border: 1px solid rgba(255,255,255,0.12);
      border-radius: var(--radius-md);
      padding: 18px;
    }

    .cheatsheet-label {
      font-size: 0.78em;
      color: var(--color-aws-orange-original);
      font-weight: 600;
      text-transform: uppercase;
      letter-spacing: 0.05em;
      margin-bottom: 8px;
    }

    .cheatsheet-value {
      font-size: 0.92em;
      line-height: 1.6;
      color: rgba(255,255,255,0.9);
    }

    /* ========================================
       Glossary
       ======================================== */
    .glossary-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 14px;
      margin: 24px 0;
    }

    .glossary-item {
      padding: 16px 18px;
      background: var(--color-bg-light);
      border-radius: var(--radius-md);
      border-left: 3px solid var(--color-info);
    }

    .glossary-term {
      font-weight: 700;
      font-size: 0.9em;
      color: var(--color-aws-dark);
      margin-bottom: 4px;
    }

    .glossary-def {
      font-size: 0.82em;
      color: var(--color-text-secondary);
      line-height: 1.6;
    }

    /* ========================================
       Scroll to Top
       ======================================== */
    .scroll-top {
      position: fixed;
      bottom: 30px;
      right: 30px;
      width: 48px;
      height: 48px;
      background: var(--color-aws-orange-original);
      color: white;
      border: none;
      border-radius: 50%;
      cursor: pointer;
      font-size: 1.3em;
      box-shadow: var(--shadow-md);
      z-index: var(--z-scroll-top);
      display: none;
      align-items: center;
      justify-content: center;
      transition: all var(--transition-base);
    }

    .scroll-top:hover {
      background: var(--color-aws-orange-hover);
      transform: translateY(-3px);
    }

    /* ========================================
       Footer
       ======================================== */
    .footer {
      text-align: center;
      padding: 32px 0;
      font-size: 0.8em;
      color: var(--color-text-secondary);
    }

    /* ========================================
       Responsive
       ======================================== */
    @media (max-width: 768px) {
      body { font-size: 18px; }
      .hero h1 { font-size: 1.6em; }
      .takeaway-grid,
      .card-grid-2,
      .card-grid-3,
      .card-grid-4,
      .compare-grid,
      .cheatsheet-grid,
      .glossary-grid { grid-template-columns: 1fr; }
      .fixed-nav-links { display: none; }
      .section { padding: 28px 20px; }
    }

    /* ========================================
       Flowchart Process
       ======================================== */
    .process-flow {
      display: flex;
      align-items: center;
      justify-content: center;
      gap: 0;
      margin: 30px 0;
      flex-wrap: wrap;
    }

    .process-step {
      display: flex;
      flex-direction: column;
      align-items: center;
      text-align: center;
      padding: 18px;
      min-width: 160px;
    }

    .process-step-circle {
      width: 56px;
      height: 56px;
      border-radius: 50%;
      display: flex;
      align-items: center;
      justify-content: center;
      font-size: 1.5em;
      margin-bottom: 10px;
    }

    .process-step-label {
      font-size: 0.82em;
      font-weight: 600;
      color: var(--color-aws-dark);
    }

    .process-step-desc {
      font-size: 0.75em;
      color: var(--color-text-secondary);
      margin-top: 4px;
    }

    .process-arrow {
      font-size: 1.5em;
      color: var(--color-aws-orange-original);
      margin: 0 6px;
    }

    /* ========================================
       Meter/Bar visual
       ======================================== */
    .perf-meter {
      margin: 20px 0;
    }

    .perf-meter-row {
      display: flex;
      align-items: center;
      gap: 14px;
      margin-bottom: 14px;
    }

    .perf-meter-label {
      width: 180px;
      font-size: 0.82em;
      font-weight: 600;
      text-align: right;
      flex-shrink: 0;
    }

    .perf-meter-track {
      flex: 1;
      height: 28px;
      background: var(--color-bg-light);
      border-radius: 14px;
      overflow: hidden;
      position: relative;
    }

    .perf-meter-fill {
      height: 100%;
      border-radius: 14px;
      display: flex;
      align-items: center;
      justify-content: flex-end;
      padding-right: 12px;
      font-size: 0.72em;
      font-weight: 700;
      color: white;
      transition: width 1s ease;
    }

    .fill-orange { background: linear-gradient(90deg, #FF9900, #EC7211); }
    .fill-blue { background: linear-gradient(90deg, #3B82F6, #2563EB); }
    .fill-green { background: linear-gradient(90deg, #10B981, #059669); }
    .fill-purple { background: linear-gradient(90deg, #8B5CF6, #7C3AED); }
    .fill-red { background: linear-gradient(90deg, #EF4444, #DC2626); }

    /* ========================================
       Timeline / Roadmap
       ======================================== */
    .decision-tree {
      margin: 24px 0;
    }

    .decision-node {
      display: flex;
      align-items: flex-start;
      gap: 16px;
      margin-bottom: 20px;
      padding: 18px 22px;
      background: var(--color-bg-light);
      border-radius: var(--radius-base);
      border-left: 4px solid var(--color-info);
    }

    .decision-node-q {
      border-left-color: var(--color-aws-orange-original);
      background: #FFF7ED;
    }

    .decision-icon {
      font-size: 1.5em;
      flex-shrink: 0;
    }

    .decision-content h3 {
      font-size: 0.92em;
      font-weight: 700;
      color: var(--color-aws-dark);
      margin-bottom: 6px;
    }

    .decision-content p {
      font-size: 0.82em;
      color: var(--color-text-secondary);
      margin: 0;
    }