/* ========================================
   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-tertiary: #6f7682;
    --color-text-white: #FFFFFF;
    --color-bg-light: #F9FAFB;
    --color-bg-white: #FFFFFF;
    --color-bg-dark: #1F2937;
    --color-bg-gradient-start: #232F3E;
    --color-bg-gradient-end: #374151;
    --color-border: #909296;
    --color-border-light: #E5E7EB;
    --color-shadow: rgba(0, 0, 0, 0.1);
    --color-success: #10B981;
    --color-warning: #F59E0B;
    --color-error: #EF4444;
    --color-info: #3B82F6;
    --spacing-xs: 5px;
    --spacing-sm: 10px;
    --spacing-md: 15px;
    --spacing-base: 20px;
    --spacing-lg: 25px;
    --spacing-xl: 30px;
    --spacing-2xl: 40px;
    --spacing-3xl: 60px;
    --spacing-4xl: 80px;
    --font-size-xs: 0.75em;
    --font-size-sm: 0.85em;
    --font-size-base: 0.95em;
    --font-size-md: 1em;
    --font-size-lg: 1.2em;
    --font-size-xl: 1.5em;
    --font-size-2xl: 2em;
    --font-size-3xl: 2.5em;
    --font-weight-normal: 400;
    --font-weight-medium: 500;
    --font-weight-semibold: 600;
    --font-weight-bold: 700;
    --line-height-tight: 1.25;
    --line-height-normal: 1.5;
    --line-height-relaxed: 1.75;
    --radius-sm: 6px;
    --radius-md: 8px;
    --radius-base: 10px;
    --radius-lg: 15px;
    --radius-xl: 20px;
    --radius-full: 50%;
    --shadow-xs: 0 1px 2px rgba(0, 0, 0, 0.05);
    --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, 0.2);
    --shadow-xl: 0 20px 50px rgba(0, 0, 0, 0.3);
    --shadow-focus: 0 0 0 3px rgba(255, 153, 0, 0.3);
    --shadow-orange: 0 4px 12px rgba(255, 153, 0, 0.4);
    --shadow-orange-hover: 0 6px 20px rgba(255, 153, 0, 0.6);
    --z-header: 1002;
    --z-progress-bar: 1001;
    --z-scroll-top: 1000;
    --transition-fast: 0.15s ease;
    --transition-base: 0.3s ease;
    --transition-slow: 0.5s ease;
    --header-height: 60px;
    --container-max-width: 1200px;
}

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Helvetica Neue', Arial, sans-serif;
    line-height: var(--line-height-normal);
    color: var(--color-text-primary);
    margin: 0;
    padding: var(--spacing-base);
    padding-top: var(--spacing-4xl);
    background-color: var(--color-bg-light);
    font-size: 20px;
}

/* ========================================
   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 var(--spacing-xl);
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.fixed-nav-logo {
    font-size: 1.3em;
    font-weight: var(--font-weight-bold);
    color: var(--color-aws-orange-original);
    text-decoration: none;
    display: flex;
    align-items: center;
    gap: 8px;
}

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

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

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

/* ========================================
   Reading Progress Bar
   ======================================== */
.reading-progress {
    position: fixed;
    top: var(--header-height);
    left: 0;
    width: 100%;
    height: 4px;
    background-color: var(--color-border-light);
    z-index: var(--z-progress-bar);
    opacity: 0;
    transition: opacity var(--transition-base);
}

.reading-progress.show {
    opacity: 1;
}

.reading-progress-bar {
    height: 100%;
    background: linear-gradient(90deg, var(--color-aws-orange-original) 0%, var(--color-aws-orange-hover) 100%);
    width: 0%;
    transition: width 0.1s ease;
}

/* ========================================
   Container
   ======================================== */
.container {
    max-width: var(--container-max-width);
    margin: 0 auto;
    padding: var(--spacing-2xl);
    background-color: var(--color-bg-white);
    border-radius: 16px;
    box-shadow: var(--shadow-lg);
}

/* ========================================
   Skip Link
   ======================================== */
.skip-link {
    position: absolute;
    top: -40px;
    left: 0;
    background: var(--color-aws-orange);
    color: var(--color-text-white);
    padding: 8px 16px;
    text-decoration: none;
    border-radius: 0 0 4px 0;
    font-weight: var(--font-weight-bold);
    z-index: var(--z-scroll-top);
}

.skip-link:focus {
    top: 0;
}

/* ========================================
   Headings
   ======================================== */
h1, h2, h3, h4, h5, h6 {
    color: var(--color-text-primary);
    line-height: var(--line-height-tight);
    margin-top: 0;
}

h2 {
    font-size: var(--font-size-2xl);
    margin-bottom: var(--spacing-md);
    border-bottom: 2px solid var(--color-aws-orange);
    padding-bottom: var(--spacing-sm);
}

h3 {
    font-size: var(--font-size-xl);
    margin-bottom: var(--spacing-md);
}

h4 {
    font-size: var(--font-size-lg);
    margin-bottom: var(--spacing-sm);
}

/* ========================================
   Section
   ======================================== */
.section {
    margin-bottom: var(--spacing-2xl);
    background-color: var(--color-bg-light);
    padding: var(--spacing-xl);
    border-radius: var(--radius-base);
    box-shadow: var(--shadow-sm);
}

/* ========================================
   Hero Section
   ======================================== */
.hero {
    background: linear-gradient(135deg, #232F3E 0%, #374151 100%);
    color: var(--color-text-white);
    padding: var(--spacing-3xl) var(--spacing-2xl);
    border-radius: var(--radius-xl);
    margin-bottom: var(--spacing-2xl);
    text-align: center;
}

.hero h1 {
    color: var(--color-text-white);
    font-size: 2.4em;
    margin-bottom: var(--spacing-md);
}

.hero-subtitle {
    font-size: 1.2em;
    color: rgba(255, 255, 255, 0.85);
    margin-bottom: var(--spacing-xl);
}

.hero-badge {
    display: inline-block;
    background: var(--color-aws-orange-original);
    color: var(--color-text-white);
    padding: 8px 24px;
    border-radius: var(--radius-xl);
    font-weight: var(--font-weight-bold);
    font-size: 0.95em;
}

/* ========================================
   Conclusion-First Box
   ======================================== */
.conclusion-box {
    background: linear-gradient(135deg, #FFF7ED 0%, #FFFBEB 100%);
    border: 2px solid var(--color-aws-orange-original);
    border-radius: var(--radius-lg);
    padding: var(--spacing-xl);
    margin-bottom: var(--spacing-2xl);
}

.conclusion-box h2 {
    border-bottom: none;
    color: var(--color-aws-orange);
    padding-bottom: 0;
    margin-bottom: var(--spacing-base);
}

.conclusion-item {
    display: flex;
    align-items: flex-start;
    gap: 12px;
    margin-bottom: var(--spacing-md);
    padding: 12px 16px;
    background: var(--color-bg-white);
    border-radius: var(--radius-md);
    box-shadow: var(--shadow-xs);
}

.conclusion-number {
    flex-shrink: 0;
    width: 36px;
    height: 36px;
    background: var(--color-aws-orange-original);
    color: var(--color-text-white);
    border-radius: var(--radius-full);
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: var(--font-weight-bold);
    font-size: 0.9em;
}

.conclusion-text {
    font-size: 1em;
    line-height: 1.6;
}

/* ========================================
   Analogy Mapping Table
   ======================================== */
.analogy-table-wrapper {
    overflow-x: auto;
    margin-bottom: var(--spacing-2xl);
}

.analogy-table {
    width: 100%;
    border-collapse: collapse;
    font-size: 1em;
}

.analogy-table thead {
    background: var(--color-aws-dark);
    color: var(--color-text-white);
}

.analogy-table th {
    padding: 14px 20px;
    text-align: left;
    font-weight: var(--font-weight-bold);
}

.analogy-table td {
    padding: 14px 20px;
    border-bottom: 1px solid var(--color-border-light);
}

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

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

.analogy-emoji {
    font-size: 1.3em;
    margin-right: 6px;
}

/* ========================================
   Grid Layouts
   ======================================== */
.grid-2 {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: var(--spacing-base);
}

.grid-3 {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: var(--spacing-base);
}

.grid-4 {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: var(--spacing-base);
}

@media (max-width: 900px) {
    .grid-2, .grid-3, .grid-4 {
        grid-template-columns: 1fr;
    }
}

/* ========================================
   Cards
   ======================================== */
.card {
    background-color: var(--color-bg-white);
    border-radius: var(--radius-lg);
    padding: var(--spacing-base);
    box-shadow: var(--shadow-sm);
    transition: all var(--transition-base);
}

.card:hover {
    transform: translateY(-3px);
    box-shadow: var(--shadow-md);
}

.card-icon {
    font-size: 2em;
    margin-bottom: var(--spacing-sm);
}

.card h4 {
    color: var(--color-aws-dark);
    margin-bottom: var(--spacing-xs);
}

.card p {
    color: var(--color-text-secondary);
    font-size: 0.95em;
    line-height: 1.6;
}

/* Feature Card with left border */
.card-feature {
    border-left: 4px solid var(--color-aws-orange);
}

/* ========================================
   Comparison Table
   ======================================== */
.comparison-table {
    width: 100%;
    border-collapse: collapse;
    font-size: 1em;
}

.comparison-table thead {
    background: var(--color-aws-dark);
    color: var(--color-text-white);
}

.comparison-table th {
    padding: 14px 16px;
    text-align: center;
    font-weight: var(--font-weight-bold);
    font-size: 0.95em;
}

.comparison-table th:first-child {
    text-align: left;
}

.comparison-table td {
    padding: 14px 16px;
    border-bottom: 1px solid var(--color-border-light);
    text-align: center;
    font-size: 0.95em;
}

.comparison-table td:first-child {
    text-align: left;
    font-weight: var(--font-weight-semibold);
}

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

.comparison-table .highlight-col {
    background: #FFF7ED;
}

.comparison-table thead .highlight-col {
    background: var(--color-aws-orange);
}

/* ========================================
   Use Case Cards
   ======================================== */
.usecase-card {
    background: var(--color-bg-white);
    border-radius: var(--radius-lg);
    padding: var(--spacing-base);
    box-shadow: var(--shadow-sm);
    border-top: 4px solid var(--color-info);
    transition: all var(--transition-base);
}

.usecase-card:hover {
    transform: translateY(-3px);
    box-shadow: var(--shadow-md);
}

.usecase-icon {
    font-size: 2.2em;
    margin-bottom: var(--spacing-sm);
}

.usecase-card h4 {
    color: var(--color-aws-dark);
    margin-bottom: var(--spacing-xs);
}

/* ========================================
   Best Practice / Anti-Pattern
   ======================================== */
.practice-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: var(--spacing-base);
}

@media (max-width: 900px) {
    .practice-grid {
        grid-template-columns: 1fr;
    }
}

.practice-good {
    background: #ECFDF5;
    border: 2px solid var(--color-success);
    border-radius: var(--radius-lg);
    padding: var(--spacing-base);
}

.practice-bad {
    background: #FEF2F2;
    border: 2px solid var(--color-error);
    border-radius: var(--radius-lg);
    padding: var(--spacing-base);
}

.practice-good h3,
.practice-bad h3 {
    margin-bottom: var(--spacing-md);
}

.practice-item {
    display: flex;
    align-items: flex-start;
    gap: 10px;
    margin-bottom: var(--spacing-sm);
    font-size: 0.95em;
    line-height: 1.6;
}

.practice-icon {
    flex-shrink: 0;
    font-size: 1.2em;
}

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

.faq-question {
    width: 100%;
    padding: 16px 20px;
    background: var(--color-bg-white);
    border: none;
    cursor: pointer;
    display: flex;
    justify-content: space-between;
    align-items: center;
    font-size: 1em;
    font-weight: var(--font-weight-semibold);
    color: var(--color-text-primary);
    text-align: left;
    transition: background var(--transition-base);
}

.faq-question:hover {
    background: var(--color-bg-light);
}

.faq-arrow {
    transition: transform var(--transition-base);
    font-size: 0.9em;
    color: var(--color-aws-orange);
}

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

.faq-answer {
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.4s ease;
    background: var(--color-bg-light);
}

.faq-answer-inner {
    padding: 16px 20px;
    line-height: 1.7;
    color: var(--color-text-secondary);
    font-size: 0.95em;
}

/* ========================================
   Cheat Sheet
   ======================================== */
.cheatsheet {
    background: linear-gradient(135deg, #232F3E 0%, #1a2332 100%);
    color: var(--color-text-white);
    border-radius: var(--radius-xl);
    padding: var(--spacing-2xl);
}

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

.cheatsheet-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: var(--spacing-base);
}

@media (max-width: 900px) {
    .cheatsheet-grid {
        grid-template-columns: 1fr;
    }
}

.cheatsheet-card {
    background: rgba(255, 255, 255, 0.08);
    border: 1px solid rgba(255, 255, 255, 0.15);
    border-radius: var(--radius-lg);
    padding: var(--spacing-base);
}

.cheatsheet-card h4 {
    color: var(--color-aws-orange-original);
    margin-bottom: var(--spacing-sm);
}

.cheatsheet-card p {
    color: rgba(255, 255, 255, 0.8);
    font-size: 0.95em;
    line-height: 1.6;
}

/* ========================================
   Code Block with Tabs
   ======================================== */
.code-tabs {
    margin-bottom: var(--spacing-base);
}

.code-tab-buttons {
    display: flex;
    gap: 0;
    border-bottom: 2px solid var(--color-border-light);
}

.code-tab-btn {
    padding: 10px 20px;
    border: none;
    background: var(--color-bg-light);
    cursor: pointer;
    font-size: 0.9em;
    font-weight: var(--font-weight-semibold);
    color: var(--color-text-secondary);
    border-radius: var(--radius-sm) var(--radius-sm) 0 0;
    transition: all var(--transition-base);
}

.code-tab-btn.active {
    background: var(--color-aws-dark);
    color: var(--color-aws-orange-original);
}

.code-tab-content {
    display: none;
}

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

.code-block {
    background: #1E293B;
    color: #E2E8F0;
    padding: var(--spacing-base);
    border-radius: 0 0 var(--radius-md) var(--radius-md);
    overflow-x: auto;
    font-family: 'Courier New', Courier, monospace;
    font-size: 0.85em;
    line-height: 1.7;
}

.code-comment {
    color: #64748B;
}

.code-keyword {
    color: #38BDF8;
}

.code-string {
    color: #34D399;
}

.code-value {
    color: #FBBF24;
}

/* ========================================
   SVG Container
   ======================================== */
.svg-container {
    width: 100%;
    max-width: 100%;
    margin: var(--spacing-base) auto;
    overflow-x: auto;
}

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

/* ========================================
   Highlight / Tag
   ======================================== */
.highlight {
    color: var(--color-aws-orange);
    font-weight: var(--font-weight-bold);
}

.tag {
    display: inline-block;
    background-color: #E6F7FF;
    color: #0062cc;
    padding: 3px 10px;
    border-radius: 12px;
    font-size: 0.8em;
    margin-right: 5px;
}

/* ========================================
   Step-Flow (Visual Process)
   ======================================== */
.step-flow {
    display: flex;
    align-items: flex-start;
    gap: 12px;
    margin-bottom: var(--spacing-base);
}

.step-number {
    flex-shrink: 0;
    width: 44px;
    height: 44px;
    background: var(--color-info);
    color: var(--color-text-white);
    border-radius: var(--radius-full);
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: var(--font-weight-bold);
    font-size: 1em;
}

.step-content h4 {
    margin-bottom: 4px;
}

.step-content p {
    color: var(--color-text-secondary);
    font-size: 0.95em;
    line-height: 1.6;
}

/* ========================================
   Scroll to Top Button
   ======================================== */
.scroll-to-top {
    position: fixed;
    bottom: var(--spacing-xl);
    right: var(--spacing-xl);
    width: 50px;
    height: 50px;
    background: linear-gradient(135deg, var(--color-aws-orange-original) 0%, var(--color-aws-orange-hover) 100%);
    color: var(--color-text-white);
    border: none;
    border-radius: var(--radius-full);
    font-size: var(--font-size-xl);
    cursor: pointer;
    box-shadow: var(--shadow-orange);
    opacity: 0;
    visibility: hidden;
    transition: all var(--transition-base);
    z-index: var(--z-scroll-top);
    display: flex;
    align-items: center;
    justify-content: center;
}

.scroll-to-top.show {
    opacity: 1;
    visibility: visible;
}

.scroll-to-top:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-orange-hover);
}

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

/* ========================================
   Responsive
   ======================================== */
@media (max-width: 768px) {
    body {
        padding: var(--spacing-sm);
        padding-top: 70px;
        font-size: 18px;
    }

    .container {
        padding: var(--spacing-base);
    }

    .hero {
        padding: var(--spacing-2xl) var(--spacing-base);
    }

    .hero h1 {
        font-size: 1.8em;
    }

    .fixed-nav-links {
        display: none;
    }
}