/* CSS Variables - Design System */
:root {
    --color-background: hsl(0, 0%, 99%);
    --color-foreground: hsl(220, 13%, 9%);
    --color-muted: hsl(220, 14%, 96%);
    --color-muted-foreground: hsl(220, 9%, 46%);
    --color-card: hsl(0, 0%, 100%);
    --color-border: hsl(220, 13%, 91%);
    
    --color-tech-blue: hsl(217, 91%, 60%);
    --color-tech-cyan: hsl(189, 85%, 60%);
    --color-tech-green: hsl(142, 76%, 36%);
    --color-destructive: hsl(0, 84%, 60%);
    
    --gradient-tech: linear-gradient(135deg, var(--color-tech-blue), var(--color-tech-cyan));
    --gradient-hero: linear-gradient(180deg, var(--color-background), hsl(220, 14%, 98%));
    
    --radius: 0.5rem;
    --shadow: 0 1px 3px 0 rgb(0 0 0 / 0.1), 0 1px 2px -1px rgb(0 0 0 / 0.1);
    --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.1), 0 4px 6px -4px rgb(0 0 0 / 0.1);
}

/* Reset and Base Styles */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Roboto', 'Oxygen', 'Ubuntu', 'Cantarell', 'Fira Sans', 'Droid Sans', 'Helvetica Neue', sans-serif;
    line-height: 1.6;
    color: var(--color-foreground);
    background: var(--color-background);
}

.container {
    min-height: 100vh;
    background: linear-gradient(to bottom, var(--color-background), hsl(220, 14%, 98%));
}

/* Hero Section */
.hero-section {
  max-width: 64rem;
  margin: 0 auto;
  position: relative;
  overflow: hidden;   /* keeps image + overlays clipped */
  height: 60vh;       /* set the height here instead of on the image */
}

.hero-overlay {
    position: absolute;
    inset: 0;
    background: linear-gradient(to right, hsla(217, 91%, 60%, 0.2), hsla(189, 85%, 60%, 0.2));
    z-index: 1;
}

.hero-image {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;   /* keeps aspect ratio while covering */
}

.hero-gradient {
    position: absolute;
    inset: 0;
    background: linear-gradient(to top, hsla(0, 0%, 99%, 0.8), transparent, transparent);
    z-index: 2;
}

.hero-content {
    position: absolute;
    bottom: 0;
    left: 0;
    right: 0;
    padding: 2rem;
    z-index: 3;
}

.hero-text {
    max-width: 64rem;
    margin: 0 auto;
}

.badges {
    display: flex;
    gap: 0.5rem;
    margin-bottom: 1rem;
    flex-wrap: wrap;
}

.badge {
    padding: 0.25rem 0.75rem;
    border-radius: var(--radius);
    font-size: 0.875rem;
    font-weight: 500;
    color: white;
}

.badge-blue {
    background-color: var(--color-tech-blue);
}

.badge-green {
    background-color: var(--color-tech-green);
}

.badge-cyan {
    background-color: var(--color-tech-cyan);
}

.hero-title {
    font-size: 3rem;
    font-weight: 700;
    line-height: 1.1;
    margin-bottom: 1rem;
    color: var(--color-foreground);
}

.hero-subtitle {
    font-size: 1.25rem;
    color: var(--color-muted-foreground);
    max-width: 48rem;
}

/* Article Styles */
.article {
    max-width: 64rem;
    margin: 0 auto;
    padding: 4rem 2rem;
}

.intro {
    margin-bottom: 3rem;
}

.intro-text {
    font-size: 1.125rem;
    color: var(--color-muted-foreground);
    line-height: 1.7;
}

.section {
    margin-bottom: 4rem;
}

.section-title {
    font-size: 2rem;
    font-weight: 700;
    color: var(--color-foreground);
    margin-bottom: 1.5rem;
}

.section-text {
    color: var(--color-muted-foreground);
    line-height: 1.7;
    margin-top: 2rem;
}

.section-image {
    width: 100%;
    border-radius: var(--radius);
    box-shadow: var(--shadow-lg);
    margin-bottom: 1.5rem;
}

/* Card Styles */
.card {
    background: var(--color-card);
    border: 1px solid var(--color-border);
    border-radius: var(--radius);
    padding: 2rem;
    box-shadow: var(--shadow);
}

.tech-card {
    border-left: 4px solid var(--color-tech-blue);
    margin-bottom: 2rem;
}

.card-title {
    font-size: 1.5rem;
    font-weight: 600;
    color: var(--color-foreground);
    margin-bottom: 1rem;
}

.card-title-blue {
    font-size: 1.25rem;
    font-weight: 600;
    color: var(--color-tech-blue);
    margin-bottom: 0.75rem;
}

.card-title-green {
    font-size: 1.25rem;
    font-weight: 600;
    color: var(--color-tech-green);
    margin-bottom: 0.75rem;
}

.card-text {
    color: var(--color-muted-foreground);
    line-height: 1.7;
    margin-bottom: 1rem;
}

.tech-list {
    list-style: disc;
    list-style-position: inside;
    color: var(--color-muted-foreground);
    space-y: 0.5rem;
}

.tech-list li {
    margin-bottom: 0.5rem;
}

.benefit-list {
    color: var(--color-muted-foreground);
}

.benefit-list li {
    margin-bottom: 0.5rem;
}

/* Grid Layout */
.grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: 2rem;
    margin-bottom: 2rem;
}

@media (min-width: 768px) {
    .grid {
        grid-template-columns: 1fr 1fr;
    }
}

/* Pipeline Styles */
.pipeline-container {
    background: linear-gradient(to right, hsla(217, 91%, 60%, 0.1), hsla(189, 85%, 60%, 0.1));
    border-radius: var(--radius);
    padding: 2rem;
    margin-bottom: 2rem;
}

.pipeline-title {
    font-size: 1.5rem;
    font-weight: 600;
    color: var(--color-foreground);
    margin-bottom: 1rem;
}

.pipeline-steps {
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

.step {
    display: flex;
    align-items: center;
    gap: 1rem;
}

.step-number {
    width: 2rem;
    height: 2rem;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 700;
    color: white;
    flex-shrink: 0;
}

.step-blue {
    background-color: var(--color-tech-blue);
}

.step-cyan {
    background-color: var(--color-tech-cyan);
}

.step-green {
    background-color: var(--color-tech-green);
}

.step-title {
    font-weight: 600;
    color: var(--color-foreground);
    margin-bottom: 0.25rem;
}

.step-description {
    color: var(--color-muted-foreground);
}

/* Metrics Grid */
.metrics-grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: 1.5rem;
    margin-bottom: 2rem;
}

@media (min-width: 768px) {
    .metrics-grid {
        grid-template-columns: repeat(3, 1fr);
    }
}

.metric-card {
    background: var(--color-card);
    border: 2px solid;
    border-radius: var(--radius);
    padding: 1.5rem;
    text-align: center;
    box-shadow: var(--shadow);
}

.metric-blue {
    border-color: var(--color-tech-blue);
}

.metric-cyan {
    border-color: var(--color-tech-cyan);
}

.metric-green {
    border-color: var(--color-tech-green);
}

.metric-value {
    font-size: 2rem;
    font-weight: 700;
    margin-bottom: 0.5rem;
}

.metric-blue .metric-value {
    color: var(--color-tech-blue);
}

.metric-cyan .metric-value {
    color: var(--color-tech-cyan);
}

.metric-green .metric-value {
    color: var(--color-tech-green);
}

.metric-label {
    color: var(--color-muted-foreground);
}

/* Challenges */
.challenges {
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
}

.challenge-red {
    border-left: 4px solid var(--color-destructive);
}

.challenge-green {
    border-left: 4px solid var(--color-tech-green);
}

.challenge-blue {
    border-left: 4px solid var(--color-tech-blue);
}

.challenge-title {
    font-size: 1.25rem;
    font-weight: 600;
    color: var(--color-foreground);
    margin-bottom: 0.75rem;
}

.challenge-text {
    color: var(--color-muted-foreground);
    line-height: 1.7;
}

/* Future Directions */
.future-container {
    background: linear-gradient(to bottom right, hsla(217, 91%, 60%, 0.05), hsla(142, 76%, 36%, 0.05));
    border-radius: var(--radius);
    padding: 2rem;
}

.future-text {
    color: var(--color-muted-foreground);
    line-height: 1.7;
    margin-bottom: 1.5rem;
}

.future-subtitle {
    font-size: 1.25rem;
    font-weight: 600;
    color: var(--color-foreground);
    margin-bottom: 1rem;
}

.future-list {
    list-style: disc;
    list-style-position: inside;
    color: var(--color-muted-foreground);
}

.future-list li {
    margin-bottom: 0.5rem;
}

/* Conclusion */
.conclusion {
    background: var(--color-card);
    border: 2px solid hsla(217, 91%, 60%, 0.2);
    border-radius: var(--radius);
    padding: 2rem;
}

.conclusion-text {
    color: var(--color-muted-foreground);
    line-height: 1.7;
    font-size: 1.125rem;
}

/* Responsive Typography */
@media (max-width: 768px) {
    .hero-title {
        font-size: 2rem;
    }
    
    .hero-subtitle {
        font-size: 1.125rem;
    }
    
    .section-title {
        font-size: 1.75rem;
    }
    
    .hero-content {
        padding: 1rem;
    }
    
    .article {
        padding: 2rem 1rem;
    }
}

@media (max-width: 480px) {
    .hero-title {
        font-size: 1.75rem;
    }
    
    .badges {
        justify-content: center;
    }
    
    .step {
        flex-direction: column;
        text-align: center;
    }
    
    .step-content {
        text-align: center;
    }
}


.back-button-container {
  max-width: 64rem;      /* same width constraint as hero/article */
  margin: 2rem auto 2rem auto;  /* top margin, bottom margin (line gap) */
  padding: 0 2rem;       /* same side padding as article */
}

.back-button {
  background-color: #1e3a8a;
  color: white;
  border: none;
  padding: 10px 16px;
  width: 250px;
  border-radius: 8px;
  font-size: 16px;
  cursor: pointer;
  transition: background 0.3s ease;
}

.back-button:hover {
  background-color: #2563eb;
}