/* =========================================================
   AWS Student Builder Group — Article Stylesheet
   Design: light "sky" surface, deep navy ink, electric-blue
   accent, amber signal color for warnings/highlights.
   ========================================================= */

:root {
  --color-bg: #eef4ff;
  --color-bg-alt: #ffffff;
  --color-surface: #ffffff;
  --color-surface-2: #f4f8ff;
  --color-border: #dbe6fb;
  --color-ink: #0b1830;
  --color-ink-soft: #46536b;
  --color-blue: #2563eb;
  --color-blue-dark: #1745a8;
  --color-blue-tint: #e6efff;
  --color-amber: #f59e0b;
  --color-amber-tint: #fff4e0;
  --color-green: #16a34a;
  --color-green-tint: #e8f8ee;

  --font-display: "Sora", "Segoe UI", sans-serif;
  --font-body: "Inter", "Segoe UI", sans-serif;
  --font-mono: "JetBrains Mono", ui-monospace, monospace;

  --radius-sm: 8px;
  --radius-md: 14px;
  --radius-lg: 22px;
  --shadow-card: 0 8px 24px -12px rgba(11, 24, 48, 0.18);
  --shadow-card-hover: 0 16px 36px -14px rgba(37, 99, 235, 0.3);
  --max-width: 1180px;
}

[data-theme="dark"] {
  --color-bg: #060b16;
  --color-bg-alt: #0c1424;
  --color-surface: #0e1728;
  --color-surface-2: #121d33;
  --color-border: #22314e;
  --color-ink: #e9eefc;
  --color-ink-soft: #a7b4cf;
  --color-blue: #5b9dff;
  --color-blue-dark: #8fbcff;
  --color-blue-tint: #142544;
  --color-amber: #fbbf51;
  --color-amber-tint: #2c220f;
  --color-green: #4ade80;
  --color-green-tint: #0f2419;
  --shadow-card: 0 8px 24px -12px rgba(0, 0, 0, 0.5);
  --shadow-card-hover: 0 16px 36px -14px rgba(91, 157, 255, 0.35);
}

@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --color-bg: #060b16;
    --color-bg-alt: #0c1424;
    --color-surface: #0e1728;
    --color-surface-2: #121d33;
    --color-border: #22314e;
    --color-ink: #e9eefc;
    --color-ink-soft: #a7b4cf;
    --color-blue: #5b9dff;
    --color-blue-dark: #8fbcff;
    --color-blue-tint: #142544;
    --color-amber: #fbbf51;
    --color-amber-tint: #2c220f;
    --color-green: #4ade80;
    --color-green-tint: #0f2419;
    --shadow-card: 0 8px 24px -12px rgba(0, 0, 0, 0.5);
    --shadow-card-hover: 0 16px 36px -14px rgba(91, 157, 255, 0.35);
  }
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  font-family: var(--font-body);
  background: var(--color-bg);
  color: var(--color-ink);
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
}

img, svg { max-width: 100%; display: block; }

a { color: var(--color-blue); text-decoration: none; }
a:hover { text-decoration: underline; }

.skip-link {
  position: absolute;
  left: -9999px;
  top: 0;
  background: var(--color-blue);
  color: #fff;
  padding: 0.75rem 1.25rem;
  z-index: 1000;
  border-radius: 0 0 var(--radius-sm) 0;
}
.skip-link:focus {
  left: 0;
}

:focus-visible {
  outline: 3px solid var(--color-blue);
  outline-offset: 2px;
  border-radius: 4px;
}

/* ---------- Header ---------- */
.site-header {
  border-bottom: 1px solid var(--color-border);
  background: var(--color-bg-alt);
  position: sticky;
  top: 0;
  z-index: 50;
}
.site-nav {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 1rem 1.5rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
}
.brand {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 1.05rem;
  color: var(--color-ink);
  display: flex;
  align-items: center;
  gap: 0.5rem;
}
.brand:hover { text-decoration: none; color: var(--color-blue); }
.brand-mark { color: var(--color-blue); font-size: 1.1rem; }
.back-link { font-weight: 500; font-size: 0.95rem; }

/* ---------- Hero ---------- */
.hero {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 3.5rem 1.5rem 2.5rem;
  display: grid;
  grid-template-columns: 1.15fr 0.85fr;
  gap: 3rem;
  align-items: center;
}
.eyebrow {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  letter-spacing: 0.12em;
  font-weight: 500;
  color: var(--color-blue-dark);
  background: var(--color-blue-tint);
  padding: 0.35rem 0.85rem;
  border-radius: 999px;
  margin: 0 0 1.25rem;
}
.hero h1 {
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(2.1rem, 4.2vw, 3.3rem);
  line-height: 1.08;
  margin: 0 0 1rem;
  letter-spacing: -0.01em;
}
.hero-subtitle {
  font-size: 1.15rem;
  color: var(--color-ink-soft);
  max-width: 46ch;
  margin: 0 0 2rem;
}
.hero-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 1.75rem;
  margin-bottom: 1.25rem;
}
.meta-item { display: flex; flex-direction: column; gap: 0.15rem; }
.meta-label {
  font-size: 0.72rem;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--color-ink-soft);
}
.meta-value { font-weight: 600; font-size: 0.92rem; }

.tag-list {
  list-style: none;
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  padding: 0;
  margin: 0;
}
.tag {
  font-size: 0.78rem;
  font-weight: 600;
  padding: 0.3rem 0.75rem;
  border-radius: 999px;
  background: var(--color-surface-2);
  border: 1px solid var(--color-border);
  color: var(--color-ink-soft);
}

.hero-figure { margin: 0; }
.hero-illustration {
  aspect-ratio: 4 / 3;
  border-radius: var(--radius-lg);
  background:
    radial-gradient(circle at 25% 25%, rgba(37,99,235,0.35), transparent 55%),
    radial-gradient(circle at 75% 70%, rgba(245,158,11,0.28), transparent 55%),
    linear-gradient(150deg, var(--color-blue-dark), var(--color-ink));
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 1.5rem;
  box-shadow: var(--shadow-card);
}
.illustration-note {
  color: rgba(255,255,255,0.85);
  font-family: var(--font-mono);
  font-size: 0.8rem;
  text-align: center;
}
.hero-figure figcaption {
  margin-top: 0.75rem;
  font-size: 0.85rem;
  color: var(--color-ink-soft);
  text-align: center;
}

/* ---------- Layout shell ---------- */
.content-shell {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 1.5rem 4rem;
  display: grid;
  grid-template-columns: 240px 1fr;
  gap: 3rem;
  align-items: start;
}

.toc-sticky {
  position: sticky;
  top: 5.5rem;
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: 1.25rem 1.25rem 1.5rem;
}
.toc-title {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--color-ink-soft);
  margin: 0 0 0.75rem;
}
.toc ol { list-style: none; margin: 0; padding: 0; display: flex; flex-direction: column; gap: 0.5rem; }
.toc a {
  color: var(--color-ink-soft);
  font-size: 0.9rem;
  font-weight: 500;
}
.toc a:hover { color: var(--color-blue); text-decoration: none; }

.article-body { min-width: 0; }
.article-body h2 {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(1.4rem, 2.4vw, 1.85rem);
  margin: 3rem 0 1.1rem;
  scroll-margin-top: 5.5rem;
  letter-spacing: -0.01em;
}
.article-body h3 {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 1.1rem;
  margin: 0 0 0.5rem;
}
.article-body p { margin: 0 0 1.1rem; color: var(--color-ink); }
.article-body ul, .article-body ol.roadmap { margin: 0 0 1.25rem; padding-left: 1.3rem; }
.article-body li { margin-bottom: 0.55rem; }

.lede {
  font-size: 1.2rem;
  color: var(--color-ink);
  font-weight: 500;
}

/* ---------- Callouts ---------- */
.callout {
  border-radius: var(--radius-md);
  padding: 1.1rem 1.3rem;
  margin: 1.5rem 0;
  border: 1px solid var(--color-border);
  background: var(--color-surface-2);
}
.callout-title {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  font-weight: 600;
  margin: 0 0 0.4rem;
}
.callout p:last-child { margin-bottom: 0; }
.callout-note { border-left: 4px solid var(--color-blue); }
.callout-note .callout-title { color: var(--color-blue-dark); }
.callout-tip { border-left: 4px solid var(--color-green); background: var(--color-green-tint); }
.callout-tip .callout-title { color: var(--color-green); }
.callout-warning { border-left: 4px solid var(--color-amber); background: var(--color-amber-tint); }
.callout-warning .callout-title { color: #b46b02; }

/* ---------- Timeline ---------- */
.timeline {
  position: relative;
  margin: 1.5rem 0 2rem;
  padding-left: 1.75rem;
  border-left: 2px solid var(--color-border);
}
.timeline-item { position: relative; padding-bottom: 1.75rem; }
.timeline-item:last-child { padding-bottom: 0; }
.timeline-marker {
  position: absolute;
  left: -2.05rem;
  top: 0.35rem;
  width: 12px;
  height: 12px;
  border-radius: 50%;
  background: var(--color-blue);
  box-shadow: 0 0 0 4px var(--color-blue-tint);
}
.timeline-content h3 { margin-bottom: 0.35rem; }
.timeline-content p { margin-bottom: 0; color: var(--color-ink-soft); }

/* ---------- Card grid ---------- */
.card-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 1rem;
  margin: 1.5rem 0 2rem;
}
.card-grid.three-col { grid-template-columns: repeat(3, 1fr); }
.info-card {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: 1.25rem 1.35rem;
  transition: transform 0.18s ease, box-shadow 0.18s ease, border-color 0.18s ease;
}
.info-card:hover {
  transform: translateY(-3px);
  box-shadow: var(--shadow-card-hover);
  border-color: var(--color-blue);
}
.info-card h3 { margin-bottom: 0.5rem; font-size: 1rem; }
.info-card p { margin-bottom: 0; font-size: 0.92rem; color: var(--color-ink-soft); }
.provider-card { border-top: 3px solid var(--color-blue); }

/* ---------- Tables ---------- */
.table-wrapper { overflow-x: auto; margin: 1.5rem 0 2rem; border-radius: var(--radius-md); border: 1px solid var(--color-border); }
table { border-collapse: collapse; width: 100%; min-width: 560px; background: var(--color-surface); }
caption { caption-side: top; text-align: left; padding: 0.9rem 1.1rem; font-weight: 600; font-family: var(--font-display); background: var(--color-surface-2); }
th, td { padding: 0.85rem 1.1rem; text-align: left; border-top: 1px solid var(--color-border); font-size: 0.92rem; }
thead th { background: var(--color-surface-2); font-family: var(--font-mono); font-size: 0.75rem; text-transform: uppercase; letter-spacing: 0.05em; color: var(--color-ink-soft); }
tbody th { font-weight: 600; }
.th-sub { display: block; font-weight: 400; font-size: 0.78rem; color: var(--color-ink-soft); }

/* ---------- Definition grid ---------- */
.definition-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 1rem;
  margin: 1.5rem 0 2rem;
}
.definition-item {
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: 1.1rem 1.3rem;
  background: var(--color-surface);
}
.definition-item dt { font-family: var(--font-display); font-weight: 700; margin-bottom: 0.4rem; }
.definition-item dd { margin: 0; color: var(--color-ink-soft); font-size: 0.92rem; }

/* ---------- Checklist ---------- */
.checklist { list-style: none; padding: 0; }
.checklist li {
  position: relative;
  padding-left: 1.75rem;
}
.checklist li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.35rem;
  width: 16px;
  height: 16px;
  border-radius: 5px;
  background: var(--color-blue-tint);
  border: 1.5px solid var(--color-blue);
}
.checklist li::after {
  content: "✓";
  position: absolute;
  left: 2px;
  top: 0.15rem;
  font-size: 0.72rem;
  font-weight: 700;
  color: var(--color-blue);
}

/* ---------- Pull quote ---------- */
.pull-quote {
  margin: 2rem 0;
  padding: 1.5rem 1.75rem;
  border-left: 4px solid var(--color-amber);
  background: var(--color-amber-tint);
  border-radius: var(--radius-md);
  font-family: var(--font-display);
  font-size: 1.15rem;
  font-weight: 600;
  line-height: 1.5;
}
.pull-quote p { margin: 0; }

/* ---------- Service cards ---------- */
.service-list {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 1rem;
  margin: 1.5rem 0 2rem;
}
.service-card {
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: 1.3rem 1.4rem;
  background: var(--color-surface);
  transition: box-shadow 0.18s ease, transform 0.18s ease;
}
.service-card:hover { box-shadow: var(--shadow-card-hover); transform: translateY(-2px); }
.service-card h3 {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  flex-wrap: wrap;
  font-size: 1.02rem;
}
.service-tag {
  font-family: var(--font-mono);
  font-size: 0.68rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  background: var(--color-blue-tint);
  color: var(--color-blue-dark);
  padding: 0.2rem 0.55rem;
  border-radius: 999px;
  font-weight: 600;
}
.service-card .analogy {
  font-style: italic;
  color: var(--color-ink-soft);
  font-size: 0.88rem;
  margin-bottom: 0.6rem;
}
.service-card p { font-size: 0.92rem; }
.service-card .use-case { margin-bottom: 0; font-size: 0.88rem; color: var(--color-ink-soft); }

/* ---------- Career list ---------- */
.career-list { display: flex; flex-direction: column; gap: 0.75rem; margin: 1.5rem 0 2rem; }
.career-item {
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  background: var(--color-surface);
  padding: 0.2rem 1.3rem;
}
.career-item summary {
  cursor: pointer;
  font-family: var(--font-display);
  font-weight: 700;
  padding: 1rem 0;
  list-style: none;
  display: flex;
  align-items: center;
  justify-content: space-between;
}
.career-item summary::-webkit-details-marker { display: none; }
.career-item summary::after {
  content: "+";
  font-size: 1.2rem;
  color: var(--color-blue);
  transition: transform 0.2s ease;
}
.career-item[open] summary::after { transform: rotate(45deg); }
.career-item p { font-size: 0.9rem; }
.career-item p:last-child { padding-bottom: 1rem; }

/* ---------- Roadmap ---------- */
.roadmap {
  list-style: none;
  padding: 0;
  margin: 1.75rem 0 2rem;
  display: flex;
  flex-direction: column;
  gap: 0;
  counter-reset: step;
}
.roadmap li { position: relative; padding: 0 0 1.6rem 2.6rem; margin: 0; }
.roadmap li::before {
  counter-increment: step;
  content: counter(step);
  position: absolute;
  left: 0;
  top: 0;
  width: 1.9rem;
  height: 1.9rem;
  border-radius: 50%;
  background: var(--color-blue);
  color: #fff;
  font-family: var(--font-mono);
  font-size: 0.8rem;
  font-weight: 600;
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 1;
}
.roadmap li:not(:last-child)::after {
  content: "";
  position: absolute;
  left: 0.95rem;
  top: 1.9rem;
  bottom: -0.1rem;
  width: 2px;
  background: var(--color-border);
}
.roadmap-step {
  display: inline-block;
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  padding: 0.6rem 1rem;
  font-weight: 600;
  font-size: 0.94rem;
}

/* ---------- Quiz ---------- */
.quiz-box { display: flex; flex-direction: column; gap: 0.75rem; margin: 1.5rem 0 2rem; }
.quiz-item {
  border: 1px dashed var(--color-blue);
  border-radius: var(--radius-md);
  background: var(--color-blue-tint);
  padding: 0.2rem 1.2rem;
}
.quiz-item summary {
  cursor: pointer;
  font-weight: 600;
  padding: 0.9rem 0;
  list-style: none;
}
.quiz-item summary::-webkit-details-marker { display: none; }
.quiz-item summary::before { content: "Q · "; color: var(--color-blue-dark); font-family: var(--font-mono); }
.quiz-item p { font-size: 0.9rem; padding-bottom: 0.9rem; margin: 0; }

/* ---------- Footer ---------- */
.site-footer {
  text-align: center;
  padding: 2.5rem 1.5rem 3.5rem;
  color: var(--color-ink-soft);
  font-size: 0.88rem;
  border-top: 1px solid var(--color-border);
}
.site-footer p { margin: 0.3rem 0; }

/* ---------- Responsive ---------- */
@media (max-width: 960px) {
  .hero { grid-template-columns: 1fr; }
  .content-shell { grid-template-columns: 1fr; }
  .toc { display: none; }
  .card-grid, .card-grid.three-col, .service-list, .definition-grid {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 560px) {
  .hero { padding: 2.5rem 1.25rem 2rem; }
  .content-shell { padding: 0 1.25rem 3rem; }
  .hero-meta { gap: 1rem 1.5rem; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  * { transition: none !important; animation: none !important; }
}