/* =========================================================================
   AzureCraft design system
   Dark-first, with automatic light mode via prefers-color-scheme.
   ========================================================================= */

:root {
  /* Palette (dark) */
  --bg: #0b1120;
  --bg-elevated: #111a2e;
  --surface: #131d33;
  --surface-2: #0f1830;
  --border: #1f2b45;
  --border-strong: #2c3b5c;
  --text: #e6edf7;
  --text-muted: #9fb0c9;
  --heading: #f3f7fd;
  --accent: #38bdf8;
  --accent-strong: #0ea5e9;
  --accent-2: #818cf8;
  --accent-contrast: #04121f;
  --code-bg: #0a1426;
  --shadow: 0 10px 30px -12px rgba(0, 0, 0, 0.6);
  --shadow-card: 0 8px 24px -16px rgba(0, 0, 0, 0.7);

  /* Type scale */
  --font-sans: "Segoe UI", system-ui, -apple-system, BlinkMacSystemFont, "Helvetica Neue", Arial, sans-serif;
  --font-mono: ui-monospace, SFMono-Regular, "Cascadia Code", Consolas, "Liberation Mono", monospace;
  --step--1: clamp(0.83rem, 0.8rem + 0.15vw, 0.9rem);
  --step-0: clamp(1.06rem, 1rem + 0.3vw, 1.18rem);
  --step-1: clamp(1.27rem, 1.18rem + 0.45vw, 1.5rem);
  --step-2: clamp(1.6rem, 1.4rem + 0.9vw, 2.1rem);
  --step-3: clamp(2rem, 1.6rem + 1.8vw, 3rem);

  /* Spacing + layout */
  --space-1: 0.5rem;
  --space-2: 1rem;
  --space-3: 1.5rem;
  --space-4: 2.5rem;
  --space-5: 4rem;
  --radius: 14px;
  --radius-sm: 9px;
  --content-width: 1120px;
  --prose-width: 72ch;
}

@media (prefers-color-scheme: light) {
  :root {
    --bg: #f6f8fc;
    --bg-elevated: #ffffff;
    --surface: #ffffff;
    --surface-2: #f1f5fb;
    --border: #e1e8f2;
    --border-strong: #cdd8e8;
    --text: #1b2538;
    --text-muted: #51607a;
    --heading: #0d1626;
    --accent: #0369a1;
    --accent-strong: #0c87c9;
    --accent-2: #4f46e5;
    --accent-contrast: #ffffff;
    --code-bg: #0d1726;
    --shadow: 0 12px 30px -18px rgba(15, 23, 42, 0.35);
    --shadow-card: 0 10px 26px -18px rgba(15, 23, 42, 0.3);
  }
}

/* ----------------------------------------------------------------- Base */

*,
*::before,
*::after {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  font-family: var(--font-sans);
  font-size: var(--step-0);
  line-height: 1.7;
  background:
    radial-gradient(1200px 600px at 80% -10%, rgba(56, 189, 248, 0.10), transparent 60%),
    radial-gradient(900px 500px at -10% 0%, rgba(129, 140, 248, 0.10), transparent 55%),
    var(--bg);
  color: var(--text);
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

a {
  color: var(--accent);
  text-decoration: none;
}

a:hover {
  text-decoration: underline;
}

img {
  max-width: 100%;
  height: auto;
}

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

.skip-link {
  position: absolute;
  left: -999px;
  top: 0;
  background: var(--accent);
  color: var(--accent-contrast);
  padding: 0.6rem 1rem;
  border-radius: 0 0 8px 0;
  z-index: 100;
}
.skip-link:focus {
  left: 0;
}

.container {
  width: min(100% - 2.5rem, var(--content-width));
  margin-inline: auto;
}

/* ------------------------------------------------------ Reading progress */

.reading-progress {
  position: fixed;
  top: 0;
  left: 0;
  height: 3px;
  width: 0;
  background: linear-gradient(90deg, var(--accent), var(--accent-2));
  z-index: 60;
  transition: width 0.1s linear;
}

/* --------------------------------------------------------------- Header */

.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  background: color-mix(in srgb, var(--bg) 82%, transparent);
  backdrop-filter: saturate(150%) blur(10px);
  border-bottom: 1px solid var(--border);
}

.site-nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-2);
  padding-block: 0.9rem;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 0.75rem;
  color: inherit;
}
.brand:hover {
  text-decoration: none;
}

.brand-mark {
  display: grid;
  place-items: center;
  width: 40px;
  height: 40px;
  border-radius: 11px;
  background: linear-gradient(135deg, var(--accent), var(--accent-2));
  color: var(--accent-contrast);
  font-weight: 800;
  letter-spacing: 0.5px;
  box-shadow: var(--shadow-card);
}

.brand-text-title {
  font-weight: 700;
  color: var(--heading);
  line-height: 1.1;
}
.brand-text-sub {
  font-size: var(--step--1);
  color: var(--text-muted);
}

.site-nav__links {
  display: flex;
  align-items: center;
  gap: 0.4rem;
}

.site-nav__links a {
  color: var(--text-muted);
  padding: 0.45rem 0.75rem;
  border-radius: 8px;
  font-weight: 600;
  font-size: 0.98rem;
}
.site-nav__links a:hover,
.site-nav__links a[aria-current="page"] {
  color: var(--heading);
  background: var(--surface-2);
  text-decoration: none;
}

.nav-toggle {
  display: none;
  background: var(--surface-2);
  border: 1px solid var(--border);
  color: var(--text);
  width: 42px;
  height: 42px;
  border-radius: 10px;
  font-size: 1.2rem;
  cursor: pointer;
}

/* ----------------------------------------------------------------- Hero */

.hero {
  padding-block: clamp(2.5rem, 6vw, 5rem) clamp(2rem, 4vw, 3.5rem);
}

.hero__eyebrow {
  display: inline-block;
  font-size: var(--step--1);
  font-weight: 700;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--accent);
  margin-bottom: 0.75rem;
}

.hero h1 {
  font-size: var(--step-3);
  line-height: 1.05;
  margin: 0 0 1rem;
  color: var(--heading);
  letter-spacing: -0.02em;
}

.hero p {
  max-width: 60ch;
  font-size: var(--step-1);
  color: var(--text-muted);
  margin: 0 0 1.75rem;
}

.hero__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
}

.btn {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.7rem 1.2rem;
  border-radius: 10px;
  font-weight: 700;
  border: 1px solid transparent;
  cursor: pointer;
}
.btn--primary {
  background: linear-gradient(135deg, var(--accent), var(--accent-strong));
  color: var(--accent-contrast);
}
.btn--primary:hover {
  text-decoration: none;
  filter: brightness(1.05);
}
.btn--ghost {
  border-color: var(--border-strong);
  color: var(--text);
}
.btn--ghost:hover {
  text-decoration: none;
  border-color: var(--accent);
  color: var(--heading);
}

/* --------------------------------------------------------- Section head */

.section {
  padding-block: clamp(2rem, 4vw, 3.5rem);
}

.section__head {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 1rem;
  margin-bottom: var(--space-3);
}

.section__head h2 {
  font-size: var(--step-2);
  color: var(--heading);
  margin: 0;
  letter-spacing: -0.01em;
}

.section__head p {
  margin: 0.3rem 0 0;
  color: var(--text-muted);
}

/* -------------------------------------------------------------- Cards */

.card-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(290px, 1fr));
  gap: var(--space-3);
}

.card {
  display: flex;
  flex-direction: column;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: var(--space-3);
  box-shadow: var(--shadow-card);
  transition: transform 0.16s ease, border-color 0.16s ease, box-shadow 0.16s ease;
}
.card:hover {
  transform: translateY(-4px);
  border-color: var(--border-strong);
  box-shadow: var(--shadow);
}

.card__meta {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  align-items: center;
  font-size: var(--step--1);
  color: var(--text-muted);
  margin-bottom: 0.75rem;
}

.card h3 {
  margin: 0 0 0.5rem;
  font-size: var(--step-1);
  line-height: 1.25;
  color: var(--heading);
}
.card h3 a {
  color: inherit;
}
.card h3 a:hover {
  color: var(--accent);
  text-decoration: none;
}

.card p {
  margin: 0 0 1rem;
  color: var(--text-muted);
}

.card__cta {
  margin-top: auto;
  font-weight: 700;
  color: var(--accent);
}

.tag {
  display: inline-block;
  padding: 0.2rem 0.6rem;
  border-radius: 999px;
  font-size: 0.78rem;
  font-weight: 700;
  letter-spacing: 0.02em;
  background: color-mix(in srgb, var(--accent) 16%, transparent);
  color: var(--accent);
  border: 1px solid color-mix(in srgb, var(--accent) 30%, transparent);
}
.tag--infra { background: color-mix(in srgb, #38bdf8 16%, transparent); color: #38bdf8; border-color: color-mix(in srgb, #38bdf8 30%, transparent); }
.tag--ai    { background: color-mix(in srgb, #818cf8 16%, transparent); color: #a5b0ff; border-color: color-mix(in srgb, #818cf8 32%, transparent); }
.tag--apps  { background: color-mix(in srgb, #34d399 16%, transparent); color: #34d399; border-color: color-mix(in srgb, #34d399 30%, transparent); }

/* ----------------------------------------------------------- Roadmap */

.roadmap-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 0.75rem;
}
.roadmap-list li {
  display: flex;
  gap: 0.85rem;
  align-items: flex-start;
  background: var(--surface-2);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  padding: 0.9rem 1.1rem;
}
.roadmap-list li::before {
  content: "→";
  color: var(--accent);
  font-weight: 800;
  line-height: 1.6;
}
.roadmap-list strong {
  color: var(--heading);
}

/* ----------------------------------------------------- Article layout */

.article-wrap {
  padding-block: clamp(2rem, 4vw, 3.5rem);
}

.article-header {
  width: min(100% - 2.5rem, var(--content-width));
  margin-inline: auto;
  margin-bottom: var(--space-3);
}

.breadcrumb {
  font-size: var(--step--1);
  color: var(--text-muted);
  margin-bottom: 1rem;
}

.article-header h1 {
  font-size: var(--step-3);
  line-height: 1.08;
  letter-spacing: -0.02em;
  color: var(--heading);
  margin: 0.4rem 0 0.9rem;
  max-width: 20ch;
}

.article-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem 1rem;
  align-items: center;
  color: var(--text-muted);
  font-size: var(--step--1);
}
.article-meta .dot {
  opacity: 0.5;
}

.prose {
  width: min(100% - 2.5rem, var(--prose-width));
  margin-inline: auto;
}

.prose > * + * {
  margin-top: 1.2em;
}

.prose h2 {
  font-size: var(--step-2);
  color: var(--heading);
  margin-top: 2.2em;
  letter-spacing: -0.01em;
  scroll-margin-top: 90px;
}
.prose h3 {
  font-size: var(--step-1);
  color: var(--heading);
  margin-top: 1.8em;
  scroll-margin-top: 90px;
}

.prose p,
.prose li {
  color: var(--text);
}

.prose ul,
.prose ol {
  padding-left: 1.3em;
}
.prose li + li {
  margin-top: 0.4em;
}

.prose a {
  text-decoration: underline;
  text-underline-offset: 3px;
  text-decoration-color: color-mix(in srgb, var(--accent) 45%, transparent);
}

.prose blockquote {
  margin: 1.6em 0;
  padding: 0.4em 1.2em;
  border-left: 4px solid var(--accent);
  background: var(--surface-2);
  border-radius: 0 10px 10px 0;
  color: var(--text);
  font-style: italic;
}

.prose code {
  font-family: var(--font-mono);
  font-size: 0.92em;
  background: var(--surface-2);
  border: 1px solid var(--border);
  padding: 0.12em 0.4em;
  border-radius: 6px;
}

.prose pre {
  background: var(--code-bg);
  border: 1px solid var(--border-strong);
  border-radius: 12px;
  padding: 1.1rem 1.2rem;
  overflow-x: auto;
  color: #d7e3f4;
  font-size: 0.92rem;
  line-height: 1.55;
}
.prose pre code {
  background: none;
  border: none;
  padding: 0;
  font-size: inherit;
}

/* Figures + diagrams */
.figure {
  margin: 2em 0;
}
.figure img {
  display: block;
  width: 100%;
  background: #ffffff;
  border: 1px solid var(--border-strong);
  border-radius: 12px;
  padding: 1rem;
}
.figure figcaption {
  margin-top: 0.6rem;
  font-size: var(--step--1);
  color: var(--text-muted);
  text-align: center;
}

/* Callouts */
.callout {
  display: flex;
  gap: 0.85rem;
  margin: 1.7em 0;
  padding: 1rem 1.15rem;
  border-radius: 12px;
  border: 1px solid var(--border-strong);
  background: var(--surface-2);
}
.callout__icon {
  font-size: 1.2rem;
  line-height: 1.5;
}
.callout p {
  margin: 0;
}
.callout strong {
  color: var(--heading);
}
.callout--tip { border-color: color-mix(in srgb, #34d399 40%, var(--border)); }
.callout--note { border-color: color-mix(in srgb, var(--accent) 40%, var(--border)); }
.callout--warn { border-color: color-mix(in srgb, #fbbf24 45%, var(--border)); }

/* Key-takeaways box */
.takeaways {
  margin: 2em 0;
  padding: 1.25rem 1.4rem;
  border: 1px solid var(--border-strong);
  border-radius: 14px;
  background: linear-gradient(180deg, var(--surface), var(--surface-2));
}
.takeaways h2 {
  margin: 0 0 0.6rem;
  font-size: var(--step-1);
}

/* Article footer nav */
.post-nav {
  width: min(100% - 2.5rem, var(--prose-width));
  margin: var(--space-4) auto 0;
  display: flex;
  justify-content: space-between;
  gap: 1rem;
  flex-wrap: wrap;
  border-top: 1px solid var(--border);
  padding-top: var(--space-3);
}
.post-nav a {
  font-weight: 700;
}

/* ----------------------------------------------------------- Newsletter */

.cta-band {
  margin-block: var(--space-4);
  padding: clamp(1.5rem, 4vw, 2.75rem);
  border-radius: 18px;
  border: 1px solid var(--border-strong);
  background:
    radial-gradient(600px 300px at 100% 0%, rgba(129, 140, 248, 0.18), transparent 60%),
    linear-gradient(180deg, var(--surface), var(--surface-2));
  text-align: center;
}
.cta-band h2 {
  margin: 0 0 0.5rem;
  color: var(--heading);
  font-size: var(--step-2);
}
.cta-band p {
  margin: 0 auto 1.4rem;
  max-width: 52ch;
  color: var(--text-muted);
}
.cta-form {
  display: flex;
  flex-wrap: wrap;
  gap: 0.6rem;
  justify-content: center;
}
.cta-form input {
  flex: 1 1 260px;
  max-width: 340px;
  padding: 0.7rem 0.9rem;
  border-radius: 10px;
  border: 1px solid var(--border-strong);
  background: var(--bg-elevated);
  color: var(--text);
  font-size: 1rem;
}

.cta-status {
  margin: 0.85rem 0 0;
  text-align: center;
  font-size: var(--step--1);
  min-height: 1.2em;
  color: var(--text-muted);
}
.cta-status[data-kind="error"] { color: #f87171; }
.cta-status[data-kind="success"] { color: #34d399; }

/* ----------------------------------------------------- Category chips */

.cat-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: var(--space-3);
}
.cat-card {
  display: block;
  padding: var(--space-3);
  border-radius: var(--radius);
  border: 1px solid var(--border);
  background: var(--surface);
  box-shadow: var(--shadow-card);
  transition: transform 0.16s ease, border-color 0.16s ease;
}
.cat-card:hover {
  text-decoration: none;
  transform: translateY(-4px);
  border-color: var(--border-strong);
}
.cat-card h3 {
  margin: 0.75rem 0 0.35rem;
  color: var(--heading);
  font-size: var(--step-1);
}
.cat-card p {
  margin: 0;
  color: var(--text-muted);
}

/* --------------------------------------------------------------- Footer */

.site-footer {
  margin-top: var(--space-5);
  border-top: 1px solid var(--border);
  background: var(--surface-2);
}
.site-footer__inner {
  display: grid;
  gap: var(--space-3);
  grid-template-columns: 1.4fr 1fr 1fr;
  padding-block: var(--space-4);
}
.site-footer h4 {
  color: var(--heading);
  margin: 0 0 0.75rem;
  font-size: 0.95rem;
  text-transform: uppercase;
  letter-spacing: 0.08em;
}
.site-footer ul {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 0.45rem;
}
.site-footer a {
  color: var(--text-muted);
}
.site-footer a:hover {
  color: var(--heading);
}
.site-footer__bottom {
  border-top: 1px solid var(--border);
  padding-block: 1.2rem;
  text-align: center;
  color: var(--text-muted);
  font-size: var(--step--1);
}

/* --------------------------------------------------------- Responsive */

@media (max-width: 760px) {
  .nav-toggle {
    display: inline-block;
  }
  .site-nav__links {
    position: absolute;
    top: 100%;
    right: 1.25rem;
    left: 1.25rem;
    flex-direction: column;
    align-items: stretch;
    gap: 0.25rem;
    padding: 0.6rem;
    background: var(--bg-elevated);
    border: 1px solid var(--border);
    border-radius: 12px;
    box-shadow: var(--shadow);
    display: none;
  }
  .site-nav__links.is-open {
    display: flex;
  }
  .site-footer__inner {
    grid-template-columns: 1fr;
  }
}