/* ========== CSS RESET (lightweight) ========== */
*,
*::before,
*::after { box-sizing: border-box; }
html, body { margin: 0; padding: 0; }
img { max-width: 100%; height: auto; display: block; }
ul, ol { padding-left: 1.25rem; }

/* ========== THEME ========== */
:root {
  --bg: #f9f9fb;
  --card: #ffffff;
  --text: #1f2937;
  --muted: #6b7280;

  --brand: #0ea5e9;     /* cyan-ish accent for links */
  --brand-strong: #0284c7;

  --accent: #fb923c;    /* your original orange header/nav */
  --accent-strong: #f97316;

  --border: #e5e7eb;
  --ring: rgba(14,165,233,0.3);

  --radius: 10px;
  --shadow: 0 1px 2px rgba(0,0,0,0.04), 0 8px 24px rgba(0,0,0,0.06);
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #0b0e14;
    --card: #121826;
    --text: #e5e7eb;
    --muted: #9ca3af;

    --brand: #38bdf8;
    --brand-strong: #0ea5e9;

    --accent: #fb923c;
    --accent-strong: #f59e0b;

    --border: #1f2937;
    --ring: rgba(56,189,248,0.25);
    --shadow: 0 1px 2px rgba(0,0,0,0.4), 0 8px 24px rgba(0,0,0,0.3);
  }
}

/* ========== GLOBAL ========== */
html { color-scheme: light dark; }
body {
  background: var(--bg);
  color: var(--text);
  font: 16px/1.6 system-ui, -apple-system, Segoe UI, Roboto, Arial, sans-serif;
}

/* Container */
.container {
  width: min(1100px, 92vw);
  margin-inline: auto;
}

/* Skip link */
.skip-link {
  position: absolute;
  left: -9999px;
  top: 0;
  background: var(--brand);
  color: white;
  padding: 8px 12px;
  border-radius: 6px;
}
.skip-link:focus {
  left: 12px;
  top: 12px;
  outline: 3px solid var(--ring);
}

/* ========== HEADER & NAV ========== */
.site-header {
  background: linear-gradient(180deg, var(--accent-strong), var(--accent));
  color: white;
  padding: 2.2rem 0 1.6rem;
  border-bottom: 1px solid rgba(255,255,255,0.15);
}
.site-title {
  margin: 0 0 0.25rem;
  font-size: clamp(1.4rem, 1rem + 2vw, 2rem);
  letter-spacing: 0.2px;
}
.site-tagline {
  margin: 0;
  opacity: 0.9;
}

.site-nav {
  background: var(--accent);
  border-bottom: 1px solid rgba(0,0,0,0.08);
}
.nav-list {
  list-style: none;
  margin: 0;
  padding: 0.65rem 0;
  display: flex;
  gap: 1rem;
  flex-wrap: wrap;
}
.nav-list a {
  color: #fff;
  text-decoration: none;
  font-weight: 600;
  padding: 0.4rem 0.6rem;
  border-radius: 8px;
}
.nav-list a:hover,
.nav-list a:focus {
  background: rgba(255,255,255,0.15);
  outline: none;
}

/* ========== MAIN SECTIONS ========== */
.section {
  background: var(--card);
  margin-block: 1.4rem;
  padding: 1.2rem 1.2rem 1rem;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
}

.section-header {
  margin-bottom: 0.6rem;
  border-bottom: 2px solid var(--brand);
  padding-bottom: 0.4rem;
}

h2 {
  margin: 0;
  font-size: clamp(1.1rem, 1rem + 1vw, 1.5rem);
}

h3, h4 { margin-top: 1rem; }

/* Lists */
.bullets li + li,
.checklist li + li,
.ordered li + li {
  margin-top: 0.25rem;
}

/* Definition list for APIs */
.definition-list {
  margin: 0;
}
.definition-list dt {
  font-weight: 700;
  margin-top: 0.6rem;
}
.definition-list dd {
  margin: 0.2rem 0 0.6rem 0;
  color: var(--muted);
}

/* Figures & media */
.figure {
  margin: 1rem 0;
}
.figure img {
  border: 1px solid var(--border);
  border-radius: 8px;
}
.figure figcaption {
  margin-top: 0.4rem;
  color: var(--muted);
  font-size: 0.9rem;
}

.media-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1rem;
}
@media (min-width: 680px) {
  .media-grid { grid-template-columns: 1fr 1fr; }
}

/* Code blocks */
.code-block {
  background: #0b1020;
  color: #e6edf3;
  border-radius: 10px;
  border: 1px solid #0f172a;
  padding: 1rem;
  overflow-x: auto;
}
@media (prefers-color-scheme: light) {
  .code-block {
    background: #f6f8fa;
    color: #0f172a;
    border-color: var(--border);
  }
}

/* Notes & checklists */
.note {
  color: var(--muted);
  margin-top: 0.6rem;
}
.checklist {
  list-style: none;
  padding-left: 1.6rem;
  position: relative;
}
.checklist li {
  position: relative;
}
.checklist li::before {
  content: "✓";
  position: absolute;
  left: -1.6rem;
  top: 0;
  color: var(--brand-strong);
  font-weight: 700;
}

/* ========== FOOTER ========== */
.site-footer {
  margin-top: 2rem;
  border-top: 1px solid var(--border);
  background: transparent;
  color: var(--muted);
  padding: 1rem 0 2rem;
  text-align: center;
}

/* ========== PRINT ========== */
@media print {
  .site-nav, .site-tagline, .skip-link { display: none !important; }
  .section { box-shadow: none; border-color: #bbb; }
}