/*
  Tutorials Design System (SigLabs)
  - Lightweight, responsive, accessible
  - Commercial yet clean; optimized for readability and conversion
*/

:root {
  --bg: #0f1226;
  --panel: #161a35;
  --panel-2: #1d2248;
  --text: #e9ecff;
  --muted: #b6bce5;
  --brand: #6c8cff;
  --brand-2: #7de1d1;
  --accent: #ffd166;
  --error: #ff6b6b;
  --code-bg: #0c0f1f;
  --code-border: #2a2f55;
  --shadow: 0 10px 30px rgba(0,0,0,0.3);
  --radius: 14px;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  font-family: ui-sans-serif, system-ui, -apple-system, Segoe UI, Roboto, Arial, "Apple Color Emoji", "Segoe UI Emoji";
  color: var(--text);
  background: linear-gradient(180deg, var(--bg), #090b18);
}

img { max-width: 100%; display: block; }
a { color: var(--brand-2); text-decoration: none; }
a:hover { text-decoration: underline; }

.container { width: min(1100px, 92%); margin: 0 auto; }

.skip-link {
  position: absolute; left: -9999px; top: auto; width: 1px; height: 1px; overflow: hidden;
}
.skip-link:focus { left: 1rem; top: 1rem; width: auto; height: auto; padding: .5rem .75rem; background: var(--brand); color: #fff; border-radius: 8px; z-index: 1000; }

/* Header */
header.site-header {
  position: sticky; top: 0; z-index: 100;
  background: rgba(15, 18, 38, 0.85);
  backdrop-filter: blur(6px);
  border-bottom: 1px solid rgba(108, 140, 255, 0.15);
}
.nav {
  display: flex; align-items: center; justify-content: space-between; gap: 1rem;
  padding: .85rem 0;
}
.brand { display: flex; align-items: center; gap: .6rem; font-weight: 700; letter-spacing: .3px; }
.brand-badge {
  width: 34px; height: 34px; display: grid; place-items: center; border-radius: 10px;
  background: linear-gradient(135deg, var(--brand) 0%, var(--brand-2) 100%);
  color: #0d1024; font-weight: 800; box-shadow: var(--shadow);
}
.nav-links { display: flex; align-items: center; gap: 1rem; }
.nav-links a { color: var(--muted); font-weight: 600; padding: .5rem .65rem; border-radius: 8px; }
.nav-links a[aria-current="page"], .nav-links a:hover { color: var(--text); background: rgba(108, 140, 255, 0.15); text-decoration: none; }

.cta { display: inline-flex; align-items: center; gap: .6rem; padding: .7rem 1rem; border-radius: 10px; background: var(--brand); color: #0d1024; font-weight: 800; box-shadow: var(--shadow); }
.cta.secondary { background: var(--accent); }
.cta:hover { filter: brightness(1.05); text-decoration: none; }

/* Hero */
.hero {
  padding: 56px 0 26px;
}
.hero .panel {
  background: linear-gradient(180deg, var(--panel), var(--panel-2));
  border: 1px solid rgba(108, 140, 255, 0.18);
  border-radius: var(--radius);
  padding: 28px;
  box-shadow: var(--shadow);
}
.eyebrow { color: var(--brand-2); font-weight: 800; letter-spacing: .12em; text-transform: uppercase; font-size: .78rem; }
.hero h1 { font-size: clamp(1.8rem, 2.8vw + 1rem, 3rem); margin: .4rem 0 .6rem; line-height: 1.1; }
.sub { color: var(--muted); font-size: 1.05rem; }
.hero-cta { display: flex; gap: .8rem; flex-wrap: wrap; margin-top: 1rem; }

/* Grid */
.grid { display: grid; gap: 18px; }
.grid.cards { grid-template-columns: repeat(auto-fit, minmax(260px, 1fr)); margin: 26px 0 6px; }

.card {
  background: linear-gradient(180deg, #131733, #0e122b);
  border: 1px solid rgba(108, 140, 255, 0.12);
  border-radius: 14px;
  padding: 18px;
  box-shadow: var(--shadow);
}
.card h3 { margin: .2rem 0 .6rem; font-size: 1.05rem; }
.card p { color: var(--muted); margin: 0; }
.card .kicker { color: var(--brand-2); font-size: .8rem; font-weight: 800; text-transform: uppercase; letter-spacing: .14em; }

/* Content */
main { padding: 10px 0 60px; }
.content { display: grid; gap: 20px; }
.content h2 { margin-top: 1.2rem; }
.prose p { color: var(--muted); line-height: 1.7; }
.prose ul { color: var(--muted); line-height: 1.8; }

/* Code blocks */
pre, code { font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, "Liberation Mono", monospace; }
pre {
  background: var(--code-bg);
  border: 1px solid var(--code-border);
  border-radius: 12px;
  padding: 14px;
  overflow: auto;
}
code { color: #bce1ff; }

/* Promo */
.promo {
  margin: 30px 0; padding: 18px; border-radius: 14px;
  background: linear-gradient(135deg, rgba(108,140,255,0.18), rgba(125,225,209,0.18));
  border: 1px solid rgba(108,140,255,0.25);
}
.promo h3 { margin: .2rem 0 .4rem; }
.promo small { color: var(--muted); }

/* Footer */
footer {
  border-top: 1px solid rgba(108,140,255,0.12);
  background: #0b0e22;
  padding: 36px 0 60px;
}
.footer-grid { display: grid; gap: 12px; grid-template-columns: 1fr; }
.footer-grid strong { color: #fff; }
.legal { color: #92a0da; font-size: .9rem; }

/* Layout helpers */
.two-col { display: grid; grid-template-columns: 1.2fr 1fr; gap: 22px; }
.hidden-sm { display: block; }

@media (max-width: 900px) {
  .two-col { grid-template-columns: 1fr; }
  .hidden-sm { display: none; }
}

/* Table of contents */
.toc {
  position: sticky; top: 86px; align-self: start;
  background: #101431; border: 1px solid rgba(108,140,255,0.18); border-radius: 12px; padding: 14px;
}
.toc h4 { margin: 0 0 .4rem; font-size: .95rem; color: var(--brand-2); }
.toc a { display: block; padding: 6px 8px; color: var(--muted); border-radius: 8px; }
.toc a:hover { background: rgba(108,140,255,.12); color: var(--text); text-decoration: none; }

/* Badges */
.badge { display: inline-block; padding: 4px 8px; border-radius: 999px; background: rgba(125,225,209,0.12); color: var(--brand-2); font-weight: 700; font-size: .78rem; }

/* Lists with checks */
.checklist { list-style: none; padding-left: 0; }
.checklist li { position: relative; padding-left: 28px; margin: .4rem 0; }
.checklist li::before { content: "✔"; position: absolute; left: 0; color: var(--brand-2); }

/* Buttons bar */
.btn-row { display: flex; gap: .8rem; flex-wrap: wrap; }

/* Small utilities */
.muted { color: var(--muted); }
.center { text-align: center; }
.mt-2 { margin-top: .5rem; }
.mt-3 { margin-top: .9rem; }
.mt-4 { margin-top: 1.2rem; }
.mb-0 { margin-bottom: 0; }
.mb-2 { margin-bottom: .5rem; }
.mb-4 { margin-bottom: 1.2rem; }

/* Mobile nav (optional JS) */
.hamburger { display: none; background: none; border: 0; color: var(--text); font-size: 1.2rem; }
@media (max-width: 720px) {
  .nav-links { display: none; }
  .nav-links.open { display: flex; position: absolute; right: 4%; top: 62px; background: #0b0e22; padding: 10px; border-radius: 12px; border: 1px solid rgba(108,140,255,.2); box-shadow: var(--shadow); flex-direction: column; }
  .hamburger { display: inline-flex; }
}