/* --------- Style for Stata & Stats Tutorials --------- */
:root{
  --bg:#0b0c10;
  --bg-alt:#0f1117;
  --card:#151823;
  --ink:#e6e9ef;
  --muted:#aab0bf;
  --brand:#8ab4f8;
  --brand-ink:#0b1324;
  --ring:#8ab4f869;
  --surface:#0c0f17;
  --border:#1e2436;
  --shadow:0 10px 25px rgba(0,0,0,.35);
}

*{box-sizing:border-box}
html,body{height:100%}
body{
  margin:0;
  color:var(--ink);
  background: radial-gradient(1200px 600px at 20% -10%, #1a2030 0%, #0b0c10 55%);
  font: 400 16px/1.7 Inter, system-ui, -apple-system, Segoe UI, Roboto, Arial, "Noto Sans", "Apple Color Emoji", "Segoe UI Emoji";
}

/* Layout helpers */
.container{width:min(1120px,92%);margin-inline:auto}
.section{padding:4.5rem 0}
.section.alt{background:var(--bg-alt)}
.section-header{text-align:center;margin-bottom:2rem}
.grid{display:grid;gap:1.25rem}
.grid.cards{grid-template-columns:repeat(auto-fit,minmax(280px,1fr))}
.grid.two{grid-template-columns:repeat(auto-fit,minmax(320px,1fr))}
.eyebrow{color:var(--muted);text-transform:uppercase;letter-spacing:.08em;font-size:.8rem;margin:0 0 .25rem}
.text-link{color:var(--brand);text-decoration:none}
.text-link:hover{text-decoration:underline}

/* Accessibility */
.skip-link{position:absolute;left:-999rem;top:auto}
.skip-link:focus{left:.5rem;top:.5rem;background:#fff;color:#111;padding:.5rem .75rem;border-radius:.5rem}

/* Header */
.site-header{position:sticky;top:0;backdrop-filter:blur(8px);background:#0b0c10cc;border-bottom:1px solid #1f2433;z-index:10}
.header-inner{display:flex;align-items:center;justify-content:space-between;padding:.85rem 0}
.brand{font-weight:800;letter-spacing:.3px;color:var(--ink);text-decoration:none;font-size:1.15rem}
.nav ul{display:flex;list-style:none;gap:1rem;margin:0;padding:0}
.nav a{color:var(--muted);text-decoration:none;padding:.35rem .5rem;border-radius:.5rem}
.nav a:hover,.nav a:focus{color:var(--ink);background:#ffffff11}

/* Hero */
.hero{padding:6rem 0 4rem;background:radial-gradient(800px 400px at 70% 0%, #1b2436 0%, transparent 60%)}
.hero h1{font-size:clamp(2rem,2.6vw + 1rem,3rem);line-height:1.15;margin:0 0 .75rem}
.hero p{color:var(--muted);max-width:48ch;margin:0 0 1.5rem}
.cta-row{display:flex;gap:.75rem}
.btn{display:inline-block;padding:.7rem 1rem;border-radius:.75rem;text-decoration:none;font-weight:600;border:1px solid #2a3350;box-shadow:var(--shadow)}
.btn.primary{background:var(--brand);color:var(--brand-ink);border-color:transparent}
.btn.primary:hover{filter:brightness(1.05)}
.btn.ghost{color:var(--ink);background:#ffffff12}
.btn.ghost:hover{background:#ffffff18}

/* Cards */
.card{background:linear-gradient(180deg,#151823 0%,#121623 100%);border:1px solid var(--border);border-radius:1rem;padding:1.1rem;box-shadow:var(--shadow);display:flex;flex-direction:column;gap:.6rem}
.card h3{margin:0 0 .25rem;font-size:1.12rem}
.card pre{background:var(--surface);color:#dfe6ff;padding:.85rem;border-radius:.75rem;overflow:auto;border:1px solid #1c2131}

/* Code (readable, monospace) */
pre,code,kbd,samp{font-family:"JetBrains Mono", ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, "Liberation Mono", "Courier New", monospace;font-size:.92rem}
code{background:#ffffff10;padding:.08rem .35rem;border-radius:.35rem;border:1px solid #1c2131}
pre code{background:transparent;border:none;padding:0}

/* Snippets */
.snippet pre{background:var(--surface);border:1px solid #1c2131;padding:.85rem;border-radius:.75rem}

/* Checklist bullets */
.checks{list-style:none;padding-left:0;margin:0}
.checks li{position:relative;padding-left:1.6rem;margin:.5rem 0}
.checks li::before{content:"✓";position:absolute;left:.35rem;top:.05rem;opacity:.7}

/* Newsletter */
.newsletter{display:grid;gap:.6rem;max-width:520px}
.newsletter label{font-weight:600}
.newsletter input{padding:.72rem .85rem;background:#0e1220;border:1px solid #262c44;color:var(--ink);border-radius:.6rem}
.newsletter input:focus{outline:none;border-color:var(--brand);box-shadow:0 0 0 .25rem var(--ring)}
.newsletter .form-hint{color:var(--muted);font-size:.9rem}

/* Footer */
.site-footer{border-top:1px solid #1f2433;background:#0b0c10}
.footer-inner{display:flex;align-items:center;justify-content:space-between;padding:2rem 0}
.site-footer ul{list-style:none;display:flex;gap:1rem;margin:0;padding:0}
.site-footer a{color:var(--muted);text-decoration:none}
.site-footer a:hover{color:var(--ink)}

/* Responsive */
@media (max-width: 720px){
  .cta-row{flex-direction:column;align-items:flex-start}
  .footer-inner{flex-direction:column;gap:.75rem}
}