/* ===========================
   Global base (site-wide)
   =========================== */

   :root {
    --bg: #f9fafb;
    --card: #ffffff;
    --text: #111827;
    --muted: #6b7280;
    --border: #e5e7eb;
    --primary: #111827;   /* dark charcoal */
    --primary-weak: rgba(17, 24, 39, 0.08);
    --radius: 12px;
    --gap: 16px;
    --container: 1100px;
  }
  
  *,
  *::before,
  *::after { box-sizing: border-box; }
  
  html { -webkit-text-size-adjust: 100%; }
  
  body {
    margin: 0;
    font-family: system-ui, -apple-system, Segoe UI, Roboto, "Helvetica Neue", Arial, "Noto Sans", sans-serif;
    color: var(--text);
    background: var(--bg);
    line-height: 1.5;
  }
  
  /* Links */
  a {
    color: var(--primary);
    text-decoration: none;
  }
  a:hover { text-decoration: underline; }
  
  /* Headings */
  h1, h2, h3 { margin: 0 0 12px; line-height: 1.2; }
  h1 { font-size: 1.5rem; }
  h2 { font-size: 1.25rem; }
  h3 { font-size: 1.1rem; }
  
  /* Container */
  .container {
    max-width: var(--container);
    margin: 0 auto;
    padding: 16px;
  }
  
  /* Header / Nav */
  .site-header {
    background: var(--card);
    border-bottom: 1px solid var(--border);
  }
  .navbar {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 12px;
    padding: 12px 0;
  }
  .brand {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    font-weight: 700;
    font-size: 1.05rem;
  }
  .nav {
    display: flex;
    gap: 12px;
  }
  .nav a {
    padding: 8px 10px;
    border-radius: 10px;
  }
  .nav a:hover {
    background: var(--primary-weak);
    text-decoration: none;
  }
  
  /* Cards / Sections */
  .card, .section {
    background: var(--card);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 16px;
  }
  .section + .section { margin-top: 16px; }
  
  /* Buttons */
  .button, button {
    appearance: none;
    border: 0;
    border-radius: 10px;
    padding: 12px 16px;
    font-weight: 600;
    cursor: pointer;
    background: var(--primary);
    color: #fff;
  }
  .button.secondary {
    background: #fff;
    color: var(--text);
    border: 1px solid var(--border);
  }
  button:disabled, .button:disabled { opacity: 0.6; cursor: not-allowed; }
  
  /* Grid helpers */
  .grid { display: grid; gap: var(--gap); }
  .grid-2 { grid-template-columns: 1fr; }
  @media (min-width: 768px) {
    .grid-2 { grid-template-columns: 1fr 1fr; }
  }
  
  /* Utilities */
  .muted { color: var(--muted); }
  .center { text-align: center; }
  .hidden { display: none !important; }
  .mt-1 { margin-top: 6px; }
  .mt-2 { margin-top: 12px; }
  .mt-3 { margin-top: 18px; }
  
  /* Footer */
  .site-footer {
    margin-top: 24px;
    padding: 16px 0 24px;
    color: var(--muted);
    border-top: 1px solid var(--border);
    background: transparent;
  }