@font-face {
    font-family: 'Inter';
    src: url('../fonts/inter-v20-latin-regular.woff2') format('woff2');
    font-weight: 400; font-style: normal; font-display: optional;
  }
  @font-face {
    font-family: 'Inter';
    src: url('../fonts/inter-v20-latin-600.woff2') format('woff2');
    font-weight: 600; font-style: normal; font-display: optional;
  }
  @font-face {
    font-family: 'Playfair Display';
    src: url('../fonts/playfair-display-v40-latin-700.woff2') format('woff2');
    font-weight: 700; font-style: normal; font-display: optional;
  }

  :root {
    --bg: #f3f3f7;
    --bg2: #ebebee;
    --bg3: #e4e4e4;
    --accent: #0066cc;
    --text: #191a1f;
    --muted: #66656a;
    --border: rgba(1,1,8,0.1);
    --border-accent: rgba(0,102,204,0.3);
    --mono: 'Inter', sans-serif;
    --sans: 'Playfair Display', serif;
  }

  *, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
  html { scroll-behavior: smooth; }
  body { background: var(--bg); color: var(--text); font-family: var(--mono); line-height: 1.7; overflow-x: hidden; font-size: 1rem; -webkit-font-smoothing: antialiased; }

  .skip-link { position: fixed; top: 1rem; left: 1rem; z-index: 200; transform: translateY(-160%); padding: 0.65rem 1rem; background: var(--accent); color: #fff; font-size: 0.78rem; font-weight: 600; text-decoration: none; transition: transform 0.2s; }
  .skip-link:focus { transform: translateY(0); }

  body::before { content: ''; position: fixed; inset: 0; background-image: linear-gradient(rgba(0,102,204,0.05) 1px, transparent 1px), linear-gradient(90deg, rgba(0,102,204,0.05) 1px, transparent 1px); background-size: 40px 40px; pointer-events: none; z-index: 0; }

  nav { position: fixed; top: 0; left: 0; right: 0; z-index: 100; display: flex; align-items: center; justify-content: space-between; padding: 1.2rem 3rem; background: rgba(248,248,250,0.92); backdrop-filter: blur(12px); border-bottom: 1px solid var(--border); }
  .nav-logo { font-family: var(--sans); font-weight: 800; font-size: 1.05rem; letter-spacing: 0.05em; color: var(--text); text-decoration: none; }
  .nav-logo span { color: var(--accent); }
  .nav-links { display: flex; gap: 2rem; list-style: none; align-items: center; }
  .nav-links a { color: var(--muted); text-decoration: none; font-size: 0.75rem; letter-spacing: 0.12em; text-transform: uppercase; transition: color 0.2s; }
  .nav-links a:hover { color: var(--accent); }
  a:focus-visible, button:focus-visible { outline: 3px solid var(--accent); outline-offset: 4px; border-radius: 8px; }
  .nav-cta { background: var(--accent) !important; color: #fff !important; padding: 0.5rem 1.1rem !important; border-radius: 4px; transition: opacity 0.2s, transform 0.15s !important; text-transform: none !important; letter-spacing: 0.04em !important; }
  .nav-cta:hover { opacity: 0.88 !important; transform: translateY(-1px); }

  .page-wrap { position: relative; z-index: 1; max-width: 780px; margin: 0 auto; padding: 9rem 3rem 6rem; }

  .back-link { display: inline-flex; align-items: center; gap: 0.4rem; font-size: 0.72rem; color: var(--muted); text-decoration: none; letter-spacing: 0.08em; margin-bottom: 2.5rem; transition: color 0.2s; }
  .back-link:hover { color: var(--accent); }

  .post-meta { display: flex; align-items: center; gap: 1rem; margin-bottom: 1.2rem; flex-wrap: wrap; }
  .post-tag { font-size: 0.62rem; padding: 0.18rem 0.55rem; border: 1px solid var(--border); color: var(--muted); letter-spacing: 0.06em; }

  h1 { font-family: var(--sans); font-size: clamp(1.8rem, 4vw, 2.8rem); font-weight: 800; line-height: 1.1; letter-spacing: -0.02em; color: var(--text); margin-bottom: 1rem; }

  .post-updated { font-size: 0.7rem; color: var(--muted); letter-spacing: 0.05em; margin: -2rem 0 3rem; display: inline-flex; align-items: center; gap: 0.5rem; }
  .post-updated::before { content: ''; width: 7px; height: 7px; border-radius: 50%; background: #1a7f4b; flex-shrink: 0; }
  .page-intro { font-size: 0.88rem; color: var(--muted); line-height: 1.9; margin-bottom: 3rem; max-width: 60ch; }
  .download-pdf { display: inline-flex; align-items: center; gap: 0.5rem; background: var(--accent); color: #fff; text-decoration: none; padding: 0.65rem 1.2rem; font-size: 0.8rem; font-weight: 600; letter-spacing: 0.02em; margin-bottom: 3rem; transition: opacity 0.2s, transform 0.15s; }
  .download-pdf:hover { opacity: 0.88; transform: translateY(-1px); }

  /* CHECKLIST SECTIONS */
  .checklist-section { margin-bottom: 3rem; }

  .checklist-section h2 {
    font-family: var(--sans); font-size: 1.1rem; font-weight: 700;
    color: var(--text); margin-bottom: 1rem; padding-bottom: 0.6rem;
    border-bottom: 1px solid var(--border);
    display: flex; align-items: center; gap: 0.75rem;
  }
  .section-letter {
    display: inline-flex; align-items: center; justify-content: center;
    width: 1.6rem; height: 1.6rem; background: var(--accent); color: #fff;
    font-size: 0.7rem; font-weight: 600; font-family: var(--mono);
    letter-spacing: 0.05em; flex-shrink: 0;
  }

  .checklist { list-style: none; display: flex; flex-direction: column; gap: 0.5rem; }
  .checklist li {
    display: flex; align-items: flex-start; gap: 0.75rem;
    font-size: 0.85rem; color: var(--muted); line-height: 1.7;
    padding: 0.6rem 0.8rem;
    background: var(--bg2); border: 1px solid var(--border);
    cursor: pointer;
    transition: border-color 0.15s;
  }
  .checklist li:hover { border-color: var(--border-accent); }
  .checklist li.checked { color: var(--text); background: var(--bg); border-color: var(--border-accent); }
  .checklist li.checked .check-box { background: var(--accent); border-color: var(--accent); }
  .checklist li.checked .check-box::after { opacity: 1; }

  .check-box {
    flex-shrink: 0; width: 1rem; height: 1rem; margin-top: 0.2rem;
    border: 1px solid var(--border); background: var(--bg); position: relative;
    transition: background 0.15s, border-color 0.15s;
  }
  .check-box::after {
    content: '';
    position: absolute; top: 1px; left: 3px;
    width: 5px; height: 8px;
    border: 2px solid #fff; border-top: none; border-left: none;
    transform: rotate(40deg);
    opacity: 0; transition: opacity 0.15s;
  }

  .progress-bar-wrap {
    margin-bottom: 3rem; background: var(--bg2); border: 1px solid var(--border); padding: 1rem 1.2rem;
  }
  .progress-label { font-size: 0.72rem; color: var(--muted); letter-spacing: 0.08em; margin-bottom: 0.5rem; display: flex; justify-content: space-between; }
  .progress-track { height: 4px; background: var(--bg3); border-radius: 2px; overflow: hidden; }
  .progress-fill { height: 100%; background: var(--accent); border-radius: 2px; transition: width 0.3s; width: 0%; }

  /* RELATED TOOL */
  .related-tool {
    margin-top: 3rem; padding: 1.5rem; background: var(--bg2);
    border: 1px solid var(--border-accent);
  }
  .related-tool p { font-size: 0.78rem; color: var(--muted); line-height: 1.8; margin-top: 0.5rem; }
  .related-tool a { color: var(--accent); text-decoration: none; }
  .related-tool a:hover { text-decoration: underline; }
  .related-label { font-size: 0.65rem; letter-spacing: 0.15em; text-transform: uppercase; color: var(--accent); margin-bottom: 0.4rem; }

  .divider { height: 1px; background: var(--border); max-width: 1100px; margin: 0 auto; position: relative; z-index: 1; }
  footer { border-top: 1px solid var(--border); padding: 2rem 3rem; display: flex; justify-content: space-between; align-items: center; max-width: 1100px; margin: 0 auto; font-size: 0.72rem; color: var(--muted); position: relative; z-index: 1; }
  footer a { color: var(--muted); text-decoration: none; }
  footer a:hover { color: var(--accent); }

  ::-webkit-scrollbar { width: 4px; }
  ::-webkit-scrollbar-track { background: var(--bg); }
  ::-webkit-scrollbar-thumb { background: rgba(0,102,204,0.3); border-radius: 2px; }

  @media (max-width: 768px) {
    nav { padding: 1rem 1.5rem; }
    .nav-links { display: none; }
    .page-wrap { padding: 7rem 1.5rem 4rem; }
    footer { padding: 2rem 1.5rem; flex-direction: column; gap: 0.5rem; text-align: center; }
  }
  @media (prefers-reduced-motion: reduce) {
    html { scroll-behavior: auto; }
    *, *::before, *::after { animation-duration: 0.01ms !important; transition-duration: 0.01ms !important; }
  }