:root {
  --bg: #ffffff;
  --surface: #f8f9fb;
  --surface-raised: #f1f3f6;
  --border: #e2e5ea;
  --border-subtle: #eceef2;
  --text: #1a1d23;
  --text-secondary: #555d6e;
  --text-dim: #8590a2;
  --accent: #1a56db;
  --accent-dim: #1447b8;
  --accent-bg: rgba(26, 86, 219, 0.06);
  --accent-border: rgba(26, 86, 219, 0.15);
  --green: #0d7a4f;
  --green-text: #0d7a4f;
  --green-bg: rgba(13, 122, 79, 0.08);
  --amber: #9a6700;
  --amber-text: #9a6700;
  --amber-bg: rgba(154, 103, 0, 0.08);
  --max-w: 1080px;
}

* { margin: 0; padding: 0; box-sizing: border-box; }

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Helvetica Neue', Arial, sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

a { color: var(--accent); text-decoration: none; }
a:hover { text-decoration: underline; }

.wrap { max-width: var(--max-w); margin: 0 auto; padding: 0 28px; }

/* ---- NAV ---- */
nav {
  position: sticky; top: 0; z-index: 100;
  background: rgba(255, 255, 255, 0.95);
  backdrop-filter: blur(16px);
  border-bottom: 1px solid var(--border);
  padding: 14px 0;
}
nav .wrap { display: flex; align-items: center; justify-content: space-between; }
.logo { font-weight: 700; font-size: 0.95rem; letter-spacing: 0.02em; color: var(--text); text-decoration: none; }
.logo:hover { text-decoration: none; color: var(--text); }
.nav-links { display: flex; gap: 32px; align-items: center; }
.nav-links a { color: var(--text-secondary); font-size: 0.82rem; font-weight: 500; letter-spacing: 0.01em; }
.nav-links a:hover { color: var(--text); text-decoration: none; }
.nav-links a.btn-primary { color: #fff; }
.nav-links a.btn-primary:hover { color: #fff; }

/* ---- BUTTONS ---- */
.btn {
  display: inline-block; padding: 11px 26px; border-radius: 6px;
  font-weight: 600; font-size: 0.85rem; letter-spacing: 0.01em;
  transition: all 0.12s ease; border: none; text-decoration: none; cursor: pointer;
}
.btn:hover { text-decoration: none; }
.btn-primary { background: var(--text); color: #fff; }
.btn-primary:hover { background: #2d3340; }
.btn-outline { background: transparent; color: var(--text-secondary); border: 1px solid var(--border); }
.btn-outline:hover { color: var(--text); border-color: var(--text-dim); background: var(--surface); }
.btn-sm { padding: 7px 18px; font-size: 0.8rem; }

/* ---- PAGE HEADER ---- */
.page-header { padding: 72px 0 56px; }
.page-header h1 {
  font-size: clamp(1.6rem, 3.5vw, 2.2rem); font-weight: 700;
  letter-spacing: -0.02em; line-height: 1.25; margin-bottom: 16px; color: var(--text);
}
.page-desc { font-size: 1rem; color: var(--text-secondary); max-width: 580px; line-height: 1.7; }

/* ---- HERO ---- */
.hero { padding: 96px 0 72px; }
.hero-label {
  display: inline-block; padding: 5px 14px; border-radius: 4px;
  background: var(--accent-bg); color: var(--accent);
  font-size: 0.72rem; font-weight: 600; letter-spacing: 0.05em;
  text-transform: uppercase; margin-bottom: 28px;
  border: 1px solid var(--accent-border);
}
.hero h1 {
  font-size: clamp(2rem, 4.5vw, 2.8rem); font-weight: 700;
  letter-spacing: -0.025em; line-height: 1.2; margin-bottom: 20px; color: var(--text);
}
.hero .sub {
  font-size: 1.05rem; color: var(--text-secondary); max-width: 580px;
  line-height: 1.75; margin-bottom: 40px;
}
.hero-actions { display: flex; gap: 12px; flex-wrap: wrap; }

/* ---- STRIP ---- */
.strip {
  padding: 32px 0;
  border-top: 1px solid var(--border);
  border-bottom: 1px solid var(--border);
  background: var(--surface);
}
.strip-row { display: flex; justify-content: center; gap: 36px; flex-wrap: wrap; }
.strip-item { display: flex; align-items: center; gap: 8px; font-size: 0.8rem; color: var(--text-dim); }
.dot { width: 6px; height: 6px; border-radius: 50%; flex-shrink: 0; }
.dot-green { background: var(--green); }
.dot-amber { background: var(--amber); }

/* ---- SECTIONS ---- */
section { padding: 80px 0; }
.alt-bg { background: var(--surface); }
.label {
  text-transform: uppercase; font-size: 0.7rem; font-weight: 700;
  letter-spacing: 0.1em; color: var(--accent); margin-bottom: 10px;
}
.heading {
  font-size: clamp(1.5rem, 3vw, 1.9rem); font-weight: 700;
  letter-spacing: -0.02em; margin-bottom: 12px; color: var(--text);
}
.desc { color: var(--text-secondary); max-width: 560px; margin-bottom: 48px; font-size: 0.95rem; }

/* ---- GRID ---- */
.g3 { display: grid; grid-template-columns: repeat(3, 1fr); gap: 20px; }
.g2 { display: grid; grid-template-columns: repeat(2, 1fr); gap: 20px; }

/* ---- CARDS ---- */
.card {
  background: var(--bg); border: 1px solid var(--border);
  border-radius: 8px; padding: 28px;
  transition: border-color 0.15s, box-shadow 0.15s;
}
.card:hover { border-color: var(--accent-border); box-shadow: 0 2px 8px rgba(0,0,0,0.04); }
.alt-bg .card { background: var(--bg); }
.card-label {
  font-size: 0.7rem; font-weight: 700; letter-spacing: 0.08em;
  text-transform: uppercase; color: var(--accent); margin-bottom: 12px;
}
.card h3 { font-size: 1rem; font-weight: 700; margin-bottom: 8px; color: var(--text); }
.card p { color: var(--text-secondary); font-size: 0.88rem; line-height: 1.65; }
.card ul { list-style: none; margin-top: 16px; }
.card ul li {
  padding: 6px 0; font-size: 0.85rem; color: var(--text-secondary);
  border-bottom: 1px solid var(--border-subtle);
}
.card ul li:last-child { border-bottom: none; }
.card .btn { margin-top: 20px; }

/* ---- STEPS ---- */
.steps { display: grid; grid-template-columns: repeat(4, 1fr); gap: 28px; }
.step { text-align: left; }
.step-n {
  font-size: 0.7rem; font-weight: 700; color: var(--accent);
  letter-spacing: 0.06em; text-transform: uppercase; margin-bottom: 12px;
  padding-bottom: 12px; border-bottom: 2px solid var(--accent-border);
}
.step h4 { font-size: 0.95rem; font-weight: 700; margin-bottom: 6px; color: var(--text); }
.step p { color: var(--text-secondary); font-size: 0.84rem; }

/* ---- SECURITY ---- */
.sec-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 28px; }
.sec-col h3 { font-size: 0.95rem; font-weight: 700; margin-bottom: 16px; color: var(--text); }
.sec-col ul { list-style: none; }
.sec-col ul li {
  padding: 9px 0; font-size: 0.85rem; color: var(--text-secondary);
  border-bottom: 1px solid var(--border-subtle);
}
.sec-col ul li:last-child { border-bottom: none; }
.mark-done { color: var(--green-text); margin-right: 10px; font-weight: 700; font-size: 0.8rem; }
.mark-open { color: var(--amber-text); margin-right: 10px; font-weight: 700; font-size: 0.8rem; }

/* ---- FAQ ---- */
.faq { max-width: 680px; }
.faq-row { border-bottom: 1px solid var(--border); padding: 20px 0; }
.faq-row:first-child { border-top: 1px solid var(--border); }
.faq-q {
  font-weight: 700; font-size: 0.92rem; cursor: pointer; color: var(--text);
  display: flex; justify-content: space-between; align-items: center;
}
.faq-q::after { content: "+"; font-size: 1.1rem; color: var(--text-dim); font-weight: 400; }
.faq-row.open .faq-q::after { content: "\2013"; }
.faq-a {
  color: var(--text-secondary); font-size: 0.88rem; line-height: 1.7;
  max-height: 0; overflow: hidden; transition: max-height 0.3s ease, padding 0.3s ease;
}
.faq-row.open .faq-a { max-height: 300px; padding-top: 12px; }

/* ---- CTA BLOCK ---- */
.cta-block { text-align: center; padding: 96px 0; background: var(--surface); }
.cta-block h2 { font-size: clamp(1.5rem, 3vw, 2rem); font-weight: 700; color: var(--text); margin-bottom: 12px; }
.cta-block p { color: var(--text-secondary); margin-bottom: 32px; }
.cta-actions { display: flex; gap: 12px; justify-content: center; flex-wrap: wrap; }

/* ---- FOOTER ---- */
footer {
  padding: 36px 0; border-top: 1px solid var(--border);
  color: var(--text-dim); font-size: 0.78rem; text-align: center; line-height: 1.8;
}

/* ---- CODE BLOCKS ---- */
pre {
  background: var(--surface) !important;
  border: 1px solid var(--border) !important;
  color: var(--text-secondary) !important;
}
code {
  font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
  font-size: 0.85em;
  background: var(--surface);
  border: 1px solid var(--border-subtle);
  border-radius: 3px;
  padding: 1px 5px;
  color: var(--text);
}
pre code {
  background: transparent;
  border: none;
  padding: 0;
  color: inherit;
  font-size: inherit;
}

/* ---- RESPONSIVE ----
   Mobile-first principle: nothing is hidden, nothing is removed. Content
   reflows, scrolls, or stacks. Every byte of information remains reachable
   on a 320px-wide viewport. */

/* Tablet breakpoint — first grid collapse */
@media (max-width: 900px) {
  .g3 { grid-template-columns: 1fr; }
  .g2 { grid-template-columns: 1fr; }
  .sec-grid { grid-template-columns: 1fr; }
  .steps { grid-template-columns: 1fr 1fr; }
  .nav-links { gap: 22px; }
  .nav-links a { font-size: 0.8rem; }
  .hero { padding: 64px 0 48px; }
  .page-header { padding: 56px 0 40px; }
  section { padding: 64px 0; }
  .cta-block { padding: 72px 0; }
}

/* Mobile breakpoint — nav wraps, hero shrinks, layout tightens.
   The :not(.btn) selector keeps the Live Demo button styled normally
   while still letting it wrap into the same row as the text links. */
@media (max-width: 760px) {
  .wrap { padding: 0 20px; }

  /* Nav: logo on top row, links wrap onto a second row */
  nav { padding: 12px 0; }
  nav .wrap {
    flex-wrap: wrap;
    gap: 10px;
    justify-content: space-between;
    align-items: center;
  }
  .logo { flex: 0 0 auto; }
  .nav-links {
    flex: 1 0 100%;
    flex-wrap: wrap;
    gap: 12px 18px;
    justify-content: flex-start;
    padding-top: 8px;
    border-top: 1px solid var(--border-subtle);
  }
  .nav-links a:not(.btn) { font-size: 0.85rem; }
  .nav-links .btn { margin-left: auto; }

  /* Steps stack to single column */
  .steps { grid-template-columns: 1fr; }

  /* Hero */
  .hero { padding: 48px 0 40px; }
  .hero h1 { font-size: clamp(1.7rem, 7vw, 2.2rem); line-height: 1.22; }
  .hero h1 br { display: none; }
  .hero .sub { font-size: 0.95rem; }
  .hero-actions .btn { padding: 10px 20px; font-size: 0.82rem; }

  /* Page header */
  .page-header { padding: 48px 0 32px; }
  .page-header h1 { font-size: clamp(1.4rem, 6vw, 1.9rem); line-height: 1.25; }
  .page-header h1 br { display: none; }
  .page-desc { font-size: 0.95rem; }

  /* Section padding tighter */
  section { padding: 52px 0; }
  .heading { font-size: clamp(1.35rem, 5vw, 1.7rem); }
  .desc { margin-bottom: 36px; }

  /* Card padding */
  .card { padding: 22px; }

  /* CTA block */
  .cta-block { padding: 56px 0; }
  .cta-block h2 { font-size: clamp(1.4rem, 5vw, 1.8rem); }

  /* Strip */
  .strip { padding: 24px 0; }
  .strip-row { gap: 16px 20px; }
  .strip-item { font-size: 0.78rem; }

  /* Inline code snippets — wrap long hex/hashes/identifiers so they
     never punch out of their card on mobile. Block-level pre still
     scrolls horizontally so code remains literal and copyable. */
  code {
    word-break: break-all;
    overflow-wrap: anywhere;
  }
  pre code {
    word-break: normal;
    overflow-wrap: normal;
  }

  /* Table cell text wraps instead of pushing the table wider. Tables
     that genuinely cannot wrap (long hex hashes, code) are wrapped by
     the page in a div with overflow-x:auto so they horizontally scroll
     while every cell remains reachable. No data loss. */
  table { max-width: 100%; }
  td, th { word-break: break-word; overflow-wrap: anywhere; }
}

/* Tiny phones — final tightening for 360px-class viewports */
@media (max-width: 480px) {
  .wrap { padding: 0 16px; }

  .hero { padding: 36px 0 32px; }
  .hero h1 { font-size: clamp(1.5rem, 7.5vw, 1.95rem); }
  .hero .sub { font-size: 0.92rem; margin-bottom: 28px; }

  .page-header { padding: 36px 0 28px; }
  .page-header h1 { font-size: clamp(1.3rem, 7vw, 1.7rem); }

  section { padding: 44px 0; }
  .heading { font-size: clamp(1.25rem, 6vw, 1.55rem); margin-bottom: 10px; }
  .desc { font-size: 0.9rem; margin-bottom: 28px; }

  .card { padding: 18px; }
  .card h3 { font-size: 0.95rem; }

  .cta-block { padding: 48px 0; }

  /* Buttons stretch in stacked CTA rows to give a real tap target */
  .hero-actions, .cta-actions { gap: 10px; }
  .hero-actions .btn, .cta-actions .btn {
    flex: 1 0 100%;
    text-align: center;
    padding: 12px 18px;
  }

  .nav-links { gap: 10px 16px; }
  .nav-links a:not(.btn) { font-size: 0.82rem; }
  .nav-links .btn-sm { padding: 6px 14px; font-size: 0.76rem; }
}