/* ==========================================================================
   sslguides.com — design tokens
   Concept: the "chain of trust" — root CA → intermediate → leaf certificate.
   Link-node motif used sparingly as the site's signature (dividers, footer).
   ========================================================================== */

:root {
  /* color */
  --ink:        #0B1220;
  --surface:    #121B2E;
  --surface-2:  #182338;
  --border:     #24304A;
  --teal:       #4FD1C5;
  --teal-dim:   #2E7D74;
  --amber:      #E8B34C;
  --amber-dim:  #A67B2E;
  --text:       #E7ECF3;
  --text-muted: #8FA0B8;
  --text-faint: #5C6B84;

  /* type */
  --font-display: "Fraunces", Georgia, serif;
  --font-body: "Inter", -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  --font-mono: "JetBrains Mono", ui-monospace, SFMono-Regular, Menlo, monospace;

  /* layout */
  --max-w: 1120px;
  --radius: 10px;
  --radius-sm: 6px;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }

body {
  margin: 0;
  background: var(--ink);
  background-image:
    radial-gradient(ellipse 900px 500px at 15% -10%, rgba(79,209,197,0.08), transparent 60%),
    radial-gradient(ellipse 700px 400px at 100% 0%, rgba(232,179,76,0.05), transparent 60%);
  color: var(--text);
  font-family: var(--font-body);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

a { color: inherit; text-decoration: none; }
img, svg { display: block; max-width: 100%; }

:focus-visible {
  outline: 2px solid var(--teal);
  outline-offset: 3px;
  border-radius: 3px;
}

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

h1, h2, h3 { font-family: var(--font-display); font-weight: 600; line-height: 1.15; margin: 0; }
h1 { font-size: clamp(2.1rem, 4vw, 3.2rem); letter-spacing: -0.01em; }
h2 { font-size: clamp(1.5rem, 2.6vw, 2rem); letter-spacing: -0.005em; }
h3 { font-size: 1.15rem; }
p { margin: 0 0 1em; color: var(--text-muted); }
code, .mono { font-family: var(--font-mono); font-size: 0.9em; }

.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--teal);
}
.eyebrow::before {
  content: "";
  width: 6px; height: 6px;
  border-radius: 50%;
  background: var(--teal);
  box-shadow: 0 0 0 3px rgba(79,209,197,0.15);
}

/* ---------------------------------------------------------------------- */
/* Site header                                                            */
/* ---------------------------------------------------------------------- */

.site-header {
  border-bottom: 1px solid var(--border);
  position: sticky;
  top: 0;
  background: rgba(11,18,32,0.85);
  backdrop-filter: blur(10px);
  z-index: 40;
}
.site-header .wrap {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 68px;
}
.brand {
  display: flex;
  align-items: center;
  gap: 10px;
  font-family: var(--font-display);
  font-size: 1.15rem;
  font-weight: 600;
  color: var(--text);
}
.brand .mark { color: var(--teal); }
.brand .dot { color: var(--amber); }

.main-nav { display: flex; gap: 26px; }
.main-nav a {
  font-size: 0.88rem;
  color: var(--text-muted);
  transition: color 0.15s ease;
  white-space: nowrap;
}
.main-nav a:hover, .main-nav a.active { color: var(--text); }

.header-actions { display: flex; align-items: center; gap: 8px; }
.icon-btn {
  background: none;
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  color: var(--text-muted);
  width: 40px; height: 40px;
  display: flex; align-items: center; justify-content: center;
  cursor: pointer;
  transition: border-color 0.15s ease, color 0.15s ease;
}
.icon-btn:hover { border-color: var(--teal-dim); color: var(--teal); }
.icon-btn svg { width: 17px; height: 17px; }

.nav-toggle {
  display: none;
  background: none;
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  color: var(--text);
  width: 40px; height: 40px;
  cursor: pointer;
}

/* ---------------------------------------------------------------------- */
/* Search overlay                                                          */
/* ---------------------------------------------------------------------- */

.search-overlay {
  position: fixed; inset: 0;
  background: rgba(11,18,32,0.88);
  backdrop-filter: blur(6px);
  z-index: 100;
  display: none;
  align-items: flex-start;
  justify-content: center;
  padding: 12vh 20px 20px;
}
.search-overlay.open { display: flex; }
.search-box {
  width: 100%;
  max-width: 620px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  box-shadow: 0 20px 60px rgba(0,0,0,0.5);
  overflow: hidden;
  max-height: 70vh;
  display: flex;
  flex-direction: column;
}
.search-input-row {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 16px 18px;
  border-bottom: 1px solid var(--border);
  flex-shrink: 0;
}
.search-input-row svg { width: 18px; height: 18px; color: var(--text-faint); flex-shrink: 0; }
.search-input {
  flex: 1;
  background: none;
  border: none;
  outline: none;
  color: var(--text);
  font-family: var(--font-body);
  font-size: 1rem;
}
.search-input::placeholder { color: var(--text-faint); }
.search-close {
  background: none; border: none; color: var(--text-faint);
  font-size: 1.4rem; line-height: 1; cursor: pointer; padding: 0 2px;
}
.search-close:hover { color: var(--text); }
.search-results { overflow-y: auto; padding: 8px; }
.search-result-item {
  display: block;
  padding: 12px 14px;
  border-radius: var(--radius-sm);
  transition: background 0.1s ease;
}
.search-result-item:hover, .search-result-item.active { background: var(--surface-2); }
.search-result-item .r-cat {
  font-family: var(--font-mono); font-size: 0.68rem; letter-spacing: 0.06em;
  text-transform: uppercase; color: var(--teal); margin-bottom: 4px; display: block;
}
.search-result-item .r-title { font-size: 0.95rem; font-weight: 600; color: var(--text); margin-bottom: 3px; }
.search-result-item .r-excerpt { font-size: 0.82rem; color: var(--text-muted); }
.search-empty, .search-hint { padding: 22px 14px; color: var(--text-faint); font-size: 0.86rem; text-align: center; }

@media (max-width: 860px) {
  .main-nav {
    position: absolute;
    top: 68px; left: 0; right: 0;
    flex-direction: column;
    background: var(--surface);
    border-bottom: 1px solid var(--border);
    padding: 14px 28px 20px;
    gap: 14px;
    display: none;
  }
  .main-nav.open { display: flex; }
  .nav-toggle { display: block; }
}

/* ---------------------------------------------------------------------- */
/* Chain-of-trust divider — the signature element                        */
/* ---------------------------------------------------------------------- */

.chain-divider {
  display: flex;
  align-items: center;
  gap: 10px;
  margin: 0 0 28px;
  color: var(--text-faint);
}
.chain-divider .link {
  width: 7px; height: 7px;
  border: 1.5px solid var(--teal-dim);
  border-radius: 2px;
  transform: rotate(45deg);
  flex-shrink: 0;
}
.chain-divider .line { flex: 1; height: 1px; background: var(--border); }
.chain-divider .label {
  font-family: var(--font-mono);
  font-size: 0.7rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--text-faint);
}

/* ---------------------------------------------------------------------- */
/* Hero                                                                    */
/* ---------------------------------------------------------------------- */

.hero {
  padding: 76px 0 64px;
  border-bottom: 1px solid var(--border);
}
.hero-grid {
  display: grid;
  grid-template-columns: 1.1fr 0.9fr;
  gap: 56px;
  align-items: center;
}
.hero h1 { margin: 16px 0 20px; }
.hero .lede { font-size: 1.08rem; max-width: 46ch; }
.hero-actions { display: flex; gap: 12px; margin-top: 28px; flex-wrap: wrap; }

@media (max-width: 860px) {
  .hero-grid { grid-template-columns: 1fr; }
  .hero { padding: 48px 0 40px; }
}

.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 12px 20px;
  border-radius: var(--radius-sm);
  font-size: 0.92rem;
  font-weight: 600;
  border: 1px solid transparent;
  cursor: pointer;
  transition: transform 0.12s ease, border-color 0.15s ease, background 0.15s ease;
}
.btn-primary { background: var(--teal); color: #06231F; }
.btn-primary:hover { transform: translateY(-1px); background: #64DBD0; }
.btn-ghost { border-color: var(--border); color: var(--text); }
.btn-ghost:hover { border-color: var(--teal-dim); color: var(--teal); }
.btn-amber { background: var(--amber); color: #2B1B00; }
.btn-amber:hover { transform: translateY(-1px); background: #F0C266; }

/* ---------------------------------------------------------------------- */
/* Chain-of-trust hero graphic                                            */
/* ---------------------------------------------------------------------- */

.trust-chain { width: 100%; height: auto; }
.trust-chain .node-label {
  font-family: var(--font-mono);
  font-size: 10px;
  fill: var(--text-faint);
  letter-spacing: 0.05em;
}
.trust-chain .node-title {
  font-family: var(--font-body);
  font-size: 12.5px;
  font-weight: 600;
  fill: var(--text);
}
.trust-chain .chain-line { stroke: var(--border); stroke-width: 1.5; }
.trust-chain .pulse { fill: var(--teal); }

/* ---------------------------------------------------------------------- */
/* Section headers                                                        */
/* ---------------------------------------------------------------------- */

.section { padding: 64px 0; }
.section-head {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  margin-bottom: 34px;
  gap: 20px;
  flex-wrap: wrap;
}
.section-head p { margin: 6px 0 0; max-width: 60ch; }
.view-all { font-size: 0.85rem; color: var(--teal); white-space: nowrap; }
.view-all:hover { text-decoration: underline; }

/* ---------------------------------------------------------------------- */
/* Category grid (home)                                                   */
/* ---------------------------------------------------------------------- */

.cat-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 16px;
}
@media (max-width: 920px) { .cat-grid { grid-template-columns: repeat(2, 1fr); } }
@media (max-width: 560px) { .cat-grid { grid-template-columns: 1fr; } }

.cat-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 22px;
  transition: border-color 0.15s ease, transform 0.15s ease;
  position: relative;
  overflow: hidden;
}
.cat-card:hover { border-color: var(--teal-dim); transform: translateY(-2px); }
.cat-card .num {
  font-family: var(--font-mono);
  font-size: 0.7rem;
  color: var(--text-faint);
  letter-spacing: 0.08em;
}
.cat-card h3 { margin: 10px 0 8px; }
.cat-card p { font-size: 0.88rem; margin: 0 0 14px; }
.cat-card .count { font-family: var(--font-mono); font-size: 0.72rem; color: var(--teal); }

/* ---------------------------------------------------------------------- */
/* Article cards (with simple generated cover)                            */
/* ---------------------------------------------------------------------- */

.article-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 22px;
}
@media (max-width: 920px) { .article-grid { grid-template-columns: repeat(2, 1fr); } }
@media (max-width: 620px) { .article-grid { grid-template-columns: 1fr; } }

.article-card {
  display: block;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  overflow: hidden;
  transition: border-color 0.15s ease, transform 0.15s ease;
}
.article-card:hover { border-color: var(--teal-dim); transform: translateY(-2px); }

.cover {
  height: 128px;
  position: relative;
  display: flex;
  align-items: center;
  justify-content: center;
  overflow: hidden;
}
.cover svg { width: 34px; height: 34px; }
.cover::after {
  content: "";
  position: absolute; inset: 0;
  background-image: repeating-linear-gradient(135deg, rgba(255,255,255,0.035) 0 2px, transparent 2px 14px);
}

.article-body { padding: 18px 20px 20px; }
.article-tag {
  font-family: var(--font-mono);
  font-size: 0.68rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--text-faint);
}
.article-card h3 { margin: 8px 0 8px; font-size: 1.02rem; }
.article-card .excerpt { font-size: 0.86rem; margin: 0; color: var(--text-muted); }
.article-meta {
  display: flex; gap: 12px; align-items: center;
  margin-top: 14px;
  font-family: var(--font-mono);
  font-size: 0.7rem;
  color: var(--text-faint);
}

/* ---------------------------------------------------------------------- */
/* Category page header                                                   */
/* ---------------------------------------------------------------------- */

.cat-hero {
  padding: 52px 0 40px;
  border-bottom: 1px solid var(--border);
}
.cat-hero .eyebrow { margin-bottom: 14px; }
.cat-hero p.lede { max-width: 60ch; font-size: 1.02rem; }

/* ---------------------------------------------------------------------- */
/* Article single page                                                    */
/* ---------------------------------------------------------------------- */

.article-header { padding: 48px 0 32px; border-bottom: 1px solid var(--border); }
.article-header h1 { margin: 14px 0 16px; max-width: 24ch; }
.article-meta-bar {
  display: flex; gap: 16px; align-items: center; flex-wrap: wrap;
  font-family: var(--font-mono); font-size: 0.76rem; color: var(--text-faint);
  margin-top: 18px;
}
.article-banner {
  height: 220px;
  border-radius: var(--radius);
  border: 1px solid var(--border);
  margin: 34px 0 0;
  position: relative;
  display: flex;
  align-items: center;
  justify-content: center;
  overflow: hidden;
}
.article-banner svg { width: 64px; height: 64px; }
.article-banner::after {
  content: "";
  position: absolute; inset: 0;
  background-image: repeating-linear-gradient(135deg, rgba(255,255,255,0.03) 0 2px, transparent 2px 16px);
}

.article-content {
  max-width: 72ch;
  padding: 44px 0;
}

.diagram-figure {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 22px 20px 18px;
  margin: 26px 0;
}
.diagram-figure svg { width: 100%; height: auto; }
.diagram-figure figcaption {
  font-family: var(--font-mono);
  font-size: 0.7rem;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--text-faint);
  margin-top: 12px;
  text-align: center;
}
.diagram-node-title { font-family: var(--font-body); font-size: 12.5px; font-weight: 600; fill: var(--text); }
.diagram-node-sub { font-family: var(--font-mono); font-size: 10px; fill: var(--text-faint); }
.diagram-line { stroke: var(--border); stroke-width: 1.5; }
.diagram-accent-line { stroke: var(--teal); stroke-width: 1.5; }
.article-content h2 { margin: 40px 0 14px; }
.article-content h3 { margin: 28px 0 10px; color: var(--text); }
.article-content p, .article-content li { color: var(--text-muted); font-size: 1.01rem; }
.article-content ul, .article-content ol { padding-left: 22px; }
.article-content pre {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  padding: 16px 18px;
  overflow-x: auto;
  margin: 18px 0;
}
.article-content code { color: var(--teal); }
.article-content pre code { color: var(--text); }
.callout {
  border-left: 2px solid var(--amber);
  background: rgba(232,179,76,0.06);
  padding: 14px 18px;
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
  margin: 22px 0;
  font-size: 0.92rem;
}
.callout strong { color: var(--amber); }
.affiliate-note {
  border-left: 2px solid var(--teal-dim);
  background: rgba(79,209,197,0.05);
  padding: 12px 18px;
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
  margin: 22px 0;
  font-size: 0.85rem;
  color: var(--text-faint);
}

/* ---------------------------------------------------------------------- */
/* Buy-a-certificate: affiliate cards                                     */
/* ---------------------------------------------------------------------- */

.offer-card {
  display: grid;
  grid-template-columns: auto 1fr auto;
  align-items: center;
  gap: 20px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 20px 22px;
  margin-bottom: 14px;
}
.offer-card .badge {
  font-family: var(--font-mono);
  font-size: 0.65rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--amber);
  border: 1px solid var(--amber-dim);
  padding: 4px 8px;
  border-radius: 20px;
  white-space: nowrap;
}
.offer-card h3 { margin: 0 0 4px; }
.offer-card p { margin: 0; font-size: 0.86rem; }
.offer-card .price { font-family: var(--font-mono); color: var(--text-faint); font-size: 0.78rem; }
@media (max-width: 640px) {
  .offer-card { grid-template-columns: 1fr; text-align: left; }
}

/* ---------------------------------------------------------------------- */
/* Tools grid                                                             */
/* ---------------------------------------------------------------------- */

.tool-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 22px;
}
.tool-card .icon-wrap {
  width: 40px; height: 40px;
  border-radius: 9px;
  background: var(--surface-2);
  border: 1px solid var(--border);
  display: flex; align-items: center; justify-content: center;
  margin-bottom: 14px;
}
.tool-card .icon-wrap svg { width: 20px; height: 20px; color: var(--teal); }

/* ---------------------------------------------------------------------- */
/* Timeline (SSL history)                                                 */
/* ---------------------------------------------------------------------- */

.timeline { position: relative; padding-left: 28px; }
.timeline::before {
  content: "";
  position: absolute; left: 5px; top: 6px; bottom: 6px;
  width: 1px; background: var(--border);
}
.timeline-item { position: relative; padding-bottom: 34px; }
.timeline-item:last-child { padding-bottom: 0; }
.timeline-item::before {
  content: "";
  position: absolute; left: -28px; top: 4px;
  width: 9px; height: 9px;
  border: 1.5px solid var(--teal);
  background: var(--ink);
  border-radius: 2px;
  transform: rotate(45deg);
}
.timeline-item .year {
  font-family: var(--font-mono);
  color: var(--teal);
  font-size: 0.82rem;
  margin-bottom: 4px;
  display: block;
}
.timeline-item h3 { margin-bottom: 6px; }
.timeline-item p { margin: 0; font-size: 0.92rem; }

/* ---------------------------------------------------------------------- */
/* Simple content pages (about, contact, legal)                          */
/* ---------------------------------------------------------------------- */

.page-header { padding: 52px 0 36px; border-bottom: 1px solid var(--border); }
.page-body { max-width: 72ch; padding: 40px 0 80px; }
.page-body h2 { margin: 34px 0 12px; }
.page-body p, .page-body li { color: var(--text-muted); }
.page-body ul { padding-left: 22px; }
.updated-note { font-family: var(--font-mono); font-size: 0.78rem; color: var(--text-faint); margin-top: 10px; }

.contact-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 40px; }
@media (max-width: 760px) { .contact-grid { grid-template-columns: 1fr; } }
.contact-form { display: grid; gap: 14px; }
.contact-form label {
  font-family: var(--font-mono); font-size: 0.72rem; letter-spacing: 0.06em;
  text-transform: uppercase; color: var(--text-faint); display: block; margin-bottom: 6px;
}
.contact-form input, .contact-form textarea {
  width: 100%;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  padding: 12px 14px;
  color: var(--text);
  font-family: var(--font-body);
  font-size: 0.92rem;
}
.contact-form input:focus, .contact-form textarea:focus { border-color: var(--teal-dim); }
.contact-form textarea { min-height: 130px; resize: vertical; }
.contact-info h3 { margin-bottom: 8px; }
.contact-info .item { margin-bottom: 22px; }
.contact-info .label { font-family: var(--font-mono); font-size: 0.7rem; color: var(--text-faint); text-transform: uppercase; letter-spacing: 0.06em; }
.contact-info .value { color: var(--text); margin-top: 4px; }

/* ---------------------------------------------------------------------- */
/* Footer                                                                  */
/* ---------------------------------------------------------------------- */

.site-footer { border-top: 1px solid var(--border); padding: 48px 0 32px; margin-top: 40px; }
.footer-grid {
  display: grid;
  grid-template-columns: 1.4fr 1fr 1fr 1fr;
  gap: 32px;
  padding-bottom: 34px;
}
@media (max-width: 760px) { .footer-grid { grid-template-columns: 1fr 1fr; } }
.footer-col h4 {
  font-family: var(--font-mono); font-size: 0.7rem; letter-spacing: 0.08em;
  text-transform: uppercase; color: var(--text-faint); margin: 0 0 14px;
}
.footer-col a { display: block; font-size: 0.86rem; color: var(--text-muted); margin-bottom: 10px; }
.footer-col a:hover { color: var(--teal); }
.footer-brand p { font-size: 0.86rem; max-width: 32ch; }
.footer-bottom {
  display: flex; justify-content: space-between; align-items: center;
  padding-top: 24px; border-top: 1px solid var(--border);
  font-size: 0.78rem; color: var(--text-faint); flex-wrap: wrap; gap: 10px;
}
.footer-bottom a { color: var(--text-faint); }
.footer-bottom a:hover { color: var(--teal); }

/* ---------------------------------------------------------------------- */
/* Utility                                                                 */
/* ---------------------------------------------------------------------- */

.stack { display: grid; gap: 14px; }
.breadcrumb {
  font-family: var(--font-mono); font-size: 0.76rem; color: var(--text-faint);
  margin-bottom: 18px;
}
.breadcrumb a:hover { color: var(--teal); }

/* ---------------------------------------------------------------------- */
/* Pagination                                                              */
/* ---------------------------------------------------------------------- */

.pagination {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  margin-top: 40px;
  flex-wrap: wrap;
}
.page-link, .page-current, .page-dots {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-width: 38px;
  height: 38px;
  padding: 0 10px;
  border-radius: var(--radius-sm);
  font-family: var(--font-mono);
  font-size: 0.82rem;
}
.page-link {
  border: 1px solid var(--border);
  color: var(--text-muted);
  transition: border-color 0.15s ease, color 0.15s ease;
}
.page-link:hover { border-color: var(--teal-dim); color: var(--teal); }
.page-current {
  border: 1px solid var(--teal-dim);
  background: rgba(79,209,197,0.08);
  color: var(--teal);
  font-weight: 600;
}
.page-dots { color: var(--text-faint); border: none; }
.page-nav-label { font-size: 0.78rem; }

/* ---------------------------------------------------------------------- */
/* Related guides                                                          */
/* ---------------------------------------------------------------------- */

.related-section {
  border-top: 1px solid var(--border);
  padding: 40px 0 8px;
}
.related-section h2 { font-size: 1.3rem; margin-bottom: 22px; }

@media (prefers-reduced-motion: reduce) {
  * { transition: none !important; scroll-behavior: auto !important; }
}