/* ═══════════════════════════════════════════════════════════════
   SFMC Study Guide — reader theme
   Dark gradient reader, adapted from UI_Design_System.html for a
   real multi-page static site (no single-page JS reader).
   ═══════════════════════════════════════════════════════════════ */

:root {
  --bg:           #0b0e14;
  --panel:        #131826;
  --code:         #191f30;
  --quote:        #10141f;
  --th:           #1a2133;
  --accent-soft:  #221d47;

  --text:         #d7dce6;
  --muted:        #8a93a6;
  --codetext:     #e3e8f2;

  --border:       #232b3d;

  --accent:       #8b7ff7;
  --accent2:      #22d3ee;
  --gold:         #f0b429;

  --grad: linear-gradient(120deg, #8b7ff7 0%, #5aa7f0 55%, #22d3ee 100%);

  --c-strong:       #f0b429;
  --c-strong-quote: #34d399;
  --c-em:           #67e8f9;

  --danger:    #e5484d;
  --danger-bg: rgba(229,72,77,.13);
  --success:   #34d399;
  --success-bg:rgba(52,211,153,.14);

  --svg-line:         #7d8aa0;
  --svg-box-fill:     #1a2133;
  --svg-box-stroke:   #3a4658;
  --svg-text:         #e3e8f2;
  --svg-text-inverse: #ffffff;

  --sidebar-w: 300px;
  --content-max: 880px;
  --topbarH: 58px;
}

* , *::before, *::after { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  font-size: 16px;
  line-height: 1.7;
}
a { color: var(--accent2); text-decoration: none; }
a:hover { text-decoration: underline; }

/* ── SHELL ─────────────────────────────────────────────────────── */
.shell { display: flex; min-height: 100vh; }

.sidebar {
  width: var(--sidebar-w);
  min-width: var(--sidebar-w);
  height: 100vh;
  position: sticky;
  top: 0;
  overflow-y: auto;
  background: var(--panel);
  border-right: 1px solid var(--border);
  padding: 14px 10px 60px;
}
.sidebar h2 {
  font-size: 12px;
  text-transform: uppercase;
  letter-spacing: .07em;
  color: var(--muted);
  margin: 10px 10px 8px;
}
.sidebar .home-link {
  display: block;
  padding: 8px 10px 14px;
  margin-bottom: 6px;
  border-bottom: 1px solid var(--border);
  font-size: 13px;
  color: var(--muted);
}
.sidebar .home-link:hover { color: var(--accent2); text-decoration: none; }

.main { flex: 1; min-width: 0; display: flex; flex-direction: column; }

.topbar {
  position: sticky;
  top: 0;
  z-index: 40;
  background: var(--panel);
  border-bottom: 1px solid var(--border);
  padding: 12px 20px;
  display: flex;
  gap: 14px;
  align-items: center;
}
.topbar .brand {
  font-weight: 800;
  font-size: 16px;
  white-space: nowrap;
  background: var(--grad);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}
.topbar .brand small {
  display: block;
  font-weight: 500;
  color: var(--muted);
  font-size: 11.5px;
  -webkit-text-fill-color: var(--muted);
}
.topbar a.brand-link { display: block; }
#hamburger {
  display: none;
  border: 1px solid var(--border);
  background: var(--bg);
  color: var(--text);
  border-radius: 8px;
  width: 36px; height: 36px;
  font-size: 16px;
  cursor: pointer;
}
.scrim { display: none; }

.content {
  max-width: var(--content-max);
  width: 100%;
  margin: 0 auto;
  padding: 28px 24px 140px;
}

/* ── SIDEBAR NAV ───────────────────────────────────────────────── */
.grp {
  font-size: 12px;
  text-transform: uppercase;
  letter-spacing: .07em;
  color: var(--accent2);
  margin: 18px 10px 5px;
  padding-top: 10px;
  border-top: 1px solid var(--border);
  font-weight: 700;
}
.grp:first-child { border-top: none; margin-top: 4px; }

.nav-item {
  display: flex;
  gap: 8px;
  align-items: baseline;
  padding: 7px 10px;
  border-radius: 8px;
  color: var(--text);
  font-size: 13.5px;
  line-height: 1.35;
}
.nav-item:hover { background: var(--accent-soft); text-decoration: none; }
.nav-item.cur { background: var(--grad); color: #0b0e14; font-weight: 700; }
.nav-item .badge {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-width: 26px;
  height: 20px;
  padding: 0 4px;
  border-radius: 6px;
  background: var(--accent-soft);
  color: var(--accent2);
  font-size: 11px;
  font-weight: 800;
  flex: 0 0 auto;
}
.nav-item.cur .badge { background: rgba(11,14,20,.25); color: #0b0e14; }

.nav-subs {
  list-style: none;
  margin: 2px 0 6px;
  padding: 0 0 0 34px;
}
.nav-subs a {
  display: block;
  padding: 5px 8px;
  font-size: 12.5px;
  color: var(--muted);
  border-radius: 6px;
  line-height: 1.4;
}
.nav-subs a:hover { background: var(--accent-soft); color: var(--text); text-decoration: none; }

/* ── ON-PAGE CONTENTS BOX ──────────────────────────────────────── */
.toc-box {
  margin: 16px 0 24px;
  padding: 14px 16px;
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: 10px;
}
.toc-title {
  font-size: 11px;
  text-transform: uppercase;
  letter-spacing: .07em;
  color: var(--accent2);
  font-weight: 800;
  margin-bottom: 8px;
}
.toc-box ul { list-style: none; margin: 0; padding: 0; columns: 1; }
.toc-box li { margin: 3px 0; }
.toc-box a { font-size: 13.5px; color: var(--text); }
.toc-box a:hover { color: var(--accent2); }
@media (min-width: 640px) {
  .toc-box ul { columns: 2; column-gap: 20px; }
  .toc-box li { break-inside: avoid; }
}

/* ── PREV/NEXT BAR ─────────────────────────────────────────────── */
.pagenav {
  position: sticky;
  top: var(--topbarH);
  z-index: 30;
  display: flex;
  gap: 8px;
  align-items: center;
  flex-wrap: wrap;
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 9px 12px;
  margin: 0 auto 6px;
  max-width: var(--content-max);
  box-shadow: 0 2px 8px rgba(0,0,0,.35);
}
.pnav {
  border: 1px solid var(--border);
  background: var(--bg);
  color: var(--text);
  padding: 8px 14px;
  border-radius: 9px;
  font-weight: 700;
  font-size: 13.5px;
  white-space: nowrap;
}
.pnav:hover { background: var(--grad); color: #0b0e14; border-color: transparent; text-decoration: none; }
.pnav.disabled { opacity: .3; pointer-events: none; }
.crumb { flex: 1; min-width: 100px; text-align: center; font-size: 13px; line-height: 1.3; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.crumb .cmod { color: var(--muted); }
.crumb .csep { color: var(--muted); margin: 0 6px; }
.crumb .cpage { font-weight: 700; }

/* ── TYPOGRAPHY ────────────────────────────────────────────────── */
.content > h1 {
  font-size: 26px;
  line-height: 1.28;
  margin: 10px 0 18px;
  padding-bottom: 12px;
  border-bottom: 3px solid;
  border-image: var(--grad) 1;
}
.content h2 { font-size: 21px; margin: 30px 0 10px; }
.content h3 { font-size: 17px; margin: 22px 0 8px; }
.content h4 { font-size: 15px; margin: 16px 0 6px; color: var(--muted); }
.content p  { margin: 10px 0; }
.content ul, .content ol { margin: 8px 0; padding-left: 24px; }
.content li { margin: 4px 0; }

.content strong { color: var(--c-strong); }
.content em     { color: var(--c-em); }
.content blockquote strong { color: var(--c-strong-quote); }
.content h1 strong, .content h2 strong, .content h3 strong,
.content h4 strong, .content a strong { color: inherit; }

.content blockquote {
  margin: 14px 0;
  padding: 8px 14px;
  background: var(--quote);
  border-left: 4px solid var(--accent);
  border-radius: 0 8px 8px 0;
}
.content blockquote p { margin: 5px 0; }

.content code {
  font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
  font-size: .9em;
  background: var(--code);
  color: var(--codetext);
  padding: 2px 5px;
  border-radius: 5px;
}
.content pre {
  background: var(--code);
  color: var(--codetext);
  padding: 14px 16px;
  border-radius: 10px;
  overflow: auto;
  border: 1px solid var(--border);
  font-size: 13.3px;
  line-height: 1.55;
}
.content pre code { background: none; padding: 0; }

.content table { border-collapse: collapse; width: 100%; font-size: 14px; margin: 12px 0; }
.content .table-wrap { overflow-x: auto; margin: 12px 0; border: 1px solid var(--border); border-radius: 10px; }
.content th, .content td { border: 1px solid var(--border); padding: 8px 11px; text-align: left; vertical-align: top; }
.content th { background: var(--th); font-weight: 700; }
.content tr:nth-child(even) td { background: rgba(127,127,127,.05); }

.content hr { border: none; border-top: 1px solid var(--border); margin: 24px 0; }

.content .diagram { margin: 16px 0; overflow-x: auto; text-align: center; }
.content .diagram svg { max-width: 100%; height: auto; display: inline-block; }
.content .diagram text { fill: var(--svg-text); }

/* ── HUB / MODULE INDEX CARDS ─────────────────────────────────── */
.hero {
  margin-bottom: 8px;
}
.hero h1 {
  font-size: 32px;
  background: var(--grad);
  -webkit-background-clip: text; background-clip: text; color: transparent;
  margin: 4px 0 8px;
  border: none; padding: 0;
}
.hero p { color: var(--muted); font-size: 15.5px; max-width: 640px; }

.card-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
  gap: 16px;
  margin: 26px 0;
}
.card {
  display: block;
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: 14px;
  padding: 18px;
  color: var(--text);
}
.card:hover { border-color: var(--accent); text-decoration: none; }
.card .card-num {
  display: inline-block;
  font-size: 11px;
  font-weight: 800;
  color: var(--accent2);
  text-transform: uppercase;
  letter-spacing: .06em;
  margin-bottom: 8px;
}
.card h3 { margin: 0 0 6px; font-size: 17px; color: var(--text); }
.card p { margin: 0; font-size: 13.5px; color: var(--muted); line-height: 1.5; }
.card .card-meta { margin-top: 12px; font-size: 12px; color: var(--accent2); font-weight: 700; }

.chapter-list { list-style: none; margin: 18px 0; padding: 0; counter-reset: ch; }
.chapter-list li {
  counter-increment: ch;
}
.chapter-list a {
  display: flex;
  gap: 12px;
  align-items: baseline;
  padding: 12px 14px;
  border: 1px solid var(--border);
  border-radius: 10px;
  margin: 8px 0;
  background: var(--panel);
  color: var(--text);
}
.chapter-list a:hover { border-color: var(--accent); text-decoration: none; background: var(--accent-soft); }
.chapter-list .num {
  flex: 0 0 auto;
  min-width: 28px;
  height: 28px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  background: var(--grad);
  color: #0b0e14;
  border-radius: 8px;
  font-size: 12.5px;
  font-weight: 800;
}
.chapter-list .ttl { font-weight: 600; font-size: 14.5px; }

.resource-list { list-style: none; margin: 18px 0; padding: 0; }
.resource-list li {
  display: flex;
  gap: 12px;
  align-items: center;
  padding: 14px 16px;
  border: 1px solid var(--border);
  border-radius: 10px;
  margin: 10px 0;
  background: var(--panel);
}
.resource-list .r-body { flex: 1; min-width: 0; }
.resource-list .r-title { font-weight: 700; font-size: 15px; }
.resource-list .r-desc { color: var(--muted); font-size: 13px; margin-top: 2px; }
.resource-list .r-btn {
  flex: 0 0 auto;
  border: 1px solid var(--border);
  background: var(--bg);
  padding: 8px 14px;
  border-radius: 8px;
  font-size: 13px;
  font-weight: 700;
  color: var(--text);
}
.resource-list .r-btn:hover { background: var(--grad); color: #0b0e14; border-color: transparent; text-decoration: none; }

/* ── FOOTER ────────────────────────────────────────────────────── */
.site-footer {
  text-align: center;
  color: var(--muted);
  font-size: 12.5px;
  padding: 30px 20px 60px;
}
.site-footer a { color: var(--muted); }

/* ── MOBILE (≤900px) ───────────────────────────────────────────── */
@media (max-width: 900px) {
  .sidebar {
    position: fixed;
    left: 0; top: 0;
    z-index: 60;
    transform: translateX(-100%);
    transition: transform .25s;
    box-shadow: 0 0 30px rgba(0,0,0,.5);
  }
  .sidebar.open { transform: translateX(0); }
  #hamburger { display: inline-block; }
  .scrim.show {
    display: block;
    position: fixed;
    inset: 0;
    background: rgba(0,0,0,.55);
    z-index: 55;
  }
  .pagenav { margin: 0 6px 6px; padding: 8px; }
  .crumb .cmod { display: none; }
  .content { padding: 18px 14px 120px; }
  body { font-size: 15px; }
  .content > h1 { font-size: 22px; }
  .content pre { font-size: 12.5px; }
  .content table { font-size: 13px; }
  .hero h1 { font-size: 26px; }
}