:root {
  --ink: #0f172a;
  --ink-soft: rgba(15, 23, 42, 0.7);
  --ink-faint: rgba(15, 23, 42, 0.5);
  --line: rgba(2, 6, 23, 0.1);
  --brand-from: #2563eb;
  --brand-to: #22c55e;
  --bg: #f1f5f9;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  font-family: "Sarabun", "Segoe UI", system-ui, -apple-system, sans-serif;
  color: var(--ink);
  background: linear-gradient(180deg, rgba(2, 6, 23, 0.04), rgba(2, 6, 23, 0.01)), var(--bg);
  line-height: 1.65;
}

.manual-shell {
  width: min(900px, 100%);
  margin: 0 auto;
  padding: 16px 16px 64px;
}

.manual-topbar {
  position: sticky;
  top: 0;
  z-index: 5;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  padding: 14px 0;
  margin-bottom: 8px;
  background: linear-gradient(180deg, var(--bg), rgba(241, 245, 249, 0.9));
  backdrop-filter: blur(6px);
}

.manual-badge {
  display: inline-grid;
  place-items: center;
  width: 46px;
  height: 46px;
  border-radius: 14px;
  color: #fff;
  font-weight: 800;
  letter-spacing: 0.5px;
  background: linear-gradient(135deg, var(--brand-from), var(--brand-to));
  box-shadow: 0 10px 24px rgba(37, 99, 235, 0.25);
}

.manual-back {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 9px 16px;
  border-radius: 999px;
  border: 1px solid var(--line);
  background: #fff;
  color: var(--ink);
  font-weight: 700;
  font-size: 14px;
  text-decoration: none;
}
.manual-back:hover {
  border-color: rgba(37, 99, 235, 0.45);
}

.manual-hero {
  padding: 28px 24px;
  border-radius: 22px;
  color: #fff;
  background: linear-gradient(135deg, var(--brand-from), var(--brand-to));
  box-shadow: 0 18px 40px rgba(37, 99, 235, 0.2);
}
.manual-hero .kicker {
  font-size: 13px;
  font-weight: 700;
  letter-spacing: 1px;
  text-transform: uppercase;
  opacity: 0.85;
}
.manual-hero h1 {
  margin: 6px 0 8px;
  font-size: 26px;
}
.manual-hero p {
  margin: 0;
  opacity: 0.92;
}

.manual-toc {
  margin: 22px 0;
  padding: 18px 20px;
  border-radius: 18px;
  background: #fff;
  border: 1px solid var(--line);
}
.manual-toc h2 {
  margin: 0 0 10px;
  font-size: 15px;
  color: var(--ink-soft);
}
.manual-toc ol {
  margin: 0;
  padding-left: 20px;
  columns: 2;
  column-gap: 24px;
}
.manual-toc a {
  color: var(--brand-from);
  text-decoration: none;
  font-weight: 600;
}
.manual-toc a:hover {
  text-decoration: underline;
}

.manual-step {
  margin: 18px 0;
  padding: 22px 24px;
  border-radius: 18px;
  background: #fff;
  border: 1px solid var(--line);
  box-shadow: 0 8px 24px rgba(2, 6, 23, 0.04);
  scroll-margin-top: 80px;
}
.manual-step-head {
  display: flex;
  align-items: center;
  gap: 12px;
  margin-bottom: 12px;
}
.manual-step-num {
  display: inline-grid;
  place-items: center;
  flex: 0 0 auto;
  width: 34px;
  height: 34px;
  border-radius: 10px;
  color: #fff;
  font-weight: 800;
  background: linear-gradient(135deg, var(--brand-from), var(--brand-to));
}
.manual-step-head h3 {
  margin: 0;
  font-size: 19px;
}
.manual-step p {
  margin: 8px 0;
  color: var(--ink-soft);
}
.manual-step ul,
.manual-step ol.sub {
  margin: 8px 0;
  padding-left: 22px;
  color: var(--ink-soft);
}
.manual-step li {
  margin: 4px 0;
}
.manual-step strong {
  color: var(--ink);
}

.tag {
  display: inline-block;
  padding: 2px 10px;
  border-radius: 999px;
  font-size: 12px;
  font-weight: 700;
  background: rgba(37, 99, 235, 0.1);
  color: var(--brand-from);
}

.note {
  margin: 12px 0;
  padding: 12px 16px;
  border-radius: 12px;
  border-left: 4px solid var(--brand-from);
  background: rgba(37, 99, 235, 0.06);
  color: var(--ink-soft);
  font-size: 14px;
}
.note.warn {
  border-left-color: #f59e0b;
  background: rgba(245, 158, 11, 0.08);
}

/* Screenshot image */
.figure {
  margin: 14px 0 4px;
}
.figure-img {
  display: block;
  width: 100%;
  height: auto;
  border-radius: 14px;
  border: 1px solid var(--line);
  box-shadow: 0 8px 24px rgba(2, 6, 23, 0.08);
  background: #fff;
}
.figure figcaption {
  margin-top: 8px;
  font-size: 13px;
  color: var(--ink-faint);
  text-align: center;
}

.manual-footer {
  margin-top: 34px;
  padding-top: 18px;
  border-top: 1px solid var(--line);
  text-align: center;
  color: var(--ink-faint);
  font-size: 13px;
}

@media (max-width: 640px) {
  .manual-toc ol {
    columns: 1;
  }
  .manual-hero h1 {
    font-size: 22px;
  }
}