:root {
  --paper: #fff;
  --ink: #182235;
  --muted: #687386;
  --soft: #8e97a5;
  --line: #e4e8ee;
  --line-strong: #d3dbe4;
  --gold: #b98a25;
  --gold-deep: #966d18;
  --gold-soft: #fbf8f0;
  --rail: #fcfcfd;
  --success: #357b5a;
  --danger: #a44545;
  --shadow: 0 18px 46px rgba(26, 38, 58, .07);
  --sans: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", "Noto Sans Thai", "Leelawadee UI", sans-serif;
  --mono: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, "Liberation Mono", monospace;
}

* { box-sizing: border-box; }
html { scroll-behavior: auto; }
body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font-family: var(--sans);
  font-size: 17px;
  line-height: 1.72;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

a { color: inherit; }
button { font: inherit; }
button, a { -webkit-tap-highlight-color: transparent; }
:focus-visible { outline: 3px solid #c59631; outline-offset: 3px; }
[hidden] { display: none !important; }
.sr-only { position: absolute; width: 1px; height: 1px; padding: 0; margin: -1px; overflow: hidden; clip: rect(0, 0, 0, 0); white-space: nowrap; border: 0; }
.icon { display: inline-block; width: 18px; height: 18px; flex: 0 0 auto; fill: none; stroke: currentColor; stroke-width: 1.7; stroke-linecap: round; stroke-linejoin: round; vertical-align: -.18em; }
.icon-chevron { width: 16px; height: 16px; vertical-align: -.24em; }

.site-header {
  position: sticky;
  top: 0;
  z-index: 30;
  height: 68px;
  background: rgba(255,255,255,.97);
  border-bottom: 1px solid var(--line);
  backdrop-filter: blur(14px);
}
.header-inner {
  width: min(1320px, calc(100% - 48px));
  height: 100%;
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 28px;
}
.top-nav { display: flex; align-items: center; gap: 28px; height: 100%; }
.top-nav a, .mobile-builder-link {
  position: relative;
  display: inline-flex;
  align-items: center;
  gap: 7px;
  height: 100%;
  color: var(--muted);
  font-size: 14px;
  font-weight: 650;
  text-decoration: none;
  white-space: nowrap;
}
.top-nav a:hover, .top-nav a.is-active, .mobile-builder-link:hover { color: var(--ink); }
.top-nav a.is-active::after {
  content: "";
  position: absolute;
  right: 0;
  bottom: 0;
  left: 0;
  height: 3px;
  background: var(--gold);
}
.top-nav .with-divider { padding-left: 28px; border-left: 1px solid var(--line-strong); }
.mobile-builder-link { display: none; height: auto; font-size: 13px; }

.app { width: min(1320px, calc(100% - 48px)); margin: 0 auto; }
.entry-view {
  position: relative;
  isolation: isolate;
  overflow: hidden;
  max-width: 900px;
  margin: 0 auto;
  padding: 78px 0 90px;
}
.entry-art {
  position: absolute;
  z-index: 0;
  top: -18px;
  right: -214px;
  width: min(840px, 94vw);
  height: 392px;
  object-fit: cover;
  object-position: right center;
  opacity: .76;
  pointer-events: none;
}
.entry-view > * { position: relative; z-index: 1; }
.entry-view > .entry-art { position: absolute; z-index: 0; }
.entry-copy { max-width: 760px; }
.eyebrow, .view-label, .lesson-group, .media-label {
  margin: 0 0 10px;
  color: var(--gold-deep);
  font-size: 13px;
  font-weight: 750;
  letter-spacing: .055em;
}
.entry-copy h1, .learn-heading h1, .guide-heading h1 {
  margin: 0;
  font-size: clamp(31px, 4.2vw, 46px);
  line-height: 1.22;
  letter-spacing: -.038em;
}
.entry-lede, .learn-heading > p:last-child, .guide-heading > p:last-child {
  max-width: 720px;
  margin: 14px 0 0;
  color: var(--muted);
  font-size: 20px;
  line-height: 1.6;
}
.entry-settings {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 28px;
  margin: 46px 0 20px;
  padding: 20px 0;
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
}
.entry-settings h2 { margin: 0; font-size: 17px; line-height: 1.35; }
.entry-settings p { margin: 5px 0 0; color: var(--muted); font-size: 14px; }
.platform-picker { display: inline-flex; padding: 3px; border: 1px solid var(--line-strong); border-radius: 6px; background: #fafbfc; }
.platform-choice {
  min-width: 84px;
  min-height: 39px;
  padding: 7px 18px;
  border: 0;
  border-radius: 4px;
  background: transparent;
  color: var(--muted);
  font-size: 15px;
  font-weight: 750;
  cursor: pointer;
}
.platform-choice:hover { color: var(--ink); }
.platform-choice.is-selected { background: var(--gold-soft); color: var(--gold-deep); box-shadow: inset 0 0 0 1px #dec78e; }
.mode-choices { display: grid; gap: 12px; }
.mode-card {
  display: grid;
  grid-template-columns: 44px minmax(0, 1fr) auto;
  align-items: center;
  gap: 17px;
  width: 100%;
  padding: 20px 22px;
  border: 1px solid var(--line);
  border-radius: 7px;
  background: #fff;
  color: inherit;
  text-align: left;
  box-shadow: 0 10px 28px rgba(24,34,53,.035);
  cursor: pointer;
  transition: border-color .18s ease, box-shadow .18s ease, transform .18s ease;
}
.mode-card:hover { border-color: #d2b875; box-shadow: var(--shadow); transform: translateY(-1px); }
.mode-card-icon { display: inline-grid; place-items: center; width: 40px; height: 40px; border: 1px solid #d7be7c; border-radius: 50%; color: var(--gold-deep); font-weight: 800; }
.mode-card-icon .icon { width: 21px; height: 21px; stroke-width: 1.8; vertical-align: 0; }
.mode-card-copy { display: grid; gap: 3px; }
.mode-card-copy strong { font-size: 18px; line-height: 1.35; }
.mode-card-copy span { color: var(--muted); font-size: 14px; line-height: 1.6; }
.mode-card-arrow { display: inline-flex; color: var(--gold-deep); }
.mode-card-arrow .icon { width: 22px; height: 22px; stroke-width: 1.8; vertical-align: 0; }
.entry-note { margin-top: 34px; border-bottom: 1px solid var(--line); }
.entry-note summary, .troubleshooting summary { display: flex; align-items: center; justify-content: space-between; gap: 12px; padding: 14px 0; color: var(--muted); font-size: 14px; font-weight: 700; cursor: pointer; list-style: none; }
.entry-note summary::-webkit-details-marker, .troubleshooting summary::-webkit-details-marker { display: none; }
.entry-note summary span, .troubleshooting summary span { color: var(--soft); font-size: 18px; transition: transform .2s ease; }
details[open] > summary span[aria-hidden="true"] { transform: rotate(180deg); }
.entry-note p { margin: 0 0 16px; color: var(--muted); font-size: 14px; }

.mode-view { padding: 28px 0 70px; }
.mode-view.is-view-entering { animation: view-in .2s ease both; }
.mode-topline { display: flex; align-items: center; justify-content: space-between; gap: 16px; margin-bottom: 35px; }
.back-to-entry { color: var(--muted); font-size: 14px; text-decoration: none; }
.back-to-entry:hover { color: var(--gold-deep); }
.mode-switch { display: inline-flex; gap: 18px; }
.mode-switch a { color: var(--muted); font-size: 14px; font-weight: 700; text-decoration: none; }
.mode-switch a:hover, .mode-switch a.is-active { color: var(--gold-deep); }
.learn-layout { display: block; }
.learn-main { width: min(100%, 780px); margin: 0 auto; }
.learn-heading, .guide-heading { margin-bottom: 20px; }
.learn-heading .view-label, .guide-heading .view-label { margin-bottom: 8px; }
.learn-heading h1, .guide-heading h1 { font-size: clamp(27px, 3.4vw, 38px); }
.learn-heading > p:last-child, .guide-heading > p:last-child { margin-top: 8px; font-size: 17px; }
.learn-progress { margin: 26px 0 27px; }
.progress-meta { display: flex; justify-content: space-between; gap: 12px; margin-bottom: 8px; color: var(--soft); font-size: 13px; font-variant-numeric: tabular-nums; }
.progress-track { height: 7px; overflow: hidden; border-radius: 10px; background: #e9edf1; }
.progress-track span { display: block; width: 0; height: 100%; border-radius: inherit; background: var(--gold); transition: width .25s ease; }
.lesson-host { min-height: 350px; }
.learn-lesson { padding: 27px 30px 31px; border: 1px solid var(--line); border-radius: 7px; box-shadow: var(--shadow); }
.learn-lesson.is-lesson-entering { animation: lesson-in .18s ease both; }
.lesson-heading, .guide-lesson-heading { display: flex; align-items: flex-start; gap: 16px; padding-bottom: 21px; border-bottom: 1px solid var(--line); }
.lesson-index { flex: 0 0 auto; display: inline-grid; place-items: center; min-width: 39px; height: 39px; padding: 0 7px; border: 1px solid #d7be7c; border-radius: 50%; color: var(--gold-deep); font-size: 13px; font-weight: 800; line-height: 1.1; }
.lesson-heading h2, .guide-lesson-heading h2 { margin: 0; font-size: 25px; line-height: 1.35; letter-spacing: -.025em; }
.lesson-heading > div:last-child > p:last-child, .guide-lesson-heading > div:last-child > p:last-child { margin: 5px 0 0; color: var(--muted); font-size: 15px; line-height: 1.6; }
.lesson-heading .lesson-group, .guide-lesson-heading .lesson-group { margin-bottom: 3px; font-size: 12px; }
.lesson-copy { padding-top: 23px; }
.learn-compact { padding-top: 21px; }
.learn-prompt { max-width: 690px; margin: 0; color: var(--ink); font-size: 17px; line-height: 1.65; }
.learn-result { display: flex; align-items: flex-start; gap: 10px; margin-top: 21px; padding: 11px 13px; border-left: 3px solid var(--gold); background: var(--gold-soft); }
.learn-result .result-icon { width: 20px; height: 20px; font-size: 12px; }
.learn-result p { margin: 0; color: #6f603c; font-size: 14px; line-height: 1.55; }
.learn-result strong { display: block; margin-bottom: 1px; color: #675326; font-size: 13px; }
.completion-card { display: grid; grid-template-columns: 52px minmax(0, 1fr); gap: 16px; align-items: start; margin-top: 26px; padding: 24px; border: 1px solid #e2d2a8; border-radius: 10px; background: linear-gradient(135deg, #fffdf8, #fbf8f0); }
.completion-mark { display: grid; place-items: center; width: 48px; height: 48px; border-radius: 50%; background: var(--gold); color: #fff; }
.completion-mark .icon { width: 25px; height: 25px; stroke-width: 2.4; }
.completion-kicker { margin: 0 0 4px; color: var(--gold-deep); font-size: 12px; font-weight: 800; letter-spacing: .08em; text-transform: uppercase; }
.completion-card h3 { margin: 0; font-size: 22px; line-height: 1.35; }
.completion-card p:last-child { margin: 7px 0 0; color: var(--muted); font-size: 15px; line-height: 1.6; }
.completion-actions { display: flex; flex-wrap: wrap; gap: 10px; margin-top: 22px; }
.completion-actions .button { text-decoration: none; }
.lesson-details { margin-top: 16px; border-bottom: 1px solid var(--line); }
.lesson-details summary { display: flex; align-items: center; justify-content: space-between; gap: 10px; padding: 11px 0; color: var(--muted); font-size: 13px; font-weight: 750; cursor: pointer; list-style: none; }
.lesson-details summary::-webkit-details-marker { display: none; }
.lesson-details summary .icon { color: var(--soft); transition: transform .18s ease; }
.lesson-details[open] summary .icon { transform: rotate(180deg); }
.lesson-details .instruction-list { padding: 0 0 16px; }
.detail-troubleshooting { padding: 3px 0 15px; color: var(--muted); font-size: 14px; }
.detail-troubleshooting strong { color: var(--ink); font-size: 13px; }
.detail-troubleshooting ul { margin: 5px 0 0; padding-left: 21px; }
.ready-platform { display: flex; align-items: center; justify-content: space-between; gap: 14px; margin-bottom: 17px; padding: 12px 13px; border: 1px solid var(--line); border-radius: 5px; background: #fff; }
.ready-platform > div:first-child { display: grid; gap: 1px; }
.ready-platform strong { font-size: 14px; }
.ready-platform span { color: var(--muted); font-size: 12px; }
.ready-platform .platform-picker { flex: 0 0 auto; }
.prep-chips { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 7px; margin: 0 0 20px; }
.prep-chips > span { display: flex; align-items: center; gap: 7px; min-height: 40px; padding: 7px 9px; border: 1px solid var(--line); border-radius: 4px; color: var(--muted); font-size: 11px; line-height: 1.35; }
.prep-chips > span > .icon { width: 17px; height: 17px; flex: 0 0 auto; color: var(--gold-deep); stroke-width: 1.65; }
.prep-chips > span > span { display: block; }
.lesson-platform-note { display: inline-flex; flex-wrap: wrap; align-items: center; gap: 9px; margin: 0 0 18px; padding: 8px 11px; border-left: 3px solid var(--gold); background: var(--gold-soft); color: var(--muted); font-size: 14px; }
.lesson-platform-note strong { color: var(--gold-deep); }
.instruction-list { display: grid; gap: 18px; margin: 0; padding: 0; list-style: none; }
.instruction-list li { display: grid; grid-template-columns: 29px minmax(0, 1fr); align-items: start; gap: 12px; }
.instruction-number { display: inline-grid; place-items: center; width: 28px; height: 28px; border: 1px solid var(--line-strong); border-radius: 50%; color: var(--muted); font-size: 12px; font-weight: 800; line-height: 1; }
.instruction-list strong { display: block; font-size: 16px; line-height: 1.45; }
.instruction-list p { margin: 3px 0 0; color: var(--muted); font-size: 15px; line-height: 1.65; }
code { padding: 1px 4px; border-radius: 3px; background: #f4f5f7; color: #4b586c; font-family: var(--mono); font-size: .88em; }
.inline-builder-link { display: inline-flex; align-items: center; gap: 8px; margin-top: 18px; color: var(--gold-deep); font-size: 14px; font-weight: 750; text-decoration: none; }
.inline-builder-link:hover { text-decoration: underline; text-underline-offset: 4px; }

.lesson-media { margin: 28px 0 0; border: 1px solid var(--line); border-radius: 6px; overflow: hidden; background: #fafbfc; }
.media-head { display: flex; align-items: center; justify-content: space-between; gap: 14px; padding: 14px 16px; border-bottom: 1px solid var(--line); }
.media-head-compact { padding: 9px 11px; justify-content: flex-end; }
.media-head figcaption { font-size: 15px; font-weight: 750; line-height: 1.4; }
.media-label { margin-bottom: 2px; font-size: 11px; }
.media-actions { display: inline-flex; gap: 4px; }
.media-mode-button { padding: 7px 10px; border: 1px solid var(--line-strong); border-radius: 4px; background: #fff; color: var(--muted); font-size: 12px; font-weight: 700; cursor: pointer; }
.media-mode-button.is-active { border-color: #d1b36a; background: var(--gold-soft); color: var(--gold-deep); }
.media-frame { position: relative; display: grid; place-items: center; min-height: 170px; background: #f0f2f5; }
.media-frame.is-still { min-height: 0; background: #fff; }
.media-video, .media-still { display: block; width: 100%; max-height: 420px; object-fit: contain; background: #edf0f3; }
.media-still { max-height: 420px; object-fit: contain; }
.media-demo { aspect-ratio: auto; }
.media-play { position: absolute; right: 12px; bottom: 12px; padding: 7px 11px; border: 1px solid rgba(255,255,255,.8); border-radius: 4px; background: rgba(24,34,53,.78); color: #fff; font-size: 12px; font-weight: 750; cursor: pointer; }
.media-error { padding: 24px; color: var(--muted); font-size: 14px; }
.media-caption { margin: 0; padding: 9px 14px 11px; color: var(--soft); font-size: 12px; line-height: 1.5; }
.expected-result { display: flex; align-items: flex-start; gap: 11px; margin-top: 25px; padding: 13px 14px; border: 1px solid #e5ddc4; border-radius: 5px; background: var(--gold-soft); }
.result-icon { display: inline-grid; place-items: center; width: 22px; height: 22px; flex: 0 0 auto; margin-top: 1px; border-radius: 50%; background: var(--gold); color: #fff; font-size: 13px; font-weight: 800; line-height: 1; }
.result-icon .icon { width: 15px; height: 15px; stroke-width: 2.1; vertical-align: 0; }
.expected-result strong { display: block; color: #675326; font-size: 14px; }
.expected-result p { margin: 2px 0 0; color: #766741; font-size: 14px; line-height: 1.6; }
.troubleshooting { margin-top: 4px; border-bottom: 1px solid var(--line); }
.troubleshooting ul { margin: 0 0 14px; padding: 0 0 0 23px; color: var(--muted); font-size: 14px; }
.troubleshooting li { padding: 2px 0; }
.manual-checks { margin-top: 25px; padding: 15px 16px 13px; border: 1px solid var(--line); border-radius: 5px; background: #fff; }
.manual-checks > strong { display: block; margin-bottom: 7px; font-size: 14px; }
.manual-checks ul { display: grid; gap: 5px; margin: 0; padding: 0; list-style: none; }
.manual-checks label { display: flex; align-items: flex-start; gap: 9px; color: var(--muted); font-size: 14px; line-height: 1.5; cursor: pointer; }
.manual-checks input { position: absolute; width: 1px; height: 1px; overflow: hidden; clip: rect(0,0,0,0); }
.manual-box { width: 18px; height: 18px; flex: 0 0 auto; margin-top: 2px; border: 1px solid var(--line-strong); border-radius: 3px; background: #fff; }
.manual-checks input:checked + .manual-box { border-color: var(--success); background: var(--success); box-shadow: inset 0 0 0 3px #fff; }
.lesson-actions { display: flex; align-items: center; justify-content: space-between; gap: 13px; margin-top: 24px; }
.button { display: inline-flex; align-items: center; justify-content: center; gap: 9px; min-height: 43px; padding: 9px 16px; border: 1px solid transparent; border-radius: 5px; font-size: 14px; font-weight: 750; line-height: 1.25; text-decoration: none; cursor: pointer; transition: background .18s ease, border-color .18s ease, color .18s ease, transform .18s ease; }
.button .icon { width: 17px; height: 17px; vertical-align: 0; }
.button:hover { transform: translateY(-1px); }
.button:disabled { opacity: .45; cursor: not-allowed; transform: none; }
.button-primary { background: var(--gold); color: #fff; }
.button-primary:hover { background: var(--gold-deep); }
.button-secondary { border-color: var(--line-strong); background: #fff; color: var(--muted); }
.button-secondary:hover { border-color: var(--gold); color: var(--gold-deep); }
.learn-rail { display: none; }

.guide-layout { display: grid; grid-template-columns: minmax(0, 1fr) 255px; gap: 48px; align-items: start; }
.guide-main { min-width: 0; }
.guide-platform-row { display: flex; align-items: center; gap: 13px; margin: 27px 0 32px; color: var(--muted); font-size: 14px; }
.platform-picker-compact { padding: 2px; }
.platform-picker-compact .platform-choice { min-width: 63px; min-height: 33px; padding: 5px 10px; font-size: 13px; }
.guide-list { display: grid; gap: 40px; }
.guide-lesson { scroll-margin-top: 91px; padding: 27px 0 42px; border-bottom: 1px solid var(--line); }
.guide-lesson.is-current .lesson-index { background: var(--gold-soft); }
.guide-lesson-heading { padding-bottom: 21px; }
.guide-lesson-heading h2 { font-size: 24px; }
.guide-lesson .lesson-copy { padding-top: 22px; }
.guide-lesson .lesson-media { max-width: 850px; }
.guide-lesson-actions { display: flex; align-items: center; justify-content: space-between; gap: 14px; margin-top: 20px; }
.guide-learn-link { color: var(--gold-deep); font-size: 13px; font-weight: 750; text-decoration: none; }
.guide-learn-link .icon { width: 16px; height: 16px; vertical-align: -.26em; }
.guide-learn-link:hover { text-decoration: underline; text-underline-offset: 4px; }
.guide-complete { padding: 8px 12px; border: 1px solid var(--line-strong); border-radius: 4px; background: #fff; color: var(--muted); font-size: 13px; font-weight: 750; cursor: pointer; }
.guide-complete:hover { border-color: var(--gold); color: var(--gold-deep); }
.guide-complete.is-complete { border-color: #a8cbb7; background: #f3faf5; color: var(--success); }
.guide-toc { position: sticky; top: 91px; min-width: 0; }
.toc-desktop { padding-left: 21px; border-left: 1px solid var(--line); }
.toc-desktop h2 { margin: 0 0 16px; font-size: 16px; }
.toc-nav { display: grid; gap: 5px; }
.toc-group { display: grid; gap: 3px; margin-bottom: 13px; }
.toc-group > p { margin: 0 0 3px; color: var(--gold-deep); font-size: 11px; font-weight: 800; letter-spacing: .06em; text-transform: uppercase; }
.toc-item { display: grid; grid-template-columns: 24px minmax(0, 1fr) 14px; align-items: center; gap: 7px; padding: 6px 7px; border-radius: 4px; color: var(--muted); font-size: 12px; line-height: 1.35; text-decoration: none; }
.toc-item span { color: var(--soft); font-variant-numeric: tabular-nums; }
.toc-item strong { font-weight: 600; }
.toc-item em { color: var(--success); font-size: 12px; font-style: normal; text-align: right; }
.toc-item:hover { background: #f5f6f8; color: var(--ink); }
.toc-item.is-active { background: var(--gold-soft); color: var(--gold-deep); }
.toc-item.is-complete strong { color: var(--success); }
.toc-progress { margin-top: 20px; }
.toc-progress .progress-track { height: 5px; }
.toc-progress p { margin: 7px 0 0; color: var(--soft); font-size: 12px; }
.toc-mobile { display: none; }

.site-footer { width: min(1320px, calc(100% - 48px)); margin: 0 auto; padding: 21px 0 30px; border-top: 1px solid var(--line); display: flex; justify-content: space-between; gap: 18px; color: var(--soft); font-size: 12px; }
.site-footer a { color: var(--muted); text-decoration: none; }
.site-footer a:hover { color: var(--gold-deep); }

@keyframes view-in { from { opacity: .01; transform: translateY(4px); } to { opacity: 1; transform: translateY(0); } }
@keyframes lesson-in { from { opacity: .01; transform: translateY(4px); } to { opacity: 1; transform: translateY(0); } }

@media (max-width: 920px) {
  .top-nav .docs-link { display: none; }
  .guide-layout { grid-template-columns: minmax(0, 1fr) 220px; gap: 27px; }
  .toc-desktop { padding-left: 16px; }
}

@media (max-width: 720px) {
  body { font-size: 16px; }
  .site-header { height: 60px; }
  .header-inner, .app, .site-footer { width: min(100% - 32px, 680px); }
  .top-nav { display: none; }
  .mobile-builder-link { display: inline-flex; }
  .entry-view { padding: 49px 0 64px; }
  .entry-art {
    top: 4px;
    right: -230px;
    width: 650px;
    height: 286px;
    opacity: .44;
  }
  .entry-copy h1 { font-size: clamp(29px, 8vw, 38px); }
  .entry-lede { font-size: 17px; }
  .entry-settings { display: grid; gap: 17px; margin-top: 34px; }
  .mode-card { grid-template-columns: 38px minmax(0, 1fr) auto; gap: 12px; padding: 16px; }
  .mode-card-icon { width: 34px; height: 34px; }
  .mode-card-copy strong { font-size: 16px; }
  .mode-card-copy span { font-size: 13px; }
  .mode-card-arrow { font-size: 20px; }
  .mode-view { padding-top: 20px; }
  .mode-topline { margin-bottom: 16px; }
  .learn-main { width: 100%; }
  .learn-heading, .guide-heading { margin-bottom: 16px; }
  .learn-heading h1, .guide-heading h1 { font-size: 28px; }
  .learn-heading > p:last-child, .guide-heading > p:last-child { font-size: 16px; }
  .learn-progress { margin: 18px 0 18px; }
  .learn-lesson { padding: 16px 14px 18px; }
  .lesson-heading h2, .guide-lesson-heading h2 { font-size: 22px; }
  .lesson-heading, .guide-lesson-heading { gap: 11px; }
  .lesson-heading { padding-bottom: 14px; }
  .lesson-index { min-width: 34px; height: 34px; font-size: 12px; }
  .instruction-list { gap: 15px; }
  .instruction-list strong { font-size: 15px; }
  .instruction-list p { font-size: 14px; }
  .ready-platform { align-items: flex-start; flex-direction: column; gap: 8px; margin-bottom: 12px; padding: 9px; }
  .ready-platform .platform-picker { width: 100%; }
  .ready-platform .platform-choice { flex: 1; }
  .prep-chips { grid-template-columns: 1fr; gap: 6px; }
  .prep-chips > span { min-height: 31px; padding: 5px 8px; }
  .learn-result { margin-top: 14px; padding: 9px 10px; }
  .completion-card { grid-template-columns: 40px minmax(0, 1fr); gap: 12px; margin-top: 18px; padding: 17px 15px; }
  .completion-mark { width: 38px; height: 38px; }
  .completion-mark .icon { width: 20px; height: 20px; }
  .completion-card h3 { font-size: 19px; }
  .completion-card p:last-child { font-size: 14px; }
  .completion-actions { display: grid; }
  .completion-actions .button { width: 100%; }
  .lesson-details { margin-top: 10px; }
  .lesson-actions { margin-top: 16px; }
  .media-head { align-items: flex-start; flex-direction: column; }
  .media-actions { width: 100%; }
  .media-mode-button { flex: 1; }
  .media-video, .media-still { max-height: 360px; }
  .guide-layout { display: flex; flex-direction: column; gap: 0; }
  .guide-main { width: 100%; min-width: 0; }
  .guide-toc { order: -1; width: 100%; position: sticky; top: 59px; z-index: 15; margin-bottom: 26px; background: #fff; }
  .toc-desktop { display: none; }
  .toc-mobile { display: block; border: 1px solid var(--line); border-radius: 5px; background: #fff; }
  .toc-mobile summary { display: flex; justify-content: space-between; padding: 11px 13px; color: var(--muted); font-size: 14px; font-weight: 750; cursor: pointer; list-style: none; }
  .toc-mobile summary::-webkit-details-marker { display: none; }
  .toc-mobile summary span:last-child { transition: transform .2s ease; }
  .toc-mobile[open] summary span:last-child { transform: rotate(180deg); }
  .toc-nav-mobile { padding: 2px 8px 10px; max-height: 60vh; overflow-y: auto; }
  .toc-nav-mobile .toc-group { margin: 7px 0; }
  .guide-list { gap: 12px; }
  .guide-lesson { scroll-margin-top: 120px; padding: 25px 0 35px; }
  .guide-platform-row { justify-content: space-between; margin: 22px 0 24px; }
  .site-footer { display: grid; gap: 5px; }
}

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { scroll-behavior: auto !important; transition: none !important; }
  .mode-view.is-view-entering, .learn-lesson.is-lesson-entering { animation: none !important; }
}

/* Dashboard layout inspired by the supplied customer reference. */
body {
  padding: 28px 0;
  background: #dcefff;
}
.site-header,
.app,
.site-footer {
  width: min(1520px, calc(100% - 64px));
  background: #fff;
}
.site-header {
  top: 14px;
  margin: 0 auto;
  border: 1px solid rgba(174, 197, 215, .7);
  border-bottom-color: var(--line);
  border-radius: 24px 24px 0 0;
  box-shadow: 0 20px 58px rgba(64, 105, 136, .16);
}
.header-inner { width: 100%; padding: 0 28px; justify-content: space-between; }
.brand-word {
  display: inline-flex;
  align-items: center;
  flex: 0 0 auto;
  color: var(--ink);
  font-size: 20px;
  font-weight: 850;
  letter-spacing: -.045em;
  line-height: 1;
  text-decoration: none;
}
.brand-word::before {
  content: "";
  width: 7px;
  height: 7px;
  margin-right: 9px;
  border-radius: 2px;
  background: var(--gold);
  transform: rotate(45deg);
}
.brand-word:hover { color: var(--gold-deep); }
.app {
  min-height: calc(100vh - 170px);
  padding: 0 28px;
  border-right: 1px solid rgba(174, 197, 215, .7);
  border-left: 1px solid rgba(174, 197, 215, .7);
  box-shadow: 0 20px 58px rgba(64, 105, 136, .16);
}
.site-footer {
  margin: 0 auto;
  padding: 18px 28px 22px;
  border: 1px solid rgba(174, 197, 215, .7);
  border-top-color: var(--line);
  border-radius: 0 0 24px 24px;
  box-shadow: 0 28px 58px rgba(64, 105, 136, .16);
}
.mode-view { padding-top: 22px; }
.mode-topline { margin-bottom: 24px; }

.learn-layout {
  display: grid;
  grid-template-columns: 232px minmax(0, 1fr) 270px;
  align-items: start;
  gap: 28px;
}
.learn-main { width: 100%; min-width: 0; margin: 0; }
.learn-progress { margin: 0 0 20px; }
.learn-lesson {
  padding: 25px 26px 29px;
  border-color: #dfe6ec;
  border-radius: 12px;
  box-shadow: 0 8px 28px rgba(31, 55, 75, .07);
}

.learn-rail,
.learn-status { display: block; min-width: 0; }
.rail-panel,
.status-panel {
  position: sticky;
  top: 98px;
  overflow: hidden;
  border: 1px solid #e0e7ed;
  border-radius: 12px;
  background: #fff;
}
.rail-heading {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 16px 16px 14px;
  border-bottom: 1px solid var(--line);
}
.rail-heading h2 { margin: 0; font-size: 15px; line-height: 1.35; }
.rail-mark {
  width: 9px;
  height: 9px;
  border: 2px solid var(--gold);
  border-radius: 3px;
  transform: rotate(45deg);
}
.learn-nav {
  display: grid;
  max-height: calc(100vh - 190px);
  padding: 10px 8px 14px;
  overflow-y: auto;
}
.learn-nav-group { display: grid; gap: 3px; padding: 7px 0 9px; }
.learn-nav-group + .learn-nav-group { border-top: 1px solid #edf1f4; }
.learn-nav-group > p {
  margin: 0;
  padding: 4px 9px 5px;
  color: #98a5b2;
  font-size: 10px;
  font-weight: 800;
  letter-spacing: .08em;
  text-transform: uppercase;
}
.learn-nav-item {
  display: grid;
  grid-template-columns: 25px minmax(0, 1fr) 14px;
  align-items: center;
  gap: 7px;
  min-height: 39px;
  padding: 7px 8px;
  border-radius: 7px;
  color: #667487;
  font-size: 12px;
  line-height: 1.35;
  text-decoration: none;
  transition: background .16s ease, color .16s ease, transform .16s ease;
}
.learn-nav-item:hover { background: #f3f7fa; color: var(--ink); transform: translateX(2px); }
.learn-nav-item > span {
  display: inline-grid;
  place-items: center;
  width: 23px;
  height: 23px;
  border: 1px solid #dce4ea;
  border-radius: 50%;
  color: #8693a1;
  font-size: 10px;
  font-variant-numeric: tabular-nums;
}
.learn-nav-item strong { overflow: hidden; font-weight: 650; text-overflow: ellipsis; white-space: nowrap; }
.learn-nav-item em { color: var(--success); font-size: 11px; font-style: normal; text-align: center; }
.learn-nav-item.is-active { background: #f5f8fa; color: var(--ink); box-shadow: inset 3px 0 0 var(--gold); }
.learn-nav-item.is-active > span { border-color: #d3b568; background: var(--gold-soft); color: var(--gold-deep); }
.learn-nav-item.is-complete strong { color: var(--success); }

.status-tabs {
  display: grid;
  grid-template-columns: 1fr 1fr;
  border-bottom: 1px solid var(--line);
}
.status-tabs strong,
.status-tabs a {
  position: relative;
  padding: 13px 12px;
  color: #7a8794;
  font-size: 12px;
  text-align: center;
  text-decoration: none;
}
.status-tabs strong { color: var(--ink); }
.status-tabs strong::after {
  content: "";
  position: absolute;
  right: 24%;
  bottom: -1px;
  left: 24%;
  height: 2px;
  background: var(--gold);
}
.status-summary { display: grid; padding: 18px 18px 16px; border-bottom: 1px solid var(--line); }
.status-summary > span { color: #7d8996; font-size: 11px; font-weight: 700; }
.status-summary > strong { margin-top: 3px; color: var(--ink); font-size: 32px; line-height: 1.15; font-variant-numeric: tabular-nums; }
.status-summary > small { margin-top: 2px; color: #95a0ac; font-size: 11px; }
.status-timeline { display: grid; padding: 18px 17px 9px; }
.status-step {
  position: relative;
  display: grid;
  grid-template-columns: 28px minmax(0, 1fr);
  gap: 10px;
  min-height: 67px;
}
.status-step:not(:last-child)::after {
  content: "";
  position: absolute;
  top: 29px;
  bottom: 3px;
  left: 13px;
  width: 1px;
  background: #dce4ea;
}
.status-step > span {
  position: relative;
  z-index: 1;
  display: inline-grid;
  place-items: center;
  width: 28px;
  height: 28px;
  border: 1px solid #dce4ea;
  border-radius: 50%;
  background: #fff;
  color: #8996a4;
  font-size: 11px;
  font-weight: 800;
}
.status-step > div { display: grid; align-content: start; padding-top: 2px; }
.status-step strong { font-size: 12px; line-height: 1.4; }
.status-step small { margin-top: 2px; color: #97a2ad; font-size: 10px; }
.status-step.is-active > span { border-color: #30a3e7; background: #30a3e7; color: #fff; box-shadow: 0 0 0 4px #e9f6fd; }
.status-step.is-complete > span { border-color: #3daf72; background: #3daf72; color: #fff; }
.status-current { display: grid; gap: 3px; margin: 0 17px 15px; padding: 12px 13px; border: 1px solid #e0e7ed; border-radius: 8px; background: #f8fafc; }
.status-current span { color: #8b98a5; font-size: 10px; font-weight: 750; }
.status-current strong { font-size: 12px; line-height: 1.45; }
.status-help { display: block; padding: 12px 17px 15px; border-top: 1px solid var(--line); color: var(--gold-deep); font-size: 11px; font-weight: 750; text-decoration: none; }
.status-help:hover { text-decoration: underline; text-underline-offset: 3px; }

@media (max-width: 1160px) {
  .learn-layout { grid-template-columns: 214px minmax(0, 1fr); gap: 24px; }
  .learn-status { display: none; }
}

@media (max-width: 820px) {
  body { padding: 0; background: #fff; }
  .site-header,
  .app,
  .site-footer { width: 100%; border-right: 0; border-left: 0; border-radius: 0; box-shadow: none; }
  .site-header { top: 0; border-top: 0; }
  .header-inner, .app { padding-right: 16px; padding-left: 16px; }
  .brand-word { font-size: 18px; }
  .site-footer { padding-right: 16px; padding-left: 16px; }
  .learn-layout { display: block; }
  .learn-rail,
  .learn-status { display: none; }
  .learn-lesson { border-radius: 9px; }
}