:root {
  --bg: #050a0f;
  --bg-2: #09131a;
  --panel: #0c171e;
  --panel-2: #101d25;
  --ink: #f5f8fb;
  --muted: #9aa9b4;
  --line: rgba(207, 224, 234, .16);
  --line-strong: rgba(207, 224, 234, .28);
  --cyan: #6de0d2;
  --blue: #8caaff;
  --gold: #e2bd70;
  --shadow: 0 28px 90px rgba(0, 0, 0, .36);
}

* { box-sizing: border-box; }

html {
  background: var(--bg);
  scroll-behavior: smooth;
}

body {
  min-width: 320px;
  margin: 0;
  color: var(--ink);
  font-family: Inter, "PingFang SC", "Microsoft YaHei", system-ui, sans-serif;
  line-height: 1.65;
  background:
    linear-gradient(rgba(187, 210, 224, .035) 1px, transparent 1px),
    linear-gradient(90deg, rgba(187, 210, 224, .035) 1px, transparent 1px),
    linear-gradient(145deg, #050a0f 0%, #09141b 54%, #071018 100%);
  background-size: 88px 88px, 88px 88px, auto;
}

body::before { content: none; }

a { color: inherit; text-decoration: none; }
button { color: inherit; font: inherit; }
h1, h2, p { margin-top: 0; }

.topbar {
  position: sticky;
  top: 0;
  z-index: 30;
  border-bottom: 1px solid var(--line);
  background: rgba(5, 10, 15, .84);
  backdrop-filter: blur(18px);
}

.nav,
.wrap,
.footer-inner {
  width: min(1180px, calc(100% - 40px));
  margin: 0 auto;
}

.nav {
  min-height: 66px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 11px;
  font-weight: 900;
  white-space: nowrap;
}

.mark {
  width: 38px;
  height: 38px;
  display: grid;
  place-items: center;
  border: 1px solid rgba(140, 170, 255, .32);
  border-radius: 8px;
  color: #dce5ff;
  background: #0d1720;
  box-shadow: inset 0 0 20px rgba(140, 170, 255, .08);
}

.links {
  display: flex;
  gap: 4px;
  color: #9dabb5;
  font-size: 14px;
  font-weight: 800;
}

.links a {
  padding: 8px 11px;
  border: 1px solid transparent;
  border-radius: 6px;
  white-space: nowrap;
  transition: color .2s ease, border-color .2s ease, background .2s ease;
}

.links a:hover,
.links a.active {
  color: #fff;
  border-color: var(--line);
  background: rgba(255, 255, 255, .05);
}

.hero { padding: 38px 0 22px; }

.hero-intro {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 310px;
  align-items: end;
  gap: 48px;
}

.eyebrow {
  margin-bottom: 9px;
  color: var(--blue);
  font-size: 12px;
  font-weight: 900;
}

h1 {
  max-width: 880px;
  margin-bottom: 12px;
  font-size: clamp(36px, 4.1vw, 52px);
  line-height: 1.12;
  letter-spacing: 0;
}

.lead {
  max-width: 760px;
  margin-bottom: 0;
  color: #adbac3;
  font-size: 17px;
}

.chips {
  display: flex;
  flex-wrap: wrap;
  gap: 7px;
  margin-top: 16px;
}

.chip {
  min-height: 28px;
  display: inline-flex;
  align-items: center;
  padding: 4px 9px;
  border: 1px solid var(--line);
  border-radius: 5px;
  color: #bbc7cf;
  background: rgba(255, 255, 255, .035);
  font-size: 12px;
  font-weight: 800;
}

.chip.is-test {
  color: #07110f;
  border-color: transparent;
  background: var(--cyan);
}

.access-summary {
  min-height: 124px;
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto;
  align-content: center;
  gap: 3px 14px;
  padding: 16px 0 16px 18px;
  border-left: 2px solid var(--cyan);
}

.access-summary.is-closed { border-left-color: var(--gold); }
.access-kicker { color: var(--muted); font-size: 11px; font-weight: 800; }
.access-summary strong { grid-column: 1; font-size: 19px; line-height: 1.35; }
.access-note { grid-column: 1; color: var(--muted); font-size: 12px; }
.access-price { grid-column: 2; grid-row: 1 / span 2; align-self: center; color: var(--gold); font-weight: 900; }

.source-action {
  grid-column: 2;
  grid-row: 1 / span 3;
  align-self: center;
  min-height: 40px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 8px 13px;
  border: 1px solid var(--cyan);
  border-radius: 6px;
  color: #06110f;
  background: var(--cyan);
  font-size: 13px;
  font-weight: 900;
}

.source-action.is-disabled {
  color: #8e9ba4;
  border-color: var(--line);
  background: rgba(255, 255, 255, .035);
}

.preview-section { padding: 0 0 66px; }

.courseware-preview { margin-top: 8px; }

.preview-toolbar {
  min-height: 38px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  color: #8f9da7;
  font: 800 11px ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
}

.preview-stage {
  position: relative;
  aspect-ratio: 16 / 9;
  overflow: hidden;
  border: 1px solid var(--line-strong);
  border-radius: 8px;
  background: #071018;
  box-shadow: var(--shadow);
  isolation: isolate;
}

.preview-stage:focus-visible {
  outline: 2px solid var(--blue);
  outline-offset: 4px;
}

.preview-slide {
  position: absolute;
  inset: 0;
  display: grid;
  align-items: center;
  padding: clamp(34px, 6vw, 84px);
  opacity: 0;
  visibility: hidden;
  transform: translateX(18px);
  transition: opacity .28s ease, transform .28s ease;
}

.preview-slide.is-active {
  z-index: 2;
  opacity: 1;
  visibility: visible;
  transform: translateX(0);
}

.preview-art,
.preview-art::after {
  position: absolute;
  inset: 0;
}

.preview-art { overflow: hidden; }

.preview-art::after {
  content: "";
  background: linear-gradient(90deg, rgba(4, 10, 15, .96) 4%, rgba(4, 10, 15, .72) 48%, rgba(4, 10, 15, .12) 100%);
}

.preview-art .cover,
.preview-art .slide-frame,
.preview-art svg {
  width: 100%;
  height: 100%;
}

.preview-art .slide-frame { position: relative; }
.preview-art svg { display: block; transform: scale(1.15); }
.preview-art .cover-index,
.preview-art .slide-badge { display: none; }
.preview-slide:nth-child(2) .preview-art svg { transform: scale(1.28) translateX(4%); }
.preview-slide:nth-child(3) .preview-art svg { transform: scale(1.34) translateX(-3%); }

.preview-copy {
  position: relative;
  z-index: 2;
  width: min(64%, 690px);
}

.slide-eyebrow {
  display: block;
  margin-bottom: 12px;
  color: var(--cyan);
  font-size: clamp(11px, 1.2vw, 15px);
  font-weight: 900;
}

.poem .slide-eyebrow { color: var(--gold); }

.preview-copy h2 {
  margin-bottom: 14px;
  font-size: clamp(38px, 5.7vw, 76px);
  line-height: 1.08;
  letter-spacing: 0;
  text-shadow: 0 16px 44px rgba(0, 0, 0, .42);
}

.preview-copy p {
  max-width: 620px;
  margin-bottom: 20px;
  color: #d3dde3;
  font-size: clamp(15px, 1.7vw, 22px);
}

.slide-points {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.slide-points span {
  padding: 5px 9px;
  border: 1px solid rgba(255, 255, 255, .2);
  border-radius: 5px;
  color: #d9e4ea;
  background: rgba(5, 12, 17, .5);
  font-size: 12px;
  font-weight: 800;
  backdrop-filter: blur(8px);
}

.preview-controls {
  position: absolute;
  right: 18px;
  bottom: 18px;
  z-index: 5;
  min-height: 42px;
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 5px;
  border: 1px solid rgba(255, 255, 255, .17);
  border-radius: 7px;
  background: rgba(4, 10, 15, .66);
  backdrop-filter: blur(14px);
}

.preview-controls > button {
  width: 32px;
  height: 32px;
  display: grid;
  place-items: center;
  padding: 0;
  border: 0;
  border-radius: 5px;
  background: transparent;
  cursor: pointer;
  transition: color .2s ease, background .2s ease;
}

.preview-controls > button:hover { color: #07110f; background: var(--cyan); }
.poem .preview-controls > button:hover { background: var(--gold); }

.preview-dots { display: flex; align-items: center; gap: 5px; }

.preview-dot {
  width: 7px;
  height: 7px;
  padding: 0;
  border: 0;
  border-radius: 50%;
  background: rgba(255, 255, 255, .32);
  cursor: pointer;
  transition: width .2s ease, border-radius .2s ease, background .2s ease;
}

.preview-dot.is-active { width: 22px; border-radius: 4px; background: var(--cyan); }
.poem .preview-dot.is-active { background: var(--gold); }

.package-panel,
.more-info {
  margin-top: 18px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: rgba(10, 21, 28, .82);
}

.package-panel { padding: 20px; }

.package-head {
  display: flex;
  justify-content: space-between;
  gap: 20px;
  margin-bottom: 14px;
}

.package-head span { color: var(--muted); font-size: 12px; font-weight: 800; }
.package-head strong { color: var(--cyan); font-size: 13px; }

.package-files {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 8px;
  margin: 0;
  padding: 0;
  list-style: none;
}

.package-files li {
  min-height: 46px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  padding: 9px 11px;
  border: 1px solid var(--line);
  border-radius: 6px;
  color: #dbe4e9;
  font-size: 13px;
}

.package-files li span { color: var(--muted); font: 800 11px ui-monospace, SFMono-Regular, Menlo, monospace; }
.format-line { margin: 13px 0 0; color: var(--muted); font-size: 12px; }

.more-info { overflow: hidden; }

.more-info summary {
  min-height: 58px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 18px;
  padding: 0 18px;
  cursor: pointer;
  list-style: none;
  font-size: 14px;
  font-weight: 900;
}

.more-info summary::-webkit-details-marker { display: none; }
.summary-icon { color: var(--muted); font-size: 20px; transition: transform .2s ease; }
.more-info[open] .summary-icon { transform: rotate(45deg); }

.more-body {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 0 28px;
  padding: 18px;
  border-top: 1px solid var(--line);
}

.more-row {
  min-height: 54px;
  display: grid;
  grid-template-columns: 84px 1fr;
  gap: 14px;
  align-items: start;
  padding: 12px 0;
  border-bottom: 1px solid var(--line);
}

.more-row strong { color: #d4dee4; font-size: 12px; }
.more-row p { margin: 0; color: var(--muted); font-size: 12px; }
.use-case-tags { display: flex; flex-wrap: wrap; gap: 6px; }
.use-case-tags span { color: var(--muted); font-size: 12px; }
.use-case-tags span + span::before { content: "·"; margin-right: 6px; color: #65747e; }

.resource-code {
  grid-column: 1 / -1;
  padding-top: 14px;
  color: #65747e;
  font: 700 10px ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
}

footer {
  border-top: 1px solid var(--line);
  padding: 24px 0;
  color: #75848e;
  background: rgba(5, 10, 15, .72);
  font-size: 12px;
}

.footer-inner {
  display: flex;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 10px 24px;
}

:where(a, button, summary):focus-visible {
  outline: 2px solid var(--blue);
  outline-offset: 3px;
}

@media (max-width: 900px) {
  .hero-intro { grid-template-columns: 1fr; gap: 22px; }
  .access-summary { min-height: 82px; }
  .preview-copy { width: 74%; }
}

@media (max-width: 640px) {
  .nav {
    width: 100%;
    padding: 11px 14px 9px;
    align-items: stretch;
    flex-direction: column;
    gap: 8px;
  }

  .links {
    width: calc(100% + 28px);
    margin: 0 -14px;
    overflow-x: auto;
    padding: 0 14px 3px;
    scrollbar-width: none;
  }

  .links::-webkit-scrollbar { display: none; }
  .links a { flex: 0 0 auto; border-color: var(--line); background: rgba(255, 255, 255, .025); }
  .wrap,
  .footer-inner { width: calc(100% - 28px); }
  .hero { padding: 27px 0 16px; }
  h1 { font-size: 32px; }
  .lead { font-size: 15px; line-height: 1.7; }
  .chips { margin-top: 13px; }

  .access-summary {
    min-height: 70px;
    padding: 10px 0 10px 14px;
  }

  .access-summary strong { font-size: 17px; }
  .access-note { font-size: 11px; }
  .preview-section { padding-bottom: 42px; }
  .preview-toolbar { min-height: 32px; }
  .preview-stage { border-radius: 6px; }
  .preview-slide { padding: 20px 18px 54px; }
  .preview-copy { width: 82%; }
  .slide-eyebrow { margin-bottom: 7px; font-size: 9px; }
  .preview-copy h2 { margin-bottom: 7px; font-size: clamp(24px, 8vw, 31px); }
  .preview-copy p { margin-bottom: 10px; font-size: 11px; line-height: 1.45; }
  .slide-points { gap: 4px; }
  .slide-points span { padding: 3px 5px; border-radius: 3px; font-size: 8px; }
  .preview-controls { right: 8px; bottom: 8px; min-height: 34px; gap: 7px; padding: 3px; }
  .preview-controls > button { width: 27px; height: 27px; }
  .preview-dot { width: 5px; height: 5px; }
  .preview-dot.is-active { width: 15px; }
  .package-panel { padding: 14px; }
  .package-files { grid-template-columns: 1fr; }
  .more-info summary { min-height: 54px; padding: 0 14px; }
  .more-body { grid-template-columns: 1fr; padding: 12px 14px 14px; }
  .more-row { grid-template-columns: 76px 1fr; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after {
    transition-duration: .01ms !important;
    animation-duration: .01ms !important;
    animation-iteration-count: 1 !important;
  }
}