:root {
  --bg: #0b0c12;
  --bg-panel: rgba(20, 23, 34, 0.92);
  --bg-soft: rgba(28, 32, 45, 0.92);
  --ink: #f5efe4;
  --ink-soft: #d4cfc5;
  --ink-dim: #9aa0ad;
  --gold: #d6a44d;
  --gold-soft: rgba(214, 164, 77, 0.14);
  --cyan: #54b8ff;
  --cyan-soft: rgba(84, 184, 255, 0.12);
  --green: #3bd48e;
  --green-soft: rgba(59, 212, 142, 0.12);
  --red: #ff6b63;
  --red-soft: rgba(255, 107, 99, 0.12);
  --purple: #af8dff;
  --purple-soft: rgba(175, 141, 255, 0.12);
  --line: rgba(214, 164, 77, 0.16);
  --line-strong: rgba(214, 164, 77, 0.32);
  --shadow-lg: 0 28px 60px rgba(0, 0, 0, 0.32);
  --shadow-md: 0 16px 34px rgba(0, 0, 0, 0.24);
  --radius-xl: 34px;
  --radius-lg: 24px;
  --radius-md: 18px;
  --radius-sm: 14px;
  --max-width: 1380px;
}

* {
  box-sizing: border-box;
  min-width: 0;
}

html {
  scroll-behavior: smooth;
  background:
    radial-gradient(circle at 10% 0%, rgba(214, 164, 77, 0.12), transparent 24%),
    radial-gradient(circle at 100% 25%, rgba(84, 184, 255, 0.08), transparent 28%),
    linear-gradient(180deg, #0a0b11 0%, #0e1017 100%);
}

body {
  margin: 0;
  min-height: 100vh;
  color: var(--ink);
  font-family: "PingFang SC", "Hiragino Sans GB", "Noto Sans SC", sans-serif;
  background: var(--bg);
  overflow-x: clip;
}

h1,
h2,
h3,
p,
li {
  overflow-wrap: anywhere;
}

img {
  display: block;
  max-width: 100%;
}

a {
  color: inherit;
}

.ambient {
  position: fixed;
  border-radius: 999px;
  filter: blur(56px);
  pointer-events: none;
  z-index: 0;
}

.ambient-a {
  top: -120px;
  left: -100px;
  width: 420px;
  height: 420px;
  background: rgba(214, 164, 77, 0.12);
}

.ambient-b {
  right: -100px;
  top: 320px;
  width: 380px;
  height: 380px;
  background: rgba(84, 184, 255, 0.1);
}

.ambient-c {
  left: 40%;
  bottom: -120px;
  width: 420px;
  height: 420px;
  background: rgba(175, 141, 255, 0.08);
}

.hero,
.nav,
.page,
.footer {
  position: relative;
  z-index: 1;
}

.hero {
  width: min(var(--max-width), calc(100vw - 32px));
  margin: 0 auto;
  min-height: 100vh;
  padding: 44px 0 24px;
  display: grid;
  grid-template-columns: minmax(0, 1.06fr) 360px;
  gap: 28px;
  align-items: center;
}

.hero-copy,
.cover-panel,
.thesis-card,
.nav,
.section,
.footer,
.metric-card,
.overview-card,
.domain-panel,
.tool-panel,
.tool-card,
.part-tab,
.part-detail-card,
.algo-card,
.side-card,
.timeline-card,
.future-card,
.quote-card,
.method-card,
.route-card {
  border: 1px solid var(--line);
  background:
    linear-gradient(160deg, rgba(255, 255, 255, 0.035), rgba(255, 255, 255, 0.012)),
    var(--bg-panel);
  box-shadow: var(--shadow-md);
  backdrop-filter: blur(16px);
}

.hero-copy {
  padding: 34px;
  border-radius: 38px;
}

.hero-kicker,
.section-kicker,
.meta-kicker,
.metric-card span,
.domain-name span,
.method-filter button,
.nav-link {
  font-size: 12px;
  text-transform: uppercase;
  letter-spacing: 0.18em;
}

.hero-kicker,
.section-kicker,
.meta-kicker,
.metric-card span {
  color: var(--gold);
}

.hero-title,
.section-title,
.cover-meta h2,
.part-tab h3,
.part-detail-card h3,
.tool-card h3,
.algo-copy h3,
.side-card h3,
.timeline-card h3,
.future-card h3,
.quote-card h3,
.method-card h3,
.route-card h3 {
  font-family: "Songti SC", "STSong", "Noto Serif SC", serif;
  color: var(--ink);
}

.hero-title {
  margin: 18px 0 0;
  font-size: clamp(3rem, 7vw, 6.2rem);
  line-height: 0.96;
  letter-spacing: -0.06em;
}

.hero-title span {
  display: block;
  color: var(--gold);
}

.hero-summary {
  max-width: 760px;
  margin: 22px 0 0;
  color: var(--ink-soft);
  line-height: 1.86;
  font-size: 1.08rem;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 28px;
}

.hero-button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 48px;
  padding: 0 18px;
  border-radius: 999px;
  border: 1px solid transparent;
  text-decoration: none;
  transition: transform 180ms ease, border-color 180ms ease, background-color 180ms ease;
}

.hero-button:hover,
.hero-button:focus-visible {
  transform: translateY(-1px);
  outline: none;
}

.hero-button-primary {
  color: var(--ink);
  border-color: rgba(214, 164, 77, 0.36);
  background: linear-gradient(135deg, rgba(214, 164, 77, 0.2), rgba(255, 140, 69, 0.16));
}

.hero-button-secondary {
  border-color: var(--line);
  color: var(--ink-soft);
  background: rgba(255, 255, 255, 0.03);
}

.hero-metrics {
  margin-top: 28px;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 14px;
}

.metric-card {
  padding: 18px;
  border-radius: var(--radius-md);
}

.metric-card strong {
  display: block;
  margin-top: 8px;
  font-family: "Songti SC", serif;
  font-size: 2.3rem;
  line-height: 1;
}

.metric-card p,
.cover-meta p,
.thesis-card p,
.section-desc,
.overview-card p,
.overview-card li,
.tool-card p,
.part-tab p,
.part-summary,
.detail-box p,
.detail-box li,
.algo-copy p,
.algo-copy li,
.side-card p,
.timeline-card p,
.future-card p,
.future-card li,
.quote-card p,
.method-card p,
.route-card p,
.footer p {
  color: var(--ink-soft);
  line-height: 1.78;
}

.hero-side {
  display: grid;
  gap: 16px;
  align-content: start;
}

.cover-panel {
  padding: 18px;
  border-radius: 28px;
}

.cover-shell {
  border-radius: 22px;
  overflow: hidden;
  box-shadow: var(--shadow-lg);
}

.cover-art {
  position: relative;
  width: 100%;
  aspect-ratio: 0.75;
  padding: 26px;
  display: flex;
  flex-direction: column;
  justify-content: flex-end;
  background:
    radial-gradient(circle at 28% 20%, rgba(214, 164, 77, 0.26), transparent 24%),
    radial-gradient(circle at 70% 72%, rgba(84, 184, 255, 0.18), transparent 18%),
    linear-gradient(160deg, #141824 0%, #0c1018 52%, #080a11 100%);
}

.cover-art::before {
  content: "";
  position: absolute;
  inset: 18px;
  border-radius: 18px;
  border: 1px solid rgba(214, 164, 77, 0.18);
}

.cover-art-kicker,
.cover-art-line,
.cover-art-title {
  position: relative;
  z-index: 1;
}

.cover-art-kicker {
  margin: 0 0 auto;
  color: var(--gold);
  font-size: 0.92rem;
  letter-spacing: 0.34em;
}

.cover-art-title {
  margin: 0;
  font-family: "Songti SC", "STSong", "Noto Serif SC", serif;
  font-size: clamp(2.4rem, 5vw, 4rem);
  line-height: 0.94;
  color: var(--ink);
}

.cover-art-line {
  margin: 14px 0 0;
  color: var(--ink-dim);
  letter-spacing: 0.16em;
  font-size: 0.9rem;
}

.cover-art-orbit {
  position: absolute;
  right: 24px;
  top: 28px;
  width: 128px;
  height: 128px;
  border-radius: 50%;
  border: 1px dashed rgba(214, 164, 77, 0.2);
}

.cover-art-dot {
  position: absolute;
  border-radius: 50%;
  box-shadow: 0 0 28px currentColor;
}

.cover-art-dot-a {
  right: 76px;
  top: 78px;
  width: 18px;
  height: 18px;
  color: #58b4ff;
  background: radial-gradient(circle at 35% 35%, #9cd4ff, #2a63ed 72%);
}

.cover-art-dot-b {
  right: 34px;
  top: 136px;
  width: 42px;
  height: 42px;
  color: #ff7c57;
  background: radial-gradient(circle at 35% 35%, #ffab72, #b6381e 76%);
}

.cover-meta {
  padding: 18px 4px 2px;
}

.cover-meta h2 {
  margin: 10px 0 0;
  font-size: 2rem;
  line-height: 1.08;
}

.thesis-card {
  padding: 18px 20px;
  border-radius: 22px;
  background:
    linear-gradient(135deg, rgba(84, 184, 255, 0.08), rgba(214, 164, 77, 0.07)),
    var(--bg-panel);
}

.thesis-card p:last-child {
  margin: 10px 0 0;
}

.nav {
  position: sticky;
  top: 10px;
  width: min(var(--max-width), calc(100vw - 32px));
  margin: 0 auto 18px;
  padding: 12px;
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  border-radius: 999px;
}

.nav-link {
  padding: 10px 14px;
  border-radius: 999px;
  text-decoration: none;
  color: var(--ink-dim);
  transition: background-color 180ms ease, color 180ms ease, transform 180ms ease;
}

.nav-link:hover,
.nav-link.is-active,
.nav-link:focus-visible {
  color: var(--gold);
  background: var(--gold-soft);
  transform: translateY(-1px);
  outline: none;
}

.page {
  width: min(var(--max-width), calc(100vw - 32px));
  margin: 0 auto;
  display: grid;
  gap: 18px;
}

.section {
  padding: 34px;
  border-radius: var(--radius-xl);
}

.section-head {
  max-width: 920px;
  margin-bottom: 26px;
}

.section-title {
  margin: 10px 0 0;
  font-size: clamp(2rem, 4vw, 3.6rem);
  line-height: 1.06;
  letter-spacing: -0.05em;
}

.section-desc {
  margin: 14px 0 0;
  font-size: 1rem;
}

.overview-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: 14px;
}

.overview-card {
  min-height: 246px;
  padding: 18px;
  border-radius: 22px;
  position: relative;
  overflow: hidden;
  transition: transform 180ms ease, border-color 180ms ease;
}

.overview-card::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0;
  width: 100%;
  height: 3px;
}

.overview-card:nth-child(1)::before { background: linear-gradient(90deg, var(--gold), #ff9753); }
.overview-card:nth-child(2)::before { background: linear-gradient(90deg, var(--red), #ff77a9); }
.overview-card:nth-child(3)::before { background: linear-gradient(90deg, var(--cyan), #75e5ff); }
.overview-card:nth-child(4)::before { background: linear-gradient(90deg, var(--green), var(--purple)); }

.overview-card:hover {
  transform: translateY(-3px);
  border-color: var(--line-strong);
}

.overview-card h3 {
  margin: 12px 0 10px;
  font-size: 1.38rem;
  line-height: 1.12;
}

.overview-card ul {
  margin: 12px 0 0;
  padding-left: 18px;
}

.framework-layout {
  display: grid;
  grid-template-columns: 1.05fr 0.95fr;
  gap: 16px;
}

.domain-panel,
.tool-panel {
  padding: 22px;
  border-radius: 26px;
}

.domain-panel h3,
.tool-panel h3 {
  margin: 0 0 18px;
  font-size: 1.9rem;
}

.domain-list,
.tool-list {
  display: grid;
  gap: 16px;
}

.domain-row {
  display: grid;
  gap: 10px;
}

.domain-name {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
}

.domain-name strong {
  font-size: 1.12rem;
  color: var(--ink);
}

.domain-name span {
  color: var(--gold);
}

.domain-bar {
  height: 10px;
  border-radius: 999px;
  background: rgba(255, 255, 255, 0.05);
  overflow: hidden;
}

.domain-fill {
  height: 100%;
  border-radius: 999px;
}

.domain-note {
  margin: 0;
  color: var(--ink-dim);
  line-height: 1.74;
}

.tool-list {
  grid-template-columns: 1fr;
}

.tool-card {
  padding: 18px;
  border-radius: 20px;
  position: relative;
  overflow: hidden;
}

.tool-card h3 {
  margin: 10px 0 0;
  font-size: 1.36rem;
}

.tool-card ul {
  margin: 12px 0 0;
  padding-left: 18px;
  color: var(--ink-soft);
  line-height: 1.72;
}

.tool-card li + li {
  margin-top: 6px;
}

.parts-layout {
  display: grid;
  grid-template-columns: 320px minmax(0, 1fr);
  gap: 16px;
  align-items: start;
}

.part-tabs {
  display: grid;
  gap: 12px;
}

.part-tab {
  min-height: 172px;
  padding: 18px;
  border-radius: 22px;
  text-align: left;
  cursor: pointer;
  transition: transform 180ms ease, border-color 180ms ease, background-color 180ms ease;
}

.part-tab:hover,
.part-tab:focus-visible {
  transform: translateY(-2px);
  outline: none;
}

.part-tab.is-active {
  border-color: var(--line-strong);
  background:
    linear-gradient(135deg, rgba(214, 164, 77, 0.14), rgba(255, 255, 255, 0.02)),
    var(--bg-panel);
}

.part-tab h3 {
  margin: 12px 0 8px;
  font-size: 1.28rem;
}

.part-detail-card {
  padding: 28px;
  border-radius: 28px;
  min-width: 0;
}

.part-detail-card h3 {
  margin: 10px 0 0;
  font-size: 2.3rem;
  line-height: 1.04;
}

.part-summary {
  margin: 16px 0 0;
}

.part-meta,
.chip-row {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

.part-meta {
  margin-top: 16px;
}

.part-meta span,
.chip-row span {
  padding: 8px 12px;
  border-radius: 999px;
  border: 1px solid var(--line);
  background: rgba(255, 255, 255, 0.04);
  color: var(--ink-soft);
}

.detail-grid {
  margin-top: 18px;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 14px;
}

.detail-box {
  padding: 18px;
  border-radius: 18px;
  border: 1px solid var(--line);
  background: rgba(255, 255, 255, 0.03);
}

.detail-box h4 {
  margin: 0 0 10px;
  font-size: 1rem;
  color: var(--ink);
}

.detail-box ul {
  margin: 0;
  padding-left: 18px;
}

.algorithm-layout {
  display: grid;
  grid-template-columns: 1.08fr 0.92fr;
  gap: 16px;
}

.algorithm-steps,
.algorithm-side {
  display: grid;
  gap: 12px;
}

.algo-card {
  display: grid;
  grid-template-columns: 64px 1fr;
  gap: 16px;
  padding: 18px;
  border-radius: 22px;
}

.algo-index {
  width: 64px;
  height: 64px;
  display: grid;
  place-items: center;
  border-radius: 16px;
  background: var(--gold-soft);
  color: var(--gold);
  font-family: "Songti SC", serif;
  font-size: 1.85rem;
}

.algo-copy h3 {
  margin: 0;
  font-size: 1.28rem;
}

.algo-copy ul {
  margin: 10px 0 0;
  padding-left: 18px;
}

.side-card {
  padding: 18px;
  border-radius: 22px;
}

.side-card h3 {
  margin: 10px 0 0;
  font-size: 1.36rem;
}

.timeline-list {
  display: grid;
  gap: 14px;
}

.timeline-card {
  display: grid;
  grid-template-columns: 120px 1fr;
  gap: 18px;
  padding: 20px;
  border-radius: 24px;
}

.timeline-body {
  min-width: 0;
}

.timeline-year {
  color: var(--gold);
  font-size: 1rem;
}

.timeline-card h3 {
  margin: 0;
  font-size: 1.48rem;
}

.timeline-card p {
  margin: 10px 0 0;
}

.timeline-tags {
  margin-top: 12px;
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

.timeline-tags span {
  padding: 8px 12px;
  border-radius: 999px;
  border: 1px solid var(--line);
  background: rgba(255, 255, 255, 0.04);
  color: var(--ink-soft);
}

.future-layout {
  display: grid;
  grid-template-columns: 0.95fr 1.05fr;
  gap: 16px;
  align-items: start;
}

.planet-panel {
  min-height: 720px;
  display: grid;
  place-items: center;
  border: 1px solid var(--line);
  border-radius: 28px;
  background:
    radial-gradient(circle at center, rgba(255, 255, 255, 0.02), transparent 55%),
    rgba(7, 8, 12, 0.9);
}

.planet-map {
  position: relative;
  width: min(460px, 100%);
  aspect-ratio: 1;
}

.orbit-ring {
  position: absolute;
  left: 50%;
  top: 50%;
  width: 72%;
  aspect-ratio: 1;
  transform: translate(-50%, -50%);
  border-radius: 50%;
  border: 2px dashed rgba(214, 164, 77, 0.18);
}

.planet-earth,
.planet-mars {
  position: absolute;
  border-radius: 50%;
}

.planet-earth {
  top: 26%;
  left: 48%;
  width: 44px;
  height: 44px;
  background: radial-gradient(circle at 35% 35%, #7cc8ff, #2661e8 70%);
  box-shadow: 0 0 26px rgba(84, 184, 255, 0.42);
}

.planet-mars {
  bottom: 18%;
  left: 40%;
  width: 122px;
  height: 122px;
  background: radial-gradient(circle at 35% 35%, #ff9056, #b8351d 76%);
  box-shadow: 0 0 34px rgba(255, 107, 99, 0.28);
}

.orbit-label {
  position: absolute;
  left: 50%;
  bottom: 18%;
  transform: translateX(-50%);
  color: var(--ink-dim);
  font-size: 0.9rem;
  letter-spacing: 0.22em;
  text-transform: uppercase;
  white-space: nowrap;
}

.future-grid {
  display: grid;
  gap: 14px;
}

.future-card {
  padding: 20px;
  border-radius: 24px;
  position: relative;
  overflow: hidden;
}

.future-card h3 {
  margin: 10px 0 0;
  font-size: 1.46rem;
  line-height: 1.12;
}

.future-card ul {
  margin: 12px 0 0;
  padding-left: 18px;
}

.quote-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 14px;
}

.quote-card {
  min-height: 210px;
  padding: 20px;
  border-radius: 22px;
  position: relative;
  overflow: hidden;
}

.quote-card::before {
  content: "“";
  position: absolute;
  right: 18px;
  top: 12px;
  font-family: "Songti SC", serif;
  font-size: 4.6rem;
  line-height: 1;
  color: rgba(214, 164, 77, 0.14);
}

.quote-card h3 {
  position: relative;
  z-index: 1;
  margin: 0;
  font-size: 1.34rem;
  line-height: 1.56;
}

.quote-card p {
  margin: 18px 0 0;
  color: var(--ink-dim);
}

.quote-card .meta-kicker {
  margin-top: 18px;
}

.method-shell {
  display: grid;
  gap: 16px;
}

.method-filter {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

.method-filter button {
  min-height: 42px;
  padding: 0 14px;
  border-radius: 999px;
  border: 1px solid var(--line);
  background: rgba(255, 255, 255, 0.03);
  color: var(--ink-dim);
  cursor: pointer;
  transition: background-color 180ms ease, color 180ms ease, transform 180ms ease;
}

.method-filter button:hover,
.method-filter button.is-active,
.method-filter button:focus-visible {
  color: var(--gold);
  background: var(--gold-soft);
  transform: translateY(-1px);
  outline: none;
}

.method-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 14px;
}

.method-card {
  min-height: 188px;
  padding: 18px;
  border-radius: 22px;
  position: relative;
  overflow: hidden;
  transition: transform 180ms ease, border-color 180ms ease;
}

.method-card:hover {
  transform: translateY(-2px);
  border-color: var(--line-strong);
}

.method-card h3 {
  margin: 10px 0 0;
  font-size: 1.18rem;
  line-height: 1.16;
}

.method-card p {
  margin: 10px 0 0;
}

.method-card.is-featured {
  grid-column: 1 / -1;
  min-height: auto;
  background:
    linear-gradient(135deg, rgba(214, 164, 77, 0.14), rgba(84, 184, 255, 0.08)),
    var(--bg-panel);
}

.method-card.is-featured h3 {
  font-size: 1.5rem;
  line-height: 1.22;
}

.method-card.is-featured p:last-child {
  max-width: 840px;
}

.route-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 14px;
}

.route-card {
  padding: 22px;
  border-radius: 24px;
}

.route-card h3 {
  margin: 10px 0 0;
  font-size: 1.5rem;
}

.footer {
  width: min(var(--max-width), calc(100vw - 32px));
  margin: 0 auto 24px;
  padding: 22px 28px;
  display: flex;
  justify-content: space-between;
  gap: 16px;
  align-items: center;
  border-radius: 24px;
}

.footer a {
  color: var(--gold);
  text-decoration: none;
  white-space: nowrap;
}

.reveal {
  opacity: 0;
  transform: translateY(22px);
  transition: opacity 540ms ease, transform 540ms ease;
}

.reveal.is-visible {
  opacity: 1;
  transform: translateY(0);
}

@media (max-width: 1180px) {
  .hero,
  .framework-layout,
  .parts-layout,
  .algorithm-layout,
  .future-layout {
    grid-template-columns: 1fr;
  }

  .planet-panel {
    min-height: 480px;
  }
}

@media (max-width: 820px) {
  .hero,
  .section,
  .footer {
    width: min(var(--max-width), calc(100vw - 20px));
    padding-left: 22px;
    padding-right: 22px;
  }

  .nav,
  .page {
    width: min(var(--max-width), calc(100vw - 20px));
  }

  .hero-metrics,
  .detail-grid {
    grid-template-columns: 1fr;
  }

  .timeline-card,
  .footer {
    grid-template-columns: 1fr;
    flex-direction: column;
    align-items: flex-start;
  }
}

@media (max-width: 640px) {
  .hero-title {
    font-size: 2.8rem;
  }

  .metric-card strong {
    font-size: 2rem;
  }

  .algo-card {
    grid-template-columns: 1fr;
  }

  .algo-index {
    width: 56px;
    height: 56px;
  }

  .nav {
    top: 8px;
    border-radius: 26px;
  }
}