:root {
  --bg: #f2efe7;
  --bg-accent: #ece6d9;
  --paper: rgba(251, 248, 242, 0.86);
  --paper-solid: #fbf8f2;
  --ink: #121212;
  --muted: #5e625d;
  --line: rgba(18, 18, 18, 0.12);
  --line-strong: rgba(18, 18, 18, 0.24);
  --teal: #1b6b6f;
  --gold: #c8a26a;
  --shadow: 0 24px 80px rgba(35, 34, 31, 0.08);
  --radius-xl: 32px;
  --radius-lg: 24px;
  --radius-md: 18px;
  --radius-pill: 999px;
  --max-width: 1220px;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  min-width: 320px;
  color: var(--ink);
  font-family: "Noto Sans SC", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  background:
    radial-gradient(circle at top left, rgba(27, 107, 111, 0.1), transparent 32%),
    radial-gradient(circle at 88% 10%, rgba(200, 162, 106, 0.16), transparent 30%),
    linear-gradient(180deg, #f5f1e9 0%, var(--bg) 48%, #efe8dc 100%);
  line-height: 1.65;
}

body::before,
body::after {
  content: "";
  position: fixed;
  inset: 0;
  pointer-events: none;
  z-index: -2;
}

body::before {
  background-image:
    linear-gradient(rgba(18, 18, 18, 0.03) 1px, transparent 1px),
    linear-gradient(90deg, rgba(18, 18, 18, 0.03) 1px, transparent 1px);
  background-size: 56px 56px;
  mask-image: linear-gradient(180deg, rgba(0, 0, 0, 0.9), transparent 86%);
}

body::after {
  z-index: -1;
  background:
    radial-gradient(circle at 10% 24%, rgba(255, 255, 255, 0.5) 0 1px, transparent 1px),
    radial-gradient(circle at 72% 36%, rgba(255, 255, 255, 0.42) 0 1px, transparent 1px),
    radial-gradient(circle at 82% 70%, rgba(255, 255, 255, 0.35) 0 1.2px, transparent 1.2px);
  opacity: 0.6;
}

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

a {
  color: inherit;
}

button,
a,
summary {
  transition:
    transform 180ms ease,
    border-color 180ms ease,
    background-color 180ms ease,
    color 180ms ease,
    opacity 180ms ease;
}

a:focus-visible,
button:focus-visible,
summary:focus-visible {
  outline: 2px solid var(--teal);
  outline-offset: 4px;
}

.skip-link {
  position: absolute;
  left: 1rem;
  top: -3rem;
  z-index: 30;
  padding: 0.8rem 1rem;
  border-radius: var(--radius-pill);
  background: var(--ink);
  color: #fff;
  text-decoration: none;
}

.skip-link:focus {
  top: 1rem;
}

.page-shell {
  width: min(var(--max-width), calc(100% - 2rem));
  margin: 0 auto;
  padding-bottom: 3rem;
}

.topbar {
  position: sticky;
  top: 0;
  z-index: 20;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1.25rem;
  padding: 1.1rem 0 0.95rem;
  transition:
    backdrop-filter 180ms ease,
    background-color 180ms ease,
    border-color 180ms ease;
}

.topbar.is-scrolled {
  backdrop-filter: blur(18px);
  background: rgba(242, 239, 231, 0.74);
  border-bottom: 1px solid rgba(18, 18, 18, 0.06);
}

.brand-link {
  flex: 0 1 20rem;
  text-decoration: none;
}

.brand-link img {
  width: 100%;
  height: auto;
}

.topnav {
  display: flex;
  flex-wrap: wrap;
  justify-content: flex-end;
  gap: 0.75rem;
}

.topnav a {
  padding: 0.68rem 1rem;
  border: 1px solid transparent;
  border-radius: var(--radius-pill);
  color: var(--muted);
  text-decoration: none;
}

.topnav a[data-active="true"],
.topnav a:hover {
  border-color: rgba(27, 107, 111, 0.18);
  background: rgba(255, 255, 255, 0.55);
  color: var(--ink);
}

.section,
.footer {
  scroll-margin-top: 6rem;
}

.section {
  margin-top: 4.5rem;
}

.hero {
  display: grid;
  grid-template-columns: minmax(0, 1.05fr) minmax(320px, 0.95fr);
  gap: 1.5rem;
  align-items: stretch;
  padding-top: 1.5rem;
}

.hero-copy,
.artifact-card,
.philosophy-panel,
.principle-card,
.faq-list details,
.footer {
  position: relative;
  overflow: hidden;
  border: 1px solid var(--line);
  border-radius: var(--radius-xl);
  background:
    linear-gradient(180deg, rgba(255, 255, 255, 0.68), rgba(251, 248, 242, 0.9)),
    var(--paper);
  box-shadow: var(--shadow);
}

.hero-copy {
  padding: 3rem;
}

.hero-copy::after,
.artifact-card::after,
.principle-card::after {
  content: "";
  position: absolute;
  inset: auto -4rem -4rem auto;
  width: 14rem;
  height: 14rem;
  border-radius: 50%;
  background: radial-gradient(circle, rgba(27, 107, 111, 0.12), transparent 72%);
}

.eyebrow,
.principle-tag,
.artifact-meta,
.artifact-caption div,
.footer-mark {
  text-transform: uppercase;
  letter-spacing: 0.18em;
  font-family: "IBM Plex Mono", "SFMono-Regular", "SF Mono", "Menlo", monospace;
}

.eyebrow {
  margin: 0 0 1rem;
  color: var(--teal);
  font-size: 0.82rem;
}

h1,
h2,
h3 {
  margin: 0;
  font-family: "Noto Serif SC", "Songti SC", "STSong", serif;
  font-weight: 600;
  line-height: 1.12;
  letter-spacing: 0.01em;
}

h1 {
  max-width: 12ch;
  font-size: clamp(3rem, 6vw, 5.2rem);
}

h2 {
  max-width: 16ch;
  font-size: clamp(2rem, 4.3vw, 3.4rem);
}

h3 {
  font-size: 1.45rem;
}

p,
dd {
  margin: 0;
  color: var(--muted);
}

.hero-dek {
  max-width: 31rem;
  margin-top: 1.4rem;
  font-size: 1.08rem;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 1rem;
  margin-top: 2rem;
}

.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 3rem;
  padding: 0.85rem 1.35rem;
  border-radius: var(--radius-pill);
  border: 1px solid transparent;
  font-weight: 600;
  text-decoration: none;
}

.button-primary {
  background: var(--ink);
  color: #f7f2e8;
}

.button-primary:hover {
  transform: translateY(-2px);
}

.micro-note {
  max-width: 18rem;
  font-size: 0.92rem;
}

.signal-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 1rem;
  margin: 2.3rem 0 0;
}

.signal-card {
  padding: 1rem 1.05rem;
  border-radius: var(--radius-md);
  border: 1px solid rgba(18, 18, 18, 0.08);
  background: rgba(255, 255, 255, 0.42);
}

.signal-card dt {
  margin-bottom: 0.35rem;
  color: var(--muted);
  font-size: 0.88rem;
}

.signal-card dd {
  color: var(--ink);
  font-weight: 600;
}

.artifact-card {
  display: flex;
  flex-direction: column;
  height: 100%;
  min-height: 100%;
  padding: 1.1rem;
}

.artifact-meta,
.artifact-caption div {
  display: flex;
  justify-content: space-between;
  gap: 1rem;
  color: var(--muted);
  font-size: 0.76rem;
}

.artifact-stage {
  display: grid;
  place-items: center;
  min-height: 28rem;
  margin: 1rem 0;
  border-radius: calc(var(--radius-xl) - 10px);
  border: 1px solid rgba(18, 18, 18, 0.08);
  background:
    linear-gradient(rgba(18, 18, 18, 0.04) 1px, transparent 1px),
    linear-gradient(90deg, rgba(18, 18, 18, 0.04) 1px, transparent 1px),
    linear-gradient(180deg, rgba(255, 255, 255, 0.78), rgba(245, 239, 226, 0.94));
  background-size: 38px 38px, 38px 38px, auto;
}

.artifact-stage img {
  width: min(76%, 25rem);
  height: auto;
  filter: drop-shadow(0 20px 30px rgba(18, 18, 18, 0.08));
}

.artifact-caption {
  display: grid;
  gap: 0.8rem;
}

.section-header {
  display: grid;
  gap: 0.9rem;
  margin-bottom: 1.4rem;
}

.section-header p {
  max-width: 42rem;
}

.philosophy-grid,
.principles-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 1rem;
}

.philosophy-panel,
.principle-card {
  padding: 1.5rem;
}

.panel-index {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-width: 3rem;
  padding: 0.3rem 0.65rem;
  border-radius: var(--radius-pill);
  border: 1px solid rgba(27, 107, 111, 0.2);
  color: var(--teal);
  font-size: 0.8rem;
  font-family: "IBM Plex Mono", "SFMono-Regular", "SF Mono", "Menlo", monospace;
}

.philosophy-panel h3,
.principle-card h3 {
  margin-top: 1rem;
}

.philosophy-panel p,
.principle-card p:last-child {
  margin-top: 0.8rem;
}

.principle-tag {
  color: var(--teal);
  font-size: 0.78rem;
}

.faq-list {
  display: grid;
  gap: 0.95rem;
}

.faq-list details {
  padding: 1.15rem 1.2rem;
}

.faq-list summary {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  cursor: pointer;
  list-style: none;
  color: var(--ink);
  font-weight: 600;
}

.faq-list summary::-webkit-details-marker {
  display: none;
}

.faq-list summary::after {
  content: "+";
  color: var(--teal);
  font-size: 1.35rem;
  line-height: 1;
}

.faq-list details[open] summary::after {
  content: "−";
}

.faq-list details p {
  max-width: 46rem;
  margin-top: 0.9rem;
}

.footer {
  display: grid;
  gap: 0.85rem;
  margin-top: 4rem;
  padding: 1.5rem;
}

.footer-mark {
  color: var(--teal);
  font-size: 0.82rem;
}

.footer-copy span {
  color: var(--ink);
  font-weight: 600;
}

.footer-meta {
  font-size: 0.9rem;
}

.js .reveal-pending {
  opacity: 0;
  transform: translateY(22px);
  transition:
    opacity 600ms ease,
    transform 600ms ease;
}

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

@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }

  .reveal,
  .reveal-pending,
  button,
  a,
  summary {
    transition: none;
    transform: none;
  }

  .reveal,
  .reveal-pending {
    opacity: 1;
  }
}

@media (max-width: 1040px) {
  .hero,
  .philosophy-grid,
  .principles-grid {
    grid-template-columns: 1fr;
  }

  .artifact-stage {
    min-height: 24rem;
  }
}

@media (max-width: 720px) {
  .page-shell {
    width: min(var(--max-width), calc(100% - 1.2rem));
  }

  .topbar {
    flex-direction: column;
    align-items: stretch;
  }

  .brand-link {
    flex-basis: auto;
    width: min(100%, 17rem);
  }

  .topnav {
    justify-content: flex-start;
  }

  .hero-copy,
  .artifact-card {
    padding: 1.15rem;
  }

  .signal-grid {
    grid-template-columns: 1fr;
  }

  h1 {
    max-width: none;
    font-size: clamp(2.5rem, 12vw, 4rem);
  }

  h2 {
    max-width: none;
  }

  .artifact-stage {
    min-height: 18rem;
  }

  .artifact-caption div {
    flex-direction: column;
    gap: 0.35rem;
  }

  .faq-list summary {
    align-items: flex-start;
  }
}