:root {
  color-scheme: light dark;
  --ink: #2d2927;
  --muted: #6b625c;
  --paper: #fbf7f1;
  --paper-deep: #f1e8dd;
  --line: #d8cbbd;
  --accent: #b73532;
  --accent-deep: #932d2a;
  --cta-ink: #fffaf6;
  --cta-bg: #b73532;
  --cta-bg-hover: #932d2a;
  --gold: #b28648;
  --radius: 14px;
  --shadow: 0 18px 42px rgba(72, 47, 31, 0.14);
  font-family: "Microsoft YaHei", "PingFang SC", sans-serif;
}

* { box-sizing: border-box; }

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

body {
  margin: 0;
  min-width: 320px;
  overflow-x: hidden;
  color: var(--ink);
  background: var(--paper);
  font-size: 16px;
  line-height: 1.75;
}

a { color: inherit; text-decoration-thickness: 1px; text-underline-offset: 0.24em; }

a:focus-visible {
  outline: 3px solid var(--gold);
  outline-offset: 4px;
}

::selection { color: #fffaf5; background: var(--accent); }

.shell { width: min(1120px, calc(100% - 40px)); margin: 0 auto; }

.skip-link {
  position: fixed;
  z-index: 2;
  top: -60px;
  left: 20px;
  padding: 8px 12px;
  border-radius: 8px;
  color: #fff;
  background: var(--accent);
}

.skip-link:focus { top: 16px; }

.site-header {
  padding-top: env(safe-area-inset-top);
  border-bottom: 1px solid color-mix(in srgb, var(--line) 74%, transparent);
  background: color-mix(in srgb, var(--paper) 94%, transparent);
}

.header-inner { display: flex; align-items: center; justify-content: space-between; min-height: 70px; gap: 24px; }

.brand { display: inline-flex; flex: 0 0 auto; width: 142px; }
.brand img { display: block; width: 100%; height: auto; }

nav { display: flex; flex: 1 1 0; flex-wrap: wrap; align-items: center; justify-content: flex-end; gap: clamp(12px, 3vw, 36px); }
nav a { min-height: 44px; display: inline-flex; align-items: center; color: var(--muted); font-size: 0.95rem; text-decoration: none; }
nav a:hover { color: var(--accent); }

.hero { padding: clamp(36px, 7vw, 104px) 0 clamp(64px, 9vw, 120px); overflow: clip; }
.hero-grid { display: grid; grid-template-columns: minmax(0, 0.9fr) minmax(320px, 1.1fr); align-items: center; gap: clamp(32px, 7vw, 92px); }
.hero-copy { padding: 24px 0; }
.hero-mark { margin: 0 0 16px; color: var(--accent); font-weight: 700; letter-spacing: 0.12em; }
h1, h2, h3, p { margin-top: 0; }
h1 { max-width: 100%; margin-bottom: 24px; font-size: clamp(2.5rem, 5.5vw, 5.5rem); font-weight: 700; letter-spacing: -0.035em; line-height: 1.16; text-wrap: balance; }
.hero-lede { max-width: 26ch; margin-bottom: 30px; color: var(--muted); font-size: clamp(1.04rem, 1.6vw, 1.2rem); }

.primary-cta {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  min-height: 52px;
  padding: 12px 24px;
  border-radius: var(--radius);
  color: var(--cta-ink);
  background: var(--cta-bg);
  box-shadow: 0 11px 23px rgba(183, 53, 50, 0.22);
  font-weight: 700;
  text-decoration: none;
  transition: background-color 180ms ease-out, box-shadow 180ms ease-out, transform 180ms ease-out;
}

.primary-cta:hover { background: var(--cta-bg-hover); box-shadow: 0 14px 28px rgba(183, 53, 50, 0.28); transform: translateY(-2px); }
.primary-cta__arrow { flex: 0 0 auto; transition: transform 180ms ease-out; }
.primary-cta:hover .primary-cta__arrow { transform: translateX(3px); }
.primary-cta:active .primary-cta__arrow { transform: translateX(1px); }
.primary-cta { touch-action: manipulation; }
.primary-cta__spinner { display: none; width: 18px; height: 18px; flex: 0 0 auto; border: 2px solid rgba(255, 255, 255, 0.42); border-top-color: currentColor; border-radius: 50%; animation: cta-spin 720ms linear infinite; }
.primary-cta.is-pending { cursor: progress; transform: none; }
.primary-cta.is-pending .primary-cta__arrow { display: none; }
.primary-cta.is-pending .primary-cta__spinner { display: block; }
@keyframes cta-spin { to { transform: rotate(360deg); } }

.hero-visual { margin: 0; }
.hero-visual picture { display: block; overflow: hidden; border-radius: var(--radius); box-shadow: var(--shadow); }
.hero-visual img { display: block; width: 100%; height: auto; }
.hero-visual figcaption { margin-top: 10px; color: var(--muted); font-size: 0.82rem; }

.intro, .boundaries { display: grid; grid-template-columns: minmax(220px, 0.75fr) minmax(0, 1.25fr); gap: clamp(32px, 8vw, 120px); padding: clamp(64px, 10vw, 136px) 0; }
.section-heading h2 { max-width: 13ch; margin-bottom: 0; font-size: clamp(1.7rem, 3vw, 2.8rem); letter-spacing: -0.025em; line-height: 1.32; text-wrap: balance; }
.intro-copy { max-width: 42rem; color: var(--muted); font-size: 1.05rem; }
.intro-copy p + p { margin-top: 22px; }

.path-section { background: var(--paper-deep); }
.path-layout { display: grid; grid-template-columns: minmax(220px, 0.8fr) minmax(0, 1.2fr); gap: clamp(32px, 8vw, 120px); padding: clamp(64px, 10vw, 128px) 0; }
.path-heading p { max-width: 20ch; margin: 20px 0 0; color: var(--muted); }
.path-list { margin: 0; padding: 0; list-style: none; counter-reset: path; }
.path-list li { display: grid; grid-template-columns: 48px 1fr; gap: 18px; padding: 0 0 30px; }
.path-list li + li { padding-top: 30px; border-top: 1px solid var(--line); }
.path-list span { width: 40px; height: 40px; display: grid; place-items: center; border-radius: 50%; color: var(--accent); background: color-mix(in srgb, var(--accent) 9%, transparent); font-weight: 700; }
.path-list h3 { margin-bottom: 4px; font-size: 1.14rem; }
.path-list p { margin-bottom: 0; color: var(--muted); }

.boundaries { align-items: start; }
.boundary-copy { max-width: 42rem; padding-left: clamp(20px, 3vw, 34px); border-left: 1px solid var(--gold); color: var(--muted); font-size: 1.05rem; }
.boundary-copy p:last-child { margin-bottom: 0; }

.safety-section { padding: clamp(64px, 9vw, 112px) 0; color: #fff9f2; background: #3a302d; }
.safety-layout { display: grid; grid-template-columns: minmax(220px, 0.82fr) minmax(0, 1.18fr); gap: clamp(32px, 8vw, 120px); }
.safety-list { display: grid; gap: 18px; margin: 0; padding: 0; list-style: none; }
.safety-list li { position: relative; padding-left: 22px; }
.safety-list li::before { content: ""; position: absolute; top: 0.78em; left: 0; width: 7px; height: 7px; border-radius: 50%; background: var(--gold); }

.site-footer { padding: 28px 0 calc(28px + env(safe-area-inset-bottom)); color: var(--muted); border-top: 1px solid var(--line); }
.site-footer p { margin: 0; font-size: 0.9rem; }

@media (max-width: 720px) {
  .shell { width: min(100% - 32px, 560px); }
  .header-inner { min-height: 64px; gap: 16px; }
  .brand { width: 118px; }
  nav { gap: 6px 12px; }
  nav a { font-size: 0.86rem; }
  .hero-grid, .intro, .path-layout, .boundaries, .safety-layout { grid-template-columns: 1fr; }
  .hero-copy { padding: 0; }
  .hero-visual { order: -1; }
  .intro, .boundaries { gap: 26px; }
  .path-layout, .safety-layout { gap: 34px; }
  .section-heading h2 { max-width: 15ch; }
}

@media (prefers-color-scheme: dark) {
  :root { --ink: #f7eee5; --muted: #d2c2b2; --paper: #201d1b; --paper-deep: #2d2825; --line: #4e433b; --accent: #dc5d58; --accent-deep: #ee716a; --cta-ink: #fffaf6; --cta-bg: #9f3835; --cta-bg-hover: #8a302d; --gold: #d2ad72; --shadow: 0 18px 42px rgba(0, 0, 0, 0.3); }
  .site-header { background: color-mix(in srgb, var(--paper) 94%, transparent); }
  .safety-section { background: #161311; }
}

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { scroll-behavior: auto !important; transition-duration: 0.01ms !important; animation-duration: 0.01ms !important; animation-iteration-count: 1 !important; }
}