:root {
  color-scheme: dark;
  --background: #101114;
  --text: #f6f5f2;
  --secondary: #c4c4c5;
  --ui-font: -apple-system, BlinkMacSystemFont, "PingFang SC", "Microsoft YaHei", sans-serif;
  --display-font: "Songti SC", "STSong", "Noto Serif CJK SC", serif;
  font-family: var(--ui-font);
  font-synthesis: none;
  -webkit-text-size-adjust: 100%;
}

* { box-sizing: border-box; }
html { min-height: 100%; }
body { min-width: 320px; min-height: 100%; margin: 0; background: var(--background); color: var(--text); }
button, a { -webkit-tap-highlight-color: transparent; }
button { font: inherit; }
a { color: inherit; text-decoration: none; }
button:focus-visible, a:focus-visible { outline: 2px solid #fff; outline-offset: 5px; }
.skip-link { position: fixed; top: 10px; left: 10px; z-index: 30; padding: 11px 15px; background: #fff; color: #111; transform: translateY(-160%); }
.skip-link:focus { transform: none; }

.site-header { position: absolute; z-index: 10; top: 0; right: 0; left: 0; height: 94px; padding: 0 clamp(28px, 3.8vw, 58px); display: flex; align-items: center; justify-content: space-between; gap: 20px; }
.brand { display: inline-flex; align-items: center; gap: 15px; white-space: nowrap; font-size: 19px; font-weight: 650; letter-spacing: .16em; }
.brand-mark { width: 35px; height: 35px; display: block; flex: none; }
.home-link { display: inline-flex; align-items: center; gap: 13px; min-height: 44px; font-size: 14px; letter-spacing: .13em; transition: opacity .2s ease; }
.home-link:hover { opacity: .68; }
.home-link svg { display: block; width: 20px; height: 20px; stroke: currentColor; stroke-width: 1.4; stroke-linecap: round; stroke-linejoin: round; }

.stage { position: relative; isolation: isolate; min-height: 760px; min-height: 100svh; overflow: hidden; background: radial-gradient(circle at 76% 38%, rgba(48, 50, 55, .17), transparent 36%), #101114; }
.background-art { position: absolute; z-index: -2; inset: 0; width: 100%; height: 100%; pointer-events: none; }
.facets { pointer-events: none; }
.hero-copy { position: absolute; z-index: 2; left: clamp(34px, 6.1vw, 98px); top: 31%; max-width: min(46vw, 620px); }
.hero-copy h1 { margin: 0; font-family: var(--display-font); font-size: clamp(52px, 5.2vw, 82px); font-weight: 500; line-height: 1.27; letter-spacing: -.07em; text-shadow: 0 2px 20px rgba(0,0,0,.16); }
.hero-copy p { margin: 34px 0 0; color: #d2d1d1; font-family: var(--display-font); font-size: clamp(17px, 1.45vw, 23px); line-height: 1.7; letter-spacing: .035em; }
.letter-note { max-width: 410px; margin-top: 32px; }
.letter-note[hidden] { display: none; }
.letter-note h2 { margin: 0; font-family: var(--display-font); font-size: clamp(23px, 2vw, 29px); font-weight: 500; line-height: 1.4; letter-spacing: .035em; }
.letter-note p { margin: 10px 0 0; color: #d8d8d7; font-family: var(--display-font); font-size: 16px; line-height: 1.8; letter-spacing: .025em; }

.constellation { position: absolute; inset: 0; z-index: 3; pointer-events: none; }
.connections { position: absolute; inset: 0; display: block; width: 100%; height: 100%; overflow: visible; pointer-events: none; }
.connections path { vector-effect: non-scaling-stroke; stroke-width: 1; }
.connections-base { stroke: rgba(184, 186, 190, .15); }
.connections-active { stroke: rgba(231, 231, 229, .32); }
.star { position: absolute; display: flex; align-items: center; gap: 14px; min-width: 86px; min-height: 60px; padding: 0; border: 0; color: #e5e5e5; background: transparent; cursor: pointer; pointer-events: auto; text-align: left; transform: translate(-29px, -50%); }
.star-core { position: relative; display: grid; place-items: center; flex: 0 0 58px; width: 58px; height: 58px; }
.star-core::before { content: ""; position: absolute; width: 7px; height: 7px; border-radius: 50%; background: #fff; box-shadow: 0 0 10px 4px rgba(255,255,255,.42), 0 0 36px 12px rgba(255,255,255,.12); animation: star-breathe 4.8s ease-in-out infinite; }
.star-core::after { content: ""; position: absolute; left: 50%; top: 50%; width: 50px; height: 50px; border: 1px solid rgba(231,231,230,.08); border-radius: 50%; pointer-events: none; transform: translate(-50%, -50%) scale(.5); opacity: 0; transition: transform .3s ease, opacity .3s ease; }
.star:hover .star-core::after, .star:focus-visible .star-core::after, .star.is-selected .star-core::after { transform: translate(-50%, -50%) scale(1.4); opacity: 1; }
.star:nth-of-type(2) .star-core::before { animation-delay: -.9s; }
.star:nth-of-type(3) .star-core::before { animation-delay: -2.7s; }
.star:nth-of-type(4) .star-core::before { animation-delay: -1.7s; }
.star:nth-of-type(5) .star-core::before { animation-delay: -3.5s; }
.star-core svg { position: relative; display: block; width: 24px; height: 24px; fill: #fff; stroke: #fff; stroke-width: .7; opacity: .9; filter: drop-shadow(0 0 12px rgba(255,255,255,.9)); transition: transform .3s ease, opacity .3s ease; }
.star:hover .star-core svg, .star:focus-visible .star-core svg, .star.is-selected .star-core svg { transform: scale(1.22); opacity: 1; }
.star-label { color: #e4e4e3; font-family: var(--display-font); font-size: 19px; letter-spacing: .12em; white-space: nowrap; text-shadow: 0 2px 12px #000; }
.star-advice { left: 50.95%; top: 22.2%; }
.star-encourage { left: 79%; top: 28.4%; }
.star-collaborate { left: 87%; top: 50%; }
.star-trust { left: 70%; top: 63.8%; }
.star-company { left: 47%; top: 59.6%; }

.instruction { position: absolute; z-index: 4; left: clamp(34px, 4vw, 64px); bottom: 82px; display: flex; align-items: center; gap: 16px; margin: 0; color: #e4e3e2; font-family: var(--display-font); font-size: 14px; letter-spacing: .08em; }
.instruction-icon { display: block; flex: 0 0 32px; width: 32px; height: 32px; overflow: visible; stroke: #f5f5f3; stroke-width: 1.7; stroke-linecap: round; stroke-linejoin: round; filter: drop-shadow(0 1px 2px rgba(0,0,0,.45)); }
.instruction-icon circle { stroke-width: 1; }
.instruction-star { fill: #f5f5f3; stroke: none; }
.site-footer { position: absolute; z-index: 4; left: clamp(34px, 4vw, 64px); bottom: 28px; color: #a6a7aa; font-family: var(--ui-font); font-size: 12px; line-height: 1.4; letter-spacing: .08em; }

@keyframes star-breathe { 0%, 100% { opacity: .72; transform: scale(.84); } 50% { opacity: 1; transform: scale(1.12); } }

@media (max-width: 850px) {
  .site-header { height: 76px; padding-inline: 28px; }
  .brand { font-size: 16px; gap: 11px; }
  .brand-mark { width: 31px; height: 31px; }
  .hero-copy { top: 22%; max-width: 60vw; }
  .hero-copy h1 { font-size: clamp(48px, 6vw, 68px); }
  .star-label { font-size: 16px; }
  .star-advice { left: 58%; top: 23%; }
  .star-encourage { left: 80%; top: 35%; }
  .star-collaborate { left: 82%; top: 52%; }
  .star-trust { left: 60%; top: 63%; }
  .star-company { left: 36%; top: 63%; }
}

@media (max-width: 640px) {
  .stage { min-height: 790px; min-height: max(790px, 100svh); }
  .site-header { height: 68px; padding-inline: 22px; }
  .brand { font-size: 14px; letter-spacing: .08em; }
  .brand-mark { width: 28px; height: 28px; }
  .home-link { gap: 5px; font-size: 12px; letter-spacing: .02em; }
  .home-link svg { width: 20px; height: 20px; }
  .hero-copy { top: 108px; left: 28px; right: 28px; max-width: none; }
  .hero-copy h1 { font-size: clamp(43px, 11.4vw, 58px); line-height: 1.23; letter-spacing: -.08em; }
  .hero-copy p { max-width: 340px; margin-top: 16px; font-size: 15px; line-height: 1.65; }
  .constellation { top: 300px; bottom: 140px; height: auto; min-height: 290px; }
  .star { gap: 5px; min-width: 60px; min-height: 50px; transform: translate(-21px, -50%); }
  .star-core { flex-basis: 42px; width: 42px; height: 42px; }
  .star-core svg { width: 21px; height: 21px; }
  .star-label { font-size: 14px; letter-spacing: .04em; }
  .star-advice { left: 32%; top: 10%; }
  .star-encourage { left: 70%; top: 16%; }
  .star-collaborate { left: 76%; top: 53%; }
  .star-trust { left: 56%; top: 77%; }
  .star-company { left: 23%; top: 62%; }
  .instruction { left: 28px; bottom: 88px; font-size: 12px; gap: 10px; }
  .instruction-icon { flex-basis: 27px; width: 27px; height: 27px; }
  .letter-note { position: absolute; top: 520px; left: 0; right: 0; max-width: 340px; margin: 0; }
  .letter-note h2 { font-size: 23px; }
  .letter-note p { margin-top: 8px; font-size: 14px; }
  .site-footer { left: 28px; bottom: 24px; }
  .stage.has-letter .instruction { visibility: hidden; }
}

@media (max-width: 360px) {
  .stage { min-height: 820px; min-height: max(820px, 100svh); }
  .hero-copy { left: 22px; right: 22px; }
  .hero-copy h1 { font-size: 41px; }
  .star-encourage { left: 67%; }
  .star-collaborate { left: 70%; }
}

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