.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0px;
  margin: -1px;
  overflow: hidden;
  clip-path: inset(50%);
  white-space: nowrap;
  border: 0px;
}

.orbit-instruction button {
  pointer-events: auto;
  min-height: 36px;
  padding: 7px 0px 7px 12px;
  margin-left: 4px;
  background: transparent;
  color: rgb(141, 172, 192);
  border-left: 1px solid rgba(154, 184, 206, 0.2);
  font-size: 8px;
  letter-spacing: 0.03em;
}

.orbit-instruction button:hover { color: rgb(222, 242, 255); }

.hero .core-toggle {
  position: absolute;
  opacity: 1;
  pointer-events: auto;
  z-index: 7;
  border: 0px;
  border-radius: 0px;
  background: none;
  right: clamp(32px, 5vw, 96px);
  bottom: 30px;
  padding: 0px;
  font-size: 9px;
  min-height: 44px;
  color: rgb(129, 157, 178);
  letter-spacing: 0.03em;
}

.hero .core-toggle:hover { color: rgb(215, 235, 250); }

.hero {
  height: 100svh;
  min-height: 720px;
  display: block;
  background-position: center center;
  isolation: isolate;
}

.hero::before { z-index: 0; background: rgba(3, 8, 15, 0.937); }

.hero::after {
  z-index: 4;
  background: linear-gradient(0deg, rgb(5, 11, 18) 0%, transparent 8%, transparent 90%, rgba(5, 11, 18, 0.333));
  pointer-events: none;
}

.hero #orbit-core {
  position: absolute;
  inset: 0px;
  width: 100%;
  height: 100%;
  z-index: 2;
  pointer-events: auto;
  touch-action: pan-y;
}

.orbit-nodes { position: absolute; inset: 0px; z-index: 3; pointer-events: none; overflow: hidden; }










.hero-foot {
  bottom: 30px;
  z-index: 6;
  display: grid;
  grid-template-columns: 1fr auto 1fr;
  align-items: center;
  font-size: 9px;
  pointer-events: none;
}

.hero-foot a { pointer-events: auto; }

.orbit-instruction {
  display: flex;
  align-items: center;
  gap: 11px;
  font-size: 8px;
  letter-spacing: 0.05em;
  color: rgb(114, 144, 166);
}

.drag-symbol { font-size: 20px; color: rgb(157, 187, 209); }

.orbit-hit {
  position: absolute;
  inset: 0px auto auto 0px;
  padding: 0px;
  border: 0px;
  border-radius: 50%;
  background: transparent;
  pointer-events: none;
}

.orbit-hit[data-visible="true"] { pointer-events: auto; }

.orbit-tooltip {
  position: absolute;
  top: calc(100% + 7px);
  left: 50%;
  transform: translateX(-50%);
  padding: 5px 8px;
  color: rgb(224, 237, 247);
  background: rgba(10, 21, 35, 0.93);
  border: 1px solid rgba(172, 206, 237, 0.22);
  border-radius: 5px;
  font-size: 11px;
  line-height: 1.4;
  white-space: nowrap;
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.16s ease-out;
}

.orbit-hit[data-visible="true"]:hover .orbit-tooltip, .orbit-hit:focus-visible .orbit-tooltip { opacity: 1; }

.is-dragging .orbit-hit[data-visible="true"] { pointer-events: none; }

@media (prefers-reduced-motion: reduce) {
  .orbit-tooltip { transition: none; }
}

.stardust-observatory {
  min-height: 680px;
  height: 100svh;
  max-height: none;
  background: radial-gradient(at 50% 52%, rgb(7, 24, 40), rgb(3, 16, 29) 75%);
}

.hero.stardust-observatory::before { display: none; }

.hero.stardust-observatory::after { z-index: 4; background: linear-gradient(0deg, rgba(4, 10, 19, 0.35), transparent 8%); }

.observatory-sky {
  position: absolute;
  inset: 0px auto auto 50%;
  height: 100%;
  aspect-ratio: 1586 / 992;
  transform: translateX(-50%);
  pointer-events: none;
  background: url("../assets/observatory-sky.webp") center center / 100% 100% no-repeat;
  mask-image: linear-gradient(90deg, transparent, rgb(0, 0, 0) 10%, rgb(0, 0, 0) 90%, transparent);
}

.observatory-deck {
  position: absolute;
  inset: auto auto 0px 50%;
  width: 100%;
  aspect-ratio: 1585 / 992;
  transform: translateX(-50%);
  z-index: 3;
  pointer-events: none;
  background: url("../assets/observatory-foreground.webp") center bottom / 100% 100% no-repeat;
}

.observatory-deck.has-viewers { background-image: url("../assets/observatory-platform.webp"); }

.observatory-deck .observatory-viewers { position: absolute; inset: auto 0px 0px; width: 100%; height: 30%; }

.hero #orbit-core { cursor: grab; }

.hero.is-dragging #orbit-core { cursor: grabbing; }

.orbit-nodes { z-index: 4; }

.orbit-tooltip {
  color: rgb(230, 237, 245);
  background: rgba(9, 19, 33, 0.95);
  border-color: rgba(185, 214, 237, 0.294);
  box-shadow: rgba(2, 6, 13, 0.698) 0px 6px 22px;
}

.orbit-hit:focus-visible { outline: rgb(192, 220, 252) solid 1px; outline-offset: 3px; }



.core-eyebrow::before, .core-eyebrow::after {
  content: "";
  width: clamp(28px, 3.65vw, 68px);
  height: 1px;
  background: linear-gradient(90deg, rgba(201, 215, 225, 0.404), rgba(237, 243, 253, 0.93));
}









.hero-foot { bottom: clamp(23px, 4vh, 50px); grid-template-columns: auto auto; justify-content: space-between; }

.hero-foot .orbit-instruction, .orbit-instruction button, .hero .core-toggle { color: rgb(170, 189, 209); font-size: 10px; }

.hero .core-toggle { bottom: clamp(23px, 4vh, 50px); right: max(24px, 50% - 45vw); }

.hero .core-toggle:hover, .orbit-instruction button:hover { color: rgb(240, 246, 255); }

@media (hover: hover) and (pointer: fine) {
  .hero-foot, .hero .core-toggle { opacity: 0; transition: opacity 0.24s; }
  .hero-foot .orbit-instruction { pointer-events: auto; }
  .hero:has(.hero-foot:is(:hover, :focus-within), .core-toggle:is(:hover, :focus-visible)) :is(.hero-foot, .core-toggle),
  .hero.is-dragging .hero-foot { opacity: 1; }
}

@media (max-width: 900px) {
  .hero-foot { width: calc(100% - 40px); }
}

@media (min-width: 620px) and (max-aspect-ratio: 5 / 4) {
  .observatory-sky {
    inset: 50.7% auto auto 50%;
    width: 121%;
    height: auto;
    transform: translate(-50%, -50%);
    mask-image: linear-gradient(transparent, rgb(0, 0, 0) 6%, rgb(0, 0, 0) 94%, transparent);
  }
  .observatory-deck { width: auto; height: 72%; }
  .hero-foot { bottom: 9px; }
  .hero .core-toggle { bottom: 8px; }
}

@media (max-width: 619px) {
  .observatory-sky {
    inset: 46% auto auto 50%;
    width: 151%;
    height: auto;
    transform: translate(-50%, -50%);
    mask-image: linear-gradient(transparent, rgb(0, 0, 0) 6%, rgb(0, 0, 0) 94%, transparent);
  }
  .observatory-deck { left: 50%; width: 148%; height: auto; transform: translateX(-50%); }

.hero-core-copy::before { inset: -34px -18px; }

.core-eyebrow { gap: 12px; margin-bottom: 18px; font-size: 10px; }
  .core-eyebrow::before, .core-eyebrow::after { width: 24px; }

.core-actions { gap: 9px; margin-top: 22px; }

.hero .core-button svg { width: 24px; height: 24px; }
  .hero-foot { bottom: 10px; }
  .hero-foot .orbit-instruction { font-size: 8px; gap: 5px; }
  .hero-foot .orbit-instruction .drag-symbol { font-size: 14px; }
  .orbit-instruction button { margin-left: 1px; padding-left: 6px; font-size: 8px; }
  .hero .core-toggle { right: 16px; bottom: 8px; font-size: 8px; }
}

@media (prefers-reduced-motion: reduce) {

}

/* 宽屏以 1500px 定稿为基准；场景始终铺满窗口。 */
@supports (zoom: min(100vw / 1500px, 100svh / 755px)) {
@media (min-width: 768px) and (min-height: 400px) and (min-aspect-ratio: 3 / 2) {
  .observatory-frame {
    min-height: 100svh;
    display: grid;
    place-items: center;
    background: linear-gradient(180deg, #05111e 32%, #050b12 75%);
  }

  .stardust-observatory {
    --frame-scale: calc(100vw / 1500px);
    width: 1500px;
    height: calc(100svh / var(--frame-scale));
    min-height: 0;
    zoom: var(--frame-scale);
  }

  .observatory-sky {
    inset: 0 auto auto 50%;
    width: auto;
    height: 100%;
    transform: translateX(-50%);
    mask-image: linear-gradient(90deg, transparent, #000 10%, #000 90%, transparent);
  }

  .observatory-deck { width: 100%; height: auto; }

.core-eyebrow { font-size: 19.7055px; margin-bottom: 18px; }
  .core-eyebrow::before, .core-eyebrow::after { width: 54.75px; height: max(1px, 1px / var(--frame-scale)); }

.core-description { font-size: 23.7825px; margin-top: 11px; }

.hero .core-button[data-open] { flex-basis: 291px; min-height: 53.2275px; font-size: 19.328px; }

.hero-foot, .hero .core-toggle { bottom: 30.2px; }
  .hero-foot { width: 1350px; }
  .hero-foot .orbit-instruction { max-width: none; }
  .hero .core-toggle { right: 75px; }
}
}

/* 窄窗口保持满屏观景；文字和交互图标不随横幅一起缩小。 */
@media (min-width: 620px) and (max-aspect-ratio: 3 / 2) {
  .observatory-frame { min-height: 100svh; }
  .stardust-observatory { min-height: 680px; height: 100svh; }
  .observatory-sky {
    inset: 48% auto auto 50%;
    width: 108%; height: auto;
    transform: translate(-50%, -50%);
    mask-image: linear-gradient(transparent, #000 6%, #000 94%, transparent);
  }
  .observatory-deck { width: 136%; height: auto; }

.hero .hero-core-copy h1 { font-size: clamp(38px, 5.15vw, 62px); text-indent: .5em; }

.core-description { font-size: clamp(17px, 2.2vw, 24px); margin-top: 14px; }

.hero .core-button[data-open] { flex-basis: 270px; min-height: 54px; font-size: 19px; }

.hero-foot, .hero .core-toggle { bottom: 4px; }
}

/* 首屏文字与入口：统一尺度，独立于背景构图。 */
.hero-core-copy {
  position:absolute; left:50%; top:43%; transform:translate(-50%,-50%);
  width: min(900px, 92%); max-width:none; z-index:5; text-align:center; pointer-events:none;
}
.hero-core-copy::before { content:""; position:absolute; inset:-30px 4%; z-index:-1; pointer-events:none; background:radial-gradient(ellipse, #05111d70, transparent 72%); }
.core-eyebrow { display:flex; align-items:center; justify-content:center; gap:12px; margin:0 0 22px; color:#9fb4c8; font:400 11px/1.5 "Microsoft YaHei",sans-serif; letter-spacing:.18em; }
.core-eyebrow span { color:#d0e0ed; font-size:11px; letter-spacing:.18em; }
.core-eyebrow i { width:3px; height:3px; border-radius:50%; background:#80bfd5; box-shadow:0 0 8px #80bfd560; }
.core-eyebrow::before,.core-eyebrow::after { content:none; }
.hero .hero-core-copy h1 { position:static; margin:0; width:100%; max-width:none; min-height:0; text-indent:.28em; font-family:"Source Han Serif SC","Noto Serif SC","Songti SC",STSong,SimSun,serif; font-size:58px; line-height:1.32; font-weight:600; letter-spacing:.025em; color:#edf3f9; text-shadow:0 4px 25px #02091480; text-wrap:balance; }
.core-description { margin:18px 0 0; min-height:0; color:#aabcca; font:400 15px/1.8 "Microsoft YaHei",sans-serif; letter-spacing:.035em; text-wrap:balance; }
.core-actions { display:flex; justify-content:center; gap:14px; margin-top:30px; pointer-events:auto; }
.hero .core-button[data-open] {
  --accent:160,203,235;
  display:inline-flex; align-items:center; justify-content:center; gap:10px; flex:0 0 156px;
  min-width:0; min-height:44px; padding:0 18px; border:1px solid rgba(var(--accent),.32); border-radius:12px;
  background:linear-gradient(160deg,rgba(var(--accent),.10),#091724e6 65%);
  box-shadow:inset 0 1px 0 #e0f2ff12,0 6px 18px #00000020; backdrop-filter:blur(12px);
  color:#dce9f4; font:500 13px/1.4 "Microsoft YaHei",sans-serif; letter-spacing:.04em;
  transition:border-color .2s,background .2s,box-shadow .2s,transform .2s; isolation:isolate; overflow:hidden;
}
.hero .core-button[data-open="community"] { --accent:166,210,199; }
.hero .core-button::before,.hero .core-button::after { display:none; }
.hero .core-button svg { width:17px; height:17px; flex:none; color:rgb(var(--accent)); stroke-width:1.6; stroke-linecap:round; stroke-linejoin:round; }
.hero .core-button[data-open]:hover { border-color:rgba(var(--accent),.7); background:linear-gradient(150deg,rgba(var(--accent),.19),#102332ee); box-shadow:inset 0 1px 0 #e0f2ff20,0 5px 22px rgba(var(--accent),.10); transform:translateY(-2px); }
.hero .core-button[data-open]:focus-visible { outline:2px solid rgb(var(--accent)); outline-offset:4px; }
.hero .core-button[data-open]:active { transform:translateY(0); }
@media (min-width:768px) and (min-height:400px) and (min-aspect-ratio:3 / 2) {
  .hero .core-button[data-open] { min-height:max(44px,calc(44px / var(--frame-scale,1))); }
}
@media (min-width:620px) and (max-aspect-ratio:3 / 2) {
  .hero .hero-core-copy h1 { font-size:clamp(38px,5.2vw,58px); }
  .core-description { font-size:14px; }
}
@media (max-width:619px) {
  .hero-core-copy { top:40%; width:calc(100% - 32px); }
  .core-eyebrow { font-size:10px; gap:9px; margin-bottom:18px; }
  .core-eyebrow span { font-size:10px; }
  .hero .hero-core-copy h1 { font-size:clamp(29px,8.4vw,46px); letter-spacing:0; text-indent:.25em; }
  .core-description { max-width:290px; margin:16px auto 0; font-size:12px; line-height:1.9; }
  .core-actions { gap:10px; margin-top:24px; }
  .hero .core-button[data-open] { flex-basis:142px; min-height:44px; padding-inline:12px; font-size:12px; gap:8px; }
}
@media (prefers-reduced-motion:reduce) { .hero .core-button[data-open] { transition:none; } }
/* Only a quiet mouse hint remains; controls never reappear on hover or drag. */
.hero .core-reset,.hero .core-flight,.hero .core-toggle { display:none !important; }
.hero .hero-foot { opacity:.65; pointer-events:none; transition:opacity .2s; }
.hero .hero-foot .orbit-instruction { display:inline-flex;align-items:center;gap:9px;font-size:10px;letter-spacing:.07em; }
.drag-mouse { width:17px;height:21px;flex:none;color:#bad4df; }
.hero.is-dragging .hero-foot { opacity:0 !important; visibility:hidden; transition:none; }
@media (max-width:619px),(hover:none),(pointer:coarse) {
 .hero .hero-foot { display:none !important; }
}