:root {
  --ink: #101317;
  --muted: #727980;
  --line: #e2e5e8;
  --soft: #f5f6f7;
  --blue: #1769e0;
  --shadow: 0 24px 70px rgba(16, 26, 36, .09);
}
* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body { margin: 0; color: var(--ink); background: #f7f7f8; font-family: Arial, Helvetica, "Microsoft YaHei", sans-serif; }
button, select, input { font: inherit; }
.site-shell { max-width: 1320px; margin: 0 auto; padding: 0 28px 32px; }
.topbar { height: 74px; display: flex; align-items: center; gap: 22px; position: sticky; top: 0; z-index: 10; background: rgba(247,247,248,.82); backdrop-filter: blur(22px); border-bottom: 1px solid rgba(226,229,232,.72); }
.brand { display: inline-flex; align-items: center; gap: 10px; color: var(--ink); text-decoration: none; }
.brand-mark, .about-mark { display: grid; place-items: center; width: 33px; height: 33px; border-radius: 11px; color: white; background: #101317; font-size: 18px; font-weight: 800; letter-spacing: -.08em; }
.brand-word { font-size: 14px; font-weight: 800; letter-spacing: .15em; }
.institution { color: #5d646c; font-size: 13px; border-left: 1px solid #d8dce0; padding-left: 22px; }
.topbar-right { display: flex; align-items: center; gap: 8px; margin-left: auto; color: #858c93; font-size: 12px; }
.status-dot { width: 7px; height: 7px; border-radius: 50%; background: #23a26d; box-shadow: 0 0 0 4px rgba(35,162,109,.12); }
.hero-panel { min-height: 510px; margin-top: 28px; border-radius: 30px; overflow: hidden; position: relative; display: flex; align-items: center; color: white; background: radial-gradient(circle at 85% 35%, #24344e 0, #10151f 28%, #090b0f 72%); box-shadow: 0 30px 90px rgba(13,20,30,.18); }
.hero-copy { position: relative; z-index: 2; padding: 68px 7%; width: 59%; }
.eyebrow { margin: 0 0 12px; color: var(--blue); font-size: 10px; font-weight: 800; letter-spacing: .18em; }
.eyebrow.inverse { color: #9aaed0; }
h1 { margin: 0; font-size: clamp(38px, 5.2vw, 72px); line-height: 1.03; letter-spacing: -.055em; font-weight: 700; }
h1 span { color: #9ebcff; }
.hero-subtitle { max-width: 420px; color: #aeb7c4; font-size: 17px; line-height: 1.7; margin: 25px 0 0; }
.hero-actions { display: flex; align-items: center; gap: 20px; margin-top: 38px; }
.hero-button { display: inline-flex; align-items: center; gap: 22px; padding: 13px 17px 13px 20px; border-radius: 999px; background: white; color: #101317; text-decoration: none; font-size: 13px; font-weight: 700; }
.hero-button span { font-size: 18px; line-height: .6; }
.hero-note { color: #7f8b9b; font-size: 12px; }
.orbit-art { position: absolute; inset: 0 0 0 54%; overflow: hidden; opacity: .94; }
.orbit { position: absolute; border: 1px solid rgba(161,190,243,.27); border-radius: 50%; transform: rotate(-27deg); }
.orbit-one { width: 720px; height: 255px; top: 105px; left: -15px; }
.orbit-two { width: 680px; height: 215px; top: 150px; left: 40px; transform: rotate(31deg); border-color: rgba(120,165,239,.2); }
.orbit-three { width: 450px; height: 450px; top: 4px; left: 160px; border-color: rgba(179,205,255,.13); }
.earth-glow { position: absolute; width: 330px; height: 330px; left: 255px; top: 83px; border-radius: 50%; background: radial-gradient(circle, rgba(66,132,245,.26), rgba(35,76,143,.13) 45%, transparent 70%); filter: blur(3px); }
.earth-core { position: absolute; width: 205px; height: 205px; left: 317px; top: 145px; border-radius: 50%; background: radial-gradient(circle at 35% 31%, #7aa5ee 0, #2e5d9f 28%, #13213a 68%, #090c13 100%); box-shadow: inset -25px -15px 55px rgba(0,0,0,.42), 0 0 80px rgba(64,124,238,.32); }
.orbit-label { position: absolute; color: #879bbc; font-size: 9px; letter-spacing: .18em; }
.label-top { top: 105px; right: 14%; }
.label-bottom { bottom: 95px; left: 30%; }
.signal-row { display: grid; grid-template-columns: repeat(4, 1fr); gap: 1px; margin: 0 10px; padding: 27px 0 48px; }
.signal-row > div { padding: 0 24px; border-left: 1px solid var(--line); }
.signal-row > div:first-child { border-left: 0; }
.signal-row strong { display: block; font-size: 18px; letter-spacing: -.03em; }
.signal-row span { display: block; color: var(--muted); font-size: 11px; margin-top: 7px; letter-spacing: .04em; }
.workspace-section { scroll-margin-top: 90px; }
.section-heading { display: flex; align-items: end; justify-content: space-between; gap: 35px; margin: 0 9px 22px; }
h2 { margin: 0; font-size: 31px; letter-spacing: -.045em; }
.section-description { max-width: 420px; margin: 0; color: var(--muted); font-size: 14px; line-height: 1.65; }
.card { background: #fff; border: 1px solid rgba(224,228,232,.9); border-radius: 20px; box-shadow: var(--shadow); }
.controls { padding: 23px; margin-bottom: 19px; }
.control-row { display: flex; align-items: center; gap: 13px; flex-wrap: wrap; }
.dataset-badge { display: inline-flex; align-items: center; border: 1px solid #b9d3c3; background: #edf7f0; color: #23613a; border-radius: 999px; padding: 9px 14px; font-size: 12px; font-weight: 800; letter-spacing: .02em; }
.muted, .status, footer { color: var(--muted); }
.quiet-button { background: var(--soft); border-color: transparent; }
.control-grid { display: grid; grid-template-columns: 1fr 1.35fr auto auto; align-items: end; gap: 14px; margin-top: 19px; }
label:not(.upload) { display: grid; gap: 7px; color: #6d757d; font-size: 11px; font-weight: 700; }
select { min-height: 42px; border: 1px solid var(--line); border-radius: 10px; padding: 0 11px; color: var(--ink); background: #fff; }
.check { display: flex !important; align-items: center; gap: 7px; min-height: 42px; white-space: nowrap; }
.check input { accent-color: var(--blue); }
button { border: 1px solid var(--line); background: #fff; border-radius: 10px; min-height: 42px; padding: 0 15px; cursor: pointer; color: var(--ink); font-size: 13px; font-weight: 700; transition: transform .18s ease, border-color .18s ease, color .18s ease, background .18s ease; }
button:hover:not(:disabled) { border-color: var(--blue); color: var(--blue); transform: translateY(-1px); }
button:disabled, select:disabled { opacity: .45; cursor: not-allowed; }
button.primary { background: var(--blue); border-color: var(--blue); color: white; }
.status { font-size: 12px; margin: 15px 0 0; }
.chart-card { padding: 23px; }
.chart-header { display: flex; justify-content: space-between; align-items: center; gap: 20px; margin-bottom: 16px; }
h3 { margin: 0; font-size: 20px; letter-spacing: -.025em; }
.actions { display: flex; gap: 8px; flex-wrap: wrap; justify-content: flex-end; }
.chart-wrap { min-height: 520px; display: grid; place-items: center; background: #fff; border-top: 1px solid var(--line); padding-top: 15px; }
.chart-wrap svg { width: 100%; height: auto; display: block; }
.empty { display: flex; flex-direction: column; align-items: center; gap: 11px; color: var(--muted); border: 1px dashed #cbd3da; border-radius: 16px; padding: 62px; text-align: center; width: 100%; }
.empty-icon { display: grid; place-items: center; width: 36px; height: 36px; border-radius: 50%; background: var(--soft); color: var(--blue); font-size: 24px; font-weight: 300; }
.about-panel { display: grid; grid-template-columns: auto 1fr 1.35fr; gap: 20px; align-items: center; margin: 82px 9px 47px; padding: 28px 0; border-top: 1px solid var(--line); border-bottom: 1px solid var(--line); }
.about-mark { width: 54px; height: 54px; border-radius: 17px; font-size: 28px; }
.about-panel h2 { font-size: 26px; }
.about-panel p:not(.eyebrow) { color: var(--muted); line-height: 1.55; font-size: 13px; margin: 8px 0 0; }
.about-copy { color: #5e6770; font-size: 13px; line-height: 1.75; max-width: 450px; }
.data-library { display: grid; grid-template-columns: 1fr 1fr; gap: 24px 45px; align-items: end; margin: 0 9px 55px; padding: 28px 0 0; border-top: 1px solid var(--line); }
.data-library h2 { font-size: 26px; }
.data-links { grid-column: 1 / -1; display: grid; grid-template-columns: repeat(3, 1fr); gap: 10px; }
.data-links a { display: flex; justify-content: space-between; gap: 12px; padding: 15px 16px; color: var(--ink); background: white; border: 1px solid var(--line); border-radius: 12px; text-decoration: none; font-size: 13px; font-weight: 700; transition: border-color .18s ease, color .18s ease, transform .18s ease; }
.data-links a:hover { color: var(--blue); border-color: var(--blue); transform: translateY(-2px); }
.data-links span { color: var(--blue); font-size: 18px; line-height: .7; }
footer { display: flex; justify-content: space-between; gap: 15px; font-size: 11px; padding: 0 9px; }
footer strong { color: var(--ink); letter-spacing: .12em; }
@media (max-width: 900px) { .hero-panel { min-height: 560px; } .hero-copy { width: 75%; } .orbit-art { opacity: .52; left: 42%; } .control-grid { grid-template-columns: 1fr 1fr; } .about-panel { grid-template-columns: auto 1fr; } .about-copy { grid-column: 1 / -1; } .data-links { grid-template-columns: 1fr; } }
@media (max-width: 620px) { .site-shell { padding: 0 14px 24px; } .topbar { height: 62px; gap: 11px; } .institution, .topbar-right { display: none; } .hero-panel { margin-top: 15px; min-height: 620px; border-radius: 23px; } .hero-copy { width: 100%; align-self: flex-start; padding: 48px 28px; } .orbit-art { left: 0; top: 260px; opacity: .62; transform: scale(.76); transform-origin: top center; } .signal-row { grid-template-columns: 1fr 1fr; gap: 24px 0; padding-bottom: 38px; } .signal-row > div:nth-child(3) { border-left: 0; } .section-heading { display: block; margin: 0 4px 20px; } .section-description { margin-top: 13px; } .control-grid { grid-template-columns: 1fr; } .chart-header { align-items: flex-start; flex-direction: column; } .actions { justify-content: flex-start; } .chart-wrap { min-height: 390px; } .about-panel { margin-top: 58px; } .data-library { display: block; margin-top: 55px; } .data-library .section-description { margin-top: 12px; } .data-links { margin-top: 18px; } footer { flex-direction: column; gap: 8px; } }

/* DEPTH visual system: real satellite imagery, gravity-field motion, and institutional identity */
.institution-logos { display: flex; align-items: center; gap: 10px; margin-left: 4px; }
.institution-logos img { display: block; width: auto; height: 28px; max-width: 105px; object-fit: contain; }
.institution-logos .logo-whu { width: 72px; height: 30px; object-fit: contain; }
.institution-lockup { display: flex; align-items: center; justify-content: center; gap: 7px; min-height: 30px; flex: 0 0 auto; }
.institution-lockup span { color: #163b68; font-size: 11px; font-weight: 700; white-space: nowrap; letter-spacing: .02em; }
.institution-lockup-whu .logo-whu { width: 28px; height: 28px; max-width: 28px; border-radius: 50%; }
.institution-lockup-esst img { width: 108px; height: 24px; max-width: 108px; }
.institution-lockup-sgg img { width: 112px; height: 26px; max-width: 112px; }
.hero-visual { position: absolute; inset: 0 0 0 50%; overflow: hidden; pointer-events: none; }
.hero-globe { position: absolute; width: min(42vw, 510px); aspect-ratio: 1; right: 7%; top: 4px; border-radius: 50%; object-fit: cover; mix-blend-mode: screen; filter: saturate(1.08) contrast(1.04); box-shadow: 0 0 90px rgba(65, 132, 255, .25); animation: globeFloat 9s ease-in-out infinite; }
.hero-orbit { position: absolute; border: 1px solid rgba(157, 190, 248, .28); border-radius: 50%; transform-origin: center; }
.hero-orbit-one { width: 700px; height: 240px; right: -120px; top: 108px; transform: rotate(-25deg); }
.hero-orbit-two { width: 640px; height: 200px; right: -90px; top: 168px; border-color: rgba(89, 145, 244, .23); transform: rotate(27deg); }
.visual-chip { position: absolute; z-index: 2; color: #afc1e2; font-size: 9px; letter-spacing: .16em; white-space: nowrap; }
.chip-top { top: 74px; right: 11%; }
.chip-bottom { bottom: 72px; right: 12%; color: #7185a8; }
@keyframes globeFloat { 0%, 100% { transform: translate3d(0, 0, 0) rotate(-2deg); } 50% { transform: translate3d(0, 10px, 0) rotate(2deg); } }
.fleet-section { margin: 34px 9px 0; }
.fleet-heading { margin-left: 0; margin-right: 0; }
.fleet-grid { display: grid; grid-template-columns: repeat(6, 1fr); gap: 12px; }
.satellite-card { grid-column: span 2; overflow: hidden; background: #fff; border: 1px solid rgba(224, 228, 232, .95); border-radius: 18px; box-shadow: 0 16px 38px rgba(16, 26, 36, .06); transition: transform .2s ease, box-shadow .2s ease; }
.satellite-card-wide { grid-column: span 3; }
.satellite-card:hover { transform: translateY(-4px); box-shadow: 0 22px 48px rgba(16, 26, 36, .12); }
.satellite-card-link { display: block; color: inherit; text-decoration: none; }
.satellite-card-link:focus-visible { outline: 3px solid rgba(23, 105, 224, .35); outline-offset: 3px; }
.satellite-card img { display: block; width: 100%; height: 155px; object-fit: cover; background: #10151f; }
.satellite-card-wide img { height: 205px; }
.satellite-card > div { padding: 15px 16px 16px; }
.satellite-kicker { color: #7a8590; font-size: 10px; font-weight: 800; letter-spacing: .12em; }
.satellite-card h3 { margin-top: 6px; font-size: 22px; }
.satellite-card p { margin: 5px 0 0; color: var(--muted); font-size: 12px; line-height: 1.45; }
.asset-credit { margin: 13px 2px 0; color: #8b9299; font-size: 11px; line-height: 1.55; }
.asset-credit a, .source-link { color: #496f9e; }
.gravity-showcase { display: grid; grid-template-columns: .85fr 1.15fr; gap: 36px; align-items: center; margin: 74px 9px 80px; padding: 34px; min-height: 350px; overflow: hidden; border-radius: 24px; color: white; background: linear-gradient(120deg, #09111b, #111f32 56%, #0a121d); box-shadow: 0 28px 70px rgba(13, 20, 30, .16); }
.gravity-copy h2 { max-width: 420px; margin-top: 10px; font-size: clamp(28px, 4vw, 45px); }
.gravity-copy > p:not(.eyebrow) { max-width: 390px; margin: 18px 0 0; color: #a9b7c9; font-size: 14px; line-height: 1.7; }
.text-link { display: inline-flex; gap: 8px; margin-top: 26px; color: #d5e3ff; text-decoration: none; font-size: 13px; font-weight: 700; }
.gravity-gif-frame { position: relative; min-height: 282px; display: grid; place-items: center; overflow: hidden; border: 1px solid rgba(172, 201, 242, .18); border-radius: 18px; background: radial-gradient(circle at 50% 48%, rgba(77, 135, 222, .2), transparent 60%); }
.gravity-gif-frame img { display: block; width: min(100%, 470px); max-height: 310px; object-fit: contain; mix-blend-mode: screen; }
.gravity-gif-frame span { position: absolute; left: 16px; bottom: 14px; color: #9caec8; font-size: 9px; letter-spacing: .16em; }
.team-section { display: grid; grid-template-columns: 160px 1fr 260px; gap: 28px; align-items: center; margin: 24px 9px 62px; padding: 28px 0 0; border-top: 1px solid var(--line); }
.team-photo { width: 160px; height: 190px; overflow: hidden; border-radius: 20px; background: #e9edf2; }
.team-photo img { width: 100%; height: 100%; object-fit: cover; object-position: center top; }
.team-copy h2 { font-size: 30px; }
.team-copy h2 span { color: #a7b2bf; font-size: .55em; font-weight: 600; letter-spacing: 0; }
.team-copy .role { margin: 7px 0 0; color: #3f6da6; font-size: 13px; font-weight: 700; }
.team-copy > p:not(.eyebrow):not(.role) { max-width: 570px; margin: 14px 0 0; color: var(--muted); font-size: 13px; line-height: 1.7; }
.team-tags { display: flex; flex-wrap: wrap; gap: 7px; margin-top: 16px; }
.team-tags span { padding: 7px 10px; border: 1px solid #dfe5eb; border-radius: 999px; color: #657383; font-size: 11px; }
.source-link { display: inline-block; margin-top: 18px; font-size: 12px; text-decoration: none; }
.wechat-card { padding: 22px; border-radius: 18px; background: #eef5f1; border: 1px solid #dcebe2; }
.wechat-icon { display: grid; place-items: center; width: 38px; height: 38px; margin-bottom: 18px; border-radius: 12px; color: #fff; background: #1f9a69; font-size: 20px; }
.wechat-card h3 { font-size: 20px; }
.wechat-card > p:not(.eyebrow) { margin: 7px 0 0; color: #527461; font-size: 13px; }
.wechat-note { display: block; margin-top: 18px; color: #739382; font-size: 11px; line-height: 1.5; }
.affiliation-strip { display: grid; grid-template-columns: repeat(3, 1fr); gap: 12px; margin: 0 9px 64px; padding: 20px 0; border-top: 1px solid var(--line); border-bottom: 1px solid var(--line); }
.affiliation-strip > div { display: flex; align-items: center; justify-content: center; gap: 12px; min-height: 44px; color: #69737e; font-size: 12px; }
.affiliation-strip img { display: block; width: auto; height: 30px; max-width: 120px; object-fit: contain; }
@media (max-width: 900px) {
  .institution-logos img { height: 24px; max-width: 78px; }
  .hero-visual { inset: 0 0 0 38%; opacity: .8; }
  .hero-globe { width: 430px; right: -12%; top: 50px; }
  .fleet-grid { grid-template-columns: repeat(2, 1fr); }
  .satellite-card, .satellite-card-wide { grid-column: span 1; }
  .satellite-card-wide img, .satellite-card img { height: 175px; }
  .gravity-showcase { grid-template-columns: 1fr; }
  .gravity-gif-frame { min-height: 300px; }
  .team-section { grid-template-columns: 140px 1fr; }
  .team-photo { width: 140px; height: 170px; }
  .wechat-card { grid-column: 1 / -1; }
}
@media (max-width: 620px) {
  .institution-logos { display: none; }
  .hero-visual { inset: 225px 0 0 0; opacity: .72; }
  .hero-globe { width: 330px; right: 4%; top: 26px; }
  .hero-orbit-one { width: 480px; height: 180px; right: -90px; top: 82px; }
  .hero-orbit-two { width: 450px; height: 160px; right: -74px; top: 115px; }
  .visual-chip { font-size: 8px; }
  .chip-top { top: 37px; right: 9%; }
  .chip-bottom { bottom: 48px; right: 8%; }
  .fleet-section { margin-top: 22px; }
  .fleet-grid { grid-template-columns: 1fr; }
  .satellite-card, .satellite-card-wide { grid-column: 1; }
  .satellite-card-wide img, .satellite-card img { height: 190px; }
  .gravity-showcase { margin: 55px 0 60px; padding: 25px 20px; }
  .gravity-gif-frame { min-height: 220px; }
  .team-section { grid-template-columns: 1fr; margin-top: 0; }
  .team-photo { width: 132px; height: 160px; }
  .wechat-card { grid-column: auto; }
  .affiliation-strip { grid-template-columns: 1fr; gap: 16px; margin-bottom: 52px; }
}