:root{
  --bg-0:#05070d; --bg-1:#080b16; --bg-2:#0d1122;
  --panel:rgba(18,24,42,0.62); --panel-solid:#111527;
  --border:rgba(148,163,184,0.14); --border-strong:rgba(148,163,184,0.28);
  --text-hi:#f1f5f9; --text:#cbd5e1; --text-dim:#8b96ab;
  --accent:#5ec8f8; --accent-2:#9f7aea;
  --good:#4ade80; --warn:#fbbf24; --bad:#f87171; --star:#ffd27a;
  --radius:14px; --radius-sm:9px;
  font-size:16px;
}
*{box-sizing:border-box;}
html,body{margin:0;padding:0;background:var(--bg-0);color:var(--text);font-family:'Inter',system-ui,-apple-system,Segoe UI,Roboto,sans-serif;overflow-x:hidden;}
body{min-height:100vh;line-height:1.5;}
h1,h2,h3{color:var(--text-hi);font-weight:650;letter-spacing:.2px;}
p{margin:.4em 0;}
a{color:var(--accent);}
input,button,select{font-family:inherit;}
::selection{background:rgba(94,200,248,.3);}
#starfield{position:fixed;inset:0;width:100%;height:100%;z-index:0;pointer-events:none;}

/* ---------------- Topbar ---------------- */
.topbar{position:sticky;top:0;z-index:50;display:flex;align-items:center;justify-content:space-between;padding:14px 26px;background:rgba(6,9,18,0.72);backdrop-filter:blur(14px);border-bottom:1px solid var(--border);}
.brand{display:flex;align-items:center;gap:8px;cursor:pointer;user-select:none;}
.brand-icon{color:var(--star);font-size:20px;}
.brand-text{font-weight:700;letter-spacing:1px;color:var(--text-hi);font-size:15px;}
.brand-text b{color:var(--accent);}
.mainnav{display:flex;gap:6px;}
.mainnav button{background:transparent;border:1px solid transparent;color:var(--text-dim);padding:8px 14px;border-radius:999px;font-size:13.5px;cursor:pointer;transition:.15s;}
.mainnav button:hover{color:var(--text-hi);background:rgba(148,163,184,0.08);}
.mainnav button.active{color:var(--accent);border-color:rgba(94,200,248,.3);background:rgba(94,200,248,.08);}
.hamburger{display:none;background:none;border:none;color:var(--text-hi);font-size:22px;cursor:pointer;}

/* ---------------- Layout ---------------- */
#app{position:relative;z-index:1;max-width:1180px;margin:0 auto;padding:28px 22px 80px;}
.view{display:none;animation:fadeIn .35s ease;}
.view.active{display:block;}
@keyframes fadeIn{from{opacity:0;transform:translateY(6px);}to{opacity:1;transform:none;}}
.view-title{font-size:23px;margin-bottom:4px;letter-spacing:.2px;}
.view-title::after{content:"";display:block;width:44px;height:3px;margin-top:10px;border-radius:999px;background:linear-gradient(90deg,var(--accent),var(--accent-2));}
.section-title{font-size:16px;color:var(--text-hi);margin-top:34px;border-top:1px solid var(--border);padding-top:20px;}
.hint{color:var(--text-dim);font-size:13.5px;}

/* ---------------- Hero ---------------- */
.hero{display:flex;align-items:center;gap:40px;padding:40px 0 20px;flex-wrap:wrap;}
.hero-copy{flex:1 1 420px;}
.eyebrow{color:var(--accent);letter-spacing:2px;font-size:12px;font-weight:700;text-transform:uppercase;}
.hero h1{font-size:48px;line-height:1;margin:10px 0;letter-spacing:1px;}
.hero h1 span{color:var(--accent);}
.subtitle{font-size:19px;color:var(--text-hi);font-weight:500;}
.lead{color:var(--text-dim);max-width:520px;}
.hero-search{display:flex;gap:10px;margin:20px 0 12px;max-width:520px;}
.hero-search input{flex:1;background:var(--panel-solid);border:1px solid var(--border-strong);color:var(--text-hi);padding:13px 16px;border-radius:var(--radius-sm);font-size:14.5px;}
.hero-search input:focus{outline:none;border-color:var(--accent);}
.hero-actions{display:flex;gap:12px;flex-wrap:wrap;margin-bottom:18px;}
.landing-stats{display:flex;gap:26px;flex-wrap:wrap;margin-top:10px;}
.landing-stats .lstat b{display:block;font-size:22px;color:var(--accent);}
.landing-stats .lstat span{font-size:11.5px;color:var(--text-dim);text-transform:uppercase;letter-spacing:.4px;}
.hero-visual{flex:1 1 360px;min-width:300px;}
#hero-orbits{width:100%;height:360px;}

/* ---------------- Buttons ---------------- */
.btn{border-radius:999px;padding:12px 22px;font-size:13.5px;font-weight:650;letter-spacing:.4px;cursor:pointer;border:1px solid var(--border-strong);background:var(--panel);color:var(--text-hi);transition:.15s;text-transform:uppercase;}
.btn:hover{transform:translateY(-1px);border-color:var(--accent);}
.btn-primary{background:linear-gradient(135deg,var(--accent),var(--accent-2));border:none;color:#04101c;}
.btn-primary:hover{filter:brightness(1.08);}
.btn-ghost{background:rgba(255,255,255,0.02);}
.btn-back{margin-bottom:16px;}
.btn:disabled{opacity:.4;cursor:not-allowed;transform:none;}

/* ---------------- Browse ---------------- */
.browse-toolbar{display:flex;gap:10px;margin:18px 0 12px;flex-wrap:wrap;}
#browse-search{flex:1;min-width:220px;background:var(--panel-solid);border:1px solid var(--border-strong);color:var(--text-hi);padding:12px 16px;border-radius:var(--radius-sm);font-size:14.5px;}
#browse-search:focus{outline:none;border-color:var(--accent);}
#browse-sort{background:var(--panel-solid);border:1px solid var(--border-strong);color:var(--text-hi);padding:10px 14px;border-radius:var(--radius-sm);}

.browse-filters{display:flex;gap:16px;align-items:center;flex-wrap:wrap;margin-bottom:18px;padding:12px 16px;background:var(--panel);border:1px solid var(--border);border-radius:var(--radius-sm);}
.browse-filters label{display:flex;align-items:center;gap:6px;font-size:12.5px;color:var(--text-dim);}
.browse-filters select{background:var(--panel-solid);border:1px solid var(--border-strong);color:var(--text-hi);padding:6px 10px;border-radius:var(--radius-sm);}
.filter-checkbox{cursor:pointer;}
.browse-count{margin-left:auto;font-size:12.5px;color:var(--text-dim);}

.timeline-card{margin-top:18px;position:relative;}
.timeline-head{display:flex;justify-content:space-between;align-items:center;flex-wrap:wrap;gap:10px;margin-bottom:6px;}
.timeline-head h3{font-size:14.5px;margin:0;color:var(--text-hi);}
.timeline-legend{display:flex;gap:14px;flex-wrap:wrap;}
.tl-legend-item{display:flex;align-items:center;gap:6px;font-size:11.5px;color:var(--text-dim);}
.tl-legend-item i{width:9px;height:9px;border-radius:2px;display:inline-block;}
#timeline-canvas{width:100%;display:block;cursor:crosshair;}
.timeline-tooltip{position:absolute;background:rgba(10,14,24,0.95);border:1px solid var(--border-strong);border-radius:8px;padding:8px 10px;font-size:11.5px;color:var(--text);pointer-events:none;white-space:nowrap;box-shadow:0 10px 24px -10px rgba(0,0,0,0.7);}
.timeline-tooltip.hidden{display:none;}

.browse-mode-toggle{display:flex;gap:8px;margin:16px 0 4px;}
.browse-mode-toggle .chip{background:rgba(148,163,184,0.08);border:1px solid var(--border);color:var(--text);padding:8px 16px;border-radius:999px;font-size:13px;cursor:pointer;transition:.15s;}
.browse-mode-toggle .chip[data-active="true"]{background:rgba(94,200,248,.16);border-color:rgba(94,200,248,.5);color:var(--accent);}

.browse-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(240px,1fr));gap:16px;}
.planet-card{background:var(--panel);border:1px solid var(--border);border-radius:var(--radius);padding:16px;cursor:pointer;transition:.18s;box-shadow:0 1px 0 rgba(255,255,255,0.02) inset,0 8px 20px -14px rgba(0,0,0,0.6);display:flex;gap:14px;align-items:flex-start;}
.planet-card:hover{border-color:var(--accent);transform:translateY(-3px);box-shadow:0 1px 0 rgba(255,255,255,0.03) inset,0 14px 28px -16px rgba(94,200,248,0.35);}
.planet-swatch{flex:0 0 auto;width:38px;height:38px;border-radius:50%;box-shadow:0 0 0 1px rgba(255,255,255,0.06),0 6px 14px -6px rgba(0,0,0,0.7);margin-top:2px;}
.planet-card .pname{font-weight:650;color:var(--text-hi);font-size:15px;}
.planet-card .phost{font-size:12px;color:var(--text-dim);margin-top:2px;}
.planet-card .pmeta{display:flex;gap:8px;flex-wrap:wrap;margin-top:12px;font-size:11.5px;}
.planet-card .pmeta span{background:rgba(255,255,255,0.03);border:1px solid var(--border);border-radius:999px;padding:3px 9px;color:var(--text);}
.pbadge{display:inline-block;font-size:10.5px;text-transform:uppercase;letter-spacing:.4px;padding:3px 8px;border-radius:999px;}
.badge-row{display:flex;gap:8px;flex-wrap:wrap;margin-top:10px;}
.badge-hz{background:rgba(74,222,128,.15);color:var(--good);border:1px solid rgba(74,222,128,.4);}
.badge-binary{background:rgba(94,200,248,.15);color:var(--accent);border:1px solid rgba(94,200,248,.4);}
.badge-pulsar{background:rgba(190,220,255,.15);color:#dbe8ff;border:1px solid rgba(190,220,255,.4);}
.browse-pager{text-align:center;margin-top:22px;}

.browse-grid-stars{grid-template-columns:repeat(auto-fill,minmax(260px,1fr));}
.star-card{background:var(--panel);border:1px solid var(--border);border-radius:var(--radius);padding:16px;cursor:pointer;transition:.18s;display:flex;gap:14px;align-items:center;box-shadow:0 1px 0 rgba(255,255,255,0.02) inset,0 8px 20px -14px rgba(0,0,0,0.6);}
.star-card:hover{border-color:var(--accent);transform:translateY(-3px);box-shadow:0 1px 0 rgba(255,255,255,0.03) inset,0 14px 28px -16px rgba(255,210,120,0.3);}
.star-swatch{flex:0 0 auto;width:48px;height:48px;border-radius:50%;box-shadow:0 0 18px -2px rgba(255,210,120,0.35),0 0 0 1px rgba(255,255,255,0.08);}
.pulsar-swatch{background:radial-gradient(circle at 50% 50%, #fff 0%, #bcdcff 30%, rgba(150,190,255,0.15) 70%, transparent 100%);box-shadow:0 0 22px -2px rgba(150,190,255,0.55),0 0 0 1px rgba(255,255,255,0.1);}
.star-card-body .pname{font-weight:650;color:var(--text-hi);font-size:15.5px;}
.star-card-body .phost{font-size:12px;color:var(--text-dim);margin-top:2px;}
.star-card-body .pmeta{display:flex;gap:8px;flex-wrap:wrap;margin-top:10px;font-size:11.5px;}
.star-card-body .pmeta span{background:rgba(255,255,255,0.03);border:1px solid var(--border);border-radius:999px;padding:3px 9px;color:var(--text);}

/* ---------------- Detail ---------------- */
.detail-hero{background:radial-gradient(circle at 20% 30%,rgba(94,200,248,0.08),transparent 60%),var(--panel);border:1px solid var(--border-strong);border-radius:var(--radius);padding:6px 6px 14px;margin-bottom:20px;overflow:hidden;}
.detail-hero canvas{width:100%;display:block;}
.detail-hero-note{padding:0 16px;margin:8px 0 2px;}
.detail-head{display:flex;justify-content:space-between;align-items:flex-start;flex-wrap:wrap;gap:16px;margin-bottom:8px;}
.detail-head h2{font-size:30px;margin:0;}
.detail-head .dhost{color:var(--text-dim);font-size:14.5px;}
.detail-group-title{font-size:13px;text-transform:uppercase;letter-spacing:.5px;color:var(--text-dim);margin:26px 0 10px;font-weight:650;}
.detail-props{display:grid;grid-template-columns:repeat(auto-fill,minmax(160px,1fr));gap:14px;margin-top:10px;}
.detail-props-star .prop{border-color:rgba(255,210,120,0.22);background:linear-gradient(180deg,rgba(255,210,120,0.05),transparent 60%),var(--panel);}
.prop{background:var(--panel);border:1px solid var(--border);border-radius:var(--radius-sm);padding:12px 14px;box-shadow:0 6px 16px -12px rgba(0,0,0,0.6);transition:.15s;}
.prop:hover{border-color:var(--border-strong);}
.prop .plabel{font-size:11px;color:var(--text-dim);text-transform:uppercase;letter-spacing:.4px;}
.prop .pvalue{font-size:17px;color:var(--text-hi);font-weight:650;margin-top:3px;}

.size-compare{background:var(--panel);border:1px solid var(--border);border-radius:var(--radius);padding:22px;margin-top:24px;display:flex;align-items:flex-end;gap:30px;flex-wrap:wrap;}
.size-compare canvas{display:block;max-width:100%;height:auto;}

.system-view-controls{display:flex;align-items:center;gap:10px;margin:14px 0;color:var(--text-dim);font-size:13px;flex-wrap:wrap;}
.system-view-controls .chip{background:rgba(148,163,184,0.08);border:1px solid var(--border);color:var(--text);padding:6px 12px;border-radius:999px;font-size:12.5px;cursor:pointer;transition:.15s;}
.system-view-controls .chip[data-active="true"]{background:rgba(94,200,248,.16);border-color:rgba(94,200,248,.5);color:var(--accent);}
.system-view-note{font-size:12px;color:var(--text-dim);margin-top:8px;}
.system-siblings{display:flex;flex-direction:column;gap:8px;margin-top:14px;}
.sibling-row{display:flex;justify-content:space-between;background:var(--panel);border:1px solid var(--border);border-radius:var(--radius-sm);padding:10px 14px;cursor:pointer;font-size:13.5px;}
.sibling-row:hover{border-color:var(--accent);}
.sibling-row.current{border-color:var(--accent);background:rgba(94,200,248,.06);}

.chart-card{background:var(--panel);border:1px solid var(--border);border-radius:var(--radius);padding:14px;backdrop-filter:blur(10px);min-width:0;box-shadow:0 10px 26px -18px rgba(0,0,0,0.7);}
.chart-card canvas{width:100%;display:block;cursor:crosshair;max-width:100%;}
.transit-status{padding:14px 16px;background:var(--panel);border:1px solid var(--border);border-radius:var(--radius-sm);font-size:13.5px;margin-top:14px;}
.btn-fetch-transit{margin-top:14px;}

/* ---------------- Compare ---------------- */
.compare-search{position:relative;max-width:480px;margin-bottom:18px;}
.compare-search input{width:100%;background:var(--panel-solid);border:1px solid var(--border-strong);color:var(--text-hi);padding:12px 16px;border-radius:var(--radius-sm);}
.compare-search-results{position:absolute;top:calc(100% + 6px);left:0;right:0;background:var(--panel-solid);border:1px solid var(--border-strong);border-radius:var(--radius-sm);max-height:260px;overflow-y:auto;z-index:20;}
.compare-search-results .csr-item{padding:10px 14px;cursor:pointer;font-size:13.5px;border-bottom:1px solid var(--border);}
.compare-search-results .csr-item:hover{background:rgba(94,200,248,.08);}
.compare-table-wrap{overflow-x:auto;}
.compare-table{width:100%;border-collapse:collapse;min-width:520px;}
.compare-table th,.compare-table td{padding:10px 14px;border-bottom:1px solid var(--border);text-align:left;font-size:13.5px;}
.compare-table th{color:var(--text-dim);font-size:11px;text-transform:uppercase;}
.compare-table td.remove-cell{cursor:pointer;color:var(--bad);}

/* ---------------- Records ---------------- */
.records-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(240px,1fr));gap:16px;margin-top:18px;}
.record-card{background:var(--panel);border:1px solid var(--border-strong);border-radius:var(--radius);padding:20px;cursor:pointer;transition:.18s;box-shadow:0 1px 0 rgba(255,255,255,0.02) inset,0 8px 20px -14px rgba(0,0,0,0.6);}
.record-card:hover{border-color:var(--accent);transform:translateY(-3px);box-shadow:0 1px 0 rgba(255,255,255,0.03) inset,0 14px 28px -16px rgba(94,200,248,0.35);}
.record-card.record-stat{cursor:default;}
.record-card.record-stat:hover{border-color:var(--border-strong);transform:none;box-shadow:0 1px 0 rgba(255,255,255,0.02) inset,0 8px 20px -14px rgba(0,0,0,0.6);}
.record-icon{font-size:26px;margin-bottom:8px;}
.record-title{font-size:11.5px;color:var(--text-dim);text-transform:uppercase;letter-spacing:.4px;min-height:28px;}
.record-planet{font-size:19px;font-weight:700;color:var(--text-hi);margin-top:6px;}
.record-value{font-size:14px;color:var(--accent);margin-top:6px;font-weight:600;}
.record-value-big{font-size:32px;color:var(--accent);}
.record-host{margin-top:8px;}

/* ---------------- Science ---------------- */
.science-block{margin-top:16px;}
.accordion{display:flex;flex-direction:column;gap:10px;margin-top:16px;}
.acc-item{background:var(--panel);border:1px solid var(--border);border-radius:var(--radius-sm);overflow:hidden;}
.acc-head{padding:14px 18px;cursor:pointer;display:flex;justify-content:space-between;align-items:center;color:var(--text-hi);font-weight:600;font-size:14.5px;}
.acc-body{max-height:0;overflow:hidden;transition:max-height .25s ease;padding:0 18px;color:var(--text-dim);font-size:13.8px;}
.acc-item.open .acc-body{max-height:400px;padding:0 18px 16px;}
.acc-item.open .acc-head{color:var(--accent);}

.panel-card{background:var(--panel);border:1px solid var(--border-strong);border-radius:var(--radius);padding:22px;}
.chip{background:rgba(148,163,184,0.08);border:1px solid var(--border);color:var(--text);padding:7px 14px;border-radius:999px;font-size:12.5px;cursor:pointer;transition:.15s;}
.chip[data-active="true"]{background:rgba(94,200,248,.16);border-color:rgba(94,200,248,.5);color:var(--accent);}
.chip:hover{border-color:var(--border-strong);}

/* ---------------- Transit demo ---------------- */
.transit-demo-card{margin-top:14px;}
#transit-demo-canvas{width:100%;display:block;margin-bottom:10px;}
#transit-demo-chart{width:100%;display:block;}
.transit-demo-controls{display:flex;align-items:center;gap:8px;flex-wrap:wrap;margin-top:14px;color:var(--text-dim);font-size:13px;}

/* ---------------- Quiz ---------------- */
.quiz-options{display:grid;grid-template-columns:repeat(auto-fit,minmax(200px,1fr));gap:10px;margin-top:16px;}
.quiz-opt{background:var(--panel-solid);border:1px solid var(--border-strong);color:var(--text-hi);padding:14px 16px;border-radius:var(--radius-sm);font-size:14px;text-align:left;cursor:pointer;transition:.15s;}
.quiz-opt:hover:not(:disabled){border-color:var(--accent);}
.quiz-opt:disabled{cursor:default;opacity:.75;}
.quiz-opt.quiz-correct{border-color:var(--good);background:rgba(74,222,128,.1);color:var(--good);opacity:1;}
.quiz-opt.quiz-wrong{border-color:var(--bad);background:rgba(248,113,113,.1);color:var(--bad);opacity:1;}
.quiz-feedback-ok{color:var(--good);font-weight:650;}
.quiz-feedback-bad{color:var(--bad);font-weight:650;}
#quiz-feedback{margin-top:16px;}
.quiz-intro{text-align:center;}

/* ---------------- Footer ---------------- */
.appfooter{position:relative;z-index:1;text-align:center;padding:22px;color:var(--text-dim);font-size:12px;border-top:1px solid var(--border);}

/* ---------------- Responsive ---------------- */
@media (max-width: 760px){
  .mainnav{display:none;position:absolute;top:56px;right:12px;flex-direction:column;background:var(--panel-solid);border:1px solid var(--border-strong);border-radius:var(--radius-sm);padding:8px;}
  .mainnav.open{display:flex;}
  .hamburger{display:block;}
  .hero h1{font-size:36px;}
  #app{padding:18px 14px 60px;}
}