:root{--sn25-bg:#061326;--sn25-cream:#f4d79b;--sn25-blue:#a9e6ff;--sn25-border:rgba(158,211,245,.30)}
*{box-sizing:border-box}html{scroll-behavior:smooth}body.sn25{margin:0;min-height:100vh;font:16px/1.65 system-ui,-apple-system,Segoe UI,sans-serif;color:#edf5fd;background:radial-gradient(ellipse at 82% 4%,#1b3260,transparent 33%),radial-gradient(ellipse at 12% 30%,#103955,transparent 44%),#061326}
.sn25 .wrap{width:min(1200px,calc(100% - 36px));margin:auto}.sn25 a{color:var(--sn25-blue)}.sn25 header{padding:23px 0 38px}.sn25 .crumb{font-weight:650;font-size:.87rem}.sn25 .crumb a{text-decoration:none;margin-right:12px}.sn25 .eyebrow{color:#87d6fa;letter-spacing:.20em;font-size:12px;font-weight:800;text-transform:uppercase}.sn25 h1,.sn25 h2,.sn25 h3{font-family:Georgia,serif;color:var(--sn25-cream);font-weight:500;line-height:1.14}.sn25 h1{font-size:clamp(2.3rem,5.3vw,4.5rem);margin:13px 0}.sn25 h2{font-size:clamp(1.8rem,3vw,2.65rem)}.sn25 h3{font-size:1.45rem}.sn25 p{margin:.5em 0 1em}.sn25 .intro{max-width:72ch;font-size:clamp(1rem,2vw,1.18rem);color:#d3e1f3}.sn25 .pillbar{display:flex;flex-wrap:wrap;gap:10px;margin-top:25px}.sn25 .pillbar a,.sn25 button,.sn25 .btn{font:700 .92rem/1.35 system-ui,sans-serif;min-height:44px;border-radius:12px;border:1px solid rgba(151,212,250,.4);background:#153657;color:#eef8ff;padding:11px 15px;cursor:pointer;text-decoration:none;display:inline-flex;align-items:center;justify-content:center}.sn25 .pillbar a:first-child,.sn25 .primary{background:linear-gradient(110deg,#fff1ca,#dcb570);border-color:#e4c183;color:#152037}.sn25 button:disabled{opacity:.4;cursor:not-allowed}.sn25 :focus-visible{outline:3px solid #ffe5a4;outline-offset:3px}
.sn25 .stage{border-radius:26px;border:1px solid rgba(244,205,140,.52);overflow:hidden;box-shadow:0 35px 90px #0008,inset 0 1px #ffffff21;background:radial-gradient(ellipse at 50% 60%,rgba(28,92,159,.27),transparent 48%),linear-gradient(130deg,#0d2c50,#070f24 72%)}
.sn25 .scene{min-height:430px;position:relative;display:grid;grid-template-columns:1.2fr 1fr;align-items:center;gap:22px;padding:clamp(22px,5vw,60px);isolation:isolate}
.sn25 .scene:before{content:'';z-index:-1;position:absolute;inset:0;background:radial-gradient(1px 1px at 15% 23%,#fff 99%,transparent),radial-gradient(2px 2px at 75% 38%,#ffd5a2 99%,transparent),radial-gradient(1.5px 1.5px at 48% 86%,#b1eaff 99%,transparent);background-size:180px 170px,260px 230px,150px 150px;opacity:.42;animation:sn25drift 16s linear infinite alternate}
.sn25 .scene-art{aspect-ratio:4/3;border-radius:26px;border:1px solid rgba(242,209,138,.4);background:radial-gradient(circle at 50% 40%,rgba(97,184,255,.25),transparent 47%),linear-gradient(140deg,#18385b,#0a1b34);box-shadow:0 0 50px #0a83d022,inset 0 0 35px #ebd3a419;display:grid;place-content:center;position:relative;overflow:hidden}
.sn25 .orbit{width:min(33vw,310px);height:min(33vw,310px);border:2px solid rgba(246,212,147,.58);box-shadow:0 0 35px #75c4ff44,inset 0 0 30px #debe6940;border-radius:50%;display:grid;place-content:center;animation:sn25spin 36s linear infinite;position:relative}.sn25 .orbit:before{content:'';position:absolute;inset:16%;border:1px dashed #91d8ec99;border-radius:50%}.sn25 .orbit:after{content:'';position:absolute;inset:28%;border:2px solid #f8df98a0;border-radius:50%;box-shadow:0 0 35px #79c4ff66}.sn25 .symbol{font-size:clamp(3.2rem,8vw,6rem);line-height:1;filter:drop-shadow(0 0 17px #88d6ff88);animation:sn25spinReverse 36s linear infinite}.sn25 .scene-copy h2{margin-top:10px}.sn25 .scene-copy p{max-width:46ch}.sn25 .source{font-weight:700;color:#b8e6ff}.sn25 .controls{padding:22px;display:flex;flex-wrap:wrap;gap:10px;align-items:center;border-top:1px solid rgba(255,255,255,.13);background:#061c34}.sn25 .controls [role=status]{color:#b5d6e8;font-size:13px;flex:1 0 100%}.sn25 .track{height:5px;background:#193956}.sn25 .track span{display:block;width:0%;height:100%;background:linear-gradient(90deg,#6fc7f2,#f7d58b);transition:width .4s}.sn25 .index{display:flex;gap:10px;overflow:auto;padding:20px 22px;scrollbar-width:thin}.sn25 .index button{white-space:nowrap;font-weight:650;background:#0d2747}.sn25 .index button[aria-pressed=true]{color:#14253d;background:#efd193}.sn25 .grid{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:15px;margin:28px 0}.sn25 .tile{border:1px solid var(--sn25-border);border-radius:18px;padding:22px;background:linear-gradient(145deg,#0d2948,#09192e);box-shadow:0 9px 22px #0003}.sn25 .tile p{color:#d4e5f4}.sn25 .tile a{font-weight:700}.sn25 footer{padding:40px 0;color:#a8bbcb;font-size:.88rem}.sn25 .quiz{max-width:850px;margin:24px auto;padding:clamp(20px,4vw,38px);background:linear-gradient(145deg,#0b2747,#08192e);border:1px solid var(--sn25-border);border-radius:22px}.sn25 .quiz .options{display:grid;gap:10px;margin:16px 0}.sn25 .quiz .options button{justify-content:flex-start;text-align:left;background:#102d4f;color:#edf6fd}.sn25 .quiz .options button[aria-pressed=true]{background:#e1c58c;color:#1b2938}.sn25 .quiz-feedback{border-left:3px solid #ebd18f;padding:12px 16px;margin:18px 0;background:#133151;color:#e5f0f9}.sn25 .status-line{color:#a6e8ff;font-weight:750}.sn25 .score{font-size:1.45rem;color:#f9d895}
@keyframes sn25spin{to{transform:rotate(360deg)}}@keyframes sn25spinReverse{to{transform:rotate(-360deg)}}@keyframes sn25drift{to{transform:translateY(-10px)}}
@media(max-width:800px){.sn25 .scene{grid-template-columns:1fr;padding:22px;min-height:0}.sn25 .scene-art{aspect-ratio:16/10}.sn25 .orbit{width:min(55vw,255px);height:min(55vw,255px)}.sn25 .grid{grid-template-columns:1fr 1fr}}
@media(max-width:520px){.sn25 .wrap{width:calc(100% - 20px)}.sn25 .grid{grid-template-columns:1fr}.sn25 .controls button{flex:1}.sn25 .scene-art{aspect-ratio:16/11}.sn25 .index{padding:16px}.sn25 .scene-copy h2{font-size:1.8rem}}
@media(prefers-reduced-motion:reduce){.sn25 .orbit,.sn25 .symbol,.sn25 .scene:before{animation:none!important}html{scroll-behavior:auto}}