:root{--bg:#0b0e11;--bg2:#12161c;--bg3:#1a2029;--line:#2a3340;--text:#e8edf5;--muted:#8b97a8;--or:#ff7a1a;
  --mono:"IBM Plex Mono","SF Mono","Menlo","Consolas",monospace;--sans:"Inter","Segoe UI",system-ui,sans-serif}
*{box-sizing:border-box;margin:0;padding:0}
html,body{background:var(--bg);color:var(--text);font-family:var(--sans);min-height:100%}
.page{max-width:1120px;margin:0 auto;padding:20px 18px 56px}
.top{display:flex;align-items:center;justify-content:space-between;gap:12px;padding-bottom:16px;margin-bottom:28px;border-bottom:1px solid var(--line)}
.brand-logo{height:36px;width:auto;display:block}
.top-links{display:flex;align-items:center;gap:18px}
.top-links a{font-size:13px;text-decoration:none;white-space:nowrap}
.back{color:var(--muted)}
.back:hover,.back:focus-visible{color:var(--text)}
a.mission-link{color:var(--or);text-decoration:none}
a.mission-link:hover,a.mission-link:focus-visible{color:#ff9a4d}
.intro{margin-bottom:26px}
.eyebrow{font-family:var(--mono);font-size:12px;letter-spacing:.14em;text-transform:uppercase;color:var(--or);margin-bottom:8px}
h1{font-size:30px;font-weight:800;line-height:1.2;margin-bottom:10px}
.sub{font-size:16px;line-height:1.55;color:var(--muted);max-width:760px}
.tut-grid{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:26px}
.tut-frame{border:1px solid var(--line);border-radius:16px;overflow:hidden;background:var(--bg2);box-shadow:0 24px 60px rgba(0,0,0,.4)}
.tut-bar{display:flex;align-items:center;gap:6px;padding:9px 13px;border-bottom:1px solid var(--line);font-family:var(--mono);font-size:12px;color:var(--muted)}
.tut-bar i{width:10px;height:10px;border-radius:50%;background:#2a3340}
.tut-bar i:first-child{background:var(--or)}
.tut-bar span{margin-left:10px}
.tut-frame video{display:block;width:100%;height:auto;aspect-ratio:16/10;object-fit:cover;background:#0b0e11}
.tut-card h2{display:flex;align-items:center;gap:10px;font-size:18px;font-weight:700;margin:14px 2px 6px}
.tut-card .num{display:inline-flex;align-items:center;justify-content:center;width:26px;height:26px;border-radius:50%;border:1px solid var(--or);color:var(--or);font:700 13px var(--mono);flex-shrink:0}
.tut-card p{font-size:14.5px;line-height:1.55;color:var(--muted);margin:0 2px}
.note{margin-top:32px;font-size:13px;color:var(--muted)}
.footer-links{margin-top:10px;font-size:13px;color:var(--muted)}
.footer-links a{color:var(--muted)}
.footer-links a:hover{color:var(--text)}
.footer-links a.mission-link{color:var(--or)}
@media (max-width:820px){.tut-grid{grid-template-columns:1fr}h1{font-size:25px}}