*,*::before,*::after{box-sizing:border-box}
        body{background-color:#020617;color:#fff;-webkit-tap-highlight-color:transparent;overflow-x:hidden;font-family:'DM Sans',system-ui,-apple-system,sans-serif;padding-top:env(safe-area-inset-top);padding-left:env(safe-area-inset-left);padding-right:env(safe-area-inset-right)}
        html{-webkit-text-size-adjust:100%;scroll-behavior:smooth}
        footer{padding-bottom:max(3rem,calc(3rem + env(safe-area-inset-bottom)))}
        .full-screen{height:100vh;height:calc(var(--vh,1vh)*100);height:100dvh}
        /* Platform video */
        
        .cs-video-grid{display:grid;gap:2rem;align-items:center;padding:1.25rem;border-radius:24px;border:1px solid rgba(56,189,248,.2);background:linear-gradient(135deg,rgba(56,189,248,.08),rgba(129,140,248,.06) 60%,rgba(255,255,255,.02));box-shadow:0 30px 80px -40px rgba(56,189,248,.5)}
        @media(min-width:900px){.cs-video-grid{grid-template-columns:1.55fr 1fr;padding:1.5rem}}
        .cs-video-frame{position:relative;aspect-ratio:16/9;border-radius:16px;overflow:hidden;background:#01030b;border:1px solid rgba(255,255,255,.08)}
        .cs-video-frame video,.cs-video-play{position:absolute;inset:0;width:100%;height:100%;border:0}.cs-video-frame video{background:#000;object-fit:contain}.cs-video-play picture{display:block;width:100%;height:100%}.cs-video-frame .video-error{position:absolute;inset:0;display:grid;place-items:center;margin:0;padding:20px;text-align:center;font-size:14px;color:#fff;background:#01030b}
        .cs-video-play{padding:0;cursor:pointer;background:#01030b;display:block}
        .cs-video-play img{width:100%;height:100%;object-fit:cover;display:block;transition:transform .6s cubic-bezier(.2,.7,.2,1)}
        .cs-video-play:hover img{transform:scale(1.03)}
        .cs-video-shade{position:absolute;inset:0;background:radial-gradient(ellipse at center,rgba(1,3,11,.05),rgba(1,3,11,.55))}
        .cs-video-btn{position:absolute;left:50%;top:50%;width:76px;height:76px;margin:-38px 0 0 -38px;border-radius:50%;display:grid;place-items:center;color:#020617;background:linear-gradient(135deg,#38bdf8,#818cf8);box-shadow:0 0 0 10px rgba(56,189,248,.18),0 18px 40px -10px rgba(0,0,0,.7);transition:transform .25s ease}
        .cs-video-btn svg{margin-left:4px}
        .cs-video-play:hover .cs-video-btn,.cs-video-play:focus-visible .cs-video-btn{transform:scale(1.08)}
        .cs-video-play:focus-visible{outline:2px solid #38bdf8;outline-offset:-4px}
        .cs-video-time{position:absolute;right:12px;bottom:12px;font-family:'JetBrains Mono',monospace;font-size:11px;font-weight:700;color:#fff;background:rgba(0,0,0,.65);padding:3px 8px;border-radius:6px}
        .cs-video-cta{display:inline-flex;align-items:center;gap:8px;min-height:44px;padding:0 16px;border-radius:12px;font-size:13px;font-weight:700;color:#fff;border:1px solid rgba(255,255,255,.14);background:rgba(255,255,255,.04);transition:background .2s}
        .cs-video-cta:hover{background:rgba(255,255,255,.08)}
        .cs-video-cta--yt{border-color:rgba(239,68,68,.45);background:rgba(239,68,68,.12)}
        @media (prefers-reduced-motion:reduce){.cs-video-play img,.cs-video-btn{transition:none}.cs-video-play:hover img{transform:none}}
        .gradient-text{background:linear-gradient(90deg,#38bdf8,#818cf8);-webkit-background-clip:text;-webkit-text-fill-color:transparent;font-weight:900}
        .glass-card{background:rgba(30,41,59,0.4);backdrop-filter:blur(12px);-webkit-backdrop-filter:blur(12px);border:1px solid rgba(255,255,255,0.1)}
        section{width:100%;max-width:100vw}
        #splash{position:fixed;inset:0;z-index:9999;background:#020617;display:flex;flex-direction:column;align-items:center;justify-content:center;gap:1.5rem;transition:opacity .5s ease,visibility .5s ease}
        #splash.hidden{opacity:0;visibility:hidden;pointer-events:none}
        .splash-ring{width:56px;height:56px;border:3px solid rgba(56,189,248,0.15);border-top-color:#38bdf8;border-radius:50%;animation:spin .9s linear infinite}
        @keyframes spin{to{transform:rotate(360deg)}}
        .splash-logo-text{font-family:'DM Sans',system-ui,sans-serif;font-size:1.35rem;font-weight:900;letter-spacing:-.02em;background:linear-gradient(90deg,#38bdf8,#818cf8);-webkit-background-clip:text;-webkit-text-fill-color:transparent}
        #mobile-menu{display:none}
        #mobile-menu.open{display:flex}
        nav.sticky{top:0;top:env(safe-area-inset-top)}
        .edu-tabs{display:flex;overflow-x:auto;gap:0;border-bottom:1px solid rgba(255,255,255,0.08);padding:0 1rem;scrollbar-width:none;-webkit-overflow-scrolling:touch}
        .edu-tabs::-webkit-scrollbar{display:none}
        .edu-tab{flex-shrink:0;padding:.65rem 1.1rem;font-size:.78rem;font-weight:700;text-transform:uppercase;letter-spacing:.1em;cursor:pointer;color:rgba(255,255,255,0.45);border-bottom:2px solid transparent;background:none;border-top:none;border-left:none;border-right:none;transition:color .15s,border-color .15s;white-space:nowrap;-webkit-tap-highlight-color:transparent;touch-action:manipulation}
        .edu-tab.active{color:#38bdf8;border-bottom-color:#38bdf8}
        .edu-tab:hover{color:rgba(255,255,255,0.8)}
        .edu-section{display:none}
        .edu-section.visible{display:block}
        .chain-wrap{display:flex;overflow-x:auto;gap:0;padding-bottom:.5rem;-webkit-overflow-scrolling:touch;overscroll-behavior-x:contain}
        .block-card{flex-shrink:0;width:175px;background:rgba(30,41,59,0.6);border:1px solid rgba(255,255,255,0.1);border-radius:14px;padding:.85rem 1rem}
        .block-card.genesis{border-color:rgba(56,189,248,0.5)}
        .block-card.invalid{border-color:rgba(226,75,74,0.5)}
        .block-num{font-family:'JetBrains Mono',monospace;font-size:.65rem;color:#38bdf8;margin-bottom:.5rem}
        .block-field{margin-bottom:.4rem}
        .block-field label{display:block;font-size:.6rem;text-transform:uppercase;letter-spacing:.07em;color:rgba(255,255,255,0.4);margin-bottom:2px}
        .block-field span{font-family:'JetBrains Mono',monospace;font-size:.64rem;word-break:break-all}
        .hash-ok{color:#34d399}
        .hash-err{color:#f87171}
        .chain-arrow{display:flex;align-items:center;justify-content:center;width:24px;flex-shrink:0;color:rgba(255,255,255,0.3);font-size:.9rem;align-self:center}
        .tamper-btn{width:100%;margin-top:.5rem;font-size:.68rem;padding:.28rem .5rem;border-radius:6px;border:1px solid rgba(255,255,255,0.12);background:transparent;color:rgba(255,255,255,0.45);cursor:pointer;transition:all .15s;font-family:'DM Sans',sans-serif;font-weight:600;touch-action:manipulation}
        .tamper-btn:hover{background:rgba(226,75,74,0.15);color:#f87171;border-color:rgba(226,75,74,0.4)}
        .tamper-btn.restore:hover{background:rgba(52,211,153,0.12);color:#34d399;border-color:rgba(52,211,153,0.4)}
        .quiz-opt{display:flex;align-items:flex-start;gap:.75rem;padding:.7rem 1rem;border:1px solid rgba(255,255,255,0.1);border-radius:10px;cursor:pointer;font-size:.85rem;background:rgba(30,41,59,0.4);transition:border-color .15s;color:rgba(255,255,255,0.8);margin-bottom:.45rem;touch-action:manipulation}
        .quiz-opt:hover{border-color:#38bdf8}
        .quiz-opt.correct{border-color:#34d399;background:rgba(52,211,153,0.08);color:#34d399}
        .quiz-opt.wrong{border-color:#f87171;background:rgba(248,113,113,0.08);color:#f87171}
        .glos-item{display:none}
        .glos-item.show{display:block}
        .tl-wrap{position:relative;padding-left:1.6rem}
        .tl-wrap::before{content:'';position:absolute;left:5px;top:0;bottom:0;width:1px;background:rgba(56,189,248,0.2)}
        .tl-item{position:relative;margin-bottom:1.4rem}
        .tl-dot{position:absolute;left:-1.6rem;top:4px;width:11px;height:11px;border-radius:50%;background:#38bdf8;border:2px solid #020617;box-shadow:0 0 0 1px #38bdf8}
        .tl-year{font-family:'JetBrains Mono',monospace;font-size:.68rem;color:#38bdf8;margin-bottom:.2rem}
        .hash-out{background:rgba(15,23,42,0.8);border:1px solid rgba(255,255,255,0.08);border-radius:10px;padding:.75rem 1rem;margin-top:.6rem}
        .hash-out label{font-size:.65rem;text-transform:uppercase;letter-spacing:.1em;color:rgba(255,255,255,0.35);display:block;margin-bottom:.4rem}
        .hash-out code{font-family:'JetBrains Mono',monospace;font-size:.72rem;word-break:break-all;color:#38bdf8}
        .uc-tile{background:rgba(30,41,59,0.4);border:1px solid rgba(255,255,255,0.08);border-radius:14px;padding:1rem;cursor:pointer;transition:border-color .15s,transform .12s;touch-action:manipulation}
        .uc-tile:hover{border-color:#818cf8;transform:translateY(-2px)}
        .edu-card{background:rgba(30,41,59,0.4);border:1px solid rgba(255,255,255,0.08);border-radius:14px;padding:1.1rem 1.2rem}
        .blog-card{background:rgba(30,41,59,0.4);border:1px solid rgba(255,255,255,0.08);border-radius:16px;padding:1.5rem;transition:border-color .2s,transform .15s;min-width:0}
        /* Feed summaries are publisher text and can hold an unbroken URL; let it wrap
           instead of widening the card past a phone screen. Scoped to the feed so the
           library tables keep their column sizing. */
        #feed-grid .blog-card{overflow-wrap:anywhere}
        .blog-card:hover{border-color:rgba(56,189,248,0.4);transform:translateY(-3px)}
        .blog-tag{display:inline-block;font-size:.65rem;font-weight:800;text-transform:uppercase;letter-spacing:.1em;padding:3px 10px;border-radius:99px;background:rgba(56,189,248,0.1);color:#38bdf8;border:1px solid rgba(56,189,248,0.25);margin-bottom:.75rem}
        .blog-tag.purple{background:rgba(129,140,248,0.1);color:#818cf8;border-color:rgba(129,140,248,0.25)}
        .blog-tag.green{background:rgba(52,211,153,0.1);color:#34d399;border-color:rgba(52,211,153,0.25)}
        .blog-tag.red{background:rgba(248,113,113,0.1);color:#f87171;border-color:rgba(248,113,113,0.25)}
        .blog-tag.amber{background:rgba(251,191,36,0.1);color:#fbbf24;border-color:rgba(251,191,36,0.25)}
        .stat-pill{display:inline-flex;align-items:center;gap:.4rem;background:rgba(15,23,42,0.7);border:1px solid rgba(255,255,255,0.08);border-radius:10px;padding:.55rem .9rem;font-family:'JetBrains Mono',monospace;font-size:.72rem}
        .stat-up{color:#34d399}
        .stat-down{color:#f87171}
        .stat-neu{color:#38bdf8}
        .data-table{width:100%;border-collapse:collapse;font-size:.8rem}
        .data-table th{text-align:left;font-size:.65rem;font-weight:800;text-transform:uppercase;letter-spacing:.08em;color:rgba(255,255,255,0.35);padding:.5rem .75rem;border-bottom:1px solid rgba(255,255,255,0.07)}
        .data-table td{padding:.6rem .75rem;border-bottom:1px solid rgba(255,255,255,0.05);color:rgba(255,255,255,0.75)}
        .data-table tr:last-child td{border-bottom:none}
        .data-table td.mono{font-family:'JetBrains Mono',monospace;font-size:.75rem}
        @media(max-width:640px){.block-card{width:152px}}
        .brand-link{text-decoration:none;display:flex;align-items:center;cursor:pointer;touch-action:manipulation}
        .brand-link:hover{opacity:.85}
        .ai-chip{padding:.5rem 1rem;border-radius:99px;border:1px solid rgba(255,255,255,0.12);background:rgba(30,41,59,0.5);color:rgba(255,255,255,0.7);font-size:.78rem;font-weight:700;cursor:pointer;font-family:'DM Sans',sans-serif;transition:border-color .15s,background .15s,color .15s;touch-action:manipulation}
        .ai-chip:hover{border-color:#38bdf8;color:#38bdf8;background:rgba(56,189,248,0.08)}
        .ai-msg{display:flex;gap:.75rem;align-items:flex-start;margin-bottom:1rem;font-size:.85rem;line-height:1.65}
        .ai-msg-bot{color:rgba(255,255,255,0.82)}
        .ai-msg-user{color:#38bdf8;flex-direction:row-reverse}
        .ai-msg-user span:last-child{text-align:right}
        .ai-avatar{flex-shrink:0;width:26px;height:26px;border-radius:50%;display:flex;align-items:center;justify-content:center;font-size:.7rem;background:linear-gradient(135deg,#38bdf8,#818cf8);color:#fff;font-weight:900}
        .ai-avatar-user{flex-shrink:0;width:26px;height:26px;border-radius:50%;background:rgba(56,189,248,0.15);display:flex;align-items:center;justify-content:center;font-size:.7rem;border:1px solid rgba(56,189,248,0.3);color:#38bdf8;font-weight:900}
        .ai-typing span{display:inline-block;width:6px;height:6px;border-radius:50%;background:#38bdf8;margin:0 2px;animation:blink 1.2s infinite}
        .ai-typing span:nth-child(2){animation-delay:.2s}
        .ai-typing span:nth-child(3){animation-delay:.4s}
        @keyframes blink{0%,80%,100%{opacity:.2}40%{opacity:1}}
        #ai-chat{scrollbar-width:thin;scrollbar-color:rgba(56,189,248,0.2) transparent;-webkit-overflow-scrolling:touch;overscroll-behavior:contain}
        .icon-bars{display:block;width:22px;height:16px}
        .icon-bars span{display:block;width:100%;height:2px;background:#38bdf8;border-radius:2px;margin-bottom:5px;transition:transform .2s,opacity .2s}
        .icon-bars span:last-child{margin-bottom:0}
        html,body{overscroll-behavior:none}
        .scroll-container{overscroll-behavior:contain}
        .course-card{border-radius:18px;padding:1.5rem 1.4rem 1.4rem;border:1px solid rgba(255,255,255,0.08);background:rgba(10,20,40,0.7);display:flex;flex-direction:column;gap:0;transition:transform .15s,border-color .15s}
        .course-card:hover{transform:translateY(-3px)}
        .course-beginner{border-color:rgba(0,200,160,0.25)}
        .course-intermediate{border-color:rgba(251,191,36,0.25)}
        .course-advanced{border-color:rgba(239,100,72,0.25)}
        .course-beginner:hover{border-color:rgba(0,200,160,0.55)}
        .course-intermediate:hover{border-color:rgba(251,191,36,0.55)}
        .course-advanced:hover{border-color:rgba(239,100,72,0.55)}
        .course-icon-wrap{width:48px;height:48px;border-radius:12px;display:flex;align-items:center;justify-content:center;margin-bottom:1rem}
        .course-icon-beginner{background:rgba(0,200,160,0.12);border:1px solid rgba(0,200,160,0.25)}
        .course-icon-intermediate{background:rgba(251,191,36,0.12);border:1px solid rgba(251,191,36,0.25)}
        .course-icon-advanced{background:rgba(239,100,72,0.12);border:1px solid rgba(239,100,72,0.25)}
        .course-level{font-size:.62rem;font-weight:900;letter-spacing:.18em;text-transform:uppercase;margin-bottom:.6rem;padding:4px 12px;border-radius:99px;display:inline-block;width:fit-content}
        .course-level-beginner{color:#00c8a0;background:rgba(0,200,160,0.08);border:1px solid rgba(0,200,160,0.22)}
        .course-level-intermediate{color:#fbbf24;background:rgba(251,191,36,0.08);border:1px solid rgba(251,191,36,0.22)}
        .course-level-advanced{color:#ef6448;background:rgba(239,100,72,0.08);border:1px solid rgba(239,100,72,0.22)}
        .course-title{font-size:1.2rem;font-weight:900;color:#fff;margin:0 0 .55rem;line-height:1.25}
        .course-desc{font-size:.82rem;color:rgba(255,255,255,0.5);line-height:1.6;margin-bottom:1rem}
        .course-list{list-style:none;padding:0;margin:0 0 1.3rem;border-top:1px solid rgba(255,255,255,0.07);padding-top:.75rem;display:flex;flex-direction:column;gap:0}
        .course-list li{font-size:.82rem;color:rgba(255,255,255,0.7);padding:.45rem 0;border-bottom:1px solid rgba(255,255,255,0.05);display:flex;align-items:center;gap:.55rem;cursor:pointer;transition:color .15s;touch-action:manipulation}
        .course-list li:hover{color:#fff}
        .course-list li::before{content:'•';font-size:.9rem;flex-shrink:0}
        .course-beginner .course-list li::before{color:#00c8a0}
        .course-intermediate .course-list li::before{color:#fbbf24}
        .course-advanced .course-list li::before{color:#ef6448}
        .course-btn{margin-top:auto;width:100%;padding:.65rem 1rem;border-radius:10px;font-size:.82rem;font-weight:800;letter-spacing:.04em;border:none;cursor:pointer;transition:opacity .15s,transform .12s;font-family:inherit;touch-action:manipulation}
        .course-btn:hover{opacity:.88;transform:translateY(-1px)}
        .course-btn-beginner{background:#00c8a0;color:#000}
        .course-btn-intermediate{background:#fbbf24;color:#000}
        .course-btn-advanced{background:#ef6448;color:#fff}
        .mob-nav{display:none;position:fixed;bottom:0;left:0;right:0;background:#0c1018;border-top:.5px solid rgba(255,255,255,0.08);z-index:100;align-items:center;justify-content:space-around;padding:0 4px;padding-bottom:env(safe-area-inset-bottom);height:calc(60px + env(safe-area-inset-bottom))}
        @media(max-width:1023px){.mob-nav{display:flex}body{padding-bottom:calc(60px + env(safe-area-inset-bottom))}}
        .mob-nav-btn{display:flex;flex-direction:column;align-items:center;gap:3px;background:none;border:none;cursor:pointer;padding:8px 4px;border-radius:12px;flex:1;color:#4a6a7a;transition:color .2s;-webkit-tap-highlight-color:transparent;touch-action:manipulation}
        .mob-nav-btn.active{color:#38bdf8}
        .mob-nav-btn svg{width:20px;height:20px;flex-shrink:0}
        .mob-nav-btn span{font-size:10px;font-weight:600;color:inherit;white-space:nowrap}
        .app-icon{border-radius:22%;object-fit:cover;flex-shrink:0}
        .app-icon-nav{width:34px;height:34px;border-radius:22%;margin-right:.55rem}
        .app-icon-splash{width:72px;height:72px;border-radius:22%}
        .app-icon-download{width:72px;height:72px;border-radius:22%}
        .app-icon-footer{width:40px;height:40px;border-radius:22%}
        .gplay-btn{display:inline-flex;align-items:center;gap:.6rem;background:#fff;color:#000;border:none;border-radius:12px;padding:.55rem 1.2rem;font-weight:800;font-size:.82rem;cursor:pointer;text-decoration:none;font-family:'DM Sans',sans-serif;transition:opacity .15s,transform .1s;letter-spacing:.01em}
        .gplay-btn:hover{opacity:.88;transform:translateY(-1px)}
        .gplay-btn svg{flex-shrink:0}
        .app-download-section{background:rgba(15,23,42,0.7);border-top:1px solid rgba(255,255,255,0.07);border-bottom:1px solid rgba(255,255,255,0.07)}
    
/* HSZB Technologies social row (4 official profiles) */
.hszb-social{list-style:none;margin:0;padding:0;display:flex;flex-wrap:wrap;justify-content:center;gap:10px}
.hszb-social li{margin:0;padding:0}
.hszb-social a{position:relative;display:grid;place-items:center;width:44px;height:44px;text-decoration:none;transition:color .25s ease,border-color .25s ease,box-shadow .25s ease,transform .25s ease,background-color .25s ease}
.hszb-social a:hover{transform:translateY(-2px)}
.hszb-social svg{display:block}
.hszb-social-badge{position:absolute;top:-4px;right:-4px;min-width:16px;height:16px;padding:0 4px;box-sizing:border-box;border-radius:999px;display:grid;place-items:center;font-size:9px;font-weight:700;line-height:1}
@media (prefers-reduced-motion:reduce){.hszb-social a{transition:none}.hszb-social a:hover{transform:none}}
.hszb-social a{color:rgba(255,255,255,.62);border:1px solid rgba(255,255,255,.12);border-radius:999px;background:rgba(255,255,255,.03)}
.hszb-social a:hover{color:#38bdf8;border-color:rgba(56,189,248,.5);background:rgba(56,189,248,.08);box-shadow:0 0 18px -4px rgba(56,189,248,.6)}
.hszb-social a:focus-visible{outline:2px solid #38bdf8;outline-offset:3px;color:#38bdf8}
.hszb-social-badge{background:#020617;border:1px solid rgba(251,191,36,.6);color:#fbbf24}

/* ── multi-page navigation (2026-10-03) ── */
.cs-crumbs ol{list-style:none;margin:0;padding:0;display:flex;flex-wrap:wrap;gap:4px 0;font-family:'JetBrains Mono',monospace;font-size:10px;font-weight:700;text-transform:uppercase;letter-spacing:.12em;color:rgba(255,255,255,.45)}
.cs-crumbs li{display:flex;align-items:center}
.cs-crumbs li+li::before{content:'/';margin:0 8px;opacity:.4}
.cs-crumbs a{color:#38bdf8;text-decoration:none}
.cs-crumbs a:hover{text-decoration:underline}
.hub-card{position:relative;display:flex;flex-direction:column;gap:6px;min-height:44px;padding:18px 44px 18px 18px;border-radius:16px;border:1px solid rgba(255,255,255,.08);background:rgba(15,23,42,.6);text-decoration:none;color:#fff;transition:border-color .15s,background .15s}
.hub-card:hover{border-color:rgba(56,189,248,.45);background:rgba(15,23,42,.85)}
.hub-kicker{font-family:'JetBrains Mono',monospace;font-size:10px;font-weight:700;text-transform:uppercase;letter-spacing:.14em;color:#38bdf8}
.hub-title{font-weight:800;font-size:1rem;line-height:1.3}
.hub-desc{font-size:.82rem;line-height:1.55;color:rgba(255,255,255,.55)}
.hub-go{position:absolute;right:18px;top:50%;transform:translateY(-50%);color:rgba(255,255,255,.35);font-size:1.1rem}
.uc-tile .uc-detail{font-size:.78rem;color:rgba(255,255,255,.62);line-height:1.6;margin-top:.6rem}
.module-block{padding:1.1rem 1.2rem;border:1px solid rgba(255,255,255,.08);border-radius:14px;background:rgba(15,23,42,.5)}
.module-block h2{font-size:1.05rem;font-weight:900;color:#fff;margin-bottom:.4rem}
.module-block p{font-size:.88rem;color:rgba(255,255,255,.65);line-height:1.75}
.kb-item{padding:1rem 1.15rem;border:1px solid rgba(255,255,255,.08);border-radius:14px;background:rgba(15,23,42,.5)}
.kb-item h3{font-size:.95rem;font-weight:900;color:#fff;margin-bottom:.35rem}
.kb-item p{font-size:.85rem;color:rgba(255,255,255,.62);line-height:1.7}
a.course-list-link{color:inherit;text-decoration:none;display:block}
.article-nav a{min-height:44px}

/* ═══ CHAINSOURCES DESIGN SYSTEM (2026-10-03) ═══ */
:root{
  --cs-ink:#060a14;--cs-ink-2:#0a1120;--cs-surface:#0c1424;--cs-surface-2:#111b2f;--cs-surface-3:#16223a;
  --cs-line:rgba(148,163,184,.13);--cs-line-2:rgba(148,163,184,.24);
  --cs-cyan:#38bdf8;--cs-cyan-rgb:56,189,248;--cs-indigo:#818cf8;--cs-indigo-rgb:129,140,248;--cs-mint:#34d399;--cs-mint-rgb:52,211,153;--cs-rose:#fb7185;
  --cs-text:#e6edf7;--cs-text-2:#9fb0c7;--cs-text-3:#6b7d96;
  --cs-r:18px;--cs-r-sm:12px;
  --cs-h:'Space Grotesk','DM Sans',system-ui,sans-serif;--cs-b:'DM Sans',system-ui,-apple-system,sans-serif;--cs-m:'JetBrains Mono',ui-monospace,SFMono-Regular,Menlo,monospace;
  --cs-shadow:0 1px 0 rgba(255,255,255,.04) inset,0 18px 40px -28px rgba(0,0,0,.9);
}
body{background:var(--cs-ink)!important;color:var(--cs-text)}
html body{font-family:var(--cs-b)!important}
body::before{content:'';position:fixed;inset:0;pointer-events:none;z-index:0;
  background-image:linear-gradient(rgba(148,163,184,.055) 1px,transparent 1px),linear-gradient(90deg,rgba(148,163,184,.055) 1px,transparent 1px);
  background-size:56px 56px;-webkit-mask-image:radial-gradient(ellipse 85% 55% at 50% 0%,#000 25%,transparent 78%);mask-image:radial-gradient(ellipse 85% 55% at 50% 0%,#000 25%,transparent 78%)}
main,footer,#app-download,section{position:relative;z-index:1}
::selection{background:rgba(var(--cs-cyan-rgb),.3)}
:focus-visible{outline:2px solid var(--cs-cyan);outline-offset:3px;border-radius:8px}
.gradient-text{background:linear-gradient(90deg,var(--cs-cyan),var(--cs-indigo));-webkit-background-clip:text;background-clip:text;-webkit-text-fill-color:transparent}

/* Typography: sentence-case geometric headings, comfortable reading text */
main h1,main h2,main h3,.cs-h{font-family:var(--cs-h)!important;text-transform:none!important;letter-spacing:-.022em!important;font-weight:700!important}
main h1{font-size:clamp(2rem,4.4vw,3rem)!important;line-height:1.08!important}
main h2.cs-h2{font-size:clamp(1.5rem,3vw,2rem)!important;line-height:1.15!important}
main p.text-sky-400,.cs-eyebrow{font-family:var(--cs-m)!important;font-size:11px!important;font-weight:600!important;letter-spacing:.14em!important;text-transform:uppercase;color:var(--cs-cyan)!important}

/* Header */
nav.cs-top{background:rgba(6,10,20,.84)!important;backdrop-filter:blur(14px);-webkit-backdrop-filter:blur(14px);border-bottom:1px solid var(--cs-line)!important;padding-top:12px!important;padding-bottom:12px!important}
.cs-links{display:none;align-items:center;gap:4px}
@media (min-width:1024px){.cs-links{display:flex}}
.cs-links a{position:relative;padding:8px 11px;border-radius:10px;font-size:14px;font-weight:600;color:var(--cs-text-2);text-decoration:none;transition:color .15s,background .15s}
.cs-links a:hover{color:var(--cs-text);background:rgba(148,163,184,.08)}
.cs-links a[aria-current]{color:var(--cs-text)}
.cs-links a[aria-current]::after{content:'';position:absolute;left:11px;right:11px;bottom:2px;height:2px;border-radius:2px;background:var(--cs-cyan)}
.cs-nav-cta{margin-left:10px;padding:9px 14px!important;color:#04121f!important;background:linear-gradient(180deg,#67d0fb,var(--cs-cyan))!important;font-weight:700!important}
.cs-nav-cta:hover{filter:brightness(1.06)}
#mobile-menu a.cs-mlink{display:flex;align-items:center;justify-content:space-between;min-height:48px;padding:0 4px;font-size:16px;font-weight:600;color:var(--cs-text-2);border-bottom:1px solid var(--cs-line);text-decoration:none}
#mobile-menu a.cs-mlink[aria-current]{color:var(--cs-cyan)}
#mobile-menu a.cs-mlink::after{content:'→';color:var(--cs-text-3)}

/* Breadcrumbs */
.cs-crumbs ol{font-family:var(--cs-m)!important;font-size:11px!important;letter-spacing:.06em!important;color:var(--cs-text-3)!important}
.cs-crumbs a{color:var(--cs-cyan)!important}

/* Cards */
.hub-card{background:linear-gradient(180deg,var(--cs-surface-2),var(--cs-surface))!important;border:1px solid var(--cs-line)!important;border-radius:var(--cs-r)!important;box-shadow:var(--cs-shadow);padding:20px 48px 20px 20px!important;gap:8px!important;transition:border-color .18s,transform .18s,box-shadow .18s!important;overflow:hidden}
.hub-card::before{content:'';position:absolute;left:0;right:0;top:0;height:2px;background:var(--k,var(--cs-cyan));opacity:0;transition:opacity .18s}
.hub-card:hover{border-color:var(--cs-line-2)!important;transform:translateY(-2px);box-shadow:0 1px 0 rgba(255,255,255,.05) inset,0 24px 44px -26px rgba(0,0,0,.95)}
.hub-card:hover::before{opacity:1}
.hub-kicker{align-self:flex-start;display:inline-flex;align-items:center;gap:7px;font-family:var(--cs-m)!important;font-size:10.5px!important;font-weight:600!important;letter-spacing:.08em!important;color:var(--k,var(--cs-cyan))!important}
.hub-kicker::before{content:'';width:6px;height:6px;border-radius:2px;background:currentColor;opacity:.9}
.hub-title{font-family:var(--cs-h);font-size:1.05rem!important;font-weight:700!important;letter-spacing:-.01em;color:var(--cs-text)}
.hub-desc{font-size:.86rem!important;color:var(--cs-text-2)!important;line-height:1.6!important}
.hub-go{width:28px;height:28px;display:grid;place-items:center;border-radius:9px;border:1px solid var(--cs-line);font-size:.85rem!important;color:var(--cs-text-3)!important;transition:all .18s}
.hub-card:hover .hub-go{color:var(--k,var(--cs-cyan))!important;border-color:currentColor;transform:translate(2px,-50%)}
.hub-card[data-kind=learn]{--k:var(--cs-cyan)}
.hub-card[data-kind=tool]{--k:var(--cs-mint)}
.hub-card[data-kind=course],.hub-card[data-kind=ai]{--k:var(--cs-indigo)}
.hub-card[data-kind=read]{--k:#a5b4fc}
.hub-card[data-kind=nav]{--k:var(--cs-text-2)}

/* Homepage hero */
.cs-hero{max-width:64rem;margin:0 auto;padding:56px 24px 40px;display:grid;gap:40px;align-items:center}
@media (min-width:960px){.cs-hero{grid-template-columns:1.15fr .85fr;padding:76px 24px 56px}}
.cs-pills{display:flex;flex-wrap:wrap;gap:8px;margin-bottom:22px}
.cs-pill{font-family:var(--cs-m);font-size:11px;font-weight:600;letter-spacing:.06em;padding:6px 11px;border-radius:999px;border:1px solid var(--cs-line-2);color:var(--cs-text-2);background:rgba(148,163,184,.05)}
.cs-pill.on{color:var(--cs-cyan);border-color:rgba(var(--cs-cyan-rgb),.35);background:rgba(var(--cs-cyan-rgb),.07)}
main .cs-hero h1{font-size:clamp(2.3rem,4.8vw,3.5rem)!important;line-height:1.02!important;letter-spacing:-.035em!important;margin:0 0 18px;color:var(--cs-text)}
.cs-lead{font-size:clamp(1rem,1.5vw,1.12rem);line-height:1.75;color:var(--cs-text-2);max-width:60ch;margin:0}
.cs-actions{display:flex;flex-wrap:wrap;align-items:center;gap:12px;margin-top:28px}
.cs-btn{display:inline-flex;align-items:center;justify-content:center;gap:8px;min-height:48px;padding:0 20px;border-radius:12px;font-weight:700;font-size:15px;text-decoration:none;transition:transform .15s,background .15s,border-color .15s,color .15s}
.cs-btn-primary{color:#04121f!important;background:linear-gradient(180deg,#67d0fb,var(--cs-cyan));box-shadow:0 1px 0 rgba(255,255,255,.35) inset,0 12px 28px -14px rgba(var(--cs-cyan-rgb),.8)}
.cs-btn-primary:hover{transform:translateY(-1px)}
.cs-btn-secondary{color:var(--cs-text)!important;border:1px solid var(--cs-line-2);background:rgba(148,163,184,.04)}
.cs-btn-secondary:hover{border-color:rgba(var(--cs-cyan-rgb),.5);color:var(--cs-cyan)!important}
.cs-btn-text{color:var(--cs-cyan)!important;font-weight:600;text-decoration:none;min-height:48px;display:inline-flex;align-items:center}
.cs-btn-text:hover{text-decoration:underline;text-underline-offset:4px}
.cs-chain{display:grid;gap:10px;padding:18px;border-radius:22px;border:1px solid var(--cs-line);background:linear-gradient(180deg,rgba(17,27,47,.9),rgba(12,20,36,.9));box-shadow:var(--cs-shadow)}
.cs-chain-cap{font-family:var(--cs-m);font-size:10.5px;letter-spacing:.08em;color:var(--cs-text-3);display:flex;justify-content:space-between}
.cs-blk{position:relative;padding:14px 16px;border-radius:14px;border:1px solid var(--cs-line);background:rgba(6,10,20,.6);font-family:var(--cs-m);font-size:11.5px;line-height:1.7}
.cs-blk b{font-family:var(--cs-h);font-size:14px;color:var(--cs-text);font-weight:600}
.cs-blk .k{color:var(--cs-text-3);display:inline-block;width:72px}
.cs-blk .h{color:var(--cs-mint)}
.cs-blk .p{color:var(--cs-cyan)}
.cs-blk+.cs-blk::before{content:'';position:absolute;left:28px;top:-11px;width:2px;height:10px;background:linear-gradient(var(--cs-cyan),var(--cs-mint));border-radius:2px}

/* Learning path */
.cs-path{list-style:none;margin:0;padding:0;display:grid;gap:12px;counter-reset:step}
@media (min-width:768px){.cs-path{grid-template-columns:repeat(4,1fr)}}
.cs-path li{counter-increment:step}
.cs-step{position:relative;display:flex;flex-direction:column;gap:6px;height:100%;padding:18px;border-radius:var(--cs-r);border:1px solid var(--cs-line);background:linear-gradient(180deg,var(--cs-surface-2),var(--cs-surface));text-decoration:none;color:var(--cs-text);transition:border-color .18s,transform .18s}
.cs-step:hover{border-color:rgba(var(--cs-cyan-rgb),.45);transform:translateY(-2px)}
.cs-step::before{content:counter(step,decimal-leading-zero);font-family:var(--cs-m);font-size:12px;font-weight:600;color:var(--cs-cyan);width:34px;height:34px;display:grid;place-items:center;border-radius:10px;border:1px solid rgba(var(--cs-cyan-rgb),.35);background:rgba(var(--cs-cyan-rgb),.07);margin-bottom:6px}
.cs-step-kind{font-family:var(--cs-m);font-size:10.5px;letter-spacing:.08em;color:var(--cs-text-3)}
.cs-step-title{font-family:var(--cs-h);font-weight:700;font-size:1.05rem}
.cs-step-desc{font-size:.86rem;line-height:1.55;color:var(--cs-text-2)}

/* Explore grid with icons */
.cs-explore{display:grid;gap:12px;grid-template-columns:1fr}
@media (min-width:640px){.cs-explore{grid-template-columns:repeat(2,1fr)}}
@media (min-width:1024px){.cs-explore{grid-template-columns:repeat(3,1fr)}}
.cs-tile{display:grid;grid-template-columns:44px 1fr;gap:14px;align-items:start;padding:18px;border-radius:var(--cs-r);border:1px solid var(--cs-line);background:linear-gradient(180deg,var(--cs-surface-2),var(--cs-surface));color:var(--cs-text);text-decoration:none;transition:border-color .18s,transform .18s}
.cs-tile:hover{border-color:var(--cs-line-2);transform:translateY(-2px)}
.cs-ico{width:44px;height:44px;border-radius:12px;display:grid;place-items:center;color:var(--k);background:rgba(148,163,184,.06);border:1px solid var(--cs-line)}
.cs-ico svg{width:22px;height:22px}
.cs-tile-t{font-family:var(--cs-h);font-weight:700;font-size:1.02rem;display:block}
.cs-tile-d{font-size:.86rem;line-height:1.55;color:var(--cs-text-2);display:block;margin-top:3px}

/* Lesson reading experience */
.cs-lesson .edu-section{padding-top:28px!important}
.cs-lesson .edu-section > p:not(.text-sky-400){font-size:1.04rem!important;line-height:1.78!important;color:var(--cs-text-2)!important;max-width:68ch!important}
.cs-lesson .edu-section h1{margin-bottom:14px!important}
.cs-lesson .edu-section .grid > div,.cs-lesson .uc-tile,.cs-lesson .tl-item{border-radius:14px!important}
.cs-progress{display:flex;flex-wrap:wrap;align-items:center;gap:10px 14px;margin:18px 24px 0;font-family:var(--cs-m);font-size:11px;letter-spacing:.06em;color:var(--cs-text-3)}
.cs-progress b{color:var(--cs-cyan);font-weight:600}
.cs-progress-bar{flex:1 1 160px;max-width:260px;height:4px;border-radius:4px;background:rgba(148,163,184,.14);overflow:hidden}
.cs-progress-bar i{display:block;height:100%;border-radius:4px;background:linear-gradient(90deg,var(--cs-cyan),var(--cs-mint))}
nav[aria-label="Lesson navigation"] .hub-card,nav.article-nav .hub-card{padding:18px 20px!important;min-height:84px}
nav[aria-label="Lesson navigation"] .hub-card[rel=next],nav.article-nav .hub-card[rel=next]{text-align:right;align-items:flex-end}
nav[aria-label="Lesson navigation"] .hub-card[rel=next] .hub-kicker,nav.article-nav .hub-card[rel=next] .hub-kicker{align-self:flex-end}

/* Tool panels: input → process → output → explanation */
.cs-panels{display:grid;gap:14px;margin-top:22px}
.cs-panels>*{min-width:0}
.cs-panel .chain-wrap{max-width:100%}
.cs-panel{border:1px solid var(--cs-line);border-radius:var(--cs-r);background:linear-gradient(180deg,var(--cs-surface-2),var(--cs-surface));padding:18px 18px 20px;box-shadow:var(--cs-shadow)}
.cs-panel-h{display:flex;align-items:center;gap:10px;margin:0 0 12px;font-family:var(--cs-m);font-size:11px;font-weight:600;letter-spacing:.12em;text-transform:uppercase;color:var(--cs-text-2)}
.cs-panel-h span{display:grid;place-items:center;width:24px;height:24px;border-radius:8px;font-size:11px;color:var(--k,var(--cs-cyan));border:1px solid currentColor;background:rgba(148,163,184,.05)}
.cs-panel[data-step=input]{--k:var(--cs-cyan)}
.cs-panel[data-step=process]{--k:var(--cs-indigo)}
.cs-panel[data-step=output]{--k:var(--cs-mint)}
.cs-panel[data-step=explain]{--k:#a5b4fc}
.cs-panel p.cs-note{font-size:.92rem;line-height:1.7;color:var(--cs-text-2);margin:0;max-width:70ch}
.cs-panel dl{margin:0;display:grid;gap:12px}
.cs-panel dt{font-family:var(--cs-h);font-weight:700;color:var(--cs-text)}
.cs-panel dd{margin:2px 0 0;font-size:.9rem;line-height:1.65;color:var(--cs-text-2)}
.cs-panel .hash-out{margin-top:0!important;background:rgba(6,10,20,.7)!important;border-color:var(--cs-line)!important}
.cs-panel .hash-out code{font-family:var(--cs-m)!important;font-size:.82rem!important;color:var(--cs-mint)!important}
#hash-input{font-family:var(--cs-m)!important;font-size:.95rem!important;border-color:var(--cs-line-2)!important;background:rgba(6,10,20,.7)!important;border-radius:12px!important}
#hash-input:focus{border-color:rgba(var(--cs-cyan-rgb),.6)!important;box-shadow:0 0 0 3px rgba(var(--cs-cyan-rgb),.15)}
.block-card{background:rgba(6,10,20,.7)!important;border-color:var(--cs-line-2)!important;font-family:var(--cs-m)}
.block-card.invalid{border-color:rgba(251,113,133,.6)!important;box-shadow:0 0 0 3px rgba(251,113,133,.12)}
#chain-status{display:inline-flex;align-items:center;gap:8px;margin:0!important;font-family:var(--cs-m);font-size:.85rem!important;padding:8px 12px;border-radius:10px;border:1px solid currentColor;background:rgba(148,163,184,.05)}

/* Ask AI */
#ai{background:none!important;padding-top:28px!important}
#ai h1{font-size:clamp(2.2rem,6vw,3.6rem)!important;line-height:1.02!important;text-transform:none!important}
.cs-ai-label{font-family:var(--cs-m);font-size:11px;font-weight:600;letter-spacing:.12em;text-transform:uppercase;color:var(--cs-text-3);text-align:left;margin:0 0 8px}
.ai-chip{min-height:40px;border-radius:999px!important;font-family:var(--cs-b)!important}
#ai-chat{background:linear-gradient(180deg,var(--cs-surface-2),var(--cs-surface))!important;border-color:var(--cs-line)!important}
#ai-input{min-height:48px;border-color:var(--cs-line-2)!important}
.kb-item,.module-block{background:linear-gradient(180deg,var(--cs-surface-2),var(--cs-surface))!important;border-color:var(--cs-line)!important;border-radius:16px!important}
.kb-item h3{font-family:var(--cs-h)!important}

/* Courses */
.module-block{position:relative;padding:20px 22px 20px 64px!important}
.module-block .hub-kicker{position:absolute;left:18px;top:20px;width:32px;height:32px;display:grid!important;place-items:center;border-radius:10px;border:1px solid rgba(var(--cs-indigo-rgb),.4);color:var(--cs-indigo)!important;font-size:0!important;margin:0!important}
.module-block .hub-kicker::before{display:none}
.module-block .hub-kicker::after{content:attr(data-n);font-size:12px;font-family:var(--cs-m)}
.module-block h2{font-family:var(--cs-h)!important;font-size:1.15rem!important}
.module-block p{font-size:.98rem!important;line-height:1.75!important;max-width:68ch}
.cs-syllabus{margin-top:22px;padding:18px 20px;border:1px solid var(--cs-line);border-radius:var(--cs-r);background:rgba(6,10,20,.5);max-width:40rem}
.cs-syllabus p{font-family:var(--cs-m);font-size:11px;letter-spacing:.12em;text-transform:uppercase;color:var(--cs-text-3);margin:0 0 8px}
.cs-syllabus ol{margin:0!important}
.cs-syllabus li{padding:5px 0}

/* Library & insights */
.blog-card{border-radius:var(--cs-r)!important}
main .blog-card p{line-height:1.8}

/* Lesson glyphs (replace emoji icons) */
.cs-glyph{width:26px;height:26px;color:var(--cs-cyan);display:inline-block;vertical-align:middle}
.cs-lesson .cs-glyph{padding:6px;width:38px;height:38px;border-radius:11px;border:1px solid rgba(var(--cs-cyan-rgb),.28);background:rgba(var(--cs-cyan-rgb),.07)}
.cs-panel-h{font-size:12px!important;color:var(--cs-text)!important}
.app-download-section h2,.app-download-section h3{font-family:var(--cs-h)!important;text-transform:none!important;letter-spacing:-.02em!important}

/* Footer and mobile bar */
footer{border-top:1px solid var(--cs-line)}
.mob-nav{background:rgba(6,10,20,.94)!important;border-top:1px solid var(--cs-line)!important;backdrop-filter:blur(14px)}
.mob-nav-btn.active{color:var(--cs-cyan)!important}
.mob-nav-btn{min-height:52px}

@media (max-width:640px){
  .cs-hero{padding:36px 18px 28px;gap:28px}
  .cs-actions .cs-btn{flex:1 1 auto}
  .hub-card{padding:18px 46px 18px 16px!important}
  .cs-progress{margin:14px 24px 0}
}
@media (prefers-reduced-motion:reduce){*{transition:none!important;animation-duration:.01ms!important}}