:root{
  --bg:#060E1C; --bg2:#0A1628; --panel:#0E1D33; --panel2:#13243F;
  --ink:#E5EEF8; --muted:#8FA6C0; --line:#1E3354;
  --cyan:#22D3EE; --amber:#FCD34D; --red:#F87171; --green:#34D399; --violet:#A78BFA;
}
*{box-sizing:border-box}
body{margin:0; background:var(--bg); color:var(--ink);
  font-family:"Manrope","Inter",system-ui,Segoe UI,Roboto,sans-serif; line-height:1.55; padding:0 0 80px}
a{color:var(--cyan)}
img{max-width:100%}
header{padding:38px 20px 18px; text-align:center; background:linear-gradient(180deg,var(--bg2),transparent); border-bottom:1px solid var(--line)}
header .tag{color:var(--cyan); font-family:"JetBrains Mono",monospace; font-size:12px; letter-spacing:1px; text-transform:uppercase}
header h1{margin:6px 0 4px; font-size:28px; letter-spacing:-.5px}
header p{color:var(--muted); margin:6px auto 0; font-size:15px; max-width:720px}
.wrap{max-width:1160px; margin:0 auto; padding:0 20px}

/* ===== progress rail (chapter pages) ===== */
.railwrap{max-width:1160px;margin:18px auto 0;padding:0 20px}
.rail{display:flex;gap:8px;flex-wrap:wrap;align-items:stretch}
.rail a{flex:1 1 120px;min-width:120px;text-decoration:none;display:block;border:1px solid var(--line);border-radius:10px;padding:9px 12px;background:var(--panel);transition:.14s}
.rail a:hover{border-color:var(--cyan);transform:translateY(-2px)}
.rail a .rn{font-family:"JetBrains Mono",monospace;font-size:11px;color:var(--muted)}
.rail a .rt{font-size:13px;color:var(--ink);font-weight:700;margin-top:2px;line-height:1.25}
.rail a.cur{border-color:var(--cyan);background:linear-gradient(180deg,rgba(34,211,238,.12),transparent)}
.rail a.cur .rn{color:var(--cyan)}
.rail a.done .rt::after{content:" ✓";color:var(--green)}
@media(max-width:760px){.rail a{flex:1 1 45%;min-width:0}}

/* ===== NAV ===== */
.topnav{max-width:1160px;margin:14px auto 0;padding:0 20px}
.nav-back{display:inline-flex;align-items:center;gap:7px;text-decoration:none;font-family:"JetBrains Mono",monospace;font-size:13px;padding:7px 14px;border-radius:9px;border:1px solid var(--line);background:var(--panel);color:var(--muted)}
.nav-back:hover{border-color:var(--cyan);color:var(--cyan);background:rgba(34,211,238,.06)}
.modnav{display:flex;justify-content:space-between;align-items:center;flex-wrap:wrap;gap:14px;max-width:1160px;margin:38px auto 0;padding:18px;border:1px solid var(--line);border-radius:14px;background:linear-gradient(180deg,var(--panel),var(--bg2))}
.modnav .mn-label{font-family:"JetBrains Mono",monospace;font-size:11px;color:var(--muted);text-transform:uppercase;letter-spacing:.06em;margin-bottom:4px}
.modnav .mn-title{font-size:15px;color:var(--ink);font-weight:700}
.nav-next{display:inline-flex;align-items:center;gap:9px;text-decoration:none;padding:12px 20px;border-radius:11px;background:var(--cyan);color:#04222b;font-weight:700;font-size:14px}
.nav-next:hover{filter:brightness(1.08)}
.nav-prev{display:inline-flex;align-items:center;gap:7px;text-decoration:none;font-family:"JetBrains Mono",monospace;font-size:13px;padding:9px 16px;border-radius:9px;border:1px solid var(--line);background:var(--panel2);color:var(--muted)}
.nav-prev:hover{border-color:var(--cyan);color:var(--cyan)}
@media(max-width:620px){.modnav{flex-direction:column;align-items:stretch}}

/* ===== SECTION SHELL ===== */
.section{margin-top:46px}
.sec-head{display:flex; align-items:baseline; gap:14px; flex-wrap:wrap; margin-bottom:6px}
.sec-num{font-family:"JetBrains Mono",monospace; font-size:13px; color:var(--cyan); border:1px solid var(--line); border-radius:8px; padding:4px 10px; background:var(--bg2)}
.sec-head h2{font-size:23px; margin:0; letter-spacing:-.3px}
.sec-sub{color:var(--muted); font-size:14.5px; margin:4px 0 0; max-width:820px; line-height:1.6}
.badges{display:flex; gap:7px; flex-wrap:wrap; margin:12px 0 2px}
.b{font-family:"JetBrains Mono",monospace; font-size:11px; letter-spacing:.04em; text-transform:uppercase; padding:4px 10px; border-radius:999px; border:1px solid var(--line)}
.b.fgos{color:var(--green); background:rgba(52,211,153,.08); border-color:rgba(52,211,153,.35)}
.b.fop{color:var(--violet); background:rgba(167,139,250,.08); border-color:rgba(167,139,250,.35)}
.b.exam{color:var(--amber); background:rgba(252,211,77,.08); border-color:rgba(252,211,77,.35)}

/* intro card */
.intro{background:var(--panel); border:1px solid var(--line); border-left:4px solid var(--amber); border-radius:14px; padding:20px 22px; margin-top:26px}
.intro p{margin:8px 0; font-size:15px; color:#d7e3f2; line-height:1.7}
.intro p:first-child{margin-top:0}
.intro b{color:var(--ink)}
.intro .hook{font-size:16px;color:var(--ink)}

/* theory card */
.theory{background:var(--panel); border:1px solid var(--line); border-radius:14px; padding:20px 22px; margin-top:18px}
.theory h4{font-size:15px; color:var(--cyan); margin:18px 0 6px; border-left:3px solid var(--cyan); padding-left:10px}
.theory h4:first-child{margin-top:4px}
.theory p{font-size:14.5px; line-height:1.7; color:#d7e3f2; margin:8px 0}
.theory b{color:var(--ink)}
.theory i{color:#cfe0f1}
.theory code,.mono{font-family:"JetBrains Mono",monospace; font-size:.92em; background:var(--bg2); border:1px solid var(--line); border-radius:5px; padding:1px 6px; color:var(--amber)}
.theory ul,.theory ol{margin:8px 0; padding-left:20px}
.theory li{font-size:14.5px; line-height:1.7; color:#d7e3f2; margin:4px 0}
.callout{background:var(--bg2); border:1px solid var(--line); border-left:3px solid var(--violet); border-radius:10px; padding:12px 14px; margin:14px 0; font-size:13.5px; color:#cdddef}
.callout .ct{font-family:"JetBrains Mono",monospace; font-size:11px; text-transform:uppercase; letter-spacing:.06em; color:var(--violet); display:block; margin-bottom:4px}
.callout.amber{border-left-color:var(--amber)} .callout.amber .ct{color:var(--amber)}
.callout.cyan{border-left-color:var(--cyan)} .callout.cyan .ct{color:var(--cyan)}
.callout.green{border-left-color:var(--green)} .callout.green .ct{color:var(--green)}
.callout.red{border-left-color:var(--red)} .callout.red .ct{color:var(--red)}

/* figure */
.fig{margin:16px 0 6px;background:var(--bg2);border:1px solid var(--line);border-radius:12px;padding:16px;text-align:center}
.fig svg{width:100%;height:auto;max-width:760px;display:block;margin:0 auto}
.fig .cap{margin-top:10px;font-size:12.5px;color:var(--muted);font-family:"JetBrains Mono",monospace}
.fig .cap b{color:var(--amber)}

/* photo placeholder */
.ph{position:relative;background:repeating-linear-gradient(45deg,var(--bg2),var(--bg2) 10px,rgba(255,255,255,.02) 10px,rgba(255,255,255,.02) 20px);border:1.5px dashed var(--line);border-radius:12px;min-height:150px;display:flex;flex-direction:column;align-items:center;justify-content:center;gap:6px;text-align:center;padding:18px;color:var(--muted)}
.ph .pico{font-size:30px;opacity:.6}
.ph .pname{font-family:"JetBrains Mono",monospace;font-size:12px;color:var(--cyan)}
.ph .pdesc{font-size:12px;max-width:280px}
.phgrid{display:grid;grid-template-columns:repeat(auto-fill,minmax(200px,1fr));gap:12px;margin-top:16px}
.shot{background:var(--panel);border:1px solid var(--line);border-radius:12px;overflow:hidden}
.shot .ph{border:none;border-radius:0;min-height:120px}
.shot img{display:block;width:100%;height:150px;object-fit:cover;background:var(--bg2)}
.shot .cap{padding:9px 12px;font-size:12.5px;color:#cdddef}
.shot .cap b{color:var(--ink)}

/* analogy grid */
.agrid{display:grid; grid-template-columns:repeat(auto-fill,minmax(240px,1fr)); gap:14px; margin-top:16px}
.acard{background:var(--panel); border:1px solid var(--line); border-radius:12px; padding:16px; border-top:3px solid var(--cyan); transition:.15s}
.acard:hover{border-color:var(--cyan); transform:translateY(-2px); box-shadow:0 8px 28px rgba(34,211,238,.16)}
.acard .ico{font-size:26px; line-height:1; margin-bottom:8px}
.acard h5{margin:0 0 4px; font-size:16px}
.acard .ana{font-family:"JetBrains Mono",monospace; font-size:12px; color:var(--amber); margin:0 0 8px}
.acard p{margin:0; font-size:13px; color:var(--muted); line-height:1.55}

/* tables */
.tblbox{margin:16px 0 6px; overflow:auto; border:1px solid var(--line); border-radius:12px}
table.dt{width:100%; border-collapse:collapse; font-size:13.5px; min-width:520px}
table.dt th{background:var(--panel2); color:var(--amber); text-align:left; padding:9px 12px; border-bottom:1px solid var(--line); font-weight:700; font-size:12.5px}
table.dt td{padding:9px 12px; border-bottom:1px solid var(--line); color:#d7e3f2; vertical-align:top}
table.dt tr:last-child td{border-bottom:none}
table.dt tr:nth-child(even) td{background:rgba(255,255,255,.02)}
table.dt td:first-child{color:var(--cyan); font-family:"JetBrains Mono",monospace; white-space:nowrap}
table.dt td.txt:first-child{color:#d7e3f2;font-family:inherit;white-space:normal}

/* ===== INTERACTIVE shell ===== */
.iv{background:var(--panel); border:1px solid var(--line); border-radius:16px; margin-top:18px; overflow:hidden}
.iv-head{display:flex; align-items:center; gap:12px; padding:14px 18px; background:linear-gradient(180deg,var(--panel2),transparent); border-bottom:1px solid var(--line)}
.iv-head .iv-ico{font-size:22px; line-height:1}
.iv-head .iv-t{flex:1}
.iv-head h3{margin:0; font-size:17px}
.iv-head .iv-s{font-size:12px; color:var(--muted); font-family:"JetBrains Mono",monospace; margin-top:2px}
.iv-head .iv-tag{font-family:"JetBrains Mono",monospace; font-size:11px; text-transform:uppercase; letter-spacing:.06em; color:var(--cyan); border:1px solid var(--line); border-radius:999px; padding:4px 10px;white-space:nowrap}
.iv-body{padding:18px}
.btn{cursor:pointer; font-family:inherit; font-size:13.5px; font-weight:600; border-radius:9px; padding:9px 16px; border:1px solid var(--line); background:var(--panel2); color:var(--ink); transition:.13s}
.btn:hover{border-color:var(--cyan); color:var(--cyan)}
.btn.primary{background:var(--cyan); color:#04222b; border-color:var(--cyan)}
.btn.primary:hover{filter:brightness(1.08); color:#04222b}
.btn:disabled{opacity:.45; cursor:not-allowed}
.btnrow{display:flex; gap:10px; flex-wrap:wrap; margin-top:14px}
.feed{margin-top:14px; font-size:13.5px; min-height:22px; font-family:"JetBrains Mono",monospace}
.feed.good{color:var(--green)} .feed.warn{color:var(--amber)} .feed.bad{color:var(--red)}

/* ===== Process lifecycle ===== */
.proc-wrap{display:grid; grid-template-columns:1fr 320px; gap:18px}
@media(max-width:820px){ .proc-wrap{grid-template-columns:1fr} }
.proc-stage{background:var(--bg2); border:1px solid var(--line); border-radius:12px; padding:14px}
.proc-stage svg{width:100%; height:auto; display:block}
.pstate{fill:var(--panel2); stroke:var(--line); stroke-width:1.5; transition:.3s}
.pstate.on{fill:rgba(34,211,238,.18); stroke:var(--cyan); stroke-width:2.5}
.plabel{fill:var(--ink); font-size:13px; font-weight:700; text-anchor:middle; pointer-events:none; font-family:"Manrope",sans-serif}
.psub{fill:var(--muted); font-size:9.5px; text-anchor:middle; pointer-events:none; font-family:"JetBrains Mono",monospace}
.parrow{stroke:var(--line); stroke-width:2; fill:none; marker-end:url(#parr)}
.parrow.on{stroke:var(--cyan)}
.proc-info{background:var(--bg2); border:1px solid var(--line); border-radius:12px; padding:16px}
.proc-info .pi-state{font-family:"JetBrains Mono",monospace; font-size:12px; color:var(--cyan); text-transform:uppercase; letter-spacing:.06em}
.proc-info h4{margin:4px 0 8px; font-size:18px}
.proc-info p{margin:0; font-size:13.5px; color:#cdddef; line-height:1.6}
.proc-info .pi-ana{margin-top:12px; font-size:12.5px; color:var(--muted); border-top:1px dashed var(--line); padding-top:10px}
.proc-info .pi-ana b{color:var(--amber)}

/* ===== OS builder (drag) ===== */
.osb{display:grid; grid-template-columns:1fr 1fr; gap:18px}
@media(max-width:760px){ .osb{grid-template-columns:1fr} }
.osb-pool,.osb-slots{background:var(--bg2); border:1px solid var(--line); border-radius:12px; padding:14px; min-height:120px}
.osb h4{margin:0 0 10px; font-size:13px; text-transform:uppercase; letter-spacing:.05em; color:var(--amber); font-family:"JetBrains Mono",monospace}
.chip{display:flex; align-items:center; gap:8px; background:var(--panel2); border:1px solid var(--line); border-radius:9px; padding:9px 12px; margin:6px 0; cursor:grab; font-size:13.5px; transition:.12s}
.chip:hover{border-color:var(--cyan)}
.chip.dragging{opacity:.4}
.chip .ci{font-size:17px}
.slot{border:1.5px dashed var(--line); border-radius:9px; padding:10px 12px; margin:8px 0; min-height:46px; transition:.12s; display:flex; align-items:center; gap:10px}
.slot .sl-need{font-size:12px; color:var(--muted); font-family:"JetBrains Mono",monospace}
.slot.over{border-color:var(--cyan); background:rgba(34,211,238,.06)}
.slot.ok{border-style:solid; border-color:var(--green); background:rgba(52,211,153,.07)}
.slot.bad{border-style:solid; border-color:var(--red); background:rgba(248,113,113,.07)}
.slot .placed{display:flex; align-items:center; gap:8px; font-size:13.5px; font-weight:600}

/* ===== Terminal (filesystem) ===== */
.term-wrap{display:grid; grid-template-columns:1fr 300px; gap:18px}
@media(max-width:820px){ .term-wrap{grid-template-columns:1fr} }
.term{background:#03101f; border:1px solid var(--line); border-radius:12px; padding:14px; font-family:"JetBrains Mono",monospace; font-size:13px; height:300px; overflow:auto}
.term .ln{white-space:pre-wrap; word-break:break-word; margin:2px 0; line-height:1.5}
.term .ln.cmd{color:var(--ink)} .term .pr{color:var(--green)}
.term .ln.out{color:#9fb6cf} .term .ln.err{color:var(--red)} .term .ln.ok{color:var(--cyan)}
.term-input{display:flex; align-items:center; gap:8px; margin-top:10px; background:#03101f; border:1px solid var(--line); border-radius:10px; padding:8px 12px; font-family:"JetBrains Mono",monospace}
.term-input .pr{color:var(--green); font-size:13px}
.term-input input{flex:1; background:transparent; border:none; outline:none; color:var(--ink); font-family:"JetBrains Mono",monospace; font-size:13px}
.fstree{background:var(--bg2); border:1px solid var(--line); border-radius:12px; padding:14px; font-family:"JetBrains Mono",monospace; font-size:12.5px; height:300px; overflow:auto}
.fstree h4{margin:0 0 8px; font-size:11px; text-transform:uppercase; letter-spacing:.05em; color:var(--amber)}
.fstree .row{padding:1px 0; color:#cdddef; white-space:pre}
.fstree .row.dir{color:var(--cyan)}
.term-hint{font-size:12px; color:var(--muted); margin-top:10px; font-family:"JetBrains Mono",monospace}

/* ===== Mask trainer ===== */
.mask-grid{display:grid;grid-template-columns:1fr 1fr;gap:18px}
@media(max-width:760px){.mask-grid{grid-template-columns:1fr}}
.mask-files{background:var(--bg2);border:1px solid var(--line);border-radius:12px;padding:14px}
.mask-files h4{margin:0 0 8px;font-size:11px;text-transform:uppercase;letter-spacing:.05em;color:var(--amber);font-family:"JetBrains Mono",monospace}
.mfile{font-family:"JetBrains Mono",monospace;font-size:13px;padding:4px 8px;border-radius:6px;margin:3px 0;color:#cdddef;transition:.15s}
.mfile.hit{background:rgba(52,211,153,.12);color:var(--green)}
.mfile .dir{color:var(--muted)}
.mask-panel{background:var(--bg2);border:1px solid var(--line);border-radius:12px;padding:14px}
.mask-panel label{font-size:12px;color:var(--muted);font-family:"JetBrains Mono",monospace}
.mask-in{display:flex;gap:8px;margin:6px 0 12px}
.mask-in input{flex:1;background:#03101f;border:1px solid var(--line);border-radius:9px;padding:9px 12px;color:var(--amber);font-family:"JetBrains Mono",monospace;font-size:14px;outline:none}
.mask-in input:focus{border-color:var(--cyan)}
.mask-count{font-size:14px;margin-top:8px}
.mask-count b{color:var(--cyan);font-family:"JetBrains Mono",monospace}
.mask-chips{display:flex;flex-wrap:wrap;gap:6px;margin-top:10px}
.mask-chips .mc{cursor:pointer;font-family:"JetBrains Mono",monospace;font-size:12px;padding:5px 9px;border:1px solid var(--line);border-radius:7px;background:var(--panel2);color:var(--ink)}
.mask-chips .mc:hover{border-color:var(--cyan);color:var(--cyan)}

/* ===== URL builder ===== */
.urlb-pool{display:flex;flex-wrap:wrap;gap:8px;background:var(--bg2);border:1px solid var(--line);border-radius:12px;padding:14px;min-height:54px}
.urlb-drop{display:flex;flex-wrap:wrap;gap:8px;align-items:center;background:#03101f;border:1.5px dashed var(--line);border-radius:12px;padding:14px;min-height:54px;margin-top:14px;font-family:"JetBrains Mono",monospace}
.urlb-drop.over{border-color:var(--cyan)}
.urlb-drop .ph-slot{color:var(--muted);font-size:13px}
.upiece{cursor:grab;font-family:"JetBrains Mono",monospace;font-size:13px;padding:7px 11px;border:1px solid var(--line);border-radius:8px;background:var(--panel2);color:var(--ink);transition:.12s}
.upiece:hover{border-color:var(--cyan)}
.upiece.dragging{opacity:.4}
.upiece.inb{background:var(--bg2)}
.upiece.k-proto{color:var(--violet)} .upiece.k-sep{color:var(--muted)} .upiece.k-host{color:var(--cyan)} .upiece.k-path{color:var(--amber)} .upiece.k-file{color:var(--green)}

/* ===== SW sort (drag classify) ===== */
.swsort{display:grid; grid-template-columns:1fr; gap:16px}
.sw-pool{display:flex; flex-wrap:wrap; gap:8px; background:var(--bg2); border:1px solid var(--line); border-radius:12px; padding:14px; min-height:60px}
.sw-bins{display:grid; grid-template-columns:1fr 1fr; gap:14px}
@media(max-width:620px){ .sw-bins{grid-template-columns:1fr} }
.sw-bin{background:var(--bg2); border:1px solid var(--line); border-radius:12px; padding:14px; min-height:120px; transition:.12s}
.sw-bin.sys{border-top:3px solid var(--cyan)} .sw-bin.app{border-top:3px solid var(--green)}
.sw-bin.over{border-color:var(--cyan); background:rgba(34,211,238,.05)}
.sw-bin h4{margin:0 0 10px; font-size:13px; font-family:"JetBrains Mono",monospace; text-transform:uppercase; letter-spacing:.04em}
.sw-bin.sys h4{color:var(--cyan)} .sw-bin.app h4{color:var(--green)}
.swchip{display:inline-flex; align-items:center; gap:7px; background:var(--panel2); border:1px solid var(--line); border-radius:8px; padding:7px 11px; font-size:13px; cursor:grab; transition:.12s}
.swchip:hover{border-color:var(--cyan)}
.swchip.dragging{opacity:.4}
.swchip.ok{border-color:var(--green)} .swchip.bad{border-color:var(--red)}

/* ===== Software pyramid + glossary ===== */
.pyr-wrap{display:grid;grid-template-columns:1fr 320px;gap:18px}
@media(max-width:820px){.pyr-wrap{grid-template-columns:1fr}}
.pyr{background:var(--bg2);border:1px solid var(--line);border-radius:12px;padding:14px}
.pyr svg{width:100%;height:auto;display:block}
.pyr-layer{cursor:pointer;transition:.15s}
.pyr-layer rect{transition:.15s}
.pyr-layer:hover rect,.pyr-layer.on rect{stroke:var(--cyan);stroke-width:2.5}
.pyr-layer .pl-t{fill:var(--ink);font-weight:700;font-size:13px;text-anchor:middle;pointer-events:none;font-family:"Manrope",sans-serif}
.pyr-layer .pl-s{fill:var(--muted);font-size:10px;text-anchor:middle;pointer-events:none;font-family:"JetBrains Mono",monospace}
.pyr-info{background:var(--bg2);border:1px solid var(--line);border-radius:12px;padding:16px}
.pyr-info .pi-k{font-family:"JetBrains Mono",monospace;font-size:11px;color:var(--cyan);text-transform:uppercase;letter-spacing:.06em}
.pyr-info h4{margin:4px 0 8px;font-size:17px}
.pyr-info p{margin:0 0 8px;font-size:13.5px;color:#cdddef;line-height:1.6}
.pyr-info .ex{font-size:12.5px;color:var(--muted);border-top:1px dashed var(--line);padding-top:8px;margin-top:8px}
.pyr-info .ex b{color:var(--amber)}

/* software cards + glossary */
.soft-cards{display:grid;grid-template-columns:repeat(auto-fill,minmax(150px,1fr));gap:12px;margin-top:16px}
.scard{background:var(--panel);border:1px solid var(--line);border-radius:12px;padding:14px;text-align:center;cursor:default;transition:.15s}
.scard:hover{border-color:var(--cyan);transform:translateY(-2px)}
.scard.sys{border-top:3px solid var(--cyan)} .scard.app{border-top:3px solid var(--green)}
.scard .slogo{width:48px;height:48px;margin:0 auto 8px;border-radius:11px;display:flex;align-items:center;justify-content:center;font-size:24px;background:var(--bg2);border:1px solid var(--line)}
.scard .sn{font-size:14px;font-weight:700;margin-bottom:2px}
.scard .sk{font-family:"JetBrains Mono",monospace;font-size:10.5px;text-transform:uppercase;letter-spacing:.04em}
.scard.sys .sk{color:var(--cyan)} .scard.app .sk{color:var(--green)}
.scard .sd{font-size:12px;color:var(--muted);margin-top:6px;line-height:1.5}

/* ===== Access control game ===== */
.acc-table{overflow:auto; border:1px solid var(--line); border-radius:12px}
table.acc{width:100%; border-collapse:collapse; font-size:13px; min-width:560px}
table.acc th{background:var(--panel2); color:var(--amber); padding:10px 12px; border-bottom:1px solid var(--line); text-align:left; font-size:12.5px}
table.acc td{padding:8px 12px; border-bottom:1px solid var(--line); border-right:1px solid var(--line)}
table.acc td:last-child{border-right:none}
table.acc .rolecell{color:var(--cyan); font-weight:700; font-size:13.5px}
table.acc .rolecell small{display:block; color:var(--muted); font-weight:400; font-family:"JetBrains Mono",monospace; font-size:11px; margin-top:2px}
.perms{display:flex; gap:6px}
.perm{cursor:pointer; user-select:none; width:30px; height:30px; display:flex; align-items:center; justify-content:center; border:1px solid var(--line); border-radius:7px; font-family:"JetBrains Mono",monospace; font-size:12px; font-weight:700; color:var(--muted); background:var(--bg2); transition:.1s}
.perm.on{color:#04222b; background:var(--green); border-color:var(--green)}
.perm:hover{border-color:var(--cyan)}
.acc-feed{margin-top:14px; padding:12px 14px; border-radius:10px; font-size:13.5px; display:none}
.acc-feed.show{display:block}
.acc-feed.win{background:rgba(52,211,153,.08); border:1px solid rgba(52,211,153,.4); color:var(--green)}
.acc-feed.lose{background:rgba(248,113,113,.08); border:1px solid rgba(248,113,113,.4); color:var(--red)}
.acc-feed ul{margin:8px 0 0; padding-left:18px} .acc-feed li{margin:3px 0}

/* ===== Error finder / Security lab (choice cards) ===== */
.scenario{background:var(--bg2); border:1px solid var(--line); border-radius:12px; padding:16px; font-size:14px; color:#d7e3f2; line-height:1.7}
.scenario .scr-err{font-family:"JetBrains Mono",monospace; color:var(--red); background:rgba(248,113,113,.07); border:1px solid rgba(248,113,113,.3); border-radius:8px; padding:10px 12px; margin:10px 0; display:block}
.opts{display:grid; gap:10px; margin-top:14px}
.opt{text-align:left; cursor:pointer; background:var(--panel2); border:1px solid var(--line); border-radius:10px; padding:12px 14px; font-size:13.5px; color:var(--ink); font-family:inherit; transition:.12s}
.opt:hover{border-color:var(--cyan)}
.opt.correct{border-color:var(--green); background:rgba(52,211,153,.08)}
.opt.wrong{border-color:var(--red); background:rgba(248,113,113,.08)}
.opt .why{display:none; margin-top:8px; font-size:12.5px; color:var(--muted); border-top:1px dashed var(--line); padding-top:8px}
.opt.reveal .why{display:block}

/* ===== Quest (exam) ===== */
.quest{background:var(--panel);border:1px solid var(--line);border-radius:16px;margin-top:18px;overflow:hidden}
.quest-bar{display:flex;align-items:center;gap:14px;padding:14px 18px;background:linear-gradient(180deg,var(--panel2),transparent);border-bottom:1px solid var(--line);flex-wrap:wrap}
.quest-bar .xp{font-family:"JetBrains Mono",monospace;font-size:13px;color:var(--amber)}
.quest-bar .prog{flex:1;min-width:120px;height:8px;background:var(--bg2);border:1px solid var(--line);border-radius:999px;overflow:hidden}
.quest-bar .prog i{display:block;height:100%;width:0;background:linear-gradient(90deg,var(--cyan),var(--green));transition:.4s}
.quest-body{padding:18px}
.quest .qn{font-family:"JetBrains Mono",monospace;font-size:12px;color:var(--cyan);text-transform:uppercase;letter-spacing:.05em}
.quest .qchar{font-size:13px;color:var(--muted);font-style:italic;margin:6px 0 2px}
.quest .qtext{font-size:15px;color:var(--ink);margin:8px 0 14px;line-height:1.6}
.quest .qtext code{font-family:"JetBrains Mono",monospace;background:var(--bg2);border:1px solid var(--line);border-radius:5px;padding:1px 6px;color:var(--amber)}
.quest-fb{margin-top:14px;padding:12px 14px;border-radius:10px;font-size:13.5px;display:none}
.quest-fb.show{display:block}
.quest-fb.ok{background:rgba(52,211,153,.08);border:1px solid rgba(52,211,153,.4);color:var(--green)}
.quest-fb.no{background:rgba(248,113,113,.08);border:1px solid rgba(248,113,113,.4);color:var(--red)}
.quest-fb .tag{font-family:"JetBrains Mono",monospace;font-size:11px;color:var(--amber);display:block;margin-top:6px}
.quest-done{text-align:center;padding:30px 18px}
.quest-done .big{font-size:34px;font-family:"JetBrains Mono",monospace;font-weight:800;color:var(--amber)}
.quest-done p{color:var(--muted);margin:8px 0 0}

/* ===== Final test ===== */
.q{background:var(--panel); border:1px solid var(--line); border-radius:12px; padding:16px 18px; margin-top:14px}
.q .qn{font-family:"JetBrains Mono",monospace; font-size:12px; color:var(--cyan); text-transform:uppercase; letter-spacing:.05em}
.q .qtype{font-family:"JetBrains Mono",monospace; font-size:11px; color:var(--muted); float:right}
.q .qtext{font-size:14.5px; color:var(--ink); margin:8px 0 12px; line-height:1.6}
.q .qtext code{font-family:"JetBrains Mono",monospace; background:var(--bg2); border:1px solid var(--line); border-radius:5px; padding:1px 6px; color:var(--amber); font-size:.92em}
.ans{display:grid; gap:8px}
.ans label{display:flex; align-items:center; gap:10px; background:var(--bg2); border:1px solid var(--line); border-radius:9px; padding:10px 13px; font-size:13.5px; cursor:pointer; transition:.1s}
.ans label:hover{border-color:var(--cyan)}
.ans input{accent-color:var(--cyan)}
.ans.match .mrow{display:flex; align-items:center; gap:10px; background:var(--bg2); border:1px solid var(--line); border-radius:9px; padding:8px 12px}
.ans.match .mrow .ml{flex:1; font-size:13.5px}
.ans.match select,.q input.txt{background:var(--panel2); color:var(--ink); border:1px solid var(--line); border-radius:8px; padding:7px 10px; font-family:inherit; font-size:13.5px}
.q input.txt{width:160px}
.seq{display:grid; gap:8px}
.seq .srow{display:flex; align-items:center; gap:10px; background:var(--bg2); border:1px solid var(--line); border-radius:9px; padding:8px 12px}
.seq .srow .sl{flex:1; font-size:13.5px}
.seq select{background:var(--panel2); color:var(--ink); border:1px solid var(--line); border-radius:8px; padding:6px 9px; font-family:"JetBrains Mono",monospace; font-size:13px; width:64px}
.q.correct{border-color:var(--green); box-shadow:0 0 0 1px rgba(52,211,153,.4)}
.q.wrong{border-color:var(--red); box-shadow:0 0 0 1px rgba(248,113,113,.4)}
.q .qfb{margin-top:10px; font-size:13px; display:none}
.q.correct .qfb,.q.wrong .qfb{display:block}
.q.correct .qfb{color:var(--green)} .q.wrong .qfb{color:var(--red)}
.q .qfb b{color:var(--ink)}
.testbar{display:flex; align-items:center; gap:16px; flex-wrap:wrap; margin-top:20px; padding:16px 18px; background:var(--panel); border:1px solid var(--line); border-radius:12px}
.score{font-size:20px; font-weight:800}
.score.big{font-family:"JetBrains Mono",monospace}
.scoremsg{font-size:13.5px; color:var(--muted)}

/* extended task */
.ext{background:var(--panel); border:1px solid var(--line); border-left:4px solid var(--violet); border-radius:14px; padding:20px 22px; margin-top:20px}
.ext h4{margin:0 0 6px; font-size:16px; color:var(--violet)}
.ext p{font-size:14px; color:#d7e3f2; line-height:1.7; margin:8px 0}
.ext textarea{width:100%; min-height:140px; background:var(--bg2); border:1px solid var(--line); border-radius:10px; padding:12px; color:var(--ink); font-family:inherit; font-size:14px; line-height:1.6; resize:vertical; margin-top:6px}
.ext .crit{margin-top:14px; background:var(--bg2); border:1px solid var(--line); border-radius:10px; padding:14px; display:none}
.ext .crit.show{display:block}
.ext .crit h5{margin:0 0 8px; font-size:13px; color:var(--amber); font-family:"JetBrains Mono",monospace; text-transform:uppercase}
.ext .crit ul{margin:0; padding-left:18px} .ext .crit li{font-size:13.5px; margin:5px 0; color:#cdddef}

/* loading / error */
.loadbox{margin-top:26px;padding:16px 18px;border:1px solid var(--line);border-radius:12px;background:var(--panel);color:var(--muted);font-family:"JetBrains Mono",monospace;font-size:13px}
.errbox{margin-top:26px;padding:16px 18px;border:1px solid rgba(248,113,113,.4);border-radius:12px;background:rgba(248,113,113,.07);color:var(--red);font-size:13.5px;display:none}
.errbox.show{display:block}

/* ===== СОБЕРИ ПУТЬ ===== */
.btn.tiny{padding:5px 11px;font-size:12px}
.pathb{display:grid;grid-template-columns:1fr 1fr;gap:16px;align-items:start}
.pathb-tree{background:var(--bg2);border:1px solid var(--line);border-radius:11px;padding:12px 14px}
.pathb-tree h4{margin:0 0 8px;font-size:12px;font-family:"JetBrains Mono",monospace;color:var(--muted);text-transform:uppercase;letter-spacing:.05em}
.ptrow{font-family:"JetBrains Mono",monospace;font-size:13px;color:var(--ink);padding:4px 7px;border-radius:6px;cursor:pointer;white-space:nowrap;transition:.1s}
.ptrow:hover{background:var(--panel2)}
.ptrow.dir{color:var(--cyan)}
.ptrow.root{color:var(--muted);cursor:default}
.ptrow.root:hover{background:none}
.ptrow.sel{background:rgba(34,211,238,.16);outline:1px solid var(--cyan)}
.ptrow.iscur{background:rgba(252,211,77,.12)}
.curtag{font-size:10px;color:#04222b;background:var(--amber);border-radius:5px;padding:1px 6px;margin-left:4px}
.pathb-panel{display:flex;flex-direction:column;gap:10px}
.pathb-mode{display:flex;gap:8px}
.pmode{flex:1;padding:8px 10px;border-radius:9px;border:1px solid var(--line);background:var(--panel2);color:var(--muted);font-size:13px;font-weight:600;cursor:pointer;transition:.1s}
.pmode:hover{border-color:var(--cyan)}
.pmode.on{background:var(--cyan);color:#04222b;border-color:var(--cyan)}
.pathb-cur{font-size:12.5px;color:var(--muted);background:var(--bg2);border:1px solid var(--line);border-radius:9px;padding:8px 11px;display:flex;align-items:center;gap:8px;flex-wrap:wrap}
.pathb-cur b{color:var(--amber);font-family:"JetBrains Mono",monospace}
.pathb-addr{min-height:46px;background:var(--bg2);border:1px dashed var(--line);border-radius:10px;padding:12px 14px;display:flex;align-items:center;font-size:15px}
.pathb-addr .mono{font-family:"JetBrains Mono",monospace;color:var(--amber);word-break:break-all}
.ph-slot{color:var(--muted);font-size:13px;font-style:italic}

/* ===== RLE ===== */
.rle-in input,.find-bar input[type=text]{width:100%;background:var(--bg2);border:1px solid var(--line);border-radius:9px;padding:10px 13px;color:var(--ink);font-family:"JetBrains Mono",monospace;font-size:14px;letter-spacing:.04em}
.rle-chips,.find-chips{display:flex;flex-wrap:wrap;gap:7px;margin:10px 0}
.rle-out{display:flex;flex-wrap:wrap;gap:8px;margin-top:12px}
.rle-run{display:inline-flex;align-items:center;gap:6px;border:1px solid var(--line);border-left-width:3px;border-radius:8px;padding:5px 9px;background:var(--bg2);font-family:"JetBrains Mono",monospace;font-size:13px}
.rle-run .rr-src{color:var(--muted)}
.rle-run .rr-arr{color:var(--line)}
.rle-run .rr-enc{color:var(--cyan);font-weight:600}
.rle-stat{margin-top:14px;font-size:13.5px;color:var(--ink);background:var(--bg2);border:1px solid var(--line);border-radius:9px;padding:11px 14px}
.rle-stat.good{border-color:var(--green)} .rle-stat.bad{border-color:var(--red)} .rle-stat.warn{border-color:var(--amber)}
.rle-stat b{color:var(--amber)}

/* ===== Поиск в тексте ===== */
.find-bar{display:flex;align-items:center;gap:12px;flex-wrap:wrap}
.find-bar input[type=text]{flex:1;min-width:180px}
.find-cs{display:flex;align-items:center;gap:6px;font-size:13px;color:var(--muted);cursor:pointer;white-space:nowrap}
.find-cs input{accent-color:var(--cyan)}
.find-count{font-family:"JetBrains Mono",monospace;font-size:13px;color:var(--cyan);white-space:nowrap}
.find-count b{color:var(--amber)}
.find-text{margin-top:14px;background:var(--bg2);border:1px solid var(--line);border-radius:10px;padding:16px 18px;font-size:15px;line-height:1.85;color:#d7e3f2}
.find-text mark{background:var(--amber);color:#221a02;border-radius:3px;padding:0 2px;font-weight:700}

/* ===== Два мира адресов ===== */
.addr2{display:grid;grid-template-columns:1fr 1fr;gap:16px;margin-top:8px}
.addr2-card{background:var(--bg2);border:1px solid var(--line);border-radius:12px;padding:16px 18px}
.addr2-card.local{border-top:3px solid var(--cyan)}
.addr2-card.net{border-top:3px solid var(--green)}
.addr2-card .a2-h{font-size:15px;font-weight:700;color:var(--ink);margin:0 0 8px}
.addr2-card.local .a2-h{color:var(--cyan)} .addr2-card.net .a2-h{color:var(--green)}
.addr2-card .a2-ex{display:block;font-family:"JetBrains Mono",monospace;font-size:13px;background:var(--panel);border:1px solid var(--line);border-radius:8px;padding:8px 11px;color:var(--amber);word-break:break-all;margin-bottom:10px}
.addr2-card ul{margin:0;padding-left:18px} .addr2-card li{font-size:13px;color:#cdddef;margin:4px 0}

/* ===== Типовые задания ОГЭ ===== */
.oge-q{background:var(--panel);border:1px solid var(--line);border-radius:12px;padding:16px 18px;margin-top:14px}
.oge-q .oge-n{font-family:"JetBrains Mono",monospace;font-size:12px;color:var(--cyan);text-transform:uppercase;letter-spacing:.05em}
.oge-q .oge-t{font-size:14.5px;color:var(--ink);margin:8px 0 12px;line-height:1.65}
.oge-q .oge-t .mono,.oge-q .opt .mono{font-family:"JetBrains Mono",monospace;font-size:.92em}

/* ===== mobile ===== */
/* ===== витрина логотипов (карусель) ===== */
.logo-carousel{position:relative;overflow:hidden;margin-top:16px;padding:6px 0;
  border:1px solid var(--line);border-radius:14px;background:linear-gradient(180deg,var(--panel),var(--bg2))}
.logo-carousel::before,.logo-carousel::after{content:"";position:absolute;top:0;bottom:0;width:60px;z-index:2;pointer-events:none}
.logo-carousel::before{left:0;background:linear-gradient(90deg,var(--bg2),transparent)}
.logo-carousel::after{right:0;background:linear-gradient(270deg,var(--bg2),transparent)}
.logo-track{display:flex;gap:14px;width:max-content;will-change:transform;
  animation:logoScroll 80s linear infinite}
.logo-carousel:hover .logo-track{animation-play-state:paused}
@keyframes logoScroll{from{transform:translateX(0)}to{transform:translateX(-50%)}}
.logo-item{flex:0 0 auto;width:118px;height:104px;display:flex;flex-direction:column;
  align-items:center;justify-content:center;gap:8px;padding:10px 8px;
  border:1px solid var(--line);border-radius:12px;background:var(--panel);
  text-decoration:none;transition:border-color .15s,transform .15s,box-shadow .15s}
.logo-item:hover{border-color:var(--cyan);transform:translateY(-3px);
  box-shadow:0 8px 26px rgba(34,211,238,.18)}
.logo-item.ru{border-color:rgba(52,211,153,.4)}
.logo-item.ru:hover{border-color:var(--green);box-shadow:0 8px 26px rgba(52,211,153,.18)}
.logo-item img{width:54px;height:54px;object-fit:contain;display:block}
.logo-fallback{display:flex;align-items:center;justify-content:center;width:54px;height:54px;
  border-radius:10px;background:var(--bg2);color:var(--muted);font-size:11px;text-align:center;
  font-family:"JetBrains Mono",monospace;padding:2px;line-height:1.1}
.logo-cap{font-size:11.5px;color:#cdddef;text-align:center;line-height:1.2;
  max-width:104px;overflow:hidden;text-overflow:ellipsis;white-space:nowrap}
.logo-item.ru .logo-cap{color:var(--green)}

/* ===== шифр Цезаря ===== */
.caesar{display:flex;flex-direction:column;gap:12px;margin:4px 0 12px}
.caesar-row{display:flex;align-items:center;gap:10px;flex-wrap:wrap;color:var(--muted);font-size:14px}
.caesar-row input[type=text]{flex:1;min-width:180px;background:var(--bg2);border:1px solid var(--line);
  border-radius:9px;color:var(--ink);padding:9px 12px;font-size:15px;font-family:"JetBrains Mono",monospace}
.caesar-row input[type=range]{flex:1;min-width:160px;accent-color:var(--cyan)}
.caesar-row b{color:var(--cyan);font-family:"JetBrains Mono",monospace;min-width:22px;text-align:center}
.caesar-out{background:var(--bg2);border:1px solid var(--line);border-radius:9px;padding:10px 12px;
  font-size:15px;word-break:break-word}
.caesar-out .mono{color:var(--amber)}
.caesar-lbl{color:var(--muted);font-size:13px;margin-right:6px}

@media(max-width:560px){
  header h1{font-size:22px}
  .wrap{padding:0 13px}
  .sec-head h2{font-size:20px}
  .term,.fstree{height:auto; min-height:200px; max-height:340px}
  .term-wrap{grid-template-columns:1fr}
  .pathb,.addr2{grid-template-columns:1fr}
  .logo-item{width:96px;height:92px}
  .logo-item img,.logo-fallback{width:44px;height:44px}
  .btn{padding:12px 18px;font-size:14px;min-height:44px}
  .btnrow{flex-direction:column}
  .btnrow .btn{width:100%}
  .ans label{padding:12px 14px;min-height:44px}
  .sc-opt,.sec-opt{padding:12px 14px;min-height:44px}
  .caesar-row{flex-direction:column;align-items:stretch}
  .caesar-row input[type=text],.caesar-row input[type=range]{min-width:auto;width:100%}
  .tblbox{margin-left:-13px;margin-right:-13px;border-radius:0;border-left:none;border-right:none}
  .testbar{flex-direction:column;align-items:stretch;text-align:center}
  .testbar > div:last-child{margin-top:8px}
  .quest-bar{flex-direction:column;align-items:stretch}
}
@media(prefers-reduced-motion:reduce){
  *{animation:none !important; transition:none !important}
}