@import url('themes.css');
*{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);text-decoration:none}
a:hover{text-decoration:underline}
img{max-width:100%}
code{font-family:"JetBrains Mono",monospace;color:var(--cyan);font-size:.92em;background:rgba(34,211,238,.07);padding:1px 6px;border-radius:4px}
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:760px}
.wrap{max-width:1160px;margin:0 auto;padding:0 20px}
.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);text-decoration:none}
.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{border-color:rgba(52,211,153,.45);background:rgba(52,211,153,.06)}
.rail a.done .rt::after{content:" \2713";color:var(--green)}
@media(max-width:760px){.rail a{flex:1 1 45%;min-width:0}}
.topnav{max-width:1160px;margin:14px auto 0;padding:0 20px;display:flex;align-items:center;gap:10px}
.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);text-decoration:none}
.theme-fab{position:fixed;top:14px;right:14px;z-index:9999;width:36px;height:36px;border-radius:50%;border:1px solid var(--line);background:var(--panel);color:var(--muted);font-size:16px;cursor:pointer;display:flex;align-items:center;justify-content:center;transition:.25s}
.theme-fab:hover{border-color:var(--cyan);color:var(--cyan);background:var(--panel2)}
.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);text-decoration:none}
.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);text-decoration:none}
@media(max-width:620px){.modnav{flex-direction:column;align-items:stretch}}
.intro{margin-top:28px}
.hook{font-size:16px;color:var(--ink);line-height:1.7;padding:14px 18px;background:var(--panel);border:1px solid var(--line);border-radius:10px;border-left:3px solid var(--cyan)}
.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.exam{color:var(--amber);background:rgba(252,211,77,.08);border-color:rgba(252,211,77,.35)}
.b.fop{color:var(--violet);background:rgba(167,139,250,.08);border-color:rgba(167,139,250,.35)}
.b.adv{color:var(--orange);background:rgba(251,146,60,.08);border-color:rgba(251,146,60,.35)}
.info-card{background:var(--panel);border:1px solid var(--line);border-radius:12px;padding:20px;margin:16px 0}
.info-card h4{font-size:16px;color:var(--cyan);margin-bottom:8px;font-weight:700}
.info-card p,.info-card li{font-size:14.5px;color:var(--ink);line-height:1.65}
.info-card ul,.info-card ol{padding-left:18px;margin:8px 0}
.info-card li{margin-bottom:4px}
.code-box{background:var(--panel2);border:1px solid var(--line);border-radius:8px;padding:14px 18px;font-family:"JetBrains Mono",monospace;font-size:13px;color:var(--amber);overflow-x:auto;margin:12px 0;line-height:1.7;word-break:break-all}
.code-box b{color:var(--ink)}
.theory-block{background:rgba(34,211,238,.03);border-left:3px solid var(--cyan);padding:16px 20px;border-radius:0 10px 10px 0;margin:16px 0}
.theory-block h4{color:var(--cyan);margin-bottom:10px;font-size:15px}
.theory-block p,.theory-block li{font-size:14.5px;color:var(--ink);line-height:1.7}
.example-box{background:rgba(252,211,77,.04);border-left:3px solid var(--amber);padding:16px 20px;border-radius:0 10px 10px 0;margin:16px 0}
.example-box h4{color:var(--amber);margin-bottom:10px;font-size:15px}
.example-box p,.example-box li{font-size:14.5px;color:var(--ink);line-height:1.7}
.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:14px;color:#cdddef;line-height:1.6}
.callout .ct{font-family:"JetBrains Mono",monospace;font-size:11px;text-transform:uppercase;letter-spacing:.06em;color:var(--violet);display:block;margin-bottom:4px;font-weight:700}
.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)}
.iv-shell{background:var(--panel);border:1px solid var(--line);border-radius:14px;padding:24px;margin:28px 0;position:relative;overflow:hidden}
.iv-shell::before{content:'';position:absolute;top:0;left:0;right:0;height:3px;background:linear-gradient(90deg,var(--cyan),var(--amber))}
.iv-head{display:flex;align-items:center;gap:10px;margin-bottom:18px}
.iv-head .iv-icon{width:34px;height:34px;border-radius:10px;display:flex;align-items:center;justify-content:center;font-size:17px;background:var(--bg2);border:1px solid var(--line)}
.iv-head .iv-title{font-weight:700;font-size:16px}
.iv-sub{font-size:12px;color:var(--muted);margin:-10px 0 14px;font-family:"JetBrains Mono",monospace}
.iv-body{min-height:80px}
.iv-opts{display:flex;gap:8px;flex-wrap:wrap;margin-top:8px}
.iv-opt{cursor:pointer;user-select:none;padding:10px 18px;border-radius:9px;border:1px solid var(--line);background:var(--panel2);color:var(--ink);font-size:13px;font-weight:600;transition:all .18s ease}
.iv-opt:hover{border-color:var(--cyan);color:var(--cyan);transform:translateY(-2px);box-shadow:0 4px 12px rgba(34,211,238,.12)}
.iv-opt.sel{border-color:var(--cyan)!important;background:rgba(34,211,238,.12)!important;color:var(--cyan)!important;transform:translateY(-2px)}
.iv-opt.right{background:rgba(52,211,153,.15)!important;border-color:var(--green)!important;color:var(--green)!important}
.iv-opt.wrong{background:rgba(248,113,113,.15)!important;border-color:var(--red)!important;color:var(--red)!important}
.btn-c{padding:10px 20px;border-radius:9px;border:1px solid var(--line);background:var(--panel2);color:var(--ink);font-weight:600;font-size:13px;cursor:pointer;transition:all .18s ease;display:inline-flex;align-items:center;gap:6px}
.btn-c:hover{border-color:var(--cyan);color:var(--cyan);transform:translateY(-2px);box-shadow:0 4px 12px rgba(34,211,238,.15)}
.btn-c.primary{background:var(--cyan);color:#04222b;border-color:var(--cyan)}
.btn-c.primary:hover{filter:brightness(1.08);color:#04222b}
.btn-c:disabled{opacity:.45;cursor:not-allowed;transform:none;box-shadow:none}
.btn-c.danger{border-color:rgba(248,113,113,.5);color:var(--red)}
.btn-c.danger:hover{border-color:var(--red);color:var(--red)}
.btn-c.ok{border-color:rgba(52,211,153,.5);color:var(--green)}
.btn-c.ok:hover{border-color:var(--green);color:var(--green)}
.drop-zone{min-height:54px;border:2px dashed var(--line);border-radius:10px;padding:14px;margin:8px 0;display:flex;flex-wrap:wrap;gap:8px;align-items:center;transition:.14s;background:var(--bg2)}
.drop-zone.over{border-color:var(--cyan);background:rgba(34,211,238,.06)}
.drop-zone.ok{border-color:var(--green);background:rgba(52,211,153,.08)}
.drop-zone.bad{border-color:var(--red);background:rgba(248,113,113,.08)}
.drop-item{font-family:"JetBrains Mono",monospace;font-size:13px;padding:8px 14px;border-radius:8px;cursor:pointer;user-select:none;background:var(--panel);border:1px solid var(--line);transition:all .14s ease}
.drop-item:hover{border-color:var(--cyan);transform:translateY(-1px)}
.drop-item.placed{background:rgba(34,211,238,.12);border-color:var(--cyan)}
.drop-item.right{background:rgba(52,211,153,.12);border-color:var(--green)}
.drop-item.bad{background:rgba(248,113,113,.12);border-color:var(--red)}
.result-box{padding:12px 16px;border-radius:8px;margin:12px 0;font-size:14px;animation:fadeIn .35s ease}
.result-box.ok{background:rgba(52,211,153,.08);border:1px solid rgba(52,211,153,.35);color:var(--green)}
.result-box.fail{background:rgba(248,113,113,.08);border:1px solid rgba(248,113,113,.35);color:var(--red)}
.feedback{margin-top:10px;font-size:13.5px;min-height:22px}
.feedback.good{color:var(--green)}
.feedback.warn{color:var(--amber)}
.feedback.bad{color:var(--red)}
.diagram-box{background:var(--panel);border:1px solid var(--line);border-radius:12px;padding:20px;margin:16px 0;overflow-x:auto;text-align:center}
.diagram-box svg{max-width:100%;height:auto;display:inline-block}
.fig{background:var(--bg2);border:1px solid var(--line);border-radius:10px;padding:16px;margin:14px 0;text-align:center}
.fig svg{max-width:100%;height:auto}
.fig .cap{font-size:12px;color:var(--muted);margin-top:8px;font-family:"JetBrains Mono",monospace}
table.dt,table.ttable{width:100%;border-collapse:collapse;font-size:14px;margin:10px 0}
table.dt th,table.ttable th{background:var(--bg2);color:var(--cyan);font-family:"JetBrains Mono",monospace;font-size:12px;text-transform:uppercase;letter-spacing:.05em;padding:9px 12px;text-align:left;border-bottom:2px solid var(--line)}
table.dt td,table.ttable td{padding:9px 12px;border-bottom:1px solid var(--line);color:var(--ink)}
table.dt tr:hover{background:rgba(34,211,238,.03)}
table.ttable{font-family:"JetBrains Mono",monospace;font-size:13px;text-align:center}
table.ttable td{text-align:center}
table.ttable th{text-align:center}
.tblbox{margin:16px 0;overflow-x:auto}
.grid3{display:grid;grid-template-columns:repeat(3,1fr);gap:14px;margin:16px 0}
.grid2{display:grid;grid-template-columns:repeat(2,1fr);gap:14px;margin:16px 0}
.grid4{display:grid;grid-template-columns:repeat(4,1fr);gap:12px;margin:16px 0}
.card-sm{background:var(--panel2);border:1px solid var(--line);border-radius:10px;padding:15px;text-align:center;transition:all .2s ease}
.card-sm:hover{border-color:var(--cyan);transform:translateY(-2px);box-shadow:0 6px 20px rgba(34,211,238,.08)}
.card-sm .cs-num{font-family:"JetBrains Mono",monospace;font-size:28px;color:var(--cyan);font-weight:700;line-height:1}
.card-sm .cs-label{font-size:13px;color:var(--muted);margin-top:6px}
.card-link{display:block;background:var(--panel2);border:1px solid var(--line);border-radius:10px;padding:18px;text-align:left;border-left:3px solid var(--cyan);transition:all .14s ease;text-decoration:none;color:inherit}
.card-link:hover{border-color:var(--cyan);transform:translateY(-2px);text-decoration:none}
.card-link .cl-num{font-family:"JetBrains Mono",monospace;font-size:12px;color:var(--cyan);margin-bottom:4px}
.card-link .cl-title{font-size:16px;font-weight:700;margin-bottom:6px}
.card-link .cl-desc{font-size:13px;color:var(--muted)}
.acard{background:var(--panel2);border:1px solid var(--line);border-radius:12px;padding:18px;text-align:left;transition:.14s}
.acard:hover{border-color:var(--cyan);transform:translateY(-2px)}
.acard .ico{font-size:30px;margin-bottom:6px}
.acard h5{color:var(--ink);font-size:16px;margin:0 0 6px}
.acard .ana{font-family:"JetBrains Mono",monospace;font-size:11px;color:var(--muted);text-transform:uppercase;letter-spacing:.05em;margin-bottom:8px}
.acard p{font-size:14px;color:var(--ink);line-height:1.6;margin:0}
.agrid{display:grid;grid-template-columns:repeat(auto-fit,minmax(220px,1fr));gap:14px;margin:16px 0}
.agrid2{display:grid;grid-template-columns:repeat(auto-fit,minmax(280px,1fr));gap:14px;margin:16px 0}
input[type=range]{-webkit-appearance:none;width:100%;height:6px;background:var(--bg2);border-radius:4px;outline:none;accent-color:var(--cyan)}
input[type=range]::-webkit-slider-thumb{-webkit-appearance:none;width:18px;height:18px;background:var(--cyan);border-radius:50%;cursor:pointer}
input[type=text],input[type=number]{background:var(--bg2);border:1px solid var(--line);border-radius:8px;color:var(--ink);padding:9px 12px;font-family:"JetBrains Mono",monospace;font-size:14px;width:100%}
input[type=text]:focus,input[type=number]:focus{border-color:var(--cyan);outline:none}
textarea{background:var(--bg2);border:1px solid var(--line);border-radius:8px;padding:12px;color:var(--ink);font-family:"JetBrains Mono",monospace;font-size:13px;width:100%;min-height:120px;resize:vertical;line-height:1.5}
textarea:focus{border-color:var(--cyan);outline:none}
.test-q{background:var(--panel2);border:1px solid var(--line);border-radius:10px;padding:16px;margin-bottom:12px;transition:background .2s}
.test-q:hover{background:rgba(34,211,238,.04)}
.test-q label{display:flex;align-items:center;gap:10px;background:var(--bg2);border:1px solid var(--line);border-radius:9px;padding:10px 13px;font-size:14px;cursor:pointer;transition:.1s;margin-top:8px}
.test-q label:hover{border-color:var(--cyan)}
.test-q input{accent-color:var(--cyan)}
.quest{background:var(--panel);border:1px solid var(--line);border-radius:14px;padding:24px;margin:28px 0}
.quest-bar{display:flex;align-items:center;gap:16px;margin-bottom:20px;flex-wrap:wrap}
.quest-bar .xp{font-family:"JetBrains Mono",monospace;font-size:14px;color:var(--amber);font-weight:700}
.quest-bar .prog{flex:1;height:8px;background:var(--bg2);border-radius:999px;overflow:hidden;border:1px solid var(--line);min-width:120px}
.quest-bar .prog i{display:block;width:0%;height:100%;background:linear-gradient(90deg,var(--cyan),var(--green));transition:.3s}
.quest-body{font-size:15px;line-height:1.7;min-height:80px}
.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}
.dash-wrap{background:var(--panel);border:1px solid var(--line);border-radius:14px;padding:20px;margin:20px 0}
.dash-head{margin-bottom:12px;display:flex;justify-content:space-between;flex-wrap:wrap;gap:8px}
.dash-head .ttl{font-weight:700;color:var(--cyan)}
.dash-grid{display:grid;grid-template-columns:1fr 1fr;gap:16px}
@media(max-width:760px){.dash-grid{grid-template-columns:1fr}}
.cnv-inp{font-family:"JetBrains Mono",monospace;font-size:13px;color:var(--cyan);background:var(--panel2);border:1px solid var(--line);border-radius:8px;padding:6px 14px}
.btnrow{display:flex;gap:12px;flex-wrap:wrap;align-items:center;margin-top:14px}
.svg-diag{margin:16px 0;border-radius:12px;background:var(--bg2);padding:14px;text-align:center}
.svg-diag svg{max-width:100%;height:auto}
.gate-svg{display:block;margin:8px auto;max-width:100%}
.palette-grid{display:grid;gap:2px;margin:12px 0}
.palette-cell{aspect-ratio:1;border-radius:3px;transition:transform .12s}
.palette-cell:hover{transform:scale(1.12);z-index:2;position:relative}
.graph-canvas{width:100%;height:380px;background:var(--bg2);border:1px solid var(--line);border-radius:10px;margin:12px 0;display:block;cursor:crosshair;touch-action:none}
.graph-canvas-sm{height:260px}
.bit-row{display:flex;gap:3px;flex-wrap:wrap;margin:8px 0}
.bit{width:36px;height:44px;border:1px solid var(--line);border-radius:6px;background:var(--panel2);color:var(--ink);font-family:"JetBrains Mono",monospace;font-size:14px;font-weight:700;display:flex;align-items:center;justify-content:center;cursor:pointer;user-select:none;transition:all .14s ease}
.bit:hover{border-color:var(--cyan);transform:translateY(-2px)}
.bit.on{background:var(--cyan);color:#04222b;border-color:var(--cyan);box-shadow:0 0 14px rgba(34,211,238,.4)}
.bit.sign{background:var(--red);color:#fff;border-color:var(--red)}
.bit.sign.on{background:var(--amber);color:#04222b;border-color:var(--amber);box-shadow:0 0 14px rgba(252,211,77,.4)}
.bit-label{font-family:"JetBrains Mono",monospace;font-size:11px;color:var(--muted);text-align:center;margin-top:2px}
.bit-block{text-align:center}
.karnaugh{display:grid;gap:2px;margin:14px 0;background:var(--line);padding:2px;border-radius:8px;width:max-content;margin-left:auto;margin-right:auto}
.kcell{width:64px;height:48px;background:var(--panel);display:flex;align-items:center;justify-content:center;font-family:"JetBrains Mono",monospace;font-size:14px;font-weight:700;cursor:pointer;user-select:none;transition:.1s}
.kcell:hover{background:rgba(34,211,238,.1)}
.kcell.on{background:var(--cyan);color:#04222b}
.kcell.dc{background:var(--violet);color:#fff;font-size:11px}
.kcell.g{box-shadow:inset 0 0 0 3px var(--green)}
.kcell.a{box-shadow:inset 0 0 0 3px var(--amber)}
.kcell.r{box-shadow:inset 0 0 0 3px var(--red)}
.toast{position:fixed;right:20px;top:80px;background:var(--panel2);border:1px solid var(--cyan);border-radius:10px;padding:12px 18px;color:var(--ink);font-size:14px;z-index:1000;animation:toastIn .3s ease,toastOut .3s ease 2.4s forwards;box-shadow:0 8px 24px rgba(0,0,0,.4)}
.toast.ok{border-color:var(--green)}
.toast.bad{border-color:var(--red)}
@keyframes toastIn{0%{opacity:0;transform:translateX(20px)}100%{opacity:1;transform:translateX(0)}}
@keyframes toastOut{0%{opacity:1}100%{opacity:0;transform:translateX(20px)}}
@keyframes fadeIn{0%{opacity:0;transform:translateY(8px)}100%{opacity:1;transform:translateY(0)}}
.fade-in{animation:fadeIn .35s ease}
@media(max-width:760px){
  .grid3,.grid2,.grid4{grid-template-columns:1fr}
  .test-q label{font-size:13px;padding:8px 10px}
  .bit{width:32px;height:40px;font-size:13px}
  .kcell{width:54px;height:42px;font-size:13px}
}
@media print{
  body{background:#fff;color:#000}
  .topnav,.railwrap,.modnav,.iv-shell,.callout{display:none}
}