@font-face { font-family:"Manrope"; font-weight:600; font-display:swap;
  src:url("/static/fonts/manrope-latin-600.woff2") format("woff2");
  unicode-range:U+0000-00FF,U+0131,U+0152-0153,U+2000-206F,U+2122,U+2212; }
@font-face { font-family:"Manrope"; font-weight:600; font-display:swap;
  src:url("/static/fonts/manrope-cyr-600.woff2") format("woff2");
  unicode-range:U+0400-045F,U+0490-0491,U+04B0-04B1,U+2116; }
@font-face { font-family:"Manrope"; font-weight:700; font-display:swap;
  src:url("/static/fonts/manrope-latin-700.woff2") format("woff2");
  unicode-range:U+0000-00FF,U+0131,U+0152-0153,U+2000-206F,U+2122,U+2212; }
@font-face { font-family:"Manrope"; font-weight:700; font-display:swap;
  src:url("/static/fonts/manrope-cyr-700.woff2") format("woff2");
  unicode-range:U+0400-045F,U+0490-0491,U+04B0-04B1,U+2116; }

@font-face { font-family:"JetBrains Mono"; font-weight:400; font-display:swap;
  src:url("/static/fonts/jbm-latin-400.woff2") format("woff2");
  unicode-range:U+0000-00FF,U+0131,U+0152-0153,U+2000-206F,U+2122,U+2212; }
@font-face { font-family:"JetBrains Mono"; font-weight:400; font-display:swap;
  src:url("/static/fonts/jbm-cyr-400.woff2") format("woff2");
  unicode-range:U+0400-045F,U+0490-0491,U+04B0-04B1,U+2116; }
@font-face { font-family:"JetBrains Mono"; font-weight:700; font-display:swap;
  src:url("/static/fonts/jbm-latin-700.woff2") format("woff2");
  unicode-range:U+0000-00FF,U+0131,U+0152-0153,U+2000-206F,U+2122,U+2212; }
@font-face { font-family:"JetBrains Mono"; font-weight:700; font-display:swap;
  src:url("/static/fonts/jbm-cyr-700.woff2") format("woff2");
  unicode-range:U+0400-045F,U+0490-0491,U+04B0-04B1,U+2116; }

:root {
  --bg:    #0f1016;
  --bg2:   #15171f;
  --bg3:   #1c1f2a;
  --line:  #2a2e3b;
  --line2: #363b4c;
  --ink:   #e8e9f0;
  --muted: #8b8fa3;
  --dim:   #5b5f72;
  --acc:   #f2b441;
  --acc2:  #6fcbda;
  --ok:    #4fd18b;
  --bad:   #ef6b6b;

  --h: 220;
  --tone:   hsl(var(--h) 70% 62%);
  --tone-d: hsl(var(--h) 55% 46%);
  --tone-bg: hsl(var(--h) 45% 14%);
  --tone-line: hsl(var(--h) 40% 30%);

  --mono: "JetBrains Mono", ui-monospace, "SFMono-Regular", Menlo, Consolas, monospace;
  --disp: "Manrope", system-ui, sans-serif;
  --sans: system-ui, -apple-system, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;

  --maxw: 1180px;
}

* { box-sizing: border-box; }
html { scroll-padding-top: 84px; }
body {
  margin: 0;
  background:
    radial-gradient(1200px 600px at 80% -10%, hsl(var(--h) 40% 10% / .5), transparent 70%),
    var(--bg);
  color: var(--ink);
  font-family: var(--sans);
  font-size: 16px;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}
a { color: var(--acc2); text-decoration: none; }
a:hover { text-decoration: underline; text-underline-offset: 3px; }

::selection { background: var(--tone); color: #0b0c11; }

.top {
  position: sticky; top: 0; z-index: 50;
  display: flex; align-items: center; gap: 18px;
  padding: 14px 24px;
  background: color-mix(in srgb, var(--bg) 86%, transparent);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--line);
}
.brand {
  font-family: var(--disp); font-weight: 700; letter-spacing: .14em;
  font-size: 17px; color: var(--ink); white-space: nowrap;
}
.brand b { color: var(--acc); }
.crumbs { color: var(--muted); font-size: 14px; display: flex; gap: 8px; align-items: center; min-width: 0; }
.crumbs .sep { color: var(--dim); }
.crumbs a { color: var(--muted); }
.crumbs .here { color: var(--ink); overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.top .spacer { flex: 1; }
.top .mono { font-family: var(--mono); font-size: 12px; color: var(--dim); }

.wrap { max-width: var(--maxw); margin: 0 auto; padding: 0 24px; }

.hero { padding: 54px 0 30px; }
.hero h1 {
  font-family: var(--disp); font-weight: 700;
  font-size: clamp(34px, 6vw, 62px); line-height: 1.02;
  letter-spacing: -.01em; margin: 0 0 14px;
}
.hero h1 .dot { color: var(--acc); }
.hero p.lead { font-size: clamp(16px, 2vw, 19px); color: var(--muted); max-width: 64ch; margin: 0 0 26px; }
.hero .meta { display: flex; flex-wrap: wrap; gap: 10px 28px; font-family: var(--mono); font-size: 13px; color: var(--dim); }
.hero .meta b { color: var(--ink); font-weight: 700; }

.railtop { margin: 22px 0 6px; }
.railtop .bar { height: 6px; background: var(--bg3); border-radius: 99px; overflow: hidden; border: 1px solid var(--line); }
.railtop .bar > i { display: block; height: 100%; width: 0; background: linear-gradient(90deg, var(--acc), #ffd27a); transition: width .6s cubic-bezier(.2,.7,.2,1); }
.railtop .lab { display: flex; justify-content: space-between; font-family: var(--mono); font-size: 12px; color: var(--dim); margin-top: 8px; }

.grid {
  display: grid; gap: 16px; padding: 24px 0 70px;
  grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
}
.tile {
  position: relative; display: block;
  background: var(--bg2); border: 1px solid var(--line);
  border-left: 3px solid var(--tone);
  border-radius: 4px; padding: 20px 22px 18px;
  color: var(--ink); overflow: hidden;
  transition: border-color .15s, transform .15s, background .15s;
}
.tile:hover { text-decoration: none; transform: translateY(-2px); border-color: var(--tone-line); background: var(--bg3); }
.tile .idx { position: absolute; top: 14px; right: 16px; font-family: var(--mono); font-size: 12px; color: var(--dim); }
.tile .glyph { font-family: var(--disp); font-weight: 700; font-size: 15px; color: var(--tone); letter-spacing: .18em; }
.tile h3 { font-family: var(--disp); font-weight: 600; font-size: 23px; margin: 6px 0 6px; }
.tile p { color: var(--muted); font-size: 14px; margin: 0 0 16px; min-height: 2.8em; }
.tile .foot { display: flex; align-items: center; gap: 16px; font-family: var(--mono); font-size: 12px; color: var(--dim); }
.tile .foot .count b { color: var(--ink); }
.tile .pbar { flex: 1; height: 4px; background: var(--bg); border-radius: 99px; overflow: hidden; }
.tile .pbar > i { display: block; height: 100%; width: 0; background: var(--tone); transition: width .5s; }
.tile .done { color: var(--tone); }

.shell { display: grid; grid-template-columns: 290px 1fr; gap: 34px; padding: 26px 0 80px; align-items: start; }
.rail { position: sticky; top: 84px; border-left: 2px solid var(--tone-line); padding-left: 0; }
.rail .cathead { padding: 0 0 14px 16px; }
.rail .cathead .glyph { font-family: var(--disp); font-weight: 700; color: var(--tone); letter-spacing: .16em; font-size: 13px; }
.rail .cathead h2 { font-family: var(--disp); font-weight: 600; font-size: 22px; margin: 4px 0 0; }
.rail .seclab { font-family: var(--mono); font-size: 11px; letter-spacing: .12em; color: var(--dim); padding: 14px 0 6px 16px; }
.step {
  display: flex; gap: 11px; align-items: baseline;
  padding: 7px 14px 7px 16px; margin-left: -2px;
  border-left: 2px solid transparent; color: var(--muted);
  font-size: 14.5px; transition: color .12s, border-color .12s, background .12s;
}
.step:hover { color: var(--ink); text-decoration: none; background: var(--bg2); }
.step.active { color: var(--ink); border-left-color: var(--tone); background: var(--bg2); }
.step .tick { font-family: var(--mono); font-size: 12px; width: 1.2em; flex: none; color: var(--dim); }
.step.solved .tick { color: var(--ok); }
.step .k { font-family: var(--mono); font-size: 10px; color: var(--dim); flex: none; align-self: center; }

.content { min-width: 0; max-width: 76ch; }
.pagehead { margin: 0 0 22px; }
.pagehead .chips { display: flex; gap: 8px; margin-bottom: 12px; flex-wrap: wrap; }
.chip {
  font-family: var(--mono); font-size: 11px; letter-spacing: .05em;
  padding: 3px 9px; border-radius: 3px; border: 1px solid var(--tone-line);
  color: var(--tone); background: var(--tone-bg);
}
.chip.k-theory   { color: var(--acc2); border-color: #335a66; background: #11232a; }
.chip.k-practice { color: var(--ok);   border-color: #2d5a42; background: #0f2219; }
.chip.k-task     { color: var(--acc);  border-color: #5a4a22; background: #231d0f; }
.chip.lvl        { color: var(--muted); border-color: var(--line2); background: transparent; }
.chip.pts        { color: var(--ink);  border-color: var(--line2); background: var(--bg3); }
.pagehead h1 { font-family: var(--disp); font-weight: 600; font-size: clamp(27px, 4vw, 38px); line-height: 1.12; margin: 0; letter-spacing: -.005em; }

.prose { font-size: 16px; }
.prose > *:first-child { margin-top: 0; }
.prose h2 { font-family: var(--disp); font-weight: 600; font-size: 25px; margin: 36px 0 12px; padding-top: 6px; letter-spacing: -.005em; }
.prose h3 { font-family: var(--disp); font-weight: 600; font-size: 19px; margin: 26px 0 8px; color: var(--ink); }
.prose p, .prose li { color: #d2d4e0; }
.prose strong { color: var(--ink); }
.prose ul, .prose ol { padding-left: 1.3em; }
.prose li { margin: 5px 0; }
.prose li::marker { color: var(--tone); }
.prose a { color: var(--acc2); }
.prose hr { border: none; border-top: 1px solid var(--line); margin: 30px 0; }
.prose blockquote {
  margin: 18px 0; padding: 2px 18px; border-left: 3px solid var(--tone);
  background: var(--bg2); color: var(--muted); border-radius: 0 4px 4px 0;
}
.prose table { border-collapse: collapse; width: 100%; margin: 18px 0; font-size: 14.5px; }
.prose th, .prose td { border: 1px solid var(--line); padding: 7px 11px; text-align: left; }
.prose th { background: var(--bg3); font-family: var(--mono); font-weight: 700; font-size: 12.5px; color: var(--ink); }
.prose td { color: #cfd1dd; }
.prose code { font-family: var(--mono); font-size: 13.5px; background: var(--bg3); padding: 1.5px 6px; border-radius: 3px; color: #ffd9a0; border: 1px solid var(--line); }
.prose pre { background: #0b0c12; border: 1px solid var(--line); border-radius: 6px; padding: 16px 18px; overflow-x: auto; margin: 16px 0; }
.prose pre code { background: none; border: none; padding: 0; color: #d6d8e3; font-size: 13.5px; line-height: 1.55; }

.pagenav { display: flex; justify-content: space-between; gap: 14px; margin-top: 46px; padding-top: 22px; border-top: 1px solid var(--line); }
.pagenav a { display: block; max-width: 48%; color: var(--muted); font-size: 14px; }
.pagenav a:hover { color: var(--ink); text-decoration: none; }
.pagenav a .k { display: block; font-family: var(--mono); font-size: 11px; color: var(--dim); margin-bottom: 2px; }
.pagenav a.next { text-align: right; margin-left: auto; }

.files { margin: 20px 0; }
.files .fl {
  display: inline-flex; align-items: center; gap: 10px; margin: 0 8px 8px 0;
  padding: 9px 14px; background: var(--bg2); border: 1px solid var(--line2);
  border-radius: 5px; font-family: var(--mono); font-size: 13px; color: var(--ink);
}
.files .fl:hover { border-color: var(--tone); text-decoration: none; background: var(--bg3); }
.files .fl .ic { color: var(--tone); }

.launch {
  display: inline-flex; align-items: center; gap: 10px; margin: 6px 0 2px;
  padding: 11px 18px; background: var(--tone-bg); border: 1px solid var(--tone-line);
  border-radius: 6px; font-family: var(--mono); font-size: 14px; color: var(--tone); font-weight: 700;
}
.launch:hover { background: var(--tone); color: #0b0c11; text-decoration: none; }

.reveal { margin: 14px 0; border: 1px solid var(--line); border-radius: 6px; background: var(--bg2); overflow: hidden; }
.reveal > summary {
  cursor: pointer; list-style: none; padding: 12px 16px;
  font-family: var(--mono); font-size: 13.5px; color: var(--muted);
  display: flex; align-items: center; gap: 10px; user-select: none;
}
.reveal > summary::-webkit-details-marker { display: none; }
.reveal > summary:hover { color: var(--ink); }
.reveal > summary .plus { color: var(--tone); font-weight: 700; transition: transform .2s; }
.reveal[open] > summary .plus { transform: rotate(45deg); }
.reveal[open] > summary { border-bottom: 1px solid var(--line); color: var(--ink); }
.reveal .body { padding: 4px 18px 10px; }
.reveal.hint .body { animation: fade .25s ease; }
.reveal.writeup > summary .plus { color: var(--acc); }

@keyframes fade { from { opacity: 0; transform: translateY(-4px); } to { opacity: 1; transform: none; } }

.flagbox { margin: 26px 0 8px; padding: 18px; border: 1px solid var(--line2); border-radius: 8px; background: var(--bg2); }
.flagbox .lab { font-family: var(--mono); font-size: 12px; color: var(--muted); margin-bottom: 10px; letter-spacing: .04em; }
.flagform { display: flex; gap: 10px; flex-wrap: wrap; }
.flagform input {
  flex: 1; min-width: 220px; font-family: var(--mono); font-size: 15px;
  padding: 11px 14px; background: var(--bg); border: 1px solid var(--line2);
  border-radius: 6px; color: var(--ink);
}
.flagform input:focus { outline: 2px solid var(--tone); outline-offset: 0; border-color: transparent; }
.flagform button {
  font-family: var(--mono); font-weight: 700; font-size: 14px; cursor: pointer;
  padding: 11px 22px; background: var(--acc); color: #0b0c11; border: none; border-radius: 6px;
}
.flagform button:hover { background: #ffd27a; }
.flagform button:disabled { opacity: .5; cursor: default; }
.flagmsg { margin-top: 12px; font-family: var(--mono); font-size: 13.5px; min-height: 1.2em; }
.flagmsg.ok  { color: var(--ok); }
.flagmsg.bad { color: var(--bad); }
.flagbox.solved { border-color: var(--ok); }
.flagbox.solved .lab::before { content: "✓ "; color: var(--ok); }

.catlead { color: var(--muted); font-size: 16px; max-width: 70ch; margin: 2px 0 10px; }
.notfound { padding: 90px 0; text-align: center; }
.notfound h1 { font-family: var(--disp); font-size: 80px; margin: 0; color: var(--tone); }
.footer { border-top: 1px solid var(--line); color: var(--dim); font-size: 13px; padding: 26px 0 50px; font-family: var(--mono); }
.footer a { color: var(--muted); }

@media (max-width: 860px) {
  .shell { grid-template-columns: 1fr; gap: 0; }
  .rail { position: static; border-left: none; border-bottom: 1px solid var(--line); margin-bottom: 24px; padding-bottom: 12px; }
  .content { max-width: none; }
  .crumbs { display: none; }
}
@media (prefers-reduced-motion: reduce) {
  * { animation: none !important; transition: none !important; }
}

:root {
  --ink:   #f0f2fb;
  --acc:   #ffc23d;
  --acc2:  #67d4ff;
  --ok:    #3ee694;
  --bad:   #ff6473;
  --tone:    hsl(var(--h) 92% 68%);
  --tone-d:  hsl(var(--h) 80% 54%);
  --tone-bg: hsl(var(--h) 60% 15%);
  --tone-line: hsl(var(--h) 70% 44%);
  --tone-glow: hsl(var(--h) 95% 60% / .35);
}

body {
  background:
    radial-gradient(1000px 560px at 84% -12%, hsl(var(--h) 90% 58% / .22), transparent 60%),
    radial-gradient(760px 520px at -8% 6%, hsl(calc(var(--h) + 55) 85% 58% / .13), transparent 62%),
    radial-gradient(900px 900px at 50% 120%, hsl(calc(var(--h) - 40) 80% 55% / .08), transparent 60%),
    var(--bg);
}

.top { border-bottom: 1px solid transparent;
  border-image: linear-gradient(90deg, var(--tone), var(--acc2) 55%, var(--acc)) 1; }
.brand { text-shadow: 0 0 18px var(--tone-glow); }
.brand b { color: var(--acc); }

.hero h1 {
  background: linear-gradient(100deg, var(--ink) 20%, var(--acc2) 55%, var(--acc) 90%);
  -webkit-background-clip: text; background-clip: text;
  -webkit-text-fill-color: transparent; color: transparent;
}
.hero h1 .dot { -webkit-text-fill-color: var(--acc); color: var(--acc); }

.tile {
  border-left: 3px solid transparent;
  border-image: linear-gradient(180deg, var(--tone), var(--tone-d)) 1;
  background:
    linear-gradient(180deg, hsl(var(--h) 55% 12% / .55), transparent 42%),
    var(--bg2);
}
.tile::after {
  content: ""; position: absolute; inset: 0; pointer-events: none;
  background: radial-gradient(420px 150px at 100% 0%, var(--tone-glow), transparent 70%);
  opacity: .5; transition: opacity .18s;
}
.tile:hover { transform: translateY(-3px); box-shadow: 0 12px 34px -14px var(--tone-glow); }
.tile:hover::after { opacity: 1; }
.tile .glyph { color: var(--tone); text-shadow: 0 0 16px var(--tone-glow); }
.tile h3 { color: var(--ink); }
.tile .pbar > i { background: linear-gradient(90deg, var(--tone), var(--acc)); }

.rail { border-left: 2px solid transparent;
  border-image: linear-gradient(180deg, var(--tone), transparent) 1; }
.rail .cathead .glyph { color: var(--tone); text-shadow: 0 0 14px var(--tone-glow); }
.rail .seclab { color: var(--tone); opacity: .85; }
.step .t { overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.step.active {
  border-left-color: var(--tone);
  background: linear-gradient(90deg, var(--tone-bg), transparent);
  box-shadow: inset 0 0 20px -10px var(--tone-glow);
}
.step.active .t { color: var(--ink); font-weight: 600; }
.tick-theory   { color: var(--acc2) !important; }
.tick-practice { color: var(--ok) !important; }
.task-step { padding-left: 30px !important; position: relative; }
.task-step .tick { color: var(--acc) !important; font-size: 10px !important; }
.task-step::before {
  content: ""; position: absolute; left: 20px; top: 0; bottom: 50%;
  border-left: 1px solid var(--tone-line); border-bottom: 1px solid var(--tone-line);
  width: 7px; opacity: .6;
}
.step.solved .tick { color: var(--ok) !important; text-shadow: 0 0 10px hsl(145 80% 55% / .6); }

.pagehead h1 {
  background: linear-gradient(95deg, var(--ink), var(--tone) 95%);
  -webkit-background-clip: text; background-clip: text;
  -webkit-text-fill-color: transparent; color: transparent;
}
.prose h2 {
  padding-left: 14px; border-left: 4px solid var(--tone);
  color: var(--ink);
}
.prose h3 { color: var(--tone); }
.prose li::marker { color: var(--acc); }

.chip { box-shadow: 0 0 0 1px transparent; }
.chip.k-theory   { color: #8fe3ff; border-color: #2f6b7d; background: #0e2630; }
.chip.k-practice { color: #5ff0a8; border-color: #27694a; background: #0c2619; }
.chip.k-task     { color: #ffd166; border-color: #6b5420; background: #2a2109; }

.prose code { color: #ffdca0; border-color: var(--tone-line); background: hsl(var(--h) 30% 12%); }
.prose pre { border-color: var(--tone-line);
  box-shadow: inset 3px 0 0 var(--tone), 0 8px 24px -18px var(--tone-glow); }
.prose blockquote {
  border-left: 3px solid var(--acc);
  background: linear-gradient(90deg, hsl(var(--h) 45% 13% / .7), transparent);
  color: #c9ccdc;
}

.flagform button { background: linear-gradient(135deg, var(--acc), #ff9f45); box-shadow: 0 6px 18px -8px var(--acc); }
.flagform button:hover { background: linear-gradient(135deg, #ffd27a, var(--acc)); }
.launch { background: linear-gradient(135deg, var(--tone-bg), hsl(var(--h) 55% 20%)); color: var(--tone); }
.launch:hover { background: linear-gradient(135deg, var(--tone), var(--tone-d)); color: #0b0c11; box-shadow: 0 8px 22px -10px var(--tone-glow); }
.flagbox.solved {
  border-color: var(--ok);
  background: linear-gradient(180deg, hsl(145 55% 12% / .6), var(--bg2));
  box-shadow: 0 0 30px -16px hsl(145 80% 55% / .7);
}
.railtop .bar > i { background: linear-gradient(90deg, var(--tone), var(--acc)); }
.notfound h1 { text-shadow: 0 0 40px var(--tone-glow); }

.chl .s, .chl .s1, .chl .s2, .chl .sb, .chl .sd { color: #a7e88f !important; }
.chl .k, .chl .kd, .chl .kn, .chl .kc { color: #ff9ad2 !important; }
.chl .nf, .chl .nb { color: #74d7ff !important; }
.chl .mi, .chl .mf, .chl .mh { color: #ffc66b !important; }
.chl .c, .chl .c1, .chl .cm { color: #6b7187 !important; font-style: italic; }

.lgroup { }
.lrow { display: flex; align-items: center; }
.lrow .lesson-link { flex: 1; min-width: 0; }
.caret {
  flex: none; background: none; border: none; cursor: pointer;
  color: var(--dim); padding: 6px 12px 6px 6px; line-height: 1;
  align-self: stretch; display: flex; align-items: center;
}
.caret:hover { color: var(--tone); }
.caret .chev { display: inline-block; font-size: 11px; transition: transform .15s ease; }
.lgroup.open > .lrow .caret .chev { transform: rotate(90deg); }

.lgroup .subs { display: none; }
.lgroup.open .subs { display: block; animation: subsIn .16s ease; }
@keyframes subsIn { from { opacity: 0; transform: translateY(-3px); } to { opacity: 1; transform: none; } }

.lgroup.open { border-left: 2px solid var(--tone-line); margin-left: -2px;
  background: linear-gradient(90deg, hsl(var(--h) 45% 12% / .35), transparent 70%);
  border-radius: 0 6px 6px 0; }
.lgroup.open > .lrow .lesson-link { color: var(--ink); }

.caret::after {
  content: attr(data-count); font-family: var(--mono); font-size: 10px;
  color: var(--dim); margin-left: 2px;
}
.lgroup.open > .lrow .caret::after { content: ""; }

.uchip {
  font-family: var(--mono); font-size: 12px; color: var(--muted);
  padding: 5px 11px; border: 1px solid var(--line2); border-radius: 5px;
  margin-left: 8px; background: var(--bg2);
}
.uchip:hover { color: var(--ink); text-decoration: none; border-color: var(--tone-line); }
.uchip.admin { color: var(--acc); border-color: #5a4a22; background: #231d0f; }
.uchip.logout { cursor: pointer; }

.flashwrap { margin: 14px 0 0; }
.flash {
  font-family: var(--mono); font-size: 13px; padding: 9px 14px; border-radius: 6px;
  border: 1px solid var(--line2); background: var(--bg2); color: var(--ink); margin-bottom: 8px;
}
.flash.ok  { color: var(--ok);  border-color: #2d5a42; background: #0f2219; }
.flash.bad { color: var(--bad); border-color: #5a2d2d; background: #220f0f; }

.loginwrap { min-height: 100vh; display: flex; align-items: center; justify-content: center; padding: 24px; }
.loginbox {
  width: 100%; max-width: 360px; padding: 32px 30px 28px;
  background: var(--bg2); border: 1px solid var(--line2); border-radius: 12px;
  border-top: 3px solid var(--tone); box-shadow: 0 24px 60px -30px var(--tone-glow);
}
.loginbox label { display: block; font-family: var(--mono); font-size: 12px; color: var(--muted); margin: 14px 0 5px; }
.loginbox input {
  width: 100%; font-family: var(--mono); font-size: 15px; padding: 11px 13px;
  background: var(--bg); border: 1px solid var(--line2); border-radius: 6px; color: var(--ink);
}
.loginbox input:focus { outline: 2px solid var(--tone); border-color: transparent; }
.loginbox button {
  width: 100%; margin-top: 20px; font-family: var(--mono); font-weight: 700; font-size: 14px;
  padding: 12px; border: none; border-radius: 6px; cursor: pointer; color: #0b0c11;
  background: linear-gradient(135deg, var(--tone), var(--tone-d));
}
.loginbox button:hover { filter: brightness(1.08); }

.adminbox { background: var(--bg2); border: 1px solid var(--line); border-radius: 10px; padding: 20px 22px; margin: 14px 0; }
.aform label { display: block; font-family: var(--mono); font-size: 12px; color: var(--muted); margin: 8px 0 5px; }
.aform input[type=text], .aform input[type=password] {
  font-family: var(--mono); font-size: 14px; padding: 9px 12px; background: var(--bg);
  border: 1px solid var(--line2); border-radius: 6px; color: var(--ink); min-width: 220px;
}
.aform input:focus { outline: 2px solid var(--tone); border-color: transparent; }
.aform button {
  font-family: var(--mono); font-weight: 700; font-size: 13px; cursor: pointer;
  padding: 10px 18px; border: none; border-radius: 6px; color: #0b0c11;
  background: linear-gradient(135deg, var(--acc), #ff9f45);
}
.aform button:hover { filter: brightness(1.06); }
.aform.row { display: flex; gap: 14px; align-items: flex-end; flex-wrap: wrap; }
.aform.row .chk { display: flex; align-items: center; gap: 7px; font-family: var(--mono); font-size: 13px; color: var(--muted); margin-bottom: 9px; }

.sechead { font-family: var(--disp); font-weight: 600; font-size: 20px; margin: 28px 0 10px; padding-left: 12px; border-left: 4px solid var(--tone); }

.utable { width: 100%; border-collapse: collapse; font-size: 14px; }
.utable th { text-align: left; font-family: var(--mono); font-size: 11px; color: var(--dim); font-weight: 400; padding: 8px 12px; border-bottom: 1px solid var(--line); letter-spacing: .04em; }
.utable td { padding: 11px 12px; border-bottom: 1px solid var(--line); vertical-align: middle; }
.utable tr:hover td { background: var(--bg2); }
.utable .dim { color: var(--dim); }

.minibar { display: inline-block; width: 140px; height: 7px; background: var(--bg3); border-radius: 99px; overflow: hidden; vertical-align: middle; border: 1px solid var(--line); }
.minibar > i { display: block; height: 100%; background: linear-gradient(90deg, var(--tone), var(--acc)); }

.catprog { display: flex; flex-direction: column; gap: 8px; }
.cprow { display: flex; align-items: center; gap: 14px; }
.cprow .cname { width: 150px; font-size: 14px; color: var(--ink); }
.cprow .minibar { flex: 1; width: auto; }
.cprow .cnum { color: var(--muted); font-size: 12.5px; width: 56px; text-align: right; }

.solvedgrp { margin: 10px 0; }
.solvedgrp .sgcat { font-family: var(--mono); font-size: 12px; color: var(--tone); letter-spacing: .06em; margin: 10px 0 6px; }
.sgitem { display: flex; align-items: center; gap: 10px; padding: 5px 0; font-size: 14px; color: #d2d4e0; }
.sgitem .tick { color: var(--ok); }
.sgitem .dim { margin-left: auto; font-size: 12px; }

.actrow { margin: 6px 0; }
.actrow.btns { display: flex; gap: 10px; flex-wrap: wrap; margin-top: 14px; }
.actrow.btns button { font-family: var(--mono); font-size: 13px; cursor: pointer; padding: 9px 16px; border-radius: 6px; border: 1px solid var(--line2); background: var(--bg3); color: var(--ink); }
.actrow.btns button:hover { border-color: var(--tone-line); }
.btn-warn   { color: var(--acc) !important; border-color: #5a4a22 !important; }
.btn-danger { color: var(--bad) !important; border-color: #5a2d2d !important; }

.standpanel { margin: 14px 0 4px; }
.standpanel .sp-row { display: flex; align-items: center; gap: 12px; flex-wrap: wrap; }
.launch.open { background: linear-gradient(135deg, var(--ok), #2fae73); color: #04140c; }
.launch.open:hover { filter: brightness(1.08); }
.standpanel .sp-info { color: var(--muted); font-size: 12.5px; }
.standpanel .sp-stop {
  font-family: var(--mono); font-size: 12px; cursor: pointer; color: var(--bad);
  background: none; border: 1px solid #5a2d2d; border-radius: 5px; padding: 6px 12px;
}
.standpanel .sp-stop:hover { background: #220f0f; }
.standpanel .sp-note { color: var(--dim); font-size: 12px; margin: 8px 0 0; max-width: 62ch; }

[hidden] { display: none !important; }

.chip.k-quiz { color: #c9a0ff; border-color: #4a3a6b; background: #190f2a; }
.quiz-step .tick { color: #c9a0ff !important; }

.quizform { margin: 6px 0 0; }
.qcard {
  border: 1px solid var(--line); border-left: 3px solid var(--tone-line);
  border-radius: 8px; padding: 16px 18px; margin: 14px 0; background: var(--bg2);
}
.qcard .qq { font-size: 15.5px; margin-bottom: 12px; color: var(--ink); }
.qopts { display: flex; flex-direction: column; gap: 8px; }
.qopt {
  display: flex; align-items: flex-start; gap: 10px; cursor: pointer;
  padding: 8px 12px; border: 1px solid var(--line2); border-radius: 6px;
  font-size: 14.5px; color: #d2d4e0; transition: border-color .12s, background .12s;
}
.qopt:hover { border-color: var(--tone-line); background: var(--bg3); }
.qopt input { margin-top: 3px; accent-color: var(--tone); }
.qopt.correct { border-color: var(--ok); background: #0f2219; color: #bdf0d3; }
.qcard.qbad { border-left-color: var(--bad); }
.qcard.qok  { border-left-color: var(--ok); }
.qexplain {
  margin-top: 10px; padding: 9px 12px; border-radius: 6px;
  background: var(--bg3); color: var(--muted); font-size: 13px;
  border-left: 2px solid var(--tone);
}
.quizbar { display: flex; align-items: center; gap: 14px; margin-top: 18px; flex-wrap: wrap; }
.qcheck {
  font-family: var(--mono); font-weight: 700; font-size: 14px; cursor: pointer;
  padding: 11px 22px; border: none; border-radius: 6px; color: #0b0c11;
  background: linear-gradient(135deg, #b98cff, #8a63d6);
}
.qcheck:hover { filter: brightness(1.08); }
.quizmsg { font-family: var(--mono); font-size: 13.5px; }
.quizmsg.ok  { color: var(--ok); }
.quizmsg.bad { color: var(--bad); }

.chip.k-drill { color:#c9a6ff; border-color:#4a3a6e; background:#1a1430; }
.drillbox {
  margin:34px 0 8px; padding:20px 20px 8px;
  border:1px solid var(--line2); border-radius:10px;
  background:linear-gradient(180deg,#171326, #14151d 70%);
}
.drillhead { display:flex; align-items:flex-start; gap:14px; margin-bottom:6px; }
.drillhead .dh-ico { font-size:22px; line-height:1.2; filter:drop-shadow(0 0 6px #7a5cff66); }
.drillhead h2 { margin:0 0 3px; font-size:17px; color:var(--ink); }
.drillhead p { margin:0; color:var(--muted); font-size:13.5px; max-width:60ch; }
.drillcount {
  margin-left:auto; flex:none; align-self:center;
  font-family:var(--mono); font-size:13px; color:var(--muted);
  padding:4px 10px; border:1px solid var(--line2); border-radius:99px; background:var(--bg);
}
.drillcount.full { color:var(--ok); border-color:#2d5a42; background:#0f2219; }
.drillcount b { color:var(--ink); }
.drillcount.full b { color:var(--ok); }

.drill {
  margin:14px 0; padding:14px 16px;
  border:1px solid var(--line); border-radius:8px; background:var(--bg2);
  border-left:3px solid #6a53b8;
}
.drill.done { border-left-color:var(--ok); background:#0f1a16; }
.drill-cmd { display:flex; align-items:center; gap:9px; flex-wrap:wrap; margin-bottom:8px; }
.drill-cmd code {
  font-family:var(--mono); font-size:13px; color:#ffd9a0;
  background:var(--bg3); border:1px solid var(--line); padding:2px 8px; border-radius:4px;
}
.drill-q { color:var(--ink); font-size:14.5px; }
.drill-q p { margin:0; }
.drill-q code { font-family:var(--mono); font-size:13px; background:var(--bg3); padding:1.5px 6px; border-radius:3px; color:#ffd9a0; border:1px solid var(--line); }
.drill-hint { margin:8px 0 2px; }
.drill-hint summary { cursor:pointer; color:var(--acc2); font-size:13px; }
.drill-hint > div { margin-top:7px; color:var(--muted); font-size:13.5px; }
.drill-hint > div p { margin:0; }
.drillform { display:flex; gap:8px; align-items:center; margin-top:11px; flex-wrap:wrap; }
.drillform input {
  flex:1; min-width:160px; padding:9px 12px; font-family:var(--mono); font-size:13.5px;
  background:var(--bg); border:1px solid var(--line2); border-radius:6px; color:var(--ink);
}
.drillform input:focus { outline:none; border-color:#8a74d6; }
.drillform input:disabled { opacity:.6; }
.drillform button {
  padding:9px 16px; border:none; border-radius:6px; cursor:pointer; font-weight:700; font-size:13px;
  color:#120f22; background:linear-gradient(135deg,#b79bff,#8a74d6);
}
.drillform button:disabled { opacity:.5; cursor:default; }
.drillmsg { font-size:13px; font-family:var(--mono); }
.drillmsg.ok { color:var(--ok); }
.drillmsg.bad { color:var(--bad); }
.drill-explain { margin-top:10px; padding:10px 12px; border-left:2px solid var(--ok); background:#0e1813; color:#bfe8d2; font-size:13.5px; border-radius:0 4px 4px 0; }
.drilltick { margin-left:6px; font-size:11px; filter:saturate(.7); }
.lesson-link.drilled .t { color:var(--ink); }

@media (min-width: 861px) {
  body.app-view { height: 100vh; overflow: hidden; display: flex; flex-direction: column; }
  body.app-view .footer { display: none; }

  body.app-view .shellwrap {
    flex: 1 1 auto; min-height: 0; display: flex;
    max-width: none; width: 100%; padding: 0; margin: 0;
  }
  body.app-view .shell {
    flex: 1 1 auto; min-height: 0; height: auto;
    grid-template-columns: 258px minmax(0, 1fr); gap: 0;
    padding: 0; align-items: stretch;
    grid-template-rows: minmax(0, 1fr);
  }

  body.app-view .rail,
  body.app-view .content {
    min-height: 0; height: auto;
    overflow-y: auto; overflow-x: hidden;
    overscroll-behavior: contain;
    scrollbar-width: none;
  }
  body.app-view .rail::-webkit-scrollbar,
  body.app-view .content::-webkit-scrollbar { width: 0; height: 0; display: none; }

  body.app-view .rail { position: static; top: auto; padding: 20px 14px 56px 24px; }
  body.app-view .content { max-width: none; padding: 20px 48px 96px 40px; }
  body.app-view .content > * { max-width: 62rem; }
}

.taskaid {
  margin: 30px 0 8px; padding: 18px 18px 8px;
  border: 1px solid var(--line2); border-radius: 10px;
  background: linear-gradient(180deg, #16180f, #14151d 70%);
}
.aidhead { display: flex; align-items: center; gap: 14px; margin-bottom: 4px; }
.aidhead h2 { margin: 0; font-size: 17px; color: var(--ink); font-family: var(--disp); font-weight: 600; }
.aidstart {
  margin-left: auto; padding: 9px 18px; border: none; border-radius: 7px; cursor: pointer;
  font-weight: 700; font-size: 14px; color: #171200;
  background: linear-gradient(135deg, var(--acc), #e0952a);
}
.aidstart:disabled { opacity: .55; cursor: default; }
.aidtimer { margin-left: auto; font-size: 12.5px; color: var(--acc); }
.aidnote { color: var(--dim); font-size: 12.5px; margin: 2px 0 14px; max-width: 62ch; line-height: 1.5; }

.hintcard, .writeupcard {
  margin: 10px 0; padding: 11px 14px;
  border: 1px solid var(--line); border-radius: 8px; background: var(--bg2);
  border-left: 3px solid var(--line2);
}
.hintcard.open, .writeupcard.open { border-left-color: var(--ok); }
.hintcard.next { border-left-color: var(--acc); }
.hintcard.locked { opacity: .62; }
.hintrow { display: flex; align-items: center; gap: 11px; flex-wrap: wrap; }
.hintno { font-size: 12.5px; color: var(--muted); letter-spacing: .02em; }
.writeupcard .hintno { color: var(--ink); }
.hintstate { font-size: 12px; }
.hintstate.ok { color: var(--ok); }
.hintstate.mono { color: var(--dim); }
.hintbtn {
  padding: 6px 13px; border: 1px solid var(--line2); border-radius: 6px; cursor: pointer;
  font-size: 12.5px; font-weight: 600; color: var(--ink); background: var(--bg3);
}
.hintbtn:not(:disabled):hover { border-color: var(--acc); color: var(--acc); }
.hintbtn:disabled { opacity: .5; cursor: default; }
.hintcount { font-size: 12px; color: var(--dim); }
.hintbody { margin-top: 10px; }
.hintbody[hidden] { display: none; }
.hintbody > *:first-child { margin-top: 0; }