/* CyberLearn — dark theme. Orange accent, green = done/correct, red = wrong. */
:root {
  --bg: #0d0f13;
  --bg-2: #14171d;
  --panel: #171b22;
  --panel-2: #1c2129;
  --panel-3: #232a34;
  --border: #2a313c;
  --border-soft: #222833;
  --text: #e6e9ef;
  --text-dim: #9aa4b2;
  --text-faint: #6b7482;
  --accent: #ff7a18;
  --accent-2: #ff9542;
  --accent-dim: #7a3d10;
  --green: #34d17a;
  --green-dim: #1b3a2a;
  --green-bg: #10231a;
  --red: #ff5c5c;
  --red-bg: #2a1414;
  --blue: #4aa3ff;
  --purple: #b98cff;
  --mono: "JetBrains Mono", "Fira Code", "SF Mono", "Cascadia Code", Consolas, "Liberation Mono", Menlo, monospace;
  --sans: "Inter", -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  --nav-w: 56px;
  --tree-w: 320px;
  --rail-w: 52px;
  --radius: 10px;
  --shadow: 0 6px 24px rgba(0,0,0,.35);
}

* { box-sizing: border-box; }
html, body { height: 100%; }
body {
  margin: 0; background: var(--bg); color: var(--text);
  font-family: var(--sans); font-size: 15px; line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}
a { color: var(--accent-2); text-decoration: none; }
a:hover { text-decoration: underline; }
button { font-family: inherit; cursor: pointer; }
::selection { background: var(--accent-dim); color: #fff; }
::-webkit-scrollbar { width: 10px; height: 10px; }
::-webkit-scrollbar-thumb { background: #2b323d; border-radius: 6px; }
::-webkit-scrollbar-track { background: transparent; }

/* ------------------------------------------------------------ app shell */
#app { display: flex; min-height: 100vh; }
.gnav {
  width: var(--nav-w); flex: 0 0 var(--nav-w); background: #0a0c10;
  border-right: 1px solid var(--border); display: flex; flex-direction: column;
  align-items: center; padding: 10px 0; gap: 4px; position: sticky; top: 0; height: 100vh; z-index: 30;
}
.gnav .logo { font-size: 22px; margin-bottom: 10px; }
.gnav-btn {
  width: 40px; height: 40px; border-radius: 9px; background: transparent; border: none;
  color: var(--text-faint); font-size: 19px; display: flex; align-items: center; justify-content: center;
  position: relative; transition: background .12s, color .12s;
}
.gnav-btn:hover { background: var(--panel-2); color: var(--text); }
.gnav-btn.active { background: var(--accent-dim); color: var(--accent-2); }
.gnav-btn .tip {
  position: absolute; left: 52px; top: 50%; transform: translateY(-50%);
  background: #000; color: #fff; padding: 4px 9px; border-radius: 6px; font-size: 12px;
  white-space: nowrap; opacity: 0; pointer-events: none; transition: opacity .12s; z-index: 50;
  border: 1px solid var(--border);
}
.gnav-btn:hover .tip { opacity: 1; }
.gnav .spacer { flex: 1; }

.main { flex: 1; min-width: 0; display: flex; flex-direction: column; }

/* ------------------------------------------------------------ generic */
.page { padding: 28px 36px 60px; max-width: 1180px; width: 100%; margin: 0 auto; }
.page h1 { font-size: 26px; margin: 0 0 4px; letter-spacing: -.2px; }
.page .sub { color: var(--text-dim); margin: 0 0 24px; }
.section-title { font-size: 13px; text-transform: uppercase; letter-spacing: .1em; color: var(--text-faint); margin: 28px 0 12px; }
.mono { font-family: var(--mono); }
.pill { display: inline-block; padding: 2px 9px; border-radius: 999px; font-size: 12px; font-weight: 600; }
.pill.easy { background: #12291c; color: #56d98a; }
.pill.medium { background: #2b2410; color: #e0b24a; }
.pill.hard { background: #2c1518; color: #ff7b7b; }
.badge-check { color: var(--green); }
.hidden { display: none !important; }
.muted { color: var(--text-dim); }
.faint { color: var(--text-faint); }

.btn {
  background: var(--panel-3); color: var(--text); border: 1px solid var(--border);
  padding: 9px 16px; border-radius: 8px; font-size: 14px; font-weight: 600; transition: .12s;
}
.btn:hover { border-color: #3a434f; background: #262d38; }
.btn.primary { background: var(--accent); color: #1a0e03; border-color: var(--accent); }
.btn.primary:hover { background: var(--accent-2); }
.btn.full { width: 100%; }
.btn.danger { color: var(--red); border-color: #4a2626; }
.btn.danger:hover { background: var(--red-bg); }
.btn.ghost { background: transparent; }
.btn:disabled { opacity: .5; cursor: default; }
.btn.small { padding: 6px 12px; font-size: 13px; }

.progress { height: 8px; background: var(--panel-3); border-radius: 999px; overflow: hidden; }
.progress > span { display: block; height: 100%; background: linear-gradient(90deg, var(--accent), var(--accent-2)); border-radius: 999px; transition: width .4s; }
.progress.done > span { background: var(--green); }

/* ------------------------------------------------------------ cards grid */
.grid { display: grid; gap: 16px; }
.grid.cards { grid-template-columns: repeat(auto-fill, minmax(300px, 1fr)); }
.card {
  background: var(--panel); border: 1px solid var(--border); border-radius: var(--radius);
  padding: 18px; position: relative; transition: border-color .12s, transform .12s;
}
.card:hover { border-color: #39424e; }
.path-card .top { display: flex; align-items: flex-start; gap: 12px; }
.path-card .icon { font-size: 26px; line-height: 1; }
.path-card h3 { margin: 0; font-size: 17px; }
.path-card .desc { color: var(--text-dim); font-size: 13.5px; margin: 10px 0 14px; min-height: 40px; }
.path-card .meta { display: flex; gap: 10px; align-items: center; font-size: 12.5px; color: var(--text-faint); margin-bottom: 12px; flex-wrap: wrap; }
.path-card .count { font-family: var(--mono); font-size: 12px; color: var(--text-dim); margin-bottom: 6px; }
.card .done-badge { position: absolute; top: 14px; right: 14px; color: var(--green); font-size: 18px; }

.stat-row { display: grid; grid-template-columns: repeat(auto-fit, minmax(150px,1fr)); gap: 14px; }
.stat { background: var(--panel); border: 1px solid var(--border); border-radius: var(--radius); padding: 16px 18px; }
.stat .n { font-size: 28px; font-weight: 700; letter-spacing: -.5px; }
.stat .l { color: var(--text-faint); font-size: 12.5px; text-transform: uppercase; letter-spacing: .06em; }
.stat .n .unit { font-size: 15px; color: var(--text-dim); font-weight: 500; }

/* ------------------------------------------------------------ workspace */
.ws { display: flex; flex: 1; min-height: 100vh; }
.ws-topbar {
  height: 46px; flex: 0 0 46px; background: #0a0c10; border-bottom: 1px solid var(--border);
  display: flex; align-items: center; padding: 0 14px; gap: 12px; position: sticky; top: 0; z-index: 20;
}
.ws-topbar .ws-label { font-weight: 700; letter-spacing: .16em; font-size: 12px; color: var(--text-dim); }
.ws-topbar .toggle { width: 30px; height: 30px; border-radius: 7px; background: transparent; border: 1px solid transparent; color: var(--text-faint); font-size: 15px; }
.ws-topbar .toggle:hover { background: var(--panel-2); color: var(--text); }
.ws-topbar .toggle.on { color: var(--accent-2); }
.ws-topbar .spacer { flex: 1; }
.ws-topbar .exit { color: var(--text-dim); font-size: 13px; background: transparent; border: 1px solid var(--border); padding: 6px 12px; border-radius: 7px; }
.ws-topbar .exit:hover { color: var(--red); border-color: #4a2626; }

.ws-body { display: flex; flex: 1; min-height: 0; }

/* left tree */
.ws-tree {
  width: var(--tree-w); flex: 0 0 var(--tree-w); background: var(--panel); border-right: 1px solid var(--border);
  overflow-y: auto; padding: 0; display: flex; flex-direction: column;
}
.ws-tree .tree-head { padding: 18px 18px 14px; border-bottom: 1px solid var(--border-soft); }
.ws-tree .tree-head .ptitle { font-size: 16px; font-weight: 700; display: flex; gap: 8px; align-items: center; }
.ws-tree .tree-head .pcount { font-family: var(--mono); font-size: 12px; color: var(--text-dim); margin: 8px 0 8px; }
.tree-list { padding: 8px 0; }
.tnode {
  display: flex; align-items: center; gap: 10px; padding: 9px 16px; cursor: pointer;
  border-left: 3px solid transparent; user-select: none;
}
.tnode:hover { background: var(--panel-2); }
.tnode.active { background: var(--panel-2); border-left-color: var(--accent); }
.tnode .status { flex: 0 0 18px; width: 18px; height: 18px; border-radius: 50%; border: 2px solid #3b444f; display: flex; align-items: center; justify-content: center; font-size: 11px; color: #0d0f13; }
.tnode .status.done { background: var(--green); border-color: var(--green); }
.tnode .status.partial { border-color: var(--accent); }
.tnode .tbody { flex: 1; min-width: 0; }
.tnode .ttitle { font-size: 14px; color: var(--text); white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
.tnode.child .ttitle { font-family: var(--mono); font-size: 13px; }
.tnode .tsub { font-size: 11.5px; color: var(--text-faint); }
.tnode .chev { color: var(--text-faint); font-size: 12px; transition: transform .12s; }
.tnode.child { padding-left: 40px; }
.tnode.section .ttitle { font-weight: 600; }
.tnode.quiz .ttitle { color: var(--accent-2); }
.tchildren { overflow: hidden; }

/* main panel */
.ws-main { flex: 1; min-width: 0; overflow-y: auto; }
.ws-main-inner { max-width: 820px; margin: 0 auto; padding: 30px 40px 80px; }
.crumbs { font-size: 12.5px; color: var(--text-faint); margin-bottom: 6px; }
.node-title { font-size: 24px; font-weight: 700; margin: 0 0 4px; letter-spacing: -.2px; }
.node-kind { font-size: 12px; text-transform: uppercase; letter-spacing: .1em; color: var(--accent-2); margin-bottom: 22px; }

/* markdown content */
.content h2 { font-size: 20px; margin: 30px 0 10px; }
.content h3 { font-size: 16.5px; margin: 22px 0 8px; color: #d7dbe2; }
.content h4 { font-size: 14.5px; margin: 18px 0 6px; color: var(--text-dim); text-transform: uppercase; letter-spacing: .05em; }
.content p { margin: 12px 0; }
.content ul, .content ol { margin: 12px 0; padding-left: 24px; }
.content li { margin: 5px 0; }
.content code { font-family: var(--mono); background: #0c0e12; border: 1px solid var(--border-soft); border-radius: 5px; padding: 1px 6px; font-size: 13px; color: #ffcc9e; }
.content strong { color: #fff; }
.content hr { border: none; border-top: 1px solid var(--border); margin: 24px 0; }
.content .table-wrap { overflow-x: auto; margin: 14px 0; }
.content table { border-collapse: collapse; width: 100%; font-size: 13.5px; }
.content th, .content td { border: 1px solid var(--border); padding: 8px 11px; text-align: left; vertical-align: top; }
.content th { background: var(--panel-2); font-weight: 600; }
.content td code { white-space: nowrap; }
.content .md-svg { margin: 16px 0; text-align: center; color: var(--text-dim); }
.content .md-svg svg { max-width: 100%; height: auto; }

.codeblock { position: relative; margin: 14px 0; border-radius: 8px; border: 1px solid var(--border); overflow: hidden; }
.codeblock pre { margin: 0; padding: 14px 16px; overflow-x: auto; }
.codeblock code { font-family: var(--mono); font-size: 13px; background: none; border: none; padding: 0; color: inherit; white-space: pre; }
.codeblock.terminal { background: #0a0c10; }
.codeblock.terminal code { color: #cfd6e0; }
.codeblock.terminal::before { content: "▌ terminal"; display: block; padding: 6px 14px; font-family: var(--mono); font-size: 11px; color: var(--green); background: #0c0f14; border-bottom: 1px solid var(--border); }
.codeblock.code { background: #0f1217; }
.codeblock.code::before { content: attr(data-lang); display: block; padding: 6px 14px; font-family: var(--mono); font-size: 11px; color: var(--text-faint); background: #0c0f14; border-bottom: 1px solid var(--border); }
.copy-btn { position: absolute; top: 5px; right: 8px; background: var(--panel-3); color: var(--text-dim); border: 1px solid var(--border); border-radius: 5px; font-size: 11px; padding: 3px 8px; font-family: var(--mono); z-index: 2; }
.copy-btn:hover { color: var(--text); }

.callout { margin: 14px 0; padding: 12px 16px; border-radius: 8px; border-left: 3px solid var(--border); background: var(--panel-2); font-size: 14px; }
.callout-tip { border-left-color: var(--green); background: var(--green-bg); }
.callout-note { border-left-color: var(--blue); }
.callout-warn { border-left-color: var(--red); background: var(--red-bg); }
.callout-employer { border-left-color: var(--accent); background: #221708; }
.callout-employer::before { content: "💼 What an employer expects  "; font-weight: 700; color: var(--accent-2); }
.callout-win { border-left-color: var(--purple); background: #1a1526; }
.callout-win::before { content: "🪟 → 🐧  Windows to Linux  "; font-weight: 700; color: var(--purple); }
.callout-remember { border-left-color: var(--accent-2); background: #221708; }

/* questions */
.qblock { margin: 20px 0; background: var(--panel); border: 1px solid var(--border); border-radius: var(--radius); padding: 18px; }
.qblock .qtext { font-weight: 600; margin-bottom: 10px; }
.qblock .qfmt { font-family: var(--mono); font-size: 12px; color: var(--text-faint); margin-bottom: 10px; }
.qblock .answer-row { display: flex; gap: 8px; flex-wrap: wrap; }
.qblock input.answer { flex: 1; min-width: 200px; background: #0c0e12; border: 1px solid var(--border); color: var(--text); font-family: var(--mono); padding: 10px 12px; border-radius: 8px; font-size: 14px; }
.qblock input.answer:focus { outline: none; border-color: var(--accent); }
.qblock input.answer.correct { border-color: var(--green); background: var(--green-bg); }
.qblock input.answer.wrong { border-color: var(--red); background: var(--red-bg); animation: shake .3s; }
.qblock .opts { display: flex; flex-direction: column; gap: 8px; }
.qopt { display: flex; align-items: center; gap: 10px; padding: 10px 12px; border: 1px solid var(--border); border-radius: 8px; cursor: pointer; background: #0c0e12; }
.qopt:hover { border-color: #3a434f; }
.qopt.selected { border-color: var(--accent); }
.qopt.correct { border-color: var(--green); background: var(--green-bg); }
.qopt.wrong { border-color: var(--red); background: var(--red-bg); }
.qopt input { accent-color: var(--accent); }
.qfeedback { margin-top: 10px; font-size: 13.5px; }
.qfeedback.ok { color: var(--green); }
.qfeedback.bad { color: var(--red); }
.qhint { margin-top: 10px; font-size: 13.5px; color: var(--accent-2); background: #221708; border-radius: 8px; padding: 10px 12px; border-left: 3px solid var(--accent); }
@keyframes shake { 0%,100%{transform:translateX(0)} 25%{transform:translateX(-5px)} 75%{transform:translateX(5px)} }

/* solved screen */
.solved-screen { text-align: center; padding: 40px 20px; }
.solved-screen .big-check { width: 92px; height: 92px; border-radius: 50%; background: var(--green); color: #06210f; display: flex; align-items: center; justify-content: center; font-size: 50px; margin: 0 auto 20px; box-shadow: 0 0 0 8px rgba(52,209,122,.12); animation: pop .4s; }
@keyframes pop { 0%{transform:scale(.4);opacity:0} 60%{transform:scale(1.1)} 100%{transform:scale(1)} }
.solved-screen h2 { font-size: 24px; margin: 0 0 8px; }
.solved-screen .cname { font-family: var(--mono); color: var(--accent-2); font-size: 15px; }
.solved-screen .notes { color: var(--text-dim); margin: 14px 0; font-size: 14px; }
.rate-row { display: flex; gap: 12px; justify-content: center; align-items: center; margin-top: 18px; }
.rate-row .rlabel { color: var(--text-faint); font-size: 13px; }
.rate-btn { background: var(--panel-2); border: 1px solid var(--border); border-radius: 8px; padding: 8px 14px; font-size: 18px; }
.rate-btn.up.on { border-color: var(--green); background: var(--green-bg); }
.rate-btn.down.on { border-color: var(--red); background: var(--red-bg); }

.node-footer { margin-top: 30px; }
.resolve-link { display: block; text-align: center; margin-top: 12px; color: var(--text-faint); font-size: 13px; background: none; border: none; width: 100%; }
.resolve-link:hover { color: var(--red); }
.markread-row { margin-top: 24px; }

/* right rail */
.ws-rail { width: var(--rail-w); flex: 0 0 var(--rail-w); background: #0a0c10; border-left: 1px solid var(--border); display: flex; flex-direction: column; align-items: center; padding: 12px 0; gap: 6px; }
.rail-btn { width: 38px; height: 38px; border-radius: 9px; background: transparent; border: 1px solid transparent; color: var(--text-faint); font-size: 18px; position: relative; }
.rail-btn:hover { background: var(--panel-2); color: var(--text); }
.rail-btn.active { background: var(--accent-dim); color: var(--accent-2); }
.rail-btn .tip { position: absolute; right: 46px; top: 50%; transform: translateY(-50%); background: #000; border: 1px solid var(--border); color: #fff; padding: 4px 9px; border-radius: 6px; font-size: 12px; white-space: nowrap; opacity: 0; pointer-events: none; transition: .12s; z-index: 40; }
.rail-btn:hover .tip { opacity: 1; }

/* slide-out drawer (terminal / lab / cheatsheet) */
.drawer { position: fixed; top: 0; right: 0; height: 100vh; width: 620px; max-width: 92vw; background: var(--panel); border-left: 1px solid var(--border); box-shadow: var(--shadow); z-index: 60; display: flex; flex-direction: column; transform: translateX(100%); transition: transform .22s ease; }
.drawer.open { transform: translateX(0); }
.drawer-head { display: flex; align-items: center; gap: 10px; padding: 12px 16px; border-bottom: 1px solid var(--border); }
.drawer-head .dtitle { font-weight: 700; font-size: 14px; flex: 1; }
.drawer-head .dclose { background: transparent; border: none; color: var(--text-dim); font-size: 20px; }
.drawer-head .dclose:hover { color: var(--red); }
.drawer-body { flex: 1; overflow: auto; padding: 0; min-height: 0; }
.drawer-body.pad { padding: 16px 18px; }
.drawer-actions { padding: 8px 12px; border-top: 1px solid var(--border); display: flex; gap: 8px; align-items: center; }

/* terminal */
.term-sim { display: flex; flex-direction: column; height: 100%; background: #07090c; }
.term-screen { flex: 1; overflow-y: auto; padding: 12px 14px; font-family: var(--mono); font-size: 13px; color: #cfd6e0; }
.term-line { white-space: pre-wrap; word-break: break-word; }
.term-input-line { display: flex; align-items: center; padding: 6px 14px 12px; font-family: var(--mono); font-size: 13px; }
.term-prompt { color: var(--green); white-space: pre; }
.term-input { flex: 1; background: transparent; border: none; color: #fff; font-family: var(--mono); font-size: 13px; outline: none; }
.term-frame { width: 100%; height: 100%; border: none; background: #000; }
.term-note { padding: 8px 14px; font-size: 12px; color: var(--text-faint); background: var(--panel-2); border-bottom: 1px solid var(--border); }

/* lab panel */
.lab-block { font-family: var(--mono); font-size: 12.5px; background: #0a0c10; border: 1px solid var(--border); border-radius: 8px; padding: 12px 14px; overflow-x: auto; white-space: pre; }
.lab-log { counter-reset: ln; }
.lab-log .lline { display: block; white-space: pre-wrap; }
.lab-log .lline::before { counter-increment: ln; content: counter(ln); display: inline-block; width: 34px; color: var(--text-faint); text-align: right; margin-right: 12px; user-select: none; }
.fakeform { background: var(--panel-2); border: 1px solid var(--border); border-radius: 10px; padding: 18px; max-width: 340px; }
.fakeform h4 { margin: 0 0 12px; }
.fakeform label { display: block; font-size: 12px; color: var(--text-dim); margin: 10px 0 4px; }
.fakeform input { width: 100%; background: #0c0e12; border: 1px solid var(--border); color: var(--text); padding: 8px 10px; border-radius: 6px; font-family: var(--mono); }
.fakeform button { margin-top: 14px; }
.fakeform .result { margin-top: 12px; font-size: 13px; padding: 10px; border-radius: 6px; }
.fakeform .result.ok { background: var(--green-bg); color: var(--green); }
.fakeform .result.no { background: var(--red-bg); color: var(--red); }

/* login */
.login-wrap { display: flex; align-items: center; justify-content: center; min-height: 100vh; width: 100%; padding: 20px; }
.login-card { background: var(--panel); border: 1px solid var(--border); border-radius: 14px; padding: 34px; width: 100%; max-width: 380px; box-shadow: var(--shadow); }
.login-card .brand { font-size: 24px; font-weight: 800; text-align: center; margin-bottom: 4px; }
.login-card .brand .dot { color: var(--accent); }
.login-card .tagline { text-align: center; color: var(--text-dim); font-size: 13px; margin-bottom: 24px; }
.login-card label { display: block; font-size: 12px; color: var(--text-dim); margin: 12px 0 5px; }
.login-card input { width: 100%; background: #0c0e12; border: 1px solid var(--border); color: var(--text); padding: 11px 13px; border-radius: 8px; font-size: 14px; }
.login-card input:focus { outline: none; border-color: var(--accent); }
.login-card .err { color: var(--red); font-size: 13px; margin-top: 12px; min-height: 18px; }
.login-card .keep { display: flex; align-items: center; gap: 8px; font-size: 13px; color: var(--text-dim); margin-top: 14px; }

/* glossary / lists */
.searchbar { width: 100%; background: var(--panel); border: 1px solid var(--border); color: var(--text); padding: 11px 14px; border-radius: 9px; font-size: 14px; margin-bottom: 18px; }
.searchbar:focus { outline: none; border-color: var(--accent); }
.gloss-item { border-bottom: 1px solid var(--border-soft); padding: 14px 0; }
.gloss-item .term { font-weight: 700; font-size: 15px; }
.gloss-item .cat { font-size: 11px; color: var(--accent-2); text-transform: uppercase; letter-spacing: .06em; margin-left: 8px; }
.gloss-item .def { color: var(--text-dim); margin-top: 4px; font-size: 14px; }
.gloss-item .rel { margin-top: 6px; font-size: 12px; color: var(--text-faint); }

.badges-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(150px,1fr)); gap: 12px; }
.badge-item { background: var(--panel); border: 1px solid var(--border); border-radius: 10px; padding: 16px; text-align: center; }
.badge-item.locked { opacity: .38; filter: grayscale(1); }
.badge-item .bi { font-size: 30px; }
.badge-item .bn { font-weight: 700; font-size: 13.5px; margin-top: 6px; }
.badge-item .bd { color: var(--text-faint); font-size: 11.5px; margin-top: 3px; }

/* toast */
.toast-wrap { position: fixed; bottom: 22px; left: 50%; transform: translateX(-50%); z-index: 100; display: flex; flex-direction: column; gap: 8px; align-items: center; }
.toast { background: #06210f; color: var(--green); border: 1px solid #1f5136; border-radius: 10px; padding: 12px 18px; font-weight: 600; box-shadow: var(--shadow); animation: rise .3s; }
.toast.points { background: #221708; color: var(--accent-2); border-color: #6a4111; }
.toast.badge { background: #1a1526; color: var(--purple); border-color: #3d2c66; }
@keyframes rise { from { transform: translateY(14px); opacity: 0; } }

/* tabs */
.tabs { display: flex; gap: 4px; border-bottom: 1px solid var(--border); margin-bottom: 20px; flex-wrap: wrap; }
.tab { padding: 9px 16px; background: transparent; border: none; color: var(--text-dim); font-size: 14px; font-weight: 600; border-bottom: 2px solid transparent; }
.tab:hover { color: var(--text); }
.tab.active { color: var(--accent-2); border-bottom-color: var(--accent); }

.qa-item { background: var(--panel); border: 1px solid var(--border); border-radius: 10px; margin: 10px 0; overflow: hidden; }
.qa-q { padding: 14px 16px; font-weight: 600; cursor: pointer; display: flex; justify-content: space-between; gap: 12px; }
.qa-q:hover { background: var(--panel-2); }
.qa-a { padding: 0 16px; max-height: 0; overflow: hidden; color: var(--text-dim); transition: max-height .2s, padding .2s; }
.qa-item.open .qa-a { padding: 0 16px 16px; max-height: 800px; }

.roadmap-step { background: var(--panel); border: 1px solid var(--border); border-left: 3px solid var(--accent); border-radius: 10px; padding: 16px 18px; margin: 12px 0; }
.cert-table td .pill { font-size: 11px; }

/* drawer backdrop */
.backdrop { position: fixed; inset: 0; background: rgba(0,0,0,.4); z-index: 55; opacity: 0; pointer-events: none; transition: opacity .2s; }
.backdrop.show { opacity: 1; pointer-events: auto; }

/* mobile */
.mobile-tree-toggle { display: none; }
@media (max-width: 900px) {
  :root { --tree-w: 280px; }
  .page { padding: 20px 16px 60px; }
  .ws-main-inner { padding: 20px 18px 80px; }
  .ws-tree { position: fixed; left: var(--nav-w); top: 46px; bottom: 0; z-index: 25; transform: translateX(-120%); transition: transform .2s; }
  .ws-tree.mobile-open { transform: translateX(0); }
  .mobile-tree-toggle { display: inline-flex; }
}
@media (max-width: 560px) {
  :root { --nav-w: 48px; }
  .gnav-btn { font-size: 17px; width: 36px; height: 36px; }
  .ws-tree { left: 0; width: 86vw; }
  .drawer { width: 100vw; }
  .page h1 { font-size: 22px; }
}

/* light theme opt-in (Settings) */
body.light {
  --bg: #f4f5f7; --bg-2: #eceef1; --panel: #ffffff; --panel-2: #f1f3f6; --panel-3: #e6e9ee;
  --border: #d6dae0; --border-soft: #e5e8ec; --text: #1a1e26; --text-dim: #56606e; --text-faint: #8a93a1;
}
body.light .gnav, body.light .ws-topbar, body.light .ws-rail { background: #1a1e26; }
body.light .codeblock.terminal, body.light .term-sim { background: #0a0c10; }