:root {
  --bg: #f6f7fb;
  --surface: #ffffff;
  --surface-2: #f0f2f8;
  --border: #e2e5ef;
  --text: #1b2033;
  --muted: #646b84;
  --primary: #3776ab;
  --primary-strong: #285a85;
  --primary-soft: #e6eff8;
  --accent: #ffd43b;
  --accent-soft: #fff6d6;
  --ok: #1f9d55;
  --ok-soft: #e3f6ea;
  --warn: #c27c0e;
  --warn-soft: #fdf1dc;
  --err: #d23f3f;
  --err-soft: #fde8e8;
  --tip: #6b5bd2;
  --tip-soft: #eeebfc;
  --locked: #a5abbd;
  --shadow: 0 1px 2px rgba(20, 30, 60, .06), 0 4px 16px rgba(20, 30, 60, .06);
  --radius: 14px;
  --code-bg: #f7f8fc;
  --mono: 'JetBrains Mono', ui-monospace, Menlo, Consolas, monospace;
  color-scheme: light;
}
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --bg: #0f1320; --surface: #171c2c; --surface-2: #1e2438; --border: #2a3149; --text: #e7eaf4; --muted: #9aa2bd;
    --primary: #5aa0dc; --primary-strong: #82b8e6; --primary-soft: #1d2d45; --accent: #ffd43b; --accent-soft: #3a3313;
    --ok: #3ccf7f; --ok-soft: #15301f; --warn: #f0b04a; --warn-soft: #382a12; --err: #ff6b6b; --err-soft: #3a1b1d;
    --tip: #a598ff; --tip-soft: #25213f; --locked: #4b536d; --shadow: 0 1px 2px rgba(0,0,0,.3), 0 6px 20px rgba(0,0,0,.25);
    --code-bg: #12172a; color-scheme: dark;
  }
}
:root[data-theme="dark"] {
  --bg: #0f1320; --surface: #171c2c; --surface-2: #1e2438; --border: #2a3149; --text: #e7eaf4; --muted: #9aa2bd;
  --primary: #5aa0dc; --primary-strong: #82b8e6; --primary-soft: #1d2d45; --accent: #ffd43b; --accent-soft: #3a3313;
  --ok: #3ccf7f; --ok-soft: #15301f; --warn: #f0b04a; --warn-soft: #382a12; --err: #ff6b6b; --err-soft: #3a1b1d;
  --tip: #a598ff; --tip-soft: #25213f; --locked: #4b536d; --shadow: 0 1px 2px rgba(0,0,0,.3), 0 6px 20px rgba(0,0,0,.25);
  --code-bg: #12172a; color-scheme: dark;
}

* { box-sizing: border-box; }
html, body { margin: 0; padding: 0; }
body { background: var(--bg); color: var(--text); font: 15px/1.6 Inter, system-ui, -apple-system, Segoe UI, sans-serif; -webkit-font-smoothing: antialiased; }
a { color: var(--primary); text-decoration: none; }
a:hover { text-decoration: underline; }
h1, h2, h3, h4 { line-height: 1.25; margin: 0 0 .5em; }
h1 { font-size: 1.75rem; font-weight: 800; letter-spacing: -.02em; }
h2 { font-size: 1.3rem; font-weight: 700; }
h3 { font-size: 1.08rem; font-weight: 700; }
code, pre, kbd { font-family: var(--mono); font-size: .88em; }
:not(pre) > code { background: var(--surface-2); padding: .1em .35em; border-radius: 5px; }
.muted { color: var(--muted); }
.small { font-size: .85rem; }
.hidden { display: none !important; }
.row { display: flex; gap: 12px; align-items: center; flex-wrap: wrap; }
.grow { flex: 1; }
.stack > * + * { margin-top: 12px; }

/* layout */
.topbar { position: sticky; top: 0; z-index: 30; background: color-mix(in srgb, var(--surface) 92%, transparent); backdrop-filter: blur(10px); border-bottom: 1px solid var(--border); }
.topbar-inner { max-width: 1400px; margin: 0 auto; padding: 10px 20px; display: flex; align-items: center; gap: 18px; }
.brand { display: flex; align-items: center; gap: 10px; font-weight: 800; color: var(--text); font-size: 1.05rem; }
.brand:hover { text-decoration: none; }
.logo { width: 30px; height: 30px; border-radius: 9px; background: var(--primary); display: grid; place-items: center; color: var(--accent); font-weight: 900; font-size: 15px; }
.nav { display: flex; gap: 4px; flex: 1; flex-wrap: wrap; }
.nav a { color: var(--muted); padding: 6px 12px; border-radius: 9px; font-weight: 600; font-size: .92rem; }
.nav a:hover { background: var(--surface-2); color: var(--text); text-decoration: none; }
.nav a.active { background: var(--primary-soft); color: var(--primary); }
.user-chip { display: flex; align-items: center; gap: 8px; font-size: .9rem; color: var(--muted); }
.avatar { width: 30px; height: 30px; border-radius: 50%; background: var(--accent); color: #3b2f00; display: grid; place-items: center; font-weight: 800; font-size: .85rem; }
.page { max-width: 1180px; margin: 0 auto; padding: 28px 20px 80px; }
.page.wide { max-width: 1500px; }
.page.full { max-width: none; padding: 0; }
.crumbs { font-size: .88rem; color: var(--muted); margin-bottom: 10px; }
.crumbs a { color: var(--muted); }

/* cards and controls */
.card { background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius); padding: 20px; box-shadow: var(--shadow); }
.card.flat { box-shadow: none; }
.grid { display: grid; gap: 16px; }
.grid.cols-2 { grid-template-columns: repeat(auto-fit, minmax(320px, 1fr)); }
.grid.cols-3 { grid-template-columns: repeat(auto-fit, minmax(240px, 1fr)); }
.grid.cols-4 { grid-template-columns: repeat(auto-fit, minmax(180px, 1fr)); }
.btn { display: inline-flex; align-items: center; gap: 7px; border: 1px solid var(--border); background: var(--surface); color: var(--text); padding: 8px 14px; border-radius: 10px; font: 600 .9rem Inter, sans-serif; cursor: pointer; transition: background .15s, border-color .15s, transform .05s; white-space: nowrap; }
.btn:hover { background: var(--surface-2); text-decoration: none; }
.btn:active { transform: translateY(1px); }
.btn:disabled { opacity: .5; cursor: not-allowed; }
.btn.primary { background: var(--primary); border-color: var(--primary); color: #fff; }
.btn.primary:hover { background: var(--primary-strong); }
.btn.ok { background: var(--ok); border-color: var(--ok); color: #fff; }
.btn.danger { color: var(--err); }
.btn.danger:hover { background: var(--err-soft); }
.btn.accent { background: var(--accent); border-color: var(--accent); color: #3b2f00; }
.btn.ghost { border-color: transparent; background: transparent; }
.btn.sm { padding: 5px 10px; font-size: .82rem; border-radius: 8px; }
.btn .kbd { font-size: .72rem; opacity: .7; font-weight: 500; }
input, select, textarea { font: inherit; color: var(--text); background: var(--surface); border: 1px solid var(--border); border-radius: 10px; padding: 9px 12px; width: 100%; }
input:focus, select:focus, textarea:focus { outline: 2px solid var(--primary-soft); border-color: var(--primary); }
textarea { font-family: var(--mono); font-size: .85rem; }
label { font-weight: 600; font-size: .88rem; display: block; margin-bottom: 5px; }
.field { margin-bottom: 14px; }
.checkbox { display: flex; gap: 8px; align-items: center; font-weight: 500; }
.checkbox input { width: auto; }
.chip { display: inline-flex; align-items: center; gap: 5px; padding: 2px 9px; border-radius: 999px; font-size: .76rem; font-weight: 700; background: var(--surface-2); color: var(--muted); white-space: nowrap; }
.chip.ok { background: var(--ok-soft); color: var(--ok); }
.chip.warn { background: var(--warn-soft); color: var(--warn); }
.chip.err { background: var(--err-soft); color: var(--err); }
.chip.primary { background: var(--primary-soft); color: var(--primary); }
.chip.tip { background: var(--tip-soft); color: var(--tip); }
.chip.accent { background: var(--accent-soft); color: #8a6d00; }
:root[data-theme="dark"] .chip.accent { color: var(--accent); }
.bar { height: 8px; border-radius: 99px; background: var(--surface-2); overflow: hidden; }
.bar > span { display: block; height: 100%; background: linear-gradient(90deg, var(--primary), #4fa3e0); border-radius: 99px; transition: width .4s; }
.bar.ok > span { background: var(--ok); }
table { width: 100%; border-collapse: collapse; }
th, td { text-align: left; padding: 9px 10px; border-bottom: 1px solid var(--border); font-size: .9rem; vertical-align: middle; }
th { color: var(--muted); font-weight: 600; font-size: .8rem; text-transform: uppercase; letter-spacing: .04em; }
.table-wrap { overflow-x: auto; }
.empty { text-align: center; padding: 40px 20px; color: var(--muted); }

/* auth */
.auth-wrap { min-height: 100vh; display: grid; place-items: center; padding: 20px; background: radial-gradient(1200px 600px at 10% -10%, var(--primary-soft), transparent), radial-gradient(900px 500px at 110% 110%, var(--accent-soft), transparent), var(--bg); }
.auth-card { width: 100%; max-width: 420px; }
.auth-card .logo { width: 48px; height: 48px; font-size: 22px; border-radius: 14px; margin-bottom: 14px; }

/* hero / stats */
.hero { display: flex; gap: 28px; align-items: center; flex-wrap: wrap; margin-bottom: 28px; }
.ring { --size: 120px; width: var(--size); height: var(--size); position: relative; flex: none; }
.ring svg { transform: rotate(-90deg); }
.ring .ring-label { position: absolute; inset: 0; display: grid; place-items: center; text-align: center; font-weight: 800; font-size: 1.5rem; line-height: 1.1; }
.ring .ring-label small { display: block; font-size: .7rem; color: var(--muted); font-weight: 600; }
.stat { background: var(--surface); border: 1px solid var(--border); border-radius: 12px; padding: 14px 16px; }
.stat b { display: block; font-size: 1.5rem; font-weight: 800; }
.stat span { color: var(--muted); font-size: .85rem; }

/* roadmap */
.module { margin: 34px 0 10px; }
.module-head { display: flex; align-items: baseline; gap: 12px; margin-bottom: 8px; }
.module-head h2 { margin: 0; }
.path { position: relative; padding: 8px 0 8px 0; }
.path::before { content: ''; position: absolute; left: 33px; top: 0; bottom: 0; width: 4px; border-radius: 4px; background: var(--border); }
.node { position: relative; display: flex; gap: 18px; align-items: center; padding: 10px 0; color: inherit; }
.node:hover { text-decoration: none; }
.node .dot { width: 70px; height: 70px; flex: none; position: relative; display: grid; place-items: center; z-index: 1; }
.node .dot .num { position: absolute; inset: 9px; border-radius: 50%; display: grid; place-items: center; font-weight: 800; background: var(--surface); border: 2px solid var(--border); font-size: 1.05rem; }
.node.done .dot .num { background: var(--ok); color: #fff; border-color: var(--ok); }
.node.active .dot .num { background: var(--primary); color: #fff; border-color: var(--primary); }
.node.locked .dot .num { color: var(--locked); background: var(--surface-2); }
.node .info { flex: 1; background: var(--surface); border: 1px solid var(--border); border-radius: 12px; padding: 12px 16px; transition: border-color .15s, transform .15s; }
.node:not(.locked):hover .info { border-color: var(--primary); transform: translateX(3px); }
.node.locked .info { background: transparent; border-style: dashed; }
.node .title { font-weight: 700; }
.node.locked .title { color: var(--muted); }
.node .meta { display: flex; gap: 8px; flex-wrap: wrap; margin-top: 4px; }
.node.next-up .info { box-shadow: 0 0 0 3px var(--accent); border-color: var(--accent); }

/* session page */
.session-head { margin-bottom: 22px; }
.item-list { display: grid; gap: 10px; }
.item { display: flex; gap: 14px; align-items: center; padding: 14px 16px; background: var(--surface); border: 1px solid var(--border); border-radius: 12px; color: inherit; }
.item:hover { border-color: var(--primary); text-decoration: none; }
.item .icon { width: 36px; height: 36px; border-radius: 10px; display: grid; place-items: center; background: var(--primary-soft); color: var(--primary); flex: none; font-weight: 800; }
.item.done .icon { background: var(--ok-soft); color: var(--ok); }
.item .grow .t { font-weight: 650; }
.callout { border-radius: 12px; padding: 14px 16px; background: var(--accent-soft); border: 1px solid color-mix(in srgb, var(--accent) 50%, transparent); }
.callout.info { background: var(--primary-soft); border-color: color-mix(in srgb, var(--primary) 30%, transparent); }

/* article */
.article { max-width: 760px; margin: 0 auto; }
.prose { font-size: 1.02rem; }
.prose h3 { margin-top: 1.6em; }
.prose p, .prose ul, .prose ol, .prose table { margin: 0 0 1em; }
.prose table { border: 1px solid var(--border); border-radius: 10px; overflow: hidden; display: block; overflow-x: auto; }
.prose td, .prose th { border-bottom: 1px solid var(--border); }
.prose blockquote { margin: 0 0 1em; padding: 10px 16px; border-left: 4px solid var(--accent); background: var(--accent-soft); border-radius: 0 10px 10px 0; }
.prose details { background: var(--surface-2); border-radius: 10px; padding: 10px 14px; margin-bottom: 1em; }
.prose summary { cursor: pointer; font-weight: 650; color: var(--primary); }
.codeblock { position: relative; margin: 0 0 1em; }
.codeblock pre { background: var(--code-bg); border: 1px solid var(--border); border-radius: 10px; padding: 14px 16px; overflow-x: auto; margin: 0; line-height: 1.55; }
.codeblock .try { position: absolute; top: 8px; right: 8px; opacity: .85; }

/* CodeMirror */
.CodeMirror { height: 100%; font-family: var(--mono); font-size: 14px; background: var(--code-bg); color: var(--text); line-height: 1.55; }
.CodeMirror-gutters { background: var(--surface-2); border-right: 1px solid var(--border); }
.CodeMirror-linenumber { color: var(--muted); cursor: pointer; padding: 0 6px 0 4px; }
.CodeMirror-cursor { border-left: 2px solid var(--primary); }
.CodeMirror-activeline-background { background: color-mix(in srgb, var(--primary) 6%, transparent); }
.CodeMirror-selected { background: color-mix(in srgb, var(--primary) 22%, transparent) !important; }
.CodeMirror-matchingbracket { color: var(--ok) !important; font-weight: 700; }
.cm-s-default .cm-keyword { color: #a626a4; font-weight: 600; }
.cm-s-default .cm-def { color: #2f6fd0; font-weight: 600; }
.cm-s-default .cm-builtin { color: #0184bc; }
.cm-s-default .cm-string { color: #3d8b2f; }
.cm-s-default .cm-number { color: #c46a12; }
.cm-s-default .cm-comment { color: #8b93a8; font-style: italic; }
.cm-s-default .cm-variable-2 { color: #b5432c; }
.cm-s-default .cm-operator { color: var(--text); }
.cm-s-default .cm-meta { color: #c46a12; }
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) .cm-s-default .cm-keyword { color: #d58cf0; }
  :root:not([data-theme="light"]) .cm-s-default .cm-def { color: #74b0ff; }
  :root:not([data-theme="light"]) .cm-s-default .cm-builtin { color: #5cc8e6; }
  :root:not([data-theme="light"]) .cm-s-default .cm-string { color: #98d379; }
  :root:not([data-theme="light"]) .cm-s-default .cm-number { color: #f2a65a; }
  :root:not([data-theme="light"]) .cm-s-default .cm-variable { color: var(--text); }
  :root:not([data-theme="light"]) .cm-s-default .cm-variable-2 { color: #ff9c85; }
}
:root[data-theme="dark"] .cm-s-default .cm-keyword { color: #d58cf0; }
:root[data-theme="dark"] .cm-s-default .cm-def { color: #74b0ff; }
:root[data-theme="dark"] .cm-s-default .cm-builtin { color: #5cc8e6; }
:root[data-theme="dark"] .cm-s-default .cm-string { color: #98d379; }
:root[data-theme="dark"] .cm-s-default .cm-number { color: #f2a65a; }
:root[data-theme="dark"] .cm-s-default .cm-variable { color: var(--text); }
:root[data-theme="dark"] .cm-s-default .cm-variable-2 { color: #ff9c85; }
.line-current { background: color-mix(in srgb, var(--accent) 35%, transparent) !important; }
.line-error { background: color-mix(in srgb, var(--err) 18%, transparent) !important; }
.bp-gutter { width: 14px; }
.bp-marker { color: var(--err); font-size: 14px; line-height: 1; padding-left: 2px; cursor: pointer; }

/* IDE */
.ide-page { display: grid; grid-template-columns: minmax(320px, 40%) 1fr; height: calc(100vh - 53px); }
.ide-side { overflow-y: auto; border-right: 1px solid var(--border); background: var(--surface); padding: 20px 22px 60px; }
.ide-main { display: grid; grid-template-rows: auto minmax(200px, 1fr) auto minmax(180px, 38%); min-width: 0; min-height: 0; }
.ide-toolbar { display: flex; gap: 8px; align-items: center; padding: 8px 12px; border-bottom: 1px solid var(--border); background: var(--surface); flex-wrap: wrap; }
.ide-editor { min-height: 0; overflow: hidden; }
.ide-tabs { display: flex; gap: 2px; padding: 0 10px; border-top: 1px solid var(--border); border-bottom: 1px solid var(--border); background: var(--surface); overflow-x: auto; }
.ide-tabs button { background: none; border: 0; padding: 9px 12px; font: 600 .85rem Inter, sans-serif; color: var(--muted); border-bottom: 2px solid transparent; cursor: pointer; white-space: nowrap; }
.ide-tabs button.active { color: var(--primary); border-bottom-color: var(--primary); }
.ide-panel { overflow: auto; background: var(--surface); padding: 12px 16px; min-height: 0; }
.ide-page.playground { grid-template-columns: 1fr; }
.status-dot { width: 8px; height: 8px; border-radius: 50%; background: var(--locked); display: inline-block; }
.status-dot.ready { background: var(--ok); }
.status-dot.busy, .status-dot.loading { background: var(--warn); animation: pulse 1s infinite; }
.status-dot.error { background: var(--err); }
@keyframes pulse { 50% { opacity: .35; } }
pre.out { margin: 0; white-space: pre-wrap; word-break: break-word; font-family: var(--mono); font-size: .86rem; }
.err-box { background: var(--err-soft); border: 1px solid color-mix(in srgb, var(--err) 30%, transparent); border-radius: 10px; padding: 10px 14px; margin-top: 10px; }
.err-box .t { color: var(--err); font-weight: 700; }
.test-row { display: flex; gap: 10px; align-items: flex-start; padding: 8px 0; border-bottom: 1px solid var(--border); font-size: .88rem; }
.test-row .mark { width: 22px; height: 22px; border-radius: 50%; display: grid; place-items: center; flex: none; font-size: .75rem; font-weight: 900; color: #fff; background: var(--err); }
.test-row.pass .mark { background: var(--ok); }
.test-row code { font-size: .8rem; }
.fb { border-radius: 12px; padding: 12px 14px; margin-bottom: 10px; border: 1px solid var(--border); background: var(--surface-2); }
.fb .t { font-weight: 700; display: flex; gap: 8px; align-items: center; }
.fb .d { margin-top: 4px; font-size: .9rem; white-space: pre-wrap; }
.fb.error { background: var(--err-soft); border-color: color-mix(in srgb, var(--err) 25%, transparent); }
.fb.error .t { color: var(--err); }
.fb.warn { background: var(--warn-soft); border-color: color-mix(in srgb, var(--warn) 25%, transparent); }
.fb.warn .t { color: var(--warn); }
.fb.tip { background: var(--tip-soft); border-color: color-mix(in srgb, var(--tip) 25%, transparent); }
.fb.tip .t { color: var(--tip); }
.fb.ok { background: var(--ok-soft); border-color: color-mix(in srgb, var(--ok) 30%, transparent); }
.fb.ok .t { color: var(--ok); }
.fb .jump { font-size: .8rem; }
.hint { border-left: 4px solid var(--tip); background: var(--tip-soft); border-radius: 0 10px 10px 0; padding: 10px 14px; margin-bottom: 8px; }
.hint .lvl { font-size: .75rem; font-weight: 800; color: var(--tip); text-transform: uppercase; letter-spacing: .05em; }
.tutor { border: 1px solid color-mix(in srgb, var(--primary) 30%, transparent); background: var(--primary-soft); border-radius: 12px; padding: 12px 14px; margin-top: 8px; }
.solved-banner { background: linear-gradient(135deg, var(--ok), #2bb673); color: #fff; border-radius: 12px; padding: 14px 16px; margin-bottom: 12px; }
.solved-banner b { font-size: 1.05rem; }
.side-section { margin-top: 22px; }
.side-section > h3 { display: flex; gap: 8px; align-items: center; }
.problem-nav { display: flex; gap: 6px; flex-wrap: wrap; margin-bottom: 14px; }

/* debugger */
.dbg-controls { display: flex; gap: 6px; align-items: center; flex-wrap: wrap; margin-bottom: 10px; }
.dbg-controls input[type=range] { flex: 1; min-width: 120px; padding: 0; }
.dbg-grid { display: grid; grid-template-columns: 1.3fr 1fr; gap: 14px; }
.dbg-box { border: 1px solid var(--border); border-radius: 10px; overflow: hidden; }
.dbg-box h4 { margin: 0; padding: 7px 10px; font-size: .78rem; text-transform: uppercase; letter-spacing: .04em; color: var(--muted); background: var(--surface-2); }
.dbg-box table td { font-family: var(--mono); font-size: .8rem; padding: 5px 10px; }
.dbg-box table td:first-child { color: var(--primary); font-weight: 600; width: 1%; white-space: nowrap; }
.dbg-box .changed td { background: var(--accent-soft); }
.dbg-box pre { margin: 0; padding: 8px 10px; max-height: 160px; overflow: auto; }
.stack-item { padding: 5px 10px; font-family: var(--mono); font-size: .8rem; border-bottom: 1px solid var(--border); }
.stack-item:last-child { background: var(--primary-soft); color: var(--primary); font-weight: 700; }

/* admin */
.tabs-bar { display: flex; gap: 4px; margin-bottom: 18px; flex-wrap: wrap; }
.matrix { border-collapse: separate; border-spacing: 3px; }
.matrix td, .matrix th { border: 0; padding: 0; }
.matrix th { font-size: .7rem; text-align: center; padding: 2px; }
.matrix td.name { padding-right: 10px; white-space: nowrap; font-weight: 600; font-size: .85rem; }
.cell { width: 22px; height: 22px; border-radius: 5px; background: var(--surface-2); display: block; }
.cell.rel { background: color-mix(in srgb, var(--primary) 12%, var(--surface-2)); }
.toggle { position: relative; width: 42px; height: 24px; flex: none; }
.toggle input { opacity: 0; width: 0; height: 0; }
.toggle span { position: absolute; inset: 0; border-radius: 99px; background: var(--border); cursor: pointer; transition: .2s; }
.toggle span::after { content: ''; position: absolute; left: 3px; top: 3px; width: 18px; height: 18px; border-radius: 50%; background: #fff; transition: .2s; box-shadow: 0 1px 2px rgba(0,0,0,.2); }
.toggle input:checked + span { background: var(--ok); }
.toggle input:checked + span::after { transform: translateX(18px); }
.modal-back { position: fixed; inset: 0; background: rgba(10, 14, 30, .5); display: grid; place-items: center; z-index: 100; padding: 20px; }
.modal { background: var(--surface); border-radius: 16px; width: 100%; max-width: 880px; max-height: 88vh; overflow: auto; padding: 22px; box-shadow: 0 20px 60px rgba(0,0,0,.3); }
.code-view { background: var(--code-bg); border: 1px solid var(--border); border-radius: 10px; padding: 12px; font-family: var(--mono); font-size: .82rem; white-space: pre; overflow-x: auto; }
.dropzone { border: 2px dashed var(--border); border-radius: 14px; padding: 28px; text-align: center; color: var(--muted); transition: .15s; }
.dropzone.over { border-color: var(--primary); background: var(--primary-soft); }

/* toasts */
#toasts { position: fixed; bottom: 18px; right: 18px; display: grid; gap: 8px; z-index: 200; }
.toast { background: var(--text); color: var(--bg); padding: 10px 16px; border-radius: 10px; font-weight: 600; font-size: .9rem; box-shadow: var(--shadow); animation: slidein .2s; max-width: 380px; }
.toast.err { background: var(--err); color: #fff; }
.toast.ok { background: var(--ok); color: #fff; }
@keyframes slidein { from { transform: translateY(10px); opacity: 0; } }
.boot { min-height: 100vh; display: grid; place-items: center; }
.spinner { width: 34px; height: 34px; border-radius: 50%; border: 3px solid var(--border); border-top-color: var(--primary); animation: spin .8s linear infinite; }
.spinner.sm { width: 16px; height: 16px; border-width: 2px; }
@keyframes spin { to { transform: rotate(360deg); } }
.confetti { position: fixed; inset: 0; pointer-events: none; z-index: 300; }

@media (max-width: 900px) {
  .ide-page { grid-template-columns: 1fr; height: auto; }
  .ide-side { border-right: 0; border-bottom: 1px solid var(--border); max-height: none; }
  .ide-main { grid-template-rows: auto 380px auto 320px; }
  .dbg-grid { grid-template-columns: 1fr; }
  .topbar-inner { padding: 8px 16px; gap: 10px; flex-wrap: wrap; }
  .nav { order: 3; width: 100%; }
  .page { padding: 20px 16px 60px; }
  .user-chip .uname { display: none; }
}