:root {
  --bg: #f6f7f9; --surface: #ffffff; --surface-2: #eef1f5; --border: #d9dee6; --text: #141a22; --muted: #5b6673;
  --accent: #2563eb; --accent-ink: #ffffff; --ok: #059669; --warn: #d97706; --err: #dc2626;
  --mono: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
  --sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Inter, Roboto, Helvetica, Arial, sans-serif;
  --radius: 10px; --shadow: 0 1px 2px rgba(20, 26, 34, 0.06), 0 4px 16px rgba(20, 26, 34, 0.04);
}
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --bg: #0f1318; --surface: #171c23; --surface-2: #1f262f; --border: #2b343f; --text: #e6eaf0; --muted: #96a1ae;
    --accent: #5b8cff; --accent-ink: #0b1220; --shadow: 0 1px 2px rgba(0,0,0,0.4);
  }
}
* { box-sizing: border-box; }
html { font-size: 15px; }
body { margin: 0; background: var(--bg); color: var(--text); font-family: var(--sans); line-height: 1.5; -webkit-font-smoothing: antialiased; }
a { color: var(--accent); text-decoration: none; }
a:hover { text-decoration: underline; }
h1, h2, h3, h4 { margin: 0 0 0.4em; line-height: 1.25; letter-spacing: -0.01em; }
h1 { font-size: 1.7rem; } h2 { font-size: 1.3rem; } h3 { font-size: 1.05rem; } h4 { font-size: 0.95rem; color: var(--muted); font-weight: 600; }
p { margin: 0 0 0.8em; }
.muted { color: var(--muted); }
.small { font-size: 0.85rem; }
.skip { position: absolute; left: -999px; top: 8px; background: var(--accent); color: var(--accent-ink); padding: 8px 12px; border-radius: 6px; z-index: 50; }
.skip:focus { left: 8px; }

.topbar { display: flex; align-items: center; gap: 24px; padding: 0 20px; height: 54px; background: var(--surface); border-bottom: 1px solid var(--border); position: sticky; top: 0; z-index: 20; }
.brand { font-weight: 700; font-size: 1.05rem; color: var(--text); letter-spacing: -0.01em; }
.nav { display: flex; gap: 4px; }
.nav a { padding: 6px 10px; border-radius: 6px; color: var(--muted); font-weight: 500; }
.nav a.active, .nav a:hover { color: var(--text); background: var(--surface-2); text-decoration: none; }
.topbar-right { margin-left: auto; font-size: 0.82rem; color: var(--muted); display: flex; gap: 10px; align-items: center; }
.main { max-width: 1120px; margin: 0 auto; padding: 24px 16px 60px; }
.foot { max-width: 1120px; margin: 0 auto; padding: 16px; color: var(--muted); font-size: 0.8rem; border-top: 1px solid var(--border); }

.page-head { display: flex; align-items: flex-start; gap: 16px; margin-bottom: 20px; flex-wrap: wrap; }
.page-head .grow { flex: 1; min-width: 240px; }
.page-head p { color: var(--muted); margin: 0; }
.crumb { display: inline-flex; align-items: center; gap: 6px; color: var(--muted); font-size: 0.85rem; margin-bottom: 6px; }

.card { background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius); box-shadow: var(--shadow); margin-bottom: 16px; }
.card-head { display: flex; align-items: center; gap: 12px; padding: 12px 16px; border-bottom: 1px solid var(--border); }
.card-head h3 { margin: 0; flex: 1; }
.card-body { padding: 16px; }
.grid { display: grid; gap: 16px; }
.grid-2 { grid-template-columns: repeat(auto-fit, minmax(min(100%, 420px), 1fr)); }
.grid-3 { grid-template-columns: repeat(auto-fit, minmax(min(100%, 240px), 1fr)); }
.row { display: flex; gap: 10px; flex-wrap: wrap; align-items: center; }
.stack > * + * { margin-top: 12px; }

.btn { display: inline-flex; align-items: center; gap: 7px; padding: 8px 14px; border-radius: 8px; border: 1px solid var(--border); background: var(--surface); color: var(--text); font: inherit; font-weight: 500; cursor: pointer; transition: background 0.12s, border-color 0.12s; }
.btn:hover { background: var(--surface-2); }
.btn:focus-visible, a:focus-visible, select:focus-visible, input:focus-visible, .tab:focus-visible, summary:focus-visible { outline: 2px solid var(--accent); outline-offset: 2px; }
.btn.primary { background: var(--accent); color: var(--accent-ink); border-color: transparent; }
.btn.primary:hover { filter: brightness(1.08); }
.btn.ghost { border-color: transparent; background: transparent; color: var(--muted); }
.btn.ghost:hover { background: var(--surface-2); color: var(--text); }
.btn.danger { color: var(--err); }
.btn.small { padding: 4px 9px; font-size: 0.82rem; }
.btn:disabled { opacity: 0.5; cursor: not-allowed; }
.icon { flex-shrink: 0; }

.notice { display: flex; gap: 10px; padding: 10px 12px; border-radius: 8px; border: 1px solid var(--border); background: var(--surface-2); margin-bottom: 10px; font-size: 0.92rem; }
.notice .icon { margin-top: 3px; }
.notice-warn { border-color: color-mix(in srgb, var(--warn) 50%, var(--border)); color: var(--text); }
.notice-warn .icon { color: var(--warn); }
.notice-error { border-color: color-mix(in srgb, var(--err) 50%, var(--border)); }
.notice-error .icon { color: var(--err); }
.notice-ok .icon { color: var(--ok); }
.notice-info .icon { color: var(--accent); }

.code-wrap { margin: 6px 0 10px; border: 1px solid var(--border); border-radius: 8px; overflow: hidden; }
.code-bar { display: flex; align-items: center; justify-content: space-between; padding: 2px 6px 2px 12px; background: var(--surface-2); border-bottom: 1px solid var(--border); }
.code-lang { font-size: 0.72rem; text-transform: uppercase; letter-spacing: 0.05em; color: var(--muted); }
.code { margin: 0; background: var(--surface-2); padding: 10px 12px; font-family: var(--mono); font-size: 0.8rem; overflow-x: auto; white-space: pre; }

.table-scroll { overflow-x: auto; }
.table { width: 100%; border-collapse: collapse; font-size: 0.88rem; }
.table th, .table td { text-align: left; padding: 7px 10px; border-bottom: 1px solid var(--border); white-space: nowrap; }
.table th { color: var(--muted); font-weight: 600; font-size: 0.78rem; text-transform: uppercase; letter-spacing: 0.03em; }
.table .num { text-align: right; font-variant-numeric: tabular-nums; }
.table tr.clickable { cursor: pointer; }
.table tr.clickable:hover { background: var(--surface-2); }
.table.compact th, .table.compact td { padding: 4px 8px; font-size: 0.82rem; }

.tiles { display: grid; grid-template-columns: repeat(auto-fill, minmax(130px, 1fr)); gap: 10px; }
.tile { border: 1px solid var(--border); border-radius: 8px; padding: 10px 12px; background: var(--surface); }
.tile.primary { border-color: var(--accent); }
.tile-label { font-size: 0.75rem; text-transform: uppercase; letter-spacing: 0.04em; color: var(--muted); }
.tile-value { font-size: 1.3rem; font-weight: 600; font-variant-numeric: tabular-nums; }

.narration { list-style: none; padding: 0; margin: 0; counter-reset: step; }
.narration li { position: relative; padding: 10px 0 10px 40px; border-left: 2px solid var(--border); margin-left: 12px; }
.narration li::before { counter-increment: step; content: counter(step); position: absolute; left: -13px; top: 10px; width: 24px; height: 24px; border-radius: 50%; background: var(--accent); color: var(--accent-ink); font-size: 0.75rem; font-weight: 700; display: grid; place-items: center; }
.narr-step { font-weight: 600; font-size: 0.85rem; color: var(--muted); text-transform: uppercase; letter-spacing: 0.03em; }
.narration p { margin: 2px 0 6px; }

.field { display: flex; flex-direction: column; gap: 4px; font-size: 0.9rem; }
.field-label { font-weight: 600; font-size: 0.82rem; color: var(--muted); }
.field-help { font-size: 0.78rem; color: var(--muted); }
select, input[type=text], input[type=number], input[type=password], textarea { font: inherit; padding: 7px 10px; border: 1px solid var(--border); border-radius: 8px; background: var(--surface); color: var(--text); min-width: 0; }
textarea { font-family: var(--mono); font-size: 0.82rem; }
input[type=checkbox] { width: 16px; height: 16px; accent-color: var(--accent); }
.check { display: flex; align-items: center; gap: 8px; font-size: 0.9rem; cursor: pointer; }
.chips { display: flex; flex-wrap: wrap; gap: 6px; }
.chip { display: inline-flex; align-items: center; gap: 6px; padding: 4px 10px; border: 1px solid var(--border); border-radius: 999px; font-size: 0.82rem; cursor: pointer; background: var(--surface); user-select: none; }
.chip.on { border-color: var(--accent); background: var(--accent); color: var(--accent-ink); font-weight: 600; }
.chip input { position: absolute; opacity: 0; pointer-events: none; }
.badge { display: inline-block; padding: 1px 8px; border-radius: 999px; font-size: 0.74rem; font-weight: 600; background: var(--surface-2); color: var(--muted); border: 1px solid var(--border); }
.badge.ok { color: var(--ok); } .badge.err { color: var(--err); } .badge.warn { color: var(--warn); } .badge.accent { color: var(--accent); }

.spinner-row { display: flex; align-items: center; gap: 10px; color: var(--muted); }
.spinner-row .icon { animation: spin 0.9s linear infinite; }
@keyframes spin { to { transform: rotate(360deg); } }
@media (prefers-reduced-motion: reduce) { .spinner-row .icon { animation: none; } }
.progress { position: relative; height: 26px; background: var(--surface-2); border-radius: 8px; overflow: hidden; border: 1px solid var(--border); }
.progress-bar { height: 100%; background: var(--accent); transition: width 0.4s; }
.progress-label { position: absolute; inset: 0; display: flex; align-items: center; padding: 0 10px; font-size: 0.82rem; mix-blend-mode: difference; color: #fff; }

details { border: 1px solid var(--border); border-radius: 8px; padding: 0 12px; margin-bottom: 10px; background: var(--surface); }
summary { cursor: pointer; padding: 10px 0; font-weight: 600; font-size: 0.92rem; }
.details-body { padding: 4px 0 12px; }

.tabs { display: flex; gap: 2px; border-bottom: 1px solid var(--border); margin-bottom: 14px; overflow-x: auto; }
.tab { padding: 8px 14px; border: none; border-bottom: 2px solid transparent; background: none; color: var(--muted); font: inherit; font-weight: 500; cursor: pointer; white-space: nowrap; }
.tab.active { color: var(--text); border-bottom-color: var(--accent); }

.chart { width: 100%; max-width: 680px; height: auto; display: block; font-family: var(--sans); }
.chart-mini { max-width: none; }
.chart-mini .tick { font-size: 9px; }
.chart .grid { stroke: var(--border); stroke-width: 1; }
.chart .tick { font-size: 13px; fill: var(--muted); }
.chart .axis-label { font-size: 13px; fill: var(--muted); font-weight: 600; }
.chart .bar-label { font-size: 12px; fill: var(--text); }
.chart .bar-value { font-size: 11px; fill: var(--muted); font-variant-numeric: tabular-nums; }
.chart .errbar { stroke: var(--text); stroke-width: 1.5; opacity: 0.6; }
.chart .diag { stroke: var(--muted); stroke-dasharray: 4 4; stroke-width: 1; }
.chart .cell { font-size: 13px; fill: var(--text); }
.chart .cell-light { font-size: 13px; fill: #fff; font-weight: 600; }
.chart-wrap { max-width: 640px; }
.chart-note { font-size: 0.82rem; color: var(--muted); margin-top: 4px; }

.drop { display: flex; flex-direction: column; align-items: center; gap: 6px; border: 2px dashed var(--border); border-radius: var(--radius); padding: 28px; text-align: center; color: var(--muted); transition: border-color 0.12s, background 0.12s; cursor: pointer; }
.drop.over, .drop:hover { border-color: var(--accent); background: color-mix(in srgb, var(--accent) 6%, var(--surface)); }
.drop input { display: none; }
.sample-list { display: grid; gap: 8px; grid-template-columns: repeat(auto-fill, minmax(260px, 1fr)); }
.sample { border: 1px solid var(--border); border-radius: 8px; padding: 10px 12px; background: var(--surface); display: flex; flex-direction: column; gap: 4px; }
.sample strong { font-size: 0.95rem; }
.sample p { font-size: 0.82rem; color: var(--muted); margin: 0; }
.sample .row { margin-top: 4px; }
.sample .badge { align-self: flex-start; }

.launch { display: grid; gap: 12px; grid-template-columns: repeat(auto-fit, minmax(220px, 1fr)); }
.launch a { display: block; padding: 14px; border: 1px solid var(--border); border-radius: 8px; color: var(--text); background: var(--surface); }
.launch a:hover { border-color: var(--accent); text-decoration: none; }
.launch strong { display: flex; align-items: center; gap: 8px; margin-bottom: 4px; }
.launch span { font-size: 0.84rem; color: var(--muted); }

.col-card { border: 1px solid var(--border); border-radius: 8px; padding: 10px 12px; background: var(--surface); }
.col-card .row { justify-content: space-between; }
.col-card .stat { font-size: 0.8rem; color: var(--muted); display: flex; gap: 10px; flex-wrap: wrap; }

.leader-row td:first-child { font-weight: 600; }
.winner { color: var(--ok); font-weight: 600; }
.diag-good { color: var(--ok); } .diag-bad { color: var(--err); } .diag-mid { color: var(--warn); }

.glossary dt { font-weight: 600; margin-top: 10px; }
.glossary dd { margin: 2px 0 0; color: var(--muted); }
.lesson-step { display: flex; gap: 12px; align-items: flex-start; padding: 10px 0; border-top: 1px solid var(--border); }
.lesson-step .n { width: 26px; height: 26px; border-radius: 50%; background: var(--surface-2); display: grid; place-items: center; font-size: 0.8rem; font-weight: 700; flex-shrink: 0; }
.lesson-step .grow { flex: 1; }

#toasts { position: fixed; bottom: 16px; right: 16px; display: flex; flex-direction: column; gap: 8px; z-index: 100; }
.toast { background: var(--text); color: var(--bg); padding: 10px 14px; border-radius: 8px; font-size: 0.88rem; box-shadow: var(--shadow); max-width: 360px; }
.toast-error { background: var(--err); color: #fff; }

.empty { padding: 32px; text-align: center; color: var(--muted); }
@media (max-width: 640px) {
  .topbar { gap: 12px; padding: 0 12px; }
  .topbar-right { display: none; }
  .main { padding: 16px 12px 40px; }
  .card-body { padding: 12px; }
  html { font-size: 14px; }
}

.step .step-n { width: 28px; height: 28px; border-radius: 50%; background: var(--accent); color: var(--accent-ink); display: grid; place-items: center; font-weight: 700; font-size: 0.85rem; flex-shrink: 0; }
.step.done .step-n { background: var(--ok); }
.step.locked { opacity: 0.55; }
.step.locked .step-n { background: var(--border); color: var(--muted); }
.choices { display: grid; gap: 10px; grid-template-columns: repeat(auto-fit, minmax(210px, 1fr)); }
.choice { text-align: left; padding: 14px; border: 1px solid var(--border); border-radius: 10px; background: var(--surface); color: var(--text); font: inherit; cursor: pointer; display: flex; flex-direction: column; gap: 4px; }
.choice:hover { border-color: var(--accent); }
.choice.on { border-color: var(--accent); background: color-mix(in srgb, var(--accent) 10%, var(--surface)); }
.choice strong { display: flex; align-items: center; gap: 8px; }
.choice span { font-size: 0.84rem; color: var(--muted); }
.plain { font-size: 1.02rem; }
.result-head { display: flex; align-items: center; gap: 10px; flex-wrap: wrap; margin-bottom: 8px; }
.big-answer { font-size: 1.15rem; font-weight: 600; margin: 4px 0 10px; }

.hbars { display: flex; flex-direction: column; gap: 6px; }
.hbar-row { display: grid; grid-template-columns: minmax(110px, 40%) 1fr 64px; align-items: center; gap: 10px; font-size: 0.86rem; }
.hbar-label { text-align: right; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
.hbar-track { position: relative; height: 18px; background: var(--surface-2); border-radius: 4px; overflow: hidden; }
.hbar { position: absolute; top: 0; bottom: 0; background: var(--accent); border-radius: 4px; opacity: 0.9; }
.hbar-err { position: absolute; top: 7px; height: 4px; background: var(--text); opacity: 0.5; border-radius: 2px; }
.hbar-value { font-variant-numeric: tabular-nums; font-size: 0.82rem; }
@media (max-width: 640px) { .hbar-row { grid-template-columns: minmax(70px, 38%) 1fr 56px; font-size: 0.78rem; } }

.btn.big { padding: 12px 22px; font-size: 1.05rem; }
.verdict { margin: 0 0 12px; padding-left: 20px; }
.verdict li { margin-bottom: 4px; }