:root {
  --ink: #1c2433; --muted: #5d6779; --line: #e1e5ec; --paper: #f5f6f9; --card: #ffffff;
  --brand: #2b3f8f; --brand-ink: #ffffff; --focus: #1d6fe0;
  --red-bg: #ffc7ce; --red-fg: #9c0006; --red: #e5484d;
  --amb-bg: #ffeb9c; --amb-fg: #7a4a00; --amb: #f5a524;
  --grn-bg: #c6efce; --grn-fg: #0b5c2b; --grn: #30a46c;
  --none: #d5dae3;
  --radius: 14px;
  color-scheme: light dark;
}
@media (prefers-color-scheme: dark) {
  :root {
    --ink: #e8ecf4; --muted: #9aa5b8; --line: #2b3446; --paper: #0f1420; --card: #171e2d;
    --brand: #7c93f0; --brand-ink: #0f1420; --focus: #6ea8ff;
    --red-bg: #4a1a20; --red-fg: #ffb3b9; --amb-bg: #4a3a10; --amb-fg: #ffd978; --grn-bg: #14391f; --grn-fg: #9be3b2;
    --none: #364056;
  }
}
* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }
body { margin: 0; background: var(--paper); color: var(--ink); font: 16px/1.5 system-ui, -apple-system, "Segoe UI", Roboto, sans-serif; }
h1, h2, h3 { line-height: 1.2; margin: 0 0 .5rem; letter-spacing: -.01em; }
h1 { font-size: 1.6rem; } h2 { font-size: 1.2rem; } h3 { font-size: 1rem; }
p { margin: 0 0 .75rem; }
a { color: var(--brand); }
:focus-visible { outline: 3px solid var(--focus); outline-offset: 2px; border-radius: 6px; }
.muted { color: var(--muted); } .small { font-size: .875rem; }
.top { position: sticky; top: 0; z-index: 5; background: var(--card); border-bottom: 1px solid var(--line); display: flex; align-items: center; gap: 1rem; padding: .6rem 1rem; }
.brand { font-weight: 800; font-size: 1.15rem; color: var(--ink); text-decoration: none; display: flex; align-items: center; gap: .45rem; }
.dots { display: inline-flex; gap: 3px; } .dots i { width: 9px; height: 9px; border-radius: 50%; display: block; }
.dots i:nth-child(1) { background: var(--red); } .dots i:nth-child(2) { background: var(--amb); } .dots i:nth-child(3) { background: var(--grn); }
nav { display: flex; gap: .25rem; overflow-x: auto; margin-left: auto; scrollbar-width: none; }
nav a, nav button { white-space: nowrap; padding: .4rem .7rem; border-radius: 999px; text-decoration: none; color: var(--muted); font: inherit; font-size: .9rem; background: none; border: 0; cursor: pointer; }
nav a[aria-current="page"] { background: var(--paper); color: var(--ink); font-weight: 600; }
main { max-width: 860px; margin: 0 auto; padding: 1.25rem 1rem 4rem; outline: none; }
.card { background: var(--card); border: 1px solid var(--line); border-radius: var(--radius); padding: 1rem 1.1rem; margin-bottom: .85rem; }
.grid { display: grid; gap: .85rem; }
@media (min-width: 640px) { .grid.two { grid-template-columns: 1fr 1fr; } }
.btn { display: inline-flex; align-items: center; justify-content: center; gap: .4rem; font: inherit; font-weight: 600; padding: .65rem 1.1rem; border-radius: 10px; border: 1px solid var(--line); background: var(--card); color: var(--ink); cursor: pointer; text-decoration: none; min-height: 44px; }
.btn.primary { background: var(--brand); color: var(--brand-ink); border-color: var(--brand); }
.btn.small { min-height: 34px; padding: .3rem .75rem; font-size: .875rem; }
.btn[disabled] { opacity: .5; cursor: not-allowed; }
.btn.danger { color: var(--red-fg); }
.row { display: flex; align-items: center; gap: .75rem; flex-wrap: wrap; } .row.between { justify-content: space-between; }
.stack > * + * { margin-top: .75rem; }
label { display: block; font-weight: 600; margin-bottom: .25rem; }
input[type=text], input[type=email], input[type=password], input[type=number], select {
  width: 100%; font: inherit; padding: .65rem .8rem; border-radius: 10px; border: 1px solid var(--line); background: var(--paper); color: var(--ink); min-height: 44px; }
.err { background: var(--red-bg); color: var(--red-fg); padding: .6rem .8rem; border-radius: 10px; margin-bottom: .75rem; }
.ok { background: var(--grn-bg); color: var(--grn-fg); padding: .6rem .8rem; border-radius: 10px; margin-bottom: .75rem; }
.bar { display: flex; height: 10px; border-radius: 99px; overflow: hidden; background: var(--none); }
.bar i { display: block; height: 100%; } .bar .r { background: var(--red); } .bar .a { background: var(--amb); } .bar .g { background: var(--grn); }
.legend { display: flex; gap: .9rem; flex-wrap: wrap; font-size: .85rem; color: var(--muted); margin-top: .4rem; }
.legend b { color: var(--ink); }
.chip { display: inline-block; padding: .15rem .65rem; border-radius: 999px; font-size: .8rem; font-weight: 700; white-space: nowrap; }
.chip.Red { background: var(--red-bg); color: var(--red-fg); } .chip.Amber { background: var(--amb-bg); color: var(--amb-fg); }
.chip.Green { background: var(--grn-bg); color: var(--grn-fg); } .chip.none { background: var(--paper); color: var(--muted); border: 1px solid var(--line); }
.filters { display: flex; gap: .4rem; flex-wrap: wrap; margin: .75rem 0 1rem; }
.filters button { font: inherit; font-size: .875rem; padding: .3rem .8rem; border-radius: 999px; border: 1px solid var(--line); background: var(--card); color: var(--ink); cursor: pointer; }
.filters button[aria-pressed="true"] { background: var(--brand); color: var(--brand-ink); border-color: var(--brand); }
.area { margin: 1.4rem 0 .4rem; font-size: .8rem; text-transform: uppercase; letter-spacing: .06em; color: var(--muted); font-weight: 700; }
.topic { display: grid; grid-template-columns: 1fr auto; gap: .35rem .75rem; align-items: center; padding: .7rem 0; border-top: 1px solid var(--line); }
.topic:first-of-type { border-top: 0; }
.topic .t { font-weight: 500; } .topic .meta { grid-column: 1; }
.topic .act { grid-row: 1 / span 2; grid-column: 2; display: flex; gap: .5rem; align-items: center; }
.hero { padding: 1.4rem 1.1rem; }
.progress { height: 6px; background: var(--line); border-radius: 99px; overflow: hidden; margin-bottom: 1.25rem; } .progress i { display: block; height: 100%; background: var(--brand); transition: width .25s; }
.qprompt { font-size: 1.2rem; font-weight: 600; margin-bottom: 1rem; }
.opts { display: grid; gap: .6rem; }
.opt { display: flex; gap: .75rem; align-items: flex-start; text-align: left; font: inherit; padding: .85rem 1rem; border-radius: 12px; border: 2px solid var(--line); background: var(--card); color: var(--ink); cursor: pointer; width: 100%; }
.opt .k { flex: 0 0 1.6rem; height: 1.6rem; border-radius: 6px; background: var(--paper); display: grid; place-items: center; font-weight: 700; font-size: .8rem; color: var(--muted); }
.opt[aria-checked="true"] { border-color: var(--brand); background: color-mix(in srgb, var(--brand) 10%, var(--card)); }
.opt[aria-checked="true"] .k { background: var(--brand); color: var(--brand-ink); }
.result-hero { text-align: center; padding: 1.6rem 1rem; border-radius: var(--radius); margin-bottom: 1rem; }
.result-hero.Red { background: var(--red-bg); color: var(--red-fg); } .result-hero.Amber { background: var(--amb-bg); color: var(--amb-fg); } .result-hero.Green { background: var(--grn-bg); color: var(--grn-fg); }
.result-hero .big { font-size: 2.4rem; font-weight: 800; line-height: 1.1; }
.item { border-left: 5px solid var(--line); } .item.correct { border-left-color: var(--grn); } .item.wrong, .item.blank { border-left-color: var(--red); } .item.spelling, .item.unit { border-left-color: var(--amb); }
.item .verdict { font-weight: 700; font-size: .85rem; text-transform: uppercase; letter-spacing: .04em; }
.item.correct .verdict { color: var(--grn-fg); } .item.wrong .verdict, .item.blank .verdict { color: var(--red-fg); } .item.spelling .verdict, .item.unit .verdict { color: var(--amb-fg); }
.kv { display: grid; grid-template-columns: 8.5rem 1fr; gap: .15rem .75rem; font-size: .95rem; margin: .4rem 0; } .kv dt { color: var(--muted); } .kv dd { margin: 0; font-weight: 600; }
.why { background: var(--paper); border-radius: 10px; padding: .55rem .75rem; font-size: .92rem; margin-top: .5rem; }
.code { font: 700 1.6rem ui-monospace, SFMono-Regular, Menlo, monospace; letter-spacing: .25em; background: var(--paper); padding: .5rem .9rem; border-radius: 10px; display: inline-block; }
.switch { display: inline-flex; align-items: center; gap: .6rem; }
.badge { font-size: .72rem; font-weight: 700; padding: .1rem .5rem; border-radius: 6px; background: var(--amb-bg); color: var(--amb-fg); text-transform: uppercase; letter-spacing: .04em; }
.empty { text-align: center; padding: 2rem 1rem; color: var(--muted); }
table { width: 100%; border-collapse: collapse; } td, th { text-align: left; padding: .5rem .4rem; border-top: 1px solid var(--line); font-size: .95rem; } th { color: var(--muted); font-weight: 600; font-size: .8rem; text-transform: uppercase; letter-spacing: .04em; border-top: 0; }
@media (max-width: 600px) { .top { flex-wrap: wrap; row-gap: .25rem; } nav { order: 3; width: 100%; margin-left: 0; flex-wrap: wrap; overflow: visible; } nav a, nav button { padding: .35rem .6rem; } }
.card.soon { opacity: .72; } .soon-tag { font-weight: 600; color: var(--muted); }
@media (max-width: 520px) { .kv { grid-template-columns: 1fr; } .kv dt { margin-top: .3rem; } }
@media (prefers-reduced-motion: reduce) { * { transition: none !important; } }

.card.hold { opacity: .5; filter: grayscale(1); cursor: not-allowed; }

/* flag buttons */
.flagbar { display: flex; align-items: center; gap: .4rem; margin-top: .6rem; }
.flagbtn { display: inline-flex; align-items: center; justify-content: center; min-width: 44px; min-height: 44px; border: 1px solid var(--line); border-radius: 10px; background: var(--card); color: var(--muted); cursor: pointer; }
.flagbtn .x { stroke: var(--red); fill: none; }
.flagbtn:hover { border-color: var(--brand); }
.flagbtn:focus-visible { outline: 3px solid var(--focus); outline-offset: 2px; }
.flagbtn[aria-pressed="true"] { background: var(--red-bg); color: var(--red-fg); border-color: var(--red); }
.flagtag { display: inline-flex; align-items: center; gap: .3rem; color: var(--red-fg); }
.flagtag .x { stroke: var(--red); fill: none; }