:root {
  --bg: #f4f6fb; --card: #ffffff; --ink: #1d2433; --muted: #5b6475; --line: #dde2ec;
  --brand: #1f4fd1; --brand-soft: #e7eeff; --ok: #12805c; --ok-soft: #e3f6ee; --bad: #c62828; --bad-soft: #fdeaea;
  --warn: #b26a00; --mk: #f5b301; --mk-soft: #fff6d6; --cf: #7b3fc4; --cf-soft: #f1e9fb; --e: #6b7280; --e-soft: #eef0f3;
  --code: #f3f4f8; --shadow: 0 1px 3px rgba(20, 30, 60, .08);
}
[data-theme="dark"] {
  --bg: #11141b; --card: #1a1f2a; --ink: #e7eaf1; --muted: #9aa3b5; --line: #2c3342;
  --brand: #7ea2ff; --brand-soft: #22305a; --ok: #43c08f; --ok-soft: #173327; --bad: #ff7b7b; --bad-soft: #3a1d22;
  --warn: #ffb547; --mk: #ffcf3d; --mk-soft: #3a3115; --cf: #c19bff; --cf-soft: #2c2240; --e: #a3abb9; --e-soft: #262c38;
  --code: #232937; --shadow: none;
}
* { box-sizing: border-box; }
html { font-size: 16.5px; }
body { margin: 0; font-family: "Segoe UI", system-ui, -apple-system, Roboto, Arial, sans-serif; background: var(--bg); color: var(--ink); line-height: 1.5; }
a { color: var(--brand); text-decoration: none; }
button { font: inherit; color: inherit; }
code, pre { font-family: Consolas, "Cascadia Mono", "Courier New", monospace; font-size: .92em; }
code { background: var(--code); padding: 0 .25em; border-radius: 4px; }
pre { background: var(--code); padding: .6em .8em; border-radius: 8px; overflow-x: auto; white-space: pre; margin: .5em 0; }
table { border-collapse: collapse; margin: .4em 0; }
th, td { border: 1px solid var(--line); padding: .25em .6em; text-align: left; vertical-align: top; }
th { background: var(--brand-soft); }

.topbar { position: sticky; top: 0; z-index: 20; display: flex; align-items: center; justify-content: space-between; gap: 1rem;
  padding: .55rem 1.2rem; background: var(--card); border-bottom: 1px solid var(--line); box-shadow: var(--shadow); flex-wrap: wrap; }
.brand { font-weight: 800; font-size: 1.15rem; color: var(--ink); }
.brand span { color: var(--brand); }
.topbar nav { display: flex; gap: .2rem; align-items: center; flex-wrap: wrap; }
.topbar nav a { padding: .35rem .7rem; border-radius: 8px; color: var(--ink); font-weight: 500; }
.topbar nav a:hover { background: var(--brand-soft); }
.iconbtn { border: 1px solid var(--line); background: transparent; border-radius: 8px; padding: .25rem .55rem; cursor: pointer; }

main { max-width: 1180px; margin: 0 auto; padding: 1.2rem 1rem 4rem; }
.loading { padding: 3rem; text-align: center; color: var(--muted); }
h1 { font-size: 1.7rem; margin: .2rem 0 .4rem; }
h2 { font-size: 1.25rem; margin: 1.6rem 0 .7rem; }
h3 { font-size: 1.05rem; margin: 0 0 .3rem; }
.muted { color: var(--muted); }
.small { font-size: .88rem; }
.bad { color: var(--bad); font-weight: 600; }
.good { color: var(--ok); font-weight: 600; }

.card { background: var(--card); border: 1px solid var(--line); border-radius: 14px; padding: 1rem 1.1rem; box-shadow: var(--shadow); }
.grid { display: grid; gap: 1rem; grid-template-columns: repeat(auto-fill, minmax(300px, 1fr)); }
.hero { margin-bottom: 1.2rem; }
.rules { background: var(--brand-soft); border-radius: 12px; padding: .7rem 1rem; margin: .6rem 0 1rem; }
.notice { background: var(--mk-soft); border: 1px solid var(--mk); border-radius: 12px; padding: .7rem 1rem; margin-bottom: 1rem; display: flex; gap: .7rem; align-items: center; flex-wrap: wrap; }
a.card.subj { color: var(--ink); display: block; transition: transform .1s; }
a.card.subj:hover { transform: translateY(-2px); border-color: var(--brand); }
.card.soon { opacity: .6; }

.tiles { display: grid; grid-template-columns: repeat(auto-fill, minmax(150px, 1fr)); gap: .7rem; margin: .8rem 0 1rem; }
.tile { background: var(--card); border: 1px solid var(--line); border-radius: 12px; padding: .6rem .8rem; }
.tile b { display: block; font-size: 1.35rem; }
.tile span { color: var(--muted); font-size: .85rem; }
a.tile { color: var(--ink); }
a.tile:hover { border-color: var(--brand); }
.tile.bad b { color: var(--bad); } .tile.mk b { color: var(--warn); } .tile.cf b { color: var(--cf); } .tile.ok b { color: var(--ok); }

.bar { height: 8px; background: var(--line); border-radius: 99px; overflow: hidden; margin: .5rem 0 .3rem; }
.bar span { display: block; height: 100%; background: var(--brand); border-radius: 99px; }
.row { display: flex; gap: .5rem; align-items: center; flex-wrap: wrap; margin-top: .6rem; }
.btn { display: inline-flex; align-items: center; gap: .3rem; border: 1px solid var(--brand); background: var(--brand); color: #fff; border-radius: 10px;
  padding: .45rem .9rem; cursor: pointer; font-weight: 600; }
.btn:hover { filter: brightness(1.08); }
.btn.ghost { background: transparent; color: var(--brand); }
.btn.danger { background: var(--bad); border-color: var(--bad); }
.btn.small { padding: .25rem .65rem; font-size: .88rem; border-radius: 8px; }
.btn.big { padding: .7rem 1.2rem; font-size: 1.02rem; }
.btn:disabled { opacity: .45; cursor: not-allowed; }

.units { display: grid; gap: 1rem; grid-template-columns: repeat(auto-fill, minmax(340px, 1fr)); }
.unit-head { display: flex; justify-content: space-between; gap: .5rem; align-items: start; }
.tag { font-size: .75rem; background: var(--brand-soft); color: var(--brand); padding: .1rem .5rem; border-radius: 99px; white-space: nowrap; font-weight: 600; }
.tag.hot { background: var(--bad-soft); color: var(--bad); }
.chips { display: flex; flex-wrap: wrap; gap: .4rem; margin-top: .5rem; }
.chip { border: 1px solid var(--line); background: var(--card); border-radius: 10px; padding: .25rem .6rem; cursor: pointer; text-align: left; line-height: 1.2; }
.chip small { display: block; color: var(--muted); font-size: .72rem; }
.chip:hover { border-color: var(--brand); }
.chip.part { border-color: var(--brand); background: var(--brand-soft); }
.chip.done { border-color: var(--ok); background: var(--ok-soft); }
.search { display: flex; gap: .5rem; margin: .8rem 0; }
.search input { flex: 1; padding: .55rem .8rem; border-radius: 10px; border: 1px solid var(--line); background: var(--card); color: var(--ink); font-size: 1rem; }

/* quiz */
.quiz { display: grid; grid-template-columns: minmax(0, 1fr) 280px; gap: 1rem; align-items: start; }
.qhead { display: flex; justify-content: space-between; align-items: center; gap: .6rem; flex-wrap: wrap; margin-bottom: .6rem; }
.qhead .title { font-weight: 700; }
.timer { font-variant-numeric: tabular-nums; font-weight: 700; font-size: 1.15rem; padding: .2rem .7rem; border-radius: 8px; background: var(--brand-soft); color: var(--brand); }
.timer.low { background: var(--bad-soft); color: var(--bad); }
.qmeta { font-size: .82rem; color: var(--muted); margin-bottom: .5rem; display: flex; gap: .4rem; flex-wrap: wrap; align-items: center; }
.qtext { font-size: 1.08rem; margin-bottom: .9rem; }
.qtext pre { font-size: .9rem; }
.opts { display: grid; gap: .55rem; }
.opt { display: flex; gap: .7rem; align-items: flex-start; text-align: left; width: 100%; border: 2px solid var(--line); background: var(--card);
  border-radius: 12px; padding: .6rem .8rem; cursor: pointer; line-height: 1.4; }
.opt:hover:not(:disabled) { border-color: var(--brand); }
.opt .L { flex: 0 0 auto; width: 1.8rem; height: 1.8rem; border-radius: 50%; display: grid; place-items: center; font-weight: 700;
  background: var(--brand-soft); color: var(--brand); }
.opt .T { padding-top: .1rem; min-width: 0; }
.opt.sel { border-color: var(--brand); background: var(--brand-soft); }
.opt.sel .L { background: var(--brand); color: #fff; }
.opt.e { border-style: dashed; color: var(--e); }
.opt.e .L { background: var(--e-soft); color: var(--e); }
.opt.e.sel { border-color: var(--e); background: var(--e-soft); }
.opt.e.sel .L { background: var(--e); color: #fff; }
.opt.right { border-color: var(--ok); background: var(--ok-soft); }
.opt.right .L { background: var(--ok); color: #fff; }
.opt.wrong { border-color: var(--bad); background: var(--bad-soft); }
.opt.wrong .L { background: var(--bad); color: #fff; }
.opt:disabled { cursor: default; }
.explain { margin-top: .9rem; border-radius: 12px; padding: .7rem .9rem; background: var(--brand-soft); }
.explain.ok { background: var(--ok-soft); border-left: 4px solid var(--ok); }
.explain.no { background: var(--bad-soft); border-left: 4px solid var(--bad); }
.explain.sk { background: var(--e-soft); border-left: 4px solid var(--e); }
.explain .meta { margin-top: .4rem; font-size: .8rem; color: var(--muted); }
.note { color: var(--warn); font-size: .92rem; }
.flags { display: flex; gap: .5rem; flex-wrap: wrap; margin-top: .8rem; }
.flag { border: 1px solid var(--line); background: var(--card); border-radius: 99px; padding: .25rem .8rem; cursor: pointer; font-size: .9rem; }
.flag.on { background: var(--mk-soft); border-color: var(--mk); color: var(--warn); font-weight: 600; }
.flag.cf.on { background: var(--cf-soft); border-color: var(--cf); color: var(--cf); }
.nav { display: flex; justify-content: space-between; gap: .5rem; margin-top: 1rem; }
.side .card { position: sticky; top: 4.2rem; }
.palette { display: grid; grid-template-columns: repeat(auto-fill, minmax(38px, 1fr)); gap: .35rem; margin: .6rem 0; }
.pal { height: 36px; border-radius: 8px; border: 1px solid var(--line); background: var(--card); cursor: pointer; font-weight: 600; font-size: .85rem; position: relative; }
.pal.cur { outline: 2px solid var(--brand); outline-offset: 1px; }
.pal.done { background: var(--brand); color: #fff; border-color: var(--brand); }
.pal.ok { background: var(--ok); color: #fff; border-color: var(--ok); }
.pal.no { background: var(--bad); color: #fff; border-color: var(--bad); }
.pal.e { background: var(--e-soft); color: var(--e); border-color: var(--e); }
.pal.mk::after, .pal.cf::before { content: ""; position: absolute; top: -3px; width: 9px; height: 9px; border-radius: 50%; border: 1px solid var(--card); }
.pal.mk::after { right: -3px; background: var(--mk); }
.pal.cf::before { left: -3px; background: var(--cf); }
.legend { display: grid; grid-template-columns: 1fr 1fr; gap: .2rem .6rem; font-size: .78rem; color: var(--muted); }
.legend i { display: inline-block; width: 11px; height: 11px; border-radius: 3px; margin-right: .3rem; vertical-align: -1px; border: 1px solid var(--line); }
.counts { font-size: .88rem; display: grid; grid-template-columns: 1fr auto; gap: .1rem .5rem; margin: .4rem 0; }
.hist-badge { font-size: .78rem; padding: .05rem .5rem; border-radius: 99px; background: var(--bad-soft); color: var(--bad); font-weight: 600; }

/* review cards */
.qcard { background: var(--card); border: 1px solid var(--line); border-left: 5px solid var(--line); border-radius: 12px; padding: .8rem 1rem; margin-bottom: .8rem; }
.qcard.is-wrong { border-left-color: var(--bad); }
.qcard.is-mk { background: linear-gradient(90deg, var(--mk-soft), var(--card) 40%); }
.qcard.is-cf { border-left-color: var(--cf); }
.qcard.is-wrong.is-cf { border-left-color: var(--bad); }
.olist { list-style: none; padding: 0; margin: .4rem 0; display: grid; gap: .3rem; }
.olist li { display: flex; gap: .55rem; padding: .3rem .5rem; border-radius: 8px; }
.olist li .L { font-weight: 700; color: var(--muted); }
.olist li.right { background: var(--ok-soft); }
.olist li.right .L { color: var(--ok); }
.olist li.wrong { background: var(--bad-soft); text-decoration: line-through; text-decoration-color: var(--bad); }
.olist li.wrong .L { color: var(--bad); }
details summary { cursor: pointer; color: var(--brand); font-weight: 600; margin-top: .3rem; }
.pill { font-size: .75rem; font-weight: 700; padding: .05rem .5rem; border-radius: 99px; }
.pill.ok { background: var(--ok-soft); color: var(--ok); } .pill.no { background: var(--bad-soft); color: var(--bad); }
.pill.e { background: var(--e-soft); color: var(--e); } .pill.b { background: var(--bad-soft); color: var(--bad); }
.hist { display: inline-flex; gap: 3px; margin-right: auto; align-items: center; font-size: .78rem; color: var(--muted); }
.hist i { width: 10px; height: 10px; border-radius: 50%; display: inline-block; }
.hist i.c { background: var(--ok); } .hist i.w { background: var(--bad); } .hist i.s, .hist i.b { background: var(--e); } .hist i.l { background: var(--brand); }
.tabs { display: flex; gap: .4rem; flex-wrap: wrap; margin: .6rem 0 1rem; }
.tabs a { padding: .35rem .8rem; border-radius: 99px; border: 1px solid var(--line); color: var(--ink); background: var(--card); font-weight: 600; font-size: .9rem; }
.tabs a.on { background: var(--brand); border-color: var(--brand); color: #fff; }
.toolbar { display: flex; gap: .6rem; align-items: center; flex-wrap: wrap; margin-bottom: 1rem; }
select, input[type=number] { padding: .4rem .5rem; border-radius: 8px; border: 1px solid var(--line); background: var(--card); color: var(--ink); font: inherit; }
.result-top { display: flex; gap: 1.2rem; align-items: center; flex-wrap: wrap; }
.score-big { font-size: 2.4rem; font-weight: 800; }
.score-big small { font-size: 1.1rem; color: var(--muted); font-weight: 600; }
table.plain { width: 100%; }
table.plain td, table.plain th { border: none; border-bottom: 1px solid var(--line); padding: .45rem .5rem; }
table.plain th { background: transparent; color: var(--muted); font-size: .85rem; }

/* modal / toast */
.modal { position: fixed; inset: 0; background: rgba(10, 15, 30, .55); display: grid; place-items: center; z-index: 50; padding: 1rem; }
.modal.hidden, .toast.hidden { display: none; }
.modal .box { background: var(--card); color: var(--ink); border-radius: 16px; padding: 1.2rem 1.3rem; width: min(560px, 100%); max-height: 90vh; overflow: auto; }
.modal label.radio { display: flex; gap: .6rem; align-items: flex-start; border: 1px solid var(--line); border-radius: 10px; padding: .6rem .7rem; margin: .45rem 0; cursor: pointer; }
.modal .field { display: flex; gap: .6rem; align-items: center; margin: .6rem 0; flex-wrap: wrap; }
.modal .unitpick { display: grid; grid-template-columns: 1fr 1fr; gap: .2rem .8rem; max-height: 230px; overflow: auto; border: 1px solid var(--line); border-radius: 10px; padding: .5rem; font-size: .9rem; }
.toast { position: fixed; bottom: 1.2rem; left: 50%; transform: translateX(-50%); background: var(--ink); color: var(--bg); padding: .6rem 1rem; border-radius: 10px; z-index: 60; }

@media (max-width: 860px) {
  .quiz { grid-template-columns: 1fr; }
  .side .card { position: static; }
  html { font-size: 16px; }
  .units { grid-template-columns: 1fr; }
}

/* Authentication and approval workflow */
.topbar nav #quizNav:not([hidden]) { display: flex; align-items: center; gap: .2rem; flex-wrap: wrap; }
#accountNav { display: flex; align-items: center; gap: .45rem; flex-wrap: wrap; }
.account-email { color: var(--muted); font-size: .78rem; max-width: 180px; overflow: hidden; text-overflow: ellipsis; }
.auth-wrap { min-height: min(720px, 82vh); display: grid; grid-template-columns: minmax(0, 1fr) minmax(320px, 440px); gap: clamp(2rem, 8vw, 7rem); align-items: center; padding: 2rem clamp(.3rem, 5vw, 4rem); }
.auth-intro h1 { font-size: clamp(2.3rem, 5vw, 4rem); line-height: 1.08; max-width: 620px; margin: .5rem 0 1rem; letter-spacing: -.04em; }
.auth-intro > p { max-width: 520px; font-size: 1.08rem; }
.auth-kicker { color: var(--brand); text-transform: uppercase; letter-spacing: .14em; font-size: .75rem; font-weight: 800; }
.auth-points { display: grid; gap: .55rem; margin-top: 1.5rem; color: var(--ok); font-weight: 650; }
.auth-card { padding: 1.4rem; }
.auth-card h2 { margin-top: 0; }
.auth-form { display: grid; gap: .65rem; }
.auth-form label { display: grid; gap: .25rem; font-weight: 600; font-size: .9rem; }
.auth-form input { width: 100%; border: 1px solid var(--line); border-radius: 9px; padding: .65rem .75rem; background: var(--bg); color: var(--ink); font: inherit; }
.auth-form input:focus { outline: 2px solid var(--brand); outline-offset: 1px; }
.auth-form small { color: var(--muted); font-weight: 400; }
.auth-divider { display: flex; align-items: center; gap: .7rem; color: var(--muted); font-size: .78rem; margin: 1rem 0; }
.auth-divider::before, .auth-divider::after { content: ""; height: 1px; background: var(--line); flex: 1; }
.auth-message { background: var(--warn); color: #fff; border-radius: 9px; padding: .65rem .8rem; overflow-wrap: anywhere; }
.status-card { max-width: 660px; margin: 12vh auto; text-align: center; padding: clamp(1.4rem, 5vw, 3rem); }
.status-card h1 { margin: .5rem 0; }
.status-icon { width: 3rem; height: 3rem; margin: 0 auto .75rem; border-radius: 50%; display: grid; place-items: center; font-size: 1.6rem; font-weight: 800; }
.status-icon.pending { color: var(--warn); background: var(--mk-soft); }
.status-icon.blocked { color: var(--bad); background: var(--bad-soft); }
.admin-head { display: flex; align-items: center; justify-content: space-between; gap: 1rem; flex-wrap: wrap; }
.admin-table { min-width: 680px; }
.admin-table td { vertical-align: middle; }
.admin-table .row { margin: 0; }
.status-pill { display: inline-block; border-radius: 99px; padding: .12rem .55rem; font-size: .78rem; font-weight: 700; text-transform: capitalize; }
.status-pill.approved { color: var(--ok); background: var(--ok-soft); }
.status-pill.pending { color: var(--warn); background: var(--mk-soft); }
.status-pill.blocked { color: var(--bad); background: var(--bad-soft); }
@media (max-width: 760px) {
  .auth-wrap { grid-template-columns: 1fr; gap: 1.2rem; padding-top: 1rem; }
  .auth-intro h1 { font-size: 2.4rem; }
  .auth-points { grid-template-columns: 1fr; }
  .account-email { max-width: 110px; }
}