/* Answer-sheet language shared with the landing page: ballpen-blue ink on cool exam paper, one highlighter accent. */
:root {
  --paper: #f5f7fa;
  --sheet: #ffffff;
  --ink: #16224a;
  --ink-soft: #4a5578;
  --rule: #d9deea;
  --pen: #1f47c7;
  --pen-tint: #e6ecfc;
  --mark: #ffe14d;
  --good: #137a4b;
  --good-tint: #e3f4ea;
  --bad: #b3262f;
  --bad-tint: #fbe6e7;
  --warn: #a15c00;
  --warn-tint: #fff1d6;
  --display: "Bricolage Grotesque", "Segoe UI", system-ui, sans-serif;
  --body: "Figtree", "Segoe UI", system-ui, sans-serif;
  --mono: "JetBrains Mono", ui-monospace, Consolas, monospace;
}
@media (prefers-color-scheme: dark) {
  :root {
    --paper: #0e1324; --sheet: #161d33; --ink: #e8ecf8; --ink-soft: #a5aecb; --rule: #2a3352;
    --pen: #7d9cff; --pen-tint: #1d2850; --mark: #e8c93a;
    --good: #5fd39a; --good-tint: #133525; --bad: #ff8088; --bad-tint: #3d1a1e;
    --warn: #ffbf5c; --warn-tint: #3a2a10; color-scheme: dark;
  }
}
* { box-sizing: border-box }
html, body { margin: 0 }
body { background: var(--paper); color: var(--ink); font: 400 1rem/1.55 var(--body); min-height: 100vh }
h1, h2, h3 { font-family: var(--display); line-height: 1.12; margin: 0; text-wrap: balance }
h1 { font-size: clamp(1.6rem, 4vw, 2.2rem); font-weight: 800; letter-spacing: -0.02em }
h2 { font-size: 1.25rem; font-weight: 700 }
h3 { font-size: 1.02rem; font-weight: 700 }
p { margin: 0 }
a { color: var(--pen) }
button, input, select { font: inherit; color: inherit }
:focus-visible { outline: 3px solid var(--pen); outline-offset: 2px; border-radius: 6px }
@media (prefers-reduced-motion: reduce) { * { transition: none !important; animation: none !important } }

.top { position: sticky; top: 0; z-index: 10; background: var(--sheet); border-bottom: 1px solid var(--rule) }
.top-in, .wrap { max-width: 1040px; margin: 0 auto; padding-left: max(16px, env(safe-area-inset-left)); padding-right: max(16px, env(safe-area-inset-right)) }
.top-in { display: flex; align-items: center; justify-content: space-between; gap: 12px; min-height: 58px }
.brand { display: flex; align-items: center; gap: 9px; font: 800 1.15rem/1 var(--display); color: var(--ink); text-decoration: none }
.brand i { width: 20px; height: 20px; border-radius: 50%; background: var(--pen); box-shadow: inset 0 0 0 4px var(--sheet), 0 0 0 2px var(--pen) }
.nav { display: flex; gap: 4px; flex-wrap: wrap }
.nav a { text-decoration: none; color: var(--ink-soft); font-weight: 600; font-size: .92rem; padding: 7px 10px; border-radius: 8px }
.nav a.on, .nav a:hover { color: var(--pen); background: var(--pen-tint) }
main.wrap { padding-block: 28px 64px; display: grid; gap: 20px }

.label { font: 700 .72rem/1 var(--mono); letter-spacing: .12em; text-transform: uppercase; color: var(--pen) }
.muted { color: var(--ink-soft) }
.small { font-size: .88rem }
.num { font-family: var(--mono); font-variant-numeric: tabular-nums }

.card { background: var(--sheet); border: 1px solid var(--rule); border-radius: 14px; padding: 20px; display: grid; gap: 12px; align-content: start; min-width: 0 }
.grid { display: grid; gap: 16px; grid-template-columns: repeat(auto-fit, minmax(240px, 1fr)) }
.row { display: flex; gap: 10px; flex-wrap: wrap; align-items: center }
.between { justify-content: space-between }

.btn { display: inline-flex; align-items: center; justify-content: center; gap: 8px; font-weight: 700; font-size: .95rem; line-height: 1;
  padding: 12px 16px; border-radius: 10px; border: 2px solid var(--pen); background: var(--pen); color: var(--sheet); cursor: pointer; text-decoration: none }
.btn.ghost { background: transparent; color: var(--pen) }
.btn.quiet { border-color: var(--rule); background: var(--sheet); color: var(--ink) }
.btn.danger { border-color: var(--bad); background: transparent; color: var(--bad) }
.btn[disabled] { opacity: .5; cursor: not-allowed }
.btn.sm { padding: 8px 11px; font-size: .86rem }

form.stack, .stack { display: grid; gap: 12px }
label.f { display: grid; gap: 6px; font-weight: 600; font-size: .92rem }
input[type=email], input[type=password], input[type=text], input[type=date], select {
  width: 100%; padding: 11px 12px; border: 1px solid var(--rule); border-radius: 10px; background: var(--paper) }
.seg { display: flex; border: 1px solid var(--rule); border-radius: 10px; overflow: hidden }
.seg label { flex: 1; text-align: center; padding: 10px; cursor: pointer; font-weight: 600; font-size: .92rem }
.seg input { position: absolute; opacity: 0 }
.seg label:has(input:checked) { background: var(--pen-tint); color: var(--pen) }

.msg { padding: 11px 14px; border-radius: 10px; font-size: .93rem }
.msg.err { background: var(--bad-tint); color: var(--bad) }
.msg.ok { background: var(--good-tint); color: var(--good) }
.msg.warn { background: var(--warn-tint); color: var(--warn) }

.auth { max-width: 420px; margin: 6vh auto 0 }

.big { font: 800 2.4rem/1 var(--display); font-variant-numeric: tabular-nums }
.pill { display: inline-block; font: 700 .74rem/1 var(--mono); letter-spacing: .04em; padding: 6px 8px; border-radius: 999px; background: var(--pen-tint); color: var(--pen) }
.pill.good { background: var(--good-tint); color: var(--good) }
.pill.bad { background: var(--bad-tint); color: var(--bad) }
.pill.warn { background: var(--warn-tint); color: var(--warn) }

.bars { display: grid; gap: 10px }
.bar { display: grid; grid-template-columns: minmax(7em, 10em) 1fr 3.6em; gap: 10px; align-items: center; font-size: .9rem }
.track { position: relative; height: 10px; background: var(--paper); border-radius: 999px; overflow: hidden }
.fill { height: 100%; background: var(--pen); border-radius: 999px }
.fill.good { background: var(--good) }
.fill.bad { background: var(--bad) }
.passline { position: absolute; top: -3px; bottom: -3px; width: 2px; background: var(--ink); left: 80% }
.bar .v { text-align: right; font: 700 .85rem/1 var(--mono) }

.gauge { display: grid; gap: 8px }
.gauge .track { height: 14px }

.plan { display: grid; gap: 8px; margin: 0; padding: 0; list-style: none }
.plan li { display: flex; justify-content: space-between; align-items: center; gap: 10px; padding: 10px 12px; border: 1px solid var(--rule); border-radius: 10px }

/* exam */
.exam-head { display: flex; justify-content: space-between; align-items: center; gap: 10px; flex-wrap: wrap }
.timer { font: 700 1.1rem/1 var(--mono); font-variant-numeric: tabular-nums; color: var(--pen); background: var(--pen-tint); padding: 8px 11px; border-radius: 8px }
.timer.low { color: var(--bad); background: var(--bad-tint) }
.exam { display: grid; grid-template-columns: minmax(0, 1fr) 260px; gap: 18px; align-items: start }
.qcard { background: var(--sheet); border: 1px solid var(--rule); border-radius: 14px; padding: 22px; display: grid; gap: 14px; min-width: 0 }
.passage { background: var(--paper); border-left: 3px solid var(--pen); padding: 14px 16px; border-radius: 0 10px 10px 0; font-size: .96rem; max-height: 340px; overflow: auto }
.tablewrap { overflow-x: auto }
table.data { border-collapse: collapse; font-size: .9rem; min-width: 100% }
table.data caption { text-align: left; font-weight: 700; padding-bottom: 6px }
table.data th, table.data td { border: 1px solid var(--rule); padding: 7px 10px; text-align: left; font-variant-numeric: tabular-nums }
table.data th { background: var(--paper) }
.qtext { font-size: 1.07rem; font-weight: 600 }
.opts { display: grid; gap: 8px }
.opt { display: flex; align-items: center; gap: 12px; width: 100%; text-align: left; background: transparent; border: 1px solid var(--rule); border-radius: 10px; padding: 11px 12px; cursor: pointer; font-size: .98rem }
.opt:hover:not([disabled]) { border-color: var(--pen); background: var(--pen-tint) }
.bub { flex: none; width: 28px; height: 28px; border-radius: 50%; border: 2px solid var(--ink-soft); display: grid; place-items: center; font: 700 .8rem/1 var(--mono); color: var(--ink-soft) }
.opt.sel { border-color: var(--pen); background: var(--pen-tint) }
.opt.sel .bub { background: var(--pen); border-color: var(--pen); color: var(--sheet) }
.opt.right { border-color: var(--good); background: var(--good-tint) }
.opt.right .bub { background: var(--good); border-color: var(--good); color: var(--sheet) }
.opt.wrong { border-color: var(--bad); background: var(--bad-tint) }
.opt.wrong .bub { background: var(--bad); border-color: var(--bad); color: var(--sheet) }
.opt[disabled] { cursor: default }
.explain { border-left: 3px solid var(--pen); background: var(--pen-tint); padding: 12px 14px; border-radius: 0 10px 10px 0; display: grid; gap: 6px; font-size: .94rem }
.navgrid { display: grid; grid-template-columns: repeat(auto-fill, minmax(34px, 1fr)); gap: 5px; max-height: 360px; overflow: auto }
.navgrid button { height: 32px; border: 1px solid var(--rule); background: var(--sheet); border-radius: 6px; font: 600 .78rem/1 var(--mono); cursor: pointer }
.navgrid button.ans { background: var(--pen-tint); border-color: var(--pen); color: var(--pen) }
.navgrid button.flag { box-shadow: inset 0 -3px 0 var(--mark) }
.navgrid button.cur { outline: 2px solid var(--ink) }
.side { position: sticky; top: 76px; display: grid; gap: 12px }

.review { display: grid; gap: 12px }
.ritem { border: 1px solid var(--rule); border-radius: 12px; padding: 16px; display: grid; gap: 10px; background: var(--sheet) }
.ritem .head { display: flex; justify-content: space-between; gap: 10px; flex-wrap: wrap }

.dialog { position: fixed; inset: 0; background: rgba(10, 15, 35, .45); display: grid; place-items: center; padding: 16px; z-index: 50 }
.dialog .card { max-width: 440px; width: 100% }

.list { display: grid; gap: 8px }
.list .item { display: flex; justify-content: space-between; gap: 10px; align-items: center; flex-wrap: wrap; padding: 12px 14px; border: 1px solid var(--rule); border-radius: 10px; background: var(--sheet) }
.empty { padding: 24px; text-align: center; color: var(--ink-soft); border: 1px dashed var(--rule); border-radius: 12px }

@media (max-width: 820px) {
  .exam { grid-template-columns: 1fr }
  .side { position: static }
}
@media (max-width: 520px) {
  .nav a { padding: 6px 7px; font-size: .84rem }
  .bar { grid-template-columns: 6.5em 1fr 3.2em }
  .qcard { padding: 16px }
}