:root {
  --ink: #15212B;
  --text: #1B2630;
  --muted: #5A646D;
  --bg: #F3F0E8;
  --card: #FBFAF6;
  --line: #DCD5C6;
  --accent: #A64F0C;
  --accent-2: #F28C38;
  --blue: #24609A;
  --good: #1E7A46;
  --good-bg: #E3F2E8;
  --bad: #B3261E;
  --bad-bg: #FBE6E4;
  --radius: 12px;
}
* { box-sizing: border-box; }
html, body { margin: 0; }
body { background: var(--bg); color: var(--text); font: 16px/1.55 "Public Sans", system-ui, -apple-system, "Segoe UI", Arial, sans-serif; }
a { color: var(--blue); }
h1, h2, h3 { font-family: "Oswald", "Arial Narrow", Arial, sans-serif; font-weight: 600; color: var(--ink); line-height: 1.15; margin: 0 0 .5em; }
h1 { font-size: 2rem; } h2 { font-size: 1.5rem; } h3 { font-size: 1.15rem; }
p { margin: 0 0 1em; }

/* top bar */
.topbar { background: var(--ink); color: #F3F0E8; border-top: 6px solid var(--accent-2); }
.topbar .inner { max-width: 1120px; margin: 0 auto; padding: 12px 16px; display: flex; align-items: center; gap: 20px; flex-wrap: wrap; }
.brand { font-family: "Oswald", Arial, sans-serif; font-size: 1.25rem; color: #F3F0E8; text-decoration: none; letter-spacing: .5px; }
.brand span { color: var(--accent-2); }
.nav { display: flex; gap: 4px; flex-wrap: wrap; flex: 1; }
.nav a { color: #C3CCD3; text-decoration: none; padding: 6px 10px; border-radius: 8px; }
.nav a:hover, .nav a.on { background: #24323E; color: #fff; }
.who { color: #C3CCD3; font-size: .9rem; display: flex; gap: 10px; align-items: center; }
.who form { margin: 0; }
.linkbtn { background: none; border: 0; color: #C3CCD3; text-decoration: underline; cursor: pointer; font: inherit; padding: 0; }

.wrap { max-width: 1120px; margin: 0 auto; padding: 28px 16px 64px; }
.eyebrow { text-transform: uppercase; letter-spacing: 2px; font-size: .8rem; font-weight: 700; color: var(--accent); margin-bottom: 4px; }
.lead { color: var(--muted); font-size: 1.05rem; }

/* cards & grids */
.card { background: var(--card); border: 1px solid var(--line); border-radius: var(--radius); padding: 20px; }
.grid { display: grid; gap: 16px; grid-template-columns: repeat(auto-fill, minmax(300px, 1fr)); }
.stack > * + * { margin-top: 16px; }
.row { display: flex; gap: 12px; align-items: center; flex-wrap: wrap; }
.spacer { flex: 1; }

/* lesson card */
.lesson { display: flex; flex-direction: column; gap: 10px; }
.lesson .num { font-family: "Oswald", Arial, sans-serif; color: var(--accent); font-size: .95rem; letter-spacing: 1px; text-transform: uppercase; }
.lesson h3 { margin: 0; }
.lesson .meta { color: var(--muted); font-size: .9rem; }
.lesson .actions { margin-top: auto; display: flex; gap: 8px; align-items: center; flex-wrap: wrap; }

/* badges */
.badge { display: inline-block; font-size: .78rem; font-weight: 700; padding: 3px 10px; border-radius: 999px; background: #E8E3D7; color: var(--text); }
.badge.open { background: var(--good-bg); color: var(--good); }
.badge.closed { background: #E8E3D7; color: var(--muted); }
.badge.pass { background: var(--good-bg); color: var(--good); }
.badge.fail { background: var(--bad-bg); color: var(--bad); }
.badge.prog { background: #FBF1E6; color: var(--accent); }

/* buttons & forms */
.btn { display: inline-block; border: 0; border-radius: 8px; padding: 10px 18px; font: 600 .95rem/1.2 "Public Sans", Arial, sans-serif; cursor: pointer; text-decoration: none; background: var(--ink); color: #fff; }
.btn:hover { filter: brightness(1.15); }
.btn.accent { background: var(--accent); }
.btn.blue { background: var(--blue); }
.btn.ghost { background: transparent; color: var(--ink); border: 1px solid var(--line); }
.btn.danger { background: var(--bad); }
.btn.sm { padding: 6px 12px; font-size: .85rem; }
.btn[disabled] { opacity: .5; cursor: not-allowed; }
label { display: block; font-weight: 600; margin-bottom: 4px; }
.field { margin-bottom: 14px; }
.hint { color: var(--muted); font-size: .85rem; font-weight: 400; }
input[type=text], input[type=email], input[type=password], input[type=number], select, textarea {
  width: 100%; padding: 10px 12px; border: 1px solid var(--line); border-radius: 8px; background: #fff; font: inherit; color: var(--text);
}
textarea { min-height: 90px; }
textarea.big { min-height: 420px; font-family: ui-monospace, Menlo, Consolas, monospace; font-size: .9rem; }
input:focus, select:focus, textarea:focus { outline: 2px solid var(--accent-2); outline-offset: 1px; }
.check { display: flex; gap: 8px; align-items: center; font-weight: 400; }
.cols-2 { display: grid; gap: 14px; grid-template-columns: 1fr 1fr; }
@media (max-width: 700px) { .cols-2 { grid-template-columns: 1fr; } }

/* alerts */
.alert { padding: 12px 16px; border-radius: 10px; margin-bottom: 16px; }
.alert.ok { background: var(--good-bg); color: var(--good); }
.alert.err { background: var(--bad-bg); color: var(--bad); }
.alert.info { background: #E6EEF6; color: var(--blue); }
.alert ul { margin: 6px 0 0 18px; padding: 0; }

/* tables */
.table-wrap { overflow-x: auto; }
table { width: 100%; border-collapse: collapse; background: var(--card); border: 1px solid var(--line); border-radius: var(--radius); overflow: hidden; }
th, td { text-align: left; padding: 10px 12px; border-bottom: 1px solid var(--line); vertical-align: top; }
th { background: var(--ink); color: #F3F0E8; font-weight: 600; font-size: .9rem; }
tr:last-child td { border-bottom: 0; }
td.num, th.num { text-align: right; font-variant-numeric: tabular-nums; }
.inline { display: inline; margin: 0; }

/* exam taking */
.exam-head { position: sticky; top: 0; z-index: 5; background: var(--bg); padding: 12px 0; border-bottom: 1px solid var(--line); margin-bottom: 20px; }
.timer { font-family: ui-monospace, Menlo, Consolas, monospace; font-weight: 700; font-size: 1.15rem; background: var(--ink); color: #fff; padding: 6px 12px; border-radius: 8px; }
.timer.low { background: var(--bad); }
.progress { height: 8px; background: #E8E3D7; border-radius: 99px; overflow: hidden; flex: 1; min-width: 120px; }
.progress > div { height: 100%; background: var(--accent-2); width: 0; transition: width .2s; }
.q { background: var(--card); border: 1px solid var(--line); border-radius: var(--radius); padding: 22px; margin-bottom: 18px; }
.q .qn { font-family: "Oswald", Arial, sans-serif; color: var(--accent); letter-spacing: 1px; text-transform: uppercase; font-size: .9rem; margin-bottom: 6px; }
.q .stem { font-size: 1.05rem; margin-bottom: 14px; white-space: pre-line; }
.opt { display: flex; gap: 12px; align-items: flex-start; padding: 12px 14px; border: 1px solid var(--line); border-radius: 10px; margin-bottom: 8px; cursor: pointer; background: #fff; font-weight: 400; }
.opt:hover { border-color: var(--accent-2); }
.opt input { margin-top: 4px; accent-color: var(--accent); width: 18px; height: 18px; flex: none; }
.opt .k { font-weight: 700; min-width: 1.4em; }
.opt.chosen { border-color: var(--accent); background: #FBF1E6; }

/* review */
.score-hero { display: flex; gap: 24px; align-items: center; flex-wrap: wrap; }
.score-big { font-family: "Oswald", Arial, sans-serif; font-size: 4rem; line-height: 1; color: var(--ink); }
.review .opt { cursor: default; }
.review .opt.right { border-color: var(--good); background: var(--good-bg); }
.review .opt.wrong { border-color: var(--bad); background: var(--bad-bg); }
.review .tag { margin-left: auto; font-size: .78rem; font-weight: 700; white-space: nowrap; }
.review .tag.right { color: var(--good); } .review .tag.wrong { color: var(--bad); }
.why { font-size: .9rem; color: var(--muted); margin-top: 4px; }
.explain { background: #EEF3F8; border-left: 4px solid var(--blue); padding: 12px 14px; border-radius: 6px; margin-top: 12px; white-space: pre-line; }
.result-line { font-weight: 700; margin-top: 10px; }
.result-line.right { color: var(--good); } .result-line.wrong { color: var(--bad); }

/* login */
.login-wrap { min-height: 100vh; display: grid; place-items: center; padding: 16px; background: var(--ink); }
.login { width: 100%; max-width: 420px; background: var(--card); border-radius: 16px; padding: 32px; border-top: 8px solid var(--accent-2); }
.login h1 { font-size: 1.8rem; }

.muted { color: var(--muted); }
.small { font-size: .85rem; }
pre.sample { background: #fff; border: 1px solid var(--line); border-radius: 8px; padding: 12px; overflow-x: auto; font-size: .85rem; white-space: pre-wrap; }
.pagination { margin-top: 16px; }
.pagination nav > div:first-child { display: none; }
.pagination svg { width: 16px; height: 16px; }