/* ============================================================ tokens ==== */
:root {
  --bg: #f4f6fb;
  --surface: #ffffff;
  --surface-2: #f8fafc;
  --border: #e3e7f0;
  --border-strong: #cbd3e3;
  --text: #111a2e;
  --muted: #64708b;
  --brand: #4f46e5;
  --brand-ink: #ffffff;
  --brand-soft: #eef0ff;
  --brand-line: #d5d8ff;
  --good: #128a4c;
  --good-soft: #e6f6ec;
  --bad: #cf2f45;
  --bad-soft: #fdecee;
  --warn: #b4690e;
  --warn-soft: #fdf2e2;
  --paper: #ffffff;
  --paper-text: #111a2e;
  --shadow: 0 1px 2px rgba(17, 26, 46, .05), 0 8px 24px -12px rgba(17, 26, 46, .18);
  --shadow-lg: 0 24px 60px -22px rgba(17, 26, 46, .38);
  --r: 14px;
  /* Crops are black ink on a transparent background, so they sit cleanly on any
     panel and the dark theme only has to flip the ink. */
  --img-filter: none;
  --paper-w: 720px;
}

[data-theme="dark"] {
  --bg: #0b1020;
  --surface: #141b2d;
  --surface-2: #1a2338;
  --border: #26314c;
  --border-strong: #38456a;
  --text: #e9edf8;
  --muted: #94a1c0;
  --brand: #7c85ff;
  --brand-ink: #0b1020;
  --brand-soft: #1b2242;
  --brand-line: #333d66;
  --good: #46c98a;
  --good-soft: #10301f;
  --bad: #ff7285;
  --bad-soft: #351520;
  --warn: #e0a45a;
  --warn-soft: #33260f;
  --paper: #131a2b;
  --paper-text: #e9edf8;
  --shadow: 0 1px 2px rgba(0, 0, 0, .4), 0 10px 30px -14px rgba(0, 0, 0, .7);
  --shadow-lg: 0 30px 70px -24px rgba(0, 0, 0, .8);
  --img-filter: invert(1);
}

* { box-sizing: border-box; }

html, body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font: 15px/1.55 "Inter", -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  -webkit-font-smoothing: antialiased;
}

h1, h2, h3, h4 { margin: 0; line-height: 1.2; letter-spacing: -.02em; font-weight: 650; }
p { margin: 0; }
a { color: inherit; text-decoration: none; }
button { font: inherit; color: inherit; }

::selection { background: var(--brand-soft); }

/* ============================================================ topbar ==== */
.topbar {
  position: sticky; top: 0; z-index: 50;
  display: flex; align-items: center; gap: 28px;
  padding: 0 24px; height: 62px;
  background: color-mix(in srgb, var(--surface) 86%, transparent);
  backdrop-filter: saturate(1.6) blur(12px);
  border-bottom: 1px solid var(--border);
}
.brand { display: flex; align-items: center; gap: 10px; }
.brand-mark {
  width: 30px; height: 30px; border-radius: 9px; flex: none;
  background: linear-gradient(140deg, var(--brand), #8b5cf6);
  color: #fff; display: grid; place-items: center;
  font-weight: 800; font-size: 16px; letter-spacing: -.04em;
}
.brand-name { display: flex; flex-direction: column; font-weight: 680; letter-spacing: -.02em; }
.brand-name em { font: 500 10.5px/1 inherit; font-style: normal; color: var(--muted); letter-spacing: .08em; text-transform: uppercase; margin-top: 3px; }
.topnav { display: flex; gap: 4px; margin-left: auto; }
.topnav a {
  padding: 8px 13px; border-radius: 9px; font-size: 13.5px; font-weight: 550; color: var(--muted);
}
.topnav a:hover { background: var(--surface-2); color: var(--text); }
.topnav a.on { background: var(--brand-soft); color: var(--brand); }
.icon-btn {
  width: 36px; height: 36px; display: grid; place-items: center; flex: none;
  border: 1px solid var(--border); border-radius: 10px; background: var(--surface); cursor: pointer;
}
.icon-btn:hover { border-color: var(--border-strong); }
.icon-btn svg { width: 17px; height: 17px; fill: none; stroke: currentColor; stroke-width: 1.9; stroke-linecap: round; stroke-linejoin: round; }
.ico-moon { display: none; }
[data-theme="dark"] .ico-sun { display: none; }
[data-theme="dark"] .ico-moon { display: block; }

/* ============================================================= layout === */
.view { max-width: 1160px; margin: 0 auto; padding: 34px 24px 90px; }
.view.wide { max-width: 100%; padding: 0; }
.stack { display: flex; flex-direction: column; gap: 26px; }
.row { display: flex; align-items: center; gap: 12px; }
.spread { display: flex; align-items: center; justify-content: space-between; gap: 16px; }
.grid { display: grid; gap: 16px; }
.muted { color: var(--muted); }
.small { font-size: 13px; }
.tiny { font-size: 11.5px; }

.page-head { display: flex; flex-direction: column; gap: 7px; margin-bottom: 26px; }
.page-head h1 { font-size: 27px; }
.eyebrow { font-size: 11.5px; font-weight: 700; letter-spacing: .1em; text-transform: uppercase; color: var(--brand); }

.card {
  background: var(--surface); border: 1px solid var(--border);
  border-radius: var(--r); box-shadow: var(--shadow);
}
.card-pad { padding: 20px; }

.btn {
  display: inline-flex; align-items: center; justify-content: center; gap: 8px;
  padding: 10px 17px; border-radius: 10px; border: 1px solid var(--border-strong);
  background: var(--surface); font-weight: 600; font-size: 14px; cursor: pointer;
  transition: background .13s, border-color .13s, transform .06s;
}
.btn:hover { background: var(--surface-2); }
.btn:active { transform: translateY(1px); }
.btn.primary { background: var(--brand); border-color: var(--brand); color: var(--brand-ink); }
.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(--bad); border-color: color-mix(in srgb, var(--bad) 35%, var(--border)); }
.btn.lg { padding: 13px 22px; font-size: 15px; border-radius: 12px; }
.btn.sm { padding: 6px 11px; font-size: 12.5px; border-radius: 8px; }
.btn:disabled { opacity: .45; cursor: not-allowed; }

.chip {
  display: inline-flex; align-items: center; gap: 6px; padding: 3px 9px;
  border-radius: 999px; font-size: 11.5px; font-weight: 650;
  background: var(--surface-2); border: 1px solid var(--border); color: var(--muted);
}
.chip.E { background: var(--good-soft); color: var(--good); border-color: transparent; }
.chip.M { background: var(--warn-soft); color: var(--warn); border-color: transparent; }
.chip.H { background: var(--bad-soft); color: var(--bad); border-color: transparent; }
.chip.brand { background: var(--brand-soft); color: var(--brand); border-color: transparent; }

/* ============================================================== home ==== */
.hero {
  position: relative; overflow: hidden; padding: 30px;
  border-radius: 20px; border: 1px solid var(--border); background: var(--surface);
  box-shadow: var(--shadow);
}
.hero::after {
  content: ''; position: absolute; inset: -60% 40% 40% -10%; z-index: 0;
  background: radial-gradient(circle at 30% 40%, color-mix(in srgb, var(--brand) 16%, transparent), transparent 62%);
  pointer-events: none;
}
.hero-inner { position: relative; z-index: 1; display: flex; gap: 34px; align-items: center; flex-wrap: wrap; }
.hero h1 { font-size: 32px; margin-bottom: 8px; }
.hero p { color: var(--muted); max-width: 46ch; }
.hero-actions { display: flex; gap: 10px; margin-top: 18px; flex-wrap: wrap; }

.ring { --p: 0; width: 132px; height: 132px; flex: none; position: relative; display: grid; place-items: center; }
.ring::before {
  content: ''; position: absolute; inset: 0; border-radius: 50%;
  background: conic-gradient(var(--brand) calc(var(--p) * 1%), var(--border) 0);
  mask: radial-gradient(farthest-side, transparent calc(100% - 11px), #000 calc(100% - 10px));
}
.ring b { font-size: 27px; letter-spacing: -.03em; }
.ring span { display: block; font-size: 10.5px; color: var(--muted); text-transform: uppercase; letter-spacing: .08em; font-weight: 650; }

.stat-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(150px, 1fr)); gap: 14px; }
.stat { padding: 16px 18px; border-radius: 12px; background: var(--surface); border: 1px solid var(--border); }
.stat b { display: block; font-size: 24px; letter-spacing: -.03em; }
.stat span { font-size: 12px; color: var(--muted); font-weight: 550; }

.sec-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(310px, 1fr)); gap: 18px; }
.sec-card { display: block; padding: 24px; border-radius: 16px; border: 1px solid var(--border); background: var(--surface); box-shadow: var(--shadow); transition: transform .14s, border-color .14s; }
.sec-card:hover { transform: translateY(-2px); border-color: var(--brand-line); }
.sec-card h3 { font-size: 19px; margin-bottom: 5px; }
.sec-icon { width: 42px; height: 42px; border-radius: 12px; display: grid; place-items: center; margin-bottom: 14px; background: var(--brand-soft); color: var(--brand); }
.sec-icon svg { width: 21px; height: 21px; fill: none; stroke: currentColor; stroke-width: 1.8; stroke-linecap: round; stroke-linejoin: round; }
.sec-skills { display: flex; flex-wrap: wrap; gap: 6px; margin-top: 15px; }

/* ========================================================== domains ===== */
.dom-list { display: grid; gap: 14px; }
.dom {
  border: 1px solid var(--border); border-radius: 15px; background: var(--surface);
  box-shadow: var(--shadow); overflow: hidden;
}
.dom-head { display: flex; align-items: center; gap: 16px; padding: 18px 20px; cursor: pointer; }
.dom-head:hover { background: var(--surface-2); }
.dom-head h3 { font-size: 16.5px; }
.dom-bar { height: 6px; border-radius: 4px; background: var(--border); overflow: hidden; width: 130px; flex: none; }
.dom-bar i { display: block; height: 100%; background: var(--brand); border-radius: 4px; }
.caret { width: 18px; height: 18px; flex: none; color: var(--muted); transition: transform .18s; }
.dom.open .caret { transform: rotate(90deg); }
.dom-body { display: none; border-top: 1px solid var(--border); }
.dom.open .dom-body { display: block; }
.skill-row {
  display: flex; align-items: center; gap: 14px; padding: 13px 20px;
  border-bottom: 1px solid var(--border);
}
.skill-row:last-child { border-bottom: 0; }
.skill-row:hover { background: var(--surface-2); }
.skill-row .nm { flex: 1; font-weight: 550; font-size: 14px; }
.acc-pill { font-size: 11.5px; font-weight: 700; padding: 2px 8px; border-radius: 999px; background: var(--surface-2); border: 1px solid var(--border); }

/* ============================================================ setup ===== */
.setup-grid { display: grid; grid-template-columns: minmax(0, 1fr) 300px; gap: 22px; align-items: start; }
.field { margin-bottom: 22px; }
.field > label { display: block; font-size: 12px; font-weight: 700; letter-spacing: .05em; text-transform: uppercase; color: var(--muted); margin-bottom: 9px; }
.opt-row { display: flex; flex-wrap: wrap; gap: 8px; }
.opt {
  display: inline-flex; align-items: center; gap: 7px; padding: 8px 13px; cursor: pointer;
  border: 1px solid var(--border-strong); border-radius: 10px; background: var(--surface);
  font-size: 13.5px; font-weight: 550; user-select: none;
}
.opt:hover { border-color: var(--brand-line); }
.opt.on { background: var(--brand-soft); border-color: var(--brand); color: var(--brand); }
.opt input { display: none; }
.skill-pick { display: grid; gap: 8px; }
.skill-pick .opt { justify-content: space-between; width: 100%; }
.summary-card { position: sticky; top: 84px; }
.summary-line { display: flex; justify-content: space-between; padding: 7px 0; font-size: 13.5px; border-bottom: 1px dashed var(--border); }
.summary-line:last-of-type { border-bottom: 0; }
.summary-line b { font-weight: 650; }
input[type="number"], input[type="text"], select {
  width: 100%; padding: 9px 12px; border-radius: 10px; font: inherit;
  border: 1px solid var(--border-strong); background: var(--surface); color: var(--text);
}
input:focus, select:focus { outline: 2px solid var(--brand); outline-offset: 1px; }
.range-row { display: flex; align-items: center; gap: 14px; }
input[type=range] { flex: 1; accent-color: var(--brand); }

/* =========================================================== player ===== */
.player { display: flex; flex-direction: column; min-height: calc(100vh - 62px); }
.pbar {
  display: flex; align-items: center; gap: 16px; padding: 12px 24px;
  border-bottom: 1px solid var(--border); background: var(--surface); position: sticky; top: 62px; z-index: 20;
}
.pbar .lbl { font-weight: 650; font-size: 14px; }
.pbar .sub { font-size: 12px; color: var(--muted); }
.timer {
  font-variant-numeric: tabular-nums; font-weight: 700; font-size: 19px; letter-spacing: -.01em;
  padding: 5px 13px; border-radius: 10px; background: var(--surface-2); border: 1px solid var(--border);
}
.timer.warn { background: var(--warn-soft); color: var(--warn); border-color: transparent; }
.timer.crit { background: var(--bad-soft); color: var(--bad); border-color: transparent; animation: pulse 1.1s infinite; }
@keyframes pulse { 50% { opacity: .55; } }
.progress-track { flex: 1; height: 5px; border-radius: 3px; background: var(--border); overflow: hidden; max-width: 320px; }
.progress-track i { display: block; height: 100%; background: var(--brand); transition: width .25s; }

.paper-wrap { flex: 1; display: grid; place-items: start center; padding: 30px 24px 120px; }
.paper {
  width: 100%; max-width: var(--paper-w); background: var(--paper); color: var(--paper-text);
  border: 1px solid var(--border); border-radius: 16px; box-shadow: var(--shadow);
  padding: 30px 34px 34px;
}
/* Artwork is cropped at the printed page width (584pt of content), so sizing it
   as a share of the column reproduces the original layout exactly.  Choices sit
   in a narrower box, and --choice-inset adds that difference back so a formula
   inside an option is drawn at the same scale as one in the question. */
.paper { --choice-inset: 71px; }
.paper[data-sec="rw"] { max-width: 780px; }
.paper[data-sec="math"] { max-width: 960px; }
.paper[data-sec="math"] .qbody,
.paper[data-sec="math"] .rationale { font-size: 13.7px; line-height: 1.6; }

.paper-head { display: flex; align-items: center; gap: 10px; padding-bottom: 14px; margin-bottom: 20px; border-bottom: 1px solid var(--border); }
.qnum {
  width: 27px; height: 27px; border-radius: 8px; display: grid; place-items: center; flex: none;
  background: var(--text); color: var(--surface); font-weight: 700; font-size: 13px;
}
.flag-btn { margin-left: auto; display: inline-flex; align-items: center; gap: 6px; border: 0; background: none; cursor: pointer; color: var(--muted); font-size: 12.5px; font-weight: 600; padding: 5px 9px; border-radius: 8px; }
.flag-btn:hover { background: var(--surface-2); }
.flag-btn.on { color: var(--warn); background: var(--warn-soft); }
.flag-btn svg { width: 14px; height: 14px; fill: none; stroke: currentColor; stroke-width: 2; }
.flag-btn.on svg { fill: currentColor; }

.qbody { font-size: 15.5px; line-height: 1.62; }
.qbody p { margin: 0 0 14px; }
.qbody p:last-child { margin-bottom: 0; }
.qbody img, .rationale img, .choice .ct img {
  display: block; filter: var(--img-filter);
  image-rendering: -webkit-optimize-contrast;
}
.qbody u { text-underline-offset: 3px; }

.choices { display: grid; gap: 10px; margin-top: 22px; }
.choice {
  display: flex; align-items: flex-start; gap: 13px; width: 100%; text-align: left;
  padding: 13px 15px; border: 1.5px solid var(--border-strong); border-radius: 12px;
  background: var(--paper); cursor: pointer; transition: border-color .12s, background .12s;
}
.choice:hover { border-color: var(--brand); }
.choice .ltr {
  width: 25px; height: 25px; flex: none; border-radius: 50%; display: grid; place-items: center;
  border: 1.5px solid var(--border-strong); font-size: 12.5px; font-weight: 700; color: var(--muted);
}
.choice .ct { flex: 1; min-width: 0; padding-top: 1px; }
.choice .ct img { max-width: 100%; }
.choice.sel { border-color: var(--brand); background: var(--brand-soft); }
.choice.sel .ltr { background: var(--brand); border-color: var(--brand); color: #fff; }
.choice.out { opacity: .45; }
.choice.out .ct { text-decoration: line-through; text-decoration-thickness: 1.5px; }
.choice.right { border-color: var(--good); background: var(--good-soft); }
.choice.right .ltr { background: var(--good); border-color: var(--good); color: #fff; }
.choice.wrong { border-color: var(--bad); background: var(--bad-soft); }
.choice.wrong .ltr { background: var(--bad); border-color: var(--bad); color: #fff; }
.cross {
  border: 0; background: none; cursor: pointer; color: var(--muted); font-size: 11px; font-weight: 700;
  padding: 3px 7px; border-radius: 6px; align-self: center; flex: none; letter-spacing: .04em;
  text-decoration: line-through; text-decoration-thickness: 1.3px;
}
.cross:hover { background: var(--surface-2); color: var(--text); }

.spr-box { margin-top: 22px; }
.spr-box input { max-width: 260px; font-size: 17px; font-weight: 600; letter-spacing: .01em; }
.spr-hint { margin-top: 8px; font-size: 12.5px; color: var(--muted); }

.verdict { margin-top: 22px; padding: 15px 18px; border-radius: 12px; border: 1px solid var(--border); }
.verdict.ok { background: var(--good-soft); border-color: transparent; }
.verdict.no { background: var(--bad-soft); border-color: transparent; }
.verdict h4 { font-size: 14px; margin-bottom: 6px; display: flex; align-items: center; gap: 7px; }
.verdict.ok h4 { color: var(--good); }
.verdict.no h4 { color: var(--bad); }
.rationale { font-size: 14.5px; line-height: 1.6; margin-top: 10px; }
.rationale p { margin: 0 0 12px; }

.pfoot {
  position: fixed; bottom: 0; left: 0; right: 0; z-index: 30;
  display: flex; align-items: center; gap: 12px; padding: 13px 24px;
  background: color-mix(in srgb, var(--surface) 92%, transparent);
  backdrop-filter: blur(12px); border-top: 1px solid var(--border);
}
.pfoot .mid { margin: 0 auto; display: flex; gap: 10px; align-items: center; }
.nav-toggle {
  display: inline-flex; align-items: center; gap: 8px; padding: 9px 15px; border-radius: 10px;
  border: 1px solid var(--border-strong); background: var(--surface); cursor: pointer; font-weight: 600; font-size: 13.5px;
}
.nav-toggle:hover { border-color: var(--brand); }

/* ========================================================= navigator ==== */
.overlay { position: fixed; inset: 0; z-index: 60; background: rgba(9, 14, 28, .45); display: grid; place-items: center; padding: 24px; }
.overlay[hidden] { display: none; }   /* an explicit display would beat [hidden] */
.modal { width: 100%; max-width: 520px; background: var(--surface); border-radius: 18px; box-shadow: var(--shadow-lg); border: 1px solid var(--border); overflow: hidden; }
.modal-head { padding: 18px 22px; border-bottom: 1px solid var(--border); display: flex; align-items: center; justify-content: space-between; }
.modal-body { padding: 20px 22px; max-height: 60vh; overflow: auto; }
.modal-foot { padding: 15px 22px; border-top: 1px solid var(--border); display: flex; gap: 10px; justify-content: flex-end; }
.qgrid { display: grid; grid-template-columns: repeat(auto-fill, minmax(46px, 1fr)); gap: 9px; }
.qcell {
  aspect-ratio: 1; border-radius: 10px; border: 1.5px solid var(--border-strong); background: var(--surface);
  font-weight: 650; font-size: 13.5px; cursor: pointer; position: relative;
}
.qcell:hover { border-color: var(--brand); }
.qcell.done { background: var(--brand-soft); border-color: var(--brand-line); color: var(--brand); }
.qcell.cur { outline: 2.5px solid var(--brand); outline-offset: 1px; }
.qcell.flag::after { content: ''; position: absolute; top: -4px; right: -4px; width: 9px; height: 9px; border-radius: 50%; background: var(--warn); }
.qcell.ok { background: var(--good-soft); border-color: var(--good); color: var(--good); }
.qcell.bad { background: var(--bad-soft); border-color: var(--bad); color: var(--bad); }
.legend { display: flex; gap: 16px; flex-wrap: wrap; font-size: 12px; color: var(--muted); margin-bottom: 16px; }
.legend i { width: 11px; height: 11px; border-radius: 4px; display: inline-block; margin-right: 5px; vertical-align: -1px; border: 1.5px solid var(--border-strong); }

/* ========================================================== results ==== */
.score-hero { display: flex; align-items: center; gap: 34px; flex-wrap: wrap; padding: 28px; }
.score-hero .ring { width: 156px; height: 156px; }
.score-hero .ring b { font-size: 34px; }
.bd-table { width: 100%; border-collapse: collapse; font-size: 13.5px; }
.bd-table th { text-align: left; font-size: 11.5px; text-transform: uppercase; letter-spacing: .06em; color: var(--muted); padding: 0 10px 10px; font-weight: 700; }
.bd-table td { padding: 11px 10px; border-top: 1px solid var(--border); }
.bd-table .mini-bar { height: 6px; border-radius: 3px; background: var(--border); overflow: hidden; min-width: 90px; }
.bd-table .mini-bar i { display: block; height: 100%; background: var(--brand); }

.rev-list { display: grid; gap: 10px; }
.rev-item { border: 1px solid var(--border); border-radius: 12px; background: var(--surface); overflow: hidden; }
.rev-head { display: flex; align-items: center; gap: 13px; padding: 13px 16px; cursor: pointer; }
.rev-head:hover { background: var(--surface-2); }
.rev-badge { width: 26px; height: 26px; border-radius: 8px; display: grid; place-items: center; font-size: 12px; font-weight: 700; flex: none; }
.rev-badge.ok { background: var(--good-soft); color: var(--good); }
.rev-badge.bad { background: var(--bad-soft); color: var(--bad); }
.rev-badge.skip { background: var(--surface-2); color: var(--muted); }
.rev-title { flex: 1; min-width: 0; font-size: 13.5px; font-weight: 550; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.rev-body { display: none; padding: 4px 16px 20px; border-top: 1px solid var(--border); }
.rev-item.open .rev-body { display: block; }
.ans-cmp { display: flex; gap: 22px; flex-wrap: wrap; margin: 16px 0; font-size: 13.5px; }
.ans-cmp div b { display: block; font-size: 11px; text-transform: uppercase; letter-spacing: .06em; color: var(--muted); margin-bottom: 3px; }

.empty { text-align: center; padding: 70px 20px; color: var(--muted); }
.empty h3 { font-size: 17px; margin-bottom: 8px; color: var(--text); }
.loading { display: grid; place-items: center; padding: 90px 20px; gap: 14px; color: var(--muted); }
.spinner { width: 30px; height: 30px; border: 3px solid var(--border); border-top-color: var(--brand); border-radius: 50%; animation: spin .8s linear infinite; }
@keyframes spin { to { transform: rotate(360deg); } }

.hist-row { display: flex; align-items: center; gap: 16px; padding: 15px 18px; border-bottom: 1px solid var(--border); }
.hist-row:last-child { border-bottom: 0; }
.hist-row:hover { background: var(--surface-2); }
.hist-score { font-size: 19px; font-weight: 700; letter-spacing: -.02em; width: 62px; flex: none; }

.test-card { display: flex; gap: 18px; align-items: center; padding: 22px; }
.test-card .num { width: 46px; height: 46px; border-radius: 13px; background: var(--brand-soft); color: var(--brand); display: grid; place-items: center; font-weight: 750; flex: none; }

@media (max-width: 860px) {
  .topnav { display: none; }
  .setup-grid { grid-template-columns: 1fr; }
  .summary-card { position: static; }
  .paper { padding: 22px 18px 26px; }
  .view { padding: 22px 16px 90px; }
  .score-hero { gap: 22px; padding: 20px; }
}