/* =========================================================================
   RIPE NCC Trainer — design system
   Ported from the original single-file IPv6 Fundamentals trainer artifact:
   graph-paper paper stock, mono display type, aqua / amber / crimson accents,
   the nibble ruler progress strip and the option/feedback card.

   Fonts are a self-contained stack: IBM Plex if the machine happens to have it,
   otherwise the platform's own UI mono/sans. Nothing is fetched from a CDN.
   ========================================================================= */

:root {
  --ink: #0d1b21;
  --ink2: #4d626b;
  --ink3: #7b8e96;
  --paper: #e7eceb;
  --card: #ffffff;
  --card2: #f4f8f8;
  --rule: #c3d0d1;
  --rule2: #e0e8e8;
  --track: #d6dede;

  --aqua: #00807d;
  --aqua-bg: #dcefee;
  --aqua-dk: #005d5b;
  --amber: #9a6a05;
  --amber-bg: #f8eed6;
  --crimson: #9e2246;
  --crimson-bg: #f8e4e9;
  --violet: #453a6b;
  --violet-bg: #e6e3f1;

  --code-bg: #eef3f3;
  --shadow: 0 1px 0 rgba(13, 27, 33, .04);
  --overlay: rgba(13, 27, 33, .45);

  --mono: "IBM Plex Mono", ui-monospace, SFMono-Regular, "SF Mono", Menlo, Consolas, "DejaVu Sans Mono", monospace;
  --sans: "IBM Plex Sans", system-ui, -apple-system, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;

  --sp: 1.25rem;
  --page: 880px;
  --wide: 1180px;
  --radius: 2px;
  color-scheme: light;
}

:root[data-theme="dark"] {
  --ink: #dde8e7;
  --ink2: #9fb3b4;
  --ink3: #7a8f93;
  --paper: #0b1316;
  --card: #121e22;
  --card2: #17262b;
  --rule: #29393e;
  --rule2: #172428;
  --track: #24343a;

  --aqua: #3fb3ab;
  --aqua-bg: #0e2c2b;
  --aqua-dk: #74d3cb;
  --amber: #d9a441;
  --amber-bg: #2d2413;
  --crimson: #e57f97;
  --crimson-bg: #331520;
  --violet: #a99ce0;
  --violet-bg: #211d33;

  --code-bg: #1b2b30;
  --shadow: none;
  --overlay: rgba(0, 0, 0, .6);
  color-scheme: dark;
}

@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --ink: #dde8e7;
    --ink2: #9fb3b4;
    --ink3: #7a8f93;
    --paper: #0b1316;
    --card: #121e22;
    --card2: #17262b;
    --rule: #29393e;
    --rule2: #172428;
    --track: #24343a;

    --aqua: #3fb3ab;
    --aqua-bg: #0e2c2b;
    --aqua-dk: #74d3cb;
    --amber: #d9a441;
    --amber-bg: #2d2413;
    --crimson: #e57f97;
    --crimson-bg: #331520;
    --violet: #a99ce0;
    --violet-bg: #211d33;

    --code-bg: #1b2b30;
    --shadow: none;
    --overlay: rgba(0, 0, 0, .6);
    color-scheme: dark;
  }
}

/* --------------------------------------------------------------- base --- */

* { box-sizing: border-box; }
html, body { margin: 0; padding: 0; }
html { -webkit-text-size-adjust: 100%; }

body {
  background: var(--paper);
  background-image:
    linear-gradient(var(--rule2) 1px, transparent 1px),
    linear-gradient(90deg, var(--rule2) 1px, transparent 1px);
  background-size: 28px 28px;
  color: var(--ink);
  font-family: var(--sans);
  font-size: 16px;
  line-height: 1.55;
  -webkit-font-smoothing: antialiased;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

#app { display: flex; flex-direction: column; min-height: 100vh; }

a { color: var(--aqua-dk); text-underline-offset: .15em; }
a:hover { color: var(--aqua); }

:focus-visible { outline: 2px solid var(--ink); outline-offset: 2px; }
:root[data-theme="dark"] :focus-visible { outline-color: var(--aqua-dk); }

code {
  font-family: var(--mono);
  font-size: .94em;
  background: var(--code-bg);
  padding: .05em .28em;
  border-radius: var(--radius);
  overflow-wrap: anywhere;
}

hr { border: 0; border-top: 1px solid var(--rule); margin: 1.4rem 0; }

.skip {
  position: absolute; left: -999px; top: 0; z-index: 100;
  background: var(--ink); color: var(--paper); padding: .6rem 1rem;
  font-family: var(--mono); font-size: .8rem;
}
.skip:focus { left: 0; }

.wrap {
  width: 100%;
  max-width: var(--page);
  margin: 0 auto;
  padding: 0 var(--sp) 4rem;
  flex: 1 0 auto;
}
.wrap.wide { max-width: var(--wide); }
main:focus { outline: none; }

/* -------------------------------------------------------------- topbar --- */

header.bar {
  position: sticky; top: 0; z-index: 20;
  background: color-mix(in srgb, var(--paper) 93%, transparent);
  backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--rule);
}
@supports not (background: color-mix(in srgb, red 50%, blue)) {
  header.bar { background: var(--paper); }
}
.bar-in {
  max-width: var(--page); margin: 0 auto;
  padding: .6rem var(--sp);
  display: flex; align-items: center; gap: .8rem; flex-wrap: wrap;
}
.wide-page .bar-in { max-width: var(--wide); }

.mark {
  font-family: var(--mono); font-weight: 700; font-size: .82rem;
  letter-spacing: .12em; text-transform: uppercase; white-space: nowrap;
  color: var(--ink); text-decoration: none;
}
.mark span { color: var(--aqua); }
.mark:hover { color: var(--ink); }

.nav { display: flex; align-items: center; gap: .35rem; margin-left: auto; flex-wrap: wrap; }
.navlink {
  font-family: var(--mono); font-size: .72rem; letter-spacing: .1em; text-transform: uppercase;
  color: var(--ink2); text-decoration: none; padding: .34rem .55rem; border: 1px solid transparent;
  border-radius: var(--radius); white-space: nowrap;
}
.navlink:hover { color: var(--ink); border-color: var(--rule); }
.navlink.on { color: var(--aqua-dk); border-color: var(--aqua); background: var(--aqua-bg); }
.navlink.as-button { background: none; cursor: pointer; font: inherit; font-family: var(--mono); font-size: .72rem; letter-spacing: .1em; text-transform: uppercase; }
.who {
  font-family: var(--mono); font-size: .72rem; color: var(--ink3);
  max-width: 16ch; overflow: hidden; text-overflow: ellipsis; white-space: nowrap;
}
.iconbtn {
  background: none; border: 1px solid transparent; color: var(--ink2);
  cursor: pointer; font-size: .95rem; line-height: 1; padding: .32rem .45rem; border-radius: var(--radius);
}
.iconbtn:hover { color: var(--ink); border-color: var(--rule); }

.bar-meta { display: flex; align-items: center; gap: .4rem; flex-wrap: wrap; width: 100%; }
.bar-meta:empty { display: none; }
.ruler-slot { max-width: var(--page); margin: 0 auto; padding: 0 var(--sp) .5rem; }
.wide-page .ruler-slot { max-width: var(--wide); }
.ruler-slot.hidden { display: none; }

.foot {
  flex: 0 0 auto;
  border-top: 1px solid var(--rule);
  padding: 1.2rem 0 2rem;
  font-size: .78rem; color: var(--ink3);
}
.foot .wrap { padding-bottom: 0; }
.foot p { margin: 0; max-width: 70ch; }

/* --------------------------------------------------------- typography --- */

h1 {
  font-family: var(--mono); font-weight: 700;
  font-size: clamp(1.5rem, 4.4vw, 2.25rem); line-height: 1.14; letter-spacing: -.02em;
  margin: 0;
}
h2 {
  font-family: var(--mono); font-size: .78rem; letter-spacing: .16em; text-transform: uppercase;
  color: var(--ink2); margin: 0; font-weight: 600;
}
h3 { font-family: var(--mono); font-size: 1rem; margin: 0 0 .4rem; letter-spacing: -.01em; }
h4 { font-family: var(--mono); font-size: .8rem; margin: 0 0 .3rem; letter-spacing: .04em; }
p { margin: 0 0 .8rem; }
p:last-child { margin-bottom: 0; }

.eyebrow {
  font-family: var(--mono); font-size: .7rem; letter-spacing: .18em; text-transform: uppercase;
  color: var(--aqua-dk); margin: 0 0 .6rem;
}
.lede { font-size: 1.02rem; color: var(--ink2); max-width: 62ch; margin: .8rem 0 0; }
.muted { color: var(--ink2); }
.dim { color: var(--ink3); }
.small { font-size: .84rem; }
.mono { font-family: var(--mono); }
.nowrap { white-space: nowrap; }
.breakall { overflow-wrap: anywhere; }
.center { text-align: center; }
.right { text-align: right; }
.ok-text { color: var(--aqua-dk); }
.bad-text { color: var(--crimson); }
.warn-text { color: var(--amber); }

.pagehead { padding: 2.4rem 0 .4rem; }
.pagehead-row { display: flex; align-items: flex-start; gap: 1rem; flex-wrap: wrap; }
.pagehead-row h1 { flex: 1 1 20ch; }
.pagehead-actions { display: flex; gap: .5rem; flex-wrap: wrap; }
.pagehead-meta { display: flex; gap: .45rem; flex-wrap: wrap; margin-top: .8rem; }

.sechead {
  display: flex; align-items: center; gap: 1rem; flex-wrap: wrap;
  margin: 2.4rem 0 1rem; padding-bottom: .5rem; border-bottom: 1px solid var(--rule);
}
.sechead h2 { flex: 1 1 auto; }
.sechead-right { display: flex; gap: .5rem; align-items: center; flex-wrap: wrap; }

/* ------------------------------------------------------------- layout --- */

.stack > * + * { margin-top: 1rem; }
.stack-lg > * + * { margin-top: 1.8rem; }
.row { display: flex; gap: .8rem; align-items: center; flex-wrap: wrap; }
.row.tight { gap: .4rem; }
.row.between { justify-content: space-between; }
.row.top { align-items: flex-start; }
.spacer { flex: 1 1 auto; }
.grow { flex: 1 1 auto; min-width: 0; }
.grid-2 { display: grid; grid-template-columns: 1fr 1fr; gap: 1rem; }
.grid-3 { display: grid; grid-template-columns: repeat(3, 1fr); gap: 1rem; }
.cards { display: grid; grid-template-columns: repeat(auto-fill, minmax(260px, 1fr)); gap: 1rem; }
.mt { margin-top: 1rem; }
.mt-sm { margin-top: .5rem; }
.mt-lg { margin-top: 2rem; }
.hidden { display: none !important; }
.sr-only {
  position: absolute; width: 1px; height: 1px; padding: 0; margin: -1px;
  overflow: hidden; clip: rect(0 0 0 0); white-space: nowrap; border: 0;
}

/* --------------------------------------------------------------- chips --- */

.chip {
  font-family: var(--mono); font-size: .7rem; letter-spacing: .08em; text-transform: uppercase;
  border: 1px solid var(--rule); background: var(--card); padding: .24rem .55rem;
  border-radius: var(--radius); color: var(--ink2); white-space: nowrap;
  display: inline-flex; align-items: center; gap: .35rem;
}
.chip b { font-weight: 600; color: var(--ink); }
.chip.live, .chip.ok { border-color: var(--aqua); color: var(--aqua-dk); background: var(--aqua-bg); }
.chip.warn { border-color: var(--amber); color: var(--amber); background: var(--amber-bg); }
.chip.bad { border-color: var(--crimson); color: var(--crimson); background: var(--crimson-bg); }
button.chip { cursor: pointer; }

.badge {
  font-family: var(--mono); font-size: .64rem; letter-spacing: .12em; text-transform: uppercase;
  font-weight: 600; padding: .18rem .45rem; border: 1px solid var(--rule); border-radius: var(--radius);
  color: var(--ink2); background: var(--card); white-space: nowrap;
}
.badge-aqua { color: var(--aqua-dk); border-color: var(--aqua); background: var(--aqua-bg); }
.badge-violet { color: var(--violet); border-color: var(--violet); background: var(--violet-bg); }
.badge-crimson { color: var(--crimson); border-color: var(--crimson); background: var(--crimson-bg); }
.badge-amber { color: var(--amber); border-color: var(--amber); background: var(--amber-bg); }

kbd {
  font-family: var(--mono); font-size: .72rem; border: 1px solid var(--rule);
  border-bottom-width: 2px; background: var(--card); padding: .06rem .35rem;
  border-radius: var(--radius); color: var(--ink);
}
.keyhint { display: inline-flex; align-items: center; gap: .35rem; font-size: .76rem; color: var(--ink2); }
.keybar {
  display: flex; gap: 1rem; flex-wrap: wrap; margin-top: 1rem;
  padding-top: .8rem; border-top: 1px dashed var(--rule);
}

/* -------------------------------------------------------- nibble ruler --- */

.ruler { display: flex; gap: 2px; flex-wrap: wrap; width: 100%; padding-bottom: .15rem; }
.nib {
  width: 13px; height: 9px; background: var(--track); border-radius: 1px; flex: 0 0 auto;
  border: 0; padding: 0; cursor: pointer; position: relative;
}
/* The cells are deliberately tiny, so extend the hit area vertically well past
   the ink. Previous/Next and the "Review flagged" dialog remain the full-size
   alternative for anyone who cannot hit a cell. */
.nib::after { content: ""; position: absolute; left: -1px; right: -1px; top: -8px; bottom: -8px; }
.nib:hover { outline: 1px solid var(--ink3); outline-offset: 1px; }
.nib.done { background: var(--aqua); }
.nib.bad { background: var(--crimson); }
.nib.answered { background: var(--ink2); }
.nib.now { background: var(--ink); height: 13px; margin-top: -4px; }
.nib.flag { box-shadow: inset 0 0 0 2px var(--amber); }
.nib.gap { margin-right: 6px; }
:root[data-theme="dark"] .nib.now { background: var(--aqua-dk); }

/* --------------------------------------------------------------- cards --- */

.card {
  background: var(--card); border: 1px solid var(--rule);
  padding: 1.25rem; box-shadow: var(--shadow); border-radius: var(--radius);
}
.card.pad-lg { padding: 1.8rem; }
.card.flush { padding: 0; }
.card-hd {
  display: flex; align-items: baseline; gap: .8rem; flex-wrap: wrap;
  margin: -1.25rem -1.25rem 1rem; padding: .9rem 1.25rem;
  border-bottom: 1px solid var(--rule); background: var(--card2);
}
.card-hd h3 { margin: 0; }
.card-ft {
  margin: 1.25rem -1.25rem -1.25rem; padding: .9rem 1.25rem;
  border-top: 1px solid var(--rule); background: var(--card2);
  display: flex; gap: .6rem; flex-wrap: wrap; align-items: center;
}
.panel { border: 1px solid var(--rule); background: var(--card2); padding: 1rem; border-radius: var(--radius); }
.panel.ok { border-color: var(--aqua); background: var(--aqua-bg); }
.panel.warn { border-color: var(--amber); background: var(--amber-bg); }
.panel.bad { border-color: var(--crimson); background: var(--crimson-bg); }

/* exam cards on the dashboard */
.examcard {
  display: flex; flex-direction: column; gap: .8rem;
  background: var(--card); border: 1px solid var(--rule); padding: 1.1rem;
  border-radius: var(--radius); text-decoration: none; color: inherit;
  transition: border-color .12s, transform .12s;
}
a.examcard:hover { border-color: var(--aqua); transform: translateY(-2px); color: inherit; }
.examcard-top { display: flex; gap: .8rem; align-items: flex-start; }
.examcard-top .grow { flex: 1 1 auto; min-width: 0; }
.examcard h3 { font-size: .98rem; margin: 0 0 .35rem; }
.examcard .summary { font-size: .84rem; color: var(--ink2); margin: 0; }
.examcard-facts {
  display: flex; gap: .8rem; flex-wrap: wrap; font-family: var(--mono);
  font-size: .7rem; letter-spacing: .06em; text-transform: uppercase; color: var(--ink3);
  border-top: 1px solid var(--rule2); padding-top: .7rem; margin-top: auto;
}
.examcard-facts b { color: var(--ink); font-weight: 600; }
.examcard.disabled { opacity: .72; background: var(--card2); border-style: dashed; }
.examcard.disabled:hover { transform: none; border-color: var(--rule); }

/* ------------------------------------------------------------- buttons --- */

.btn {
  font-family: var(--mono); font-size: .76rem; letter-spacing: .1em; text-transform: uppercase;
  font-weight: 600; background: var(--ink); color: var(--paper);
  border: 1px solid var(--ink); padding: .62rem 1.15rem; cursor: pointer;
  border-radius: var(--radius); text-decoration: none; display: inline-flex;
  align-items: center; justify-content: center; gap: .5rem; line-height: 1.2;
}
a.btn { color: var(--paper); }
.btn:hover { background: color-mix(in srgb, var(--ink) 88%, var(--paper)); color: var(--paper); }
.btn:disabled, .btn[aria-disabled="true"] { opacity: .38; cursor: not-allowed; }
.btn.ghost { background: transparent; color: var(--ink); border-color: var(--rule); }
.btn.ghost:hover { background: transparent; border-color: var(--ink); color: var(--ink); }
.btn.ghost.on { border-color: var(--amber); color: var(--amber); background: var(--amber-bg); }
.btn.danger { background: var(--crimson); border-color: var(--crimson); color: #fff; }
.btn.danger:hover { background: color-mix(in srgb, var(--crimson) 85%, #000); }
:root[data-theme="dark"] .btn.danger { color: #1a0a10; }
.btn.small { font-size: .68rem; padding: .38rem .7rem; letter-spacing: .08em; }
.btn.block { width: 100%; }

/* Large call-to-action. The default .btn is a compact toolbar control; a primary action a
   page is built around (Sign in, Accept invitation, Finish setup) needs real presence. */
.btn.lg {
  font-size: .92rem;
  letter-spacing: .07em;
  padding: .95rem 1.6rem;
  min-height: 3.1rem;
  gap: .6rem;
}

/* Accent fill, for the one action that is the point of the screen. */
.btn.accent {
  background: var(--aqua);
  border-color: var(--aqua);
  color: #fff;
  box-shadow: 0 1px 0 color-mix(in srgb, var(--aqua) 60%, #000);
  transition: background .12s, border-color .12s, transform .12s, box-shadow .12s;
}
a.btn.accent { color: #fff; }
.btn.accent:hover:not(:disabled) {
  background: var(--aqua-dk);
  border-color: var(--aqua-dk);
  color: #fff;
  transform: translateY(-1px);
  box-shadow: 0 3px 0 color-mix(in srgb, var(--aqua) 55%, #000);
}
.btn.accent:active:not(:disabled) {
  transform: translateY(0);
  box-shadow: 0 1px 0 color-mix(in srgb, var(--aqua) 60%, #000);
}
/* In dark mode the accent is a light teal, so the label must go dark to stay readable. */
:root[data-theme="dark"] .btn.accent,
:root[data-theme="dark"] a.btn.accent { color: #06201f; box-shadow: none; }
:root[data-theme="dark"] .btn.accent:hover:not(:disabled) { color: #06201f; box-shadow: none; }
.btn.link {
  background: none; border: none; color: var(--aqua-dk); text-transform: none;
  letter-spacing: 0; font-family: var(--sans); font-size: .88rem; padding: 0; text-decoration: underline;
}
.btn.link:hover { background: none; color: var(--aqua); }
.btnrow { display: flex; gap: .6rem; flex-wrap: wrap; align-items: center; }

/* launch buttons on the exam page */
.launch {
  display: flex; gap: .9rem; align-items: flex-start; text-align: left; width: 100%;
  background: var(--card); border: 1px solid var(--rule); padding: 1rem;
  font: inherit; color: inherit; cursor: pointer; border-radius: var(--radius);
  transition: border-color .12s, transform .12s;
}
.launch:hover:not(:disabled) { border-color: var(--aqua); transform: translateY(-2px); }
.launch:disabled { opacity: .5; cursor: not-allowed; }
.launch .lnum { font-family: var(--mono); font-size: .7rem; letter-spacing: .14em; color: var(--aqua-dk); }
.launch h3 { font-size: .95rem; margin: .15rem 0 .35rem; }
.launch p { margin: 0; font-size: .85rem; color: var(--ink2); }

/* --------------------------------------------------------------- forms --- */

.field { margin: 0 0 1rem; }
.field:last-child { margin-bottom: 0; }
.field label {
  display: block; font-family: var(--mono); font-size: .72rem; letter-spacing: .1em;
  text-transform: uppercase; color: var(--ink2); margin-bottom: .35rem;
}
.field .req { color: var(--crimson); margin-left: .2rem; }
input[type="text"], input[type="email"], input[type="password"], input[type="number"],
input[type="url"], input[type="search"], textarea, select {
  width: 100%; font: inherit; font-size: .95rem; color: var(--ink);
  background: var(--card); border: 1px solid var(--rule); border-radius: var(--radius);
  padding: .58rem .7rem;
}
input[type="text"], input[type="password"], input[type="email"], input[type="url"] { font-family: var(--sans); }
textarea { font-family: var(--mono); font-size: .85rem; resize: vertical; }
input:focus-visible, textarea:focus-visible, select:focus-visible { outline: 2px solid var(--aqua); outline-offset: 0; border-color: var(--aqua); }
input:disabled, select:disabled, textarea:disabled { background: var(--card2); color: var(--ink3); cursor: not-allowed; }
input::placeholder, textarea::placeholder { color: var(--ink3); }
.field.has-err input, .field.has-err select, .field.has-err textarea { border-color: var(--crimson); }
.field-hint { font-size: .78rem; color: var(--ink3); margin: .35rem 0 0; }
.field-err { font-size: .78rem; color: var(--crimson); margin: .35rem 0 0; font-weight: 500; }
.selectwrap { position: relative; }
.selectwrap select { appearance: none; padding-right: 2rem; }
.selectwrap::after {
  content: "▾"; position: absolute; right: .7rem; top: 50%; transform: translateY(-50%);
  pointer-events: none; color: var(--ink3); font-size: .8rem;
}
.field-check { margin-bottom: .8rem; }
.check { display: flex; align-items: flex-start; gap: .6rem; cursor: pointer; text-transform: none; letter-spacing: 0; font-family: var(--sans); font-size: .92rem; color: var(--ink); }
.check input { width: 1.05rem; height: 1.05rem; margin: .18rem 0 0; flex: 0 0 auto; accent-color: var(--aqua); }
.form-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 0 1rem; }
.form-grid .full { grid-column: 1 / -1; }
fieldset { border: 1px solid var(--rule); border-radius: var(--radius); padding: 1rem; margin: 0 0 1rem; }
legend { font-family: var(--mono); font-size: .72rem; letter-spacing: .1em; text-transform: uppercase; color: var(--ink2); padding: 0 .4rem; }

.formmsg {
  font-size: .88rem; padding: .65rem .8rem; border: 1px solid var(--crimson);
  background: var(--crimson-bg); color: var(--crimson); border-radius: var(--radius);
  margin: 0 0 1rem;
}
.formmsg-ok { border-color: var(--aqua); background: var(--aqua-bg); color: var(--aqua-dk); }
.formmsg-info { border-color: var(--rule); background: var(--card2); color: var(--ink2); }
.formmsg-warn { border-color: var(--amber); background: var(--amber-bg); color: var(--amber); }

.pwmeter { margin: -.4rem 0 1rem; }
.pm-bars { display: flex; gap: 3px; }
.pm-seg { height: 4px; flex: 1 1 0; background: var(--track); border-radius: 1px; }
.pm-seg.on { background: var(--amber); }
.pm-seg.on.s3 { background: var(--aqua); }
.pm-seg.on.s4 { background: var(--aqua); }
.pm-text { display: flex; gap: .5rem; flex-wrap: wrap; margin-top: .35rem; font-size: .76rem; }
.pm-label { font-family: var(--mono); text-transform: uppercase; letter-spacing: .08em; color: var(--ink2); }
.pm-hint { color: var(--ink3); }

.authcard { max-width: 30rem; margin: 3rem auto 0; }
.authcard .card { padding: 1.6rem; }
.authcard h1 { font-size: 1.4rem; margin-bottom: .3rem; }

/* ------------------------------------------------------------ question --- */

.qcard { background: var(--card); border: 1px solid var(--rule); padding: 1.5rem; border-radius: var(--radius); }
.qhead { display: flex; gap: .7rem; align-items: baseline; flex-wrap: wrap; margin-bottom: 1rem; }
.qnum { font-family: var(--mono); font-size: .72rem; letter-spacing: .14em; text-transform: uppercase; color: var(--aqua-dk); }
.qtag {
  font-family: var(--mono); font-size: .64rem; letter-spacing: .1em; text-transform: uppercase;
  color: var(--ink3); border: 1px solid var(--rule); padding: .1rem .4rem; border-radius: var(--radius);
}
.qtext { font-size: 1.1rem; font-weight: 500; line-height: 1.45; margin: 0 0 .3rem; }
.qtext code, .opt code, .exp code, .qhint code, .ans code { font-family: var(--mono); font-size: .94em; background: var(--code-bg); padding: .05em .28em; border-radius: var(--radius); }
.qhint {
  font-family: var(--mono); font-size: .72rem; letter-spacing: .06em; text-transform: uppercase;
  color: var(--amber); margin: .7rem 0 0; display: flex; gap: .5rem; align-items: center; flex-wrap: wrap;
}
.qhint.done { color: var(--aqua-dk); }

.opts { margin: 1.2rem 0 0; display: flex; flex-direction: column; gap: .5rem; }
.opt {
  display: flex; gap: .8rem; align-items: flex-start; text-align: left; width: 100%;
  background: var(--card); border: 1px solid var(--rule); padding: .75rem .85rem;
  font: inherit; color: inherit; cursor: pointer; line-height: 1.45; border-radius: var(--radius);
  transition: border-color .1s, background .1s;
}
.opt:hover:not(:disabled) { border-color: var(--ink3); background: var(--card2); }
.opt .hexm {
  font-family: var(--mono); font-size: .78rem; font-weight: 600; color: var(--ink3);
  border: 1px solid var(--rule); width: 1.6rem; height: 1.6rem; display: flex;
  align-items: center; justify-content: center; flex: 0 0 auto; border-radius: var(--radius);
}
.opt.multi .hexm { border-radius: var(--radius); }
.opt.sel { border-color: var(--ink); background: var(--card2); }
.opt.sel .hexm { background: var(--ink); color: var(--paper); border-color: var(--ink); }
.opt.right { border-color: var(--aqua); background: var(--aqua-bg); }
.opt.right .hexm { background: var(--aqua); color: var(--card); border-color: var(--aqua); }
.opt.wrong { border-color: var(--crimson); background: var(--crimson-bg); }
.opt.wrong .hexm { background: var(--crimson); color: var(--card); border-color: var(--crimson); }
.opt.missed { border-style: dashed; border-color: var(--aqua); }
.opt:disabled { cursor: default; opacity: 1; }
.opt .otxt { flex: 1; }
.opt .mark-note {
  font-family: var(--mono); font-size: .64rem; letter-spacing: .1em; text-transform: uppercase;
  color: var(--ink2); align-self: center; white-space: nowrap;
}

/* per-option feedback — the heart of the trainer */
.exp { margin-top: 1.2rem; border-top: 1px solid var(--rule); padding-top: 1.1rem; font-size: .95rem; }
.verdict {
  font-family: var(--mono); font-size: .8rem; font-weight: 700; letter-spacing: .12em;
  text-transform: uppercase; margin-bottom: .9rem;
}
.verdict.ok { color: var(--aqua-dk); }
.verdict.no { color: var(--crimson); }
.block { border-left: 3px solid var(--rule); padding: .1rem 0 .1rem .85rem; margin-bottom: .9rem; }
.block:last-child { margin-bottom: 0; }
.block.no { border-color: var(--crimson); }
.block.ok { border-color: var(--aqua); }
.block.warn { border-color: var(--amber); }
.block h4 {
  font-family: var(--mono); font-size: .68rem; letter-spacing: .12em; text-transform: uppercase;
  color: var(--ink2); margin: 0 0 .3rem; font-weight: 600;
}
.block p { margin: 0; }
.ref { font-family: var(--mono); font-size: .7rem; letter-spacing: .06em; color: var(--ink3); margin-top: .9rem; }

.controls { display: flex; gap: .6rem; align-items: center; margin-top: 1.3rem; flex-wrap: wrap; }

/* ------------------------------------------------------------ progress --- */

.track { display: inline-block; height: 6px; background: var(--track); position: relative; width: 100%; border-radius: 1px; overflow: hidden; vertical-align: middle; }
.track b { position: absolute; inset: 0 auto 0 0; background: var(--aqua); display: block; }
.track b.fill-aqua { background: var(--aqua); }
.track b.fill-crimson { background: var(--crimson); }
.track b.fill-amber { background: var(--amber); }
.track b.fill-ink { background: var(--ink2); }
.track b.fill-plain { background: var(--ink3); }
.track.tall { height: 10px; }

.ringwrap { position: relative; display: inline-flex; align-items: center; justify-content: center; flex: 0 0 auto; }
.ring circle { transition: stroke-dasharray .4s ease; }
.ring-bg { stroke: var(--track); }
.ring-fg { stroke: var(--aqua); }
.ring-ok { stroke: var(--aqua); }
.ring-warn { stroke: var(--amber); }
.ring-bad { stroke: var(--crimson); }
.ring-plain { stroke: var(--ink3); }
.ring-val {
  position: absolute; font-family: var(--mono); font-weight: 700; font-size: .95rem; letter-spacing: -.02em;
}
.ring-val.unknown { color: var(--ink3); font-weight: 400; }

.stats { display: grid; grid-template-columns: repeat(auto-fit, minmax(140px, 1fr)); gap: 1px; background: var(--rule); border: 1px solid var(--rule); border-radius: var(--radius); overflow: hidden; }
.stat { background: var(--card); padding: 1rem; }
.stat-val { font-family: var(--mono); font-size: 1.6rem; font-weight: 700; line-height: 1.1; letter-spacing: -.02em; }
.stat-label { font-family: var(--mono); font-size: .66rem; letter-spacing: .12em; text-transform: uppercase; color: var(--ink3); margin-top: .3rem; }
.stat-hint { font-size: .78rem; color: var(--ink2); margin-top: .35rem; }

.dom-row { display: flex; align-items: center; gap: .8rem; padding: .6rem 0; border-bottom: 1px solid var(--rule2); flex-wrap: wrap; }
.dom-row:last-child { border-bottom: 0; }
.dom-num { font-family: var(--mono); font-size: .72rem; color: var(--aqua-dk); font-weight: 600; flex: 0 0 1.6rem; }
.dom-name { flex: 1 1 14ch; min-width: 0; font-size: .92rem; }
.dom-weight { font-family: var(--mono); font-size: .7rem; color: var(--ink3); flex: 0 0 auto; }
.dom-bar { flex: 0 0 140px; }
.dom-val { font-family: var(--mono); font-size: .76rem; color: var(--ink2); width: 4.5rem; text-align: right; flex: 0 0 auto; }

/* -------------------------------------------------------------- tables --- */

.tablewrap { overflow-x: auto; border: 1px solid var(--rule); background: var(--card); border-radius: var(--radius); }
table.table { width: 100%; border-collapse: collapse; font-size: .88rem; }
table.table th {
  text-align: left; font-family: var(--mono); font-size: .66rem; letter-spacing: .12em;
  text-transform: uppercase; color: var(--ink2); font-weight: 600; padding: .7rem .8rem;
  border-bottom: 1px solid var(--rule); background: var(--card2); white-space: nowrap; position: sticky; top: 0;
}
table.table td { padding: .65rem .8rem; border-bottom: 1px solid var(--rule2); vertical-align: middle; }
table.table tr:last-child td { border-bottom: 0; }
table.table tbody tr:hover { background: var(--card2); }
table.table td.num, table.table th.num { text-align: right; font-family: var(--mono); font-size: .82rem; }
table.table td.actions { text-align: right; white-space: nowrap; }
table.table .cell-main { font-weight: 500; }
table.table .cell-sub { font-size: .78rem; color: var(--ink3); }
table.table select { font-size: .8rem; padding: .3rem .4rem; width: auto; min-width: 6.5rem; }

/* ------------------------------------------------------------- dialogs --- */

dialog.modal {
  border: 1px solid var(--rule); background: var(--card); color: var(--ink);
  padding: 0; border-radius: var(--radius); width: min(34rem, calc(100vw - 2rem));
  max-height: calc(100vh - 4rem); box-shadow: 0 18px 40px rgba(0, 0, 0, .22);
}
dialog.modal.modal-lg { width: min(52rem, calc(100vw - 2rem)); }
dialog.modal.modal-sm { width: min(26rem, calc(100vw - 2rem)); }
dialog.modal::backdrop { background: var(--overlay); backdrop-filter: blur(2px); }
.modal-form { display: flex; flex-direction: column; max-height: calc(100vh - 4rem); }
.modal-hd {
  display: flex; align-items: center; gap: 1rem; padding: .9rem 1.1rem;
  border-bottom: 1px solid var(--rule); background: var(--card2);
}
.modal-hd h2 { flex: 1 1 auto; font-size: .78rem; }
.modal-bd { padding: 1.1rem; overflow-y: auto; }
.modal-ft {
  display: flex; gap: .6rem; justify-content: flex-end; flex-wrap: wrap;
  padding: .9rem 1.1rem; border-top: 1px solid var(--rule); background: var(--card2);
}

/* -------------------------------------------------------------- toasts --- */

.toasts {
  position: fixed; right: 1rem; bottom: 1rem; z-index: 60;
  display: flex; flex-direction: column; gap: .5rem; max-width: min(26rem, calc(100vw - 2rem));
}
.toast {
  display: flex; align-items: flex-start; gap: .6rem; background: var(--card);
  border: 1px solid var(--rule); border-left-width: 3px; padding: .65rem .8rem;
  border-radius: var(--radius); box-shadow: 0 6px 18px rgba(0, 0, 0, .14); font-size: .88rem;
  animation: toast-in .18s ease-out;
}
.toast-ok { border-left-color: var(--aqua); }
.toast-warn { border-left-color: var(--amber); }
.toast-error { border-left-color: var(--crimson); }
.toast-info { border-left-color: var(--ink3); }
.toast-msg { flex: 1 1 auto; }
@keyframes toast-in { from { opacity: 0; transform: translateY(6px); } to { opacity: 1; transform: none; } }

/* ---------------------------------------------------------------- tabs --- */

.tabs { display: flex; gap: .3rem; border-bottom: 1px solid var(--rule); margin: 1.6rem 0 1.4rem; flex-wrap: wrap; }
.tab {
  font-family: var(--mono); font-size: .72rem; letter-spacing: .1em; text-transform: uppercase;
  background: none; border: 1px solid transparent; border-bottom: 0; color: var(--ink2);
  padding: .55rem .9rem; cursor: pointer; margin-bottom: -1px; text-decoration: none;
}
.tab:hover { color: var(--ink); }
.tab.on { color: var(--ink); border-color: var(--rule); background: var(--card); border-bottom: 1px solid var(--card); }

/* --------------------------------------------------------------- steps --- */

.steps { display: flex; gap: .4rem; flex-wrap: wrap; margin: 0 0 1.6rem; padding: 0; list-style: none; }
.step {
  display: flex; align-items: center; gap: .45rem; font-family: var(--mono);
  font-size: .68rem; letter-spacing: .08em; text-transform: uppercase; color: var(--ink3);
  border: 1px solid var(--rule); padding: .3rem .55rem; border-radius: var(--radius); background: var(--card);
}
.step-num { font-weight: 700; }
button.step { cursor: pointer; font: inherit; font-family: var(--mono); font-size: .68rem; letter-spacing: .08em; text-transform: uppercase; }
button.step:disabled { cursor: default; }
.step.on { color: var(--ink); border-color: var(--ink); }
.step.done { color: var(--aqua-dk); border-color: var(--aqua); background: var(--aqua-bg); }

/* -------------------------------------------------------------- score --- */

.score { background: var(--card); border: 1px solid var(--rule); padding: 2rem 1.5rem; text-align: center; border-radius: var(--radius); }
.score .pct { font-family: var(--mono); font-size: clamp(3rem, 13vw, 5rem); font-weight: 700; line-height: 1; letter-spacing: -.03em; }
.score .pct.pass { color: var(--aqua); }
.score .pct.fail { color: var(--crimson); }
.stamp {
  font-family: var(--mono); font-size: .8rem; letter-spacing: .22em; text-transform: uppercase;
  font-weight: 700; display: inline-block; border: 2px solid; padding: .35rem 1rem;
  margin-top: .9rem; transform: rotate(-1.5deg);
}
.stamp.pass { color: var(--aqua); border-color: var(--aqua); }
.stamp.fail { color: var(--crimson); border-color: var(--crimson); }
.score .sub { color: var(--ink2); font-size: .92rem; margin-top: 1rem; }

.brk-row { display: flex; align-items: center; gap: .8rem; padding: .5rem 0; border-bottom: 1px solid var(--rule2); font-size: .88rem; flex-wrap: wrap; }
.brk-row:last-child { border-bottom: 0; }
.brk-row .nm { flex: 1 1 12ch; min-width: 0; }
.brk-row .tr { width: 130px; flex: 0 0 auto; }
.brk-row .vv { font-family: var(--mono); font-size: .76rem; color: var(--ink2); width: 5.5rem; text-align: right; flex: 0 0 auto; }

.rev { background: var(--card); border: 1px solid var(--rule); padding: 1.2rem; border-radius: var(--radius); }
.rev .qtext { font-size: 1rem; }
.rev .yours { font-family: var(--mono); font-size: .72rem; letter-spacing: .06em; text-transform: uppercase; margin: .9rem 0 .3rem; color: var(--crimson); }
.rev .theirs { font-family: var(--mono); font-size: .72rem; letter-spacing: .06em; text-transform: uppercase; margin: .9rem 0 .3rem; color: var(--aqua-dk); }
.ans { font-size: .95rem; margin: 0 0 .4rem; }
.ans .m { font-family: var(--mono); color: var(--ink3); margin-right: .4rem; }

/* -------------------------------------------------------------- states --- */

.state { text-align: center; padding: 2.6rem 1.2rem; border: 1px dashed var(--rule); background: var(--card); border-radius: var(--radius); }
.state-title { font-family: var(--mono); font-size: .9rem; font-weight: 600; margin: 0 0 .4rem; }
.state-msg { color: var(--ink2); font-size: .9rem; margin: 0 auto .9rem; max-width: 52ch; }
.state-error { border-color: var(--crimson); border-style: solid; background: var(--crimson-bg); }
.state-error .state-title { color: var(--crimson); }
.state-loading { border-style: dashed; color: var(--ink2); }
.state-empty { border-style: dashed; color: var(--ink2); }
.spinner {
  display: inline-block; width: 1.1rem; height: 1.1rem; border: 2px solid var(--rule);
  border-top-color: var(--aqua); border-radius: 50%; animation: spin .7s linear infinite; margin-bottom: .6rem;
}
@keyframes spin { to { transform: rotate(360deg); } }

.skeleton { background: linear-gradient(90deg, var(--track), var(--rule2), var(--track)); background-size: 200% 100%; animation: sk 1.2s linear infinite; border-radius: var(--radius); height: 1rem; }
@keyframes sk { to { background-position: -200% 0; } }

/* ----------------------------------------------------------- clipboard --- */

.copyblock { margin: 1rem 0 0; }
.copy-label { font-family: var(--mono); font-size: .7rem; letter-spacing: .1em; text-transform: uppercase; color: var(--ink2); margin: 0 0 .35rem; }
.copyrow { display: flex; gap: .4rem; align-items: stretch; }
.copy-input { font-family: var(--mono) !important; font-size: .78rem !important; flex: 1 1 auto; min-width: 0; }
.copy-note { font-size: .78rem; color: var(--ink3); margin: .4rem 0 0; }

/* --------------------------------------------------------- responsive --- */

@media (max-width: 720px) {
  .grid-2, .grid-3, .form-grid { grid-template-columns: 1fr; }
  .pagehead { padding-top: 1.6rem; }
  .bar-in { padding: .5rem .9rem; gap: .5rem; }
  :root { --sp: .9rem; }
  .card { padding: 1rem; }
  .card-hd { margin: -1rem -1rem .9rem; padding: .8rem 1rem; }
  .card-ft { margin: 1rem -1rem -1rem; padding: .8rem 1rem; }
  .qcard { padding: 1.1rem; }
  .dom-bar { flex: 1 1 100%; order: 5; }
  .brk-row .tr { width: 100%; order: 5; }
  .who { display: none; }
  .toasts { left: 1rem; right: 1rem; max-width: none; }
}

@media (max-width: 420px) {
  .nib { width: 11px; }
  .btn { padding: .55rem .85rem; }
}

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    transition: none !important;
    animation-duration: .001ms !important;
    animation-iteration-count: 1 !important;
    scroll-behavior: auto !important;
  }
  a.examcard:hover, .launch:hover:not(:disabled), .btn.accent:hover:not(:disabled) { transform: none; }
}

@media print {
  header.bar, .foot, .toasts, .controls, .btn { display: none !important; }
  body { background: #fff; }
}