:root {
  color-scheme: light;
  --page: #f9f9f7;
  --surface: #fcfcfb;
  --surface-2: #f0efec;
  --text: #0b0b0b;
  --text-2: #52514e;
  --muted: #898781;
  --grid: #e1e0d9;
  --axis: #c3c2b7;
  --border: rgba(11, 11, 11, 0.10);
  --accent: #2a78d6;
  --accent-ink: #1c5cab;
  --accent-wash: #e6f0fc;
  --good: #0ca30c;
  --good-ink: #006300;
  --good-wash: #e5f4e5;
  --bad: #d03b3b;
  --bad-ink: #b02f2f;
  --bad-wash: #fbe9e9;
  --warn: #fab219;
  --warn-wash: #fef4dc;
  --radius: 10px;
  --font: system-ui, -apple-system, "Segoe UI", sans-serif;
}
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    color-scheme: dark;
    --page: #0d0d0d;
    --surface: #1a1a19;
    --surface-2: #232321;
    --text: #ffffff;
    --text-2: #c3c2b7;
    --muted: #898781;
    --grid: #2c2c2a;
    --axis: #383835;
    --border: rgba(255, 255, 255, 0.10);
    --accent: #3987e5;
    --accent-ink: #86b6ef;
    --accent-wash: #16263a;
    --good-ink: #0ca30c;
    --good-wash: #132613;
    --bad-ink: #e66767;
    --bad-wash: #331818;
    --warn-wash: #332710;
  }
}
:root[data-theme="dark"] {
  color-scheme: dark;
  --page: #0d0d0d;
  --surface: #1a1a19;
  --surface-2: #232321;
  --text: #ffffff;
  --text-2: #c3c2b7;
  --muted: #898781;
  --grid: #2c2c2a;
  --axis: #383835;
  --border: rgba(255, 255, 255, 0.10);
  --accent: #3987e5;
  --accent-ink: #86b6ef;
  --accent-wash: #16263a;
  --good-ink: #0ca30c;
  --good-wash: #132613;
  --bad-ink: #e66767;
  --bad-wash: #331818;
  --warn-wash: #332710;
}

* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }
body {
  margin: 0;
  background: var(--page);
  color: var(--text);
  font: 15px/1.55 var(--font);
}
a { color: var(--accent-ink); }
code {
  font: 0.9em ui-monospace, SFMono-Regular, Menlo, monospace;
  background: var(--surface-2);
  padding: 1px 5px;
  border-radius: 4px;
}
h1, h2, h3 { line-height: 1.25; margin: 0 0 12px; }
h1 { font-size: 26px; }
h2 { font-size: 19px; }
h3 { font-size: 16px; }
p { margin: 0 0 12px; }
.muted { color: var(--text-2); }
.small { font-size: 13px; }
.num { font-variant-numeric: tabular-nums; }

/* Layout */
.topbar {
  display: flex; align-items: center; justify-content: space-between; gap: 12px;
  padding: 12px 16px;
  background: var(--surface);
  border-bottom: 1px solid var(--border);
  position: sticky; top: 0; z-index: 10;
}
.brand { font-weight: 700; color: var(--text); text-decoration: none; }
.topnav { display: flex; align-items: center; gap: 4px; }
.topnav a { color: var(--text-2); text-decoration: none; padding: 6px 10px; border-radius: 8px; }
.topnav a:hover { background: var(--surface-2); color: var(--text); }
@media (max-width: 380px) {
  .topbar { flex-wrap: wrap; row-gap: 4px; }
  .topnav { width: 100%; justify-content: space-between; gap: 2px; }
  .topnav a, .topnav button.ghost { padding-left: 6px; padding-right: 6px; }
}
main { max-width: 1000px; margin: 0 auto; padding: 24px 16px 48px; outline: none; }
.footer { max-width: 1000px; margin: 0 auto; padding: 0 16px 32px; color: var(--muted); font-size: 13px; }

.card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 20px;
  margin-bottom: 16px;
}
.grid-2 { display: grid; grid-template-columns: 1fr 1fr; gap: 16px; }
.grid-2 > .card { margin-bottom: 0; }
.grid-2 > * { min-width: 0; }
.stack-16 > * + * { margin-top: 16px; }
.row { display: flex; flex-wrap: wrap; align-items: center; gap: 8px; }
.row.between { justify-content: space-between; }
@media (max-width: 720px) {
  .grid-2 { grid-template-columns: 1fr; }
}
/* Keep Previous, Check answer and Next on one line on narrow screens */
.narrow-only { display: none; }
@media (max-width: 560px) {
  .q-nav { flex-wrap: nowrap; width: 100%; }
  .q-nav button { flex: 1 1 0; min-width: 0; padding: 9px 8px; white-space: nowrap; }
  .q-nav .wide-only { display: none; }
  .q-nav .narrow-only { display: inline; }
}

/* Buttons & controls */
button, .btn {
  font: inherit; font-weight: 600;
  display: inline-flex; align-items: center; justify-content: center; gap: 6px;
  padding: 9px 16px; min-height: 40px;
  border-radius: 8px; border: 1px solid var(--border);
  background: var(--surface-2); color: var(--text);
  cursor: pointer; text-decoration: none;
}
button:hover, .btn:hover { filter: brightness(0.97); }
button:focus-visible, .btn:focus-visible, input:focus-visible, select:focus-visible, .option:focus-within {
  outline: 2px solid var(--accent); outline-offset: 2px;
}
button.primary, .btn.primary { background: var(--accent); border-color: var(--accent); color: #fff; }
button.danger { color: var(--bad-ink); }
button.ghost { background: transparent; border-color: transparent; color: var(--text-2); font-weight: 500; padding: 6px 10px; min-height: 32px; }
button.ghost:hover { background: var(--surface-2); }
button:disabled { opacity: 0.45; cursor: not-allowed; }
select, input[type="number"] {
  font: inherit; color: var(--text); background: var(--surface);
  border: 1px solid var(--axis); border-radius: 8px; padding: 7px 10px; min-height: 40px;
}
label.field select, label.field input { width: 100%; min-width: 0; }
label.field { display: grid; gap: 4px; min-width: 0; font-size: 13px; color: var(--text-2); font-weight: 600; }
.form-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(200px, 1fr)); gap: 14px; margin: 14px 0 18px; }
.check { display: flex; align-items: center; gap: 8px; font-size: 14px; }

/* Stat tiles */
.tiles { display: grid; grid-template-columns: repeat(auto-fit, minmax(150px, 1fr)); gap: 12px; margin-bottom: 16px; }
.tile { background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius); padding: 14px 16px; }
.tile .label { font-size: 13px; color: var(--text-2); }
.tile .value { font-size: 26px; font-weight: 700; margin-top: 2px; }
.tile .sub { font-size: 12px; color: var(--muted); }

/* Badges */
.badge { display: inline-flex; align-items: center; gap: 4px; font-size: 12px; font-weight: 600; padding: 2px 8px; border-radius: 999px; background: var(--surface-2); color: var(--text-2); white-space: nowrap; }
.badge.pass { background: var(--good-wash); color: var(--good-ink); }
.badge.fail { background: var(--bad-wash); color: var(--bad-ink); }
.badge.accent { background: var(--accent-wash); color: var(--accent-ink); }

/* Tables */
.table-wrap { overflow-x: auto; }
table { width: 100%; border-collapse: collapse; font-size: 14px; }
th, td { text-align: left; padding: 9px 10px; border-bottom: 1px solid var(--grid); vertical-align: middle; }
th { font-size: 12px; color: var(--text-2); font-weight: 600; text-transform: uppercase; letter-spacing: 0.03em; }
td.num, th.num { text-align: right; }

/* Meter (per-domain accuracy) */
.meter-row { display: grid; grid-template-columns: minmax(140px, 1.3fr) 2fr 56px; align-items: center; gap: 12px; padding: 6px 0; }
.meter-row .name { font-size: 14px; }
.meter-row .name .muted { font-size: 12px; display: block; }
.meter { position: relative; height: 12px; background: var(--surface-2); border-radius: 4px; }
.meter .fill { position: absolute; inset: 0 auto 0 0; background: var(--accent); border-radius: 4px; }
.meter .target { position: absolute; top: -4px; bottom: -4px; width: 2px; background: var(--text-2); opacity: 0.55; }
.meter-row .pct { text-align: right; font-weight: 600; font-variant-numeric: tabular-nums; }
@media (max-width: 560px) {
  .meter-row { grid-template-columns: 1fr 52px; }
  .meter-row .meter { grid-column: 1 / -1; grid-row: 2; }
}

/* Chart */
.chart { position: relative; }
.chart svg { display: block; width: 100%; height: auto; overflow: visible; }
.chart .tick { fill: var(--muted); font-size: 11px; font-variant-numeric: tabular-nums; }
.chart .gridline { stroke: var(--grid); stroke-width: 1; }
.chart .passline { stroke: var(--text-2); stroke-width: 1.5; stroke-dasharray: 4 4; }
.chart .passlabel { fill: var(--text-2); font-size: 11px; }
.chart .series { fill: none; stroke: var(--accent); stroke-width: 2; stroke-linejoin: round; stroke-linecap: round; }
.chart .dot { fill: var(--accent); stroke: var(--surface); stroke-width: 2; }
.chart .hit { fill: transparent; cursor: pointer; }
.chart .crosshair { stroke: var(--axis); stroke-width: 1; }
.tooltip {
  position: absolute; pointer-events: none; z-index: 5;
  background: var(--surface); border: 1px solid var(--border);
  box-shadow: 0 4px 16px rgba(0, 0, 0, 0.12);
  border-radius: 8px; padding: 8px 10px; font-size: 13px; white-space: nowrap;
  transform: translate(-50%, calc(-100% - 12px));
}
.tooltip.edge-right { transform: translate(calc(-100% + 12px), calc(-100% - 12px)); }
.tooltip.edge-left { transform: translate(-12px, calc(-100% - 12px)); }
.empty { color: var(--text-2); text-align: center; padding: 28px 12px; border: 1px dashed var(--axis); border-radius: var(--radius); }

/* Exam view */
.exam-bar {
  display: flex; flex-wrap: wrap; align-items: center; justify-content: space-between; gap: 10px;
  margin-bottom: 12px;
}
.progress { height: 6px; background: var(--surface-2); border-radius: 3px; overflow: hidden; margin-bottom: 18px; }
.progress > div { height: 100%; background: var(--accent); transition: width 0.2s; }
.timer { font-variant-numeric: tabular-nums; font-weight: 600; }
.timer.low { color: var(--bad-ink); }
.q-meta { font-size: 13px; color: var(--text-2); margin-bottom: 8px; }
.q-stem { font-size: 17px; margin-bottom: 16px; }
.select-hint { font-weight: 600; color: var(--accent-ink); }
.options { display: grid; gap: 10px; margin-bottom: 18px; }
.option {
  display: flex; gap: 12px; align-items: flex-start;
  padding: 12px 14px; border: 1px solid var(--axis); border-radius: 8px;
  background: var(--surface); cursor: pointer;
}
.option:hover { border-color: var(--accent); }
.option input { margin-top: 4px; width: 18px; height: 18px; accent-color: var(--accent); flex: none; }
.option .key { font-weight: 700; color: var(--text-2); flex: none; width: 18px; }
.option.selected { border-color: var(--accent); background: var(--accent-wash); }
.option.correct { border-color: var(--good); background: var(--good-wash); }
.option.wrong { border-color: var(--bad); background: var(--bad-wash); }
.option.locked { cursor: default; }
.option .otext { flex: 1; min-width: 0; overflow-wrap: anywhere; }
@media (max-width: 560px) {
  .option { flex-wrap: wrap; }
  .option .verdict { flex-basis: 100%; margin-left: 0; text-align: right; }
}
.option .why { display: block; margin-top: 4px; font-size: 13px; color: var(--text-2); }
.option .verdict { margin-left: auto; font-size: 12px; font-weight: 700; flex: none; }
.option.correct .verdict { color: var(--good-ink); }
.option.wrong .verdict { color: var(--bad-ink); }
.explain { overflow-wrap: anywhere; border-left: 3px solid var(--accent); background: var(--surface-2); padding: 12px 14px; border-radius: 0 8px 8px 0; margin-bottom: 16px; }
.explain.good { border-left-color: var(--good); }
.explain.bad { border-left-color: var(--bad); }

.navigator { display: grid; grid-template-columns: repeat(auto-fill, minmax(38px, 1fr)); gap: 6px; }
.navigator button {
  min-height: 36px; padding: 0; font-size: 13px; font-weight: 600;
  background: var(--surface); border-color: var(--axis); color: var(--text-2);
  position: relative;
}
.navigator button.answered { background: var(--accent-wash); border-color: var(--accent); color: var(--accent-ink); }
.navigator button.current { outline: 2px solid var(--text); outline-offset: 1px; }
.navigator button.flagged::after { content: ""; position: absolute; top: 3px; right: 3px; width: 7px; height: 7px; border-radius: 50%; background: var(--warn); }
.navigator button.is-correct { background: var(--good-wash); border-color: var(--good); color: var(--good-ink); }
.navigator button.is-wrong { background: var(--bad-wash); border-color: var(--bad); color: var(--bad-ink); }
.legend { display: flex; flex-wrap: wrap; gap: 14px; font-size: 12px; color: var(--text-2); margin-top: 10px; }
.legend span::before { content: ""; display: inline-block; width: 10px; height: 10px; border-radius: 3px; margin-right: 5px; vertical-align: -1px; border: 1px solid var(--axis); background: var(--surface); }
.legend .l-answered::before { background: var(--accent-wash); border-color: var(--accent); }
.legend .l-flagged::before { background: var(--warn); border-color: var(--warn); border-radius: 50%; }

.flag-on { background: var(--warn-wash); border-color: var(--warn); }

/* Results */
.score-hero { display: flex; flex-wrap: wrap; align-items: center; gap: 24px; }
.score-hero .big { font-size: 48px; font-weight: 700; line-height: 1; }
.review-item { border-top: 1px solid var(--grid); padding: 16px 0; }
.review-item:first-child { border-top: 0; }
.tabs { display: flex; flex-wrap: wrap; gap: 6px; margin-bottom: 8px; }
.tabs button { min-height: 32px; padding: 4px 12px; font-weight: 500; }
.tabs button[aria-pressed="true"] { background: var(--accent); border-color: var(--accent); color: #fff; }

dialog {
  border: 1px solid var(--border); border-radius: var(--radius);
  background: var(--surface); color: var(--text);
  padding: 20px; max-width: min(440px, calc(100vw - 32px));
}
dialog::backdrop { background: rgba(0, 0, 0, 0.4); }

/* Architecture diagrams (AWS group colours: Region teal, VPC purple, AZ blue, public subnet green,
   private subnet teal, security group red) */
:root {
  --ar-cloud: #232f3e; --ar-account: #e7157b; --ar-region: #00a4a6; --ar-vpc: #8c4fff; --ar-az: #147eba;
  --ar-public: #7aa116; --ar-public-bg: rgba(122, 161, 22, 0.08); --ar-private: #00a4a6; --ar-private-bg: rgba(0, 164, 166, 0.08);
  --ar-sg: #dd344c; --ar-onprem: #7d8998;
}
@media (prefers-color-scheme: dark) { :root:not([data-theme="light"]) { --ar-cloud: #c3c2b7; --ar-az: #4fa3e0; } }
:root[data-theme="dark"] { --ar-cloud: #c3c2b7; --ar-az: #4fa3e0; }
.arch-wrap { position: relative; margin: 10px 0 8px; overflow: hidden; }
.arch-wrap.shrunk { cursor: zoom-in; }
.arch {
  position: relative; display: inline-flex; align-items: center; gap: 64px; width: max-content;
  padding: 6px 6px 24px; transform-origin: 0 0; font-size: 12px; line-height: 1.25; overflow-wrap: normal;
}
.ar-zoom { display: none; position: absolute; left: 0; bottom: 0; min-height: 28px; padding: 2px 10px; font-size: 12px; }
.arch-wrap.shrunk .ar-zoom { display: block; }
.ar-box { position: relative; border: 1.5px solid var(--ar-onprem); padding: 6px 10px 10px; border-radius: 2px; }
.ar-title { display: flex; align-items: center; gap: 6px; font-weight: 600; font-size: 12px; color: var(--text-2); margin-bottom: 8px; white-space: nowrap; }
.ar-title small { font-weight: 400; }
.ar-tag { width: 22px; height: 22px; flex: none; margin: -6px 0 0 -10px; }
.ar-tag img { width: 22px; height: 22px; display: block; }
.arch img.on-dark { display: none; }
@media (prefers-color-scheme: dark) { :root:not([data-theme="light"]) .arch img.on-light { display: none; } :root:not([data-theme="light"]) .arch img.on-dark { display: block; } }
:root[data-theme="dark"] .arch img.on-light { display: none; }
:root[data-theme="dark"] .arch img.on-dark { display: block; }
.ar-kids { display: flex; flex-direction: row; align-items: flex-start; gap: 64px; }
.ar-box.d-col > .ar-kids { flex-direction: column; align-items: center; gap: 40px; }
.ar-box.d-row > .ar-kids { flex-direction: row; align-items: flex-start; gap: 64px; }
.k-az > .ar-kids { flex-direction: column; align-items: stretch; gap: 16px; }
.k-cloud { border-color: var(--ar-cloud); }
.k-account { border-color: var(--ar-account); }
.k-region { border: 1.5px dotted var(--ar-region); }
.k-vpc { border-color: var(--ar-vpc); }
.k-az { border: 1.5px dashed var(--ar-az); } .k-az > .ar-title { color: var(--ar-az); }
.k-public { border-color: transparent; background: var(--ar-public-bg); } .k-public > .ar-title { color: var(--ar-public); }
.k-private { border-color: transparent; background: var(--ar-private-bg); } .k-private > .ar-title { color: var(--ar-private); }
.k-sg { border: 1.5px solid var(--ar-sg); } .k-sg > .ar-title { color: var(--ar-sg); }
.k-group { border-style: dashed; }
.k-asg { border: 1.5px dashed #ed7100; } .k-asg > .ar-title { color: #ed7100; }
.ar-box.hl { box-shadow: 0 0 0 3px var(--good); }
.ar-node { position: relative; z-index: 1; display: flex; flex-direction: column; align-items: center; width: 92px; text-align: center; }
.ar-icon { display: block; width: 40px; height: 40px; margin-bottom: 4px; }
.ar-icon img { width: 40px; height: 40px; display: block; }
.ar-node.hl .ar-icon { outline: 3px solid var(--good); outline-offset: 3px; border-radius: 2px; }
.ar-node.hl .ar-label { color: var(--good-ink); }
.ar-label { font-weight: 600; color: var(--text); }
.ar-node small { color: var(--text-2); font-size: 11px; }
.ar-lines { position: absolute; left: 0; top: 0; overflow: visible; pointer-events: none; z-index: 2; }
.ar-path { fill: none; stroke: var(--text-2); stroke-width: 1.6; }
.ar-path.d { stroke-dasharray: 5 4; }
.ar-path.x { stroke: var(--bad); stroke-dasharray: 5 4; }
.ar-fill { fill: var(--text-2); } .ar-fill-x { fill: var(--bad); }
.ar-lbl rect { fill: var(--surface); stroke: var(--axis); }
.ar-lbl text { font-size: 11px; fill: var(--text-2); }
.ar-lbl.x text { fill: var(--bad-ink); }
.ar-no { fill: var(--accent); }
.ar-lbl text.ar-no-t { fill: #fff; font-weight: 700; }
.ar-dialog { width: 100vw; height: 100vh; max-width: none; max-height: none; margin: 0; padding: 0; border: 0; border-radius: 0; }
.ar-dialog-bar { position: sticky; top: 0; left: 0; display: flex; justify-content: space-between; align-items: center; padding: 8px 16px; background: var(--surface); border-bottom: 1px solid var(--grid); z-index: 3; }
.ar-dialog-body { overflow: auto; padding: 16px; height: calc(100vh - 50px); background: var(--surface-2); }
.ar-row, .ar-col { display: flex; gap: 64px; }
.ar-col { gap: 40px; }
.ar-row { flex-direction: row; align-items: flex-start; }
.ar-col { flex-direction: column; align-items: center; }
.ar-kids > .k-az, .ar-row > .k-az { align-self: stretch; }
.ar-row > .ar-box { flex: 1; }
.ar-kids:has(> .ar-col), .ar-row:has(> .ar-col) { align-items: center; }