:root {
  font-family:
    system-ui,
    -apple-system,
    BlinkMacSystemFont,
    "Segoe UI",
    sans-serif;
  color: #202636;
  background: #f6f7fb;
  line-height: 1.55;
  --panel: #fff;
  --line: #dce1eb;
  --muted: #59657a;
  --accent: #5b46c6;
  --soft: #efedff;
  --good: #16774c;
  --bad: #b33247;
}
* {
  box-sizing: border-box;
}
body {
  margin: 0;
}
a {
  color: var(--accent);
}
header {
  background: var(--panel);
  border-bottom: 1px solid var(--line);
}
.top {
  max-width: 1100px;
  margin: auto;
  display: flex;
  align-items: center;
  gap: 2rem;
  padding: 1rem 1.25rem;
}
.brand {
  text-decoration: none;
  font-size: 1.2rem;
  color: inherit;
  white-space: nowrap;
}
.brand span {
  color: var(--accent);
}
nav {
  display: flex;
  gap: 1.3rem;
  margin-left: auto;
}
nav a {
  color: var(--muted);
  text-decoration: none;
  font-weight: 600;
}
nav a:hover,
a:hover {
  text-decoration: underline;
}
main {
  max-width: 1100px;
  margin: 0 auto;
  padding: 3.5rem 1.25rem;
  min-height: 75vh;
}
footer {
  max-width: 1100px;
  margin: auto;
  padding: 2rem 1.25rem;
  color: var(--muted);
  font-size: 0.9rem;
  border-top: 1px solid var(--line);
}
footer a {
  float: right;
}
h1,
h2,
h3,
p {
  margin-top: 0;
}
h1 {
  font-size: clamp(2rem, 5vw, 3.5rem);
  line-height: 1.12;
  letter-spacing: -0.04em;
  margin-bottom: 1rem;
}
h2 {
  letter-spacing: -0.02em;
}
.lead {
  font-size: 1.15rem;
  color: var(--muted);
  max-width: 650px;
}
.eyebrow {
  text-transform: uppercase;
  letter-spacing: 0.12em;
  color: var(--accent);
  font-weight: 750;
  font-size: 0.75rem;
}
.hero {
  padding: 1rem 0 3rem;
}
.grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 1rem;
}
.card {
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: 14px;
  padding: 1.35rem;
}
.card h3 {
  margin-bottom: 0.4rem;
}
.card p {
  color: var(--muted);
}
button,
.button {
  font: inherit;
  cursor: pointer;
  border: 1px solid var(--line);
  background: var(--panel);
  color: inherit;
  border-radius: 9px;
  padding: 0.65rem 1rem;
  font-weight: 650;
  text-decoration: none;
  display: inline-block;
}
button:hover,
.button:hover {
  border-color: var(--accent);
  text-decoration: none;
}
button:focus-visible,
a:focus-visible,
input:focus-visible,
select:focus-visible,
textarea:focus-visible {
  outline: 3px solid #a79bf7;
  outline-offset: 2px;
}
.primary {
  background: var(--accent);
  border-color: var(--accent);
  color: white;
}
.icon {
  padding: 0.4rem 0.7rem;
}
.actions {
  display: flex;
  gap: 0.7rem;
  flex-wrap: wrap;
  align-items: center;
}
.section {
  margin-top: 2.5rem;
}
.muted {
  color: var(--muted);
}
.small {
  font-size: 0.88rem;
}
.stats {
  display: flex;
  gap: 2rem;
  flex-wrap: wrap;
}
.stats strong {
  display: block;
  font-size: 1.8rem;
}
.question {
  max-width: 800px;
  margin: auto;
}
.question h1 {
  font-size: clamp(1.5rem, 4vw, 2.2rem);
  line-height: 1.3;
}
.bar {
  height: 7px;
  background: var(--line);
  border-radius: 10px;
  overflow: hidden;
  margin: 1rem 0 2rem;
}
.bar span {
  display: block;
  height: 100%;
  background: var(--accent);
}
.answers {
  display: grid;
  gap: 0.65rem;
  margin: 1.5rem 0;
}
.answer {
  text-align: left;
  padding: 1rem;
  font-weight: 500;
  display: flex;
  gap: 1rem;
  align-items: baseline;
}
.answer .letter {
  color: var(--accent);
  font-weight: 750;
}
.answer.correct {
  border-color: var(--good);
  background: color-mix(in srgb, var(--good) 12%, var(--panel));
}
.answer.wrong {
  border-color: var(--bad);
  background: color-mix(in srgb, var(--bad) 10%, var(--panel));
}
.feedback {
  border-left: 4px solid var(--accent);
  padding: 1rem 1.2rem;
  background: var(--soft);
  margin: 1rem 0;
}
.feedback p:last-child {
  margin-bottom: 0;
}
code,
pre {
  font-family: Consolas, monospace;
  background: var(--soft);
  border-radius: 4px;
  padding: 0.1em 0.3em;
  overflow-wrap: anywhere;
}
pre {
  padding: 1rem;
  overflow: auto;
  white-space: pre;
}
pre code {
  padding: 0;
}
.filters {
  display: flex;
  gap: 0.7rem;
  flex-wrap: wrap;
  margin: 1rem 0;
}
input,
select,
textarea {
  font: inherit;
  color: inherit;
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 0.65rem;
  max-width: 100%;
}
textarea {
  width: 100%;
  min-height: 90px;
}
label {
  display: block;
  font-weight: 600;
  margin: 0.8rem 0 0.3rem;
}
fieldset {
  border: 1px solid var(--line);
  border-radius: 10px;
  margin: 1rem 0;
  padding: 1rem;
}
fieldset label {
  font-weight: 400;
  margin: 0.35rem 0;
}
fieldset input {
  margin-right: 0.5rem;
}
.list {
  display: grid;
  gap: 0.6rem;
}
.list button {
  text-align: left;
  width: 100%;
}
.list .meta {
  display: block;
  color: var(--muted);
  font-size: 0.8rem;
  margin-bottom: 0.25rem;
}
.progress-row {
  margin: 1rem 0;
}
.progress-row .bar {
  margin: 0.4rem 0;
}
.error {
  color: var(--bad);
}
.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;
}
@media (max-width: 600px) {
  .top {
    gap: 0.7rem;
    flex-wrap: wrap;
  }
  .brand {
    margin-right: auto;
  }
  nav {
    order: 3;
    width: 100%;
    justify-content: space-between;
    margin: 0;
  }
  .icon {
    order: 2;
  }
  main {
    padding-top: 2rem;
  }
  .hero {
    padding-bottom: 2rem;
  }
  .stats {
    gap: 1.4rem;
  }
}
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    color: #eef0f8;
    background: #151722;
    --panel: #202331;
    --line: #393d50;
    --muted: #b1b8cc;
    --accent: #b7aaff;
    --soft: #302c49;
    --good: #75d3a4;
    --bad: #ff9bab;
  }
}
:root[data-theme="dark"] {
  color: #eef0f8;
  background: #151722;
  --panel: #202331;
  --line: #393d50;
  --muted: #b1b8cc;
  --accent: #b7aaff;
  --soft: #302c49;
  --good: #75d3a4;
  --bad: #ff9bab;
}
:root[data-theme="dark"] .primary {
  color: #171426;
}
.keyword {
  color: #a044b2;
  font-weight: 700;
}
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) .primary {
    color: #171426;
  }
}