/* Programmer Corner design tokens (from programmer-corner.com). Logical properties are used throughout,
   so right-to-left languages need no separate stylesheet. */
:root {
  --bg: #0a0e17;
  --bg-alt: #0d1420;
  --surface: #101927;
  --surface-2: #131e2f;
  --border: #1e2937;
  --border-strong: #33455e;
  --text: #e7edf6;
  --text-dim: #9fb0c8;      /* lightened from the site's #93a4bd so body text keeps 4.5:1 on every surface */
  --cyan: #22d3ee;
  --blue: #3b82f6;
  --danger: #f87171;
  --ok: #34d399;
  --on-accent: #04121a;
  --grad: linear-gradient(90deg, var(--cyan), var(--blue));
  --mono: ui-monospace, "Cascadia Code", "JetBrains Mono", "SFMono-Regular", Consolas, monospace;
  --sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, "Noto Sans", sans-serif;
  --radius: 14px;
  --focus: 3px solid var(--cyan);
  color-scheme: dark;
}

:root[data-theme="light"] {
  --bg: #f6f8fb; --bg-alt: #eef2f7; --surface: #ffffff; --surface-2: #f1f5fa;
  --border: #d5dde8; --border-strong: #93a4bd; --text: #0f172a; --text-dim: #42526b;
  --cyan: #0369a1; --blue: #1d4ed8; --danger: #b91c1c; --ok: #047857; --on-accent: #ffffff;
  --focus: 3px solid #1d4ed8;
  color-scheme: light;
}

:root[data-contrast="high"] {
  --bg: #000; --bg-alt: #000; --surface: #000; --surface-2: #0a0a0a;
  --border: #fff; --border-strong: #fff; --text: #fff; --text-dim: #f0f0f0;
  --cyan: #00e5ff; --blue: #7ab8ff; --danger: #ff8a8a; --ok: #5dffb0; --on-accent: #000;
  --focus: 4px solid #ffea00;
}
:root[data-theme="light"][data-contrast="high"] {
  --bg: #fff; --bg-alt: #fff; --surface: #fff; --surface-2: #fff;
  --border: #000; --border-strong: #000; --text: #000; --text-dim: #111;
  --cyan: #00455f; --blue: #0a2a8a; --danger: #8b0000; --ok: #00563b; --on-accent: #fff;
  --focus: 4px solid #b30000;
}
:root[data-contrast="high"] a { text-decoration: underline; }

/* Text size steps from the accessibility panel */
:root { font-size: 100%; }
:root[data-size="-1"] { font-size: 90%; }
:root[data-size="1"] { font-size: 115%; }
:root[data-size="2"] { font-size: 130%; }
:root[data-size="3"] { font-size: 150%; }

*, *::before, *::after { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; scroll-behavior: smooth; }
body {
  margin: 0; min-block-size: 100vh; display: flex; flex-direction: column;
  background: var(--bg); color: var(--text);
  font: 1rem/1.65 var(--sans);
}
main { flex: 1; padding-block: 2rem 4rem; }
main:focus { outline: none; }
h1, h2, h3 { line-height: 1.2; margin-block: 0 .75rem; letter-spacing: -.01em; }
h1 { font-size: clamp(1.9rem, 4vw + 1rem, 3rem); }
h2 { font-size: 1.5rem; }
h3 { font-size: 1.15rem; }
p { margin-block: 0 1rem; }
a { color: var(--cyan); text-underline-offset: .2em; }
img { max-inline-size: 100%; block-size: auto; }
ul { padding-inline-start: 1.25rem; }
.muted { color: var(--text-dim); }
.lead { font-size: 1.2rem; color: var(--text-dim); max-inline-size: 46rem; }

:focus-visible { outline: var(--focus); outline-offset: 3px; border-radius: 6px; }

.wrap { inline-size: min(100% - 2rem, 72rem); margin-inline: auto; }
.narrow { inline-size: min(100% - 2rem, 46rem); }
.sr-only { position: absolute; inline-size: 1px; block-size: 1px; overflow: hidden; clip-path: inset(50%); white-space: nowrap; }
.skip {
  position: absolute; inset-inline-start: 1rem; inset-block-start: -4rem; z-index: 100;
  background: var(--cyan); color: var(--on-accent); padding: .6rem 1rem; border-radius: 8px; font-weight: 700;
}
.skip:focus { inset-block-start: 1rem; }
[hidden] { display: none !important; }

/* Header */
.site-header { background: var(--bg-alt); border-block-end: 1px solid var(--border); position: sticky; inset-block-start: 0; z-index: 20; }
.bar { display: flex; align-items: center; gap: 1.25rem; padding-block: .7rem; }
.brand { font: 700 1.05rem var(--mono); color: var(--text); text-decoration: none; white-space: nowrap; }
.prompt { color: var(--cyan); }
.cursor { color: var(--cyan); animation: blink 1.1s steps(2) infinite; }
.main-nav { display: flex; gap: 1.25rem; flex: 1; }
.main-nav a { color: var(--text-dim); text-decoration: none; font-weight: 600; }
.main-nav a:hover { color: var(--text); }
.tools { display: flex; align-items: center; gap: .5rem; margin-inline-start: auto; }

.lang { position: relative; }
.lang summary {
  list-style: none; cursor: pointer; padding: .45rem .8rem; border: 1px solid var(--border-strong);
  border-radius: 999px; font-weight: 600; user-select: none;
}
.lang summary::-webkit-details-marker { display: none; }
.lang summary::after { content: "▾"; margin-inline-start: .45rem; font-size: .8em; }
.lang ul {
  position: absolute; inset-inline-end: 0; margin: .4rem 0 0; padding: .4rem; list-style: none; min-inline-size: 12rem;
  background: var(--surface); border: 1px solid var(--border-strong); border-radius: var(--radius); box-shadow: 0 12px 32px #0008;
}
.lang li a { display: block; padding: .5rem .7rem; border-radius: 8px; color: var(--text); text-decoration: none; }
.lang li a:hover, .lang li a[aria-current="true"] { background: var(--surface-2); color: var(--cyan); }

.icon-btn {
  display: inline-grid; place-items: center; inline-size: 2.5rem; block-size: 2.5rem; border-radius: 999px;
  background: transparent; color: var(--text); border: 1px solid var(--border-strong); cursor: pointer;
}
.icon-btn[aria-expanded="true"] { background: var(--surface-2); color: var(--cyan); }

.a11y-panel { background: var(--surface); border-block-start: 1px solid var(--border); padding-block: 1rem; }
.a11y-title { font-size: 1.05rem; margin-block-end: .75rem; }
.a11y-grid { display: flex; flex-wrap: wrap; gap: 1rem 2rem; align-items: center; }
.a11y-row { display: flex; align-items: center; gap: .6rem; cursor: pointer; }
.a11y-row input { inline-size: 1.15rem; block-size: 1.15rem; accent-color: var(--cyan); }
.group { display: inline-flex; gap: .4rem; }

/* Buttons and cards */
.btn {
  display: inline-flex; align-items: center; justify-content: center; gap: .5rem; padding: .7rem 1.15rem;
  border-radius: 10px; border: 1px solid var(--border-strong); background: var(--surface-2); color: var(--text);
  font: 600 1rem var(--sans); text-decoration: none; cursor: pointer; min-block-size: 2.75rem;
  transition: transform .12s ease, border-color .12s ease, background .12s ease;
}
.btn:hover { border-color: var(--cyan); transform: translateY(-1px); }
.btn.primary { background: var(--grad); color: var(--on-accent); border-color: transparent; }
.btn.primary:hover { filter: brightness(1.08); }
.btn.ghost { background: transparent; }
.btn.danger { background: var(--danger); color: var(--on-accent); border-color: transparent; }
.btn.small { padding: .35rem .8rem; min-block-size: 2.25rem; font-size: .95rem; }
.btn.large { padding: .9rem 1.6rem; font-size: 1.1rem; }
:root[data-contrast="high"] .btn { border-width: 2px; }

.card { background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius); padding: 1.25rem; }
.pill {
  display: inline-block; padding: .25rem .8rem; border: 1px solid var(--border-strong); border-radius: 999px;
  font-size: .9rem; color: var(--text-dim);
}
.notice { border-color: var(--cyan); }
.error { color: var(--danger); font-weight: 600; }
.hint { color: var(--text-dim); font-size: .9rem; }

/* Home */
.hero { padding-block: 2rem 1rem; }
.term { font: 600 1rem var(--mono); color: var(--cyan); margin-block-end: 1rem; }
.flags { display: flex; flex-wrap: wrap; gap: .5rem; font: .9rem var(--mono); }
.flags span { padding: .2rem .7rem; border: 1px solid var(--border-strong); border-radius: 999px; color: var(--cyan); }
.section-title { margin-block: 2.5rem 1rem; }
.grid { display: grid; gap: 1rem; padding: 0; margin: 0; list-style: none; }
.topics { grid-template-columns: repeat(auto-fill, minmax(13rem, 1fr)); }
.topic { display: flex; flex-direction: column; align-items: flex-start; gap: .75rem; transition: border-color .15s ease, transform .15s ease; }
.topic:hover { border-color: var(--cyan); transform: translateY(-2px); }
.topic h4 { margin: 0; font-size: 1.3rem; line-height: 1.25; }
.group-title { font-size: 1.05rem; font-weight: 700; color: var(--cyan); margin-block: 2rem .9rem; letter-spacing: 0; }
.group-title::before { content: "// "; color: var(--text-dim); font-family: var(--mono); }
.disclaimer {
  font-size: .92rem; color: var(--text-dim); max-inline-size: 46rem;
  border-inline-start: 3px solid var(--border-strong); padding-inline-start: .9rem; margin-block: 1rem;
}
.topic .btn, .topic .pill { margin-block-start: auto; }
.topic.is-soon { opacity: .75; }
.sigil {
  display: grid; place-items: center; min-inline-size: 3rem; padding-inline: .6rem; block-size: 3rem; border-radius: 12px;
  background: var(--grad); color: var(--on-accent); font: 800 1.05rem var(--mono);
}
.how { display: grid; grid-template-columns: repeat(auto-fit, minmax(15rem, 1fr)); gap: 1rem; margin-block-start: 3rem; }
.how h3 { color: var(--cyan); }
.how p { margin: 0; color: var(--text-dim); }

/* Start page */
.checks { list-style: none; padding: 0; margin-block: 1.5rem; display: grid; gap: .6rem; }
.checks li::before { content: "✓"; color: var(--ok); font-weight: 800; margin-inline-end: .6rem; }

/* Question */
.progress-label { font: 600 .95rem var(--mono); color: var(--text-dim); margin-block-end: .4rem; }
.progress, .meter { inline-size: 100%; block-size: .6rem; appearance: none; border: 0; border-radius: 99px; overflow: hidden; background: var(--surface-2); display: block; }
.progress::-webkit-progress-bar, .meter::-webkit-meter-bar { background: var(--surface-2); border-radius: 99px; }
.progress::-webkit-progress-value, .meter::-webkit-meter-optimum-value { background: var(--grad); border-radius: 99px; }
.progress::-moz-progress-bar, .meter::-moz-meter-bar { background: var(--cyan); }
.question fieldset { border: 0; padding: 0; margin: 1.5rem 0 1rem; min-inline-size: 0; }
.question legend { font-size: 1.35rem; font-weight: 700; line-height: 1.4; padding: 0; margin-block-end: 1rem; }
.code { margin: 0 0 1.25rem; border: 1px solid var(--border-strong); border-radius: var(--radius); overflow: hidden; background: var(--bg-alt); }
.code figcaption { padding: .4rem 1rem; font: .8rem var(--mono); color: var(--text-dim); border-block-end: 1px solid var(--border); }
.code pre { margin: 0; padding: 1rem; overflow-x: auto; font: .95rem/1.6 var(--mono); tab-size: 4; text-align: left; }
.options { display: grid; gap: .7rem; }
.option {
  display: flex; align-items: flex-start; gap: .85rem; padding: .9rem 1.1rem; cursor: pointer;
  background: var(--surface); border: 1px solid var(--border-strong); border-radius: 12px;
  transition: border-color .12s ease, background .12s ease;
}
.option:hover { border-color: var(--cyan); }
.option input { inline-size: 1.25rem; block-size: 1.25rem; margin-block-start: .25rem; accent-color: var(--cyan); flex: none; }
.option:has(input:checked) { border-color: var(--cyan); background: var(--surface-2); box-shadow: inset 0 0 0 1px var(--cyan); }
.option:has(input:focus-visible) { outline: var(--focus); outline-offset: 3px; }
.question .btn { margin-block-start: 1rem; }

/* Result */
.stats { display: grid; grid-template-columns: repeat(auto-fit, minmax(13rem, 1fr)); gap: 1rem; margin-block: 1.5rem; }
.stat-label { margin: 0; color: var(--text-dim); font-size: .9rem; }
.stat-value { margin: .25rem 0 .6rem; font-size: 1.8rem; font-weight: 800; }
.level-1 { color: var(--text); } .level-2 { color: var(--cyan); } .level-3 { color: var(--blue); } .level-4 { color: var(--ok); }
.breakdown { list-style: none; padding: 0; display: grid; gap: .5rem; }
.breakdown li { display: flex; justify-content: space-between; gap: 1rem; padding: .7rem 1rem; background: var(--surface); border: 1px solid var(--border); border-radius: 10px; }
.cert-form { margin-block: 2rem; }
.cert-form label { display: block; font-weight: 700; margin-block-end: .4rem; }
.input {
  inline-size: 100%; padding: .8rem 1rem; font: 1.05rem var(--sans); color: var(--text); background: var(--bg-alt);
  border: 1px solid var(--border-strong); border-radius: 10px; margin-block-end: .4rem;
}
.input[aria-invalid="true"] { border-color: var(--danger); }
.cert-form .btn { margin-block-start: .6rem; }

/* Certificate page */
.cert-img { display: block; inline-size: 100%; max-inline-size: 60rem; margin-block: 1.25rem; border-radius: var(--radius); border: 1px solid var(--border-strong); box-shadow: 0 20px 60px #0007; }
.verified { color: var(--text-dim); max-inline-size: 60rem; }
.share, .actions { display: flex; flex-wrap: wrap; gap: .6rem; align-items: center; margin-block: 1rem 1.5rem; }
.copied { color: var(--ok); font-weight: 700; }
.prose p { max-inline-size: 42rem; color: var(--text-dim); font-size: 1.08rem; }

/* Footer */
.site-footer { border-block-start: 1px solid var(--border); background: var(--bg-alt); padding-block: 1.5rem; color: var(--text-dim); }
.foot { display: flex; flex-wrap: wrap; gap: 1rem; justify-content: space-between; }
.foot p { margin: 0; }
.foot-links { display: flex; gap: 1.25rem; }
.foot-links a { color: var(--text-dim); }

@media (max-width: 40rem) {
  .main-nav { display: none; }
  .bar { gap: .6rem; }
  .brand { font-size: .95rem; }
  main { padding-block: 1.25rem 3rem; }
}

/* Very small phones: let the header wrap instead of forcing sideways scrolling */
@media (max-width: 26rem) {
  .bar { flex-wrap: wrap; gap: .4rem .6rem; }
  .cursor { display: none; }
  .brand { font-size: .85rem; }
  .lang summary { padding: .4rem .65rem; font-size: .9rem; }
  .lang ul { min-inline-size: 10rem; }
  .btn.large { padding-inline: 1.1rem; }
  .flags { font-size: .8rem; }
}

@keyframes blink { 50% { opacity: 0; } }
@media (prefers-reduced-motion: reduce) {
  * { animation: none !important; transition: none !important; scroll-behavior: auto !important; }
}
:root[data-motion="reduce"] * { animation: none !important; transition: none !important; scroll-behavior: auto !important; }