:root {
  --arcade-night: #08111b;
  --arcade-ink: #101a24;
  --arcade-snow: #f7f4ec;
  --arcade-frost: #dce8ed;
  --arcade-glacier: #86b9cb;
  --arcade-amber: #e3a94a;
  --arcade-line: rgba(247, 244, 236, .22);
  --arcade-panel: rgba(8, 17, 27, .88);
}
* { box-sizing: border-box; }
html { min-height: 100%; scroll-behavior: smooth; }
body { min-height: 100vh; background: none; color: var(--arcade-snow); }
body::before {
  content: "";
  position: fixed;
  inset: 0;
  z-index: -1;
  background:
    linear-gradient(90deg, rgba(5, 13, 22, .94) 0%, rgba(5, 13, 22, .72) 48%, rgba(5, 13, 22, .46) 100%),
    linear-gradient(180deg, rgba(4, 10, 18, .12) 0%, rgba(4, 10, 18, .5) 64%, #08111b 100%),
    url("/assets/hero-bg.jpg") center 34% / cover no-repeat;
  transform: scale(1.002);
}
body::after {
  content: "KULSHAN  /  48.7768 N  /  121.8144 W";
  position: fixed;
  right: 22px;
  bottom: 18px;
  z-index: -1;
  color: rgba(247, 244, 236, .46);
  font: 500 .58rem/1 var(--f-mono);
  letter-spacing: .12em;
  writing-mode: vertical-rl;
}
.site-nav {
  position: relative;
  display: flex;
  min-height: 68px;
  align-items: center;
  justify-content: space-between;
  padding: 0 max(24px, calc((100% - 1180px) / 2));
  border-bottom: 1px solid var(--arcade-line);
  background: rgba(6, 14, 23, .72);
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
}
.site-nav .nav-logo, .site-nav .nav-links a { color: var(--arcade-snow); }
.site-nav .nav-logo { display: inline-flex; align-items: center; gap: 10px; }
.site-nav .logo-mark { display: grid; width: 28px; height: 28px; place-items: center; border: 1px solid var(--arcade-line); color: var(--arcade-amber); font: 600 .72rem/1 var(--f-mono); }
.arcade-wrap {
  width: min(1180px, calc(100% - 48px));
  margin: 0 auto;
  padding: clamp(48px, 7vw, 96px) 0;
}
.arcade-kicker, .hud-label, .domain-tag {
  font: 600 .67rem/1.3 var(--f-mono);
  letter-spacing: .14em;
  text-transform: uppercase;
}
.arcade-kicker { color: var(--arcade-amber); }
.arcade-title {
  max-width: 880px;
  margin: 18px 0 24px;
  color: var(--arcade-snow);
  font: 400 clamp(3.5rem, 9vw, 7.6rem)/.86 var(--f-serif);
  letter-spacing: -.035em;
  text-wrap: balance;
}
.arcade-lede {
  max-width: 650px;
  margin: 0;
  color: rgba(247, 244, 236, .78);
  font-size: clamp(1rem, 1.7vw, 1.2rem);
  line-height: 1.7;
}
.arcade-hero {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(250px, 340px);
  gap: clamp(40px, 8vw, 120px);
  align-items: end;
  min-height: calc(100vh - 166px);
}
.hero-copy { padding: clamp(30px, 5vw, 80px) 0; }
.course-manifest {
  margin-bottom: clamp(30px, 7vw, 86px);
  border-top: 1px solid var(--arcade-line);
  background: rgba(7, 16, 25, .24);
  backdrop-filter: blur(5px);
}
.manifest-row {
  display: grid;
  grid-template-columns: 42px 1fr;
  gap: 14px;
  padding: 18px 0;
  border-bottom: 1px solid var(--arcade-line);
}
.manifest-num { color: var(--arcade-amber); font: 500 .68rem/1.5 var(--f-mono); }
.manifest-row strong { display: block; margin-bottom: 4px; font-size: .96rem; }
.manifest-row span:last-child { color: rgba(247, 244, 236, .62); font-size: .83rem; line-height: 1.5; }
.arcade-actions { display: flex; gap: 12px; flex-wrap: wrap; margin-top: 34px; }
.arcade-button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 50px;
  padding: 0 20px;
  border: 1px solid var(--arcade-snow);
  border-radius: 2px;
  background: var(--arcade-snow);
  color: var(--arcade-ink);
  font: 700 .83rem/1 var(--f-sans);
  cursor: pointer;
  text-decoration: none;
  transition: background .18s ease, color .18s ease, border-color .18s ease;
}
.arcade-button:hover { border-color: var(--arcade-amber); background: var(--arcade-amber); color: var(--arcade-night); }
.arcade-button.secondary { background: rgba(8, 17, 27, .2); color: var(--arcade-snow); }
.arcade-button.secondary:hover { border-color: var(--arcade-glacier); background: rgba(134, 185, 203, .15); }
.arcade-button:disabled { cursor: not-allowed; opacity: .4; }
.run-nav { display: flex; justify-content: flex-end; gap: 10px 18px; margin: 0 0 28px; padding-bottom: 12px; border-bottom: 1px solid var(--arcade-line); }
.run-nav a { color: rgba(247, 244, 236, .7); font: 600 .68rem/1.3 var(--f-mono); letter-spacing: .1em; text-decoration: none; text-transform: uppercase; }
.run-nav a::before { content: "← "; color: var(--arcade-amber); }
.run-nav a:hover { color: var(--arcade-snow); }
.run-nav a:focus-visible { outline: 2px solid var(--arcade-amber); outline-offset: 5px; }.filter-row {
  display: flex;
  gap: 0;
  margin: 0 0 24px;
  overflow-x: auto;
  border-bottom: 1px solid var(--arcade-line);
  scrollbar-width: thin;
}
.filter {
  flex: 0 0 auto;
  padding: 12px 14px 11px;
  border: 0;
  border-bottom: 2px solid transparent;
  background: transparent;
  color: rgba(247, 244, 236, .62);
  font: 600 .72rem/1.2 var(--f-mono);
  cursor: pointer;
}
.filter:hover { color: var(--arcade-snow); }
.filter.active { border-bottom-color: var(--arcade-amber); color: var(--arcade-snow); }
.hud {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  margin: 0 0 18px;
  border: 1px solid var(--arcade-line);
  border-bottom: 0;
  background: rgba(8, 17, 27, .68);
  backdrop-filter: blur(12px);
}
.hud-cell { min-width: 0; padding: 14px 16px; border-right: 1px solid var(--arcade-line); border-bottom: 1px solid var(--arcade-line); }
.hud-cell:last-child { border-right: 0; }
.hud-label { display: block; margin-bottom: 7px; color: rgba(247, 244, 236, .5); }
.hud-value { display: block; overflow: hidden; color: var(--arcade-snow); font: 400 1.18rem/1.2 var(--f-serif); text-overflow: ellipsis; white-space: nowrap; }
.progress-track { height: 2px; margin: 0 0 22px; background: rgba(247, 244, 236, .16); overflow: hidden; }
.progress-fill { height: 100%; background: var(--arcade-amber); transition: width .25s ease; }
.study-card, .exam-card {
  position: relative;
  padding: clamp(26px, 5vw, 58px);
  border: 1px solid var(--arcade-line);
  border-radius: 2px;
  background: var(--arcade-panel);
  box-shadow: 0 24px 70px rgba(0, 0, 0, .24);
  backdrop-filter: blur(18px);
  -webkit-backdrop-filter: blur(18px);
}
.domain-tag { color: var(--arcade-glacier); }
.study-card h2, .exam-card h2 {
  max-width: 920px;
  margin: 24px 0;
  color: var(--arcade-snow);
  font: 400 clamp(1.8rem, 4vw, 3.2rem)/1.14 var(--f-serif);
  text-wrap: balance;
}
.answer {
  display: none;
  margin: 28px 0 0;
  padding: 22px 0 2px;
  border-top: 1px solid var(--arcade-line);
  color: rgba(247, 244, 236, .8);
  font-size: 1.04rem;
  line-height: 1.7;
}
.answer.visible { display: block; }
.answer .hud-label { color: var(--arcade-amber); }

.answer-copy { margin: 0; }
.aws-nugget { position: relative; margin-top: 26px; padding: 24px 0 0 24px; border-top: 1px solid rgba(134, 185, 203, .52); border-left: 2px solid var(--arcade-glacier); }
.aws-nugget::before { content: "AWS / ML"; position: absolute; top: -9px; right: 0; padding-left: 10px; background: var(--arcade-night); color: rgba(134, 185, 203, .7); font: 600 .58rem/1 var(--f-mono); letter-spacing: .14em; }
.aws-nugget-label, .aws-docs-label { display: block; color: var(--arcade-glacier); font: 600 .66rem/1.3 var(--f-mono); letter-spacing: .13em; text-transform: uppercase; }
.aws-nugget p { max-width: 880px; margin: 10px 0 18px; color: rgba(247, 244, 236, .82); }
.aws-docs { display: flex; gap: 9px 18px; align-items: baseline; flex-wrap: wrap; }
.aws-docs-label { color: rgba(247, 244, 236, .48); }
.aws-doc-link { color: var(--arcade-amber); font-weight: 700; text-underline-offset: 4px; }
.aws-doc-link:hover { color: var(--arcade-snow); }
.aws-doc-link:focus-visible { outline: 2px solid var(--arcade-amber); outline-offset: 5px; }
.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; }
.controls { display: flex; justify-content: space-between; gap: 12px; margin-top: 28px; flex-wrap: wrap; }
.option-list { display: grid; gap: 9px; margin: 26px 0; }
.option {
  width: 100%;
  padding: 16px 18px;
  text-align: left;
  border: 1px solid var(--arcade-line);
  border-radius: 2px;
  background: rgba(247, 244, 236, .035);
  color: rgba(247, 244, 236, .9);
  font: 500 .98rem/1.5 var(--f-sans);
  cursor: pointer;
  transition: border-color .16s ease, background .16s ease;
}
.option:hover, .option:focus-visible { border-color: var(--arcade-glacier); background: rgba(134, 185, 203, .08); }
.option.selected { border-color: var(--arcade-amber); background: rgba(227, 169, 74, .1); }
.option.correct { border-color: #86c59a; background: rgba(134, 197, 154, .12); }
.option.wrong { border-color: #d9827e; background: rgba(217, 130, 126, .1); }
.results { min-height: calc(100vh - 190px); text-align: left; }
.results-score { margin: 30px 0 10px; color: var(--arcade-amber); font: 400 clamp(5rem, 14vw, 10rem)/.8 var(--f-serif); }
.arcade-footer {
  display: flex;
  justify-content: space-between;
  gap: 20px;
  padding: 24px max(24px, calc((100% - 1180px) / 2));
  border-top: 1px solid var(--arcade-line);
  background: rgba(6, 14, 23, .72);
  color: rgba(247, 244, 236, .52);
  font-size: .78rem;
  backdrop-filter: blur(12px);
}
.arcade-footer a { color: var(--arcade-snow); }
@media (max-width: 360px) { .aws-doc-link span[aria-hidden="true"] { display: none; } }
@media (max-width: 800px) {
  body::before { background-position: 58% 30%; }
  body::after { display: none; }
  .arcade-wrap { width: min(100% - 28px, 680px); padding: 42px 0 54px; }
  .arcade-hero { grid-template-columns: 1fr; gap: 18px; min-height: auto; }
  .hero-copy { padding: 28px 0 0; }
  .course-manifest { margin: 8px 0 42px; }
  .hud { grid-template-columns: repeat(2, 1fr); }
  .hud-cell:nth-child(2) { border-right: 0; }
  .study-card, .exam-card { padding: 24px 20px; }
  .aws-nugget { padding-left: 16px; }
  .site-nav .nav-links { display: none; }
  .arcade-footer { flex-direction: column; }
}
@media (prefers-reduced-motion: reduce) {
  * { scroll-behavior: auto !important; transition: none !important; }
}