:root {
  --bg: #f7f7f4;
  --text: #0b1220;
  --muted: #5b6472;
  --accent: #1f7a5c;
  --border: #e4e2da;

  /* Light-on-dark tokens, shared by the hero and footer, the two places on
     this site that intentionally use the dark gradient chrome (mirroring
     TopBar's role in the game app). */
  --dark-gradient: linear-gradient(135deg, #1e3348, #2a495b, #264355);
  --dark-text: #e8e6dc;
  --dark-muted: #b2bdca;
  --dark-border: rgba(255, 255, 255, 0.14);
  /* Lighter derivative of --accent: flat --accent measures 1.8-2.5:1 against
     this gradient (fails badly), this lighter tint is verified for text and
     links on the dark gradient instead. */
  --dark-accent: #63c9a0;

  --font-body: 'Public Sans', sans-serif;
  --font-mono: 'IBM Plex Mono', monospace;
  --font-nav: 'Roboto', sans-serif;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  font-family: var(--font-body);
  background-color: var(--bg);
  color: var(--text);
}

a {
  color: inherit;
}

/* Container, a single reusable width/alignment system for every section,
   modeled directly on Bootstrap 5's real container breakpoints */

.container {
  width: 100%;
  margin: 0 auto;
  padding-left: 24px;
  padding-right: 24px;
}

@media (min-width: 576px) {
  .container {
    max-width: 540px;
  }
}

@media (min-width: 768px) {
  .container {
    max-width: 720px;
  }
}

@media (min-width: 992px) {
  .container {
    max-width: 960px;
  }
}

@media (min-width: 1200px) {
  .container {
    max-width: 1140px;
  }
}

@media (min-width: 1400px) {
  .container {
    max-width: 1320px;
  }
}

@media (min-width: 1800px) {
  .container {
    max-width: 1600px;
  }
}

/* Nav */

.site-nav {
  position: relative;
  border-bottom: 1px solid var(--border);
}

.nav-inner {
  padding-top: 36px;
  padding-bottom: 36px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.wordmark {
  display: flex;
  align-items: center;
  gap: 20px;
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: 26px;
  letter-spacing: 0.02em;
  color: var(--text);
  text-decoration: none;
}

.wordmark-dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background-color: var(--accent);
}

.wordmark-mark {
  width: 38px;
  height: 38px;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 32px;
}

.nav-links a {
  font-family: var(--font-nav);
  font-size: 16px;
  font-weight: 500;
  color: var(--muted);
  text-decoration: none;
}

.nav-links a:hover {
  color: var(--text);
}

.nav-toggle {
  display: none;
  align-items: center;
  justify-content: center;
  background: none;
  border: none;
  padding: 8px;
  cursor: pointer;
  color: var(--text);
}

.nav-toggle-icon {
  width: 24px;
  height: 24px;
  stroke: currentColor;
  stroke-width: 1.75;
  stroke-linecap: round;
  stroke-linejoin: round;
}

@media (max-width: 767px) {
  .nav-toggle {
    display: inline-flex;
  }

  .nav-links {
    display: none;
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    z-index: 100;
    flex-direction: column;
    align-items: flex-start;
    gap: 20px;
    padding: 20px 24px 28px;
    background-color: var(--bg);
    border-bottom: 1px solid var(--border);
  }

  .nav-links.is-open {
    display: flex;
  }
}

/* Hero */

.hero {
  background: var(--dark-gradient);
  color: var(--dark-text);
}

.hero-inner {
  padding-top: 96px;
  padding-bottom: 96px;
}

.hero-headline {
  max-width: 780px;
  margin: 0 0 24px;
  font-size: clamp(38px, 5.2vw, 60px);
  font-weight: 700;
  line-height: 1.15;
  letter-spacing: -0.01em;
  color: var(--dark-text);
}

.hero-subhead {
  max-width: 560px;
  margin: 0 0 36px;
  font-size: 20px;
  line-height: 1.6;
  color: var(--dark-muted);
}

.hero-actions {
  display: flex;
  align-items: center;
  gap: 16px;
}

.hero .button-secondary {
  border-color: var(--dark-accent);
  color: var(--dark-text);
}

.credibility-strip {
  display: flex;
  align-items: center;
  gap: 14px;
  margin-top: 48px;
  padding-top: 24px;
  border-top: 1px solid var(--border);
}

.hero .credibility-strip {
  border-top-color: var(--dark-border);
}

.credibility-text {
  margin: 0;
  font-size: 14px;
  color: var(--muted);
}

.hero .credibility-text {
  color: var(--dark-muted);
}

.credibility-badges {
  display: flex;
  align-items: center;
  gap: 8px;
}

.framework-badge {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 0.02em;
  color: var(--muted);
  border: 1px solid var(--border);
  border-radius: 4px;
  padding: 4px 10px;
}

.hero .framework-badge {
  color: var(--dark-muted);
  border-color: var(--dark-border);
}

.button {
  display: inline-block;
  font-family: var(--font-body);
  font-size: 16px;
  font-weight: 600;
  text-decoration: none;
  padding: 12px 24px;
  border-radius: 6px;
  border: 1.5px solid transparent;
}

.button-primary {
  background-color: var(--accent);
  color: #ffffff;
}

.button-secondary {
  background-color: transparent;
  border-color: var(--accent);
  color: var(--text);
}

/* Challenges */

.challenges {
  border-bottom: 1px solid var(--border);
}

.challenges-inner {
  padding-top: 80px;
  padding-bottom: 80px;
}

.section-eyebrow {
  margin: 0 0 8px;
  font-family: var(--font-mono);
  font-size: 14px;
  font-weight: 600;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--accent);
}

.section-heading {
  margin: 0 0 40px;
  font-size: 36px;
  font-weight: 700;
  letter-spacing: -0.01em;
  color: var(--text);
}

.challenge-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
}

.challenge-card {
  background-color: #ffffff;
  border: 1px solid var(--border);
  border-radius: 8px;
  box-shadow: 0 1px 3px rgba(11, 18, 32, 0.06);
  padding: 24px;
  display: flex;
  flex-direction: column;
}

.challenge-card-upcoming {
  background-color: var(--bg);
  border-color: var(--border);
}

.challenge-card-top {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 16px;
}

.challenge-card-top-left {
  display: flex;
  align-items: center;
  gap: 8px;
}

.challenge-icon {
  width: 20px;
  height: 20px;
  flex-shrink: 0;
  color: var(--muted);
  stroke: currentColor;
  stroke-width: 1.75;
  stroke-linecap: round;
  stroke-linejoin: round;
}

.challenge-icon-heavy {
  width: 22px;
  height: 22px;
  stroke-width: 2.25;
}

.challenge-number {
  font-family: var(--font-mono);
  font-size: 13px;
  font-weight: 600;
  letter-spacing: 0.04em;
  color: var(--muted);
}

.challenge-title {
  margin: 0 0 8px;
  font-size: 20px;
  font-weight: 700;
  color: var(--text);
}

.challenge-card-upcoming .challenge-title {
  color: var(--muted);
}

.challenge-teaser {
  margin: 0 0 20px;
  font-size: 16px;
  line-height: 1.6;
  color: var(--muted);
  flex: 1;
}

.badge {
  display: inline-block;
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 0.03em;
  padding: 4px 10px;
  border-radius: 4px;
}

.badge-live {
  background-color: var(--accent);
  color: #ffffff;
}

.badge-upcoming {
  background-color: var(--border);
  color: var(--muted);
}

.badge-difficulty {
  background-color: rgba(31, 122, 92, 0.14);
  color: var(--accent);
  margin-top: auto;
  align-self: flex-start;
}

.badge-difficulty-muted {
  background-color: var(--border);
  color: var(--muted);
}

@media (max-width: 860px) {
  .challenge-grid {
    grid-template-columns: 1fr;
  }
}

/* How It Works */

.how-it-works {
  border-bottom: 1px solid var(--border);
}

.how-it-works-inner {
  padding-top: 80px;
  padding-bottom: 80px;
}

.steps-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 40px;
}

.step-number {
  display: block;
  font-family: var(--font-mono);
  font-size: 14px;
  font-weight: 700;
  letter-spacing: 0.04em;
  color: var(--accent);
  margin-bottom: 12px;
}

.step-title {
  margin: 0 0 8px;
  font-size: 20px;
  font-weight: 700;
  color: var(--text);
}

.step-description {
  margin: 0;
  font-size: 16px;
  line-height: 1.6;
  color: var(--muted);
}

.step-code {
  margin: 16px 0 0;
  padding: 12px 16px;
  background-color: var(--bg);
  border: 1px solid var(--border);
  border-radius: 6px;
}

.step-code code {
  font-family: var(--font-mono);
  font-size: 14px;
  color: var(--text);
}

@media (max-width: 860px) {
  .steps-grid {
    grid-template-columns: 1fr;
    gap: 32px;
  }
}

/* Footer, dark gradient chrome closing out the page */

.site-footer {
  background: var(--dark-gradient);
  color: var(--dark-text);
}

.footer-inner {
  padding-top: 64px;
  padding-bottom: 32px;
}

.footer-columns {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: 32px;
}

.site-footer .wordmark {
  color: var(--dark-text);
}

.footer-description {
  margin: 16px 0 0;
  font-size: 16px;
  line-height: 1.6;
  color: var(--dark-muted);
  max-width: 320px;
}

.footer-heading {
  margin: 0 0 16px;
  font-family: var(--font-mono);
  font-size: 13px;
  font-weight: 900;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  color: var(--dark-text);
}

.footer-links {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.footer-links a {
  font-size: 16px;
  color: var(--dark-muted);
  text-decoration: none;
}

.footer-links a:hover {
  color: var(--dark-accent);
}

.footer-bottom {
  margin-top: 48px;
  padding-top: 24px;
  border-top: 1px solid var(--dark-border);
}

.footer-copyright {
  margin: 0;
  font-size: 14px;
  color: var(--dark-muted);
}

@media (max-width: 860px) {
  .footer-columns {
    grid-template-columns: 1fr;
    gap: 32px;
  }
}

/* Scroll reveal, restrained: fade + slight upward slide, one-time per
   element. JS adds .reveal only when it can also animate it, so without JS
   (or with prefers-reduced-motion below) content just renders normally. */

.reveal {
  opacity: 0;
  transform: translateY(10px);
  transition: opacity 500ms ease-out, transform 500ms ease-out;
}

.reveal.is-visible {
  opacity: 1;
  transform: translateY(0);
}

@media (prefers-reduced-motion: reduce) {
  .reveal {
    opacity: 1;
    transform: none;
    transition: none;
  }
}

/* Challenge card hover polish */

.challenge-card {
  transition: transform 200ms ease-out, box-shadow 200ms ease-out;
}

.challenge-card:hover {
  transform: translateY(-2px);
  box-shadow: 0 4px 12px rgba(11, 18, 32, 0.1);
}