:root {
  color-scheme: dark;
  --bg: #05091a;
  --surface: #0d1935;
  --surface-2: #142548;
  --text: #f7f9ff;
  --muted: #aeb9d1;
  --cyan: #00c8e8;
  --yellow: #ffc72c;
  --green: #69db67;
  --pink: #ff5c7a;
  --line: rgba(255, 255, 255, 0.14);
  --content: 1120px;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  line-height: 1.6;
}
a { color: var(--cyan); }
a:hover { color: #8cecff; }

.site-header {
  position: sticky;
  top: 0;
  z-index: 20;
  border-bottom: 1px solid var(--line);
  background: rgba(5, 9, 26, 0.94);
  backdrop-filter: blur(14px);
}
nav {
  width: min(calc(100% - 32px), var(--content));
  min-height: 64px;
  margin: auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
}
.brand {
  color: var(--text);
  font-size: 20px;
  font-weight: 900;
  text-decoration: none;
}
.nav-links { display: flex; align-items: center; gap: 22px; }
.nav-links a { color: var(--muted); font-size: 14px; font-weight: 750; text-decoration: none; }

.hero {
  position: relative;
  min-height: min(780px, calc(88vh - 32px));
  display: grid;
  align-items: end;
  overflow: hidden;
  border-bottom: 1px solid var(--line);
  background: #020513;
}
.hero-media {
  position: absolute;
  inset: 0;
  background-image: linear-gradient(90deg, rgba(2, 5, 19, 0.92) 0%, rgba(2, 5, 19, 0.36) 50%, rgba(2, 5, 19, 0.7) 100%), url("mathrush-logo.webp");
  background-repeat: no-repeat;
  background-position: center;
  background-size: min(76vh, 760px);
}
.hero-media::after {
  content: "";
  position: absolute;
  inset: auto 0 0;
  height: 38%;
  background: linear-gradient(transparent, #05091a);
}
.hero-copy {
  position: relative;
  z-index: 1;
  width: min(calc(100% - 32px), var(--content));
  margin: 0 auto;
  padding: 60px 0 72px;
}
.eyebrow {
  margin: 0 0 8px;
  color: var(--cyan);
  font-size: 13px;
  font-weight: 850;
  text-transform: uppercase;
  letter-spacing: 0;
}
h1, h2, h3 { margin-top: 0; line-height: 1.12; letter-spacing: 0; }
h1 { max-width: 700px; margin-bottom: 6px; font-size: clamp(54px, 10vw, 104px); }
h2 { margin-bottom: 16px; font-size: clamp(32px, 5vw, 52px); }
h3 { margin-bottom: 10px; font-size: 21px; }
.hero-lead { margin: 0; color: var(--yellow); font-size: clamp(20px, 3vw, 30px); font-weight: 850; }
.hero-detail { max-width: 560px; margin: 12px 0 0; color: var(--muted); font-size: 17px; }
.actions { display: flex; flex-wrap: wrap; gap: 12px; margin-top: 28px; }
.button {
  min-height: 46px;
  padding: 11px 18px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  border: 1px solid var(--cyan);
  border-radius: 6px;
  background: var(--cyan);
  color: #031019;
  font-weight: 850;
  text-decoration: none;
}
.button.secondary { border-color: rgba(255,255,255,.3); background: rgba(5,9,26,.78); color: var(--text); }

.proof-band {
  width: min(100%, var(--content));
  margin: -24px auto 0;
  position: relative;
  z-index: 2;
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--surface);
}
.proof-band div { padding: 20px 24px; border-right: 1px solid var(--line); }
.proof-band div:last-child { border-right: 0; }
.proof-band strong, .proof-band span { display: block; }
.proof-band strong { color: var(--yellow); font-size: 24px; }
.proof-band span { color: var(--muted); font-size: 13px; }

.section { width: min(calc(100% - 32px), var(--content)); margin: auto; padding: 92px 0; }
.section-heading { max-width: 760px; margin-bottom: 34px; }
.section-heading.compact { margin-bottom: 28px; }
.section-heading > p:last-child, .family-copy > p:last-child, .support-band p { color: var(--muted); font-size: 17px; }
.feature-grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: 14px; }
.feature {
  min-height: 250px;
  padding: 28px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--surface);
}
.feature-primary { grid-column: span 2; min-height: 280px; background: #102345; }
.feature-number { display: block; margin-bottom: 42px; color: var(--cyan); font-weight: 900; }
.feature p { max-width: 680px; margin: 0; color: var(--muted); }
.mechanic-strip { display: flex; flex-wrap: wrap; gap: 8px; margin-top: 26px; }
.mechanic-strip span { padding: 6px 10px; border: 1px solid rgba(0,200,232,.35); border-radius: 4px; color: #c7f8ff; font-size: 13px; font-weight: 750; }

.progression-band { border-top: 1px solid var(--line); }
.progress-list { border-top: 1px solid var(--line); }
.progress-list article { display: grid; grid-template-columns: minmax(230px, .7fr) 1.3fr; gap: 30px; padding: 25px 0; border-bottom: 1px solid var(--line); }
.progress-list h3, .progress-list p { margin: 0; }
.progress-list p { color: var(--muted); }
.progress-list article:nth-child(1) h3 { color: var(--green); }
.progress-list article:nth-child(2) h3 { color: var(--yellow); }
.progress-list article:nth-child(3) h3 { color: var(--cyan); }
.progress-list article:nth-child(4) h3 { color: #c69cff; }

.family-band { display: grid; grid-template-columns: 1.15fr .85fr; gap: 64px; border-top: 1px solid var(--line); }
.family-facts { margin: 0; }
.family-facts div { padding: 18px 0; border-bottom: 1px solid var(--line); }
.family-facts dt { color: var(--yellow); font-weight: 850; }
.family-facts dd { margin: 5px 0 0; color: var(--muted); }

.support-band { display: flex; align-items: end; justify-content: space-between; gap: 40px; border-top: 1px solid var(--line); }
.support-band > div:first-child { max-width: 670px; }
.support-actions { display: flex; flex-direction: column; align-items: flex-start; gap: 14px; flex: 0 0 auto; }
.text-link { font-weight: 800; }

.legal { width: min(calc(100% - 32px), 820px); margin: auto; padding: 56px 0 88px; }
.legal h1 { font-size: clamp(38px, 7vw, 56px); }
.legal h2 { margin-top: 42px; color: var(--yellow); font-size: 24px; }
.legal li { margin-bottom: 8px; }
.notice { padding: 16px; border-left: 4px solid var(--green); background: var(--surface); }

footer {
  min-height: 88px;
  padding: 24px max(16px, calc((100% - var(--content)) / 2));
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
  border-top: 1px solid var(--line);
  color: var(--muted);
  font-size: 14px;
}

@media (max-width: 760px) {
  .site-header { position: static; }
  nav { min-height: auto; padding: 14px 0; align-items: flex-start; }
  .nav-links { max-width: 220px; flex-wrap: wrap; justify-content: flex-end; gap: 8px 14px; }
  .hero { min-height: 700px; }
  .hero-media { background-image: linear-gradient(180deg, rgba(2,5,19,.12) 0%, rgba(2,5,19,.34) 48%, #05091a 76%), url("mathrush-logo.webp"); background-position: center 7%; background-size: min(94vw, 540px); }
  .hero-copy { padding-bottom: 52px; }
  .proof-band { width: calc(100% - 32px); grid-template-columns: repeat(2, 1fr); }
  .proof-band div:nth-child(2) { border-right: 0; }
  .proof-band div:nth-child(-n+2) { border-bottom: 1px solid var(--line); }
  .section { padding: 68px 0; }
  .feature-grid { grid-template-columns: 1fr; }
  .feature-primary { grid-column: auto; }
  .progress-list article { grid-template-columns: 1fr; gap: 8px; }
  .family-band { grid-template-columns: 1fr; gap: 28px; }
  .support-band { align-items: flex-start; flex-direction: column; }
  footer { align-items: flex-start; flex-direction: column; }
}

@media (max-width: 430px) {
  .nav-links a:first-child, .nav-links a:nth-child(2) { display: none; }
  .hero { min-height: 650px; }
  .hero-copy { padding-top: 300px; }
  h1 { font-size: 54px; }
  .actions { flex-direction: column; align-items: stretch; }
  .proof-band div { padding: 16px; }
  .feature { min-height: 0; padding: 22px; }
  .feature-number { margin-bottom: 24px; }
}