:root {
  --bg: #ffffff;
  --text: #050505;
  --muted: #5f5f5f;
  --line: #e5e5e5;
  --accent: #cf0000;
  --max-width: 760px;
}

*,
*::before,
*::after {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: Arial, Helvetica, sans-serif;
  line-height: 1.5;
}

a {
  color: inherit;
  text-decoration: none;
}

.container {
  width: min(calc(100% - 2rem), var(--max-width));
  margin: 0 auto;
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 10;
  width: 100%;
  background: rgba(255, 255, 255, 0.97);
  border-bottom: 1px solid var(--line);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  padding: 0.9rem 0;
}

.brand {
  font-size: 1rem;
  font-weight: 700;
  color: var(--accent);
}

.site-nav {
  display: flex;
  flex-wrap: wrap;
  gap: 1rem;
  font-size: 0.95rem;
}

.site-nav a {
  color: var(--muted);
  border-bottom: 1px solid transparent;
  transition: color 160ms ease, border-color 160ms ease;
}

.site-nav a:hover,
.site-nav a.is-active {
  color: var(--accent);
  border-color: var(--accent);
}

.hero,
.section {
  padding: 2.75rem 0;
  border-bottom: 1px solid var(--line);
}

.kicker {
  margin: 0 0 0.75rem;
  color: var(--muted);
  font-size: 0.82rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

h1,
h2 {
  margin: 0 0 1rem;
  line-height: 1.15;
  font-weight: 400;
}

h1 {
  font-size: clamp(2.5rem, 7vw, 4.75rem);
  color: var(--accent);
}

h2 {
  font-size: 1.75rem;
  color: var(--accent);
}

.subtitle {
  margin: 0;
  font-size: 1.45rem;
  color: var(--text);
  line-height: 1.35;
}

.hero-actions {
  display: flex;
  gap: 0.75rem;
  margin-top: 1.5rem;
}

.button {
  display: inline-block;
  padding: 0.7rem 1rem;
  border: 1px solid var(--line);
  background: #ffffff;
  font-size: 0.95rem;
  transition: background-color 160ms ease, border-color 160ms ease, color 160ms ease;
}

.button:hover {
  color: var(--accent);
  border-color: var(--accent);
}

.button-secondary {
  color: var(--muted);
}

p,
li {
  font-size: 1.15rem;
}

p {
  margin: 0 0 1rem;
}

h3 {
  margin: 1.5rem 0 0.75rem;
  font-size: 1.1rem;
  font-weight: 700;
  color: var(--text);
}

.pillar-list {
  margin: 0;
  padding-left: 1.25rem;
}

.pillar-title {
  display: block;
  margin-bottom: 0.2rem;
  color: var(--accent);
  font-size: 1.28rem;
  font-weight: 700;
  line-height: 1.2;
}

.section-note {
  color: var(--muted);
  font-size: 0.98rem;
}

.pillar-list li + li {
  margin-top: 0.85rem;
}

.diagram {
  margin: 1.75rem 0 0;
}

.diagram img {
  display: block;
  width: 100%;
  height: auto;
  border: 1px solid var(--line);
}

@media (max-width: 720px) {
  .header-inner,
  .hero-actions {
    flex-direction: column;
    align-items: flex-start;
  }

  .site-header {
    position: static;
  }
}

@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }

  * {
    transition: none !important;
  }
}