/* ── Reset & Base ── */
*, *::before, *::after {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

:root {
  --accent: #0284C7;
  --accent-light: #E6F7FA;
  --text: #111111;
  --text-body: #444444;
  --text-secondary: #888888;
  --text-muted: #999999;
  --bg: #FFFFFF;
  --bg-alt: #F9FAFB;
  --border: #E5E7EB;
}

html {
  font-size: 16px;
  scroll-behavior: smooth;
}

body {
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  color: var(--text-body);
  background: var(--bg);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

a {
  color: var(--accent);
  text-decoration: none;
}

a:hover {
  text-decoration: underline;
}

/* ── Header ── */
.site-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  max-width: 960px;
  margin: 0 auto;
  padding: 1.5rem 1.5rem;
}

.logo {
  font-family: 'Space Grotesk', sans-serif;
  font-weight: 700;
  font-size: 1.75rem;
  letter-spacing: -0.5px;
  color: var(--text);
  text-decoration: none;
}

.logo:hover {
  text-decoration: none;
}

.dot {
  color: var(--accent);
}

.site-header nav a {
  font-size: 0.9rem;
  font-weight: 500;
  color: var(--text-secondary);
  transition: color 0.2s;
}

.site-header nav a:hover,
.site-header nav a.active {
  color: var(--text);
  text-decoration: none;
}

/* ── Hero ── */
.hero {
  max-width: 960px;
  margin: 0 auto;
  padding: 6rem 1.5rem 5rem;
  text-align: center;
}

.hero h1 {
  font-family: 'Space Grotesk', sans-serif;
  font-weight: 700;
  font-size: 3rem;
  color: var(--text);
  letter-spacing: -1px;
  line-height: 1.15;
  margin-bottom: 1.25rem;
}

.hero-sub {
  font-size: 1.15rem;
  color: var(--text-secondary);
  max-width: 600px;
  margin: 0 auto 2.5rem;
  line-height: 1.7;
}

.hero-buttons {
  display: flex;
  gap: 1rem;
  justify-content: center;
  flex-wrap: wrap;
}

.btn {
  display: inline-block;
  padding: 0.75rem 1.75rem;
  border-radius: 6px;
  font-size: 0.95rem;
  font-weight: 600;
  text-decoration: none;
  transition: all 0.2s;
}

.btn:hover {
  text-decoration: none;
}

.btn-primary {
  background: var(--accent);
  color: #fff;
}

.btn-primary:hover {
  background: #0270a8;
  color: #fff;
}

.btn-secondary {
  background: var(--accent-light);
  color: var(--accent);
}

.btn-secondary:hover {
  background: #d0eff5;
  color: var(--accent);
}

/* ── Philosophy ── */
.philosophy {
  max-width: 960px;
  margin: 0 auto;
  padding: 4rem 1.5rem 5rem;
}

.philosophy h2 {
  font-family: 'Space Grotesk', sans-serif;
  font-weight: 700;
  font-size: 1.75rem;
  color: var(--text);
  text-align: center;
  margin-bottom: 2.5rem;
}

.philosophy-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 1.5rem;
}

.philosophy-card {
  padding: 2rem;
  border: 1px solid var(--border);
  border-radius: 8px;
}

.philosophy-card h3 {
  font-family: 'Space Grotesk', sans-serif;
  font-weight: 700;
  font-size: 1.1rem;
  color: var(--text);
  margin-bottom: 0.5rem;
}

.philosophy-card p {
  font-size: 0.95rem;
  line-height: 1.65;
}

/* ── Principles page ── */
.principles-hero {
  max-width: 960px;
  margin: 0 auto;
  padding: 5rem 1.5rem 3rem;
  text-align: center;
}

.principles-hero h1 {
  font-family: 'Space Grotesk', sans-serif;
  font-weight: 700;
  font-size: 2.75rem;
  color: var(--text);
  letter-spacing: -1px;
  margin-bottom: 1rem;
}

.principles {
  max-width: 720px;
  margin: 0 auto;
  padding: 0 1.5rem 3rem;
}

.principle {
  display: flex;
  gap: 1.5rem;
  padding: 2.5rem 0;
  border-bottom: 1px solid var(--border);
}

.principle:last-child {
  border-bottom: none;
}

.principle-number {
  font-family: 'Space Grotesk', sans-serif;
  font-weight: 700;
  font-size: 2rem;
  color: var(--accent);
  line-height: 1;
  flex-shrink: 0;
  width: 3rem;
  padding-top: 0.15rem;
}

.principle-content h2 {
  font-family: 'Space Grotesk', sans-serif;
  font-weight: 700;
  font-size: 1.25rem;
  color: var(--text);
  margin-bottom: 0.5rem;
}

.principle-content p {
  font-size: 0.95rem;
  line-height: 1.65;
  margin-bottom: 0.75rem;
}

.principle-content ul {
  list-style: none;
  padding: 0;
}

.principle-content ul li {
  position: relative;
  padding-left: 1.25rem;
  font-size: 0.9rem;
  line-height: 1.6;
  color: var(--text-secondary);
  margin-bottom: 0.35rem;
}

.principle-content ul li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.55rem;
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--accent);
}

/* ── Four layers table ── */
.layers-table {
  display: grid;
  gap: 0;
  border: 1px solid var(--border);
  border-radius: 6px;
  overflow: hidden;
  margin-top: 0.5rem;
}

.layer {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 0.65rem 1rem;
  font-size: 0.9rem;
  border-bottom: 1px solid var(--border);
}

.layer:last-child {
  border-bottom: none;
}

.layer:nth-child(odd) {
  background: var(--bg-alt);
}

.layer strong {
  color: var(--text);
  font-weight: 600;
  min-width: 5.5rem;
}

.layer span {
  color: var(--text-secondary);
}

/* ── Principles note ── */
.principles-note {
  max-width: 720px;
  margin: 0 auto;
  padding: 2rem 1.5rem 4rem;
  text-align: center;
}

.principles-note h2 {
  font-family: 'Space Grotesk', sans-serif;
  font-weight: 700;
  font-size: 1.25rem;
  color: var(--text);
  margin-bottom: 0.5rem;
}

.principles-note p {
  font-size: 0.95rem;
  color: var(--text-secondary);
  max-width: 540px;
  margin: 0 auto;
  line-height: 1.65;
}

/* ── Footer ── */
.site-footer {
  border-top: 1px solid var(--border);
  text-align: center;
  padding: 2rem 1.5rem;
}

.footer-logo {
  font-family: 'Space Grotesk', sans-serif;
  font-weight: 700;
  font-size: 1.25rem;
  color: var(--text);
  margin-bottom: 0.35rem;
}

.site-footer p {
  font-size: 0.8rem;
  color: var(--text-muted);
}

.site-footer .disclaimer {
  font-size: 0.7rem;
  margin-top: 0.5rem;
  max-width: 480px;
  margin-left: auto;
  margin-right: auto;
}

/* ── Responsive ── */
@media (max-width: 640px) {
  .hero h1 {
    font-size: 2rem;
  }

  .hero-sub {
    font-size: 1rem;
  }

  .philosophy-grid {
    grid-template-columns: 1fr;
  }

  .principle {
    flex-direction: column;
    gap: 0.5rem;
  }

  .principle-number {
    font-size: 1.5rem;
  }

  .principles-hero h1 {
    font-size: 2rem;
  }

  .layer {
    flex-direction: column;
    align-items: flex-start;
    gap: 0.15rem;
  }
}