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

/* ── Design tokens ── */
:root {
  --bg:           #f5f5f8;
  --surface:      #ffffff;
  --surface-hi:   #ebebf0;
  --border:       #dddde8;
  --text:         #111116;
  --text-2:       #53536d;
  --text-3:       #9898b2;
  --accent:       #5254e0;
  --accent-light: #4547cc;
  --glow:         rgba(82, 84, 224, 0.18);
  --radius:       12px;
  --nav-bg:       rgba(245, 245, 248, 0.88);
}

/* ── Base ── */
html {
  scroll-behavior: smooth;
  background: var(--bg);
}

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

a { color: inherit; }

/* ── Nav ── */
nav {
  position: sticky;
  top: 0;
  z-index: 100;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 28px;
  height: 64px;
  background: var(--nav-bg);
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
  border-bottom: 1px solid var(--border);
}

.nav-brand {
  display: flex;
  align-items: center;
  gap: 10px;
  text-decoration: none;
}
.nav-brand-icon { font-size: 22px; color: var(--accent); }
.nav-brand-name { font-size: 16px; font-weight: 700; letter-spacing: -0.3px; color: var(--text); }

.nav-cta {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 9px 20px;
  background: var(--accent);
  color: #fff;
  font-size: 14px;
  font-weight: 600;
  border-radius: 8px;
  text-decoration: none;
  transition: opacity 0.15s, transform 0.15s;
}
.nav-cta:hover { opacity: 0.88; transform: translateY(-1px); }

/* ── Footer ── */
footer {
  border-top: 1px solid var(--border);
  padding: 28px;
  text-align: center;
  font-size: 13px;
  color: var(--text-3);
}
footer a { color: var(--text-3); text-decoration: none; }
footer a:hover { color: var(--text-2); }

/* ── Responsive base ── */
@media (max-width: 640px) {
  nav { padding: 0 18px; }
}