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

:root {
  --violet:      #1959C7;
  --violet-dark: #0B1F3A;
  --green:       #058C8C;
  --gold:        #D9A820;
  --white:       #FFFFFF;
  --gray:        #F2F5FB;
  --text:        #12203A;
  --muted:       #6B7280;
  --radius:      16px;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  color: var(--text); background: var(--white); line-height: 1.7;
}

/* ── NAV ─────────────────────────────────────────────────────── */
nav {
  position: sticky; top: 0; z-index: 100;
  display: flex; align-items: center; justify-content: space-between;
  padding: 0 5vw; height: 64px;
  background: rgba(255,255,255,0.92);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid rgba(0,0,0,0.06);
}
.nav-logo {
  display: flex; align-items: center; gap: 10px;
  font-size: 1.2rem; font-weight: 800; color: var(--violet-dark);
  text-decoration: none; white-space: nowrap;
}
.nav-logo img { width: 32px; height: 32px; border-radius: 8px; }
.logo-text span { color: var(--violet); }
.nav-links { display: flex; align-items: center; gap: 24px; list-style: none; }
.nav-links a { font-size: 0.9rem; font-weight: 500; color: var(--muted); text-decoration: none; }
.nav-links a:hover { color: var(--violet); }
.nav-cta { background: var(--violet); color: #fff !important; padding: 8px 18px; border-radius: 20px; }
.nav-cta:hover { background: var(--violet-dark); }
@media (max-width: 640px) { .nav-links li:not(:last-child) { display: none; } }

/* ── HERO ────────────────────────────────────────────────────── */
.hero-strip {
  position: relative;
  background: linear-gradient(135deg, var(--violet-dark) 0%, #103a6b 55%, var(--violet) 100%);
  color: #fff; padding: 56px 5vw 48px;
}
.hero-strip .inner { max-width: 760px; margin: 0 auto; }
.hero-strip h1 { font-size: clamp(1.7rem, 4.2vw, 2.6rem); font-weight: 800; line-height: 1.2; letter-spacing: -0.02em; }
.hero-strip .lead { margin-top: 14px; color: rgba(255,255,255,0.78); font-size: 1.05rem; }
.hero-strip .meta { margin-top: 18px; font-size: 0.82rem; color: rgba(255,255,255,0.6); }
.accent-bar {
  position: absolute; bottom: 0; left: 0; right: 0; height: 5px;
  background: linear-gradient(to right, var(--violet) 0%, var(--green) 50%, var(--gold) 100%);
}
.breadcrumbs { font-size: 0.82rem; margin-bottom: 18px; color: rgba(255,255,255,0.6); }
.breadcrumbs a { color: rgba(255,255,255,0.8); text-decoration: none; }
.breadcrumbs a:hover { text-decoration: underline; }

/* ── ARTICLE ─────────────────────────────────────────────────── */
article.content { max-width: 760px; margin: 0 auto; padding: 48px 5vw 32px; }
article h2 {
  font-size: 1.45rem; font-weight: 800; color: var(--violet-dark);
  margin: 44px 0 14px; letter-spacing: -0.01em;
}
article h3 { font-size: 1.12rem; font-weight: 700; color: var(--violet-dark); margin: 28px 0 10px; }
article p, article li { font-size: 1.02rem; color: #2B3445; }
article p { margin-bottom: 16px; }
article ul, article ol { margin: 0 0 18px 24px; }
article li { margin-bottom: 8px; }
article a { color: var(--violet); }
article strong { color: var(--text); }
article table { width: 100%; border-collapse: collapse; margin: 8px 0 22px; font-size: 0.95rem; }
article th, article td { border: 1px solid #E2E8F2; padding: 9px 12px; text-align: left; vertical-align: top; }
article th { background: var(--gray); font-weight: 700; }
.table-wrap { overflow-x: auto; }

.toc {
  background: var(--gray); border-radius: var(--radius);
  padding: 20px 24px; margin-bottom: 32px;
}
.toc strong { display: block; margin-bottom: 8px; font-size: 0.9rem; text-transform: uppercase; letter-spacing: 0.05em; color: var(--muted); }
.toc ol { margin: 0 0 0 20px; }
.toc li { margin-bottom: 4px; font-size: 0.95rem; }
.toc a { text-decoration: none; }
.toc a:hover { text-decoration: underline; }

.formula {
  background: #F7F9FD; border-left: 4px solid var(--violet);
  border-radius: 8px; padding: 14px 18px; margin: 4px 0 20px;
  font-family: "SF Mono", Menlo, Consolas, monospace; font-size: 0.98rem;
  overflow-x: auto; line-height: 1.9;
}
.example {
  border: 1px solid #DCE5F3; border-radius: var(--radius);
  padding: 20px 22px; margin: 8px 0 24px;
}
.example .label {
  display: inline-block; font-size: 0.75rem; font-weight: 700; letter-spacing: 0.06em;
  text-transform: uppercase; color: var(--green); margin-bottom: 8px;
}
.tip, .warning {
  border-radius: 12px; padding: 14px 18px; margin: 8px 0 22px; font-size: 0.98rem;
}
.tip { background: #E8F6F6; border-left: 4px solid var(--green); }
.warning { background: #FDF6E3; border-left: 4px solid var(--gold); }
.tip p:last-child, .warning p:last-child, .example p:last-child { margin-bottom: 0; }

.faq h3 { margin-top: 22px; }

/* ── CTA ─────────────────────────────────────────────────────── */
.app-cta {
  display: flex; gap: 18px; align-items: center;
  background: linear-gradient(135deg, var(--violet-dark), var(--violet));
  color: #fff; border-radius: var(--radius); padding: 24px; margin: 40px 0 8px;
}
.app-cta img { width: 64px; height: 64px; border-radius: 14px; flex-shrink: 0; }
.app-cta h2 { color: #fff; margin: 0 0 6px; font-size: 1.15rem; }
.app-cta p { color: rgba(255,255,255,0.8); margin: 0 0 12px; font-size: 0.95rem; }
.app-cta a.btn {
  display: inline-block; background: #fff; color: var(--violet-dark);
  font-weight: 700; text-decoration: none; padding: 9px 18px; border-radius: 20px; font-size: 0.92rem;
}
@media (max-width: 520px) { .app-cta { flex-direction: column; align-items: flex-start; } }

.related { max-width: 760px; margin: 0 auto; padding: 8px 5vw 64px; }
.related h2 { font-size: 1.2rem; font-weight: 800; color: var(--violet-dark); margin-bottom: 14px; }
.related ul { list-style: none; display: grid; gap: 10px; }
.related a {
  display: block; padding: 14px 18px; border-radius: 12px; background: var(--gray);
  color: var(--violet-dark); text-decoration: none; font-weight: 600;
}
.related a:hover { background: #E4EBF8; }

/* ── HUB ─────────────────────────────────────────────────────── */
.hub { max-width: 1000px; margin: 0 auto; padding: 48px 5vw 72px; }
.hub h2 { font-size: 1.4rem; font-weight: 800; color: var(--violet-dark); margin: 36px 0 16px; }
.hub h2:first-child { margin-top: 0; }
.cards { display: grid; grid-template-columns: repeat(auto-fill, minmax(280px, 1fr)); gap: 16px; }
.card {
  display: block; border: 1px solid #E2E8F2; border-radius: var(--radius);
  padding: 20px; text-decoration: none; color: var(--text); transition: box-shadow .2s, transform .2s;
}
.card:hover { box-shadow: 0 8px 24px rgba(11,31,58,0.08); transform: translateY(-2px); }
.card h3 { font-size: 1.02rem; color: var(--violet-dark); margin-bottom: 6px; line-height: 1.35; }
.card p { font-size: 0.9rem; color: var(--muted); line-height: 1.5; }

/* ── FOOTER ──────────────────────────────────────────────────── */
footer {
  background: var(--text); color: rgba(255,255,255,0.5);
  padding: 28px 5vw; text-align: center; font-size: 0.85rem;
}
footer a { color: rgba(255,255,255,0.65); text-decoration: none; margin: 0 12px; }
footer a:hover { color: #fff; }
footer p { margin-top: 10px; }
.footer-credit { font-size: 0.78rem; color: rgba(255,255,255,0.4); }
.footer-credit a { color: rgba(255,255,255,0.55); font-weight: 600; margin: 0; }