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

body {
  font-family: 'Inter', system-ui, -apple-system, sans-serif;
  background: #ffffff;
  color: #1f2937;
  line-height: 1.68;
  font-size: 1.05rem;
}

.container {
  max-width: 1180px;
  margin: 0 auto;
  padding: 0 20px;
}

a { text-decoration: none; }

/* ── Hero ─────────────────────────────────────────────── */
.hero {
  background: linear-gradient(135deg, #001f3f 0%, #000d22 100%);
  color: white;
  padding: clamp(5rem, 12vw, 10rem) 0 6rem;
  text-align: center;
}

.top-bar {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 3.5rem;
  flex-wrap: wrap;
  gap: 1.5rem;
}

.logo {
  font-family: 'Montserrat', sans-serif;
  font-weight: 800;
  font-size: clamp(1.6rem, 5vw, 2.1rem);
  letter-spacing: 1px;
}

.top-nav {
  display: flex;
  gap: 1.8rem;
}

.top-nav a {
  color: #a5c4ff;
  font-weight: 500;
  transition: color 0.2s;
}

.top-nav a:hover { color: white; }

.hero h1 {
  font-family: 'Montserrat', sans-serif;
  font-weight: 800;
  font-size: clamp(2.8rem, 9vw, 5.5rem);
  line-height: 1.05;
  margin-bottom: 1.2rem;
}

.subtitle {
  font-size: clamp(1.15rem, 3vw, 1.4rem);
  opacity: 0.92;
  max-width: 720px;
  margin: 0 auto 1.4rem;
}

.update-date {
  font-size: 0.98rem;
  opacity: 0.75;
}

/* ── Main Content ─────────────────────────────────────── */
.main-content {
  padding: clamp(3rem, 8vw, 6rem) 0;
  background: #f9fafb;
}

.toc-wrapper {
  margin-bottom: 2.5rem;
}

/* Mobile TOC (details/summary) */
.toc-mobile {
  display: block;
  background: white;
  border-radius: 10px;
  box-shadow: 0 2px 12px rgba(0,0,0,0.08);
  margin-bottom: 2rem;
}

.toc-mobile summary {
  font-family: 'Montserrat', sans-serif;
  font-weight: 700;
  padding: 1.1rem 1.4rem;
  cursor: pointer;
  font-size: 1.15rem;
  color: #001f3f;
}

.toc-mobile[open] summary {
  border-bottom: 1px solid #e5e7eb;
}

.toc-list {
  list-style: none;
  padding: 0.6rem 0;
}

.toc-list li a {
  display: block;
  padding: 0.75rem 1.4rem;
  color: #374151;
  transition: all 0.15s;
}

.toc-list li a:hover {
  background: #f1f5f9;
  color: #c8102e;
  padding-left: 1.8rem;
}

/* Desktop TOC (sticky sidebar) */
.toc-desktop {
  display: none;
  width: 240px;
  flex-shrink: 0;
  position: sticky;
  top: 2rem;
  align-self: start;
}

@media (min-width: 992px) {
  .toc-mobile { display: none; }
  .toc-desktop { display: block; }
  .main-content .container {
    display: flex;
    gap: 3.5rem;
  }
}

.toc-desktop h3 {
  font-family: 'Montserrat', sans-serif;
  color: #001f3f;
  font-size: 1.35rem;
  margin-bottom: 1.4rem;
}

/* Sections */
.sections section {
  background: white;
  padding: clamp(1.8rem, 4vw, 2.8rem);
  margin-bottom: 2.5rem;
  border-radius: 12px;
  box-shadow: 0 4px 16px rgba(0,0,0,0.06);
}

.sections h2 {
  font-family: 'Montserrat', sans-serif;
  color: #001f3f;
  font-size: clamp(1.8rem, 4.5vw, 2.25rem);
  margin-bottom: 1.2rem;
  padding-left: 0.9rem;
  border-left: 5px solid #c8102e;
}

.sections ul {
  margin: 1.3rem 0;
  padding-left: 1.6rem;
}

.sections li {
  margin-bottom: 0.8rem;
}

/* CTA */
.cta-section {
  background: #001f3f;
  color: white;
  text-align: center;
  padding: clamp(5rem, 12vw, 8rem) 0 5rem;
}

.cta-section h2 {
  font-family: 'Montserrat', sans-serif;
  font-size: clamp(2rem, 6vw, 3.2rem);
  margin-bottom: 1.1rem;
}

.cta-section p {
  max-width: 620px;
  margin: 0 auto 2rem;
  font-size: 1.15rem;
  opacity: 0.95;
}

.btn-primary {
  display: inline-block;
  background: #c8102e;
  color: white;
  font-weight: 600;
  padding: 0.95rem 2.2rem;
  border-radius: 50px;
  font-size: 1.1rem;
  transition: all 0.22s ease;
}

.btn-primary:hover {
  background: #a50d24;
  transform: translateY(-3px);
  box-shadow: 0 8px 20px rgba(200,16,46,0.3);
}

/* Footer */
.footer {
  background: #000d22;
  color: #a5c4ff;
  padding: clamp(4rem, 10vw, 6rem) 0 3rem;
}

.footer-brand {
  font-family: 'Montserrat', sans-serif;
  font-weight: 800;
  font-size: clamp(1.8rem, 5vw, 2.4rem);
  color: white;
  margin-bottom: 2.5rem;
}

.footer-columns {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
  gap: 2.5rem;
  margin-bottom: 3.5rem;
}

.footer-column h4 {
  color: white;
  font-family: 'Montserrat', sans-serif;
  margin-bottom: 1.1rem;
  font-size: 1.1rem;
}

.footer ul li a {
  color: inherit;
  line-height: 2.1;
  transition: color 0.2s;
}

.footer ul li a:hover { color: white; }

.copyright {
  text-align: center;
  font-size: 0.92rem;
  opacity: 0.8;
  border-top: 1px solid #1a2f4a;
  padding-top: 2rem;
}

/* Back to top button */
#back-to-top {
  position: fixed;
  bottom: 24px;
  right: 24px;
  width: 52px;
  height: 52px;
  border-radius: 50%;
  background: #c8102e;
  color: white;
  border: none;
  font-size: 1.6rem;
  cursor: pointer;
  opacity: 0;
  visibility: hidden;
  transition: all 0.3s ease;
  z-index: 999;
  box-shadow: 0 4px 12px rgba(0,0,0,0.3);
}

#back-to-top.show {
  opacity: 1;
  visibility: visible;
}

/* ── Responsive adjustments ───────────────────────────── */
@media (max-width: 576px) {
  .top-bar { flex-direction: column; text-align: center; }
  .top-nav { justify-content: center; }
  .sections section { padding: 1.6rem; }
}

@media (max-width: 400px) {
  .container { padding: 0 16px; }
}


@media (max-width: 768px) {
  .top-bar {
    flex-direction: column;
    text-align: center;
  }

  .top-nav {
    flex-wrap: wrap;
    justify-content: center;
    gap: 1rem;
  }

  .top-nav a {
    font-size: 0.95rem;
  }
}
@media (max-width: 576px) {
  .hero {
    padding: 4rem 0 4rem;
  }

  .hero h1 {
    font-size: 2.2rem;
  }

  .subtitle {
    font-size: 1rem;
  }
}
@media (min-width: 768px) and (max-width: 991px) {
  .toc-desktop {
    width: 200px;
  }

  .main-content .container {
    gap: 2rem;
  }
}
@media (max-width: 576px) {
  body {
    font-size: 0.98rem;
    line-height: 1.6;
  }

  .sections h2 {
    font-size: 1.4rem;
  }

  .sections section {
    margin-bottom: 1.6rem;
  }
}
@media (max-width: 576px) {
  #back-to-top {
    width: 46px;
    height: 46px;
    font-size: 1.3rem;
    bottom: 18px;
    right: 18px;
  }
}
@media (max-width: 576px) {
  .footer {
    padding: 3rem 0 2rem;
  }

  .footer-columns {
    gap: 1.5rem;
  }

  .footer-column h4 {
    font-size: 1rem;
  }
}
@media (min-width: 1600px) {
  .container {
    max-width: 1320px;
  }
}
.footer ul {
  list-style: none;
  padding: 0;
  margin: 0;
}

.footer ul li {
  margin-bottom: 0.4rem;
}