body {
      margin: 0;
      font-family: system-ui, -apple-system, Segoe UI, Roboto, sans-serif;
      background: #0B1E3A;
      color: #E6EDF3;
      line-height: 1.6;
    }

    .container {
      max-width: 1000px;
      margin: 0 auto;
      padding: 48px 20px;
      text-align: justify;
    }

    h1 {
      font-size: 2.2rem;
      margin-bottom: 8px;
      color: #f9fafb;
    }

    .subtitle {
      font-size: 1.05rem;
      color: #cbd5f5;
      max-width: 760px;
    }

    h2 {
      margin-top: 48px;
      margin-bottom: 12px;
      font-size: 1.4rem;
      color: #d1d5db;
    }

    p {
      max-width: 820px;
      color: #cbd5f5;
    }

    /* Calculator cards */
    .calculator-card {
      display: block;
      margin-top: 16px;
      padding: 18px 20px;
      background: #111827;
      border: 1px solid #1f2937;
      border-radius: 8px;
      text-decoration: none;
      color: #e5e7eb;
      cursor: pointer;
      transition: border-color 0.15s ease, transform 0.15s ease;
    }

    .calculator-card:hover {
      border-color: #60a5fa;
      transform: translateY(-2px);
    }

    .calculator-title {
      font-size: 1.05rem;
      font-weight: 600;
      color: #f9fafb;
    }

    .calculator-desc {
      font-size: 0.9rem;
      margin-top: 6px;
      color: #cbd5f5;
    }

    /* Notes */
    .note {
      max-width: 1000;
      margin-top: 16px;
      padding: 14px 18px;
      background: #111827;
      border-left: 3px solid #60a5fa;
      font-size: 0.9rem;
    }

    /* Info cards */
    .info-links {
      display: grid;
      grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
      gap: 16px;
      margin-top: 20px;
    }

    .info-card {
      display: block;
      padding: 16px 18px;
      background: #111827;
      border: 1px solid #1f2937;
      border-radius: 8px;
      color: #e5e7eb;
      text-decoration: none;
    }

    .info-card:hover {
      border-color: #60a5fa;
    }

    .info-card strong {
      display: block;
      font-size: 0.95rem;
      color: #f9fafb;
    }

    .info-card span {
      display: block;
      margin-top: 6px;
      font-size: 0.85rem;
      color: #cbd5f5;
    }

    footer {
      margin-top: 64px;
      padding-top: 24px;
      border-top: 1px solid #1f2937;
      font-size: 0.85rem;
      background: linear-gradient(
      180deg,
      #0f2a22,
      #0c201b
      );
      color: #ffffff;
    }

    .calculator-cta {
      margin-top: 10px;
      font-size: 0.85rem;
      font-weight: 600;
      color: #60a5fa;
    }  

    /* ===============================
   Highlight Section
================================ */

.highlight-section {
  margin-top: 40px;
  padding: 20px 28px;
  
  border-radius: 12px;
}

.highlight-title {
  font-size: 1.6rem;
  margin-bottom: 24px;
  color: #ffffff;
  border-left: 4px solid #60a5fa;
  padding-left: 12px;
}

/* Category blocks */
.category-block {
  margin-bottom: 40px;
}

.category-title {
  font-size: 1.2rem;
  margin-bottom: 16px;
  color: #93c5fd;
}

/* ===============================
   HERO HEADER
================================ */

.hero-header {
  display: flex;
  align-items: center;
  gap: 24px;
  margin-bottom: 40px;
}

.hero-logo {
  height: 85px;
  width: auto;
  object-fit: contain;
}

.hero-text h1 {
  margin: 0;
  font-size: 2.4rem;
  color: #ffffff;
}

.hero-text .subtitle {
  margin-top: 8px;
  max-width: 700px;
}

/* Mobile */
@media (max-width: 640px) {
  .hero-header {
    flex-direction: column;
    align-items: flex-start;
  }

  .hero-logo {
    height: 70px;
  }
}

.hero-logo {
  height: 85px;
  filter: drop-shadow(0 0 8px rgba(96,165,250,0.25));
}

.footer-copy {
  font-size: 0.8rem;
  background: linear-gradient(
    180deg,
    #0f2a22,
    #0c201b
  );
  color: #b7f7dc;
}

.author-box {
      max-width: 1000px;
      margin: 0 auto;
      padding: 20px 20px;
      text-align: justify;
}

/* ============================
PAGE LAYOUT
============================ */

.page-wrapper {
  display: grid;
  grid-template-columns: 320px 1fr;
  gap: 0px;
  max-width: 1400px;
  margin: auto;
  padding: 20px 0px;
}

/* ============================
Left Sidebar
============================ */
.left-sidebar {

  display: flex;
  flex-direction: column;

  gap: 18px;

}

@media (max-width: 1000px) {

  .left-sidebar {
    display: none;
  }

}

/* ============================
STICKY SIDEBAR
============================ */

.side-nav {
  position: sticky;
  top: 50px;
  align-self: start;
  background: #0f1c2f;
  border-radius: 8px;
  padding: 10px 10px;
  border: 1px solid #223a5e;
  box-shadow: 0 8px 24px rgba(0,0,0,0.35);
}

.side-nav-title {
  font-weight: 600;
  color: #9fb3d9;
  margin-bottom: 12px;
}

.side-nav-links {
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.side-nav-links a {
  text-decoration: none;
  color: #cbd5f5;
  font-size: 0.75rem;
  padding: 6px 8px;
  border-radius: 4px;
  transition: background 0.15s ease;
}

.side-nav-links a:hover {
  background: rgba(96,165,250,0.15);
  color: #ffffff;
}

/* ============================
MAIN CONTENT
============================ */

.page-content {
  min-width: 0;
}

@media (max-width: 1000px) {

  .page-wrapper {
    grid-template-columns: 1fr;
  }

  .side-nav {
    display: none;
  }

}

/* ============================
MOBILE NAV
============================ */
.mobile-nav {
  display: none;
  margin-bottom: 20px;
}

.mobile-nav-toggle {
  width: 100%;
  padding: 10px;
  background: #0f1c2f;
  border: 1px solid #223a5e;
  color: #e5e7eb;
  border-radius: 8px;
  cursor: pointer;
}

.mobile-nav-links {
  display: none;
  flex-direction: column;
  margin-top: 10px;
  gap: 8px;
}

.mobile-nav-links a {
  text-decoration: none;
  padding: 8px;
  color: #cbd5f5;
  border-radius: 6px;
}

/* Mobile only */

@media (max-width: 1000px) {

  .mobile-nav {
    display: block;
  }

}


/* ===============================
   TOP EXPLORE BUTTON
================================ */
.explore-button {
  align-self: start;
  display: block;
  width: 100%;
  padding: 10px 10px;
  font-size: 0.9rem;
  font-weight: 500;
  background: #60a5fa;
  color: #0b1220;
  border-radius: 6px;
  text-align: center;
  text-decoration: none;
  transition: background 0.15s ease;
}

.explore-button:hover {
  background: #3b82f6;
}

/* ===============================
   Left Side Ads
================================ */
.sidebar-ad {

  position: sticky;
  top: 360px;
  min-height: 250px;
  background: #0f1c2f;
  border-radius: 8px;
  padding: 10px;
  border: 1px solid #223a5e;
  box-shadow: 0 8px 24px rgba(0,0,0,0.35);

}