* { box-sizing: border-box; }

:root {
  --navy: #061a35;
  --blue: #1473e6;
  --light-blue: #eef6ff;
  --text: #10213f;
  --muted: #5d6b82;
  --border: #d8e4f2;
  --white: #ffffff;
}

body {
  margin: 0;
  font-family: Arial, Helvetica, sans-serif;
  color: var(--text);
  background: #f7fbff;
  line-height: 1.6;
}

a { color: var(--blue); text-decoration: none; }
a:hover { text-decoration: underline; }

.container {
  width: min(1120px, 92%);
  margin: 0 auto;
}

.site-header {
  background: var(--navy);
  color: var(--white);
  padding: 18px 0;
}

.header-inner {
  display: flex;
  justify-content: space-between;
  gap: 24px;
  align-items: center;
}

.brand {
  display: flex;
  gap: 12px;
  align-items: center;
  color: var(--white);
}

.logo-mark {
  width: 54px;
  height: 54px;
  border-radius: 16px;
  background: linear-gradient(135deg, #ffffff, #5db4ff);
  color: var(--navy);
  display: grid;
  place-items: center;
  font-size: 25px;
  font-weight: 800;
}

.brand-name {
  font-size: 30px;
  font-weight: 800;
  letter-spacing: 1px;
  text-transform: uppercase;
}

.brand-line {
  font-size: 14px;
  color: #d7e7ff;
}

.main-nav {
  display: flex;
  gap: 26px;
  flex-wrap: wrap;
}

.main-nav a {
  color: var(--white);
  font-weight: 700;
}

.hero {
  display: grid;
  grid-template-columns: 1.2fr 0.8fr;
  gap: 40px;
  align-items: center;
  padding: 70px 0 45px;
}

.hero h1 {
  font-size: clamp(36px, 5vw, 58px);
  line-height: 1.1;
  margin: 0 0 18px;
}

.hero p, .intro {
  font-size: 20px;
  color: var(--muted);
}

.button, button {
  display: inline-block;
  border: 0;
  background: var(--blue);
  color: white;
  padding: 12px 20px;
  border-radius: 8px;
  font-weight: 800;
  cursor: pointer;
}

.hero-card, .calculator-box, .content-section, .related-tools, .cta, .category-card {
  background: var(--white);
  border: 1px solid var(--border);
  border-radius: 18px;
  box-shadow: 0 12px 30px rgba(6, 26, 53, 0.08);
}

.hero-card {
  padding: 40px;
  text-align: center;
}

.big-logo { font-size: 100px; }

.section-title { text-align: center; }

.card-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 22px;
  margin: 30px 0;
}

.category-card {
  padding: 28px;
  text-align: center;
  color: var(--text);
}

.category-card span { font-size: 45px; }

.cta {
  margin: 40px auto;
  padding: 28px;
  display: flex;
  justify-content: space-between;
  gap: 20px;
  align-items: center;
}

.page-layout {
  padding: 45px 0;
  max-width: 860px;
}

.breadcrumb {
  color: var(--muted);
}

.calculator-box, .content-section, .related-tools {
  padding: 28px;
  margin: 26px 0;
}

.calculator-box label {
  display: block;
  margin-top: 14px;
  font-weight: 700;
}

.calculator-box input {
  width: 100%;
  padding: 12px;
  border: 1px solid var(--border);
  border-radius: 8px;
  font-size: 18px;
}

.calculator-box button {
  margin-top: 18px;
}

.result-box {
  background: var(--light-blue);
  border-radius: 12px;
  padding: 18px;
  margin-top: 22px;
}

.tool-list li {
  margin: 10px 0;
}

.site-footer {
  background: var(--navy);
  color: white;
  padding: 35px 0;
  margin-top: 50px;
}

.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr;
  gap: 30px;
}

.site-footer a {
  display: block;
  color: #d7e7ff;
  margin-top: 6px;
}

@media (max-width: 800px) {
  .header-inner, .hero, .cta, .footer-grid {
    grid-template-columns: 1fr;
    display: grid;
  }

  .main-nav {
    gap: 14px;
  }

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