:root {
  --primary-color: #dc3545;
  --dark-bg: #1a1a1a;
  --light-bg: #f8f9fa;
  --text-dark: #333333;
  --text-light: #666666;
  --border-color: #e0e0e0;
}

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

html,
body {
  height: 100%;
  font-family: "Segoe UI", Tahoma, Geneva, Verdana, sans-serif;
}

body {
  display: flex;
  flex-direction: column;
  color: var(--text-dark);
  background-color: #ffffff;
}

.brand-text {
  font-size: 24px;
  color: var(--primary-color);
  letter-spacing: 1px;
}

nav.navbar {
  box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
}

.nav-link {
  color: var(--text-dark) !important;
  font-weight: 500;
  margin-left: 15px;
  transition: color 0.3s;
}

.nav-link:hover {
  color: var(--primary-color) !important;
}

.nav-link.active {
  color: var(--primary-color) !important;
}

.hero-section {
  background: linear-gradient(135deg, #ffffff 0%, var(--light-bg) 100%);
  padding: 80px 0;
  min-height: 500px;
}

.hero-section h1 {
  color: var(--text-dark);
  font-weight: 700;
  line-height: 1.2;
  margin-bottom: 20px;
}

.hero-section .lead {
  color: var(--text-light);
  font-size: 18px;
  line-height: 1.6;
}

.hero-section img {
  box-shadow: 0 10px 30px rgba(0, 0, 0, 0.1);
}

.page-header {
  background: linear-gradient(135deg, var(--light-bg) 0%, #ffffff 100%);
  border-bottom: 2px solid var(--primary-color);
}

.page-header h1 {
  color: var(--text-dark);
  font-weight: 700;
}

.page-header .lead {
  color: var(--text-light);
}

.calculator-section {
  background-color: var(--light-bg);
}

.calculator-section h2 {
  color: var(--text-dark);
  font-weight: 700;
  margin-bottom: 40px;
}

.card {
  border: 1px solid var(--border-color);
  border-radius: 8px;
  transition: all 0.3s;
}

.card:hover {
  box-shadow: 0 15px 35px rgba(220, 53, 69, 0.1) !important;
  transform: translateY(-5px);
}

.card-img-top {
  height: 250px;
  object-fit: cover;
}

.card-title {
  color: var(--text-dark);
  font-weight: 600;
}

.card-text {
  color: var(--text-light);
}

.btn-primary {
  background-color: var(--primary-color);
  border-color: var(--primary-color);
  color: white;
  font-weight: 600;
  padding: 10px 30px;
  transition: all 0.3s;
}

.btn-primary:hover {
  background-color: #c82333;
  border-color: #c82333;
  color: white;
  box-shadow: 0 5px 15px rgba(220, 53, 69, 0.3);
}

.form-control {
  border: 1px solid var(--border-color);
  border-radius: 6px;
  padding: 10px 15px;
  transition: border-color 0.3s;
}

.form-control:focus {
  border-color: var(--primary-color);
  box-shadow: 0 0 0 0.2rem rgba(220, 53, 69, 0.25);
}

.form-group label {
  color: var(--text-dark);
  font-weight: 600;
  margin-bottom: 8px;
}

.certification-badge {
  padding: 30px;
  background-color: var(--light-bg);
  border-radius: 8px;
  border-left: 4px solid var(--primary-color);
}

.certification-badge h4 {
  color: var(--primary-color);
  font-weight: 700;
}

.certification-badge p {
  color: var(--text-light);
  margin-top: 10px;
}

.testimonials-section h2 {
  color: var(--text-dark);
  font-weight: 700;
}

footer {
  background-color: var(--dark-bg);
  margin-top: auto;
}

footer h6 {
  color: white;
  text-transform: uppercase;
  letter-spacing: 1px;
}

footer a {
  transition: color 0.3s;
}

footer a:hover {
  color: var(--primary-color) !important;
}

.text-white-50 {
  color: rgba(255, 255, 255, 0.5);
}

.services-preview {
  background-color: var(--light-bg);
}

.services-preview h2 {
  color: var(--text-dark);
  font-weight: 700;
}

#bmiResult {
  padding: 20px;
  background-color: var(--light-bg);
  border-radius: 8px;
  border-left: 4px solid var(--primary-color);
}

#bmiResult h4 {
  color: var(--primary-color);
  font-weight: 700;
}

.alert {
  border-radius: 8px;
}

.success-message h1 {
  color: var(--primary-color);
  font-weight: 700;
}

@media (max-width: 768px) {
  .hero-section {
    padding: 60px 0;
    min-height: auto;
  }

  .hero-section h1 {
    font-size: 28px;
  }

  .hero-section .lead {
    font-size: 16px;
  }

  .page-header h1 {
    font-size: 28px;
  }

  .display-4 {
    font-size: 24px;
  }

  .navbar-brand {
    font-size: 20px;
  }

  .nav-link {
    margin-left: 0;
    padding: 10px 0;
  }

  .card-img-top {
    height: 200px;
  }

  .btn-block {
    width: 100%;
  }
}

@media (max-width: 576px) {
  .hero-section {
    padding: 40px 0;
  }

  .hero-section h1 {
    font-size: 24px;
  }

  .page-header h1 {
    font-size: 24px;
  }

  .lead {
    font-size: 14px;
  }
}