/* ====================================
   HALTINE - CSS FOUNDATION
   Modular Institutional Composition
   ==================================== */

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

/* ====================================
   COLOR PALETTE
   ==================================== */
:root {
  --primary-bg: #F8F8F8;
  --secondary-dark: #34495E;
  --accent-light: #A9CCE3;
  --accent-grey: #D0D3D4;
  --text-primary: #34495E;
  --text-secondary: #7F8C8D;
  --border-subtle: #E8E8E8;
  --white: #FFFFFF;
}

/* ====================================
   TYPOGRAPHY SYSTEM
   ==================================== */
html {
  font-size: 16px;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
  background-color: var(--primary-bg);
  color: var(--text-primary);
  line-height: 1.6;
  letter-spacing: 0.3px;
}

h1 {
  font-size: 3.5rem;
  font-weight: 700;
  color: var(--secondary-dark);
  line-height: 1.2;
  margin-bottom: 1.5rem;
  letter-spacing: -1px;
}

h2 {
  font-size: 2.5rem;
  font-weight: 700;
  color: var(--secondary-dark);
  line-height: 1.3;
  margin-bottom: 1rem;
  margin-top: 2rem;
}

h3 {
  font-size: 1.75rem;
  font-weight: 600;
  color: var(--secondary-dark);
  line-height: 1.4;
  margin-bottom: 0.75rem;
  margin-top: 1.5rem;
}

h4 {
  font-size: 1.25rem;
  font-weight: 600;
  color: var(--secondary-dark);
  margin-bottom: 0.5rem;
}

p {
  font-size: 1rem;
  color: var(--text-primary);
  line-height: 1.8;
  margin-bottom: 1.5rem;
}

a {
  color: var(--secondary-dark);
  text-decoration: none;
  transition: color 0.3s ease, border-color 0.3s ease;
  border-bottom: 1px solid transparent;
}

a:hover {
  border-bottom-color: var(--accent-light);
  color: var(--accent-light);
}

ul, ol {
  margin-left: 2rem;
  margin-bottom: 1.5rem;
}

li {
  margin-bottom: 0.75rem;
  line-height: 1.8;
}

strong {
  font-weight: 700;
  color: var(--secondary-dark);
}

/* ====================================
   LAYOUT STRUCTURE
   ==================================== */
body {
  display: flex;
  flex-direction: column;
  min-height: 100vh;
}

main {
  flex: 1;
}

.container {
  max-width: 1440px;
  margin: 0 auto;
  padding: 0 2rem;
}

/* ====================================
   HEADER & NAVIGATION
   ==================================== */
header {
  background-color: var(--white);
  border-bottom: 1px solid var(--border-subtle);
  position: fixed;
  top: 0;
  width: 100%;
  z-index: 1000;
  box-shadow: 0 1px 3px rgba(0, 0, 0, 0.05);
}

.header-container {
  max-width: 1440px;
  margin: 0 auto;
  padding: 1rem 2rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.logo {
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--secondary-dark);
  letter-spacing: 1px;
}

nav ul {
  list-style: none;
  display: flex;
  gap: 3rem;
  margin: 0;
}

nav a {
  font-size: 0.95rem;
  font-weight: 500;
  color: var(--text-primary);
  border-bottom: 2px solid transparent;
  padding-bottom: 0.25rem;
  transition: all 0.3s ease;
}

nav a:hover,
nav a.active {
  border-bottom-color: var(--secondary-dark);
  color: var(--secondary-dark);
}

/* ====================================
   SECTIONAL SPACING & RHYTHM
   ==================================== */
section {
  padding: 120px 0;
}

section:nth-child(even) {
  background-color: var(--white);
}

section:nth-child(odd) {
  background-color: var(--primary-bg);
}

.full-width {
  width: 100%;
  margin: 0;
  padding-left: 0;
  padding-right: 0;
}

.section-intro {
  text-align: center;
  max-width: 900px;
  margin: 0 auto 4rem;
}

.section-intro h2 {
  margin-top: 0;
}

/* ====================================
   MODULAR BLOCKS
   ==================================== */
.module {
  background-color: var(--white);
  border: 1px solid var(--border-subtle);
  padding: 4rem;
  margin-bottom: 3rem;
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.04);
  transition: box-shadow 0.3s ease;
}

.module:hover {
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.08);
}

.module-with-image {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 3rem;
  align-items: center;
}

.module-image {
  width: 100%;
  height: 400px;
  background: linear-gradient(135deg, var(--accent-light) 0%, var(--accent-grey) 100%);
  border: 1px solid var(--border-subtle);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--text-secondary);
  font-size: 0.9rem;
  position: relative;
  overflow: hidden;
}

.module-image img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

/* ====================================
   FULL-WIDTH HERO SECTIONS
   ==================================== */
.hero {
  background: linear-gradient(rgba(52, 73, 94, 0.1), rgba(52, 73, 94, 0.1)), url('about:blank');
  background-size: cover;
  background-position: center;
  padding: 200px 0 120px;
  text-align: center;
  color: var(--secondary-dark);
  margin-top: 80px;
}

.hero h1 {
  font-size: 4rem;
  margin-bottom: 2rem;
}

.hero-subtitle {
  font-size: 1.25rem;
  color: var(--text-secondary);
  max-width: 800px;
  margin: 0 auto;
  line-height: 1.8;
}

/* ====================================
   GRID LAYOUTS
   ==================================== */
.grid-2 {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 2rem;
  margin-bottom: 2rem;
}

.grid-3 {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 2rem;
  margin-bottom: 2rem;
}

.grid-item {
  background-color: var(--white);
  border: 1px solid var(--border-subtle);
  padding: 2rem;
  text-align: left;
}

/* ====================================
   CARDS (Blog, Glossary, etc.)
   ==================================== */
.card {
  background-color: var(--white);
  border: 1px solid var(--border-subtle);
  padding: 2.5rem;
  margin-bottom: 2rem;
  transition: all 0.3s ease;
  cursor: pointer;
}

.card:hover {
  box-shadow: 0 6px 16px rgba(0, 0, 0, 0.08);
  transform: translateY(-2px);
}

.card-title {
  font-size: 1.5rem;
  font-weight: 600;
  color: var(--secondary-dark);
  margin-bottom: 1rem;
}

.card-meta {
  font-size: 0.9rem;
  color: var(--text-secondary);
  margin-bottom: 1rem;
}

.card-excerpt {
  font-size: 1rem;
  line-height: 1.8;
  color: var(--text-primary);
}

.card-link {
  display: inline-block;
  margin-top: 1rem;
  font-weight: 600;
  color: var(--secondary-dark);
  border-bottom: 1px solid transparent;
}

.card-link:hover {
  border-bottom-color: var(--secondary-dark);
}

/* ====================================
   BUTTONS & CTAs
   ==================================== */
.btn {
  display: inline-block;
  padding: 1rem 2rem;
  background-color: var(--secondary-dark);
  color: var(--white);
  font-weight: 600;
  text-transform: uppercase;
  font-size: 0.9rem;
  letter-spacing: 1px;
  border: 1px solid var(--secondary-dark);
  cursor: pointer;
  transition: all 0.3s ease;
  text-decoration: none;
}

.btn:hover {
  background-color: var(--primary-bg);
  color: var(--secondary-dark);
  transform: translateY(-2px);
}

.btn-secondary {
  background-color: transparent;
  color: var(--secondary-dark);
  border: 1px solid var(--secondary-dark);
}

.btn-secondary:hover {
  background-color: var(--accent-light);
  border-color: var(--accent-light);
  color: var(--secondary-dark);
}

/* ====================================
   ACCENT BACKGROUNDS
   ==================================== */
.bg-accent-light {
  background-color: var(--accent-light);
}

.bg-accent-grey {
  background-color: var(--accent-grey);
}

.callout {
  background-color: rgba(169, 204, 227, 0.15);
  border-left: 4px solid var(--accent-light);
  padding: 2rem;
  margin: 2rem 0;
}

/* ====================================
   FOOTER
   ==================================== */
footer {
  background-color: var(--secondary-dark);
  color: var(--white);
  padding: 4rem 0 2rem;
  margin-top: 6rem;
}

.footer-container {
  max-width: 1440px;
  margin: 0 auto;
  padding: 0 2rem;
}

.footer-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 3rem;
  margin-bottom: 3rem;
}

.footer-section h4 {
  color: var(--white);
  margin-bottom: 1.5rem;
}

.footer-section ul {
  list-style: none;
  margin: 0;
}

.footer-section a {
  color: rgba(255, 255, 255, 0.8);
  border-bottom: 1px solid transparent;
}

.footer-section a:hover {
  color: var(--white);
  border-bottom-color: var(--accent-light);
}

.footer-bottom {
  border-top: 1px solid rgba(255, 255, 255, 0.2);
  padding-top: 2rem;
  text-align: center;
  font-size: 0.9rem;
  color: rgba(255, 255, 255, 0.7);
}

/* ====================================
   FORMS
   ==================================== */
.form-group {
  margin-bottom: 1.5rem;
}

label {
  display: block;
  font-weight: 600;
  color: var(--secondary-dark);
  margin-bottom: 0.5rem;
  font-size: 0.95rem;
}

input[type="text"],
input[type="email"],
input[type="tel"],
textarea,
select {
  width: 100%;
  padding: 1rem;
  border: 1px solid var(--border-subtle);
  font-family: inherit;
  font-size: 1rem;
  color: var(--text-primary);
  background-color: var(--white);
  transition: border-color 0.3s ease;
}

input[type="text"]:focus,
input[type="email"]:focus,
input[type="tel"]:focus,
textarea:focus,
select:focus {
  outline: none;
  border-color: var(--accent-light);
  box-shadow: 0 0 0 3px rgba(169, 204, 227, 0.1);
}

textarea {
  resize: vertical;
  min-height: 150px;
}

/* ====================================
   RESPONSIVE DESIGN
   ==================================== */
@media (max-width: 1024px) {
  .container {
    padding: 0 1.5rem;
  }

  h1 {
    font-size: 2.75rem;
  }

  h2 {
    font-size: 2rem;
  }

  .module-with-image {
    grid-template-columns: 1fr;
    gap: 2rem;
  }

  .grid-3 {
    grid-template-columns: 1fr 1fr;
  }

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

@media (max-width: 768px) {
  nav ul {
    gap: 1.5rem;
    font-size: 0.9rem;
  }

  h1 {
    font-size: 2rem;
  }

  h2 {
    font-size: 1.5rem;
  }

  section {
    padding: 80px 0;
  }

  .module {
    padding: 2rem;
  }

  .grid-2,
  .grid-3,
  .footer-grid {
    grid-template-columns: 1fr;
  }

  .hero {
    padding: 120px 0 80px;
    margin-top: 60px;
  }

  .hero h1 {
    font-size: 2rem;
  }
}

/* ====================================
   UTILITY CLASSES
   ==================================== */
.text-center {
  text-align: center;
}

.text-right {
  text-align: right;
}

.mb-0 {
  margin-bottom: 0;
}

.mb-2 {
  margin-bottom: 1rem;
}

.mt-4 {
  margin-top: 2rem;
}

.hidden {
  display: none;
}