/* ========================================
   AndanteFit Design System
   Professional, data-driven design for geriatric research
   ======================================== */

/* === FONTS === */
@import url('https://fonts.googleapis.com/css2?family=Inter:wght@300;400;500;600;700;800;900&display=swap');

/* === CSS VARIABLES === */
:root {
  /* Colors */
  --color-deep-blue: #0F4C81;
  --color-deep-blue-dark: #0B3A62;
  --color-deep-blue-light: #1F6FB2;
  --color-soft-gray: #F8FAFC;
  --color-border: #E2E8F0;
  --color-text-primary: #0F172A;
  --color-text-secondary: #475569;
  --color-text-muted: #94A3B8;
  --color-white: #FFFFFF;
  --color-accent: #18BFBF;
  
  /* Typography */
  --font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
  --line-height-base: 1.7;
  --line-height-tight: 1.3;
  
  /* Spacing */
  --spacing-unit: 8px;
  --spacing-section: 80px;
  --spacing-component: 40px;
  
  /* Layout */
  --max-width: 1200px;
  --border-radius: 12px;
  
  /* Shadows */
  --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.05);
  --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.08);
  --shadow-lg: 0 10px 40px rgba(0, 0, 0, 0.12);
}

/* === RESET & BASE === */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

body {
  font-family: var(--font-family);
  font-size: 16px;
  line-height: var(--line-height-base);
  color: var(--color-text-primary);
  background-color: var(--color-soft-gray);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

/* === TYPOGRAPHY === */
h1, h2, h3, h4, h5, h6 {
  font-weight: 700;
  line-height: var(--line-height-tight);
  letter-spacing: -0.02em;
  color: var(--color-text-primary);
  margin-bottom: calc(var(--spacing-unit) * 2);
}

h1 {
  font-size: clamp(2.5rem, 5vw, 3.5rem);
  font-weight: 800;
}

h2 {
  font-size: clamp(2rem, 4vw, 2.75rem);
}

h3 {
  font-size: clamp(1.5rem, 3vw, 2rem);
}

h4 {
  font-size: 1.25rem;
}

p {
  margin-bottom: calc(var(--spacing-unit) * 3);
  color: var(--color-text-secondary);
}

a {
  color: var(--color-deep-blue);
  text-decoration: none;
  transition: color 0.2s ease;
}

a:hover {
  color: var(--color-deep-blue-light);
}

/* === LAYOUT === */
.container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 calc(var(--spacing-unit) * 3);
}

.section {
  padding: var(--spacing-section) 0;
}

.section-header {
  text-align: center;
  margin-bottom: calc(var(--spacing-unit) * 8);
}

.section-label {
  display: inline-block;
  font-size: 0.75rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--color-deep-blue);
  background-color: rgba(15, 76, 129, 0.08);
  padding: calc(var(--spacing-unit) * 1) calc(var(--spacing-unit) * 2);
  border-radius: 999px;
  margin-bottom: calc(var(--spacing-unit) * 2);
}

/* === NAVIGATION === */
.nav {
  background-color: var(--color-white);
  border-bottom: 1px solid var(--color-border);
  position: sticky;
  top: 0;
  z-index: 1000;
  backdrop-filter: blur(10px);
  background-color: rgba(255, 255, 255, 0.95);
}

.nav-container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 calc(var(--spacing-unit) * 3);
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 72px;
}

.nav-logo {
  font-size: 1.5rem;
  font-weight: 800;
  color: var(--color-deep-blue);
  display: flex;
  align-items: center;
  gap: calc(var(--spacing-unit) * 2);
}

.nav-logo img {
  height: 28px;
  width: auto;
}

.nav-menu {
  display: flex;
  gap: calc(var(--spacing-unit) * 5);
  list-style: none;
}

.nav-link {
  font-size: 0.9375rem;
  font-weight: 500;
  color: var(--color-text-secondary);
  transition: color 0.2s ease;
}

.nav-link:hover,
.nav-link.active {
  color: var(--color-deep-blue);
}

/* Mobile Navigation */
.nav-toggle {
  display: none;
  background: none;
  border: none;
  font-size: 1.5rem;
  color: var(--color-text-primary);
  cursor: pointer;
}

@media (max-width: 768px) {
  .nav-menu {
    display: none;
    position: absolute;
    top: 72px;
    left: 0;
    right: 0;
    background-color: var(--color-white);
    border-bottom: 1px solid var(--color-border);
    flex-direction: column;
    gap: 0;
    padding: calc(var(--spacing-unit) * 2) 0;
  }
  
  .nav-menu.active {
    display: flex;
  }
  
  .nav-link {
    display: block;
    padding: calc(var(--spacing-unit) * 2) calc(var(--spacing-unit) * 3);
  }
  
  .nav-toggle {
    display: block;
  }
}

/* === HERO === */
.hero {
  background: linear-gradient(135deg, rgba(15, 76, 129, 0.03) 0%, rgba(15, 76, 129, 0.08) 100%);
  padding: calc(var(--spacing-unit) * 15) 0 calc(var(--spacing-unit) * 12) 0;
  position: relative;
  overflow: hidden;
}

.hero-content {
  position: relative;
  z-index: 1;
}

.hero-headline {
  margin-bottom: calc(var(--spacing-unit) * 4);
}

.hero-subtitle {
  font-size: 1.25rem;
  color: var(--color-text-secondary);
  max-width: 720px;
  margin-bottom: calc(var(--spacing-unit) * 6);
}

.hero-features {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: calc(var(--spacing-unit) * 3);
  margin-top: calc(var(--spacing-unit) * 8);
}

/* === CARDS === */
.card {
  background-color: var(--color-white);
  border: 1px solid var(--color-border);
  border-radius: var(--border-radius);
  padding: calc(var(--spacing-unit) * 4);
  transition: all 0.3s ease;
}

.card:hover {
  box-shadow: var(--shadow-md);
  border-color: var(--color-deep-blue);
  transform: translateY(-2px);
}

.card-icon {
  width: 48px;
  height: 48px;
  display: flex;
  align-items: center;
  justify-content: center;
  background-color: rgba(15, 76, 129, 0.08);
  border-radius: calc(var(--border-radius) / 2);
  color: var(--color-deep-blue);
  font-size: 1.5rem;
  margin-bottom: calc(var(--spacing-unit) * 2);
}

.card-title {
  font-size: 1.125rem;
  font-weight: 700;
  margin-bottom: calc(var(--spacing-unit) * 1.5);
}

.card-description {
  font-size: 0.9375rem;
  color: var(--color-text-secondary);
  margin-bottom: 0;
}

/* === BUTTONS === */
.btn {
  display: inline-flex;
  align-items: center;
  gap: calc(var(--spacing-unit) * 1);
  padding: calc(var(--spacing-unit) * 2) calc(var(--spacing-unit) * 4);
  font-family: var(--font-family);
  font-size: 0.9375rem;
  font-weight: 600;
  border-radius: calc(var(--border-radius) / 2);
  cursor: pointer;
  transition: all 0.2s ease;
  border: none;
  text-decoration: none;
}

.btn-primary {
  background-color: var(--color-deep-blue);
  color: var(--color-white);
}

.btn-primary:hover {
  background-color: var(--color-deep-blue-dark);
  transform: translateY(-1px);
  box-shadow: var(--shadow-md);
}

.btn-secondary {
  background-color: transparent;
  color: var(--color-deep-blue);
  border: 2px solid var(--color-deep-blue);
}

.btn-secondary:hover {
  background-color: var(--color-deep-blue);
  color: var(--color-white);
}

/* === GRID === */
.grid {
  display: grid;
  gap: calc(var(--spacing-unit) * 4);
}

.grid-2 {
  grid-template-columns: repeat(auto-fit, minmax(500px, 1fr));
}

.grid-3 {
  grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
}

@media (max-width: 768px) {
  .grid-2,
  .grid-3 {
    grid-template-columns: 1fr;
  }
}

/* === VALIDATION CONTEXT BOX === */
.validation-context {
  background-color: rgba(15, 76, 129, 0.04);
  border-left: 4px solid var(--color-deep-blue);
  padding: calc(var(--spacing-unit) * 4);
  margin: calc(var(--spacing-unit) * 8) 0;
  border-radius: var(--border-radius);
}

.validation-context p {
  margin-bottom: 0;
  color: var(--color-text-primary);
  font-size: 0.9375rem;
}

/* === PUBLICATION LIST === */
.publication-item {
  background-color: var(--color-white);
  border: 1px solid var(--color-border);
  border-radius: var(--border-radius);
  padding: calc(var(--spacing-unit) * 3);
  margin-bottom: calc(var(--spacing-unit) * 2);
  transition: all 0.2s ease;
}

.publication-item:hover {
  box-shadow: var(--shadow-sm);
}

.publication-title {
  font-size: 1rem;
  font-weight: 600;
  margin-bottom: calc(var(--spacing-unit) * 1);
  color: var(--color-deep-blue);
}

.publication-meta {
  font-size: 0.875rem;
  color: var(--color-text-muted);
  display: flex;
  gap: calc(var(--spacing-unit) * 2);
  flex-wrap: wrap;
}

.publication-authors {
  font-style: italic;
}

/* === CASE STUDIES GRID === */
.case-study-card {
  background-color: var(--color-white);
  border: 1px solid var(--color-border);
  border-radius: var(--border-radius);
  overflow: hidden;
  transition: all 0.3s ease;
}

.case-study-card:hover {
  box-shadow: var(--shadow-lg);
  transform: translateY(-4px);
}

.case-study-date {
  background-color: var(--color-deep-blue);
  color: var(--color-white);
  padding: calc(var(--spacing-unit) * 2) calc(var(--spacing-unit) * 3);
  font-size: 0.8125rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.case-study-content {
  padding: calc(var(--spacing-unit) * 3);
}

.case-study-title {
  font-size: 1.25rem;
  font-weight: 700;
  margin-bottom: calc(var(--spacing-unit) * 2);
}

/* === FOOTER === */
.footer {
  background-color: var(--color-deep-blue-dark);
  color: var(--color-white);
  padding: calc(var(--spacing-unit) * 8) 0 calc(var(--spacing-unit) * 4) 0;
}

.footer-content {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr;
  gap: calc(var(--spacing-unit) * 8);
  margin-bottom: calc(var(--spacing-unit) * 6);
}

.footer-section h4 {
  color: var(--color-white);
  font-size: 1rem;
  margin-bottom: calc(var(--spacing-unit) * 2);
}

.footer-section p,
.footer-section a {
  color: rgba(255, 255, 255, 0.7);
  font-size: 0.875rem;
}

.footer-section a:hover {
  color: var(--color-white);
}

.footer-bottom {
  border-top: 1px solid rgba(255, 255, 255, 0.1);
  padding-top: calc(var(--spacing-unit) * 3);
  text-align: center;
  font-size: 0.8125rem;
  color: rgba(255, 255, 255, 0.5);
}

@media (max-width: 768px) {
  .footer-content {
    grid-template-columns: 1fr;
    gap: calc(var(--spacing-unit) * 4);
  }
}

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

.mt-4 {
  margin-top: calc(var(--spacing-unit) * 4);
}

.mb-4 {
  margin-bottom: calc(var(--spacing-unit) * 4);
}

.hidden {
  display: none;
}
.name-highlight {
  color: var(--color-deep-blue-light);
}