/* =========================================
   TPC Pharma & Chemicals - Base Styles
   ========================================= */

/* --- CSS Variables --- */
:root {
  /* Colors */
  --color-primary: #012B54; /* Deep Blue */
  --color-primary-light: #0D47A1;
  --color-primary-dark: #001A38;
  --color-accent: #1565C0; /* Secondary Blue */
  
  --color-white: #FFFFFF;
  --color-gray-50: #F8FAFC;
  --color-gray-100: #F1F5F9;
  --color-gray-200: #E2E8F0;
  --color-gray-300: #CBD5E1;
  --color-gray-600: #475569;
  --color-gray-800: #1E293B;
  --color-gray-900: #0F172A;
  
  --color-success: #10B981;
  --color-error: #EF4444;

  /* Typography */
  --font-primary: 'Inter', system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  
  /* Sizing & Spacing */
  --space-0: 0;
  --space-1: 0.25rem;
  --space-2: 0.5rem;
  --space-3: 0.75rem;
  --space-4: 1rem;
  --space-6: 1.5rem;
  --space-8: 2rem;
  --space-12: 3rem;
  --space-16: 4rem;
  --space-24: 6rem;
  
  --container-width: 1200px;
  --border-radius-sm: 4px;
  --border-radius-md: 8px;
  --border-radius-lg: 12px;
  
  /* Transitions */
  --transition-fast: 0.15s ease-in-out;
  --transition-normal: 0.3s ease-in-out;
}

/* --- Base Reset --- */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  font-size: 16px;
  scroll-behavior: smooth;
}

body {
  font-family: var(--font-primary);
  color: var(--color-gray-800);
  background-color: var(--color-gray-50);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

/* --- Typography --- */
h1, h2, h3, h4, h5, h6 {
  font-weight: 700;
  color: var(--color-primary);
  line-height: 1.2;
}

h1 { font-size: clamp(2.5rem, 5vw, 4rem); letter-spacing: -0.02em; }
h2 { font-size: clamp(2rem, 4vw, 3rem); letter-spacing: -0.01em; margin-bottom: var(--space-6); }
h3 { font-size: clamp(1.5rem, 3vw, 2rem); margin-bottom: var(--space-4); }
p { margin-bottom: var(--space-4); color: var(--color-gray-600); }
a { color: var(--color-primary); text-decoration: none; transition: color var(--transition-fast); }
a:hover { color: var(--color-accent); }

/* --- Layout --- */
.container {
  width: 100%;
  max-width: var(--container-width);
  margin: 0 auto;
  padding: 0 var(--space-4);
}

section {
  padding: var(--space-16) 0;
}

.section-light { background-color: var(--color-white); }
.section-dark { 
  background-color: var(--color-primary); 
  color: var(--color-white);
}
.section-dark p { color: var(--color-gray-200); }
.section-dark h1, .section-dark h2, .section-dark h3 { color: var(--color-white); }

/* --- Components --- */
/* Buttons */
.btn {
  display: inline-block;
  padding: var(--space-3) var(--space-8);
  font-weight: 600;
  border-radius: var(--border-radius-sm);
  text-align: center;
  transition: all var(--transition-fast);
  cursor: pointer;
  border: 2px solid transparent;
}

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

.btn-primary:hover {
  background-color: var(--color-primary-light);
  color: var(--color-white);
  transform: translateY(-1px);
}

.btn-outline {
  border-color: var(--color-primary);
  color: var(--color-primary);
  background-color: transparent;
}

.btn-outline:hover {
  background-color: var(--color-primary);
  color: var(--color-white);
}

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

.btn-white:hover {
  background-color: var(--color-gray-100);
  color: var(--color-primary);
}

/* Header & Nav */
.site-header {
  background-color: var(--color-white);
  box-shadow: 0 1px 3px rgba(0,0,0,0.05);
  position: sticky;
  top: 0;
  z-index: 1000;
}

.nav-container {
  display: flex;
  justify-content: space-between;
  align-items: center;
  height: 80px;
}

.logo {
  font-size: 1.5rem;
  font-weight: 800;
  color: var(--color-primary);
  letter-spacing: -0.5px;
}

.nav-links {
  display: flex;
  gap: var(--space-6);
  list-style: none;
}

.nav-links a {
  color: var(--color-gray-700);
  font-weight: 500;
  font-size: 0.95rem;
}

.nav-links a:hover, .nav-links a.active {
  color: var(--color-primary);
}

.mobile-menu-btn {
  display: none;
  background: none;
  border: none;
  font-size: 1.5rem;
  color: var(--color-primary);
  cursor: pointer;
}

/* Cards */
.card-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: var(--space-8);
}

.card {
  background-color: var(--color-white);
  border: 1px solid var(--color-gray-200);
  border-radius: var(--border-radius-md);
  padding: var(--space-8);
  transition: transform var(--transition-normal), box-shadow var(--transition-normal);
}

.card:hover {
  transform: translateY(-4px);
  box-shadow: 0 12px 24px -10px rgba(0,0,0,0.1);
  border-color: var(--color-gray-300);
}

.card-icon {
  font-size: 2.5rem;
  color: var(--color-primary);
  margin-bottom: var(--space-4);
}

/* Forms */
.form-group {
  margin-bottom: var(--space-4);
}

.form-label {
  display: block;
  font-weight: 600;
  margin-bottom: var(--space-2);
  color: var(--color-gray-800);
  font-size: 0.9rem;
}

.form-control {
  width: 100%;
  padding: var(--space-3) var(--space-4);
  border: 1px solid var(--color-gray-300);
  border-radius: var(--border-radius-sm);
  font-family: inherit;
  font-size: 1rem;
  transition: border-color var(--transition-fast), box-shadow var(--transition-fast);
  background-color: var(--color-white);
}

.form-control:focus {
  outline: none;
  border-color: var(--color-primary);
  box-shadow: 0 0 0 3px rgba(1, 43, 84, 0.1);
}

textarea.form-control {
  min-height: 120px;
  resize: vertical;
}

/* Footer */
.site-footer {
  background-color: var(--color-primary-dark);
  color: var(--color-gray-300);
  padding: var(--space-12) 0 var(--space-6);
}

.footer-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: var(--space-8);
  margin-bottom: var(--space-8);
}

.footer-col h4 {
  color: var(--color-white);
  margin-bottom: var(--space-4);
  font-size: 1.1rem;
}

.footer-links {
  list-style: none;
}

.footer-links li {
  margin-bottom: var(--space-2);
}

.footer-links a {
  color: var(--color-gray-300);
}

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

.footer-bottom {
  border-top: 1px solid rgba(255,255,255,0.1);
  padding-top: var(--space-6);
  text-align: center;
  font-size: 0.875rem;
}

/* Utilities */
.text-center { text-align: center; }
.mb-2 { margin-bottom: var(--space-2); }
.mb-4 { margin-bottom: var(--space-4); }
.mb-8 { margin-bottom: var(--space-8); }
.mt-8 { margin-top: var(--space-8); }

/* --- Responsive --- */
@media (max-width: 768px) {
  .nav-links {
    display: none; /* Hide by default on mobile, toggled via JS */
    position: absolute;
    top: 80px;
    left: 0;
    right: 0;
    background-color: var(--color-white);
    flex-direction: column;
    padding: var(--space-4);
    box-shadow: 0 4px 6px rgba(0,0,0,0.05);
    gap: var(--space-4);
  }
  
  .nav-links.active {
    display: flex;
  }
  
  .mobile-menu-btn {
    display: block;
  }
  
  section {
    padding: var(--space-12) 0;
  }
}