/* ============================================
   Biostarhealth - Main CSS
   Base styles, variables, reset, utilities
   ============================================ */

/* CSS Variables */
:root {
  /* Colors */
  --primary-teal: #00A8A8;
  --primary-teal-dark: #008B8B;
  --secondary-green: #4CAF50;
  --accent-coral: #FF6B6B;
  --neutral-white: #FFFFFF;
  --neutral-light: #F5F7FA;
  --neutral-light-alt: #E8EDF2;
  --neutral-gray: #9E9E9E;
  --neutral-dark: #1A2332;
  --neutral-text: #2C3E50;
  --neutral-text-light: #5A6C7D;
  
  /* Typography */
  --font-primary: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Roboto', 'Oxygen', 'Ubuntu', 'Cantarell', 'Fira Sans', 'Droid Sans', 'Helvetica Neue', sans-serif;
  --font-heading: 'Poppins', var(--font-primary);
  
  /* Font Sizes */
  --fs-xs: 0.75rem;    /* 12px */
  --fs-sm: 0.875rem;   /* 14px */
  --fs-base: 1rem;     /* 16px */
  --fs-lg: 1.125rem;   /* 18px */
  --fs-xl: 1.25rem;    /* 20px */
  --fs-2xl: 1.5rem;    /* 24px */
  --fs-3xl: 1.875rem;  /* 30px */
  --fs-4xl: 2.25rem;   /* 36px */
  --fs-5xl: 3rem;      /* 48px */
  --fs-6xl: 3.75rem;   /* 60px */
  
  /* Spacing */
  --spacing-xs: 0.25rem;   /* 4px */
  --spacing-sm: 0.5rem;    /* 8px */
  --spacing-md: 1rem;      /* 16px */
  --spacing-lg: 1.5rem;    /* 24px */
  --spacing-xl: 2rem;     /* 32px */
  --spacing-2xl: 3rem;    /* 48px */
  --spacing-3xl: 4rem;    /* 64px */
  --spacing-4xl: 6rem;    /* 96px */
  
  /* Layout */
  --container-max-width: 1200px;
  --container-padding: 1.5rem;
  --border-radius: 0.5rem;
  --border-radius-lg: 1rem;
  --border-radius-xl: 1.5rem;
  
  /* Shadows */
  --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
  --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
  --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 10px 10px -5px rgba(0, 0, 0, 0.04);
  
  /* Transitions */
  --transition-fast: 150ms ease-in-out;
  --transition-base: 300ms ease-in-out;
  --transition-slow: 500ms ease-in-out;
  
  /* Z-index layers */
  --z-dropdown: 1000;
  --z-sticky: 1020;
  --z-fixed: 1030;
  --z-modal-backdrop: 1040;
  --z-modal: 1050;
  --z-popover: 1060;
  --z-tooltip: 1070;
}

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

html {
  font-size: 16px;
  scroll-behavior: smooth;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

body {
  font-family: var(--font-primary);
  font-size: var(--fs-base);
  line-height: 1.6;
  color: var(--neutral-text);
  background-color: var(--neutral-white);
  overflow-x: hidden;
}

/* Typography */
h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-heading);
  font-weight: 600;
  line-height: 1.2;
  color: var(--neutral-dark);
  margin-bottom: var(--spacing-md);
}

h1 { font-size: var(--fs-5xl); }
h2 { font-size: var(--fs-4xl); }
h3 { font-size: var(--fs-3xl); }
h4 { font-size: var(--fs-2xl); }
h5 { font-size: var(--fs-xl); }
h6 { font-size: var(--fs-lg); }

p {
  margin-bottom: var(--spacing-md);
  color: var(--neutral-text-light);
}

a {
  color: var(--primary-teal);
  text-decoration: none;
  transition: color var(--transition-fast);
}

a:hover {
  color: var(--primary-teal-dark);
}

img {
  max-width: 100%;
  height: auto;
  display: block;
}

ul, ol {
  list-style: none;
}

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

.container-fluid {
  width: 100%;
  padding: 0 var(--container-padding);
}

/* Utility Classes */

/* Display */
.d-none { display: none !important; }
.d-block { display: block !important; }
.d-inline { display: inline !important; }
.d-inline-block { display: inline-block !important; }
.d-flex { display: flex !important; }
.d-grid { display: grid !important; }

@media (max-width: 768px) {
  .d-md-none { display: none !important; }
  .d-md-block { display: block !important; }
}

/* Flexbox Utilities */
.flex { display: flex; }
.flex-column { flex-direction: column; }
.flex-row { flex-direction: row; }
.flex-wrap { flex-wrap: wrap; }
.flex-nowrap { flex-wrap: nowrap; }
.items-center { align-items: center; }
.items-start { align-items: flex-start; }
.items-end { align-items: flex-end; }
.justify-center { justify-content: center; }
.justify-between { justify-content: space-between; }
.justify-around { justify-content: space-around; }
.justify-start { justify-content: flex-start; }
.justify-end { justify-content: flex-end; }
.gap-sm { gap: var(--spacing-sm); }
.gap-md { gap: var(--spacing-md); }
.gap-lg { gap: var(--spacing-lg); }
.gap-xl { gap: var(--spacing-xl); }

/* Spacing Utilities */
.m-0 { margin: 0 !important; }
.mt-0 { margin-top: 0 !important; }
.mb-0 { margin-bottom: 0 !important; }
.mt-auto { margin-top: auto !important; }
.mb-auto { margin-bottom: auto !important; }

.mt-sm { margin-top: var(--spacing-sm); }
.mt-md { margin-top: var(--spacing-md); }
.mt-lg { margin-top: var(--spacing-lg); }
.mt-xl { margin-top: var(--spacing-xl); }
.mt-2xl { margin-top: var(--spacing-2xl); }

.mb-sm { margin-bottom: var(--spacing-sm); }
.mb-md { margin-bottom: var(--spacing-md); }
.mb-lg { margin-bottom: var(--spacing-lg); }
.mb-xl { margin-bottom: var(--spacing-xl); }
.mb-2xl { margin-bottom: var(--spacing-2xl); }

.p-0 { padding: 0 !important; }
.pt-sm { padding-top: var(--spacing-sm); }
.pt-md { padding-top: var(--spacing-md); }
.pt-lg { padding-top: var(--spacing-lg); }
.pt-xl { padding-top: var(--spacing-xl); }
.pt-2xl { padding-top: var(--spacing-2xl); }
.pt-3xl { padding-top: var(--spacing-3xl); }
.pt-4xl { padding-top: var(--spacing-4xl); }

.pb-sm { padding-bottom: var(--spacing-sm); }
.pb-md { padding-bottom: var(--spacing-md); }
.pb-lg { padding-bottom: var(--spacing-lg); }
.pb-xl { padding-bottom: var(--spacing-xl); }
.pb-2xl { padding-bottom: var(--spacing-2xl); }
.pb-3xl { padding-bottom: var(--spacing-3xl); }
.pb-4xl { padding-bottom: var(--spacing-4xl); }

.py-sm { padding-top: var(--spacing-sm); padding-bottom: var(--spacing-sm); }
.py-md { padding-top: var(--spacing-md); padding-bottom: var(--spacing-md); }
.py-lg { padding-top: var(--spacing-lg); padding-bottom: var(--spacing-lg); }
.py-xl { padding-top: var(--spacing-xl); padding-bottom: var(--spacing-xl); }
.py-2xl { padding-top: var(--spacing-2xl); padding-bottom: var(--spacing-2xl); }
.py-3xl { padding-top: var(--spacing-3xl); padding-bottom: var(--spacing-3xl); }
.py-4xl { padding-top: var(--spacing-4xl); padding-bottom: var(--spacing-4xl); }

/* Text Utilities */
.text-center { text-align: center; }
.text-left { text-align: left; }
.text-right { text-align: right; }
.text-primary { color: var(--primary-teal) !important; }
.text-secondary { color: var(--secondary-green) !important; }
.text-accent { color: var(--accent-coral) !important; }
.text-dark { color: var(--neutral-dark) !important; }
.text-light { color: var(--neutral-text-light) !important; }
.text-white { color: var(--neutral-white) !important; }

.font-bold { font-weight: 700; }
.font-semibold { font-weight: 600; }
.font-medium { font-weight: 500; }
.font-normal { font-weight: 400; }

/* Width & Height */
.w-full { width: 100%; }
.w-auto { width: auto; }
.h-full { height: 100%; }
.h-auto { height: auto; }

/* Position */
.position-relative { position: relative; }
.position-absolute { position: absolute; }
.position-fixed { position: fixed; }
.position-sticky { position: sticky; }

/* Visibility */
.visible { visibility: visible; }
.invisible { visibility: hidden; }

/* Overflow */
.overflow-hidden { overflow: hidden; }
.overflow-auto { overflow: auto; }

/* Cursor */
.cursor-pointer { cursor: pointer; }

/* Responsive Typography */
@media (max-width: 768px) {
  :root {
    --fs-5xl: 2.5rem;
    --fs-4xl: 2rem;
    --fs-3xl: 1.5rem;
  }
  
  h1 { font-size: var(--fs-4xl); }
  h2 { font-size: var(--fs-3xl); }
  h3 { font-size: var(--fs-2xl); }
}

/* Performance: GPU-accelerated transforms */
.animate-on-scroll,
.card,
.btn,
.navbar-link {
  will-change: transform;
  transform: translateZ(0);
  backface-visibility: hidden;
}

/* Accessibility */
.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border-width: 0;
}

/* Focus Styles */
*:focus-visible {
  outline: 2px solid var(--primary-teal);
  outline-offset: 2px;
}

/* Smooth Animations */
@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }
  
  html {
    scroll-behavior: auto;
  }
}