/* ============================================
   PeriodGuide.com — Base CSS
   Mobile-first, accessible, privacy-respecting
   ============================================ */

/* --- CSS Custom Properties --- */
:root {
  /* Brand Colors */
  --color-primary: #E85D75;
  --color-primary-dark: #C94B62;
  --color-primary-light: #FFB3C1;
  --color-primary-pale: #FFF0F3;
  --color-secondary: #7C5CFC;
  --color-secondary-dark: #5A3ED9;
  --color-secondary-light: #B8A9FF;
  --color-secondary-pale: #F3F0FF;

  /* Phase Colors */
  --color-menstrual: #E85D75;
  --color-follicular: #56B870;
  --color-ovulation: #F5A623;
  --color-luteal: #7C5CFC;

  /* Semantic Colors */
  --color-success: #2ECC71;
  --color-warning: #F39C12;
  --color-danger: #E74C3C;
  --color-info: #3498DB;

  /* Neutrals */
  --color-white: #FFFFFF;
  --color-gray-50: #FAFAFA;
  --color-gray-100: #F5F5F5;
  --color-gray-200: #EEEEEE;
  --color-gray-300: #E0E0E0;
  --color-gray-400: #BDBDBD;
  --color-gray-500: #9E9E9E;
  --color-gray-600: #757575;
  --color-gray-700: #616161;
  --color-gray-800: #424242;
  --color-gray-900: #212121;
  --color-black: #1A1A2E;

  /* Typography */
  --font-primary: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  --font-display: 'Plus Jakarta Sans', 'Inter', -apple-system, sans-serif;
  --font-mono: 'JetBrains Mono', 'Fira Code', monospace;

  --text-xs: 0.75rem;
  --text-sm: 0.875rem;
  --text-base: 1rem;
  --text-lg: 1.125rem;
  --text-xl: 1.25rem;
  --text-2xl: 1.5rem;
  --text-3xl: 1.875rem;
  --text-4xl: 2.25rem;
  --text-5xl: 3rem;
  --text-6xl: 3.75rem;

  --leading-tight: 1.2;
  --leading-snug: 1.375;
  --leading-normal: 1.5;
  --leading-relaxed: 1.625;

  --weight-normal: 400;
  --weight-medium: 500;
  --weight-semibold: 600;
  --weight-bold: 700;
  --weight-extrabold: 800;

  /* Spacing */
  --space-1: 0.25rem;
  --space-2: 0.5rem;
  --space-3: 0.75rem;
  --space-4: 1rem;
  --space-5: 1.25rem;
  --space-6: 1.5rem;
  --space-8: 2rem;
  --space-10: 2.5rem;
  --space-12: 3rem;
  --space-16: 4rem;
  --space-20: 5rem;
  --space-24: 6rem;
  --space-32: 8rem;

  /* Border Radius */
  --radius-sm: 0.375rem;
  --radius-md: 0.5rem;
  --radius-lg: 0.75rem;
  --radius-xl: 1rem;
  --radius-2xl: 1.5rem;
  --radius-full: 9999px;

  /* Shadows */
  --shadow-xs: 0 1px 2px rgba(0, 0, 0, 0.05);
  --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.1), 0 1px 2px rgba(0, 0, 0, 0.06);
  --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);
  --shadow-2xl: 0 25px 50px -12px rgba(0, 0, 0, 0.25);
  --shadow-glow: 0 0 20px rgba(232, 93, 117, 0.3);
  --shadow-glow-purple: 0 0 20px rgba(124, 92, 252, 0.3);

  /* Transitions */
  --transition-fast: 150ms ease;
  --transition-base: 250ms ease;
  --transition-slow: 350ms ease;
  --transition-spring: 500ms cubic-bezier(0.34, 1.56, 0.64, 1);

  /* Z-index layers */
  --z-dropdown: 100;
  --z-sticky: 200;
  --z-fixed: 300;
  --z-modal-backdrop: 400;
  --z-modal: 500;
  --z-toast: 600;

  /* Container */
  --container-sm: 640px;
  --container-md: 768px;
  --container-lg: 1024px;
  --container-xl: 1200px;
  --container-2xl: 1400px;
}

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

html {
  font-size: 16px;
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
  text-size-adjust: 100%;
}

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

body {
  font-family: var(--font-primary);
  font-size: var(--text-base);
  line-height: var(--leading-normal);
  color: var(--color-gray-900);
  background-color: var(--color-white);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  overflow-x: hidden;
}

/* --- Typography --- */
h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-display);
  font-weight: var(--weight-bold);
  line-height: var(--leading-tight);
  color: var(--color-black);
}

h1 { font-size: var(--text-3xl); margin-bottom: var(--space-6); }
h2 { font-size: var(--text-2xl); margin-bottom: var(--space-5); }
h3 { font-size: var(--text-xl); margin-bottom: var(--space-4); }
h4 { font-size: var(--text-lg); margin-bottom: var(--space-3); }
h5 { font-size: var(--text-base); margin-bottom: var(--space-2); }
h6 { font-size: var(--text-sm); margin-bottom: var(--space-2); }

@media (min-width: 768px) {
  h1 { font-size: var(--text-4xl); }
  h2 { font-size: var(--text-3xl); }
  h3 { font-size: var(--text-2xl); }
  h4 { font-size: var(--text-xl); }
}

@media (min-width: 1024px) {
  h1 { font-size: var(--text-5xl); }
  h2 { font-size: var(--text-4xl); }
  h3 { font-size: var(--text-3xl); }
}

p {
  margin-bottom: var(--space-4);
  line-height: var(--leading-relaxed);
}

a {
  color: var(--color-primary);
  text-decoration: none;
  transition: color var(--transition-fast);
}
a:hover { color: var(--color-primary-dark); }
a:focus-visible {
  outline: 2px solid var(--color-primary);
  outline-offset: 2px;
  border-radius: var(--radius-sm);
}

strong { font-weight: var(--weight-semibold); }
small { font-size: var(--text-sm); }

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

@media (min-width: 768px) {
  .container { padding: 0 var(--space-6); }
}

@media (min-width: 1024px) {
  .container { padding: 0 var(--space-8); }
}

.section {
  padding: var(--space-12) 0;
}

@media (min-width: 768px) {
  .section { padding: var(--space-16) 0; }
}

@media (min-width: 1024px) {
  .section { padding: var(--space-20) 0; }
}

/* Grid System */
.grid {
  display: grid;
  gap: var(--space-6);
}

.grid-2 { grid-template-columns: 1fr; }
.grid-3 { grid-template-columns: 1fr; }
.grid-4 { grid-template-columns: 1fr; }

@media (min-width: 640px) {
  .grid-2 { grid-template-columns: repeat(2, 1fr); }
  .grid-4 { grid-template-columns: repeat(2, 1fr); }
}

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

@media (min-width: 1024px) {
  .grid-4 { grid-template-columns: repeat(4, 1fr); }
}

/* Flexbox utilities */
.flex { display: flex; }
.flex-col { flex-direction: column; }
.flex-wrap { flex-wrap: wrap; }
.items-center { align-items: center; }
.items-start { align-items: flex-start; }
.justify-center { justify-content: center; }
.justify-between { justify-content: space-between; }
.gap-2 { gap: var(--space-2); }
.gap-3 { gap: var(--space-3); }
.gap-4 { gap: var(--space-4); }
.gap-6 { gap: var(--space-6); }
.gap-8 { gap: var(--space-8); }

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

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

.img-rounded { border-radius: var(--radius-lg); }
.img-circle { border-radius: var(--radius-full); }

/* --- Lists --- */
ul, ol {
  padding-left: var(--space-6);
  margin-bottom: var(--space-4);
}

li {
  margin-bottom: var(--space-2);
  line-height: var(--leading-relaxed);
}

/* --- Forms Base --- */
input, select, textarea, button {
  font-family: inherit;
  font-size: inherit;
  line-height: inherit;
}

input:focus-visible,
select:focus-visible,
textarea:focus-visible {
  outline: 2px solid var(--color-primary);
  outline-offset: 2px;
}

/* --- 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;
}

.skip-link {
  position: absolute;
  top: -100%;
  left: var(--space-4);
  z-index: var(--z-toast);
  padding: var(--space-3) var(--space-6);
  background: var(--color-primary);
  color: var(--color-white);
  border-radius: 0 0 var(--radius-md) var(--radius-md);
  font-weight: var(--weight-semibold);
  transition: top var(--transition-fast);
}
.skip-link:focus {
  top: 0;
  color: var(--color-white);
}

/* Focus visible for keyboard users */
:focus:not(:focus-visible) {
  outline: none;
}

/* --- Utility Classes --- */
.text-center { text-align: center; }
.text-left { text-align: left; }
.text-right { text-align: right; }

.text-xs { font-size: var(--text-xs); }
.text-sm { font-size: var(--text-sm); }
.text-base { font-size: var(--text-base); }
.text-lg { font-size: var(--text-lg); }
.text-xl { font-size: var(--text-xl); }
.text-2xl { font-size: var(--text-2xl); }

.font-medium { font-weight: var(--weight-medium); }
.font-semibold { font-weight: var(--weight-semibold); }
.font-bold { font-weight: var(--weight-bold); }

.text-primary { color: var(--color-primary); }
.text-secondary { color: var(--color-secondary); }
.text-muted { color: var(--color-gray-600); }
.text-white { color: var(--color-white); }

.bg-white { background-color: var(--color-white); }
.bg-gray-50 { background-color: var(--color-gray-50); }
.bg-primary-pale { background-color: var(--color-primary-pale); }
.bg-secondary-pale { background-color: var(--color-secondary-pale); }

.rounded-sm { border-radius: var(--radius-sm); }
.rounded-md { border-radius: var(--radius-md); }
.rounded-lg { border-radius: var(--radius-lg); }
.rounded-xl { border-radius: var(--radius-xl); }
.rounded-2xl { border-radius: var(--radius-2xl); }
.rounded-full { border-radius: var(--radius-full); }

.shadow-sm { box-shadow: var(--shadow-sm); }
.shadow-md { box-shadow: var(--shadow-md); }
.shadow-lg { box-shadow: var(--shadow-lg); }
.shadow-xl { box-shadow: var(--shadow-xl); }

.mb-2 { margin-bottom: var(--space-2); }
.mb-4 { margin-bottom: var(--space-4); }
.mb-6 { margin-bottom: var(--space-6); }
.mb-8 { margin-bottom: var(--space-8); }
.mb-12 { margin-bottom: var(--space-12); }

.mt-2 { margin-top: var(--space-2); }
.mt-4 { margin-top: var(--space-4); }
.mt-6 { margin-top: var(--space-6); }
.mt-8 { margin-top: var(--space-8); }

.p-2 { padding: var(--space-2); }
.p-3 { padding: var(--space-3); }
.p-4 { padding: var(--space-4); }
.p-6 { padding: var(--space-6); }
.p-8 { padding: var(--space-8); }

.hidden { display: none !important; }
.block { display: block; }
.inline-block { display: inline-block; }

@media (min-width: 768px) {
  .md\:hidden { display: none !important; }
  .md\:block { display: block !important; }
  .md\:flex { display: flex !important; }
  .md\:grid { display: grid !important; }
}

@media (min-width: 1024px) {
  .lg\:hidden { display: none !important; }
  .lg\:block { display: block !important; }
  .lg\:flex { display: flex !important; }
}

/* --- Selection --- */
::selection {
  background-color: var(--color-primary-light);
  color: var(--color-black);
}

/* --- Scrollbar --- */
::-webkit-scrollbar {
  width: 8px;
}
::-webkit-scrollbar-track {
  background: var(--color-gray-100);
}
::-webkit-scrollbar-thumb {
  background: var(--color-gray-400);
  border-radius: var(--radius-full);
}
::-webkit-scrollbar-thumb:hover {
  background: var(--color-gray-500);
}