/* ============================================
   AI News Portal - Main Styles
   Design System & Core Utilities
   ============================================ */

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

/* ============================================
   CSS Custom Properties
   ============================================ */
:root {
  /* Colors - AI Theme */
  --color-primary: hsl(260, 85%, 60%);
  --color-primary-dark: hsl(260, 85%, 45%);
  --color-primary-light: hsl(260, 85%, 75%);

  --color-secondary: hsl(190, 95%, 55%);
  --color-secondary-dark: hsl(190, 95%, 40%);
  --color-secondary-light: hsl(190, 95%, 70%);

  --color-accent: hsl(280, 100%, 70%);
  --color-accent-glow: hsla(280, 100%, 70%, 0.3);

  /* Neutrals */
  --color-bg-dark: hsl(0, 0%, 100%);
  --color-bg-darker: hsl(0, 0%, 98%);
  --color-bg-card: hsla(0, 0%, 100%, 0.9);
  --color-bg-card-hover: hsla(240, 15%, 97%, 1);

  --color-text-primary: hsl(0, 0%, 10%);
  --color-text-secondary: hsl(0, 0%, 30%);
  --color-text-muted: hsl(0, 0%, 50%);

  /* Gradients */
  --gradient-primary: linear-gradient(135deg, var(--color-primary) 0%, var(--color-secondary) 100%);
  --gradient-hero: linear-gradient(135deg, hsl(260, 85%, 95%) 0%, hsl(0, 0%, 100%) 50%, hsl(190, 95%, 95%) 100%);
  --gradient-card: linear-gradient(135deg, hsla(260, 85%, 60%, 0.05) 0%, hsla(190, 95%, 55%, 0.05) 100%);

  /* Spacing */
  --space-xs: 0.5rem;
  --space-sm: 1rem;
  --space-md: 1.5rem;
  --space-lg: 2rem;
  --space-xl: 3rem;
  --space-2xl: 4rem;
  --space-3xl: 6rem;

  /* Typography */
  --font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  --font-size-xs: 0.75rem;
  --font-size-sm: 0.875rem;
  --font-size-base: 1rem;
  --font-size-lg: 1.125rem;
  --font-size-xl: 1.25rem;
  --font-size-2xl: 1.5rem;
  --font-size-3xl: 2rem;
  --font-size-4xl: 2.5rem;
  --font-size-5xl: 3rem;

  /* Borders & Radius */
  --radius-sm: 0.5rem;
  --radius-md: 0.75rem;
  --radius-lg: 1rem;
  --radius-xl: 1.5rem;
  --radius-full: 9999px;

  /* Shadows */
  --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.08);
  --shadow-md: 0 4px 16px rgba(0, 0, 0, 0.12);
  --shadow-lg: 0 8px 32px rgba(0, 0, 0, 0.15);
  --shadow-glow: 0 0 30px var(--color-accent-glow);

  /* Transitions */
  --transition-fast: 150ms ease-in-out;
  --transition-base: 250ms ease-in-out;
  --transition-slow: 400ms ease-in-out;

  /* Glass Effect */
  --glass-bg: hsla(0, 0%, 100%, 0.8);
  --glass-border: hsla(0, 0%, 0%, 0.1);
  --glass-blur: blur(12px);
}

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

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

body {
  font-family: var(--font-family);
  font-size: var(--font-size-base);
  line-height: 1.6;
  color: var(--color-text-primary);
  background: var(--color-bg-dark);
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

/* Background Pattern */
body::before {
  content: '';
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background:
    radial-gradient(circle at 20% 30%, hsla(260, 85%, 60%, 0.05) 0%, transparent 50%),
    radial-gradient(circle at 80% 70%, hsla(190, 95%, 55%, 0.05) 0%, transparent 50%);
  pointer-events: none;
  z-index: -1;
}

/* ============================================
   Typography
   ============================================ */
h1,
h2,
h3,
h4,
h5,
h6 {
  font-weight: 700;
  line-height: 1.2;
  margin-bottom: var(--space-md);
}

h1 {
  font-size: var(--font-size-5xl);
}

h2 {
  font-size: var(--font-size-4xl);
}

h3 {
  font-size: var(--font-size-3xl);
}

h4 {
  font-size: var(--font-size-2xl);
}

h5 {
  font-size: var(--font-size-xl);
}

h6 {
  font-size: var(--font-size-lg);
}

p {
  margin-bottom: var(--space-sm);
  color: var(--color-text-secondary);
}

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

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

/* ============================================
   Layout Utilities
   ============================================ */
.container {
  width: 100%;
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 var(--space-md);
}

.container-wide {
  max-width: 1400px;
}

.container-narrow {
  max-width: 800px;
}

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

.grid-2 {
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
}

.grid-3 {
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
}

.grid-4 {
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
}

/* ============================================
   Flex Utilities
   ============================================ */
.flex {
  display: flex;
}

.flex-center {
  display: flex;
  align-items: center;
  justify-content: center;
}

.flex-between {
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.flex-column {
  flex-direction: column;
}

.gap-sm {
  gap: var(--space-sm);
}

.gap-md {
  gap: var(--space-md);
}

.gap-lg {
  gap: var(--space-lg);
}

/* ============================================
   Glass Effect Utility
   ============================================ */
.glass {
  background: var(--glass-bg);
  backdrop-filter: var(--glass-blur);
  -webkit-backdrop-filter: var(--glass-blur);
  border: 1px solid var(--glass-border);
}

/* ============================================
   Animations
   ============================================ */
@keyframes fadeIn {
  from {
    opacity: 0;
    transform: translateY(20px);
  }

  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@keyframes slideInLeft {
  from {
    opacity: 0;
    transform: translateX(-30px);
  }

  to {
    opacity: 1;
    transform: translateX(0);
  }
}

@keyframes slideInRight {
  from {
    opacity: 0;
    transform: translateX(30px);
  }

  to {
    opacity: 1;
    transform: translateX(0);
  }
}

@keyframes pulse {

  0%,
  100% {
    opacity: 1;
  }

  50% {
    opacity: 0.7;
  }
}

@keyframes glow {

  0%,
  100% {
    box-shadow: 0 0 20px var(--color-accent-glow);
  }

  50% {
    box-shadow: 0 0 40px var(--color-accent-glow);
  }
}

.fade-in {
  animation: fadeIn 0.6s ease-out forwards;
}

.slide-in-left {
  animation: slideInLeft 0.6s ease-out forwards;
}

.slide-in-right {
  animation: slideInRight 0.6s ease-out forwards;
}

/* ============================================
   Responsive Design
   ============================================ */
@media (max-width: 768px) {
  :root {
    --font-size-5xl: 2rem;
    --font-size-4xl: 1.75rem;
    --font-size-3xl: 1.5rem;
  }

  .container {
    padding: 0 var(--space-sm);
  }

  .grid {
    gap: var(--space-md);
  }

  h1 {
    font-size: var(--font-size-4xl);
  }

  h2 {
    font-size: var(--font-size-3xl);
  }

  h3 {
    font-size: var(--font-size-2xl);
  }
}

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

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

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

.text-primary {
  color: var(--color-text-primary);
}

.text-secondary {
  color: var(--color-text-secondary);
}

.text-muted {
  color: var(--color-text-muted);
}

.mb-sm {
  margin-bottom: var(--space-sm);
}

.mb-md {
  margin-bottom: var(--space-md);
}

.mb-lg {
  margin-bottom: var(--space-lg);
}

.mb-xl {
  margin-bottom: var(--space-xl);
}

.mt-sm {
  margin-top: var(--space-sm);
}

.mt-md {
  margin-top: var(--space-md);
}

.mt-lg {
  margin-top: var(--space-lg);
}

.mt-xl {
  margin-top: var(--space-xl);
}

.hidden {
  display: none;
}

.visible {
  display: block;
}