/* ================================================================
   ImageTools - Main Stylesheet
   Light theme, DM Sans font, CSS custom properties
   ================================================================ */

/* ----------------------------------------------------------------
   Google Fonts
   ---------------------------------------------------------------- */
@import url('https://fonts.googleapis.com/css2?family=DM+Sans:ital,opsz,wght@0,9..40,300;0,9..40,400;0,9..40,500;0,9..40,600;0,9..40,700;1,9..40,400&display=swap');

/* ----------------------------------------------------------------
   CSS Custom Properties (Design Tokens)
   ---------------------------------------------------------------- */
:root {
  /* Primary - Main brand/action color */
  --color-primary: #2563eb;
  --color-primary-hover: #1d4ed8;
  --color-primary-light: #dbeafe;
  --color-primary-50: #eff6ff;

  /* Backgrounds */
  --color-bg: #ffffff;
  --color-bg-secondary: #f8fafc;
  --color-bg-tertiary: #f1f5f9;
  --color-bg-elevated: #ffffff;

  /* Text */
  --color-text: #0f172a;
  --color-text-secondary: #475569;
  --color-text-muted: #94a3b8;
  --color-text-inverse: #ffffff;

  /* Borders & Dividers */
  --color-border: #e2e8f0;
  --color-border-light: #f1f5f9;
  --color-border-focus: #2563eb;

  /* Semantic - Status colors */
  --color-success: #16a34a;
  --color-success-light: #dcfce7;
  --color-error: #dc2626;
  --color-error-light: #fef2f2;
  --color-warning: #f59e0b;
  --color-warning-light: #fffbeb;

  /* Accent */
  --color-accent: #7c3aed;
  --color-accent-light: #ede9fe;

  /* Pricing */
  --color-most-popular: #2563eb;
  --color-savings-badge: #16a34a;
  --color-pro-badge: #16a34a;
  --color-free-badge: #64748b;

  /* Checkerboard (transparency display) */
  --checker-light: #f0f0f0;
  --checker-dark: #d9d9d9;

  /* Font families */
  --font-display: 'DM Sans', -apple-system, BlinkMacSystemFont, sans-serif;
  --font-body: 'DM Sans', -apple-system, BlinkMacSystemFont, sans-serif;
  --font-mono: 'JetBrains Mono', 'Fira Code', 'Consolas', monospace;

  /* Type scale */
  --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;

  /* Font weights */
  --font-light: 300;
  --font-normal: 400;
  --font-medium: 500;
  --font-semibold: 600;
  --font-bold: 700;

  /* Line heights */
  --leading-tight: 1.15;
  --leading-snug: 1.3;
  --leading-normal: 1.5;
  --leading-relaxed: 1.75;

  /* Letter spacing */
  --tracking-tight: -0.02em;
  --tracking-normal: 0;
  --tracking-wide: 0.05em;

  /* Spacing scale (4px base) */
  --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;

  /* Border radius */
  --radius-sm: 4px;
  --radius-md: 8px;
  --radius-lg: 12px;
  --radius-xl: 16px;
  --radius-full: 9999px;

  /* Shadows */
  --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.07), 0 2px 4px -2px rgba(0, 0, 0, 0.05);
  --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.08), 0 4px 6px -4px rgba(0, 0, 0, 0.05);
  --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.08), 0 8px 10px -6px rgba(0, 0, 0, 0.04);

  /* Content widths */
  --max-width-sm: 640px;
  --max-width-md: 768px;
  --max-width-lg: 1024px;
  --max-width-xl: 1200px;
  --max-width-2xl: 1400px;

  /* Transitions */
  --transition-fast: 150ms ease;
  --transition-base: 200ms ease;
  --transition-slow: 300ms ease;
}

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

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

body {
  font-family: var(--font-body);
  font-size: var(--text-base);
  font-weight: var(--font-normal);
  line-height: var(--leading-normal);
  color: var(--color-text-secondary);
  background-color: var(--color-bg);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

img,
svg {
  display: block;
  max-width: 100%;
}

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

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

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

h1 { font-size: var(--text-3xl); letter-spacing: var(--tracking-tight); }
h2 { font-size: var(--text-2xl); font-weight: var(--font-semibold); }
h3 { font-size: var(--text-xl); font-weight: var(--font-semibold); }

p {
  margin-bottom: var(--space-4);
}

ul, ol {
  list-style: none;
}

button {
  font-family: inherit;
  cursor: pointer;
}

input, textarea, select {
  font-family: inherit;
  font-size: inherit;
}

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

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

.text-center { text-align: center; }
.text-sm { font-size: var(--text-sm); }
.text-muted { color: var(--color-text-muted); }

/* Focus visible for accessibility */
:focus-visible {
  outline: 3px solid var(--color-primary);
  outline-offset: 2px;
}

/* Main content area */
main {
  flex: 1;
}

/* ----------------------------------------------------------------
   Animations
   ---------------------------------------------------------------- */
@keyframes fadeUp {
  to { opacity: 1; transform: translateY(0); }
}

@keyframes spin {
  to { transform: rotate(360deg); }
}

@keyframes shake {
  0%, 100% { transform: translateX(0); }
  25% { transform: translateX(-4px); }
  75% { transform: translateX(4px); }
}

@keyframes slideInRight {
  from { transform: translateX(120%); opacity: 0; }
  to { transform: translateX(0); opacity: 1; }
}

@keyframes slideOutRight {
  from { transform: translateX(0); opacity: 1; }
  to { transform: translateX(120%); opacity: 0; }
}

.stagger-enter {
  opacity: 0;
  transform: translateY(20px);
  animation: fadeUp 0.6s ease forwards;
}
.stagger-enter:nth-child(1) { animation-delay: 0.1s; }
.stagger-enter:nth-child(2) { animation-delay: 0.2s; }
.stagger-enter:nth-child(3) { animation-delay: 0.3s; }
.stagger-enter:nth-child(4) { animation-delay: 0.4s; }