/* PhotoSort Design System - Inspired by Claude (Anthropic) */

/* ========================================
   CSS Custom Properties (Design Tokens)
   ======================================== */

:root {
  /* Primary Colors */
  --color-near-black: #141413;
  --color-terracotta: #c96442;
  --color-coral: #d97757;
  
  /* Secondary & Accent */
  --color-error: #b53333;
  --color-focus: #3898ec;
  
  /* Surface & Background */
  --color-parchment: #f5f4ed;
  --color-ivory: #faf9f5;
  --color-white: #ffffff;
  --color-sand: #e8e6dc;
  --color-dark-surface: #30302e;
  --color-deep-dark: #141413;
  
  /* Neutrals & Text */
  --color-charcoal: #4d4c48;
  --color-olive: #5e5d59;
  --color-stone: #87867f;
  --color-dark-warm: #3d3d3a;
  --color-warm-silver: #b0aea5;
  
  /* Borders */
  --color-border-cream: #f0eee6;
  --color-border-warm: #e8e6dc;
  --color-border-dark: #30302e;
  
  /* Rings */
  --color-ring-warm: #d1cfc5;
  --color-ring-subtle: #dedc01;
  --color-ring-deep: #c2c0b6;
  
  /* Typography */
  --font-serif: Georgia, 'Times New Roman', serif;
  --font-sans: system-ui, -apple-system, BlinkMacSystemFont, 'Segoe UI', Arial, sans-serif;
  --font-mono: 'SF Mono', 'Cascadia Code', 'Fira Code', Consolas, monospace;
  
  /* Font Sizes */
  --text-display: 4rem;
  --text-hero: 3.25rem;
  --text-section: 2.3rem;
  --text-subheading: 2rem;
  --text-subheading-sm: 1.6rem;
  --text-feature: 1.3rem;
  --text-body-lg: 1.25rem;
  --text-body: 1rem;
  --text-body-sm: 0.94rem;
  --text-caption: 0.88rem;
  --text-label: 0.75rem;
  --text-overline: 0.63rem;
  --text-micro: 0.6rem;
  
  /* Line Heights */
  --leading-tight: 1.10;
  --leading-snug: 1.20;
  --leading-normal: 1.30;
  --leading-relaxed: 1.60;
  --leading-loose: 1.75;
  
  /* Spacing Scale */
  --space-xs: 3px;
  --space-sm: 4px;
  --space-md: 6px;
  --space-base: 8px;
  --space-lg: 10px;
  --space-xl: 12px;
  --space-2xl: 16px;
  --space-3xl: 20px;
  --space-4xl: 24px;
  --space-5xl: 30px;
  --space-6xl: 40px;
  --space-7xl: 48px;
  --space-8xl: 60px;
  --space-9xl: 80px;
  --space-10xl: 100px;
  
  /* Border Radius */
  --radius-sharp: 4px;
  --radius-subtle: 6px;
  --radius-comfortable: 8px;
  --radius-generous: 12px;
  --radius-very-rounded: 16px;
  --radius-high: 24px;
  --radius-max: 32px;
  
  /* Shadows */
  --shadow-whisper: 0px 4px 24px rgba(0, 0, 0, 0.05);
  --shadow-soft: 0px 8px 32px rgba(0, 0, 0, 0.08);
  --shadow-ring: 0px 0px 0px 1px;
  
  /* Transitions */
  --transition-fast: 150ms ease;
  --transition-base: 250ms ease;
  --transition-slow: 400ms ease;
  
  /* Layout */
  --container-max: 1200px;
  --container-narrow: 780px;
  --section-spacing: 100px;
}

/* Dark Theme */
[data-theme="dark"] {
  --color-parchment: #141413;
  --color-ivory: #faf9f5;
  --color-white: #ffffff;
  --color-sand: #30302e;
  --color-dark-surface: #1a1a18;
  --color-border-cream: #30302e;
  --color-border-warm: #4d4c48;
  --color-charcoal: #b0aea5;
  --color-olive: #87867f;
  --color-stone: #5e5d59;
}

/* ========================================
   Base Styles
   ======================================== */

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

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

body {
  font-family: var(--font-sans);
  font-size: var(--text-body);
  line-height: var(--leading-relaxed);
  color: var(--color-charcoal);
  background-color: var(--color-parchment);
  min-height: 100vh;
}

/* ========================================
   Typography
   ======================================== */

h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-serif);
  font-weight: 500;
  line-height: var(--leading-tight);
  color: var(--color-near-black);
}

h1 {
  font-size: var(--text-display);
}

h2 {
  font-size: var(--text-hero);
}

h3 {
  font-size: var(--text-section);
}

h4 {
  font-size: var(--text-subheading);
}

h5 {
  font-size: var(--text-subheading-sm);
}

h6 {
  font-size: var(--text-feature);
}

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

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

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

/* ========================================
   Utility Classes
   ======================================== */

.container {
  max-width: var(--container-max);
  margin: 0 auto;
  padding: 0 var(--space-4xl);
}

.container--narrow {
  max-width: var(--container-narrow);
}

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

.text-serif {
  font-family: var(--font-serif);
}

.text-sans {
  font-family: var(--font-sans);
}

.text-mono {
  font-family: var(--font-mono);
}

/* ========================================
   Buttons
   ======================================== */

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-sm);
  padding: var(--space-base) var(--space-xl);
  font-family: var(--font-sans);
  font-size: var(--text-body);
  font-weight: 500;
  line-height: 1;
  text-decoration: none;
  border: none;
  border-radius: var(--radius-generous);
  cursor: pointer;
  transition: all var(--transition-base);
  user-select: none;
}

.btn:focus-visible {
  outline: 2px solid var(--color-focus);
  outline-offset: 2px;
}

.btn--primary {
  background-color: var(--color-terracotta);
  color: var(--color-ivory);
  box-shadow: var(--shadow-ring) var(--color-terracotta),
              var(--shadow-ring) var(--color-ring-warm);
}

.btn--primary:hover,
.btn--primary:focus {
  background-color: var(--color-coral);
  transform: translateY(-2px);
  color: var(--color-ivory);
}

.btn--primary:visited {
  color: var(--color-ivory);
}

.btn--secondary {
  background-color: var(--color-sand);
  color: var(--color-charcoal);
  box-shadow: var(--shadow-ring) var(--color-sand),
              var(--shadow-ring) var(--color-ring-warm);
}

.btn--secondary:hover,
.btn--secondary:focus {
  background-color: var(--color-border-warm);
  color: var(--color-charcoal);
}

.btn--secondary:visited {
  color: var(--color-charcoal);
}

.btn--outline {
  background-color: transparent;
  color: var(--color-terracotta);
  border: 1px solid var(--color-terracotta);
}

.btn--outline:hover {
  background-color: var(--color-terracotta);
  color: var(--color-ivory);
}

.btn--dark {
  background-color: var(--color-dark-surface);
  color: var(--color-ivory);
}

.btn--dark:hover,
.btn--dark:focus {
  background-color: var(--color-near-black);
  color: var(--color-ivory);
}

.btn--dark:visited {
  color: var(--color-ivory);
}

.btn--lg {
  padding: var(--space-xl) var(--space-3xl);
  font-size: var(--text-body-lg);
  border-radius: var(--radius-very-rounded);
}

/* ========================================
   Cards
   ======================================== */

.card {
  background-color: var(--color-ivory);
  border: 1px solid var(--color-border-cream);
  border-radius: var(--radius-comfortable);
  padding: var(--space-4xl);
  box-shadow: var(--shadow-whisper);
}

.card--elevated {
  box-shadow: var(--shadow-soft);
}

.card--interactive {
  cursor: pointer;
  transition: all var(--transition-base);
}

.card--interactive:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-soft);
  border-color: var(--color-terracotta);
}

/* ========================================
   Section Styles
   ======================================== */

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

.section--dark {
  background-color: var(--color-near-black);
  color: var(--color-ivory);
}

.section--dark h1,
.section--dark h2,
.section--dark h3,
.section--dark h4,
.section--dark h5,
.section--dark h6 {
  color: var(--color-ivory);
}

.section--sand {
  background-color: var(--color-sand);
}

.section--ivory {
  background-color: var(--color-ivory);
}

/* ========================================
   Responsive Breakpoints
   ======================================== */

@media (max-width: 991px) {
  :root {
    --text-display: 3rem;
    --text-hero: 2.5rem;
    --section-spacing: 80px;
  }
}

@media (max-width: 767px) {
  :root {
    --text-display: 2.5rem;
    --text-hero: 2rem;
    --text-section: 1.75rem;
    --section-spacing: 60px;
  }
  
  .container {
    padding: 0 var(--space-2xl);
  }
}

@media (max-width: 479px) {
  :root {
    --text-display: 2rem;
    --text-hero: 1.75rem;
    --text-section: 1.5rem;
  }
}