:root {
  /* Mandatory Palette */
  --bg-color: #ffffff;
  --text-color: #171717;
  --primary-color: #D32F2F; /* Rouge - Timbre rouge/prioritaire */
  --secondary-color: #2E7D32; /* Vert - Timbre vert/écologique */
  
  /* Additional UI Variables */
  --text-muted: #4a4a4a;
  --glass-bg: rgba(255, 255, 255, 0.65);
  --glass-border: rgba(23, 23, 23, 0.08);
  --glass-shadow: 0 8px 32px 0 rgba(23, 23, 23, 0.06);
  --glass-blur: blur(12px);
  
  /* Typography */
  --font-serif: 'Playfair Display', 'Merriweather', 'Georgia', serif;
  --font-sans: 'Inter', 'Segoe UI', 'Roboto', 'Helvetica Neue', sans-serif;
  
  /* Paper Grain Texture (Subtle SVG Noise) */
  --paper-texture: url('data:image/svg+xml;utf8,<svg viewBox="0 0 200 200" xmlns="http://www.w3.org/2000/svg"><filter id="noiseFilter"><feTurbulence type="fractalNoise" baseFrequency="0.75" numOctaves="3" stitchTiles="stitch"/></filter><rect width="100%" height="100%" filter="url(%23noiseFilter)" opacity="0.05"/></svg>');
  
  /* Animations */
  --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

/* ==========================================================================
   Base Styles & Reset
   ========================================================================== */

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

body {
  background-color: var(--bg-color);
  background-image: var(--paper-texture);
  background-attachment: fixed;
  color: var(--text-color);
  font-family: var(--font-sans);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

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

h1, .site-title, h2, h3, h4, h5, h6 {
  font-family: var(--font-serif);
  font-weight: 600;
  color: var(--text-color);
  margin-bottom: 1rem;
  line-height: 1.2;
}

h1, .site-title {
  font-size: clamp(2.5rem, 5vw, 4rem);
  letter-spacing: -0.02em;
}

h2 {
  font-size: clamp(1.75rem, 3vw, 2.5rem);
}

h3 {
  font-size: 1.5rem;
}

p {
  margin-bottom: 1rem;
  color: var(--text-color);
}

.text-muted {
  color: var(--text-muted);
  font-size: 0.95rem;
}

/* ==========================================================================
   Links & Accents
   ========================================================================== */

a {
  color: var(--primary-color);
  text-decoration: none;
  font-weight: 500;
  transition: var(--transition);
  position: relative;
}

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

a::after {
  content: '';
  position: absolute;
  width: 100%;
  transform: scaleX(0);
  height: 2px;
  bottom: -2px;
  left: 0;
  background-color: var(--secondary-color);
  transform-origin: bottom right;
  transition: transform 0.3s ease-out;
}

a:hover::after {
  transform: scaleX(1);
  transform-origin: bottom left;
}

.accent-red {
  color: var(--primary-color);
}

.accent-green {
  color: var(--secondary-color);
}

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

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0.75rem 1.5rem;
  font-family: var(--font-sans);
  font-weight: 600;
  font-size: 1rem;
  border-radius: 8px;
  border: none;
  cursor: pointer;
  transition: var(--transition);
  text-decoration: none;
}

.btn::after {
  display: none; /* Disable link underline animation for buttons */
}

.btn-primary {
  background-color: var(--primary-color);
  color: #ffffff;
  box-shadow: 0 4px 12px rgba(211, 47, 47, 0.2);
}

.btn-primary:hover, .btn-primary:focus {
  background-color: #b71c1c; /* Darker primary */
  color: #ffffff;
  transform: translateY(-2px);
  box-shadow: 0 6px 16px rgba(211, 47, 47, 0.3);
}

.btn-secondary {
  background-color: var(--secondary-color);
  color: #ffffff;
  box-shadow: 0 4px 12px rgba(46, 125, 50, 0.2);
}

.btn-secondary:hover, .btn-secondary:focus {
  background-color: #1b5e20; /* Darker secondary */
  color: #ffffff;
  transform: translateY(-2px);
  box-shadow: 0 6px 16px rgba(46, 125, 50, 0.3);
}

/* ==========================================================================
   Layout: Bento Grid
   ========================================================================== */

.container {
  max-width: 1280px;
  margin: 0 auto;
  padding: 2rem;
}

.bento-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  grid-auto-rows: minmax(200px, auto);
  gap: 1.5rem;
  margin-top: 2rem;
}

/* Bento Card with Frosted Glassmorphism */
.bento-card {
  background: var(--glass-bg);
  backdrop-filter: var(--glass-blur);
  -webkit-backdrop-filter: var(--glass-blur);
  border: 1px solid var(--glass-border);
  border-radius: 20px;
  padding: 2rem;
  box-shadow: var(--glass-shadow);
  transition: var(--transition);
  display: flex;
  flex-direction: column;
  position: relative;
  overflow: hidden;
}

.bento-card:hover {
  transform: translateY(-4px);
  box-shadow: 0 12px 40px 0 rgba(23, 23, 23, 0.1);
  border-color: rgba(23, 23, 23, 0.15);
}

/* Highlight Accents on Bento Cards */
.bento-card.highlight-red::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 4px;
  background-color: var(--primary-color);
}

.bento-card.highlight-green::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 4px;
  background-color: var(--secondary-color);
}

/* Grid Spans for larger screens */
@media (min-width: 900px) {
  .span-2 {
    grid-column: span 2;
  }
  
  .span-3 {
    grid-column: span 3;
  }
  
  .row-span-2 {
    grid-row: span 2;
  }
}

/* ==========================================================================
   Tables (Comparatifs Tarifaires)
   ========================================================================== */

.table-wrapper {
  overflow-x: auto;
  margin-top: 1.5rem;
  border-radius: 12px;
  border: 1px solid var(--glass-border);
}

table {
  width: 100%;
  border-collapse: collapse;
  text-align: left;
  font-family: var(--font-sans);
}

th {
  background-color: rgba(23, 23, 23, 0.04);
  padding: 1rem 1.5rem;
  font-weight: 600;
  color: var(--text-color);
  font-size: 0.9rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  border-bottom: 2px solid var(--glass-border);
}

td {
  padding: 1rem 1.5rem;
  border-bottom: 1px solid var(--glass-border);
  font-size: 0.95rem;
}

tr:last-child td {
  border-bottom: none;
}

tr:hover td {
  background-color: rgba(23, 23, 23, 0.02);
}

/* ==========================================================================
   Header & Navigation
   ========================================================================== */

.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: var(--glass-bg);
  backdrop-filter: var(--glass-blur);
  -webkit-backdrop-filter: var(--glass-blur);
  border-bottom: 1px solid var(--glass-border);
  padding: 1rem 2rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.site-header .site-title {
  margin-bottom: 0;
  font-size: 1.75rem;
}

.main-nav ul {
  list-style: none;
  display: flex;
  gap: 2rem;
}

.main-nav a {
  color: var(--text-color);
  font-weight: 500;
  font-size: 1rem;
}

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

/* ==========================================================================
   Badges / Tags (For stamp categories)
   ========================================================================== */

.badge {
  display: inline-block;
  padding: 0.25rem 0.75rem;
  border-radius: 20px;
  font-size: 0.8rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  margin-bottom: 1rem;
}

.badge-red {
  background-color: rgba(211, 47, 47, 0.1);
  color: var(--primary-color);
  border: 1px solid rgba(211, 47, 47, 0.2);
}

.badge-green {
  background-color: rgba(46, 125, 50, 0.1);
  color: var(--secondary-color);
  border: 1px solid rgba(46, 125, 50, 0.2);
}