:root {
    /* Baseline M3 Dark Scheme pour Primary #000080 */
    --md-primary: #000080;
    --md-on-primary: #ffffff;
    --md-primary-container: #00005a;
    --md-on-primary-container: #e0e0ff;
    
    /* Couleurs de Surface */
    --md-surface: #1a1b1f; 
    --md-on-surface: #e3e2e6;
    --md-surface-variant: #2e3036; /* Un bleu-gris très sombre pour les cartes */
    --md-on-surface-variant: #c4c6d0;
    
    /* Accent pour les liens et icônes */
    --md-accent: #00ffff; 

    /* Shadow tokens (Material Elevation) */
    --shadow-lv1: 0 1px 3px rgba(0,0,0,0.2);
    --shadow-lv3: 0 4px 8px rgba(0,0,0,0.4);
}

body {
    background-color: var(--md-surface);
    color: var(--md-on-surface);
    font-family: 'Roboto', 'Segoe UI', system-ui, sans-serif;
    margin: 0;
    padding-top: 80px;
    line-height: 1.6;
}

/* Navbar M3 */
.navbar {
    position: fixed;
    top: 0; left: 0; right: 0;
    height: 64px;
    background-color: rgba(26, 27, 31, 0.95);
    backdrop-filter: blur(8px);
    border-bottom: 1px solid var(--md-surface-variant);
    display: flex;
    align-items: center;
    z-index: 1000;
}

.nav-content {
    max-width: 900px;
    margin: 0 auto;
    width: 100%;
    padding: 0 24px;
    display: flex;
    align-items: center;
    gap: 16px;
}

.nav-logo {
    height: 36px;
    border-radius: 4px;
}

.nav-brand {
    font-weight: 500;
    letter-spacing: 0.5px;
    text-transform: uppercase;
    font-size: 0.85rem;
    color: var(--md-on-surface);
}

/* Main Layout */
.container {
    max-width: 700px;
    margin: 0 auto;
    padding: 20px 24px;
}

h1 {
    font-size: 2.8rem;
    font-weight: 400;
    margin: 0;
    color: var(--md-on-surface);
}

.subtitle {
    font-size: 1.1rem;
    color: var(--md-on-surface-variant);
    margin-top: 4px;
}

/* Section Titles (Badge style M3) */
h3 {
    display: inline-block;
    background-color: var(--md-primary-container);
    color: var(--md-on-primary-container);
    padding: 6px 16px;
    border-radius: 100px; /* Style "Pill" Material 3 */
    font-size: 0.75rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 1px;
    margin: 40px 0 20px;
}

ul { list-style: none; padding: 0; }
ul li {
    margin-bottom: 12px;
    padding-left: 32px;
    position: relative;
    color: var(--md-on-surface-variant);
}

ul li::before {
    content: "→";
    position: absolute;
    left: 8px;
    color: var(--md-accent);
    font-weight: bold;
}

/* Grid & Cards */
.grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 16px;
}

@media (max-width: 550px) { .grid { grid-template-columns: 1fr; } }

.card {
    background-color: var(--md-surface-variant);
    padding: 24px;
    border-radius: 16px; /* M3 Large Shape */
    text-decoration: none;
    transition: all 0.2s ease-out;
    box-shadow: var(--shadow-lv1);
    border: 1px solid transparent;
}

.card:hover {
    background-color: #383a42;
    transform: translateY(-4px);
    box-shadow: var(--shadow-lv3);
    border-color: var(--md-primary);
}

.card strong {
    color: var(--md-on-surface);
    display: block;
    font-size: 1.1rem;
    margin-bottom: 4px;
}

.card span {
    font-size: 0.85rem;
    color: var(--md-on-surface-variant);
}

footer {
    margin-top: 80px;
    padding: 40px;
    text-align: center;
    border-top: 1px solid var(--md-surface-variant);
    color: var(--md-on-surface-variant);
    font-size: 0.8rem;
}

/* Classes spécifiques pour la page 404 */
.error-container {
    text-align: center;
    padding-top: 8vh;
}

.error-code {
    font-size: clamp(5rem, 15vw, 8rem); /* S'adapte à la taille de l'écran */
    font-weight: 700;
    color: var(--md-accent);
    margin: 0;
}

.tech-note {
    font-family: 'Courier New', Courier, monospace;
    background-color: var(--md-primary-container);
    color: var(--md-on-primary-container);
    padding: 12px 20px;
    border-radius: 8px;
    display: inline-block;
    margin: 24px 0;
    font-size: 0.9rem;
    text-align: left;
    border-left: 4px solid var(--md-accent);
}