:root {
    /* Core Colors - Neutral */
    --color-bg-body: #0f172a; /* Slate 900 */
    --color-bg-card: #1e293b; /* Slate 800 */
    --color-text-main: #f8fafc; /* Slate 50 */
    --color-text-muted: #94a3b8; /* Slate 400 */
    --color-border: #334155; /* Slate 700 */

    /* Typography */
    --font-sans: 'Inter', system-ui, -apple-system, sans-serif;
    
    /* Spacing */
    --spacing-xs: 0.5rem;
    --spacing-sm: 1rem;
    --spacing-md: 2rem;
    --spacing-lg: 4rem;
    --spacing-xl: 8rem;

    /* Transitions */
    --transition-fast: 0.2s ease;
    --transition-medium: 0.3s ease;
}

/* Brand Colors - To be overridden by specific sites if needed, 
   but defaults provided here */
:root {
    --color-accent-main: #3b82f6; /* Blue 500 */
    --color-accent-glow: rgba(59, 130, 246, 0.5);
}

/* Deu Theme Override Hint */
[data-theme="deu"] {
    --color-accent-main: #ef4444; /* Red 500 - German Black/Red/Gold hint */
    --color-accent-secondary: #eab308; /* Yellow 500 */
    --color-accent-glow: rgba(239, 68, 68, 0.5);
}

/* Trade Theme Override Hint */
[data-theme="trade"] {
    --color-accent-main: #10b981; /* Emerald 500 */
    --color-accent-glow: rgba(16, 185, 129, 0.5);
}

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

body {
    background-color: var(--color-bg-body);
    color: var(--color-text-main);
    font-family: var(--font-sans);
    line-height: 1.6;
    -webkit-font-smoothing: antialiased;
}

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

a:hover {
    color: var(--color-accent-main);
}

/* Utilities */
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--spacing-sm);
}

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

.btn {
    display: inline-block;
    padding: 0.75rem 1.5rem;
    background-color: var(--color-accent-main);
    color: white;
    border-radius: 0.375rem;
    font-weight: 500;
    transition: transform var(--transition-fast), box-shadow var(--transition-fast);
    border: none;
    cursor: pointer;
}

.btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 12px var(--color-accent-glow);
}

.card {
    background-color: var(--color-bg-card);
    border: 1px solid var(--color-border);
    border-radius: 0.75rem;
    padding: var(--spacing-md);
    transition: transform var(--transition-medium);
}

.card:hover {
    transform: translateY(-4px);
    border-color: var(--color-accent-main);
}

/* Header/Nav Shared Styles */
.header {
    padding: var(--spacing-sm) 0;
    border-bottom: 1px solid var(--color-border);
    backdrop-filter: blur(10px);
    position: sticky;
    top: 0;
    z-index: 100;
    background-color: rgba(15, 23, 42, 0.8);
}

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

.logo {
    font-weight: 700;
    font-size: 1.5rem;
    letter-spacing: -0.05em;
}

.nav-links {
    display: flex;
    gap: var(--spacing-md);
}

@media (max-width: 768px) {
    .nav-links {
        display: none; /* Simple mobile hide for now, needs hamburger later */
    }
}