:root {
    /* Color Palette - Premium HSL optimized */
    --hue-primary: 250;
    /* Deep Indigo/Purple */
    --hue-secondary: 190;
    /* Cyan/Teal */

    /* Light Mode Variables */
    --bg-app: hsl(220, 20%, 97%);
    --bg-surface: hsla(0, 0%, 100%, 0.7);
    --bg-surface-2: hsla(0, 0%, 100%, 0.5);
    --text-primary: hsl(220, 40%, 10%);
    --text-secondary: hsl(220, 20%, 40%);
    --border-color: hsla(220, 20%, 80%, 0.5);
    --accent: hsl(var(--hue-primary), 60%, 50%);
    --accent-glow: hsla(var(--hue-primary), 60%, 50%, 0.3);

    /* Neumorphic/Glassmorphic Shadows */
    --shadow-sm: 0 4px 6px -1px rgba(0, 0, 0, 0.05), 0 2px 4px -1px rgba(0, 0, 0, 0.03);
    --shadow-glass:
        0 8px 32px 0 rgba(31, 38, 135, 0.05),
        inset 0 0 0 1px rgba(255, 255, 255, 0.4);
}

/* Dark Mode overrides (Media Query OR .dark class) */
@media (prefers-color-scheme: dark) {
    :root {
        --bg-app: hsl(222, 47%, 11%);
        --bg-surface: hsla(217, 33%, 17%, 0.4);
        --bg-surface-2: hsla(217, 33%, 25%, 0.3);
        --text-primary: hsl(210, 40%, 98%);
        --text-secondary: hsl(215, 20%, 65%);
        --border-color: hsla(217, 33%, 50%, 0.1);
        --shadow-glass:
            0 8px 32px 0 rgba(0, 0, 0, 0.3),
            inset 0 0 0 1px rgba(255, 255, 255, 0.05);
    }
}

/* Force Dark Mode via class */
body.dark {
    --bg-app: hsl(222, 47%, 11%);
    --bg-surface: hsla(217, 33%, 17%, 0.4);
    --bg-surface-2: hsla(217, 33%, 25%, 0.3);
    --text-primary: hsl(210, 40%, 98%);
    --text-secondary: hsl(215, 20%, 65%);
    --border-color: hsla(217, 33%, 50%, 0.1);
    --shadow-glass:
        0 8px 32px 0 rgba(0, 0, 0, 0.3),
        inset 0 0 0 1px rgba(255, 255, 255, 0.05);
}

/* Global Styles */
body {
    background-color: var(--bg-app);
    color: var(--text-primary);
    font-family: 'Inter', system-ui, -apple-system, sans-serif;
    transition: background-color 0.5s ease, color 0.5s ease;
    min-height: 100vh;
    overflow-x: hidden;
}

/* Glassmorphism Utilities */
.glass-panel {
    background: var(--bg-surface);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border-radius: 16px;
    box-shadow: var(--shadow-glass);
    border: 1px solid var(--border-color);
}

.btn-primary {
    background: var(--accent);
    color: white;
    border: none;
    padding: 10px 20px;
    border-radius: 8px;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.2s ease;
    box-shadow: 0 4px 15px var(--accent-glow);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 20px var(--accent-glow);
}