:root {
    /* Color Palette - Dark & Premium */
    --color-bg-main: #0f172a;
    /* Slate 900 */
    --color-bg-card: #1e293b;
    /* Slate 800 */
    --color-bg-card-hover: #334155;
    /* Slate 700 */
    --color-text-primary: #f8fafc;
    /* Slate 50 */
    --color-text-secondary: #94a3b8;
    /* Slate 400 */
    --color-primary: #3b82f6;
    /* Blue 500 */
    --color-primary-glow: rgba(59, 130, 246, 0.5);
    --color-accent: #8b5cf6;
    /* Violet 500 */
    --color-accent-glow: rgba(139, 92, 246, 0.5);

    /* Gradients */
    --gradient-primary: linear-gradient(135deg, var(--color-primary), var(--color-accent));
    --gradient-bg: radial-gradient(circle at top right, #1e293b, #0f172a);

    /* Spacing & Layout */
    --spacing-sm: 0.5rem;
    --spacing-md: 1rem;
    --spacing-lg: 2rem;
    --radius-sm: 0.5rem;
    --radius-md: 1rem;
    --radius-lg: 1.5rem;

    /* Effects */
    --shadow-soft: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
    --shadow-glow: 0 0 20px var(--color-primary-glow);
    --glass-bg: rgba(30, 41, 59, 0.7);
    --glass-border: rgba(255, 255, 255, 0.1);
}

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

:root {
    --sidebar-width: 250px;
}

body {
    background-color: var(--color-bg-main);
    background-image: var(--gradient-bg);
    color: var(--color-text-primary);
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
    min-height: 100vh;
    line-height: 1.6;
    display: flex;
}

/* Layout */
.app-container {
    display: flex;
    width: 100%;
    min-height: 100vh;
}

@media (max-width: 768px) {
    .app-container {
        flex-direction: column;
    }
}

/* Sidebar */
.sidebar {
    width: var(--sidebar-width);
    background-color: var(--glass-bg);
    backdrop-filter: blur(12px);
    border-right: 1px solid var(--glass-border);
    padding: var(--spacing-lg);
    display: flex;
    flex-direction: column;
    position: sticky;
    top: 0;
    height: 100vh;
    z-index: 100;
}

@media (max-width: 768px) {
    .sidebar {
        width: 100%;
        height: auto;
        position: relative;
        padding: var(--spacing-md);
        border-right: none;
        border-bottom: 1px solid var(--glass-border);
    }
}

.brand {
    font-size: 1.5rem;
    font-weight: 700;
    margin-bottom: var(--spacing-lg);
    background: var(--gradient-primary);
    background-clip: text;
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
}

@media (max-width: 768px) {
    .brand {
        margin-bottom: var(--spacing-md);
    }
}

.nav-links {
    list-style: none;
    display: flex;
    flex-direction: column;
    gap: var(--spacing-sm);
}

@media (max-width: 768px) {
    .nav-links {
        flex-direction: row;
        overflow-x: auto;
        padding-bottom: var(--spacing-xs);
    }
}

.nav-link {
    display: flex;
    align-items: center;
    padding: var(--spacing-md);
    border-radius: var(--radius-sm);
    color: var(--color-text-secondary);
    text-decoration: none;
    transition: all 0.3s ease;
}

.nav-link:hover,
.nav-link.active {
    background-color: var(--color-bg-card-hover);
    color: var(--color-text-primary);
    transform: translateX(5px);
}

/* Main Content */
.main-content {
    flex: 1;
    padding: var(--spacing-lg);
    overflow-y: auto;
}

.header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: var(--spacing-lg);
}

.page-title {
    font-size: 2rem;
    font-weight: 600;
}

/* Dashboard Grid */
.modules-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: var(--spacing-lg);
}

.module-card {
    background-color: var(--color-bg-card);
    border: 1px solid var(--glass-border);
    border-radius: var(--radius-md);
    padding: var(--spacing-lg);
    transition: all 0.3s ease;
    display: flex;
    flex-direction: column;
    justify-content: space-between;
    height: 100%;
}

.module-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-glow);
    border-color: var(--color-primary);
}

.module-icon {
    font-size: 2rem;
    margin-bottom: var(--spacing-md);
    color: var(--color-primary);
}

.module-title {
    font-size: 1.25rem;
    font-weight: 600;
    margin-bottom: var(--spacing-sm);
    color: var(--color-text-primary);
}

.module-desc {
    color: var(--color-text-secondary);
    font-size: 0.95rem;
    margin-bottom: var(--spacing-md);
}

.btn-primary {
    display: inline-block;
    padding: var(--spacing-sm) var(--spacing-md);
    background: var(--gradient-primary);
    color: white;
    text-decoration: none;
    border-radius: var(--radius-sm);
    font-weight: 500;
    text-align: center;
    transition: filter 0.3s;
}

.btn-primary:hover {
    filter: brightness(1.1);
}

/* Animations */
@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(10px);
    }

    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.fade-in {
    animation: fadeIn 0.5s ease-out forwards;
}