:root {
    --primary-color: #6366f1;
    --primary-hover: #4f46e5;
    --bg-color: #f8fafc;
    --card-bg: rgba(255, 255, 255, 0.8);
    --text-main: #1e293b;
    --text-muted: #64748b;
    --border-color: #e2e8f0;
    --success: #10b981;
    --warning: #f59e0b;
    --danger: #ef4444;
    --sidebar-width: 260px;
    --glass-shadow: 0 8px 32px 0 rgba(31, 38, 135, 0.07);
}

[data-theme='dark'] {
    --bg-color: #0f172a;
    --card-bg: rgba(30, 41, 59, 0.8);
    --text-main: #f1f5f9;
    --text-muted: #94a3b8;
    --border-color: #334155;
    --glass-shadow: 0 8px 32px 0 rgba(0, 0, 0, 0.3);
}

[data-theme='sepia'] {
    --bg-color: #f4ecd8;
    --card-bg: rgba(255, 253, 241, 0.9);
    --text-main: #5b4636;
    --text-muted: #8c7355;
    --border-color: #d6c4a8;
    --glass-shadow: 0 8px 32px 0 rgba(91, 70, 54, 0.05);
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: 'Inter', system-ui, -apple-system, sans-serif;
}

body {
    background: var(--bg-color);
    color: var(--text-main);
    min-height: 100vh;
    display: flex;
}

/* Glassmorphism Sidebar */
.sidebar {
    width: var(--sidebar-width);
    height: 100vh;
    background: var(--card-bg);
    backdrop-filter: blur(10px);
    border-right: 1px solid var(--border-color);
    position: fixed;
    padding: 2rem 1.5rem;
    display: flex;
    flex-direction: column;
    z-index: 100;
}

.logo {
    font-size: 1.5rem;
    font-weight: 800;
    color: var(--primary-color);
    margin-bottom: 3rem;
    display: flex;
    align-items: center;
    gap: 0.75rem;
}

.nav-links {
    list-style: none;
    flex: 1;
}

.nav-links li {
    margin-bottom: 0.5rem;
}

.nav-links a {
    text-decoration: none;
    color: var(--text-muted);
    padding: 0.75rem 1rem;
    border-radius: 12px;
    display: flex;
    align-items: center;
    gap: 1rem;
    transition: all 0.3s ease;
    font-weight: 500;
}

.nav-links a:hover, .nav-links a.active {
    background: rgba(99, 102, 241, 0.1);
    color: var(--primary-color);
}

/* Main Content */
.main-content {
    margin-left: var(--sidebar-width);
    flex: 1;
    padding: 2rem;
}

.top-bar {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 2rem;
}

/* Cards */
.card {
    background: var(--card-bg);
    backdrop-filter: blur(4px);
    border: 1px solid var(--border-color);
    border-radius: 20px;
    padding: 1.5rem;
    box-shadow: var(--glass-shadow);
    transition: transform 0.3s ease;
}

.card:hover {
    transform: translateY(-5px);
}

/* Grid Layout */
.dashboard-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
    gap: 1.5rem;
}

/* Buttons */
.btn {
    padding: 0.75rem 1.5rem;
    border-radius: 12px;
    border: none;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
}

.btn-primary {
    background: var(--primary-color);
    color: white;
}

.btn-primary:hover {
    background: var(--primary-hover);
    box-shadow: 0 4px 12px rgba(99, 102, 241, 0.3);
}

/* Animations */
@keyframes fadeIn {
    from { opacity: 0; transform: translateY(10px); }
    to { opacity: 1; transform: translateY(0); }
}

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