:root {
    /* LIGHT THEME VARIABLES */
    --bg-base: #f3f4f6;
    --bg-surface: #ffffff;
    --bg-surface-hover: #f9fafb;
    --text-main: #1f2937;
    --text-muted: #6b7280;
    --border-color: #e5e7eb;
    --primary: #3b82f6;
    --primary-hover: #2563eb;
    --danger: #ef4444;
    --success: #10b981;
    --warning: #f59e0b;
    --sidebar-bg: #111827;
    --sidebar-text: #d1d5db;
    --sidebar-active: #1f2937;
    --glass-bg: rgba(255, 255, 255, 0.7);
    --glass-border: rgba(255, 255, 255, 0.2);
}

[data-theme="dark"] {
    /* DARK THEME VARIABLES */
    --bg-base: #0f172a;
    --bg-surface: #1e293b;
    --bg-surface-hover: #334155;
    --text-main: #f8fafc;
    --text-muted: #94a3b8;
    --border-color: #334155;
    --primary: #3b82f6;
    --primary-hover: #60a5fa;
    --sidebar-bg: #0f172a;
    --sidebar-text: #cbd5e1;
    --sidebar-active: #1e293b;
    --glass-bg: rgba(30, 41, 59, 0.7);
    --glass-border: rgba(255, 255, 255, 0.05);
}

body {
    background-color: var(--bg-base);
    color: var(--text-main);
    font-family: 'Inter', sans-serif;
    transition: background-color 0.3s ease, color 0.3s ease;
    margin: 0;
}

/* Scrollbar */
::-webkit-scrollbar { width: 8px; height: 8px; }
::-webkit-scrollbar-track { background: var(--bg-base); }
::-webkit-scrollbar-thumb { background: var(--border-color); border-radius: 4px; }
::-webkit-scrollbar-thumb:hover { background: var(--text-muted); }

/* Layout */
.app-wrapper { display: flex; height: 100vh; overflow: hidden; }
.sidebar { width: 260px; background: var(--sidebar-bg); color: var(--sidebar-text); display: flex; flex-direction: column; transition: transform 0.3s ease; z-index: 40; }
.main-content { flex: 1; display: flex; flex-direction: column; overflow: hidden; }
.top-navbar { height: 64px; background: var(--glass-bg); backdrop-filter: blur(10px); border-bottom: 1px solid var(--border-color); display: flex; align-items: center; justify-content: space-between; padding: 0 1.5rem; z-index: 30; transition: background 0.3s ease; }
.content-area { flex: 1; overflow-y: auto; padding: 1.5rem; }

/* Premium Cards */
.glass-card { background: var(--bg-surface); border: 1px solid var(--border-color); border-radius: 12px; box-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06); transition: transform 0.2s, box-shadow 0.2s; }
.glass-card:hover { transform: translateY(-2px); box-shadow: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05); }

/* Buttons */
.btn { display: inline-flex; align-items: center; justify-content: center; padding: 0.5rem 1rem; border-radius: 6px; font-weight: 500; transition: all 0.2s; cursor: pointer; border: none; }
.btn-primary { background: var(--primary); color: white; }
.btn-primary:hover { background: var(--primary-hover); }

/* Typography */
h1, h2, h3, h4, h5, h6 { color: var(--text-main); margin-top: 0; }
a { color: var(--primary); text-decoration: none; }
a:hover { color: var(--primary-hover); }

/* Forms */
.form-input { width: 100%; padding: 0.5rem 0.75rem; border-radius: 6px; border: 1px solid var(--border-color); background: var(--bg-surface); color: var(--text-main); transition: border-color 0.2s; }
.form-input:focus { outline: none; border-color: var(--primary); box-shadow: 0 0 0 3px rgba(59, 130, 246, 0.25); }
.form-label { display: block; margin-bottom: 0.5rem; font-size: 0.875rem; font-weight: 500; color: var(--text-main); }

/* Table */
.data-table { width: 100%; border-collapse: collapse; }
.data-table th, .data-table td { padding: 0.75rem 1rem; text-align: left; border-bottom: 1px solid var(--border-color); }
.data-table th { font-weight: 600; color: var(--text-muted); text-transform: uppercase; font-size: 0.75rem; letter-spacing: 0.05em; }
.data-table tr:hover { background-color: var(--bg-surface-hover); }

/* Responsive Sidebar */
@media (max-width: 768px) {
    .sidebar { position: absolute; transform: translateX(-100%); height: 100%; }
    .sidebar.open { transform: translateX(0); }
}