:root {
    --primary: #6366f1;
    --primary-hover: #4f46e5;
    --bg: #f3f4f6;
    --sidebar-bg: #ffffff;
    --text-main: #1f2937;
    --text-muted: #6b7280;
    --white: #ffffff;
    --danger: #ef4444;
}

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

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background-color: var(--bg);
    color: var(--text-main);
    display: flex;
    min-height: 100vh;
}

a {
    text-decoration: none;
    color: inherit;
}

/* Layout */
.sidebar {
    width: 260px;
    background: var(--sidebar-bg);
    border-right: 1px solid #e5e7eb;
    display: flex;
    flex-direction: column;
    padding: 1.5rem;
}

.main-content {
    flex: 1;
    padding: 2rem;
}

/* UI Elements */
.logo {
    font-size: 1.25rem;
    font-weight: bold;
    color: var(--primary);
    margin-bottom: 2rem;
    display: block;
}

.nav-link {
    display: block;
    padding: 0.75rem 1rem;
    border-radius: 0.5rem;
    margin-bottom: 0.5rem;
    transition: 0.2s;
    font-weight: 500;
}

.nav-link:hover, .nav-link.active {
    background: #f9fafb;
    color: var(--primary);
}

.card {
    background: var(--white);
    padding: 1.5rem;
    border-radius: 1rem;
    box-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
}

.btn {
    display: inline-block;
    padding: 0.6rem 1.2rem;
    border-radius: 0.5rem;
    font-weight: 600;
    cursor: pointer;
    border: none;
    transition: 0.2s;
    font-size: 0.9rem;
}

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

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

.form-group {
    margin-bottom: 1.25rem;
}

label {
    display: block;
    margin-bottom: 0.5rem;
    font-size: 0.875rem;
    font-weight: 600;
}

input, select {
    width: 100%;
    padding: 0.75rem;
    border: 1px solid #d1d5db;
    border-radius: 0.5rem;
    font-size: 1rem;
}

table {
    width: 100%;
    border-collapse: collapse;
    margin-top: 1rem;
}

th, td {
    padding: 1rem;
    text-align: left;
    border-bottom: 1px solid #f3f4f6;
}

th {
    background: #f9fafb;
    font-size: 0.8rem;
    text-transform: uppercase;
    color: var(--text-muted);
}

/* Auth Page */
.auth-container {
    display: flex;
    justify-content: center;
    align-items: center;
    width: 100%;
}
.auth-card {
    width: 100%;
    max-width: 400px;
}