:root {
    --primary-color: #4361ee;
    --primary-dark: #3651d4;
    --secondary-color: #3f37c9;
    --success-color: #10b981;
    --warning-color: #f59e0b;
    --danger-color: #ef4444;
    --light-color: #f8fafc;
    --dark-color: #1e293b;
    --gray-100: #f1f5f9;
    --gray-200: #e2e8f0;
    --gray-300: #cbd5e1;
    --gray-400: #94a3b8;
    --gray-500: #64748b;
    --gray-600: #475569;
    --border-radius: 0.5rem;
    --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.05);
    --shadow: 0 1px 3px 0 rgb(0 0 0 / 0.1), 0 1px 2px -1px rgb(0 0 0 / 0.1);
    --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.1), 0 2px 4px -2px rgb(0 0 0 / 0.1);
    --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.1), 0 4px 6px -4px rgb(0 0 0 / 0.1);
}

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

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    background-color: var(--gray-100);
    color: var(--dark-color);
    line-height: 1.6;
}

.auth-container {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 1rem;
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--secondary-color) 100%);
}

.auth-card {
    background: white;
    padding: 2.5rem;
    border-radius: var(--border-radius);
    box-shadow: var(--shadow-lg);
    width: 100%;
    max-width: 420px;
}

.auth-card h1 {
    font-size: 1.75rem;
    font-weight: 700;
    color: var(--dark-color);
    margin-bottom: 0.5rem;
    text-align: center;
}

.auth-card .subtitle {
    color: var(--gray-500);
    text-align: center;
    margin-bottom: 2rem;
}

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

.form-group label {
    display: block;
    font-weight: 500;
    color: var(--gray-600);
    margin-bottom: 0.5rem;
    font-size: 0.875rem;
}

.form-group input {
    width: 100%;
    padding: 0.75rem 1rem;
    border: 1px solid var(--gray-300);
    border-radius: var(--border-radius);
    font-size: 1rem;
    transition: border-color 0.2s, box-shadow 0.2s;
}

.form-group input:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(67, 97, 238, 0.1);
}

.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 0.75rem 1.5rem;
    font-size: 1rem;
    font-weight: 500;
    border-radius: var(--border-radius);
    border: none;
    cursor: pointer;
    transition: all 0.2s;
    text-decoration: none;
}

.btn-primary {
    background-color: var(--primary-color);
    color: white;
    width: 100%;
}

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

.btn-secondary {
    background-color: var(--gray-200);
    color: var(--gray-600);
}

.btn-secondary:hover {
    background-color: var(--gray-300);
}

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

.auth-link {
    text-align: center;
    margin-top: 1.5rem;
    color: var(--gray-500);
}

.auth-link a {
    color: var(--primary-color);
    text-decoration: none;
    font-weight: 500;
}

.auth-link a:hover {
    text-decoration: underline;
}

.forgot-password {
    text-align: right;
    margin-bottom: 1rem;
    margin-top: -0.5rem;
}

.forgot-password a {
    color: var(--gray-500);
    text-decoration: none;
    font-size: 0.875rem;
}

.forgot-password a:hover {
    color: var(--primary-color);
    text-decoration: underline;
}

.alert {
    padding: 1rem;
    border-radius: var(--border-radius);
    margin-bottom: 1.5rem;
    font-size: 0.875rem;
}

.alert-success {
    background-color: #d1fae5;
    color: #065f46;
    border: 1px solid #a7f3d0;
}

.alert-error {
    background-color: #fee2e2;
    color: #991b1b;
    border: 1px solid #fecaca;
}

.alert-warning {
    background-color: #fef3c7;
    color: #92400e;
    border: 1px solid #fde68a;
}

.alert-info {
    background-color: #dbeafe;
    color: #1e40af;
    border: 1px solid #bfdbfe;
}

.dashboard {
    display: flex;
    min-height: 100vh;
}

.sidebar {
    width: 260px;
    background: white;
    border-right: 1px solid var(--gray-200);
    padding: 1.5rem;
    position: fixed;
    height: 100vh;
    overflow-y: auto;
}

.sidebar-logo {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--primary-color);
    margin-bottom: 2rem;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.sidebar-nav {
    list-style: none;
}

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

.sidebar-nav a {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    padding: 0.75rem 1rem;
    color: var(--gray-600);
    text-decoration: none;
    border-radius: var(--border-radius);
    transition: all 0.2s;
}

.sidebar-nav a:hover,
.sidebar-nav a.active {
    background-color: var(--gray-100);
    color: var(--primary-color);
}

.main-content {
    flex: 1;
    margin-left: 260px;
    padding: 2rem;
}

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

.header h1 {
    font-size: 1.75rem;
    font-weight: 700;
    color: var(--dark-color);
}

.user-menu {
    display: flex;
    align-items: center;
    gap: 1rem;
}

.user-menu span {
    color: var(--gray-600);
}

.stats-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
    gap: 1.5rem;
    margin-bottom: 2rem;
}

.stat-card {
    background: white;
    padding: 1.5rem;
    border-radius: var(--border-radius);
    box-shadow: var(--shadow);
}

.stat-card h3 {
    font-size: 0.875rem;
    font-weight: 500;
    color: var(--gray-500);
    margin-bottom: 0.5rem;
}

.stat-card .value {
    font-size: 2rem;
    font-weight: 700;
    color: var(--dark-color);
}

.stat-card .change {
    font-size: 0.875rem;
    margin-top: 0.5rem;
}

.stat-card .change.positive {
    color: var(--success-color);
}

.stat-card .change.negative {
    color: var(--danger-color);
}

.card {
    background: white;
    border-radius: var(--border-radius);
    box-shadow: var(--shadow);
    margin-bottom: 1.5rem;
}

.card-header {
    padding: 1.25rem 1.5rem;
    border-bottom: 1px solid var(--gray-200);
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.card-header h2 {
    font-size: 1.125rem;
    font-weight: 600;
    color: var(--dark-color);
}

.card-body {
    padding: 1.5rem;
}

.data-table {
    width: 100%;
    border-collapse: collapse;
}

.data-table th,
.data-table td {
    padding: 1rem;
    text-align: left;
    border-bottom: 1px solid var(--gray-200);
}

.data-table th {
    font-weight: 600;
    color: var(--gray-600);
    background-color: var(--gray-100);
    font-size: 0.875rem;
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.data-table tr:hover {
    background-color: var(--gray-100);
}

.data-table tr:last-child td {
    border-bottom: none;
}

.empty-state {
    text-align: center;
    padding: 3rem;
    color: var(--gray-500);
}

.empty-state svg {
    width: 64px;
    height: 64px;
    margin-bottom: 1rem;
    opacity: 0.5;
}

.empty-state h3 {
    font-size: 1.125rem;
    margin-bottom: 0.5rem;
    color: var(--gray-600);
}

.sheet-selector {
    display: flex;
    gap: 0.5rem;
    flex-wrap: wrap;
}

.sheet-btn {
    padding: 0.5rem 1rem;
    background-color: var(--gray-100);
    border: 1px solid var(--gray-300);
    border-radius: var(--border-radius);
    cursor: pointer;
    font-size: 0.875rem;
    transition: all 0.2s;
}

.sheet-btn:hover,
.sheet-btn.active {
    background-color: var(--primary-color);
    color: white;
    border-color: var(--primary-color);
}

.config-form {
    display: grid;
    gap: 1rem;
    max-width: 500px;
}

.config-info {
    background-color: var(--gray-100);
    padding: 1rem;
    border-radius: var(--border-radius);
    font-size: 0.875rem;
    color: var(--gray-600);
}

.config-info code {
    background-color: var(--gray-200);
    padding: 0.125rem 0.375rem;
    border-radius: 0.25rem;
    font-family: monospace;
}

.refresh-btn {
    background: none;
    border: none;
    cursor: pointer;
    color: var(--gray-500);
    padding: 0.5rem;
    border-radius: var(--border-radius);
    transition: all 0.2s;
}

.refresh-btn:hover {
    background-color: var(--gray-100);
    color: var(--primary-color);
}

.loading {
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 2rem;
}

.spinner {
    width: 40px;
    height: 40px;
    border: 3px solid var(--gray-200);
    border-top-color: var(--primary-color);
    border-radius: 50%;
    animation: spin 1s linear infinite;
}

@keyframes spin {
    to {
        transform: rotate(360deg);
    }
}

@media (max-width: 768px) {
    .sidebar {
        width: 100%;
        position: relative;
        height: auto;
    }
    
    .main-content {
        margin-left: 0;
    }
    
    .dashboard {
        flex-direction: column;
    }
    
    .stats-grid {
        grid-template-columns: 1fr;
    }
}