:root {
    --primary: #2563eb;
    --primary-dark: #1d4ed8;
    --success: #10b981;
    --warning: #f59e0b;
    --error: #ef4444;
    --gray-50: #f9fafb;
    --gray-100: #f3f4f6;
    --gray-200: #e5e7eb;
    --gray-300: #d1d5db;
    --gray-500: #6b7280;
    --gray-700: #374151;
    --gray-900: #111827;
    --white: #ffffff;
    --shadow: 0 1px 3px rgba(0,0,0,0.12), 0 1px 2px rgba(0,0,0,0.08);
    --shadow-lg: 0 10px 15px -3px rgba(0,0,0,0.1), 0 4px 6px -2px rgba(0,0,0,0.05);
    --radius: 8px;
}

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

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, sans-serif;
    background: var(--gray-100);
    color: var(--gray-900);
    line-height: 1.5;
}

.hidden {
    display: none !important;
}

.screen {
    min-height: 100vh;
}

/* Login Screen */
#login-screen {
    display: flex;
    align-items: center;
    justify-content: center;
    background: linear-gradient(135deg, var(--primary) 0%, var(--primary-dark) 100%);
}

.login-container {
    background: var(--white);
    padding: 48px;
    border-radius: var(--radius);
    box-shadow: var(--shadow-lg);
    width: 100%;
    max-width: 400px;
    text-align: center;
}

.logo h1 {
    font-size: 24px;
    color: var(--gray-900);
    margin-bottom: 4px;
}

.logo p {
    color: var(--gray-500);
    font-size: 14px;
    margin-bottom: 32px;
}

#login-form {
    text-align: left;
}

#login-form label {
    display: block;
    font-size: 14px;
    font-weight: 500;
    color: var(--gray-700);
    margin-bottom: 6px;
}

#login-form input {
    width: 100%;
    padding: 12px 16px;
    font-size: 16px;
    border: 1px solid var(--gray-300);
    border-radius: var(--radius);
    margin-bottom: 16px;
    transition: border-color 0.2s, box-shadow 0.2s;
}

#login-form input:focus {
    outline: none;
    border-color: var(--primary);
    box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.1);
}

#login-form button {
    width: 100%;
    padding: 12px 24px;
    font-size: 16px;
    font-weight: 500;
    color: var(--white);
    background: var(--primary);
    border: none;
    border-radius: var(--radius);
    cursor: pointer;
    transition: background 0.2s;
}

#login-form button:hover {
    background: var(--primary-dark);
}

#login-form button:disabled {
    background: var(--gray-300);
    cursor: not-allowed;
}

.message {
    margin-top: 16px;
    padding: 12px;
    border-radius: var(--radius);
    font-size: 14px;
}

.message.success {
    background: #d1fae5;
    color: #065f46;
}

.message.error {
    background: #fee2e2;
    color: #991b1b;
}

/* Dashboard Header */
header {
    background: var(--white);
    padding: 16px 24px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    box-shadow: var(--shadow);
    position: sticky;
    top: 0;
    z-index: 100;
}

.header-left h1 {
    font-size: 20px;
    color: var(--gray-900);
}

.header-right {
    display: flex;
    align-items: center;
    gap: 16px;
}

#client-name {
    font-size: 14px;
    color: var(--gray-500);
}

#logout-btn {
    padding: 8px 16px;
    font-size: 14px;
    color: var(--gray-700);
    background: var(--gray-100);
    border: 1px solid var(--gray-300);
    border-radius: var(--radius);
    cursor: pointer;
    transition: background 0.2s;
}

#logout-btn:hover {
    background: var(--gray-200);
}

/* Main Dashboard */
main {
    padding: 24px;
    max-width: 1200px;
    margin: 0 auto;
}

.dashboard-grid {
    display: grid;
    grid-template-columns: repeat(12, 1fr);
    gap: 24px;
}

.card {
    background: var(--white);
    border-radius: var(--radius);
    padding: 24px;
    box-shadow: var(--shadow);
}

.card h2 {
    font-size: 24px;
    margin-bottom: 4px;
}

.card h3 {
    font-size: 16px;
    font-weight: 600;
    color: var(--gray-700);
    margin-bottom: 16px;
}

/* Welcome Card */
.welcome-card {
    grid-column: span 8;
}

.welcome-card #company-name {
    color: var(--gray-500);
    margin-bottom: 24px;
}

.quick-stats {
    display: flex;
    gap: 48px;
}

.stat {
    display: flex;
    flex-direction: column;
}

.stat-value {
    font-size: 36px;
    font-weight: 700;
    color: var(--primary);
}

.stat-label {
    font-size: 14px;
    color: var(--gray-500);
}

/* Preview Card */
.preview-card {
    grid-column: span 4;
    display: flex;
    flex-direction: column;
}

.preview-card p {
    color: var(--gray-500);
    font-size: 14px;
    margin-bottom: 16px;
    flex-grow: 1;
}

.btn-primary {
    display: inline-block;
    padding: 12px 24px;
    font-size: 14px;
    font-weight: 500;
    color: var(--white);
    background: var(--primary);
    border-radius: var(--radius);
    text-decoration: none;
    text-align: center;
    transition: background 0.2s;
}

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

/* Modules Card */
.modules-card {
    grid-column: span 6;
}

.modules-list {
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.module-item {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 12px 16px;
    background: var(--gray-50);
    border-radius: var(--radius);
}

.module-name {
    font-weight: 500;
    text-transform: capitalize;
}

.module-status {
    font-size: 12px;
    font-weight: 500;
    padding: 4px 12px;
    border-radius: 9999px;
    text-transform: uppercase;
}

.module-status.inactive {
    background: var(--gray-200);
    color: var(--gray-500);
}

.module-status.active {
    background: #fef3c7;
    color: #92400e;
}

.module-status.complete {
    background: #d1fae5;
    color: #065f46;
}

/* Activity Card */
.activity-card {
    grid-column: span 6;
}

.activity-feed {
    display: flex;
    flex-direction: column;
    gap: 12px;
    max-height: 300px;
    overflow-y: auto;
}

.activity-item {
    display: flex;
    gap: 12px;
    padding: 12px;
    background: var(--gray-50);
    border-radius: var(--radius);
}

.activity-icon {
    width: 32px;
    height: 32px;
    background: var(--primary);
    color: var(--white);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 14px;
    flex-shrink: 0;
}

.activity-content {
    flex-grow: 1;
}

.activity-action {
    font-weight: 500;
    margin-bottom: 2px;
}

.activity-time {
    font-size: 12px;
    color: var(--gray-500);
}

/* Invoice Card */
.invoice-card {
    grid-column: span 12;
}

.invoice-info {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 16px;
    background: var(--gray-50);
    border-radius: var(--radius);
}

.invoice-details {
    display: flex;
    gap: 32px;
}

.invoice-field {
    display: flex;
    flex-direction: column;
}

.invoice-label {
    font-size: 12px;
    color: var(--gray-500);
}

.invoice-value {
    font-weight: 500;
}

.invoice-status {
    font-size: 12px;
    font-weight: 500;
    padding: 4px 12px;
    border-radius: 9999px;
    text-transform: uppercase;
}

.invoice-status.paid {
    background: #d1fae5;
    color: #065f46;
}

.invoice-status.unpaid {
    background: #fef3c7;
    color: #92400e;
}

.invoice-status.overdue {
    background: #fee2e2;
    color: #991b1b;
}

.no-invoice {
    color: var(--gray-500);
    font-size: 14px;
}

/* Footer */
footer {
    text-align: center;
    padding: 24px;
    color: var(--gray-500);
    font-size: 14px;
}

/* Loading Overlay */
.loading {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(255, 255, 255, 0.9);
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    z-index: 1000;
}

.spinner {
    width: 40px;
    height: 40px;
    border: 3px solid var(--gray-200);
    border-top-color: var(--primary);
    border-radius: 50%;
    animation: spin 0.8s linear infinite;
}

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

.loading p {
    margin-top: 16px;
    color: var(--gray-500);
}

/* Responsive */
@media (max-width: 768px) {
    .dashboard-grid {
        grid-template-columns: 1fr;
    }

    .card {
        grid-column: span 1 !important;
    }

    .quick-stats {
        gap: 24px;
    }

    .stat-value {
        font-size: 28px;
    }

    header {
        flex-direction: column;
        gap: 12px;
        text-align: center;
    }

    .login-container {
        margin: 16px;
        padding: 32px 24px;
    }
}